bluuebunny/crossref_metadata_2025 huggingface dataset:
Human Exposure: Indoor and Outdoor
Authors: Vardoulakis Sotiris
Published: October 2009

Human exposure to air pollution is highly variable, reflecting the strong spatial and temporal variability of air pollutant concentrations in urban environments. A wide variety of outdoor and indoor sources contribute to acute and chronic exposures to respirable particles, carbon monoxide, nitrogen oxides, sulfur dioxide, ozone, volatile organic compounds and polycyclic aromatic hydrocarbons. Ambient air quality measurements and dispersion model simulations are commonly used to estimate population exposure to air pollutants in cities. In addition, time-activity micro-environmental and other dynamic time-space models can be used to characterise the personal exposure of individuals or population subgroups. People in developed countries typically spend 90% of their time indoors, and impact of indoor sources, such as tobacco smoking, gas cooking, construction and furnishing materials, and household chemicals (e.g. paints, adhesives, cleaning products, etc.), on personal exposure can become dominant. Recent exposure surveys have shown that personal exposure is typically higher than both indoor and outdoor concentrations of traffic-related pollutants such as benzene. In most cases, this is due to peak personal exposures occurring within transient (e.g. commuting) and other highly polluted micro-environments (e.g. petrol stations, garages, etc.). In developing countries, domestic fuel combustion (e.g. biomass burning for cooking and heating) has been identified as a major factor contributing to elevated exposure of the population to respirable particles, carbon monoxide, polycyclic aromatic hydrocarbons, nitrogen oxides and sulfur dioxide.
Double circular erosion patterns on dielectric target in magnetron sputtering
Authors: Suzaki Yoshifumi , Miyagawa Hayato , Ejima Seiki
Published: October 2009

In rf magnetron sputtering, a circular erosion pattern forms on the surface of a circular metal conductor target with permanent magnets on its back. In this case, the theory behind the erosion pattern has been established. However, in the case of a dielectric target, a double circular erosion pattern is formed. So far, this pattern has been phenomenologically recognized by experimenters; however, it has not yet been investigated. In this study, we performed a magnetron sputtering experiment with a SiO2 dielectric target, and confirmed the formation of a double circular erosion pattern. The dimensions of the double circular erosion pattern varied depending on the insulation resistance or the thickness of the SiO2 target. Furthermore, we found that the dimensions of a double circular erosion pattern changed by making a gap between the SiO2 target and guard ring. Based on the experimental results, we have proposed a qualitative model to explain the formation mechanism of double circular erosion patterns.
Structural phase transition and physical properties of tetragonal 0.85Pb(Zn1/3Nb2/3)O3–0.15PbTiO3 single crystals
Authors: Fang Bijun , Du Qingbo , Zhou Limin , Zhao Xiangyong , Xu Haiqing , Luo Haosu
Published: October 2009

Large-size and high-quality 0.85Pb(Zn1/3Nb2/3)O3–0.15PbTiO3 (0.85PZN-0.15PT) single crystals were grown by a modified Bridgman method using an allomeric 0.69Pb(Mg1/3Nb2/3)O3–0.31PbTiO3 single crystal as a seed. The as-grown 0.85PZN-0.15PT single crystals exhibit a tetragonal perovskite structure, which changes wholly into a cubic structure between 190 and 215 °C confirmed by high-temperature x-ray diffraction measurement. 0.85PZN-0.15PT exhibits sharp dielectric-response peaks with slight dielectric frequency dispersion where the ferroelectric-paraelectric phase transition is nearly first order. Polarization induces an additional dielectric anomaly around 147 °C accompanied by the increase in Curie temperature (TC), the decrease in the value of dielectric maximum (εm), and the enhancement of frequency dispersion, which can be assigned to the orientation of a ferroelectric domain or a macro-micro domain transition upon heating. The [001]-oriented 0.85PZN-0.15PT crystal planes exhibit excellent electrical properties, where remanent polarization Pr is 58.27 μC/cm2 and piezoelectric constant d33 is around 530–570 pC/N. Pyroelectric coefficient p, detectivity, and voltage responsivity figures of merit Fd and Fv of the 0.85PZN-0.15PT single crystals are 460 μC/K m2, 13.14 μPa−1/2, and 0.0302 m2/C, respectively, which increase greatly over the temperature range measured. It is needed to improve the temperature stability and the voltage responsivity to meet the requirements of practical applications. 0.85PZN-0.15PT exhibits rather high transparency, with the ultraviolet cut-off edge near 380 nm indicating a low-lying electronic energy gap of ∼3.16 eV. The infrared-absorption band occurs at 597 cm−1, which can be attributed to the normal vibration of the [Zn1/3Nb2/3]/TiO3 group.
Flow alignment phenomena in liquid crystals studied by molecular dynamics simulation
Authors: Sarman Sten , Laaksonen Aatto
Published: October 2009

The flow alignment of a nematic liquid crystal has been studied as a function of temperature, beginning at high temperature in the nematic phase and down to the nematic-smectic A phase transition. The alignment angle is obtained by estimating the twist viscosities by nonequilibrium molecular dynamics (NEMD) methods. These estimates are cross-checked by evaluating the corresponding equilibrium fluctuation relations. As a further comparison, shear flow simulations are carried out by application of the SLLOD equations of motion (so named because of their close relationship to the Doll's equation of motion, which can be derived from the Doll's tensor Hamiltonian), whereby the alignment angle is obtained directly. All these methods give consistent results for the alignment angle. At low temperatures near the nematic-smectic A transition the system becomes flow unstable. In this region the alignment angle has been calculated as a function of time.
Nanolamellar magnetoelectric BaTiO3–CoFe2O4 bicrystal
Authors: Ren Shenqiang , Laver Mark , Wuttig Manfred
Published: October 2009

