Large-scale shell-model calculation with core excitations for neutron-rich nuclei beyond 132Sn

NASA Astrophysics Data System (ADS)

Jin, Hua; Hasegawa, Munetake; Tazaki, Shigeru; Kaneko, Kazunari; Sun, Yang

2011-10-01

The structure of neutron-rich nuclei with a few nucleons beyond 132Sn is investigated by means of large-scale shell-model calculations. For a considerably large model space, including neutron core excitations, a new effective interaction is determined by employing the extended pairing-plus-quadrupole model with monopole corrections. The model provides a systematical description for energy levels of A=133-135 nuclei up to high spins and reproduces available data of electromagnetic transitions. The structure of these nuclei is analyzed in detail, with emphasis of effects associated with core excitations. The results show evidence of hexadecupole correlation in addition to octupole correlation in this mass region. The suggested feature of magnetic rotation in 135Te occurs in the present shell-model calculation.

Effects of food restriction on expression of place conditioning and biochemical correlates in rat nucleus accumbens.

PubMed

Jung, Caroline; Rabinowitsch, Ariana; Lee, Wei Ting; Zheng, Danielle; de Vaca, Soledad Cabeza; Carr, Kenneth D

2016-09-01

When ad libitum-fed rats undergo cocaine place preference conditioning (CPP) but are switched to food restriction for testing, CPP becomes resistant to extinction and correlates with phosphorylation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluA1 at Ser845 in nucleus accumbens (NAc) core. This study tested whether food restriction increases persistence of morphine CPP and conditioned place aversions (CPA) induced by LiCl and naloxone-precipitated morphine withdrawal. Ad libitum-fed rats were conditioned with morphine (6.0 mg/kg, i.p.), LiCl (50.0/75.0 mg/kg, i.p.), or naloxone (1.0 mg/kg, s.c.) 22 h post-morphine (20.0 mg/kg, s.c.). Half of the subjects were then switched to food restriction. Daily testing resumed 3 weeks later, and brains were harvested when one diet group met extinction criterion. Western analyses probed for pSer845-GluA1, pERK1, and pERK2 in NAc. Food restriction increased persistence of morphine CPP and preference scores correlated with pSer845-GluA1 in NAc core and shell. LiCl CPA was curtailed by food restriction, yet pSer845-GluA1 and pERK2 were elevated in NAc core of food-restricted rats. Food restriction increased persistence of naloxone CPA and elevated pSer845-GluA1 in NAc core and shell, and aversion scores were negatively correlated with pERK1 and pERK2 in NAc core. These results suggest that food restriction prolongs responsiveness to environmental contexts paired with subjective effects of both morphine and morphine withdrawal. A mechanistic scheme, attributing these effects to upregulation of pSer845-GluA1, but subject to override by CPA-specific, pERK2-mediated extinction learning, is explored to accommodate opposite effects of food restriction on LiCl and naloxone CPA.

Petrophysical Properties of Twenty Drill Cores from the Los Azufres, Mexico, Geothermal Field

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

Iglesias, E.R.; Contreras L., E.; Garcia G., A.

1987-01-20

For this study we selected 20 drill cores covering a wide range of depths (400-3000 m), from 15 wells, that provide a reasonable coverage of the field. Only andesite, the largely predominant rock type in the field, was included in this sample. We measured bulk density, grain (solids) density, effective porosity and (matrix) permeability on a considerable number of specimens taken from the cores; and inferred the corresponding total porosity and fraction of interconnected total porosity. We characterized the statistical distributions of the measured and inferred variables. The distributions of bulk density and grain density resulted approximately normal; the distributionsmore » of effective porosity, total porosity and fraction of total porosity turned out to be bimodal; the permeability distribution resulted highly skewed towards very small (1 mdarcy) values, though values as high as 400 mdarcies were measured. We also characterized the internal inhomogeneity of the cores by means of the ratio (standard deviation/mean) corresponding to the bulk density in each core (in average there are 9 specimens per core). The cores were found to present clearly discernible inhomogeneity; this quantitative characterization will help design new experimental work and interpret currently available and forthcoming results. We also found statistically significant linear correlations between total density and density of solids, effective porosity and total density, total porosity and total density, fraction of interconnected total porosity and the inverse of the effective porosity, total porosity and effective porosity; bulk density and total porosity also correlate with elevation. These results provide the first sizable and statistically detailed database available on petrophysical properties of the Los Azufres andesites. 1 tab., 16 figs., 4 refs.« less

Integration of ANFIS, NN and GA to determine core porosity and permeability from conventional well log data

NASA Astrophysics Data System (ADS)

Ja'fari, Ahmad; Hamidzadeh Moghadam, Rasoul

2012-10-01

Routine core analysis provides useful information for petrophysical study of the hydrocarbon reservoirs. Effective porosity and fluid conductivity (permeability) could be obtained from core analysis in laboratory. Coring hydrocarbon bearing intervals and analysis of obtained cores in laboratory is expensive and time consuming. In this study an improved method to make a quantitative correlation between porosity and permeability obtained from core and conventional well log data by integration of different artificial intelligent systems is proposed. The proposed method combines the results of adaptive neuro-fuzzy inference system (ANFIS) and neural network (NN) algorithms for overall estimation of core data from conventional well log data. These methods multiply the output of each algorithm with a weight factor. Simple averaging and weighted averaging were used for determining the weight factors. In the weighted averaging method the genetic algorithm (GA) is used to determine the weight factors. The overall algorithm was applied in one of SW Iran’s oil fields with two cored wells. One-third of all data were used as the test dataset and the rest of them were used for training the networks. Results show that the output of the GA averaging method provided the best mean square error and also the best correlation coefficient with real core data.

Stratigraphic correlations in mid- to late-Proterozoic carbonates of the Democratic Republic of Congo using magnetic susceptibility

NASA Astrophysics Data System (ADS)

Delpomdor, Franck R. A.; Devleeschouwer, Xavier; Spassov, Simo; Préat, Alain R.

2017-04-01

In this paper, we have tested the application of magnetic susceptibility measurements in Cu-Ag-Zn-Pb-(Fe)-mineralized carbonates of the BIe subgroup (Democratic Republic of Congo) as an efficient tool for regional and global high-resolution stratigraphic correlations in the Neoproterozoic marine carbonates. To achieve this goal, we integrate the low-field magnetic susceptibility (XLF) data with facies analyses, geochemistry and isotope stratigraphy. The microfacies analyses of two cores, Tshinyama#S70 and Kafuku#15, drilled in the early Neoproterozoic carbonates of the Mbuji-Mayi Supergroup reveal a deep carbonate ramp setting associated with a microbial/stromatolitic mid-ramp environment. High-resolution stratigraphic correlations using magnetic susceptibility and C-isotope curves established for both cores, 190 km apart, suggest a sedimentary hiatus at the base of the Tshinyama#S70 succession. C-O and Sr isotopes and Sr/Ca and Fe abundances show that a diagenetic meteoric overprint affected the series of the Tshinyama#S70 core and a thermal effect related to mineralizing fluids affected the Kafuku#15 core carbonates.

Assessment of Lumbar Lordosis and Lumbar Core Strength in Information Technology Professionals.

PubMed

Mehta, Roma Satish; Nagrale, Sanket; Dabadghav, Rachana; Rairikar, Savita; Shayam, Ashok; Sancheti, Parag

2016-06-01

Observational study. To correlate lumbar lordosis and lumbar core strength in information technology (IT) professionals. IT professionals have to work for long hours in a sitting position, which can affect lumbar lordosis and lumbar core strength. Flexicurve was used to assess the lumbar lordosis, and pressure biofeedback was used to assess the lumbar core strength in the IT professionals. All subjects, both male and female, with and without complaint of low back pain and working for two or more years were included, and subjects with a history of spinal surgery or spinal deformity were excluded from the study. Analysis was done using Pearson's correlation. For the IT workers, no correlation was seen between lumbar lordosis and lumbar core strength (r=-0.04); however, a weak negative correlation was seen in IT people who complained of pain (r=-0.12), while there was no correlation of lumbar lordosis and lumbar core in IT people who had no complains of pain (r=0.007). The study shows that there is no correlation of lumbar lordosis and lumbar core strength in IT professionals, but a weak negative correlation was seen in IT people who complained of pain.

Benchmark calculations with correlated molecular wavefunctions. XIII. Potential energy curves for He2, Ne2 and Ar2 using correlation consistent basis sets through augmented sextuple zeta

NASA Astrophysics Data System (ADS)

van Mourik, Tanja

1999-02-01

The potential energy curves of the rare gas dimers He2, Ne2, and Ar2 have been computed using correlation consistent basis sets ranging from singly augmented aug-cc-pVDZ sets through triply augmented t-aug-cc-pV6Z sets, with the augmented sextuple basis sets being reported herein. Several methods for including electron correlation were investigated, namely Moller-Plesset perturbation theory (MP2, MP3 and MP4) and coupled cluster theory [CCSD and CCSD(T)]. For He2CCSD(T)/d-aug-cc-pV6Z calculations yield a well depth of 7.35cm-1 (10.58K), with an estimated complete basis set (CBS) limit of 7.40cm-1 (10.65K). The latter is smaller than the 'exact' well depth (Aziz, R. A., Janzen, A. R., and Moldover, M. R., 1995, Phys. Rev. Lett., 74, 1586) by about 0.2cm-1 (0.35K). The Ne well depth, computed with the CCSD(T)/d-aug-cc-pV6Z method, is 28.31cm-1 and the estimated CBS limit is 28.4cm-1, approximately 1cm-1 smaller than the empirical potential of Aziz, R. A., and Slaman, M., J., 1989, Chem. Phys., 130, 187. Inclusion of core and core-valence correlation effects has a negligible effect on the Ne well depth, decreasing it by only 0.04cm-1. For Ar2, CCSD(T)/ d-aug-cc-pV6Z calculations yield a well depth of 96.2cm-1. The corresponding HFDID potential of Aziz, R. A., 1993, J. chem. Phys., 99, 4518 predicts of D of 99.7cm-1. Inclusion of core and core-valence effects in Ar increases the well depth and decreases the discrepancy by approximately 1cm-1.

Temperature anisotropy instabilities stimulated by the interplay of the core and halo electrons in space plasmas

NASA Astrophysics Data System (ADS)

Lazar, M.; Shaaban, S. M.; Fichtner, H.; Poedts, S.

2018-02-01

Two central components are revealed by electron velocity distributions measured in space plasmas, a thermal bi-Maxwellian core and a bi-Kappa suprathermal halo. A new kinetic approach is proposed to characterize the temperature anisotropy instabilities driven by the interplay of core and halo electrons. Suggested by the observations in the solar wind, direct correlations of these two populations are introduced as co-variations of the key parameters, e.g., densities, temperature anisotropies, and (parallel) plasma betas. The approach involving correlations enables the instability characterization in terms of either the core or halo parameters and a comparative analysis to depict mutual effects. In the present paper, the instability conditions are described for an extended range of plasma beta parameters, making the new dual approach relevant for a wide variety of space plasmas, including the solar wind and planetary magnetospheres.

Oxygen-18 concentrations in recent precipitation and ice cores on the Tibetan Plateau

USGS Publications Warehouse

Tian, L.; Yao, T.; Schuster, P.F.; White, J.W.C.; Ichiyanagi, K.; Pendall, Elise; Pu, J.; Yu, W.

2003-01-01

A detailed study of the climatic significance of ??18O in precipitation was completed on a 1500 km southwest-northeast transect of the Tibetan Plateau in central Asia. Precipitation samples were collected at four meteorological stations for up to 9 years. This study shows that the gradual impact of monsoon precipitation affects the spatial variation of ??18O-T relationship along the transect. Strong monsoon activity in the southern Tibetan Plateau results in high precipitation rates and more depleted heavy isotopes. This depletion mechanism is described as a precipitation "amount effect" and results in a poor ??18O-T relationship at both seasonal and annual scales. In the middle of the Tibetan Plateau, the effects of the monsoon are diminished but continue to cause a reduced correlation of ??18O and temperature at the annual scale. At the monthly scale, however, a significant ??18O-T relationship does exist. To the north of the Tibetan Plateau beyond the extent of the effects of monsoon precipitation, ??18O in precipitation shows a strong temperature dependence. ??18O records from two shallow ice cores and historic air temperature data were compared to verify the modern ??18O-T relationship. ??18O in Dunde ice core was positively correlated with air temperature from a nearby meteorological station in the north of the plateau. The ??18O variation in an ice core from the southern Plateau, however, was inversely correlated with precipitation amount at a nearby meteorological station and also the accumulation record in the ice core. The long-term variation of ??18O in the ice core record in the monsoon regions of the southern Tibetan Plateau suggest past monsoon seasons were probably more expansive. It is still unclear, however, how changes in large-scale atmosphere circulation might influence summer monsoon precipitation on the Tibetan Plateau.

Changes in transport and confinement in the EXTRAP-T2 reversed field pinch

NASA Astrophysics Data System (ADS)

Sallander, E.; Sallander, J.; Hedqvist, A.

1999-09-01

At the EXTRAP-T2 reversed field pinch a non-intrusive approach has been undertaken to monitor transport driven by magnetic fluctuations. Correlations are presented between fluctuations observed in the core and at the edge of the plasma. The fluctuations are characterized and their effect on the confinement of core electron energy is estimated.

RTI Strategies That Work in the 3-6 Classroom

ERIC Educational Resources Information Center

Johnson, Eli; Karns, Michelle

2012-01-01

This is a must-have resource for educators committed to meeting the needs of their struggling students in Grades 3-6. Teachers get a whole toolbox filled with research-based, easy to implement RTI interventions that really work! Get strategies in five core areas--plus correlations to the Common Core State Standards and effective scaffolding tips…

Catheter placement for lysis of spontaneous intracerebral hematomas: does a catheter position in the core of the hematoma allow more effective and faster hematoma lysis?

PubMed

Malinova, Vesna; Schlegel, Anna; Rohde, Veit; Mielke, Dorothee

2017-07-01

For the fibrinolytic therapy of intracerebral hematomas (ICH) using recombinant tissue plasminogen activator (rtPA), a catheter position in the core of the hematoma along the largest clot diameter was assumed to be optimal for an effective clot lysis. However, it never had been proven that core position indeed enhances clot lysis if compared with less optimal catheter positions. In this study, the impact of the catheter position on the effectiveness and on the time course of clot lysis was evaluated. We analyzed the catheter position using a relative error calculating the distance perpendicular to the catheter's center in relation to hematoma's diameter and evaluated the relative hematoma volume reduction (RVR). The correlation of the RVR with the catheter position was evaluated. Additionally, we tried to identify patterns of clot lysis with different catheter positions. The patient's outcome at discharge was evaluated using the Glasgow outcome score. A total of 105 patients were included in the study. The mean hematoma volume was 56 ml. The overall RVR was 62.7 %. In 69 patients, a catheter position in the core of the clot was achieved. We found no significant correlation between catheter position and hematoma RVR (linear regression, p = 0.14). Core catheter position leads to more symmetrical hematoma RVR. Faster clot lysis happens in the vicinity of the catheter openings. We found no significant difference in the patient's outcome dependent on the catheter position (linear regression, p = 0.90). The catheter position in the core of the hematoma along its largest diameter does not significantly influence the effectiveness of clot lysis after rtPA application.

A partitioned correlation function interaction approach for describing electron correlation in atoms

NASA Astrophysics Data System (ADS)

Verdebout, S.; Rynkun, P.; Jönsson, P.; Gaigalas, G.; Froese Fischer, C.; Godefroid, M.

2013-04-01

The traditional multiconfiguration Hartree-Fock (MCHF) and configuration interaction (CI) methods are based on a single orthonormal orbital basis. For atoms with many closed core shells, or complicated shell structures, a large orbital basis is needed to saturate the different electron correlation effects such as valence, core-valence and correlation within the core shells. The large orbital basis leads to massive configuration state function (CSF) expansions that are difficult to handle, even on large computer systems. We show that it is possible to relax the orthonormality restriction on the orbital basis and break down the originally very large calculations into a series of smaller calculations that can be run in parallel. Each calculation determines a partitioned correlation function (PCF) that accounts for a specific correlation effect. The PCFs are built on optimally localized orbital sets and are added to a zero-order multireference (MR) function to form a total wave function. The expansion coefficients of the PCFs are determined from a low dimensional generalized eigenvalue problem. The interaction and overlap matrices are computed using a biorthonormal transformation technique (Verdebout et al 2010 J. Phys. B: At. Mol. Phys. 43 074017). The new method, called partitioned correlation function interaction (PCFI), converges rapidly with respect to the orbital basis and gives total energies that are lower than the ones from ordinary MCHF and CI calculations. The PCFI method is also very flexible when it comes to targeting different electron correlation effects. Focusing our attention on neutral lithium, we show that by dedicating a PCF to the single excitations from the core, spin- and orbital-polarization effects can be captured very efficiently, leading to highly improved convergence patterns for hyperfine parameters compared with MCHF calculations based on a single orthogonal radial orbital basis. By collecting separately optimized PCFs to correct the MR function, the variational degrees of freedom in the relative mixing coefficients of the CSFs building the PCFs are inhibited. The constraints on the mixing coefficients lead to small off-sets in computed properties such as hyperfine structure, isotope shift and transition rates, with respect to the correct values. By (partially) deconstraining the mixing coefficients one converges to the correct limits and keeps the tremendous advantage of improved convergence rates that comes from the use of several orbital sets. Reducing ultimately each PCF to a single CSF with its own orbital basis leads to a non-orthogonal CI approach. Various perspectives of the new method are given.

Correlation of the neutron star crust-core properties with the slope of the symmetry energy and the lead skin thickness

NASA Astrophysics Data System (ADS)

Pais, H.; Sulaksono, A.; Agrawal, B. K.; Providência, C.

2016-04-01

The correlations of the crust-core transition density and pressure in neutron stars with the slope of the symmetry energy and the neutron skin thickness are investigated, using different families of relativistic mean-field parametrizations with constant couplings and nonlinear terms mixing the σ - , ω - , and ρ -meson fields. It is shown that the modification of the density dependence of the symmetry energy, involving the σ or the ω meson, gives rise to different behaviors: the effect of the ω meson may also be reproduced within nonrelativistic phenomenological models, while the effect of the σ meson is essentially relativistic. Depending on the parametrization with σ -ρ or ω -ρ mixing terms, different values of the slope of the symmetry energy at saturation must be considered in order to obtain a neutron matter equation of state compatible with results from chiral effective field theory. This difference leads to different pressures at the crust-core transition density. A linear correlation between the transition density and the symmetry energy slope or the neutron skin thickness of the 208Pb nucleus is obtained, only when the ω meson is used to describe the density dependence of the symmetry energy. A comparison is made between the crust-core transition properties of neutron stars obtained by three different methods, the relativistic random phase approximation (RRPA), the Vlasov equation, and thermodynamical method. It is shown that the RRPA and the Vlasov methods predict similar transition densities for p n e β -equilibrium stellar matter.

Effect of alloying on screw dislocation structure in Mo: atomistic modelling approach with ab-initio parametrization

NASA Astrophysics Data System (ADS)

Gornostyrev, Yu. N.

2005-03-01

The plastic deformation in bcc metals is realized by the motion of screw dislocations with a complex star-like non-planar core. In this case, the direct investigation of the solute effect by first principles electronic structure calculations is a challenging problem for which we follow a combined approach that includes atomistic dislocation modelling with ab-initio parametrization of interatomic interactions. The screw dislocation core structure in Mo alloys is described within the model of atomic row displacements along a dislocation line with the interatomic row potential estimated from total energy full-potential linear muffin-tin orbital (FLMTO) calculations with the generalized gradient approximation (GGA) for the exchange-correlation potential. We demonstrate (1) that the solute effect on the dislocation structure is different for ``hard'' and ``easy'' cores and (2) that the softener addition in a ``hard'' core gives rise to a structural transformation into a configuration with a lower energy through an intermediate state. The softener solute is shown to disturb locally the three-fold symmetry of the dislocation core and the dislocation structure tends to the split planar core.

Cavity-Creating Mutations in Pseudomonas aeruginosa Azurin: Effects on Protein Dynamics and Stability

PubMed Central

Gabellieri, Edi; Balestreri, Ettore; Galli, Alvaro; Cioni, Patrizia

2008-01-01

Changes in flexibility and structural stability of Pseudomonas aeruginosa azurin in response to cavity-creating mutations were probed by the phosphorescence emission of Trp-48, which was deeply buried in the compact hydrophobic core of the macromolecule, and by measurements of guanidinum hydrochloride unfolding, respectively. Replacement of the bulky side chains Phe-110, Phe-29, and Tyr-108 with the smaller Ala introduced cavities at different distances from the hydrophobic core. The phosphorescence lifetime (τ0) of Trp-48, buried inside the protein core, and the acrylamide quenching rate constant (kq) were used to monitor local and global flexibility changes induced by the introduction of the cavity. The results of this work demonstrate the following: 1), the effect on core flexibility of the insertion of cavities is not correlated readily to the distance of the cavity from the core; 2), the protein global flexibility results are related to the cavity distance from the packed core of the macromolecule; and 3), the increase in protein flexibility does not correspond necessarily to a comparable destabilizing effect of some mutations. PMID:18424505

Measuring and predicting reservoir heterogeneity in complex deposystems. Annual report, September 20, 1990--September 20, 1991

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

Donaldson, A.; Shumaker, R.; Laughrey, C.

1992-08-01

The Lower Mississippian Big Injun sandstone, a major oil producer in the western half of West Virginia, consists of several sandstones that overstep each west. Examination of cores and thin sections has led to preliminary interpretations of depositional environments for the Big Injun. These include distributary-mouth bars with associated distal, bar crest and back bar environments in a marine-deltaic system; and channel, point bar and chute environments in a fluvial system. Overall, the Big Injun is a medium-grained sublitharenite in which initially high porosity has been modified by compaction and diagenesis. Chlorite grain coatings helped to preserve original porosity, whereasmore » illite promoted pressure solution during compaction, resulting in a loss of porosity. Diagenetic effects within specific environments are being evaluated to determine if environmental interpretations can be used to predict porosity preservation. Core plugs taken from cores in Granny Creek field were analyzed for porosity and horizontal and vertical permeability. Directional permeability was negligible, but permeability does correlate with depth. Changes in permeability with depth can be related to subdivisions of the Big Injun determined from density logs. Permeability also correlated with porosity, but porosity values derived from both cores and logs show no significant correlation trend at present. A layered reservoir model is being developed to evaluate the effect of these vertical heterogeneities. Initial attempts to characterize the heterogeneity of the Big Injun reservoir in Granny Creek field used a number of direct and indirect methods.« less

Measuring and predicting reservoir heterogeneity in complex deposystems

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

Donaldson, A.; Shumaker, R.; Laughrey, C.

1992-08-01

The Lower Mississippian Big Injun sandstone, a major oil producer in the western half of West Virginia, consists of several sandstones that overstep each west. Examination of cores and thin sections has led to preliminary interpretations of depositional environments for the Big Injun. These include distributary-mouth bars with associated distal, bar crest and back bar environments in a marine-deltaic system; and channel, point bar and chute environments in a fluvial system. Overall, the Big Injun is a medium-grained sublitharenite in which initially high porosity has been modified by compaction and diagenesis. Chlorite grain coatings helped to preserve original porosity, whereasmore » illite promoted pressure solution during compaction, resulting in a loss of porosity. Diagenetic effects within specific environments are being evaluated to determine if environmental interpretations can be used to predict porosity preservation. Core plugs taken from cores in Granny Creek field were analyzed for porosity and horizontal and vertical permeability. Directional permeability was negligible, but permeability does correlate with depth. Changes in permeability with depth can be related to subdivisions of the Big Injun determined from density logs. Permeability also correlated with porosity, but porosity values derived from both cores and logs show no significant correlation trend at present. A layered reservoir model is being developed to evaluate the effect of these vertical heterogeneities. Initial attempts to characterize the heterogeneity of the Big Injun reservoir in Granny Creek field used a number of direct and indirect methods.« less

The Pearson-Readhead Survey of Compact Extragalactic Radio Sources from Space. II. Analysis of Source Properties

NASA Astrophysics Data System (ADS)

Lister, M. L.; Tingay, S. J.; Preston, R. A.

2001-06-01

We have performed a multidimensional correlation analysis on the observed properties of a statistically complete core-selected sample of compact radio-loud active galactic nuclei based on data from the VLBI Space Observing Programme (Paper I) and previously published studies. Our sample is drawn from the well-studied Pearson-Readhead (PR) survey and is ideally suited for investigating the general effects of relativistic beaming in compact radio sources. In addition to confirming many previously known correlations, we have discovered several new trends that lend additional support to the beaming model. These trends suggest that the most highly beamed sources in core-selected samples tend to have (1) high optical polarizations; (2) large parsec- kiloparsec-scale jet misalignments; (3) prominent VLBI core components; (4) one-sided, core, or halo radio morphology on kiloparsec scales; (5) narrow emission line equivalent widths; and (6) a strong tendency for intraday variability at radio wavelengths. We have used higher resolution space and ground-based VLBI maps to confirm the bimodality of the jet misalignment distribution for the PR survey and find that the sources with aligned parsec- and kiloparsec-scale jets generally have arcsecond-scale radio emission on both sides of the core. The aligned sources also have broader emission line widths. We find evidence that the BL Lacertae objects in the PR survey are all highly beamed and have very similar properties to the high optically polarized quasars, with the exception of smaller redshifts. A cluster analysis on our data shows that after partialing out the effects of redshift, the luminosities of our sample objects in various wave bands are generally well correlated with each other but not with other source properties.

Spent Fuel Test-Climax: core logging for site investigation and instrumentation

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

Wilder, D.G.; Yow, J.L. Jr.; Thorpe, R.K.

1982-05-28

As an integral part of the Spent Fuel Test-Climax 5150 ft (1570 m) of granite core was obtained. This core was diamond drilled in various sizes, mainly 38-mm and 76-mm diameters. The core was teken with single tube core barrels and was unoriented. Techniques used to drill and log this core are discussed, as well as techniques to orient the core. Of the 5150 ft (1570 m) of core more than 3645 ft (1111 m) was retained and logged in some detail. As a result of the core logging, geologic discontinuities were identified, joint frequency and spacing characterized. Discontinuities identifiedmore » included several joint sets, shear zones and faults. Correlations based on coring along were generally found to be impossible, even for the more prominent features. The only feature properly correlated from the exploratory drilling was the fault system at the end of the facility, but it was not identified from the exploratory core as a fault. Identification of discontinuities was later helped by underground mapping that identified several different joint sets with different characteristics. It was found that joint frequency varied from 0.3 to 1.1 joint per foot of core for open fractures and from 0.3 to 3.3/ft for closed or healed fractures. Histograms of fracture spacing indicate that there is likely a random distribution of spacing superimposed upon uniformly spaced fractures. It was found that a low angle joint set had a persistent mean orientation. These joints were healed and had pervasive wall rock alteration which made identification of joints in this set possible. The recognition of a joint set with known attitude allowed orientation of much of the core. This orientation technique was found to be effective. 10 references, 25 figures, 4 tables.« less

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

Hill, J. Grant, E-mail: grant.hill@sheffield.ac.uk, E-mail: kipeters@wsu.edu; Peterson, Kirk A., E-mail: grant.hill@sheffield.ac.uk, E-mail: kipeters@wsu.edu

New correlation consistent basis sets, cc-pVnZ-PP-F12 (n = D, T, Q), for all the post-d main group elements Ga–Rn have been optimized for use in explicitly correlated F12 calculations. The new sets, which include not only orbital basis sets but also the matching auxiliary sets required for density fitting both conventional and F12 integrals, are designed for correlation of valence sp, as well as the outer-core d electrons. The basis sets are constructed for use with the previously published small-core relativistic pseudopotentials of the Stuttgart-Cologne variety. Benchmark explicitly correlated coupled-cluster singles and doubles with perturbative triples [CCSD(T)-F12b] calculations of themore » spectroscopic properties of numerous diatomic molecules involving 4p, 5p, and 6p elements have been carried out and compared to the analogous conventional CCSD(T) results. In general the F12 results obtained with a n-zeta F12 basis set were comparable to conventional aug-cc-pVxZ-PP or aug-cc-pwCVxZ-PP basis set calculations obtained with x = n + 1 or even x = n + 2. The new sets used in CCSD(T)-F12b calculations are particularly efficient at accurately recovering the large correlation effects of the outer-core d electrons.« less

A PILOT STUDY OF CORE STABILITY AND ATHLETIC PERFORMANCE: IS THERE A RELATIONSHIP?

PubMed Central

Sharrock, Chris; Cropper, Jarrod; Mostad, Joel; Johnson, Matt

2011-01-01

Study Design: Correlation study Objectives: To objectively evaluate the relationship between core stability and athletic performance measures in male and female collegiate athletes. Background: The relationship between core stability and athletic performance has yet to be quantified in the available literature. The current literature does not demonstrate whether or not core strength relates to functional performance. Questions remain regarding the most important components of core stability, the role of sport specificity, and the measurement of core stability in relation to athletic performance. Methods: A sample of 35 volunteer student athletes from Asbury College (NAIA Division II) provided informed consent. Participants performed a series of five tests: double leg lowering (core stability test), the forty yard dash, the T-test, vertical jump, and a medicine ball throw. Participants performed three trials of each test in a randomized order. Results: Correlations between the core stability test and each of the other four performance tests were determined using a General Linear Model. Medicine ball throw negatively correlated to the core stability test (r –0.389, p=0.023). Participants that performed better on the core stability test had a stronger negative correlation to the medicine ball throw (r =–0.527). Gender was the most strongly correlated variable to core strength, males with a mean measurement of double leg lowering of 47.43 degrees compared to females having a mean of 54.75 degrees. Conclusions: There appears to be a link between a core stability test and athletic performance tests; however, more research is needed to provide a definitive answer on the nature of this relationship. Ideally, specific performance tests will be able to better define and to examine relationships to core stability. Future studies should also seek to determine if there are specific sub-categories of core stability which are most important to allow for optimal training and performance for individual sports. PMID:21713228

The effect of thermocycling on the fracture toughness and hardness of core buildup materials.

PubMed

Medina Tirado, J I; Nagy, W W; Dhuru, V B; Ziebert, A J

2001-11-01

Thermocycling has been shown to cause surface degradation of many dental materials, but its effect on the fracture toughness and hardness of direct core buildup materials is unknown. This study was designed to determine the effect of thermocycling on the fracture toughness and hardness of 5 core buildup materials. Fifteen specimens were prepared from each of the following materials: Fluorocore, VariGlass VLC, Valiant PhD, Vitremer, and Chelon-Silver. American Standard for Testing Materials guidelines for single-edge notch, bar-shaped specimens were used. Ten specimens of each material were thermocycled for 2000 cycles; the other 5 specimens were not thermocycled. All specimens were subjected to 3-point bending in a universal testing machine. The load at fracture was recorded, and the fracture toughness (K(IC)) was calculated. Barcol hardness values were also determined. Data were analyzed with 1-way analysis of variance and compared with the Tukey multiple range test (P<.05). Pearson's correlation coefficient was also calculated to measure the association between fracture toughness and hardness. Fluorocore had the highest thermocycled mean K(IC) and Valiant PhD the highest non-thermocycled K(IC). Chelon-Silver demonstrated the lowest mean K(IC) both before and after thermocycling. One-way analysis of variance demonstrated significant differences between conditions, and the Tukey test showed significant differences (P<.05) between materials for both conditions. Most specimens also showed significant hardness differences between conditions. Pearson's correlation coefficient indicated only a mild-to-moderate correlation between hardness and fracture toughness. Within the limitations of this study, the thermocycling process negatively affected the fracture toughness and hardness of the core buildup materials tested.

Ion Structure Near a Core-Shell Dielectric Nanoparticle

NASA Astrophysics Data System (ADS)

Ma, Manman; Gan, Zecheng; Xu, Zhenli

2017-02-01

A generalized image charge formulation is proposed for the Green's function of a core-shell dielectric nanoparticle for which theoretical and simulation investigations are rarely reported due to the difficulty of resolving the dielectric heterogeneity. Based on the formulation, an efficient and accurate algorithm is developed for calculating electrostatic polarization charges of mobile ions, allowing us to study related physical systems using the Monte Carlo algorithm. The computer simulations show that a fine-tuning of the shell thickness or the ion-interface correlation strength can greatly alter electric double-layer structures and capacitances, owing to the complicated interplay between dielectric boundary effects and ion-interface correlations.

Recombination energy for negatively charged excitons inside type-II core/shell spherical quantum dots

NASA Astrophysics Data System (ADS)

Chafai, A.; Essaoudi, I.; Ainane, A.; Dujardin, F.; Ahuja, R.

2018-07-01

The recombination energy of isolated neutral exciton and that of isolated negatively charged exciton inside a type-II core/shell spherical quantum dot are studied. Our investigation considers the charge-carriers effective mass discontinuity at the surface contact between the core and shell materials. Although our model omits the effect of the surface polarization, the dielectric-constant mismatch at the nanodot boundaries was taken into account. In order to achieve the exciton and negative trion energies, we proceed by a variational calculation in the framework of the envelope approximation. Our results reveal a strong correlation between the nanodot morphology and the energy spectrum of the neutral and negatively charged exciton.

Leadership values in academic medicine.

PubMed

Souba, Wiley W; Day, David V

2006-01-01

To gain a deeper understanding of the guiding core values that deans of academic medical centers (AMCs) considered most essential for their leadership and the major leadership challenges that confront them. In 2003-04, semistructured interviews of 18 deans at U.S. colleges of medicine or AMCs were organized around four dimensions: background, leadership challenges, organizational effectiveness, and systems enablers/restrainers for leadership. A values Q-sort was used to determine how widely core values were shared among deans and how the complex challenges they faced did or did not align with these values. Fourteen of the 18 (78%) deans identified financial difficulties as their most pressing leadership challenge, followed by weak institutional alignment (61%), staffing problems (33%), and poor morale (28%). Open, candid communication was reported as the most effective means of addressing these complex problems. Enacting espoused shared values and having a positive attitude were identified as the most important enablers of systemic leadership, whereas micromanagement and difficult people were the major restraints. Q-sort results on 38 positive leadership values indicated that participants considered integrity most essential. Integrity was positively correlated with humanistic values and negatively correlated with results. Vision, another highly espoused value, correlated strongly with performance-oriented values but correlated negatively with humanistic values. A dynamic tension exists in AMCs between humanistic values and performance-based core values. The ability to manage that tension (i.e., when to prioritize one set of values over the other) is inherent in a dean's work.

Universal distribution of mutational effects on protein stability, uncoupling of protein robustness from sequence evolution and distinct evolutionary modes of prokaryotic and eukaryotic proteins

NASA Astrophysics Data System (ADS)

Faure, Guilhem; Koonin, Eugene V.

2015-05-01

Robustness to destabilizing effects of mutations is thought of as a key factor of protein evolution. The connections between two measures of robustness, the relative core size and the computationally estimated effect of mutations on protein stability (ΔΔG), protein abundance and the selection pressure on protein-coding genes (dN/dS) were analyzed for the organisms with a large number of available protein structures including four eukaryotes, two bacteria and one archaeon. The distribution of the effects of mutations in the core on protein stability is universal and indistinguishable in eukaryotes and bacteria, centered at slightly destabilizing amino acid replacements, and with a heavy tail of more strongly destabilizing replacements. The distribution of mutational effects in the hyperthermophilic archaeon Thermococcus gammatolerans is significantly shifted toward strongly destabilizing replacements which is indicative of stronger constraints that are imposed on proteins in hyperthermophiles. The median effect of mutations is strongly, positively correlated with the relative core size, in evidence of the congruence between the two measures of protein robustness. However, both measures show only limited correlations to the expression level and selection pressure on protein-coding genes. Thus, the degree of robustness reflected in the universal distribution of mutational effects appears to be a fundamental, ancient feature of globular protein folds whereas the observed variations are largely neutral and uncoupled from short term protein evolution. A weak anticorrelation between protein core size and selection pressure is observed only for surface residues in prokaryotes but a stronger anticorrelation is observed for all residues in eukaryotic proteins. This substantial difference between proteins of prokaryotes and eukaryotes is likely to stem from the demonstrable higher compactness of prokaryotic proteins.

[A new machinability test machine and the machinability of composite resins for core built-up].

PubMed

Iwasaki, N

2001-06-01

A new machinability test machine especially for dental materials was contrived. The purpose of this study was to evaluate the effects of grinding conditions on machinability of core built-up resins using this machine, and to confirm the relationship between machinability and other properties of composite resins. The experimental machinability test machine consisted of a dental air-turbine handpiece, a control weight unit, a driving unit of the stage fixing the test specimen, and so on. The machinability was evaluated as the change in volume after grinding using a diamond point. Five kinds of core built-up resins and human teeth were used in this study. The machinabilities of these composite resins increased with an increasing load during grinding, and decreased with repeated grinding. There was no obvious correlation between the machinability and Vickers' hardness; however, a negative correlation was observed between machinability and scratch width.

Orbital breathing effects in the computation of x-ray d -ion spectra in solids by ab initio wave-function-based methods

DOE PAGES

Bogdanov, Nikolay A.; Bisogni, Valentina; Kraus, Roberto; ...

2016-11-21

In existing theoretical approaches to core-level excitations of transition-metal ions in solids relaxation and polarization effects due to the inner core hole are often ignored or described phenomenologically. Here, we set up an ab initio computational scheme that explicitly accounts for such physics in the calculation of x-ray absorption and resonant inelastic x-ray scattering spectra. Good agreement is found with experimental transition-metal L-edge data for the strongly correlated d 9 cuprate Li 2CuO 2, for which we also determine the absolute scattering intensities. The newly developed methodology opens the way for the investigation of even more complex d n electronicmore » structures of group VI B to VIII B correlated oxide compounds.« less

A Numerical Study on the Edgewise Compression Strength of Sandwich Structures with Facesheet-Core Disbonds

NASA Technical Reports Server (NTRS)

Bergan, Andrew C.

2017-01-01

Damage tolerant design approaches require determination of critical damage modes and flaw sizes in order to establish nondestructive evaluation detection requirements. A finite element model is developed to assess the effect of circular facesheet-core disbonds on the strength of sandwich specimens subjected to edgewise compressive loads for the purpose of predicting the critical flaw size for a variety of design parameters. Postbuckling analyses are conducted in which an initial imperfection is seeded using results from a linear buckling analysis. Both the virtual crack closure technique (VCCT) and cohesive elements are considered for modeling disbond growth. Predictions from analyses using the VCCT and analyses using cohesive elements are in good correlation. A series of parametric analyses are conducted to investigate the effect of core thickness and material, facesheet layup, facesheet-core interface properties, and curvature on the criticality of facesheet-core disbonds of various sizes. The results from these analyses provide a basis for determining the critical flaw size for facesheet-core disbonds subjected to edgewise compression loads and, therefore, nondestructive evaluation flaw detection requirements for this configuration.

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

Bogdanov, Nikolay A.; Bisogni, Valentina; Kraus, Roberto

In existing theoretical approaches to core-level excitations of transition-metal ions in solids relaxation and polarization effects due to the inner core hole are often ignored or described phenomenologically. Here, we set up an ab initio computational scheme that explicitly accounts for such physics in the calculation of x-ray absorption and resonant inelastic x-ray scattering spectra. Good agreement is found with experimental transition-metal L-edge data for the strongly correlated d 9 cuprate Li 2CuO 2, for which we also determine the absolute scattering intensities. The newly developed methodology opens the way for the investigation of even more complex d n electronicmore » structures of group VI B to VIII B correlated oxide compounds.« less

A Study of the X(sup 2) Sigma(sup +) and A(sup 2) Pi States of MgAr(sup +) and MgKr(sup +)

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

The ground (sup 2)Sigma(sup +) and lowest excited (sup 2)Pi states of MgAr(sup +) and MgKr(sup +) are studied using the singles and doubles configuration interaction (SDCI) approach, in conjunction with large basis sets. The effect of Mg core correlation and core polarization are accounted for using the core-polarization potential (CPP) approach. Franck-Condon factors, oscillator strengths, radiative lifetimes, dissociation energies, bond lengths, and excitation energies are reported. The computed results are in good agreement with the available experimental data.

Monte Carlo Approach for Estimating Density and Atomic Number From Dual-Energy Computed Tomography Images of Carbonate Rocks

NASA Astrophysics Data System (ADS)

Victor, Rodolfo A.; Prodanović, Maša.; Torres-Verdín, Carlos

2017-12-01

We develop a new Monte Carlo-based inversion method for estimating electron density and effective atomic number from 3-D dual-energy computed tomography (CT) core scans. The method accounts for uncertainties in X-ray attenuation coefficients resulting from the polychromatic nature of X-ray beam sources of medical and industrial scanners, in addition to delivering uncertainty estimates of inversion products. Estimation of electron density and effective atomic number from CT core scans enables direct deterministic or statistical correlations with salient rock properties for improved petrophysical evaluation; this condition is specifically important in media such as vuggy carbonates where CT resolution better captures core heterogeneity that dominates fluid flow properties. Verification tests of the inversion method performed on a set of highly heterogeneous carbonate cores yield very good agreement with in situ borehole measurements of density and photoelectric factor.

Theoretical study of the hyperfine-interaction constants and the isotope-shift factors for the 3 s21S0-3 s 3 p 3,1P1o transitions in Al+

NASA Astrophysics Data System (ADS)

Zhang, Tingxian; Xie, Luyou; Li, Jiguang; Lu, Zehuang

2017-07-01

We calculated the magnetic dipole and the electric quadrupole hyperfine interaction constants of 3 s 3 p 3,1P1o states and the isotope shift, including mass and field shift, factors for transitions from these two states to the ground state 3 s 2 1S0 in Al+ ions using the multiconfiguration Dirac-Hartree-Fock method. The effects of the electron correlations and the Breit interaction on these physical quantities were investigated in detail based on the active space approach. It is found that the core-core and the higher order correlations are considerable for evaluating the uncertainties of the atomic parameters concerned. The uncertainties of the hyperfine interaction constants in this work are less than 1.6%. Although the isotope shift factors are highly sensitive to the electron correlations, reasonable uncertainties were obtained by exploring the effects of the electron correlations. Moreover, we found that the relativistic nuclear recoil corrections to the mass shift factors are very small and insensitive to the electron correlations for Al+. These atomic parameters present in this work are valuable for extracting the nuclear electric quadrupole moments and the mean-square charge radii of Al isotopes.

Planet Traps and Planetary Cores: Origins of the Planet-Metallicity Correlation

NASA Astrophysics Data System (ADS)

Hasegawa, Yasuhiro; Pudritz, Ralph E.

2014-10-01

Massive exoplanets are observed preferentially around high metallicity ([Fe/H]) stars while low-mass exoplanets do not show such an effect. This so-called planet-metallicity correlation generally favors the idea that most observed gas giants at r < 10 AU are formed via a core accretion process. We investigate the origin of this phenomenon using a semi-analytical model, wherein the standard core accretion takes place at planet traps in protostellar disks where rapid type I migrators are halted. We focus on the three major exoplanetary populations—hot Jupiters, exo-Jupiters located at r ~= 1 AU, and the low-mass planets. We show using a statistical approach that the planet-metallicity correlations are well reproduced in these models. We find that there are specific transition metallicities with values [Fe/H] = -0.2 to -0.4, below which the low-mass population dominates, and above which the Jovian populations take over. The exo-Jupiters significantly exceed the hot Jupiter population at all observed metallicities. The low-mass planets formed via the core accretion are insensitive to metallicity, which may account for a large fraction of the observed super-Earths and hot-Neptunes. Finally, a controlling factor in building massive planets is the critical mass of planetary cores (M c, crit) that regulates the onset of rapid gas accretion. Assuming the current data is roughly complete at [Fe/H] > -0.6, our models predict that the most likely value of the "mean" critical core mass of Jovian planets is langM c, critrang ~= 5 M ⊕ rather than 10 M ⊕. This implies that grain opacities in accreting envelopes should be reduced in order to lower M c, crit.

Planet traps and planetary cores: origins of the planet-metallicity correlation

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

Hasegawa, Yasuhiro; Pudritz, Ralph E., E-mail: yasu@asiaa.sinica.edu.tw, E-mail: pudritz@physics.mcmaster.ca

2014-10-10

Massive exoplanets are observed preferentially around high metallicity ([Fe/H]) stars while low-mass exoplanets do not show such an effect. This so-called planet-metallicity correlation generally favors the idea that most observed gas giants at r < 10 AU are formed via a core accretion process. We investigate the origin of this phenomenon using a semi-analytical model, wherein the standard core accretion takes place at planet traps in protostellar disks where rapid type I migrators are halted. We focus on the three major exoplanetary populations—hot Jupiters, exo-Jupiters located at r ≅ 1 AU, and the low-mass planets. We show using a statisticalmore » approach that the planet-metallicity correlations are well reproduced in these models. We find that there are specific transition metallicities with values [Fe/H] = –0.2 to –0.4, below which the low-mass population dominates, and above which the Jovian populations take over. The exo-Jupiters significantly exceed the hot Jupiter population at all observed metallicities. The low-mass planets formed via the core accretion are insensitive to metallicity, which may account for a large fraction of the observed super-Earths and hot-Neptunes. Finally, a controlling factor in building massive planets is the critical mass of planetary cores (M {sub c,} {sub crit}) that regulates the onset of rapid gas accretion. Assuming the current data is roughly complete at [Fe/H] > –0.6, our models predict that the most likely value of the 'mean' critical core mass of Jovian planets is (M {sub c,} {sub crit}) ≅ 5 M {sub ⊕} rather than 10 M {sub ⊕}. This implies that grain opacities in accreting envelopes should be reduced in order to lower M {sub c,} {sub crit}.« less

Experimental study of the effect of 2/1 classical tearing mode on (intermediate, small)-scale microturbulence in the core of an EAST L mode plasma

NASA Astrophysics Data System (ADS)

Sun, P. J.; Li, Y. D.; Ren, Y.; Zhang, X. D.; Wu, G. J.; Lyu, B.; Shi, T. H.; Xu, L. Q.; Wang, F. D.; Li, Q.; Zhang, J. Z.; Hu, L. Q.; Li, J. G.; the EAST Team

2018-02-01

In this paper, we report an experimental study of the effect of a m/n = -2/-1 (m, n being poloidal and toroidal mode number, separately) classical tearing mode on (intermediate, small)-scale microturbulence (see the definition in section 1) in the core of an EAST L mode plasma discharge. The microturbulence at different scales k ⊥ = 10, 18 and 26 cm-1 (i.e., {k}\\perp {ρ }i˜ 2, 3.6 and 5.2, respectively. Here, {ρ }i is the ion gyroradius and k ⊥ is the perpendicular wavenumber) were measured simultaneously by the EAST multi-channel tangential CO2 laser collective scattering diagnostics. Experimental results confirm that the decrease of microturbulent Doppler shift ({f}{{Doppler}}={k}t{v}t/2π ), inversely correlated to the increase of microturbulent mean frequency (defined in equation (1)), is due to the 2/1 tearing mode. Temporal evolution of frequency-integrated spectral power S tot of microturbulence, found to be correlated with the width of 2/1 magnetic island, suggests the modulation effect on microturbulence by the tearing mode beyond Doppler shift effect. Modulation effects on microturbulence by the tearing mode are further demonstrated by the correlation between microturbulent envelope and magnetic fluctuations.

Geomagnetic field variations during the last 400 kyr in the western equatorial Pacific: Paleointensity-inclination correlation revisited

NASA Astrophysics Data System (ADS)

Yamazaki, T.; Kanamatsu, T.; Mizuno, S.; Hokanishi, N.; Gaffar, E. Z.

2008-12-01

A paleomagnetic study was conducted on four piston cores newly obtained from the West Caroline Basin in the western equatorial Pacific in order to investigate variations in paleointensity and inclination during the last 400 kyr. An inclination-intensity correlation was previously reported in this region using giant piston cores, but the quality of the paleomagnetic data of the younger end, the last ca. 300 kyr, was needed to be checked because the upper part of the giant piston cores could suffer from perturbation by oversampling. Age control is based on the oxygen-isotope ratios for one core and inter-core correlation using relative paleointensity for other cores. The mean inclinations of the four cores show negative inclination anomalies ranging from -5.2 to -11.2 degree. The western equatorial Pacific is documented as a region of a large negative inclination anomalies, and the observed values are comparable to those expected from the time-averaged field (TAF) models [Johnson and Constable, 1997; Hatakeyama and Kono, 2002]. Stacked curves of paleointensity and inclination were constructed from the four cores. It was confirmed that geomagnetic variations on the order of 10 to 100 kyrs occur in inclination as well as paleointensity. A cross-correlation analysis showed that significant in-phase correlation occurs between intensity and inclination for periods longer than about 25 kyr, and power spectra of both paleointensity and inclination variations have peaks at ~100 kyr periods. The regional paleointensity stack with higher resolution than the Sint-800 stack [Guyodo and Valet, 1999] should be useful for paleointensity-assisted chronostratigraphy.

Deriving the nuclear shell model from first principles

NASA Astrophysics Data System (ADS)

Barrett, Bruce R.; Dikmen, Erdal; Vary, James P.; Maris, Pieter; Shirokov, Andrey M.; Lisetskiy, Alexander F.

2014-09-01

The results of an 18-nucleon No Core Shell Model calculation, performed in a large basis space using a bare, soft NN interaction, can be projected into the 0 ℏω space, i.e., the sd -shell. Because the 16 nucleons in the 16O core are frozen in the 0 ℏω space, all the correlations of the 18-nucleon system are captured by the two valence, sd -shell nucleons. By the projection, we obtain microscopically the sd -shell 2-body effective interactions, the core energy and the sd -shell s.p. energies. Thus, the input for standard shell-model calculations can be determined microscopically by this approach. If the same procedure is then applied to 19-nucleon systems, the sd -shell 3-body effective interactions can also be obtained, indicating the importance of these 3-body effective interactions relative to the 2-body effective interactions. Applications to A = 19 and heavier nuclei with different intrinsic NN interactions will be presented and discussed. The results of an 18-nucleon No Core Shell Model calculation, performed in a large basis space using a bare, soft NN interaction, can be projected into the 0 ℏω space, i.e., the sd -shell. Because the 16 nucleons in the 16O core are frozen in the 0 ℏω space, all the correlations of the 18-nucleon system are captured by the two valence, sd -shell nucleons. By the projection, we obtain microscopically the sd -shell 2-body effective interactions, the core energy and the sd -shell s.p. energies. Thus, the input for standard shell-model calculations can be determined microscopically by this approach. If the same procedure is then applied to 19-nucleon systems, the sd -shell 3-body effective interactions can also be obtained, indicating the importance of these 3-body effective interactions relative to the 2-body effective interactions. Applications to A = 19 and heavier nuclei with different intrinsic NN interactions will be presented and discussed. Supported by the US NSF under Grant No. 0854912, the US DOE under Grants Nos. DESC0008485 and DE-FG02-87ER40371, the Higher Education Council of Turkey(YOK), and the Ministry of Education and Science of Russian Fed. under contracts P521 and 14.v37.21.1297.

Feasibility, reliability, and validity of the Pediatric Quality of Life Inventory ™ generic core scales, cancer module, and multidimensional fatigue scale in long-term adult survivors of pediatric cancer.

PubMed

Robert, Rhonda S; Paxton, Raheem J; Palla, Shana L; Yang, Grace; Askins, Martha A; Joy, Shaini E; Ater, Joann L

2012-10-01

Most health-related quality of life assessments are designed for either children or adults and have not been evaluated for adolescent and young adult survivors of pediatric cancer. The objective of this study was to examine the feasibility, reliability, and validity of the Pediatric Quality of Life Inventory (PedsQL ™ Generic Core Scales, Cancer Module, and Multidimensional Fatigue Scale in adult survivors of pediatric cancer. Adult survivors (n = 64; Mean age 35 year old; >2 years after treatment) completed the PedsQL™ Generic Core Scales, Cancer Module, and Multidimensional Fatigue Scale. Feasibility was examined with floor and ceiling effects; and internal consistency was determined by Cronbach's coefficient alpha calculations. Inter-factor correlations were also assessed. Significant ceiling effects were observed for the scales of social function, nausea, procedural anxiety, treatment anxiety, and communication. Internal consistency for all subscales was within the recommended ranges (α ≥ 0.70). Moderate to strong correlations between most Cancer Module and Generic Core Scales (r = 0.25 to r = 0.76) and between the Multidimensional Fatigue Scale and Generic Core Scales (r = 0.37 to r = 0.73). The PedsQL™ Generic Core Scales, Cancer Module, and Multidimensional Fatigue Scale appear to be feasible for an older population of pediatric cancer survivors; however, some of the Cancer Module Scales (nausea, procedural/treatment anxiety, and communication) were deemed not relevant for long-term survivors. More information is needed to determine whether the issues addressed by these modules are meaningful to long-term adult survivors of pediatric cancers. Copyright © 2012 Wiley Periodicals, Inc.

Relativistic many-body XMCD theory including core degenerate effects

NASA Astrophysics Data System (ADS)

Fujikawa, Takashi

2009-11-01

A many-body relativistic theory to analyze X-ray Magnetic Circular Dichroism (XMCD) spectra has been developed on the basis of relativistic quantum electrodynamic (QED) Keldysh Green's function approach. This theoretical framework enables us to handle relativistic many-body effects in terms of correlated nonrelativistic Green's function and relativistic correction operator Q, which naturally incorporates radiation field screening and other optical field effects in addition to electron-electron interactions. The former can describe the intensity ratio of L2/L3 which deviates from the statistical weight (branching ratio) 1/2. In addition to these effects, we consider the degenerate or nearly degenerate effects of core levels from which photoelectrons are excited. In XPS spectra, for example in Rh 3d sub level excitations, their peak shapes are quite different: This interesting behavior is explained by core-hole moving after the core excitation. We discuss similar problems in X-ray absorption spectra in particular excitation from deep 2p sub levels which are degenerate in each sub levels and nearly degenerate to each other in light elements: The hole left behind is not frozen there. We derive practical multiple scattering formulas which incorporate all those effects.

Analysis of linkage effects among industry sectors in China's stock market before and after the financial crisis

NASA Astrophysics Data System (ADS)

Yang, Rui; Li, Xiangyang; Zhang, Tong

2014-10-01

This paper uses two physics-derived techniques, the minimum spanning tree and the hierarchical tree, to investigate the networks formed by CITIC (China International Trust and Investment Corporation) industry indices in three periods from 2006 to 2013. The study demonstrates that obvious industry clustering effects exist in the networks, and Durable Consumer Goods, Industrial Products, Information Technology, Frequently Consumption and Financial Industry are the core nodes in the networks. We also use the rolling window technique to investigate the dynamic evolution of the networks' stability, by calculating the mean correlations and mean distances, as well as the variance of correlations and the distances of these indices. China's stock market is still immature and subject to administrative interventions. Therefore, through this analysis, regulators can focus on monitoring the core nodes to ensure the overall stability of the entire market, while investors can enhance their portfolio allocations or investment decision-making.

The JCMT Gould Belt Survey: Dense Core Clusters in Orion B

NASA Astrophysics Data System (ADS)

Kirk, H.; Johnstone, D.; Di Francesco, J.; Lane, J.; Buckle, J.; Berry, D. S.; Broekhoven-Fiene, H.; Currie, M. J.; Fich, M.; Hatchell, J.; Jenness, T.; Mottram, J. C.; Nutter, D.; Pattle, K.; Pineda, J. E.; Quinn, C.; Salji, C.; Tisi, S.; Hogerheijde, M. R.; Ward-Thompson, D.; The JCMT Gould Belt Survey Team

2016-04-01

The James Clerk Maxwell Telescope Gould Belt Legacy Survey obtained SCUBA-2 observations of dense cores within three sub-regions of Orion B: LDN 1622, NGC 2023/2024, and NGC 2068/2071, all of which contain clusters of cores. We present an analysis of the clustering properties of these cores, including the two-point correlation function and Cartwright’s Q parameter. We identify individual clusters of dense cores across all three regions using a minimal spanning tree technique, and find that in each cluster, the most massive cores tend to be centrally located. We also apply the independent M-Σ technique and find a strong correlation between core mass and the local surface density of cores. These two lines of evidence jointly suggest that some amount of mass segregation in clusters has happened already at the dense core stage.

Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials

NASA Astrophysics Data System (ADS)

Callewaert, Vincent; Saniz, Rolando; Barbiellini, Bernardo; Bansil, Arun; Partoens, Bart

2017-08-01

We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes.

Exploring cosmic origins with CORE: Mitigation of systematic effects

NASA Astrophysics Data System (ADS)

Natoli, P.; Ashdown, M.; Banerji, R.; Borrill, J.; Buzzelli, A.; de Gasperis, G.; Delabrouille, J.; Hivon, E.; Molinari, D.; Patanchon, G.; Polastri, L.; Tomasi, M.; Bouchet, F. R.; Henrot-Versillé, S.; Hoang, D. T.; Keskitalo, R.; Kiiveri, K.; Kisner, T.; Lindholm, V.; McCarthy, D.; Piacentini, F.; Perdereau, O.; Polenta, G.; Tristram, M.; Achucarro, A.; Ade, P.; Allison, R.; Baccigalupi, C.; Ballardini, M.; Banday, A. J.; Bartlett, J.; Bartolo, N.; Basak, S.; Baumann, D.; Bersanelli, M.; Bonaldi, A.; Bonato, M.; Boulanger, F.; Brinckmann, T.; Bucher, M.; Burigana, C.; Cai, Z.-Y.; Calvo, M.; Carvalho, C.-S.; Castellano, M. G.; Challinor, A.; Chluba, J.; Clesse, S.; Colantoni, I.; Coppolecchia, A.; Crook, M.; D'Alessandro, G.; de Bernardis, P.; De Zotti, G.; Di Valentino, E.; Diego, J.-M.; Errard, J.; Feeney, S.; Fernandez-Cobos, R.; Finelli, F.; Forastieri, F.; Galli, S.; Genova-Santos, R.; Gerbino, M.; González-Nuevo, J.; Grandis, S.; Greenslade, J.; Gruppuso, A.; Hagstotz, S.; Hanany, S.; Handley, W.; Hernandez-Monteagudo, C.; Hervías-Caimapo, C.; Hills, M.; Keihänen, E.; Kitching, T.; Kunz, M.; Kurki-Suonio, H.; Lamagna, L.; Lasenby, A.; Lattanzi, M.; Lesgourgues, J.; Lewis, A.; Liguori, M.; López-Caniego, M.; Luzzi, G.; Maffei, B.; Mandolesi, N.; Martinez-González, E.; Martins, C. J. A. P.; Masi, S.; Matarrese, S.; Melchiorri, A.; Melin, J.-B.; Migliaccio, M.; Monfardini, A.; Negrello, M.; Notari, A.; Pagano, L.; Paiella, A.; Paoletti, D.; Piat, M.; Pisano, G.; Pollo, A.; Poulin, V.; Quartin, M.; Remazeilles, M.; Roman, M.; Rossi, G.; Rubino-Martin, J.-A.; Salvati, L.; Signorelli, G.; Tartari, A.; Tramonte, D.; Trappe, N.; Trombetti, T.; Tucker, C.; Valiviita, J.; Van de Weijgaert, R.; van Tent, B.; Vennin, V.; Vielva, P.; Vittorio, N.; Wallis, C.; Young, K.; Zannoni, M.

2018-04-01

We present an analysis of the main systematic effects that could impact the measurement of CMB polarization with the proposed CORE space mission. We employ timeline-to-map simulations to verify that the CORE instrumental set-up and scanning strategy allow us to measure sky polarization to a level of accuracy adequate to the mission science goals. We also show how the CORE observations can be processed to mitigate the level of contamination by potentially worrying systematics, including intensity-to-polarization leakage due to bandpass mismatch, asymmetric main beams, pointing errors and correlated noise. We use analysis techniques that are well validated on data from current missions such as Planck to demonstrate how the residual contamination of the measurements by these effects can be brought to a level low enough not to hamper the scientific capability of the mission, nor significantly increase the overall error budget. We also present a prototype of the CORE photometric calibration pipeline, based on that used for Planck, and discuss its robustness to systematics, showing how CORE can achieve its calibration requirements. While a fine-grained assessment of the impact of systematics requires a level of knowledge of the system that can only be achieved in a future study phase, the analysis presented here strongly suggests that the main areas of concern for the CORE mission can be addressed using existing knowledge, techniques and algorithms.

The influence of radiative core growth on coronal X-ray emission from pre-main-sequence stars

NASA Astrophysics Data System (ADS)

Gregory, Scott G.; Adams, Fred C.; Davies, Claire L.

2016-04-01

Pre-main-sequence (PMS) stars of mass ≳0.35 M⊙ transition from hosting fully convective interiors to configurations with a radiative core and outer convective envelope during their gravitational contraction. This stellar structure change influences the external magnetic field topology and, as we demonstrate herein, affects the coronal X-ray emission as a stellar analogue of the solar tachocline develops. We have combined archival X-ray, spectroscopic, and photometric data for ˜1000 PMS stars from five of the best studied star-forming regions: the Orion Nebula Cluster, NGC 2264, IC 348, NGC 2362, and NGC 6530. Using a modern, PMS calibrated, spectral type-to-effective temperature and intrinsic colour scale, we de-redden the photometry using colours appropriate for each spectral type, and determine the stellar mass, age, and internal structure consistently for the entire sample. We find that PMS stars on Henyey tracks have, on average, lower fractional X-ray luminosities (LX/L*) than those on Hayashi tracks, where this effect is driven by changes in LX. X-ray emission decays faster with age for higher mass PMS stars. There is a strong correlation between L* and LX for Hayashi track stars but no correlation for Henyey track stars. There is no correlation between LX and radiative core mass or radius. However, the longer stars have spent with radiative cores, the less X-ray luminous they become. The decay of coronal X-ray emission from young early K to late G-type PMS stars, the progenitors of main-sequence A-type stars, is consistent with the dearth of X-ray detections of the latter.

Effects of sulfate-reducing bacteria on methylmercury at the sediment-water interface.

PubMed

Zeng, Lingxia; Luo, Guangjun; He, Tianrong; Guo, Yanna; Qian, Xiaoli

2016-08-01

Sediment cores (containing sediment and overlying water) from Baihua Reservoir (SW China) were cultured under different redox conditions with different microbial activities, to understand the effects of sulfate-reducing bacteria (SRB) on mercury (Hg) methylation at sediment-water interfaces. Concentrations of dissolved methyl mercury (DMeHg) in the overlying water of the control cores with bioactivity maintained (BAC) and cores with only sulfate-reducing bacteria inhibited (SRBI) and bacteria fully inhibited (BACI) were measured at the anaerobic stage followed by the aerobic stage. For the BAC and SRBI cores, DMeHg concentrations in waters were much higher at the anaerobic stage than those at the aerobic stage, and they were negatively correlated to the dissolved oxygen concentrations (r=-0.5311 and r=-0.4977 for BAC and SRBI, respectively). The water DMeHg concentrations of the SRBI cores were 50% lower than those of the BAC cores, indicating that the SRB is of great importance in Hg methylation in sediment-water systems, but there should be other microbes such as iron-reducing bacteria and those containing specific gene cluster (hgcAB), besides SRB, causing Hg methylation in the sediment-water system. Copyright © 2016. Published by Elsevier B.V.

The correlation between the amplitude of Osborn wave and core body temperature.

PubMed

Omar, Hesham R; Camporesi, Enrico M

2015-08-01

Several reports illustrate an inverse correlation between the Osborn wave (J wave) amplitude and core body temperature. We attempted to study the strength of this correlation. We reviewed all articles reporting hypothermic J waves from 1950-2014 for patient demographics, core body temperature in Celsius (°C), amplitude of the J wave in millimeters (mm), lead with the highest amplitude of J wave, presence of acidosis, PO2, electrolytes and outcome. In cases with more than one electrocardiogram (ECG), the respective core body temperature and J wave amplitude of each ECG were recorded. The main study outcome is to evaluate the correlation between the J wave amplitude and core body temperature in the admission ECG. We have also examined the strength of this relationship in cases with more than one ECG. We attempted to find the most frequent lead that recorded the highest amplitude of the J wave in addition to the correlation between the amplitude of J wave and pH. We found 64 articles comprising a total of 68 cases. When analyzing only cases with more than one reported ECG, there was a strong inverse correlation (r = - 0.682, p<0.001) between J wave amplitude and body temperature: however, when analyzing admission ECG of all cases, the correlation was only moderate (r = - 0.410, p<0.001). The lead with the highest amplitude of the J wave was V4 (44% of the cases, p<0.001) followed by V3 (23.7% of the cases, p<0.001). The amplitude of the J wave in the admission ECG of hypothermic patients may not accurately predict the core body temperature. © The European Society of Cardiology 2014.

Relationship between scapular muscle and core endurance in healthy subjects.

PubMed

Hazar Kanik, Zeynep; Pala, Omer Osman; Gunaydin, Gurkan; Sozlu, Ugur; Alkan, Zeynep Beyza; Basar, Selda; Citaker, Seyit

2017-01-01

Scapular muscle endurance and core endurance reportedly influence shoulder injury risk. The exact relationship between scapular muscle endurance and core endurance, and how they impact one another in the healthy subjects remain unclear. To investigate the relationship between scapular muscle endurance and core endurance in healthy subjects. Fifty healthy volunteers (23 males, 27 females; mean age 20.42 ± 1.04 years) were participated in this study. Endurance of the serratus anterior and trapezius muscles was assessed using the scapular muscle endurance test. Sorensen test (endurance of trunk extensor muscles), trunk flexor endurance test, and side bridge test (endurance of lateral core muscles) were conducted to assess the core endurance. Pearson's product moment correlations examined relationships between scapular muscle endurance and each of the core endurance tests scores. Scapular muscle endurance test scores showed a positive correlation with the side bridge test scores (r = 0.414; p = 0.003). No significant correlation was found between scapular muscle endurance test scores and the other core endurance tests scores (p > 0.05). There appears to be a link between the scapular muscle endurance and lateral core muscles in healthy subjects; however, more research is needed to provide a definitive answer on the nature of this relationship. Further studies involving patients with shoulder pathology are warranted.

Evidence for biasing in the CfA survey

NASA Technical Reports Server (NTRS)

Hamilton, A. J. S.

1988-01-01

Intrinsically bright galaxies appear systematically more correlated than faint galaxies in the Center for Astrophysics redshift survey. The amplification of the two-point correlation function behaves exponentially with luminosity, being essentially flat up to the knee of the luminosity function, then increasing markedly. The amplification reaches a factor of 3.5e + or - 0.4 in the very brightest galaxies. The effect is dominated by spirals rather than ellipticals, so that the correlation function of bright spirals becomes comparable to that of normal ellipticals. Similar results are obtained whether the correlation function is measured in two or three dimensions. The effect persists to separations of a correlation length or more, and is not confined to the cores of the Virgo, Coma, and Abell 1367 clusters, suggesting that the effect is caused by biasing, that is, galaxies kindle preferentially in more clustered regions, rather than by gravitational relaxation.

The CoreWall Project: An Update for 2007

NASA Astrophysics Data System (ADS)

Yu-Chung Chen, J.; Higgins, S.; Hur, H.; Ito, E.; Jenkins, C. J.; Johnson, A.; Leigh, J.; Morin, P.; Lee, J.

2007-12-01

The CoreWall Suite is a NSF-supported collaborative development for a real-time core description (Corelyzer), stratigraphic correlation (Correlater), and data visualization (CoreNavigator) software to be used by the marine, terrestrial and Antarctic science communities. The overall goal of the Corewall software development is to bring portable cross-platform tools to the broader drilling and coring communities to expand and enhance data visualization and enhance collaborative integration of multiple datasets. The CoreWall Project is now in its second year and significant progress has been made on all 3 software components. Corelyzer has undergone 2 field deployments and testing by ANDRILL program in 2006 (and again in Fall 2007) and by ICDP's SAFOD project (summer 2007). In addition, Corewall group and ICDP are working together so that the core description (DIS) system can expose DIS core data directly into Corelyzer seamlessly and be available to future ICDP and IODP-Mission Specific Platform expeditions. Educators have also taken note of the software's ease of use and strong visualization capabilities to begin exploring curriculum projects with Corelyzer software. To ensure that the software development is integrated with other community IT activities the development of the U.S. IODP-Phase 2 Scientific Ocean Drilling Vessel (SODV), a Steering Committee was constituted. It is composed of key U.S. IODP and related database (e.g., CHRONOS, SedDB) developers and users as well as representatives of other core-based enterprises (e.g., ANDRILL, ICDP, LacCore). Corelyzer (CoreWall's main visual core description tool) software displays digital core images from one or more cores along with discrete data streams (eg. physical properties, downhole logs) and nested images (eg. thin sections, fossils) to provide a robust approach to the description of sediment cores. Corelyzer's digital image handling allows the cores to be viewed from micron to km scale determined by the image resolution along a sliding plane, effectively making it a "digital microscope". Detailed features such as lithologic variation, macroscopic grain size variation, bioturbation intensity, chemical composition and micropaleontology are easier to interpret and annotate. Significant new capabilities have been added to allow for importing multiple images and data types, sharing/exporting Corelyzer "work sessions" for multiple users, enhanced annotations, as well as support for other activities like examining clasts, and sample requests. The new Correlator software, the updated version of Splicer/Sagan software used by ODP for over 10 years, has been ported into a single new analysis tool that will work across multiple platforms and interact seamlessly with both JANUS (ODP's relational database), CHRONOS, PetDB, SedDB, dbSEABED and other databases. This functionality will result in a CoreWall Suite module that can be used and distributed anywhere for stratigraphic and age correlation tasks. CoreNavigator, a spatial data discovery tool, has taken on a virtual Globe interface that allows users to enter Corelyzer from a geographic-visual standpoint.

Chromatin ionic atmosphere analyzed by a mesoscale electrostatic approach.

PubMed

Gan, Hin Hark; Schlick, Tamar

2010-10-20

Characterizing the ionic distribution around chromatin is important for understanding the electrostatic forces governing chromatin structure and function. Here we develop an electrostatic model to handle multivalent ions and compute the ionic distribution around a mesoscale chromatin model as a function of conformation, number of nucleosome cores, and ionic strength and species using Poisson-Boltzmann theory. This approach enables us to visualize and measure the complex patterns of counterion condensation around chromatin by examining ionic densities, free energies, shielding charges, and correlations of shielding charges around the nucleosome core and various oligonucleosome conformations. We show that: counterions, especially divalent cations, predominantly condense around the nucleosomal and linker DNA, unburied regions of histone tails, and exposed chromatin surfaces; ionic screening is sensitively influenced by local and global conformations, with a wide ranging net nucleosome core screening charge (56-100e); and screening charge correlations reveal conformational flexibility and interactions among chromatin subunits, especially between the histone tails and parental nucleosome cores. These results provide complementary and detailed views of ionic effects on chromatin structure for modest computational resources. The electrostatic model developed here is applicable to other coarse-grained macromolecular complexes. Copyright © 2010 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Structure factor of blends of solvent-free nanoparticle-organic hybrid materials: density-functional theory and small angle X-ray scattering.

PubMed

Yu, Hsiu-Yu; Srivastava, Samanvaya; Archer, Lynden A; Koch, Donald L

2014-12-07

We investigate the static structure factor S(q) of solvent-free nanoparticle-organic hybrid materials consisting of silica nanocores and space-filling polyethylene glycol coronas using a density-functional theory and small angle X-ray scattering measurements. The theory considers a bidisperse suspension of hard spheres with different radii and tethered bead-spring oligomers with different grafting densities to approximate the polydispersity effects in experiments. The experimental systems studied include pure samples with different silica core volume fractions and the associated mean corona grafting densities, and blends with different mixing ratios of the pure samples, in order to introduce varying polydispersity of corona grafting density. Our scattering experiments and theory show that, compared to the hard-sphere suspension with the same core volume fraction, S(q) for pure samples exhibit both substantially smaller values at small q and stronger particle correlations corresponding to a larger effective hard core at large q, indicating that the tethered incompressible oligomers enforce a more uniform particle distribution, and the densely grafted brush gives rise to an additional exclusionary effect between the nanoparticles. According to the theory, polydispersity in the oligomer grafting density controls the deviation of S(q) from the monodisperse system at smaller q, and the interplay of the enhanced effective core size and the entropic attraction among the particles is responsible for complex variations in the particle correlations at larger q. The successful comparison between the predictions and the measurements for the blends further suggests that S(q) can be used to assess the uniformity of grafting density in polymer-grafted nanoparticle materials.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion.

PubMed

Wilson, Jordan L; Samaranayake, V A; Limmer, Matt A; Burken, Joel G

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman's correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal equipment at the PCE Southeast Contamination Site was sufficient to delineate vapor intrusion potential in the study area and offered comparable delineation to traditional sub-slab sampling performed at 140 properties over a period of approximately 2 years.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

USGS Publications Warehouse

Wilson, Jordan L.; Samaranayake, V.A.; Limmer, Matthew A.; Burken, Joel G.

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal equipment at the PCE Southeast Contamination Site was sufficient to delineate vapor intrusion potential in the study area and offered comparable delineation to traditional sub-slab sampling performed at 140 properties over a period of approximately 2 years.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

PubMed Central

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal equipment at the PCE Southeast Contamination Site was sufficient to delineate vapor intrusion potential in the study area and offered comparable delineation to traditional sub-slab sampling performed at 140 properties over a period of approximately 2 years. PMID:29451904

Correlation between core ion energization, suprathermal electron bursts, and broadband ELF plasma waves

NASA Astrophysics Data System (ADS)

Knudsen, David J.; Clemmons, James H.; Wahlund, Jan-Erik

1998-03-01

Observations of the lowest energy or core ions provide a particularly sensitive measure of the early stages of auroral ion energization. Freja satellite observations of 0-20 eV core ions in the topside auroral ionosphere and cusp/cleft show signs of heating within both regions of VLF hiss and broadband ELF plasma waves. However, heating to several eV or more is associated predominantly with the ELF waves. A correlation analysis of wave and core ion data formed from orbital segments shows that, on average, correlations are highest for wave frequencies below several hundred Hz, and less at VLF hiss frequencies. A similar analysis shows a higher correlation between electron precipitation and ion heating for electron energies below several hundred eV (i.e., the energies associated with suprathermal electron bursts) and a lower correlation above the 1 keV energies associated with auroral inverted-V's. Signs of core ion heating begin to appear when wave power at the O+ gyrofrequency exceeds about 10-3(mVm-1)2/Hz, and when the integrated field-aligned electron flux exceeds a few times 107cm-2s-1sr-1. This electron energy flux threshold is at least an order of magnitude lower than previously inferred from earlier studies comparing suprathermal electron fluxes and energetic ions. Almost all observed heating events occur during enhanced or active geomagnetic conditions; i.e., Kp>=4. While the most intense core ion heating is correlated with broadband ELF waves, we also present one example of weak ion heating of a few eV in a region of VLF auroral hiss.

The correcting method for the estimation of correlation energies of MF2 (M = Be, Mg, Ca) set molecules

NASA Astrophysics Data System (ADS)

Zhuo, Shuping; Wei, Jichong; Ju, Guanzhi

The intrapair and interpair correlation energies of MF2 (M = Be, Mg, Ca) set molecules are calculated and analysed, and the transferability of inner core correlation effects of Mδ+ are investigated. A detailed analysis of the comparison of correlation energies of neutral atoms with their corresponding ions of Mδ+ and Fδ-/2 is given in terms of the correlation contribution of this component. The study reveals that the total correlation energy of MF2 molecules can be obtained by summing the correlation contributions of Mδ+ and two Fδ-/2 components. This simple estimation method does shed light on the importance of searching useful means for the calculation of electron correlation energy for large biological systems.

Effects of ambient temperature on mechanomyography of resting quadriceps muscle.

PubMed

McKay, William P; Vargo, Michael; Chilibeck, Philip D; Daku, Brian L

2013-03-01

It has been speculated that resting muscle mechanical activity, also known as minor tremor, microvibration, and thermoregulatory tonus, has evolved to maintain core temperature in homeotherms, and may play a role in nonshivering thermogenesis. This experiment was done to determine whether resting muscle mechanical activity increases with decreasing ambient temperature. We cooled 20 healthy, human, resting, supine subjects from an ambient temperature of 40° to 12 °C over 65 min. Core temperature, midquadriceps mechanomyography, surface electromyography, and oxygen consumption (VO2) were recorded. Resting muscle mechanical and electrical activity in the absence of shivering increased significantly at temperatures below 21.5 °C. Women defended core temperature more effectively than men, and showed increased resting muscle activity earlier than men. Metabolism measured by VO2 correlated with resting muscle mechanical activity (R = 0.65; p = 0.01). Resting muscle mechanical activity may have evolved, in part, to maintain core temperature in the face of mild cooling.

Sediment Relative Paleointensity Record With Slow-sedimentation Rates: Implication For a Chronological Tool In The Slow-sedimentation Sequence

NASA Astrophysics Data System (ADS)

Kanamatsu, T.

2006-12-01

Usefulness of paleointensity records with high-sedimentation rates in stratigraphic correlation have been proved (e.g. Stoner et al., 1998, Laj et al., 2000, Stoner et al., 2000), because the sediment geomagnetic paleointensity data makes possible the fine time correlation between cores on the older sediment than the range of AMS 14C. As father application of the sediment paleointensity for chronological tool, we examined the paleointensity record of much slower sedimentation rate. The paleointensity record of the slower sedimentation sequence is supposed to show the convoluted record by the filtering effect of the post- depositional remanent magnetization, then a unique and different pattern depending on the sedimentation rate (e.g. Guyodo and Channell, 2002). We studied the record of the cores obtained from the West Philippine Sea Basin (Water depth ca. 5000 to 6000 m). The analyses of paleomagnetic direction proved that the cores contain Jaramillo and Olduvai Events. The sedimentation rates of cores estimated from magnetostratigraphy are less than 1cm/kyr (0.6-0.4 cm/kyr). Proxy of paleointensity (NRM20mT/ARM20mT) applied to cores reveals the variations in the records are dominate in c.a. 100 ky cycle. Comparing to other published paleointensity record, it is clear that the record includes ca.100-ky cycle in spite of slower sedimentation rates, although other high frequency records were not identified. It is suggests that geomagnetic events of a few to several kys are recordable in the sediment. The paleointensity in the slow-sedimentation record is still useful for the age control utilizing the lower frequency signal, especially for investigating of less age information sequence such as the deep sea sediment below CCD, but not for fine correlation by high frequency data.

Effect of buoyancy on fuel containment in an open-cycle gas-core nuclear rocket engine.

NASA Technical Reports Server (NTRS)

Putre, H. A.

1971-01-01

Analysis aimed at determining the scaling laws for the buoyancy effect on fuel containment in an open-cycle gas-core nuclear rocket engine, so conducted that experimental conditions can be related to engine conditions. The fuel volume fraction in a short coaxial flow cavity is calculated with a programmed numerical solution of the steady Navier-Stokes equations for isothermal, variable density fluid mixing. A dimensionless parameter B, called the Buoyancy number, was found to correlate the fuel volume fraction for large accelerations and various density ratios. This parameter has the value B = 0 for zero acceleration, and B = 350 for typical engine conditions.

Spatial fluorescence cross-correlation spectroscopy between core and ring pinholes

NASA Astrophysics Data System (ADS)

Blancquaert, Yoann; Delon, Antoine; Derouard, Jacques; Jaffiol, Rodolphe

2006-04-01

Fluorescence Correlation Spectroscopy (FCS) is an attractive method to measure molecular concentration, mobility parameters and chemical kinetics. However its ability to descriminate different diffusing species needs to be improved. Recently, we have proposed a simplified spatial Fluorescence cross Correlation Spectroscopy (sFCCS) method, allowing, with only one focused laser beam to obtain two confocal volumes spatially shifted. Now, we present a new sFCCS optical geometry where the two pinholes, a ring and core, are encapsulated one in the other. In this approach all physical and chemical processes that occur in a single volume, like singlet-triplet dynamics and photobleaching, can be eliminated; moreover, this new optical geometry optimises the collection of fluorescence. The first cross Correlation curves for Rhodamine 6G (Rh6G) in Ethanol are presented, in addition to the effect of the size of fluorescent particules (nano-beads, diameters : 20, 100 and 200 nm). The relative simplicity of the method leads us to propose sFCCS as an appropriate method for the determination of diffusion parameters of fluorophores in solution or cells. Nevertheless, progresses in the ingeniering of the optical Molecular Detection Efficiency volumes are highly desirable, in order to improve the descrimination between the cross correlated volumes.

The Effects of Non-Redox Active Metal Ions on the Activation of Dioxygen: Isolation and Characterization of a Heterobimetallic Complex Containing a MnIII–(μ-OH)–CaII core

PubMed Central

Park, Young Jun; Ziller, Joseph W.; Borovik, A. S.

2011-01-01

Rate enhancements for the reduction of dioxygen by a MnII complex were observed in the presence of redox inactive Group 2 metal ions. The rate changes correlated with an increase in the Lewis acidity of the Group 2 metal ions. These studies led to the isolation of heterobimetallic complexes that contain MnIII-(μ-OH)-MII cores (MII = CaII, BaII), in which the hydroxo oxygen atom is derived from O2. This type of core structure has relevance to the oxygen evolving complexes within photosystem II. PMID:21595481

Measurement of Correlation Between Flow Density, Velocity, and Density*velocity(sup 2) with Far Field Noise in High Speed Jets

NASA Technical Reports Server (NTRS)

Panda, Jayanta; Seasholtz, Richard G.; Elam, Kristie A.

2002-01-01

To locate noise sources in high-speed jets, the sound pressure fluctuations p', measured at far field locations, were correlated with each of radial velocity v, density rho, and phov(exp 2) fluctuations measured from various points in jet plumes. The experiments follow the cause-and-effect method of sound source identification, where correlation is related to the first, and correlation to the second source terms of Lighthill's equation. Three fully expanded, unheated plumes of Mach number 0.95, 1.4 and 1.8 were studied for this purpose. The velocity and density fluctuations were measured simultaneously using a recently developed, non-intrusive, point measurement technique based on molecular Rayleigh scattering. It was observed that along the jet centerline the density fluctuation spectra S(sub rho) have different shapes than the radial velocity spectra S(sub v), while data obtained from the peripheral shear layer show similarity between the two spectra. Density fluctuations in the jet showed significantly higher correlation, than either rhov(sub 2) or v fluctuations. It is found that a single point correlation from the peak sound emitting region at the end of the potential core can account for nearly 10% of all noise at 30 to the jet axis. The correlation, representing the effectiveness of a longitudinal quadrupole in generating noise 90 to the jet axis, is found to be zero within experimental uncertainty. In contrast rhov(exp 2) fluctuations were better correlated with sound pressure fluctuation at the 30 location. The strongest source of sound is found to lie at the centerline and beyond the end of potential core.

Predicting response to primary chemotherapy: gene expression profiling of paraffin-embedded core biopsy tissue.

PubMed

Mina, Lida; Soule, Sharon E; Badve, Sunil; Baehner, Fredrick L; Baker, Joffre; Cronin, Maureen; Watson, Drew; Liu, Mei-Lan; Sledge, George W; Shak, Steve; Miller, Kathy D

2007-06-01

Primary chemotherapy provides an ideal opportunity to correlate gene expression with response to treatment. We used paraffin-embedded core biopsies from a completed phase II trial to identify genes that correlate with response to primary chemotherapy. Patients with newly diagnosed stage II or III breast cancer were treated with sequential doxorubicin 75 mg/M2 q2 wks x 3 and docetaxel 40 mg/M2 weekly x 6; treatment order was randomly assigned. Pretreatment core biopsy samples were interrogated for genes that might correlate with pathologic complete response (pCR). In addition to the individual genes, the correlation of the Oncotype DX Recurrence Score with pCR was examined. Of 70 patients enrolled in the parent trial, core biopsies samples with sufficient RNA for gene analyses were available from 45 patients; 9 (20%) had inflammatory breast cancer (IBC). Six (14%) patients achieved a pCR. Twenty-two of the 274 candidate genes assessed correlated with pCR (p < 0.05). Genes correlating with pCR could be grouped into three large clusters: angiogenesis-related genes, proliferation related genes, and invasion-related genes. Expression of estrogen receptor (ER)-related genes and Recurrence Score did not correlate with pCR. In an exploratory analysis we compared gene expression in IBC to non-inflammatory breast cancer; twenty-four (9%) of the genes were differentially expressed (p < 0.05), 5 were upregulated and 19 were downregulated in IBC. Gene expression analysis on core biopsy samples is feasible and identifies candidate genes that correlate with pCR to primary chemotherapy. Gene expression in IBC differs significantly from noninflammatory breast cancer.

Site 765: Sediment Lithostratigraphy

USGS Publications Warehouse

,

1990-01-01

A 935-m-thick succession of Quaternary through Lower Cretaceous sediments was recovered at Site 765 (Fig. 10). A single core of Quaternary sediment was obtained from Hole 765A; drilling terminated and a new hole was drilled in an attempt to establish the mud line. Quaternary through middle Miocene sediments were cored in Hole 765B down to a depth of 395.6 mbsf. Middle Miocene through Lower Cretaceous sediments were cored in Hole 765C, after washing the interval between 0 and 350.2 mbsf. Exact lithologic correlation of the basal cores from Hole 765B with the upper cores from Hole 765C is not possible because of poor recovery; hence, correlation is based solely on matching sub-bottom depths.

Synthetic seismograms from vibracores: A case study in correlating the late quaternary seismic stratigraphy of the New Jersey inner continental shelf

USGS Publications Warehouse

Esker, D.; Sheridan, R.E.; Ashley, G.M.; Waldner, J.S.; Hall, D.W.

