bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender and New Labour's Social Policies
Authors: RAKE KATHERINE
Published: August 2008

Since its election to government in 1997, the programme of social policy
reform introduced by the British Labour government has proceeded at a
dizzying pace. This article analyses the impact of these reforms on gender
relations, and how policy is working to shape the roles of citizen worker;
parent and carer and spouse or partner. The article focuses on how the
New Deals, tax and benefit policy (including the Working Families Tax
Credit) and childcare policy affect these roles. The analysis reveals how,
in institutionalising paid work as the key route to citizenship, New
Labour runs the risk of building implicit gender bias into a number of its
policies. The analysis suggests that more gender-sensitive policy would
follow where consideration was given both to how individuals relate to
the labour market over their lifetimes and to the effect of policy on the
division and distribution of unpaid caring work.
‘Making Work Pay’ – Devising the Best Strategy for Lone Parents in Britain
Authors: GRAY ANNE
Published: August 2008

‘Making work pay’ is the keystone of New Labour's strategy to reduce
welfare dependency. This strategy is especially directed at lone parents,
through increased financial support for childcare, a specific ‘New Deal’
and reduced benefits for non-working lone parents. Reducing welfare
dependency for lone parents has several possible objectives; minimising
welfare expenditures, maximising the employment rate, improving the
socioeconomic status of women, or improving conditions for their children.
This article analyses the implications of each of these objectives for
policy design, using evidence from other countries as well as the United
Kingdom, and examines the internal coherence of New Labour's policy
approach to lone parents and its coherence with other policies on the
family and on lifelong learning. The potential effectiveness of ‘making
work pay’ is examined through the findings of recent literature, leading
to arguments for a carer's allowance.
Piloting Princes: Hugh Clifford and the Malay Rulers
Authors: Smith Simon C.
Published: August 2008

Hugh Clifford has been described as “one of the most unusual colonial governors in British history”. Widely regarded as the “doyen of the colonial service”, Clifford held successive governorships in the Gold Coast, Nigeria, Ceylon, and the Straits Settlements. As a writer of novels, short stories, and reminiscences, moreover, he enjoyed a successful literary career; he moved in literary circles and counted Joseph Conrad among his particular friends. Clifford's inspiration was drawn almost exclusively from his experiences in Malaya, the territory where he not only started his career in the early 1880s, but also ended it in tragic circumstances nearly fifty years later. Throughout his Malayan career Clifford came into frequent contact with Malaya's ruling families. “To act the part of officer in attendance upon Malayan royalties is a task with which circumstances have familiarised me”, he declared in “Piloting Princes”, a 1902 contribution to Blackwood's Magazine. His attitude towards them ranged from disgust and condemnation, to admiration and a paternalistic concern for their dignity and survival. Unravelling Clifford's complex, and apparently contradictory, relationship with Malay royalty will be the subject of this article.
Distribution of the ultraviolet nitric oxide Martian night airglow: Observations from Mars Express and comparisons with a one‐dimensional model
Authors: Cox C. , Saglam A. , Gérard J.‐C. , Bertaux J.‐L. , González‐Galindo F. , Leblanc F. , Reberac A.
Published: August 2008

Limb observations with the SPICAM ultraviolet spectrometer on board the Mars Express orbiter revealed ultraviolet nightglow emission in the δ (190–240 nm) and γ (225–270 nm) bands of nitric oxide. This emission arises from radiative recombination between O(3P) and N(4S) atoms that are produced on the day side and form excited NO molecules on the night side. In this study, we analyze the night limb observations obtained during the MEX mission. In particular, we describe the variability of the emission brightness and its peak altitude. We examine possible correlations with latitude, local time, magnetic field strength or solar activity. We show that the altitude of maximum emission varies between 55 and 92 km while the brightness is in the range 0.2 to 10.5 kR. The total vertical emission rate ranges from 8 to 237 R with an average value of 36 ± 52 R. The observed topside scale height of the emission profile varies between 3.8 and 11.0 km, with a mean value of 6 ± 1.7 km. We use a chemical‐diffusive atmospheric model where the eddy coefficient, whose value in the Mars thermosphere is uncertain, is a free parameter to match the observed peak altitude of the emission. The model solves the continuity equation for O(3P), N(4S), and NO using a finite volume method on a one‐dimensional grid. We find that the downward flux of N atoms at 100 km varies by two orders of magnitude, ranging from 107 to 109 atoms cm−2 s−1.
Effects of diurnal variation of solar zenith angle on a tropical coupling system: A two‐dimensional coupled ocean‐cloud resolving atmosphere modeling study
Authors: Gao Shouting , Zhou Yushu
Published: August 2008

