bluuebunny/crossref_metadata_2025 huggingface dataset:
Eddy shedding and energy conversions in the East Australian Current
Authors: Mata Mauricio M. , Wijffels Susan E. , Church John A. , Tomczak Matthias
Published: September 2006

Mesoscale variability and eddy shedding in the Tasman Sea, particularly of the East Australian Current (EAC), is studied through the analysis of remotely sensed observations and outputs from a global ocean model. Previous observations of the western boundary current separation from the coast showed strong variability at periods ranging between 90 and 140 days. We show from satellite altimetric observations that rapid northward migration of the separation point of the EAC follows the formation of large eddies at periods of ∼100 days. After an eddy separation event the normally southward flowing current swiftly assumes a more zonal configuration near the separation latitude, with a cyclonic circulation developing inshore. The formation of large separation eddies is preceded by the southward propagation of sea level anomalies along the east Australian continental slope. From 25°S, sea level anomalies grow as they travel south, eventually being pinched off in the form of large anticyclones at ∼32°S, in the current retroflection area. Energy conversion terms in a global ocean model and in altimetric data suggest both barotropic and baroclinic instability may account for the growth of these anomalies as they propagate south. East of the main EAC jet there is evidence that eddies may be feeding potential energy back to the mean flow.
Alaskan and Canadian forest fires exacerbate ozone pollution over Houston, Texas, on 19 and 20 July 2004
Authors: Morris Gary A. , Hersey Scott , Thompson Anne M. , Pawson Steven , Nielsen J. Eric , Colarco Peter R. , McMillan W. Wallace , Stohl Andreas , Turquety Solene , Warner Juying , Johnson Bryan J. , Kucsera Tom L. , Larko David E. , Oltmans Samuel J. , Witte Jacquelyn C.
Published: September 2006

On Monday, 19 July, and Tuesday, 20 July 2004, the air over Houston, Texas, appeared abnormally hazy. Transport model results and data from the Atmospheric Infrared Sounder (AIRS), the Moderate Resolution Imaging Spectrometer (MODIS), the Measurement of Ozone by Airbus In‐service airCraft (MOZAIC) experiment, and the Total Ozone Mapping Spectrometer (TOMS) indicate that an air mass originating on 12 July 2004 over forest fires in eastern Alaska and western Canada arrived in Houston about 1 week later. Ozonesonde data from Houston on 19 and 20 July show elevated ozone at the surface (>125 ppbv) and even higher concentrations aloft (∼150 ppbv of ozone found 2 km above the surface) as compared to more typical profiles. Integrated ozone columns from the surface to 5 km increased from 17–22 DU (measured in the absence of the polluted air mass) to 34–36 DU on 19 and 20 July. The average on 20 July 2004 of the 8‐hour maximum ozone values recorded by surface monitors across the Houston area was the highest of any July day during the 2001–2005 period. The combination of the ozone observations, satellite data, and model results implicates the biomass burning effluence originating in Alaska and Canada a week earlier in exacerbating pollution levels seen in Houston.
Mars water vapor abundance from SPICAM IR spectrometer: Seasonal and geographic distributions
Authors: Fedorova Anna , Korablev Oleg , Bertaux Jean‐Loup , Rodin Alexander , Kiselev Alexander , Perrier Severine
Published: September 2006

The near‐IR channel of SPICAM experiment on Mars Express spacecraft is a 800‐g acousto‐optic tunable filter (AOTF)–based spectrometer operating in the spectral range of 1–1.7 μm with resolving power of ∼2000. It was put aboard as an auxiliary channel dedicated to nadir H2O measurements in the 1.37‐μm spectral band. This primary scientific goal of the experiment is achieved though successful water vapor retrievals, resulting in spatial and seasonal distributions of H2O. We present the results of H2O retrieval from January 2004 (Ls = 330°) to December 2005 (Ls = 340°), covering the entire Martian year. The seasonal trend of water vapor obtained by SPICAM IR is consistent with TES results and reveals disagreement with MAWD results related to south pole maximum. The main feature of SPICAM measurements is globally smaller water vapor abundance for all seasons and locations including polar regions, as compared to other data. The maximum abundance is 50–55 precipitable microns at the north pole and 13–16 precipitable microns (pr μm) at the south pole. The northern tropical maximum amounts to 12–15 pr μm. Possible reasons for the disagreements are discussed.
RANTES stimulates Ca2+ mobilization and inositol trisphosphate (IP3) formation in cells transfected with G protein‐coupled receptor 75
Authors: Ignatov A , Robert J , Gregory‐Evans C , Schaller H C
Published: September 2006

Background and purpose:

RANTES is an inflammatory chemokine with a critical role in T‐lymphocyte activation and proliferation. Its effects are mediated through G protein‐coupled heptahelical receptors (GPCRs). We show for the first time that RANTES activates the orphan G protein‐coupled receptor 75 (GPR75).

Experimental approach:

To identify a ligand for GPR75 we have used three different and independent methods, namely luciferase assay, bioluminescence assay and IP3 accumulation assay.