1996-01-01

A new technique, using empirical relationships between median grain size and density and velocity to calculate proxy values for density and velocity, avoids many of the problems associated with the use of well logs and shipboard measurements to construct synthetic seismograms. This method was used to groundtruth and correlate across both analog and digital shallow high-resolution seismic data on the New Jersey shelf. Sampling dry vibracores to determine median grain size eliminates the detrimental effects that coring disturbances and preservation variables have on the sediment and water content of the core. The link between seismic response to lithology and bed spacing is more exact. The exact frequency of the field seismic data can be realistically simulated by a 10-20 cm sampling interval of the vibracores. The estimate of the percentage error inherent in this technique, 12% for acoustic impedance and 24% for reflection amplitude, is calculated to one standard deviation and is within a reasonable limit for such a procedure. The synthetic seismograms of two cores, 4-6 m long, were used to correlate specific sedimentary deposits to specific seismic reflection responses. Because this technique is applicable to unconsolidated sediments, it is ideal for upper Pleistocene and Holocene strata. Copyright ?? 1996, SEPM (Society for Sedimentary Geology).

Deformation Behavior of Al/a-Si Core-shell Nanostructures

NASA Astrophysics Data System (ADS)

Fleming, Robert

Al/a-Si core-shell nanostructures (CSNs), consisting of a hemispherical Al core surrounded by a hard shell of a-Si, have been shown to display unusual mechanical behavior in response to compression loading. Most notably, these nanostructures exhibit substantial deformation recovery, even when loaded much beyond the elastic limit. Nanoindentation measurements revealed a unique mechanical response characterized by discontinuous signatures in the load-displacement data. In conjunction with the indentation signatures, nearly complete deformation recovery is observed. This behavior is attributed to dislocation nucleation and annihilation events enabled by the 3-dimensional confinement of the Al core. As the core confinement is reduced, either through an increase in confined core volume or a change in the geometrical confinement, the indentation signatures and deformation resistance are significantly reduced. Complimentary molecular dynamics simulations show that a substantial amount of dislocation egression occurs in the core of CSNs during unloading as dislocations annihilate at the core/shell interface. Smaller core diameters correlate with the development of a larger back-stress within the core during unloading, which further correlates with improved dislocation annihilation after unloading. Furthermore, dislocations nucleated in the core of core-shell nanorods are not as effectively removed as compared to CSNs. Nanostructure-textured surfaces (NSTSs) composed of Al/a-Si CSNs have improved tribological properties compared surfaces patterned with Al nanodots and a flat (100) Si surface. NSTSs have a coefficient of friction (COF) as low as 0.015, exhibit low adhesion with adhesion forces on the order of less than 1 microN, and are highly deformation resistant, with no apparent surface deformation after nanoscratch testing, even at contact forces up to 8000 microN. In comparison, (100) Si has substantially higher adhesion and COF ( 10 microN and 0.062, respectively), while the Al nanodots have both higher friction (COF 0.044) and are deformed when subjected to contact loads as low as 250 microN. This integrated experimental and computational study elucidates the mechanisms that contribute to the novel properties of Al/a-Si CSNs and characterizes the tribological properties of surface composed of these nanostructures, which provides a foundation for the rational design of novel technologies based on CSNs.

Differential Relationships of Reactive Astrocytes and Microglia to Fibrillar Amyloid Deposits in Alzheimer Disease

PubMed Central

Serrano-Pozo, Alberto; Muzikansky, Alona; Gómez-Isla, Teresa; Growdon, John H.; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.

2013-01-01

While it is clear that astrocytes and microglia cluster around dense-core amyloid plaques in Alzheimer disease (AD), whether they are primarily attracted to amyloid deposits or are just reacting to plaque-associated neuritic damage remains elusive. We postulate that astrocytes and microglia may differentially respond to fibrillar amyloid β (Aβ). Therefore, we quantified the size distribution of dense-core Thioflavin-S (ThioS)-positive plaques in the temporal neocortex of 40 AD patients and the microglial and astrocyte responses in their vicinity (≤50 μm), and performed correlations between both measures. As expected, both astrocytes and microglia were clearly spatially associated with ThioS-positive plaques (p = 0.0001, ≤50 μm vs. >50 μm from their edge), but their relationship to ThioS-positive plaque size differed; larger ThioS-positive plaques were associated with more surrounding activated microglia (p = 0.0026), but this effect was not observed with reactive astrocytes. Microglial response to dense-core plaques appears to be proportional to their size, which we postulate reflects a chemotactic effect of Aβ. By contrast, plaque-associated astrocytic response does not correlate with plaque size and seems to parallel the behavior of plaque-associated neuritic damage. PMID:23656989

Study of the effect of varying core diameter, shell thickness and strain velocity on the tensile properties of single crystals of Cu-Ag core-shell nanowire using molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Sarkar, Jit; Das, D. K.

2018-01-01

Core-shell type nanostructures show exceptional properties due to their unique structure having a central solid core of one type and an outer thin shell of another type which draw immense attention among researchers. In this study, molecular dynamics simulations are carried out on single crystals of copper-silver core-shell nanowires having wire diameter ranging from 9 to 30 nm with varying core diameter, shell thickness, and strain velocity. The tensile properties like yield strength, ultimate tensile strength, and Young's modulus are studied and correlated by varying one parameter at a time and keeping the other two parameters constant. The results obtained for a fixed wire size and different strain velocities were extrapolated to calculate the tensile properties like yield strength and Young's modulus at standard strain rate of 1 mm/min. The results show ultra-high tensile properties of copper-silver core-shell nanowires, several times than that of bulk copper and silver. These copper-silver core-shell nanowires can be used as a reinforcing agent in bulk metal matrix for developing ultra-high strength nanocomposites.

The ice-core record - Climate sensitivity and future greenhouse warming

NASA Technical Reports Server (NTRS)

Lorius, C.; Raynaud, D.; Jouzel, J.; Hansen, J.; Le Treut, H.

1990-01-01

The prediction of future greenhouse-gas-warming depends critically on the sensitivity of earth's climate to increasing atmospheric concentrations of these gases. Data from cores drilled in polar ice sheets show a remarkable correlation between past glacial-interglacial temperature changes and the inferred atmospheric concentration of gases such as carbon dioxide and methane. These and other palaeoclimate data are used to assess the role of greenhouse gases in explaining past global climate change, and the validity of models predicting the effect of increasing concentrations of such gases in the atmosphere.

A Higher Correlation of HCV Core Antigen with CD4+ T Cell Counts Compared with HCV RNA in HCV/HIV-1 Coinfected Patients

PubMed Central

Zhang, Weidong; Xi, Yuanlin; Cao, Guanghua; Zhi, Yuhong; Wang, Shuiwang; Xu, Chunhui; Wei, Lai; Lu, Fengmin; Zhuang, Hui

2011-01-01

Development of HCV infection is typically followed by chronic hepatitis C (CHC) in most patients, while spontaneous HCV viral clearance (SVC) occurs in only a minority of subjects. Compared with the widespread application of HCV RNA testing by quantitative RT-PCR technique, HCV core antigen detection may be an alternative indicator in the diagnosis of hepatitis C virus infections and in monitoring the status of infectious individuals. However, the correlation and differences between these two indicators in HCV infection need more investigation, especially in patients coinfected by HIV-1. In this study, a total of 354 anti-HCV and/or anti-HIV serum positive residents from a village of central China were enrolled. Besides HCV-related hepatopathic variables including clinical status, ALT, AST, anti-HCV Abs, as well as the altered CD4+/CD8+ T cell counts, HCV core antigen and HCV viral load were also measured. The concentration of serum HCV core antigen was highly correlated with level of HCV RNA in CHC patients with or without HIV-1 coinfection. Of note, HCV core antigen concentration was negatively correlated with CD4+ T cell count, while no correlation was found between HCV RNA level and CD4+ T cell count. Our findings suggested that quantitative detection of plasma HCV core antigen may be an alternative indicator of HCV RNA qPCR assay when evaluating the association between HCV replication and host immune status in HCV/HIV-1 coinfected patients. PMID:21858166

Development of Ferrite-Coated Soft Magnetic Composites: Correlation of Microstructure to Magnetic Properties

NASA Astrophysics Data System (ADS)

Sunday, Katie Jo

Soft magnetic composites (SMCs) comprised of ferrite-coated ferrous powder permit isotropic magnetic flux capabilities, lower core losses, and complex designs through the use of traditional powder metallurgy techniques. Current coating materials and methods are vastly limited by the nonmagnetic properties of organic and some inorganic coatings and their inability to withstand high heat treatments for proper stress relief of core powder after compaction. Ferrite-based coatings are ferrimagnetic, highly resistive, and boast high melting temperatures, thus providing adequate electrical barriers between metallic particles. These insulating layers are necessary for reducing eddy current losses by increasing resistivity in order to improve the overall magnetic efficiency and subsequent frequency range. The goals of this work are to correlate ferrite-coated Fe powder composites microstructure for the coating and core powder to magnetic properties such as permeability, coercivity, and core loss. We first explore the relevant concepts of SMC materials from their composition to processing steps to pertinent properties. This thesis employs a suite of characterization techniques for powder and composite properties. We use X-ray diffraction, scanning electron microscopy, and transmission electron microscopy to provide a complete understanding of the effect of processing conditions on ferrite-coated Fe-based SMCs. Magnetic, mechanical, and electrical properties are then analyzed to correlate microstructural features and determine their effect on such properties. In the second part of this thesis, we present a proof of concept study on Al2O3- and Al2O3- Fe3O4-coated Fe powder composites, illustrating magnetization is highly dependent on ferromagnetic volume. We then expand on previous work to compare an ideal, crystalline state using Fe3O 4-Fe thin film heterostructures to a highly strained state using bulk powder studies. Fe3O4-coated Fe composites are produced via mechanical milling and analyzed for magnetic core loss dependence on particle size, cure temperature, and microstructure of both coating and core powder. We present a significant increase in core loss related to eddy current loss from coating particles sintering and Fe grain growth. Lastly, a more resistive coating material, NiZnCu-ferrite, is applied for improved resistivity, which leads to lower eddy current loss and improved magnetic performance. By highlighting the importance of microstructure and composition on magnetic properties, a closer look at interfacial features and local microstrain are necessary and accomplished in this work. Future developments of ferrite-based SMC coatings are required to transform the use of electromagnetic devices in today's society.

Effect of an alternating electric field on the polluting emission from propane flame.

NASA Astrophysics Data System (ADS)

Ukradiga, I.; Turlajs, D.; Purmals, M.; Barmina, I.; Zake, M.

2001-12-01

The experimental investigations of the AC field effect on the propane combustion and processes that cause the formation of polluting emissions (NO_x, CO, CO_2) are performed. The AC-enhanced variations of the temperature and composition of polluting emissions are studied for the fuel-rich and fuel-lean conditions of the flame core. The results show that the AC field-enhanced mixing of the fuel-rich core with the surrounding air coflow enhances the propane combustion with increase in the mass fraction of NO_x and CO_2 in the products. The reverse field effect on the composition of polluting emissions is observed under the fuel-lean conditions in the flame core. The field-enhanced CO_2 destruction is registered when the applied voltage increase. The destruction of CO_2 leads to a correlating increase in the mass fraction of CO in the products and enhances the process of NO_x formation within the limit of the fuel lean and low temperature combustion. Figs 11, Refs 18.

Management of intraductal papilloma without atypia of the breast diagnosed on core biopsy: Size and sampling matter.

PubMed

Symbol, Brittany; Ricci, Andrew

2018-04-23

Due to the potential for atypia (atypical ductal or lobular hyperplasia) or carcinoma (in situ or invasive) on excision, aggressive reflex surgical excision protocols following core biopsy diagnosis of papillary lesions of the breast (ie, intraductal papilloma) are commonplace. Concepts in risk stratification, including radiologic-pathologic correlation, are emerging in an effort to curb unnecessary surgeries. To this end, we examined all excised intraductal papillomas diagnosed at our institution from 2010-2015 (N = 336) and found an overall atypia rate of 20%. To investigate further, we stratified all excised papillomas according to total lesion size (range = 1-40 mm) and found that the atypia rate for lesions ≤1.2 cm (16% with atypia) was statistically significantly lower (P = .008) than the atypia rate for lesions >1.2 cm (36% with atypia). To explore to effects of radiologic-pathologic correlation on the ability of the core biopsy to accurately predict nonatypical lesions we assessed thirteen consecutive paired nonatypical core biopsy/follow-up surgical excision specimens for the percent of the total lesion (on imaging) sampled by the core biopsy (measured histologically). None of the thirteen paired specimens showed upgrade on excision (0/13); the percent of total lesion sampled by biopsy in this cohort averaged 59%. We propose that in the absence of discordant clinical/radiological findings, small lesions (≤1.2 cm) with radiologic-pathologic concordance (>50% sampling of total lesion by core biopsy) may safely forego surgery for close clinical and radiographic follow-up. © 2018 Wiley Periodicals, Inc.

The Science of Inaccurate Temperatures: Explaining How the Bahamas Did Not Form in a Jacuzzi

NASA Astrophysics Data System (ADS)

Murray, S.; Swart, P. K.; McNeill, D. F.

2016-12-01

The Bahamas archipelago is a carbonate platform that formed in the warm waters of the Gulf Stream current. Using clumped isotope paleothermometry, it has been shown that carbonates extending back through the Miocene taken from cores throughout the Bahamas have all precipitated from fluids at temperatures similar to what is found in the Bahamas in the present day (15 to 35°C). However, in a single core, (Clino), collected off the western edge of Great Bahama Bank, Δ47 values have been measured which suggest formation at significantly warmer temperatures (42 to 53°C). These values are present in spite of the fact that the sediments have never been deeply buried. In a parallel study, these same cores were measured for their carbonate associated sulfate (CAS). The only core that presented evidence of elevated CAS, indicative of bacterial sulfate reduction (BSR), was the Clino core. In this core the clumped isotope temperatures are correlated with changes in the δ34S of the CAS. This finding suggests that BSR can have a significant effect on the Δ47 value producing erroneous temperatures. This is further supported by examining a carbonate concretion with extreme negative δ13C values (-30‰) taken as evidence of BSR. The clumped isotope temperatures in this nodule are elevated relative to its burial history with an increase of 15 °C from the outer edge of the concretion to the center. The increase in temperature correlates well with the decreasing δ13C suggesting increasing fractionation associated with BSR is directly impacting the clumped isotope measurements.

[The relevance of core muscles in ice hockey players: a feasibility study].

PubMed

Rogan, S; Blasimann, A; Nyffenegger, D; Zimmerli, N; Radlinger, L

2013-12-01

Good core strength is seen as a condition for high performance in sports. In general, especially maximum voluntary contraction (MVC) and strength endurance (SE) measurements of the core muscles are used. In addition, a few studies can be found that examine the core muscles in terms of MVC, rate of force development (RFD) and SE. Primary aims of this feasibility study were to investigate the feasibility regarding recruiting process, compliance and safety of the testing conditions and raise the force capabilities MVC, RFD and SE of the core muscles in amateur ice hockey players. Secondarily, tendencies of correlations between muscle activity and either shot speed and sprint time shall be examined. In this feasibility study the recruitment process has been approved by 29 ice hockey players, their adherence to the study measurements of trunk muscles, and safety of the measurements was evaluated. To determine the MVC, RFD and SE for the ventral, lateral and dorsal core muscles a dynamic force measurement was performed. To determine the correlation between core muscles and shot speed and 40-m sprint, respectively, the rank correlation coefficient (rho) from Spearman was used. The recruited number of eight field players and one goal-keeper was not very high. The compliance with 100 % was excellent. The players reported no adverse symptoms or injuries after the measurements. The results show median values for the ventral core muscles for MVC with 46.5 kg for RFD with 2.23 m/s2 and 96 s for the SE. For lateral core muscle median values of the lateral core muscles for MVC with 71.10 kg, RFD with 2.59 m/s2 and for SE over 66 s were determined. The dorsal core muscles shows values for MVC 69.7 kg, for RFD 3.39 m/s2 and for SE of 75 s. High correlations between MVC of the ventral core muscles (rho = -0.721, p = 0.021), and between the SE of the ventral core muscles (rho = 0.787, p = 0.012), and the shot velocity rate were determined. Another high correlation between SE of the ventral core muscles and sprint over 40 m (rho = 0.717, p = 0.030) could be demonstrated. This feasibility study has shown that the implementation of the selected design is adapted for future studies. Further studies are needed to better understand the relationship between the velocity rate and the MVC, and the SE respectively, as well as between the sprint and the SE. © Georg Thieme Verlag KG Stuttgart · New York.

The Metabolic Core and Catalytic Switches Are Fundamental Elements in the Self-Regulation of the Systemic Metabolic Structure of Cells

PubMed Central

De la Fuente, Ildefonso M.; Cortes, Jesus M.; Perez-Pinilla, Martin B.; Ruiz-Rodriguez, Vicente; Veguillas, Juan

2011-01-01

Background Experimental observations and numerical studies with dissipative metabolic networks have shown that cellular enzymatic activity self-organizes spontaneously leading to the emergence of a metabolic core formed by a set of enzymatic reactions which are always active under all environmental conditions, while the rest of catalytic processes are only intermittently active. The reactions of the metabolic core are essential for biomass formation and to assure optimal metabolic performance. The on-off catalytic reactions and the metabolic core are essential elements of a Systemic Metabolic Structure which seems to be a key feature common to all cellular organisms. Methodology/Principal Findings In order to investigate the functional importance of the metabolic core we have studied different catalytic patterns of a dissipative metabolic network under different external conditions. The emerging biochemical data have been analysed using information-based dynamic tools, such as Pearson's correlation and Transfer Entropy (which measures effective functionality). Our results show that a functional structure of effective connectivity emerges which is dynamical and characterized by significant variations of bio-molecular information flows. Conclusions/Significance We have quantified essential aspects of the metabolic core functionality. The always active enzymatic reactions form a hub –with a high degree of effective connectivity- exhibiting a wide range of functional information values being able to act either as a source or as a sink of bio-molecular causal interactions. Likewise, we have found that the metabolic core is an essential part of an emergent functional structure characterized by catalytic modules and metabolic switches which allow critical transitions in enzymatic activity. Both, the metabolic core and the catalytic switches in which also intermittently-active enzymes are involved seem to be fundamental elements in the self-regulation of the Systemic Metabolic Structure. PMID:22125607

Tephra layers in the Siple Dome and Taylor Dome ice cores, Antarctica: Sources and correlations

NASA Astrophysics Data System (ADS)

Dunbar, Nelia W.; Zielinski, Gregory A.; Voisins, Daniel T.

2003-08-01

Volcanic ash, or tephra layers, are found in the Taylor Dome, Siple Dome A, and Siple Dome B ice cores. Significant shard concentrations are found at a number of depths in all three cores. Electron and ion microprobe analyses indicate that the geochemical composition of most layers is basaltic, basanitic, or trachytic, and the geochemical signatures of the layers suggest derivation from the Pleiades volcanic center, Mt. Melbourne volcano, or small mafic centers, probably in the Royal Society Range area. Presence of tephra layers suggests an episode of previously unrecognized Antarctic volcanic activity between 1776 and 1805 A.D., from at least two volcanic centers. A strong geochemical correlation (D = 3.49 and 3.97 with a value of 4 considered identical) is observed between tephra layers at depth of 79.2 m in the Taylor Dome ice core, and layers between 97.2 and 97.7 m depth in the Siple B core. This correlation, and the highly accurate depth-age scale of the Siple B core suggest that the age of this horizon in the Taylor Dome ice core presented by [1998a, 2000] should be revised downward, to the younger age of 675 ± 25 years before 1995. This revised chronology is consistent with vertical strain measurements presented by [2003].

Exciton and core-level electron confinement effects in transparent ZnO thin films

PubMed Central

Mosquera, Adolfo A.; Horwat, David; Rashkovskiy, Alexandr; Kovalev, Anatoly; Miska, Patrice; Wainstein, Dmitry; Albella, Jose M.; Endrino, Jose L.

2013-01-01

The excitonic light emission of ZnO films have been investigated by means of photoluminescence measurements in ultraviolet-visible region. Exciton confinement effects have been observed in thin ZnO coatings with thickness below 20 nm. This is enhanced by a rise of the intensity and a blue shift of the photoluminescence peak after extraction of the adsorbed species upon annealing in air. It is found experimentally that the free exciton energy (determined by the photoluminescence peak) is inversely proportional to the square of the thickness while core-level binding energy is inversely proportional to the thickness. These findings correlate very well with the theory of kinetic and potential confinements.

A Study of the Vacancy-Impurity Interaction in Dilute Nickel Alloys by Core Electron Annihilation

NASA Astrophysics Data System (ADS)

Arbuzov, V. L.; Danilov, S. E.; Druzhkov, A. P.

1997-08-01

It is shown that the angular correlation of annihilation radiation can be used to identify vacancy-impurity complexes in dilute alloys. Annihilation of trapped positrons with core electrons bears information about the chemical environment of a vacancy defect. The method is especially effective for d-matrices doped with sp-impurities since annihilation parameters of positrons with d- and sp-shell electrons differ considerably. The potentialities of the method of core-electron annihilation of positrons are demonstrated taking electron-irradiated dilute Ni-P and Ni-Si alloys as an example. It is shown that the interaction between the vacancies, which migrate at the III stage of annealing, and P atoms in Ni-P causes a considerable change in the annihilation parameters of positrons with core electrons compared to pure Ni. In Ni-Si alloys the annihilation parameters of trapped positrons with core electrons do not differ from those in Ni. This fact is an evidence that Si atoms do not interact with vacancies in Ni.

Improved Thermoplastic/Iron-Particle Transformer Cores

NASA Technical Reports Server (NTRS)

Wincheski, Russell A.; Bryant, Robert G.; Namkung, Min

2004-01-01

A method of fabricating improved transformer cores from composites of thermoplastic matrices and iron-particles has been invented. Relative to commercially available laminated-iron-alloy transformer cores, the cores fabricated by this method weigh less and are less expensive. Relative to prior polymer-matrix/ iron-particle composite-material transformer cores, the cores fabricated by this method can be made mechanically stronger and more magnetically permeable. In addition, whereas some prior cores have exhibited significant eddy-current losses, the cores fabricated by this method exhibit very small eddy-current losses. The cores made by this method can be expected to be attractive for use in diverse applications, including high-signal-to-noise transformers, stepping motors, and high-frequency ignition coils. The present method is a product of an experimental study of the relationships among fabrication conditions, final densities of iron particles, and mechanical and electromagnetic properties of fabricated cores. Among the fabrication conditions investigated were molding pressures (83, 104, and 131 MPa), and molding temperatures (250, 300, and 350 C). Each block of core material was made by uniaxial-compression molding, at the applicable pressure/temperature combination, of a mixture of 2 weight percent of LaRC (or equivalent high-temperature soluble thermoplastic adhesive) with 98 weight percent of approximately spherical iron particles having diameters in the micron range. Each molded block was cut into square cross-section rods that were used as core specimens in mechanical and electromagnetic tests. Some of the core specimens were annealed at 900 C and cooled slowly before testing. For comparison, a low-carbon-steel core was also tested. The results of the tests showed that density, hardness, and rupture strength generally increased with molding pressure and temperature, though the correlation was rather weak. The weakness of the correlation was attributed to the pores in the specimens. The maximum relative permeabilities of cores made without annealing ranged from 30 to 110, while those of cores made with annealing ranged from 900 to 1,400. However, the greater permeabilities of the annealed specimens were not associated with noticeably greater densities. The major practical result of the investigation was the discovery of an optimum distribution of iron-particle sizes: It was found that eddy-current losses in the molded cores were minimized by using 100 mesh (corresponding to particles with diameters less than or equal to 100 m) iron particles. The effect of optimization of particle sizes on eddy-current losses is depicted in the figure.

Sensitivity of geomagnetic reversal rate on core evolution from numerical dynamos

NASA Astrophysics Data System (ADS)

Driscoll, P. E.; Davies, C. J.

2017-12-01

The paleomagnetic record indicates the geodynamo has evolved from frequently reversing to non-reversing (superchron) magnetic states several times over the Phanerozoic. Previous theoretical studies demonstrated a positive correlation between magnetic reversal rate and core-mantle boundary heat flux. However, attempts to identify such a correlation between reversal rates and proxies for internal cooling rate, such as plume events, superchron cycles, and subduction rates, have been inconclusive. Here we revisit the magnetic reversal occurrence rate in numerical dynamos at low Ekman numbers (faster rotation) and high magnetic Prandtl numbers (ratio of viscous and magnetic diffusivities). We focus on how the correlation between reversal rate and convective power depends on the core evolution rate and on other factors, such as Ek, Pm, and thermal boundary conditions. We apply our results to the seafloor reversal record in an attempt to infer the energetic evolution of the lower mantle and core over that period.

Revisiting the origin of satellites in core-level photoemission of transparent conducting oxides: The case of n -doped SnO2

NASA Astrophysics Data System (ADS)

Borgatti, Francesco; Berger, J. A.; Céolin, Denis; Zhou, Jianqiang Sky; Kas, Joshua J.; Guzzo, Matteo; McConville, C. F.; Offi, Francesco; Panaccione, Giancarlo; Regoutz, Anna; Payne, David J.; Rueff, Jean-Pascal; Bierwagen, Oliver; White, Mark E.; Speck, James S.; Gatti, Matteo; Egdell, Russell G.

2018-04-01

The longstanding problem of interpretation of satellite structures in core-level photoemission spectra of metallic systems with a low density of conduction electrons is addressed using the specific example of Sb-doped SnO2. Comparison of ab initio many-body calculations with experimental hard x-ray photoemission spectra of the Sn 4 d states shows that strong satellites are produced by coupling of the Sn core hole to the plasma oscillations of the free electrons introduced by doping. Within the same theoretical framework, spectral changes of the valence band spectra are also related to dynamical screening effects. These results demonstrate that, for the interpretation of electron correlation features in the core-level photoelectron spectra of such narrow-band materials, going beyond the homogeneous electron gas electron-plasmon coupling model is essential.

Quantum dust magnetosonic waves with spin and exchange correlation effects

NASA Astrophysics Data System (ADS)

Maroof, R.; Mushtaq, A.; Qamar, A.

2016-01-01

Dust magnetosonic waves are studied in degenerate dusty plasmas with spin and exchange correlation effects. Using the fluid equations of magnetoplasma with quantum corrections due to the Bohm potential, temperature degeneracy, spin magnetization energy, and exchange correlation, a generalized dispersion relation is derived. Spin effects are incorporated via spin force and macroscopic spin magnetization current. The exchange-correlation potentials are used, based on the adiabatic local-density approximation, and can be described as a function of the electron density. For three different values of angle, the dispersion relation is reduced to three different modes under the low frequency magnetohydrodynamic assumptions. It is found that the effects of quantum corrections in the presence of dust concentration significantly modify the dispersive properties of these modes. The results are useful for understanding numerous collective phenomena in quantum plasmas, such as those in compact astrophysical objects (e.g., the cores of white dwarf stars and giant planets) and in plasma-assisted nanotechnology (e.g., quantum diodes, quantum free-electron lasers, etc.).

Correlations of HBV Genotypes, Mutations Affecting HBeAg Expression and HBeAg/ anti-HBe Status in HBV Carriers

PubMed Central

Lim, Chee Kent; Tan, Joanne Tsui Ming; Khoo, Jason Boo Siang; Ravichandran, Aarthi; Low, Hsin Mei; Chan, Yin Chyi; Ton, So Har

2006-01-01

This study was carried out to determine the effects of hepatitis B virus genotypes, core promoter mutations (A1762G1764→T1762A1764) as well as precore stop codon mutations (TGG→TAG) on HBeAg expression and HBeAg/ anti-HBe status. Study was also performed on the effects of codon 15 variants (C1858/ T1858) on the predisposition of precore stop codon mutations (TGG→TAG). A total of 77 sera samples were analyzed. Fifty one samples were successfully genotyped of which the predominant genotype was genotype B (29/ 51, 56.9 %), followed by genotype C (16/ 51, 31.4 %). Co-infections by genotypes B and C were observed in four samples (7.8 %). To a lesser degree, genotypes D and E (2.0 % each) were also observed. For core promoter mutations, the prevalence was 68.8 % (53/ 77) for A1762G1764 wild-type and 14.3 % (11/ 77) for T1762A1764 mutant while 9.1 % (7/ 77) was co-infected by both strains. The prevalence of codon 15 variants was found to be 42.9 % (33/ 77) for T1858 variant and 16.9 % (13/ 77) for C1858 variant. No TAG mutation was found. In our study, no associations were found between genotypes (B and C) and core promoter mutations as well as codon 15 variants. Also no correlation was observed between HBeAg/ anti-HBe status with genotypes (B and C) and core promoter mutations. PMID:16421626

Safety margins in zircaloy oxidation and embrittlement criteria for emergency core cooling system acceptance

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

Williford, R.E.

1986-09-01

Current emergency core cooling system acceptance criteria for light water reactors specify that, under loss-of-coolant accident (LOCA) conditions, the Baker-Just (BJ) correlation must be used to calculate Zircaloy-steam oxidation, calculated peak cladding temperatures (PCT) must not exceed 1204/sup 0/C, and calculated oxidation must not exceed 17% equivalent cladding reacted (ECR). An appropriately defined minimum margin of safety was estimated for each of these criteria. The currently required BJ oxidation correlation provides margins only over the 1100 to 1500/sup 0/C temperature range at the 95% confidence level. The PCT margins for thermal shock and handling failures are adequate at oxidation temperaturesmore » above 1204/sup 0/C for up to 210 and 160 s, respectively, at the 95% confidence level. The ECR thermal shock and handling margins at the 50 and 95% confidence levels, respectively, range between 2 and 7% ECR for the BJ correlation, but vanish at temperatures above 1100 to 1160/sup 0/C for the best-estimate Cathcart-Pawel correlation. However, use of the Cathcart Pawel correlation for ''design basis'' LOCA calculations can be justified at the 85 to 88% confidence level if cooling rate effects can be neglected.« less

Questa baseline and premining ground-water quality investigation. 8. Lake-sediment geochemical record from 1960 to 2002, Eagle Rock and Fawn Lakes, Taos County, New Mexico

USGS Publications Warehouse

Church, S.E.; Fey, D.L.; Marot, M.E.

2005-01-01

Geochemical studies of lake sediment from Eagle Rock Lake and upper Fawn Lake were conducted to evaluate the effect of mining at the Molycorp Questa porphyry molybdenum deposit located immediately north of the Red River. Two cores were taken, one from each lake near the outlet where the sediment was thinnest, and they were sampled at 1-cm intervals to provide geochemical data at less than 1-year resolution. Samples from the core intervals were digested and analyzed for 34 elements using ICP-AES (inductively coupled plasma-atomic emission spectrometry). The activity of 137Cs has been used to establish the beginning of sedimentation in the two lakes. Correlation of the geochemistry of heavy-mineral suites in the cores from both Fawn and Eagle Rock Lakes has been used to develop a sedimentation model to date the intervals sampled. The core from upper Fawn Lake, located upstream of the deposit, provided an annual sedimentary record of the geochemical baseline for material being transported in the Red River, whereas the core from Eagle Rock Lake, located downstream of the deposit, provided an annual record of the effect of mining at the Questa mine on the sediment in the Red River. Abrupt changes in the concentrations of many lithophile and deposit-related metals occur in the middle of the Eagle Rock Lake core, which we correlate with the major flood-of-record recorded at the Questa gage at Eagle Rock Lake in 1979. Sediment from the Red River collected at low flow in 2002 is a poor match for the geochemical data from the sediment core in Eagle Rock Lake. The change in sediment geochemistry in Eagle Rock Lake in the post-1979 interval is dramatic and requires that a new source of sediment be identified that has substantially different geochemistry from that in the pre-1979 core interval. Loss of mill tailings from pipeline breaks are most likely responsible for some of the spikes in trace-element concentrations in the Eagle Rock Lake core. Enrichment of Al2O3, Cu, and Zn occurred as a result of chemical precipitation of these metals from ground water upstream in the Red River. Comparisons of the geochemistry of the post-1979 sediment core with both mine wastes and with premining sediment from the vicinity of the Questa mine indicate that both are possible sources for this new component of sediment. Existing data have not resolved this enigma.

Effective field theory description of halo nuclei

NASA Astrophysics Data System (ADS)

Hammer, H.-W.; Ji, C.; Phillips, D. R.

2017-10-01

Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction. Individual nucleons inside the core are thus unresolved in the halo configuration, and the low-energy effective interactions are short-range forces between the core and the valence nucleons. Similar phenomena occur in clusters of 4He atoms, cold atomic gases near a Feshbach resonance, and some exotic hadrons. In these weakly-bound quantum systems universal scaling laws for s-wave binding emerge that are independent of the details of the interaction. Effective field theory (EFT) exposes these correlations and permits the calculation of non-universal corrections to them due to short-distance effects, as well as the extension of these ideas to systems involving the Coulomb interaction and/or binding in higher angular-momentum channels. Halo nuclei exhibit all these features. Halo EFT, the EFT for halo nuclei, has been used to compute the properties of single-neutron, two-neutron, and single-proton halos of s-wave and p-wave type. This review summarizes these results for halo binding energies, radii, Coulomb dissociation, and radiative capture, as well as the connection of these properties to scattering parameters, thereby elucidating the universal correlations between all these observables. We also discuss how Halo EFT's encoding of the long-distance physics of halo nuclei can be used to check and extend ab initio calculations that include detailed modeling of their short-distance dynamics.

Pore Structure and Limit Pressure of Gas Slippage Effect in Tight Sandstone

PubMed Central

You, Lijun; Xue, Kunlin; Kang, Yili; Liao, Yi

2013-01-01

Gas slip effect is an important mechanism that the gas flow is different from liquid flow in porous media. It is generally considered that the lower the permeability in porous media is, the more severe slip effect of gas flow will be. We design and then carry out experiments with the increase of backpressure at the outlet of the core samples based on the definition of gas slip effect and in view of different levels of permeability of tight sandstone reservoir. This study inspects a limit pressure of the gas slip effect in tight sandstones and analyzes the characteristic parameter of capillary pressure curves. The experimental results indicate that gas slip effect can be eliminated when the backpressure reaches a limit pressure. When the backpressure exceeds the limit pressure, the measured gas permeability is a relatively stable value whose range is less than 3% for a given core sample. It is also found that the limit pressure increases with the decreasing in permeability and has close relation with pore structure of the core samples. The results have an important influence on correlation study on gas flow in porous medium, and are beneficial to reduce the workload of laboratory experiment. PMID:24379747

Non-destructive electromechanical assessment (Arthro-BST) of human articular cartilage correlates with histological scores and biomechanical properties.

PubMed

Sim, S; Chevrier, A; Garon, M; Quenneville, E; Yaroshinsky, A; Hoemann, C D; Buschmann, M D

2014-11-01

The hand-held Arthro-BST™ device is used to map electromechanical properties of articular cartilage. The purpose of the study was to evaluate correlation of electromechanical properties with histological, biochemical and biomechanical properties of cartilage. Electromechanical properties (quantitative parameter (QP)) of eight human distal femurs were mapped manually ex vivo using the Arthro-BST (1 measure/site, 5 s/measure, 3209 sites). Osteochondral cores were then harvested from different areas on the femurs and assessed with the Mankin histological score. Prior to histoprocessing, cores were tested in unconfined compression. A subset of the cores was analyzed with polarized light microscopy (PLM) to assess collagen structure. Biochemical assays were done on additional cores to obtain water content and glycosaminoglycan (GAG) content. The QP corresponding to each core was calculated by averaging all QPs collected within 6 mm of the core center. The electromechanical QP correlated strongly with both the Mankin score and the PLM score (r = 0.73, P < 0.0001 and r = -0.70, P < 0.0001 respectively) thus accurately reflecting tissue quality and collagen architecture. Electromechanical QP also correlated strongly with biomechanical properties including fibril modulus (r = -0.76, P < 0.0001), matrix modulus (r = -0.69, P < 0.0001), and log of permeability (r = 0.72, P < 0.0001). The QP correlated weakly with GAG per wet weight and with water content (r = -0.50, P < 0.0003 and r = 0.39, P < 0.006 respectively). Non-destructive electromechanical QP measurements correlate strongly with histological scores and biomechanical parameters providing a rapid and reliable assessment of articular cartilage quality. Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Stable Size Distribution of Amyloid Plaques Over the Course of Alzheimer Disease

PubMed Central

Serrano-Pozo, Alberto; Mielke, Matthew L.; Muzitansky, Alona; Gómez-Isla, Teresa; Growdon, John H.; Bacskai, Brian J.; Betensky, Rebecca A.; Frosch, Matthew P.; Hyman, Bradley T.

2012-01-01

Amyloid-β plaques are a key pathological feature of Alzheimer disease (AD), but whether plaque sizes increase or stabilize over the course of AD is unknown. We measured the size distribution of total immunoreactive (10D5-positive) and dense-core (Thioflavine-S-positive) plaques in the temporal neocortex of a large group of AD and plaque-bearing age-matched non-demented subjects to test the hypothesis that amyloid plaques continue to grow along with the progression of the disease. The size of amyloid-β (10D5)-positive plaques did not differ between groups whereas dense-core plaques from the AD group were slightly larger than those in the non-demented group (~25%–30%, p = 0.01). Within the AD group, dense-core plaque size did not independently correlate with duration of clinical disease (from 4 to 21 years, p = 0.68), whereas 10D5-positive plaque size correlated negatively with disease duration (p = 0.01). By contrast, an earlier age of symptom onset strongly predicted a larger postmortem plaque size; this effect was independent of disease duration and the presence of the APOEε4 allele (p = 0.0001). We conclude that plaques vary in size among patients, with larger size distributions correlating with an earlier age of onset, but plaques do not substantially increase in size over the clinical course of the disease. PMID:22805771

The effect of basis set and exchange-correlation functional on time-dependent density functional theory calculations within the Tamm-Dancoff approximation of the x-ray emission spectroscopy of transition metal complexes.

PubMed

Roper, Ian P E; Besley, Nicholas A

2016-03-21

The simulation of X-ray emission spectra of transition metal complexes with time-dependent density functional theory (TDDFT) is investigated. X-ray emission spectra can be computed within TDDFT in conjunction with the Tamm-Dancoff approximation by using a reference determinant with a vacancy in the relevant core orbital, and these calculations can be performed using the frozen orbital approximation or with the relaxation of the orbitals of the intermediate core-ionised state included. Both standard exchange-correlation functionals and functionals specifically designed for X-ray emission spectroscopy are studied, and it is shown that the computed spectral band profiles are sensitive to the exchange-correlation functional used. The computed intensities of the spectral bands can be rationalised by considering the metal p orbital character of the valence molecular orbitals. To compute X-ray emission spectra with the correct energy scale allowing a direct comparison with experiment requires the relaxation of the core-ionised state to be included and the use of specifically designed functionals with increased amounts of Hartree-Fock exchange in conjunction with high quality basis sets. A range-corrected functional with increased Hartree-Fock exchange in the short range provides transition energies close to experiment and spectral band profiles that have a similar accuracy to those from standard functionals.

A Chronostratigraphic and Environment Magnetic Study of Drill Cores Collected in the Mozambique Channel on Cruise MD13

NASA Astrophysics Data System (ADS)

Ray, D. J.; DeBone, K. N.; Smesny, J.; Chadinha, C.; Mitchell, B.; Acton, G. D.; Kulhanek, D. K.

2017-12-01

The South Atlantic Petroleum Company donated drill cores from 18 sites cored in October 2013 in the Mozambique Channel off Madagascar by the RV Marion Dufresne. Up to 30.11 m of sediment was recovered from cores collected at two localities, referred to as Juan de Nova ( 16.5°S, 42.9°E) and Belo Profound ( 19.5°S, 42.2°E), in water depths of 2,157-2,795 m. The cores are composed mostly of mixtures of fairly homogenous biogenic ooze and clay that is highly bioturbated, with turbidites occurring relatively commonly (about every meter or two) in most of the cores, although rarely in others (e.g., Core MD13-3506). The core color varies between light tan, olive gray, light brown, and light reddish brown. The darker colors probably reflect higher proportion of terrigenous input and the lighter intervals more biogenic input. We collected rock magnetic and paleomagnetic data along the cores and conducted initial calcareous nannofossil biostratigraphic analyses in order to provide stratigraphic and chronologic constraints and to investigate paleoenvironment changes. Records of magnetic susceptibility are used to correlate stratigraphy between sites and then are correlated to well-dated global records of climate change, such as the marine oxygen isotope record. The correlation to oxygen isotope records, which is constrained by biostratigraphic and paleomagnetic observations, helps refine the chronostratigraphy and allows us to interpret the variations in lithology and magnetic properties in the context of global climate change.

[Effect of leader-member exchange on nurses'sense of calling in workplace].

PubMed

Zhang, L G; Ma, H L; Wang, Z J; Zhou, Y Y; Jin, T T

2017-12-20

Objective: To investigate the effect of leader-member exchange on nurses'sense of calling in workplace based on self-determination theory. Methods: A total of 381 nurses were randomly selected from five tertiary general hospitals in Zhejiang province, China from October to December, 2016. They were subjected to a survey using the Leader-Member Exchange Scale, Job Autonomy Scale, Core Self-Evaluation Scale, and Calling Scale. The mediating effect was used to test the procedures and the data were subjected to hierarchical regression analysis. Results: The leader-member exchange was positively correlated with job autonomy, core self-evaluation, and sense of calling ( r =0.471, P <0.001; r =0.373, P <0.001; r =0.475, P <0.001) ; the leader-member exchange had a positive predictive effect on job autonomy and sense of calling ( β = 0.47, P <0.001; β =0.48, P <0.001) ; the job autonomy had a partial mediating effect on the relationship between leader-member exchange and sense of calling ( F =66.50, P <0.001) ; the core self-evaluation negatively adjusted the positive relationship between leader-member exchange and job autonomy ( F =27.81, P <0.001) . Conclusion: High-quality leader-member exchange enhances the sense of calling by improving staffs' job autonomy and the core self-evaluation reduces the positive relationship between leader-member exchange and job autonomy.

Ice core records of monoterpene- and isoprene-SOA tracers from Aurora Peak in Alaska since 1660s: Implication for climate variability in the North Pacific Rim

NASA Astrophysics Data System (ADS)

Pokhrel, A.; Kawamura, K.; Seki, O.; Ono, K.; Matoba, S.; Shiraiwa, T.

2015-12-01

180 m long ice core (ca. 343 years old) was drilled in the saddle of the Aurora Peak of Alaska, which is located southeast of Fairbanks (63.52°N; 146.54°W, elevation: 2,825 m). Samples were directly transported to the Institute of Low Temperature Science, Hokkaido University and have been analyzed for monoterpene- and isoprene-SOA tracers using gas chromatograph (GC; HP 6890) and mass spectrometry system (GC/MS; Agilent). Ice core collected from mountain glacier has not been explored for SOA yet. We found significantly high concentrations of these tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylrythritol), which show historical trends with good correlation with each other since 1665-2008. They show positive correlations with sugar compounds (e.g., mannitol, glucose, fructose, inositol, and sucrose), and anti-correlations with diacids (e.g., C9), w-oxocarboxylic (wC4-wC9), a-dicarbonyls and low molecular weight fatty acids (LFAs) (e.g., C18:1). LFAs show strong correlations with MSA- and nss-SO42- in the same ice core. These results suggest source regions of SOA tracers and ice core chemistry of Alaska. Concentrations of C5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) have increased in the ice core after the Great Pacific Climate Shift (late 1970's). They show positive correlations with a-dicarbonyls and LFAs (e.g., C18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the surface microlayer are recorded in the ice core. Photochemical oxidation processes for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations (e.g., North Pacific Index) and we can look at a whole range of environmental parameters in parallel with the robust reconstructed temperature changes in the Northern Hemisphere.

Development of a new academic digital library: a study of usage data of a core medical electronic journal collection

PubMed Central

Shearer, Barbara S.; Klatt, Carolyn; Nagy, Suzanne P.

2009-01-01

Objectives: The current study evaluates the results of a previously reported method for creating a core medical electronic journal collection for a new medical school library, validates the core collection created specifically to meet the needs of the new school, and identifies strategies for making cost-effective e-journal selection decisions. Methods: Usage data were extracted for four e-journal packages (Blackwell-Synergy, Cell Press, Lippincott Williams & Wilkins, and ScienceDirect). Usage was correlated with weighted point values assigned to a core list of journal titles, and each package was evaluated for relevancy and cost-effectiveness to the Florida State University College of Medicine (FSU COM) population. Results: The results indicated that the development of the core list was a valid method for creating a new twenty-first century, community-based medical school library. Thirty-seven journals are identified for addition to the FSU COM core list based on use by the COM, and areas of overlapping research interests between the university and the COM are identified based on use of specific journals by each population. Conclusions: The collection development approach that evolved at the FSU COM library was useful during the initial stages of identifying and evaluating journal selections and in assessing the relative value of a particular journal package for the FSU COM after the school was established. PMID:19404499

Development of a new academic digital library: a study of usage data of a core medical electronic journal collection.

PubMed

Shearer, Barbara S; Klatt, Carolyn; Nagy, Suzanne P

2009-04-01

The current study evaluates the results of a previously reported method for creating a core medical electronic journal collection for a new medical school library, validates the core collection created specifically to meet the needs of the new school, and identifies strategies for making cost-effective e-journal selection decisions. Usage data were extracted for four e-journal packages (Blackwell-Synergy, Cell Press, Lippincott Williams & Wilkins, and ScienceDirect). Usage was correlated with weighted point values assigned to a core list of journal titles, and each package was evaluated for relevancy and cost-effectiveness to the Florida State University College of Medicine (FSU COM) population. The results indicated that the development of the core list was a valid method for creating a new twenty-first century, community-based medical school library. Thirty-seven journals are identified for addition to the FSU COM core list based on use by the COM, and areas of overlapping research interests between the university and the COM are identified based on use of specific journals by each population. The collection development approach that evolved at the FSU COM library was useful during the initial stages of identifying and evaluating journal selections and in assessing the relative value of a particular journal package for the FSU COM after the school was established.

The X40×10 Halogen Bonding Benchmark Revisited: Surprising Importance of (n-1)d Subvalence Correlation.

PubMed

Kesharwani, Manoj K; Manna, Debashree; Sylvetsky, Nitai; Martin, Jan M L

2018-03-01

We have re-evaluated the X40×10 benchmark for halogen bonding using conventional and explicitly correlated coupled cluster methods. For the aromatic dimers at small separation, improved CCSD(T)-MP2 "high-level corrections" (HLCs) cause substantial reductions in the dissociation energy. For the bromine and iodine species, (n-1)d subvalence correlation increases dissociation energies and turns out to be more important for noncovalent interactions than is generally realized; (n-1)sp subvalence correlation is much less important. The (n-1)d subvalence term is dominated by core-valence correlation; with the smaller cc-pVDZ-F12-PP and cc-pVTZ-F12-PP basis sets, basis set convergence for the core-core contribution becomes sufficiently erratic that it may compromise results overall. The two factors conspire to generate discrepancies of up to 0.9 kcal/mol (0.16 kcal/mol RMS) between the original X40×10 data and the present revision.

Ice core records of monoterpene- and isoprene-SOA tracers from Aurora Peak in Alaska since 1660s: Implication for climate change variability in the North Pacific Rim

NASA Astrophysics Data System (ADS)

Pokhrel, Ambarish; Kawamura, Kimitaka; Ono, Kaori; Seki, Osamu; Fu, Pingqing; Matoba, Sumio; Shiraiwa, Takayuki

2016-04-01

Monoterpene and isoprene secondary organic aerosol (SOA) tracers are reported for the first time in an Alaskan ice core to better understand the biological source strength before and after the industrial revolution in the Northern Hemisphere. We found significantly high concentrations of monoterpene- and isoprene-SOA tracers (e.g., pinic, pinonic, and 2-methylglyceric acids, 2-methylthreitol and 2-methylerythritol) in the ice core, which show historical trends with good correlation to each other since 1660s. They show positive correlations with sugar compounds (e.g., mannitol, fructose, glucose, inositol and sucrose), and anti-correlations with α-dicarbonyls (glyoxal and methylglyoxal) and fatty acids (e.g., C18:1) in the same ice core. These results suggest similar sources and transport pathways for monoterpene- and isoprene-SOA tracers. In addition, we found that concentrations of C5-alkene triols (e.g., 3-methyl-2,3,4-trihydroxy-1-butene, cis-2-methyl 1,3,4-trihydroxy-1-butene and trans-2-methyl-1,3,4-trihydroxy-1-butene) in the ice core have increased after the Great Pacific Climate Shift (late 1970s). They show positive correlations with α-dicarbonyls and fatty acids (e.g., C18:1) in the ice core, suggesting that enhanced oceanic emissions of biogenic organic compounds through the marine boundary layer are recorded in the ice core from Alaska. Photochemical oxidation process for these monoterpene- and isoprene-/sesquiterpene-SOA tracers are suggested to be linked with the periodicity of multi-decadal climate oscillations and retreat of sea ice in the Northern Hemisphere.

Theoretical study of LiK and LiK+ in adiabatic representation

NASA Astrophysics Data System (ADS)

Al-dossary, Omar M.; Khelifi, Neji

2014-01-01

The potential energy curves have been calculated for the electronic states of the molecule LiK within the range 3 to 300 a.u., of the internuclear distance R. Using an ab initio method, through a semiempirical spin-orbit pseudo-potential for the Li (1 s 2) and K (1 s 22 s 22 p 63 s 23 p 6) cores and core valence correlation correction added to the electrostatic Hamiltonian with Gaussian basis sets for both atoms. The core valence effects including core-polarization and core-valence correlation are taken into account by using an l-dependent core-polarization potential. The molecular orbitals have been derived from self-consistent field (SCF) calculation. The spectroscopic constants, dipole moments and vibrational levels of the lowest electronic states of the LiK molecule dissociating into K (4 s, 4 p, 5 s, 3 d, and 5 p) + Li (2 s, 2 p, 3 s, and 3 p) in 1, 3Σ, 1, 3Π, and 1, 3Δ symmetries. Adiabatic results are also reported for 2Σ, 2Π, and 2Δ electronic states of the molecular ion LiK+ dissociating into Li (2 s, 2 p, 3 s, and 3 p) + K+ and Li+ + K (4 s, 4 p, 5 s, 3 d, and 5 p). The comparison of the present results with those available in the literature shows a very good agreement in spectroscopic constants of some lowest states of the LiK and LiK+ molecules, especially with the available theoretical works. The existence of numerous avoided crossing between electronic states of 2Σ and 2Π symmetries is related to the charge transfer process between the two ionic systems Li+K and LiK+.

Core-temperature sensor ingestion timing and measurement variability.

PubMed

Domitrovich, Joseph W; Cuddy, John S; Ruby, Brent C

2010-01-01

Telemetric core-temperature monitoring is becoming more widely used as a noninvasive means of monitoring core temperature during athletic events. To determine the effects of sensor ingestion timing on serial measures of core temperature during continuous exercise. Crossover study. Outdoor dirt track at an average ambient temperature of 4.4°C ± 4.1°C and relative humidity of 74.1% ± 11.0%. Seven healthy, active participants (3 men, 4 women; age  =  27.0 ± 7.5 years, height  =  172.9 ± 6.8 cm, body mass  =  67.5 ± 6.1 kg, percentage body fat  =  12.7% ± 6.9%, peak oxygen uptake [Vo(2peak)]  =  54.4 ± 6.9 mL•kg⁻¹•min⁻¹) completed the study. Participants completed a 45-minute exercise trial at approximately 70% Vo(2peak). They consumed core-temperature sensors at 24 hours (P1) and 40 minutes (P2) before exercise. Core temperature was recorded continuously (1-minute intervals) using a wireless data logger worn by the participants. All data were analyzed using a 2-way repeated-measures analysis of variance (trial × time), Pearson product moment correlation, and Bland-Altman plot. Fifteen comparisons were made between P1 and P2. The main effect of time indicated an increase in core temperature compared with the initial temperature. However, we did not find a main effect for trial or a trial × time interaction, indicating no differences in core temperature between the sensors (P1  =  38.3°C ± 0.2°C, P2  =  38.3°C ± 0.4°C). We found no differences in the temperature recordings between the 2 sensors. These results suggest that assumed sensor location (upper or lower gastrointestinal tract) does not appreciably alter the transmission of reliable and repeatable measures of core temperature during continuous running in the cold.

Evaluating genetic diversity and constructing core collections of Chinese Lentinula edodes cultivars using ISSR and SRAP markers.

PubMed

Liu, Jun; Wang, Zhuo-Ren; Li, Chuang; Bian, Yin-Bing; Xiao, Yang

2015-06-01

Genetic diversity among 89 Chinese Lentinula edodes cultivars was analyzed by inter-simple sequence repeat (ISSR) and sequence-related amplified polymorphism (SRAP) markers. A 123 out of 126 ISSR loci (97.62%) and 108 out of 129 SRAP loci (83.73%) were polymorphic between two or more strains. A dendrogram constructed by cluster analysis based on the ISSR and SRAP markers separated the L. edodes strains into two major groups, of which group B was further divided into five subgroups. Clustering results also showed a positive correlation with the main agronomic traits of the strains, and that strains with similar traits clustered together into the same groups or subgroups in most cases. The average coefficient of pairwise genetic similarity was 0.820 (range: 0.576-0.988). Compared to the wild strains, Chinese L. edodes cultivars indicated a lower level of genetic diversity. Two preliminary core collections of L. edodes, Core1 and Core2, were established based on the ISSR and SRAP data, respectively. Core1 was constructed by the advanced M (maximization) strategy using the PowerCore version 1.0 software and contained 21 strains, whereas Core2 was created by the allele preferred sampling strategy using the cluster method and contained 18 strains. Both core collections were highly representative of the genetic diversity of the original germplasm, as confirmed by the values of Na (observed number of alleles), Ne (effective number of alleles), H (Nei's gene diversity) and I (Shannon's information index), as well as results of principal coordinate analysis. The loci retention ratio of Core1 (99.61%) was higher than that of Core2 (97.65%). Moreover, Core1 contained strains with more types of agronomic traits than those in Core2. This study builds the basis for further effective protection, management and use of L. edodes germplasm resource. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimum Selection Age for Wood Density in Loblolly Pine

Treesearch

D.P. Gwaze; K.J. Harding; R.C. Purnell; Floyd E. Brigwater

2002-01-01

Genetic and phenotypic parameters for core wood density of Pinus taeda L. were estimated for ages ranging from 5 to 25 years at two sites in southern United States. Heritability estimates on an individual-tree basis for core density were lower than expected (0.20-0.31). Age-age genetic correlations were higher than phenotypic correlations,...

Temperature and moisture effects on greenhouse gas emissions from deep active-layer boreal soils

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

Bond-Lamberty, Ben; Smith, A. Peyton; Bailey, Vanessa L.

Rapid climatic changes, rising air temperatures, and increased fires are expected to drive permafrost degradation and alter soil carbon (C) cycling in many high-latitude ecosystems. How these soils will respond to changes in their temperature, moisture, and overlying vegetation is uncertain but critical to understand given the large soil C stocks in these regions. We used a laboratory experiment to examine how temperature and moisture control CO 2 and CH 4 emissions from mineral soils sampled from the bottom of the annual active layer, i.e., directly above permafrost, in an Alaskan boreal forest. Gas emissions from 30 cores, subjected tomore » two temperatures and either field moisture conditions or experimental drought, were tracked over a 100-day incubation; we also measured a variety of physical and chemical characteristics of the cores. Gravimetric water content was 0.31 ± 0.12 (unitless) at the beginning of the incubation; cores at field moisture were unchanged at the end, but drought cores had declined to 0.06 ± 0.04. Daily CO 2 fluxes were positively correlated with incubation chamber temperature, core water content, and percent soil nitrogen. They also had a temperature sensitivity ( Q 10) of 1.3 and 1.9 for the field moisture and drought treatments, respectively. Daily CH 4 emissions were most strongly correlated with percent nitrogen, but neither temperature nor water content was a significant first-order predictor of CH 4 fluxes. The cumulative production of C from CO 2 was over 6 orders of magnitude higher than that from CH 4; cumulative CO 2 was correlated with incubation temperature and moisture treatment, with drought cores producing 52–73 % lower C. Cumulative CH 4 production was unaffected by any treatment. These results suggest that deep active-layer soils may be sensitive to changes in soil moisture under aerobic conditions, a critical factor as discontinuous permafrost thaws in interior Alaska. Furthermore, deep but unfrozen high-latitude soils have been shown to be strongly affected by long-term experimental warming, and these results provide insight into their future dynamics and feedback potential with future climate change.« less

First identification of cryptotephra from Kamchatka in a Greenland ice core and new tephra links between distal climate records from Greenland and the northwest Pacific

NASA Astrophysics Data System (ADS)

Cook, E.; Ponomareva, V.; Portnyagin, M.; Bazanova, L.; Svensson, A.; Davies, S. M.

2017-12-01

Our work presents new correlations between cryptotephra deposits found in Greenland ice cores and widespread tephra layers found in terrestrial and marine records in the northern Pacific, providing: 1) a unique opportunity to examine climate records in distal locations and 2) an independent assessment of radiocarbon dates and marine reservoir calculations, using ages derived from Greenland Ice Core Chronology 2005 (GICC05).Low concentrations of tephra grains from two well-known eruptions from northern Pacific Arc volcanoes have been traced in the NGRIP and NEEM ice cores; the first from a Holocene eruption from Khangar volcano in the Kamchatka Peninsula (eastern Russia), and the second from an eruption during the late glacial/interglacial transition (LGIT) from Towada in Japan. Correlations were based on the chronological position of layers and geochemical characterisation by EPMA and LA-ICP-MS to derive major oxide and trace element concentrations. In NGRIP the rhyolitic KHG tephra from Khangar volcano (western Kamchatka) has a GICC05 age of 7950 ± 41 years b2k and is located close to the termination of the 8.2 ka cold event that affected the Northern Hemisphere. KHG is a key terrestrial marker deposit in Kamchatka and is stratigraphically significant as it marks the end of this cold event in Kamchatka in a number of records. This is the first finding of the KHG tephra outside Kamchatka and the first confirmed identification of any Kamchatka tephra in Greenland ice. Additionally, the correlation of a rhyolitic cryptotephra in found in NEEM and NGRIP to a widespread Japanese deposit, Towada To-H (15,706 ± 113 a b2k) represents the first long range tie-point to be established within the LGIT, creating an opportunity help validate local marine reservoir effect calculations of cores containing To-H from the forearc terrace of the Japan Trench. The findings highlight the relevance of locating long-range, low-concentration cryptotephra deposits in well-dated ice cores.

Temperature and moisture effects on greenhouse gas emissions from deep active-layer boreal soils

DOE PAGES

Bond-Lamberty, Ben; Smith, A. Peyton; Bailey, Vanessa L.

2016-12-21

Rapid climatic changes, rising air temperatures, and increased fires are expected to drive permafrost degradation and alter soil carbon (C) cycling in many high-latitude ecosystems. How these soils will respond to changes in their temperature, moisture, and overlying vegetation is uncertain but critical to understand given the large soil C stocks in these regions. We used a laboratory experiment to examine how temperature and moisture control CO 2 and CH 4 emissions from mineral soils sampled from the bottom of the annual active layer, i.e., directly above permafrost, in an Alaskan boreal forest. Gas emissions from 30 cores, subjected tomore » two temperatures and either field moisture conditions or experimental drought, were tracked over a 100-day incubation; we also measured a variety of physical and chemical characteristics of the cores. Gravimetric water content was 0.31 ± 0.12 (unitless) at the beginning of the incubation; cores at field moisture were unchanged at the end, but drought cores had declined to 0.06 ± 0.04. Daily CO 2 fluxes were positively correlated with incubation chamber temperature, core water content, and percent soil nitrogen. They also had a temperature sensitivity ( Q 10) of 1.3 and 1.9 for the field moisture and drought treatments, respectively. Daily CH 4 emissions were most strongly correlated with percent nitrogen, but neither temperature nor water content was a significant first-order predictor of CH 4 fluxes. The cumulative production of C from CO 2 was over 6 orders of magnitude higher than that from CH 4; cumulative CO 2 was correlated with incubation temperature and moisture treatment, with drought cores producing 52–73 % lower C. Cumulative CH 4 production was unaffected by any treatment. These results suggest that deep active-layer soils may be sensitive to changes in soil moisture under aerobic conditions, a critical factor as discontinuous permafrost thaws in interior Alaska. Furthermore, deep but unfrozen high-latitude soils have been shown to be strongly affected by long-term experimental warming, and these results provide insight into their future dynamics and feedback potential with future climate change.« less

Temperature and moisture effects on greenhouse gas emissions from deep active-layer boreal soils

NASA Astrophysics Data System (ADS)

Bond-Lamberty, Ben; Smith, A. Peyton; Bailey, Vanessa

2016-12-01

Rapid climatic changes, rising air temperatures, and increased fires are expected to drive permafrost degradation and alter soil carbon (C) cycling in many high-latitude ecosystems. How these soils will respond to changes in their temperature, moisture, and overlying vegetation is uncertain but critical to understand given the large soil C stocks in these regions. We used a laboratory experiment to examine how temperature and moisture control CO2 and CH4 emissions from mineral soils sampled from the bottom of the annual active layer, i.e., directly above permafrost, in an Alaskan boreal forest. Gas emissions from 30 cores, subjected to two temperatures and either field moisture conditions or experimental drought, were tracked over a 100-day incubation; we also measured a variety of physical and chemical characteristics of the cores. Gravimetric water content was 0.31 ± 0.12 (unitless) at the beginning of the incubation; cores at field moisture were unchanged at the end, but drought cores had declined to 0.06 ± 0.04. Daily CO2 fluxes were positively correlated with incubation chamber temperature, core water content, and percent soil nitrogen. They also had a temperature sensitivity (Q10) of 1.3 and 1.9 for the field moisture and drought treatments, respectively. Daily CH4 emissions were most strongly correlated with percent nitrogen, but neither temperature nor water content was a significant first-order predictor of CH4 fluxes. The cumulative production of C from CO2 was over 6 orders of magnitude higher than that from CH4; cumulative CO2 was correlated with incubation temperature and moisture treatment, with drought cores producing 52-73 % lower C. Cumulative CH4 production was unaffected by any treatment. These results suggest that deep active-layer soils may be sensitive to changes in soil moisture under aerobic conditions, a critical factor as discontinuous permafrost thaws in interior Alaska. Deep but unfrozen high-latitude soils have been shown to be strongly affected by long-term experimental warming, and these results provide insight into their future dynamics and feedback potential with future climate change.

Support vector regression to predict porosity and permeability: Effect of sample size

NASA Astrophysics Data System (ADS)

Al-Anazi, A. F.; Gates, I. D.

2012-02-01

Porosity and permeability are key petrophysical parameters obtained from laboratory core analysis. Cores, obtained from drilled wells, are often few in number for most oil and gas fields. Porosity and permeability correlations based on conventional techniques such as linear regression or neural networks trained with core and geophysical logs suffer poor generalization to wells with only geophysical logs. The generalization problem of correlation models often becomes pronounced when the training sample size is small. This is attributed to the underlying assumption that conventional techniques employing the empirical risk minimization (ERM) inductive principle converge asymptotically to the true risk values as the number of samples increases. In small sample size estimation problems, the available training samples must span the complexity of the parameter space so that the model is able both to match the available training samples reasonably well and to generalize to new data. This is achieved using the structural risk minimization (SRM) inductive principle by matching the capability of the model to the available training data. One method that uses SRM is support vector regression (SVR) network. In this research, the capability of SVR to predict porosity and permeability in a heterogeneous sandstone reservoir under the effect of small sample size is evaluated. Particularly, the impact of Vapnik's ɛ-insensitivity loss function and least-modulus loss function on generalization performance was empirically investigated. The results are compared to the multilayer perception (MLP) neural network, a widely used regression method, which operates under the ERM principle. The mean square error and correlation coefficients were used to measure the quality of predictions. The results demonstrate that SVR yields consistently better predictions of the porosity and permeability with small sample size than the MLP method. Also, the performance of SVR depends on both kernel function type and loss functions used.

The Relationship between Elementary Teachers' Perceived Self-Efficacy and Principals' Facilitation of Professional Learning Communities

ERIC Educational Resources Information Center

Mathews, Tracy A.

2017-01-01

This quantitative correlation survey study investigated the relationship between teachers' perceptions of the effectiveness of school principals as instructional leaders in professional learning communities (PLCs) and self-efficacy beliefs of teachers. Social Cognitive Theory, self-efficacy concept, and Adult Learning Theory were at the core of…

Towards Accurate Ab Initio Predictions of the Spectrum of Methane

NASA Technical Reports Server (NTRS)

Schwenke, David W.; Kwak, Dochan (Technical Monitor)

2001-01-01

We have carried out extensive ab initio calculations of the electronic structure of methane, and these results are used to compute vibrational energy levels. We include basis set extrapolations, core-valence correlation, relativistic effects, and Born- Oppenheimer breakdown terms in our calculations. Our ab initio predictions of the lowest lying levels are superb.

Satellite Gravity Drilling the Earth

NASA Technical Reports Server (NTRS)

vonFrese, R. R. B.; Potts, L. V.; Leftwich, T. E.; Kim, H. R.; Han, S.-H.; Taylor, P. T.; Ashgharzadeh, M. F.

2005-01-01

Analysis of satellite-measured gravity and topography can provide crust-to-core mass variation models for new insi@t on the geologic evolution of the Earth. The internal structure of the Earth is mostly constrained by seismic observations and geochemical considerations. We suggest that these constraints may be augmented by gravity drilling that interprets satellite altitude free-air gravity observations for boundary undulations of the internal density layers related to mass flow. The approach involves separating the free-air anomalies into terrain-correlated and -decorrelated components based on the correlation spectrum between the anomalies and the gravity effects of the terrain. The terrain-decorrelated gravity anomalies are largely devoid of the long wavelength interfering effects of the terrain gravity and thus provide enhanced constraints for modeling mass variations of the mantle and core. For the Earth, subcrustal interpretations of the terrain-decorrelated anomalies are constrained by radially stratified densities inferred from seismic observations. These anomalies, with frequencies that clearly decrease as the density contrasts deepen, facilitate mapping mass flow patterns related to the thermodynamic state and evolution of the Earth's interior.

Developing comprehensive and Brief ICF core sets for morbid obesity for disability assessment in Taiwan: a preliminary study.

PubMed

Lin, Y-N; Chang, K-H; Lin, C-Y; Hsu, M-I; Chen, H-C; Chen, H-H; Liou, T-H

2014-04-01

The International Classification of Functioning, Disability, and Health (ICF) provides a framework for measuring functioning and disability based on a biopsychosocial model. The aim of this study was to develop comprehensive and brief ICF core sets for morbid obesity for disability assessment in Taiwan. Observational Other Twenty-nine multidisciplinary experts of ICF METHODS: The questionnaire contained 112 obesity-relevant and second-level ICF categories. Using a 5-point Likert scale, the participants rated the significance of the effects of each category on the heath status of people with obesity. Correlation between an individual's score and the average score of the group indicated consensus. The categories were selected for the comprehensive core set for obesity if more than 50% of the experts rated them as "important" in the third round of the Delphi exercise, and for the brief core set if more than 80% of the experts rated them "very important." Twenty-nine experts participated in the study. These included 18 physicians, 4 dieticians, 3 physical therapists, 2 nurses, and 2 ICF experts. The comprehensive core set for morbid obesity contained 61 categories. Of these, 26 categories were from the component body function, 8 were from body structure, 18 were from activities and participation, and 9 were from environmental factors. The brief core set for obesity disability contained 29 categories. Of these, 19 categories were from the component body function, 3 were from body structure, 6 were from activities and participation, and one was from environmental factors. The comprehensive and brief ICF core sets provide comprehensive information on the health effects of morbid obesity and concise information for clinical practice. Comprehensive and brief core sets were created after three rounds of Delphi technique. Further validation study of these core sets by applying to patients with morbid obesity is needed. The comprehensive ICF core set for morbid obesity provides comprehensive information on the health effects of morbid obesity; the brief core set can provide concise information for clinical practice.

Unexpected electronic perturbation effects of simple PEG environments on the optical properties of small cadmium chalcogenide clusters

NASA Astrophysics Data System (ADS)

Fukunaga, Naoto; Konishi, Katsuaki

2015-12-01

Poly(ethylene glycol) (PEG) has been widely used for the surface protection of inorganic nanoobjects because of its virtually `inert' nature, but little attention has been paid to its inherent electronic impacts on inorganic cores. Herein, we definitively show, through studies on optical properties of a series of PEG-modified Cd10Se4(SR)10 clusters, that the surrounding PEG environments can electronically affect the properties of the inorganic core. For the clusters with PEG units directly attached to an inorganic core (R = (CH2CH2O)nOCH3, 1-PEGn, n = 3, ~7, ~17, ~46), the absorption bands, associated with the low-energy transitions, continuously blue-shifted with the increasing PEG chain length. The chain length dependencies were also observed in the photoluminescence properties, particularly in the excitation spectral profiles. By combining the spectral features of several PEG17-modified clusters (2-Cm-PEG17 and 3) whose PEG and core units are separated by various alkyl chain-based spacers, it was demonstrated that sufficiently long PEG units, including PEG17 and PEG46, cause electronic perturbations in the cluster properties when they are arranged near the inorganic core. These unique effects of the long-PEG environments could be correlated with their large dipole moments, suggesting that the polarity of the proximal chemical environment is critical when affecting the electronic properties of the inorganic cluster core.Poly(ethylene glycol) (PEG) has been widely used for the surface protection of inorganic nanoobjects because of its virtually `inert' nature, but little attention has been paid to its inherent electronic impacts on inorganic cores. Herein, we definitively show, through studies on optical properties of a series of PEG-modified Cd10Se4(SR)10 clusters, that the surrounding PEG environments can electronically affect the properties of the inorganic core. For the clusters with PEG units directly attached to an inorganic core (R = (CH2CH2O)nOCH3, 1-PEGn, n = 3, ~7, ~17, ~46), the absorption bands, associated with the low-energy transitions, continuously blue-shifted with the increasing PEG chain length. The chain length dependencies were also observed in the photoluminescence properties, particularly in the excitation spectral profiles. By combining the spectral features of several PEG17-modified clusters (2-Cm-PEG17 and 3) whose PEG and core units are separated by various alkyl chain-based spacers, it was demonstrated that sufficiently long PEG units, including PEG17 and PEG46, cause electronic perturbations in the cluster properties when they are arranged near the inorganic core. These unique effects of the long-PEG environments could be correlated with their large dipole moments, suggesting that the polarity of the proximal chemical environment is critical when affecting the electronic properties of the inorganic cluster core. Electronic supplementary information (ESI) available: Details of synthetic procedures and characterisation data of the PEGylated thiols and clusters and additional absorption, photoluminescence emission and excitation spectral data. See DOI: 10.1039/c5nr06307h

Magnetic properties and core electron binding energies of liquid water

NASA Astrophysics Data System (ADS)

Galamba, N.; Cabral, Benedito J. C.

2018-01-01

The magnetic properties and the core and inner valence electron binding energies of liquid water are investigated. The adopted methodology relies on the combination of molecular dynamics and electronic structure calculations. Born-Oppenheimer molecular dynamics with the Becke and Lee-Yang-Parr functionals for exchange and correlation, respectively, and includes an empirical correction (BLYP-D3) functional and classical molecular dynamics with the TIP4P/2005-F model were carried out. The Keal-Tozer functional was applied for predicting magnetic shielding and spin-spin coupling constants. Core and inner valence electron binding energies in liquid water were calculated with symmetry adapted cluster-configuration interaction. The relationship between the magnetic shielding constant σ(17O), the role played by the oxygen atom as a proton acceptor and donor, and the tetrahedral organisation of liquid water are investigated. The results indicate that the deshielding of the oxygen atom in water is very dependent on the order parameter (q) describing the tetrahedral organisation of the hydrogen bond network. The strong sensitivity of magnetic properties on changes of the electronic density in the nuclei environment is illustrated by a correlation between σ(17O) and the energy gap between the 1a1[O1s] (core) and the 2a1 (inner valence) orbitals of water. Although several studies discussed the eventual connection between magnetic properties and core electron binding energies, such a correlation could not be clearly established. Here, we demonstrate that for liquid water this correlation exists although involving the gap between electron binding energies of core and inner valence orbitals.

The Record of Geomagnetic Excursions from a ~150 m Sediment Core: Clear Lake, Northern California

NASA Astrophysics Data System (ADS)

Levin, E.; Byrne, R.; Looy, C. V.; Wahl, D.; Noren, A. J.; Verosub, K. L.

2015-12-01

We are studying the paleomagnetic properties of a new ~150 meter drill core from Clear Lake, CA. Step-wise demagnetization of the natural remanent magnetism (NRM) yields stable directions after 20 mT, implying that the sediments are reliable recorders of geomagnetic field behavior. Several intervals of low relative paleointensity (RPI) from the core appear to be correlated with known geomagnetic excursions. At about 46 m depth, and ~33 ka according to an age model based on radiocarbon dates obtained from pollen and the Olema ash bed, a low RPI zone seems to agree with the age and duration of the Mono Lake Excursion, previously identified between 32 and 35 ka. Slightly lower in the core, at about 50 m depth and ~40 ka, noticeably low RPI values seem to be coeval with the Laschamp excursion, which has been dated at ~41 ka. A volcanic ash near the bottom of the core (141 mblf) is near the same depth as an ash identified in 1988 by Andrei Sarna-Wojcicki and others as the Loleta ash bed in a previous Clear Lake core. If the basal ash in the new core is indeed the, Loleta ash bed, then the core may date back to about 270-300 ka. Depending on the age of the lowest ash, a sequence of low RPI intervals could correlate with the Blake (120 ka), Iceland Basin (188 ka), Jamaica/Pringle Falls (211 ka), and CR0 (260 ka) excursions. Correlation of the low RPI intervals to these geomagnetic excursions will help in the development of a higher resolution chronostratigraphy for the core, resolve a long-standing controversy about a possible hiatus in the Clear Lake record, and provide information about climatically-driven changes in sedimentation.

Communication: a density functional with accurate fractional-charge and fractional-spin behaviour for s-electrons.

PubMed

Johnson, Erin R; Contreras-García, Julia

2011-08-28

We develop a new density-functional approach combining physical insight from chemical structure with treatment of multi-reference character by real-space modeling of the exchange-correlation hole. We are able to recover, for the first time, correct fractional-charge and fractional-spin behaviour for atoms of groups 1 and 2. Based on Becke's non-dynamical correlation functional [A. D. Becke, J. Chem. Phys. 119, 2972 (2003)] and explicitly accounting for core-valence separation and pairing effects, this method is able to accurately describe dissociation and strong correlation in s-shell many-electron systems. © 2011 American Institute of Physics

Crystallization in Micellar Cores: confinement effects and dynamics

NASA Astrophysics Data System (ADS)

Lund, Reidar; Zinn, Thomas; Willner, Lutz; Department of Chemistry, University of Oslo Team; Forschungszentrum Jülich Collaboration

It is well known that liquids confined to small nanoscopic pores and droplets exhibit thermal behavior very different from bulk samples. Here we demonstrate that n-alkanes forming 2-3 nm small micellar cores are considerably affected by confinement in analogue with hard confined systems. We study micelles form by self-assembly of a series of well-defined n-Alkyl-PEO polymers in aqueous solutions. By using small-angle X-ray scattering (SAXS), densiometry and differential scanning calorimetry (DSC), we show that n-alkane exhibit a first-order phase transition i.e. melting. Correlating the structural and thermodynamic data, we find that a melting depression can be accurately described by the Gibbs-Thomson equation. ∖f1 The effect of core crystallinity on the molecular exchange kinetics is investigated using time-resolved small-angle neutron scattering (TR-SANS). We show that there are considerable entropic and enthalpic contributions from the chain packing that affect the kinetic stability of micelles. ∖pard

Multiple cores of Gleason score 6 correlate with favourable findings at radical prostatectomy

PubMed Central

Ellis, Carla L.; Walsh, Patrick C.; Partin, Alan W.; Epstein, Jonathan I.

2014-01-01

Objective To establish whether the good prognosis of Gleason score 6 (GS6) is maintained in the setting of multiple involved cores. Patients and Methods In total, 6156 men (from 1 April 2000 to 30 April 2007) with GS6 on biopsy underwent radical prostatectomy (RP) at our institution. The number of positive cores was correlated with the outcome at RP. Results More positive cores correlated with less organ-confined disease (P < 0.001), positive margins (P < 0.012), increasing RP grade (P < 0.001) and increased seminal vesicles/lymph node involvement (P = 0.012). For men with data available, the actuarial risk of being biochemically free of disease at 5 years was 93.2% when ≤6 cores were positive (812 men followed to 5 years) vs 89.1% if >6 cores were positive (41 men followed to 2 years) (P = 0.6). Although the predicted ‘cure rate’ of >75% probability of a tumour showing no evidence of biochemical recurrence at 10 years after RP was statistically different between cases with ≤6 vs >6 positive cores (P < 0.0001), the outcome in both groups was still favourable (90.5% vs 84%). Partin-like tables were generated factoring in the number of positive cores to predict organ-confined disease as a guide for urologists to perform nerve-sparing surgery. For example, with T1c disease, there was a ≥75% probability of organ-confined disease with one to three positive cores regardless of prostate-specific antigen (PSA) level, and the same probability was present with four to six positive cores and a PSA level of 0–4 ng/mL. Conclusion A low Gleason score on biopsy is a powerful prognostic finding, such that this favourable outcome is maintained even in the setting of multiple positive cores with GS6. PMID:23350787

Multiple cores of Gleason score 6 correlate with favourable findings at radical prostatectomy.

PubMed

Ellis, Carla L; Walsh, Patrick C; Partin, Alan W; Epstein, Jonathan I

2013-06-01

To establish whether the good prognosis of Gleason score 6 (GS6) is maintained in the setting of multiple involved cores. In total, 6156 men (from 1 April 2000 to 30 April 2007) with GS6 on biopsy underwent radical prostatectomy (RP) at our institution. The number of positive cores was correlated with the outcome at RP. More positive cores correlated with less organ-confined disease (P < 0.001), positive margins (P < 0.012), increasing RP grade (P < 0.001) and increased seminal vesicles/lymph node involvement (P = 0.012). For men with data available, the actuarial risk of being biochemically free of disease at 5 years was 93.2% when ≤6 cores were positive (812 men followed to 5 years) vs 89.1% if >6 cores were positive (41 men followed to 2 years) (P = 0.6). Although the predicted 'cure rate' of >75% probability of a tumour showing no evidence of biochemical recurrence at 10 years after RP was statistically different between cases with ≤6 vs >6 positive cores (P < 0.0001), the outcome in both groups was still favourable (90.5% vs 84%). Partin-like tables were generated factoring in the number of positive cores to predict organ-confined disease as a guide for urologists to perform nerve-sparing surgery. For example, with T1c disease, there was a ≥75% probability of organ-confined disease with one to three positive cores regardless of prostate-specific antigen (PSA) level, and the same probability was present with four to six positive cores and a PSA level of 0-4 ng/mL. A low Gleason score on biopsy is a powerful prognostic finding, such that this favourable outcome is maintained even in the setting of multiple positive cores with GS6. © 2013 BJU International.

Rise in central west Greenland surface melt unprecedented over the last three centuries

NASA Astrophysics Data System (ADS)

Trusel, Luke; Das, Sarah; Osman, Matthew; Evans, Matthew; Smith, Ben; McConnell, Joe; Noël, Brice; van den Broeke, Michiel

2017-04-01

Greenland Ice Sheet surface melting has intensified and expanded over the last several decades and is now a leading component of ice sheet mass loss. Here, we constrain the multi-century temporal evolution of surface melt across central west Greenland by quantifying layers of refrozen melt within well-dated firn and ice cores collected in 2014 and 2015, as well as from a core collected in 2004. We find significant agreement among ice core, satellite, and regional climate model melt datasets over recent decades, confirming the fidelity of the ice core melt stratigraphy as a reliable record of past variability in the magnitude of surface melt. We also find a significant correlation between the melt records derived from our new 100-m GC-2015 core (2436 m.a.s.l.) and the older (2004) 150-m D5 core (2472 m.a.s.l.) located 50 km to the southeast. This agreement demonstrates the robustness of the ice core-derived melt histories and the potential for reconstructing regional melt evolution from a single site, despite local variability in melt percolation and refreeze processes. Our array of upper percolation zone cores reveals that although the overall frequency of melt at these sites has not increased, the intensification of melt over the last three decades is unprecedented within at least the last 365 years. Utilizing the regional climate model RACMO 2.3, we show that this melt intensification is a nonlinear response to warming summer air temperatures, thus underscoring the heightened sensitivity of this sector of Greenland to further climate warming. Finally, we examine spatial correlations between the ice core melt records and modeled melt fields across the ice sheet to assess the broader representation of each ice core record. This analysis reveals wide-ranging significant correlations, including to modeled meltwater runoff. As such, our ice core melt records may furthermore offer unique, observationally-constrained insights into past variability in ice sheet mass loss.

MELT Bibliography. Materials Correlated with the Core Curriculum Competencies of the Mainstream English Language Training Project, Office of Refugee Resettlement.

ERIC Educational Resources Information Center

Brod, Shirley, Comp.; Sample, Barbara J.

This bibliography is intended to assist teachers and administrators involved in competency-based, English as a second language (ESL) instruction. The materials included in the bibliography have been correlated with the core curriculum competencies of the Mainstream English Language Training (MELT) Project. The guide is divided into three parts.…

Spatial Correlation in the Ambient Core Noise Field of a Turbofan Engine

NASA Technical Reports Server (NTRS)

Miles, Jeffrey Hilton

2012-01-01

An acoustic transfer function relating combustion noise and turbine exit noise in the presence of enclosed ambient core noise is investigated using a dynamic system model and an acoustic system model for the particular turbofan engine studied and for a range of operating conditions. Measurements of cross-spectra magnitude and phase between the combustor and turbine exit and auto-spectra at the turbine exit and combustor are used to show the presence of indirect and direct combustion noise over the frequency range of 0 400 Hz. The procedure used evaluates the ratio of direct to indirect combustion noise. The procedure used also evaluates the post-combustion residence time in the combustor which is a factor in the formation of thermal NOx and soot in this region. These measurements are masked by the ambient core noise sound field in this frequency range which is observable since the transducers are situated within an acoustic wavelength of one another. An ambient core noise field model based on one and two dimensional spatial correlation functions is used to replicate the spatially correlated response of the pair of transducers. The spatial correlation function increases measured attenuation due to destructive interference and masks the true attenuation of the turbine.

Estimating a Preference-Based Index from the Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM)

PubMed Central

Brazier, John E.; Rowen, Donna; Barkham, Michael

2013-01-01

Background. The Clinical Outcomes in Routine Evaluation–Outcome Measure (CORE-OM) is used to evaluate the effectiveness of psychological therapies in people with common mental disorders. The objective of this study was to estimate a preference-based index for this population using CORE-6D, a health state classification system derived from the CORE-OM consisting of a 5-item emotional component and a physical item, and to demonstrate a novel method for generating states that are not orthogonal. Methods. Rasch analysis was used to identify 11 emotional health states from CORE-6D that were frequently observed in the study population and are, thus, plausible (in contrast, conventional statistical design might generate implausible states). Combined with the 3 response levels of the physical item of CORE-6D, they generate 33 plausible health states, 18 of which were selected for valuation. A valuation survey of 220 members of the public in South Yorkshire, United Kingdom, was undertaken using the time tradeoff (TTO) method. Regression analysis was subsequently used to predict values for all possible states described by CORE-6D. Results. A number of multivariate regression models were built to predict values for the 33 health states of CORE-6D, using the Rasch logit value of the emotional state and the response level of the physical item as independent variables. A cubic model with high predictive value (adjusted R2 = 0.990) was selected to predict TTO values for all 729 CORE-6D health states. Conclusion. The CORE-6D preference-based index will enable the assessment of cost-effectiveness of interventions for people with common mental disorders using existing and prospective CORE-OM data sets. The new method for generating states may be useful for other instruments with highly correlated dimensions. PMID:23178639

Historical trace element accumulation in marine sediments from the Tamaulipas shelf, Gulf of Mexico: An assessment of natural vs anthropogenic inputs.

PubMed

Celis-Hernandez, Omar; Rosales-Hoz, Leticia; Cundy, Andrew B; Carranza-Edwards, Arturo; Croudace, Ian W; Hernandez-Hernandez, Hector

2018-05-01

The Gulf of Mexico is considered one of the world's major marine ecosystems, supporting important fisheries and habitats such as barrier islands, mangrove forests, seagrass beds, coral reefs etc. It also hosts a range of complex offshore petroleum exploration, extraction, and refining industries, which may have chronic or acute impacts on ecosystem functioning. Previous work on the marine effects of this activity is geographically incomplete, and has tended to focus on direct hydrocarbon impacts, while impacts from other related contaminants (e.g. heavy metals, salt-rich drilling muds) which may be discharged from oil facilities have not been widely assessed. Here, we examine historical trace element accumulation in marine sediments collected from four sites in the Tamaulipas shelf, Gulf of Mexico, in the area of the Arenque oil field. Dated sediment cores were used to examine the sources, and historical and contemporary inputs, of trace metals (including those typically present in oil industry discharges) and their potential biological impact in the Tamaulipas aquatic environment over the last 100years. CaO (i.e. biogenic component) normalized data showed increasing V, Cr, Zn, Cu, Pb, Zr and Ba towards the sediment surface in three of the four cores, with Ba and V (based on an adverse effect index) possibly associated with adverse effects on organisms. Dated Ba/CaO profiles show an increase of 30-137% after opening of oil installations in the study area, and can be broadly correlated with increasing oil industry activities across the wider Gulf of Mexico. Data do not record however a clear enhancement of Ba concentration in sediment cores collected near to oil platforms over more distal cores, indicating that any Ba released from drilling platforms is incorporated quickly into the sediments around the drilling sites, and once this element has been deposited its rate of resuspension and mobility is low. Sediment core data from the Tamaulipas shelf show the influence of oil industry activities on selected trace element concentrations, with Ba/CaO broadly correlating with increasing oil industry activities across the wider Gulf of Mexico. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of the timings between abrupt climate changes in Greenland, Antarctica, China and Japan based on robust correlation using Lake Suigetsu as a template.

