bluuebunny/crossref_metadata_2025 huggingface dataset:
Observed seasonal to decadal scale responses in mesospheric water vapor
Authors: Remsberg Ellis
Published: March 2010

The 14 year (1991–2005) time series of mesospheric water vapor from the Halogen Occultation Experiment (HALOE) are analyzed using multiple linear regression (MLR) techniques for their seasonal and longer‐period terms from 45°S to 45°N. The distribution of annual average water vapor shows a decrease from a maximum of 6.5 ppmv at 0.2 hPa to about 3.2 ppmv at 0.01 hPa, in accord with the effects of the photolysis of water vapor due to the Lyman‐α flux. The distribution of the semiannual cycle amplitudes is nearly hemispherically symmetric at the low latitudes, while that of the annual cycles shows larger amplitudes in the Northern Hemisphere. The diagnosed 11 year, or solar cycle, max minus min, water vapor values are of the order of several percent at 0.2 hPa to about 23% at 0.01 hPa. The solar cycle terms have larger values in the Northern than in the Southern Hemisphere, particularly in the middle mesosphere, and the associated linear trend terms are anomalously large in the same region. Those anomalies are due, at least in part, to the fact that the amplitudes of the seasonal cycles were varying at northern midlatitudes during 1991–2005, while the corresponding seasonal terms of the MLR model do not allow for that possibility. Although the 11 year variation in water vapor is essentially hemispherically symmetric and antiphased with the solar cycle flux near 0.01 hPa, the concurrent temperature variations produce slightly colder conditions at the northern high latitudes at solar minimum. It is concluded that this temperature difference is most likely the reason for the greater occurrence of polar mesospheric clouds at the northern versus the southern high latitudes at solar minimum during the HALOE time period.
On pressure measurement and seasonal pressure variations during the Phoenix mission
Authors: Taylor Peter A. , Kahanpää Henrik , Weng Wensong , Akingunola Ayodeji , Cook Clive , Daly Mike , Dickinson Cameron , Harri Ari‐Matti , Hill Darren , Hipkin Victoria , Polkko Jouni , Whiteway Jim
Published: March 2010

In situ surface pressures measured at 2 s intervals during the 150 sol Phoenix mission are presented and seasonal variations discussed. The lightweight Barocap®/Thermocap® pressure sensor system performed moderately well. However, the original data processing routine had problems because the thermal environment of the sensor was subject to more rapid variations than had been expected. Hence, the data processing routine was updated after Phoenix landed. Further evaluation and the development of a correction are needed since the temperature dependences of the Barocap sensor heads have drifted after the calibration of the sensor. The inaccuracy caused by this appears when the temperature of the unit rises above 0°C. This frequently affects data in the afternoons and precludes a full study of diurnal pressure variations at this time. Short‐term fluctuations, on time scales of order 20 s are unaffected and are reported in a separate paper in this issue. Seasonal variations are not significantly affected by this problem and show general agreement with previous measurements from Mars. During the 151 sol mission the surface pressure dropped from around 860 Pa to a minimum (daily average) of 724 Pa on sol 140 (Ls 143). This local minimum occurred several sols earlier than expected based on GCM studies and Viking data. Since battery power was lost on sol 151 we are not sure if the timing of the minimum that we saw could have been advanced by a low‐pressure meteorological event. On sol 95 (Ls 122), we also saw a relatively low‐pressure feature. This was accompanied by a large number of vertical vortex events, characterized by short, localized (in time), low‐pressure perturbations.
How strong are lunar crustal magnetic fields at the surface?: Considerations from a reexamination of the electron reflectometry technique
Authors: Halekas J. S. , Lillis R. J. , Lin R. P. , Manga M. , Purucker M. E. , Carley R. A.
Published: March 2010

Despite extensive study, we do not yet fully understand the origins of the unique lunar crustal magnetism. The strength of surface fields and their relation to local geology are crucial pieces of the puzzle. However, only a few surface measurements exist, and spacecraft magnetometers cannot detect magnetization with wavelengths much smaller than the orbital altitude. Meanwhile, electron reflectometry (ER) enables a remote measurement of surface fields, but its sensitivity to magnetization with different spatial scales is not well understood. In this paper, we report on new simulations of the ER technique and its sensitivity to magnetic fields produced by simulated crustal magnetization with various strengths and spatial distributions, utilizing full particle tracing simulations and the same data analysis techniques used for space data. We find that the ER technique reliably detects surface fields from magnetization with wavelengths larger than ∼10 km but has increasingly less sensitivity to smaller wavelengths. Since the few surface measurements we have imply very incoherent near‐surface magnetization, this implies that the ER technique may seriously underestimate the strength of lunar fields in some areas. Our results imply that small‐scale impact‐related crustal magnetization may prove even more important than previously thought.
Structural reform and productivity in the water and wastewater industry: Emerging issues
Authors: Abbott Malcolm , Cohen Bruce
Published: March 2010