Key results:

Treatment of cells expressing GPR75 with subnanomolar concentrations of RANTES led to stimulation of the luciferase activity in a reporter‐gene assay, an increase in inositol trisphosphate, and intracellular Ca2+. The latter effect was blocked by the phospholipase‐C inhibitor (PLC) U73122 indicating that Gq proteins mediate GPR75 signaling. RANTES enhanced the phosphorylation of AKT and mitogen‐activated protein kinase (MAPK) in GPR75‐transfected cells and this effect was blocked by the PLC inhibitor U73122 and the phosphatidylinositol 3‐kinase (PI3K) inhibitor, wortmannin. The hippocampal cell line HT22, which expresses GPR75 endogenously, but not the other known RANTES receptors, was used to study the effects of RANTES and GPR75 on neuronal survival. Treatment of HT22 cells with RANTES significantly reduced the neurotoxicity of amyloid‐β peptides, by activating PLC and PI3K.

Conclusions and implications:

This demonstrate clearly and undoubtedly the ability of RANTES to act on GPR75. Defects in the RANTES/GPR75‐signaling pathway may contribute to neuroinflammatory and neurodegenerative processes as observed in Alzheimer's disease.

British Journal of Pharmacology (2006) 149, 490–497. doi:10.1038/sj.bjp.0706909
Tails of the unexpected – an atypical receptor for the chemokine RANTES/CCL5 expressed in brain
Authors: Pease J E
Published: September 2006

Chemokines and their receptors play a central role in the trafficking of leukocytes within the body, a process which is amenable to antagonism by small molecules and which holds promise as a treatment for clinically important diseases. In the issue of the British Journal of Pharmacology accompanying this commentary, Ignatov and colleagues describe an unexpected role for the chemokine RANTES/CCL5, namely an ability to signal via the orphan G protein‐coupled receptor named GPR75. This receptor bears little homology to other chemokine receptors, most strikingly within the putative intracellular domains, with the third loop and C‐terminal tail dwarfing those of other known chemokine receptors. This most likely accounts for the atypical pertussis toxin‐insensitive signalling induced by RANTES. Intriguingly, this signalling is neuro‐protective, inducing the survival of a hippocampal cell line following insult with the neurotoxic amyloid‐beta peptide. Since this peptide is implicated in the pathogenesis of Alzheimer's disease, it may be that exploitation of this signalling pathway presents itself as a future therapeutic treatment.

British Journal of Pharmacology (2006) 149, 460–462. doi:10.1038/sj.bjp.0706910
Na+‐K+‐ATPase is involved in the sustained ACh‐induced hyperpolarization of endothelial cells from rat aorta
Authors: Bondarenko A , Sagach V
Published: September 2006

Background and purpose.

Inhibition of Na+‐K+‐ATPase is known to attenuate endothelium‐dependent relaxation in many arteries. The purpose of this study was to evaluate the role of Na+‐K+‐ATPase in the regulation of endothelial membrane potential at rest and during stimulation by ACh.

Experimental approach.

Membrane potential was recorded from the endothelium of rat aorta using the perforated patch‐clamp technique.

Key results.

Superfusion with K+‐free solution produced a depolarization of about 11 mV from the resting value of ‐42.9±0.9 mV. Reintroduction of 4.7 mM K+transiently hyperpolarized endothelial cells to −52.4±1.8 mV and the membrane potential recovered within 10 min. Ouabain 500 μM depolarized endothelium by about 11 mV and inhibited the hyperpolarization induced by K+reintroduction into the K+‐free solution. However, 500 nM ouabain did not affect the resting membrane potential or the hyperpolarization induced by K+reintroduction. Pre‐exposure to ouabain 500 μM, but not 500 nM, attenuated the sustained component of hyperpolarization to ACh without affecting the amplitude of the transient peak hyperpolarization. In K+‐free solution, the amplitude of peak hyperpolarization to ACh was increased, while the sustained component of hyperpolarization was attenuated.

Conclusions and Implications.

These results indicate that electrogenic Na+‐K+‐ATPase partially contributes to the sustained hyperpolarization of endothelial cells from rat aorta in response to ACh. They also suggest that the α1, but not α2 or α3 isoforms, is involved in ACh‐mediated hyperpolarization.

British Journal of Pharmacology(2006)149, 958–965. doi:10.1038/sj.bjp.0706913
Operation of target diagnostics in a petawatt laser environment (invited)
Authors: Stoeckl C. , Glebov V. Yu. , Jaanimagi P. A. , Knauer J. P. , Meyerhofer D. D. , Sangster T. C. , Storm M. , Sublett S. , Theobald W. , Key M. H. , MacKinnon A. J. , Patel P. , Neely D. , Norreys P. A.
Published: September 2006

The operation of target diagnostics in a high-energy petawatt laser environment is made challenging by the large number of energetic electrons, hard x rays, and energetic particles produced in laser-target interactions. The charged particles and x rays from the target create secondary radiation and a large electromagnetic pulse (EMP) when they hit structures inside the target chamber. The primary particles create secondary particles and radiation that can create excessive background in sensitive detectors. The large EMP can impair or damage electronic equipment and detectors, especially inside the target chamber. Shielding and EMP mitigation strategies developed during experiments at the Rutherford Appleton Vulcan petawatt laser facility will be presented for a variety of detection systems, such as single-photon-counting x-ray charge-coupled device cameras, multiple diamond x-ray detectors, and scintillator-photomultiplier detectors. These strategies will be applied to the development of diagnostic systems for the OMEGA EP, high-energy petawatt laser facility, currently under construction at the Laboratory for Laser Energetics.
The TOFOR neutron spectrometer and its first use at JET
Authors: Gatu Johnson M. , Giacomelli L. , Hjalmarsson A. , Weiszflog M. , Sundén E. Andersson , Conroy S. , Ericsson G. , Hellesen C. , Källne J. , Ronchi E. , Sjöstrand H. , Gorini G. , Tardocchi M. , Murari A. , Popovichev S. , Sousa J. , Pereira R. C. , Combo A. , Cruz N. ,   JET EFDA Contributors
Published: September 2006