NASA Astrophysics Data System (ADS)

Nakagawa, T.

2014-12-01

High-resolution pollen-derived climate records from Lake Suigetsu varved sediment core were compared with climate archives from other regions and revealed a particular spatio-temporal structure of the monsoon climate change during so-called D-O events. Leads and lags of the climate change between different regions hold the key to understand the climate system. However, robust assessment of the relative timing of the climate change is often very challenging because correlation of the climatic archives from different regions often has inevitable uncertainties. Greenland and Cariaco basin, for example, provide two of the most frequently sited palaeoclimatic proxy data representative of the high- and low-latitudinal Atlantic regions. However, robust correlation of the records from those regions is difficult because of the uncertainties in layer countings, lack of the radiocarbon age control from ice cores, marine reservoir age of the Cariaco sediments, and the absence of the tephra layers shared by both cites. Similarly, Speleothem and ice core records are not robustly correlated to each other, either for the dead carbon fraction in the speleothems and lack of reliable correlation markers. The generally accepted hypothesis of synchronous climate change between China and the Greenland is, therefore, essentially hypothetical. Lake Suigetsu provides solution to this problem. The lake Suigetsu chronology is supposed to be coherent to the speleothems' U-Th age scale. Suigetsu's semi-continuous radiocarbon dataset, which constitutes major component of the IntCal13 radiocarbon calibration model, also provides opportunity to correlate lake Suigetsu and the Greenland and Antarctic ice cores using cosmogenic isotopes as the correlation key. Results of the correlation and timing comparison, which cast new lights to the mechanism of the monsoon change, will be presented.

An Evolutionarily Conserved Family of Virion Tail Needles Related to Bacteriophage P22 gp26: Correlation between Structural Stability and Length of the -Helical Trimeric Coiled Coil

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

Bhardwaj, A.; Walker-Kopp, N; Casjens, S

2009-01-01

Bacteriophages of the Podoviridae family use short noncontractile tails to inject their genetic material into Gram-negative bacteria. In phage P22, the tail contains a thin needle, encoded by the phage gene 26, which is essential both for stabilization and for ejection of the packaged viral genome. Bioinformatic analysis of the N-terminal domain of gp26 (residues 1-60) led us to identify a family of genes encoding putative homologues of the tail needle gp26. To validate this idea experimentally and to explore their diversity, we cloned the gp26-like gene from phages HK620, Sf6 and HS1, and characterized these gene products in solution.more » All gp26-like factors contain an elongated {alpha}-helical coiled-coil core consisting of repeating, adjacent trimerization heptads and form trimeric fibers with length ranging between about 240 to 300 {angstrom}. gp26 tail needles display a high level of structural stability in solution, with Tm (temperature of melting) between 85 and 95 C. To determine how the structural stability of these phage fibers correlates with the length of the {alpha}-helical core, we investigated the effect of insertions and deletions in the helical core. In the P22 tail needle, we identified an 85-residue-long helical domain, termed MiCRU (minimal coiled-coil repeat unit), that can be inserted in-frame inside the gp26 helical core, preserving the straight morphology of the fiber. Likewise, we were able to remove three quarters of the helical core of the HS1 tail needle, minimally decreasing the stability of the fiber. We conclude that in the gp26 family of tail needles, structural stability increases nonlinearly with the length of the {alpha}-helical core. Thus, the overall stability of these bacteriophage fibers is not solely dependent on the number of trimerization repeats in the {alpha}-helical core.« less

Comparison of volumetric bone mineral density in the tibial region of interest for ACL reconstruction.

PubMed

Klein, Scott A; Nyland, John; Caborn, David N M; Kocabey, Yavuz; Nawab, Akbar

2005-12-01

Adequate tibial bone mineral density (BMD) is essential to soft tissue graft fixation during anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to compare volumetric bone plug density measurements at the tibial region of interest for ACL reconstruction using a standardized immersion technique and Archimedes' principle. Cancellous bone cores were harvested from the proximal, middle, and distal metaphyseal regions of the lateral tibia and from the standard tibial tunnel location used for ACL reconstruction of 18 cadaveric specimens. Proximal tibial cores displayed 32.6% greater BMD than middle tibial cores and 31.8% greater BMD than distal tibial cores, but did not differ from the BMD of the tibial tunnel cores. Correlational analysis confirmed that the cancellous BMD in the tibial tunnel related to the cancellous BMD of the proximal and distal lateral tibial metaphysis. In conjunction with its adjacent cortical bone, the cancellous BMD of the region used for standard tibial tunnel placement provides an effective foundation for ACL graft fixation. In tibia with poor BMD, bicortical fixation that incorporates cortical bone from the distal tibial tunnel region is recommended.

Reliability and Validity of the Turkish Version of the PedsQL 3.0 Cancer Module for 2- to 7-Year-Old and the PedsQL 4.0 Generic Core Scales for 5- to 7-Year-Old: The Hacettepe University Experience.

PubMed

Yıldız Kabak, Vesile; Yakut, Yavuz; Çetin, Mualla; Düger, Tülin

2016-09-05

The aim of this study was to investigate the reliability and validity of the Turkish version of the Pediatric Quality of Life Inventory (PedsQL) 3.0 Cancer Module for 2- to 7-year-old and the PedsQL 4.0 Generic Core Scales for 5- to 7-year-old in childhood cancer. The PedsQL 3.0 Cancer Module and PedsQL 4.0 Generic Core Scales were administered to children with cancer and their parents at Hacettepe University. Internal consistency was determined by using Cronbach's alpha and test-retest reliability was determined by using the intraclass correlation coefficient (ICC). Construct validity was assessed by comparing the results of the PedsQL 3.0 Cancer Module with those of the PedsQL 4.0 Generic Core Scales. Cronbach's alpha of the PedsQL 3.0 Cancer Module varied from 0.803 to 0.873 and that of the PedsQL 4.0 Generic Core Scales from 0.665 to 0.841. Test-retest ICC values of the PedsQL 3.0 Cancer Module varied from 0.877 to 0.949 and those of the PedsQL 4.0 Generic Core Scales from 0.681 to 0.824. The correlation of the PedsQL 3.0 Cancer Module with subscale scores of the PedsQL 4.0 Generic Core Scales showed that there were excellent to fair correlations between the two scales. The relationship between parent proxy-report and child self-report of the PedsQL 3.0 Cancer Module had very good correlation (r=0.694, p<0.001), as did the PedsQL 4.0 Generic Core Scales (r=0.540, p=0.002). This study demonstrated the reliability, validity, and feasibility of the Turkish version of the PedsQL 3.0 Cancer Module in 2- to 4-year-old and 5- to 7-year-old and the PedsQL 4.0 Generic Core Scales in 5- to 7-year-old in childhood cancer.

Distribution and transport of total mercury and methylmercury in mercury-contaminated sediments in reservoirs and wetlands of the Sudbury River, east-central Massachusetts

USGS Publications Warehouse

Colman, John A.; Waldron, Marcus C.; Breault, Robert F.; Lent, Robert M.

1999-01-01

Total mercury and methylmercury were measured in 4 reservoir cores and 12 wetland cores from Sudbury River. The distribution of total mercury and methylmercury in these cores was evaluated to determine the potential for total mercury and methylmercury transport from reservoir and wetlands sediments to the water column. Concentrations of methylmercury were corrected for an analytical artifact introduced during the separation distillation used in the analysis procedure. Corrected methylmercury concentrations correlated with total mercury concentrations in bulk sediment from below the top layers of reservoir and wetland cores; methylmercury concentrations at the top layers of cores were relatively high, however, and were not correlated with total mercury concentrations. Concentrations of methylmercury in pore water were positively correlated with methylmercury concentrations in the bulk sediment. High concentrations of total mercury and methylmercury in sediment (73 and 0.047 micrograms per gram dry-weight basis, respectively) contributed less to the water column in the reservoir than in the wetlands probably because of burial by low concentration sediment and differences in the processes available to transport mercury from the sediments to the water in the reservoirs, as compared to the wetlands .

High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones

PubMed Central

Zairov, Rustem; Mustafina, Asiya; Shamsutdinova, Nataliya; Nizameev, Irek; Moreira, Beatriz; Sudakova, Svetlana; Podyachev, Sergey; Fattakhova, Alfia; Safina, Gulnara; Lundstrom, Ingemar; Gubaidullin, Aidar; Vomiero, Alberto

2017-01-01

Polyelectrolyte-coated nanoparticles consisting of terbium and gadolinium complexes with calix[4]arene tetra-diketone ligand were first synthesized. The antenna effect of the ligand on Tb(III) green luminescence and the presence of water molecules in the coordination sphere of Gd(III) bring strong luminescent and magnetic performance to the core-shell nanoparticles. The size and the core-shell morphology of the colloids were studied using transmission electron microscopy and dynamic light scattering. The correlation between photophysical and magnetic properties of the nanoparticles and their core composition was highlighted. The core composition was optimized for the longitudinal relaxivity to be greater than that of the commercial magnetic resonance imaging (MRI) contrast agents together with high level of Tb(III)-centered luminescence. The tuning of both magnetic and luminescent output of nanoparticles is obtained via the simple variation of lanthanide chelates concentrations in the initial synthetic solution. The exposure of the pheochromocytoma 12 (PC 12) tumor cells and periphery human blood lymphocytes to nanoparticles results in negligible effect on cell viability, decreased platelet aggregation and bright coloring, indicating the nanoparticles as promising candidates for dual magneto-fluorescent bioimaging. PMID:28091590

High performance magneto-fluorescent nanoparticles assembled from terbium and gadolinium 1,3-diketones

NASA Astrophysics Data System (ADS)

Zairov, Rustem; Mustafina, Asiya; Shamsutdinova, Nataliya; Nizameev, Irek; Moreira, Beatriz; Sudakova, Svetlana; Podyachev, Sergey; Fattakhova, Alfia; Safina, Gulnara; Lundstrom, Ingemar; Gubaidullin, Aidar; Vomiero, Alberto

2017-01-01

Polyelectrolyte-coated nanoparticles consisting of terbium and gadolinium complexes with calix[4]arene tetra-diketone ligand were first synthesized. The antenna effect of the ligand on Tb(III) green luminescence and the presence of water molecules in the coordination sphere of Gd(III) bring strong luminescent and magnetic performance to the core-shell nanoparticles. The size and the core-shell morphology of the colloids were studied using transmission electron microscopy and dynamic light scattering. The correlation between photophysical and magnetic properties of the nanoparticles and their core composition was highlighted. The core composition was optimized for the longitudinal relaxivity to be greater than that of the commercial magnetic resonance imaging (MRI) contrast agents together with high level of Tb(III)-centered luminescence. The tuning of both magnetic and luminescent output of nanoparticles is obtained via the simple variation of lanthanide chelates concentrations in the initial synthetic solution. The exposure of the pheochromocytoma 12 (PC 12) tumor cells and periphery human blood lymphocytes to nanoparticles results in negligible effect on cell viability, decreased platelet aggregation and bright coloring, indicating the nanoparticles as promising candidates for dual magneto-fluorescent bioimaging.

Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

PubMed Central

Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

2017-01-01

TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties. PMID:28067318

Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

NASA Astrophysics Data System (ADS)

Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

2017-01-01

TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel.

PubMed

Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

2017-01-09

TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

Direct correlations of structural and optical properties of three-dimensional GaN/InGaN core/shell micro-light emitting diodes

NASA Astrophysics Data System (ADS)

Sadat Mohajerani, Matin; Müller, Marcus; Hartmann, Jana; Zhou, Hao; Wehmann, Hergo-H.; Veit, Peter; Bertram, Frank; Christen, Jürgen; Waag, Andreas

2016-05-01

Three-dimensional (3D) InGaN/GaN quantum-well (QW) core-shell light emitting diodes (LEDs) are a promising candidate for the future solid state lighting. In this contribution, we study direct correlations of structural and optical properties of the core-shell LEDs using highly spatially-resolved cathodoluminescence spectroscopy (CL) in combination with scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM). Temperature-dependent resonant photoluminescence (PL) spectroscopy has been performed to understand recombination mechanisms and to estimate the internal quantum efficiency (IQE).

Deepwater Gulf of Mexico turbidites -- Compaction effects on porosity and permeability

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

Ostermeier, R.M.

1995-06-01

The deepwater Gulf of Mexico is now a major area of activity for the US oil industry. Compaction causes particular concern because most prospective deepwater reservoirs are highly geo-pressured and many have limited aquifer support; water injection may also be problematic. To address some of the issues associated with compaction, the authors initiated a special core-analysis program to study compaction effects on turbidite sand porosity and permeability specifically. This program also addressed a number of subsidiary but no less important issues, such as sample characterization and quality, sample preparation, and test procedures. These issues are particularly pertinent, because Gulf ofmore » Mexico turbidites are generally unconsolidated, loose sands, and are thus susceptible to a whole array of potentially serious core-disturbing processes. One key result of the special core analysis program is that turbidite compressibilities exhibit large variations in both magnitude and stress dependence. These variations correlate with creep response in the laboratory measurements. The effects of compaction on permeability are significant. To eliminate complicating effects caused by fines movement, the authors made oil flow measurements at initial water saturation. The measurements indicate compaction reduces permeability four to five times more than porosity on a relative basis.« less

Correlation study of sodium-atom chemisorption on the GaAs(110) surface

NASA Astrophysics Data System (ADS)

Song, K. M.; Khan, D. C.; Ray, A. K.

1994-01-01

Different possible adsorption sites of sodium atoms on a gallium arsenide surface have been investigated using ab initio self-consistent unrestricted Hartree-Fock total-energy cluster calculations with Hay-Wadt effective core potentials. The effects of electron correlation have been included by invoking the concepts of many-body perturbation theory and are found to be highly significant. We find that the Na-atom adsorption at a site modeled with an NaGa5As4H12 cluster is most favored energetically followed by Na adsorption at the site modeled with the NaGa4As5H12 cluster. The effects of charge transfer from Na to the GaAs surface as also possibilities of metallization are also analyzed and discussed.

The QAP weighted network analysis method and its application in international services trade

NASA Astrophysics Data System (ADS)

Xu, Helian; Cheng, Long

2016-04-01

Based on QAP (Quadratic Assignment Procedure) correlation and complex network theory, this paper puts forward a new method named QAP Weighted Network Analysis Method. The core idea of the method is to analyze influences among relations in a social or economic group by building a QAP weighted network of networks of relations. In the QAP weighted network, a node depicts a relation and an undirect edge exists between any pair of nodes if there is significant correlation between relations. As an application of the QAP weighted network, we study international services trade by using the QAP weighted network, in which nodes depict 10 kinds of services trade relations. After the analysis of international services trade by QAP weighted network, and by using distance indicators, hierarchy tree and minimum spanning tree, the conclusion shows that: Firstly, significant correlation exists in all services trade, and the development of any one service trade will stimulate the other nine. Secondly, as the economic globalization goes deeper, correlations in all services trade have been strengthened continually, and clustering effects exist in those services trade. Thirdly, transportation services trade, computer and information services trade and communication services trade have the most influence and are at the core in all services trade.

Individual and family environment correlates differ for consumption of core and non-core foods in children.

PubMed

Johnson, Laura; van Jaarsveld, Cornelia H M; Wardle, Jane

2011-03-01

Children's diets contain too few fruits and vegetables and too many foods high in saturated fat. Food intake is affected by multiple individual and family factors, which may differ for core foods (that are important to a healthy diet) and non-core foods (that are eaten more for pleasure than health). Data came from a sample of twins aged 11 years (n 342) and their parents from the Twins Early Development Study. Foods were categorised into two types: core (e.g. cereals, vegetables and dairy) and non-core (e.g. fats, crisps and biscuits). Parents' and children's intake was assessed by an FFQ. Mothers' and children's preference ratings and home availability were assessed for each food type. Parental feeding practices were assessed with the child feeding questionnaire and child television (TV) watching was maternally reported. Physical activity was measured using accelerometers. Correlates of the child's consumption of each food type were examined using a complex samples general linear model adjusted for potential confounders. Children's non-core food intake was associated with more TV watching, higher availability and greater maternal intake of non-core foods. Children's core food intake was associated with higher preferences for core foods and greater maternal intake of core foods. These results suggest that maternal intake influences both food types, while preferences affect intake of core foods but not of non-core foods, and availability and TV exposure were only important for non-core food intake. Cross-sectional studies cannot determine causality, but the present results suggest that different approaches may be needed to change the balance of core and non-core foods in children's diets.

Determining the size of nanoparticles in the example of magnetic iron oxide core-shell systems

NASA Astrophysics Data System (ADS)

Jarzębski, Maciej; Kościński, Mikołaj; Białopiotrowicz, Tomasz

2017-08-01

The size of nanoparticles is one of the most important factors for their possible applications. Various techniques for the nanoparticle size characterization are available. In this paper selected techniques will be considered base on the prepared core-shell magnetite nanoparticles. Magnetite is one of the most investigated and developed magnetic material. It shows interesting magnetic properties which can be used for biomedical applications, such as drug delivery, hypothermia and also as a contrast agent. To reduce the toxic effects of Fe3O4, magnetic core was covered by dextran and gelatin. Moreover, the shell was doped by fluorescent dye for confocal microscopy investigation. The main investigation focused on the methods for particles size determination of modified magnetite nanoparticles prepared with different techniques. The size distribution were obtained by nanoparticle tracking analysis, dynamic light scattering and transmission electron microscopy. Furthermore, fluorescent correlation spectroscopy (FCS) and confocal microscopy were used to compare the results for particle size determination of core-shell systems.

The effects of therapeutic hip exercise with abdominal core activation on recruitment of the hip muscles.

PubMed

Chan, Mandy Ky; Chow, Ka Wai; Lai, Alfred Ys; Mak, Noble Kc; Sze, Jason Ch; Tsang, Sharon Mh

2017-07-21

Core stabilization has been utilized for rehabilitation and prevention of lower limb musculoskeletal injuries. Previous studies showed that activation of the abdominal core muscles enhanced the hip muscle activity in hip extension and abduction exercises. However, the lack of the direct measurement and quantification of the activation level of the abdominal core muscles during the execution of the hip exercises affect the level of evidence to substantiate the proposed application of core exercises to promote training and rehabilitation outcome of the hip region. The aim of the present study was to examine the effects of abdominal core activation, which is monitored directly by surface electromyography (EMG), on hip muscle activation while performing different hip exercises, and to explore whether participant characteristics such as gender, physical activity level and contractile properties of muscles, which is assessed by tensiomyography (TMG), have confounding effect to the activation of hip muscles in enhanced core condition. Surface EMG of bilateral internal obliques (IO), upper gluteus maximus (UGMax), lower gluteus maximus (LGMax), gluteus medius (GMed) and biceps femoris (BF) of dominant leg was recorded in 20 young healthy subjects while performing 3 hip exercises: Clam, side-lying hip abduction (HABD), and prone hip extension (PHE) in 2 conditions: natural core activation (NC) and enhanced core activation (CO). EMG signals normalized to percentage of maximal voluntary isometric contraction (%MVIC) were compared between two core conditions with the threshold of the enhanced abdominal core condition defined as >20%MVIC of IO. Enhanced abdominal core activation has significantly promoted the activation level of GMed in all phases of clam exercise (P < 0.05), and UGMax in all phases of PHE exercise (P < 0.05), LGMax in eccentric phases of all 3 exercises (P < 0.05), and BF in all phases of all 3 exercises except the eccentric phase of PHE exercise (P < 0.05). The %MVIC of UGMax was significantly higher than that of LGMax in all phases of clam and HABD exercises under both CO and NC conditions (P < 0.001) while the %MVIC of LGMax was significantly higher than UGMax in concentric phase of PHE exercise under NC condition (P = 0.003). Gender, physical activity level and TMG parameters were not major covariates to activation of hip muscles under enhanced core condition. Abdominal core activation enhances the hip muscles recruitment in Clam, HABD and PHE exercises, and this enhancement is correlated with higher physical activity and stiffer hip muscle. Our results suggest the potential application of abdominal core activation for lower limb rehabilitation since the increased activation of target hip muscles may enhance the therapeutic effects of hip strengthening exercises.

Towards accurate ab initio predictions of the vibrational spectrum of methane

NASA Technical Reports Server (NTRS)

Schwenke, David W.

2002-01-01

We have carried out extensive ab initio calculations of the electronic structure of methane, and these results are used to compute vibrational energy levels. We include basis set extrapolations, core-valence correlation, relativistic effects, and Born-Oppenheimer breakdown terms in our calculations. Our ab initio predictions of the lowest lying levels are superb.

TACTILE RESPONSIVENESS PATTERNS AND THEIR ASSOCIATION WITH CORE FEATURES IN AUTISM SPECTRUM DISORDERS

PubMed Central

Foss-Feig, Jennifer H.; Heacock, Jessica L.; Cascio, Carissa J.

2011-01-01

Autism spectrum disorders (ASD) are often associated with aberrant responses to sensory stimuli, which are thought to contribute to the social, communication, and repetitive behavior deficits that define ASD. However, there are few studies that separate aberrant sensory responses by individual sensory modality to assess modality-specific associations between sensory features and core symptoms. Differences in response to tactile stimuli are prevalent in ASD, and tactile contact early in infancy is a foundation for the development of social and communication skills affected by ASD. We assessed the association between three aberrant patterns of tactile responsiveness (hyper-responsiveness, hypo-responsiveness, sensory seeking) and core symptoms of ASD. Both sensory and core features were measured with converging methods including both parent-report and direct observation. Our results demonstrate that for the tactile modality, sensory hypo-responsiveness correlates strongly with increased social and communication impairments, and to a lesser degree, repetitive behaviors. Sensory seeking was found to correlate strongly with social impairment, nonverbal communication impairment, and repetitive behaviors. Surprisingly, tactile hyper-responsiveness did not significantly correlate with any core features of ASD. This differential association between specific tactile processing patterns and core features provides an important step in defining the significance of sensory symptoms in ASD, and may be useful in the development of sensory–based approaches for early detection and intervention. PMID:22059092

Statistical core design methodology using the VIPRE thermal-hydraulics code

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

Lloyd, M.W.; Feltus, M.A.

1994-12-31

This Penn State Statistical Core Design Methodology (PSSCDM) is unique because it not only includes the EPRI correlation/test data standard deviation but also the computational uncertainty for the VIPRE code model and the new composite box design correlation. The resultant PSSCDM equation mimics the EPRI DNBR correlation results well, with an uncertainty of 0.0389. The combined uncertainty yields a new DNBR limit of 1.18 that will provide more plant operational flexibility. This methodology and its associated correlation and uniqe coefficients are for a very particular VIPRE model; thus, the correlation will be specifically linked with the lumped channel and subchannelmore » layout. The results of this research and methodology, however, can be applied to plant-specific VIPRE models.« less

Tools and techniques for developing tephra stratigraphies in lake cores: A case study from the basaltic Auckland Volcanic Field, New Zealand

NASA Astrophysics Data System (ADS)

Hopkins, Jenni L.; Millet, Marc-Alban; Timm, Christian; Wilson, Colin J. N.; Leonard, Graham S.; Palin, J. Michael; Neil, Helen

2015-09-01

Probabilistic hazard forecasting for a volcanic region relies on understanding and reconstructing the eruptive record (derived potentially from proximal as well as distal volcanoes). Tephrostratigraphy is commonly used as a reconstructive tool by cross-correlating tephra deposits to create a stratigraphic framework that can be used to assess magnitude-frequency relationships for eruptive histories. When applied to widespread rhyolitic deposits, tephra identifications and correlations have been successful; however, the identification and correlation of basaltic tephras are more problematic. Here, using tephras in drill cores from six maars in the Auckland Volcanic Field (AVF), New Zealand, we show how X-ray density scanning coupled with magnetic susceptibility analysis can be used to accurately and reliably identify basaltic glass shard-bearing horizons in lacustrine sediments and which, when combined with the major and trace element signatures of the tephras, can be used to distinguish primary from reworked layers. After reliably identifying primary vs. reworked basaltic horizons within the cores, we detail an improved method for cross-core correlation based on stratigraphy and geochemical fingerprinting. We present major and trace element data for individual glass shards from 57 separate basaltic horizons identified within the cores. Our results suggest that in cases where major element compositions (SiO2, CaO, Al2O3, FeO, MgO) do not provide unambiguous correlations, trace elements (e.g. La, Gd, Yb, Zr, Nb, Nd) and trace element ratios (e.g. [La/Yb]N, [Gd/Yb]N, [Zr/Yb]N) are successful in improving the compositional distinction between the AVF basaltic tephra horizons, thereby allowing an improved eruptive history of the AVF to be reconstructed.

Analysis of the dielectric properties of trunk wood in dominant conifer species from New England and Siberia

NASA Technical Reports Server (NTRS)

Ranson, K. J.; Rock, B. N.; Salas, W. A.; Smith, K.; Williams, D. L.

1992-01-01

Data were collected for dominant conifer species. Dielectric properties of trunk wood were measured using a C-band dielectric probe. For certain specimens, electrical resistance was also measured using a shigometer. The water status of the trees studies was determined either by use of a Scholander pressure chamber on branch samples collected simultaneously with dielectric measurements or by fresh-weight/dry-weight assessment of wood core samples extracted and analyzed with the dielectric probe and shigometer. Diurnal delectric properties and xylem water column tension are inversely correlated such that real and imaginary dielectric values drop as tension increases. The dielectric properties were positively correlated with wood core moisture content while electrical resistance was poorly correlated with wood core moisture content in one species studied. Results support the view that dielectric properties are strongly correlated with moisture status in trunk wood, and possibly ion concentrations associated with decay processes in damaged specimens.

High-level ab initio potential energy surface and dynamics of the F- + CH3I SN2 and proton-transfer reactions.

PubMed

Olasz, Balázs; Szabó, István; Czakó, Gábor

2017-04-01

Bimolecular nucleophilic substitution (S N 2) and proton transfer are fundamental processes in chemistry and F - + CH 3 I is an important prototype of these reactions. Here we develop the first full-dimensional ab initio analytical potential energy surface (PES) for the F - + CH 3 I system using a permutationally invariant fit of high-level composite energies obtained with the combination of the explicitly-correlated CCSD(T)-F12b method, the aug-cc-pVTZ basis, core electron correlation effects, and a relativistic effective core potential for iodine. The PES accurately describes the S N 2 channel producing I - + CH 3 F via Walden-inversion, front-side attack, and double-inversion pathways as well as the proton-transfer channel leading to HF + CH 2 I - . The relative energies of the stationary points on the PES agree well with the new explicitly-correlated all-electron CCSD(T)-F12b/QZ-quality benchmark values. Quasiclassical trajectory computations on the PES show that the proton transfer becomes significant at high collision energies and double-inversion as well as front-side attack trajectories can occur. The computed broad angular distributions and hot internal energy distributions indicate the dominance of indirect mechanisms at lower collision energies, which is confirmed by analyzing the integration time and leaving group velocity distributions. Comparison with available crossed-beam experiments shows usually good agreement.

Core decompression of the equine navicular bone: an in vivo study in healthy horses.

PubMed

Jenner, Florien; Kirker-Head, Carl

2011-02-01

To determine the physiologic response of the equine navicular bone to core decompression surgery in healthy horses. Experimental in vivo study. Healthy adult horses (n=6). Core decompression was completed by creating three 2.5-mm-diameter drill channels into the navicular bone under arthroscopic control. The venous (P(V)), arterial (P(A)), articular (P(DIPJ)), and intraosseous pressures (IOP) were recorded before and after decompression drilling. Each IOP measurement consisted of a baseline (IOP(B)) and a stress test (intramedullary injection of saline solution, IOP(S)) recording. Lameness was assessed subjectively and using force plate gait analysis. Fluorochrome bone labeling was performed. Horses were euthanatized at 12 weeks. Navicular bone mineral density (BMD) was measured, and bone histology evaluated. Peak IOP (IOP(max)) after stress testing was significantly (P<.05) reduced immediately after core decompression; however, the magnitude of these effects was decreased at 3 and 6 weeks after decompression. A significant (P<.05) correlation existed between IOP(max) and BMD. No lameness was observed beyond the first week after surgery. Substantial remodeling and neovascularization was evident adjacent the surgery sites. Navicular bone core decompression surgery reduced IOP(max), and, with the exception of a mild short-lived lameness, caused no other adverse effects in healthy horses during the 12-week study period. © Copyright 2011 by The American College of Veterinary Surgeons.

Effect of Surface Functionalization on Structural and Optical Properties of Luminescent LaF₃:Sm Nanoparticles.

PubMed

Ansari, Anees A

2018-02-01

Samarium (Sm3+)-doped LaF3 nanoparticles (NPs) subsequently encapsulated with inert crystalline LaF3 and amorphous silica layers were prepared by polyol and sol-gel chemical process, respectively. These surface modified core/shell/SiO2-nanostructured were characterized by X-ray diffraction (XRD), FE-transmission electron microscopy (TEM), thermal analysis, FTIR, UV/Vis absorption, bang gap energy and photoluminescence spectroscopy. The FETEM, EDX and FTIR spectral studies clearly revealed that the silica layer has been formed surrounding the core-NPs. Comparative spectral analysis indicated that core/shell/SiO2-NPs revealed high solubility in aqueous and non-aqueous solvents. The decrease in band gap energy after surface growth of an inert LaF3 and silica shells is directly correlated to the increase in grain size. On comparing the emission intensity, a significant enhancement was observed after inert layer coating, whereas, it suppress after silica encapsulation due to the non-radiative transitions. The increase luminescent intensity after inert shell growth indicates that a significant amount of non-radiative centers existing on the surface of core/shell nanoparticles can be eliminated by the shielding effect of LaF3 shells. These observed results indicate that the as-prepared core/shell/SiO2-NPs could be highly useful in broad photonic based applications such as optical sensor/optical bio-probe and light emitting diode.

T1 relaxivity of core-encapsulated gadolinium liposomal contrast agents--effect of liposome size and internal gadolinium concentration.

PubMed

Ghaghada, Ketan; Hawley, Catherine; Kawaji, Keigo; Annapragada, Ananth; Mukundan, Srinivasan

2008-10-01

Long circulating core-encapsulated gadolinium (CE-Gd) liposomal nanoparticles that have surface conjugated polyethylene glycol are a promising platform technology for use as blood pool T1-based magnetic resonance (MR) contrast agents. The objective of this study was to investigate the effect of liposome size and internal (core) Gd concentration on the T1 relaxivity of CE-Gd liposomes. Twelve different liposomal formulations were synthesized and characterized, resulting in a size (50, 100, 200, and 400 nm) and core Gd-concentration (200, 350, and 500 mM) "matrix" of test samples. Subsequently, CE-Gd liposomes were diluted in deionized water (four diluted samples) and molar T1 relaxivity (r1) measurements were performed at 2- and 7-T MR field strengths. The r1 of CE-Gd liposomes was inversely related to the liposome size. The largest change in r1 was observed between liposomes that were extruded through 50- and 100-nm filter membranes. At both field strengths, the variation in internal gadolinium concentration did not show any significant correlation (alpha < or = 0.05) with r1. The size of CE-Gd liposomal nanoparticles significantly affects the T1 relaxivity. An inverse relation was observed between liposome size and T1 relaxivity. The T1 relaxivity did not change significantly with core Gd concentration over the measured concentration range.

The Role of Protected Areas in the Avoidance of Anthropogenic Conversion in a High Pressure Region: A Matching Method Analysis in the Core Region of the Brazilian Cerrado

PubMed Central

Paiva, Rodrigo José Oliveira; Brites, Ricardo Seixas; Machado, Ricardo Bomfim

2015-01-01

Global efforts to avoid anthropogenic conversion of natural habitat rely heavily on the establishment of protected areas. Studies that evaluate the effectiveness of these areas with a focus on preserving the natural habitat define effectiveness as a measure of the influence of protected areas on total avoided conversion. Changes in the estimated effectiveness are related to local and regional differences, evaluation methods, restriction categories that include the protected areas, and other characteristics. The overall objective of this study was to evaluate the effectiveness of protected areas to prevent the advance of the conversion of natural areas in the core region of the Brazil’s Cerrado Biome, taking into account the influence of the restriction degree, governmental sphere, time since the establishment of the protected area units, and the size of the area on the performance of protected areas. The evaluation was conducted using matching methods and took into account the following two fundamental issues: control of statistical biases caused by the influence of covariates on the likelihood of anthropogenic conversion and the non-randomness of the allocation of protected areas throughout the territory (spatial correlation effect) and the control of statistical bias caused by the influence of auto-correlation and leakage effect. Using a sample design that is not based on ways to control these biases may result in outcomes that underestimate or overestimate the effectiveness of those units. The matching method accounted for a bias reduction in 94–99% of the estimation of the average effect of protected areas on anthropogenic conversion and allowed us to obtain results with a reduced influence of the auto-correlation and leakage effects. Most protected areas had a positive influence on the maintenance of natural habitats, although wide variation in this effectiveness was dependent on the type, restriction, governmental sphere, size and age group of the unit. PMID:26222140

Chemical compositions of sulfate and chloride salts over the last termination reconstructed from the Dome Fuji ice core, inland Antarctica

NASA Astrophysics Data System (ADS)

Oyabu, Ikumi; Iizuka, Yoshinori; Uemura, Ryu; Miyake, Takayuki; Hirabayashi, Motohiro; Motoyama, Hideaki; Sakurai, Toshimitsu; Suzuki, Toshitaka; Hondoh, Takeo

2014-12-01

The flux and chemical composition of aerosols impact the climate. Antarctic ice cores preserve the record of past atmospheric aerosols, providing useful information about past atmospheric environments. However, few studies have directly measured the chemical composition of aerosol particles preserved in ice cores. Here we present the chemical compositions of sulfate and chloride salts from aerosol particles in the Dome Fuji ice core. The analysis method involves ice sublimation, and the period covers the last termination, 25.0-11.0 thousand years before present (kyr B.P.), with a 350 year resolution. The major components of the soluble particles are CaSO4, Na2SO4, and NaCl. The dominant sulfate salt changes at 16.8 kyr B.P. from CaSO4, a glacial type, to Na2SO4, an interglacial type. The sulfate salt flux (CaSO4 plus Na2SO4) inversely correlates with δ18O in Dome Fuji over millennial timescales. This correlation is consistent with the idea that sulfate salt aerosols contributed to the last deglacial warming of inland Antarctica by reducing the aerosol indirect effect. Between 16.3 and 11.0 kyr B.P., the presence of NaCl suggests that winter atmospheric aerosols are preserved. A high NaCl/Na2SO4 fraction between 12.3 and 11.0 kyr B.P. indicates that the contribution from the transport of winter atmospheric aerosols increased during this period.

Spatial correlation in the ambient core noise field of a turbofan engine.

PubMed

Miles, Jeffrey Hilton

2012-06-01

An acoustic transfer function relating combustion noise and turbine exit noise in the presence of enclosed ambient core noise is investigated using a dynamic system model and an acoustic system model for the particular turbofan engine studied and for a range of operating conditions. Measurements of cross-spectra magnitude and phase between the combustor and turbine exit and auto-spectra at the turbine exit and combustor are used to show the presence of indirect and direct combustion noise over the frequency range of 0-400 Hz. The procedure used evaluates the ratio of direct to indirect combustion noise. The procedure used also evaluates the post-combustion residence time in the combustor which is a factor in the formation of thermal NO(x) and soot in this region. These measurements are masked by the ambient core noise sound field in this frequency range which is observable since the transducers are situated within an acoustic wavelength of one another. An ambient core noise field model based on one and two dimensional spatial correlation functions is used to replicate the spatially correlated response of the pair of transducers. The spatial correlation function increases measured attenuation due to destructive interference and masks the true attenuation of the turbine.

Japanese Reference Panel of Blood Specimens for Evaluation of Hepatitis C Virus RNA and Core Antigen Quantitative Assays

PubMed Central

Murayama, Asako; Sugiyama, Nao; Watashi, Koichi; Masaki, Takahiro; Suzuki, Ryosuke; Aizaki, Hideki; Mizuochi, Toshiaki; Wakita, Takaji

2012-01-01

An accurate and reliable quantitative assay for hepatitis C virus (HCV) is essential for measuring viral propagation and the efficacy of antiviral therapy. There is a growing need for domestic reference panels for evaluation of clinical assay kits because the performance of these kits may vary with region-specific genotypes or polymorphisms. In this study, we established a reference panel by selecting 80 donated blood specimens in Japan that tested positive for HCV. Using this panel, we quantified HCV viral loads using two HCV RNA kits and five core antigen (Ag) kits currently available in Japan. The data from the two HCV RNA assay kits showed excellent correlation. All RNA titers were distributed evenly across a range from 3 to 7 log IU/ml. Although the data from the five core Ag kits also correlated with RNA titers, the sensitivities of individual kits were not sufficient to quantify viral load in all samples. As calculated by the correlation with RNA titers, the theoretical lower limits of detection by these core Ag assays were higher than those for the detection of RNA. Moreover, in several samples in our panel, core Ag levels were underestimated compared to RNA titers. Sequence analysis in the HCV core region suggested that polymorphisms at amino acids 47 to 49 of the core Ag were responsible for this underestimation. The panel established in this study will be useful for estimating the quality of currently available and upcoming HCV assay kits; such quality control is essential for clinical usage of these kits. PMID:22495557

Validation of the Polish version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care in patients with advanced cancer.

PubMed

Leppert, Wojciech; Majkowicz, Mikolaj

2013-05-01

Limited data exist on the validation of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care in advanced cancer patients. To adapt the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care to the Polish clinical setting and to evaluate its psychometric properties in advanced cancer patients. Two quality-of-life measurements were performed at baseline and after 7 days. The concurrent validity of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care was established by the Pearson correlation coefficients with the modified Edmonton Symptom Assessment System, the Karnofsky Performance Status and the Brief Pain Inventory - Short Form. Reliability was assessed using Cronbach's alpha coefficients and the Spearman correlation coefficients of the baseline and of the second measurement of European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care items. A total of 160 consecutive patients in one academic palliative medicine centre were included. A total of 129 patients completed the study. The concurrent validity revealed significant correlations of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care pain scale with the Brief Pain Inventory - Short Form, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care symptom items with the modified Edmonton Symptom Assessment System and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care functional scales with the Karnofsky Performance Status scores. High Cronbach's alpha and standardised Cronbach's alpha values were found in the case of both functional (range: 0.830-0.925; 0.830-0.932) and symptom scales (range: 0.784-0.940; 0.794-0.941) of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care, respectively. The Spearman correlation coefficients between the first and the second measurements were significant (p < 0.0001) for all European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care items. Polish version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire - Core 15 - Palliative Care is a valid and reliable tool recommended for quality-of-life assessment and monitoring in advanced cancer patients.

Flowing gas, non-nuclear experiments on the gas core reactor

NASA Technical Reports Server (NTRS)

Kunze, J. F.; Suckling, D. H.; Copper, C. G.

1972-01-01

Flow tests were conducted on models of the gas core (cavity) reactor. Variations in cavity wall and injection configurations were aimed at establishing flow patterns that give a maximum of the nuclear criticality eigenvalue. Correlation with the nuclear effect was made using multigroup diffusion theory normalized by previous benchmark critical experiments. Air was used to simulate the hydrogen propellant in the flow tests, and smoked air, argon, or freon to simulate the central nuclear fuel gas. All tests were run in the down-firing direction so that gravitational effects simulated the acceleration effect of a rocket. Results show that acceptable flow patterns with high volume fraction for the simulated nuclear fuel gas and high flow rate ratios of propellant to fuel can be obtained. Using a point injector for the fuel, good flow patterns are obtained by directing the outer gas at high velocity along the cavity wall, using louvered or oblique-angle-honeycomb injection schemes.

Effect of nucleoside analogue antimetabolites on the structure of PEO–PPO–PEO micelles investigated by SANS

DOE PAGES

Han, Youngkyu; Zhang, Zhe; Smith, Gregory S.; ...

2017-04-19

In this work, the effect of three nucleoside analogue antimetabolites (5-fluorouracil, floxuridine, and gemcitabine) on the structure of Pluronic L62 copolymer micelles was investigated using small-angle neutron scattering. These antimetabolites used for cancer chemotherapy have analogous molecular structures but different molecular sizes and aqueous solubilities. It was found that the addition of the three antimetabolites slightly reduced the micellar size and aggregation number, and the micellar anisotropy. The added antimetabolites also changed the internal molecular distribution of the micelles as measured by the scattering length densities, resulting in enhanced hydration of the hydrophobic core region of the micelle. The strengthmore » of the effect was found to correlate with the molecular properties of the model drugs, i.e. a larger molecular size and a higher aqueous solubility lead to enhanced hydration of the micellar core.« less

Photoabsorption in sodium clusters: first principles configuration interaction calculations

NASA Astrophysics Data System (ADS)

Priya, Pradip Kumar; Rai, Deepak Kumar; Shukla, Alok

2017-05-01

We present systematic and comprehensive correlated-electron calculations of the linear photoabsorption spectra of small neutral closed- and open-shell sodium clusters (Nan, n = 2 - 6), as well as closed-shell cation clusters (Nan+, n = 3, 5). We have employed the configuration interaction (CI) methodology at the full CI (FCI) and quadruple CI (QCI) levels to compute the ground, and the low-lying excited states of the clusters. For most clusters, besides the minimum energy structures, we also consider their energetically close isomers. The photoabsorption spectra were computed under the electric-dipole approximation, employing the dipole-matrix elements connecting the ground state with the excited states of each isomer. Our calculations were tested rigorously for convergence with respect to the basis set, as well as with respect to the size of the active orbital space employed in the CI calculations. These calculations reveal that as far as electron-correlation effects are concerned, core excitations play an important role in determining the optimized ground state geometries of various clusters, thereby requiring all-electron correlated calculations. But, when it comes to low-lying optical excitations, only valence electron correlation effects play an important role, and excellent agreement with the experimental results is obtained within the frozen-core approximation. For the case of Na6, the largest cluster studied in this work, we also discuss the possibility of occurrence of plasmonic resonance in the optical absorption spectrum. Supplementary material in the form of one pdf file available from the Journal web page at http://https://doi.org/10.1140/epjd/e2017-70728-3

Is HCV core antigen a reliable marker of viral load? An evaluation of HCV core antigen automated immunoassay

PubMed Central

Hadziyannis, Emilia; Minopetrou, Martha; Georgiou, Anastasia; Spanou, Fotini; Koskinas, John

2013-01-01

Background Hepatitis C viral (HCV) load detection and quantification is routinely accomplished by HCV RNA measurement, an expensive but essential test, both for the diagnosis and treatment of chronic hepatitis C (CHC). HCV core antigen (Ag) testing has been suggested as an attractive alternative to molecular diagnostics. The aim of the study was to evaluate an automated chemiluminescent immunoassay (CLIA) for HCV core Ag measurement in comparison to quantitative HCV RNA determination. Methods HCV Ag was measured in 105 anti-HCV positive patients, from which 89 were HCV RNA positive with CHC and 16 HCV RNA negative after spontaneous HCV clearance. Viral load was quantified with branched DNA (bDNA, Versant, Siemens). Sera were stored at -70°C and then tested with the Architect HCV Ag test (Abbott Laboratories), a two-step CLIA assay, with high throughput and minimal handling of the specimens. Statistical analysis was performed on logarithmically transformed values. Results HCV-Ag was detectable and quantifiable in 83/89 and in grey zone in 4/89 HCV RNA positive sera. HCV-Ag was undetectable in all 16 HCV RNA negative samples. The sample with the lowest viral load that tested positive for HCV-Ag contained 1200 IU/mL HCV RNA. There was a positive correlation between HCV RNA and HCV-Ag (r=0.89). The HCV RNA/ HCV Ag ratio varied from 1.5 to 3.25. Conclusion The HCV core Ag is an easy test with comparable sensitivity (>90%) and satisfactory correlation with the HCV RNA bDNA assay. Its role in diagnostics and other clinical applications has to be determined based on cost effectiveness. PMID:24714621

Neural correlates of Pavlovian-to-instrumental transfer in the nucleus accumbens shell are selectively potentiated following cocaine self-administration

PubMed Central

Saddoris, Michael P.; Stamatakis, Alice; Carelli, Regina M.

2013-01-01

During Pavlovian-to-instrumental transfer (PIT), learned Pavlovian cues significantly modulate ongoing instrumental actions. This phenomenon is suggested as a mechanism under which conditioned stimuli may lead to relapse in addicted populations. Following discriminative Pavlovian learning and instrumental conditioning with sucrose, one group of rats (naive) underwent electrophysiological recordings in the nucleus accumbens core and shell during a single PIT session. Other groups, following Pavlovian and instrumental conditioning, were subsequently trained to self-administer cocaine with nosepoke responses, or received yoked saline infusions and nosepoked for water rewards, and then performed PIT while electrophysiological recordings were taken in the nucleus accumbens. Behaviorally, although both naive and saline-treated groups showed increases in lever pressing during the conditioned stimulus cue, this effect was significantly enhanced in the cocaine-treated group. Neurons in the core and shell tracked these behavioral changes. In control animals, core neurons were significantly more likely to encode general information about cues, rewards and responses than those in the shell, and positively correlated with behavioral PIT performance, whereas PIT-specific encoding in the shell, but not core, tracked PIT performance. In contrast, following cocaine exposure, there was a significant increase in neural encoding of all task-relevant events that was selective to the shell. Given that cocaine exposure enhanced both behavior and shell-specific task encoding, these findings suggest that, whereas the core is important for acquiring the information about cues and response contingencies, the shell is important for using this information to guide and modulate behavior and is specifically affected following a history of cocaine self-administration. PMID:21507084

Reservoir characterization of the Mt. Simon Sandstone, Illinois Basin, USA

USGS Publications Warehouse

Frailey, S.M.; Damico, J.; Leetaru, H.E.

2011-01-01

The integration of open hole well log analyses, core analyses and pressure transient analyses was used for reservoir characterization of the Mt. Simon sandstone. Characterization of the injection interval provides the basis for a geologic model to support the baseline MVA model, specify pressure design requirements of surface equipment, develop completion strategies, estimate injection rates, and project the CO2 plume distribution.The Cambrian-age Mt. Simon Sandstone overlies the Precambrian granite basement of the Illinois Basin. The Mt. Simon is relatively thick formation exceeding 800 meters in some areas of the Illinois Basin. In the deeper part of the basin where sequestration is likely to occur at depths exceeding 1000 m, horizontal core permeability ranges from less than 1 ?? 10-12 cm 2 to greater than 1 ?? 10-8 cm2. Well log and core porosity can be up to 30% in the basal Mt. Simon reservoir. For modeling purposes, reservoir characterization includes absolute horizontal and vertical permeability, effective porosity, net and gross thickness, and depth. For horizontal permeability, log porosity was correlated with core. The core porosity-permeability correlation was improved by using grain size as an indication of pore throat size. After numerous attempts to identify an appropriate log signature, the calculated cementation exponent from Archie's porosity and resistivity relationships was used to identify which porosity-permeability correlation to apply and a permeability log was made. Due to the relatively large thickness of the Mt. Simon, vertical permeability is an important attribute to understand the distribution of CO2 when the injection interval is in the lower part of the unit. Only core analyses and specifically designed pressure transient tests can yield vertical permeability. Many reservoir flow models show that 500-800 m from the injection well most of the CO2 migrates upward depending on the magnitude of the vertical permeability and CO2 injection rate (CO2 velocity). Assigning a specific value of vertical permeability to model cells is dependent on the vertical height of the model cell. Measured vertical permeability on core is scale dependent, such that lower vertical permeability is expected over longer core lengths compared to smaller lengths. Consequently, a series of vertical permeability tests were conducted on whole core varying in lengths of samples from 7 cm to 30 cm that showed vertical perm could change by an order of magnitude over a 30 cm height. For one well, the results from a series of pressure transient tests over a perforated interval much smaller than the gross thickness (<2%) confirmed the core-log based geologic model for vertical and horizontal permeability. A partial penetration model was used to estimate the horizontal and vertical permeability over a portion of the modeled area using series and parallel flow averaging techniques. ?? 2011 Published by Elsevier Ltd.

Theory of L -edge spectroscopy of strongly correlated systems

NASA Astrophysics Data System (ADS)

Lüder, Johann; Schött, Johan; Brena, Barbara; Haverkort, Maurits W.; Thunström, Patrik; Eriksson, Olle; Sanyal, Biplab; Di Marco, Igor; Kvashnin, Yaroslav O.

2017-12-01

X-ray absorption spectroscopy measured at the L edge of transition metals (TMs) is a powerful element-selective tool providing direct information about the correlation effects in the 3 d states. The theoretical modeling of the 2 p →3 d excitation processes remains to be challenging for contemporary ab initio electronic structure techniques, due to strong core-hole and multiplet effects influencing the spectra. In this work, we present a realization of the method combining the density-functional theory with multiplet ligand field theory, proposed in Haverkort et al. [Phys. Rev. B 85, 165113 (2012), 10.1103/PhysRevB.85.165113]. In this approach, a single-impurity Anderson model (SIAM) is constructed, with almost all parameters obtained from first principles, and then solved to obtain the spectra. In our implementation, we adopt the language of the dynamical mean-field theory and utilize the local density of states and the hybridization function, projected onto TM 3 d states, in order to construct the SIAM. The developed computational scheme is applied to calculate the L -edge spectra for several TM monoxides. A very good agreement between the theory and experiment is found for all studied systems. The effect of core-hole relaxation, hybridization discretization, possible extensions of the method as well as its limitations are discussed.

Density fluctuation correlation measurements in ASDEX Upgrade using poloidal and radial correlation reflectometry

NASA Astrophysics Data System (ADS)

Prisiazhniuk, D.; Conway, G. D.; Krämer-Flecken, A.; Stroth, U.; the ASDEX Upgrade Team

2018-07-01

The poloidal correlation reflectometry diagnostic operated in ordinary mode with additional radial correlation channel is applied in this paper to investigate the correlation of the turbulent density fluctuations. The perpendicular and radial correlation lengths, l ⊥ and l r , the perpendicular velocity v⊥ and the dissipation (mutation) time τ d are measured simultaneously from the outer core to edge in the L-mode plasmas of ASDEX Upgrade. It is shown that in the outer core region (0.6 < ρ pol < 0.9) the measured correlation lengths scale with the drift wave length, l ⊥ ≈ 5ρ s and l r ≈ 10ρ s , while the dissipation time is inversely correlated with the velocity τ d ≈ 40/v ⊥(τ d is in μs and v ⊥ in km s–1). In the pedestal region (0.925 < ρ pol < 0.98), where the E × B shear flows are present, a loss of measured correlation is observed which can be explained by a combination of small propagation velocity and an additional reduction of τ d . In the E r well region (ρ pol ≈ 0.99), the measured perpendicular correlation length increases {l}\\perp ≈ 13{ρ }s and the radial correlation length decreases l r ≈ 4ρ s compared to the outer core values. The correlation measurements are interpreted in the frame of the linear regime of reflectometry (applied only to ρ pol < 0.9). Using the Born approximation we show that the finite wavenumber sensitivity of the reflectometer increases the measured l ⊥and l r , but does not affect the measured τ d . By the including diagnostic correction the real correlation lengths l ⊥ ≈ l r ≈ 3ρ s are estimated.

Increasing the applicability of density functional theory. V. X-ray absorption spectra with ionization potential corrected exchange and correlation potentials.

PubMed

Verma, Prakash; Bartlett, Rodney J

2016-07-21

Core excitation energies are computed with time-dependent density functional theory (TD-DFT) using the ionization energy corrected exchange and correlation potential QTP(0,0). QTP(0,0) provides C, N, and O K-edge spectra to about an electron volt. A mean absolute error (MAE) of 0.77 and a maximum error of 2.6 eV is observed for QTP(0,0) for many small molecules. TD-DFT based on QTP (0,0) is then used to describe the core-excitation spectra of the 22 amino acids. TD-DFT with conventional functionals greatly underestimates core excitation energies, largely due to the significant error in the Kohn-Sham occupied eigenvalues. To the contrary, the ionization energy corrected potential, QTP(0,0), provides excellent approximations (MAE of 0.53 eV) for core ionization energies as eigenvalues of the Kohn-Sham equations. As a consequence, core excitation energies are accurately described with QTP(0,0), as are the core ionization energies important in X-ray photoionization spectra or electron spectroscopy for chemical analysis.

Virtual Design Method for Controlled Failure in Foldcore Sandwich Panels

NASA Astrophysics Data System (ADS)

Sturm, Ralf; Fischer, S.

2015-12-01

For certification, novel fuselage concepts have to prove equivalent crashworthiness standards compared to the existing metal reference design. Due to the brittle failure behaviour of CFRP this requirement can only be fulfilled by a controlled progressive crash kinematics. Experiments showed that the failure of a twin-walled fuselage panel can be controlled by a local modification of the core through-thickness compression strength. For folded cores the required change in core properties can be integrated by a modification of the fold pattern. However, the complexity of folded cores requires a virtual design methodology for tailoring the fold pattern according to all static and crash relevant requirements. In this context a foldcore micromodel simulation method is presented to identify the structural response of a twin-walled fuselage panels with folded core under crash relevant loading condition. The simulations showed that a high degree of correlation is required before simulation can replace expensive testing. In the presented studies, the necessary correlation quality could only be obtained by including imperfections of the core material in the micromodel simulation approach.

Predicted trends of core-shell preferences for 132 late transition-metal binary-alloy nanoparticles.

PubMed

Wang, Lin-Lin; Johnson, Duane D

2009-10-07

Transition-metal alloyed nanoparticles with core-shell features (shell enrichment by one of the metals) are becoming ubiquitous, from (electro-)catalysis to biomedical applications, due to their size control, performance, biocompatibility, and cost. We investigate 132 binary-alloyed nanoparticle systems (groups 8 to 11 in the Periodic Table) using density functional theory (DFT) and systematically explore their segregation energies to determine core-shell preferences. We find that core-shell preferences are generally described by two independent factors: (1) cohesive energy (related to vapor pressure) and (2) atomic size (quantified by the Wigner-Seitz radius), and the interplay between them. These independent factors are shown to provide general trends for the surface segregation preference for atoms in nanoparticles, as well as semi-infinite surfaces, and give a simple correlation (a "design map") for the alloying and catalytic behavior. Finally, we provide a universal description of core-shell preference via tight-binding theory (band-energy differences) that (i) quantitatively reproduces the DFT segregation energies and (ii) confirms the electronic origins and correlations for core-shell behavior.

The contribution of cytologic imprints of stereotactically guided core needle biopsies of the breast in the management of patients with mammographic abnormalities.

PubMed

Green, R S; Mathew, S

2001-01-01

Between 1995 and 1996, 96 consecutive patients with nonpalpable breast lesions detected by abnormal mammogram underwent core needle biopsies under stereotactic guidance at Johns Hopkins Bayview Medical Center. The cytologic diagnoses rendered on touch imprints and the histopathologic diagnoses made on the core needle biopsies were retrospectively reviewed to ascertain the accuracy and the validity of this procedure. These imprints were made of the cores as on-site evaluation in order to assist the radiologist. Separate diagnoses were rendered on the imprints and the cores. Follow-up excisional/open biopsies were then correlated to determine the usefulness of making touch imprints from the core needle biopsies toward the overall management of a patient with an abnormal mammogram. The core needle biopsies were obtained with a 14-gauge needle and biopsy gun. The cytologic diagnoses rendered on touch imprints and histopathologic diagnoses on core needle biopsies were compared and the concordance rate was determined. The subsequent surgical follow-up was analyzed and correlated with the imprint cytology and the core needle biopsy interpretation to ascertain the pathologic outcome. A total of 100 cases were reviewed: 4 patients had two lesions biopsied. Eighty-four cases showed complete cytohistologic correlation, that is, a high concordance rate. These 84 cases were divided into four categories: malignant (24), atypical (2), benign (55), and unsatisfactory (3). Of these concordant cases, there were 34 subsequent excisional biopsies and all except one confirmed the core needle biopsy diagnosis. The exception had a benign touch imprint and core but the excisional biopsy showed multifocal ductal carcinoma in situ. Of the 100 cases, 16 were nonconcordant (the cytologic diagnosis fell into a different category from the histologic diagnosis). Seven of these nonconcordant cases resulted in excisional biopsies and all but one showed the core diagnosis to be correct. The only exception was a case with atypical cytology and a benign core biopsy with the follow-up excision showing atypia. The rest of the nonconcordant cases with atypical imprints and benign cores had no follow-up surgery, showing that the clinicians are inclined to depend on the core biopsy diagnosis. While our study demonstrates the accuracy and concordance of cytologic touch imprints, the surgical follow-up data reveal that there does not appear to be any additive value to rendering a separate diagnosis on touch imprints of core needle biopsies.

The effects of passive heating and head-cooling on perception of exercise in the heat.

PubMed

Simmons, Shona E; Mündel, Toby; Jones, David A

2008-09-01

The capacity to perform exercise is reduced in a hot environment when compared to cooler conditions. A limiting factor appears to be a higher core body temperature (T (core)) and it has been suggested that an elevated T (core) reduces the drive to exercise, this being reflected in higher ratings of perceived exertion (RPE). The purpose of the present study was to determine whether passive heating to increase T (core) would have a detrimental effect on RPE and thermal comfort during subsequent exercise in the heat and whether head-cooling during passive heating would attenuate these unpleasant sensations of an elevated T (core) during subsequent exercise in the heat. Nine physically-active, non-heat-acclimated volunteers [6 males, 3 females; age: 21 +/- 1 year, VO(2max) 50 +/- 9 ml kg(-1).min(-1), peak power output: 286 +/- 43 W (mean +/- SD)] performed two 12-minute constant-load cycling tests at 70% VO(2max) in a warm-dry environment (34 +/- 1 degrees C, relative humidity <30%) separated by a period of passive heating in a sauna (68 +/- 3 degrees C) to increase T (core). In one trial, subjects had their head and face cooled continually in the sauna (HC), the other trial was a control (CON). Passive heating increased T (core) by 1.22 +/- 0.03 degrees C in the CON and by 0.75 +/- 0.07 degrees C in the HC trial (P < 0.01). Passive heating increased weighted mean skin temperature (T (msk)) in both the CON and HC trials (P < 0.01), however, head-cooling lowered T (msk) during passive heating (P < 0.05). Exercise time following passive heating was reduced in both the CON and HC trials (P < 0.05). Passive heating increased RPE (P < 0.01), however, RPE was lower following passive heating with head-cooling (P < 0.05). There was a significant correlation between T (core) and RPE (r = 0.82, P < 0.001). In conclusion, our results suggest increased RPE during exercise in the heat is primarily due to the increase in T (core). Furthermore, head-cooling attenuates the rise in T (core) and the effect on RPE is proportional to the rise on T (core).

Acute Effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or Paraquat on Core Temperature in C57BL/6J Mice

PubMed Central

Jiao, Yun; Dou, Yuchen; Lockwood, Georgina; Pani, Amar; Jay Smeyne, Richard

2015-01-01

Abstract Background: MPTP and paraquat are two compounds that have been used to model Parkinson’s disease in mice. Previous studies in two non-traditional strains of mice have shown that a single dose of MPTP can induce changes in body temperature, while the effects of paraquat have not been examined. Examination of body temperature is important since small fluctuations in an animal’s core temperature can significantly affect drug metabolism, and if significant enough can even culminate in an animal’s death. Objective: To determine how external heating can alter the survival of C57BL/6J mice following MPTP administration. Methods: In this study, we examine the effects of MPTP (4×20 mg/kg, 2 hours apart) and paraquat (2×10 mg/kg/week for 3 weeks) on core temperature of C57BL/6J mice. Correlations of purine and catecholamine levels were also done in mice treated with MPTP. Results: We find that MPTP induces a significant hypothermia in C57BL/6J mice that reduces their core temperature below the limit of fatal hypothermia. Unlike MPTP, paraquat did not induce a significant hypothermia. Placement of animals on heating pads significantly abrogates the loss of core temperature. In both heated and non-heated conditions, mice treated with MPTP showed a significant depletion of ATP within 2 hours of administration in both striatum and SN that started to recover 2 hours after MPTP administration was complete. Striatal DA and DOPAC are significantly reduced starting 4–6 hours after MPTP. Conclusions: The fatal hypothermic effects of MPTP can be abrogated through use of external heating. PMID:25633843

Resonances in positron-potassium (e +-K) system with natural and unnatural parities

NASA Astrophysics Data System (ADS)

Umair, M.; Jonsell, S.

2016-01-01

We present an investigation of resonances with natural and unnatural parities in the positron-potassium system using the complex scaling method. A model potential is used to represent the interaction between the core and the valence electron. Explicitly correlated Gaussian wave functions are used to represent the correlation effects between the valence electron, the positron and the K+ core. Resonance energies and widths for two partial waves (S- and P-wave) below the {{K}}(4p,5 s,5p,4 d,4f) excitation thresholds and positronium n = 2 formation threshold are calculated for natural parity. Resonance states for P e below the {{K}}(4d) excitation threshold and positronium n = 2, 3 formation thresholds are calculated for unnatural parity which has not been previously reported. Below both positronium thresholds we have found a dipole series of resonances, with binding energies scaling in good agreement with exceptions from an analytical calculation. The present results are compared with those in the literature.

Frozen-Orbital and Downfolding Calculations with Auxiliary-Field Quantum Monte Carlo.

PubMed

Purwanto, Wirawan; Zhang, Shiwei; Krakauer, Henry

2013-11-12

We describe the implementation of the frozen-orbital and downfolding approximations in the auxiliary-field quantum Monte Carlo (AFQMC) method. These approaches can provide significant computational savings, compared to fully correlating all of the electrons. While the many-body wave function is never explicit in AFQMC, its random walkers are Slater determinants, whose orbitals may be expressed in terms of any one-particle orbital basis. It is therefore straightforward to partition the full N-particle Hilbert space into active and inactive parts to implement the frozen-orbital method. In the frozen-core approximation, for example, the core electrons can be eliminated in the correlated part of the calculations, greatly increasing the computational efficiency, especially for heavy atoms. Scalar relativistic effects are easily included using the Douglas-Kroll-Hess theory. Using this method, we obtain a way to effectively eliminate the error due to single-projector, norm-conserving pseudopotentials in AFQMC. We also illustrate a generalization of the frozen-orbital approach that downfolds high-energy basis states to a physically relevant low-energy sector, which allows a systematic approach to produce realistic model Hamiltonians to further increase efficiency for extended systems.

One-year measurements of chloroethenes in tree cores and groundwater at the SAP Mimoň Site, Northern Bohemia.

PubMed

Wittlingerova, Z; Machackova, J; Petruzelkova, A; Trapp, S; Vlk, K; Zima, J

2013-02-01

Chlorinated ethenes (CE) are among the most frequent contaminants of soil and groundwater in the Czech Republic. Because conventional methods of subsurface contamination investigation are costly and technically complicated, attention is directed on alternative and innovative field sampling methods. One promising method is sampling of tree cores (plugs of woody tissue extracted from a host tree). Volatile organic compounds can enter into the trunks and other tissues of trees through their root systems. An analysis of the tree core can thus serve as an indicator of the subsurface contamination. Four areas of interest were chosen at the experimental site with CE groundwater contamination and observed fluctuations in groundwater concentrations. CE concentrations in groundwater and tree cores were observed for a 1-year period. The aim was to determine how the CE concentrations in obtained tree core samples correlate with the level of contamination of groundwater. Other factors which can affect the transfer of contaminants from groundwater to wood were also monitored and evaluated (e.g., tree species and age, level of groundwater table, river flow in the nearby Ploučnice River, seasonal effects, and the effect of the remediation technology operation). Factors that may affect the concentration of CE in wood were identified. The groundwater table level, tree species, and the intensity of transpiration appeared to be the main factors within the framework of the experiment. Obtained values documented that the results of tree core analyses can be used to indicate the presence of CE in the subsurface. The results may also be helpful to identify the best sampling period for tree coring and to learn about the time it takes until tree core concentrations react to changes in groundwater conditions. Interval sampling of tree cores revealed possible preservation of the contaminant in the wood of trees.

Accurate virial coefficients of gaseous krypton from state-of-the-art ab initio potential and polarizability of the krypton dimer

NASA Astrophysics Data System (ADS)

Song, Bo; Waldrop, Jonathan M.; Wang, Xiaopo; Patkowski, Konrad

2018-01-01

We have developed a new krypton-krypton interaction-induced isotropic dipole polarizability curve based on high-level ab initio methods. The determination was carried out using the coupled-cluster singles and doubles plus perturbative triples method with very large basis sets up to augmented correlation-consistent sextuple zeta as well as the corrections for core-core and core-valence correlation and relativistic effects. The analytical function of polarizability and our recently constructed reference interatomic potential [J. M. Waldrop et al., J. Chem. Phys. 142, 204307 (2015)] were used to predict the thermophysical and electromagnetic properties of krypton gas. The second pressure, acoustic, and dielectric virial coefficients were computed for the temperature range of 116 K-5000 K using classical statistical mechanics supplemented with high-order quantum corrections. The virial coefficients calculated were compared with the generally less precise available experimental data as well as with values computed from other potentials in the literature {in particular, the recent highly accurate potential of Jäger et al. [J. Chem. Phys. 144, 114304 (2016)]}. The detailed examination in this work suggests that the present theoretical prediction can be applied as reference values in disciplines involving thermophysical and electromagnetic properties of krypton gas.

Reliability and Validity of the Turkish Version of the PedsQL 3.0 Cancer Module for 2- to 7-Year-Old and the PedsQL 4.0 Generic Core Scales for 5- to 7-Year-Old: The Hacettepe University Experience

PubMed Central

Yıldız Kabak, Vesile; Yakut, Yavuz; Çetin, Mualla; Düger, Tülin

2016-01-01

Objective: The aim of this study was to investigate the reliability and validity of the Turkish version of the Pediatric Quality of Life Inventory (PedsQL) 3.0 Cancer Module for 2- to 7-year-old and the PedsQL 4.0 Generic Core Scales for 5- to 7-year-old in childhood cancer. Materials and Methods: The PedsQL 3.0 Cancer Module and PedsQL 4.0 Generic Core Scales were administered to children with cancer and their parents at Hacettepe University. Internal consistency was determined by using Cronbach’s alpha and test-retest reliability was determined by using the intraclass correlation coefficient (ICC). Construct validity was assessed by comparing the results of the PedsQL 3.0 Cancer Module with those of the PedsQL 4.0 Generic Core Scales. Results: Cronbach’s alpha of the PedsQL 3.0 Cancer Module varied from 0.803 to 0.873 and that of the PedsQL 4.0 Generic Core Scales from 0.665 to 0.841. Test-retest ICC values of the PedsQL 3.0 Cancer Module varied from 0.877 to 0.949 and those of the PedsQL 4.0 Generic Core Scales from 0.681 to 0.824. The correlation of the PedsQL 3.0 Cancer Module with subscale scores of the PedsQL 4.0 Generic Core Scales showed that there were excellent to fair correlations between the two scales. The relationship between parent proxy-report and child self-report of the PedsQL 3.0 Cancer Module had very good correlation (r=0.694, p<0.001), as did the PedsQL 4.0 Generic Core Scales (r=0.540, p=0.002). Conclusion: This study demonstrated the reliability, validity, and feasibility of the Turkish version of the PedsQL 3.0 Cancer Module in 2- to 4-year-old and 5- to 7-year-old and the PedsQL 4.0 Generic Core Scales in 5- to 7-year-old in childhood cancer. PMID:27095607

Influence of internal composition on physicochemical properties of alginate aqueous-core capsules.

PubMed

Ben Messaoud, Ghazi; Sánchez-González, Laura; Probst, Laurent; Desobry, Stéphane

2016-05-01

To enhance physicochemical properties of alginate aqueous-core capsules, conventional strategies were focused in literature on designing composite and coated capsules. In the present study, own effect of liquid-core composition on mechanical and release properties was investigated. Capsules were prepared by dripping a CaCl2 solution into an alginate gelling solution. Viscosity of CaCl2 solution was adjusted by adding cationic, anionic and non-ionic naturally derived polymers, respectively chitosan, xanthan gum and guar gum. In parallel, uniform alginate hydrogels were prepared by different methods (pouring, in situ forming and mixing). Mechanical stability of capsules and plane hydrogels were respectively evaluated by compression experiments and small amplitude oscillatory shear rheology and then correlated. Capsules permeability was evaluated by monitoring diffusion of encapsulated cochineal dye, riboflavin and BSA. The core-shell interactions were investigated by ATR-FTIR. Results showed that inner polymer had an impact on membrane stability and could act as an internal coating or provide mechanical reinforcement. Mechanical properties of alginate capsules were in a good agreement with rheological behavior of plane hydrogels. Release behavior of the entrapped molecules changed considerably. This study demonstrated the importance of aqueous-core composition, and gave new insights for possible adjusting of microcapsules physicochemical properties by modulating core-shell interactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Wide-Field CCD Photometry around Nine Open Clusters

NASA Astrophysics Data System (ADS)

Sharma, Saurabh; Pandey, A. K.; Ogura, K.; Mito, H.; Tarusawa, K.; Sagar, R.

2006-10-01

In this paper we study the evolution of the core and corona of nine open clusters using the projected radial density profiles derived from homogeneous CCD photometric data obtained with the 105 cm Kiso Schmidt telescope. The age and galactocentric distance of the target clusters vary from 16 to 2000 Myr and 9 to 10.8 kpc, respectively. Barring Be 62, which is a young open cluster, other clusters show a uniform reddening across the cluster region. The reddening in Be 62 varies from E(B-V)min=0.70 mag to E(B-V)max=1.00 mag. The coronae of six of the clusters in the present sample are found to be elongated; however, on the basis of the present sample it is not possible to establish any correlation between the age and shape of the core. The elongated core in the case of the young cluster Be 62 may reflect the initial conditions in the parental molecular cloud. The other results of the present study are as follows: (1) Core radius rc and corona size rcn/cluster radius rcl are linearly correlated. (2) The rc, rcn, and rcl are linearly correlated with the number of stars in that region. (3) In the age range 10-1000 Myr, the core and corona shrink with age. (4) We find that in the galactocentric distance range 9-10 kpc, the core and corona/cluster extent of the clusters increase with the galactocentric distance.

A core competency-based objective structured clinical examination (OSCE) can predict future resident performance.

PubMed

Wallenstein, Joshua; Heron, Sheryl; Santen, Sally; Shayne, Philip; Ander, Douglas

2010-10-01

This study evaluated the ability of an objective structured clinical examination (OSCE) administered in the first month of residency to predict future resident performance in the Accreditation Council for Graduate Medical Education (ACGME) core competencies. Eighteen Postgraduate Year 1 (PGY-1) residents completed a five-station OSCE in the first month of postgraduate training. Performance was graded in each of the ACGME core competencies. At the end of 18 months of training, faculty evaluations of resident performance in the emergency department (ED) were used to calculate a cumulative clinical evaluation score for each core competency. The correlations between OSCE scores and clinical evaluation scores at 18 months were assessed on an overall level and in each core competency. There was a statistically significant correlation between overall OSCE scores and overall clinical evaluation scores (R = 0.48, p < 0.05) and in the individual competencies of patient care (R = 0.49, p < 0.05), medical knowledge (R = 0.59, p < 0.05), and practice-based learning (R = 0.49, p < 0.05). No correlation was noted in the systems-based practice, interpersonal and communication skills, or professionalism competencies. An early-residency OSCE has the ability to predict future postgraduate performance on a global level and in specific core competencies. Used appropriately, such information can be a valuable tool for program directors in monitoring residents' progress and providing more tailored guidance. © 2010 by the Society for Academic Emergency Medicine.

Ionic bonding of lanthanides, as influenced by d- and f-atomic orbitals, by core-shells and by relativity.

PubMed

Ji, Wen-Xin; Xu, Wei; Schwarz, W H Eugen; Wang, Shu-Guang

2015-03-15

Lanthanide trihalide molecules LnX3 (X = F, Cl, Br, I) were quantum chemically investigated, in particular detail for Ln = Lu (lutetium). We applied density functional theory (DFT) at the nonrelativistic and scalar and SO-coupled relativistic levels, and also the ab initio coupled cluster approach. The chemically active electron shells of the lanthanide atoms comprise the 5d and 6s (and 6p) valence atomic orbitals (AO) and also the filled inner 4f semivalence and outer 5p semicore shells. Four different frozen-core approximations for Lu were compared: the (1s(2) -4d(10) ) [Pd] medium core, the [Pd+5s(2) 5p(6) = Xe] and [Pd+4f(14) ] large cores, and the [Pd+4f(14) +5s(2) 5p(6) ] very large core. The errors of LuX bonding are more serious on freezing the 5p(6) shell than the 4f(14) shell, more serious upon core-freezing than on the effective-core-potential approximation. The LnX distances correlate linearly with the AO radii of the ionic outer shells, Ln(3+) -5p(6) and X(-) -np(6) , characteristic for dominantly ionic Ln(3+) -X(-) binding. The heavier halogen atoms also bind covalently with the Ln-5d shell. Scalar relativistic effects contract and destabilize the LuX bonds, spin orbit coupling hardly affects the geometries but the bond energies, owing to SO effects in the free atoms. The relativistic changes of bond energy BE, bond length Re , bond force k, and bond stretching frequency vs do not follow the simple rules of Badger and Gordy (Re ∼BE∼k∼vs ). The so-called degeneracy-driven covalence, meaning strong mixing of accidentally near-degenerate, nearly nonoverlapping AOs without BE contribution is critically discussed. © 2015 Wiley Periodicals, Inc.

The Survival of the Core Fundamental Plane against Galactic Mergers

NASA Astrophysics Data System (ADS)

Holley-Bockelmann, Kelly; Richstone, Douglas

1999-05-01

The basic dimensional properties of the centers of elliptical galaxies, such as length scale, luminosity, and velocity dispersion, lie on a fundamental plane similar to that of elliptical galaxies as a whole. The orientation of this plane, and the distribution of core parameters within it, point to a strong correlation of core density with either core or total luminosity, and indicate that low-luminosity ellipticals are much denser than high-luminosity galaxies (Hubble Space Telescope data suggest that this relationship may be as steep as ρc~L-2). In addition, low-luminosity ellipticals have a much smaller length scale than their high-luminosity counterparts. Since we think that small galaxies are occasionally accreted by big ones, the high density of these galaxies and their likely durability against the time-varying tidal field of the bigger ones suggests that they will survive substantially intact in the cores of larger galaxies and would be easily visible. Their presence would destroy the observed correlation. Motivated by this apparent inconsistency between an observed fact and a simple physical argument, we have developed an effective simulation method and applied it to the problem of the accretion of very dense secondary companions by tenuous primaries. We have studied the accretion of objects of varying luminosity ratios, with sizes and densities drawn from the fundamental plane under the assumption that the mass distribution in the central parts of the galaxies follows the light. The results indicate that in mergers with mass ratios greater than 10, chosen with an appropriate central density dependence on luminosity, the smaller object is only stripped down to the highest density encountered in the primary during the accretion process. Thus, the form of the core fundamental plane suggests that the mass distribution in galaxy centers is different from the light distribution, or that an understanding of secondary survival requires more than the dynamics of visible stars.

The effect of mining on the sediment - trace element geochemistry of cores from the Cheyenne River arm of Lake Oahe, South Dakota, U.S.A.

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Callender, E.

1988-01-01

Six cores, ranging in length from 1 to 2 m, were collected in the Cheyenne River arm of Lake Oahe, South Dakota, to investigate potential impacts from gold-mining operations around Lead, South Dakota. Sedimentation rates in the river arm appear to be event-dominated and rapid, on the order of 6-7 cm yr.-1. All the chemical concentrations in the core samples fall within the wide ranges previously reported for the Pierre Shale of Cretaceous age and with the exception of As, generally are similar to bed sediment levels in the Cheyenne River, Lake Oahe and Foster Bay. Based on the downcore distribution of Mn, it appears that reducing conditions exist in the sediment column of the river arm below 2-3 cm. The reducing conditions do not appear to be severe enough to produce differentiation of Fe and Mn throughout the sediment column in the river arm. Cross-correlations for high-level metal-bearing strata within the sediment column can be made for several strata and for several cores; however, cross-correlations for all the high-level metal-bearing strata are not feasible. As is the only element which appears enriched in the core samples compared to surface sediment levels. Well-crystallized arsenopyrite was found in high-As bearing strata from two cores and probably was transported in that form from reducing sediment-storage sites in the banks or floodplains of Whitewood Creek and the Belle Fourche River. It has not oxidized due to the reducing conditions in the sediment column of the Cheyenne River arm. Some As may also be transported in association with Fe- and Mn-oxides and -hydroxides, remobilized under the reducing conditions in the river arm, and then reprecipitated in authigenic sulfide phases. In either case, the As appears to be relatively immobile in the sediment column. ?? 1988.

Strong Neutron Pairing in core+4 n Nuclei

NASA Astrophysics Data System (ADS)

Revel, A.; Marqués, F. M.; Sorlin, O.; Aumann, T.; Caesar, C.; Holl, M.; Panin, V.; Vandebrouck, M.; Wamers, F.; Alvarez-Pol, H.; Atar, L.; Avdeichikov, V.; Beceiro-Novo, S.; Bemmerer, D.; Benlliure, J.; Bertulani, C. A.; Boillos, J. M.; Boretzky, K.; Borge, M. J. G.; Caamaño, M.; Casarejos, E.; Catford, W. N.; Cederkäll, J.; Chartier, M.; Chulkov, L.; Cortina-Gil, D.; Cravo, E.; Crespo, R.; Datta Pramanik, U.; Díaz Fernández, P.; Dillmann, I.; Elekes, Z.; Enders, J.; Ershova, O.; Estradé, A.; Farinon, F.; Fraile, L. M.; Freer, M.; Galaviz, D.; Geissel, H.; Gernhäuser, R.; Golubev, P.; Göbel, K.; Hagdahl, J.; Heftrich, T.; Heil, M.; Heine, M.; Heinz, A.; Henriques, A.; Ignatov, A.; Johansson, H. T.; Jonson, B.; Kahlbow, J.; Kalantar-Nayestanaki, N.; Kanungo, R.; Kelic-Heil, A.; Knyazev, A.; Kröll, T.; Kurz, N.; Labiche, M.; Langer, C.; Le Bleis, T.; Lemmon, R.; Lindberg, S.; Machado, J.; Marganiec, J.; Movsesyan, A.; Nacher, E.; Najafi, M.; Nilsson, T.; Nociforo, C.; Paschalis, S.; Perea, A.; Petri, M.; Pietri, S.; Plag, R.; Reifarth, R.; Ribeiro, G.; Rigollet, C.; Röder, M.; Rossi, D.; Savran, D.; Scheit, H.; Simon, H.; Syndikus, I.; Taylor, J. T.; Tengblad, O.; Thies, R.; Togano, Y.; Velho, P.; Volkov, V.; Wagner, A.; Weick, H.; Wheldon, C.; Wilson, G.; Winfield, J. S.; Woods, P.; Yakorev, D.; Zhukov, M.; Zilges, A.; Zuber, K.; R³B Collaboration

2018-04-01

The emission of neutron pairs from the neutron-rich N =12 isotones 18C and 20O has been studied by high-energy nucleon knockout from 19N and 21O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n -n correlations shows that the decay 19N (-1 p ) 18C* → 16C +n +n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a 14C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay 21O (-1 n )20O*→18O +n +n , attributed to its formation through the knockout of a deeply bound neutron that breaks the 16O core and reduces the number of pairs.

Inorganic biochemistry with short-lived radioisotopes as nuclear probes

NASA Astrophysics Data System (ADS)

Tröger, W.; Butz, T.

2000-12-01

Metal ions are ubiquitous in the biosphere. In living organisms metalloproteins with specifically designed metal cores perform vital chemical processes. On the other hand, several heavy metals are detrimental to living organisms and nature has developed effective enzymatic detoxification systems which convert toxic metal ions to less toxic species. The nuclear spectroscopy technique Time Differential Perturbed Angular Correlation (TDPAC) of γ-rays uses radioactive isotopes as nuclear probes in these metal cores to obtain a better understanding of the structural and functional significance of these metal cores by monitoring the nuclear quadrupole interaction of the TDPAC probe. Since this technique is based on the nuclear decay, it is also applicable under physiological conditions, i.e., especially at picomolar concentrations. For these studies an indispensable prerequisite is the production of the TDPAC probes with highest possible specific activity and purity as is done by the on-line mass separator ISOLDE at CERN in Geneva.

Nonequilibrium dynamics of one-dimensional hard-core anyons following a quench: complete relaxation of one-body observables.

PubMed

Wright, Tod M; Rigol, Marcos; Davis, Matthew J; Kheruntsyan, Karén V

2014-08-01

We demonstrate the role of interactions in driving the relaxation of an isolated integrable quantum system following a sudden quench. We consider a family of integrable hard-core lattice anyon models that continuously interpolates between noninteracting spinless fermions and strongly interacting hard-core bosons. A generalized Jordan-Wigner transformation maps the entire family to noninteracting fermions. We find that, aside from the singular free-fermion limit, the entire single-particle density matrix and, therefore, all one-body observables relax to the predictions of the generalized Gibbs ensemble (GGE). This demonstrates that, in the presence of interactions, correlations between particles in the many-body wave function provide the effective dissipation required to drive the relaxation of all one-body observables to the GGE. This relaxation does not depend on translational invariance or the tracing out of any spatial domain of the system.

Accounting for crustal magnetization in models of the core magnetic field

NASA Technical Reports Server (NTRS)

Jackson, Andrew

1990-01-01

The problem of determining the magnetic field originating in the earth's core in the presence of remanent and induced magnetization is considered. The effect of remanent magnetization in the crust on satellite measurements of the core magnetic field is investigated. The crust as a zero-mean stationary Gaussian random process is modelled using an idea proposed by Parker (1988). It is shown that the matrix of second-order statistics is proportional to the Gram matrix, which depends only on the inner-products of the appropriate Green's functions, and that at a typical satellite altitude of 400 km the data are correlated out to an angular separation of approximately 15 deg. Accurate and efficient means of calculating the matrix elements are given. It is shown that the variance of measurements of the radial component of a magnetic field due to the crust is expected to be approximately twice that in horizontal components.

Assessment of safety margins in zircaloy oxidation and embrittlement criteria for ECCS acceptance

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

Williford, R.E.

1986-04-01

Current Emergency Core Cooling System (ECCS) Acceptance Criteria for light-water reactors include certain requirements pertaining to calculations of core performance during a Loss of Coolant Accident (LOCA). The Baker-Just correlation must be used to calculate Zircaloy-steam oxidation, calculated peak cladding temperatures (PCT) must not exceed 1204/sup 0/C, and calculated oxidation must not exceed 17% equivalent cladding reacted (17% ECR). The minimum margin of safety was estimated for each of these criteria, based on research performed in the last decade. Margins were defined as the amounts of conservatism over and above the expected extreme values computed from the data base atmore » specified confidence levels. The currently required Baker-Just oxidation correlation provides margins only over the 1100/sup 0/C to 1500/sup 0/C temperature range at the 95% confidence level. The PCT margins for thermal shock and handling failures are adequate at oxidation temperatures above 1204/sup 0/C for 210 and 160 seconds, respectively, at the 95% confidence level. ECR thermal shock and handling margins at the 50% and 95% confidence levels, respectively, range between 2% and 7% ECR for the Baker-Just correlation, but vanish at temperatures between 1100/sup 0/C and 1160/sup 0/C for the best-estimate Cathcart-Pawel correlation. Use of the Cathcart-Pawel correlation for LOCA calculations can be justified at the 85% to 88% confidence level if cooling rate effects can be neglected. 75 refs., 21 figs.« less

Brain stimulation, mathematical, and numerical training: Contribution of core and noncore skills.

PubMed

Looi, C Y; Cohen Kadosh, R

2016-01-01

Mathematical abilities that are correlated with various life outcomes vary across individuals. One approach to improve mathematical abilities is by understanding the underlying cognitive functions. Theoretical and experimental evidence suggest that mathematical abilities are subserved by "core" and "noncore" skills. Core skills are commonly regarded as the "innate" capacity to attend to and process numerical information, while noncore skills are those that are important for mathematical cognition, but are not exclusive to the mathematical domain such as executive functions, spatial skills, and attention. In recent years, mathematical training has been combined with the application of noninvasive brain stimulation to further enhance training outcomes. However, the development of more strategic training paradigms is hindered by the lack of understanding on the contributory nature of core and noncore skills and their neural underpinnings. In the current review, we will examine the effects of brain stimulation with focus on transcranial electrical stimulation on core and noncore skills, and its impact on mathematical and numerical training. We will conclude with a discussion on the theoretical and experimental implications of these studies and directions for further research. © 2016 Elsevier B.V. All rights reserved.

Correlation consistent basis sets for actinides. I. The Th and U atoms.