Over the past 2 decades there has been a range of reforms to the structure of the water supply and wastewater industries around the world. As yet these reforms have not been as extensive, or as uniform, as in other utilities such as telecommunications, gas, and electricity supply. One focus of reform has been to enhance the structure of water supply and wastewater industries to improve levels of productivity and efficiency while at the same time maintaining environmental and water quality standards, providing affordable access to clean water and encouraging innovation and improvement in service delivery. Now, however, a changing climate, new technologies, and greater emphasis on environmental impacts of supply from traditional sources are creating forces which are requiring a rethinking of traditional water and wastewater industry structures. The purpose of this paper is to examine emerging issues that confront the structure of the water and wastewater industries and to assess them in light of the findings of productivity and efficiency analysis undertaken to date. In doing so, this paper considers how industry structure may impact upon, and be influenced by, the dual achievement of both economic efficiency and issues such as water quality standards, environmental outcomes, innovation, and social goals in an evolving industry environment.
In Memoriam
Authors: Anonymous
Published: March 2010

Ken Olsen, 80, 15 February 2010, Tectonophysics, 1965

William W. Patton, 86, 2 June 2009, Tectonophysics, 1973
Importance of regions outside the cytoplasmic tail of G-protein-coupled receptors for phosphorylation and dephosphorylation
Authors: Gehret Austin U. , Hinkle Patricia M.
Published: March 2010

Two GPCRs (G-protein-coupled receptors), TRHR (thyrotropin-releasing hormone receptor) and β2AR (β2-adrenergic receptor), are regulated in distinct manners. Following agonist binding, TRHR undergoes rapid phosphorylation attributable to GRKs (GPCR kinases); β2AR is phosphorylated by both second messenger-activated PKA (protein kinase A) and GRKs with slower kinetics. TRHR co-internalizes with arrestin, whereas β2AR recruits arrestin, but internalizes without it. Both receptors are dephosphorylated following agonist removal, but TRHR is dephosphorylated much more rapidly while it remains at the plasma membrane. We generated chimaeras swapping the C-terminal domains of these receptors to clarify the role of different receptor regions in phosphorylation, internalization and dephosphorylation. β2AR with a TRHR cytoplasmic tail (β2AR–TRHR) and TRHR with a β2AR tail (TRHR–β2AR) signalled to G-proteins normally. β2AR–TRHR was phosphorylated well at the PKA site in the third intracellular loop, but poorly at GRK sites in the tail, whereas TRHR–β2AR was phosphorylated strongly at GRK sites in the tail (Ser355/Ser356 of the β2AR). Both chimaeric receptors exhibited prolonged, but weak, association with arrestin at the plasma membrane, but high-affinity arrestin interactions and extensive co-internalization of receptor with arrestin required a phosphorylated TRHR tail. In contrast, swapping C-terminal domains did not change the rates of phosphorylation and dephosphorylation or the dependence of TRHR dephosphorylation on the length of agonist exposure. Thus the interactions of GPCRs with GRKs and phosphatases are determined not simply by the amino acid sequences of the substrates, but by regions outside the cytoplasmic tails.
Tetrahydrobiopterin supplementation reduces atherosclerosis and vascular inflammation in apolipoprotein E-knockout mice
Authors: Schmidt Tim S. , McNeill Eileen , Douglas Gillian , Crabtree Mark J. , Hale Ashley B. , Khoo Jeffrey , O'Neill Charles A. , Cheng Alphonsus , Channon Keith M. , Alp Nicholas J.
Published: March 2010

BH4 (tetrahydrobiopterin) supplementation improves endothelial function in models of vascular disease by maintaining eNOS (endothelial nitric oxide synthase) coupling and NO (nitric oxide) bioavailability. However, the cellular mechanisms through which enhanced endothelial function leads to reduced atherosclerosis remain unclear. We have used a pharmaceutical BH4 formulation to investigate the effects of BH4 supplementation on atherosclerosis progression in ApoE-KO (apolipoprotein E-knockout) mice. Single oral dose pharmacokinetic studies revealed rapid BH4 uptake into plasma and organs. Plasma BH4 levels returned to baseline by 8 h after oral dosing, but remained markedly increased in aorta at 24 h. Daily oral BH4 supplementation in ApoE-KO mice from 8 weeks of age, for a period of 8 or 12 weeks, had no effect on plasma lipids or haemodynamic parameters, but significantly reduced aortic root atherosclerosis compared with placebo-treated animals. BH4 supplementation significantly reduced VCAM-1 (vascular cell adhesion molecule 1) mRNA levels in aortic endothelial cells, markedly reduced the infiltration of T-cells, macrophages and monocytes into plaques, and reduced T-cell infiltration in the adjacent adventitia, but importantly had no effect on circulating leucocytes. GCH (GTP cyclohydrolase I)-transgenic mice, with a specific increase in endothelial BH4 levels, exhibited a similar reduction in vascular immune cell infiltration compared with BH4-deficient controls, suggesting that BH4 reduces vascular inflammation via endothelial cell signalling. In conclusion, BH4 supplementation reduces vascular immune cell infiltration in atherosclerosis and may therefore be a rational therapeutic approach to reduce the progression of atherosclerosis.
Gyrokinetic equations in an extended ordering
Authors: Dimits Andris M.
Published: March 2010