The effects of diurnal variation of solar zenith angle on tropical atmospheric and oceanic variability are investigated with a two‐dimensional coupled ocean‐cloud resolving atmosphere model. The experiment with a time‐invariant solar zenith angle is compared to the control experiment with a diurnally‐varied solar zenith angle. In both experiments, the model, with imposed large‐scale vertical velocity and zonal wind derived from Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA COARE), is integrated over a 30‐day period. The control simulation shows a good agreement with the observations in terms of atmospheric temperature, specific humidity, and mixed‐layer temperature and salinity. The experiment with the time‐invariant solar zenith angle produces a colder and drier atmosphere and a colder and saltier ocean mixed layer than the experiment with the diurnally‐varied solar zenith angle does. The atmospheric temperature and precipitable water budgets and oceanic mixed‐layer temperature and salinity budgets are analyzed. Compared to the experiment with the diurnally‐varied solar zenith angle, the experiment with the time‐invariant solar zenith angle has smaller solar heating, consumes more atmospheric water vapor through more condensation, and generates smaller thermal forcing through deeper mixed layer and more saline entrainment. The results indicate the importance of the inclusion of diurnal variation of solar zenith angle in coupled model simulations to avoid atmospheric and oceanic cooling biases and atmospheric drying bias.
Modeling interannual variability of the Amazon hydroclimate
Authors: Medvigy D. , Walko R. L. , Avissar R.
Published: August 2008

El Niño/Southern Oscillation (ENSO) strongly influences the interannual variability of Amazon hydroclimate. But current global climate models are unable to represent the associated variability, raising the question of their aptitude to simulate current and changing climate in that region. We explore this critical issue with the Ocean‐Land‐Atmosphere Model (OLAM), a new Earth System Model (ESM) capable of simulating regions like mountain ranges at high resolution while efficiently simulating the rest of the world at coarser resolution. We find that simulations representing the Andes at resolutions coarser than 100 km lead to a ‘reverse’ ENSO effect, with large precipitation rates in the Amazon during ENSO events. In contrast, the model correctly simulates the ENSO dry anomaly provided the Andes are simulated at resolutions finer than 100 km. Furthermore, we find that the grid mesh over the Andes has important implications for ENSO teleconnections, especially over the continents.
Cytosolic Ca2+Oscillations in Human Cerebrovascular Endothelial Cells after Subarachnoid Hemorrhage
Authors: Scharbrodt Wolfram , Abdallah Yaser , Kasseckert Sascha A , Gligorievski Dragan , Piper Hans M , Böker Dieter-K , Deinsberger Wolfgang , Oertel Matthias F
Published: August 2008

Molecular mechanisms of cerebral vasospasm after subarachnoid hemorrhage (SAH) include specific modes of cell signaling like activation of nuclear factor (NF)-kB and vascular cell adhesion molecules (VCAM)-1 expression. The study's hypothesis is that cisternal cerebral spinal fluid (CSF) from patients after SAH may cause Ca2+oscillations which induce these modes of vascular inflammation in an in vitro model of human cerebral endothelial cells (HCECs). HCECs were incubated with cisternal CSF from 10 SAH patients with confirmed cerebral vasospasm. The CSF was collected on days 5 and 6 after hemorrhage. Cytosolic Ca2+concentrations and cell contraction as an indicator of endothelial barrier function were examined by fura-2 microflurometry. Activation of NF-κB and VCAM-1 expression were measured by immunocytochemistry. Incubation of HCEC with SAH-CSF provoked cytosolic Ca2+oscillations (0.31 ± 0.09 per min), cell contraction, NF-κB activation, and VCAM-1 expression, whereas exposure to native CSF had no significant effect. When endoplasmic reticulum (ER) Ca2+-ATPase and ER inositol trisphosphate (IP3)-sensitive Ca2+channels were blocked by thapsigargin or xestospongin, the frequency of the Ca2+oscillations was reduced significantly. In analogy to the reduction of Ca2+oscillation frequency, the blockers impaired HCEC contraction, NF-κB activation, and VCAM-1 expression. Cisternal SAH-CSF induces cytosolic Ca2+oscillations in HCEC that results in cellular constriction, NF-κB activation, and VCAM-1 expression. The Ca2+oscillations depend on the function of ER Ca2+-ATPase and IP3-sensitive Ca2+channels.
Permanent Middle Cerebral Artery Occlusion in Sheep: A Novel Large Animal Model of Focal Cerebral Ischemia
Authors: Boltze Johannes , Förschler Annette , Nitzsche Björn , Waldmin Daniela , Hoffmann Anke , Boltze Christiane M , Dreyer Antje Y , Goldammer Axel , Reischauer Anne , Hartig Wolfgang , Geiger Kathrin D , Barthel Henryk , Emmrich Frank , Gille Uwe
Published: August 2008