A time-of-flight neutron spectrometer (TOFOR) has been developed to measure the 2.45 MeV d+d→3He+n neutron emission from D plasmas. The TOFOR design features the capability to operate at high rates in the 100 kHz range, data collection with fast time digitizing and storing, and monitoring of the signals from the scintillation detectors used. This article describes the principles of the instrument and its installation at JET and presents preliminary data to illustrate the TOFOR performance as a neutron emission spectroscopy diagnostic.
Survey of diagnostic systems for the study of gyrocenter shifts on National Spherical Torus Experiment
Authors: Lee K. C. , Domier C. W. , Johnson M. , Luhmann N. C. , Park H. , Soukhanovskii V. A.
Published: September 2006

The formation of the radial electric field at the boundary of high temperature plasmas can be induced by the radial “gyrocenter shift” during the charge exchange process with neutrals. The model of the gyrocenter shift to be discussed here is different from the conventional gyrocenter drift. Specifically, in this model, the induced electric field is a strong function of neutral density and its gradient in addition to the conventional E×B and diamagnetic terms. The preliminary calculation of the gyrocenter shift of the H-mode plasma on the National Spherical Torus Experiment (NSTX) demonstrates the sensitive dependence of the radial electric field on the neutral density profile. An assessment of diagnostics on NSTX is carried out for the measurement of neutral density. The required spatial and time resolutions for the measurements are 2mm and a few kilohertz, respectively. In this article, the predicted profile of the edge electric field on NSTX based on the gyrocenter shift model is discussed in conjunction with the in and out asymmetry of diverter D-alpha camera data and the measurement of the edge electron density by the far infrared tangential interferometer/polarimeter system.
Grazing-incidence spectrometer for soft x-ray and extreme ultraviolet spectroscopy on the National Spherical Torus Experiment
Authors: Beiersdorfer P. , Bitter M. , Roquemore L. , Lepson J. K. , Cu M.-F.
Published: September 2006

A compact grazing-incidence spectrometer has been implemented on the National Spherical Torus Experiment for spectral measurements in the 6–65Å spectral region. The spectrometer employed a 2400ℓ∕mm grating designed for flat-field focusing and a cryogenically cooled charge-coupled device camera for readout. The instrument was tested by recording the K-shell lines of boron, carbon, nitrogen, and oxygen, as well the L-shell lines from argon, iron, and nickel that fall into this spectral band. The observed linewidth was about 0.1Å, which corresponds to a resolving power of 400 for the CV lines. A temporal resolution as fast as 50ms was obtained.
Visible light tomography system for a high-beta field-reversed configuration plasma
Authors: Asai T. , Kiguchi T. , Takahashi T. , Matsuzawa Y. , Nogi Y.
Published: September 2006

A simple and adjustable tomographic system has been developed for studying the time evolution of the internal structure of a field-reversed configuration plasma. The optical diagnostic system consists of 35 collimators. In each collimator, a plane-convex lens made of BK7 with a focal length of 100mm collimates emissions from the plasma and focuses them onto the end of an optical-fiber tube. The collimator system gives a spatial resolution of 6mm at the center of the 0.256m diameter discharge chamber. The collimated light is transmitted through the optical-fiber tube to a photomultiplier tube (PMT) detector. In this system, the wavelength is selected by a bandpass interference filter with a central wavelength of 550nm and bandwidth of 10nm to eliminate impurities and deuterium-line spectra. The window is verified to be free of impurity lines (Matsuzawa et al., Rev. Sci. Instrum., these proceedings). Thus, only bremsstrahlung is detected by the PMTs. The 35 collimators are arranged on five holders in a fan-shaped arrangement with seven collimators per fan. A profile of the emissivity has been reconstructed by using the algebraic reconstruction technique, without any assumption regarding the symmetry of the plasma.
10-channel far-infrared polarimeter for the tokamak à configuration variable
Authors: Blanchard P. , Behn R. , Weisen H. , Zhuchkova A.
Published: September 2006

A new far-infrared polarimeter diagnostic for the tokamak à configuration variable (TCV) is under construction at CRPP. It uses two FIR lasers at 432.5μm, optically pumped by a 120W continuous wave CO2 laser. The two FIR cavities will be detuned such that the combination of the beams, using a method proposed by Dodel and Kunz [Infrared Phys. 18, 773 (1978)], produces a single beam with a linear polarization rotating at the difference frequency (set to 750kHz). For measurements across the minor radius of TCV, this beam will be split into ten beams, each equipped with a Schottky barrier diode as detector. Faraday rotation angles will be measured by coherent detection. In order to optimize the sensitivity of the polarimeter for the parameter range of interest [ne(0)<3×1019m−3], we have chosen to keep it separate from the existing 14-channel interferometer operating at 214μm. This also leads to substantial simplification of the design and signal processing. The design of the system as well as its expected sensitivity are presented and discussed. The required accuracy to measure profiles of current density and safety factor for typical operating scenarios with internal transport barriers on TCV (including cases with reversed magnetic shear) is assessed by numerical simulations.
Absolute calibration of Kodak Biomax-MS film response to x rays in the 1.5- to 8-keV energy range
Authors: Marshall F. J. , Knauer J. P. , Anderson D. , Schmitt B. L.
Published: September 2006