A gyrokinetic theory has been developed in an extended ordering in which the small parameter is the ratio of the E×B shearing rate to the gyrofrequency. This allows for long wavelength E×B flows of order of the thermal velocity, instead of the more restrictive standard orderings which either require that the electrostatic potential or the E×B flow velocity be small compared with the thermal levels. This theory generalizes prior work to allow for time dependence in the large long-wavelength component of the electric field and a continuum of scales in the field components rather than just two distinct components. In the new theory, a significant part of the polarization drift now resides in the equations of motion. However, there is still an identifiable polarization density that can be used to solve for the electrostatic potential from a quasineutrality or vorticity equation. The present derivation is carried out for the case of electrostatic perturbations and a slab equilibrium magnetic field, as this is sufficient and most clear for demonstrating the new results and issues associated specifically with the extended ordering.
Temperature dependent thermal conductivity of polycrystalline ZnO films
Authors: Alvarez-Quintana J. , Martínez E. , Pérez-Tijerina E. , Pérez-García S. A. , Rodríguez-Viejo J.
Published: March 2010

We report on measurements of the thermal conductivity of atomic layer deposited polycrystalline zinc oxide (ZnO) films between 30 and 300 K. The room temperature thermal conductivity of the films is found to be twofold less than that of single-crystal ZnO. The maximum thermal conductivities of the polycrystalline samples occur at about 60 K and their values are almost an order of magnitude lower than bulk ZnO. The effect of the grain size and the transparency of the intergrain boundary on the thermal conductivity are analyzed within the framework of the phonon-hopping transport model.
H
1
and L7i nuclear magnetic resonance study of the superionic crystals K4LiH3(SO4)4 and (NH4)4LiH3(SO4)4
Authors: Lim Ae Ran , Shin Hongkee
Published: March 2010

We have investigated the temperature dependences of the line shape, spin-lattice relaxation time, T1, and spin-spin relaxation time, T2, of the H1 and L7i nuclei in K4LiH3(SO4)4 and (NH4)4LiH3(SO4)4 single crystals. We compared the nuclear magnetic resonance (NMR) results obtained for the two crystals. According to the NMR relaxation results, the influences of the H and Li atoms of K4LiH3(SO4)4 crystals on the superionic phase transition TS are not significant, whereas the influences of the H and Li atoms of (NH4)4LiH3(SO4)4 crystals on TS are significant. The increase in the relaxation time of the hydrogen-bond protons in (NH4)4LiH3(SO4)4 crystals above TS indicates that the breaking of O–H⋯O bonds and the formation of new H-bonds with HSO4− contribute significantly to their high temperature conductivity. The main contribution to this conductivity at high temperatures is the mobility of the hydrogen-bond protons.
Growth, structure, and mechanical properties of hydrogenated amorphous carbon nitride films deposited by CH3CN dielectric barrier discharges
Authors: Niu Jinhai , Liu Dongping , Cai Haibo , Liu Yang , Cui Suolin
Published: March 2010

Hydrogenated amorphous carbon nitride (a-C:N:H) films were synthesized with CH3CN dielectric barrier discharges (DBD) plasmas. The effects of varying the CH3CN pressure (p) and the frequency of the power supply (f) on the film growth and film properties were studied. The deposited films were characterized using Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy (AFM), and AFM-based nanoindentation. p and f were found to significantly influence the structures, compositions, deposition rates, surface roughness, and nanohardess of deposited a-C:N:H films. The experimental results indicate that dense a-C:N:H films with extremely low surface roughness (rms<1.0 nm) can be deposited with CH3CN DBD plasmas at f=1 kHz and p=∼100 Pa. The deposition systems were in situ characterized by means of optical emission spectroscopy. The emission intensities of major radicals, such as CN (B Σ2→X Σ2) and NH (A Π3→X Σ3) significantly increased with increasing f or decreasing p. N2 molecules were formed in the residual gas as a stable product, which leads to a decrease in the N/C ratio in deposited a-C:N:H films. The rotational and vibrational temperature of N2 C Π3 states in CH3CN and N2 DBD plasmas were examined and the N2 molecules produced in CH3CN DBD plasmas had the rotational temperature of ∼2000 K and vibrational temperature of ∼500 K. In the N2 DBD plasma, the rotational and vibrational temperature of the N2 molecules were 470±10 and 2850±50 K, respectively. The basic chemical reactions in the gas phase are presented and correlations between the film properties, the gas-phase plasma diagnostic data, and the film growth processes are discussed.
On the renormalization of the complex scalar free field theory
Authors: Ferrari Ruggero
Published: March 2010

Polar coordinates are used for the complex scalar free field in D=4 dimensions. The resulting nonrenormalizable theory is healed by using a recently proposed symmetric subtraction procedure. The existence of the coordinate transformation is proved by construction.
Monte Carlo study of the electrothermal phenomenon in silicon-on-insulator and silicon-germanium-on-insulator metal-oxide field-effect transistors
Authors: Sadi Toufik , Kelsall Robert W.
Published: March 2010

Self-heating effects are investigated in silicon-on-insulator (SOI), silicon-germanium-on-insulator (SGOI), and strained-silicon-directly-on-insulator (SSDOI) metal-oxide field-effect transistors (MOSFETs), using a Monte Carlo simulator self-consistently coupled with the solution of the heat diffusion equation. Although the influence of thermal effects is in general higher in these structures, as compared to bulk Si MOSFETs, its impact is much more important in SGOI and SSDOI FET structures incorporating ultrathin Si channels, with SGOI FETs giving the worst thermal performance. A study of the dependence of the extent of self-heating on the buried-oxide thickness is also performed, showing that this parameter is important in designing SOI structures with better thermal management.
Kinetic theory of instability-enhanced collisional effects
Authors: Baalrud S. D. , Callen J. D. , Hegna C. C.
Published: March 2010