Here, we report a spontaneously formed nanolamellar BaTiO3–CoFe2O4 bicrystal. (11¯0) interfaces join the BaTiO3 and CoFe2O4 single crystalline periodically arranged lamellae that have a common [111] direction. The superlattice of approximately 2 nm wavelength is magnetoelectric with a frequency dependent coupling coefficient of 20 mV/Oe cm at 100 Hz. The BaTiO3 component is a ferroelectric relaxor with a Vogel–Fulcher temperature of 311 K. The relaxor behavior gives rise to a magnetic tunability of the relative dielectric constant ⟨εr⟩−1dεr/dH≈10−2. Since the material can be produced by standard ceramic processing methods, the discovery represents great potential for magnetoelectric devices.
Effect of material properties on reverse flow in nematic liquid crystal devices with homeotropic alignment
Authors: Vanbrabant Pieter J. M. , Beeckman Jeroen , Neyts Kristiaan , James Richard , Fernandez F. Anibal
Published: October 2009

Reverse flow is undesirable in liquid crystal devices with vertical alignment. The influence of the material properties on the onset of backflow is investigated for commercially available negative dielectric liquid crystals. It is shown that the threshold voltage VBF for the occurrence of backflow is an important material characteristic. This threshold is relevant for applications and a large value is desired in devices to avoid backflow while keeping a wide applicable voltage range. Accurate finite element simulation of the liquid crystal hydrodynamics allows extraction of VBF and the unknown Miesowicz coefficients ηij. The resulting values are tabulated at 20.0 °C.
Photothermal effect in narrow band gap PbTe semiconductor
Authors: Dashevsky Z. , Kasiyan V. , Asmontas S. , Gradauskas J. , Shirmulis E. , Flitsiyan E. , Chernyak L.
Published: October 2009

In this paper we report the observation of photothermal effect in PbTe p-n junction. The effect is expressed in photosignal generation due to illumination by 100 ns pulse CO2 laser with photon energy less than PbTe forbidden gap.
Effect of strain on the stability and electronic properties of ferrimagnetic Fe2−xTixO3 heterostructures from correlated band theory
Authors: Nabi Hasan Sadat , Pentcheva Rossitza
Published: October 2009

Based on density functional theory calculations including an on-site Hubbard U term, we investigate the effect of substrate-induced strain on the properties of ferrimagnetic hematite-ilmenite solid solutions and heterostructures. While the charge compensation mechanism through formation of a mixed Fe2+, Fe3+-contact layer is unaffected, strain can be used to tune the electronic properties of the system, e.g., by changing the position of impurity levels in the band gap. Straining Fe2O3–FeTiO3 films at the lateral lattice parameters of Al2O3(0001), commonly used as a substrate, is found to be energetically unfavorable as compared to films on Fe2O3(0001) or FeTiO3(0001)-substrates.
A theory of triple hysteresis in ferroelectric crystals
Authors: Weng George J.
Published: October 2009

In the vicinity of the transition temperature between two ferroelectric states, a ferroelectric crystal could exhibit a triple hysteresis under an ac field. For a BaTiO3 with the “c-plate” configuration slightly below this temperature, the middle loop is caused by the 0°→180° domain switch in the orthorhombic phase, whereas the upper and lower loops are the result of orthorhombic-to-tetragonal phase transition, and vice versa. In this article we first develop a micromechanics-based thermodynamic model to determine the thermodynamic driving force for phase transition and for domain switch as a function of electric field and temperature, and in the latter case, further supplement it with a kinetic equation and a homogenization scheme. The dependence of dielectric constant of the orthorhombic and tetragonal phases on temperature and electric field are also established. The developed theory is then applied to calculate the triple hysteresis loops of BaTiO3 at several levels of temperature. The calculated results for the triple loops, and for the variation of dielectric constant, are found to be in full accord with the test data of Huibregtse and Young [Phys. Rev. 103, 1705 (1956)].
Addressing the efficiency of the energy transfer to the water flow by underwater electrical wire explosion
Authors: Efimov S. , Gurovich V. Tz. , Bazalitski G. , Fedotov A. , Krasik Ya. E.
Published: October 2009

Experimental and hydrodynamic simulation results of submicrosecond time scale underwater electrical explosions of planar Cu and Al wire arrays are presented. A pulsed low-inductance generator having a current amplitude of up to 380 kA was used. The maximum current rise rate and maximum power achieved during wire array explosions were dI/dt≤830 A/ns and ∼10 GW, respectively. Interaction of the water flow generated during wire array explosion with the target was used to estimate the efficiency of the transfer of the energy initially stored in the generator energy to the water flow. It was shown that efficiency is in the range of 18%–24%. In addition, it was revealed that electrical explosion of the Al wire array allows almost double the energy to be transferred to the water flow due to efficient combustion of the Al wires. The latter allows one to expect a significant increase in the pressure at the front of converging strong shock waves in the case of cylindrical Al wire array underwater explosion.
Nonlinear electrostatic excitations in a weakly relativistic electron-positron-ion rotating magnetoplasma
Authors: El-Labany S. K. , Moslem W. M. , El-Awady E. I.
Published: October 2009