PubMed

Peterson, Kirk A

2015-02-21

New correlation consistent basis sets based on both pseudopotential (PP) and all-electron Douglas-Kroll-Hess (DKH) Hamiltonians have been developed from double- to quadruple-zeta quality for the actinide atoms thorium and uranium. Sets for valence electron correlation (5f6s6p6d), cc - pV nZ - PP and cc - pV nZ - DK3, as well as outer-core correlation (valence + 5s5p5d), cc - pwCV nZ - PP and cc - pwCV nZ - DK3, are reported (n = D, T, Q). The -PP sets are constructed in conjunction with small-core, 60-electron PPs, while the -DK3 sets utilized the 3rd-order Douglas-Kroll-Hess scalar relativistic Hamiltonian. Both series of basis sets show systematic convergence towards the complete basis set limit, both at the Hartree-Fock and correlated levels of theory, making them amenable to standard basis set extrapolation techniques. To assess the utility of the new basis sets, extensive coupled cluster composite thermochemistry calculations of ThFn (n = 2 - 4), ThO2, and UFn (n = 4 - 6) have been carried out. After accurately accounting for valence and outer-core correlation, spin-orbit coupling, and even Lamb shift effects, the final 298 K atomization enthalpies of ThF4, ThF3, ThF2, and ThO2 are all within their experimental uncertainties. Bond dissociation energies of ThF4 and ThF3, as well as UF6 and UF5, were similarly accurate. The derived enthalpies of formation for these species also showed a very satisfactory agreement with experiment, demonstrating that the new basis sets allow for the use of accurate composite schemes just as in molecular systems composed only of lighter atoms. The differences between the PP and DK3 approaches were found to increase with the change in formal oxidation state on the actinide atom, approaching 5-6 kcal/mol for the atomization enthalpies of ThF4 and ThO2. The DKH3 atomization energy of ThO2 was calculated to be smaller than the DKH2 value by ∼1 kcal/mol.

Effect Of Fluorine Doping On Radiation Hardness Of Graded Index Optical Fibers

NASA Astrophysics Data System (ADS)

Wei, T.; Singh, M. P.; Miniscalco, W. J.; Onorato, P. I. K.; Wall, J. A.

1987-01-01

We report an experimental and theoretical investigation of the effects of doping and processing on precursor defects in graded index multimode fibers. Fabrication parameters that significantly influence radiation sensitivity have been identified. In particular, we examined the role of fluorine doping in defect formation and its relationship to radiation sensitivity. The experimental effort included fiber fabrication and radiation-induced loss measurements on graded index, Ge-doped core fibers. Fluorine was added to the core and/or the cladding of test fibers. Two critical parameters, barrier layer thickness and core dopants, have been identified and correlate with induced loss. In addition, the reproducibility of both fiber fabrication and measurement with respect to induced loss has been tested and found to be excellent. Induced loss was found to be proportional to Ge concentration in the core; however, the trend with fluorine doping was less clear. The experimental results are consistent with molecular dynamics simulations which indicate the types and numbers of structural defects in the glasses. The simulations revealed significant differences in defect types and concentrations among glass corn-positions that included pure silica, Ge-doped silica, and Ge/F-codoped silica. Fluorine codoping decreases the number of germanium-related defects but increases the number of defects associated with silicon.

Correlations between Raman frequencies and structures for planar and nonplanar metalloporphyrins

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

Sparks, L.D.; Anderson, K.K.; Medforth, C.J.

1994-05-11

Resonance Raman spectra were obtained for two series of metalloporphyrins, and frequencies of structure-sensitive Raman lines are correlated with structural changes in the porphyrin macrocycle. In the first series, metal derivatives of tetracyclohexenyltetraphenylporphyrin (TC{sub 6}TPP), the porphinato core size is varied by varying the metal (Ni < Co < Cu), causing little change in the planarity of this nonplanar porphyrin. In the second series, nickel complexes of tetracyclopentenyl-, tetracyclohexenyl-, and tetracycloheptenyltertraphenylporphyrin (NiTc{sub x}TPP, where x = 5-7), the size of the alky ring at the {beta}-carbon positions of the pyrrole rings is varied. In the NiTc{sub x}TPP series, the porphyrinmore » macrocycle becomes significantly more nonplanar as the alkyl ring becomes larger and steric crowding increases. As a consequence of the increasing nonplanarity, the porphyrin core contracts. Correlations between Raman frequencies and structural parameters, including core size and C{sub {alpha}}-N-C{sub {alpha}} angle (obtained from molecular mechanics calculations), are found for both series of porphyrins. These new correlative relationships are compared to similar relationships previously observed for metal octaalkylporphyrins, metal tetraphenylporphyrins, and a series of Ni octaalkyltetraphenylporphyrins. Most importantly, by comparing the metal series (Ni, Co, Cu, Zn, etc.) for differing porphyrin ligands, the authors find a trend toward weaker frequency dependence on core size for the more nonplanar porphyrins. Thus, the applicability of this useful structural correlation is extended to both planar and nonplanar porphyrins. Finally, the differences between these correlative relationships are traced to more fundamental (Badger`s rule) relationships between vibrational frequencies and the length of bond contributing to the total potential energy of the vibrational modes corresponding to the structure-sensitive Raman lines.« less

Age model for a continuous, ca 250-ka Quaternary lacustrine record from Bear Lake, Utah-Idaho

USGS Publications Warehouse

Colman, Steven M.; Kaufman, D.S.; Bright, Jordon; Heil, C.; King, J.W.; Dean, W.E.; Rosenbaum, J.G.; Forester, R.M.; Bischoff, J.L.; Perkins, Marie; McGeehin, J.P.

2006-01-01

The Quaternary sediments sampled by continuous 120-m-long drill cores from Bear Lake (Utah-Idaho) comprise one of the longest lacustrine sequences recovered from an extant lake. The cores serve as a good case study for the construction of an age model for sequences that extend beyond the range of radiocarbon dating. From a variety of potential age indicators, we selected a combination of radiocarbon ages, one magnetic excursion (correlated to a standard sequence), and a single Uranium-series age to develop an initial data set. The reliability of the excursion and U-series data require consideration of their position with respect to sediments of inferred interglacial character, but not direct correlation with other paleoclimate records. Data omitted from the age model include amino acid age estimates, which have a large amount of scatter, and tephrochronology correlations, which have relatively large uncertainties. Because the initial data set was restricted to the upper half of the BL00-1 core, we inferred additional ages by direct correlation to the independently dated paleoclimate record from Devils Hole. We developed an age model for the entire core using statistical methods that consider both the uncertainties of the original data and that of the curve-fitting process, with a combination of our initial data set and the climate correlations as control points. This age model represents our best estimate of the chronology of deposition in Bear Lake. Because the age model contains assumptions about the correlation of Bear Lake to other climate records, the model cannot be used to address some paleoclimate questions, such as phase relationships with other areas.

Political attitudes in adolescence and emerging adulthood: Developmental changes in mean level, polarization, rank-order stability, and correlates.

PubMed

Rekker, Roderik; Keijsers, Loes; Branje, Susan; Meeus, Wim

2015-06-01

This three-wave cohort-sequential longitudinal study (N = 1302) examined the development of two core political attitudes, economic egalitarianism and ethnocentrism, among Dutch youths between age 12 and 31. Longitudinal regression analyses revealed a curvilinear mean level development for both attitudes, reflecting an increased disagreement with economic redistribution and multiculturalism around late adolescence. Furthermore, attitudes became decreasingly polarized (i.e., less extreme) and increasingly stable with age. Finally, several effects of attitudes' correlates gradually changed: The effect of educational level on ethnocentrism increased with age, whereas the effect of gender diminished. Regional effects on ethnocentrism developed as youths resided in a new area. No age-related change was found in the effect of parental SES. Overall, these findings support the idea that attitudes mature during the formative phase of adolescence and that this process slows down during emerging adulthood. Furthermore, these results support developmental explanations for the association between attitudes and their correlates. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Exploring cosmic origins with CORE: Effects of observer peculiar motion

NASA Astrophysics Data System (ADS)

Burigana, C.; Carvalho, C. S.; Trombetti, T.; Notari, A.; Quartin, M.; Gasperis, G. D.; Buzzelli, A.; Vittorio, N.; De Zotti, G.; de Bernardis, P.; Chluba, J.; Bilicki, M.; Danese, L.; Delabrouille, J.; Toffolatti, L.; Lapi, A.; Negrello, M.; Mazzotta, P.; Scott, D.; Contreras, D.; Achúcarro, A.; Ade, P.; Allison, R.; Ashdown, M.; Ballardini, M.; Banday, A. J.; Banerji, R.; Bartlett, J.; Bartolo, N.; Basak, S.; Bersanelli, M.; Bonaldi, A.; Bonato, M.; Borrill, J.; Bouchet, F.; Boulanger, F.; Brinckmann, T.; Bucher, M.; Cabella, P.; Cai, Z.-Y.; Calvo, M.; Castellano, M. G.; Challinor, A.; Clesse, S.; Colantoni, I.; Coppolecchia, A.; Crook, M.; D'Alessandro, G.; Diego, J.-M.; Di Marco, A.; Di Valentino, E.; Errard, J.; Feeney, S.; Fernández-Cobos, R.; Ferraro, S.; Finelli, F.; Forastieri, F.; Galli, S.; Génova-Santos, R.; Gerbino, M.; González-Nuevo, J.; Grandis, S.; Greenslade, J.; Hagstotz, S.; Hanany, S.; Handley, W.; Hernández-Monteagudo, C.; Hervias-Caimapo, C.; Hills, M.; Hivon, E.; Kiiveri, K.; Kisner, T.; Kitching, T.; Kunz, M.; Kurki-Suonio, H.; Lamagna, L.; Lasenby, A.; Lattanzi, M.; Lesgourgues, J.; Liguori, M.; Lindholm, V.; Lopez-Caniego, M.; Luzzi, G.; Maffei, B.; Mandolesi, N.; Martinez-Gonzalez, E.; Martins, C. J. A. P.; Masi, S.; Matarrese, S.; McCarthy, D.; Melchiorri, A.; Melin, J.-B.; Molinari, D.; Monfardini, A.; Natoli, P.; Paiella, A.; Paoletti, D.; Patanchon, G.; Piat, M.; Pisano, G.; Polastri, L.; Polenta, G.; Pollo, A.; Poulin, V.; Remazeilles, M.; Roman, M.; Rubiño-Martín, J.-A.; Salvati, L.; Tartari, A.; Tomasi, M.; Tramonte, D.; Trappe, N.; Tucker, C.; Väliviita, J.; Van de Weijgaert, R.; van Tent, B.; Vennin, V.; Vielva, P.; Young, K.; Zannoni, M.

2018-04-01

We discuss the effects on the cosmic microwave background (CMB), cosmic infrared background (CIB), and thermal Sunyaev-Zeldovich effect due to the peculiar motion of an observer with respect to the CMB rest frame, which induces boosting effects. After a brief review of the current observational and theoretical status, we investigate the scientific perspectives opened by future CMB space missions, focussing on the Cosmic Origins Explorer (CORE) proposal. The improvements in sensitivity offered by a mission like CORE, together with its high resolution over a wide frequency range, will provide a more accurate estimate of the CMB dipole. The extension of boosting effects to polarization and cross-correlations will enable a more robust determination of purely velocity-driven effects that are not degenerate with the intrinsic CMB dipole, allowing us to achieve an overall signal-to-noise ratio of 13; this improves on the Planck detection and essentially equals that of an ideal cosmic-variance-limited experiment up to a multipole lsimeq2000. Precise inter-frequency calibration will offer the opportunity to constrain or even detect CMB spectral distortions, particularly from the cosmological reionization epoch, because of the frequency dependence of the dipole spectrum, without resorting to precise absolute calibration. The expected improvement with respect to COBE-FIRAS in the recovery of distortion parameters (which could in principle be a factor of several hundred for an ideal experiment with the CORE configuration) ranges from a factor of several up to about 50, depending on the quality of foreground removal and relative calibration. Even in the case of simeq1 % accuracy in both foreground removal and relative calibration at an angular scale of 1o, we find that dipole analyses for a mission like CORE will be able to improve the recovery of the CIB spectrum amplitude by a factor simeq 17 in comparison with current results based on COBE-FIRAS. In addition to the scientific potential of a mission like CORE for these analyses, synergies with other planned and ongoing projects are also discussed.

Finite-size effects on current correlation functions

NASA Astrophysics Data System (ADS)

Chen, Shunda; Zhang, Yong; Wang, Jiao; Zhao, Hong

2014-02-01

We study why the calculation of current correlation functions (CCFs) still suffers from finite-size effects even when the periodic boundary condition is taken. Two important one-dimensional, momentum-conserving systems are investigated as examples. Intriguingly, it is found that the state of a system recurs in the sense of microcanonical ensemble average, and such recurrence may result in oscillations in CCFs. Meanwhile, we find that the sound mode collisions induce an extra time decay in a current so that its correlation function decays faster (slower) in a smaller (larger) system. Based on these two unveiled mechanisms, a procedure for correctly evaluating the decay rate of a CCF is proposed, with which our analysis suggests that the global energy CCF decays as ˜t-2/3 in the diatomic hard-core gas model and in a manner close to ˜t-1/2 in the Fermi-Pasta-Ulam-β model.

Jet outflow and gamma-ray emission correlations in S5 0716+714

DOE PAGES

Rani, B.; Krichbaum, T. P.; Marscher, A. P.; ...

2014-11-06

Here, using millimeter very long baseline interferometry (VLBI) observations of the BL Lac object S5 0716+714 from August 2008 to September 2013, we investigate variations in the core flux density and orientation of the sub-parsec scale jet, i.e. position angle. The γ-ray data obtained by the Fermi Large Area Telescope are used to investigate the high-energy flux variations over the same time period. For the first time in any blazar, we report a significant correlation between the γ-ray flux variations and the position angle variations in the VLBI jet. The cross-correlation analysis also indicates a positive correlation such that themore » mm-VLBI core flux density variations are delayed with respect to the γ-ray flux by 82±32 days. This suggests that the high-energy emission is coming from a region located ≥(3.8±1.9) parsecs upstream of the mm-VLBI core (closer to the central black hole). Lastly, these results imply that the observed inner jet morphology has a strong connection with the observed γ-ray flares.« less

Jet outflow and gamma-ray emission correlations in S5 0716+714

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

Rani, B.; Krichbaum, T. P.; Marscher, A. P.

Here, using millimeter very long baseline interferometry (VLBI) observations of the BL Lac object S5 0716+714 from August 2008 to September 2013, we investigate variations in the core flux density and orientation of the sub-parsec scale jet, i.e. position angle. The γ-ray data obtained by the Fermi Large Area Telescope are used to investigate the high-energy flux variations over the same time period. For the first time in any blazar, we report a significant correlation between the γ-ray flux variations and the position angle variations in the VLBI jet. The cross-correlation analysis also indicates a positive correlation such that themore » mm-VLBI core flux density variations are delayed with respect to the γ-ray flux by 82±32 days. This suggests that the high-energy emission is coming from a region located ≥(3.8±1.9) parsecs upstream of the mm-VLBI core (closer to the central black hole). Lastly, these results imply that the observed inner jet morphology has a strong connection with the observed γ-ray flares.« less

Correlation of virus load in plasma and lymph node tissue in human immunodeficiency virus infection. INCAS Study Group. Italy, Netherlands, Canada, Australia, and (United) States.

PubMed

Harris, M; Patenaude, P; Cooperberg, P; Filipenko, D; Thorne, A; Raboud, J; Rae, S; Dailey, P; Chernoff, D; Todd, J; Conway, B; Montaner, J S

1997-11-01

The impact of long-term changes in plasma viremia, produced by effective combination antiretroviral therapy, on human immunodeficiency virus (HIV) burden within tissue reservoirs is unknown. Fifteen patients who had received at least 1 year of therapy with two or three drug combinations of zidovudine, didanosine, and nevirapine had suitable samples of lymph node tissue obtained by ultrasound-guided core needle biopsy. HIV RNA was extracted from homogenized tissue samples and quantitated using a modified branched DNA assay. Results were correlated with antiretroviral treatment effect on the basis of plasma virus load measurements over the preceding 12-18 months. A statistically significant negative correlation was observed between magnitude of treatment effect on plasma viremia and lymph node virus load. These data suggest that combinations of antiretroviral drugs that produce sustained suppression of plasma HIV RNA may also be able to reduce the virus burden in lymphoid tissues.

Mercury content of Illinois soils

USGS Publications Warehouse

Dreher, G.B.; Follmer, L.R.

2004-01-01

For a survey of Illinois soils, 101 cores had been collected and analyzed to determine the current and background elemental compositions of Illinois soils. Mercury and other elements were determined in six samples per core, including a surface sample from each core. The mean mercury content in the surface samples was 33 ?? 20 ??g/kg soil, and the background content was 20 ?? 9 ??g/kg. The most probable sources of mercury in these soils were the parent material, and wet and dry deposition of Hg0 and Hg2+ derived from coal-burning power plants, other industrial plants, and medical and municipal waste incinerators. Mercury-bearing sewage sludge or other fertilizers applied to agricultural fields could have been the local sources of mercury. Although the mercury content correlated with organic carbon content or clay content in individual cores, when all the data were considered, there was no strong correlation between mercury and either the organic carbon or the clay-size content.

Solvent friction effects propagate over the entire protein molecule through low-frequency collective modes.

PubMed

Moritsugu, Kei; Kidera, Akinori; Smith, Jeremy C

2014-07-24

Protein solvation dynamics has been investigated using atom-dependent Langevin friction coefficients derived directly from molecular dynamics (MD) simulations. To determine the effect of solvation on the atomic friction coefficients, solution and vacuum MD simulations were performed for lysozyme and staphylococcal nuclease and analyzed by Langevin mode analysis. The coefficients thus derived are roughly correlated with the atomic solvent-accessible surface area (ASA), as expected from the fact that friction occurs as the result of collisions with solvent molecules. However, a considerable number of atoms with higher friction coefficients are found inside the core region. Hence, the influence of solvent friction propagates into the protein core. The internal coefficients have large contributions from the low-frequency modes, yielding a simple picture of the surface-to-core long-range damping via solvation governed by collective low-frequency modes. To make use of these findings in implicit-solvent modeling, we compare the all-atom friction results with those obtained using Langevin dynamics (LD) with two empirical representations: the constant-friction and the ASA-dependent (Pastor-Karplus) friction models. The constant-friction model overestimates the core and underestimates the surface damping whereas the ASA-dependent friction model, which damps protein atoms only on the solvent-accessible surface, reproduces well the friction coefficients for both the surface and core regions observed in the explicit-solvent MD simulations. Therefore, in LD simulation, the solvent friction coefficients should be imposed only on the protein surface.

Solvent friction effects propagate over the entire protein molecule through low-frequency collective modes

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

Moritsugu, Kei; Kidera, Akinori; Smith, Jeremy C.

2014-06-25

Protein solvation dynamics has been investigated using atom-dependent Langevin friction coefficients derived directly from molecular dynamics (MD) simulations. To determine the effect of solvation on the atomic friction coefficients, solution and vacuum MD simulations were performed for lysozyme and staphylococcal nuclease and analyzed by Langevin mode analysis. The coefficients thus derived are roughly correlated with the atomic solvent-accessible surface area (ASA), as expected from the fact that friction occurs as the result of collisions with solvent molecules. However, a considerable number of atoms with higher friction coefficients are found inside the core region. Hence, the influence of solvent friction propagatesmore » into the protein core. The internal coefficients have large contributions from the low-frequency modes, yielding a simple picture of the surface-to-core long-range damping via solvation governed by collective low-frequency modes. To make use of these findings in implicit-solvent modeling, we compare the all-atom friction results with those obtained using Langevin dynamics (LD) with two empirical representations: the constant-friction and the ASA-dependent (Pastor Karplus) friction models. The constant-friction model overestimates the core and underestimates the surface damping whereas the ASA-dependent friction model, which damps protein atoms only on the solvent-accessible surface, reproduces well the friction coefficients for both the surface and core regions observed in the explicit-solvent MD simulations. Furthermore, in LD simulation, the solvent friction coefficients should be imposed only on the protein surface.« less

Geologic logs of geotechnical cores from the subsurface Sacramento-San Joaquin Delta, California

USGS Publications Warehouse

Maier, Katherine L.; Ponti, Daniel J.; Tinsley, John C.; Gatti, Emma; Pagenkopp, Mark

2014-01-01

This report presents and summarizes descriptive geologic logs of geotechnical cores collected from 2009–12 in the Sacramento–San Joaquin Delta, California, by the California Department of Water Resources. Graphic logs are presented for 1,785.7 ft of retained cores from 56 borehole sites throughout the Sacramento-San Joaquin Delta. Most core sections are from a depth of ~100–200 feet. Cores primarily contain mud, silt, and sand lithologies. Tephra (volcanic ash and pumice), paleosols, and gravels are also documented in some core sections. Geologic observations contained in the core logs in this report provide stratigraphic context for subsequent sampling and data for future chronostratigraphic subsurface correlations.

Teleseismic Array Studies of Earth's Core-Mantle Boundary

NASA Astrophysics Data System (ADS)

Alexandrakis, Catherine

2011-12-01

The core mantle boundary (CMB) is an inaccessible and complex region, knowledge of which is vital to our understanding of many Earth processes. Above it is the heterogeneous lower-mantle. Below the boundary is the outer-core, composed of liquid iron, and/or nickel and some lighter elements. Elucidation of how these two distinct layers interact may enable researchers to better understand the geodynamo, global tectonics, and overall Earth history. One parameter that can be used to study structure and limit potential chemical compositions is seismic-wave velocity. Current global-velocity models have significant uncertainties in the 200 km above and below the CMB. In this thesis, these regions are studied using three methods. The upper outer core is studied using two seismic array methods. First, a modified vespa, or slant-stack method is applied to seismic observations at broadband seismic arrays, and at large, dense groups of broadband seismic stations dubbed 'virtual' arrays. Observations of core-refracted teleseismic waves, such as SmKS, are used to extract relative arrivaltimes. As with previous studies, lower -mantle heterogeneities influence the extracted arrivaltimes, giving significant scatter. To remove raypath effects, a new method was developed, called Empirical Transfer Functions (ETFs). When applied to SmKS waves, this method effectively isolates arrivaltime perturbations caused by outer core velocities. By removing raypath effects, the signals can be stacked further reducing scatter. The results of this work were published as a new 1D outer-core model, called AE09. This model describes a well-mixed outer core. Two array methods are used to detect lower mantle heterogeneities, in particular Ultra-Low Velocity Zones (ULVZs). The ETF method and beam forming are used to isolate a weak P-wave that diffracts along the CMB. While neither the ETF method nor beam forming could adequately image the low-amplitude phase, beam forms of two events indicate precursors to the SKS and SKKS phase, which may be ULVZ indicators. Finally, cross-correlated observed and modelled beams indicate a tendency towards a ULVZ-like lower mantle in the study region.

Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

NASA Astrophysics Data System (ADS)

Maselli, Olivia J.; Chellman, Nathan J.; Grieman, Mackenzie; Layman, Lawrence; McConnell, Joseph R.; Pasteris, Daniel; Rhodes, Rachael H.; Saltzman, Eric; Sigl, Michael

2017-01-01

Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750-2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

Validation of an Interdisciplinary Food Safety Curriculum Targeted at Middle School Students and Correlated to State Educational Standards

ERIC Educational Resources Information Center

Richards, Jennifer; Skolits, Gary; Burney, Janie; Pedigo, Ashley; Draughon, F. Ann

2008-01-01

Providing effective food safety education to young consumers is a national health priority to combat the nearly 76 million cases of foodborne illness in the United States annually. With the tremendous pressures on teachers for accountability in core subject areas, the focus of classrooms is on covering concepts that are tested on state performance…

Improvements in the chronology, geochemistry and correlation techniques of tephra in Antarctic ice

NASA Astrophysics Data System (ADS)

Iverson, N. A.; Dunbar, N. W.; McIntosh, W. C.; Pearce, N. J.; Kyle, P. R.

2013-12-01

Visible and crypto tephra layers found in West Antarctic ice provide an excellent record of Antarctic volcanism over the past 100ka. Tephra layers are deposited almost instantaneously across wide areas creating horizons that, if found in several locations, provide 'pinning points' to adjust ice time scales that may otherwise be lacking detailed chronology. Individual tephra layers can have distinct chemical fingerprints allowing them to correlate over great distances. Advances in sample preparation, geochemical analyses (major and trace elements) of fine grained tephra and higher precision 40Ar/39Ar dating of young (<100ka) proximal volcanic deposits are improving an already established tephra record in West Antarctica. Forty three of the potential hundreds of silicate layers found in a recently drilled deep West Antarctic Ice Sheet Divide core (WDC06A) have been analyzed for major elements and a subset for trace elements. Of these layers, at least 16 are homogenous tephra that could be correlated to other ice cores (e.g. Siple Dome, SDMA) and/or to source volcanoes found throughout Antarctica and even extra-continental eruptions (e.g. Sub-Antarctic islands and South America). Combining ice core tephra with those exposed in blue ice areas provide more locations to correlate widespread eruptions. For example, a period of heightened eruptive activity at Mt. Berlin, West Antarctica between 24 and 28ka produced a set of tephra layers that are found in WDC06A and SDMA ice cores, as well as at a nearby blue ice area at Mt. Moulton (BIT-151 and BIT-152). Possible correlative tephra layers are found at ice ages of 26.4, 26.9 and 28.8ka in WDC06A and 26.5, 27.0, and 28.7ka in SDMA cores. The geochemical similarities of major elements in these layers mean that ongoing trace element analyses will be vital to decipher the sequence of events during this phase of activity at Mt. Berlin. Sample WDC06A-2767.117 (ice age of 28.6×1.0ka) appears to correlate to blue ice tephra BIT-152 and to tephra layer SDMA-5683 (ice age of 28.5ka). This tephra layer also appears to be present in blue ice at Mt. Terra Nova on Ross Island, 1400km away, suggesting that it may be a possible to link ice cores in East Antarctica (e.g. Talos Dome and Law Dome). The amount of feldspar in ice core tephra is typically too small to be directly dated by 40Ar/39Ar method, making it very important to geochemically correlate these layers to proximal deposits where more and larger feldspar can be sampled. The correlation of WDC06A-2767.117 to the coarse, proximal BIT-152 provides one such link. The New Mexico Geochronology Research Lab (NMGRL) has two new multi-collector ARGUS VI mass spectrometers that can provide single crystal laser fusion ages that are approximately an order of magnitude more precise than the previous determinations. With these advancements in analytical technology, we hope to improve precision on 'pinning points' in the deep ice cores where annual layer counting becomes less precise.

Marked differences in core beliefs about self and others, between sociotropy and autonomy: personality vulnerabilities in the cognitive model of depression.

PubMed

Otani, Koichi; Suzuki, Akihito; Matsumoto, Yoshihiko; Shirata, Toshinori

2018-01-01

The cognitive model of depression posits two distinctive personality vulnerabilities termed sociotropy and autonomy, each of which is composed of a cluster of maladaptive self-schemas. It is postulated that negative core beliefs about self underlie maladaptive self-schemas as a whole, whereas those about others may be implicated in the autonomous self-schemas. Therefore, the present study examined the relations of sociotropy and autonomy with core beliefs about self and others. The sample of this study consisted of 321 healthy Japanese volunteers. Sociotropy and autonomy were evaluated by the corresponding subscales of the Sociotropy-Autonomy Scale. Core beliefs about self and others were assessed by the negative-self, positive-self, negative-other and positive-other subscales of the Brief Core Schema Scales. In the forced multiple regression analysis, sociotropy scores were correlated with negative-self scores ( β = 0.389, P < 0.001). Meanwhile, autonomy scores were correlated with positive-self scores ( β = 0.199, P < 0.01) and negative-other scores ( β = 0.191, P < 0.01). The present study suggests marked differences in core beliefs about self and others between sociotropy and autonomy, further contrasting the two personality vulnerabilities to depression.

TRACEing Last Glacial Period (25-80 ka b2k) tephra horizons within North Atlantic marine cores and exploring links to the Greenland ice-cores

NASA Astrophysics Data System (ADS)

Abbott, P. M.; Davies, S. M.; Griggs, A. J.; Bourne, A. J.; Cook, E.; Pearce, N. J. G.; Austin, W. E. N.; Chapman, M.; Hall, I. R.; Purcell, C. S.; Scourse, J. D.; Rasmussen, T. L.

2015-12-01

Tephrochronology is a powerful technique for the correlation and synchronisation of disparate palaeoclimatic records from different depositional environments and has considerable potential for testing climatic phasing. For example, the relative timing of atmospheric and marine changes caused by the abrupt climatic events that punctuated the last glacial period within the North Atlantic region. Here we report on efforts to establish a framework of tephra horizons within North Atlantic marine sequences that can correlate these records and if traced in the Greenland ice-cores can act as isochronous tie-lines. Investigations have been conducted on a network of marine cores from a number of sites across the North Atlantic. Tephra horizons have been identified using cryptotephra extraction techniques more commonly applied to the study of terrestrial sequences. There are two main challenges with assessing cryptotephras in the glacial North Atlantic; i) determining the transportation processes and ii) assessing the influence of secondary reworking processes and the stratigraphic integrity of the isochrons. These processes and their influence are investigated for each cryptotephra using shard size variations, major element heterogeneity and co-variance of IRD input for some cores. Numerous Icelandic cryptophras have been successfully identified in the marine records and we will discuss the integration of a number of these with an isochronous nature into a marine tephra framework and how potential correlations to the Greenland ice-core tephra framework are determined. Spatial patterns in the nature of tephra records that are emerging from the core network will be highlighted to outline some of the key areas that could be explored in the future. In addition, the synchronisation of multiple North Atlantic records to the Greenland ice-cores using the North Atlantic Ash Zone II to test the synchroneity of an abrupt cooling in the North Atlantic will be discussed.

The host galaxy/AGN connection in nearby early-type galaxies. Is there a miniature radio-galaxy in every "core" galaxy?

NASA Astrophysics Data System (ADS)

Balmaverde, B.; Capetti, A.

2006-02-01

This is the second of a series of three papers exploring the connection between the multiwavelength properties of AGN in nearby early-type galaxies and the characteristics of their hosts. We selected two samples with 5 GHz VLA radio flux measurements down to 1 mJy, reaching levels of radio luminosity as low as 1036 erg s-1. In Paper I we presented a study of the surface brightness profiles for the 65 objects with available archival HST images out of the 116 radio-detected galaxies. We classified early-type galaxies into "core" and "power-law" galaxies, discriminating on the basis of the slope of their nuclear brightness profiles, following the Nukers scheme. Here we focus on the 29 core galaxies (hereafter CoreG). We used HST and Chandra data to isolate their optical and X-ray nuclear emission. The CoreG invariably host radio-loud nuclei, with an average radio-loudness parameter of Log R = L5 {GHz} / LB ˜ 3.6. The optical and X-ray nuclear luminosities correlate with the radio-core power, smoothly extending the analogous correlations already found for low luminosity radio-galaxies (LLRG) toward even lower power, by a factor of ˜ 1000, covering a combined range of 6 orders of magnitude. This supports the interpretation of a common non-thermal origin of the nuclear emission also for CoreG. The luminosities of the nuclear sources, most likely dominated by jet emission, set firm upper limits, as low as L/L_Edd ˜ 10-9 in both the optical and X-ray band, on any emission from the accretion process. The similarity of CoreG and LLRG when considering the distributions host galaxies luminosities and black hole masses, as well as of the surface brightness profiles, indicates that they are drawn from the same population of early-type galaxies. LLRG represent only the tip of the iceberg associated with (relatively) high activity levels, with CoreG forming the bulk of the population. We do not find any relationship between radio-power and black hole mass. A minimum black hole mass of M_BH = 108 M⊙ is apparently associated with the radio-loud nuclei in both CoreG and LLRG, but this effect must be tested on a sample of less luminous galaxies, likely to host smaller black holes. In the unifying model for BL Lacs and radio-galaxies, CoreG likely represent the counterparts of the large population of low luminosity BL Lac now emerging from the surveys at low radio flux limits. This suggests the presence of relativistic jets also in these quasi-quiescent early-type "core" galaxies.

Near-Melting Condition of the Inner Core Boundary Revealed from Antipodal Seismic Waves

NASA Astrophysics Data System (ADS)

Cormier, V. F.; Attanayake, J.; de Silva, S. M. S.; Miller, M. S.; Thomas, C.

2014-12-01

First-principles calculations1 have suggested that the inner core's low shear velocity (3.5 km/sec) is a consequence of its temperature being very close to its melting temperature throughout its volume. Near the inner core's freezing or melting boundary, the shear modulus could possibly approach zero. A test of this is made from observations of the amplitude of PKIIKP waves at antipodal (>175o) ranges. These underside reflections are very sensitive to the S velocity beneath the inner core boundary due to energy subtracted from PKIIKP by converted S energy. This sensitivity is exploited by modeling PKIIKP waveforms observed by a transportable array in Morocco, which recorded many high-quality antipodal waveforms from Tonga. Differences in the in the sampling of the upper inner core between PKIIKP arriving from the short (<180o) and long (>180o) distances make it feasible to investigate lateral differences in the elastic and anelastic states of uppermost inner core from the amplitude and frequency content of the waveforms. In computational experiments, we show that a zero or small shear modulus in the uppermost inner core is the most effective way of matching large amplitude PKIIKP's observed from antipodal paths from Tonga to Morocco. The correlation of this bright spot in the PKIIKP reflection with a thin zone of low P velocity identified from multi-pathed PKIKP waves sampling a portion of the equatorial eastern hemisphere2suggests that at least this region of the inner core is near its melting temperature. Waveform modeling of PKIKP and PKIIKP from the combined effects of viscoelasticity and forward scattering is performed to determine whether this region of low shear modulus is consistent with freezing or melting. 1Martorell, B., L. Vocadlo, J.P. Brodholt, and I.G.Wood, (2013) Science, 342 (6157), doi: 10.1126/science.1243651. 2Stroujkova, A., and V.F. Cormier (2004), J. Geophys. Res., 109(B10), doi:10.1029/2004JB002976.

A novel approach to measure elemental concentrations in cation exchange resins using XRF-scanning technique, and its potential in water pollution studies

NASA Astrophysics Data System (ADS)

Huang, Jyh-Jaan; Lin, Sheng-Chi; Löwemark, Ludvig; Liou, Ya-Hsuan; Chang, Queenie; Chang, Tsun-Kuo; Wei, Kuo-Yen; Croudace, Ian W.

2016-04-01

X-ray fluorescence (XRF) core-scanning is a fast, and convenient technique to assess elemental variations for a wide variety of research topics. However, the XRF scanning counts are often considered a semi-quantitative measurement due to possible absorption or scattering caused by down core variability in physical properties. To overcome this problem and extend the applications of XRF-scanning to water pollution studies, we propose to use cation exchange resin (IR-120) as an "elemental carrier", and to analyze the resins using the Itrax-XRF core scanner. The use of resin minimizes the matrix effects during the measurements, and can be employed in the field in great numbers due to its low price. Therefore, the fast, and non-destructive XRF-scanning technique can provide a quick and economical method to analyze environmental pollution via absorption in the resin. Five standard resin samples were scanned by the Itrax-XRF core scanner at different exposure times (1 s, 5 s, 15 s, 30 s, 100 s) to allow the comparisons of scanning counts with the absolute concentrations. The regression lines and correlation coefficients of elements that are generally used in pollution studies (Ca, Ti, Cr, Ni, Cu, Zn, and Pb) were examined for the different exposure times. The result shows that within the test range (from few ppm to thousands ppm), the correlation coefficients are all higher than 0.97, even at the shortest exposure time (1 s). Therefore, we propose to use this method in the field to monitor for example sewage disposal events. The low price of resin, and fast, multi elements and precise XRF-scanning technique provide a viable, cost- and time-effective approach that allows large sample numbers to be processed. In this way, the properties and sources of wastewater pollution can be traced for the purpose of environmental monitoring and environmental forensics.

Core executive functions are associated with success in young elite soccer players.

PubMed

Vestberg, Torbjörn; Reinebo, Gustaf; Maurex, Liselotte; Ingvar, Martin; Petrovic, Predrag

2017-01-01

Physical capacity and coordination cannot alone predict success in team sports such as soccer. Instead, more focus has been directed towards the importance of cognitive abilities, and it has been suggested that executive functions (EF) are fundamentally important for success in soccer. However, executive functions are going through a steep development from adolescence to adulthood. Moreover, more complex EF involving manipulation of information (higher level EF) develop later than simple executive functions such as those linked to simple working memory capacity (Core EF). The link between EF and success in young soccer players is therefore not obvious. In the present study we investigated whether EF are associated with success in soccer in young elite soccer players. We performed tests measuring core EF (a demanding working memory task involving a variable n-back task; dWM) and higher level EF (Design Fluency test; DF). Color-Word Interference Test and Trail Making Test were performed on an exploratory level as they contain a linguistic element. The lower level EF test (dWM) was taken from CogStateSport computerized concussion testing and the higher level EF test (DF) was from Delis-Kaplan Executive Function System test battery (D-KEFS). In a group of young elite soccer players (n = 30; aged 12-19 years) we show that they perform better than the norm in both the dWM (+0.49 SD) and DF (+0.86 SD). Moreover, we could show that both dWM and DF correlate with the number of goals the players perform during the season. The effect was more prominent for dWM (r = 0.437) than for DF (r = 0.349), but strongest for a combined measurement (r = 0.550). The effect was still present when we controlled for intelligence, length and age in a partial correlation analysis. Thus, our study suggests that both core and higher level EF may predict success in soccer also in young players.

Core executive functions are associated with success in young elite soccer players

PubMed Central

Reinebo, Gustaf; Maurex, Liselotte; Ingvar, Martin; Petrovic, Predrag

2017-01-01

Physical capacity and coordination cannot alone predict success in team sports such as soccer. Instead, more focus has been directed towards the importance of cognitive abilities, and it has been suggested that executive functions (EF) are fundamentally important for success in soccer. However, executive functions are going through a steep development from adolescence to adulthood. Moreover, more complex EF involving manipulation of information (higher level EF) develop later than simple executive functions such as those linked to simple working memory capacity (Core EF). The link between EF and success in young soccer players is therefore not obvious. In the present study we investigated whether EF are associated with success in soccer in young elite soccer players. We performed tests measuring core EF (a demanding working memory task involving a variable n-back task; dWM) and higher level EF (Design Fluency test; DF). Color-Word Interference Test and Trail Making Test were performed on an exploratory level as they contain a linguistic element. The lower level EF test (dWM) was taken from CogStateSport computerized concussion testing and the higher level EF test (DF) was from Delis-Kaplan Executive Function System test battery (D-KEFS). In a group of young elite soccer players (n = 30; aged 12–19 years) we show that they perform better than the norm in both the dWM (+0.49 SD) and DF (+0.86 SD). Moreover, we could show that both dWM and DF correlate with the number of goals the players perform during the season. The effect was more prominent for dWM (r = 0.437) than for DF (r = 0.349), but strongest for a combined measurement (r = 0.550). The effect was still present when we controlled for intelligence, length and age in a partial correlation analysis. Thus, our study suggests that both core and higher level EF may predict success in soccer also in young players. PMID:28178738

Clinical relevance of total HCV core antigen testing for hepatitis C monitoring and for predicting patients' response to therapy.

PubMed

Maynard, M; Pradat, P; Berthillon, P; Picchio, G; Voirin, N; Martinot, M; Marcellin, P; Trepo, C

2003-07-01

To study the correlation between total Hepatitis C virus (HCV) Core antigen (Ag) and HCV-RNA, and to assess the proficiency of HCV Core Ag testing in monitoring and predicting virologic response during and after pegylated interferon (PEG-IFN) and ribavirin combination therapy. A total of 307 samples from treated and untreated patients were used to assess the correlation between the total HCV Core Ag test and quantitative HCV-RNA assays (Superquant, and Quantiplex branched DNA 2.0 assay). Twenty-four patients received combination therapy for 48 weeks. Blood samples were collected at day 0, and week 2, 4, 12, 24, 48 and 72 for virologic evaluation. A linear relation exists between total HCV Core Ag and HCV-RNA levels. At 3 months the positive predictive value (PPV) of response to therapy was 100% with either HCV Core Ag or HCV-RNA. For HCV Core Ag the negative predictive value (NPV) was 100% whereas for HCV-RNA the NPV was 80% (P > 0.05). At month 1, the PPV was 95% and 100% when determined by HCV Core Ag and HCV-RNA, respectively. The NPV value was 100% for HCV Core Ag and 33% for HCV-RNA (P = 0.005). HCV Core Ag quantification could be useful in clinical practice to predict a sustained virological response early during therapy (4 weeks), reaching an optimal performance at month 3. The determination of total HCV Core Ag levels in serum, constitutes an accurate and reliable alternative to HCV-RNA for monitoring and predicting treatment outcome in patients receiving PEG-IFN/Ribavirin combination therapy.

Constraints on the coupled thermal evolution of the Earth's core and mantle, the age of the inner core, and the origin of the 186Os/188Os “core signal” in plume-derived lavas

NASA Astrophysics Data System (ADS)

Lassiter, J. C.

2006-10-01

The possibility that some mantle plumes may carry a geochemical signature of core/mantle interaction has rightly generated considerable interest and attention in recent years. Correlated 186Os- 187Os enrichments in some plume-derived lavas (Hawaii, Gorgona, Kostomuksha) have been interpreted as deriving from an outer core with elevated Pt/Os and Re/Os ratios due to the solidification of the Earth's inner core (c.f., [A.D. Brandon, R.J. Walker, The debate over core-mantle interaction, Earth Planet. Sci. Lett. 232 (2005) 211-225.] and references therein). Conclusive identification of a "core signal" in plume-derived lavas would profoundly influence our understanding of mantle convection and evolution. This paper reevaluates the Os-isotope evidence for core/mantle interaction by examining other geochemical constraints on core/mantle interaction, geophysical constraints on the thermal evolution of the outer core, and geochemical and cosmochemical constraints on the abundance of heat-producing elements in the core. Additional study of metal/silicate and sulfide/silicate partitioning of K, Pb, and other trace elements is needed to more tightly constrain the likely starting composition of the Earth's core. However, available data suggest that the observed 186Os enrichments in Hawaiian and other plume-derived lavas are unlikely to derive from core/mantle interaction. 1) Core/mantle interaction sufficient to produce the observed 186Os enrichments would likely have significant effects on other tracers such as Pb- and W-isotopes that are not observed. 2) Significant partitioning of K or other heat-producing elements into the core would produce a "core depletion" pattern in the Silicate Earth very different from that observed. 3) In the absence of heat-producing elements in the core, core/mantle heat flow of ˜ 6-15 TW estimated from several independent geophysical constraints suggests an inner core age (< ˜ 2.5 Ga) too young for the outer core to have developed a significant 186Os enrichment. Core/mantle thermal and chemical interaction remains an important problem that warrants future research. However, Os-isotopes may have only limited utility in this area due to the relatively young age of the Earth's inner core.

Effect of Plasterboard Composition on Stachybotrys chartarum Growth and Biological Activity of Spores

PubMed Central

Murtoniemi, Timo; Nevalainen, Aino; Hirvonen, Maija-Riitta

2003-01-01

The effects of plasterboard composition on the growth and sporulation of Stachybotrys chartarum as well as on the inflammatory potential of the spores were studied. S. chartarum was grown on 13 modified plasterboards under saturated humidity conditions. The biomass was estimated by measuring the ergosterol content of the S. chartarum culture while the spore-induced cytotoxicity and production of nitric oxide (NO), tumor necrosis factor alpha (TNF-α), and interleukin-6 in mouse macrophages was used to illustrate the bioactivity of spores. The ergosterol content of S. chartarum correlated with the number of spores collected from plasterboards. The growth and sporulation decreased compared to that of the reference board in those cases where (i) the liner was treated with biocide, (ii) starch was removed from the plasterboard, or (iii) desulfurization gypsum was used in the core. Spores collected from all the plasterboards were toxic to the macrophages. The biocide added to the core did not reduce the growth; in fact, the spores collected from that board evoked the highest cytotoxicity. The conventional additives used in the core had inhibitory effects on growth. Recycled plasterboards used in the core and the board lacking the starch triggered spore-induced TNF-α production in macrophages. In summary, this study shows that the growth of a strain of S. chartarum on plasterboard and the subsequent bioactivity of spores were affected by minor changes to the composition of the core or liners, but it could not be totally prevented without resorting to the use of biocides. However, incomplete prevention of microbial growth by biocides even increased the cytotoxic potential of the spores. PMID:12839740

The dipole moment surface for hydrogen sulfide H2S

NASA Astrophysics Data System (ADS)

Azzam, Ala`a. A. A.; Lodi, Lorenzo; Yurchenko, Sergey N.; Tennyson, Jonathan

2015-08-01

In this work we perform a systematic ab initio study of the dipole moment surface (DMS) of H2S at various levels of theory and of its effect on the intensities of vibration-rotation transitions; H2S intensities are known from the experiment to display anomalies which have so far been difficult to reproduce by theoretical calculations. We use the transition intensities from the HITRAN database of 14 vibrational bands for our comparisons. The intensities of all fundamental bands show strong sensitivity to the ab initio method used for constructing the DMS while hot, overtone and combination bands up to 4000 cm-1 do not. The core-correlation and relativistic effects are found to be important for computed line intensities, for instance affecting the most intense fundamental band (ν2) by about 20%. Our recommended DMS, called ALYT2, is based on the CCSD(T)/aug-cc-pV(6+d)Z level of theory supplemented by a core-correlation/relativistic corrective surface obtained at the CCSD[T]/aug-cc-pCV5Z-DK level. The corresponding computed intensities agree significantly better (to within 10%) with experimental data taken directly from original papers. Worse agreement (differences of about 25%) is found for those HITRAN intensities obtained from fitted effective dipole models, suggesting the presence of underlying problems in those fits.

Estimating Antarctic Near-Surface Magnetic Anomalies from Oersted and CHAMP Satellite Magnetometer Observations

NASA Technical Reports Server (NTRS)

vonFrese, Ralph R. B.; Kim, Hyung Rae; Gaya-Pique, Luis R.; Taylor, Patrick T.; Golynsky, Alexander V.; Kim, Jeong Woo

2004-01-01

Significant improvement in predicting near-surface magnetic anomalies can result from the highly accurate magnetic observations of the CHAMP satellite that is orbiting at about 400 km altitude. In general, regional magnetic signals of the crust are strongly masked by the core field and its secular variations due to wavelength coupling in the spherical harmonic representation and thus are difficult to isolate in the satellite measurements. However, efforts to isolate the regional lithospheric from core field components can exploit the correlations between the CHAMP magnetic anomalies and the pseudo magnetic effects inferred from gravity-derived crustal thickness variations. In addition, we can use spectral correlation theory to filter the static lithospheric field components from the dynamic external field effects. Employing these procedures, we processed the CHAMP magnetic conservations for an improved magnetic anomaly map of the Antarctic crust. Relative to the much higher altitude Oersted and noisier Magsat observations, CHAMP magnetic anomalies at 400 km altitude reveal new details on the effects of intra-crustal magnetic features and crustal thickness variations of the Antarctic. Moreover, these results greatly facilitate predicting magnetic anomalies in the regional coverage gaps of the ADMAP compilation of Antarctic magnetic anomalies from shipborne, airborne and ground surveys. Our analysis suggests that considerable new insights on the magnetic properties of the lithosphere may be revealed by a further order-of-magnitude improvement in the accuracy of the magnetometer.

Comparison of prestellar core elongations and large-scale molecular cloud structures in the Lupus I region

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

Poidevin, Frédérick; Ade, Peter A. R.; Hargrave, Peter C.

2014-08-10

Turbulence and magnetic fields are expected to be important for regulating molecular cloud formation and evolution. However, their effects on sub-parsec to 100 parsec scales, leading to the formation of starless cores, are not well understood. We investigate the prestellar core structure morphologies obtained from analysis of the Herschel-SPIRE 350 μm maps of the Lupus I cloud. This distribution is first compared on a statistical basis to the large-scale shape of the main filament. We find the distribution of the elongation position angle of the cores to be consistent with a random distribution, which means no specific orientation of themore » morphology of the cores is observed with respect to the mean orientation of the large-scale filament in Lupus I, nor relative to a large-scale bent filament model. This distribution is also compared to the mean orientation of the large-scale magnetic fields probed at 350 μm with the Balloon-borne Large Aperture Telescope for Polarimetry during its 2010 campaign. Here again we do not find any correlation between the core morphology distribution and the average orientation of the magnetic fields on parsec scales. Our main conclusion is that the local filament dynamics—including secondary filaments that often run orthogonally to the primary filament—and possibly small-scale variations in the local magnetic field direction, could be the dominant factors for explaining the final orientation of each core.« less

The convergence of European business cycles 1978-2000

NASA Astrophysics Data System (ADS)

Ormerod, Paul; Mounfield, Craig

2002-05-01

The degree of convergence of the business cycles of the economies of the European Union (EU) is a key policy issue. In particular, a substantial degree of convergence is needed if the European Central Bank is to be capable of setting a monetary policy which is appropriate to the stage of the cycle of the Euro zone economies. We consider the annual rates of real GDP growth on a quarterly basis in the large core economies of the EU (France, Germany and Italy, plus The Netherlands) over the period 1978Q1-2000Q3. An important empirical question is the degree to which the correlations between these growth rates contain true information rather than noise. The technique of random matrix theory is able to answer this question, and has been recently applied successfully in the physics journals to financial markets data. We find that the correlations between the growth rates of the core EU economies contain substantial amounts of true information, and exhibit considerable stability over time. Even in the late 1970s and early 1980s, these economies moved together closely over the course of the business cycle. There was a slight loosening at the time of German re-unification, but the economies are now, if anything, even more closely correlated. As a benchmark for comparison, we add a series to the EU core data set which by construction is uncorrelated with these business cycles. We then analyse the EU core plus Spain, a country which has attached great importance to greater integration with Europe. In the early part of the period examined, the results are very similar to those obtained with the data set of the EU core plus the random series. However, there is a clear trend in the results, which provide strong evidence to support the view that the Spanish economy has now become closely converged with the core EU economies in terms of its movements over the business cycle. In contrast, the results obtained with a data set of the EU core plus the UK show no such trend. In the late 1970s and early 1980s, the UK economy did exhibit some degree of correlation with those of the core EU. However, there is no clear evidence to suggest that the UK business cycle has moved more closely into line with that of the core EU economies over the 1978-2000 period.

Radio core dominance of Fermi blazars

NASA Astrophysics Data System (ADS)

Pei, Zhi-Yuan; Fan, Jun-Hui; Liu, Yi; Yuan, Yi-Hai; Cai, Wei; Xiao, Hu-Bing; Lin, Chao; Yang, Jiang-He

2016-07-01

During the first 4 years of mission, Fermi/LAT detected 1444 blazars (3FGL) (Ackermann et al. in Astrophys. J. 810:14, 2015). Fermi/LAT observations of blazars indicate that Fermi blazars are luminous and strongly variable with variability time scales, for some cases, as short as hours. Those observations suggest a strong beaming effect in Fermi/LAT blazars. In the present work, we will investigate the beaming effect in Fermi/LAT blazars using a core-dominance parameter, R = S_{core}/ S_{ext.}, where S_{core} is the core emission, while S_{ext.} is the extended emission. We compiled 1335 blazars with available core-dominance parameter, out of which 169 blazars have γ-ray emission (from 3FGL). We compared the core-dominance parameters, log R, between the 169 Fermi-detected blazars (FDBs) and the rest non-Fermi-detected blazars (non-FDBs), and we found that the averaged values are < log Rrangle = 0.99±0.87 for FDBs and < log Rrangle = -0.62±1.15 for the non-FDBs. A K-S test shows that the probability for the two distributions of FDBs and non-FDBs to come from the same parent distribution is near zero (P =9.12×10^{-52}). Secondly, we also investigated the variability index (V.I.) in the γ-ray band for FDBs, and we found V.I.=(0.12 ±0.07) log R+(2.25±0.10), suggesting that a source with larger log R has larger V.I. value. Thirdly, we compared the mean values of radio spectral index for FDBs and non-FDBs, and we obtained < α_{radio}rangle =0.06±0.35 for FDBs and < α_{radio}rangle =0.57±0.46 for non-FDBs. If γ-rays are composed of two components like radio emission (core and extended components), then we can expect a correlation between log R and the γ-ray spectral index. When we used the radio core-dominance parameter, log R, to investigate the relationship, we found that the spectral index for the core component is α_{γ}|_{core} = 1.11 (a photon spectral index of α_{γ}^{ph}|_{core} = 2.11) and that for the extended component is α_{γ}|_{ext.} = 0.70 (a photon spectral index of α_{γ}^{ph}|_{ext.} = 1.70). Some discussions are also presented.

Earth Core and Inner Core: What Can We Learn From a Bayesian Inversion of Combined Nutation and Surface Gravimetry Data?

NASA Astrophysics Data System (ADS)

Lambert, S. B.; Ziegler, Y.; Rosat, S.; Bizouard, C.

2017-12-01

Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the results of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by several analysis centers affiliated to the International VLBI Service for Geodesy and Astrometry, together with surface gravity data from about 15 SG stations. We address the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting to nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package. New estimates of the resonant periods are proposed and correlations between the parameters are investigated.

Combining nutation and surface gravity observations to estimate the Earth's core and inner core resonant frequencies

NASA Astrophysics Data System (ADS)

Ziegler, Yann; Lambert, Sébastien; Rosat, Séverine; Nurul Huda, Ibnu; Bizouard, Christian

2017-04-01

Nutation time series derived from very long baseline interferometry (VLBI) and time varying surface gravity data recorded by superconducting gravimeters (SG) have long been used separately to assess the Earth's interior via the estimation of the free core and inner core resonance effects on nutation or tidal gravity. The results obtained from these two techniques have been shown recently to be consistent, making relevant the combination of VLBI and SG observables and the estimation of Earth's interior parameters in a single inversion. We present here the intermediate results of the ongoing project of combining nutation and surface gravity time series to improve estimates of the Earth's core and inner core resonant frequencies. We use VLBI nutation time series spanning 1984-2016 derived by the International VLBI Service for geodesy and astrometry (IVS) as the result of a combination of inputs from various IVS analysis centers, and surface gravity data from about 15 SG stations. We address here the resonance model used for describing the Earth's interior response to tidal excitation, the data preparation consisting of the error recalibration and amplitude fitting for nutation data, and processing of SG time-varying gravity to remove any gaps, spikes, steps and other disturbances, followed by the tidal analysis with the ETERNA 3.4 software package, the preliminary estimates of the resonant periods, and the correlations between parameters.

Accurate thermochemistry and spectroscopy of the oxygen-protonated sulfur dioxide isomers.

PubMed

Puzzarini, Cristina

2011-12-28

Despite the promising relevance of protonated sulfur dioxide in astrophysical and atmospheric fields, its thermochemical and spectroscopic characterization is very limited. High-level quantum-chemical calculations have shown that the most stable isomer is the cis oxygen-protonated sulfur dioxide, HOSO(+), while the trans form is about 2 kcal mol(-1) less stable; even less stable (by about 42 kcal mol(-1)) is the S-protonated isomer [V. Lattanzi et al., J. Chem. Phys., 2010, 133, 194305]. The enthalpy of formation for the cis- and trans-HOSO(+) is presented, based on the well tested HEAT protocol [A. Tajti et al., J. Chem. Phys., 2004, 121, 11599]. Systematically extrapolated ab initio energies, accounting for electron correlation through coupled cluster theory, including up to single, double, triple and quadruple excitations, have been corrected for core-electron correlation, anharmonic zero-point vibrational energy, diagonal Born-Oppenheimer and scalar relativistic effects. As a byproduct, proton affinity of sulfur dioxide and atomization energies have also been obtained at the same levels of theory. Vibrational and rotational spectroscopic properties have been investigated by means of composite schemes that allow us to account for truncation of basis set as well as core correlation. Where available, for both thermochemistry and spectroscopy, very good agreement with experimental data has been observed.

Effect of nucleoside analogue antimetabolites on the structure of PEO–PPO–PEO micelles investigated by SANS

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

Han, Youngkyu; Zhang, Zhe; Smith, Gregory S.

2017-01-01

The effect of three nucleoside analogue antimetabolites (5-fluorouracil, floxuridine, and gemcitabine) on the structure of Pluronic L62 copolymer micelles was investigated using small-angle neutron scattering. These antimetabolites used for cancer chemotherapy have analogous molecular structures but different molecular sizes and aqueous solubilities. It was found that the addition of the three antimetabolites slightly reduced the micellar size and aggregation number, and the micellar anisotropy. The added antimetabolites also changed the internal molecular distribution of the micelles as measured by the scattering length densities, resulting in enhanced hydration of the hydrophobic core region of the micelle. The strength of the effectmore » was found to correlate with the molecular properties of the model drugs, i.e. a larger molecular size and a higher aqueous solubility lead to enhanced hydration of the micellar core.« less

Climatic records of the last and penultimate deglaciations in the South Atlantic and South Indian Ocean

NASA Astrophysics Data System (ADS)

Michel, Elisabeth; Waelbroeck, Claire; Govin, Aline; Skinner, Luke; Vàzquez Riveiros, Natalia; Dewilde, Fabien; Isguder, Gulay; Rebaubier, Hélène

2013-04-01

Surface and deep-water records of Termination I and II in two twin South Atlantic deep-sea cores (44°09' S, 14°14' W, 3770 m depth) and one South Indian core (46°29' S, 88°01' E, 3420 m depth) are presented. Sea surface temperature has been reconstructed based on planktonic foraminifera census counts in all cases, as well as Mg/Ca of G. bulloides and N. pachyderma s. over the last deglaciation. The uncertainty on reconstructed SST using different statistical methods and different faunal databases is assessed. Over the last deglaciation, combined 14C dating and correlation of the SST record with the air temperature signal recorded in Antarctic ice cores allowed us to correct for variable surface reservoir ages in the South Atlantic core (Skinner et al., 2010). Preliminary dating of the South Indian core over the last termination has been done by correlation of its magnetic signal with those of a neighboring 14C dated core (Smart et al., 2010). We have refined the later age scale using the Atlantic core age scale as reference. Benthic isotopic signals in the South Atlantic and South Indian cores over the last deglaciation exhibit the same amplitude and timing. Our results thus indicate that bottom waters at the South Indian site remained isolated from better ventilated deep waters of northern origin until ~15 ka (Waelbroeck et al., 2011). Over Termination II, the two cores have been dated by correlation of their SST records with the air temperature signal recorded in EDC versus the EDC3 age scale (Govin et al., 2009; 2012). A careful examination of the various sources of uncertainty on the derived dating has been performed. Benthic and planktonic isotopic signals reveal analogies but also differences with respect to the last termination. SST was significantly warmer during the Last Interglacial than during the Holocene in both sites. South Atlantic deep waters were also significantly better ventilated during the Last Interglacial than during the Holocene, whereas bottom water ventilation was similar during these two interglacials at the South Indian site.

Zircon, titanite, and apatite (U-Th)/He ages and age-eU correlations from the Fennoscandian Shield, southern Sweden

NASA Astrophysics Data System (ADS)

Guenthner, William R.; Reiners, Peter W.; Drake, Henrik; Tillberg, Mikael

2017-07-01

Craton cores far from plate boundaries have traditionally been viewed as stable features that experience minimal vertical motion over 100-1000 Ma time scales. Here we show that the Fennoscandian Shield in southeastern Sweden experienced several episodes of burial and exhumation from 1800 Ma to the present. Apatite, titanite, and zircon (U-Th)/He ages from surface samples and drill cores constrain the long-term, low-temperature history of the Laxemar region. Single grain titanite and zircon (U-Th)/He ages are negatively correlated (104-838 Ma for zircon and 160-945 Ma for titanite) with effective uranium (eU = U + 0.235 × Th), a measurement proportional to radiation damage. Apatite ages are 102-258 Ma and are positively correlated with eU. These correlations are interpreted with damage-diffusivity models, and the modeled zircon He age-eU correlations constrain multiple episodes of heating and cooling from 1800 Ma to the present, which we interpret in the context of foreland basin systems related to the Neoproterozoic Sveconorwegian and Paleozoic Caledonian orogens. Inverse time-temperature models constrain an average burial temperature of 217°C during the Sveconorwegian, achieved between 944 Ma and 851 Ma, and 154°C during the Caledonian, achieved between 366 Ma and 224 Ma. Subsequent cooling to near-surface temperatures in both cases could be related to long-term exhumation caused by either postorogenic collapse or mantle dynamics related to the final assembly of Rodinia and Pangaea. Our titanite He age-eU correlations cannot currently be interpreted in the same fashion; however, this study represents one of the first examples of a damage-diffusivity relationship in this system, which deserves further research attention.

Strong Neutron Pairing in core+4n Nuclei.

PubMed

Revel, A; Marqués, F M; Sorlin, O; Aumann, T; Caesar, C; Holl, M; Panin, V; Vandebrouck, M; Wamers, F; Alvarez-Pol, H; Atar, L; Avdeichikov, V; Beceiro-Novo, S; Bemmerer, D; Benlliure, J; Bertulani, C A; Boillos, J M; Boretzky, K; Borge, M J G; Caamaño, M; Casarejos, E; Catford, W N; Cederkäll, J; Chartier, M; Chulkov, L; Cortina-Gil, D; Cravo, E; Crespo, R; Datta Pramanik, U; Díaz Fernández, P; Dillmann, I; Elekes, Z; Enders, J; Ershova, O; Estradé, A; Farinon, F; Fraile, L M; Freer, M; Galaviz, D; Geissel, H; Gernhäuser, R; Golubev, P; Göbel, K; Hagdahl, J; Heftrich, T; Heil, M; Heine, M; Heinz, A; Henriques, A; Ignatov, A; Johansson, H T; Jonson, B; Kahlbow, J; Kalantar-Nayestanaki, N; Kanungo, R; Kelic-Heil, A; Knyazev, A; Kröll, T; Kurz, N; Labiche, M; Langer, C; Le Bleis, T; Lemmon, R; Lindberg, S; Machado, J; Marganiec, J; Movsesyan, A; Nacher, E; Najafi, M; Nilsson, T; Nociforo, C; Paschalis, S; Perea, A; Petri, M; Pietri, S; Plag, R; Reifarth, R; Ribeiro, G; Rigollet, C; Röder, M; Rossi, D; Savran, D; Scheit, H; Simon, H; Syndikus, I; Taylor, J T; Tengblad, O; Thies, R; Togano, Y; Velho, P; Volkov, V; Wagner, A; Weick, H; Wheldon, C; Wilson, G; Winfield, J S; Woods, P; Yakorev, D; Zhukov, M; Zilges, A; Zuber, K

2018-04-13

The emission of neutron pairs from the neutron-rich N=12 isotones ^{18}C and ^{20}O has been studied by high-energy nucleon knockout from ^{19}N and ^{21}O secondary beams, populating unbound states of the two isotones up to 15 MeV above their two-neutron emission thresholds. The analysis of triple fragment-n-n correlations shows that the decay ^{19}N(-1p)^{18}C^{*}→^{16}C+n+n is clearly dominated by direct pair emission. The two-neutron correlation strength, the largest ever observed, suggests the predominance of a ^{14}C core surrounded by four valence neutrons arranged in strongly correlated pairs. On the other hand, a significant competition of a sequential branch is found in the decay ^{21}O(-1n)^{20}O^{*}→^{18}O+n+n, attributed to its formation through the knockout of a deeply bound neutron that breaks the ^{16}O core and reduces the number of pairs.

In-flight flow visualization with pressure measurements at low speeds on the NASA F-18 high alpha research vehicle

NASA Technical Reports Server (NTRS)

Delfrate, John H.; Fisher, David F.; Zuniga, Fanny A.

1990-01-01

In-flight results from surface and off-surface flow visualizations and from extensive pressure distributions document the vortical flow on the leading edge extensions (LEX) and forebody of the NASA F-18 high alpha research vehicle for low speeds and angles of attack up to 50 degs. Surface flow visualization data, obtained using the emitted fluid technique, were used to define separation lines and laminar separation bubbles. Off-surface flow visualization data, obtained by smoke injection, were used to document both the path of the vortex cores and the location of vortex core breakdown. The location of vortex core breakdown correlated well with the loss of suction pressure on the LEX and with the flow visualization results from ground facilities. Surface flow separation lines on the LEX and forebody corresponded well with the end of pressure recovery under the vortical flows. Correlation of the pressures with wind tunnel results show fair to good correlation.

Thermodynamic properties of arsenic compounds and the heat of formation of the As atom from high level electronic structure calculations.

PubMed

Feller, David; Vasiliu, Monica; Grant, Daniel J; Dixon, David A

2011-12-29

Structures, vibrational frequencies, atomization energies at 0 K, and heats of formation at 0 and 298 K are predicted for the compounds As(2), AsH, AsH(2), AsH(3), AsF, AsF(2), and AsF(3) from frozen core coupled cluster theory calculations performed with large correlation consistent basis sets, up through augmented sextuple zeta quality. The coupled cluster calculations involved up through quadruple excitations. For As(2) and the hydrides, it was also possible to examine the impact of full configuration interaction on some of the properties. In addition, adjustments were incorporated to account for extrapolation to the frozen core complete basis set limit, core/valence correlation, scalar relativistic effects, the diagonal Born-Oppenheimer correction, and atomic spin orbit corrections. Based on our best theoretical D(0)(As(2)) and the experimental heat of formation of As(2), we propose a revised 0 K arsenic atomic heat of formation of 68.86 ± 0.8 kcal/mol. While generally good agreement was found between theory and experiment, the heat of formation of AsF(3) was an exception. Our best estimate is more than 7 kcal/mol more negative than the single available experimental value, which argues for a re-examination of that measurement. © 2011 American Chemical Society

Minimum daily core body temperature in western grey kangaroos decreases as summer advances: a seasonal pattern, or a direct response to water, heat or energy supply?

PubMed

Maloney, Shane K; Fuller, Andrea; Meyer, Leith C R; Kamerman, Peter R; Mitchell, Graham; Mitchell, Duncan

2011-06-01

Using implanted temperature loggers, we measured core body temperature in nine western grey kangaroos every 5 min for 24 to 98 days in spring and summer. Body temperature was highest at night and decreased rapidly early in the morning, reaching a nadir at 10:00 h, after ambient temperature and solar radiation had begun to increase. On hotter days, the minimum morning body temperature was lower than on cooler days, decreasing from a mean of 36.2°C in the spring to 34.0°C in the summer. This effect correlated better with the time of the year than with proximate thermal stressors, suggesting that either season itself or some factor correlated with season, such as food availability, caused the change. Water saving has been proposed as a selective advantage of heterothermy in other large mammals, but in kangaroos the water savings would have been small and not required in a reserve with permanent standing water. We calculate that the lower core temperature could provide energy savings of nearly 7%. It is likely that the heterothermy that we observed on hot days results either from decreased energy intake during the dry season or from a seasonal pattern entrained in the kangaroos that presumably has been selected for because of decreased energy availability during the dry season.

Core stability exercise is as effective as task-oriented motor training in improving motor proficiency in children with developmental coordination disorder: a randomized controlled pilot study.

PubMed

Au, Mei K; Chan, Wai M; Lee, Lin; Chen, Tracy Mk; Chau, Rosanna Mw; Pang, Marco Yc

2014-10-01

To compare the effectiveness of a core stability program with a task-oriented motor training program in improving motor proficiency in children with developmental coordination disorder (DCD). Randomized controlled pilot trial. Outpatient unit in a hospital. Twenty-two children diagnosed with DCD aged 6-9 years were randomly allocated to the core stability program or the task-oriented motor program. Both groups underwent their respective face-to-face training session once per week for eight consecutive weeks. They were also instructed to carry out home exercises on a daily basis during the intervention period. Short Form of the Bruininks-Oseretsky Test of Motor Proficiency (Second Edition) and Sensory Organization Test at pre- and post-intervention. Intention-to-treat analysis revealed no significant between-group difference in the change of motor proficiency standard score (P=0.717), and composite equilibrium score derived from the Sensory Organization Test (P=0.100). Further analysis showed significant improvement in motor proficiency in both the core stability (mean change (SD)=6.3(5.4); p=0.008) and task-oriented training groups (mean change(SD)=5.1(4.0); P=0.007). The composite equilibrium score was significantly increased in the task-oriented training group (mean change (SD)=6.0(5.5); P=0.009), but not in the core stability group (mean change(SD) =0.0(9.6); P=0.812). In the task-oriented training group, compliance with the home program was positively correlated with change in motor proficiency (ρ=0.680, P=0.030) and composite equilibrium score (ρ=0.638, P=0.047). The core stability exercise program is as effective as task-oriented training in improving motor proficiency among children with DCD. © The Author(s) 2014.

Primary atomization of liquid jets issuing from rocket engine coaxial injectors

NASA Astrophysics Data System (ADS)

Woodward, Roger D.

1993-01-01

The investigation of liquid jet breakup and spray development is critical to the understanding of combustion phenomena in liquid-propellant rocket engines. Much work has been done to characterize low-speed liquid jet breakup and dilute sprays, but atomizing jets and dense sprays have yielded few quantitative measurements due to their optical opacity. This work focuses on a characteristic of the primary breakup process of round liquid jets, namely the length of the intact liquid core. The specific application considered is that of shear-coaxial type rocket engine injectors. Real-time x-ray radiography, capable of imaging through the dense two-phase region surrounding the liquid core, has been used to make the measurements. Nitrogen and helium were employed as the fuel simulants while an x-ray absorbing potassium iodide aqueous solution was used as the liquid oxygen (LOX) simulant. The intact-liquid-core length data have been obtained and interpreted to illustrate the effects of chamber pressure (gas density), injected-gas and liquid velocities, and cavitation. The results clearly show that the effect of cavitation must be considered at low chamber pressures since it can be the dominant breakup mechanism. A correlation of intact core length in terms of gas-to-liquid density ratio, liquid jet Reynolds number, and Weber number is suggested. The gas-to-liquid density ratio appears to be the key parameter for aerodynamic shear breakup in this study. A small number of hot-fire, LOX/hydrogen tests were also conducted to attempt intact-LOX-core measurements under realistic conditions in a single-coaxial-element rocket engine. The tests were not successful in terms of measuring the intact core, but instantaneous imaging of LOX jets suggests that LOX jet breakup is qualitatively similar to that of cold-flow, propellant-simulant jets. The liquid oxygen jets survived in the hot-fire environment much longer than expected, and LOX was even visualized exiting the chamber nozzle under some conditions. This may be an effect of the single element configuration.

Core courses in public health laboratory science and practice: findings from 2006 and 2011 surveys.

PubMed

DeBoy, John M; Beck, Angela J; Boulton, Matthew L; Kim, Deborah H; Wichman, Michael D; Luedtke, Patrick F

2013-01-01

We identified academic training courses or topics most important to the careers of U.S. public health, environmental, and agricultural laboratory (PHEAL) scientist-managers and directors, and determined what portions of the national PHEAL workforce completed these courses. We conducted electronic national surveys in 2006 and 2011, and analyzed data using numerical ranking, Chi-square tests comparing rates, and Spearman's formula measuring rank correlation. In 2006, 40 of 50 PHEAL directors identified 56 course topics as either important, useful, or not needed for someone in their position. These course topics were then ranked to provide a list of 31 core courses. In 2011, 1,659 of approximately 5,555 PHEAL scientific and technical staff, using a subset of 25 core courses, evidenced higher core course completion rates associated with higher-level job classification, advanced academic degree, and age. The 2011 survey showed that 287 PHEAL scientist-managers and directors, on average, completed 37.7% (n=5/13) of leadership/managerial core courses and 51.7% (n=6/12) of scientific core courses. For 1,659 laboratorians in all scientific and technical classifications, core-subject completion rates were higher in local laboratories (42.8%, n=11/25) than in state (36.0%, n=9/25), federal (34.4%, n=9/25), and university (31.2%, n=8/25) laboratories. There is a definable range of scientific, leadership, and managerial core courses needed by PHEAL scientist-managers and directors to function effectively in their positions. Potential PHEAL scientist-managers and directors need greater and continuing access to these courses, and academic and practice entities supporting development of this workforce should adopt curricula and core competencies aligned with these course topics.

Core Courses in Public Health Laboratory Science and Practice: Findings from 2006 and 2011 Surveys

PubMed Central

Beck, Angela J.; Boulton, Matthew L.; Kim, Deborah H.; Wichman, Michael D.; Luedtke, Patrick F.

2013-01-01

Objectives We identified academic training courses or topics most important to the careers of U.S. public health, environmental, and agricultural laboratory (PHEAL) scientist-managers and directors, and determined what portions of the national PHEAL workforce completed these courses. Methods We conducted electronic national surveys in 2006 and 2011, and analyzed data using numerical ranking, Chi-square tests comparing rates, and Spearman's formula measuring rank correlation. Results In 2006, 40 of 50 PHEAL directors identified 56 course topics as either important, useful, or not needed for someone in their position. These course topics were then ranked to provide a list of 31 core courses. In 2011, 1,659 of approximately 5,555 PHEAL scientific and technical staff, using a subset of 25 core courses, evidenced higher core course completion rates associated with higher-level job classification, advanced academic degree, and age. The 2011 survey showed that 287 PHEAL scientist-managers and directors, on average, completed 37.7% (n=5/13) of leadership/managerial core courses and 51.7% (n=6/12) of scientific core courses. For 1,659 laboratorians in all scientific and technical classifications, core-subject completion rates were higher in local laboratories (42.8%, n=11/25) than in state (36.0%, n=9/25), federal (34.4%, n=9/25), and university (31.2%, n=8/25) laboratories. Conclusions There is a definable range of scientific, leadership, and managerial core courses needed by PHEAL scientist-managers and directors to function effectively in their positions. Potential PHEAL scientist-managers and directors need greater and continuing access to these courses, and academic and practice entities supporting development of this workforce should adopt curricula and core competencies aligned with these course topics. PMID:23997310

Correlated colour temperature of morning light influences alertness and body temperature.

PubMed

Te Kulve, Marije; Schlangen, Luc; Schellen, Lisje; Souman, Jan L; van Marken Lichtenbelt, Wouter

2018-03-01

Though several studies have reported human alertness to be affected by the intensity and spectral composition of ambient light, the mechanism behind this effect is still largely unclear, especially for daytime exposure. Alerting effects of nocturnal light exposure are correlated with melatonin suppression, but melatonin levels are generally low during the day. The aim of this study was to explore the alerting effect of light in the morning for different correlated colour temperature (CCT) values, as well as its interaction with ambient temperature. Body temperature and perceived comfort were included in the study as possible mediating factors. In a randomized crossover design, 16 healthy females participated in two sessions, once under 2700K and once under 6500K light (both 55lx). Each session consisted of a baseline, a cool, a neutral and a warm thermal environment. Alertness as measured in a reaction time task was lower for the 6500K exposure, while subjective sleepiness was not affected by CCT. Also, core body temperature was higher under 6500K. Skin temperature parameters and perceived comfort were positively correlated with subjective sleepiness. Reaction time correlated with heat loss, but this association did not explain why the reaction time was improved for 2700K. Copyright © 2017 Elsevier Inc. All rights reserved.

Synergistic effect in carbon coated LiFePO4 for high yield spontaneous grafting of diazonium salt. Structural examination at the grain agglomerate scale.

PubMed

Madec, Lénaïc; Robert, Donatien; Moreau, Philippe; Bayle-Guillemaud, Pascale; Guyomard, Dominique; Gaubicher, Joël

2013-08-07

Molecular grafting of p-nitrobenzene diazonium salt at the surface of (Li)FePO4-based materials was thoroughly investigated. The grafting yields obtained by FTIR, XPS, and elemental analysis for core shell LiFePO4-C are found to be much higher than the sum of those associated with either the LiFePO4 core or the carbon shell alone, thereby revealing a synergistic effect. Electrochemical, XRD, and EELS experiments demonstrate that this effect stems from the strong participation of the LiFePO4 core that delivers large amounts of electrons to the carbon substrate at a constant energy, above the Fermi level of the diazonium salt. Correspondingly large multilayer anisotropic structures that are associated with outstanding grafting yields could be observed from TEM experiments. Results therefore constitute strong evidence of a grafting mechanism where homolytic cleavage of the N2(+) species occurs together with the formation and grafting of radical nitro-aryl intermediates. Although the oxidation and concomitant Li deintercalation of LiFePO4 grains constitute the main driving force of the functionalization reaction, EFTEM EELS mapping shows a striking lack of spatial correlation between grafted grains and oxidized ones.

Some observations of wood density and anatomical properties in a Douglas-fir sample with suppressed growth

Treesearch

J.Y. Zhu; David W. Vahey; C. Tim Scott

2008-01-01

This study used ring width correlations to examine the effects of tree-growth suppression on within-tree local wood density and tracheid anatomical properties. A wood core sample was taken from a 70-yr-old Douglas-fir that grew under various degrees of suppression in a natural forest setting. SilviScan and an imaging technique were used to obtain wood density and...

Development of a three-dimensional core dynamics analysis program for commercial boiling water reactors

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

Bessho, Yasunori; Yokomizo, Osamu; Yoshimoto, Yuichiro

1997-03-01

Development and qualification results are described for a three-dimensional, time-domain core dynamics analysis program for commercial boiling water reactors (BWRs). The program allows analysis of the reactor core with a detailed mesh division, which eliminates calculational ambiguity in the nuclear-thermal-hydraulic stability analysis caused by reactor core regional division. During development, emphasis was placed on high calculational speed and large memory size as attained by the latest supercomputer technology. The program consists of six major modules, namely a core neutronics module, a fuel heat conduction/transfer module, a fuel channel thermal-hydraulic module, an upper plenum/separator module, a feedwater/recirculation flow module, and amore » control system module. Its core neutronics module is based on the modified one-group neutron kinetics equation with the prompt jump approximation and with six delayed neutron precursor groups. The module is used to analyze one fuel bundle of the reactor core with one mesh (region). The fuel heat conduction/transfer module solves the one-dimensional heat conduction equation in the radial direction with ten nodes in the fuel pin. The fuel channel thermal-hydraulic module is based on separated three-equation, two-phase flow equations with the drift flux correlation, and it analyzes one fuel bundle of the reactor core with one channel to evaluate flow redistribution between channels precisely. Thermal margin is evaluated by using the GEXL correlation, for example, in the module.« less

Algebraic perturbation theory for dense liquids with discrete potentials

NASA Astrophysics Data System (ADS)

Adib, Artur B.

2007-06-01

A simple theory for the leading-order correction g1(r) to the structure of a hard-sphere liquid with discrete (e.g., square-well) potential perturbations is proposed. The theory makes use of a general approximation that effectively eliminates four-particle correlations from g1(r) with good accuracy at high densities. For the particular case of discrete perturbations, the remaining three-particle correlations can be modeled with a simple volume-exclusion argument, resulting in an algebraic and surprisingly accurate expression for g1(r) . The structure of a discrete “core-softened” model for liquids with anomalous thermodynamic properties is reproduced as an application.

The effects of graded levels of calorie restriction: VI. Impact of short-term graded calorie restriction on transcriptomic responses of the hypothalamic hunger and circadian signaling pathways.

PubMed

Derous, Davina; Mitchell, Sharon E; Green, Cara L; Chen, Luonan; Han, Jing-Dong J; Wang, Yingchun; Promislow, Daniel E L; Lusseau, David; Speakman, John R; Douglas, Alex

2016-04-01

Food intake and circadian rhythms are regulated by hypothalamic neuropeptides and circulating hormones, which could mediate the anti-ageing effect of calorie restriction (CR). We tested whether these two signaling pathways mediate CR by quantifying hypothalamic transcripts of male C57BL/6 mice exposed to graded levels of CR (10 % to 40 %) for 3 months. We found that the graded CR manipulation resulted in upregulation of core circadian rhythm genes, which correlated negatively with circulating levels of leptin, insulin-like growth factor 1 (IGF-1), insulin, and tumor necrosis factor alpha (TNF-α). In addition, key components in the hunger signaling pathway were expressed in a manner reflecting elevated hunger at greater levels of restriction, and which also correlated negatively with circulating levels of insulin, TNF-α, leptin and IGF-1. Lastly, phenotypes, such as food anticipatory activity and body temperature, were associated with expression levels of both hunger genes and core clock genes. Our results suggest modulation of the hunger and circadian signaling pathways in response to altered levels of circulating hormones, that are themselves downstream of morphological changes resulting from CR treatment, may be important elements in the response to CR, driving some of the key phenotypic outcomes.

The effects of graded levels of calorie restriction: VI. Impact of short-term graded calorie restriction on transcriptomic responses of the hypothalamic hunger and circadian signaling pathways

PubMed Central

Green, Cara L.; Chen, Luonan; Han, Jing‐Dong J.; Wang, Yingchun; Promislow, Daniel E.L.; Lusseau, David; Speakman, John R.; Douglas, Alex

2016-01-01

Food intake and circadian rhythms are regulated by hypothalamic neuropeptides and circulating hormones, which could mediate the anti‐ageing effect of calorie restriction (CR). We tested whether these two signaling pathways mediate CR by quantifying hypothalamic transcripts of male C57BL/6 mice exposed to graded levels of CR (10 % to 40 %) for 3 months. We found that the graded CR manipulation resulted in upregulation of core circadian rhythm genes, which correlated negatively with circulating levels of leptin, insulin‐like growth factor 1 (IGF‐1), insulin, and tumor necrosis factor alpha (TNF‐α). In addition, key components in the hunger signaling pathway were expressed in a manner reflecting elevated hunger at greater levels of restriction, and which also correlated negatively with circulating levels of insulin, TNF‐α, leptin and IGF‐1. Lastly, phenotypes, such as food anticipatory activity and body temperature, were associated with expression levels of both hunger genes and core clock genes. Our results suggest modulation of the hunger and circadian signaling pathways in response to altered levels of circulating hormones, that are themselves downstream of morphological changes resulting from CR treatment, may be important elements in the response to CR, driving some of the key phenotypic outcomes. PMID:26945906

Recent changes of the Earth's core derived from satellite observations of magnetic and gravity fields.

PubMed

Mandea, Mioara; Panet, Isabelle; Lesur, Vincent; de Viron, Olivier; Diament, Michel; Le Mouël, Jean-Louis

2012-11-20

To understand the dynamics of the Earth's fluid, iron-rich outer core, only indirect observations are available. The Earth's magnetic field, originating mainly within the core, and its temporal variations can be used to infer the fluid motion at the top of the core, on a decadal and subdecadal time-scale. Gravity variations resulting from changes in the mass distribution within the Earth may also occur on the same time-scales. Such variations include the signature of the flow inside the core, though they are largely dominated by the water cycle contributions. Our study is based on 8 y of high-resolution, high-accuracy magnetic and gravity satellite data, provided by the CHAMP and GRACE missions. From the newly derived geomagnetic models we have computed the core magnetic field, its temporal variations, and the core flow evolution. From the GRACE CNES/GRGS series of time variable geoid models, we have obtained interannual gravity models by using specifically designed postprocessing techniques. A correlation analysis between the magnetic and gravity series has demonstrated that the interannual changes in the second time derivative of the core magnetic field under a region from the Atlantic to Indian Ocean coincide in phase with changes in the gravity field. The order of magnitude of these changes and proposed correlation are plausible, compatible with a core origin; however, a complete theoretical model remains to be built. Our new results and their broad geophysical significance could be considered when planning new Earth observation space missions and devising more sophisticated Earth's interior models.

Distortion of Magnetic Fields in a Starless Core. III. Polarization–Extinction Relationship in FeSt 1-457

NASA Astrophysics Data System (ADS)

Kandori, Ryo; Tamura, Motohide; Nagata, Tetsuya; Tomisaka, Kohji; Kusakabe, Nobuhiko; Nakajima, Yasushi; Kwon, Jungmi; Nagayama, Takahiro; Tatematsu, Ken’ichi

2018-04-01

The relationship between dust polarization and extinction was determined for the cold dense starless molecular cloud core FeSt 1-457 based on the background star polarimetry of dichroic extinction at near-infrared wavelengths. Owing to the known (three-dimensional) magnetic field structure, the observed polarizations from the core were corrected by considering (a) the subtraction of the ambient polarization component, (b) the depolarization effect of inclined distorted magnetic fields, and (c) the magnetic inclination angle of the core. After these corrections, a linear relationship between polarization and extinction was obtained for the core in the range up to A V ≈ 20 mag. The initial polarization versus extinction diagram changed dramatically after the corrections of (a) to (c), with the correlation coefficient being refined from 0.71 to 0.79. These corrections should affect the theoretical interpretation of the observational data. The slope of the finally obtained polarization–extinction relationship is {P}H/{E}H-{Ks}=11.00+/- 0.72 % {mag}}-1, which is close to the statistically estimated upper limit of the interstellar polarization efficiency. This consistency suggests that the upper limit of interstellar polarization efficiency might be determined by the observational viewing angle toward polarized astronomical objects.

The 5% difference: early sensory processing predicts sarcasm perception in schizophrenia and schizo-affective disorder.

PubMed

Kantrowitz, J T; Hoptman, M J; Leitman, D I; Silipo, G; Javitt, D C

2014-01-01

Intact sarcasm perception is a crucial component of social cognition and mentalizing (the ability to understand the mental state of oneself and others). In sarcasm, tone of voice is used to negate the literal meaning of an utterance. In particular, changes in pitch are used to distinguish between sincere and sarcastic utterances. Schizophrenia patients show well-replicated deficits in auditory function and functional connectivity (FC) within and between auditory cortical regions. In this study we investigated the contributions of auditory deficits to sarcasm perception in schizophrenia. Auditory measures including pitch processing, auditory emotion recognition (AER) and sarcasm detection were obtained from 76 patients with schizophrenia/schizo-affective disorder and 72 controls. Resting-state FC (rsFC) was obtained from a subsample and was analyzed using seeds placed in both auditory cortex and meta-analysis-defined core-mentalizing regions relative to auditory performance. Patients showed large effect-size deficits across auditory measures. Sarcasm deficits correlated significantly with general functioning and impaired pitch processing both across groups and within the patient group alone. Patients also showed reduced sensitivity to alterations in mean pitch and variability. For patients, sarcasm discrimination correlated exclusively with the level of rsFC within primary auditory regions whereas for controls, correlations were observed exclusively within core-mentalizing regions (the right posterior superior temporal gyrus, anterior superior temporal sulcus and insula, and left posterior medial temporal gyrus). These findings confirm the contribution of auditory deficits to theory of mind (ToM) impairments in schizophrenia, and demonstrate that FC within auditory, but not core-mentalizing, regions is rate limiting with respect to sarcasm detection in schizophrenia.