The Bogoliubov–Born–Green–Kirkwood–Yvon (BBGKY) hierarchy is used to derive a generalization of the Lenard–Balescu plasma kinetic equation that accounts for wave-particle scattering due to instabilities that originate from discrete particle motion. Application to convective instabilities is emphasized for which the growing waves either propagate out of the domain of interest or modify the particle distribution to reduce the instability amplitude before nonlinear amplitudes are reached. Two such applications are discussed: Langmuir’s paradox and determining the Bohm criterion for multiple ion species plasmas. In these applications, collisions are enhanced by ion-acoustic and ion-ion two-stream instabilities, respectively. The relationship between this kinetic theory and quasilinear theory is discussed.
High resolution magnetostriction measurements in pulsed magnetic fields using fiber Bragg gratings
Authors: Daou Ramzy , Weickert Franziska , Nicklas Michael , Steglich Frank , Haase Ariane , Doerr Mathias
Published: March 2010

We report on a new high resolution apparatus for measuring magnetostriction suitable for use at cryogenic temperatures in pulsed high magnetic fields which we have developed at the Hochfeld-Magnetlabor Dresden. Optical fiber strain gauges based on fiber Bragg gratings are used to measure the strain in small (∼1 mm) samples. We describe the implementation of a fast measurement system capable of resolving strains in the order of 10−7 with a full bandwidth of 47 kHz, and demonstrate its use on single crystal samples of GdSb and GdSi.
Rotationally resolved spectroscopy of the Ã A21←X̃ B21 transition of H2S+ above the barrier to linearity using the mass-analyzed threshold ionization photofragment excitation technique
Authors: Han Songhee , Kang Tae Yeon , Kim Sang Kyu
Published: March 2010

The Ã A21←X̃ B21 transitions of H2S+ above the barrier to linearity have been investigated with the energy resolution high enough to identify individual rotational transition lines for the first time. The rotational cooling of the cation is achieved either by the direct ionization or mass-analyzed threshold ionization (MATI) technique employed in the vacuum-ultraviolet laser excitation of the jet-cooled H2S. Subsequent photoexcitation leads to the H2S+→H2+S+ dissociation and the S+ product yield taken as a function of the excitation energy gives the photofragment excitation (PHOFEX) spectra. The combined use of MATI and PHOFEX techniques greatly simplifies the spectrum allowing the accurate identification of the rotationally resolved bands which is otherwise a formidable task due to the intrinsic complexity of the Ã A21←X̃ B21 transition. Highly excited states of Ã(0,7,0), Ã(0,8,0), and Ã(0,9,0) vibronic levels with different K quantum numbers which are located above the barrier to linearity are thoroughly investigated. The bent-to-quasilinear transition of H2S+ above the barrier to linearity shows the characteristics of the Renner–Teller effect, showing the large A rotational constant and strong intensity borrowing of the highly vibrationally excited ground levels such as X̃(0,23,0) or X̃(0,24,0) in the dipole-allowed excitation. Spectroscopic parameters of term values, rotational, and spin-orbit coupling constants are precisely determined in this work, providing the most quantitative spectroscopic structure of the H2S+ to date. Quantum-state dependent photodissociation dynamics are also discussed from spectral features of PHOFEX.
Note: The full function test explosive generator
Authors: Reisman D. B. , Javedani J. B. , Griffith L. V. , Ellsworth G. F. , Kuklo R. M. , Goerz D. A. , White A. D. , Tallerico L. J. , Gidding D. A. , Murphy M. J. , Chase J. B.
Published: March 2010

We have conducted three tests of a new pulsed power device called the full function test. These tests represented the culmination of an effort to establish a high energy pulsed power capability based on high explosive pulsed power (HEPP) technology. This involved an extensive computational modeling, engineering, fabrication, and fielding effort. The experiments were highly successful and a new U.S. record for magnetic energy was obtained.
Identification of characteristic components in frequency domain from signal singularities
Authors: Miao Qiang , Wang Dong , Huang Hong-Zhong
Published: March 2010

In rotating machinery condition monitoring, identification of characteristic components is fundamental in many engineering applications so as to obtain fault sensitive features for fault detection and diagnosis. This paper proposed a novel method for the identification of characteristic components in frequency domain based on singularity analysis. In this process, Lipschitz exponent function is constructed from the signal through wavelet-based singularity analysis. In order to highlight the periodic phenomena, autocorrelation transform is employed to extract the periodic exponents and Fourier transform is used to map the time-domain information into frequency domain. Case study with rolling element bearing vibration data shows that the proposed has very excellent capability for the identification of characteristic components compared with traditional methods.
Statistics of polymer adsorption under shear flow
Authors: He Gui-Li , Messina René , Löwen Hartmut
Published: March 2010

Using nonequilibrium Brownian dynamics computer simulations, we have investigated the steady state statistics of a polymer chain under three different shear environments: (i) linear shear flow in the bulk (no interfaces), (ii) shear vorticity normal to the adsorbing interface, and (iii) shear gradient normal to the adsorbing interface. The statistical distribution of the chain end-to-end distance and its orientational angles are calculated within our computer simulations. Over a wide range of shear rates, this distribution can be mapped onto a simple theoretical finite-extensible-nonlinear-elastic dumbbell model with fitted anisotropic effective spring constants. The tails of the angular distribution functions are consistent with scaling predictions borrowed from the bulk dumbbell model. Finally, the frequency of the characteristic periodic tumbling motion has been investigated by simulation as well and was found to be sublinear with the shear rate for the three setups, which extends earlier results done in experiments and simulations for free and tethered polymer molecules without adsorption.
High resolution laser beam induced current images under trichromatic laser radiation: Approximation to the solar irradiation
Authors: Navas F. J. , Alcántara R. , Fernández-Lorenzo C. , Martín-Calleja J.
Published: March 2010