By using a hydrodynamic model, Zakharov–Kuznetsov (ZK) equation for a rotating magnetoplasma consisting of weakly relativistic electrons and positrons as well as stationary positive ions is derived. The existence condition as well as the pulse-shaped localized solution of the ZK equation are obtained. Numerical analysis reveal that the profile and the phase velocity of the nonlinear pulses are significantly affected by the ion concentration, the plasma streaming speeds, as well as the positron-to-electron temperature ratio. Furthermore, the bending instability of the nonlinear excitations is investigated using the direct-k perturbation expansion method.
Large-area imager of hydrogen leaks in fuel cells using laser-induced breakdown spectroscopy
Authors: Hori M. , Hayano R. S. , Fukuta M. , Koyama T. , Nobusue H. , Tanaka J.
Published: October 2009

We constructed a simple device, which utilized laser-induced breakdown spectroscopy to image H2 gas leaking from the surfaces of hydrogen fuel cells to ambient air. Nanosecond laser pulses of wavelength λ=532 nm emitted from a neodymium-doped yttrium aluminum garnet laser were first compressed to a pulse length Δt<1 ns using a stimulated Brillouin backscattering cell. Relay-imaging optics then focused this beam onto the H2 leak and initiated the breakdown plasma. The Balmer-alpha (H-α) emission that emerged from this was collected with a 2-m-long macrolens assembly with a 90-mm-diameter image area, which covered a solid angle of ∼1×10−3π steradians seen from the plasma. The H-α light was isolated by two 100-mm-diameter interference filters with a 2 nm bandpass, and imaged by a thermoelectrically cooled charge-coupled device camera. By scanning the position of the laser focus, the spatial distribution of H2 gas over a 90-mm-diameter area was photographed with a spatial resolution of ≤5 mm. Photoionization of the water vapor in the air caused a strong H-α background. By using pure N2 as a buffer gas, H2 leaks with rates of <1 cc/min were imaged. We also studied the possibilities of detecting He, Ne, or Xe gas leaks.
A spectral route to determining chirality
Authors: Pedersen Jesper Goor , Mortensen Niels Asger
Published: October 2009

We show how one-dimensional structured media can be used to measure chirality, via the spectral shift of the photonic band gap edges. Analytically, we show that a chiral contrast can, in some cases, be mapped unto an index contrast, thereby greatly simplifying the analysis of such structures. Using this mapping, we derive a first-order shift of the band gap edges with chirality. Potentially, this effect could be used for measuring enantiomeric excess.
Density matrix treatment of combined instantaneous and delayed dissipation for an electronically excited adsorbate on a solid surface
Authors: Leathers Andrew S. , Micha David A. , Kilin Dmitri S.
Published: October 2009

The interaction of an excited adsorbate with a medium undergoing electronic and vibrational transitions leads to fast dissipation due to electronic energy relaxation and slow (or delayed) dissipation from vibrational energy relaxation. A theoretical and computational treatment of these phenomena has been done in terms of a reduced density matrix satisfying a generalized Liouville–von Neumann equation, with instantaneous dissipation constructed from state-to-state transition rates, and delayed dissipation given by a memory term derived from the time-correlation function (TCF) of atomic displacements in the medium. Two representative applications are presented here, where electronic excitation may enhance vibrational relaxation of an adsorbate. They involve femtosecond excitation of (a) a CO molecule adsorbed on the Cu(001) metal surface and (b) a metal cluster on a semiconductor surface, Ag3Si(111):H, both electronically excited by visible light and undergoing electron transfer and dissipative dynamics by electronic and vibrational relaxations. Models have been parametrized in both cases from electronic structure calculations and known TCFs for the medium, which are slowly decaying in case (a) and fast decaying in case (b). This requires different numerical procedures in the solution of the integrodifferential equations for the reduced density matrix, which have been solved with an extension of the Runge–Kutta algorithm. Results for the populations of vibronic states versus time show that they oscillate due to vibrational coupling through dissipative interaction with the substrate and show quantum coherence. The total population of electronic states is, however, little affected by vibrational motions. Vibrational relaxation is important only at very long times to establish thermal equilibrium.
Collision-induced dissociation studies of FemOn+ : Bond energies in small iron oxide cluster cations, FemOn+ (m=1–3, n=1–6)
Authors: Li Ming , Liu Shu-Rong , Armentrout P. B.
Published: October 2009

A variety of iron oxide cluster cations is synthesized in a laser vaporization ion source. The kinetic energy dependence of the collision-induced dissociation (CID) of mass selected FemOn+ (m=1–3, n=1–6) clusters with Xe is studied in this work using a guided ion beam tandem mass spectrometer. Examination of the general dissociation behavior over a broad collision energy range (0–15 eV) shows that iron oxide clusters can dissociate via evaporation of neutral Fe and O atoms as well as fission by loss of neutral O2, FeO, FeO2, Fe2O2, and Fe2O3 fragments. Such fission pathways, which are not observed in the CID studies of pure Fe cluster cations and most other pure transition metal cluster cations, result from the strong iron oxygen bonds. In general, the predominant dissociation pathways are found to correlate with the oxidation state of the iron in the cluster. Thresholds for loss of neutral Fe, O, O2, FeO, FeO2, Fe2O2, and Fe2O3 from various iron oxide cluster cations are quantitatively determined. These values are used to determine bond energies and heats of formation for both neutral and cationic iron oxide clusters in this size range.
On intra- and intersubject variabilities of airflow in the human lungs
Authors: Choi Jiwoong , Tawhai Merryn H. , Hoffman Eric A. , Lin Ching-Long
Published: October 2009