Decreased Photosystem II Core Phosphorylation in a Yellow-Green Mutant of Wheat Showing Monophasic Fluorescence Induction Curve.

PubMed Central

Giardi, M. T.; Kucera, T.; Briantais, J. M.; Hodges, M.

1995-01-01

In the present work we study the regulation of the distribution of the phosphorylated photosystem II (PSII) core populations present in grana regions of the thylakoids from several plant species. The heterogeneous nature of PSII core phosphorylation has previously been reported (M.T. Giardi, F. Rigoni, R. Barbato [1992] Plant Physiol 100: 1948-1954; M.T. Giardi [1993] Planta 190: 107-113). The pattern of four phosphorylated PSII core populations in the grana regions appears to be ubiquitous in higher plants. In the dark, at least two phosphorylated PSII core populations are always detected. A mutant of wheat (Triticum durum) that shows monophasic room-temperature photoreduction of the primary quinone electron acceptor of PSII as measured by chlorophyll fluorescence increase in the presence and absence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea and by fluorescence upon flash illumination in intact leaves also lacks the usual distribution of phosphorylated PSII core populations. In this mutant, the whole PSII core population pattern is changed, probably due to altered threonine kinase activity, which leads to the absence of light-induced phosphorylation of CP43 and D2 proteins. The results, correlated to previous experiments in vivo, support the idea that the functional heterogeneity observed by fluorescence is correlated in part to the PSII protein phosphorylation in the grana. PMID:12228652

Contaminant Gradients in Trees: Directional Tree Coring Reveals Boundaries of Soil and Soil-Gas Contamination with Potential Applications in Vapor Intrusion Assessment.

PubMed

Wilson, Jordan L; Samaranayake, V A; Limmer, Matthew A; Schumacher, John G; Burken, Joel G

2017-12-19

Contaminated sites pose ecological and human-health risks through exposure to contaminated soil and groundwater. Whereas we can readily locate, monitor, and track contaminants in groundwater, it is harder to perform these tasks in the vadose zone. In this study, tree-core samples were collected at a Superfund site to determine if the sample-collection location around a particular tree could reveal the subsurface location, or direction, of soil and soil-gas contaminant plumes. Contaminant-centroid vectors were calculated from tree-core data to reveal contaminant distributions in directional tree samples at a higher resolution, and vectors were correlated with soil-gas characterization collected using conventional methods. Results clearly demonstrated that directional tree coring around tree trunks can indicate gradients in soil and soil-gas contaminant plumes, and the strength of the correlations were directly proportionate to the magnitude of tree-core concentration gradients (spearman's coefficient of -0.61 and -0.55 in soil and tree-core gradients, respectively). Linear regression indicates agreement between the concentration-centroid vectors is significantly affected by in planta and soil concentration gradients and when concentration centroids in soil are closer to trees. Given the existing link between soil-gas and vapor intrusion, this study also indicates that directional tree coring might be applicable in vapor intrusion assessment.

Contaminant gradients in trees: Directional tree coring reveals boundaries of soil and soil-gas contamination with potential applications in vapor intrusion assessment

USGS Publications Warehouse

Wilson, Jordan L.; Samaranayake, V.A.; Limmer, Matthew A.; Schumacher, John G.; Burken, Joel G.

2017-01-01

Contaminated sites pose ecological and human-health risks through exposure to contaminated soil and groundwater. Whereas we can readily locate, monitor, and track contaminants in groundwater, it is harder to perform these tasks in the vadose zone. In this study, tree-core samples were collected at a Superfund site to determine if the sample-collection location around a particular tree could reveal the subsurface location, or direction, of soil and soil-gas contaminant plumes. Contaminant-centroid vectors were calculated from tree-core data to reveal contaminant distributions in directional tree samples at a higher resolution, and vectors were correlated with soil-gas characterization collected using conventional methods. Results clearly demonstrated that directional tree coring around tree trunks can indicate gradients in soil and soil-gas contaminant plumes, and the strength of the correlations were directly proportionate to the magnitude of tree-core concentration gradients (spearman’s coefficient of -0.61 and -0.55 in soil and tree-core gradients, respectively). Linear regression indicates agreement between the concentration-centroid vectors is significantly affected by in-planta and soil concentration gradients and when concentration centroids in soil are closer to trees. Given the existing link between soil-gas and vapor intrusion, this study also indicates that directional tree coring might be applicable in vapor intrusion assessment.

Foraminifer Shell Weight and Fragmentation: A Quantitative Study of the Influence of Temperature, [CO32-] and Dissolution on Proxies of the Marine Carbonate System

NASA Astrophysics Data System (ADS)

Mekik, F.; Pourmand, A.; Ward, B. M.

2015-12-01

Quantifying the various components of the marine carbonate system is important for understanding anthropogenic ocean acidification, and the rates and magnitudes of ocean acidification/ alkalization events in Earth's past. We performed multiple statistical analyses (factor analysis, partial correlations, multiple regression analysis and independent samples t -tests) on core top data using the Globorotalia menardii fragmentation index (MFI) in 89 core tops from across the tropical Pacific, Atlantic and Indian Oceans, the fragmentation trend of four species of foraminifers (Globorotalia truncatulinoides, G. menardii, Neogloboquadrina dutertrei and Pulleniatina obliquiloculata) in the EEP, tropical Atlantic and tropical Indian Ocean core tops, and Globorotalia menardii shell weight in a suite of 25 core tops the EEP in order to isolate the effects of surface ocean parameters such as temperature and [CO32-] from dissolution in sediments. Surface ocean parameters showed no significant effect on the G. menardii fragmentation index. We found no statistically significant influence of habitat water temperature or [CO32-] on foraminifer fragmentation in any of four species. While we found a strong influence of habitat water [CO32-] on the size normalized shell weight proxy in N. dutertrei and Pulleniatina obliquiloculata in our previous work, we found a much reduced influence of [CO32-] on the shell weight of G. menardii, which is most influenced by shell dissolution.

Within-subject correlations between evening-related changes in body temperature and melatonin in the spinal cord injured.

PubMed

Jones, Helen; Eijsvogels, Thijs M H; Nyakayiru, Jean; Verheggen, Rebecca J H M; Thompson, Andrew; Groothuis, Jan T; Atkinson, Greg; Hopman, Maria T E; Thijssen, Dick H J

2014-03-01

Individuals with a spinal cord injury (SCI) demonstrate altered circadian variation in thermoregulatory control. Recently, we reported that tetraplegia is associated with a blunted release of melatonin in the evening. In order to examine whether this finding relates to circadian thermoregulation, we compared the correlations between evening changes in melatonin, core and skin temperature between thoracic and cervical SCI and able-bodied participants. In 10 able-bodied, 9 paraplegic and 8 tetraplegic participants, we measured, between 1900 and 2300 h, core temperature, proximal skin temperature (above and below the level of the lesion) and physical activity. Salivary melatonin was also sampled during this period and analyzed using enzyme linked immunosorbant assay. Between 1900 and 2300 h, core and upper limb skin temperature gradually decreased in all groups (p = 0.01). A significant group × time interaction was evident in lower body skin temperature (p = 0.03). Lower body skin temperature was significantly higher in able-bodied controls compared with tetraplegics between 1900 and 2000 h (p < 0.05). In able-bodied and paraplegic participants, the changes in melatonin and core temperature were inversely correlated (r = -0.44 and -0.54, respectively, both p = 0.01). Melatonin and mean skin temperature changes were also inversely correlated (able-bodied controls: r = -0.24; p = 0.05 and paraplegics: r = -0.30; p= 0.02). The inverse correlation between evening changes in melatonin and thermoregulation is of a similar magnitude in paraplegic and able-bodied controls. In contrast, changes in skin temperature, below the level of the lesion, are unrelated to changes in melatonin in tetraplegics.

Experimental and Theoretical Investigations on Viscosity of Fe-Ni-C Liquids at High Pressures

NASA Astrophysics Data System (ADS)

Chen, B.; Lai, X.; Wang, J.; Zhu, F.; Liu, J.; Kono, Y.

2016-12-01

Understanding and modeling of Earth's core processes such as geodynamo and heat flow via convection in liquid outer cores hinges on the viscosity of candidate liquid iron alloys under core conditions. Viscosity estimates from various methods of the metallic liquid of the outer core, however, span up to 12 orders of magnitude. Due to experimental challenges, viscosity measurements of iron liquids alloyed with lighter elements are scarce and conducted at conditions far below those expected for the outer core. In this study, we adopt a synergistic approach by integrating experiments at experimentally-achievable conditions with computations up to core conditions. We performed viscosity measurements based on the modified Stokes' floating sphere viscometry method for the Fe-Ni-C liquids at high pressures in a Paris-Edinburgh press at Sector 16 of the Advanced Photon Source, Argonne National Laboratory. Our results show that the addition of 3-5 wt.% carbon to iron-nickel liquids has negligible effect on its viscosity at pressures lower than 5 GPa. The viscosity of the Fe-Ni-C liquids, however, becomes notably higher and increases by a factor of 3 at 5-8 GPa. Similarly, our first-principles molecular dynamics calculations up to Earth's core pressures show a viscosity change in Fe-Ni-C liquids at 5 GPa. The significant change in the viscosity is likely due to a liquid structural transition of the Fe-Ni-C liquids as revealed by our X-ray diffraction measurements and first-principles molecular dynamics calculations. The observed correlation between structure and physical properties of liquids permit stringent benchmark test of the computational liquid models and contribute to a more comprehensive understanding of liquid properties under high pressures. The interplay between experiments and first-principles based modeling is shown to be a practical and effective methodology for studying liquid properties under outer core conditions that are difficult to reach with the current static high-pressure capabilities. The new viscosity data from experiments and computations would provide new insights into the internal dynamics of the outer core.

Multireference quantum chemistry through a joint density matrix renormalization group and canonical transformation theory.

PubMed

Yanai, Takeshi; Kurashige, Yuki; Neuscamman, Eric; Chan, Garnet Kin-Lic

2010-01-14

We describe the joint application of the density matrix renormalization group and canonical transformation theory to multireference quantum chemistry. The density matrix renormalization group provides the ability to describe static correlation in large active spaces, while the canonical transformation theory provides a high-order description of the dynamic correlation effects. We demonstrate the joint theory in two benchmark systems designed to test the dynamic and static correlation capabilities of the methods, namely, (i) total correlation energies in long polyenes and (ii) the isomerization curve of the [Cu(2)O(2)](2+) core. The largest complete active spaces and atomic orbital basis sets treated by the joint DMRG-CT theory in these systems correspond to a (24e,24o) active space and 268 atomic orbitals in the polyenes and a (28e,32o) active space and 278 atomic orbitals in [Cu(2)O(2)](2+).

Time-dependent local density approximation study of iodine photoionization delay

NASA Astrophysics Data System (ADS)

Magrakvelidze, Maia; Chakraborty, Himadri

2017-04-01

We investigate dipole quantum phases and Wigner-Smith (WS) time delays in the photoionization of iodine using Kohn-Sham time-dependent local density approximation (TDLDA) with the Leeuwen and Baerends exchange-correlation functional. Study of the effects of electron correlations on the absolute as well as relative delays in emissions from both valence 5p and 5s, and core 4d, 4p and 4s levels has been carried out. Particular emphasis is paid to unravel the role of correlations to induce structures in the delay as a function of energy at resonances and Cooper minima. The results should encourage attosecond measurements of iodine photoemission and probe the WS-temporal landscape of an open-shell atomic system. This work was supported by the U.S. National Science Foundation.

Interacting effects of latitude, mass, age, and sex on winter survival of Surf Scoters (Melanitta perspicillata): Implications for differential migration

USGS Publications Warehouse

Uher-Koch, Brian D.; Esler, Daniel N.; Iverson, Samuel A.; Ward, David; Boyd, Sean; Kirk, Molly; Lewis, Tyler L.; VanStratt, Corey S.; Brodhead, Katherine M.; Hupp, Jerry W.; Schmutz, Joel A.

2016-01-01

We quantified variation in winter survival of Surf Scoters (Melanitta perspicillata (L., 1758)) across nearly 30° of latitude on the Pacific coast of North America to evaluate potential effects on winter distributions, including observed differential distributions of age and sex classes. We monitored fates of 297 radio-marked Surf Scoters at three study sites: (1) near the northern periphery of their wintering range in southeast Alaska, USA, (2) the range core in British Columbia, Canada, and (3) the southern periphery in Baja California, Mexico. We detected 34 mortalities and determined that survival averaged lower at the range peripheries than in the range core, was lower during mid-winter than during late winter at all sites, and was positively correlated with body mass within locations. Although neither age nor sex class had direct effects, mass effects led to differential survival patterns among classes. When simultaneously incorporating these interacting influences, adult males of mean mass for their location had highest survival at the northern range periphery in Alaska, whereas adult females and juveniles had higher survival at the range core and the southern periphery. Our observations help to explain patterns of differential migration and distribution reported for this species and highlight seasonal periods (mid-winter) and locations (range peripheries) of elevated levels of mortality for demographically important age–sex classes (adult females).

Studies of Solar EUV Irradiance from SOHO

NASA Technical Reports Server (NTRS)

Floyd, Linton

2002-01-01

The Extreme Ultraviolet (EUV) irradiance central and first order channel time series (COC and FOC) from the Solar EUV Monitor aboard the Solar and Heliospheric observatory (SOHO) issued in early 2002 covering the time period 1/1/96-31/1201 were analyzed in terms of other solar measurements and indices. A significant solar proton effect in the first order irradiance was found and characterized. When this effect is removed, the two irradiance time series are almost perfectly correlated. Earlier studies have shown good correlation between the FOC and the Hall core-to-wing ratio and likewise, it was the strongest component of the COC. Analysis of the FOC showed dependence on the F10.7 radio flux. Analysis of the CDC signals showed additional dependences on F10.7 and the GOES x-ray fluxes. The SEM FOC was also well correlated with thein 30.4 nm channel of the SOHO EUV Imaging Telescope (EIT). The irradiance derived from all four EIT channels (30.4 nm, 17.1 nm, 28.4 nm, and 19.5 nm) showed better correlation with MgII than F10.7.

Performance of ARCHITECT HCV core antigen test with specimens from US plasma donors and injecting drug users.

PubMed

Mixson-Hayden, Tonya; Dawson, George J; Teshale, Eyasu; Le, Thao; Cheng, Kevin; Drobeniuc, Jan; Ward, John; Kamili, Saleem

2015-05-01

Hepatitis C virus (HCV) core antigen is a serological marker of current HCV infection. The aim of this study was mainly to evaluate the performance characteristics of the ARCHITECT HCV core antigen assay with specimens from US plasma donors and injecting drug users. A total of 551 serum and plasma samples with known anti-HCV and HCV RNA status were tested for HCV core antigen using the Abbott ARCHITECT HCV core antigen test. HCV core antigen was detectable in 100% of US plasma donor samples collected during the pre-seroconversion phase of infection (anti-HCV negative/HCV RNA positive). Overall sensitivity of the HCV core antigen assay was 88.9-94.3% in samples collected after seroconversion. The correlation between HCV core antigen and HCV RNA titers was 0.959. HCV core antigen testing may be reliably used to identify current HCV infection. Published by Elsevier B.V.

An 80-year summer temperature history from the Xiao Dongkemadi ice core in the central Tibetan Plateau and its association with atmospheric circulation

NASA Astrophysics Data System (ADS)

Li, Xiangying; Ding, Yongjian; Yu, Zhongbo; Mika, Sillanpää; Liu, Shiyin; Shangguan, Donghui; Lu, Chengyang

2015-02-01

The climate significance of oxygen isotopes from the central Tibetan Plateau (cTP) ice cores is a debated issue because of large scale atmospheric circulation. A high-resolution δ18O record was recovered from the Xiao Dongkemadi (XD) ice core, which expanded the spatial coverage of δ18O data in this region. Annual average δ18O correlated significantly with nearby MJJAS air temperatures, suggesting the δ18O can be used as a proxy to reconstruct regional climate change. The reconstructed temperature anomaly is related to the regional and global warming trends, and the greater warming amplitude since 1970s is related to the elevation dependency of the warming signal. The close relationship of the warming to variations in glacier mass balances and discharge reveal that recent warming has led to obvious glacier shrinkage and runoff increase. Correlation analysis suggests that monsoon and westerly moisture substantially influence the cTP ice core records, along with an increase in their level of contribution to the XD core accumulation in recent decades, and confirms a teleconnection of regional climate of the cTP ice cores with climate parameters in the Indian and North Atlantic Oceans.

Ex vivo assessment and validation of water exchange performance of 23 heat and moisture exchangers for laryngectomized patients.

PubMed

van den Boer, Cindy; Muller, Sara H; Vincent, Andrew D; van den Brekel, Michiel W M; Hilgers, Frans J M

2014-08-01

Breathing through a tracheostoma results in insufficient warming and humidification of the inspired air. This loss of air conditioning, especially humidification, can be partially restored with the application of a heat and moisture exchanger (HME) over the tracheostoma. For medical professionals, it is not easy to judge differences in water exchange performance of various HMEs owing to the lack of universal outcome measures. This study has three aims: assessment of the water exchange performance of commercially available HMEs for laryngectomized patients, validation of these results with absolute humidity outcomes, and assessment of the role of hygroscopic salt present in some of the tested HMEs. Measurements of weight and absolute humidity at end inspiration and end expiration at different breathing volumes of a healthy volunteer were performed using a microbalance and humidity sensor. Twenty-three HMEs from 6 different manufacturers were tested. Associations were determined between core weight, weight change, breathing volume, and absolute humidity, using both linear and nonlinear mixed effects models. Water exchange of the 23 HMEs at a breathing volume of 0.5 L varies between 0.5 and 3.6 mg. Both water exchange and wet core weight correlate strongly with the end-inspiratory absolute humidity values (r2 =0.89/0.87). Hygroscopic salt increases core weight. The 23 tested HMEs for laryngectomized patients show wide variation in water exchange performance. Water exchange correlates well with the end-inspiratory absolute humidity outcome, which validates the ex vivo weight change method. Wet core weight is a predictor of HME performance. Hygroscopic salt increases the weight of the core material. The results of this study can help medical professionals to obtain a more founded opinion about the performance of available HMEs for pulmonary rehabilitation in laryngectomized patients, and allow them to make an informed decision about which HME type to use.

Electrical Current Leakage and Open-Core Threading Dislocations in AlGaN-Based Deep Ultraviolet Light-Emitting Diodes.

DOE PAGES

Moseley, Michael William; Allerman, Andrew A.; Crawford, Mary H.; ...

2014-08-04

Electrical current transport through leakage paths in AlGaN-based deep ultraviolet (DUV) lightemitting diodes (LEDs) and their effect on LED performance are investigated. Open-core threading dislocations, or nanopipes, are found to conduct current through nominally insulating Al0.7Ga0.3N layers and limit the performance of DUV-LEDs. A defect-sensitive phosphoric acid etch reveals these opencore threading dislocations in the form of large, micron-scale hexagonal etch pits visible with optical microscopy, while closed-core screw-, edge-, and mixed-type threading dislocations are represented by smaller and more numerous nanometer-scale pits visible by atomic-force microscopy. The electrical and optical performances of DUV-LEDs fabricated on similar Si-doped Al0.7Ga0.3N templatesmore » are found to have a strong correlation to the density of these nanopipes, despite their small fraction (<0.1% in this study) of the total density of threading dislocations.« less

Determination of dryout localization using a five-equation model of annular flow for boiling in minichannels

NASA Astrophysics Data System (ADS)

Wajs, Jan; Mikielewicz, Dariusz

2017-03-01

Detailed studies have suggested that the critical heat flux in the form of dryout in minichannels occurs when the combined effects of entrainment, deposition, and evaporation of the film make the film flow rate go gradually and smoothly to zero. Most approaches so far used the mass balance equation for the liquid film with appropriate formulations for the rate of deposition and entrainment respectively. It must be acknowledged that any discrepancy in determination of deposition and entrainment rates, together with cross-correlations between them, leads to the loss of accuracy of model predictions. Conservation equations relating the primary parameters are established for the liquid film and vapor core. The model consists of three mass balance equations, for liquid in the film as well as two-phase core and the gas phase itself. These equations are supplemented by the corresponding momentum equations for liquid in the film and the two-phase core. Applicability of the model has been tested on some experimental data.

Orthogonal Assessment of Biotherapeutic Glycosylation: A Case Study Correlating N-Glycan Core Afucosylation of Herceptin with Mechanism of Action.

PubMed

Upton, Rosie; Bell, Leonard; Guy, Colin; Caldwell, Paul; Estdale, Sian; Barran, Perdita E; Firth, David

2016-10-18

In the development of therapeutic antibodies and biosimilars, an appropriate biopharmaceutical CMC control strategy that connects critical quality attributes with mechanism of action should enable product assessment at an early stage of development in order to mitigate risk. Here we demonstrate a new analytical workflow using trastuzumab which comprises "middle-up" analysis using a combination of IdeS and the endoglycosidases EndoS and EndoS2 to comprehensively map the glycan content. Enzymatic cleavage between the two N-acetyl glucosamine residues of the chitobiose core of N-glycans significantly simplifies the oligosaccharide component enabling facile distinction of GlcNAc from GlcNAc with core fucose. This approach facilitates quantitative determination of total Fc-glycan core-afucosylation, which was in turn correlated with receptor binding affinity by surface plasmon resonance and in vitro ADCC potency with a cell based bioassay. The strategy also quantifies Fc-glycan occupancy and the relative contribution from high mannose glycans.

Understanding luminescence properties of grain boundaries in GaN thin films and their atomistic origin

NASA Astrophysics Data System (ADS)

Yoo, Hyobin; Yoon, Sangmoon; Chung, Kunook; Kang, Seoung-Hun; Kwon, Young-Kyun; Yi, Gyu-Chul; Kim, Miyoung

2018-03-01

We report our findings on the optical properties of grain boundaries in GaN films grown on graphene layers and discuss their atomistic origin. We combine electron backscatter diffraction with cathodoluminescence to directly correlate the structural defects with their optical properties, enabling the high-precision local luminescence measurement of the grain boundaries in GaN films. To further understand the atomistic origin of the luminescence properties, we carefully probed atomic core structures of the grain boundaries by exploiting aberration-corrected scanning transmission electron microscopy. The atomic core structures of grain boundaries show different ordering behaviors compared with those observed previously in threading dislocations. Energetics of the grain boundary core structures and their correlation with electronic structures were studied by first principles calculation.

Automated real-time needle-guide tracking for fast 3-T MR-guided transrectal prostate biopsy: a feasibility study.

PubMed

Zamecnik, Patrik; Schouten, Martijn G; Krafft, Axel J; Maier, Florian; Schlemmer, Heinz-Peter; Barentsz, Jelle O; Bock, Michael; Fütterer, Jurgen J

2014-12-01

To assess the feasibility of automatic needle-guide tracking by using a real-time phase-only cross correlation ( POCC phase-only cross correlation ) algorithm-based sequence for transrectal 3-T in-bore magnetic resonance (MR)-guided prostate biopsies. This study was approved by the ethics review board, and written informed consent was obtained from all patients. Eleven patients with a prostate-specific antigen level of at least 4 ng/mL (4 μg/L) and at least one transrectal ultrasonography-guided biopsy session with negative findings were enrolled. Regions suspicious for cancer were identified on 3-T multiparametric MR images. During a subsequent MR-guided biopsy, the regions suspicious for cancer were reidentified and targeted by using the POCC phase-only cross correlation -based tracking sequence. Besides testing a general technical feasibility of the biopsy procedure by using the POCC phase-only cross correlation -based tracking sequence, the procedure times were measured, and a pathologic analysis of the biopsy cores was performed. Thirty-eight core samples were obtained from 25 regions suspicious for cancer. It was technically feasible to perform the POCC phase-only cross correlation -based biopsies in all regions suspicious for cancer in each patient, with adequate biopsy samples obtained with each biopsy attempt. The median size of the region suspicious for cancer was 8 mm (range, 4-13 mm). In each region suspicious for cancer (median number per patient, two; range, 1-4), a median of one core sample per region was obtained (range, 1-3). The median time for guidance per target was 1.5 minutes (range, 0.7-5 minutes). Nineteen of 38 core biopsy samples contained cancer. This study shows that it is feasible to perform transrectal 3-T MR-guided biopsies by using a POCC phase-only cross correlation algorithm-based real-time tracking sequence. © RSNA, 2014.

Radiocarbon ages and age models for the past 30,000 years in Bear Lake, Utah and Idaho

USGS Publications Warehouse

Colman, Steven M.; Rosenbaum, J.G.; Kaufman, D.S.; Dean, W.E.; McGeehin, J.P.

2009-01-01

Radiocarbon analyses of pollen, ostracodes, and total organic carbon (TOC) provide a reliable chronology for the sediments deposited in Bear Lake over the past 30,000 years. The differences in apparent age between TOC, pollen, and carbonate fractions are consistent and in accord with the origins of these fractions. Comparisons among different fractions indicate that pollen sample ages are the most reliable, at least for the past 15,000 years. The post-glacial radiocarbon data also agree with ages independently estimated from aspartic acid racemization in ostracodes. Ages in the red, siliclastic unit, inferred to be of last glacial age, appear to be several thousand years too old, probably because of a high proportion of reworked, refractory organic carbon in the pollen samples. Age-depth models for five piston cores and the Bear Lake drill core (BL00-1) were constructed by using two methods: quadratic equations and smooth cubic-splinefits. The two types of age models differ only in detail for individual cores, and each approach has its own advantages. Specific lithological horizons were dated in several cores and correlated among them, producing robust average ages for these horizons. The age of the correlated horizons in the red, siliclastic unit can be estimated from the age model for BL00-1, which is controlled by ages above and below the red, siliclastic unit. These ages were then transferred to the correlative horizons in the shorter piston cores, providing control for the sections of the age models in those cores in the red, siliclastic unit. These age models are the backbone for reconstructions of past environmental conditions in Bear Lake. In general, sedimentation rates in Bear Lake have been quite uniform, mostly between 0.3 and 0.8 mm yr-1 in the Holocene, and close to 0.5 mm yr-1 for the longer sedimentary record in the drill core from the deepest part of the lake. Copyright ?? 2009 The Geological Society of America.

European validation of The Comprehensive International Classification of Functioning, Disability and Health Core Set for Osteoarthritis from the perspective of patients with osteoarthritis of the knee or hip.

PubMed

Weigl, Martin; Wild, Heike

2017-09-15

To validate the International Classification of Functioning, Disability and Health Comprehensive Core Set for Osteoarthritis from the patient perspective in Europe. This multicenter cross-sectional study involved 375 patients with knee or hip osteoarthritis. Trained health professionals completed the Comprehensive Core Set, and patients completed the Short-Form 36 questionnaire. Content validity was evaluated by calculating prevalences of impairments in body function and structures, limitations in activities and participation and environmental factors, which were either barriers or facilitators. Convergent construct validity was evaluated by correlating the International Classification of Functioning, Disability and Health categories with the Short-Form 36 Physical Component Score and the SF-36 Mental Component Score in a subgroup of 259 patients. The prevalences of all body function, body structure and activities and participation categories were >40%, >32% and >20%, respectively, and all environmental factors were relevant for >16% of patients. Few categories showed relevant differences between knee and hip osteoarthritis. All body function categories and all but two activities and participation categories showed significant correlations with the Physical Component Score. Body functions from the ICF chapter Mental Functions showed higher correlations with the Mental Component Score than with the Physical Component Score. This study supports the validity of the International Classification of Functioning, Disability and Health Comprehensive Core Set for Osteoarthritis. Implications for Rehabilitation Comprehensive International Classification of Functioning, Disability and Health Core Sets were developed as practical tools for application in multidisciplinary assessments. The validity of the Comprehensive International Classification of Functioning, Disability and Health Core Set for Osteoarthritis in this study supports its application in European patients with osteoarthritis. The differences in results between this Europe validation study and a previous Singaporean validation study underscore the need to validate the International Classification of Functioning, Disability and Health Core Sets in different regions of the world.

THE L{proportional_to}{sigma}{sup 8} CORRELATION FOR ELLIPTICAL GALAXIES WITH CORES: RELATION WITH BLACK HOLE MASS

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

Kormendy, John; Bender, Ralf, E-mail: kormendy@astro.as.utexas.edu, E-mail: bender@mpe.mpg.de

We construct the Faber-Jackson correlation between velocity dispersion {sigma} and total galaxy luminosity L{sub V} separately for elliptical galaxies with and without cores. The coreless ellipticals show the well-known, steep relationship dlog {sigma}/dlog L{sub V} = 0.268 or L{sub V} {proportional_to}{sigma}{sup 3.74}. This corresponds to dlog {sigma}/dlog M = 0.203, where M is the stellar mass and we use M/L{proportional_to}L {sup 0.32}. In contrast, the velocity dispersions of core ellipticals increase much more slowly with L{sub V} and M: dlog {sigma}/dlog L{sub V} = 0.120, L{sub V} {proportional_to}{sigma}{sup 8.33}, and dlog {sigma}/dlog M = 0.091. Dissipationless major galaxy mergers aremore » expected to preserve {sigma} according to the simplest virial-theorem arguments. However, numerical simulations show that {sigma} increases slowly in dry major mergers, with dlog {sigma}/dlog M {approx_equal} +0.15. In contrast, minor mergers cause {sigma} to decrease, with dlog {sigma}/dlog M {approx_equal} -0.05. Thus, the observed relation argues for dry major mergers as the dominant growth mode of the most massive ellipticals. This is consistent with what we know about the formation of cores. We know no viable way to explain galaxy cores except through dissipationless mergers of approximately equal-mass galaxies followed by core scouring by binary supermassive black holes. The observed, shallow {sigma}{proportional_to}L{sub V}{sup +0.12} relation for core ellipticals provides further evidence that they formed in dissipationless and predominantly major mergers. Also, it explains the observation that the correlation of supermassive black hole mass with velocity dispersion, M{sub .}{proportional_to}{sigma}{sup 4}, ''saturates'' at high M{sub .} such that M{sub .} becomes almost independent of {sigma}.« less

The correlation of coal beds in Squaw Basin and part of Eden Ridge, T. 33 S., R. 11 W., W. M., southwestern Oregon

USGS Publications Warehouse

Wayland, Russell Gibson

1965-01-01

A conflict in correlation of coal beds dating from 1914 is reexamined-with the aid of new. core hole data, photogeologic interpretation, a broader understanding of the stratigraphy, and brief field studies. It is concluded that the known coal beds in Squaw Basin area of limited lateral extent and are older than those exposed at Eden Ridge. Similar coal beds may be found in other rocks of the Tyee Formation in this area. More core drilling could be justified.

"Functional" Inspiratory and Core Muscle Training Enhances Running Performance and Economy.

PubMed

Tong, Tomas K; McConnell, Alison K; Lin, Hua; Nie, Jinlei; Zhang, Haifeng; Wang, Jiayuan

2016-10-01

Tong, TK, McConnell, AK, Lin, H, Nie, J, Zhang, H, and Wang, J. "Functional" inspiratory and core muscle training enhances running performance and economy. J Strength Cond Res 30(10): 2942-2951, 2016-We compared the effects of two 6-week high-intensity interval training interventions. Under the control condition (CON), only interval training was undertaken, whereas under the intervention condition (ICT), interval training sessions were followed immediately by core training, which was combined with simultaneous inspiratory muscle training (IMT)-"functional" IMT. Sixteen recreational runners were allocated to either ICT or CON groups. Before the intervention phase, both groups undertook a 4-week program of "foundation" IMT to control for the known ergogenic effect of IMT (30 inspiratory efforts at 50% maximal static inspiratory pressure [P0] per set, 2 sets per day, 6 days per week). The subsequent 6-week interval running training phase consisted of 3-4 sessions per week. In addition, the ICT group undertook 4 inspiratory-loaded core exercises (10 repetitions per set, 2 sets per day, inspiratory load set at 50% post-IMT P0) immediately after each interval training session. The CON group received neither core training nor functional IMT. After the intervention phase, global inspiratory and core muscle functions increased in both groups (p ≤ 0.05), as evidenced by P0 and a sport-specific endurance plank test (SEPT) performance, respectively. Compared with CON, the ICT group showed larger improvements in SEPT, running economy at the speed of the onset of blood lactate accumulation, and 1-hour running performance (3.04% vs. 1.57%, p ≤ 0.05). The changes in these variables were interindividually correlated (r ≥ 0.57, n = 16, p ≤ 0.05). Such findings suggest that the addition of inspiratory-loaded core conditioning into a high-intensity interval training program augments the influence of the interval program on endurance running performance and that this may be underpinned by an improvement in running economy.

Solvation and Evolution Dynamics of an Excess Electron in Supercritical CO2

NASA Astrophysics Data System (ADS)

Wang, Zhiping; Liu, Jinxiang; Zhang, Meng; Cukier, Robert I.; Bu, Yuxiang

2012-05-01

We present an ab initio molecular dynamics simulation of the dynamics of an excess electron solvated in supercritical CO2. The excess electron can exist in three types of states: CO2-core localized, dual-core localized, and diffuse states. All these states undergo continuous state conversions via a combination of long lasting breathing oscillations and core switching, as also characterized by highly cooperative oscillations of the excess electron volume and vertical detachment energy. All of these oscillations exhibit a strong correlation with the electron-impacted bending vibration of the core CO2, and the core-switching is controlled by thermal fluctuations.

How can core self-evaluations influence job burnout? The key roles of organizational commitment and job satisfaction.

PubMed

Peng, Jiaxi; Li, Dongdong; Zhang, Zhenjiang; Tian, Yu; Miao, Danmin; Xiao, Wei; Zhang, Jiaxi

2016-01-01

This study aimed to explore how core self-evaluations influenced job burnout and mainly focused on the confirmation of the mediator roles of organizational commitment and job satisfaction. A total of 583 female nurses accomplished the Core Self-Evaluation Scale, Organizational Commitment Scale, Minnesota Satisfaction Questionnaire, and Maslach Burnout Inventory-General Survey. The results revealed that core self-evaluations, organizational commitment, job satisfaction, and job burnout were significantly correlated with each other. Structural equation modeling indicated that core self-evaluations can significantly influence job burnout and are completely mediated by organizational commitment and job satisfaction. © The Author(s) 2014.

Controlled core removal from a D-shaped optical fiber.

PubMed

Markos, Douglas J; Ipson, Benjamin L; Smith, Kevin H; Schultz, Stephen M; Selfridge, Richard H; Monte, Thomas D; Dyott, Richard B; Miller, Gregory

2003-12-20

The partial removal of a section of the core from a continuous D-shaped optical fiber is presented. In the core removal process, selective chemical etching is used with hydrofluoric (HF) acid. A 25% HF acid solution removes the cladding material above the core, and a 5% HF acid solution removes the core. A red laser with a wavelength of 670 nm is transmitted through the optical fiber during the etching. The power transmitted through the optical fiber is correlated to the etch depth by scanning electron microscope imaging. The developed process provides a repeatable method to produce an optical fiber with a specific etch depth.

Can common measures of core stability distinguish performance in a shoulder pressing task under stable and unstable conditions?

PubMed

Keogh, Justin W L; Aickin, Sam E; Oldham, Anthony R H

2010-02-01

The primary purpose of this study was to determine whether a range of static core stability (CS) measures could distinguish shoulder press performance in unstable vs. stable conditions. Thirty resistance-trained men gave informed consent to participate in this study. One-repetition maximum strength (from < 6 repetitions) was predicted in the seated shoulder dumbbell press performed in unstable (Swiss ball[SB]) and stable (back-support bench) environments. Three CS muscle endurance tests were performed, with 4 CS ratios also calculated. The degree of strength decrement, referred to as the instability strength level (ISL), was calculated by dividing the predicted 1RM Unstable score by the 1RM Stable score. All subjects were categorized as high (ISL > 0.90), moderate (0.85 < or = ISL < or = 0.90), or low (ISL < 0.85). Between-group differences for the high- and low-ISL groups were assessed using analysis of variance and effect sizes. Pearson product moment correlations were then performed to examine the relationships between the CS measures and the ISL for the entire group. No significant between-group differences (p = 0.132-0.999) or large effect sizes were observed for any of the CS measures. Trunk flexion endurance was the only CS measure significantly correlated to the ISL (r = 0.477). In line with muscular strength research, these results suggest that CS exhibits relatively high levels of task specificity and that CS performance in static single-joint exercises may not be highly related to that in more dynamic multijoint activities. Core stability training (with or without a SB) may therefore only lead to significant improvements in functional dynamic performance if the postures, mode and velocity of contraction performed in training, are similar to the competitive tasks.

Relative Roles of Deterministic and Stochastic Processes in Driving the Vertical Distribution of Bacterial Communities in a Permafrost Core from the Qinghai-Tibet Plateau, China.

PubMed

Hu, Weigang; Zhang, Qi; Tian, Tian; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; Stegen, James C; An, Lizhe; Feng, Huyuan

2015-01-01

Understanding the processes that influence the structure of biotic communities is one of the major ecological topics, and both stochastic and deterministic processes are expected to be at work simultaneously in most communities. Here, we investigated the vertical distribution patterns of bacterial communities in a 10-m-long soil core taken within permafrost of the Qinghai-Tibet Plateau. To get a better understanding of the forces that govern these patterns, we examined the diversity and structure of bacterial communities, and the change in community composition along the vertical distance (spatial turnover) from both taxonomic and phylogenetic perspectives. Measures of taxonomic and phylogenetic beta diversity revealed that bacterial community composition changed continuously along the soil core, and showed a vertical distance-decay relationship. Multiple stepwise regression analysis suggested that bacterial alpha diversity and phylogenetic structure were strongly correlated with soil conductivity and pH but weakly correlated with depth. There was evidence that deterministic and stochastic processes collectively drived bacterial vertically-structured pattern. Bacterial communities in five soil horizons (two originated from the active layer and three from permafrost) of the permafrost core were phylogenetically random, indicator of stochastic processes. However, we found a stronger effect of deterministic processes related to soil pH, conductivity, and organic carbon content that were structuring the bacterial communities. We therefore conclude that the vertical distribution of bacterial communities was governed primarily by deterministic ecological selection, although stochastic processes were also at work. Furthermore, the strong impact of environmental conditions (for example, soil physicochemical parameters and seasonal freeze-thaw cycles) on these communities underlines the sensitivity of permafrost microorganisms to climate change and potentially subsequent permafrost thaw.

Relative Roles of Deterministic and Stochastic Processes in Driving the Vertical Distribution of Bacterial Communities in a Permafrost Core from the Qinghai-Tibet Plateau, China

PubMed Central

Tian, Tian; Li, Dingyao; Cheng, Gang; Mu, Jing; Wu, Qingbai; Niu, Fujun; Stegen, James C.; An, Lizhe; Feng, Huyuan

2015-01-01

Understanding the processes that influence the structure of biotic communities is one of the major ecological topics, and both stochastic and deterministic processes are expected to be at work simultaneously in most communities. Here, we investigated the vertical distribution patterns of bacterial communities in a 10-m-long soil core taken within permafrost of the Qinghai-Tibet Plateau. To get a better understanding of the forces that govern these patterns, we examined the diversity and structure of bacterial communities, and the change in community composition along the vertical distance (spatial turnover) from both taxonomic and phylogenetic perspectives. Measures of taxonomic and phylogenetic beta diversity revealed that bacterial community composition changed continuously along the soil core, and showed a vertical distance-decay relationship. Multiple stepwise regression analysis suggested that bacterial alpha diversity and phylogenetic structure were strongly correlated with soil conductivity and pH but weakly correlated with depth. There was evidence that deterministic and stochastic processes collectively drived bacterial vertically-structured pattern. Bacterial communities in five soil horizons (two originated from the active layer and three from permafrost) of the permafrost core were phylogenetically random, indicator of stochastic processes. However, we found a stronger effect of deterministic processes related to soil pH, conductivity, and organic carbon content that were structuring the bacterial communities. We therefore conclude that the vertical distribution of bacterial communities was governed primarily by deterministic ecological selection, although stochastic processes were also at work. Furthermore, the strong impact of environmental conditions (for example, soil physicochemical parameters and seasonal freeze-thaw cycles) on these communities underlines the sensitivity of permafrost microorganisms to climate change and potentially subsequent permafrost thaw. PMID:26699734

Use of a Standardized Patient Exercise to Assess Core Competencies During Fellowship Training

PubMed Central

Barry, Curtis T.; Avissar, Uri; Asebrook, Maureen; Sostok, Michael A.; Sherman, Kenneth E.; Zucker, Stephen D.

2010-01-01

Background The Accreditation Council for Graduate Medical Education requires fellows in many specialties to demonstrate attainment of 6 core competencies, yet relatively few validated assessment tools currently exist. We present our initial experience with the design and implementation of a standardized patient (SP) exercise during gastroenterology fellowship that facilitates appraisal of all core clinical competencies. Methods Fellows evaluated an SP trained to portray an individual referred for evaluation of abnormal liver tests. The encounters were independently graded by the SP and a faculty preceptor for patient care, professionalism, and interpersonal and communication skills using quantitative checklist tools. Trainees' consultation notes were scored using predefined key elements (medical knowledge) and subjected to a coding audit (systems-based practice). Practice-based learning and improvement was addressed via verbal feedback from the SP and self-assessment of the videotaped encounter. Results Six trainees completed the exercise. Second-year fellows received significantly higher scores in medical knowledge (55.0 ± 4.2 [standard deviation], P  =  .05) and patient care skills (19.5 ± 0.7, P  =  .04) by a faculty evaluator as compared with first-year trainees (46.2 ± 2.3 and 14.7 ± 1.5, respectively). Scores correlated by Spearman rank (0.82, P  =  .03) with the results of the Gastroenterology Training Examination. Ratings of the fellows by the SP did not differ by level of training, nor did they correlate with faculty scores. Fellows viewed the exercise favorably, with most indicating they would alter their practice based on the experience. Conclusions An SP exercise is an efficient and effective tool for assessing core clinical competencies during fellowship training. PMID:21975896

Speciation and isotopic composition of sedimentary sulfur in the Everglades, Florida, USA

USGS Publications Warehouse

Bates, A.L.; Spiker, E. C.; Holmes, C.W.

1998-01-01

We have studied the sulfur speciation and isotopic composition of two peat cores from Water Conservation Area 2A (WCA 2A) in the Florida Everglades. Core site E1 is affected by agricultural runoff from the Hillsboro Canal which drains the Everglades Agricultural Area; Core site U3 is distant from the canal and relatively unaffected by agricultural runoff. Depth profiles of the total sulfur content of both cores show fairly constant levels (??0.7 wt.%) below about 25-30 cm depth in Core E1 and below 40-45 cm in Core U3. Above these depths, total sulfur increases to as much as 1.52 wt.% in Core E1 and 1.74 wt.% in Core U3, suggesting that more sulfur has entered the sediments and/or that more sulfur is being retained in recent times at both sampling sites. These changes in total sulfur content with depth in Core E1 correlate with changes in total phosphorus that have been observed in other studies at core sites near the Hillsboro Canal. This correlation of total sulfur with phosphorus with depth is not seen in Core U3 located away from the canal, possibly because phosphorus is more effectively retained than sulfur in the organic sediment near the canal. Organic-sulfur (OS) concentrations are at least twice as high as the dusulfide-sulfur (DS) concentrations in the upper parts of both cores suggesting that iron is presently limiting the amount of dusulfide minerals formed in these sediments. The degree of pyritization (DOP) in the upper parts of the cores suggest that sulfide mineralization is limited by the availability of highly reactive iron during the earliest stages of diagenesis. Positive ??34S values for reduced sulfur forms in both cores indicate a relatively restricted sulfate reservoir, consistent with nearly complete reduction of the sulfate available in the sediment at any given time. Differences between the two core appear in the ??34S values for the near-surface sediments. The DS ??34S values in the upper 10.0 cm of sediment are more posotive at site E1, with a mean ??34S value of +12.9???, than at site U3, with a mean ??34S value of +2.9???. These reuslts may indicate that increased rates of organic deposition due to nutrient loading near the canal have increased the rate of sulfate reduction at the E1 site in recent times. Acid-volatile-sulfide (AVS) concentrations are lower than DS and OS concentrations by at least a factor of 10. Increasing ??34S values for AVS with increasing depth in both cores suggests ongoing reduction of a limited porewater sulfate reservoir after deposition. The disulfide and organic-sulfur ??34S values diverge from the ??34S values for AVS with depth, suggesting that most of the transformation of AVS into disulfide minerals or incorporation of sulfur into orgnaic matter occurs in the near-surface sediments. A comparison of organic-sulfur ??34S values in the dominant flora at the U3 site (sawgrass leaves and periphyton) with organic-sulfur ??34S values at the top of the U3 core indicates that there was early incorporation of an isotopically light sulfide species into the orgnaic matter.

Reliability and validity of the Iranian version of the Pediatric Quality of Life Inventory™ 4.0 Generic Core Scales in adolescents.

PubMed

Amiri, Parisa; M Ardekani, Emad; Jalali-Farahani, Sara; Hosseinpanah, Farhad; Varni, James W; Ghofranipour, Fazlollah; Montazeri, Ali; Azizi, Fereidoun

2010-12-01

The objective of this study was to investigate the reliability and validity of the Iranian version of the Pediatric Quality of Life Inventory™ 4.0 (PedsQL™ 4.0) Generic Core Scales in adolescents After linguistic validation, the Iranian version of the PedsQL™ 4.0 was completed by 848 healthy and 26 chronically ill adolescents aged 13-18 years and their parents. The internal consistency as measured by Cronbach's alpha coefficients exceeded the minimum reliability standard of .70. No floor effects were observed. Ceiling effects detected ranged from 1.5% for adolescent self-report total scale score to 42.2% for self-report social functioning. All monotrait-multimethod correlations were higher than multitrait-multimethod correlations. The intraclass correlation coefficients (ICC) between adolescent self-report and parent proxy-report showed good to excellent agreement. Exploratory factor analysis supported mainly comparable results with the original US English dialect version. The results of the confirmatory factor analysis for 5-factor models for both self-report and proxy-report indicated acceptable fit for the proposed models. Regarding gender and health status, as hypothesized from previous studies, girls reported lower health-related quality of life than boys on the total score, physical and emotional functioning, and healthy adolescents reported significantly higher health-related quality of life than those with chronic illnesses. The findings support the initial reliability and validity of the Iranian version of the PedsQL™ 4.0 as a generic instrument to measure HRQOL of adolescents in Iran.

Correlation consistent basis sets for actinides. I. The Th and U atoms

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

Peterson, Kirk A., E-mail: kipeters@wsu.edu

New correlation consistent basis sets based on both pseudopotential (PP) and all-electron Douglas-Kroll-Hess (DKH) Hamiltonians have been developed from double- to quadruple-zeta quality for the actinide atoms thorium and uranium. Sets for valence electron correlation (5f6s6p6d), cc − pV nZ − PP and cc − pV nZ − DK3, as well as outer-core correlation (valence + 5s5p5d), cc − pwCV nZ − PP and cc − pwCV nZ − DK3, are reported (n = D, T, Q). The -PP sets are constructed in conjunction with small-core, 60-electron PPs, while the -DK3 sets utilized the 3rd-order Douglas-Kroll-Hess scalar relativistic Hamiltonian. Bothmore » series of basis sets show systematic convergence towards the complete basis set limit, both at the Hartree-Fock and correlated levels of theory, making them amenable to standard basis set extrapolation techniques. To assess the utility of the new basis sets, extensive coupled cluster composite thermochemistry calculations of ThF{sub n} (n = 2 − 4), ThO{sub 2}, and UF{sub n} (n = 4 − 6) have been carried out. After accurately accounting for valence and outer-core correlation, spin-orbit coupling, and even Lamb shift effects, the final 298 K atomization enthalpies of ThF{sub 4}, ThF{sub 3}, ThF{sub 2}, and ThO{sub 2} are all within their experimental uncertainties. Bond dissociation energies of ThF{sub 4} and ThF{sub 3}, as well as UF{sub 6} and UF{sub 5}, were similarly accurate. The derived enthalpies of formation for these species also showed a very satisfactory agreement with experiment, demonstrating that the new basis sets allow for the use of accurate composite schemes just as in molecular systems composed only of lighter atoms. The differences between the PP and DK3 approaches were found to increase with the change in formal oxidation state on the actinide atom, approaching 5-6 kcal/mol for the atomization enthalpies of ThF{sub 4} and ThO{sub 2}. The DKH3 atomization energy of ThO{sub 2} was calculated to be smaller than the DKH2 value by ∼1 kcal/mol.« less

Fuel burnup analysis for IRIS reactor using MCNPX and WIMS-D5 codes

NASA Astrophysics Data System (ADS)

Amin, E. A.; Bashter, I. I.; Hassan, Nabil M.; Mustafa, S. S.

2017-02-01

International Reactor Innovative and Secure (IRIS) reactor is a compact power reactor designed with especial features. It contains Integral Fuel Burnable Absorber (IFBA). The core is heterogeneous both axially and radially. This work provides the full core burn up analysis for IRIS reactor using MCNPX and WIMDS-D5 codes. Criticality calculations, radial and axial power distributions and nuclear peaking factor at the different stages of burnup were studied. Effective multiplication factor values for the core were estimated by coupling MCNPX code with WIMS-D5 code and compared with SAS2H/KENO-V code values at different stages of burnup. The two calculation codes show good agreement and correlation. The values of radial and axial powers for the full core were also compared with published results given by SAS2H/KENO-V code (at the beginning and end of reactor operation). The behavior of both radial and axial power distribution is quiet similar to the other data published by SAS2H/KENO-V code. The peaking factor values estimated in the present work are close to its values calculated by SAS2H/KENO-V code.

THR-TH: a high-temperature gas-cooled nuclear reactor core thermal hydraulics code

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

Vondy, D.R.

1984-07-01

The ORNL version of PEBBLE, the (RZ) pebble bed thermal hydraulics code, has been extended for application to a prismatic gas cooled reactor core. The supplemental treatment is of one-dimensional coolant flow in up to a three-dimensional core description. Power density data from a neutronics and exposure calculation are used as the basic information for the thermal hydraulics calculation of heat removal. Two-dimensional neutronics results may be expanded for a three-dimensional hydraulics calculation. The geometric description for the hydraulics problem is the same as used by the neutronics code. A two-dimensional thermal cell model is used to predict temperatures inmore » the fuel channel. The capability is available in the local BOLD VENTURE computation system for reactor core analysis with capability to account for the effect of temperature feedback by nuclear cross section correlation. Some enhancements have also been added to the original code to add pebble bed modeling flexibility and to generate useful auxiliary results. For example, an estimate is made of the distribution of fuel temperatures based on average and extreme conditions regularly calculated at a number of locations.« less

Diffusivity in the core of chronic multiple sclerosis lesions.

PubMed

Klistorner, Alexander; Wang, Chenyu; Yiannikas, Con; Parratt, John; Barton, Joshua; You, Yuyi; Graham, Stuart L; Barnett, Michael H

2018-01-01

Diffusion tensor imaging (DTI) has been suggested as a potential biomarker of disease progression, neurodegeneration and de/remyelination in MS. However, the pathological substrates that underpin alterations in brain diffusivity are not yet fully delineated. We propose that in highly cohesive fiber tracts: 1) a relative increase in parallel (axial) diffusivity (AD) may serve as a measure of increased extra-cellular space (ESC) within the core of chronic MS lesions and, as a result, may provide an estimate of the degree of tissue destruction, and 2) the contribution of the increased extra-cellular water to perpendicular (radial) diffusivity (RD) can be eliminated to provide a more accurate assessment of membranal (myelin) loss. The purpose of this study was to isolate the contribution of extra-cellular water and demyelination to observed DTI indices in the core of chronic MS lesions, using the OR as an anatomically cohesive tract. Pre- and post-gadolinium (Gd) enhanced T1, T2 and DTI images were acquired from 75 consecutive RRMS patients. In addition, 25 age and gender matched normal controls were imaged using an identical MRI protocol (excluding Gd). The optic radiation (OR) was identified in individual patients using probabilistic tractography. The T2 lesions were segmented and intersected with the OR. Average eigenvalues were calculated within the core of OR lesions mask. The proportion of extra-cellular space (ECS) within the lesional core was calculated based on relative increase of AD, which was then used to normalise the perpendicular eigenvalues to eliminate the effect of the expanded ECS. In addition, modelling was implemented to simulate potential effect of various factors on lesional anisotropy. Of 75 patients, 41 (55%) demonstrated sizable T2 lesion volume within the ORs. All lesional eigenvalues were significantly higher compared to NAWM and controls. There was a strong correlation between AD and RD within the core of OR lesions, which was, however, not seen in OR NAWM of MS patients or normal controls. In addition, lesional anisotropy (FA) was predominantly driven by the perpendicular diffusivity, while in NAWM and in OR of normal controls all eigenvectors contributed to variation in FA. Estimated volume of ECS component constituted significant proportion of OR lesional volume and correlated significantly with lesional T1 hypointensity. While perpendicular diffusivity dropped significantly following normalisation, it still remained higher compared with diffusivity in OR NAWM. The "residual" perpendicular diffusivity also showed a substantial reduction of inter-subject variability. Both observed and modelled diffusion data suggested anisotropic nature of water diffusion in ESC. In addition, the simulation procedure offered a possible explanation for the discrepancy in relationship between eigenvalues and anisotropy in lesional tissue and NAWM. This paper presents a potential technique for more reliably quantifying the effects of neurodegeneration (tissue loss) versus demyelination in OR MS lesions. This may provide a simple and effective way for applying single tract diffusion analysis in MS clinical trials, with particular relevance to pro-remyelinating and neuroprotective therapeutics.

Oxygen environment and islet size are the primary limiting factors of isolated pancreatic islet survival

PubMed Central

Komatsu, Hirotake; Cook, Colin; Wang, Chia-Hao; Medrano, Leonard; Lin, Henry; Kandeel, Fouad; Tai, Yu-Chong; Mullen, Yoko

2017-01-01

Background Type 1 diabetes is an autoimmune disease that destroys insulin-producing beta cells in the pancreas. Pancreatic islet transplantation could be an effective treatment option for type 1 diabetes once several issues are resolved, including donor shortage, prevention of islet necrosis and loss in pre- and post-transplantation, and optimization of immunosuppression. This study seeks to determine the cause of necrotic loss of isolated islets to improve transplant efficiency. Methodology The oxygen tension inside isolated human islets of different sizes was simulated under varying oxygen environments using a computational in silico model. In vitro human islet viability was also assessed after culturing in different oxygen conditions. Correlation between simulation data and experimentally measured islet viability was examined. Using these in vitro viability data of human islets, the effect of islet diameter and oxygen tension of the culture environment on islet viability was also analyzed using a logistic regression model. Principal findings Computational simulation clearly revealed the oxygen gradient inside the islet structure. We found that oxygen tension in the islet core was greatly lower (hypoxic) than that on the islet surface due to the oxygen consumption by the cells. The hypoxic core was expanded in the larger islets or in lower oxygen cultures. These findings were consistent with results from in vitro islet viability assays that measured central necrosis in the islet core, indicating that hypoxia is one of the major causes of central necrosis. The logistic regression analysis revealed a negative effect of large islet and low oxygen culture on islet survival. Conclusions/Significance Hypoxic core conditions, induced by the oxygen gradient inside islets, contribute to the development of central necrosis of human isolated islets. Supplying sufficient oxygen during culture could be an effective and reasonable method to maintain isolated islets viable. PMID:28832685

Long-term Changes of Relative Paleointensity From Sediments: Geomagnetic Field Behavior or Rock Magnetic Artifact?

NASA Astrophysics Data System (ADS)

Yamazaki, T.; Acton, G.; Channell, J. E.; Palmer, E. C.; Richter, C.; Yamamoto, Y.

2011-12-01

Since the 1960s, possible correlation between geomagnetic field strength and polarity length on 10^6 years or longer time scale has been suggested, and its relation to geodynamo processes has been discussed (e.g., Cox, 1968). Paleointensity estimation using single crystal silicate indicated that the geomagnetic field was stronger during Cretaceous Superchron, when polarity reversal was inhibited in geodynamo (e.g., Tarduno et al., 2001). However, it has not yet been understood well whether such correlation exists when polarity reversals frequently occur. Tauxe and Hartl (1997) suggested a weak correlation using Oligocene sediments (ca 23-34 Ma) from DSDP Site 522. This is the only continuous paleointensity data of these ages published so far. We have conducted a paleomagnetic study of sediment cores of Eocene and Oligocene ages taken at Sites U1331, U1332, and U1333 of IODP Exp. 320/321 "Pacific Equatorial Age Transect (PEAT)". The objective includes better understanding of long-term changes in relative paleointensity and revisiting the issue of intensity-polarity length correlation. Relative paleointensity records from individual sites showed good between-site consistency for variations of 10^4 to 10^5 year time scale, suggesting that geomagnetic field behavior was successfully recovered on these time scales. The results confirmed usefulness of relative paleointensity for high-resolution inter-core correlation, that is, paleointensity assisted chronostratigraphy. On the other hand, long-term changes (ca 10^6 years or longer) in normalized intensity showed obvious anti-correlation with ARM/SIRM, a rock magnetic proxy of magnetic grain size and/or magnetostatic interactions among magnetic grains. The normalized intensity also showed correlation with sedimentation rates. These results indicate lithological contamination to relative paleointensity records. We compare our records with that of Tauxe and Hartl (1997) during Oligocene derived from South Atlantic sediments, which belongs to a different oceanographic regime to the PEAT cores. Although some strong paleointensity intervals are reproduced in our records, overall agreement in long-term changes is not good. Emergence of significant correlation between normalized intensity and ARM/SIRM and/or sedimentation rates is not limited to PEAT cores, but occurs also in sediments of other areas. For reliable estimation of long-term paleointensity changes from sediments, it is imperative to understand physical mechanism of such correlation and develop a method for correction.

Sedimentary Environment and Climate Evolution at the Northern Continental Margin of the South China Sea During the Last Glacial Cycle and Holocene

NASA Astrophysics Data System (ADS)

Tomczak, M.; Kaiser, J.; Borowka, R. K.; Chen, H.; Zhang, J.; Harff, J.; Qiu, Y.; Witkowski, A.

2014-12-01

Climate, oceanographic and sea level history during last glacial cycle (LGC) and Holocene at the NW continental margin of the South China Sea (SCS) are investigated within the SECEB project. For that purpose two sediment cores (HDQ2 & 83PC) and single-channel seismic sections were selected to serve as a proxy data source for paleoceanographic and paleoclimatic reconstructions. The sedimentary facies is interpreted by multi-proxy approaches considering micropaleontological, sedimentological and geochemical analyses. According to 14C and OSL datings, sediments of shallow water drill core HDQ2 (88.3 m) cover a time span of ca. 115 kyr BP. Seismic images of the sampling site show a series of reflectors which can be correlated with coarse layers of core HDQ2. These layers are interpreted as transgression / regression horizons. Due to the age model it is possible to correlate these horizons with the general sea level dynamics within the SCS as it is displayed in relative sea level excursions for the MIS 5 to 2 from the Sunda Shelf (Hanebuth et al. 2011). Core 83PC (8.6 m) retrieved from the continental slope provide constant record and calm environment. Therefore, this core is used as a source for data proxy for environmental reconstructions. According to δ18O and paleomagnetic analysis, a good age model which indicate age of this core to ca. 110 kyr BP was elaborated and help correlate the paleoenvironmental data with core HDQ2. Alkenones, δ18O, the Mg/Ca ratio, and microfossil proxies serve for paleo-SST curves and monsoon variability reconstructions. δ15N and δ13C indicate nutrient supply to the marine environment. Diatomological analysis outlines the environmental evolution and interrelations between their parameters during the LGC. Interpretation of seismic profiling allowed identification of submarine paleo-delta. It's anticipated that deposited sediments descent from the Hainan Island and allow correlation of the source and sink area.Hanebuth, T.J.J, Voris, H.K., Yokoyama, Y., Saito, Y., Okuno, J., 2011. Formation and fate of sedimentary depocentres on Southeast Asia's Sunda Shelf over the past sea-level cycle and biogeographic implications. Earth-Science Reviews 104, p. 92-110The project was funded by the Polish National Science Centre allocated on the basis of the decision no. DEC-2011/01/N/ST10/07708

Moving away from exhaustion: how core self-evaluations influence academic burnout.

PubMed

Lian, Penghu; Sun, Yunfeng; Ji, Zhigang; Li, Hanzhong; Peng, Jiaxi

2014-01-01

Academic burnout refers to students who have low interest, lack of motivation, and tiredness in studying. Studies concerning how to prevent academic burnout are rare. The present study aimed to investigate the impact of core self-evaluations on the academic burnout of university students, and mainly focused on the confirmation of the mediator role of life satisfaction. A total of 470 university students accomplished the core self-evaluation scale, Satisfaction with Life, and academic burnout scale. Both core self-evaluations and life satisfaction were significantly correlated with academic burnout. Structural equation modeling indicated that life satisfaction partially mediated the relationship between core self-evaluations and academic burnout. Core self-evaluations significantly influence academic burnout and are partially mediated by life satisfaction.

Establishing an efficient way to utilize the drought resistance germplasm population in wheat.

PubMed

Wang, Jiancheng; Guan, Yajing; Wang, Yang; Zhu, Liwei; Wang, Qitian; Hu, Qijuan; Hu, Jin

2013-01-01

Drought resistance breeding provides a hopeful way to improve yield and quality of wheat in arid and semiarid regions. Constructing core collection is an efficient way to evaluate and utilize drought-resistant germplasm resources in wheat. In the present research, 1,683 wheat varieties were divided into five germplasm groups (high resistant, HR; resistant, R; moderate resistant, MR; susceptible, S; and high susceptible, HS). The least distance stepwise sampling (LDSS) method was adopted to select core accessions. Six commonly used genetic distances (Euclidean distance, Euclid; Standardized Euclidean distance, Seuclid; Mahalanobis distance, Mahal; Manhattan distance, Manhat; Cosine distance, Cosine; and Correlation distance, Correlation) were used to assess genetic distances among accessions. Unweighted pair-group average (UPGMA) method was used to perform hierarchical cluster analysis. Coincidence rate of range (CR) and variable rate of coefficient of variation (VR) were adopted to evaluate the representativeness of the core collection. A method for selecting the ideal constructing strategy was suggested in the present research. A wheat core collection for the drought resistance breeding programs was constructed by the strategy selected in the present research. The principal component analysis showed that the genetic diversity was well preserved in that core collection.

Molecular Characterization of Methanogenic Communities in Core Sediments of the Dajiuhu Peatland, Central China

NASA Astrophysics Data System (ADS)

Wang, R.; Wang, H.

2017-12-01

Methane (CH4) is an important greenhouse gas with a global warming potential 22 times greater than carbon dioxide. Large amounts of CH4 can be produced and released by methanogenesis in peatland ecosystems, which make peatland ecosystems play an important role in mediating global climate change. Here we report the abundance and distribution of methanogenic communities and their correlation with physicochemical parameters along two sediment cores in the Dajiuhu Peatland via quantitative PCR, clone library construction of functional genes and statistical analysis. Uncultured Group and Fen Cluster were found to be the dominant methanogens at the upper part of the cores, and Rice and Related Rice Cluster became dominant in the bottom of the cores. Quantitative PCR showed that abundances of methanogenic communities ranged from 104 to 106 copies/ng DNA throughout the cores. Canonical Correlation Analysis (CCA) indicated that dissolved oxygen (DO) (P=0.046, F=1.4) was the main factor significantly controlling methanogenic communities. Our results enhance the understanding of the compositions and variations of methanogenic communities vertically and greatly help us to further investigate process of microbial methanogenesis in Dajiuhu Peatland.

A rapid, controlled-environment seedling root screen for wheat correlates well with rooting depths at vegetative, but not reproductive, stages at two field sites

PubMed Central

Watt, M.; Moosavi, S.; Cunningham, S. C.; Kirkegaard, J. A.; Rebetzke, G. J.; Richards, R. A.

2013-01-01

Background and Aims Root length and depth determine capture of water and nutrients by plants, and are targets for crop improvement. Here we assess a controlled-environment wheat seedling screen to determine speed, repeatability and relatedness to performance of young and adult plants in the field. Methods Recombinant inbred lines (RILs) and diverse genotypes were grown in rolled, moist germination paper in growth cabinets, and primary root number and length were measured when leaf 1 or 2 were fully expanded. For comparison, plants were grown in the field and root systems were harvested at the two-leaf stage with either a shovel or a soil core. From about the four-leaf stage, roots were extracted with a steel coring tube only, placed directly over the plant and pushed to the required depth with a hydraulic ram attached to a tractor. Key Results In growth cabinets, repeatability was greatest (r = 0·8, P < 0·01) when the paper was maintained moist and seed weight, pathogens and germination times were controlled. Scanned total root length (slow) was strongly correlated (r = 0·7, P < 0·01) with length of the two longest seminal axile roots measured with a ruler (fast), such that 100–200 genotypes were measured per day. Correlation to field-grown roots at two sites at two leaves was positive and significant within the RILs and cultivars (r = 0·6, P = 0·01), and at one of the two sites at the five-leaf stage within the RILs (r = 0·8, P = 0·05). Measurements made in the field with a shovel or extracted soil cores were fast (5 min per core) and had significant positive correlations to scanner measurements after root washing and cleaning (>2 h per core). Field measurements at two- and five-leaf stages did not correlate with root depth at flowering. Conclusions The seedling screen was fast, repeatable and reliable for selecting lines with greater total root length in the young vegetative phase in the field. Lack of significant correlation with reproductive stage root system depth at the field sites used in this study reflected factors not captured in the screen such as time, soil properties, climate variation and plant phenology. PMID:23821620

Polychlorinated biphenyl congeners in sediment cores from the Upper Mississippi River

PubMed Central

Martinez, Andres; Schnoebelen, Douglas J.; Hornbuckle, Keri C.

2015-01-01

We determined polychlorinated biphenyls (PCBs) and radionuclide 137Cs in sediment cores from the Upper Mississippi River (UMR) and the Iowa River, Iowa, at their confluence. Vertical distribution of 137Cs indicated negligible mixing in the UMR core, while the Iowa River core showed signs of mixing. A clear 137Cs peak was found in the UMR core, which was correlated to 1963. The PCB vertical distribution in UMR core was similar to the historical trend in Aroclor production observed in Great Lakes cores, with a peak close to the 137Cs peak, suggesting a date near 1960. In general, PCB congener profiles in both cores resembled the Iowa soil background signal. We concluded that despite evidence of mixing in the Iowa River core, both cores retain the PCB signature of historical and regional environmental exposure. Further, our results indicate that this iconic waterway has a long history of PCBs that reflects national production and use. PMID:26547030

Warming rays in cluster cool cores

NASA Astrophysics Data System (ADS)

Colafrancesco, S.; Marchegiani, P.

2008-06-01

Context: Cosmic rays are confined in the atmospheres of galaxy clusters and, therefore, they can play a crucial role in the heating of their cool cores. Aims: We discuss here the thermal and non-thermal features of a model of cosmic ray heating of cluster cores that can provide a solution to the cooling-flow problems. To this aim, we generalize a model originally proposed by Colafrancesco, Dar & DeRujula (2004) and we show that our model predicts specific correlations between the thermal and non-thermal properties of galaxy clusters and enables various observational tests. Methods: The model reproduces the observed temperature distribution in clusters by using an energy balance condition in which the X-ray energy emitted by clusters is supplied, in a quasi-steady state, by the hadronic cosmic rays, which act as “warming rays” (WRs). The temperature profile of the intracluster (IC) gas is strictly correlated with the pressure distribution of the WRs and, consequently, with the non-thermal emission (radio, hard X-ray and gamma-ray) induced by the interaction of the WRs with the IC gas and the IC magnetic field. Results: The temperature distribution of the IC gas in both cool-core and non cool-core clusters is successfully predicted from the measured IC plasma density distribution. Under this contraint, the WR model is also able to reproduce the thermal and non-thermal pressure distribution in clusters, as well as their radial entropy distribution, as shown by the analysis of three clusters studied in detail: Perseus, A2199 and Hydra. The WR model provides other observable features of galaxy clusters: a correlation of the pressure ratio (WRs to thermal IC gas) with the inner cluster temperature (P_WR/P_th) ˜ (kT_inner)-2/3, a correlation of the gamma-ray luminosity with the inner cluster temperature Lγ ˜ (kT_inner)4/3, a substantial number of cool-core clusters observable with the GLAST-LAT experiment, a surface brightness of radio halos in cool-core clusters that recovers the observed one, a hard X-ray ICS emission from cool-core clusters that is systematically lower than the observed limits and yet observable with the next generation high-sensitivity and spatial resolution HXR experiments like Simbol-X. Conclusions: The specific theoretical properties and the multi-frequency distribution of the e.m. signals predicted in the WR model render it quite different from the other models so far proposed for the heating of clusters' cool-cores. Such differences make it possible to prove or disprove our model as an explanation for the cooling-flow problems on the basis of multi-frequency observations of galaxy clusters.

Can Network Linkage Effects Determine Return? Evidence from Chinese Stock Market

PubMed Central

Qiao, Haishu; Xia, Yue; Li, Ying

2016-01-01

This study used the dynamic conditional correlations (DCC) method to identify the linkage effects of Chinese stock market, and further detected the influence of network linkage effects on magnitude of security returns across different industries. Applying two physics-derived techniques, the minimum spanning tree and the hierarchical tree, we analyzed the stock interdependence within the network of the China Securities Index (CSI) industry index basket. We observed that that obvious linkage effects existed among stock networks. CII and CCE, CAG and ITH as well as COU, CHA and REI were confirmed as the core nodes in the three different networks respectively. We also investigated the stability of linkage effects by estimating the mean correlations and mean distances, as well as the normalized tree length of these indices. In addition, using the GMM model approach, we found inter-node influence within the stock network had a pronounced effect on stock returns. Our results generally suggested that there appeared to be greater clustering effect among the indexes belonging to related industrial sectors than those of diverse sectors, and network comovement was significantly affected by impactive financial events in the reality. Besides, stocks that were more central within the network of stock market usually had higher returns for compensation because they endured greater exposure to correlation risk. PMID:27257816

Can Network Linkage Effects Determine Return? Evidence from Chinese Stock Market.

PubMed

Qiao, Haishu; Xia, Yue; Li, Ying

2016-01-01

This study used the dynamic conditional correlations (DCC) method to identify the linkage effects of Chinese stock market, and further detected the influence of network linkage effects on magnitude of security returns across different industries. Applying two physics-derived techniques, the minimum spanning tree and the hierarchical tree, we analyzed the stock interdependence within the network of the China Securities Index (CSI) industry index basket. We observed that that obvious linkage effects existed among stock networks. CII and CCE, CAG and ITH as well as COU, CHA and REI were confirmed as the core nodes in the three different networks respectively. We also investigated the stability of linkage effects by estimating the mean correlations and mean distances, as well as the normalized tree length of these indices. In addition, using the GMM model approach, we found inter-node influence within the stock network had a pronounced effect on stock returns. Our results generally suggested that there appeared to be greater clustering effect among the indexes belonging to related industrial sectors than those of diverse sectors, and network comovement was significantly affected by impactive financial events in the reality. Besides, stocks that were more central within the network of stock market usually had higher returns for compensation because they endured greater exposure to correlation risk.

Cerebellar gray matter and lobular volumes correlate with core autism symptoms

PubMed Central

D'Mello, Anila M.; Crocetti, Deana; Mostofsky, Stewart H.; Stoodley, Catherine J.

2015-01-01

Neuroanatomical differences in the cerebellum are among the most consistent findings in autism spectrum disorder (ASD), but little is known about the relationship between cerebellar dysfunction and core ASD symptoms. The newly-emerging existence of cerebellar sensorimotor and cognitive subregions provides a new framework for interpreting the functional significance of cerebellar findings in ASD. Here we use two complementary analyses — whole-brain voxel-based morphometry (VBM) and the SUIT cerebellar atlas — to investigate cerebellar regional gray matter (GM) and volumetric lobular measurements in 35 children with ASD and 35 typically-developing (TD) children (mean age 10.4 ± 1.6 years; range 8–13 years). To examine the relationships between cerebellar structure and core ASD symptoms, correlations were calculated between scores on the Autism Diagnostic Observation Schedule (ADOS) and Autism Diagnostic Interview (ADI) and the VBM and volumetric data. Both VBM and the SUIT analyses revealed reduced GM in ASD children in cerebellar lobule VII (Crus I/II). The degree of regional and lobular gray matter reductions in different cerebellar subregions correlated with the severity of symptoms in social interaction, communication, and repetitive behaviors. Structural differences and behavioral correlations converged on right cerebellar Crus I/II, a region which shows structural and functional connectivity with fronto-parietal and default mode networks. These results emphasize the importance of the location within the cerebellum to the potential functional impact of structural differences in ASD, and suggest that GM differences in cerebellar right Crus I/II are associated with the core ASD profile. PMID:25844317

Earth's core and inner-core resonances from analysis of VLBI nutation and superconducting gravimeter data

NASA Astrophysics Data System (ADS)

Rosat, S.; Lambert, S. B.; Gattano, C.; Calvo, M.

2017-01-01

Geophysical parameters of the deep Earth's interior can be evaluated through the resonance effects associated with the core and inner-core wobbles on the forced nutations of the Earth's figure axis, as observed by very long baseline interferometry (VLBI), or on the diurnal tidal waves, retrieved from the time-varying surface gravity recorded by superconducting gravimeters (SGs). In this paper, we inverse for the rotational mode parameters from both techniques to retrieve geophysical parameters of the deep Earth. We analyse surface gravity data from 15 SG stations and VLBI delays accumulated over the last 35 yr. We show existing correlations between several basic Earth parameters and then decide to inverse for the rotational modes parameters. We employ a Bayesian inversion based on the Metropolis-Hastings algorithm with a Markov-chain Monte Carlo method. We obtain estimates of the free core nutation resonant period and quality factor that are consistent for both techniques. We also attempt an inversion for the free inner-core nutation (FICN) resonant period from gravity data. The most probable solution gives a period close to the annual prograde term (or S1 tide). However the 95 per cent confidence interval extends the possible values between roughly 28 and 725 d for gravity, and from 362 to 414 d from nutation data, depending on the prior bounds. The precisions of the estimated long-period nutation and respective small diurnal tidal constituents are hence not accurate enough for a correct determination of the FICN complex frequency.

Spatiotemporal exposome dynamics of soil lead and children's blood lead pre- and ten years post-Hurricane Katrina: Lead and other metals on public and private properties in the city of New Orleans, Louisiana, U.S.A.

PubMed

Mielke, Howard W; Gonzales, Christopher R; Powell, Eric T; Mielke, Paul W

2017-05-01

Anthropogenic re-distribution of lead (Pb) principally through its use in gasoline additives and lead-based paints have transformed the urban exposome. This unique study tracks urban-scale soil Pb (SPb) and blood Pb (BPb) responses of children living in public and private communities in New Orleans before and ten years after Hurricane Katrina (29 August 2005). To compare and evaluate associations of pre- and ten years post-Katrina SPb and children's BPb on public and private residential census tracts in the core and outer areas of New Orleans, and to examine correlations between SPb and nine other soil metals. The Louisiana Healthy Housing and Childhood Lead Poisoning Prevention Program BPb (µg/dL) data from pre- (2000-2005) and post-Katrina (2010-2015) for ≤6-year-old children. Data from public and adjacent private residential census tracts within core and outer areas are stratified from a database that includes 916 and 922 SPb and 13,379 and 4830 BPb results, respectively, from pre- and post-Katrina New Orleans. Statistical analyses utilize Multi-Response Permutation Procedure and Spearman's Rho Correlation. Pre- to Post-Katrina median SPb decreases in public and private core census tracts were from 285 to 55mg/kg and 710-291mg/kg, respectively. In public and private outer census tracts the median SPb decreased from 109 to 56mg/kg and 88-55mg/kg. Children's BPb percent ≥5µg/dL on public and private core areas pre-Katrina was 63.2% and 67.5%, and declined post-Katrina to 7.6% and 20.2%, respectively. BPb decreases also occurred in outer areas. Soil Pb is strongly correlated with other metals. Post-Katrina re-building of public housing plus landscaping amends the exposome and reduces children's BPb. Most importantly, Hurricane Katrina revealed that decreasing the toxicants in the soil exposome is an effective intervention for decreasing children's BPb. Copyright © 2017 Elsevier Inc. All rights reserved.

Analysis of ultradian heat production and aortic core temperature rhythms in the rat.

PubMed

Gómez-Sierra, J M; Canela, E I; Esteve, M; Rafecas, I; Closa, D; Remesar, X; Alemany, M

1993-01-01

The rhythms of aortic core temperature and overall heat production in Wistar rats was analyzed by using long series of recordings of temperature obtained from implanted thermocouple probes and heat release values from a chamber calorimeter. There was a very high degree of repetitiveness in the presentation of actual heat rhythms, with high cross-correlation values ascertained wit paired periodograms. No differences were observed between heat production between male and female adult rats. The cross-correlation for temperature gave similar figures. The cross-correlation study between heat production and aortic core temperature in the same animals was significant and showed a displacement of about 30 minutes between heat release and aortic core temperature. The analysis of heat production showed a strong predominance of rhythms with periods of 24 hours (frequencies < 11.6 microHz) or more; other rhythms detected (of roughly the same relative importance) had periods of 8 or 2.2 hours (35 or 126 microHz, respectively). The analysis of aortic core temperature showed a smaller quantitative contribution of the 8 or 2.2 hours (35 or 126 microHz) rhythms, with other harmonic rhythms interspersed (5.1 and 4.0 hours, i.e. 54 and 69 microHz). The proportion of 'noise' or cycles lower than 30 minutes (< 550 microHz) was higher in internal temperature than in the actual release of heat. The results are in agreement with the existence of a basic period of about 130 minutes (126 microHz) of warming/cooling of the blood, with a number of other harmonic rhythms superimposed upon the basic circadian rhythm.

Determining an age for the Inararo Tuff eruption of Mt. Pinatubo, based on correlation with a distal ash layer in core MD97-2142, South China Sea

USGS Publications Warehouse

Ku, Y.-P.; Chen, C.-H.; Newhall, C.G.; Song, S.-R.; Yang, T.F.; Iizuka, Y.; McGeehin, J.

2008-01-01

The largest known eruption of Mt. Pinatubo in the late Quaternary was the Inararo Tuff Formation (ITF) eruption, roughly estimated as five times larger than the 1991 eruption. The precise age of the ITF eruption has been uncertain. Here, a correlative of the ITF eruption, Layer D, is identified in marine sediments, and an age obtained. Tephras were identified in core MD97-2142 of Leg II of the IMAGES III cruise in northern offshore of Palawan, southeastern South China Sea (12??41.33???N, 119??27.90???E). On the basis of the geochemical and isotopic fingerprints, Layer D can be correlated with the ITF eruption of the modern Pinatubo-eruption sequence. By means of the MD97-2142 SPECMAP chronology, Layer D was dated at around 81??2 ka. This estimated age of the ITF eruption and tephra Layer D coincides with an anomalously high SO4-2 spike occurring within the 5 millennia from 79 to 84 ka in the GISP2 ice core record. ?? 2007.

LOWER EXTREMITY HYPERMOBILITY, BUT NOT CORE MUSCLE ENDURANCE INFLUENCES BALANCE IN FEMALE COLLEGIATE DANCERS.

PubMed

Ambegaonkar, Jatin P; Cortes, Nelson; Caswell, Shane V; Ambegaonkar, Gautam P; Wyon, Matthew

2016-04-01

Dance is a physically demanding activity, with almost 70% of all injuries in dancers occurring in the lower extremity (LE). Prior researchers report that muscle function (e.g. muscle endurance) and anatomical factors (e.g. hypermobility) affect physical performance (e.g. balance) and can subsequently influence LE injury risk. Specifically, lesser core muscle endurance, balance deficits, and greater hypermobility are related to increased LE injury risk. However, the potentials interrelationships among these factors in dancers remain unclear. The purposes of this study were to examine the relationships among core muscle endurance, balance, and LE hypermobility, and determine the relative contributions of core muscle endurance and LE hypermobility as predictors of balance in female collegiate dancers. Cross-sectional. Core muscle endurance was evaluated using the combined average anterior, left, and right lateral plank test time scores(s). LE hypermobility was measured using the LE-specific Beighton hypermobility measure, defining hypermobility if both legs had greater than 10 ° knee hyperextension. Balance was measured via the composite anterior, posterolateral, and posteromedial Star Excursion Balance Test (SEBT) reach distances (normalized to leg length) in 15 female healthy collegiate dancers (18.3 + 0.5yrs, 165.5 + 6.9cm, 63.7 + 12.1kg). Point-biserial-correlation-coefficients examined relationships and a linear regression examined whether core endurance and hypermobility predicted balance (p<.05). LE hypermobility (Yes; n = 3, No; n = 12) and balance (87.2 + 8.3% leg length) were positively correlated r(14)=.67, (p=.01). However, core endurance (103.9 + 50.6 s) and balance were not correlated r(14)=.32, (p=.26). LE hypermobility status predicted 36.9% of the variance in balance scores (p=.01). LE hypermobility, but not core muscle endurance may be related to balance in female collegiate dancers. While LE hypermobility status influenced balance in the female collegiate dancers, how this LE hypermobility status affects their longitudinal injury risk as their careers progress needs further study. Overall, the current findings suggest that rather than using isolated core endurance-centric training, clinicians may encourage dancers to use training programs that incorporate multiple muscles - in order to improve their balance, and possibly reduce their LE injury risk. 2b.

LOWER EXTREMITY HYPERMOBILITY, BUT NOT CORE MUSCLE ENDURANCE INFLUENCES BALANCE IN FEMALE COLLEGIATE DANCERS

PubMed Central

Cortes, Nelson; Caswell, Shane V.; Ambegaonkar, Gautam P.; Wyon, Matthew

2016-01-01

Background Dance is a physically demanding activity, with almost 70% of all injuries in dancers occurring in the lower extremity (LE). Prior researchers report that muscle function (e.g. muscle endurance) and anatomical factors (e.g. hypermobility) affect physical performance (e.g. balance) and can subsequently influence LE injury risk. Specifically, lesser core muscle endurance, balance deficits, and greater hypermobility are related to increased LE injury risk. However, the potentials interrelationships among these factors in dancers remain unclear. Purpose The purposes of this study were to examine the relationships among core muscle endurance, balance, and LE hypermobility, and determine the relative contributions of core muscle endurance and LE hypermobility as predictors of balance in female collegiate dancers. Study Design Cross-sectional Methods Core muscle endurance was evaluated using the combined average anterior, left, and right lateral plank test time scores(s). LE hypermobility was measured using the LE-specific Beighton hypermobility measure, defining hypermobility if both legs had greater than 10 ° knee hyperextension. Balance was measured via the composite anterior, posterolateral, and posteromedial Star Excursion Balance Test (SEBT) reach distances (normalized to leg length) in 15 female healthy collegiate dancers (18.3 + 0.5yrs, 165.5 + 6.9cm, 63.7 + 12.1kg). Point-biserial-correlation-coefficients examined relationships and a linear regression examined whether core endurance and hypermobility predicted balance (p<.05). Results LE hypermobility (Yes; n = 3, No; n = 12) and balance (87.2 + 8.3% leg length) were positively correlated r(14)=.67, (p=.01). However, core endurance (103.9 + 50.6 s) and balance were not correlated r(14)=.32, (p=.26). LE hypermobility status predicted 36.9% of the variance in balance scores (p=.01). Conclusion LE hypermobility, but not core muscle endurance may be related to balance in female collegiate dancers. While LE hypermobility status influenced balance in the female collegiate dancers, how this LE hypermobility status affects their longitudinal injury risk as their careers progress needs further study. Overall, the current findings suggest that rather than using isolated core endurance-centric training, clinicians may encourage dancers to use training programs that incorporate multiple muscles - in order to improve their balance, and possibly reduce their LE injury risk. Level of Evidence 2b PMID:27104055

Utility and applicability of the "Childhood Obesity Risk Evaluation" (CORE)-index in predicting obesity in childhood and adolescence in Greece from early life: the "National Action Plan for Public Health".