A laser beam induced current (LBIC) map of a photoactive surface is a very useful tool when it is necessary to study the spatial variability of properties such as photoconverter efficiency or factors connected with the recombination of carriers. Obtaining high spatial resolution LBIC maps involves irradiating the photoactive surface with a photonic beam with Gaussian power distribution and with a low dispersion coefficient. Laser emission fulfils these characteristics, but against it is the fact that it is highly monochromatic and therefore has a spectral distribution different to solar emissions. This work presents an instrumental system and procedure to obtain high spatial resolution LBIC maps in conditions approximating solar irradiation. The methodology developed consists of a trichromatic irradiation system based on three sources of laser excitation with emission in the red, green, and blue zones of the electromagnetic spectrum. The relative irradiation powers are determined by either solar spectrum distribution or Planck’s emission formula which provides information approximate to the behavior of the system if it were under solar irradiation. In turn, an algorithm and a procedure have been developed to be able to form images based on the scans performed by the three lasers, providing information about the photoconverter efficiency of photovoltaic devices under the irradiation conditions used. This system has been checked with three photosensitive devices based on three different technologies: a commercial silicon photodiode, a commercial photoresistor, and a dye-sensitized solar cell. These devices make it possible to check how the superficial quantum efficiency has areas dependent upon the excitation wavelength while it has been possible to measure global incident photon-to-current efficiency values approximating those that would be obtained under irradiation conditions with sunlight.
Al
4
−
cluster anion: Electronic structure, excited states, and electron detachment
Authors: Sommerfeld Thomas
Published: March 2010

Full-valence complete-active-space self-consistent-field and coupled-cluster methods are used to investigate excitation and electron detachment energies of the Al4− cluster anion. Both, Al4 and Al4−, have electronic structures with many low-energy electron configurations and exhibit accordingly pronounced configuration mixing. The complete-active-space self-consistent-field calculations show that all low-energy states of the neutral and the cluster anion can nevertheless be characterized by a single configuration, and in contrast to Møller–Plesset perturbation theory, coupled-cluster methods are found to recover enough static correlation to describe these states accurately. Coupled-cluster methods are then used to find minimal-energy structures of four states of the anion and four states of the neutral cluster, the respective ground states are identified, and vertical and adiabatic detachment energies are computed. The computed vertical detachment energies suggest that the first peak in the experimental photoelectron spectrum consists of at least three different transitions, and the computed excitation energies corroborate the conclusions from the analysis of the recently observed delayed detachment from excited Al4− ions in an electrostatic trap.
Validation of density-functional versus density-functional+U approaches for oxide ultrathin films
Authors: Barcaro Giovanni , Thomas Iorwerth Owain , Fortunelli Alessandro
Published: March 2010

A comparison between available experimental information and the predictions of density-functional and density-functional+U approaches is presented for oxide ultrathin films grown on single-crystal metal surfaces. Prototypical examples of monolayer phases of an ionic oxide (ZnO), a late transition metal oxide (NiO), and an early transition metal oxide (TiO2) are considered. The aim is to validate the theoretical approaches, focusing on the prediction of structural features and the reproduction of scanning tunneling microscopy images, rationalized in terms of the local density of states of the systems. It is found that it is possible to reasonably estimate the optimal lattice constant of ultrathin supported films and that the inclusion of the Hubbard U term appreciably improves the accuracy of theoretical predictions, especially in the case of nonpolar ultrathin phases of a transition metal oxide. Moreover, the optimal value of U for the oxide layer at the interface with the metal support is found to differ from that appropriate for the bulk oxide, as a consequence of the intermixing of oxide and support electronic states and screening effects.
Multilayered graphene used as anode of organic light emitting devices
Authors: Sun T. , Wang Z. L. , Shi Z. J. , Ran G. Z. , Xu W. J. , Wang Z. Y. , Li Y. Z. , Dai L. , Qin G. G.
Published: March 2010

In this report, we find multilayered graphene, which has good transparency, conductivity and suitable work function, can be used as the anode for the organic light emitting device. Our device structure is Al/glass/multilayered graphene/V2O5/NPB/CBP:(ppy)2Ir(acac)/Bphen/Bphen:Cs2CO3/Sm/Au. The maximum luminance efficiency and maximum power efficiency reach 0.75 cd/A and 0.38 lm/W, respectively. We believe that by optimizing the hole density and uniforming the thickness of the multilayered graphene anode, the device efficiency can be remarkably increased in the future.
A cold atom pyramidal gravimeter with a single laser beam
Authors: Bodart Q. , Merlet S. , Malossi N. , Dos Santos F. Pereira , Bouyer P. , Landragin A.
Published: March 2010