The effects of intra- and intersubject variabilities in airway geometry on airflow in the human lungs are investigated by large eddy simulation. The airway models of two human subjects consisting of extra- and intrathoracic airways are reconstructed from CT images. For intrasubject study, airflows at two inspiratory flow rates are simulated on the airway geometries of the same subject with four different levels of truncation. These airway models are the original complete geometry and three geometries obtained by truncating the original one at the subglottis, the supraglottis, and the laryngopharynx, respectively. A comparison of the airflows in the complete geometry model shows that the characteristics of the turbulent laryngeal jet in the trachea are similar regardless of Reynolds number in terms of mean velocities, turbulence statistics, coherent structures, and pressure distribution. The truncated airway models, however, do not produce the similar flow structures observed in the complete geometry. An improved inlet boundary condition is then proposed for the airway model truncated at the laryngopharynx to improve the accuracy of solution. The new boundary condition significantly improves the mean flow. The spectral analysis shows that turbulent characteristics are captured downstream away from the glottis. For intersubject study, although the overall flow characteristics are similar, two morphological factors are found to significantly affect the flows between subjects. These are the constriction ratio of the glottis with respect to the trachea and the curvature and shape of the airways.
Self-assembly of T-shaped rod-coil block copolymer melts
Authors: Xia Yingdong , Chen Jizhong , Sun Zhaoyan , Shi Tongfei , An Lijia , Jia Yuxi
Published: October 2009

Self-assembled behavior of T-shaped rod-coil block copolymer melts is studied by applying self-consistent-field lattice techniques in three-dimensional space. Compared with rod-coil diblock copolymers with the anchor point positioned at one end, the copolymers with the anchor point at the middle of the rod exhibit significantly different phase behaviors. When the rod volume fraction is low, the steric hindrance of the lateral coils prevents the rods stacking into strip or micelle as that in rod-coil diblock copolymers. The competition between interfacial energy and entropy results in the formation of lamellar structures and the increasing thickness of the lamellar layer with increasing rod volume fraction. When the rod volume fraction is high, the graft density of the planar interface is decreased, which results in space-filling requirements and stretching penalty, thus leading to the stability of nonlamellar structures with curing interface. Furthermore, our results also suggest that the effect of the chain architecture on the self-assembled behavior is remarkable when the rod volume fraction is low, whereas the effect is weak when the rod volume fraction is high.
Anisotropic stress relief mechanism in epitaxial La0.67Sr0.33MnO3 films
Authors: Vailionis Arturas , Boschker Hans , Houwman Evert , Koster Gertjan , Rijnders Guus , Blank Dave H. A.
Published: October 2009

We report an anisotropic misfit stress relief mechanism in thin La0.67Sr0.33MnO3 (LSMO) films coherently grown on NdGaO3(110) substrates. These results are uniquely related to the orthorhombicity of the LSMO. The x-ray diffraction measurements and quantitative simulations demonstrate that biaxial mismatch stress is relieved differently along in-plane directions perpendicular to each other: in the [11¯0] direction stress is accommodated by decrease of the γ angle of the orthorhombic LSMO unit cell, while in the [001] direction stress is partially relieved by periodic lattice modulations.
Ni–Mn–In–Co single-crystalline particles for magnetic shape memory composites
Authors: Liu Jian , Scheerbaum Nils , Weiß Sandra , Gutfleisch Oliver
Published: October 2009

Single- and oligo-crystalline magnetic shape memory (MSM) Ni45.2Mn36.7In13Co5.1 particles were prepared by mechanical grinding the melt-spun ribbons. The influence of annealing and grinding on the crystal structure and magnetic properties of the ribbons and particles was systematically investigated. The obtained Ni45.2Mn36.7In13Co5.1 single-crystalline particles exhibit a field-induced martensitic transformation above room temperature, thus are used for MSM-polyester composites.
Rapid Access to ω-Conotoxin Chimeras using Native Chemical Ligation
Authors: Hopping Gene , Lewis Richard J. , Alewood Paul F.
Published: October 2009

Grafting different regions of related peptides together to form a single protein chimera is a valuable tool in rapidly elucidating regions of activity or selectivity in peptides and proteins. To conveniently evaluate the contributions of the N- and C-terminal segments of ω-conotoxins CVID and MVIIC to activity, we employed native chemical ligation in CVID-MVIIC chimera design. Assembly of these peptide segments via the ligation method improved overall yield and coupling efficiency, with no difficult sequences encountered in contrast to the traditional full-length chain assembly of CVID. Radio-ligand binding assays revealed regions of importance for receptor recognition.
Reaction of the Five-Coordinate O-Nitrito Complex Fe(Por)(ONO) (Por = meso-tetra-arylporphyrinato) with THF Gives Two Six-Coordinate Isomers
Authors: Kurtikyan Tigran S. , Hovhannisyan Astghik A. , Iretskii Alexei , Ford Peter C.
Published: October 2009

The effect of the proximal ligand on the coordination of the nitrite ligand to the heme model systems Fe(Por)(η1-ONO) (Por = meso-tetraarylporphyrinato dianion) was investigated by FTIR and UV-vis spectra in solvent free, low temperature, porous layered solids and by density functional computations. The reaction of the five-coordinate complex Fe(Por)(η1-ONO) with the ether tetrahydrofuran gives a mixture of the O-nitrito and N-nitrito isomers Fe(Por)(THF)(η1-ONO) and Fe(Por)(THF)(NO2), respectively. This observation is in contrast to earlier studies with nitrogen donor Lewis bases where the N-nitrito isomers were clearly the more stable of the six-coordinated complexes. The adduct formation is reversible; the five-coordinate O-nitrito complexes Fe(Por)(η1-ONO) were largely restored upon warming under vacuum pumping.
Synthesis and Characterization of Simple Hydroxo- and Amido-Bridged Cobalt(III) Dinuclear Ions Missing from the Alfred Werner Collection
Authors: Jackson W. Gregory
Published: October 2009