The absolute response of Kodak Biomax-MS film to x rays in the range from 1.5- to 8-keV has been measured using a laboratory electron-beam generated x-ray source. The measurements were taken at specific line energies by using Bragg diffraction to produce monochromatic beams of x rays. Multiple exposures were taken on Biomax MS film up to levels exceeding optical densities of 2 as measured by a microdensitometer. The absolute beam intensity for each exposure was measured with a Si(Li) detector. Additional response measurements were taken with Kodak direct exposure film (DEF) so as to compare the results of this technique to previously published calibrations. The Biomax-MS results have been fitted to a semiempirical mathematical model (Knauer et al., these proceedings). Users of the model can infer absolute fluences from observed exposure levels at either interpolated or extrapolated energies. To summarize the results: Biomax MS has comparable sensitivity to DEF film below 3keV but has reduced sensitivity above 3keV (∼50%). The lower exposure results from thinner emulsion layers, designed for use with phosphor screens. The ease with which Biomax-MS can be used in place of DEF (same format film, same developing process, and comparable sensitivity) makes it a good replacement.
Extreme luminosity imaging conical spectrograph
Authors: Pikuz S. A. , Shelkovenko T. A. , Mitchell M. D. , Chandler K. M. , Douglass J. D. , McBride R. D. , Jackson D. P. , Hammer D. A.
Published: September 2006

A new configuration for a two-dimensional (2D) imaging x-ray spectrograph based on a conically bent crystal is introduced: extreme luminosity imaging conical spectrograph (ELICS). The ELICS configuration has important advantages over spectrographs that are based on cylindrically and spherically bent crystals. The main advantages are that a wide variety of large-aperture crystals can be used, and any desired magnification in the spatial direction (the direction orthogonal to spectral dispersion) can be achieved by the use of different experimental arrangements. The ELICS can be set up so that the detector plane is almost perpendicular to the incident rays, a good configuration for time-resolved spectroscopy. ELICSs with mica crystals of 45×90mm2 aperture have been successfully used for imaging on the XP and COBRA pulsed power generators, yielding spectra with spatial resolution in 2D of Z pinches and X pinches.
Design and commissioning of a new diagnostic for routine determination of Zeff from visible bremsstrahlung measurements on TEXTOR
Authors: Verdoolaege G. , Telesca G. , Delabie E. , Van Oost G. , Team The TEXTOR
Published: September 2006

On TEXTOR a new diagnostic was commissioned for the determination of the profile of the ion effective charge Zeff from bremsstrahlung emissivity measurements in the visible. The line-integrated bremsstrahlung emissivity is measured with high spatial resolution along 28 fiber optic channels, in one poloidal cross section of the tokamak. Twenty-four channels are coupled to a cooled fast charge-coupled device (CCD) camera and four to photomultiplier tubes for higher sampling rate. The design of the diagnostic is described, including a technique for coping with CCD image smearing, without the need for the calculation of the point spread function of the system. An in-vessel calibration was performed by means of an integrating sphere. A convenient alternative way is outlined for determining the relative calibration from plasma emissivity measurements only. Bremsstrahlung emissivity profiles can be reconstructed by Abel inversion of the line integrals measured with the camera. Overestimation of edge Zeff values due to nonbremsstrahlung contributions to the continuum radiation can be minimized via Tikhonov or maximum entropy regularization. The propagation of such edge continuum contributions towards the center of the reconstructed profile is illustrated in the case of ergodization of the edge plasma.
Multichannel ultrashort pulsed radar reflectometer on LHD
Authors: Tokuzawa T. , Kawahata K. , Tanaka K. , Group LHD Experimental
Published: September 2006

An ultrashort pulsed radar reflectometer with 24 channels in the Ka band and four channels in the X band is used for the electron density profile measurements in the Large Helical Device. An ultrashort pulse has broadband frequency components. However, we have usually utilized the discrete frequency components because we apply a filter bank system in a time-of-flight measurement. To utilize the whole frequency spectrum of the impulse we apply the switching technique of the intermediate frequency signal and the frequency modulation of the local oscillator. A more detailed reconstructed electron density profile, compared to that of the previous system, is obtained by using an Abel inversion method from the profile of the delay time as a function of the probing frequency.
Measurements of impurity spectra using UV/visible spectroscopic system in a GAMMA 10 plasma
Authors: Matama K. , Yoshikawa M. , Kobayashi T. , Kubota Y. , Cho T.
Published: September 2006

Impurity spectra have been measured and identified using a newly designed ultraviolet and visible (UV/visible) spectroscopic system in the tandem mirror GAMMA 10. It is constructed using two spectrometers to obtain an entire wavelength range of UV/visible impurity spectra with a high wavelength resolution in one plasma shot. We successfully obtained the emission intensities of the radiation spectra in detail and information on the time-varying population densities of the impurities. We evaluate radiation loss from the GAMMA 10 plasma in the UV/visible range; further we estimate the electron density and temperature after applying the measured spectral intensity to a collisional-radiative model.
Laser light backscatter from intermediate and high Z plasmas
Authors: Berger R. L. , Constantin C. , Divol L. , Meezan N. , Froula D. H. , Glenzer S. H. , Suter L. J. , Niemann C.
Published: September 2006