We demonstrate a scheme for realizing a compact cold atom gravimeter. The use of a hollow pyramidal configuration allows to achieve all functions: trapping, interferometer and detection with a unique laser beam leading to a drastic reduction in complexity and volume. In particular, we demonstrate a relative sensitivity to acceleration of gravity (g) of 1.7×10−7 at one second, with a moderate laser power of 50 mW. This simple geometry combined to such a high sensitivity opens wide perspectives for practical applications.
Plasmonics of thin film quasitriangular nanoparticles
Authors: Peng Y. , Marcoux C. , Patoka P. , Hilgendorff M. , Giersig M. , Kempa K.
Published: March 2010

We investigate optical responses of arrays of flat, quasitriangular nanoparticles made by the self-assembly sphere lithography of a 20 nm thick gold film. The measured optical absorption spectra show strong, particle size dependent resonances, in excellent agreement with our simulations. We identify those resonances as due to standing surface/edge plasmon-polariton waves.
Selective growth and ordering of self-assembly on metal/polymer thin-film heterostructures via photothermal modulation
Authors: Kim Yun Young , Huang Qiaojian , Krishnaswamy Sridhar
Published: March 2010

We show photothermal perturbation of morphology on planar aluminum/polymethyl methacrylate films, leading to alignment of location-specific self-assembled patterns. Local laser heating regularizes pattern formation in a selected area by inducing compressive stress in the metal layer as well as partial relaxation in the underlying polymer layer. Furthermore, this thermomechanical process enables the formation of complex structures such as line-gratings and concentric rings when an interferometric heating scheme is employed. Our photolithography-free technique achieves the spatial selectivity and controllability of growth initiation, providing a simpler way for bottom-up fabrication approach for integration of multicomponent devices.
Professional Citizenship and Medical Nationalism in France
Authors: Fannin Maria
Published: March 2010

In principle, the European Union provides for the free movements of workers between its member states. No worker should be discriminated against based solely on nationality, and this applies to most jobs in the public sector. In practice, however, the elimination of nationality criteria for public sector work applies only to workers from EU member states. In the French public health care system, discrimination based on nationality, either of the worker or the worker's diploma, remains salient for ‘third-country’ medical professionals whose qualifications must undergo a lengthy recognition process. In the context of expanding EU integration and anxieties over postcolonial medical migration into Europe, the historical and geographical context for nationality criteria warrants greater attention. This paper suggests that the persistence of nationality restrictions, and their effects on medical professionals seeking recognition for their qualifications in France, lies in the occluded colonial context for their development. This perspective on medical migration requires moving outside the European frame in which nationality restrictions, instantiated in French law during the Third Republic (1870 – 1914) and strengthened further under the Vichy Regime (1940 – 44), have been addressed by historians and policy makers. A more explicitly postcolonial perspective on medical migration's implications for citizenship productively demonstrates how colonial distinctions between French citizens and colonial subjects helped shape the regulatory frameworks that continue to regulate the medical professions in contemporary France.
Architectural traits of fruiting shoots in Juglans regia (Juglandaceae) related to fruiting habit and environmental conditions
Authors: Kelc Damijan , Stampar Franci , Solar Anita
Published: March 2010

The objective of the present study was to compare some basic architectural traits of annual shoots (1YS) in common walnut (Juglans regia L.), and to evaluate the impact of extreme drought and heat on the fruiting and growing response of the annual shoots. Measurements were conducted on three cultivars that have a terminal-bearing fruiting habit (Franquette), intermediate fruiting behaviour (Zdole-59) and a lateral-bearing fruiting habit (Fernor). Across 3 years, the mean 1YS of Franquette were one-third longer than those of the other two cultivars and their mean basal diameter was larger than that in Fernor and almost equal to that in Zdole-59. For Franquette, the length : diameter ratio showed a slender shoot morphology, whereas the shoot morphology was more compact in Fernor and Zdole-59. The 1YS of Franquette and Fernor had equal fruiting potential, with 2.8 and 2.7 fruits per shoot, respectively. Short but thick 1YS with the highest number of vegetative buds indicated dense branching and the good growing capacity of Zdole-59. The number of vegetative buds per 1YS changed during the 3 years in all cultivars, whereas the number of flowering buds per 1YS did not change in Franquette. Extreme dry and hot weather during the spring and summer of 2003 caused a reduction of 35–58% in length and a reduction of 2–16% in the basal diameter of the 1YS, regardless of fruiting behaviour. In the less vigorous, but highly productive lateral-bearer Fernor, unsuitable weather conditions in 2003 affected flower differentiation and resulted in significantly fewer fruits in 2004. The mean daily temperature in the period March–August was negatively correlated with the 1YS diameter and the number of vegetative buds per 1YS, whereas the mean precipitation during the same period showed a positive relationship with the length and diameter of the 1YS. Information obtained through shoot-architecture analysis could be useful in cultivar choice for new orchards, especially at a time of great climatic changes. Simple predictions for further development of the annual shoots could also be made.
Floral traits, pollination ecology and breeding system of three Clematis species (Ranunculaceae) in Yunnan province, southwestern China
Authors: Jiang Nan , Yu Wen-Bin , Li Hong-Zhe , Guan Kai-Yun
Published: March 2010