The unsymmetrical N,O-dibridging NO2– group in the threo (‘rac’) or erythro (‘meso’) isomers of [(en)2Co(μ-NH2,μ-NO2)Co(en)2]4+ is cleaved in hot triflic acid to yield a complex that is predominantly meso. This reacts in water to yield the new meso-[(en)2Co(μ-NH2,μ-OH)Co(en)2]4+ ion. The reactions of the threo- and erythro-μ-NO2– isomers in basic (0.1 M) aqueous solution are each retentive, giving the rac- and meso-[(en)2Co(μ-NH2,μ-OH)Co(en)2]4+ ions as products, respectively. The optically resolved erythro complex gives the achiral meso isomer, which completes the threo/rac and erythro/meso chemical correlations between the two series of dinuclear complexes; the meso synthesis completes the pair – the meso- and rac-[(en)2Co(μ-NH2,μ-OH)Co(en)2]4+ ions. In HCl, stable μ-Cl, μ-NH2 dinuclear ions are formed from these μ-NH2, μ-OH complexes, with retention. The peroxo or superoxo ions rac-[Co(en)2(μ-NH2,μ-O2)Co(en)2]n+ react with SnII to produce symmetrically bridged intermediates that decay to the common and new meso-[(en)2Co(μ-NH2,μ-OH)Co(en)2]4+ isomer on reaction in Me2SO. Both the rac and meso isomers of the μ-hydroxo-μ-peroxo complexes are also reduced by SnII to give intermediates that in Me2SO decay to the respective diols with retention. The new rac-[Co(en)2(μ-OH)2Co(en)2]4+ and meso-[(en)2Co(μ-NH2,μ-OH)Co(en)2]4+ isomers complete the characterization of rac/meso pairs in both systems. The corresponding μ-sulfate pairs are also reported.
Variations on a Cage Theme: Some Complexes of Bicyclic Polyamines as Supramolecular Synthons
Authors: Clark Ian J. , Crispini Alessandra , Donnelly Paul S. , Engelhardt Lutz M. , Harrowfield Jack M. , Jeong Seong-Hoon , Kim Yang , Koutsantonis George A. , Lee Young Hoon , Lengkeek Nigel A. , Mocerino Mauro , Nealon Gareth L. , Ogden Mark I. , Park Yu Chul , Pettinari Claudio , Polanzan Lara , Rukmini Elisabeth , Sargeson Alan M. , Skelton Brian W. , Sobolev Alexandre N. , Thuéry Pierre , White Allan H.
Published: October 2009

Dedication: One of Alan Sargeson’s great abilities was to seek out knowledge on topics of which he was not the master from those people with the expertise. This led occasionally to publications with a ‘cricket team’ of authors but with a rich brew of information, often international. Alan also insisted that all authors were equal since, without any one, the paper would not be what it was. Hence, he endeavoured to pursue the policy, difficult to maintain over a period where an obsession with absurdities such as the order of authors and point-scoring based on meaningless publication indices became so important in the maintenance of research, of listing authors simply in alphabetical order. In describing work begun while he was still with us, we have attempted to adhere to his principles. Analysis of a body of crystallographic information concerning metal(ii) and metal(iii) complexes of macrobicyclic hexamine ligands and some of their derivatives provides evidence for the action of a variety of intermolecular forces within the lattices. Hydrogen bonding is universal and its forms depend strongly upon the oxidation state and the particular nature of the metal ion bound to the macrobicycle. The introduction of both aliphatic and aromatic substituents leads to lattices in which these substituents associate, although, in the case of aromatic substituents, this is not necessarily a consequence of ‘π-stacking’, despite the fact that the aromatic ring planes form parallel arrays. At least in the case of CoIII, stable enantiomers of the complexes can be obtained, and in {Δ-(+)589-[Co{(NH3)(CH3)sar}]}2Cl2(C6(CO2)6)·26H2O (sar = 3,6,10,13,16,19-hexa-azabicyclo[6.6.6]icosane), the benzene hexacarboxylate anion adopts a chiral conformation in the presence of the optically active cation.
Lessons learnt about effectively applying participatory action research: a case study from the New South Wales dairy industry
Authors: Friend M. A. , Dunn A. M. , Jennings J.
Published: October 2009

A participatory action research (PAR) project was implemented in the New South Wales dairy industry. Six regional dairy groups were given funding to investigate issues relating to management of the feedbase. Facilitated meetings in the regions identified limitations to local systems and how these limitations could be addressed. Local groups then implemented research of relevance to their systems. Activities varied but groups were guided by the principles of PAR. Regional groups consisted of farmers, government extension and/or research staff, processors and other stakeholders. A leadership team, consisting of representatives from each of the regional groups and other stakeholders, was formed to administer the project and assist groups in using the PAR approach. Evaluation of the project indicated high levels of participation in all regions and a strong sense of ownership of the project and/or project work. The most commonly mentioned outcome in the groups was what they learned as a result of involvement. The project and its evaluation are discussed in relation to PAR principles, the outcomes from the approach, and lessons learnt for improving the success of PAR.
Erratum to: Performance of steer progeny of sires differing in genetic potential for fatness and meat yield following postweaning growth at different rates. 2. Carcass traits
Authors: McKiernan W. A. , Wilkins J. F. , Irwin J. , Orchard B. , Barwick S. A.
Published: October 2009