As effective stroke treatment by thrombolysis is bound to a narrow time window excluding most patients, numerous experimental treatment strategies have been developed to gain new options for stroke treatment. However, all approaches using neuroprotective agents that have been successfully evaluated in rodents have subsequently failed in clinical trials. Existing large animal models are of significant scientific value, but sometimes limited by ethical drawbacks and mostly do not allow for long-term observation. In this study, we are introducing a simple, but reliable stroke model using permanent middle cerebral artery occlusion in sheep. This model allows for control of ischemic lesion size and subsequent neurofunctional impact, and it is monitored by behavioral phenotyping, magnetic resonance imaging, and positron emission tomography. Neuropathologic and (immuno)-histologic investigations showed typical ischemic lesion patterns whereas commercially available antibodies against vascular, neuronal, astroglial, and microglial antigens were feasible for ovine brain specimens. Based on absent mortality in this study and uncomplicated species-appropriate housing, long-term studies can be realized with comparatively low expenditures. This model could be used as an alternative to existing large animal models, especially for longitudinal analyses of the safety and therapeutic impact of novel therapies in the field of translational stroke research.
Association Analysis Techniques for Discovering Functional Modules from Microarray Data
Authors: Pandey Gaurav , Atluri Gowtham , Steinbach Michael , Kumar Vipin
Published: August 2008

An application of great interest in microarray data analysis is the identification of a group of genes that show very similar patterns of expression in a data set, and are expected to represent groups of genes that perform common/similar functions, also known as functional modules. Although clustering offers a natural solution to this problem, it suffers from the limitation that it uses all the conditions to compare two genes, whereas only a subset of them may be relevant. Association analysis offers an alternative route for finding such groups of genes that may be co-expressed only over a subset of the experimental conditions used to prepare the data set. The techniques in this field attempt to find groups of data objects that contain coherent values across a set of attributes, in an exhaustive and efficient manner. In this paper, we illustrate how a generalization of the techniques in association analysis for real-valued data can be utilized to extract coherent functional modules from large microarray data sets.
Microbial N‐demethylation: biotransformation and recovery of a drug metabolite
Authors: Davis Brian L. , Liu Mark S. , Hanson Ronald L. , Parker William L. , Patel Ramesh N.
Published: August 2008

A total of 39 microbes were screened for the ability to selectively N‐demethylate (3R,5S,E)‐7‐(4‐(4‐fluorophenyl)‐6‐isopropyl‐2‐(methyl(1‐methyl‐1H‐1,2,4‐triazol‐5‐yl)aminopyrimidin‐5‐yl)‐3,5‐dihydroxy‐hept‐6‐enoic acid (I), a potential drug for lowering blood cholesterol levels. Two Streptomyces species were found to carry out the desired N‐demethylation. Bioconversion by Streptomyces griseus A.T.C.C. 13273 and product recovery were scaled up to the multi‐gram level.
Functional diversity among p24 subfamily members
Authors: Strating Jeroen R.P.M. , Hafmans Theo G.M. , Martens Gerard J.M.
Published: August 2008

Background information. The p24 protein family plays an important but unclear role at the ER (endoplasmic reticulum)–Golgi interface. A p24 member from each subfamily (p24α3, β1, γ3 and δ2) is upregulated with the prohormone POMC (pro‐opiomelanocortin) when Xenopus laevis intermediate pituitary melanotrope cells are physiologically activated. Here we explored the role of p24 by generating and analysing Xenopus with melanotrope cell‐specific transgene expression of p24β1 or p24γ3, two of the p24 proteins coexpressed with POMC, and compared the results with those previously reported for the two other coexpressed p24s (p24α3 and p24δ2).

Results. The transgene expression of p24β1 or p24γ3 did not affect the endogenous p24 proteins or affected only endogenous p24γ3 respectively, whereas in transgenics expressing p24α3 and p24δ2, the levels of all endogenous p24 proteins were strongly decreased. Nevertheless, as for p24α3 but albeit to a lesser extent, in the p24β1‐transgenic melanotrope cells the rate of cargo cleavage was reduced, probably reflecting reduced cargo transport from the ER, and POMC glycosylation and sulfation in the Golgi were not affected. The p24γ3‐transgenic cells displayed features of both the p24α3‐transgenics (reduced cargo cleavage, normal POMC sulfation) and the p24δ2‐transgenics (affected POMC glycosylation).