In experiments at the Omega Laser Facility [J. M. Soures et al., Fusion Technol. 30, 492 (1996)], stimulated Brillouin backscatter (SBS) from gasbags filled with krypton and xenon gases was ten times lower than from CO2-filled gasbags with similar electron densities. The SBS backscatter was a 1%–5% for both 527 and 351nm interaction beams at an intensity of ∼1015W∕cm2. The SRS backscatter was less than 1%. The 351nm interaction beam is below the threshold for filamentation and the SBS occurs in the density plateau between the blast waves. Inverse bremsstrahlung absorption of the incident and SBS light account for the lower reflectivity from krypton than from CO2. The 527nm interaction beam filaments in the blowoff plasma before the beam propagates through the blast wave, where it is strongly absorbed. Thus, most of the 527nm SBS occurs in the flowing plasma outside the blast waves.
Photodissociation of methane: Exploring potential energy surfaces
Authors: van Harrevelt Rob
Published: September 2006

The potential energy surface for the first excited singlet state (S1) of methane is explored using multireference singles and doubles configuration interaction calculations, employing a valence triple zeta basis set. A larger valence quadruple zeta basis is used to calculate the vertical excitation energy and dissociation energies. All stationary points found on the S1 surface are saddle points and have imaginary frequencies for symmetry-breaking vibrations. By studying several two-dimensional cuts through the potential energy surfaces, it is argued that CH4 in the S1 state will distort to planar structures. Several conical intersection seams between the ground state surface S0 and the S1 surface have been identified at planar geometries. The conical intersections provide electronically nonadiabatic pathways towards products CH3(X̃A2″2)+H, CH2(ãA11)+H2, or CH2(X̃B13)+H+H. The present results thereby make it plausible that the CH3(X̃A2″2)+H and CH2(ãA11)+H2 channels are major dissociation channels, as has been observed experimentally.
Steady states of self-gravitating incompressible fluid in two dimensions
Authors: Humi Mayer
Published: September 2006

In this paper we develop a simple model for the steady state of two-dimensional self-gravitating incompressible gas which is based on the hydrodynamic equations for stratified fluid. These equations are then reduced to a system of two equations for the mass density and the gravitational field. Analytical analysis and numerical solutions of these equations under different modeling assumptions (with special attention to the isothermal case) are then used to study the structure of the resulting steady state of the fluid.
Interplay between transport barriers and density gradient
Authors: Sarazin Y. , Grandgirard V. , Dif-Pradalier G. , Garbet X. , Ghendrih Ph.
Published: September 2006

The present paper addresses two critical issues of zonal flows: the evidence of control parameters of their driving term, namely the Reynolds stress, and how they back-react on turbulence and transport. Kinetic nonlinear simulations are performed with the GYSELA code [V. Grandgirard et al., J. Comput. Phys. (to be published)], which models the slab branch of the ion temperature gradient driven instability in the four-dimensional drift-kinetic regime. First, the numerical results show that the gradient of the guiding center density, related to the general potential vorticity, is stabilizing both linearly, by increasing the instability threshold, and nonlinearly, by activating zonal flows. Accordingly, the Reynolds stress is found to scale like LΩ−2 in the quasilinear regime, LΩ being the gradient length of the guiding center density. Second, the local temperature gradient appears to increase linearly with the curvature of the zonal flows, regardless of its sign. Such behavior agrees qualitatively with a perturbative theory. Indeed, while linear eigenmodes are localized at the maximum of the temperature gradient in the absence of zonal flows, they tend to be expelled if both exhibit a maximum at the same location. In this case, the reduction mechanism of the turbulent transport results from the ability of large zonal flow curvatures to render strong temperature gradients stable with respect to perturbations.
Electron-stimulated production of molecular oxygen in amorphous solid water on Pt(111): Precursor transport through the hydrogen bonding network
Authors: Petrik Nikolay G. , Kavetsky Alexander G. , Kimmel Greg A.
Published: September 2006

The low-energy, electron-stimulated production of molecular oxygen from thin amorphous solid water (ASW) films adsorbed on Pt(111) is investigated. For ASW coverages less than ∼60 ML, the O2 electron-stimulated desorption (ESD) yield depends on coverage in a manner that is very similar to the H2 ESD yield. In particular, both the O2 and H2 ESD yields have a pronounced maximum at ∼20 ML due to reactions at the Pt/water interface. The O2 yield is dose dependent and several precursors (OH, H2O2, and HO2) are involved in the O2 production. Layered films of H216O and H218O are used to profile the spatial distribution of the electron-stimulated reactions leading to oxygen within the water films. Independent of the ASW film thickness, the final reactions leading to O2 occur at or near the ASW/vacuum interface. However, for ASW coverages less than ∼40 ML, the results indicate that dissociation of water molecules at the ASW/Pt interface contributes to the O2 production at the ASW/vacuum interface presumably via the generation of OH radicals near the Pt substrate. The OH (or possibly OH−) segregates to the vacuum interface where it contributes to the reactions at that interface. The electron-stimulated migration of precursors to the vacuum interface occurs via transport through the hydrogen bond network of the ASW without motion of the oxygen atoms. A simple kinetic model of the nonthermal reactions leading to O2, which was previously used to account for reactions in thick ASW films, is modified to account for the electron-stimulated migration of precursors.
Crystal-melt coexistence under shear: Interpreting the nonlinear rheology
Authors: Petravic Janka , Harrowell Peter
Published: September 2006