The steer progeny of sires genetically diverse for fatness and meat yield were grown at different rates from weaning to feedlot entry and effects on growth, carcass and meat-quality traits were examined. The present paper, the second of a series, reports the effects of genetic and growth treatments on carcass traits. A total of 43 sires, within three 'carcass class' categories, defined as high potential for meat yield, marbling or both traits, was used. Where available, estimated breeding values for the carcass traits of retail beef yield (RBY%) and intramuscular fat (IMF%) were used in selection of the sires, which were drawn from Angus, Charolais, Limousin, Black Wagyu and Red Wagyu breeds, to provide a range of carcass sire types across the three carcass classes. Steer progeny of Hereford dams were grown at either conventional (slow: ~0.5 kg/day) or accelerated (fast: ~0.7 kg/day) rates from weaning to feedlot entry weight, with group means of ~400 kg. Accelerated and conventionally grown groups from successive calvings were managed to enter the feedlot at similar mean feedlot entry weights at the same time for the 100-day finish under identical conditions. Faster-backgrounded groups had greater fat levels in the carcass than did slower-backgrounded groups. Dressing percentages and fat colour were unaffected by growth treatment, whereas differences in ossification score and meat colour were explained by age at slaughter. There were significant effects of sire type for virtually all carcass traits measured in the progeny. Differences in hot standard carcass weight showed a clear advantage to European types, with variable outcomes for the Angus and Wagyu progeny. Sire selection by estimated breeding values (within the Angus breed) for yield and/or fat traits resulted in expected differences in the progeny for those traits. There were large differences in both meat yield and fatness among the types of greatest divergence in genetic potential for those traits, with the Black Wagyu and the Angus IMF clearly superior for IMF%, and the European types for RBY%. The Angus IMF progeny performed as well as that of the Black Wagyu for all fatness traits. Differences in RBY% among types were generally reflected by similar differences in eye muscle area. Results here provide guidelines for selecting sire types to target carcass traits for specific markets. The absence of interactions between growth and genetic treatments ensures that consistent responses can be expected across varying management and production systems.
The keratin-related Ouroboros proteins function as immune antigens mediating tail regression in Xenopus metamorphosis
Authors: Mukaigasa Katsuki , Hanasaki Akira , Maéno Mitsugu , Fujii Hiroshi , Hayashida Shin-ichiro , Itoh Mari , Kobayashi Makoto , Tochinai Shin , Hatta Masayuki , Iwabuchi Kazuya , Taira Masanori , Onoé Kazunori , Izutsu Yumi
Published: October 2009

Tail resorption during amphibian metamorphosis has been thought to be controlled mainly by a cell-autonomous mechanism of programmed cell death triggered by thyroid hormone. However, we have proposed a role for the immune response in metamorphosis, based on the finding that syngeneic grafts of tadpole tail skin into adult
Xenopus
animals are rejected by T cells. To test this, we identified two tail antigen genes called
ouro1
and
ouro2
that encode keratin-related proteins. Recombinant Ouro1 and Ouro2 proteins generated proliferative responses in vitro in T cells isolated from naive adult
Xenopus
animals. These genes were expressed specifically in the tail skin at the climax of metamorphosis. Overexpression of
ouro1
and
ouro2
induced T-cell accumulation and precocious tail degeneration after full differentiation of adult-type T cells when overexpressed in the tail region. When the expression of
ouro1
and
ouro2
were knocked down, tail skin tissue remained even after metamorphosis was complete. Our findings indicate that Ouro proteins participate in the process of tail regression as immune antigens and highlight the possibility that the acquired immune system contributes not only to self-defense but also to remodeling processes in vertebrate morphogenesis.
Immunologically silent cancer clone transmission from mother to offspring
Authors: Isoda Takeshi , Ford Anthony M. , Tomizawa Daisuke , van Delft Frederik W. , De Castro David Gonzalez , Mitsuiki Norkio , Score Joannah , Taki Tomohiko , Morio Tomohiro , Takagi Masatoshi , Saji Hiroh , Greaves Mel , Mizutani Shuki
Published: October 2009

Rare cases of possible materno-fetal transmission of cancer have been recorded over the past 100 years but evidence for a shared cancer clone has been very limited. We provide genetic evidence for mother to offspring transmission, in utero, of a leukemic cell clone. Maternal and infant cancer clones shared the same uniqueBCR-ABL1genomic fusion sequence, indicating a shared, single-cell origin. Microsatellite markers in the infant cancer were all of maternal origin. Additionally, the infant, maternally-derived cancer cells had a major deletion on one copy of chromosome 6p that included deletion of HLA alleles that were not inherited by the infant (i.e., foreign to the infant), suggesting a possible mechanism for immune evasion.
Statins inhibit protein lipidation and induce the unfolded protein response in the non-sterol producing nematode Caenorhabditis elegans
Authors: Mörck Catarina , Olsen Louise , Kurth Caroline , Persson Annelie , Storm Nadia Jin , Svensson Emma , Jansson John-Olov , Hellqvist Marika , Enejder Annika , Faergeman Nils J. , Pilon Marc
Published: October 2009