PubMed

Manios, Yannis; Vlachopapadopoulou, Elpis; Moschonis, George; Karachaliou, Feneli; Psaltopoulou, Theodora; Koutsouki, Dimitra; Bogdanis, Gregory; Carayanni, Vilelmine; Hatzakis, Angelos; Michalacos, Stefanos

2016-12-01

Early identification of infants being at high risk to become obese at their later childhood or adolescence can be of vital importance in any obesity prevention initiative. The aim of the present study was to examine the utility and applicability of the "Childhood Obesity Risk Evaluation (CORE)" index as a screening tool for the early prediction of obesity in childhood and adolescence. Anthropometric, socio-demographic data were collected cross-sectionally and retrospectively from a representative sample of 5946 children, and adolescents and were combined for calculating the CORE-index score. Logistic regression analyses were performed to examine the associations of the CORE-index score with obesity by gender and age group, and cut-off point analysis was also applied to identify the optimal value of the CORE-index score that differentiates obese from non-obese children. Mean CORE-index score in the total sample was 3.06 (sd 1.92) units (range 0-11 units). Each unit increase in the CORE-index score was found to be associated with a 30 % (95 % C.I. 1.24-1.36) increased likelihood for obesity in childhood or adolescence, while the optimal cut-off value of the CORE-index score that predicted obesity with the highest possible sensitivity and specificity was found to be 3.5. The present study supports the utility and applicability of the CORE-index as a screening tool for the early identification of infants that are potentially at a higher risk for becoming obese at their childhood and adolescence. This tool could be routinely used by health professionals to identify infants at high risk and provide appropriate counselling to their parents and caregivers so as to maximize the effectiveness of early obesity prevention initiatives. What is known? • Childhood obesity has reached epidemic proportions worldwide. • Certain perinatal and socio-demographic indices that were previously identified as correlates of childhood obesity in children were combined to develop the CORE-index, a screening tool that estimates obesity risk in 9-13 year-old children. What is new? • The utility and applicability of the CORE-index as screening tool can be extended to the age range of 6-15 years. • The CORE-index is a cost-effective screening tool that can assist health professionals in initiating obesity preventive measures from early life.

Gravity or turbulence? - III. Evidence of pure thermal Jeans fragmentation at ˜0.1 pc scale

NASA Astrophysics Data System (ADS)

Palau, Aina; Ballesteros-Paredes, Javier; Vázquez-Semadeni, Enrique; Sánchez-Monge, Álvaro; Estalella, Robert; Fall, S. Michael; Zapata, Luis A.; Camacho, Vianey; Gómez, Laura; Naranjo-Romero, Raúl; Busquet, Gemma; Fontani, Francesco

2015-11-01

We combine previously published interferometric and single-dish data of relatively nearby massive dense cores that are actively forming stars to test whether their `fragmentation level' is controlled by turbulent or thermal support. We find no clear correlation between the fragmentation level and velocity dispersion, nor between the observed number of fragments and the number of fragments expected when the gravitationally unstable mass is calculated including various prescriptions for `turbulent support'. On the other hand, the best correlation is found for the case of pure thermal Jeans fragmentation, for which we infer a core formation efficiency around 13 per cent, consistent with previous works. We conclude that the dominant factor determining the fragmentation level of star-forming massive dense cores at 0.1 pc scale seems to be thermal Jeans fragmentation.

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

West, Bradley M.; Stuckelberger, Michael; Guthrey, Harvey

We present that statistical and correlative analysis are increasingly important in the design and study of new materials, from semiconductors to metals. Non-destructive measurement techniques, with high spatial resolution, capable of correlating composition and/or structure with device properties, are few and far between. For the case of polycrystalline and inhomogeneous materials, the added challenge is that nanoscale resolution is in general not compatible with the large sampling areas necessary to have a statistical representation of the specimen under study. For the study of grain cores and grain boundaries in polycrystalline solar absorbers this is of particular importance since their dissimilarmore » behavior and variability throughout the samples makes it difficult to draw conclusions and ultimately optimize the material. In this study, we present a nanoscale in-operando approach based on the multimodal utilization of synchrotron nano x-ray fluorescence and x-ray beam induced current collected for grain core and grain boundary areas and correlated pixel-by-pixel in fully operational Cu(In (1-x)Ga x)Se 2 solar cells. We observe that low gallium cells have grain boundaries that over perform compared to the grain cores and high gallium cells have boundaries that under perform. In conclusion, these results demonstrate how nanoscale correlative X-ray microscopy can guide research pathways towards grain engineering low cost, high efficiency solar cells.« less

FORTRAN programs to process Magsat data for lithospheric, external field, and residual core components

NASA Technical Reports Server (NTRS)

Alsdorf, Douglas E.; Vonfrese, Ralph R. B.

1994-01-01

The FORTRAN programs supplied in this document provide a complete processing package for statistically extracting residual core, external field and lithospheric components in Magsat observations. To process the individual passes: (1) orbits are separated into dawn and dusk local times and by altitude, (2) passes are selected based on the variance of the magnetic field observations after a least-squares fit of the core field is removed from each pass over the study area, and (3) spatially adjacent passes are processed with a Fourier correlation coefficient filter to separate coherent and non-coherent features between neighboring tracks. In the second state of map processing: (1) data from the passes are normalized to a common altitude and gridded into dawn and dusk maps with least squares collocation, (2) dawn and dusk maps are correlated with a Fourier correlation efficient filter to separate coherent and non-coherent features; the coherent features are averaged to produce a total field grid, (3) total field grids from all altitudes are continued to a common altitude, correlation filtered for coherent anomaly features, and subsequently averaged to produce the final total field grid for the study region, and (4) the total field map is differentially reduced to the pole.

The Dissociation Energies of CH4 and C2H2 Revisited

NASA Technical Reports Server (NTRS)

Partridge, Harry; Bauschlicher, Charles W., Jr.; Langhoff, Stephen R. (Technical Monitor)

1995-01-01

The bond dissociation energies of CH4 and C2H2 and their fragments are investigated using basis set extrapolations and high levels of correlation. The computed bond dissociation energies (D(sub e)) are accurate to within 0.2 kcal/mol. The agreement with the experimental (D(sub 0)) values is excellent if we assume that the zero-point energy of C2H is 9.18 kcal/mol. The effect of core (1s) correlation on the bond dissociation energies of C-H bonds is shown to vary from 0.2 to 0.7 kcal/mol and that for C-C bonds varies from 0.4 to 2.2 kcal/mol.

Dependence of Coulomb Sum Rule on the Short Range Correlation by Using Av18 Potential

NASA Astrophysics Data System (ADS)

Modarres, M.; Moeini, H.; Moshfegh, H. R.

The Coulomb sum rule (CSR) and structure factor are calculated for inelastic electron scattering from nuclear matter at zero and finite temperature in the nonrelativistic limit. The effect of short-range correlation (SRC) is presented by using lowest order constrained variational (LOCV) method and the Argonne Av18 and Δ-Reid soft-core potentials. The effects of different potentials as well as temperature are investigated. It is found that the nonrelativistic version of Bjorken scaling approximately sets in at the momentum transfer of about 1.1 to 1.2 GeV/c and the increase of temperature makes it to decrease. While different potentials do not significantly change CSR, the SRC improves the Coulomb sum rule and we get reasonably close results to both experimental data and others theoretical predictions.

Accurate study on the properties of spectral lines for Br-like W39+

NASA Astrophysics Data System (ADS)

Guo, X. L.; Li, M. C.; Si, R.; He, X. D.; Wang, K.; Dai, Z. T.; Liu, Y. M.; Zhang, H. J.; Chen, C. Y.

2018-01-01

As a primary candidate in tokamak plasmas, the spectroscopic parameters of tungsten ions have been studied extensively over the past decade. In this paper, we perform calculations of excitation energies, lifetimes, wavelengths and transition rates for all levels of the 4{s}24{p}5, 4{s}24{p}44d, and 4s4{p}6 configurations of {{{W}}}39+ by using the multiconfiguration Dirac-Hartree-Fock (MCDHF) method, and also the relativistic many-body perturbation theory (RMBPT) method. Detailed convergence studies on excitation energy from electron-correlation effects and relativistic effects are presented. It is necessary to include the core-valence correlation from deep lying subshells, e.g. 3d and 3p, to produce reliable atomic parameters. Results are compared with available theoretical and experimental work, and the accuracy of the results is confirmed.

Correlates of Identity Configurations: Three Studies with Adolescent and Emerging Adult Cohorts

ERIC Educational Resources Information Center

Crocetti, Elisabetta; Scrignaro, Marta; Sica, Luigia Simona; Magrin, Maria Elena

2012-01-01

Adolescence and emerging adulthood are two core developmental periods in which individuals can develop a meaningful identity across domains. However, there is a lack of studies exploring correlates of different identity configurations. The purpose of this article was to fill this gap in examining correlates of configurations characterized by…

Effect of Heat on Space-Time Correlations in Jets

NASA Technical Reports Server (NTRS)

Bridges, James

2006-01-01

Measurements of space-time correlations of velocity, acquired in jets from acoustic Mach number 0.5 to 1.5 and static temperature ratios up to 2.7 are presented and analyzed. Previous reports of these experiments concentrated on the experimental technique and on validating the data. In the present paper the dataset is analyzed to address the question of how space-time correlations of velocity are different in cold and hot jets. The analysis shows that turbulent kinetic energy intensities, lengthscales, and timescales are impacted by the addition of heat, but by relatively small amounts. This contradicts the models and assumptions of recent aeroacoustic theory trying to predict the noise of hot jets. Once the change in jet potential core length has been factored out, most one- and two-point statistics collapse for all hot and cold jets.

The effects of the Chesapeake Bay impact crater on the geologic framework and the correlation of hydrogeologic units of southeastern Virginia, south of the James River

USGS Publications Warehouse

Powars, David S.

2000-01-01

About 35 million years ago, a large comet or meteor slammed into the shallow shelf on the western margin of the Atlantic Ocean, creating the Chesapeake Bay impact crater. This report, the second in a series, refines the geologic framework of southeastern Virginia, south of the James River in and near the impact crater, and presents evidence for the existence of a pre-impact James River structural zone. The report includes detailed correlations of core lithologies with borehole geophysical logs; the correlations provide the foundation for the compilation of stratigraphic cross sections. These cross sections are tied into the geologic framework of the lower York-James Peninsula as presented in the first report in the series, Professional Paper 1612

Cone penetration test for facies study: a review

NASA Astrophysics Data System (ADS)

Satriyo, N. A.; Soebowo, E.

2018-02-01

Engineering geology investigation through Cone Penetration Test (with pore-pressure measurements) approach is one of the most effective methods to find out sub surface layer. This method is generally used in Late Quaternary and typical deposit and can also be used for sedimentological purposes. CPTu and drilling core for high-resolution stratigraphy sub surface have been done in many research. These combined data can also be used to detail correlations of sub surface stratigraphy, to identify facies change and to determine the interpretation of sequence stratigraphy. The determination facies distribution research based on CPTu profile, which was included in quantitative data, is rarely done especially in Indonesia which has a different climate. Whereas drilling core description using grain size analysis will provide information on validation about physical lithology characteristics which are developed in research area. The interpretation is given using CPTu curve pattern and cone resistance parameter of CPTu’s data correlated with physical characteristics of drilling core. The cone resistance will provide the strength of the sediment layer which also gives the range of data between clay and sand. Finally, the review will show that each of developing facies characteristic provides a specific curve pattern and every sediment deposit facies can be determined by the transformation of CPTu curve profile. Despite the fact that the research using those methods are quite comprehensive, a review is presented on each of these methods related with the chronologic factor seen by the geological time and different characteristics sediment of different location.

Assessment of toxicology knowledge in the fourth-year medical students: Three years of data.

PubMed

Buchanan, Jennie; Windels, Daniel; Druck, Jeffrey; Heard, Kennon

2018-01-01

Pharmacology and toxicology are core content knowledge for physicians. Medical students should demonstrate understanding of general pharmacology and basic treatment of poisoning. The objective of this study was to measure the knowledge of the 4th-year medical students (MS4) on these topics over 3 years. A multiple-choice exam (15 questions) was administered to MS4 students in spring of 2010, 2011, and 2012. Questions were developed by medical toxicologists to evaluate basic knowledge in three areas: pharmacologic effects (PE), treatment of poisoning (TOP), and pharmacokinetics (PK). The students were grouped by intended specialties into pharmacologic intense (anesthesia, emergency medicine, internal medicine, pediatrics, and psychiatry), less pharmacologic intense specialties (dermatology, OB/GYN, ophthalmology, pathology, physical medicine and rehabilitation, radiology, and surgery) and by completion of a pharmacology or toxicology elective. Mean group scores were compared using ANOVA. Totally 332 of 401 (83%) students completed the survey. Mean scores were stable over the three years, higher for students completing a toxicology rotation and for students entering a pharmacologically intense specialty. The external validity is limited to a single medical school with incomplete participation and content was limited by the survey length. Consistent results over the three-year period and correlation of performance with completing a toxicology rotation and intent to enter a pharmacology intensive specialty suggest this survey may correlate with toxicology knowledge. Implementation of required core courses focused on toxicology may improve core content knowledge in fourth year medical students.

Multiscale Aspects of Generation of High-Gamma Activity during Seizures in Human Neocortex123

PubMed Central

Marcuccilli, Charles J.; Ben-Mabrouk, Faiza; Lew, Sean M.; Goodman, Robert R.; McKhann, Guy M.; Frim, David M.; Kohrman, Michael H.; Schevon, Catherine A.; van Drongelen, Wim

2016-01-01

High-gamma (HG; 80-150 Hz) activity in macroscopic clinical records is considered a marker for critical brain regions involved in seizure initiation; it is correlated with pathological multiunit firing during neocortical seizures in the seizure core, an area identified by correlated multiunit spiking and low frequency seizure activity. However, the effects of the spatiotemporal dynamics of seizure on HG power generation are not well understood. Here, we studied HG generation and propagation, using a three-step, multiscale signal analysis and modeling approach. First, we analyzed concurrent neuronal and microscopic network HG activity in neocortical slices from seven intractable epilepsy patients. We found HG activity in these networks, especially when neurons displayed paroxysmal depolarization shifts and network activity was highly synchronized. Second, we examined HG activity acquired with microelectrode arrays recorded during human seizures (n = 8). We confirmed the presence of synchronized HG power across microelectrode records and the macroscale, both specifically associated with the core region of the seizure. Third, we used volume conduction-based modeling to relate HG activity and network synchrony at different network scales. We showed that local HG oscillations require high levels of synchrony to cross scales, and that this requirement is met at the microscopic scale, but not within macroscopic networks. Instead, we present evidence that HG power at the macroscale may result from harmonics of ongoing seizure activity. Ictal HG power marks the seizure core, but the generating mechanism can differ across spatial scales. PMID:27257623

An experimental and theoretical study to relate uncommon rock/fluid properties to oil recovery. Final report

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

Watson, R.

Waterflooding is the most commonly used secondary oil recovery technique. One of the requirements for understanding waterflood performance is a good knowledge of the basic properties of the reservoir rocks. This study is aimed at correlating rock-pore characteristics to oil recovery from various reservoir rock types and incorporating these properties into empirical models for Predicting oil recovery. For that reason, this report deals with the analyses and interpretation of experimental data collected from core floods and correlated against measurements of absolute permeability, porosity. wettability index, mercury porosimetry properties and irreducible water saturation. The results of the radial-core the radial-core andmore » linear-core flow investigations and the other associated experimental analyses are presented and incorporated into empirical models to improve the predictions of oil recovery resulting from waterflooding, for sandstone and limestone reservoirs. For the radial-core case, the standardized regression model selected, based on a subset of the variables, predicted oil recovery by waterflooding with a standard deviation of 7%. For the linear-core case, separate models are developed using common, uncommon and combination of both types of rock properties. It was observed that residual oil saturation and oil recovery are better predicted with the inclusion of both common and uncommon rock/fluid properties into the predictive models.« less

Development and psychometric evaluation of the Core Nurse Resource Scale.

PubMed

Simpson, Michelle R

2010-11-01

To examine the factor structure, internal consistency reliability and concurrent-related validity of the Core Nurse Resource Scale. A cross-sectional survey study design was used to obtain a sample of 149 nurses and nursing staff [Registered Nurse (RNs), Licensed Practical Nurse (LPNs) and Certified Nursing Assistant (CNAs)] working in long-term care facilities. Exploratory factor analysis, Cronbach's alpha and bivariate correlations were used to evaluate validity and reliability. Exploratory factor analysis yielded a scale with 18 items on three factors, accounting for 52% of the variance in scores. Internal consistency reliability for the composite and Core Nurse Resource Scale factors ranged from 0.79 to 0.91. The Core Nurse Resource Scale composite scale and subscales correlated positively with a measure of work engagement (r=0.247-0.572). The initial psychometric evaluation of the Core Nurse Resource Scale demonstrates it is a sound measure. Further validity and reliability assessment will need to be explored and assessed among nurses and other nursing staff working in other practice settings. The intent of the Core Nurse Resource Scale is to evaluate the presence of physical, psychological and social resources of the nursing work environment, to identify workplaces at risk for disengaged (low work engagement) nursing staff and to provide useful diagnostic information to healthcare administrators interested in interventions to improve the nursing work environment. © 2010 The Author. Journal compilation © 2010 Blackwell Publishing Ltd.

Moving Away from Exhaustion: How Core Self-Evaluations Influence Academic Burnout

PubMed Central

Lian, Penghu; Sun, Yunfeng; Ji, Zhigang; Li, Hanzhong; Peng, Jiaxi

2014-01-01

Background Academic burnout refers to students who have low interest, lack of motivation, and tiredness in studying. Studies concerning how to prevent academic burnout are rare. Objective The present study aimed to investigate the impact of core self-evaluations on the academic burnout of university students, and mainly focused on the confirmation of the mediator role of life satisfaction. Methods A total of 470 university students accomplished the core self-evaluation scale, Satisfaction with Life, and academic burnout scale. Results Both core self-evaluations and life satisfaction were significantly correlated with academic burnout. Structural equation modeling indicated that life satisfaction partially mediated the relationship between core self-evaluations and academic burnout. Conclusions Core self-evaluations significantly influence academic burnout and are partially mediated by life satisfaction. PMID:24489857

A facile one-pot oxidation-assisted dealloying protocol to massively synthesize monolithic core-shell architectured nanoporous copper@cuprous oxide nanonetworks for photodegradation of methyl orange

PubMed Central

Liu, Wenbo; Chen, Long; Dong, Xin; Yan, Jiazhen; Li, Ning; Shi, Sanqiang; Zhang, Shichao

2016-01-01

In this report, a facile and effective one-pot oxidation-assisted dealloying protocol has been developed to massively synthesize monolithic core-shell architectured nanoporous copper@cuprous oxide nanonetworks (C-S NPC@Cu2O NNs) by chemical dealloying of melt-spun Al 37 at.% Cu alloy in an oxygen-rich alkaline solution at room temperature, which possesses superior photocatalytic activity towards photodegradation of methyl orange (MO). The experimental results show that the as-prepared nanocomposite exhibits an open, bicontinuous interpenetrating ligament-pore structure with length scales of 20 ± 5 nm, in which the ligaments comprising Cu and Cu2O are typical of core-shell architecture with uniform shell thickness of ca. 3.5 nm. The photodegradation experiments of C-S NPC@Cu2O NNs show their superior photocatalytic activities for the MO degradation under visible light irradiation with degradation rate as high as 6.67 mg min−1 gcat−1, which is a diffusion-controlled kinetic process in essence in light of the good linear correlation between photodegradation ratio and square root of irradiation time. The excellent photocatalytic activity can be ascribed to the synergistic effects between unique core-shell architecture and 3D nanoporous network with high specific surface area and fast mass transfer channel, indicating that the C-S NPC@Cu2O NNs will be a promising candidate for photocatalysts of MO degradation. PMID:27830720

A facile one-pot oxidation-assisted dealloying protocol to massively synthesize monolithic core-shell architectured nanoporous copper@cuprous oxide nanonetworks for photodegradation of methyl orange

NASA Astrophysics Data System (ADS)

Liu, Wenbo; Chen, Long; Dong, Xin; Yan, Jiazhen; Li, Ning; Shi, Sanqiang; Zhang, Shichao

2016-11-01

In this report, a facile and effective one-pot oxidation-assisted dealloying protocol has been developed to massively synthesize monolithic core-shell architectured nanoporous copper@cuprous oxide nanonetworks (C-S NPC@Cu2O NNs) by chemical dealloying of melt-spun Al 37 at.% Cu alloy in an oxygen-rich alkaline solution at room temperature, which possesses superior photocatalytic activity towards photodegradation of methyl orange (MO). The experimental results show that the as-prepared nanocomposite exhibits an open, bicontinuous interpenetrating ligament-pore structure with length scales of 20 ± 5 nm, in which the ligaments comprising Cu and Cu2O are typical of core-shell architecture with uniform shell thickness of ca. 3.5 nm. The photodegradation experiments of C-S NPC@Cu2O NNs show their superior photocatalytic activities for the MO degradation under visible light irradiation with degradation rate as high as 6.67 mg min-1 gcat-1, which is a diffusion-controlled kinetic process in essence in light of the good linear correlation between photodegradation ratio and square root of irradiation time. The excellent photocatalytic activity can be ascribed to the synergistic effects between unique core-shell architecture and 3D nanoporous network with high specific surface area and fast mass transfer channel, indicating that the C-S NPC@Cu2O NNs will be a promising candidate for photocatalysts of MO degradation.

Historical Review of the Correlation of Ballistic and Metallurgical Characteristics of Domestic Armor at Watertown Arsenal

DTIC Science & Technology

1945-12-07

really under- stood. It was learned, then that pearlitic and bainitic microstructures imparted poor impact toughness to steels , pearlitic structures...having a more detrimental effect than bainitic structures, and that a steel could show little or no free ferrite and still pofssess poor shock resistance...arsenal for metallurgical study. The studies at the arsenal revealed that presence of bainitic structures in the core of low alloy NS type steels

Does core mobility of lumbar total disc arthroplasty influence sagittal and frontal intervertebral displacement? Radiologic comparison with fixed-core prosthesis

PubMed Central

Delécrin, Joël; Allain, Jérôme; Beaurain, Jacques; Steib, Jean-Paul; Chataigner, Hervé; Aubourg, Lucie; Huppert, Jean; Ameil, Marc; Nguyen, Jean-Michel

2009-01-01

Background An artificial disc prosthesis is thought to restore segmental motion in the lumbar spine. However, it is reported that disc prosthesis can increase the intervertebral translation (VT). The concept of the mobile-core prosthesis is to mimic the kinematic effects of the migration of the natural nucleus and therefore core mobility should minimize the VT. This study explored the hypothesis that core translation should influence VT and that a mobile core prosthesis may facilitate physiological motion. Methods Vertebral translation (measured with a new method presented here), core translation, range of motion (ROM), and distribution of flexion-extension were measured on flexion-extension, neutral standing, and lateral bending films in 89 patients (63 mobile-core [M]; 33 fixed-core [F]). Results At L4-5 levels the VT with M was lower than with F and similar to the VT of untreated levels. At L5-S1 levels the VT with M was lower than with F but was significantly different compared to untreated levels. At M levels a strong correlation was found between VT and core translation; the VT decreases as the core translation increases. At F levels the VT increases as the ROM increases. No significant difference was found between the ROM of untreated levels and levels implanted with either M or F. Regarding the mobility distribution with M and F we observed a deficit in extension at L5-S1 levels and a similar distribution at L4-5 levels compared to untreated levels. Conclusion The intervertebral mobility was different between M and F. The M at L4-5 levels succeeded to replicate mobility similar to L4-5 untreated levels. The M at L5-S1 succeeded in ROM, but failed regarding VT and mobility distribution. Nevertheless M minimized VT at L5-S1 levels. The F increased VT at both L4-5 and L5-S1. Clinical Relevance This study validates the concept that the core translation of an artificial lumbar disc prosthesis minimizes the VT. PMID:25802632

The use of standardized patients in the plastic surgery residency curriculum: teaching core competencies with objective structured clinical examinations.

PubMed

Davis, Drew; Lee, Gordon

2011-07-01

As of 2006, the Accreditation Council for Graduate Medical Education had defined six "core competencies" of residency education: interpersonal communication skills, medical knowledge, patient care, professionalism, practice-based learning and improvement, and systems-based practice. Objective structured clinical examinations using standardized patients are becoming effective educational tools, and the authors developed a novel use of the examinations in plastic surgery residency education that assesses all six competencies. Six plastic surgery residents, two each from postgraduate years 4, 5, and 6, participated in the plastic surgery-specific objective structured clinical examination that focused on melanoma. The examination included a 30-minute videotaped encounter with a standardized patient actor and a postencounter written exercise. The residents were scored on their performance in all six core competencies by the standardized patients and faculty experts on a three-point scale (1 = novice, 2 = moderately skilled, and 3 = proficient). Resident performance was averaged for each postgraduate year, stratified according to core competency, and scored from a total of 100 percent. Residents overall scored well in interpersonal communications skills (84 percent), patient care (83 percent), professionalism (86 percent), and practice-based learning (84 percent). Scores in medical knowledge showed a positive correlation with level of training (86 percent). All residents scored comparatively lower in systems-based practice (65 percent). The residents reported unanimously that the objective structured clinical examination was realistic and educational. The objective structured clinical examination provided comprehensive and meaningful feedback and identified areas of strengths and weakness for the residents and for the teaching program. The examination is an effective assessment tool for the core competencies and a valuable adjunct to residency training.

Solar Wind 0.1-1 keV Electrons in the Corotating Interaction Regions

NASA Astrophysics Data System (ADS)

Wang, L.; Tao, J.; Li, G.; Wimmer-Schweingruber, R. F.; Jian, L. K.; He, J.; Tu, C.; Tian, H.; Bale, S. D.

2017-12-01

Here we present a statistical study of the 0.1-1 keV suprathermal electrons in the undisturbed and compressed slow/fast solar wind, for the 71 corotating interaction regions (CIRs) with good measurements from the WIND 3DP and MFI instruments from 1995 to 1997. For each of these CIRs, we separate the strahl and halo electrons based on their different behaviors in pitch angle distributions in the undisturbed and compressed solar wind. We fit both the strahl and halo energy spectra to a kappa function with an index κ index and effective temperature Teff, and calculate the pitch-angle width at half-maximum (PAHM) of the strahl population. We also integrate the electron measurements between 0.1 and 1.0 keV to obtain the number density n and average energy Eavg for the strahl and halo populations. We find that for both the strahl and halo populations within and around these CIRs, the fitted κ index strongly correlates with Teff, similar to the quiet-time solar wind (Tao et al., ApJ, 2016). The number density of both the strahl and halo shows a strong positive correlation with the electron core temperature. The strahl number density ns is correlated with the magnitude of interplanetary magnetic field, and the strahl PAHM width is anti-correlated with the solar wind speed. These results suggest that the origin of strahl electrons from the solar corona is likely related to the electron core temperature and magnetic field strength, while the production of halo electrons in the interplanetary medium could depend on the solar wind velocity.

Ability of sextant biopsies to predict radical prostatectomy stage.

PubMed

Wills, M L; Sauvageot, J; Partin, A W; Gurganus, R; Epstein, J I

1998-05-01

There are few studies evaluating multiple variables on sextant biopsies with the intent to predict stage in radical prostatectomy specimens. We studied 113 sextant biopsies with corresponding totally submitted radical prostatectomy specimens. Variables evaluated on sextant biopsies included total length and percent of cancer; maximum length and percent of cancer on one core; location (apex, mid, base); bilaterality; Gleason grade; number of cores involved; serum prostate-specific antigen (PSA) level; and serum PSA density (PSAD). Radical prostatectomy stage was classified as organ versus non-organ confined. The following variables individually correlated with radical prostatectomy stage: total cancer measured in millimeters (P <0.0001) or percent (P <0.0005); biopsy Gleason score (P <0.0001); number of involved cores (P <0.0001); maximum cancer on one core measured in millimeters (P = 0.0001); maximum percent of cancer on one core (P = 0.01); bilaterality (P = 0.01); PSA level (P = 0.03), and PSAD (P = 0.001). The most predictive sets of two variables that correlated with stage included high Gleason score (P <0.0001) combined with numbers of cores involved (P = 0.002). When biopsies had Gleason scores of 6 or less, two or fewer positive cores, and serum PSA of 0 to 4 ng/mL, 89% were organ confined. When biopsies had Gleason scores of 6 or less with two unilaterally positive cores, 87% were organ confined. In biopsies with Gleason scores of 7 or more and more than one positive core, only 10% were organ confined. The most important predictors of stage by sextant needle biopsy evaluation are numbers of cores involved with carcinoma and high Gleason score. Bilaterality and serum PSA values improved prediction in two small subgroups. In 37% of our population we were able to predict with a greater than 87% probability the organ-confined versus non-organ-confined status.

Discovering the desirable alleles contributing to the lignocellulosic biomass traits in saccharum germplasm collections for energy cane improvement

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

Todd, James; Comstock, Jack C.

Phenotyping Methods: The accessions (which includes 21 taxa and 1,177 accessions) in the World Collection of Sugarcane and Related Grasses (WCSRG) was evaluated for the following traits: arenchyma, internode length and diameter, pubescence, pith, Brix, stalk number and fiber. A core of 300 accessions that included each species in the World Collection was selected by using the Maximization Strategy in MStrat software. Results: The core had a higher diversity rating than random selections of 300 accessions. The Shannon–Weaver Diversity Index scores of the core and whole collection were similar indicating that the majority of the diversity was captured by themore » core collection. The ranges and medians between the core and WCSRG were similar; only two of the trait medians were not significant at P = 0.05 using the non-parametric Wilcoxon method and the coincidence rate (CR % = 96.2) was high (>80) indicating that extreme values were retained. Thus, the phenotypic diversity of these traits in the WCSRG was well represented by the core collection. Associations Methods: Genotypic and phenotypic data were collected for 1002 accessions of the WCSRG including 209 SSR markers. Association analysis was performed using both General Linear (GLM) and Maximum Likelihood (MLM) models. Different core collections with 300 accessions each were selected based on genotypic, phenotypic and combined data based on the Maximization Strategy in MStrat software. Results: A major portion of the genotyping involving SNPs is being conducted by Dr. Jianping Wang of the University of Florida under the DOE award DE-FG 02-11ER 65214 and the genotypic and phenotypic associations will be reported separately next year. In the current, study forty one and seventeen markers were found to be associated with traits using the GLM and MLM methods respectively including associations with arenchyma, internode length and diameter, pubescence, pith, and Sugar Cane Yellow Leaf Virus. The data indicates that each of the cores and the World Collection are similar to each other genotypically and phenotypically, but the core that was selected using only genotypic data was significantly different phenotypically. This indicates that there is not enough association between the genotypic and phenotypic diversity as to select using only genotypic diversity and get the full phenotypic diversity. Core Collection: Creation and Phenotyping Methods: To evaluate this germplasm for breeding purposes, a representative diversity panel selected from the WCSRG of approximately 300 accessions was planted at Canal Point, FL in three replications. These accessions were measured for stalk height and stalk number multiple times throughout the growing season and Brix and fresh biomass during harvest in 2013 and, stalk height, stalk number, stalk diameter, internode length, Brix and fresh and dry biomass was determined in the ratoon crop harvest in 2014. Results: In correlations of multiple measurements, there were higher correlations for early measurements of stalk number and stalk height with harvest traits like Brix and fresh weight. Hybrids had higher fresh mass and Brix while Saccharum spontaneum had higher stalk number and dry mass. The heritability of hybrid mass traits was lower in the ratoon crop. According to the principal component analysis, the diversity panel was divided into two groups. One group had accessions with high stalk number and high dry biomass like S. spontaneum and the other groups contained accessions with higher Brix and fresh biomass like S. officinarum. Mass traits correlated with each other as expected but hybrids had lower correlations between fresh and dry mass. Stalk number and the mass traits correlated with each other except in S. spontaneum and hybrids in the first ratoon. There were 110 accessions not significantly different in Brix from the commercial sugarcane checks including 10 S. spontaneum accessions. There were 27 dry and 6 fresh mass accessions significantly higher than the commercial sugarcane checks. Core Collection: Fiber analysis Methods: A biomass sample was taken from each accession then shredded and dried. Fiber analysis was then performed on each sample. The acetyl groups, acid insoluble lignin, acid soluble lignin, arabinan, glucan, holocellulose, total lignin, structural ash, and xylan were quantified on a % fiber basis and nonstructural ash on a % total basis. Results: There were significant, but not large differences between species for holocellulose, lignin, acetyl, acid soluble lignin, nonstructural ash, and glucan. For each trait, S. spontaneum had significantly more holocellulose, glucan, lignin, and nonstructural ash and less acetyl and acid soluble lignin than the other species. In all populations, glucan and was positively correlated with holocellulose were positively correlated and glucan and and holocellulose were negatively correlated with lignin. In hybrids, internode length correlated positively with holocellulose and nonstructural ash and negatively with lignin. The heritability estimates for each of the fiber component traits is low indicating that environment is an important factor in fiber composition. Principal component analysis indicated that a large amount of diversity exists within each of the species.« less

Gaussian basis sets for use in correlated molecular calculations. XI. Pseudopotential-based and all-electron relativistic basis sets for alkali metal (K-Fr) and alkaline earth (Ca-Ra) elements

NASA Astrophysics Data System (ADS)

Hill, J. Grant; Peterson, Kirk A.

2017-12-01

New correlation consistent basis sets based on pseudopotential (PP) Hamiltonians have been developed from double- to quintuple-zeta quality for the late alkali (K-Fr) and alkaline earth (Ca-Ra) metals. These are accompanied by new all-electron basis sets of double- to quadruple-zeta quality that have been contracted for use with both Douglas-Kroll-Hess (DKH) and eXact 2-Component (X2C) scalar relativistic Hamiltonians. Sets for valence correlation (ms), cc-pVnZ-PP and cc-pVnZ-(DK,DK3/X2C), in addition to outer-core correlation [valence + (m-1)sp], cc-p(w)CVnZ-PP and cc-pwCVnZ-(DK,DK3/X2C), are reported. The -PP sets have been developed for use with small-core PPs [I. S. Lim et al., J. Chem. Phys. 122, 104103 (2005) and I. S. Lim et al., J. Chem. Phys. 124, 034107 (2006)], while the all-electron sets utilized second-order DKH Hamiltonians for 4s and 5s elements and third-order DKH for 6s and 7s. The accuracy of the basis sets is assessed through benchmark calculations at the coupled-cluster level of theory for both atomic and molecular properties. Not surprisingly, it is found that outer-core correlation is vital for accurate calculation of the thermodynamic and spectroscopic properties of diatomic molecules containing these elements.

Learning Gains for Core Concepts in a Serious Game on Scientific Reasoning

ERIC Educational Resources Information Center

Forsyth, Carol; Pavlik, Philip, Jr.; Graesser, Arthur C.; Cai, Zhiqiang; Germany, Mae-lynn; Millis, Keith; Dolan, Robert P.; Butler, Heather; Halpern, Diane

2012-01-01

"OperationARIES!" is an Intelligent Tutoring System that teaches scientific inquiry skills in a game-like atmosphere. Students complete three different training modules, each with natural language conversations, in order to acquire deep-level knowledge of 21 core concepts of research methodology (e.g., correlation does not mean…

Constructing Core Journal Lists: Mixing Science and Alchemy.

ERIC Educational Resources Information Center

Corby, Katherine

2003-01-01

Via an overview of core journal studies, emphasizing the social sciences and education, this review looks for best practices in both motivation and methodology. Selection decisions receive particular focus. Lack of correlation between methods is indicative of the complexity of the topic and the need for judgment in design and use. (Author)

The Relationship between Leadership Behavior, the Thirteen Core Competencies, and Teacher Job Satisfaction

ERIC Educational Resources Information Center

Crane, Detris Nanette

2012-01-01

The purpose of this quantitative correlational study was to determine if teacher job satisfaction is enhanced when principals value and exhibit behaviors informed by the 13 core competencies. Principals and teachers from 70 elementary, middle, and high schools in the southeast United States participated in the study. The "Leadership Behavior…

Seasonal bacterial community succession in four typical wastewater treatment plants: correlations between core microbes and process performance.

PubMed

Zhang, Bo; Yu, Quanwei; Yan, Guoqi; Zhu, Hubo; Xu, Xiang Yang; Zhu, Liang

2018-03-15

To understand the seasonal variation of the activated sludge (AS) bacterial community and identify core microbes in different wastewater processing systems, seasonal AS samples were taken from every biological treatment unit within 4 full-scale wastewater treatment plants. These plants adopted A2/O, A/O and oxidation ditch processes and were active in the treatment of different types and sources of wastewater, some domestic and others industrial. The bacterial community composition was analyzed using high-throughput sequencing technology. The correlations among microbial community structure, dominant microbes and process performance were investigated. Seasonal variation had a stronger impact on the AS bacterial community than any variation within different wastewater treatment system. Facing seasonal variation, the bacterial community within the oxidation ditch process remained more stable those in either the A2/O or A/O processes. The core genera in domestic wastewater treatment systems were Nitrospira, Caldilineaceae, Pseudomonas and Lactococcus. The core genera in the textile dyeing and fine chemical industrial wastewater treatment systems were Nitrospira, Thauera and Thiobacillus.

Large-scale drivers of Caucasus climate variability in meteorological records and Mt El'brus ice cores

NASA Astrophysics Data System (ADS)

Kozachek, Anna; Mikhalenko, Vladimir; Masson-Delmotte, Valérie; Ekaykin, Alexey; Ginot, Patrick; Kutuzov, Stanislav; Legrand, Michel; Lipenkov, Vladimir; Preunkert, Susanne

2017-05-01

A 181.8 m ice core was recovered from a borehole drilled into bedrock on the western plateau of Mt El'brus (43°20'53.9'' N, 42°25'36.0'' E; 5115 m a.s.l.) in the Caucasus, Russia, in 2009 (Mikhalenko et al., 2015). Here, we report on the results of the water stable isotope composition from this ice core with additional data from the shallow cores. The distinct seasonal cycle of the isotopic composition allows dating by annual layer counting. Dating has been performed for the upper 126 m of the deep core combined with 20 m from the shallow cores. The whole record covers 100 years, from 2013 back to 1914. Due to the high accumulation rate (1380 mm w.e. year-1) and limited melting, we obtained isotopic composition and accumulation rate records with seasonal resolution. These values were compared with available meteorological data from 13 weather stations in the region and also with atmosphere circulation indices, back-trajectory calculations, and Global Network of Isotopes in Precipitation (GNIP) data in order to decipher the drivers of accumulation and ice core isotopic composition in the Caucasus region. In the warm season (May-October) the isotopic composition depends on local temperatures, but the correlation is not persistent over time, while in the cold season (November-April), atmospheric circulation is the predominant driver of the ice core's isotopic composition. The snow accumulation rate correlates well with the precipitation rate in the region all year round, which made it possible to reconstruct and expand the precipitation record at the Caucasus highlands from 1914 until 1966, when reliable meteorological observations of precipitation at high elevation began.

Fermionic halos at finite temperature in AdS/CFT

NASA Astrophysics Data System (ADS)

Argüelles, Carlos R.; Grandi, Nicolás E.

2018-05-01

We explore the gravitational backreaction of a system consisting in a very large number of elementary fermions at finite temperature, in asymptotically AdS space. We work in the hydrodynamic approximation, and solve the Tolman-Oppenheimer-Volkoff equations with a perfect fluid whose equation of state takes into account both the relativistic effects of the fermionic constituents, as well as its finite temperature effects. We find a novel dense core-diluted halo structure for the density profiles in the AdS bulk, similarly as recently reported in flat space, for the case of astrophysical dark matter halos in galaxies. We further study the critical equilibrium configurations above which the core undergoes gravitational collapse towards a massive black hole, and calculate the corresponding critical central temperatures, for two qualitatively different central regimes of the fermions: the diluted-Fermi case, and the degenerate case. As a probe for the dual CFT, we construct the holographic two-point correlator of a scalar operator with large conformal dimension in the worldline limit, and briefly discuss on the boundary CFT effects at the critical points.

Structural Basis for Near Unity Quantum Yield Core/Shell Nanostructures

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

McBride, James; Treadway, Joe; Pennycook, Stephen J

2006-01-01

Aberration-corrected Z-contrast scanning transmission electron microscopy of core/shell nanocrystals shows clear correlations between structure and quantum efficiency. Uniform shell coverage is obtained only for a graded CdS/ZnS shell material and is found to be critical to achieving near 100% quantum yield. The sublattice sensitivity of the images confirms that preferential growth takes place on the anion-terminated surfaces. This explains the three-dimensional "nanobullet" shape observed in the case of core/shell nanorods.

HIV-1 Protease Function and Structure Studies with the Simplicial Neighborhood Analysis of Protein Packing (SNAPP) Method

PubMed Central

Zhang, Shuxing; Kaplan, Andrew H.; Tropsha, Alexander

2009-01-01

The Simplicial Neighborhood Analysis of Protein Packing (SNAPP) method was used to predict the effect of mutagenesis on the enzymatic activity of the HIV-1 protease (HIVP). SNAPP relies on a four-body statistical scoring function derived from the analysis of spatially nearest neighbor residue compositional preferences in a diverse and representative subset of protein structures from the Protein Data Bank. The method was applied to the analysis of HIVP mutants with residue substitutions in the hydrophobic core as well as at the interface between the two protease monomers. Both wild type and tethered structures were employed in the calculations. We obtained a strong correlation, with R2 as high as 0.96, between ΔSNAPP score (i.e., the difference in SNAPP scores between wild type and mutant proteins) and the protease catalytic activity for tethered structures. A weaker but significant correlation was also obtained for non-tethered structures as well. Our analysis identified residues both in the hydrophobic core and at the dimeric interface (DI) that are very important for the protease function. This study demonstrates a potential utility of the SNAPP method for rational design of mutagenesis studies and protein engineering. PMID:18498108

Localization of yeast RNA polymerase I core subunits by immunoelectron microscopy.

PubMed Central

Klinger, C; Huet, J; Song, D; Petersen, G; Riva, M; Bautz, E K; Sentenac, A; Oudet, P; Schultz, P

1996-01-01

Immunoelectron microscopy was used to determine the spatial organization of the yeast RNA polymerase I core subunits on a three-dimensional model of the enzyme. Images of antibody-labeled enzymes were compared with the native enzyme to determine the localization of the antibody binding site on the surface of the model. Monoclonal antibodies were used as probes to identify the two largest subunits homologous to the bacterial beta and beta' subunits. The epitopes for the two monoclonal antibodies were mapped using subunit-specific phage display libraries, thus allowing a direct correlation of the structural data with functional information on conserved sequence elements. An epitope close to conserved region C of the beta-like subunit is located at the base of the finger-like domain, whereas a sequence between conserved regions C and D of the beta'-like subunit is located in the apical region of the enzyme. Polyclonal antibodies outlined the alpha-like subunit AC40 and subunit AC19 which were found co-localized also in the apical region of the enzyme. The spatial location of the subunits is correlated with their biological activity and the inhibitory effect of the antibodies. Images PMID:8887555

Identification and correlation of crypto-tephra horizons within Marine Isotope Stages 5e to 4 of the NGRIP ice-core - culmination of the SMART research project

NASA Astrophysics Data System (ADS)

Meara, R. H.; Davies, S. M.; Abbott, P. M.; Pearce, N. J.; Austin, W. E.; Bigler, M.; Steffensen, J. P.; Svensson, A.

2012-12-01

The NERC-funded SMART (Synchronising MARine and ice-core records using Tephrochronology) project has focused on dating, correlating and synchronising palaeo climatic events during the last interglacial-glacial transition by developing a regional tephrochronological framework for the North Atlantic region. The NGRIP ice-core within the Greenland ice sheet is the focus of this work and here we report on the tephra horizons identified to date. A suite of c. 1,000 ice samples (c. 173 m) were subsampled, chosen for their relation to a) known tephra horizons in marine and terrestrial proxy records, b) prominent sulphate peaks and c) rapid climate transitions. To date, 10 new tephra horizons have been identified, ranging in age from 71,430 - 121,865 years b2k which add to the NGRIP tephras identified previously by Abbott et al. Individual tephra shards within each horizon have been geochemically characterised using both EMPA and LA-ICP-MS techniques. The tephras are typically basaltic in composition and show predominantly Icelandic compositions with sources identified as the Grimsvötn, Hekla-Katla and Veidivötn volcanic systems. Together with the work on the GRIP ice-core, a comprehensive suite of tephras now provides a detailed tephrochronological framework for the Greenland ice-sheet (Abbott et al. 2012). At present, four of the identified tephra horizons are candidates for correlation with known crypto-tephra horizons from marine records. These potential correlations present a robust means for dating and testing phase relationships and climate-forcing mechanisms associated with dramatic climate transitions during MIS stages 5e - 4.

Documenting the location of systematic transrectal ultrasound-guided prostate biopsies: correlation with multi-parametric MRI.

PubMed

Turkbey, Baris; Xu, Sheng; Kruecker, Jochen; Locklin, Julia; Pang, Yuxi; Shah, Vijay; Bernardo, Marcelino; Baccala, Angelo; Rastinehad, Ardeshir; Benjamin, Compton; Merino, Maria J; Wood, Bradford J; Choyke, Peter L; Pinto, Peter A

2011-03-29

During transrectal ultrasound (TRUS)-guided prostate biopsies, the actual location of the biopsy site is rarely documented. Here, we demonstrate the capability of TRUS-magnetic resonance imaging (MRI) image fusion to document the biopsy site and correlate biopsy results with multi-parametric MRI findings. Fifty consecutive patients (median age 61 years) with a median prostate-specific antigen (PSA) level of 5.8 ng/ml underwent 12-core TRUS-guided biopsy of the prostate. Pre-procedural T2-weighted magnetic resonance images were fused to TRUS. A disposable needle guide with miniature tracking sensors was attached to the TRUS probe to enable fusion with MRI. Real-time TRUS images during biopsy and the corresponding tracking information were recorded. Each biopsy site was superimposed onto the MRI. Each biopsy site was classified as positive or negative for cancer based on the results of each MRI sequence. Sensitivity, specificity, and receiver operating curve (ROC) area under the curve (AUC) values were calculated for multi-parametric MRI. Gleason scores for each multi-parametric MRI pattern were also evaluated. Six hundred and 5 systemic biopsy cores were analyzed in 50 patients, of whom 20 patients had 56 positive cores. MRI identified 34 of 56 positive cores. Overall, sensitivity, specificity, and ROC area values for multi-parametric MRI were 0.607, 0.727, 0.667, respectively. TRUS-MRI fusion after biopsy can be used to document the location of each biopsy site, which can then be correlated with MRI findings. Based on correlation with tracked biopsies, T2-weighted MRI and apparent diffusion coefficient maps derived from diffusion-weighted MRI are the most sensitive sequences, whereas the addition of delayed contrast enhancement MRI and three-dimensional magnetic resonance spectroscopy demonstrated higher specificity consistent with results obtained using radical prostatectomy specimens.

Connecting traces of galaxy evolution: the missing core mass-morphological fine structure relation

NASA Astrophysics Data System (ADS)

Bonfini, P.; Bitsakis, T.; Zezas, A.; Duc, P.-A.; Iodice, E.; González-Martín, O.; Bruzual, G.; González Sanoja, A. J.

2018-01-01

Deep exposure imaging of early-type galaxies (ETGs) are revealing the second-order complexity of these objects, which have been long considered uniform, dispersion-supported spheroidals. `Fine structure' features (e.g. ripples, plumes, tidal tails, rings) as well as depleted stellar cores (i.e. central light deficits) characterize a number of massive ETG galaxies, and can be interpreted as the result of galaxy-galaxy interactions. We discuss how the time-scale for the evolution of cores and fine structures are comparable, and hence it is expected that they develop in parallel after the major interaction event which shaped the ETG. Using archival data, we compare the `depleted stellar mass' (i.e. the mass missing from the depleted stellar core) against the prominence of the fine structure features, and observe that they correlate inversely. This result confirms our expectation that, while the supermassive black hole (SMBH) binary (constituted by the SMBHs of the merger progenitors) excavates the core via three-body interactions, the gravitational potential of the newborn galaxy relaxes, and the fine structures fade below detection levels. We expect the inverse correlation to hold at least within the first Gyr from the merger which created the SMBH binary; after then, the fine structure evolves independently.

Management of flat epithelial atypia on breast core biopsy may be individualized based on correlation with imaging studies.

PubMed

Calhoun, Benjamin C; Sobel, Amy; White, Richard L; Gromet, Matt; Flippo, Teresa; Sarantou, Terry; Livasy, Chad A

2015-05-01

Flat epithelial atypia of the breast commonly co-exists with atypical ductal hyperplasia, lobular neoplasia, and indolent forms of invasive carcinomas such as tubular carcinoma. Most patients with pure flat epithelial atypia on core biopsy undergo surgical excision to evaluate for carcinoma in the adjacent breast tissue. Studies to date have reported varying upgrade rates with most recommending follow-up excision. These studies have often lacked detailed radiographic correlation, central review by breast pathologists and information regarding the biology of the carcinomas identified upon excision. In this study, we report the frequency of upgrade to invasive carcinoma or ductal carcinoma in situ in excision specimens following a diagnosis of pure flat epithelial atypia on core biopsy. Radiographic correlation is performed for each case and grade/receptor status of detected carcinomas is reported. Seventy-three (73) core biopsies containing pure flat epithelial atypia were identified from our files, meeting inclusion criteria for the study. In the subsequent excision biopsies, five (7%) cases contained invasive carcinoma or ductal carcinoma in situ and seventeen (23%) contained atypical ductal hyperplasia or lobular neoplasia. All of the ductal carcinoma in situ cases with estrogen receptor results were estrogen receptor positive and intermediate grade. The invasive tumors were small (pT1a) hormone receptor-positive, HER2-negative, low-grade invasive ductal or tubular carcinomas with negative sentinel lymph-node biopsies. No upgrades were identified in the 14 patients who had all of their calcifications removed by the stereotactic core biopsy. Our rate of upgrade to carcinoma, once cases with discordant imaging are excluded, is at the lower end of the range reported in the literature. Given the low upgrade rate and indolent nature of the carcinomas associated with flat epithelial atypia, case management may be individualized based on clinical and radiographic findings. Excision may not be necessary for patients without remaining calcifications following core biopsy.

Comparison of a newly developed automated and quantitative hepatitis C virus (HCV) core antigen test with the HCV RNA assay for clinical usefulness in confirming anti-HCV results.

PubMed

Kesli, Recep; Polat, Hakki; Terzi, Yuksel; Kurtoglu, Muhammet Guzel; Uyar, Yavuz

2011-12-01

Hepatitis C virus (HCV) is a global health care problem. Diagnosis of HCV infection is mainly based on the detection of anti-HCV antibodies as a screening test with serum samples. Recombinant immunoblot assays are used as supplemental tests and for the final detection and quantification of HCV RNA in confirmatory tests. In this study, we aimed to compare the HCV core antigen test with the HCV RNA assay for confirming anti-HCV results to determine whether the HCV core antigen test may be used as an alternative confirmatory test to the HCV RNA test and to assess the diagnostic values of the total HCV core antigen test by determining the diagnostic specificity and sensitivity rates compared with the HCV RNA test. Sera from a total of 212 treatment-naive patients were analyzed for anti-HCV and HCV core antigen both with the Abbott Architect test and with the molecular HCV RNA assay consisting of a reverse transcription-PCR method as a confirmatory test. The diagnostic sensitivity, specificity, and positive and negative predictive values of the HCV core antigen assay compared to the HCV RNA test were 96.3%, 100%, 100%, and 89.7%, respectively. The levels of HCV core antigen showed a good correlation with those from the HCV RNA quantification (r = 0.907). In conclusion, the Architect HCV antigen assay is highly specific, sensitive, reliable, easy to perform, reproducible, cost-effective, and applicable as a screening, supplemental, and preconfirmatory test for anti-HCV assays used in laboratory procedures for the diagnosis of hepatitis C virus infection.

City Core - detecting the anthropocene in urban lake cores

NASA Astrophysics Data System (ADS)

Kjaer, K. H.; Ilsøe, P.; Andresen, C. S.; Rasmussen, P.; Andersen, T. J.; Frei, R.; Schreiber, N.; Odgaard, B.; Funder, S.; Holm, J. M.; Andersen, K.

2011-12-01

Here, we presents the preliminary results from lake cores taken in ditches associated with the historical fortifications enclosing the oldest - central Copenhagen to achieve new knowledge from sediment deposits related to anthropogenic activities. We have examined sediment cores with X-ray fluorescence (XRF) analyzers to correlate element patterns from urban and industrial emissions. Thus, we aim to track these patterns back in time - long before regular routines of recording of atmospheric environment began around 1978. Furthermore, we compare our data to alternative sources of information in order to constrain and expand the temporal dating limits (approximately 1890) achieved from 210Pb activity. From custom reports and statistic sources, information on imported volumes from coal, metal and oil was obtained and related contaminants from these substances to the sediment archives. Intriguingly, we find a steep increase in import of coal and metals matching the exponential increase of lead and zinc counts from XRF-recordings of the sediment cores. In this finding, we claim to have constrain the initiation of urban industrialization. In order to confirm the age resolution of the lake cores, DNA was extracted from sediments, sedaDNA. Thus we attempt to trace plantation of well documented exotic plants to, for instance, the Botanical Garden. Through extraction and sampling of sedaDNA from these floral and arboreal specimens we intend to locate their strataigraphic horizons in the sediment core. These findings may correlate data back to 1872, when the garden was established on the area of the former fortification. In this line of research, we hope to achieve important supplementary knowledge of sedaDNA-leaching frequencies within freshwater sediments.

Correlation of Wissler Human Thermal Model Blood Flow and Shiver Algorithms

NASA Technical Reports Server (NTRS)

Bue, Grant; Makinen, Janice; Cognata, Thomas

2010-01-01

The Wissler Human Thermal Model (WHTM) is a thermal math model of the human body that has been widely used to predict the human thermoregulatory response to a variety of cold and hot environments. The model has been shown to predict core temperature and skin temperatures higher and lower, respectively, than in tests of subjects in crew escape suit working in a controlled hot environments. Conversely the model predicts core temperature and skin temperatures lower and higher, respectively, than in tests of lightly clad subjects immersed in cold water conditions. The blood flow algorithms of the model has been investigated to allow for more and less flow, respectively, for the cold and hot case. These changes in the model have yielded better correlation of skin and core temperatures in the cold and hot cases. The algorithm for onset of shiver did not need to be modified to achieve good agreement in cold immersion simulations

Neural evidence that human emotions share core affective properties.

PubMed

Wilson-Mendenhall, Christine D; Barrett, Lisa Feldman; Barsalou, Lawrence W

2013-06-01

Research on the "emotional brain" remains centered around the idea that emotions like fear, happiness, and sadness result from specialized and distinct neural circuitry. Accumulating behavioral and physiological evidence suggests, instead, that emotions are grounded in core affect--a person's fluctuating level of pleasant or unpleasant arousal. A neuroimaging study revealed that participants' subjective ratings of valence (i.e., pleasure/displeasure) and of arousal evoked by various fear, happiness, and sadness experiences correlated with neural activity in specific brain regions (orbitofrontal cortex and amygdala, respectively). We observed these correlations across diverse instances within each emotion category, as well as across instances from all three categories. Consistent with a psychological construction approach to emotion, the results suggest that neural circuitry realizes more basic processes across discrete emotions. The implicated brain regions regulate the body to deal with the world, producing the affective changes at the core of emotions and many other psychological phenomena.

Neural Evidence that Human Emotions Share Core Affective Properties

PubMed Central

Wilson-Mendenhall, Christine D.; Barrett, Lisa Feldman; Barsalou, Lawrence W.

2014-01-01

Research on the “emotional brain” remains centered around the idea that emotions like fear, happiness, and sadness result from specialized and distinct neural circuitry. Accumulating behavioral and physiological evidence suggests, instead, that emotions are grounded in core affect – a person's fluctuating level of pleasant or unpleasant arousal. A neuroimaging study revealed that participants' subjective ratings of valence (i.e., pleasure/displeasure) and of arousal evoked by various fear, happiness, and sadness experiences correlated with neural activity in specific brain regions (orbitofrontal cortex and amygdala, respectively). We observed these correlations across diverse instances within each emotion category, as well as across instances from all three categories. Consistent with a psychological construction approach to emotion, the results suggest that neural circuitry realizes more basic processes across discrete emotions. The implicated brain regions regulate the body to deal with the world, producing the affective changes at the core of emotions and many other psychological phenomena. PMID:23603916

An improved evaluation method for measuring TOC of the Longmaxi Formation shale in the Sichuan Basin, south China

NASA Astrophysics Data System (ADS)

Zhang, Y.; Hu, C.; Wang, M.

2017-12-01

The evaluation of total organic carbon (TOC) in shale using logging data is one of the most crucial steps in shale gas exploration. However, it didn't achieve the ideal effect for the application of `ΔlogR' method in the Longmaxi Formation shale of Sichuan Basin.The reason may be the organic matter carbonization in Longmaxi Formation. An improved evaluation method, using the classification by lithology and sedimentary structure: 1) silty mudstone (wellsite logging data show silty); 2) calcareous mudstone (calcareous content > 25%); 3) laminated mudstone (laminations are recognized by core and imaging logging technology); 4) massive mudstone (massive textures are recognized by core and imaging logging technology, was proposed. This study compares two logging evaluation methods for measuring TOC in shale: the △logR method and the new proposed method. The results showed that the correlation coefficient between the calculated TOC and the tested TOC, based on the △logR method, was only 0.17. The correlation coefficient obtained according to the new method reached 0.80. The calculation results illustrated that, because of the good correlation between lithologies and sedimentary structure zones and TOC of different types of shale, the shale reservoirs could be graded according to four shale types. The new proposed method is more efficient, faster, and has higher vertical resolution than the △logR method. In addition, a new software had been completed. It was found to be especially effective under conditions of insufficient data during the early stages of shale gas exploration in the Silurian Longmaxi Formation, Muai Syncline Belt, south of the Sichuan Basin.

Characterization of gas hydrate reservoirs by integration of core and log data in the Ulleung Basin, East Sea

USGS Publications Warehouse

Bahk, J.-J.; Kim, G.-Y.; Chun, J.-H.; Kim, J.-H.; Lee, J.Y.; Ryu, B.-J.; Lee, J.-H.; Son, B.-K.; Collett, Timothy S.

2013-01-01

Examinations of core and well-log data from the Second Ulleung Basin Gas Hydrate Drilling Expedition (UBGH2) drill sites suggest that Sites UBGH2-2_2 and UBGH2-6 have relatively good gas hydrate reservoir quality in terms of individual and total cumulative thicknesses of gas-hydrate-bearing sand (HYBS) beds. In both of the sites, core sediments are generally dominated by hemipelagic muds which are intercalated with turbidite sands. The turbidite sands are usually thin-to-medium bedded and mainly consist of well sorted coarse silt to fine sand. Anomalies in infrared core temperatures and porewater chlorinity data and pressure core measurements indicate that “gas hydrate occurrence zones” (GHOZ) are present about 68–155 mbsf at Site UBGH2-2_2 and 110–155 mbsf at Site UBGH2-6. In both the GHOZ, gas hydrates are preferentially associated with many of the turbidite sands as “pore-filling” type hydrates. The HYBS identified in the cores from Site UBGH2-6 are medium-to-thick bedded particularly in the lower part of the GHOZ and well coincident with significant high excursions in all of the resistivity, density, and velocity logs. Gas-hydrate saturations in the HYBS range from 12% to 79% with an average of 52% based on pore-water chlorinity. In contrast, the HYBS from Site UBGH2-2_2 are usually thin-bedded and show poor correlations with both of the resistivity and velocity logs owing to volume averaging effects of the logging tools on the thin HYBS beds. Gas-hydrate saturations in the HYBS range from 15% to 65% with an average of 37% based on pore-water chlorinity. In both of the sites, large fluctuations in biogenic opal contents have significant effects on the sediment physical properties, resulting in limited usage of gamma ray and density logs in discriminating sand reservoirs.

Toxicity of sediment cores collected from the Ashtabula River in northeastern Ohio, USA, to the amphipod Hyalella azteca

USGS Publications Warehouse

Ingersoll, C.G.; Kemble, N.E.; Kunz, J.L.; Brumbaugh, W.G.; MacDonald, D.D.; Smorong, D.

2009-01-01

This study was conducted to support a Natural Resource Damage Assessment and Restoration project associated with the Ashtabula River in Ohio. The objective of the study was to evaluate the chemistry and toxicity of 50 sediment samples obtained from five cores collected from the Ashtabula River (10 samples/core, with each 10-cm-diameter core collected to a total depth of about 150 cm). Effects of chemicals of potential concern (COPCs) measured in the sediment samples were evaluated by measuring whole-sediment chemistry and whole-sediment toxicity in the sediment samples (including polycyclic aromatic hydrocarbons [PAHs], polychlorinated biphenyls [PCBs], organochlorine pesticides, and metals). Effects on the amphipod Hyalella azteca at the end of a 28-day sediment toxicity test were determined by comparing survival or length of amphipods in individual sediment samples in the cores to the range of responses of amphipods exposed to selected reference sediments that were also collected from the cores. Mean survival or length of amphipods was below the lower limit of the reference envelope in 56% of the sediment samples. Concentrations of total PCBs alone in some samples or concentrations of total PAHs alone in other samples were likely high enough to have caused the reduced survival or length of amphipods (i.e., concentrations of PAHs or PCBs exceeded mechanistically based and empirically based sediment quality guidelines). While elevated concentrations of ammonia in pore water may have contributed to the reduced length of amphipods, it is unlikely that the reduced length was caused solely by elevated ammonia (i.e., concentrations of ammonia were not significantly correlated with the concentrations of PCBs or PAHs and concentrations of ammonia were elevated both in the reference sediments and in the test sediments). Results of this study show that PAHs, PCBs, and ammonia are the primary COPCs that are likely causing or substantially contributing to the toxicity to sediment-dwelling organisms. ?? 2009 US Government.

The association between negative self-descriptions and depressive symptomology: does culture make a difference?

PubMed

Saint Arnault, Denise; Sakamoto, Shinji; Moriwaki, Aiko

2005-04-01

Research findings that depressed Americans endorse more negative self-related adjectives than controls may be related to a shared self-enhancement cultural frame. This study examines the relationship between negative core self-descriptors and depressive symptoms in 79 Japanese and 50 American women. Americans had more positive self-descriptions and core self-descriptors; however, there were no cultural group differences in number of negative self-descriptors or core self-descriptors. There was a significant correlation between negative core self-descriptor and Beck Depression Inventory (BDI) for Americans only, explaining 10.6% of the BDI variance. Analysis of variance revealed that there was significant BDI group differences for American negative core self-descriptor only. Theoretical possibilities are discussed.

The Association Between Negative Self-Descriptions and Depressive Symptomology: Does Culture Make a Difference?

PubMed Central

Sakamoto, Shinji; Moriwaki, Aiko

2007-01-01

Research findings that depressed Americans endorse more negative self-related adjectives than controls may be related to a shared self-enhancement cultural frame. This study examines the relationship between negative core self-descriptors and depressive symptoms in 79 Japanese and 50 American women. Americans had more positive self-descriptions and core self-descriptors; however, there were no cultural group differences in number of negative self-descriptors or core self-descriptors. There was a significant correlation between negative core self-descriptor and Beck Depression Inventory (BDI) for Americans only, explaining 10.6% of the BDI variance. Analysis of variance revealed that there was significant BDI group differences for American negative core self-descriptor only. Theoretical possibilities are discussed. PMID:15902678

NEW EQUATIONS OF STATE IN SIMULATIONS OF CORE-COLLAPSE SUPERNOVAE

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

Hempel, M.; Liebendoerfer, M.; Fischer, T.

2012-03-20

We discuss three new equations of state (EOS) in core-collapse supernova simulations. The new EOS are based on the nuclear statistical equilibrium model of Hempel and Schaffner-Bielich (HS), which includes excluded volume effects and relativistic mean-field (RMF) interactions. We consider the RMF parameterizations TM1, TMA, and FSUgold. These EOS are implemented into our spherically symmetric core-collapse supernova model, which is based on general relativistic radiation hydrodynamics and three-flavor Boltzmann neutrino transport. The results obtained for the new EOS are compared with the widely used EOS of H. Shen et al. and Lattimer and Swesty. The systematic comparison shows that themore » model description of inhomogeneous nuclear matter is as important as the parameterization of the nuclear interactions for the supernova dynamics and the neutrino signal. Furthermore, several new aspects of nuclear physics are investigated: the HS EOS contains distributions of nuclei, including nuclear shell effects. The appearance of light nuclei, e.g., deuterium and tritium, is also explored, which can become as abundant as alphas and free protons. In addition, we investigate the black hole formation in failed core-collapse supernovae, which is mainly determined by the high-density EOS. We find that temperature effects lead to a systematically faster collapse for the non-relativistic LS EOS in comparison with the RMF EOS. We deduce a new correlation for the time until black hole formation, which allows the determination of the maximum mass of proto-neutron stars, if the neutrino signal from such a failed supernova would be measured in the future. This would give a constraint for the nuclear EOS at finite entropy, complementary to observations of cold neutron stars.« less

The ICDP Snake River Geothermal Drilling Project: preliminary overview of borehole geophysics

USGS Publications Warehouse

Schmitt, Douglas R.; Liberty, Lee M.; Kessler, James E.; Kuck, Jochem; Kofman, Randolph; Bishop, Ross; Shervais, John W.; Evans, James P.; Champion, Duane E.

2012-01-01

Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand the geothermal systems in three locations across the Snake River Plain with varying geological and hydrological structure. An extensive series of standard and specialized geophysical logs were obtained in each of the wells. Hydrogen-index neutron and γ-γ density logs employing active sources were deployed through the drill string, and although not fully calibrated for such a situation do provide semi-quantitative information related to the ‘stratigraphy’ of the basalt flows and on the existence of alteration minerals. Electrical resistivity logs highlight the existence of some fracture and mineralized zones. Magnetic susceptibility together with the vector magnetic field measurements display substantial variations that, in combination with laboratory measurements, may provide a tool for tracking magnetic field reversals along the borehole. Full waveform sonic logs highlight the variations in compressional and shear velocity along the borehole. These, together with the high resolution borehole seismic measurements display changes with depth that are not yet understood. The borehole seismic measurements indicate that seismic arrivals are obtained at depth in the formations and that strong seismic reflections are produced at lithological contacts seen in the corresponding core logging. Finally, oriented ultrasonic borehole televiewer images were obtained over most of the wells and these correlate well with the nearly 6 km of core obtained. This good image log to core correlations, particularly with regards to drilling induced breakouts and tensile borehole and core fractures will allow for confident estimates of stress directions and or placing constraints on stress magnitudes. Such correlations will be used to orient in core orientation giving information useful in hydrological assessments, paleomagnetic dating, and structural volcanology.

Statistical Mechanics of the US Supreme Court

NASA Astrophysics Data System (ADS)

Lee, Edward D.; Broedersz, Chase P.; Bialek, William

2015-07-01

We build simple models for the distribution of voting patterns in a group, using the Supreme Court of the United States as an example. The maximum entropy model consistent with the observed pairwise correlations among justices' votes, an Ising spin glass, agrees quantitatively with the data. While all correlations (perhaps surprisingly) are positive, the effective pairwise interactions in the spin glass model have both signs, recovering the intuition that ideologically opposite justices negatively influence each another. Despite the competing interactions, a strong tendency toward unanimity emerges from the model, organizing the voting patterns in a relatively simple "energy landscape." Besides unanimity, other energy minima in this landscape, or maxima in probability, correspond to prototypical voting states, such as the ideological split or a tightly correlated, conservative core. The model correctly predicts the correlation of justices with the majority and gives us a measure of their influence on the majority decision. These results suggest that simple models, grounded in statistical physics, can capture essential features of collective decision making quantitatively, even in a complex political context.

Historical Isotopic Temperature Record from the Vostok Ice Core (420,000 years BP-present)

DOE Data Explorer

Petit, J. R. [Laboratoire de Glaciogie et Geophysique de l'Environnement; Raynaud, D. [Laboratoire de Glaciogie et Geophysique de l'Environnement; Lorius, C. [Laboratoire de Glaciogie et Geophysique de l'Environnement; Jouzel, J. [Laboratoire des Sciences du Climat et de l'Environnement; Delaygue, G. [Laboratoire des Sciences du Climat et de l'Environnement; Barkov, N. I. [Arctic and Antarctic Research Inst. (AARI), St. Petersburg (Russian Federation); Kotlyakov, V. M. [Institute of Geography, Russia

2000-01-01

Because isotopic fractions of the heavier oxygen-18 (18O) and deuterium (D) in snowfall are temperature-dependent and a strong spatial correlation exists between the annual mean temperature and the mean isotopic ratio (18O or δD) of precipitation, it is possible to derive ice-core climate records. The record presented by Jouzel et al. (1987) was the first ice core record to span a full glacial-interglacial cycle. That record was based on an ice core drilled at the Russian Vostok station in central east Antarctica. The 2083-m ice core was obtained during a series of drillings in the early 1970s and 1980s and was the result of collaboration between French and former-Soviet scientists. Drilling continued at Vostok and was completed in January 1998, reaching a depth of 3623 m, the deepest ice core ever recovered (Petit et al. 1997, 1999). The resulting core allows the ice core record of climate properties at Vostok to be extended to ~420 kyr BP.

Hot spot analysis for driving the development of hits into leads in fragment based drug discovery

PubMed Central

Hall, David R.; Ngan, Chi Ho; Zerbe, Brandon S.; Kozakov, Dima; Vajda, Sandor

2011-01-01

Fragment based drug design (FBDD) starts with finding fragment-sized compounds that are highly ligand efficient and can serve as a core moiety for developing high affinity leads. Although the core-bound structure of a protein facilitates the construction of leads, effective design is far from straightforward. We show that protein mapping, a computational method developed to find binding hot spots and implemented as the FTMap server, provides information that complements the fragment screening results and can drive the evolution of core fragments into larger leads with a minimal loss or, in some cases, even a gain in ligand efficiency. The method places small molecular probes, the size of organic solvents, on a dense grid around the protein, and identifies the hot spots as consensus clusters formed by clusters of several probes. The hot spots are ranked based on the number of probe clusters, which predicts the binding propensity of the subsites and hence their importance for drug design. Accordingly, with a single exception the main hot spot identified by FTMap binds the core compound found by fragment screening. The most useful information is provided by the neighboring secondary hot spots, indicating the regions where the core can be extended to increase its affinity. To quantify this information, we calculate the density of probes from mapping, which describes the binding propensity at each point, and show that the change in the correlation between a ligand position and the probe density upon extending or repositioning the core moiety predicts the expected change in ligand efficiency. PMID:22145575

Sediment cores as archives of historical changes in floodplain lake hydrology.

PubMed

Lintern, Anna; Leahy, Paul J; Zawadzki, Atun; Gadd, Patricia; Heijnis, Henk; Jacobsen, Geraldine; Connor, Simon; Deletic, Ana; McCarthy, David T

2016-02-15

Anthropogenic activities are contributing to the changing hydrology of rivers, often resulting in their degradation. Understanding the drivers and nature of these changes is critical for the design and implementation of effective mitigation strategies for these systems. However, this can be hindered by gaps in historical measured flow data. This study therefore aims to use sediment cores to identify historical hydrological changes within a river catchment. Sediment cores from two floodplain lakes (billabongs) in the urbanised Yarra River catchment (Melbourne, South-East Australia) were collected and high resolution images, trends in magnetic susceptibility and trends in elemental composition through the sedimentary records were obtained. These were used to infer historical changes in river hydrology to determine both average trends in hydrology (i.e., coarse temporal resolution) as well as discrete flood layers in the sediment cores (i.e., fine temporal resolution). Through the 20th century, both billabongs became increasingly disconnected from the river, as demonstrated by the decreasing trends in magnetic susceptibility, particle size and inorganic matter in the cores. Additionally the number of discrete flood layers decreased up the cores. These reconstructed trends correlate with measured flow records of the river through the 20th century, which validates the methodology that has been used in this study. Not only does this study provide evidence on how natural catchments can be affected by land-use intensification and urbanisation, but it also introduces a general analytical framework that could be applied to other river systems to assist in the design of hydrological management strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

Probing the Structure near the Top of the Earth's Outer Core Using SmKS Traveltimes

NASA Astrophysics Data System (ADS)

Tang, V. C.; Zhao, L.; Hung, S.

2013-12-01

The Earth's solid inner core is composed of heavy Fe and Ni with a fraction of light elements such as O, S, Si. These light elements were expelled from the inner core during its formation and rise up through the outer core as the result of buoyancy, but their existence is still a mystery. Some authors have presented seismological evidence for lowered wave speed beneath the core-mantle boundary (CMB) relative to PREM, suggesting light elements there, but counter argument also exists. In this study, we use traveltime measurements from recorded and modeled SmKS waves to investigate the effect of the velocity under the CMB on the differential traveltimes between SKKS and S3KS waves (TS3KS-TSKKS). Due to the long propagation distance and interference with neighboring phases, the arrival times of SKKS and S3KS waves are difficult to define accurately in the records. Therefore in our analysis we measure both the observed and model-predicted differential traveltime TS3KS-TSKKS by cross-correlating the waveform of Hilbert-transformed S3KS with that of SKKS. We use synthetic seismograms calculated by the Direct-Solution Method (DSM) in a suite of 1D models with different structural profiles under the CMB to examine the existence of a zone of lowered velocity at the top of the outer core. We are conducting a systematic investigation using waveforms available at IRIS from globally distributed large deep earthquakes. Results from events we have processed so far indicate that the velocity under the CMB is slightly slower than that in PREM.

18F-FDG uptake in the colon is modulated by metformin but not associated with core body temperature and energy expenditure.

PubMed

Bahler, Lonneke; Holleman, Frits; Chan, Man-Wai; Booij, Jan; Hoekstra, Joost B; Verberne, Hein J

2017-01-01

Physiological colonic 18F-fluorodeoxyglucose (18F-FDG) uptake is a frequent finding on 18F-FDG positron emission tomography computed tomography (PET-CT). Interestingly, metformin, a glucose lowering drug associated with moderate weight loss, is also associated with an increased colonic 18F-FDG uptake. Consequently, increased colonic glucose use might partly explain the weight losing effect of metformin when this results in an increased energy expenditure and/or core body temperature. Therefore, we aimed to determine whether metformin modifies the metabolic activity of the colon by increasing glucose uptake. In this open label, non-randomized, prospective mechanistic study, we included eight lean and eight overweight males. We measured colonic 18F-FDG uptake on PET-CT, energy expenditure and core body temperature before and after the use of metformin. The maximal colonic 18F-FDG uptake was measured in 5 separate segments (caecum, colon ascendens,-transversum,-descendens and sigmoid). The maximal colonic 18F-FDG uptake increased significantly in all separate segments after the use of metformin. There was no significant difference in energy expenditure or core body temperature after the use of metformin. There was no correlation between maximal colonic 18F-FDG uptake and energy expenditure or core body temperature. Metformin significantly increases colonic 18F-FDG uptake, but this increased uptake is not associated with an increase in energy expenditure or core body temperature. Although the colon might be an important site of the glucose plasma lowering actions of metformin, this mechanism of action does not explain directly any associated weight loss.

Excitation energy shift and size difference of low-energy levels in p -shell Λ hypernuclei

NASA Astrophysics Data System (ADS)

Kanada-En'yo, Yoshiko

2018-02-01

Structures of low-lying 0 s -orbit Λ states in p -shell Λ hypernuclei (ZAΛ) are investigated by applying microscopic cluster models for nuclear structure and a single-channel folding potential model for a Λ particle. For A >10 systems, the size reduction of core nuclei is small, and the core polarization effect is regarded as a higher-order perturbation in the Λ binding. The present calculation qualitatively describes the systematic trend of experimental data for excitation energy change from Z-1A to ZAΛ, in A >10 systems. The energy change shows a clear correlation with the nuclear size difference between the ground and excited states. In Li7Λ and Be9Λ, the significant shrinkage of cluster structures occurs consistently with the prediction of other calculations.

Low-lying electronic states of Li 2+ and Li 2-

NASA Astrophysics Data System (ADS)

Konowalow, Daniel D.; Fish, James L.

1984-02-01

Potential curves for the eight lowest lying electronic states of Li2+ and the two lowest-lying states of Li2- are obtained by valence configuration calculations which-utilize an effective core potential. The calculated ionization potential of the ground state of Li2 is found to b. 5.16 eV and its electron affinity is 0.429 eV. Both values are in excellent agreement with recent experimental values and with value deduced from other high quality ab initio quantum mechanical treatments. When our potential curve for the Li2+(12Σg+ state, is corrected for the core-valence correlation error we obtain spectroscopic constants which agree nicely with the experimental values of Bernheim, Gold and Tipton (BGT). For example, we findDe = 10460 ± 140 cm-1 while BGT reportDe = 10469 ± 6 cm-1.

Correlative Microscopy of Neutron-Irradiated Materials

DOE PAGES

Briggs, Samuel A.; Sridharan, Kumar; Field, Kevin G.

2016-12-31

A nuclear reactor core is a highly demanding environment that presents several unique challenges for materials performance. Materials in modern light water reactor (LWR) cores must survive several decades in high-temperature (300-350°C) aqueous corrosion conditions while being subject to large amounts of high-energy neutron irradiation. Next-generation reactor designs seek to use more corrosive coolants (e.g., molten salts) and even greater temperatures and neutron doses. The high amounts of disorder and unique crystallographic defects and microchemical segregation effects induced by radiation inevitably lead to property degradation of materials. Thus, maintaining structural integrity and safety margins over the course of the reactor'smore » service life thus necessitates the ability to understand and predict these degradation phenomena in order to develop new, radiation-tolerant materials that can maintain the required performance in these extreme conditions.« less

Borehole Tool for the Comprehensive Characterization of Hydrate-bearing Sediments

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

Dai, Sheng; Santamarina, J. Carlos

Reservoir characterization and simulation require reliable parameters to anticipate hydrate deposits responses and production rates. The acquisition of the required fundamental properties currently relies on wireline logging, pressure core testing, and/or laboratory observations of synthesized specimens, which are challenged by testing capabilities and innate sampling disturbances. The project reviews hydrate-bearing sediments, properties, and inherent sampling effects, albeit lessen with the developments in pressure core technology, in order to develop robust correlations with index parameters. The resulting information is incorporated into a tool for optimal field characterization and parameter selection with uncertainty analyses. Ultimately, the project develops a borehole tool formore » the comprehensive characterization of hydrate-bearing sediments at in situ, with the design recognizing past developments and characterization experience and benefited from the inspiration of nature and sensor miniaturization.« less

Relativistic, correlation, and polarization effects in two-photon photoionization of Xe

NASA Astrophysics Data System (ADS)

Lagutin, B. M.; Petrov, I. D.; Sukhorukov, V. L.; Demekhin, Ph. V.; Knie, A.; Ehresmann, A.

2017-06-01

Two-photon ionization of xenon was investigated theoretically for exciting-photon energies from 6.7 to 11.5 eV, which results in the ionization of Xe between 5 p1 /2 (13.43 eV) and 5 s (23.40 eV) thresholds. We describe the extension of a previously developed computational technique for the inclusion of relativistic effects to calculate energies of intermediate resonance state and cross sections for two-photon ionization. Reasonable consistency of cross sections calculated in length and velocity form was obtained only after considering many-electron correlations. Agreement between calculated and measured resonance energies is found when core polarization was additionally included in the calculations. The presently computed two-photon photoionization cross sections of Xe are compared with Ar cross sections in our previous work. Photoelectron angular distribution parameters calculated here indicate that intermediated resonances strongly influence photoelectron angular distribution of Xe.

Correlation Energies from the Two-Component Random Phase Approximation.

PubMed

Kühn, Michael

2014-02-11

The correlation energy within the two-component random phase approximation accounting for spin-orbit effects is derived. The resulting plasmon equation is rewritten-analogously to the scalar relativistic case-in terms of the trace of two Hermitian matrices for (Kramers-restricted) closed-shell systems and then represented as an integral over imaginary frequency using the resolution of the identity approximation. The final expression is implemented in the TURBOMOLE program suite. The code is applied to the computation of equilibrium distances and vibrational frequencies of heavy diatomic molecules. The efficiency is demonstrated by calculation of the relative energies of the Oh-, D4h-, and C5v-symmetric isomers of Pb6. Results within the random phase approximation are obtained based on two-component Kohn-Sham reference-state calculations, using effective-core potentials. These values are finally compared to other two-component and scalar relativistic methods, as well as experimental data.

Grain engineering: How nanoscale inhomogeneities can control charge collection in solar cells

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

West, Bradley M.; Stuckelberger, Michael; Guthrey, Harvey

Statistical and correlative analysis are increasingly important in the design and study of new materials, from semiconductors to metals. Non-destructive measurement techniques, with high spatial resolution, capable of correlating composition and/or structure with device properties, are few and far between. For the case of polycrystalline and inhomogeneous materials, the added challenge is that nanoscale resolution is in general not compatible with the large sampling areas necessary to have a statistical representation of the specimen under study. For the study of grain cores and grain boundaries in polycrystalline solar absorbers this is of particular importance since their dissimilar behavior and variabilitymore » throughout the samples makes it difficult to draw conclusions and ultimately optimize the material. In this study, we present a nanoscale in-operando approach based on the multimodal utilization of synchrotron nano x-ray fluorescence and x-ray beam induced current collected for grain core and grain boundary areas and correlated pixel-by-pixel in fully operational Cu(In(1-x)Gax)Se2Cu(In(1-x)Gax)Se2 solar cells. We observe that low gallium cells have grain boundaries that over perform compared to the grain cores and high gallium cells have boundaries that under perform. These results demonstrate how nanoscale correlative X-ray microscopy can guide research pathways towards grain engineering low cost, high efficiency solar cells.« less

Grain engineering: How nanoscale inhomogeneities can control charge collection in solar cells

DOE PAGES

West, Bradley M.; Stuckelberger, Michael; Guthrey, Harvey; ...

2016-12-16

We present that statistical and correlative analysis are increasingly important in the design and study of new materials, from semiconductors to metals. Non-destructive measurement techniques, with high spatial resolution, capable of correlating composition and/or structure with device properties, are few and far between. For the case of polycrystalline and inhomogeneous materials, the added challenge is that nanoscale resolution is in general not compatible with the large sampling areas necessary to have a statistical representation of the specimen under study. For the study of grain cores and grain boundaries in polycrystalline solar absorbers this is of particular importance since their dissimilarmore » behavior and variability throughout the samples makes it difficult to draw conclusions and ultimately optimize the material. In this study, we present a nanoscale in-operando approach based on the multimodal utilization of synchrotron nano x-ray fluorescence and x-ray beam induced current collected for grain core and grain boundary areas and correlated pixel-by-pixel in fully operational Cu(In (1-x)Ga x)Se 2 solar cells. We observe that low gallium cells have grain boundaries that over perform compared to the grain cores and high gallium cells have boundaries that under perform. In conclusion, these results demonstrate how nanoscale correlative X-ray microscopy can guide research pathways towards grain engineering low cost, high efficiency solar cells.« less

A Comparison of Increment Core Sampling for Estimating Tree Specific Gravity

Treesearch

Michael A. Taras; Harold E. Wadlgren

1963-01-01

Increment cores have been used to evaluate such tree characteristics as age, rate of growth, percentage of various types of tissue, chemical composition, and density. Of the wood characteristics listed, density has come to be of considerable interest to numerous researchers, since it is highly correlated with the strength properties, workability, and weight of wood....

International Symposium on Palaeolimnology. Abstracts

DTIC Science & Technology

1989-09-01

Finland? 99 Siver, P. Improving palaoreconstructing efforts utilizing scaled chrysophytes: transforming scale counts to cell numbers. 100 Smol, J.P...example, to assess between core differences in diatom accumulation rates requires cross correlation or dating of individual cores; both methods have...have increased the possibilities for using such structures as paleolimnological Indicators. However, understanding of the past requires insight into the

Flowing of supersonic underexpanded micro-jets in the range of moderate Reynolds numbers

NASA Astrophysics Data System (ADS)

Mironov, S. G.; Aniskin, V. M.; Maslov, A. A.

2017-10-01

The paper presents new experimental results on the simulation of supersonic underexpanded micro-jets by macro-jet in the range of moderate Reynolds numbers of air outflow from the nozzle. A correlation is shown between the variations in the Pitot pressure in the model micro-jet with variations in the length of the supersonic core of real the micro-jets. The results of experiments on the effect of humidity on the pulsation of mass flow rate in a micro-jet are presented.

Correlation of Miocene strata on the submarine St. Croix Ridge and onland St. Croix, US Virgin Islands

NASA Astrophysics Data System (ADS)

von Salis, Katharina; Speed, Robert

1995-03-01

The nannofossils of an hydraulic piston core from the steep scarp between the St. Croix Ridge and Virgin Islands Basin were restudied. Formerly thought to represent a Pliocene debris flow, we interpret it as an early Miocene (NN1/2) hemipelagic deposit. We correlate the seismic unit sampled by piston core with the Kingshill-Jealousy Formation present on St. Croix. These sediments likely belong to an extensive, thick, deep marine cover of the St. Croix Ridge, deposited on a metamorphic—igneous basement between early Eocene and early Miocene time. Faulting did not evidently affect this sediment cover until the late Neogene.

The Correlation Entropy as a Measure of the Complexity of High-Lying Single-Particle Modes

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

Stoyanov, Chavdar; Zelevinsky, Vladimir; Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824-1321

Highly-excited single-particle states in nuclei are coupled with the excitations of a more complex character, first of all with collective phonon-like modes of the core. In the framework of the quasiparticle-phonon model we consider the structure of resulting complex configurations using the 1k17/2 orbital in 209Pb as an example. The eigenstates of the model carry significant degree of complexity that can be quantified with the aid of correlational invariant entropy. With artificially enhanced particle-core coupling, the system undergoes the doubling phase transition with the quasiparticle strength concentrated in two repelling peaks.

Correlation of reaction sites during the chlorine extraction by hydrogen atom from Cl /Si(100)-2×1

NASA Astrophysics Data System (ADS)

Hsieh, Ming-Feng; Chung, Jen-Yang; Lin, Deng-Sung; Tsay, Shiow-Fon

2007-07-01

The Cl abstraction by gas-phase H atoms from a Cl-terminated Si(100) surface was investigated by scanning tunneling microscopy (STM), high-resolution core level photoemission spectroscopy, and computer simulation. The core level measurements indicate that some additional reactions occur besides the removal of Cl. The STM images show that the Cl-extracted sites disperse randomly in the initial phase of the reaction, but form small clusters as more Cl is removed, indicating a correlation between Cl-extracted sites. These results suggest that the hot-atom process may occur during the atom-adatom collision.