Conclusions. Our results show that the four upregulated proteins p24α3, β1, γ3 and δ2 have non‐redundant roles in the early secretory pathway, and suggest that each p24 subfamily member provides a proper ER/Golgi subcompartmental microenvironment, together allowing correct secretory protein transport and processing.
Theoretical determination of rate constants for vibrational relaxation and reaction of OH(XΠ2,v=1) with O(P3) atoms
Authors: Kłos Jacek A. , Lique François , Alexander Millard H. , Dagdigian Paul J.
Published: August 2008

Collisions of the vibrationally excited OH(v=1) molecule with atomic oxygen are investigated theoretically using a coupled-states, statistical capture (CS-ST) model. Vibrational relaxation can occur by inelastic scattering, and the vibrationally excited molecule can also be removed by reaction to form O2 in both the ground (XΣg−3) and first excited (aΔg1) state. In the former case, reaction occurs on the lowest potential energy surface of A″2 symmetry, and, in the latter case, by reaction on the lowest potential energy surface of A′2 symmetry. We report new ab initio potential energy surfaces for both these states in the product and reactant regions necessary for application of the coupled-states, statistical method. Comparison with exact, reactive scattering calculations within the J-shifting approximation indicate that the CS-ST rate constants for removal of OH(v=1) can be expected to be reasonably accurate. Our calculated rate constants at 300K agree well with the experimental results of Khachatrian and Dagdigian [Chem. Phys. Lett. 415, 1 (2005)]. Reaction to yield O2 (XΣg−3) is the dominant removal pathway. At subthermal temperatures, the rate constants for the various vibrational quenching processes all increase down to T≅60K and then decrease at lower temperature.
Building Markov state models along pathways to determine free energies and rates of transitions
Authors: Pan Albert C. , Roux Benoît
Published: August 2008

An efficient method is proposed for building Markov models with discrete states able to accurately describe the slow relaxation of a complex system with two stable conformations. First, the reaction pathway described by a set of collective variables between the two stable states is determined using the string method with swarms of trajectories. Then, short trajectories are initiated at different points along this pathway to build the state-to-state transition probability matrix. It is shown, using a model system, how this strategy makes it possible to use trajectories that are significantly shorter than the slowest relaxation time to efficiently build a reliable and accurate Markov model. Extensions of the method to multiple pathways, as well as some common pitfalls arising from poorly relaxed paths or an inappropriate choice of collective variables, are illustrated and discussed.
Parallels between multiple population-period transient spectroscopy and multidimensional coherence spectroscopies
Authors: Khurmi Champak , Berg Mark A.
Published: August 2008

We have recently shown that homogeneous and heterogeneous kinetics can be distinguished by experiments that compare the evolution of the population of a state over two time intervals [E. van Veldhoven et al., ChemPhysChem 8, 1761 (2007)]. This paper elaborates on the analogy between these multiple population-period transient spectroscopy (MUPPETS) experiments and more familiar spectroscopies based on the evolution of coherences. Using a modified inverse-Laplace transform, a standard kinetics decay is re-expressed as a “rate spectrum.” A nonexponential decay creates a linewidth in this spectrum. Mechanisms for line broadening in rate spectra are compared to those for line broadening in frequency-domain spectra. Homogeneous and heterogeneous kinetics are defined precisely and are shown to be the counterparts of homogeneous and inhomogeneous line broadenings in frequency-domain spectra. Homogeneous line broadening mechanisms are further divided into equilibrium and nonequilibrium mechanisms, with equilibrium mechanisms more prevalent in frequency spectra and nonequilibrium mechanisms more prevalent in rate spectra. Spectral representations of two-dimensional MUPPETS experiments are developed that are equivalent to two-dimensional coherence spectroscopies. In particular, spectra equivalent to hole-burning and to correlation spectra are defined. Frequency-domain spectra are often modeled as an inhomogeneous distribution of identical homogeneous line shapes. A parallel homogeneous-heterogeneous model for kinetics is defined. Within this model, MUPPETS has sufficient information to completely separate the homogeneous and heterogeneous contributions to a nonexponential decay, even when the homogeneous contribution is nonexponential.
Density functional restricted-unrestricted approach for nonlinear properties: Application to electron paramagnetic resonance parameters of square planar copper complexes
Authors: Rinkevicius Zilvinas , de Almeida Katia Julia , Vahtras Olav
Published: August 2008