Statins are compounds prescribed to lower blood cholesterol in millions of patients worldwide. They act by inhibiting HMG-CoA reductase, the rate-limiting enzyme in the mevalonate pathway that leads to the synthesis of farnesyl pyrophosphate, a precursor for cholesterol synthesis and the source of lipid moieties for protein prenylation. The nematode
Caenorhabditis elegans
possesses a mevalonate pathway that lacks the branch leading to cholesterol synthesis, and thus represents an ideal organism to specifically study the noncholesterol roles of the pathway. Inhibiting HMG-CoA reductase in
C. elegans
using statins or RNAi leads to developmental arrest and loss of membrane association of a GFP-based prenylation reporter. The unfolded protein response (UPR) is also strongly activated, suggesting that impaired prenylation of small GTPases leads to the accumulation of unfolded proteins and ER stress. UPR induction was also observed upon pharmacological inhibition of farnesyl transferases or RNAi inhibition of a specific isoprenoid transferase (M57.2) and found to be dependent on both
ire-1
and
xbp-1
but not on
pek-1
or
atf-6
, which are all known regulators of the UPR. The lipid stores and fatty acid composition were unaffected in statin-treated worms, even though they showed reduced staining with Nile red. We conclude that inhibitors of HMG-CoA reductase or of farnesyl transferases induce the UPR by inhibiting the prenylation of M57.2 substrates, resulting in developmental arrest in
C. elegans
. These results provide a mechanism for the pleiotropic effects of statins and suggest that statins could be used clinically where UPR activation may be of therapeutic benefit.
Monkey visual behavior falls into the uncanny valley
Authors: Steckenfinger Shawn A. , Ghazanfar Asif A.
Published: October 2009

Very realistic human-looking robots or computer avatars tend to elicit negative feelings in human observers. This phenomenon is known as the “uncanny valley” response. It is hypothesized that this uncanny feeling is because the realistic synthetic characters elicit the concept of “human,” but fail to live up to it. That is, this failure generates feelings of unease due to character traits falling outside the expected spectrum of everyday social experience. These unsettling emotions are thought to have an evolutionary origin, but tests of this hypothesis have not been forthcoming. To bridge this gap, we presented monkeys with unrealistic and realistic synthetic monkey faces, as well as real monkey faces, and measured whether they preferred looking at one type versus the others (using looking time as a measure of preference). To our surprise, monkey visual behavior fell into the uncanny valley: They looked longer at real faces and unrealistic synthetic faces than at realistic synthetic faces.
Ca
2+
-dependent release of Munc18-1 from presynaptic mGluRs in short-term facilitation
Authors: Nakajima Yoshiaki , Mochida Sumiko , Okawa Katsuya , Nakanishi Shigetada
Published: October 2009

Short-term synaptic facilitation plays an important role in information processing in the central nervous system. Although the crucial requirement of presynaptic Ca
2+
in the expression of this plasticity has been known for decades, the molecular mechanisms underlying the plasticity remain controversial. Here, we show that presynaptic metabotropic glutamate receptors (mGluRs) bind and release Munc18-1 (also known as rbSec1/nSec1), an essential protein for synaptic transmission, in a Ca
2+
-dependent manner, whose actions decrease and increase synaptic vesicle release, respectively. We found that mGluR4 bound Munc18-1 with an EC
50
for Ca
2+
of 168 nM, close to the resting Ca
2+
concentration, and that the interaction was disrupted by Ca
2+
-activated calmodulin (CaM) at higher concentrations of Ca
2+
. Consistently, the Munc18-1-interacting domain of mGluR4 suppressed both dense-core vesicle secretion from permeabilized PC12 cells and synaptic transmission in neuronal cells. Furthermore, this domain was sufficient to induce paired-pulse facilitation. Obviously, the role of mGluR4 in these processes was independent of its classical function of activation by glutamate. On the basis of these experimental data, we propose the following model: When neurons are not active, Munc18-1 is sequestered by mGluR4, and therefore the basal synaptic transmission is kept low. After the action potential, the increase in the Ca
2+
level activates CaM, which in turn liberates Munc18-1 from mGluR4, causing short-term synaptic facilitation. Our findings unite and provide a new insight into receptor signaling and vesicular transport, which are pivotal activities involved in a variety of cellular processes.
Highly error-free role of DNA polymerase η in the replicative bypass of UV-induced pyrimidine dimers in mouse and human cells
Authors: Yoon Jung-Hoon , Prakash Louise , Prakash Satya
Published: October 2009

Cyclobutane pyrimidine dimers (CPDs) constitute the most frequent UV-induced DNA photoproduct. However, it has remained unclear how human and other mammalian cells mitigate the mutagenic and carcinogenic potential of CPDs emanating from their replicative bypass. Here, we examine in human cells the roles of translesion synthesis (TLS) DNA polymerases (Pols) in the replicative bypass of a
cis-syn
TT dimer carried on the leading or the lagging strand DNA template in a plasmid system we have designed, and we determine in mouse cells the frequencies and mutational spectra generated from TLS occurring specifically opposite CPDs formed at TT, TC, and CC dipyrimidine sites. From these studies we draw the following conclusions: (
i
) TLS makes a very prominent contribution to CPD bypass on both the DNA strands during replication; (
ii
) Pols η, κ, and ζ provide alternate pathways for TLS opposite CPDs wherein Pols κ and ζ promote mutagenic TLS opposite CPDs; and (
iii
) the absence of mutagenic TLS events opposite a
cis-syn
TT dimer in human cells and opposite CPDs formed at TT, TC, and CC sites in mouse cells that we observe upon the simultaneous knockdown of Pols κ and ζ implicates a highly error-free role of Polη in TLS opposite CPDs in mammalian cells. Such a remarkably high in vivo fidelity of Polη could not have been anticipated in view of its low intrinsic fidelity. These observations have important bearing on how mammalian cells have adapted to avoid the mutagenic and carcinogenic consequences of exposure to sunlight.
Discourse analysis: Rich pickings for counsellors and therapists
Authors: Spong Sheila
Published: October 2009