An automated full waveform logging system for high-resolution P-wave profiles in marine sediments

NASA Astrophysics Data System (ADS)

Breitzke, Monika; Spieβ, Volkhard

1993-11-01

An automated, PC-based logging system has been developed to investigate marine sediment cores by full waveform transmission seismograms. High-resolution P-wave velocity and amplitude attenuation profiles are simultaneously derived from the transmission data to characterize the acoustic properties of the sediment column. A pair of ultrasonic, piezoelectric wheel probes is used to generate and record the transmission signals travelling radially through the sediment core. Both unsplit and split cores are allowed. Mounted in a carriage driven by a stepping motor via a shaft the probes automatically move along the core liner, stopping at equidistant spacings to provide a quasi-continuous inspection of the core by the transmission data. The axial travel distance and the core diameter are determined by digital measuring tools. First arrivals are picked automatically from the transmission seismograms using either a threshold in the seismogram's envelope or a cross-correlation algorithm taking the ‘zero-offset’ signal of both wheel probes into account. Combined with the core diameter these first arrivals lead to a P-wave velocity profile with a relative precision of 1 to 2 m s-1. Simultaneously, the maximum peak-to-peak amplitudes of the transmission seismograms are evaluated to get a first idea on the amplitude attenuation along the sediment core. Two examples of gravity cores taken during a recent cruise of R.V. METEOR in the Western Equatorial Atlantic are presented. They yield that the P-wave profiles can be used for locating strong and fine-scale lithological changes, e.g. turbidite layers and slight variations in the sand, silt or clay content. In addition, the transmission seismograms and their amplitude spectra obviously seem to reveal a correlation between the relative amount of low-frequency spectral components and the sediment grain size, and thus provide a tool for the determination of additional, related physical or sedimentological parameters in future investigations.

Distribution of Alkalis (Na, Cs, Rb) Between Silicate and Sulfide: Implications for Planetary Volatile Depletion

NASA Technical Reports Server (NTRS)

Boujibar, A.; Fei, Y.; Righter, K.; Du, Z.; Bullock, E.

2018-01-01

The abundances of volatile elements in the Earth's mantle are correlated with their temperatures of condensation. This depletion can be due to either incomplete condensation of the elements during the nebula condensation or evaporation processes during planetary growth. Elements that have affinities with metals (siderophile) and sulfides (chalcophile) are additionally depleted due to their segregation into the core. Therefore, study of lithophile elements could be useful to isolate processes of volatilization and their effect on the abundance of the elements in the Earth's mantle. However, the correlation of these lithophile elements including alkali elements, with their temperatures of condensation shows a significant scatter, which is difficult to reconcile with a depletion by vaporization or incomplete condensation alone.

Free Electrons to Molecular Bonds and Back: Closing the Energetic Oxygen Reduction (ORR)-Oxygen Evolution (OER) Cycle Using Core-Shell Nanoelectrocatalysts.

PubMed

Strasser, Peter

2016-11-15

Nanomaterial science and electrocatalytic science have entered a successful "nanoelectrochemical" symbiosis, in which novel nanomaterials offer new frontiers for studies on electrocatalytic charge transfer, while electrocatalytic processes give meaning and often practical importance to novel nanomaterial concepts. Examples of this fruitful symbiosis are dealloyed core-shell nanoparticle electrocatalysts, which often exhibit enhanced kinetic charge transfer rates at greatly improved atom-efficiency. As such, they represent ideal electrocatalyst architectures for the acidic oxygen reduction reaction to water (ORR) and the acidic oxygen evolution reaction from water (OER) that require scarce Pt- and Ir-based catalysts. Together, these two reactions constitute the "O-cycle", a key elemental process loop in the field of electrochemical energy interconversion between electricity (free electrons) and molecular bonds (H 2 O/O 2 ), realized in the combination of water electrolyzers and hydrogen/oxygen fuel cells. In this Account, we describe our recent efforts to design, synthesize, understand, and test noble metal-poor dealloyed Pt and Ir core-shell nanoparticles for deployment in acidic polymer electrolyte membrane (PEM) electrolyzers and PEM fuel cells. Spherical dealloyed Pt core-shell particles, derived from PtNi 3 precursor alloys, showed favorable ORR activity. More detailed size-activity correlation studies further revealed that the 6-8 nm diameter range is a most desirable initial particle size range in order to maximize the particle Ni content after ORR testing and to preserve performance stability. Similarly, dealloyed and oxidized IrO x core-shell particles derived from Ni-rich Ir-Ni precursor particles proved highly efficient oxygen evolution reaction (OER) catalysts in acidic conditions. In addition to the noble metal savings in the particle cores, the Pt core-shell particles are believed to benefit in terms of their mass-based electrochemical kinetics from surface lattice strain effects that tune the adsorption energies and barriers of elementary steps. The molecular mechanism of the kinetic benefit of the dealloyed IrO x particle needs more attention, but there is mounting evidence for ligand hole effects in defect-rich IrO x shells that generate preactive oxygen centers.

High-lying single-particle modes, chaos, correlational entropy, and doubling phase transition

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

Stoyanov, Chavdar; Zelevinsky, Vladimir

Highly excited single-particle states in nuclei are coupled with the excitations of a more complex character, first of all with collective phononlike modes of the core. In the framework of the quasiparticle-phonon model, we consider the structure of resulting complex configurations, using the 1k{sub 17/2} orbital in {sup 209}Pb as an example. Although, on the level of one- and two-phonon admixtures, the fully chaotic Gaussian orthogonal ensemble regime is not reached, the eigenstates of the model carry a significant degree of complexity that can be quantified with the aid of correlational invariant entropy. With artificially enhanced particle-core coupling, the systemmore » undergoes the doubling phase transition with the quasiparticle strength concentrated in two repelling peaks. This phase transition is clearly detected by correlational entropy.« less

Systemic risk and spatiotemporal dynamics of the consumer market of China

NASA Astrophysics Data System (ADS)

Wang, Minggang; Tian, Lixin; Xu, Hua; Li, Weiyu; Du, Ruijin; Dong, Gaogao; Wang, Jie; Gu, Jiani

2017-05-01

The consumer price index (CPI) contains rich information of the consumer market, in order to characterize the essential characteristics of the consumer market of China, a novel method by using complex network theory is proposed to visualizing the evolution and transformation characteristics of correlated modes among the regional consumer markets. CPI data of 31 provinces and cities of China are selected as sample data. Underlying dynamics of time-evolving correlation networks are revealed. A formula to measure the systemic risk in the consumer market is designed. And the correlation modes transmission network of the regional consumer markets is obtained. Numerical simulations show that the consumer market network has co-movement, group-occurring and small-word property. Different regions played different roles in the consumer market of China. The risk in the consumer market presented a decreasing trend from April 2013 but remain at the high level. Different from the stochastic system, the consumer market of China both has the short-range correlation and the long-range correlation. The strength of correlation modes transmission network basically satisfies a power-law distribution. The correlation modes are transferred into each other conveniently, although the consumer market system is highly complicated. The transformation of the correlation patterns of the regional consumer markets mainly revolves around three core correlation modes and each transformation needs to undergo 4 non-core modes.

s-core network decomposition: A generalization of k-core analysis to weighted networks

NASA Astrophysics Data System (ADS)

Eidsaa, Marius; Almaas, Eivind

2013-12-01

A broad range of systems spanning biology, technology, and social phenomena may be represented and analyzed as complex networks. Recent studies of such networks using k-core decomposition have uncovered groups of nodes that play important roles. Here, we present s-core analysis, a generalization of k-core (or k-shell) analysis to complex networks where the links have different strengths or weights. We demonstrate the s-core decomposition approach on two random networks (ER and configuration model with scale-free degree distribution) where the link weights are (i) random, (ii) correlated, and (iii) anticorrelated with the node degrees. Finally, we apply the s-core decomposition approach to the protein-interaction network of the yeast Saccharomyces cerevisiae in the context of two gene-expression experiments: oxidative stress in response to cumene hydroperoxide (CHP), and fermentation stress response (FSR). We find that the innermost s-cores are (i) different from innermost k-cores, (ii) different for the two stress conditions CHP and FSR, and (iii) enriched with proteins whose biological functions give insight into how yeast manages these specific stresses.

Recent Increases in Snow Accumulation and Decreases in Sea-Ice Concentration Recorded in a Coastal NW Greenland Ice Core

NASA Astrophysics Data System (ADS)

Osterberg, E. C.; Thompson, J. T.; Wong, G. J.; Hawley, R. L.; Kelly, M. A.; Lutz, E.; Howley, J.; Ferris, D. G.

2013-12-01

A significant rise in summer temperatures over the past several decades has led to widespread retreat of the Greenland Ice Sheet (GIS) margin and surrounding sea ice. Recent observations from geodetic stations and GRACE show that ice mass loss progressed from South Greenland up to Northwest Greenland by 2005 (Khan et al., 2010). Observations from meteorological stations at the U.S. Thule Air Force Base, remote sensing platforms, and climate reanalyses indicate a 3.5C mean annual warming in the Thule region and a 44% decrease in summer (JJAS) sea-ice concentrations in Baffin Bay from 1980-2010. Mean annual precipitation near Thule increased by 12% over this interval, with the majority of the increase occurring in fall (SON). To improve projections of future ice loss and sea-level rise in a warming climate, we are currently developing multi-proxy records (lake sediment cores, ice cores, glacial geologic data, glaciological models) of Holocene climate variability and cryospheric response in NW Greenland, with a focus on past warm periods. As part of our efforts to develop a millennial-length ice core paleoclimate record from the Thule region, we collected and analyzed snow pit samples and short firn cores (up to 20 m) from the coastal region of the GIS (2Barrel site; 76.9317 N, 63.1467 W) and the summit of North Ice Cap (76.938 N, 67.671 W) in 2011 and 2012, respectively. The 2Barrel ice core was sampled using a continuous ice core melting system at Dartmouth, and subsequently analyzed for major anion and trace element concentrations and stable water isotope ratios. Here we show that the 2Barrel ice core spanning 1990-2010 records a 25% increase in mean annual snow accumulation, and is positively correlated (r = 0.52, p<0.01) with ERA-Interim precipitation. The 2Barrel annual sea-salt Na concentration is strongly correlated (r = 0.5-0.8, p<0.05) with summer and fall sea-ice concentrations in northern Baffin Bay near Thule (Figure 1). We hypothesize that the positive correlation represents a significant Na contribution from frost flowers growing on fall frazil ice. Ongoing analyses will evaluate the relationship between MSA concentrations and sea ice extent. Our results show that a deep ice core collected from this dynamic and climate-sensitive region of NW Greenland would produce a valuable record of late Holocene climate and sea ice extent.

OSO 8 X-ray spectra of clusters of galaxies. II - Discussion

NASA Technical Reports Server (NTRS)

Smith, B. W.; Mushotzky, R. F.; Serlemitsos, P. J.

1979-01-01

An observational description of X-ray clusters of galaxies is given based on OSO 8 X-ray results for spatially integrated spectra of 20 such clusters and various correlations obtained from these results. It is found from a correlation between temperature and velocity dispersion that the X-ray core radius should be less than the galaxy core radius or, alternatively, that the polytropic index is about 1.1 for most of the 20 clusters. Analysis of a correlation between temperature and emission integral yields evidence that more massive clusters accumulate a larger fraction of their mass as intracluster gas. Galaxy densities and optical morphology, as they correlate with X-ray properties, are reexamined for indications as to how mass injection by galaxies affects the density structure of the gas. The physical arguments used to derive iron abundances from observed equivalent widths of iron line features in X-ray spectra are critically evaluated, and the associated uncertainties in abundances derived in this manner are estimated to be quite large.

Conducting correlation seminars in basic sciences at KIST Medical College, Nepal

PubMed Central

2011-01-01

KIST Medical College is a new medical school in Lalitpur, Nepal. In Nepal, six basic science subjects are taught together in an integrated organ system-based manner with early clinical exposure and community medicine. Correlation seminars are conducted at the end of covering each organ system. The topics are decided by the core academic group (consisting of members from each basic science department, the Department of Community Medicine, the academic director, and the clinical and program coordinators) considering the public health importance of the condition and its ability to include learning objectives from a maximum number of subjects. The learning objectives are decided by individual departments and finalized after the meeting of the core group. There are two student coordinators for each seminar and an evaluation group evaluates each seminar and presenter. Correlation seminars help students revise the organ system covered and understand its clinical importance, promote teamwork and organization, and supports active learning. Correlation seminars should be considered as a learning modality by other medical schools. PMID:22066033

Update on the Search for Chemical Interactions Between the Core and Mantle

NASA Astrophysics Data System (ADS)

Walker, R. J.

2017-12-01

Recent tomographic studies provide strong geophysical evidence for deep mantle upwellings, commonly referred to as "plumes", rising from the core-mantle boundary to regions underlying some ocean island basalt occurrences. Nevertheless, the existence of plumes and their association with ocean islands remains questioned by some. In addition, the occurrence and extent of chemical exchange between the core and lowermost mantle remains essentially un-constrained. If some plumes rise from the core-mantle boundary and there has been some level of chemical interaction between the core and mantle at some point in time, then it is possible that plumes could contain a unique chemical or isotopic fingerprint that is characteristic of the core. There is currently no strong evidence supporting this possibility. The short-lived 182Hf→182W (t½ = 9 m.y.) system has been proposed as a geochemical tool for detecting possible core-mantle interactions. Mass balance constraints suggest the 182W/184W and W concentration of the core are 200 ppm lower and 20 times higher, respectively, than the bulk silicate Earth. Recent discovery of negative correlations between 182W/184W and 3He/4He in ocean island basalts (OIB) from Hawaii and Samoa suggests that these volcanic systems may access a primordial component inside the Earth with W-He isotopic characteristics broadly consistent with the core. However, direct contribution of metal from the outer core to a rising plume is inconsistent with the concentrations of highly siderophile elements (HSE) in the isotopically anomalous lavas. In order for the isotopically anomalous W and He to be tied to the core, a transfer mechanism for isotopic signal, other than metal infiltration into the mantle is needed, as is a present day storage site for the signal. The possible existence of one or more basal magma oceans at some points in Earth history present opportunity for isotopic exchange between the lowermost mantle and core, without collateral increases in HSE, within the portion of the affected mantle. Experiments, however, will be necessary to verify this presumption. The spatial correlation between ultra-low velocity zones and isotopically anomalous OIB suggest they may be repositories of the core signal. If so, they may also represent left overs of an early basal magma ocean.

Infrastructure and mechanical properties of a fault zone in sandstone as an outcrop analogue of a potential geothermal reservoir

NASA Astrophysics Data System (ADS)

Bauer, J. F.; Meier, S.; Philipp, S. L.

2013-12-01

Due to high drilling costs of geothermal projects, it is economically sensible to assess the potential suitability of a reservoir prior to drilling. Fault zones are of particular importance, because they may enhance fluid flow, or be flow barriers, respectively, depending on their particular infrastructure. Outcrop analogue studies are useful to analyze the fault zone infrastructure and thereby increase the predictability of fluid flow behavior across fault zones in the corresponding deep reservoir. The main aims of the present study are to 1) analyze the infrastructure and the differences of fracture system parameters in fault zones and 2) determine the mechanical properties of the faulted rocks. We measure fracture frequencies as well as orientations, lengths and apertures and take representative rock samples for each facies to obtain Young's modulus, compressive and tensile strengths in the laboratory. Since fractures reduce the stiffnesses of in situ rock masses we use an inverse correlation of the number of discontinuities to calculate effective (in situ) Young's moduli to investigate the variation of mechanical properties in fault zones. In addition we determine the rebound hardness, which correlates with the compressive strength measured in the laboratory, with a 'Schmidt-Hammer' in the field because this allows detailed maps of mechanical property variations within fault zones. Here we present the first results for a fault zone in the Triassic Lower Bunter of the Upper Rhine Graben in France. The outcrop at Cleebourg exposes the damage zone of the footwall and a clear developed fault core of a NNW-SSE-striking normal fault. The approximately 15 m wide fault core consists of fault gouge, slip zones, deformation bands and host rock lenses. Intensive deformation close to the core led to the formation of a distal fault core, a 5 m wide zone with disturbed layering and high fracture frequency. The damage zone also contains more fractures than the host rock. Fracture frequency and connectivity clearly increase near the fault core where the reservoir permeability may thus be higher, the effective Young's modulus lower. Similarly the Schmidt-Hammer measurements show that the rebound hardness, or the compressive strength, respectively, decreases near the fault core. This Project is part of the Research- and Development Project 'AuGE' (Outcrop Analogue Studies in Geothermal Exploration). Project partners are the companies Geothermal Engeneering GmbH as well as the Universities of Heidelberg and Erlangen. We thank the German Federal Ministry for the Environment, Nature Conversation and Nuclear Safty (BMU) for funding the project in the framework of the 5th Energy Research Program (FKZ: 0325302). Also thanks to the owner of the quarry for the permission to perform our field studies.

A Consistent and Predictable Commercial Broiler Chicken Bacterial Microbiota in Antibiotic-Free Production Displays Strong Correlations with Performance.

PubMed

Johnson, Timothy J; Youmans, Bonnie P; Noll, Sally; Cardona, Carol; Evans, Nicholas P; Karnezos, T Peter; Ngunjiri, John M; Abundo, Michael C; Lee, Chang-Won

2018-06-15

Defining the baseline bacterial microbiome is critical to understanding its relationship with health and disease. In broiler chickens, the core microbiome and its possible relationships with health and disease have been difficult to define, due to high variability between birds and flocks. Presented here are data from a large, comprehensive microbiota-based study in commercial broilers. The primary goals of this study included understanding what constitutes the core bacterial microbiota in the broiler gastrointestinal, respiratory, and barn environments; how these core players change across age, geography, and time; and which bacterial taxa correlate with enhanced bird performance in antibiotic-free flocks. Using 2,309 samples from 37 different commercial flocks within a vertically integrated broiler system and metadata from these and an additional 512 flocks within that system, the baseline bacterial microbiota was defined using 16S rRNA gene sequencing. The effects of age, sample type, flock, and successive flock cycles were compared, and results indicate a consistent, predictable, age-dependent bacterial microbiota, irrespective of flock. The tracheal bacterial microbiota of broilers was comprehensively defined, and Lactobacillus was the dominant bacterial taxon in the trachea. Numerous bacterial taxa were identified, which were strongly correlated with broiler chicken performance across multiple tissues. While many positively correlated taxa were identified, negatively associated potential pathogens were also identified in the absence of clinical disease, indicating that subclinical dynamics occur that impact performance. Overall, this work provides necessary baseline data for the development of effective antibiotic alternatives, such as probiotics, for sustainable poultry production. IMPORTANCE Multidrug-resistant bacterial pathogens are perhaps the greatest medical challenge we will face in the 21st century and beyond. Antibiotics are necessary in animal production to treat disease. As such, animal production is a contributor to the problem of antibiotic resistance. Efforts are underway to reduce antibiotic use in animal production. However, we are also challenged to feed the world's increasing population, and sustainable meat production is paramount to providing a safe and quality protein source for human consumption. In the absence of antibiotics, alternative approaches are needed to maintain health and prevent disease, and probiotics have great promise as one such approach. This work paves the way for the development of alternative approaches to raising poultry by increasing our understandings of what defines the poultry microbiome and of how it can potentially be modulated to improve animal health and performance. Copyright © 2018 American Society for Microbiology.

Skin surface temperature of broiler chickens is correlated to body core temperature and is indicative of their thermoregulatory status.

PubMed

Giloh, M; Shinder, D; Yahav, S

2012-01-01

Extreme thermal conditions may dramatically affect the performance of broilers and other domestic animals, thereby impairing animal welfare and causing economic losses. Although body core temperature is the parameter that best reflects a bird's thermal status, practical and physiological obstacles make it irrelevant as a source of information on the thermal status of commercial flocks. Advances in the technology of infrared thermal imaging have enabled highly accurate, noncontact, and noninvasive measurements of skin surface temperature. Providing that skin surface temperature correlates with body temperature, this technology could enable acquisition of reliable information on the thermal status of animals, thereby improving diagnoses of environmental stress in a flock. This study of broiler chickens found a strong positive correlation between body core temperature and facial surface temperature, as recorded by infrared thermal imaging. The correlation was equally strong at all ages from 8 to 36 d during exposure to acute heat stress with or without proper ventilation and after acclimation to chronic heat exposure. A similar correlation was found by measurements in commercial flocks of broilers. Measurements of blood plasma concentrations of corticosterone, thyroid hormones, and arginine vasotocin confirmed that metabolic activity was low after acclimation to chronic exposure to heat, whereas ventilation was at least as efficient as acclimation in reducing thermal stress but did not impair metabolism. In light of these novel results, commercial benefits of infrared thermal imaging technology are suggested, especially in climate control for commercial poultry flocks. The application of this technique to other domestic animals should be investigated in future experiments.

Insert Design and Manufacturing for Foam-Core Composite Sandwich Structures

NASA Astrophysics Data System (ADS)

Lares, Alan

Sandwich structures have been used in the aerospace industry for many years. The high strength to weight ratios that are possible with sandwich constructions makes them desirable for airframe applications. While sandwich structures are effective at handling distributed loads such as aerodynamic forces, they are prone to damage from concentrated loads at joints or due to impact. This is due to the relatively thin face-sheets and soft core materials typically found in sandwich structures. Carleton University's Uninhabited Aerial Vehicle (UAV) Project Team has designed and manufactured a UAV (GeoSury II Prototype) which features an all composite sandwich structure fuselage structure. The purpose of the aircraft is to conduct geomagnetic surveys. The GeoSury II Prototype serves as the test bed for many areas of research in advancing UAV technologies. Those areas of research include: low cost composite materials manufacturing, geomagnetic data acquisition, obstacle detection, autonomous operations and magnetic signature control. In this thesis work a methodology for designing and manufacturing inserts for foam-core sandwich structures was developed. The results of this research work enables a designer wishing to design a foam-core sandwich airframe structure, a means of quickly manufacturing optimized inserts for the safe introduction of discrete loads into the airframe. The previous GeoSury II Prototype insert designs (v.1 & v.2) were performance tested to establish a benchmark with which to compare future insert designs. Several designs and materials were considered for the new v.3 inserts. A plug and sleeve design was selected, due to its ability to effectively transfer the required loads to the sandwich structure. The insert material was chosen to be epoxy, reinforced with chopped carbon fibre. This material was chosen for its combination of strength, low mass and also compatibility with the face-sheet material. The v.3 insert assembly is 60% lighter than the previous insert designs. A casting process for manufacturing the v.3 inserts was developed. The developed casting process, when producing more than 13 inserts, becomes more economical than machining. An exploratory study was conducted looking at the effects of dynamic loading on the v.3 insert performance. The results of this study highlighted areas for improving dynamic testing of foam-core sandwich structure inserts. Correlations were developed relating design variables such as face-sheet thickness and insert diameter to a failure load for different load cases. This was done through simulations using Computer Aided Engineering (CAE) software, and experimental testing. The resulting correlations were integrated into a computer program which outputs the required insert dimensions given a set of design parameters, and load values.

Planck 2015 results. XXIII. The thermal Sunyaev-Zeldovich effect-cosmic infrared background correlation

NASA Astrophysics Data System (ADS)

Planck Collaboration; Ade, P. A. R.; Aghanim, N.; Arnaud, M.; Aumont, J.; Baccigalupi, C.; Banday, A. J.; Barreiro, R. B.; Bartlett, J. G.; Bartolo, N.; Battaner, E.; Benabed, K.; Benoit-Lévy, A.; Bernard, J.-P.; Bersanelli, M.; Bielewicz, P.; Bock, J. J.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Burigana, C.; Butler, R. C.; Calabrese, E.; Catalano, A.; Chamballu, A.; Chiang, H. C.; Christensen, P. R.; Churazov, E.; Clements, D. L.; Colombo, L. P. L.; Combet, C.; Comis, B.; Couchot, F.; Coulais, A.; Crill, B. P.; Curto, A.; Cuttaia, F.; Danese, L.; Davies, R. D.; Davis, R. J.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Dickinson, C.; Diego, J. M.; Dole, H.; Donzelli, S.; Doré, O.; Douspis, M.; Ducout, A.; Dupac, X.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Finelli, F.; Flores-Cacho, I.; Forni, O.; Frailis, M.; Fraisse, A. A.; Franceschi, E.; Galeotta, S.; Galli, S.; Ganga, K.; Génova-Santos, R. T.; Giard, M.; Giraud-Héraud, Y.; Gjerløw, E.; González-Nuevo, J.; Górski, K. M.; Gregorio, A.; Gruppuso, A.; Gudmundsson, J. E.; Hansen, F. K.; Harrison, D. L.; Helou, G.; Hernández-Monteagudo, C.; Herranz, D.; Hildebrandt, S. R.; Hivon, E.; Hobson, M.; Hornstrup, A.; Hovest, W.; Huffenberger, K. M.; Hurier, G.; Jaffe, A. H.; Jaffe, T. R.; Jones, W. C.; Keihänen, E.; Keskitalo, R.; Kisner, T. S.; Kneissl, R.; Knoche, J.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Langer, M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Leonardi, R.; Levrier, F.; Lilje, P. B.; Linden-Vørnle, M.; López-Caniego, M.; Lubin, P. M.; Macías-Pérez, J. F.; Maffei, B.; Maggio, G.; Maino, D.; Mak, D. S. Y.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Masi, S.; Matarrese, S.; Melchiorri, A.; Mennella, A.; Migliaccio, M.; Mitra, S.; Miville-Deschênes, M.-A.; Moneti, A.; Montier, L.; Morgante, G.; Mortlock, D.; Munshi, D.; Murphy, J. A.; Nati, F.; Natoli, P.; Noviello, F.; Novikov, D.; Novikov, I.; Oxborrow, C. A.; Paci, F.; Pagano, L.; Pajot, F.; Paoletti, D.; Partridge, B.; Pasian, F.; Pearson, T. J.; Perdereau, O.; Perotto, L.; Pettorino, V.; Piacentini, F.; Piat, M.; Pierpaoli, E.; Plaszczynski, S.; Pointecouteau, E.; Polenta, G.; Ponthieu, N.; Pratt, G. W.; Prunet, S.; Puget, J.-L.; Rachen, J. P.; Reinecke, M.; Remazeilles, M.; Renault, C.; Renzi, A.; Ristorcelli, I.; Rocha, G.; Rosset, C.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Rusholme, B.; Sandri, M.; Santos, D.; Savelainen, M.; Savini, G.; Scott, D.; Spencer, L. D.; Stolyarov, V.; Stompor, R.; Sunyaev, R.; Sutton, D.; Suur-Uski, A.-S.; Sygnet, J.-F.; Tauber, J. A.; Terenzi, L.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Tucci, M.; Umana, G.; Valenziano, L.; Valiviita, J.; Van Tent, B.; Vielva, P.; Villa, F.; Wade, L. A.; Wandelt, B. D.; Wehus, I. K.; Welikala, N.; Yvon, D.; Zacchei, A.; Zonca, A.

2016-09-01

We use Planck data to detect the cross-correlation between the thermal Sunyaev-Zeldovich (tSZ) effect and the infrared emission from the galaxies that make up the the cosmic infrared background (CIB). We first perform a stacking analysis towards Planck-confirmed galaxy clusters. We detect infrared emission produced by dusty galaxies inside these clusters and demonstrate that the infrared emission is about 50% more extended than the tSZ effect. Modelling the emission with a Navarro-Frenk-White profile, we find that the radial profile concentration parameter is c500 = 1.00+0.18-0.15 . This indicates that infrared galaxies in the outskirts of clusters have higher infrared flux than cluster-core galaxies. We also study the cross-correlation between tSZ and CIB anisotropies, following three alternative approaches based on power spectrum analyses: (I) using a catalogue of confirmed clusters detected in Planck data; (II) using an all-sky tSZ map built from Planck frequency maps; and (III) using cross-spectra between Planck frequency maps. With the three different methods, we detect the tSZ-CIB cross-power spectrum at significance levels of (I) 6σ; (II) 3σ; and (III) 4σ. We model the tSZ-CIB cross-correlation signature and compare predictions with the measurements. The amplitude of the cross-correlation relative to the fiducial model is AtSZ-CIB = 1.2 ± 0.3. This result is consistent with predictions for the tSZ-CIB cross-correlation assuming the best-fit cosmological model from Planck 2015 results along with the tSZ and CIB scaling relations.

Ice core records of climate variability on the Third Pole with emphasis on the Guliya ice cap, western Kunlun Mountains

NASA Astrophysics Data System (ADS)

Thompson, Lonnie G.; Yao, Tandong; Davis, Mary E.; Mosley-Thompson, Ellen; Wu, Guangjian; Porter, Stacy E.; Xu, Baiqing; Lin, Ping-Nan; Wang, Ninglian; Beaudon, Emilie; Duan, Keqin; Sierra-Hernández, M. Roxana; Kenny, Donald V.

2018-05-01

Records of recent climate from ice cores drilled in 2015 on the Guliya ice cap in the western Kunlun Mountains of the Tibetan Plateau, which with the Himalaya comprises the Third Pole (TP), demonstrate that this region has become warmer and moister since at least the middle of the 19th century. Decadal-scale linkages are suggested between ice core temperature and snowfall proxies, North Atlantic oceanic and atmospheric processes, Arctic temperatures, and Indian summer monsoon intensity. Correlations between annual-scale oxygen isotopic ratios (δ18O) and tropical western Pacific and Indian Ocean sea surface temperatures are also demonstrated. Comparisons of climate records during the last millennium from ice cores acquired throughout the TP illustrate centennial-scale differences between monsoon and westerlies dominated regions. Among these records, Guliya shows the highest rate of warming since the end of the Little Ice Age, but δ18O data over the last millennium from TP ice cores support findings that elevation-dependent warming is most pronounced in the Himalaya. This, along with the decreasing precipitation rates in the Himalaya region, is having detrimental effects on the cryosphere. Although satellite monitoring of glaciers on the TP indicates changes in surface area, only a few have been directly monitored for mass balance and ablation from the surface. This type of ground-based study is essential to obtain a better understanding of the rate of ice shrinkage on the TP.

Optimizing Mouse Surgery with Online Rectal Temperature Monitoring and Preoperative Heat Supply. Effects on Post-Ischemic Acute Kidney Injury.

PubMed

Marschner, Julian A; Schäfer, Hannah; Holderied, Alexander; Anders, Hans-Joachim

2016-01-01

Body temperature affects outcomes of tissue injury. We hypothesized that online body core temperature recording and selective interventions help to standardize peri-interventional temperature control and the reliability of outcomes in experimental renal ischemia reperfusion injury (IRI). We recorded core temperature in up to seven mice in parallel using a Thermes USB recorder and ret-3-iso rectal probes with three different protocols. Setup A: Heating pad during ischemia time; Setup B: Heating pad from incision to wound closure; Setup C: A ventilated heating chamber before surgery and during ischemia time with surgeries performed on a heating pad. Temperature profile recording displayed significant declines upon installing anesthesia. The profile of the baseline experimental setup A revealed that <1% of the temperature readings were within the target range of 36.5 to 38.5°C. Setup B and C increased the target range readings to 34.6 ± 28.0% and 99.3 ± 1.5%, respectively. Setup C significantly increased S3 tubular necrosis, neutrophil influx, and mRNA expression of kidney injury markers. In addition, using setup C different ischemia times generated a linear correlation with acute tubular necrosis parameters at a low variability, which further correlated with the degree of kidney atrophy 5 weeks after surgery. Changing temperature control setup A to C was equivalent to 10 minutes more ischemia time. We conclude that body temperature drops quickly in mice upon initiating anesthesia. Immediate heat supply, e.g. in a ventilated heating chamber, and online core temperature monitoring can help to standardize and optimize experimental outcomes.

Thermophysical properties of krypton-helium gas mixtures from ab initio pair potentials

PubMed Central

2017-01-01

A new potential energy curve for the krypton-helium atom pair was developed using supermolecular ab initio computations for 34 interatomic distances. Values for the interaction energies at the complete basis set limit were obtained from calculations with the coupled-cluster method with single, double, and perturbative triple excitations and correlation consistent basis sets up to sextuple-zeta quality augmented with mid-bond functions. Higher-order coupled-cluster excitations up to the full quadruple level were accounted for in a scheme of successive correction terms. Core-core and core-valence correlation effects were included. Relativistic corrections were considered not only at the scalar relativistic level but also using full four-component Dirac–Coulomb and Dirac–Coulomb–Gaunt calculations. The fitted analytical pair potential function is characterized by a well depth of 31.42 K with an estimated standard uncertainty of 0.08 K. Statistical thermodynamics was applied to compute the krypton-helium cross second virial coefficients. The results show a very good agreement with the best experimental data. Kinetic theory calculations based on classical and quantum-mechanical approaches for the underlying collision dynamics were utilized to compute the transport properties of krypton-helium mixtures in the dilute-gas limit for a large temperature range. The results were analyzed with respect to the orders of approximation of kinetic theory and compared with experimental data. Especially the data for the binary diffusion coefficient confirm the predictive quality of the new potential. Furthermore, inconsistencies between two empirical pair potential functions for the krypton-helium system from the literature could be resolved. PMID:28595411

Effect of discharge instructions on readmission of hospitalised patients with heart failure: do all of the Joint Commission on Accreditation of Healthcare Organizations heart failure core measures reflect better care?

PubMed Central

VanSuch, Monica; Naessens, James M; Stroebel, Robert J; Huddleston, Jeanne M; Williams, Arthur R

2006-01-01

Background Most nationally standardised quality measures use widely accepted evidence‐based processes as their foundation, but the discharge instruction component of the United States standards of Joint Commission on Accreditation of Healthcare Organizations heart failure core measure appears to be based on expert opinion alone. Objective To determine whether documentation of compliance with any or all of the six required discharge instructions is correlated with readmissions to hospital or mortality. Research design A retrospective study at a single tertiary care hospital was conducted on randomly sampled patients hospitalised for heart failure from July 2002 to September 2003. Participants Applying the Joint Commission on Accreditation of Healthcare Organizations criteria, 782 of 1121 patients were found eligible to receive discharge instructions. Eligibility was determined by age, principal diagnosis codes and discharge status codes. Measures The primary outcome measures are time to death and time to readmission for heart failure or readmission for any cause and time to death. Results In all, 68% of patients received all instructions, whereas 6% received no instructions. Patients who received all instructions were significantly less likely to be readmitted for any cause (p = 0.003) and for heart failure (p = 0.035) than those who missed at least one type of instruction. Documentation of discharge instructions is correlated with reduced readmission rates. However, there was no association between documentation of discharge instructions and mortality (p = 0.521). Conclusions Including discharge instructions among other evidence‐based heart failure core measures appears justified. PMID:17142589

Thermophysical properties of krypton-helium gas mixtures from ab initio pair potentials

NASA Astrophysics Data System (ADS)

Jäger, Benjamin; Bich, Eckard

2017-06-01

A new potential energy curve for the krypton-helium atom pair was developed using supermolecular ab initio computations for 34 interatomic distances. Values for the interaction energies at the complete basis set limit were obtained from calculations with the coupled-cluster method with single, double, and perturbative triple excitations and correlation consistent basis sets up to sextuple-zeta quality augmented with mid-bond functions. Higher-order coupled-cluster excitations up to the full quadruple level were accounted for in a scheme of successive correction terms. Core-core and core-valence correlation effects were included. Relativistic corrections were considered not only at the scalar relativistic level but also using full four-component Dirac-Coulomb and Dirac-Coulomb-Gaunt calculations. The fitted analytical pair potential function is characterized by a well depth of 31.42 K with an estimated standard uncertainty of 0.08 K. Statistical thermodynamics was applied to compute the krypton-helium cross second virial coefficients. The results show a very good agreement with the best experimental data. Kinetic theory calculations based on classical and quantum-mechanical approaches for the underlying collision dynamics were utilized to compute the transport properties of krypton-helium mixtures in the dilute-gas limit for a large temperature range. The results were analyzed with respect to the orders of approximation of kinetic theory and compared with experimental data. Especially the data for the binary diffusion coefficient confirm the predictive quality of the new potential. Furthermore, inconsistencies between two empirical pair potential functions for the krypton-helium system from the literature could be resolved.

Seismic waveform inversion for core-mantle boundary topography

NASA Astrophysics Data System (ADS)

Colombi, Andrea; Nissen-Meyer, Tarje; Boschi, Lapo; Giardini, Domenico

2014-07-01

The topography of the core-mantle boundary (CMB) is directly linked to the dynamics of both the mantle and the outer core, although it is poorly constrained and understood. Recent studies have produced topography models with mutual agreement up to degree 2. A broad-band waveform inversion strategy is introduced and applied here, with relatively low computational cost and based on a first-order Born approximation. Its performance is validated using synthetic waveforms calculated in theoretical earth models that include different topography patterns with varying lateral wavelengths, from 600 to 2500 km, and magnitudes (˜10 km peak-to-peak). The source-receiver geometry focuses mainly on the Pdiff, PKP, PcP and ScS phases. The results show that PKP branches, PcP and ScS generally perform well and in a similar fashion, while Pdiff yields unsatisfactory results. We investigate also how 3-D mantle correction influences the output models, and find that despite the disturbance introduced, the models recovered do not appear to be biased, provided that the 3-D model is correct. Using cross-correlated traveltimes, we derive new topography models from both P and S waves. The static corrections used to remove the mantle effect are likely to affect the inversion, compromising the agreement between models derived from P and S data. By modelling traveltime residuals starting from sensitivity kernels, we show how the simultaneous use of volumetric and boundary kernels can reduce the bias coming from mantle structures. The joint inversion approach should be the only reliable method to invert for CMB topography using absolute cross-correlation traveltimes.

Changes in porosity and organic matter phase distribution monitored by NMR relaxometry following hydrous pyrolysis under uniaxial confinement

USGS Publications Warehouse

Washburn, Kathryn E.; Birdwell, Justin E.; Lewan, Michael D.; Miller, Michael; Baez, Luis; Beeney, Ken; Sonnenberg, Steve

2013-01-01

Artificial maturation methods are used to induce changes in source rock thermal maturity without the uncertainties that arise when comparing natural samples from a particular basin that often represent different levels of maturation and different lithofacies. A novel uniaxial confinement clamp was used on Woodford Shale cores in hydrous pyrolysis experiments to limit sample expansion by simulating the effect of overburden present during thermal maturation in natural systems. These samples were then subjected to X-ray computed tomography (X-CT) imaging and low-field nuclear magnetic resonance (LF-NMR) relaxometry measurements. LF-NMR relaxometry is a noninvasive technique commonly used to measure porosity and pore-size distributions in fluid-filled porous media, but may also measure hydrogen present in hydrogen-bearing organic solids. Standard T1 and T2 relaxation distributions were determined and two dimensional T1-T2 correlation measurements were performed on the Woodford Shale cores. The T1-T2 correlations facilitate resolution of organic phases in the system. The changes observed in NMR-relaxation times correspond to bitumen and lighter hydrocarbon production that occur as source rock organic matter matures. The LF-NMR porosities of the core samples at maximum oil generation are significantly higher than porosities measured by other methods. This discrepancy likely arises from the measurement of highly viscous organic constituents in addition to fluid-filled porosity. An unconfined sample showed shorter relaxation times and lower porosity. This difference is attributed to the lack of fractures observed in the unconfined sample by X-CT.

Turbulent convection in microchannels

NASA Astrophysics Data System (ADS)

Adams, Thomas Mcdaniel

1998-10-01

Single-phase forced convection in microchannels is an effective cooling mechanism capable of accommodating the high heat fluxes encountered in fission reactor cores, accelerator targets, microelectronic heat sinks and micro-heat exchangers. Traditional Nusselt type correlations, however, have generally been obtained using data from channels with hydraulic diameters >2 cm. Application of such relationships to microchannels is therefore questionable. A diameter limit below which traditional correlations are invalid had not been established. The objective of this investigation was to systematically address the effect of small hydraulic diameter on turbulent single-phase forced convection of water. A number of microchannels having hydraulic diameters ranging from 0.76 to 1.13 mm were constructed and tested over a wide range of flow rates and heat fluxes. Experimentally obtained Nusselt numbers were significantly higher than the values predicted by the Gnielinski correlation for large channels, the effect of decreasing diameter being to further increase heat transfer enhancement. A working correlation predicting the heat transfer enhancement for turbulent convection in microchannels was developed. The correlation predicts the lower diameter limit below which traditional correlations are no longer valid to be approximately 1.2 mm. Of further interest was the effect of the desorption of noncondensable gases dissolved in the water on turbulent convection. In large channels noncondensables undergo little desorption and their effect is negligible. The large pressure drops coupled with large temperature increases for high heat fluxes in microchannels, however, leads to a two-phase, two-component flow thereby enhancing heat transfer coefficients above their liquid- only values. A detailed mathematical model was developed to predict the resulting void fractions and liquid- coolant accelerations due to the desorption of noncondensables in microchannels. Experiments were also performed to compare heat transfer coefficients for fully-degassed water to water saturated with air at test section inlet conditions. The data showed significant heat transfer enhancement for the air-saturated case over the fully-degassed case. The degree of enhancement was greatly under-predicted by current two-phase, two- component heat transfer correlations.

Trichloroethylene (TCE) in tree cores to complement a subsurface investigation on residential property near a former electroplating facility.

PubMed

Wilcox, Jeffrey D; Johnson, Kathy M

2016-10-01

Tree cores were collected and analyzed for trichloroethylene (TCE) on a private property between a former electroplating facility in Asheville, North Carolina (USA), and a contaminated wetland/spring complex. TCE was detected in 16 of 31 trees, the locations of which were largely consistent with a "plume core" delineated by a more detailed subsurface investigation nearly 2 years later. Concentrations in tree cores and nearby soil borings were not correlated, perhaps due to heterogeneities in both geologic and tree root structure, spatial and temporal variability in transpiration rates, or interferences caused by other contaminants at the site. Several tree cores without TCE provided evidence for significantly lower TCE concentrations in shallow groundwater along the margins of the contaminated spring complex in an area with limited accessibility. This study demonstrates that tree core analyses can complement a more extensive subsurface investigation, particularly in residential or ecologically sensitive areas.

Scientific objectives of the primitive body sample return missions: An approach from the light-induced effect on water vapor

NASA Technical Reports Server (NTRS)

Shimizu, Mikio

1994-01-01

Water is undoubtedly one of the most crucial components of the solar nebula for determining planetary composition: planets were formed from the accretion of the dust particles in the nebula, and the redox state of Fe in the particles can be determined by the reaction of Fe with water vapor diffused into the interior of the particle in the early stage of solar system formation. It has been discussed from various observations that the cores of Mercury, Venus, and the Earth might be metallic Fe, although the core of the Earth may be somewhat oxidized by the high pressure and temperature reaction of liquid Fe with perovskite at the boundary of the mantle and the core, whereas the core of Mars may be highly oxidized, as suggested by its low density. Isotopic anomalies of various elements have frequently been observed in the solar system (in planetary atmospheres and in meteorites) and some of them can be attributed to the injection of exotic particles formed in other stars into the solar nebula. Hydrogen and D anomalies in planetary atmospheres were frequently believed to correlate with the differential escape of H and D from the exospheres of Venus and Mars, although no one knows the primordial D/H ratios before thermal escape. This paper explains the decrease of the observed D/H ratios with distance from the sun by considering the light-induced drift effect to displace H2(16)O alone to the outside in the solar nebula.

A 3-D mathematical model to identify organ-specific risks in rats during thermal stress.

PubMed

Rakesh, Vineet; Stallings, Jonathan D; Helwig, Bryan G; Leon, Lisa R; Jackson, David A; Reifman, Jaques

2013-12-01

Early prediction of the adverse outcomes associated with heat stress is critical for effective management and mitigation of injury, which may sometimes lead to extreme undesirable clinical conditions, such as multiorgan dysfunction syndrome and death. Here, we developed a computational model to predict the spatiotemporal temperature distribution in a rat exposed to heat stress in an attempt to understand the correlation between heat load and differential organ dysfunction. The model includes a three-dimensional representation of the rat anatomy obtained from medical imaging and incorporates the key mechanisms of heat transfer during thermoregulation. We formulated a novel approach to estimate blood temperature by accounting for blood mixing from the different organs and to estimate the effects of the circadian rhythm in body temperature by considering day-night variations in metabolic heat generation and blood perfusion. We validated the model using in vivo core temperature measurements in control and heat-stressed rats and other published experimental data. The model predictions were within 1 SD of the measured data. The liver demonstrated the greatest susceptibility to heat stress, with the maximum temperature reaching 2°C higher than the measured core temperature and 95% of its volume exceeding the targeted experimental core temperature. Other organs also attained temperatures greater than the core temperature, illustrating the need to monitor multiple organs during heat stress. The model facilitates the identification of organ-specific risks during heat stress and has the potential to aid in the development of improved clinical strategies for thermal-injury prevention and management.

Near-Edge X-ray Absorption Fine Structure within Multilevel Coupled Cluster Theory.

PubMed

Myhre, Rolf H; Coriani, Sonia; Koch, Henrik

2016-06-14

Core excited states are challenging to calculate, mainly because they are embedded in a manifold of high-energy valence-excited states. However, their locality makes their determination ideal for local correlation methods. In this paper, we demonstrate the performance of multilevel coupled cluster theory in computing core spectra both within the core-valence separated and the asymmetric Lanczos implementations of coupled cluster linear response theory. We also propose a visualization tool to analyze the excitations using the difference between the ground-state and excited-state electron densities.

Site Fidelity in Space Use by Spider Monkeys (Ateles geoffroyi) in the Yucatan Peninsula, Mexico

PubMed Central

Ramos-Fernandez, Gabriel; Smith Aguilar, Sandra E.; Schaffner, Colleen M.; Vick, Laura G.; Aureli, Filippo

2013-01-01

Animal home ranges may vary little in their size and location in the short term but nevertheless show more variability in the long term. We evaluated the degree of site fidelity of two groups of spider monkeys (Ateles geoffroyi) over a 10- and 13-year period, respectively, in the northeastern Yucatan peninsula, Mexico. We used the Local Convex Hull method to estimate yearly home ranges and core areas (defined as the 60% probability contour) for the two groups. Home ranges varied from 7.7 to 49.6 ha and core areas varied from 3.1 to 9.2 ha. We evaluated the degree of site fidelity by quantifying the number of years in which different areas were used as either home ranges or core areas. Large tracts were used only as home ranges and only for a few years, whereas small areas were used as either core area or home range for the duration of the study. The sum of the yearly core areas coincided partially with the yearly home ranges, indicating that home ranges contain areas used intermittently. Home ranges, and especially core areas, contained a higher proportion of mature forest than the larger study site as a whole. Across years and only in one group, the size of core areas was positively correlated with the proportion of adult males in the group, while the size of home ranges was positively correlated with both the proportion of males and the number of tree species included in the diet. Our findings suggest that spider monkey home ranges are the result of a combination of long-term site fidelity and year-to-year use variation to enable exploration of new resources. PMID:23675427

Development of a core outcome set for clinical trials in facial aging: study protocol for a systematic review of the literature and identification of a core outcome set using a Delphi survey.

PubMed

Schlessinger, Daniel I; Iyengar, Sanjana; Yanes, Arianna F; Henley, Jill K; Ashchyan, Hovik J; Kurta, Anastasia O; Patel, Payal M; Sheikh, Umar A; Franklin, Matthew J; Hanna, Courtney C; Chen, Brian R; Chiren, Sarah G; Schmitt, Jochen; Deckert, Stefanie; Furlan, Karina C; Poon, Emily; Maher, Ian A; Cartee, Todd V; Sobanko, Joseph F; Alam, Murad

2017-08-01

Facial aging is a concern for many patients. Wrinkles, loss of volume, and discoloration are common physical manifestations of aging skin. Genetic heritage, prior ultraviolet light exposure, and Fitzpatrick skin type may be associated with the rate and type of facial aging. Although many clinical trials assess the correlates of skin aging, there is heterogeneity in the outcomes assessed, which limits the quality of evaluation and comparison of treatment modalities. To address the inconsistency in outcomes, in this project we will develop a core set of outcomes that are to be evaluated in all clinical trials relevant to facial aging. A long list of measureable outcomes will be created from four sources: (1) systematic medical literature review, (2) patient interviews, (3) other published sources, and (4) stakeholder involvement. Two rounds of Delphi processes with homogeneous groups of physicians and patients will be performed to prioritize and condense the list. At a consensus meeting attended by physicians, patients, and stakeholders, outcomes will be further condensed on the basis of participant scores. By the end of the meeting, members will vote and decide on a final recommended set of core outcomes. Subsequent to this, specific measures will be selected or created to assess these outcomes. The aim of this study is to develop a core outcome set and relevant measures for clinical trials relevant to facial aging. We hope to improve the reliability and consistency of outcome reporting of skin aging, thereby enabling improved evaluation of treatment efficacy and patient satisfaction. Core Outcome Measures in Effectiveness Trials (COMET) Initiative, accessible at http://www.comet-initiative.org/studies/details/737 . Core Outcomes Set Initiative, (CSG-COUSIN) accessible at https://www.uniklinikum-dresden.de/de/das-klinikum/universitaetscentren/zegv/cousin/meet-the-teams/project-groups/core-outcome-set-for-the-appearance-of-facial-aging . Protocol version date is 28 July 2016.

Carbon Dioxide Sealing Capacity: Textural or Compositional Controls?

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

Cranganu, Constantin; Soleymani, Hamidreza; Sadiqua, Soleymani

2013-11-30

This research project is aiming to assess the carbon dioxide sealing capacity of most common seal-rocks, such as shales and non-fractured limestones, by analyzing the role of textural and compositional parameters of those rocks. We hypothesize that sealing capacity is controlled by textural and/or compositional pa-rameters of caprocks. In this research, we seek to evaluate the importance of textural and compositional parameters affecting the sealing capacity of caprocks. The conceptu-al framework involves two testable end-member hypotheses concerning the sealing ca-pacity of carbon dioxide reservoir caprocks. Better understanding of the elements controlling sealing quality will advance our knowledge regarding the sealingmore » capacity of shales and carbonates. Due to relatively low permeability, shale and non-fractured carbonate units are considered relatively imper-meable formations which can retard reservoir fluid flow by forming high capillary pres-sure. Similarly, these unites can constitute reliable seals for carbon dioxide capture and sequestration purposes. This project is a part of the comprehensive project with the final aim of studying the caprock sealing properties and the relationship between microscopic and macroscopic characteristics of seal rocks in depleted gas fields of Oklahoma Pan-handle. Through this study we examined various seal rock characteristics to infer about their respective effects on sealing capacity in special case of replacing reservoir fluid with super critical carbon dioxide (scCO{sub 2}). To assess the effect of textural and compositional properties on scCO{sub 2} maximum reten-tion column height we collected 30 representative core samples in caprock formations in three counties (Cimarron, Texas, Beaver) in Oklahoma Panhandle. Core samples were collected from various seal formations (e.g., Cherokee, Keys, Morrowan) at different depths. We studied the compositional and textural properties of the core samples using several techniques. Mercury Injection Porosimetry (MIP), Scanning Electron Microsco-py SEM, and Sedigraph measurements are used to assess the pore-throat-size distribu-tion, sorting, texture, and grain size of the samples. Also, displacement pressure at 10% mercury saturation (Pd) and graphically derived threshold pressure (Pc) were deter-mined by MIP technique. SEM images were used for qualitative study of the minerals and pores texture of the core samples. Moreover, EDS (Energy Dispersive X-Ray Spec-trometer), BET specific surface area, and Total Organic Carbon (TOC) measurements were performed to study various parameters and their possible effects on sealing capaci-ty of the samples. We found that shales have the relatively higher average sealing threshold pressure (Pc) than carbonate and sandstone samples. Based on these observations, shale formations could be considered as a promising caprock in terms of retarding scCO{sub 2} flow and leak-age into above formations. We hypothesized that certain characteristics of shales (e.g., 3 fine pore size, pore size distribution, high specific surface area, and strong physical chemical interaction between wetting phase and mineral surface) make them an effi-cient caprock for sealing super critical CO{sub 2}. We found that the displacement pressure at 10% mercury saturation could not be the ultimate representative of the sealing capacity of the rock sample. On the other hand, we believe that graphical method, introduced by Cranganu (2004) is a better indicator of the true sealing capacity. Based on statistical analysis of our samples from Oklahoma Panhandle we assessed the effects of each group of properties (textural and compositional) on maximum supercriti-cal CO{sub 2} height that can be hold by the caprock. We conclude that there is a relatively strong positive relationship (+.40 to +.69) between supercritical CO{sub 2} column height based on Pc and hard/ soft mineral content index (ratio of minerals with Mohs hardness more than 5 over minerals with Mohs hardness less than 5) in both shales and limestone samples. Average median pore radius and porosity display a strong negative correlation with supercritical CO{sub 2} retention column height. Also, increasing bulk density is positive-ly correlated with the supercritical CO{sub 2} retention column height. One of the most im-portant factors affecting sealing capacity and consequently the height of supercritical CO{sub 2} column is sorting of the pore throats. We observed a strong positive correlation be-tween pore throat sorting and height of CO{sub 2} retention column, especially in shales. This correlation could not be observed in limestone samples. It suggests that the pore throat sorting is more controlling the sealing capacity in shales and shales with well sorted pore throats are the most reliable lithology as seal. We observed that Brunauer–Emmett–Teller (BET) surface area shows a very strong correlation with CO{sub 2} retention column height in limestone samples while BET surface area did not display significant correlation in shales. Pore structure based on SEM mi-crographs exhibits strong correlation with CO{sub 2} retention column height in limestones. Both intercrystalline and vuggy structures have negative correlations while intergranu-lar texture has positive correlation in limestone with respect to CO{sub 2} retention column height. Textural effects observed on SEM micrographs did not show statistically signifi-cant correlation with supercritical CO{sub 2} retention column height in shale samples. Finally, we showed that increasing hard/soft mineral index is strongly correlated with the displacement pressure in limestone samples. Vuggy texture displays a relatively strong and negative correlation with displacement pressure values at 10% mercury satu-ration in shale samples.« less

Identification and Targeting of an Interaction between a Tyrosine Motif within Hepatitis C Virus Core Protein and AP2M1 Essential for Viral Assembly

PubMed Central

Ziv-Av, Amotz; Gerber, Doron; Jacob, Yves; Einav, Shirit

2012-01-01

Novel therapies are urgently needed against hepatitis C virus infection (HCV), a major global health problem. The current model of infectious virus production suggests that HCV virions are assembled on or near the surface of lipid droplets, acquire their envelope at the ER, and egress through the secretory pathway. The mechanisms of HCV assembly and particularly the role of viral-host protein-protein interactions in mediating this process are, however, poorly understood. We identified a conserved heretofore unrecognized YXXΦ motif (Φ is a bulky hydrophobic residue) within the core protein. This motif is homologous to sorting signals within host cargo proteins known to mediate binding of AP2M1, the μ subunit of clathrin adaptor protein complex 2 (AP-2), and intracellular trafficking. Using microfluidics affinity analysis, protein-fragment complementation assays, and co-immunoprecipitations in infected cells, we show that this motif mediates core binding to AP2M1. YXXΦ mutations, silencing AP2M1 expression or overexpressing a dominant negative AP2M1 mutant had no effect on HCV RNA replication, however, they dramatically inhibited intra- and extracellular infectivity, consistent with a defect in viral assembly. Quantitative confocal immunofluorescence analysis revealed that core's YXXΦ motif mediates recruitment of AP2M1 to lipid droplets and that the observed defect in HCV assembly following disruption of core-AP2M1 binding correlates with accumulation of core on lipid droplets, reduced core colocalization with E2 and reduced core localization to trans-Golgi network (TGN), the presumed site of viral particles maturation. Furthermore, AAK1 and GAK, serine/threonine kinases known to stimulate binding of AP2M1 to host cargo proteins, regulate core-AP2M1 binding and are essential for HCV assembly. Last, approved anti-cancer drugs that inhibit AAK1 or GAK not only disrupt core-AP2M1 binding, but also significantly inhibit HCV assembly and infectious virus production. These results validate viral-host interactions essential for HCV assembly and yield compounds for pharmaceutical development. PMID:22916011

Ni@Ru and NiCo@Ru Core-Shell Hexagonal Nanosandwiches with a Compositionally Tunable Core and a Regioselectively Grown Shell.

PubMed

Hwang, Hyeyoun; Kwon, Taehyun; Kim, Ho Young; Park, Jongsik; Oh, Aram; Kim, Byeongyoon; Baik, Hionsuck; Joo, Sang Hoon; Lee, Kwangyeol

2018-01-01

The development of highly active electrocatalysts is crucial for the advancement of renewable energy conversion devices. The design of core-shell nanoparticle catalysts represents a promising approach to boost catalytic activity as well as save the use of expensive precious metals. Here, a simple, one-step synthetic route is reported to prepare hexagonal nanosandwich-shaped Ni@Ru core-shell nanoparticles (Ni@Ru HNS), in which Ru shell layers are overgrown in a regioselective manner on the top and bottom, and around the center section of a hexagonal Ni nanoplate core. Notably, the synthesis can be extended to NiCo@Ru core-shell nanoparticles with tunable core compositions (Ni 3 Co x @Ru HNS). Core-shell HNS structures show superior electrocatalytic activity for the oxygen evolution reaction (OER) to a commercial RuO 2 black catalyst, with their OER activity being dependent on their core compositions. The observed trend in OER activity is correlated to the population of Ru oxide (Ru 4+ ) species, which can be modulated by the core compositions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Performance comparison of new generation HCV core antigen test versus HCV RNA test in management of hepatitis C virus infection.

PubMed

Çetiner, Salih; Çetin Duran, Alev; Kibar, Filiz; Yaman, Akgün

2017-06-01

The study has evaluated the performance of HCV core antigen (Cag) test by comparing HCV RNA PCR assay which is considered the gold standard for management of HCV infection. Totally, 132 samples sent for HCV RNA (real-time PCR) test were included in the study. Anti-HCV antibody test and HCV Cag test were performed by chemiluminescent enzyme immunoassay (CMEI). Anti-HCV test was positive in all samples. HCV RNA was detected in 112/132 (84.8%) samples, and HCV Cag in 105/132 (79.5%). The most common HCV genotype was genotype 1 (86%). Considering the HCV RNA test as gold standard; the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of Cag test were found to be 93.75%, 100%, 100%, 74.07% and 94.69%, respectively, and paired test results were detected as highly concordant. A high level of correlation was seen between HCV RNA and Cag tests, however, the concordance between the two tests appeared to be disrupted at viral loads lower than 10 3 IU/mL. On the contrary, the correlation reached significance for the values higher than 10 3 IU/mL. Viral loads were in the 17-2500IU/mL range for the negative results for Cag test. Pearson's correlation coefficient revealed a considerably high correlation. The concordance between HCV RNA and Cag tests was disrupted under a viral load lower than 10 3 IU/mL. Therefore, it would be appropriate to consider cost effectiveness, advantages and limitations of the HCV RNA and Cag tests during the decision on which method to use for patient management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Creation of Novel Cores for β-Secretase (BACE-1) Inhibitors: A Multiparameter Lead Generation Strategy

PubMed Central

2014-01-01

In order to find optimal core structures as starting points for lead optimization, a multiparameter lead generation workflow was designed with the goal of finding BACE-1 inhibitors as a treatment for Alzheimer’s disease. De novo design of core fragments was connected with three predictive in silico models addressing target affinity, permeability, and hERG activity, in order to guide synthesis. Taking advantage of an additive SAR, the prioritized cores were decorated with a few, well-characterized substituents from known BACE-1 inhibitors in order to allow for core-to-core comparisons. Prediction methods and analyses of how physicochemical properties of the core structures correlate to in vitro data are described. The syntheses and in vitro data of the test compounds are reported in a separate paper by Ginman et al. [J. Med. Chem.2013, 56, 4181–4205]. The affinity predictions are described in detail by Roos et al. [J. Chem. Inf.2014, DOI: 10.1021/ci400374z]. PMID:24900855

Creation of Novel Cores for β-Secretase (BACE-1) Inhibitors: A Multiparameter Lead Generation Strategy.

PubMed

Viklund, Jenny; Kolmodin, Karin; Nordvall, Gunnar; Swahn, Britt-Marie; Svensson, Mats; Gravenfors, Ylva; Rahm, Fredrik

2014-04-10

In order to find optimal core structures as starting points for lead optimization, a multiparameter lead generation workflow was designed with the goal of finding BACE-1 inhibitors as a treatment for Alzheimer's disease. De novo design of core fragments was connected with three predictive in silico models addressing target affinity, permeability, and hERG activity, in order to guide synthesis. Taking advantage of an additive SAR, the prioritized cores were decorated with a few, well-characterized substituents from known BACE-1 inhibitors in order to allow for core-to-core comparisons. Prediction methods and analyses of how physicochemical properties of the core structures correlate to in vitro data are described. The syntheses and in vitro data of the test compounds are reported in a separate paper by Ginman et al. [J. Med. Chem. 2013, 56, 4181-4205]. The affinity predictions are described in detail by Roos et al. [J. Chem. Inf. 2014, DOI: 10.1021/ci400374z].

Geomagnetic reversal in brunhes normal polarity epoch.

PubMed

Smith, J D; Foster, J H

1969-02-07

The magnetic stratigraphly of seven cores of deep-sea sediment established the existence of a short interval of reversed polarity in the upper part of the Brunches epoch of normal polarity. The reversed zone in the cores correlates well with paleontological boundaries and is named the Blake event. Its boundaries are estimated to be 108,000 and 114,000 years ago +/- 10 percent.

Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - I. A simple damage structure inferred from borehole core permeability

USGS Publications Warehouse

Lockner, David A.; Tanaka, Hidemi; Ito, Hisao; Ikeda, Ryuji; Omura, Kentaro; Naka, Hisanobu

2009-01-01

The 1995 Kobe (Hyogo-ken Nanbu) earthquake, M = 7.2, ruptured the Nojima fault in southwest Japan. We have studied core samples taken from two scientific drillholes that crossed the fault zone SW of the epicentral region on Awaji Island. The shallower hole, drilled by the Geological Survey of Japan (GSJ), was started 75 m to the SE of the surface trace of the Nojima fault and crossed the fault at a depth of 624 m. A deeper hole, drilled by the National Research Institute for Earth Science and Disaster Prevention (NIED) was started 302 m to the SE of the fault and crossed fault strands below a depth of 1140 m. We have measured strength and matrix permeability of core samples taken from these two drillholes. We find a strong correlation between permeability and proximity to the fault zone shear axes. The half-width of the high permeability zone (approximately 15 to 25 m) is in good agreement with the fault zone width inferred from trapped seismic wave analysis and other evidence. The fault zone core or shear axis contains clays with permeabilities of approximately 0.1 to 1 microdarcy at 50 MPa effective confining pressure (10 to 30 microdarcy at in situ pressures). Within a few meters of the fault zone core, the rock is highly fractured but has sustained little net shear. Matrix permeability of this zone is approximately 30 to 60 microdarcy at 50 MPa effective confining pressure (300 to 1000 microdarcy at in situ pressures). Outside this damage zone, matrix permeability drops below 0.01 microdarcy. The clay-rich core material has the lowest strength with a coefficient of friction of approximately 0.55. Shear strength increases with distance from the shear axis. These permeability and strength observations reveal a simple fault zone structure with a relatively weak fine-grained core surrounded by a damage zone of fractured rock. In this case, the damage zone will act as a high-permeability conduit for vertical and horizontal flow in the plane of the fault. The fine-grained core region, however, will impede fluid flow across the fault.

Testing the Large-scale Environments of Cool-core and Non-cool-core Clusters with Clustering Bias

NASA Astrophysics Data System (ADS)

Medezinski, Elinor; Battaglia, Nicholas; Coupon, Jean; Cen, Renyue; Gaspari, Massimo; Strauss, Michael A.; Spergel, David N.

2017-02-01

There are well-observed differences between cool-core (CC) and non-cool-core (NCC) clusters, but the origin of this distinction is still largely unknown. Competing theories can be divided into internal (inside-out), in which internal physical processes transform or maintain the NCC phase, and external (outside-in), in which the cluster type is determined by its initial conditions, which in turn leads to different formation histories (I.e., assembly bias). We propose a new method that uses the relative assembly bias of CC to NCC clusters, as determined via the two-point cluster-galaxy cross-correlation function (CCF), to test whether formation history plays a role in determining their nature. We apply our method to 48 ACCEPT clusters, which have well resolved central entropies, and cross-correlate with the SDSS-III/BOSS LOWZ galaxy catalog. We find that the relative bias of NCC over CC clusters is b = 1.42 ± 0.35 (1.6σ different from unity). Our measurement is limited by the small number of clusters with core entropy information within the BOSS footprint, 14 CC and 34 NCC clusters. Future compilations of X-ray cluster samples, combined with deep all-sky redshift surveys, will be able to better constrain the relative assembly bias of CC and NCC clusters and determine the origin of the bimodality.

Core-satellite populations and seasonality of water meter biofilms in a metropolitan drinking water distribution system

PubMed Central

Ling, Fangqiong; Hwang, Chiachi; LeChevallier, Mark W; Andersen, Gary L; Liu, Wen-Tso

2016-01-01

Drinking water distribution systems (DWDSs) harbor the microorganisms in biofilms and suspended communities, yet the diversity and spatiotemporal distribution have been studied mainly in the suspended communities. This study examined the diversity of biofilms in an urban DWDS, its relationship with suspended communities and its dynamics. The studied DWDS in Urbana, Illinois received conventionally treated and disinfected water sourced from the groundwater. Over a 2-year span, biomass were sampled from household water meters (n=213) and tap water (n=20) to represent biofilm and suspended communities, respectively. A positive correlation between operational taxonomic unit (OTU) abundance and occupancy was observed. Examined under a ‘core-satellite' model, the biofilm community comprised 31 core populations that encompassed 76.7% of total 16 S rRNA gene pyrosequences. The biofilm communities shared with the suspended community highly abundant and prevalent OTUs, which related to methano-/methylotrophs (i.e., Methylophilaceae and Methylococcaceae) and aerobic heterotrophs (Sphingomonadaceae and Comamonadaceae), yet differed by specific core populations and lower diversity and evenness. Multivariate tests indicated seasonality as the main contributor to community structure variation. This pattern was resilient to annual change and correlated to the cyclic fluctuations of core populations. The findings of a distinctive biofilm community assemblage and methano-/methyltrophic primary production provide critical insights for developing more targeted water quality monitoring programs and treatment strategies for groundwater-sourced drinking water systems. PMID:26251872

Core-satellite populations and seasonality of water meter biofilms in a metropolitan drinking water distribution system.

PubMed

Ling, Fangqiong; Hwang, Chiachi; LeChevallier, Mark W; Andersen, Gary L; Liu, Wen-Tso

2016-03-01

Drinking water distribution systems (DWDSs) harbor the microorganisms in biofilms and suspended communities, yet the diversity and spatiotemporal distribution have been studied mainly in the suspended communities. This study examined the diversity of biofilms in an urban DWDS, its relationship with suspended communities and its dynamics. The studied DWDS in Urbana, Illinois received conventionally treated and disinfected water sourced from the groundwater. Over a 2-year span, biomass were sampled from household water meters (n=213) and tap water (n=20) to represent biofilm and suspended communities, respectively. A positive correlation between operational taxonomic unit (OTU) abundance and occupancy was observed. Examined under a 'core-satellite' model, the biofilm community comprised 31 core populations that encompassed 76.7% of total 16 S rRNA gene pyrosequences. The biofilm communities shared with the suspended community highly abundant and prevalent OTUs, which related to methano-/methylotrophs (i.e., Methylophilaceae and Methylococcaceae) and aerobic heterotrophs (Sphingomonadaceae and Comamonadaceae), yet differed by specific core populations and lower diversity and evenness. Multivariate tests indicated seasonality as the main contributor to community structure variation. This pattern was resilient to annual change and correlated to the cyclic fluctuations of core populations. The findings of a distinctive biofilm community assemblage and methano-/methyltrophic primary production provide critical insights for developing more targeted water quality monitoring programs and treatment strategies for groundwater-sourced drinking water systems.

Testing the Large-scale Environments of Cool-core and Non-cool-core Clusters with Clustering Bias

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

Medezinski, Elinor; Battaglia, Nicholas; Cen, Renyue

2017-02-10

There are well-observed differences between cool-core (CC) and non-cool-core (NCC) clusters, but the origin of this distinction is still largely unknown. Competing theories can be divided into internal (inside-out), in which internal physical processes transform or maintain the NCC phase, and external (outside-in), in which the cluster type is determined by its initial conditions, which in turn leads to different formation histories (i.e., assembly bias). We propose a new method that uses the relative assembly bias of CC to NCC clusters, as determined via the two-point cluster-galaxy cross-correlation function (CCF), to test whether formation history plays a role in determiningmore » their nature. We apply our method to 48 ACCEPT clusters, which have well resolved central entropies, and cross-correlate with the SDSS-III/BOSS LOWZ galaxy catalog. We find that the relative bias of NCC over CC clusters is b = 1.42 ± 0.35 (1.6 σ different from unity). Our measurement is limited by the small number of clusters with core entropy information within the BOSS footprint, 14 CC and 34 NCC clusters. Future compilations of X-ray cluster samples, combined with deep all-sky redshift surveys, will be able to better constrain the relative assembly bias of CC and NCC clusters and determine the origin of the bimodality.« less

Psychometric properties of the Sinhala version of the PedsQL™ 4.0 Generic Core Scales in early adolescents in Sri Lanka.

PubMed

Danansuriya, Manjula Nishanthi; Rajapaksa, Lalini C

2012-09-04

The concept Health related Quality of life (HRQOL) is increasingly recognized as an important health outcome measure in clinical and research fields. The present study attempted to evaluate the psychometric properties of the Sinhala version of the Pediatric Quality of Life Inventory™ 4.0 (PedsQL™ 4.0) Generic Core Scales among adolescents in Sri Lanka. The original US PedsQL™ was translated into Sinhala and conceptually validated according to international guidelines. A cross-sectional study was conducted among 142 healthy school going adolescents (12-14 years), their parents (n = 120) and a group of adolescents with asthma who attended asthma clinics (n = 115). Reliability was assessed using Cronbach's alpha and validity by examining scale structure, exploring inter-scale correlations and comparing across known groups (healthy vs. chronically ill). The PedsQL™ Sinhala version was found to be acceptable with minimal missing responses. All scales demonstrated satisfactory reliability. Cronbach's alpha for the total scale scores was 0.85 for adolescent self-report while for the parent proxy-report for the healthy group it was 0.86. No floor effects were observed. Ceiling effects were noticed in self-report and parent proxy-report for the healthy group. Overall results of the multi trait scaling analysis confirmed the scale structure with 74% item-convergent validity, 88% item-discriminant validity and an overall scaling success of 72%. Moderate to high correlations were shown among the domains of teen self-report (Spearman rho = .37-.54) and between teen self-report and parent proxy-reports (Spearman rho = .41-.57). The PedsQL™ tool was able to discriminate between the quality of life in healthy adolescents and adolescents with asthma. The findings support the reliability and validity of the Sinhala version of the PedsQL™ 4.0 Generic Core Scales as a generic instrument to measure HRQOL among early adolescents in Sri Lanka in a population setting.

Correlation between electron spin resonance spectra and oil yield in eastern oil shales

USGS Publications Warehouse

Choudhury, M.; Rheams, K.F.; Harrell, J.W.

1986-01-01

Organic free radical spin concentrations were measured in 60 raw oil shale samples from north Alabama and south Tennessee and compared with Fischer assays and uranium concentrations. No correlation was found between spin concentration and oil yield for the complete set of samples. However, for a 13 sample set taken from a single core hole, a linear correlation was obtained. No correlation between spin concentration and uranium concentration was found. ?? 1986.

A converged calculation of the energy barrier to internal rotation in the ethylene-sulfur dioxide dimer

NASA Astrophysics Data System (ADS)

Resende, Stella M.; De Almeida, Wagner B.; van Duijneveldt-van de Rijdt, Jeanne G. C. M.; van Duijneveldt, Frans B.

2001-08-01

Geometrical parameters for the equilibrium (MIN) and lowest saddle-point (TS) geometries of the C2H4⋯SO2 dimer, and the corresponding binding energies, were calculated using the Hartree-Fock and correlated levels of ab initio theory, in basis sets ranging from the D95(d,p) double-zeta basis set to the aug-cc-pVQZ correlation consistent basis set. An assessment of the effect of the basis set superposition error (BSSE) on these results was made. The dissociation energy from the lowest vibrational state was estimated to be 705±100 cm-1 at the basis set limit, which is well within the range expected from experiment. The barrier to internal rotation was found to be 53±5 cm-1, slightly higher than the (revised) experimental result of 43 cm-1, probably due to zero-point vibrational effects. Our results clearly show that, in direct contrast with recent ideas, the BSSE correction affects differentially the MIN and TS binding energies and so has to be included in the calculation of small energy barriers such as that in the C2H4⋯SO2 dimer. Previous reports of positive MP2 frozen-core binding energies for this complex in basis D95(d,p) are confirmed. The anomalies are shown to be an artifact arising from an incorrect removal of virtual orbitals by the default frozen-core option in the GAUSSIAN program.

Effects of spatial and temporal variation of acid-volatile sulfide on the bioavailability of copper and zinc in freshwater sediments

USGS Publications Warehouse

Besser, John M.; Ingersoll, Christopher G.; Giesty, John P.

1996-01-01

Variation in concentrations of acid-volatile sulfide (AVS) in sediments from the upper Clark Fork River of Montana, USA, was associated with differences in bioaccumulation of Cu and Zn and growth of larvae of the midge, Chironomus tentans. Growth of midge larvae was significantly greater and bioaccumulation of Cu was significantly less in surface sections (0–3 cm depth) of sediment cores, which had greater concentrations of AVS and lesser ratios of simultaneously extracted metals to AVS (SEM:AVS ratios) than in subsurface sediments (6–9 cm). Concentrations of AVS were significantly less in sediments incubated with oxic overlying water for 9 weeks than in the same sediments incubated under anoxic conditions. Bioaccumulation of Cu differed significantly between incubation treatments, corresponding to differences in concentrations of AVS and SEM:AVS ratios, although midge growth did not. Bioaccumulation of Zn did not differ significantly between depth strata of sediment cores or between incubation treatments. When results from the two sets of bioassays were combined, bioaccumulation of Cu and Zn, but not growth, was significantly correlated with SEM:AVS ratios and other estimates of bioavailable metal fractions in sediments. Growth of midge larvae was significantly correlated with bioaccumulation of Zn, but not Cu, suggesting that Zn was the greater contributor to the toxicity of these sediments. Assessments of the toxicity of metal-contaminated freshwater sediments should consider the effects of spatial and temporal variation in AVS concentrations on metal bioavailability.

Patterns of DNA Methylation Across the Leptin Core Promoter in Four Diverse Asian and North American Populations.

PubMed

Mosher, M J; Melton, P E; Stapleton, P; Schanfield, M S; Crawford, M H

2016-04-01

DNA methylation is the most widely studied of epigenetic mechanisms, with environmental effects recorded through patterned attachments of methyl groups along the DNA that are capable of modifying gene expression without altering the DNA sequencing. The degree to which these patterns of DNA methylation are heritable, the expected range of normality across populations, and the phenotypic relevance of pattern variation remain unclear. Genes regulating metabolic pathways appear to be vulnerable to ongoing nutritional programming over the life course, as dietary nutrients are significant environmental determinants of DNA methylation, supplying both the methyl groups and energy to generate the methylation process. Here we examine methylation patterns along a region of the metabolic gene leptin (LEP). LEP's putative functions include regulation of energy homeostasis, with its signals affecting energy intake and expenditure, adipogenesis and energy storage, lipid and glucose metabolism, bone metabolism, and reproductive endocrine function. A pattern of differential methylation across CpG sites of the LEP core promoter has been previously identified; however, any consistency of pattern or its phenotypic significance is not fully elucidated among populations. Using DNA extracted from unfractionated white blood cells of peripheral blood samples, our pilot study, divided into two parts, examined the significance of variation in DNA methylation patterns along the leptin core promoter in four populations (phase 1) and used biomarkers reflecting leptin's functional process in two of those populations, western Buryat of Siberia and the Mennonite of central Kansas, to investigate the relevance of the ethnic variation identified in the DNA methylation (phase 2). LEP's core promoter region contains both the binding site for C/EBPα (CCAAT/enhancer binding protein alpha), which tempers the final step in adipocyte maturity and capacity to synthesize leptin, and the TATA motif controlling leptin synthesis. Previous studies report that increased methylation in this region is correlated to decreased gene expression, suggesting tissue-specific methylation variation at this region ( Melzner et al. 2002 ). We hypothesized that evidence of nutritional epigenetic programming would be identified through variation in patterns of DNA methylation and that functional relevance of that variation among populations would be identified through biomarkers that reflect leptin's metabolic signals: serum leptin levels, lipoproteins of the lipid transport system, and anthropometric measures. In phase 1, our combined analyses of 313 individuals documented a distinct and consistent overall pattern of differential DNA methylation across seven CpG sites of LEP core promoter in all ethnicities and both sexes. This pattern replicates those identified in previous studies, suggesting a conserved core promoter region across populations. Phase 2 analyses of two of the four populations (n = 239), correlating methylation at the C/EBPα transcription binding site (TBS) with metabolic and anthropometric biomarkers reflecting LEP roles, showed that stature, which reflects bone growth and remodeling, was significantly and inversely correlated with the percentage of DNA methylation at this site in both sexes. We suggest that variation in DNA methylation along the LEP core promoter plays a substantial role in energy signals affecting both adipogenesis and bone metabolism.

Constraints on The Coupled Thermal Evolution of the Earth's Core and Mantle, The Age of The Inner Core, And The Origin of the 186Os/188Os Core(?) Signal in Plume-Derived Lavas

NASA Astrophysics Data System (ADS)

Lassiter, J. C.

2005-12-01

Thermal and chemical interaction between the core and mantle has played a critical role in the thermal and chemical evolution of the Earth's interior. Outer core convection is driven by core cooling and inner core crystallization. Core/mantle heat transfer also buffers mantle potential temperature, resulting in slower rates of mantle cooling (~50-100 K/Ga) than would be predicted from the discrepancy between current rates of surface heat loss (~44 TW) and internal radioactive heat production (~20 TW). Core/mantle heat transfer may also generate thermal mantle plumes responsible for ocean island volcanic chains such as the Hawaiian Islands. Several studies suggest that mantle plumes, in addition to transporting heat from the core/mantle boundary, also carry a chemical signature of core/mantle interaction. Elevated 186Os/188Os ratios in lavas from Hawaii, Gorgona, and in the 2.8 Ga Kostomuksha komatiites have been interpreted as reflecting incorporation of an outer core component with high time-integrated Pt/Os and Re/Os ( Brandon et al., 1999, 2003; Puchtel et al., 2005). Preferential partitioning of Os relative to Re and Pt into the inner core during inner core growth may generate elevated Re/Os and Pt/Os ratios in the residual outer core. Because of the long half-life of 190Pt (the parent of 186Os, t1/2 = 489 Ga), an elevated 186Os/188Os outer core signature in plume lavas requires that inner core crystallization began early in Earth history, most likely prior to 3.5 Ga. This in turn requires low time-averaged core/mantle heat flow (<~2.5 TW) or large quantities of heat-producing elements in the core. Core/mantle heat flow may be estimated using boundary-layer theory, by measuring the heat transported in mantle plumes, by estimating the heat transported along the outer core adiabat, or by comparing the rates of heat production, surface heat loss, and secular cooling of the mantle. All of these independent methods suggest time-averaged core/mantle heat flow of ~5-14 TW. In the absence of heat-producing elements in the core, such high heat flow rates require an inner core younger than ~1 Ga and preclude the development of significant 186Os enrichment in the outer core. Experimental studies suggest that potassium may partition into Fe-S-O liquids during core formation. Radioactive decay of potassium in the core could provide an additional heat source and reconcile geophysical evidence for high core/mantle heat flow with apparent geochemical evidence for an ancient inner core. However, high concentrations of chalcophile elements such as Cu in the mantle are inconsistent with significant segregation of a S-rich liquid during core formation, precluding K partitioning into the core by this mechanism. Furthermore, core formation scenarios that would lead to high K content in the core (e.g., core formation prior to terrestrial volatile depletion) also result in high core Pb concentrations. Core/mantle interaction would then produce strong negative correlations between 186Os/188Os and 207Pb/204Pb ratios, but such correlations are not observed. In summary, elevated 186Os/188Os ratios in some plume-derived lavas are unlikely to reflect core/mantle interaction because the inner core is too young for this isotopic signature to have developed in the outer core. Melt generation from pyroxenite or fractionation of PGEs between sulfide melts and monosulfide solid solutions provide alternative mechanisms for generating ancient mantle reservoirs with elevated Pt/Os and 186Os/188Os.

10 CFR Appendix K to Part 50 - ECCS Evaluation Models

Code of Federal Regulations, 2010 CFR

2010-01-01

... hypothetical accident. The modified Baroczy correlation (Baroczy, C. J., “A Systematic Correlation for Two... distribution shapes and peaking factors representing power distributions that may occur over the core lifetime must be studied. The selected combination of power distribution shape and peaking factor should be the...

10 CFR Appendix K to Part 50 - ECCS Evaluation Models

Code of Federal Regulations, 2011 CFR

2011-01-01

... hypothetical accident. The modified Baroczy correlation (Baroczy, C. J., “A Systematic Correlation for Two... distribution shapes and peaking factors representing power distributions that may occur over the core lifetime must be studied. The selected combination of power distribution shape and peaking factor should be the...

Brief Report: Relationship Between ADOS-2, Module 4 Calibrated Severity Scores (CSS) and Social and Non-Social Standardized Assessment Measures in Adult Males with Autism Spectrum Disorder (ASD).

PubMed

Morrier, Michael J; Ousley, Opal Y; Caceres-Gamundi, Gabriella A; Segall, Matthew J; Cubells, Joseph F; Young, Larry J; Andari, Elissar

2017-12-01

The ADOS-2 Modules 1-3 now include a standardized calibrated severity score (CSS) from 1 to 10 based on the overall total raw score. Subsequent research published CSS for Module 4 (Hus, Lord, Journal of Autism and Developmental Disorders 44(8):1996-2012, 2014); however more research is needed to examine the psychometric properties of this CSS. Forty males with ASD completed an assessment battery consisting of ADOS-2 Module 4 and other clinical measures assessing core ASD symptomology and comorbidity. Pearson correlation analyses found that CSS did not correlate with measures that assessed core social deficits of ASD or general psychiatric co-morbidity, but CSS did correlate negatively with intellectual quotient. These findings provide information on the limitations and relevance of CSS to be taken into account in future clinical evaluations of ASD.

Perturbation theory of structure in classical liquid mixtures: Application to metallic systems near phase separation. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Henderson, R. L.

1974-01-01

The partial structure factors of classical simple liquid mixtures near phase separation are dicussed. The theory is developed for particles interacting through pair potentials, and is thus appropriate both to insulating fluids, and also to metallic systems if these may be described by an effective ion-ion pair interaction. The motivation arose from consideration of metallic liquid mixtures, in which resistive anomalies have been observed near phase separation. A mean field theory correction appropriate to 3 pair potential for the effects of correlated motions in the reference fluid is studied. The work is cast in terms of functions which are closely related to the direct correlation functions of Ornstein and Zernike. The results are qualitatively in accord with physical expectations. Quantitative agreement with experiment seems to turn on the selection of the hard core reference potential in terms of the metallic effective pair potential. It is suggested that the present effective pair potentials are perhaps not properly used to calculate the metallic structure factors at long wavelength.

Pseudopotential plane-wave calculation of the structural properties of yttrium

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

Wang, Y.; Chou, M.Y.

1991-11-01

The structural properties of hexagonal-close-packed yttrium are studied by using the plane-wave basis within the pseudopotential method and local-density-functional approximation. By employing a soft'' pseudopotential proposed by Troullier and Martins, satisfactory convergence is achieved with a plane-wave energy cutoff of 30--40 Ry for this early-transition-metal element. The overall results for the structural properties are in good agreement with experiment. It is found that the charge overlap between core and valence electrons has a substantial effect on the accuracy of the calculated structural properties. Two different calculations are performed with and without the outer-core 4{ital p} orbital included as a valencemore » state. In addition, as found in some other local-density calculations, the uncertainty in the results due to different exchange-correlation energy functionals may not be negligible in transition metals.« less

Worry and rumination in anorexia nervosa.

PubMed

Startup, Helen; Lavender, Anna; Oldershaw, Anna; Stott, Richard; Tchanturia, Kate; Treasure, Janet; Schmidt, Ulrike

2013-05-01

Difficulties with comprehending and managing emotions are core features of the pathology of anorexia nervosa (AN). Advancements in understanding aetiology and treatment have been made within other clinical domains by targeting worry and rumination. However, worry and rumination have been given minimal consideration in AN. This study is the largest to date of worry and rumination in AN. Sixty-two outpatients with a diagnosis of AN took part. Measures of worry, rumination, core AN pathology and neuropsychological correlates were administered. Findings suggest that worry and rumination are elevated in AN patients compared with both healthy controls and anxiety disorder comparison groups. Regression analyses indicated that worry and rumination were significant predictors of eating disorder symptomatology, over and above the effects of anxiety and depression. Worry and rumination were not associated with neuropsychological measures of set-shifting and focus on detail. The data suggest that worry and rumination are major concerns for this group and warrant further study.