Flowers of Clematis display showy corollas and diversified shapes. This diversity motivates study of adaptive evolution of flower–pollinator interactions and the functional association between floral traits and plant mating strategies. An integrative study was undertaken, which focused on pollination and reproductive biology of three species representing all three floral types of Clematis. Floral traits were measured, and pollinator assemblages were observed in the field. Bagging, hand-pollination and removal treatments were used to examine breeding systems. The inbreeding depression and pollen limitation were estimated by fruit-set and seed production obtained from pollination treatments. Their floral traits are distinctly different, but are highly associated with pollination syndrome and breeding system. Among them, Clematis akebioides and C. rehderiana may be facultative autogamy (the former was delayed selfing, and the later competing selfing), and C. chrysocoma may be nearly obligate outcrossing. These conclusions are reflected in their stamen-pistil ratios. The levels of inbreeding depression are negatively associated with autonomous self-pollination. Evolution of self-pollination in C. akebioides and C. rehderiana, and pollen limitation in reproduction of the three Clematis species are discussed. This present study, integrating with previous results, will help us to comprehensively recognise and understand the pollination system and reproductive characteristics of Clematis.
Effect of storage temperature on spore viability and early gametophyte development of three vulnerable species of Alsophila (Cyatheaceae)
Authors: Li Y. , Zhang Y. L. , Jiang C. D. , Wang T. , Wang Q. , Shi L.
Published: March 2010

To effectively preserve the vulnerable species of Alsophila, we studied the effects of varying the temperature and duration of storage on spore viability, early gametophyte development and the microstructure of brown spores of three Alsophila species. Spores of A. spinulosa (Wall. ex Hook.) Tryon and A. gigantea Wall. ex Hook. lost viability quickly when stored at room temperature and suffered from great loss when stored at –18°C from 6 to 12 months. Within 1 month, spore viability of A. spinulosa and A. gigantea stored at 4°C was higher than that of those stored in liquid nitrogen. In contrast, long-term storage in liquid nitrogen resulted in a comparatively small loss of viability for these two species. The spores of A. podophylla Hook. died within 3 months after storage at room temperature, 4°C and –18°C, and they died within 12 months when stored in liquid nitrogen. The spores of A. spinulosa and A. gigantea stored at room temperature, 4°C and –18°C, were prone to develop into abnormal gametophytes. These results suggest that storage of A. spinulosa and A. gigantea spores in liquid nitrogen is an effective method of preserving these vulnerable species. The reasons for the failure to preserve ephemeral A. podophylla spores by storage in liquid nitrogen are discussed.
Fusicoccin inhibits dark-induced stomatal closure by reducing nitric oxide in the guard cells of broad bean
Authors: She Xiao-Ping , Li Jin , Huang Ai-Xia , Han Xi-Zhu
Published: March 2010

By using pharmacological approaches and laser scanning confocal microscopy based on 4,5-diaminofluorescein diacetate (DAF-2DA), the relationship between the inhibition of dark-induced stomatal closure caused by fusicoccin (FC) and the changes of nitric oxide (NO) levels in guard cells in broad bean was studied. The results show that, like 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (c-PTIO), a NO scavenger and NG-nitro-L-Arg-methyl ester (L-NAME), an inhibitor of nitric oxide synthase (NOS), FC inhibited stomatal closure induced by darkness, and reduced the levels of NO in guard cells in darkness, indicating that FC inhibits dark-induced stomatal closure through lessening NO levels in guard cells. In addition, similar to c-PTIO, both FC and butyric acid not only suppressed sodium nitroprusside (SNP)-induced stomatal closure and DAF-2DA fluorescence in guard cells, but also reopened the closed stomata induced by dark and removed NO that had been generated by dark. The results show that both FC and butyric acid cause NO removal in guard cells, and also suggest that FC-caused NO removal is probably associated with cytosolic acidification in guard cells. Taken together, our results show that FC perhaps causes cytosolic acidification in guard cells, consequently induces NO removal and reduces NO levels in guard cells, and finally inhibits stomatal closure induced by dark.
Allosteric Conformational Transition in Adenylate Kinase: Dynamic Correlations and Implication for Allostery
Authors: Liu Ming S. , Todd Billy D. , Sadus Richard J.
Published: March 2010

An essential aspect of protein science is to determine the deductive relationship between structure, dynamics, and various sets of functions. The role of dynamics is currently challenging our understanding of protein functions, both experimentally and theoretically. To verify the internal fluctuations and dynamics correlations in an enzyme protein undergoing conformational transitions, we have applied a coarse-grained dynamics algorithm using the elastic network model for adenylate kinase. Normal mode analysis reveals possible dynamical and allosteric pathways for the transition between the open and the closed states of adenylate kinase. As the ligands binding induces significant flexibility changes of the nucleotides monophosphate (NMP) domain and adenosine triphosphate (ATP) domain, the diagonalized correlation between different structural transition states shows that most correlated motions occur between the NMP domain and the helices surrounding the ATP domain. The simultaneous existence of positive and negative correlations indicates that the conformational changes of adenylate kinase take place in an allosteric manner. Analyses of the cumulated normal mode overlap coefficients and long-range correlated motion provide new insights of operating mechanisms and dynamics of adenylate kinase. They also suggest a quantitative dynamics criterion for determining the allosteric cooperativity, which may be applicable to other proteins.
Modelling Copper Binding to the Amyloid-β Peptide in Alzheimer
Authors: Epa V. Chandana , Streltsov Victor A. , Varghese Joseph N.
Published: March 2010