Aim: It is only relatively recently that discourse analysis has begun to rise to prominence in the fields of counselling and psychotherapy. This paper briefly explains ways of understanding discourse analysis, discussing what the approach can offer counselling research and practice. Approach: An initial categorisation of recent discourse analysis studies is offered, to demonstrate diverse ways in which this type of research can address issues relevant to counselling practice. The five categories proposed range from the examination of language use in therapy to analyses that focus on the social structures, meanings and power relations related to therapy. Implications: The paper demonstrates that through the critical analysis of counselling sessions, research interviews, written texts and other materials, discourse analysis can provide insight into ways in which counselling operates as a social practice, and so help counsellors to contextualise their work within broader social structures and processes.
Effects of Neuro‐Linguistic Psychotherapy on psychological difficulties and perceived quality of life
Authors: Stipancic Melita , Renner Walter , Schütz Peter , Dond Renata
Published: October 2009

Aims: The purpose of this study was to examine the effects of Neuro‐Linguistic Psychotherapy on psychological difficulties and perceived quality of life of clients who came for psychotherapy during free practice. Method: A total of 106 psychotherapy clients were randomly assigned to a therapy group or a control group. The outcome was assessed by the Structured Clinical Interview for DSM‐IV Personality Disorders (SCID II) with respect to clinical symptoms and by the Croatian Scale of Quality of Life (KVZ) with respect to Quality of Life. The therapy group received the measures at pre‐, post‐ and five‐months follow‐up occasions, whereas the control group received them initially and after a period of three months. Results: In the therapy group, as compared to the control group, there was a significant decrease of clinical symptoms and increase in the quality of life. With respect to clinical symptoms, effect sizes were 0.65 at post‐measurement and 1.09 at follow‐up, indicating a substantial reduction of symptom strain, which is comparable to the well established effects of Cognitive Behavior Therapy. We also found a significant increase in perceived quality of life after therapy, as compared to the wait‐list control group, with effect sizes between 0.51 and 0.73. Therapeutic improvements were still present five months after the end of therapy, showing further development in the same direction. Conclusions: Neuro‐linguistic psychotherapy is an efficient intervention, which is on a par with other, well‐established psychotherapeutic techniques.
Postsynaptic regulation of synaptic plasticity by synaptotagmin 4 requires both C2 domains
Authors: Barber Cynthia F. , Jorquera Ramon A. , Melom Jan E. , Littleton J. Troy
Published: October 2009

Ca2+ influx into synaptic compartments during activity is a key mediator of neuronal plasticity. Although the role of presynaptic Ca2+ in triggering vesicle fusion though the Ca2+ sensor synaptotagmin 1 (Syt 1) is established, molecular mechanisms that underlie responses to postsynaptic Ca2+ influx remain unclear. In this study, we demonstrate that fusion-competent Syt 4 vesicles localize postsynaptically at both neuromuscular junctions (NMJs) and central nervous system synapses in Drosophila melanogaster. Syt 4 messenger RNA and protein expression are strongly regulated by neuronal activity, whereas altered levels of postsynaptic Syt 4 modify synaptic growth and presynaptic release properties. Syt 4 is required for known forms of activity-dependent structural plasticity at NMJs. Synaptic proliferation and retrograde signaling mediated by Syt 4 requires functional C2A and C2B Ca2+–binding sites, as well as serine 284, an evolutionarily conserved substitution for a key Ca2+-binding aspartic acid found in other synaptotagmins. These data suggest that Syt 4 regulates activity-dependent release of postsynaptic retrograde signals that promote synaptic plasticity, similar to the role of Syt 1 as a Ca2+ sensor for presynaptic vesicle fusion.
The speed of propagation for KPP type problems. II: General domains
Authors: Berestycki Henri , Hamel François , Nadirashvili Nikolai
Published: October 2009

This paper is devoted to nonlinear propagation phenomena in general unbounded domains ofRN\mathbb {R}^N, for reaction-diffusion equations with Kolmogorov-Petrovsky-Piskunov (KPP) type nonlinearities. This article is the second in a series of two and it is the follow-up of the paperThe speed of propagation for KPP type problems. I - Periodic framework, by the authors, which dealt which the case of periodic domains. This paper is concerned with general domains, and we give various definitions of the spreading speeds at large times for solutions with compactly supported initial data. We study the relationships between these new notions and analyze their dependence on the geometry of the domain and on the initial condition. Some a priori bounds are proved for large classes of domains. The case of exterior domains is also discussed in detail. Lastly, some domains which are very thin at infinity and for which the spreading speeds are infinite are exhibited; the construction is based on some new heat kernel estimates in such domains.
The dimension of the Torelli group
Authors: Bestvina Mladen , Bux Kai-Uwe , Margalit Dan
Published: October 2009

We prove that the cohomological dimension of the Torelli group for a closed, connected, orientable surface of genus

g
≥
2

g \geq 2

is equal to

3
g
−
5

3g-5

. This answers a question of Mess, who proved the lower bound and settled the case of

g
=
2

g=2

. We also find the cohomological dimension of the Johnson kernel (the subgroup of the Torelli group generated by Dehn twists about separating curves) to be

2
g
−
3

2g-3

. For

g
≥
2

g \geq 2

, we prove that the top dimensional homology of the Torelli group is infinitely generated. Finally, we give a new proof of the theorem of Mess that gives a precise description of the Torelli group in genus 2. The main tool is a new contractible complex, called the “complex of minimizing cycles”, on which the Torelli group acts.