We propose a phenomenological model for shear-induced melting aimed at assisting the design of experimental studies of this phenomenon. For increasing strain rates, the model predicts the changes in liquid fraction and shear stress as a function of interfacial supercooling. We discuss the experimental conditions under which shear-induced melting could be observed in a range of materials.
Effect of finite trajectory length on the correlation function analysis of single molecule data
Authors: Lu Chun-Yaung , Vanden Bout David A.
Published: September 2006

The effect of finite trajectory length on single molecule rotational correlation functions has been studied by utilizing time series analysis and numerical simulations. Correlation functions obtained from the trajectories of length less than 100 times the correlation time constant (τℓ) exhibit significant deviations from the true correlation function. The distributions of sample time constants (τF) and stretching exponents (βF) are mapped by fitting a large number of rotational trajectories to stretched exponentials. As the trajectory length gets smaller, the distributions become broader and asymmetric and their mean values deviate from the true value predicted by pure rotational diffusion. Analysis based on higher order spherical harmonics is suggested as a method for minimizing the effect of the trajectory length. The distributions of time constants for different higher order spherical harmonics are also compared. While the focus of the paper is on rotational correlation functions, the general conclusions apply to any dynamical process that yields an exponentially decaying correlation function.
First-principles study of interaction of cluster Au32 with CO, H2, and O2
Authors: Wang Yao , Gong X. G.
Published: September 2006

First-principles calculations are performed to study the interaction of cluster Au32 with small molecules, such as CO, H2, and O2. The cagelike Au32(Ih) shows a higher chemical inertness than the amorphous Au32(C1) with respect to the interaction with small molecules CO, H2, and O2. H2 can only be physically adsorbed on Au32(Ih), while it can be dissociatively chemisorbed on Au32(C1). Although CO can be chemically adsorbed on Au32(Ih) and Au32(C1) with one electron transferred from Au32 to the antibonding π* orbit of CO, it is bound more strongly on Au32(C1) than on Au32(Ih). Spin polarized and spin nonpolarized calculations result almost identical ground state structures of Au32(Ih)–O2 and Au32(C1)–O2, in which O2 is dissociatively chemisorbed.
Relative energy of the high-(T2g5) and low-(A1g1) spin states of [Fe(H2O)6]2+, [Fe(NH3)6]2+, and [Fe(bpy)3]2+: CASPT2 versus density functional theory
Authors: Pierloot Kristine , Vancoillie Steven
Published: September 2006

High-level ab initio calculations using the CASPT2 method and extensive basis sets were performed on the energy differences of the high-[T2g5:t2g4eg2] and low-[A1g1:t2g6] spin states of the pseudo-octahedral Fe(II) complexes [Fe(H2O)6]2+, [Fe(NH3)6]2+, and [Fe(bpy)3]2+. The results are compared to the results obtained from density functional theory calculations with the generalized gradient approximation functional BP86 and two hybrid functionals B3LYP and PBE0, and serve as a calibration for the latter methods. We find that large basis set CASPT2 calculations may provide results for the high-spin/low-spin splitting ΔEHL that are accurate to within 1000cm−1, provided they are based on an adequately large CAS[10,12] reference wave function. The latter condition was found to be much more stringent for [Fe(bpy)3]2+ than for the other two complexes. Our “best” results for ΔEHL (including a zero-point energy correction) are −17690cm−1 for [Fe(H2O)6]2+, −8389cm−1 for [Fe(NH3)6]2+, and 3820cm−1 for [Fe(bpy)3]2+.
Intermolecular interactions of nitrobenzene-benzene complex and nitrobenzene dimer: Significant stabilization of slipped-parallel orientation by dispersion interaction
Authors: Tsuzuki Seiji , Honda Kazumasa , Uchimaru Tadafumi , Mikami Masuhiro
Published: September 2006

The CCSD(T) level interaction energies of eight orientations of nitrobenzene-benzene complexes and nine orientations of nitrobenzene dimers at the basis set limit have been estimated. The calculated interaction energy of the most stable slipped-parallel (Cs) nitrobenzene-benzene complex was −4.51kcal∕mol. That of the most stable slipped-parallel (antiparallel) (C2h) nitrobenzene dimer was −6.81kcal∕mol. The interaction energies of these complexes are significantly larger than that of the benzene dimer. The T-shaped complexes are substantially less stable. Although nitrobenzene has a polar nitro group, electrostatic interaction is always considerably weaker than the dispersion interaction. The dispersion interaction in these complexes is larger than that in the benzene dimer, which is the cause of the preference of the slipped-parallel orientation in these complexes.
Global temperature change
Authors: Hansen James , Sato Makiko , Ruedy Reto , Lo Ken , Lea David W. , Medina-Elizade Martin
Published: September 2006