Oxidative modification due to reactive oxygen species generated by Cu2+ bound to the amyloid-β peptide may be one of the sources of neurodegeneration observed in Alzheimer’s disease. Understanding the structure and function of the copper binding site can assist in the design of effective therapeutics. This paper highlights some of the most significant recent developments in computational modelling studies of the structure of the binding site and reaction mechanisms of reactive oxygen species generation.
Estimating Relative Disulfide Energies: An Accurate Ab Initio Potential Energy Surface
Authors: Haworth Naomi L. , Liu Jason Y. , Fan Samuel W. , Gready Jill E. , Wouters Merridee A.
Published: March 2010

Disulfide torsional energy, a good predictor of disulfide redox potential in proteins, may be estimated by interpolation on a potential energy surface (PES) describing the twisting of diethyl disulfide through its three central dihedral angles. Here we update PES calculations at the M05-2X level of theory with the 6-31G(d) basis set. Although the surface shows no qualitative differences from an earlier MP2(full) PES, energy differences greater than 1 kJ mol–1 were seen for conformations with χ2 between –60° and 30°, or with χ3 below 60° or above 130°. This is particularly significant for highly strained disulfides that are likely to be spontaneously reduced by mechanical means. In benchmarking against the high-level G3X method, M05-2X showed significantly reduced root mean squared deviation compared with MP2(full) (1.0 versus 2.0 kJ mol–1 respectively). Results are incorporated into a web application that calculates relative torsional energies from disulfide dihedral angles (http://www.sbinf.org/applications/pes.html).
A Simple One-Pot, Three Component Synthesis of 3-Arylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones and their Sulfur Analogues as Potential Monoamine Oxidase Inhibitors
Authors: Rimaz Mehdi , Khalafy Jabbar , Pesyan Nader Noroozi , Prager Rolf H.
Published: March 2010

Several new 3-arylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones and 3-aryl-5-oxo-7-thioxo-7,8-dihydropyrimido[4,5-c]pyridazin-5(6H)-ones have been synthesized by a three-component reaction of barbituric acid or thiobarbituric acid with arylglyoxals in the presence of a catalytic amount of pyridine and hydrazine hydrate at room temperature in water.
Temperature effect on carbon partitioning in two commercial cultivars of sugarcane
Authors: Grof Christopher P. L. , Campbell James A. , Kravchuk Olena , Lambrides Christopher J. , Albertson Peter L.
Published: March 2010

The effect of temperature upon plant growth and partitioning of dry matter in sugarcane (Saccharum spp.) was determined. Sugarcane plants of two commercial cultivars, Q117 and Q138 were grown under constant conditions for 72 days then subjected to one of four different ambient temperature regimes, 14, 18, 22 or 26°C. Plants were harvested before the imposition of the treatments, then at 85, 120, 155 and 190 days after planting (DAP) for biomass and sugar partitioning. Following the imposition of temperature treatments, the increase in stalk length and node number was linear and notably different between the temperature regimes for both cultivars. When the data was described in terms of thermal time (growth temperature (°C) × number of days), the number of internodes produced per unit of thermal time was the same irrespective of the temperature in which the plants were grown and internode number increased in a linear manner with an increase in total thermal input. Stalk dry matter accumulation over time was linear at the log-scale and highly significant, (P < 0.001) for both Q117 and Q138. The linear rate of accumulation increased with temperature ranging from 1.39 g day–1 at 14°C to 5.31 g day–1 at 26°C for Q117, whereas in Q138 it ranged from 2.24 g day–1 to 4.39 g day–1 at temperatures of 14 and 26°C, respectively. The pattern of total sucrose accumulation also followed an exponential trend, with little difference evident until 155 DAP where rates increased with temperature for both varieties. However, the increase between 14 and 26°C was more profound for Q117. The sucrose/hexose ratio also differed between the cultivars. This difference was most pronounced in plants grown at both 14 and 18°C where the ratio of sucrose/hexose in Q117 was double that measured in Q138. The production of phytomeric units in sugarcane is clearly a function of accumulated degree-days and influenced by cultivar. The elongation of internodes is influenced by temperature and varietal interaction but is not a function of degree-days.
Abundance and size of western rock lobster (Panulirus cygnus) as a function of benthic habitat: implications for ecosystem-based fisheries management
Authors: Bellchambers Lynda M. , Evans Scott N. , Meeuwig Jessica J.
Published: March 2010

Ecosystem-based fisheries management (EBFM) requires the expansion of fisheries research programs to include the relationship between target species and their habitats such that trophic and other ecological interactions can be assessed. The western rock lobster (Panulirus cygnus) is an ecologically important species that supports Australia’s most valuable single-species fisheries. We tested the relationship between abundance and size of western rock lobster and benthic habitats based on the annual independent breeding stock survey and benthic towed video transects. The work was undertaken at Dongara, Jurien Bay and Lancelin, Western Australia between 2005 and 2007. Abundance of western rock lobster was significantly but moderately related to benthic habitat (adjR2 = 0.28), with high abundances associated with high cover of mixed assemblage and Ecklonia sp. Size was effectively predicted by habitat (adjR2 = 0.65) with larger lobsters found in mixed assemblages with sponge and smaller lobsters associated with mixed assemblage with Ecklonia sp. Our study has shown that understanding the influence of habitat and fishing pressure on the abundance and size of targeted species is a critical step in the effective implementation of EBFM.