The density functional restricted-unrestricted approach for treatments of spin polarization effects in molecular properties using spin restricted Kohn–Sham theory has been extended from linear to nonlinear properties. It is shown that the spin polarization contribution to a nonlinear property has the form of a quadratic response function that includes the zero-order Kohn–Sham operator, in analogy to the lower order case where the spin polarization correction to an expectation value has the form of a linear response function. The developed approach is used to formulate new schemes for computation of electronic g-tensors and hyperfine coupling constants, which include spin polarization effects within the framework of spin restricted Kohn–Sham theory. The proposed computational schemes are in the present work employed to study the spin polarization effects on electron paramagnetic resonance spin Hamiltonian parameters of square planar copper complexes. The obtained results indicate that spin polarization gives rise to sizable contributions to the hyperfine coupling tensor of copper in all investigated complexes, while the electronic g-tensors of these complexes are only marginally affected by spin polarization and other factors, such as choice of exchange-correlation functional or molecular structures, will have more pronounced impact on the accuracy of the results.
Local versus global absorption in thin-film solar cells with randomly textured surfaces
Authors: Rockstuhl C. , Fahr S. , Lederer F. , Bittkau K. , Beckers T. , Carius R.
Published: August 2008

Enhanced light absorption in amorphous silicon thin films deposited on randomly textured zinc-oxide surfaces is investigated by means of a rigorous diffraction theory taking into account measured surface profiles and near-field optical data. Global absorption enhancement is obtained in the calculations for particular modifications of the random texture. We furthermore spatially resolve local domains of the surface texture, which show the strongest contribution to the absorption. Criteria on how random surfaces should look like to enhance absorption in thin-film solar cells are derived.
Nanocluster explosions and quasimonoenergetic spectra by homogeneously distributed impurity ions
Authors: Murakami M. , Tanaka M.
Published: August 2008

A plasma expansion into vacuum and the resultant ion acceleration are studied analytically and numerically. The expansion of an initially uniform spherical plasma (consisting of a nanocluster or microdroplet) with radius Ru0 and electron density nu0 is driven by the explosion of hot electrons having an initial temperature Te0. A self-similar solution describes the nonrelativistic expansion of a finite plasma mass with a full account of charge separation effects. Such key features as the energy spectrum, maximum ion energy, and energy transfer efficiency from the electrons to the ions are given by simple analytic formulas as a function of the normalized droplet radius, Λu=Ru0∕λD, where λD=Te0∕4πnu0e2 is the Debye length. The solution predicts that impurity ions doped homogeneously in a droplet plasma are accelerated quasimonoenergetically by the electrostatic field generated by the charge separation. The prediction is confirmed by N-body particle simulations. The origin of the monoenergetic spectrum is attributed to the spherical geometry.
Composition of the source region plasma in inertial electrostatic confinement devices
Authors: Boris D. R. , Emmert G. A.
Published: August 2008

The ion species composition in the source region of inertial electrostatic confinement (IEC) devices plays an important role in the atomic and molecular physics processes in the device and in the resulting energy spectrum of the fast ions and the neutron production rate. A zero dimensional rate equation model for the ion species composition in the source region of IEC devices is presented and compared with experimental measurements on the Wisconsin IEC device [J. F. Santarius, G. L. Kulcinski, R. P. Ashley et al., Fusion Sci. Tech. 47, 1238 (2005)]. The ion species composition is measured using an ion acoustic wave diagnostic; the results are in good agreement with the theoretical predictions. Both the theory and the experimental results show that D3+ ions are the majority species in the source region.
Finite-frequency current (shot) noise in coherent resonant tunneling through a coupled-quantum-dot interferometer
Authors: Dong Bing , Lei X. L. , Horing N. J. M.
Published: August 2008

We examine the shot noise spectrum properties of coherent resonant tunneling in coupled quantum dots (CQDs) in both series and parallel arrangements by means of quantum rate equations and MacDonald’s formula. Our results show that for a series-CQD with a relatively high dot-dot hopping Ω and Ω/Γ≳1 (Γ denotes the dot-lead tunnel-coupling strength), the noise spectrum exhibits a dip at the Rabi frequency 2Ω in the case of noninteracting electrons, but the dip is supplanted by a peak in the case of strong Coulomb repulsion; furthermore, it becomes a dip again for a completely symmetric parallel-CQD by tuning the enclosed magnetic flux.
Temperature and density characteristics of the Helicity Injected Torus-II spherical tokamak indicating closed flux sustainment using coaxial helicity injection
Authors: Hamp W. T. , Jarboe T. R. , Nelson B. A. , O’Neill R. G. , Raman R. , Redd A. J. , Stewart B. T. , Mueller D.
Published: August 2008