Global surface temperature has increased ≈0.2°C per decade in the past 30 years, similar to the warming rate predicted in the 1980s in initial global climate model simulations with transient greenhouse gas changes. Warming is larger in the Western Equatorial Pacific than in the Eastern Equatorial Pacific over the past century, and we suggest that the increased West–East temperature gradient may have increased the likelihood of strong El Niños, such as those of 1983 and 1998. Comparison of measured sea surface temperatures in the Western Pacific with paleoclimate data suggests that this critical ocean region, and probably the planet as a whole, is approximately as warm now as at the Holocene maximum and within ≈1°C of the maximum temperature of the past million years. We conclude that global warming of more than ≈1°C, relative to 2000, will constitute “dangerous” climate change as judged from likely effects on sea level and extermination of species.
Children's environmental health: Why should social disparities be considered?
Authors: KOHLHUBER MARTINA , HEINRICH JOACHIM , VAN DEN HAZEL PETER , ZUURBIER MONIEK , BISTRUP MARIE LOUISE , KOPPE JANNA G. , BOLTE GABRIELE
Published: September 2006

Background/Methods: The aim of workpackage 5 ‘Environmental exposures and children's health: impact of socioeconomic factors’ in the EU‐funded network PINCHE (Policy Interpretation Network on Children's Health and Environment) was to review and interpret the current knowledge of social inequalities in environmental exposures and children's health. Socioeconomic factors may impact on children's environmental health in two ways: 1) environmental exposures may differ according to socioeconomic status; 2) given a certain level of harmful environmental exposure, socioeconomic factors may modify the health effects by influencing the susceptibility characteristics of children. Results: There is a lack of information to evaluate and quantify the effect of socioeconomic factors on environmental exposures and children's health in Europe. In most circumstances there seems to be an inverse social gradient with increased burden concerning exposures and health outcomes in children of lower social status.

Conclusions: There is a need to improve research on social inequalities in children's health and environment. Because of the complexity, integrated approaches and a combination of different intervention measures and policies are necessary to reduce environmental exposure and adverse health effects in children. Paediatricians may contribute to improvement of children's environmental health by risk communication and health advocacy at community and governmental level.
PINCHE's policy recommendations on noise: How to prevent noise from adversely affecting children
Authors: BISTRUP MARIE LOUISE , BABISCH WOLFGANG , STANSFELD STEPHEN , SULKOWSKI WIESLAW
Published: September 2006

Background: Noise can have auditory and non‐auditory effects on children. Very few noise episodes affect children's hearing instantaneously; most effects are long‐term and cumulative. Describing the risks of noise on children's health and well‐being in a life‐course perspective can illustrate the prospects of cumulative effects.

Conclusion: The policy recommendations the Policy Interpretation Network on Children's Health and Environment (PINCHE) prepared for each age group or setting are described here.
Policy interpretation network on children's health and environment
Authors: VAN DEN HAZEL PETER , ZUURBIER MONIEK , BISTRUP MARIE LOUISE
Published: September 2006

Aim: The main objective of PINCHE is to provide policy recommendations aiming at protecting children's health and environment based on completed scientific research. The project focused on four themes: indoor and outdoor air pollutants, carcinogens, neurotoxicants, and noise. The data were evaluated in workpackages on exposure assessment, epidemiology, toxicology, and risk and health impact assessment. The data were analysed according to a framework of questions. The workpackage on socioeconomic factors studied the influence of socioeconomic status on exposures and on health effects. In the workpackage on science‐policy interface, recommendations on how to improve children's environmental health were formulated. Results: The policy recommendations resulting from the analysis were grouped according to relevant policy levels: European Commission or the European Parliament, member states and other stakeholders at regional or local level. These recommendations are general guidelines for taking action. Regional differences and variation must be reflected when policy is actually implemented. In addition, recommendations related to education and personal behaviour are presented in the reports.

Conclusions: The policy recommendations are important input for policy advisers, policy makers and public health authorities at all policy levels. The recommendations are also of direct relevance to interest groups, such as environmental NGOs including child health and advocacy groups. The policy recommendations for each policy level were prioritized. High priorities were given to reduce exposure to environmental tobacco smoke, transport related air pollution, indoor air and mercury.
Paediatric environmental health history taking: Why bother?
Authors: TUSSCHER GAVIN W. TEN , LEIJS MARIKE M. , KOPPE JANNA G.
Published: September 2006

Environmental health history taking is often not part of standard medical history taking for clinical physicians. During recent years attention has been placed on home environments and asthma and allergies, high caloric intake and obesity and type 2 diabetes mellitus, yet environmental health history taking still remains relatively uncharted terrain for the clinical physicians of today. While the reasons for this are certainly varied, ignorance of environmental influences, ignorance of environmental pollutants, politics and prejudices will certainly play a role. We suggest a simple manner of environmental health history taking, and discuss the importance of the subject in our modern‐day clinical practice.
Children's exposure to polybrominated diphenyl ethers
Authors: ZUURBIER MONIEK , LEIJS MARIKE , SCHOETERS GREET , TUSSCHER GAVIN Ten , KOPPE JANNA G.
Published: September 2006

Background: Polybrominated biphenyl ethers (PBDEs), a class of brominated flame retardants, are frequently used in consumer products. PBDEs levels in environmental and human samples have increased in recent decades. Children are exposed to PBDEs through diet, mainly through fish, meat and milk. Total dietary exposure of children in Europe was calculated to be 2–3 ng/kg b.w./day. For nursing infants the main source of PBDE exposure is breast milk; exposure levels are around 15 ng/kg b.w./day. PBDE exposure levels in North America are 10 to a 100 times higher. Because of their persistence and their similarity to polychlorinated biphenyls (PCBs), concern has been raised about the effects of PBDEs on human health. Exposure to penta‐ and octa‐BDE led to learning impairment and impaired motor behaviour in rodents. Exposure to penta‐, octa‐ and also deca‐BDE caused effects on thyroid homeostasis in animals.