Carrier states and optical response in core-shell-like semiconductor nanostructures

NASA Astrophysics Data System (ADS)

Duque, C. M.; Mora-Ramos, M. E.; Duque, C. A.

2017-02-01

The charge carrier states in a GaAs/Al?Ga?As axially symmetric core-shell quantum wire are calculated in the effective mass approximation via a spectral method. The possible presence of externally applied electric and magnetic fields is taken into account, together with the variation in the characteristic in-plane dimensions of the structure. The obtained energy spectrum is used to evaluate the optical response through the coefficients of intersubband optical absorption and relative refractive index change. The particular geometry of the system also allows to use the same theoretical model in order to determine the photoluminescence peak energies associated to correlated electron-hole states in double GaAs/Al?Ga?As quantum rings, showing a good agreement when they are compared with recent experimental reports. This agreement may validate the use of both the calculation process and the approximate model of abrupt, circularly shaped cross section geometry for the system.

On the violation of gradient wind balance at the top of tropical cyclones

NASA Astrophysics Data System (ADS)

Cohen, Yair; Harnik, Nili; Heifetz, Eyal; Nolan, David S.; Tao, Dandan; Zhang, Fuqing

2017-08-01

The existence of physical solutions for the gradient wind balance is examined at the top of 12 simulated tropical cyclones. The pressure field at the top of these storms, which depends on the vertically integrated effect of the warm core and the near surface low, is found to violate the gradient wind balance—termed here as a state of nonbalance. Using a toy model, it is shown that slight changes in the relative location and relative widths of the warm core drastically increase the isobaric curvature at the upper level pressure maps leading to nonbalance. While idealized storms return to balance within several days, simulations of real-world tropical cyclones retain a considerable degree of nonbalance throughout the model integration. Comparing mean and maximum values of different storms shows that peak nonbalance correlates with either peak intensity or intensification, implying the possible importance of nonbalance at upper levels for the near surface winds.

Nuclear quantum shape-phase transitions in odd-mass systems

NASA Astrophysics Data System (ADS)

Quan, S.; Li, Z. P.; Vretenar, D.; Meng, J.

2018-03-01

Microscopic signatures of nuclear ground-state shape-phase transitions in odd-mass Eu isotopes are explored starting from excitation spectra and collective wave functions obtained by diagonalization of a core-quasiparticle coupling Hamiltonian based on energy density functionals. As functions of the physical control parameter—the number of nucleons—theoretical low-energy spectra, two-neutron separation energies, charge isotope shifts, spectroscopic quadrupole moments, and E 2 reduced transition matrix elements accurately reproduce available data and exhibit more-pronounced discontinuities at neutron number N =90 compared with the adjacent even-even Sm and Gd isotopes. The enhancement of the first-order quantum phase transition in odd-mass systems can be attributed to a shape polarization effect of the unpaired proton which, at the critical neutron number, starts predominantly coupling to Gd core nuclei that are characterized by larger quadrupole deformation and weaker proton pairing correlations compared with the corresponding Sm isotopes.

A comparison of two nitrification inhibitors used to measure nitrification rates in estuarine sediments

USGS Publications Warehouse

Caffrey, J.M.; Miller, L.G.

1995-01-01

Nitrification rates were measured using intact sediment cores from South San Francisco Bay and two different nitrification inhibitors: acetylene and methyl fluoride. Sediment oxygen consumption and ammonium and nitrate fluxes were also measured in these cores. Four experiments were conducted in the spring, and one in the fall of 1993. There was no significant difference in nitrification rates measured using the two inhibitors, which suggests that methyl fluoride can be used as an effective inhibitor of nitrification. Nitrification was positively correlated with sediment oxygen consumption and numbers of macrofauna. This suggests that bioturbation by macrofauna is an important control of nitrification rates. Irrigation by the tube-dwelling polychaete, Asychis elongata, which dominates the benthic biomass at this location, appears particularly important. Ammonium fluxes out of the sediment were greatest about one week after the spring bloom, while nitrification peaked about one month later.

Correlation of EBIC and SWBXT Imaged Defects and Epilayer Growth Pits in 6H-SiC Schottky Diodes

NASA Technical Reports Server (NTRS)

Schnable, C. M.; Tabib-Azar, M.; Neudeck, P. G.; Bailey, S. G.; Su, H. B.; Dudley, M.; Raffaelle, R. P.

2000-01-01

We show the first direct experimental correlation between the presence of closed core screw dislocations in 6H-SiC epilayers with recombination centers, as well as with some of the small growth pits on the epilayer surface in lightly-doped 6H-SiC Schottky diodes. At every Synchrotron White-Beam X-ray Topography (SWBXT)-identified closed core screw dislocation, an Electron Beam Induced Current (EBIC) image showed a dark spot indicating a recombination center, and Nomarski optical microscope and Atomic Force Microscope (AFM) images showed a corresponding small growth pit with a sharp apex on the surface of the epilayer.

Analysis and Characterization of Dissolved Organic Matter in Ice Cores as Indicators of Past Environmental Conditions Using High Resolution FTICR-MS

NASA Astrophysics Data System (ADS)

Boschi, V.; Grannas, A. M.; Willoughby, A. S.; Catanzano, V.; Hatcher, P.

2015-12-01

With rapid changes in global temperatures, research aimed at better understanding past climatic events in order to predict future trends is an area of growing importance. Carbonaceous gases stored in ice cores are known to correlate with temperature change and provide evidence of such events. However, more complex forms of carbon preserved in ice cores such as dissolved organic matter (DOM) can provide additional information relating to changes in environmental conditions over time. The examination of ice core samples presents unique challenges including detection of ultra-low concentrations of organic material and extremely limited sample amounts. In this study, solid phase extraction techniques combined with ultra-high resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FTICR-MS) were utilized to successfully extract, concentrate and analyze the low concentrations of DOM in only 100 mL of ice core samples originating from various regions of Antarctica and Greenland. We characterize the DOM composition in each sample by evaluating elemental ratios, molecular formula distribution (CHO, CHON, CHOS and CHNOS) and compound class composition (lignin, tannin, lipid, condensed aromatic, protein and unsaturated hydrocarbon content). Upon characterization, we identified molecular trends in ice core DOM chemistry that correlated with past climatic events in addition to observing possible photochemical and microbial influences affecting DOM chemistry. Considering these samples range in age from 350-1175 years old, thus being formed during the Medieval Warm Period and Little Ice Age, we observed that DOM properties reflected anticipated changes in composition as influenced by warming and cooling events occurring during that time period.

Detection of Organic Matter in Greenland Ice Cores by Deep-UV Fluorescence

NASA Astrophysics Data System (ADS)

Willis, M.; Malaska, M.; Wanger, G.; Bhartia, R.; Eshelman, E.; Abbey, W.; Priscu, J. C.

2017-12-01

The Greenland Ice Sheet is an Earthly analog for icy ocean worlds in the outer Solar System. Future missions to such worlds including Europa, Enceladus, and Titan may potentially include spectroscopic instrumentation to examine the surface/subsurface. The primary goal of our research is to test deep UV/Raman systems for in the situ detection and localization of organics in ice. As part of this effort we used a deep-UV fluorescence instrument able to detect naturally fluorescent biological materials such as aromatic molecules found in proteins and whole cells. We correlated these data with more traditional downstream analyses of organic material in natural ices. Supraglacial ice cores (2-4 m) were collected from several sites on the southwest outlet of the Greenland Ice Sheet using a 14-cm fluid-free mechanical coring system. Repeat spectral mapping data were initially collected longitudinally on uncut core sections. Cores were then cut into 2 cm thick sections along the longitudinal axis, slowly melted and analyzed for total organic carbon (TOC), total dissolved nitrogen (TDN), and bacterial density. These data reveal a spatial correlation between organic matter concentration, cell density, and the deep UV fluorescence maps. Our results provide a profile of the organics embedded within the ice from the top surface into the glacial subsurface, and the TOC:TDN data from the clean interior of the cores are indicative of a biological origin. This work provides a background dataset for future work to characterize organic carbon in the Greenland Ice Sheet and validation of novel instrumentation for in situ data collection on icy bodies.

Physical properties of self-, dual-, and light-cured direct core materials.

PubMed

Rüttermann, Stefan; Alberts, Ian; Raab, Wolfgang H M; Janda, Ralf R

2011-08-01

The objective of this study is to evaluate flexural strength, flexural modulus, compressive strength, curing temperature, curing depth, volumetric shrinkage, water sorption, and hygroscopic expansion of two self-, three dual-, and three light-curing resin-based core materials. Flexural strength and water sorption were measured according to ISO 4049, flexural modulus, compressive strength, curing temperature, and curing depth according to well-proven, literature-known methods, and the volumetric behavior was determined by the Archimedes' principle. ANOVA was calculated to find differences between the materials' properties, and correlation of water sorption and hygroscopic expansion was analysed according to Pearson (p < 0.05). Clearfil Photo Core demonstrated the highest flexural strength (125 ± 12 MPa) and curing depth (15.2 ± 0.1 mm) and had the highest flexural modulus (≈12.6 ± 1.2 GPa) concertedly with Multicore HB. The best compressive strength was measured for Voco Rebilda SC and Clearfil DC Core Auto (≈260 ± 10 MPa). Encore SuperCure Contrast had the lowest water sorption (11.8 ± 3.3 µg mm(-3)) and hygroscopic expansion (0.0 ± 0.2 vol.%). Clearfil Photo Core and Encore SuperCure Contrast demonstrated the lowest shrinkage (≈2.1 ± 0.1 vol.%). Water sorption and hygroscopic expansion had a very strong positive correlation. The investigated core materials significantly differed in the tested properties. The performance of the materials depended on their formulation, as well as on the respective curing process.

The influence of light quality on the accumulation of flavonoids in tobacco (Nicotiana tabacum L.) leaves.

PubMed

Fu, Bo; Ji, Xiaoming; Zhao, Mingqin; He, Fan; Wang, Xiaoli; Wang, Yiding; Liu, Pengfei; Niu, Lu

2016-09-01

Flavonoids are important secondary metabolites in plants regulated by the environment. To analyze the effect of light quality on the accumulation of flavonoids, we performed a rapid analysis of flavonoids in extracts of tobacco leaves using UHPLC-QTOF. A total of 12 flavonoids were detected and identified in tobacco leaves, which were classified into flavonoid methyl derivatives and flavonoid glycoside derivatives according to the groups linked to the flavonoid core. Correlation analysis was further conducted to investigate the effect of different wavelengths of light on their accumulation. The content of flavonoid methyl derivatives was positively correlated with the proportions of far-red light (FR; 716-810nm) and near-infrared light (NIR; 810-2200nm) in the sunlight spectrum and negatively correlated with the proportion of ultraviolet (UV-A; 350-400nm) and the red/far-red ratio (R/FR). By contrast, the content of flavonoid glycoside derivatives was positively correlated with the proportion of UV-A and the R/FR, and negatively correlated with FR and NIR. The results indicated that light quality with higher proportions of FR and NIR increases the activity of flavonoid methyltransferases but suppresses the activity of flavonoid glycoside transferases. While a high proportion of UV-A and a high R/FR can increase flavonoid glycoside transferase activity but suppress flavonoid methyltransferase activity. Copyright © 2016 Elsevier B.V. All rights reserved.

18F-FDG uptake in the colon is modulated by metformin but not associated with core body temperature and energy expenditure

PubMed Central

Bahler, Lonneke; Holleman, Frits; Chan, Man-Wai; Booij, Jan; Hoekstra, Joost B.; Verberne, Hein J.

2017-01-01

Purpose Physiological colonic 18F-fluorodeoxyglucose (18F-FDG) uptake is a frequent finding on 18F-FDG positron emission tomography computed tomography (PET-CT). Interestingly, metformin, a glucose lowering drug associated with moderate weight loss, is also associated with an increased colonic 18F-FDG uptake. Consequently, increased colonic glucose use might partly explain the weight losing effect of metformin when this results in an increased energy expenditure and/or core body temperature. Therefore, we aimed to determine whether metformin modifies the metabolic activity of the colon by increasing glucose uptake. Methods In this open label, non-randomized, prospective mechanistic study, we included eight lean and eight overweight males. We measured colonic 18F-FDG uptake on PET-CT, energy expenditure and core body temperature before and after the use of metformin. The maximal colonic 18F-FDG uptake was measured in 5 separate segments (caecum, colon ascendens,—transversum,—descendens and sigmoid). Results The maximal colonic 18F-FDG uptake increased significantly in all separate segments after the use of metformin. There was no significant difference in energy expenditure or core body temperature after the use of metformin. There was no correlation between maximal colonic 18F-FDG uptake and energy expenditure or core body temperature. Conclusion Metformin significantly increases colonic 18F-FDG uptake, but this increased uptake is not associated with an increase in energy expenditure or core body temperature. Although the colon might be an important site of the glucose plasma lowering actions of metformin, this mechanism of action does not explain directly any associated weight loss. PMID:28464031

The significance of volcanic ash in Greenland ice cores during the Common Era

NASA Astrophysics Data System (ADS)

Plunkett, G.; Pilcher, J. R.; McConnell, J. R.; Sigl, M.; Chellman, N.

2017-12-01

Volcanic forcing is now widely regarded as a leading natural factor in short-term climate variability. Polar ice cores provide an unrivalled and continuous record of past volcanism through their chemical and particulate content. With an almost annual precision for the Common Era, the ice core volcanic record can be combined with historical data to investigate the climate and social impacts of the eruptions. The sulfate signature in ice cores is critical for determining the possible climate effectiveness of an eruption, but the presence and characterization of volcanic ash (tephra) in the ice is requisite for establishing the source eruption so that location and eruptive style can be better factored in to climate models. Here, we review the Greenland tephra record for the Common Era, and present the results of targeted sampling for tephra of volcanic events that are of interest either because of their suspected climate and societal impacts or because of their potential as isochrons in paleoenvironmental (including ice core) archives. The majority of identifiable tephras derive from Northern Hemisphere mid- to high latitude eruptions, demonstrating the significance of northern extra-tropical volcanic regions as a source of sulfates in Greenland. A number of targets are represented by sparse or no tephra, or shards that cannot be firmly correlated with a source. We consider the challenges faced in isolating and characterizing tephra from low latitude eruptions, and the implications for accurately modelling climate response to large, tropical events. Finally, we compare the ice core tephra record with terrestrial tephrostratigraphies in the circum-North Atlantic area to evaluate the potential for intercontinental tephra linkages and the refinement of volcanic histories.

The effects of atomoxetine on emotional control in adults with ADHD: An integrated analysis of multicenter studies.

PubMed

Asherson, P; Stes, S; Nilsson Markhed, M; Berggren, L; Svanborg, P; Kutzelnigg, A; Deberdt, W

2015-06-01

To investigate the effects of atomoxetine on emotional control in adults with ADHD. We performed an integrated analysis using individual patient data pooled from three Eli Lilly-sponsored studies. An integrated analysis can be viewed as a meta-analysis of individual patient-level data, rather than study-level summary data. Two populations were identified: a large sample of patients with pre-treatment baseline data (the "overall population"; n=2846); and a subset of these patients with placebo-controlled efficacy data from baseline to 10 or 12 weeks after initiating treatment (the "placebo-controlled population"; n=829). At baseline, in the overall population, ∼50% of ADHD patients had BRIEF-AS (Behavior Rating Inventory of Executive Function-Adult Version Self-Report) Emotional control subscores between 21 and 30, compared with ∼10% of normative subjects in the BRIEF-A manual. At endpoint, in the placebo-controlled population, atomoxetine led to a small (effect size 0.19) but significant (P=0.013) treatment effect for emotional control. The effect size was 0.32 in patients with BRIEF-AS Emotional control scores>20 at baseline. Improvements in emotional control correlated with improvements in the core ADHD symptoms and quality-of-life. As deficient emotional control is associated with impaired social, educational and occupational functioning over and above that explained by core ADHD symptoms alone, improvements in emotional control may be clinically relevant. At baseline, adults with ADHD were more likely to have impaired emotional control than normative subjects. In the adult ADHD patients, atomoxetine treatment was associated with improvements in emotional control, as well as in core ADHD symptoms and quality-of-life. Copyright © 2015. Published by Elsevier Masson SAS.

Identifying sediment discontinuities and solving dating puzzles using monitoring and palaeolimnological records

NASA Astrophysics Data System (ADS)

Dong, Xuhui; Sayer, Carl D.; Bennion, Helen; Maberly, Stephen C.; Yang, Handong; Battarbee, Richard W.

2016-12-01

Palaeolimnological studies should ideally be based upon continuous, undisturbed sediment sequences with reliable chronologies. However for some lake cores, these conditions are not met and palaeolimnologists are often faced with dating puzzles caused by sediment disturbances in the past. This study chooses Esthwaite Water from England to illustrate how to identify sedimentation discontinuities in lake cores and how chronologies can be established for imperfect cores by correlation of key sediment signatures in parallel core records and with long-term monitoring data (1945-2003). Replicated short cores (ESTH1, ESTH7, and ESTH8) were collected and subjected to loss-on-ignition, radiometric dating (210Pb, 137Cs, and 14C), particle size, trace metal, and fossil diatom analysis. Both a slumping and a hiatus event were detected in ESTH7 based on comparisons made between the cores and the long-term diatom data. Ordination analysis suggested that the slumped material in ESTH7 originated from sediment deposited around 1805-1880 AD. Further, it was inferred that the hiatus resulted in a loss of sediment deposited from 1870 to 1970 AD. Given the existence of three superior 14C dates in ESTH7, ESTH1 and ESTH7 were temporally correlated by multiple palaeolimnological proxies for age-depth model development. High variability in sedimentation rates was evident, but good agreement across the various palaeolimnological proxies indicated coherence in sediment processes within the coring area. Differences in sedimentation rates most likely resulted from the natural morphology of the lake basin. Our study suggests that caution is required in selecting suitable coring sites for palaeolimnological studies of small, relatively deep lakes and that proximity to steep slopes should be avoided wherever possible. Nevertheless, in some cases, comparisons between a range of contemporary and palaeolimnological records can be employed to diagnose sediment disturbances and establish a chronology.

Use of thermal imagery for estimation of core body temperature during precooling, exertion, and recovery in wildland firefighter protective clothing.

PubMed

Bourlai, Thirimachos; Pryor, Riana R; Suyama, Joe; Reis, Steven E; Hostler, David

2012-01-01

Monitoring core body temperature to identify heat stress in first responders and in individuals participating in mass gatherings (e.g., marathons) is difficult. This study utilized high-sensitivity thermal imaging technology to predict the core temperature of human subjects at a distance while performing simulated field operations wearing thermal protective garments. Six male subjects participating in a study of precooling prior to exertion in wildland firefighter thermal protective clothing had thermal images of the face captured with a high-resolution thermal imaging camera concomitant with measures of core and skin temperature before, during, and after treadmill exercise in a heated room. Correlations and measures of agreement between core temperature and thermal imaging-based temperature were performed. The subjects walked an average (± standard deviation) of 42.6 (±5.9) minutes and a distance of 4.2 (±0.6) km on the treadmill. Mean heart rate at the end of exercise was 152 (±33) bpm and core body temperature at the end of exercise was 38.3°C (±0.7°C). A visual relationship and a strong correlation between core temperature and thermal imaging of the face were identified in all subjects, with the closest relationship and best agreement occurring during exercise. The Bland-Altman test of agreement during exercise revealed the majority of measurement pairs to be within two standard deviations of the measured temperature. High-resolution thermal imaging in the middle-wave infrared spectrum (3-5 μm) can be used to accurately estimate core body temperature during exertion in a hot room while participants are wearing wildland firefighting garments. Although this technology is promising, it must be refined. Using alternative measurement sites such as the skin over the carotid artery, using multiple measurement sites, or adding pulse detection may improve the estimation of body temperature by thermal imagery.

Accretion rate of extraterrestrial matter: Iridium deposited over the last 70 million years

NASA Technical Reports Server (NTRS)

Kyte, Frank T.

1988-01-01

In order to quantify the accretion rate of extraterrestrial matter during the Cenozoic, Ir concentrations were measured in a continuous series of 450 samples across most of the length of piston core LL44-GPC3. LL44-GPC3 is a 25-meter-long, large-diameter piston core of abyssal clay from the central North Pacific. This core contains a nearly continuous record of sedimentation over the last 70 Ma, as this site migrated from a region near the Equator in the late Cretaceous to its present position north of Hawaii. The first-cut survey across the core is nearing completion, and all of the conclusions of the earlier study, in which was reported the concentrations of Ir, Co, and Sb across 9 meters of this core, remain unchanged. The only strongly enhanced Ir concentrations occur at the Cretaceous-Tertiary (K-T) boundary and outside the K-T boundary Ir correlates well with Co, a terrestrial element which is largely present in hydrogenous ferromanganese oxide precipitates from seawater. Concentrations of both elements appear to be inversely correlated with the sedimentation rate. Although the K-T Ir anomaly is unique in magnitude in this core, there are several small bumps in the Ir profile which may reflect smaller accretionary events. The most promising Ir enhancement was observed in a 30 cm section approximately 1 m below the K-T boundary. Preliminary data suggest deposition of an excess across this interval at a time estimate to be approximate 1 Ma before the K-T impact event, but there is insufficient evidence at present to prove that this reflects enhanced accretion of extraterrestrial matter. A detailed model is being prepared of the chemical record of sedimentation in this core using a combined database of 39 elements in approximately 450 samples across the Cenozoic. Preliminary working model indicates that the only sedimentary sources which contribute significantly to the Ir budget in this core are the hydrogenous precipitates and extraterrestrial particulates.

Improvement of geomagnetic core field modeling with a priori information about Gauss coefficient correlations

NASA Astrophysics Data System (ADS)

Schachtschneider, R.; Rother, M.; Lesur, V.

2013-12-01

We introduce a method that enables us to account for existing correlations between Gauss coefficients in core field modelling. The information about the correlations are obtained from a highly accurate field model based on CHAMP data, e.g. the GRIMM-3 model. We compute the covariance matrices of the geomagnetic field, the secular variation, and acceleration up to degree 18 and use these in the regularization scheme of the core field inversion. For testing our method we followed two different approaches by applying it to two different synthetic satellite data sets. The first is a short data set with a time span of only three months. Here we test how the information about correlations help to obtain an accurate model when only very little information are available. The second data set is a large one covering several years. In this case, besides reducing the residuals in general, we focus on the improvement of the model near the boundaries of the data set where the accerelation is generally more difficult to handle. In both cases the obtained covariance matrices are included in the damping scheme of the regularization. That way information from scales that could otherwise not be resolved by the data can be extracted. We show that by using this technique we are able to improve the models of the field and the secular variation for both, the short and the long term data set, compared to approaches using more conventional regularization techniques.

Bandgap Engineering of InP QDs Through Shell Thickness and Composition

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

Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei

2012-06-21

Fields as diverse as biological imaging and telecommunications utilize the unique photophysical and electronic properties of nanocrystal quantum dots (NQDs). The development of new NQD compositions promises material properties optimized for specific applications, while addressing material toxicity. Indium phosphide (InP) offers a 'green' alternative to the traditional cadmium-based NQDs, but suffers from extreme susceptibility to oxidation. Coating InP cores with more stable shell materials significantly improves nanocrystal resistance to oxidation and photostability. We have investigated several new InP-based core-shell compositions, correlating our results with theoretical predictions of their optical and electronic properties. Specifically, we can tailor the InP core-shell QDsmore » to a type-I, quasi-type-II, or type-II bandgap structure with emission wavelengths ranging from 500-1300 nm depending on the shell material used (ZnS, ZnSe, CdS, or CdSe) and the thickness of the shell. Single molecule microscopy assessments of photobleaching and blinking are used to correlate NQD properties with shell thickness.« less

Correlation between active-learning coursework and student retention of core content during advanced pharmacy practice experiences.

PubMed

Lucas, Kristy H; Testman, Julie A; Hoyland, Marcella N; Kimble, Angel M; Euler, Mary L

2013-10-14

To implement an active-learning approach in a pharmacotherapy course sequence in the second year (P2) and third (P3) year of a doctor of pharmacy (PharmD) program and determine whether the pedagogical changes correlated with retention of core content in the fourth year (P4). Class sessions were transitioned from slides-based lectures to discussion-based active-learning pedagogy. A comprehensive examination was created and administered to assess student retention of therapeutic topics taught. Students demonstrated significantly improved overall scores on questions derived from the active-learning pedagogy used in Pharmacotherapy II and III compared to those derived from Pharmacotherapy I in which content was delivered by lecture. The use of active-learning strategies over lecture-based methods in pharmacotherapy courses resulted in higher retention of core content. Students' performance in areas taught using the discussion-based methodology was superior to that which was taught using lecture-based slide presentations.

Correlation Between Active-Learning Coursework and Student Retention of Core Content During Advanced Pharmacy Practice Experiences

PubMed Central

Testman, Julie A.; Hoyland, Marcella N.; Kimble, Angel M.; Euler, Mary L.

2013-01-01

Objective. To implement an active-learning approach in a pharmacotherapy course sequence in the second year (P2) and third (P3) year of a doctor of pharmacy (PharmD) program and determine whether the pedagogical changes correlated with retention of core content in the fourth year (P4). Design. Class sessions were transitioned from slides-based lectures to discussion-based active-learning pedagogy. Assessment. A comprehensive examination was created and administered to assess student retention of therapeutic topics taught. Students demonstrated significantly improved overall scores on questions derived from the active-learning pedagogy used in Pharmacotherapy II and III compared to those derived from Pharmacotherapy I in which content was delivered by lecture. Conclusion. The use of active-learning strategies over lecture-based methods in pharmacotherapy courses resulted in higher retention of core content. Students’ performance in areas taught using the discussion-based methodology was superior to that which was taught using lecture-based slide presentations. PMID:24159212

Occurrence, trends, and sources in particle-associated contaminants in selected streams and lakes in Fort Worth, Texas

USGS Publications Warehouse

Van Metre, Peter C.; Wilson, Jennifer T.; Harwell, Glenn R.; Gary, Marcus O.; Heitmuller, Franklin T.; Mahler, Barbara J.

2003-01-01

Several lakes and stream segments in Fort Worth, Texas, have fish consumption bans because of elevated levels of chlordane, dieldrin, DDE, and polychlorinated biphenyls (PCBs). This study was undertaken to evaluate current loading, trends, and sources in these long-banned contaminants and other particle-associated contaminants commonly found in urban areas. Sampling included suspended sediments at 11 sites in streams and bottom-sediment cores in three lakes. Samples were analyzed for chlorinated hydrocarbons, major and trace elements, and polycyclic aromatic hydrocarbons (PAHs). All four legacy pollutants responsible for fish consumption bans were detected frequently. Concentrations of chlordane, lead, and PAHs most frequently exceeded sediment-quality guidelines. Trends in DDE and PCBs since the 1960s generally are decreasing; and trends in chlordane are mixed with a decreasing trend in Lake Como, no trend in Echo Lake, and an increasing trend in Fosdic Lake. All significant trends in trace elements are decreasing, and most significant trends in PAHs are increasing. Sedimentation surveys were conducted on each of the three lakes and used in combination with sediment core data to compute sediment mass balances for the lakes, to estimate long-term-average loads and yields of sediment, and to estimate recent loads and yields of selected contaminants.Concentrations of most trace elements in suspended sediments were similar to those at the tops of cores, but concentrations of many hydrophobic organic contaminants were two to three times larger. As a result, for these fluvial systems, sediment cores probably provide a historical record of trace element contamination but could underestimate historical concentrations of organic contaminants. However, down-core profiles suggest that relative concentration histories are preserved in these sediment cores for many organic contaminants (such as chlordane and total DDT) but not for all (such as dieldrin).Percent urban land use correlates strongly with selected contaminant concentrations in sediments. Organochlorine pesticides had significant correlations to residential land use, whereas PCBs, cadmium, lead, zinc, and PAHs more often correlate significantly with commercial and industrial land uses, which suggests different urban sources for different contaminants. The amount of enrichment in these contaminants associated with urban land use predicted from regression equations, expressed as the ratio of concentrations predicted for 100 percent urban to 30 percent urban, ranges from 3.6 to 6.9 for PCBs and heavy metals to about 15 for chlordane, total DDT, and PAHs. These data indicate that urbanization is having a substantial negative effect on sediment and water quality and that legacy pollutants are being actively transported to streams and lakes 13 to 30 years after their use was restricted or banned. They further suggest that fish in the lakes and these water bodies will continue to be exposed to legacy pollutants in sediment for many years to come.

Altering Reservoir Wettability to Improve Production from Single Wells

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

W. W. Weiss

2006-09-30

Many carbonate reservoirs are naturally fractured and typically produce less than 10% original oil in place during primary recovery. Spontaneous imbibition has proven an important mechanism for oil recovery from fractured reservoirs, which are usually weak waterflood candidates. In some situations, chemical stimulation can promote imbibition of water to alter the reservoir wettability toward water-wetness such that oil is produced at an economic rate from the rock matrix into fractures. In this project, cores and fluids from five reservoirs were used in laboratory tests: the San Andres formation (Fuhrman Masho and Eagle Creek fields) in the Permian Basin of Texasmore » and New Mexico; and the Interlake, Stony Mountain, and Red River formations from the Cedar Creek Anticline in Montana and South Dakota. Solutions of nonionic, anionic, and amphoteric surfactants with formation water were used to promote waterwetness. Some Fuhrman Masho cores soaked in surfactant solution had improved oil recovery up to 38%. Most Eagle Creek cores did not respond to any of the tested surfactants. Some Cedar Creek anticline cores had good response to two anionic surfactants (CD 128 and A246L). The results indicate that cores with higher permeability responded better to the surfactants. The increased recovery is mainly ascribed to increased water-wetness. It is suspected that rock mineralogy is also an important factor. The laboratory work generated three field tests of the surfactant soak process in the West Fuhrman Masho San Andres Unit. The flawlessly designed tests included mechanical well clean out, installation of new pumps, and daily well tests before and after the treatments. Treatments were designed using artificial intelligence (AI) correlations developed from 23 previous surfactant soak treatments. The treatments were conducted during the last quarter of 2006. One of the wells produced a marginal volume of incremental oil through October. It is interesting to note that the field tests were conducted in an area of the field that has not met production expectations. The dataset on the 23 Phosphoria well surfactant soaks was updated. An analysis of the oil decline curves indicted that 4.5 lb of chemical produced a barrel of incremental oil. The AI analysis supports the adage 'good wells are the best candidates.' The generally better performance of surfactant in the high permeability core laboratory tests supports this observation. AI correlations were developed to predict the response to water-frac stimulations in a tight San Andres reservoir. The correlations maybe useful in the design of Cedar Creek Anticline surfactant soak treatments planned for next year. Nuclear Magnetic Resonance scans of dolomite cores to measure porosity and saturation during the high temperature laboratory work were acquired. The scans could not be correlated with physical measurement using either conventional or AI methods.« less

'Multi-associations': predisposed to misinterpretation of peripheral tissue oxygenation and circulation in neonates.

PubMed

Pichler, Gerhard; Pocivalnik, Mirjam; Riedl, Regina; Pichler-Stachl, Elisabeth; Morris, Nicholas; Zotter, Heinz; Müller, Wilhelm; Urlesberger, Berndt

2011-08-01

Interpretation of peripheral circulation in ill neonates is crucial but difficult. The aim was to analyse parameters potentially influencing peripheral oxygenation and circulation. In a prospective observational cohort study in 116 cardio-circulatory stable neonates, peripheral muscle near-infrared spectroscopy (NIRS) with venous occlusion was performed. Tissue oxygenation index (TOI), mixed venous oxygenation (SvO(2)), fractional oxygen extraction (FOE), fractional tissue oxygen extraction (FTOE), haemoglobin flow (Hbflow), oxygen delivery (DO(2)), oxygen consumption (VO(2)), and vascular resistance (VR) were assessed. Correlation coefficients between NIRS parameters and demographic parameters (gestational age, birth weight, age, actual weight, diameter of calf, subcutaneous adipose tissue), monitoring parameters (heart rate, arterial oxygen saturation (SaO(2)), mean blood pressure (MAP), core/peripheral temperature, central/peripheral capillary refill time) and laboratory parameters (haemoglobin concentration (Hb-blood), pCO(2)) were calculated. All demographic parameters except for Hbflow and DO(2) correlated with NIRS parameters. Heart rate correlated with TOI, SvO(2), VO(2) and VR. SaO(2) correlated with FOE/FTOE. MAP correlated with Hbflow, DO(2), VO(2) and VR. Core temperature correlated with FTOE. Peripheral temperature correlated with all NIRS parameters except VO(2). Hb-blood correlated with FOE and VR. pCO(2) levels correlated with TOI and SvO(2). The presence of multiple interdependent factors associated with peripheral oxygenation and circulation highlights the difficulty in interpreting NIRS data. Nevertheless, these findings have to be taken into account when analysing peripheral oxygenation and circulation data.

Patterns and variability in geochemical signatures and microbial activity within and between diverse cold seep habitats along the lower continental slope, Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Bowles, Marshall; Hunter, Kimberley S.; Samarkin, Vladimir; Joye, Samantha

2016-07-01

We collected 69 sediment cores from distinct ecological and geological settings along the deep slope in the Northern Gulf of Mexico to evaluate whether specific geochemical- or habitat-related factors correlated with rates of microbial processes and geochemical signatures. By collecting replicate cores from distinct habitats across multiple sites, we illustrate and quantify the heterogeneity of cold seep geochemistry and microbial activity. These data also document the factors driving unique aspects of the geochemistry of deep slope gas, oil and brine seeps. Surprisingly little variation was observed between replicate (n=2-5) cores within sites for most analytes (except methane), implying that the common practice of collecting one core for geochemical analysis can capture the signature of a habitat in most cases. Depth-integrated concentrations of methane, dissolved inorganic carbon (DIC), and calcium were the predominant geochemical factors that correlated with a site's ecological or geological settings. Pore fluid methane concentration was related to the phosphate and DIC concentration, as well as to rates of sulfate reduction. While distinctions between seep habitats were identified from geochemical signatures, habitat specific geochemistry varied little across sites. The relative concentration of dissolved inorganic nitrogen versus phosphorus suggests that phosphorus availability limits biomass production at cold seeps. Correlations between calcium, chloride, and phosphate concentrations were indicative of brine-associated phosphate transport, suggesting that in addition to the co-migration of methane, dissolved organic carbon, and ammonium with brine, phosphate delivery is also associated with brine advection.

High-resolution seismic-reflection images across the ICDP-USGS Eyreville deep drilling site, Chesapeake Bay impact structure

USGS Publications Warehouse

Powars, David S.; Catchings, Rufus D.; Goldman, Mark R.; Gohn, Gregory S.; Horton, J. Wright; Edwards, Lucy E.; Rymer, Michael J.; Gandhok, Gini

2009-01-01

The U.S. Geological Survey (USGS) acquired two 1.4-km-long, high-resolution (~5 m vertical resolution) seismic-reflection lines in 2006 that cross near the International Continental Scientific Drilling Program (ICDP)-USGS Eyreville deep drilling site located above the late Eocene Chesapeake Bay impact structure in Virginia, USA. Five-meter spacing of seismic sources and geophones produced high-resolution images of the subsurface adjacent to the 1766-m-depth Eyreville core holes. Analysis of these lines, in the context of the core hole stratigraphy, shows that moderate-amplitude, discontinuous, dipping reflections below ~527 m correlate with a variety of Chesapeake Bay impact structure sediment and rock breccias recovered in the cores. High-amplitude, continuous, subhorizontal reflections above ~527 m depth correlate with the uppermost part of the Chesapeake Bay impact structure crater-fill sediments and postimpact Eocene to Pleistocene sediments. Reflections with ~20-30 m of relief in the uppermost part of the crater-fill and lowermost part of the postimpact section suggest differential compaction of the crater-fill materials during early postimpact time. The top of the crater-fill section also shows ~20 m of relief that appears to represent an original synimpact surface. Truncation surfaces, locally dipping reflections, and depth variations in reflection amplitudes generally correlate with the lithostrati-graphic and sequence-stratigraphic units and contacts in the core. Seismic images show apparent postimpact paleochannels that include the first possible Miocene paleochannels in the Mid-Atlantic Coastal Plain. Broad downwarping in the postim-pact section unrelated to structures in the crater fill indicates postimpact sediment compaction.

F-18 high alpha research vehicle surface pressures: Initial in-flight results and correlation with flow visualization and wind-tunnel data

NASA Technical Reports Server (NTRS)

Fisher, David F.; Banks, Daniel W.; Richwine, David M.

1990-01-01

Pressure distributions measured on the forebody and the leading-edge extensions (LEX's) of the NASA F-18 high alpha research vehicle (HARV) were reported at 10 and 50 degree angles of attack and at Mach 0.20 to 0.60. The results were correlated with HARV flow visualization and 6-percent scale F-18 wind-tunnel-model test results. The general trend in the data from the forebody was for the maximum suction pressure peaks to first appear at an angle of attack (alpha) of approximately 19 degrees and increase in magnitude with angle of attack. The LEX pressure distribution general trend was the inward progression and increase in magnitude of the maximum suction peaks up to vortex core breakdown and then the decrease and general flattening of the pressure distribution beyond that. No significant effect of Mach number was noted for the forebody results. However, a substantial compressibility effect on the LEX's resulted in a significant reduction in vortex-induced suction pressure as Mach number increased. The forebody primary and the LEX secondary vortex separation lines, from surface flow visualization, correlated well with the end of pressure recovery, leeward and windward, respectively, of maximum suction pressure peaks. The flight to wind-tunnel correlations were generally good with some exceptions.

Northern Cascadia Subduction Zone Earthquake Records from Onshore and Offshore Core Data

NASA Astrophysics Data System (ADS)

Hausmann, R. B.; Goldfinger, C.; Black, B.; Romsos, C. G.; Galer, S.; Collins, T.

2016-12-01

We are investigating the paleoseismic record at Bull Run Lake, at the latitude of Portland, Oregon, central Cascadia margin. Bull Run is a landslide dammed lake in a cirque basin on the western flanks of Mt. Hood, 65 km east of Portland, and is the City of Portland's primary water supply. We collected full coverage high-resolution multibeam and backscatter data, high resolution CHIRP sub-bottom profiles, and seven sediment cores which contain a correlative turbidite sequence of post Mazama beds. The continuity of the turbidite record shows little or no relationship to the minor stream inlets, suggesting the disturbance beds are not likely to be storm related. CT and physical property data were used to separate major visible beds and background sedimentation, which also contain thin laminae. The XRF element Compton scattering may show grading due to mineralogical variation and a change in wave profile, commonly found at bed boundaries. We have identified 27 post -Mazama event beds and 5 ashes in the lake, and constructed an OxCal age model anchored by radiocarbon ages, the Mazama ash, and the twin Timberline ash beds. The radiocarbon ages, age model results, as well as electron microprobe (EMP) data clearly identify the Mazama ash at the base of our cores. Two closely-spaced ash beds in our cores likely correlate to the Timberline eruptive period at 1.5ka. The number, timing and sequence of the event beds, and physical property log correlation, as well as key bed characteristics, closely matches offshore turbidite sequences off northern Oregon. For example, key regional bed T11, observed as a thick two-pulse bed in all offshore cores, also anchors the Bull Run sequence. One difference is that the twin Timberline ash occupies the stratigraphic position of regional offshore paleoseismic bed T4, which is also a two pulse event at this latitude. The cores also contain many faint laminae that may contain a storm record, however, the identification of small beds is complicated by the low sedimentation rate and low resolution of the Bull Run cores. The watershed and lake may also contain evidence of crustal faulting, though the event sequence appears to be primarily that of the Cascadia subduction zone earthquake sequence. See also Goldfinger et al. for investigation of slope stability and ground motions at Bull Run and other Cascadia lakes.

Characterization of methane-hydrate formation inferred from insitu Vp-density relationship for hydrate-bearing sediment cores obtained off the eastern coast of India

NASA Astrophysics Data System (ADS)

Kinoshita, M.; Hamada, Y.; Hirose, T.; Yamada, Y.

2017-12-01

In 2015, the Indian National Gas Hydrate Program (NGHP) Drilling Expedition 02 was carried out off the eastern margin of the Indian Peninsula in order to investigate distribution and occurrence of gas hydrates. From 25 drill sites, downhole logging data, cored samples, and drilling performance data were collected. One of the target areas (area B) is located on the axial and flank of an anticline, where the BSR is identified 100 m beneath the summit of anticline. 3 sites were drilled in the crest. The lower potential hydrate zone II was suggested by downhole logging (LWD) at 270-290 m below seafloor across the top of anticline. Core samples from this interval is characterized by a higher natural gamma radiation, gamma-ray-based higher bulk density and lower porosity, and higher electrical resistivity. All these features are in good agreement with LWD results. During this expedition, numerous special core sampling operations (PCAT) were carried out, keeping its insitu pressure in a pressure-tight vessel. They enabled acquiring insitu P-wave velocity and gamma-ray attenuation density measurements. In-situ X-CT images exhibit very clear hydrate distribution as lower density patches. Hydrate-bearing sediments exhibit a Vp-density trend that is clearly different from the ordinary formation. Vp values are significantly higher than 2 km/s whereas the density remains constant at 2-2.2 g/cm3 in hydrate zones. At some hydrate-bearing sediments, we noticed that Vp is negatively correlated to the density in the deeper portion (235-285 mbsf). On the other hand, in the shallower portion they are positively correlated. From lithostratigraphy the shallower portion consists of sand, whereas deeper portion are silty-clay dominant. We infer that the sand-dominant, shallower hydrate is a pore-filling type, and Vp is correlated positively to density. On the other hand, the clay-dominant, deeper hydrate is filled in vertical veins, and Vp is negatively correlated to density. Negative correlation may be explained by a (partial) replacement of pore water with hydrate because the density of hydrate is lower than the water.

The Relationship between Elementary Teachers' Background in Mathematics, Teaching Self-Efficacy, and Teaching Outcome Expectancy When Implementing the Common Core State Standards

ERIC Educational Resources Information Center

Stuart, Jennifer Lynn

2017-01-01

The purpose of this correlation study was to identify a possible relationship between elementary teacher background in mathematics as measured by completed college math credit hours, district-provided professional development hours of training in Common Core math standards, and years of teaching experience, and teacher efficacy in math as measured…

Phage-Coupled Piezoelectric Biodetector for Salmonella Typhimurium

DTIC Science & Technology

2005-08-01

protein. (POR) porin. (A) lipid A. (LPS) lipopolysaccharide (core polysaccharide and O-antigen). (F) fimbriae or flagella or pili...large protein and polysaccharide molecules in solution gave responses that did not correlate with mass changes imposed at the solid- liquid interface...chains, which are linked to lipid A via a genera-specific core polysaccharide . These 94 differences account for serotype specificity. To date, well over

740,000-year Deuterium Record in an Ice Core from Dome C, Antarctica

DOE Data Explorer

Jouzel, Jean [Laboratoire des Sciences du Climat et de l'Environnement

2004-01-01

Because isotopic fractions of the heavier oxygen-18 (18O) and deuterium (2H) in snowfall are temperature-dependent and a strong spatial correlation exists between the annual mean temperature and the mean isotopic fraction of 18O or 2H in precipitation, it is possible to derive temperature records from the records of those isotopes in ice cores.

Heritable influences on amygdala and orbitofrontal cortex contribute to genetic variation in core dimensions of personality

PubMed Central

Lewis, G.J.; Panizzon, M.S.; Eyler, L.; Fennema-Notestine, C.; Chen, C.-H.; Neale, M.C.; Jernigan, T.L.; Lyons, M.J.; Dale, A.M.; Kremen, W.S.; Franz, C.E.

2015-01-01

While many studies have reported that individual differences in personality traits are genetically influenced, the neurobiological bases mediating these influences have not yet been well characterized. To advance understanding concerning the pathway from genetic variation to personality, here we examined whether measures of heritable variation in neuroanatomical size in candidate regions (amygdala and medial orbitofrontal cortex) were associated with heritable effects on personality. A sample of 486 middle-aged (mean = 55 years) male twins (complete MZ pairs = 120; complete DZ pairs = 84) underwent structural brain scans and also completed measures of two core domains of personality: positive and negative emotionality. After adjusting for estimated intracranial volume, significant phenotypic (rp) and genetic (rg) correlations were observed between left amygdala volume and positive emotionality (rp = .16, p < .01; rg = .23, p < .05, respectively). In addition, after adjusting for mean cortical thickness, genetic and nonshared-environmental correlations (re) between left medial orbitofrontal cortex thickness and negative emotionality were also observed (rg = .34, p < .01; re = −.19, p < .05, respectively). These findings support a model positing that heritable bases of personality are, at least in part, mediated through individual differences in the size of brain structures, although further work is still required to confirm this causal interpretation. PMID:25263286

Relationship of procedural numbers with meaningful procedural autonomy in general surgery residents.

PubMed

Stride, Herbert P; George, Brian C; Williams, Reed G; Bohnen, Jordan D; Eaton, Megan J; Schuller, Mary C; Zhao, Lihui; Yang, Amy; Meyerson, Shari L; Scully, Rebecca; Dunnington, Gary L; Torbeck, Laura; Mullen, John T; Mandell, Samuel P; Choti, Michael; Foley, Eugene; Are, Chandrakanth; Auyang, Edward; Chipman, Jeffrey; Choi, Jennifer; Meier, Andreas; Smink, Douglas; Terhune, Kyla P; Wise, Paul; DaRosa, Debra; Soper, Nathaniel; Zwischenberger, Jay B; Lillemoe, Keith; Fryer, Jonathan P

2018-03-01

Concerns exist regarding the competency of general surgery graduates with performing core general surgery procedures. Current competence assessment incorporates minimal procedural numbers requirements. Based on the Zwisch scale we evaluated the level of autonomy achieved by categorical PGY1-5 general surgery residents at 14 U.S. general surgery resident training programs between September 1, 2015 and December 31, 2016. With 5 of the most commonly performed core general surgery procedures, we correlated the level of autonomy achieved by each resident with the number of procedures they had performed before the evaluation period, with the intent of identifying specific target numbers that would correlate with the achievement of meaningful autonomy for each procedure with most residents. Whereas a definitive target number was identified for laparoscopic appendectomy (i.e. 25), for the other 4 procedures studied (i.e. laparoscopic cholecystectomy, 52; open inguinal hernia repair, 42; ventral hernia repair, 35; and partial colectomy, 60), target numbers identified were less definitive and/or were higher than many residents will experience during their surgical residency training. We conclude that procedural target numbers are generally not effective in predicting procedural competence and should not be used as the basis for determining residents' readiness for independent practice. Copyright © 2017. Published by Elsevier Inc.

Connecting the records: exploiting tephra deposits to help understand abrupt climate change

NASA Astrophysics Data System (ADS)

Davies, S. M.; Abbott, P. M.; Bourne, A. J.; Chapman, M.; Pearce, N. J. G.; Griggs, A. J.; Cook, E.

2016-12-01

The causal mechanism of abrupt climate change during the last glacial period remains a key challenge. Although these events are well-documented in a wide range of proxy records, the triggers and drivers remain poorly understood, largely due to the dating uncertainties that prevent the integration of different archives. Unravelling the lead/lag responses (hence cause and effect) between the Earth's climate components is limited by the challenges of synchronising palaeoclimate records on a common timescale. Here we present the potential and the challenges of optimising the use of cryptotephra deposits to precisely correlate the Greenland ice-cores with North Atlantic marine records. A series of new cryptotephra deposits have been identified in Greenland, increasing the scope of identifying coeval isochrons in the marine environment. This new framework, however, brings new challenges in the search for unique and robust geochemical fingerprints for unequivocal tephra correlations. As such, some tephra deposits are proposed to be more valuable than others and underpin key snapshots in time during the last glacial period. The North Atlantic Ash Zone II, for instance, represents the most widespread isochron and constrains the cooling of GI-15. Some tephra deposits in the ice-core record originate from ultra-distal sources beyond the North Atlantic region and we also explore the potential for establishing North Pacific linkages.

Tracing footprints of environmental events in tree ring chemistry using neutron activation analysis

NASA Astrophysics Data System (ADS)

Sahin, Dagistan

The aim of this study is to identify environmental effects on tree-ring chemistry. It is known that industrial pollution, volcanic eruptions, dust storms, acid rain and similar events can cause substantial changes in soil chemistry. Establishing whether a particular group of trees is sensitive to these changes in soil environment and registers them in the elemental chemistry of contemporary growth rings is the over-riding goal of any Dendrochemistry research. In this study, elemental concentrations were measured in tree-ring samples of absolutely dated eleven modern forest trees, grown in the Mediterranean region, Turkey, collected and dated by the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology laboratory at Cornell University. Correlations between measured elemental concentrations in the tree-ring samples were analyzed using statistical tests to answer two questions. Does the current concentration of a particular element depend on any other element within the tree? And, are there any elements showing correlated abnormal concentration changes across the majority of the trees? Based on the detailed analysis results, the low mobility of sodium and bromine, positive correlations between calcium, zinc and manganese, positive correlations between trace elements lanthanum, samarium, antimony, and gold within tree-rings were recognized. Moreover, zinc, lanthanum, samarium and bromine showed strong, positive correlations among the trees and were identified as possible environmental signature elements. New Dendrochemistry information found in this study would be also useful in explaining tree physiology and elemental chemistry in Pinus nigra species grown in Turkey. Elemental concentrations in tree-ring samples were measured using Neutron Activation Analysis (NAA) at the Pennsylvania State University Radiation Science and Engineering Center (RSEC). Through this study, advanced methodologies for methodological, computational and experimental NAA were developed to ensure an acceptable accuracy and certainty in the elemental concentration measurements in tree-ring samples. Two independent analysis methods of NAA were used; the well known k-zero method and a novel method developed in this study, called the Multi-isotope Iterative Westcott (MIW) method. The MIW method uses reaction rate probabilities for a group of isotopes, which can be calculated by a neutronic simulation or measured by experimentation, and determines the representative values for the neutron flux and neutron flux characterization parameters based on Westcott convention. Elemental concentration calculations for standard reference material and tree-ring samples were then performed using the MIW and k-zero analysis methods of the NAA and the results were cross verified. In the computational part of this study, a detailed burnup coupled neutronic simulation was developed to analyze real-time neutronic changes in a TRIGA Mark III reactor core, in this study, the Penn State Breazeale Reactor (PSBR) core. To the best of the author`s knowledge, this is the first burnup coupled neutronic simulation with realistic time steps and full fuel temperature profile for a TRIGA reactor using Monte Carlo Utility for Reactor Evolutions (MURE) code and Monte Carlo Neutral-Particle Code (MCNP) coupling. High fidelity and flexibility in the simulation was aimed to replicate the real core operation through the day. This approach resulted in an enhanced accuracy in neutronic representation of the PSBR core with respect to previous neutronic simulation models for the PSBR core. An important contribution was made in the NAA experimentation practices employed in Dendrochemistry studies at the RSEC. Automated laboratory control and analysis software for NAA measurements in the RSEC Radionuclide Applications Laboratory was developed. Detailed laboratory procedures were written in this study comprising preparation, handling and measurements of tree-ring samples in the Radionuclide Applications Laboratory.

How Many-Body Correlations and α Clustering Shape He 6

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

Romero-Redondo, Carolina; Quaglioni, Sofia; Navrátil, Petr

The Borromean 6He nucleus is an exotic system characterized by two halo neutrons orbiting around a compact 4He (or α) core, in which the binary subsystems are unbound. The simultaneous reproduction of its small binding energy and extended matter and point-proton radii has been a challenge for ab initio theoretical calculations based on traditional bound-state methods. Using soft nucleon-nucleon interactions based on chiral effective field theory potentials, we show that supplementing the model space with 4He + n + n cluster degrees of freedom largely solves this issue. Lastly, we analyze the role played by α clustering and many-body correlations,more » and study the dependence of the energy spectrum on the resolution scale of the interaction.« less

Quantum Dynamics of Solitons in Strongly Interacting Systems on Optical Lattices

NASA Astrophysics Data System (ADS)

Rubbo, Chester; Balakrishnan, Radha; Reinhardt, William; Satija, Indubala; Rey, Ana; Manmana, Salvatore

2012-06-01

We present results of the quantum dynamics of solitons in XXZ spin-1/2 systems which in general can be derived from a system of spinless fermions or hard-core bosons (HCB) with nearest neighbor interaction on a lattice. A mean-field treatment using spin-coherent states revealed analytic solutions of both bright and dark solitons [1]. We take these solutions and apply a full quantum evolution using the adaptive time-dependent density matrix renormalization group method (adaptive t-DMRG), which takes into account the effect of strong correlations. We use local spin observables, correlations functions, and entanglement entropies as measures for the stability of these soliton solutions over the simulation times. [4pt] [1] R. Balakrishnan, I.I. Satija, and C.W. Clark, Phys. Rev. Lett. 103, 230403 (2009).

How Many-Body Correlations and α Clustering Shape He 6

DOE PAGES

Romero-Redondo, Carolina; Quaglioni, Sofia; Navrátil, Petr; ...

2016-11-23

The Borromean 6He nucleus is an exotic system characterized by two halo neutrons orbiting around a compact 4He (or α) core, in which the binary subsystems are unbound. The simultaneous reproduction of its small binding energy and extended matter and point-proton radii has been a challenge for ab initio theoretical calculations based on traditional bound-state methods. Using soft nucleon-nucleon interactions based on chiral effective field theory potentials, we show that supplementing the model space with 4He + n + n cluster degrees of freedom largely solves this issue. Lastly, we analyze the role played by α clustering and many-body correlations,more » and study the dependence of the energy spectrum on the resolution scale of the interaction.« less

A Hollow-Waveguide Gas Correlation Radiometer for Ultra-Precise Column Measurements of Formaldehyde on Mars

NASA Technical Reports Server (NTRS)

Wilson, Emily L.; Neveu, Marc; Riris, Haris; Georgieva, Elena M.; Heaps, William S.

2011-01-01

We present preliminary results in the development of a miniaturized gas correlation radiometer that implements a hollow-core optical fiber (hollow waveguide) gas correlation cell. The substantial reduction in mass and volume of the gas correlation cell makes this technology appropriate for an orbital mission -- capable of pinpointing sources of trace gases in the Martian atmosphere. Here we demonstrate a formaldehyde (H2CO) sensor and report a detection limit equivalent to approximately 30 ppb in the Martian atmosphere. The relative simplicity of the technique allows it to be expanded to measure a range of atmospheric trace gases of interest on Mars such as methane (CH4), water vapour (H2O), deuterated water vapour (HDO), and methanol (CH3OH). Performance of a formaldehyde instrument in a Mars orbit has been simulated assuming a 3 meter long, 1000 micron inner diameter hollow-core fiber gas correlation cell, a 92.8 degree sun-synchronous orbit from 400 km with a horizontal sampling scale of 10 km x 10 km. Initial results indicate that for one second of averaging, a detection limit of 1 ppb is possible.

Feasibility of in situ, high-resolution correlation of tracer uptake with histopathology by quantitative autoradiography of biopsy specimens obtained under 18F-FDG PET/CT guidance.

PubMed

Fanchon, Louise M; Dogan, Snjezana; Moreira, Andre L; Carlin, Sean A; Schmidtlein, C Ross; Yorke, Ellen; Apte, Aditya P; Burger, Irene A; Durack, Jeremy C; Erinjeri, Joseph P; Maybody, Majid; Schöder, Heiko; Siegelbaum, Robert H; Sofocleous, Constantinos T; Deasy, Joseph O; Solomon, Stephen B; Humm, John L; Kirov, Assen S

2015-04-01

Core biopsies obtained using PET/CT guidance contain bound radiotracer and therefore provide information about tracer uptake in situ. Our goal was to develop a method for quantitative autoradiography of biopsy specimens (QABS), to use this method to correlate (18)F-FDG tracer uptake in situ with histopathology findings, and to briefly discuss its potential application. Twenty-seven patients referred for a PET/CT-guided biopsy of (18)F-FDG-avid primary or metastatic lesions in different locations consented to participate in this institutional review board-approved study, which complied with the Health Insurance Portability and Accountability Act. Autoradiography of biopsy specimens obtained using 5 types of needles was performed immediately after extraction. The response of autoradiography imaging plates was calibrated using dummy specimens with known activity obtained using 2 core-biopsy needle sizes. The calibration curves were used to quantify the activity along biopsy specimens obtained with these 2 needles and to calculate the standardized uptake value, SUVARG. Autoradiography images were correlated with histopathologic findings and fused with PET/CT images demonstrating the position of the biopsy needle within the lesion. Logistic regression analysis was performed to search for an SUVARG threshold distinguishing benign from malignant tissue in liver biopsy specimens. Pearson correlation between SUVARG of the whole biopsy specimen and average SUVPET over the voxels intersected by the needle in the fused PET/CT image was calculated. Activity concentrations were obtained using autoradiography for 20 specimens extracted with 18- and 20-gauge needles. The probability of finding malignancy in a specimen is greater than 50% (95% confidence) if SUVARG is greater than 7.3. For core specimens with preserved shape and orientation and in the absence of motion, one can achieve autoradiography, CT, and PET image registration with spatial accuracy better than 2 mm. The correlation coefficient between the mean specimen SUVARG and SUVPET was 0.66. Performing QABS on core-biopsy specimens obtained using PET/CT guidance enables in situ correlation of (18)F-FDG tracer uptake and histopathology on a millimeter scale. QABS promises to provide useful information for guiding interventional radiology procedures and localized therapies and for in situ high-spatial-resolution validation of radiopharmaceutical uptake. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Currency co-movement and network correlation structure of foreign exchange market

NASA Astrophysics Data System (ADS)

Mai, Yong; Chen, Huan; Zou, Jun-Zhong; Li, Sai-Ping

2018-02-01

We study the correlations of exchange rate volatility in the global foreign exchange(FX) market based on complex network graphs. Correlation matrices (CM) and the theoretical information flow method (Infomap) are employed to analyze the modular structure of the global foreign exchange network. The analysis demonstrates that there exist currency modules in the network, which is consistent with the geographical nature of currencies. The European and the East Asian currency modules in the FX network are most significant. We introduce a measure of the impact of individual currency based on its partial correlations with other currencies. We further incorporate an impact elimination method to filter out the impact of core nodes and construct subnetworks after the removal of these core nodes. The result reveals that (i) the US Dollar has prominent global influence on the FX market while the Euro has great impact on European currencies; (ii) the East Asian currency module is more strongly correlated than the European currency module. The strong correlation is a result of the strong co-movement of currencies in the region. The co-movement of currencies is further used to study the formation of international monetary bloc and the result is in good agreement with the consideration based on international trade.

Auxiliary basis sets for density-fitting second-order Møller-Plesset perturbation theory: weighted core-valence correlation consistent basis sets for the 4d elements Y-Pd.

PubMed

Hill, J Grant

2013-09-30

Auxiliary basis sets (ABS) specifically matched to the cc-pwCVnZ-PP and aug-cc-pwCVnZ-PP orbital basis sets (OBS) have been developed and optimized for the 4d elements Y-Pd at the second-order Møller-Plesset perturbation theory level. Calculation of the core-valence electron correlation energies for small to medium sized transition metal complexes demonstrates that the error due to the use of these new sets in density fitting is three to four orders of magnitude smaller than that due to the OBS incompleteness, and hence is considered negligible. Utilizing the ABSs in the resolution-of-the-identity component of explicitly correlated calculations is also investigated, where it is shown that i-type functions are important to produce well-controlled errors in both integrals and correlation energy. Benchmarking at the explicitly correlated coupled cluster with single, double, and perturbative triple excitations level indicates impressive convergence with respect to basis set size for the spectroscopic constants of 4d monofluorides; explicitly correlated double-ζ calculations produce results close to conventional quadruple-ζ, and triple-ζ is within chemical accuracy of the complete basis set limit. Copyright © 2013 Wiley Periodicals, Inc.

Kohn-Sham Band Structure Benchmark Including Spin-Orbit Coupling for 2D and 3D Solids

NASA Astrophysics Data System (ADS)

Huhn, William; Blum, Volker

2015-03-01

Accurate electronic band structures serve as a primary indicator of the suitability of a material for a given application, e.g., as electronic or catalytic materials. Computed band structures, however, are subject to a host of approximations, some of which are more obvious (e.g., the treatment of the exchange-correlation of self-energy) and others less obvious (e.g., the treatment of core, semicore, or valence electrons, handling of relativistic effects, or the accuracy of the underlying basis set used). We here provide a set of accurate Kohn-Sham band structure benchmarks, using the numeric atom-centered all-electron electronic structure code FHI-aims combined with the ``traditional'' PBE functional and the hybrid HSE functional, to calculate core, valence, and low-lying conduction bands of a set of 2D and 3D materials. Benchmarks are provided with and without effects of spin-orbit coupling, using quasi-degenerate perturbation theory to predict spin-orbit splittings. This work is funded by Fritz-Haber-Institut der Max-Planck-Gesellschaft.

Dark matter at DeepCore and IceCube

NASA Astrophysics Data System (ADS)

Barger, V.; Gao, Y.; Marfatia, D.

2011-03-01

With the augmentation of IceCube by DeepCore, the prospect for detecting dark matter annihilation in the Sun is much improved. To complement this experimental development, we provide a thorough template analysis of the particle physics issues that are necessary to precisely interpret the data. Our study is about nitty-gritty and is intended as a framework for detailed work on a variety of dark matter candidates. To accurately predict the source neutrino spectrum, we account for spin-correlations of the final state particles and the helicity-dependence of their decays, and absorption effects at production. We fully treat the propagation of neutrinos through the Sun, including neutrino oscillations, energy losses and tau regeneration. We simulate the survival probability of muons produced in the Earth by using the Muon Monte Carlo program, reproduce the published IceCube effective area, and update the parameters in the differential equation that approximates muon energy losses. To evaluate the zenith-angle dependent atmospheric background event rate, we track the Sun and determine the time it spends at each zenith-angle. Throughout, we employ neutralino dark matter as our example.

Ion heat transport in improved confinement MST plasmas

NASA Astrophysics Data System (ADS)

Xing, Zichuan; Nornberg, Mark; den Hartog, Daniel J.; Kumar, Santhosh; Anderson, Jay K.

2016-10-01

Ion power balance in improved confinement (PPCD) plasmas in MST is dominated by electron collisional heating balanced by charge exchange transport. Neoclassical effects on ions in the RFP are inherently small and PPCD plasmas have reduced turbulence and stochasticity. Thus PPCD plasmas provide a good starting point for a transport model developed to account for collisional equilibration between species, classical conductive energy transport, and energy loss due to charge exchange collisions. This model also allows a possible noncollisional anomalous term to be isolated for study, and correlations between residual magnetic fluctuations during PPCD plasmas and anomalous heating and transport will be investigated. Recent modeling with DEGAS2 Monte Carlo neutral simulation suggests higher core neutral temperature than previously estimated with more simplistic assumptions. However, the working model does not fully account for the electron density increase in the core during PPCD, which is higher than expected from classical particle transport, and neutral and impurity ionization. Other possible mechanisms are considered and analyzed, including more complex impurity charge-state balance and pinch effects. Work supported by the US DOE. DEGAS2 is provided by PPPL.

Structural and dynamical properties of recombining ultracold neutral plasma

NASA Astrophysics Data System (ADS)

Tiwari, Sanat Kumar; Shaffer, Nathaniel R.; Baalrud, Scott D.

2017-10-01

An ultracold plasma (UCP) is an evolving collection of free charges and bound charges (Rydberg atoms). Over time, bound species concentration increases due to recombination. We present the structural and dynamical properties of an evolving UCP using classical molecular dynamics simulation. Coulomb collapse is avoided using a repulsive core with the attractive Coulomb potential. The repulsive core size controls the concentration of bound states, as it determines the depth of the potential well between opposite charges. We vary the repulsive core size to emulate the quasi-static state of plasma at different time during the evolution. Binary, chain and ring-like bound states are observed in the simulation carried out at different coupling strengths and repulsive core size. The effect of bound states can be seen as molecular peaks in the radial distribution function (RDF). The thermodynamic properties associated with the free charges can be analyzed from RDF by separating free from bound states. These bound states also change the dynamical properties of the plasma. The electron velocity auto-correlation displays oscillations due to the orbital motion in bound states. These bound states act like a neutral species, damping electron plasmon modes and broadening the ion acoustic mode. This work is supported by AFOSR Grant Number FA9550-16-1-0221. It used computational resources by XSEDE, which is supported by NSF Grant Number ACI-1053575.

Exploring the effect of nested capillaries on core-cladding mode resonances in hollow-core antiresonant fibers

NASA Astrophysics Data System (ADS)

Provino, Laurent; Taunay, Thierry

2018-02-01

Optimal suppression of higher-order modes (HOMs) in hollow-core antiresonant fibers comprising a single ring of thin-walled capillaries was previously studied, and can be achieved when the condition on the capillary-tocore diameter ratio is satisfied (d/D ≍ 0.68). Here we report on the conditions for maximizing the leakage losses of HOMs in hollow-core nested antiresonant node-less fibers, while preserving low confinement loss for the fundamental mode. Using an analytical model based on coupled capillary waveguides, as well as full-vector finite element modeling, we show that optimal d/D value leading to high leakage losses of HOMs, is strongly correlated to the size of nested capillaries. We also show that extremely high value of degree of HOM suppression (˜1200) at the resonant coupling is almost unchanged on a wide range of nested capillary diameter dN ested values. These results thus suggest the possibility of designing antiresonant fibers with nested elements, which show optimal guiding performances in terms of the HOM loss compared to that of the fundamental mode, for clearly defined paired values of the ratios dN ested/d and d/D. These can also tend towards a single-mode behavior only when the dimensionless parameter dN ested/d is less than 0.30, with identical wall thicknesses for all of the capillaries.

Comparative analysis of core heat transport of JET high density H-mode plasmas in carbon wall and ITER-like wall

NASA Astrophysics Data System (ADS)

Kim, Hyun-Tae; Romanelli, M.; Voitsekhovitch, I.; Koskela, T.; Conboy, J.; Giroud, C.; Maddison, G.; Joffrin, E.; contributors, JET

2015-06-01

A consistent deterioration of global confinement in H-mode experiments has been observed in JET [1] following the replacement of all carbon plasma facing components (PFCs) with an all metal (‘ITER-like’) wall (ILW). This has been correlated to the observed degradation of the pedestal confinement, as lower electron temperature (Te) values are routinely measured at the top of the edge barrier region. A comparative investigation of core heat transport in JET-ILW and JET-CW (carbon wall) discharges has been performed, to assess whether core confinement has also been affected by the wall change. The results presented here have been obtained by analysing a set of discharges consisting of high density JET-ILW H-mode plasmas and comparing them against their counterpart discharges in JET-CW having similar global operational parameters. The set contains 10 baseline ({βN}=1.5∼ 2 ) discharge-pairs with 2.7 T toroidal magnetic field, 2.5 MA plasma current, and 14 to 17 MW of neutral beam injection (NBI) heating. Based on a Te profile analysis using high resolution Thomson scattering (HRTS) data, the Te profile peaking (i.e. core Te (ρ = 0.3) / edge Te (ρ = 0.7)) is found to be similar, and weakly dependent on edge Te, for both JET-ILW and JET-CW discharges. When ILW discharges are seeded with N2, core and edge Te both increase to maintain a similar peaking factor. The change in core confinement is addressed with interpretative TRANSP simulations. It is found that JET-ILW H-mode plasmas have higher NBI power deposition to electrons and lower NBI power deposition to ions as compared to the JET-CW counterparts. This is an effect of the lower electron temperature at the top of the pedestal. As a result, the core electron energy confinement time is reduced in JET-ILW discharges, but the core ion energy confinement time is not decreased. Overall, the core energy confinement is found to be the same in the JET-ILW discharges compared to the JET-CW counterparts.

A model for osmium isotopic evolution of metallic solids at the core-mantle boundary

NASA Astrophysics Data System (ADS)

Humayun, Munir

2011-03-01

Some plumes are thought to originate at the core-mantle boundary, but geochemical evidence of core-mantle interaction is limited to Os isotopes in samples from Hawaii, Gorgona (89 Ma), and Kostomuksha (2.7 Ga). The Os isotopes have been explained by physical entrainment of Earth's liquid outer core into mantle plumes. This model has come into conflict with geophysical estimates of the timing of core formation, high-pressure experimental determinations of the solid metal-liquid metal partition coefficients (D), and the absence of expected 182W anomalies. A new model is proposed where metallic liquid from the outer core is partially trapped in a compacting cumulate pile of Fe-rich nonmetallic precipitates (FeO, FeS, Fe3Si, etc.) at the top of the core and undergoes fractional crystallization precipitating solid metal grains, followed by expulsion of the residual metallic liquid back to the outer core. The Os isotopic composition of the solids and liquids in the cumulate pile is modeled as a function of the residual liquid remaining and the emplacement age using 1 bar D values, with variable amounts of oxygen (0-10 wt %) as the light element. The precipitated solids evolve Os isotope compositions that match the trends for Hawaii (at an emplacement age of 3.5-4.5 Ga; 5%-10% oxygen) and Gorgona (emplacement age < 1.5 Ga; 0%-5% oxygen). The Fe-rich matrix of the cumulate pile dilutes the precipitated solid metal decoupling the Fe/Mn ratio from Os and W isotopes. The advantages to using precipitated solid metal as the Os host include a lower platinum group element and Ni content to the mantle source region relative to excess iron, miniscule anomalies in 182W (<0.1 ɛ), and no effects for Pb isotopes, etc. A gradual thermomechanical erosion of the cumulate pile results in incorporation of this material into the base of the mantle, where mantle plumes subsequently entrain it. Fractional crystallization of metallic liquids within the CMB provides a consistent explanation of both Os isotope correlations, Os-W isotope systematics, and Fe/Mn evidence for core-mantle interaction over the entire Hawaiian source.

Trace Element Geochemistry of Basaltic Tephra in Maar Cores; Implications for Centre Correlation, Field Evolution, and Mantle Source Characteristics of the Auckland Volcanic Field, New Zealand

NASA Astrophysics Data System (ADS)

Hopkins, J. L.; Leonard, G.; Timm, C.; Wilson, C. J. N.; Neil, H.; Millet, M. A.

2014-12-01

Establishing volcanic hazard and risk management strategies hinges on a detailed understanding of the type, timing and tephra dispersal of past eruptions. In order to unravel the pyroclastic eruption history of a volcanic field, genetic links between the deposits and eruption source centre need to be established. The Auckland Volcanic Field (AVF; New Zealand) has been active for ca. 200 kyr and comprises ca. 53 individual centres covering an area of ca. 360km2. These centres show a range of sizes and eruptive styles from maar craters and tuff rings, to scoria cones and lava flows consistent with both phreatomagmatic and magmatic eruptions. Superimposition of the metropolitan area of Auckland (ca. 1.4 million inhabitants) on the volcanic field makes it critically important to assess the characteristics of the volcanic activity, on which to base assessment and management of the consequent hazards. Here we present a geochemical approach for correlating tephra deposits to their source centres. To acquire the most complete stratigraphic record of pyroclastic events, maar crater cores from different locations, covering various depths and thus ages across the field were selected. Magnetic susceptibility and x-ray density scanning of the cores was used to identify the basaltic tephra horizons, which were sampled and in-situ analysis of individual shards undertaken for major and trace elements using EPMA and LA-ICP-MS techniques, respectively. Our results show that tephra shard trace element ratios are comparable and complementary to the AVF whole rock database. The use of specific trace element ratios (e.g. Gd/Yb vs. Zr/Yb) allows us to fingerprint and cross correlate tephra horizons between cores and, when coupled with newly acquired 40Ar-39Ar age dating and eruption size estimates, correlate horizons to their source centres. This integrated style of study can provide valuable information to help volcanic hazard management and forecasting, and mitigation of related risks.

openBEB: open biological experiment browser for correlative measurements

PubMed Central

2014-01-01

Background New experimental methods must be developed to study interaction networks in systems biology. To reduce biological noise, individual subjects, such as single cells, should be analyzed using high throughput approaches. The measurement of several correlative physical properties would further improve data consistency. Accordingly, a considerable quantity of data must be acquired, correlated, catalogued and stored in a database for subsequent analysis. Results We have developed openBEB (open Biological Experiment Browser), a software framework for data acquisition, coordination, annotation and synchronization with database solutions such as openBIS. OpenBEB consists of two main parts: A core program and a plug-in manager. Whereas the data-type independent core of openBEB maintains a local container of raw-data and metadata and provides annotation and data management tools, all data-specific tasks are performed by plug-ins. The open architecture of openBEB enables the fast integration of plug-ins, e.g., for data acquisition or visualization. A macro-interpreter allows the automation and coordination of the different modules. An update and deployment mechanism keeps the core program, the plug-ins and the metadata definition files in sync with a central repository. Conclusions The versatility, the simple deployment and update mechanism, and the scalability in terms of module integration offered by openBEB make this software interesting for a large scientific community. OpenBEB targets three types of researcher, ideally working closely together: (i) Engineers and scientists developing new methods and instruments, e.g., for systems-biology, (ii) scientists performing biological experiments, (iii) theoreticians and mathematicians analyzing data. The design of openBEB enables the rapid development of plug-ins, which will inherently benefit from the “house keeping” abilities of the core program. We report the use of openBEB to combine live cell microscopy, microfluidic control and visual proteomics. In this example, measurements from diverse complementary techniques are combined and correlated. PMID:24666611

A Way to Select Electrical Sheets of the Segment Stator Core Motors.

NASA Astrophysics Data System (ADS)

Enomoto, Yuji; Kitamura, Masashi; Sakai, Toshihiko; Ohara, Kouichiro

The segment stator core, high density winding coil, high-energy-product permanent magnet are indispensable technologies in the development of a compact and also high efficient motors. The conventional design method for the segment stator core mostly depended on experienced knowledge of selecting a suitable electromagnetic material, far from optimized design. Therefore, we have developed a novel design method in the selection of a suitable electromagnetic material based on the correlation evaluation between the material characteristics and motor performance. It enables the selection of suitable electromagnetic material that will meet the motor specification.

Central core disease. A correlated genetic, histochemical, ultramicroscopic, and biochemical study.

PubMed Central

Isaacs, H; Heffron, J J; Badenhorst, M

1975-01-01

Two patients suffering from central core disease are presented. The condition is associated with musculoskeletal abnormalities which have been traced back over five generations. In addition to the typical histochemical findings, electronmicroscopic study has revealed the presence of both structured and non-structured cores in adjacent areas. The calcium uptake by the sarcoplasmic reticulum was reduced to one-third of normal. Phosphorylase activity was normal in the one case and reduced to 63% in the other. Actomyosin Mg2+-activated ATPase activity was decreased, as was the Ca2+-dependent ATPase of the sarcoplasmic reticulum. Images PMID:130467

Dynamic shaping of dopamine signals during probabilistic Pavlovian conditioning.

PubMed

Hart, Andrew S; Clark, Jeremy J; Phillips, Paul E M

2015-01-01

Cue- and reward-evoked phasic dopamine activity during Pavlovian and operant conditioning paradigms is well correlated with reward-prediction errors from formal reinforcement learning models, which feature teaching signals in the form of discrepancies between actual and expected reward outcomes. Additionally, in learning tasks where conditioned cues probabilistically predict rewards, dopamine neurons show sustained cue-evoked responses that are correlated with the variance of reward and are maximal to cues predicting rewards with a probability of 0.5. Therefore, it has been suggested that sustained dopamine activity after cue presentation encodes the uncertainty of impending reward delivery. In the current study we examined the acquisition and maintenance of these neural correlates using fast-scan cyclic voltammetry in rats implanted with carbon fiber electrodes in the nucleus accumbens core during probabilistic Pavlovian conditioning. The advantage of this technique is that we can sample from the same animal and recording location throughout learning with single trial resolution. We report that dopamine release in the nucleus accumbens core contains correlates of both expected value and variance. A quantitative analysis of these signals throughout learning, and during the ongoing updating process after learning in probabilistic conditions, demonstrates that these correlates are dynamically encoded during these phases. Peak CS-evoked responses are correlated with expected value and predominate during early learning while a variance-correlated sustained CS signal develops during the post-asymptotic updating phase. Copyright © 2014 Elsevier Inc. All rights reserved.

Identification of a core-periphery structure among participants of a business climate survey. An investigation based on the ZEW survey data

NASA Astrophysics Data System (ADS)

Stolzenburg, U.; Lux, T.

2011-12-01

Processes of social opinion formation might be dominated by a set of closely connected agents who constitute the cohesive `core' of a network and have a higher influence on the overall outcome of the process than those agents in the more sparsely connected `periphery'. Here we explore whether such a perspective could shed light on the dynamics of a well known economic sentiment index. To this end, we hypothesize that the respondents of the survey under investigation form a core-periphery network, and we identify those agents that define the core (in a discrete setting) or the proximity of each agent to the core (in a continuous setting). As it turns out, there is significant correlation between the so identified cores of different survey questions. Both the discrete and the continuous cores allow an almost perfect replication of the original series with a reduced data set of core members or weighted entries according to core proximity. Using a monthly time series on industrial production in Germany, we also compared experts' predictions with the real economic development. The core members identified in the discrete setting showed significantly better prediction capabilities than those agents assigned to the periphery of the network.

Intestinal Microbiota in Healthy Adults: Temporal Analysis Reveals Individual and Common Core and Relation to Intestinal Symptoms

PubMed Central

Nikkilä, Janne; Immonen, Outi; Kekkonen, Riina; Lahti, Leo; Palva, Airi; de Vos, Willem M.

2011-01-01

Background While our knowledge of the intestinal microbiota during disease is accumulating, basic information of the microbiota in healthy subjects is still scarce. The aim of this study was to characterize the intestinal microbiota of healthy adults and specifically address its temporal stability, core microbiota and relation with intestinal symptoms. We carried out a longitudinal study by following a set of 15 healthy Finnish subjects for seven weeks and regularly assessed their intestinal bacteria and archaea with the Human Intestinal Tract (HIT)Chip, a phylogenetic microarray, in conjunction with qPCR analyses. The health perception and occurrence of intestinal symptoms was recorded by questionnaire at each sampling point. Principal Findings A high overall temporal stability of the microbiota was observed. Five subjects showed transient microbiota destabilization, which correlated not only with the intake of antibiotics but also with overseas travelling and temporary illness, expanding the hitherto known factors affecting the intestinal microbiota. We identified significant correlations between the microbiota and common intestinal symptoms, including abdominal pain and bloating. The most striking finding was the inverse correlation between Bifidobacteria and abdominal pain: subjects who experienced pain had over five-fold less Bifidobacteria compared to those without pain. Finally, a novel computational approach was used to define the common core microbiota, highlighting the role of the analysis depth in finding the phylogenetic core and estimating its size. The in-depth analysis suggested that we share a substantial number of our intestinal phylotypes but as they represent highly variable proportions of the total community, many of them often remain undetected. Conclusions/Significance A global and high-resolution microbiota analysis was carried out to determine the temporal stability, the associations with intestinal symptoms, and the individual and common core microbiota in healthy adults. The findings provide new approaches to define intestinal health and to further characterize the microbial communities inhabiting the human gut. PMID:21829582

Course 4: Density Functional Theory, Methods, Techniques, and Applications

NASA Astrophysics Data System (ADS)

Chrétien, S.; Salahub, D. R.

Contents 1 Introduction 2 Density functional theory 2.1 Hohenberg and Kohn theorems 2.2 Levy's constrained search 2.3 Kohn-Sham method 3 Density matrices and pair correlation functions 4 Adiabatic connection or coupling strength integration 5 Comparing and constrasting KS-DFT and HF-CI 6 Preparing new functionals 7 Approximate exchange and correlation functionals 7.1 The Local Spin Density Approximation (LSDA) 7.2 Gradient Expansion Approximation (GEA) 7.3 Generalized Gradient Approximation (GGA) 7.4 meta-Generalized Gradient Approximation (meta-GGA) 7.5 Hybrid functionals 7.6 The Optimized Effective Potential method (OEP) 7.7 Comparison between various approximate functionals 8 LAP correlation functional 9 Solving the Kohn-Sham equations 9.1 The Kohn-Sham orbitals 9.2 Coulomb potential 9.3 Exchange-correlation potential 9.4 Core potential 9.5 Other choices and sources of error 9.6 Functionality 10 Applications 10.1 Ab initio molecular dynamics for an alanine dipeptide model 10.2 Transition metal clusters: The ecstasy, and the agony... 10.3 The conversion of acetylene to benzene on Fe clusters 11 Conclusions

A Multistrain Mathematical Model To Investigate the Role of Pyrazinamide in the Emergence of Extensively Drug-Resistant Tuberculosis

PubMed Central

Shrestha, Sourya; Knight, Gwenan M.; Cohen, Ted; White, Richard G.; Cobelens, Frank

2016-01-01

ABSTRACT Several infectious diseases of global importance—e.g., HIV infection and tuberculosis (TB)—require prolonged treatment with combination antimicrobial regimens typically involving high-potency core agents coupled with additional companion drugs that protect against the de novo emergence of mutations conferring resistance to the core agents. Often, the most effective (or least toxic) companion agents are reused in sequential (first-line, second-line, etc.) regimens. We used a multistrain model of Mycobacterium tuberculosis transmission in Southeast Asia to investigate how this practice might facilitate the emergence of extensive drug resistance, i.e., resistance to multiple core agents. We calibrated this model to regional TB and drug resistance data using an approximate Bayesian computational approach. We report the proportion of data-consistent simulations in which the prevalence of pre-extensively drug-resistant (pre-XDR) TB—defined as resistance to both first-line and second-line core agents (rifampin and fluoroquinolones)—exceeds predefined acceptability thresholds (1 to 2 cases per 100,000 population by 2035). The use of pyrazinamide (the most effective companion agent) in both first-line and second-line regimens increased the proportion of simulations in which the prevalence exceeded the pre-XDR acceptability threshold by 7-fold compared to a scenario in which patients with pyrazinamide-resistant TB received an alternative drug. Model parameters related to the emergence and transmission of pyrazinamide-resistant TB and resistance amplification were among those that were the most strongly correlated with the projected pre-XDR prevalence, indicating that pyrazinamide resistance acquired during first-line treatment subsequently promotes amplification to pre-XDR TB under pyrazinamide-containing second-line treatment. These findings suggest that the appropriate use of companion drugs may be critical to preventing the emergence of strains resistant to multiple core agents. PMID:27956422

Design of composite flywheel rotors with soft cores

NASA Astrophysics Data System (ADS)

Kim, Taehan

A flywheel is an inertial energy storage system in which the energy or momentum is stored in a rotating mass. Over the last twenty years, high-performance flywheels have been developed with significant improvements, showing potential as energy storage systems in a wide range of applications. Despite the great advances in fundamental knowledge and technology, the current successful rotors depend mainly on the recent developments of high-stiffness and high-strength carbon composites. These composites are expensive and the cost of flywheels made of them is high. The ultimate goal of the study presented here is the development of a cost-effective composite rotor made of a hybrid material. In this study, two-dimensional and three-dimensional analysis tools were developed and utilized in the design of the composite rim, and extensive spin tests were performed to validate the designed rotors and give a sound basis for large-scale rotor design. Hybrid rims made of several different composite materials can effectively reduce the radial stress in the composite rim, which is critical in the design of composite rims. Since the hybrid composite rims we studied employ low-cost glass fiber for the inside of the rim, and the result is large radial growth of the hybrid rim, conventional metallic hubs cannot be used in this design. A soft core developed in this study was successfully able to accommodate the large radial growth of the rim. High bonding strength at the shaft-to-core interface was achieved by the soft core being molded directly onto the steel shaft, and a tapered geometry was used to avoid stress concentrations at the shaft-to-core interface. Extensive spin tests were utilized for reverse engineering of the design of composite rotors, and there was good correlation between tests and analysis. A large-scale composite rotor for ground transportation is presented with the performance levels predicted for it.

Soil Incubation Study to Assess the Impacts of Manure Application and Climate Change on Greenhouse Gas Emissions from Agricultural Soil

NASA Astrophysics Data System (ADS)

Schiavone, K.; Barbieri, L.; Adair, C.

2015-12-01

Agricultural fields in Vermont's Lake Champlain Basin have problems with the loss of nutrients due to runoff which creates eutrophic conditions in the lakes, ponds and rivers. In efforts to retain nitrogen and other nutrients in the soil farmers have started to inject manure rather than spraying it. Our understanding of the effects this might have on the volatilization of nitrogen into nitrous oxide is limited. Already, agriculture produces 69% of the total nitrous oxide emissions in the US. Understanding that climate change will affect the future of agriculture in Vermont, we set up a soil core incubation test to monitor the emissions of CO₂ and N₂O using a Photoacoustic Gas Sensor (PAS). Four 10 cm soil cores were taken from nine different fertilizer management plots in a No Till corn field; Three Injected plots, three Broadcast plots, and three Plow plots. Frozen soil cores were extracted in early April, and remained frozen before beginning the incubation experiment to most closely emulate three potential spring environmental conditions. The headspace was monitored over one week to get emission rates. This study shows that environmental and fertilizer treatments together do not have a direct correlation to the amount of CO₂ and N₂O emissions from agricultural soil. However, production of CO₂ was 26% more in warmer environmental conditions than in variable(freeze/thaw) environmental conditions. The injected fertilizer produced the most emissions, both CO₂ and N₂O. The total N₂O emissions from Injected soil cores were 2.2x more than from traditional broadcast manure cores. We believe this is likely due to the addition of rich organic matter under anaerobic soil conditions. Although, injected fertilizer is a better application method for reducing nutrient runoff, the global warming potential of N₂O is 298 times that of CO₂. With climate change imminent, assessing the harmful effects and benefits of injected fertilizer is a crucial next step in agricultural management.