The electron temperature and density profiles of plasmas in the Helicity Injected Torus [HIT-II: T. R. Jarboe et al., Phys. Plasmas 5, 1807 (1998)] experiment are measured by multipoint Thomson scattering (MPTS). The HIT-II device is a small low-aspect-ratio tokamak (major radius 0.3m, minor radius 0.2m, toroidal field of up to 0.5T), capable of inductive ohmic (OH) current drive, Coaxial Helicity Injection (CHI) current drive, or combinations of both. The temperature and density characteristics have been characterized by a ruby laser MPTS diagnostic at up to six locations within the plasma for a single diagnostic time per discharge. Observed hollow temperature profiles of CHI discharges are inconsistent with open flux only predictions for CHI and indicate a closed flux region during CHI current drive.
Water/polymer interactions in poly(amidoamine) hydrogels by H1 nuclear magnetic resonance relaxation and magnetization transfer
Authors: Calucci Lucia , Forte Claudia , Ranucci Elisabetta
Published: August 2008

Hydrated cross-linked polymers belonging to the family of poly(amidoamine)s were investigated by high and low resolution H1 nuclear magnetic resonance techniques in order to obtain information on water/polymer interactions in the swollen state. H1 spin-spin and spin-lattice relaxation time analysis, as well as magnetization transfer experiments, indicated that water and polymer proton pools are essentially uncoupled, with water molecules diffusing fast within the hydrogel structure and exchanging between “bound” and free sites. For the polymer characterized by the highest cross-linking degree, there is strong evidence of a beadlike structure resulting in higher network rigidity and hydrogel micrometric heterogeneity.
Low threshold electrically pumped quantum dot-micropillar lasers
Authors: Reitzenstein S. , Heindel T. , Kistner C. , Rahimi-Iman A. , Schneider C. , Höfling S. , Forchel A.
Published: August 2008

We report on low threshold lasing in electrically pumped quantum dot-micropillar cavities. Lasing action associated with threshold currents as low as 8μA at 10K is observed for micropillar cavities with quality factors exceeding 10.000. Due to an optimized contact scheme lasing is achieved for pillar structures with diameters as small as 1.5μm, containing on average less than 100 quantum dots in the active layer. The transition from spontaneous to stimulated emission is confirmed by autocorrelation measurements which reveal pronounced photon bunching near threshold.
Magnetic order by C-ion implantation into Mn5Si3 and Mn5Ge3 and its lateral modification
Authors: Sürgers C. , Potzger K. , Strache T. , Möller W. , Fischer G. , Joshi N. , v. Löhneysen H.
Published: August 2008

Ferromagnetic Mn5Si3C0.8 and Mn5Ge3C0.8 films with Curie temperatures TC well above room temperature are obtained by C+12-ion implantation in antiferromagnetic Mn5Si3 or ferromagnetic Mn5Ge3. Patterning of the films with a gold mesh serving as a stencil mask during implantation allows a lateral modification of magnetic order creating ferromagnetic regions of Mn5Si3C0.8 which are embedded in antiferromagnetic Mn5Si3. This provides a procedure for the fabrication of magnetoelectronic hybrid devices comprised of different magnetic phases.
Weighted-residual integral boundary-layer model for the nonlinear dynamics of thin liquid films falling on an undulating vertical wall
Authors: Oron Alexander , Heining Christian
Published: August 2008

A set of first-order weighted-residual integral boundary-layer equations describing the nonlinear dynamics of a thin liquid film falling on a corrugated periodic vertical wall is derived. The spatiotemporal dynamics of the films is analyzed analytically and numerically in the framework of this set. A steady-state flow is found in the case of an asymptotically small wall corrugation and its stability is investigated. It is found that steady flow regimes arise in the case of a relatively small wall wavelength for the Reynolds number below its critical value corresponding to the flat-wall flow and for larger amplitudes of the wall corrugation when the Reynolds number exceeds its critical value. In the case of a larger wall wavelength, the emerging flows are either genuinely nonstationary or time periodic. The temporal period of the time-periodic flows increases with the amplitude of the wall corrugation and decreases with the Reynolds number. A possibility of the emergence of reverse flows is also discussed.
Effect of zonal flow caused by microturbulence on the double tearing mode
Authors: Ishizawa A. , Nakajima N.
Published: August 2008

The effect of zonal flow shear on the double tearing mode is investigated by solving the linear reduced two-fluid equations for the equilibrium including zonal flow. The zonal flow caused by microturbulence is obtained from nonlinear simulation results presented by A. Ishizawa and N. Nakajima [Phys. Plasmas 14, 040702 (2007)]. There is no clear evidence that could indicate whether the double tearing mode is stabilized or destabilized by the zonal flow.
The contribution of grain boundary barriers to the electrical conductivity of titanium oxide thin films
Authors: Martin Nicolas , Besnard Aurélien , Sthal Fabrice , Vaz Filipe , Nouveau Corinne
Published: August 2008