Conclusions: The EU has banned the production and use of penta‐ and octa‐BDE since 2004; however, exposure will continue during the coming decades. Based upon current toxicological evidence, human exposure to deca‐BDEs is not expected to lead to health effects, but data on exposure to deca‐BDE and data on toxicity of deca‐BDE are scarce. Therefore, monitoring studies and toxicity studies on deca‐BDEs and other BDEs should continue.
Policy and science in children's health and environment: Recommendations from the PINCHE project
Authors: VAN DEN HAZEL PETER , ZUURBIER MONIEK , BISTRUP MARIE LOUISE , BUSBY CHRIS , FUCIC ALEKSANDRA , KOPPE JANNA G. , LUNDQVIST CHRISTOFER , RONCHETTI ROBERTO , TUSSCHER GAVIN TEN
Published: September 2006

Background: Policy recommendations result from the discussions and analysis of the present situation in environment and health. Such analysis was performed in PINCHE. This led to recommendations based on the scientific literature. In the field of children's environmental health the policy process will follow more or less fixed rules, but this process is still at an early level of development. The link between science and policy still faces many challenges. Scientific assessment of environmental risk must recognize and tackle the problems of data sets, variability of human and environmental systems, the range, spatial and temporal diffusion of potential health effects and many biases and confounding factors. Results: The PINCHE network recommends a general improvement of the supporting scientific fields in environment and health. Assessments from epidemiology or toxicology should play a key role in influencing science‐policy decisions in programmes that are intended to inform the public policy process. Scientific committees at a local level could play a role. The relation between health and environment needs to be better incorporated in training and education. There is a need for harmonization of data production and use. The priorities in PINCHE focus on the most important issues. A classification of low, medium or high priority for action was used to describe a range of different environmental stressors.

Conclusions: PINCHE provided recommendations to reduce exposure for children. Exposure reduction is not always linked to improved health in the short term, but it will reduce the body burden of accumulating chemicals in children. A strategic choice is reduction of exposure of children to compounds by changing production techniques or by increasing the distance of child specific settings to sources. The contribution of all players in the production, distribution and use of scientific knowledge in the field of children's environmental health is necessary.
A novel role for phagocytosis-like uptake in herpes simplex virus entry
Authors: Clement Christian , Tiwari Vaibhav , Scanlan Perry M. , Valyi-Nagy Tibor , Yue Beatrice Y.J.T. , Shukla Deepak
Published: September 2006

It is becoming increasingly clear that herpesviruses can exploit the endocytic pathway to infect cells, yet several important features of this process remain poorly defined. Using herpes simplex virus-1 (HSV-1) as a model, we demonstrate that endocytosis of the virions mimic many features of phagocytosis. During entry, HSV-1 virions associated with plasma membrane protrusions followed by a phagocytosis-like uptake involving rearrangement of actin cytoskeleton and trafficking of the virions in large phagosome-like vesicles. RhoA GTPase was activated during this process and the mode of entry was cell type–specific. Clathrin-coated vesicles had no detectable role in virion trafficking as Eps15 dominant-negative mutants failed to affect HSV-1 uptake. Binding and fusion of the virion envelope with the phagosomal membrane is likely facilitated by clustering of nectin-1 (or HVEM) in phagosomes, which was observed in infected cells. Collectively, our data suggests a novel mode of uptake by which the virus can infect both professional and nonprofessional phagocytes.
SUSP1 antagonizes formation of highly SUMO2/3-conjugated species
Authors: Mukhopadhyay Debaditya , Ayaydin Ferhan , Kolli Nagamalleswari , Tan Shyh-Han , Anan Tadashi , Kametaka Ai , Azuma Yoshiaki , Wilkinson Keith D. , Dasso Mary
Published: September 2006

Small ubiquitin-related modifier (SUMO) processing and deconjugation are mediated by sentrin-specific proteases/ubiquitin-like proteases (SENP/Ulps). We show that SUMO-specific protease 1 (SUSP1), a mammalian SENP/Ulp, localizes within the nucleoplasm. SUSP1 depletion within cell lines expressing enhanced green fluorescent protein (EGFP) fusions to individual SUMO paralogues caused redistribution of EGFP-SUMO2 and -SUMO3, particularly into promyelocytic leukemia (PML) bodies. Further analysis suggested that this change resulted primarily from a deficit of SUMO2/3-deconjugation activity. Under these circumstances, PML bodies became enlarged and increased in number. We did not observe a comparable redistribution of EGFP-SUMO1. We have investigated the specificity of SUSP1 using vinyl sulfone inhibitors and model substrates. We found that SUSP1 has a strong paralogue bias toward SUMO2/3 and that it acts preferentially on substrates containing three or more SUMO2/3 moieties. Together, our findings argue that SUSP1 may play a specialized role in dismantling highly conjugated SUMO2 and -3 species that is critical for PML body maintenance.