Titanium oxide thin films were prepared by reactive magnetron sputtering. The reactive gas pulsing process was implemented to control the oxygen injection in the deposition process and, consequently, to tune the oxygen concentration in the films from pure titanium to stoichiometric TiO2, maintaining a homogeneous in-depth concentration. The electrical conductivity of the films was investigated as a function of the oxygen injection time, the metalloid concentration and temperature, in the range 90–600K. The curved Arrhenius plots of the conductivity were examined taking into account the grain boundary limited transport model of Werner (J. H. Werner [Solid State Phenom. 37–38, 213 (1994)]). The grain barrier heights were found to depend significantly on the oxygen supplied into the deposition process and thus, on the oxygen-to-titanium atomic ratio in the films. The analysis as a function of temperature showed that the conduction mechanism in the coatings was not solely limited by the oxygen-to-titanium atomic ratio, but also by the grain boundary scattering.
Polarization-independent extraordinary optical transmission in one-dimensional metallic gratings with broad slits
Authors: Lu Yuehui , Cho Min Hyung , Lee YoungPak , Rhee Joo Yull
Published: August 2008

Extraordinary optical transmission (EOT) is achievable for transverse-magnetic polarization in one-dimensional metallic gratings with very narrow slits due to the excitation of coupled surface plasmon polaritons (SPPs). In contrast, SPP-produced EOT for transverse-electric (TE) polarized light is impossible because of the absence of SPPs for this polarization. However, TE-polarized EOT produced by trapped modes has been demonstrated. In this work, we reanalyze this phenomenon and apply it to gratings with broad slits (still in subwavelength) without the need for a specific dielectric filler in the grooves. The design proposed in this work simplifies and makes more practical the realization of gratings that possess polarization-independent EOT.
Peptidoglycan recognition protein-SD provides versatility of receptor formation in
Drosophila
immunity
Authors: Wang Lihui , Gilbert Robert J. C. , Atilano Magda L. , Filipe Sergio R. , Gay Nicholas J. , Ligoxygakis Petros
Published: August 2008

In
Drosophila
, the enzymatic activity of the glucan binding protein GNBP1 is needed to present Gram-positive peptidoglycan (PG) to peptidoglycan recognition protein SA (PGRP-SA). However, an additional PGRP (PGRP-SD) has been proposed to play a partially redundant role with GNBP1 and PGRP-SA. To reconcile the genetic results with events at the molecular level, we investigated how PGRP-SD participates in the sensing of Gram-positive bacteria. PGRP-SD enhanced the binding of GNBP1 to Gram-positive PG. PGRP-SD interacted with GNBP1 and enhanced the interaction between GNBP1 and PGRP-SA. A complex containing all three proteins could be detected in native gels in the presence of PG. In solution, addition of a highly purified PG fragment induced the occurrence not only of the ternary complex but also of dimeric subcomplexes. These results indicate that the interplay between the binding affinities of different PGRPs provides sufficient flexibility for the recognition of the highly diverse Gram-positive PG.
Both cIAP1 and cIAP2 regulate TNFα-mediated NF-κB activation
Authors: Mahoney D. J. , Cheung H. H. , Mrad R. Lejmi , Plenchette S. , Simard C. , Enwere E. , Arora V. , Mak T. W. , Lacasse E. C. , Waring J. , Korneluk R. G.
Published: August 2008

The cellular inhibitor of apoptosis 1 and 2 (cIAP1 and cIAP2) proteins have been implicated in the activation of NF-κB by TNFα; however, genetic deletion of either cIAP1 or 2 did not support a physiologically relevant role, perhaps because of functional redundancy. To address this, we used combined genetic and siRNA knockdown approaches and report that cIAP1 and 2 are indeed critical, yet redundant, regulators of NF-κB activation upon TNFα treatment. Whereas NF-κB was properly activated by TNFα in cultured and primary cells deficient in either cIAP1 or 2, removal of both cIAPs severely blunted its activation. After treatment with TNFα, cIAP1 and 2 were rapidly recruited to the TNF receptor 1, along with the adapter protein TNF receptor associated factor 2. Importantly, either cIAP1 or 2 was required for proper TNF receptor 1 signalosome function. In their combined absence, polyubiquitination of receptor interacting protein 1, an upstream event necessary for NF-κB signaling, was attenuated. As a result, phosphorylation of the inhibitor of κB kinase β was diminished, and signal transduction was severely blunted. Consequently, cells missing both cIAP1 and 2 were sensitized to TNFα-mediated apoptosis. Collectively, these data demonstrate that either cIAP1 or 2 is required for proper Rip1 polyubiquitination and NF-κB activation upon TNFα treatment.
H elimination and metastable lifetimes in the UV photoexcitation of diacetylene
Authors: Silva R. , Gichuhi W. K. , Huang C. , Doyle M. B. , Kislov V. V. , Mebel A. M. , Suits A. G.
Published: August 2008

We present an experimental investigation of the UV photochemistry of diacetylene under collisionless conditions. The H loss channel is studied using DC slice ion imaging with two-color reduced-Doppler detection at 243 nm and 212 nm. The photochemistry is further studied deep in the vacuum UV, that is, at Lyman-alpha (121.6 nm). Translational energy distributions for the H + C
4
H product arising from dissociation of C
4
H
2
after excitation at 243, 212, and 121.6 nm show an isotropic angular distribution and characteristic translational energy profile suggesting statistical dissociation from the ground state or possibly from a low-lying triplet state. From these distributions, a two-photon dissociation process is inferred at 243 nm and 212 nm, whereas at 121.6 nm, a one-photon dissociation process prevails. The results are interpreted with the aid of
ab initio
calculations on the reaction pathways and statistical calculations of the dissociation rates and product branching. In a second series of experiments, nanosecond time-resolved phototionization measurements yield a direct determination of the lifetime of metastable triplet diacetylene under collisionless conditions, as well as its dependence on excitation energy. The observed submicrosecond lifetimes suggest that reactions of metastable diacetylene are likely to be less important in Titan's atmosphere than previously believed.
The effect of particle design on cellular internalization pathways
Authors: Gratton Stephanie E. A. , Ropp Patricia A. , Pohlhaus Patrick D. , Luft J. Christopher , Madden Victoria J. , Napier Mary E. , DeSimone Joseph M.
Published: August 2008

The interaction of particles with cells is known to be strongly influenced by particle size, but little is known about the interdependent role that size, shape, and surface chemistry have on cellular internalization and intracellular trafficking. We report on the internalization of specially designed, monodisperse hydrogel particles into HeLa cells as a function of size, shape, and surface charge. We employ a top-down particle fabrication technique called PRINT that is able to generate uniform populations of organic micro- and nanoparticles with complete control of size, shape, and surface chemistry. Evidence of particle internalization was obtained by using conventional biological techniques and transmission electron microscopy. These findings suggest that HeLa cells readily internalize nonspherical particles with dimensions as large as 3 μm by using several different mechanisms of endocytosis. Moreover, it was found that rod-like particles enjoy an appreciable advantage when it comes to internalization rates, reminiscent of the advantage that many rod-like bacteria have for internalization in nonphagocytic cells.
Optical induction of plasticity at single synapses reveals input-specific accumulation of αCaMKII
Authors: Zhang Yan-Ping , Holbro Niklaus , Oertner Thomas G.
Published: August 2008

Long-term potentiation (LTP), a form of synaptic plasticity, is a primary experimental model for understanding learning and memory formation. Here, we use light-activated channelrhodopsin-2 (ChR2) as a tool to study the molecular events that occur in dendritic spines of CA1 pyramidal cells during LTP induction. Two-photon uncaging of MNI-glutamate allowed us to selectively activate excitatory synapses on optically identified spines while ChR2 provided independent control of postsynaptic depolarization by blue light. Pairing of these optical stimuli induced lasting increase of spine volume and triggered translocation of αCaMKII to the stimulated spines. No changes in αCaMKII concentration or cytoplasmic volume were observed in neighboring spines on the same dendrite, providing evidence that αCaMKII accumulation at postsynaptic sites is a synapse-specific memory trace of coincident activity.
Ice cores record significant 1940s Antarctic warmth related to tropical climate variability
Authors: Schneider David P. , Steig Eric J.
Published: August 2008

Although the 20th Century warming of global climate is well known, climate change in the high-latitude Southern Hemisphere (SH), especially in the first half of the century, remains poorly documented. We present a composite of water stable isotope data from high-resolution ice cores from the West Antarctic Ice Sheet. This record, representative of West Antarctic surface temperature, shows extreme positive anomalies in the 1936–45 decade that are significant in the context of the background 20th Century warming trend. We interpret these anomalies—previously undocumented in the high-latitude SH—as indicative of strong teleconnections in part driven by the major 1939–42 El Niño. These anomalies are coherent with tropical sea-surface temperature, mean SH air temperature, and North Pacific sea-level pressure, underscoring the sensitivity of West Antarctica's climate, and potentially its ice sheet, to large-scale changes in the global climate.
Metastatic osteosarcoma induced by inactivation of
Rb
and
p53
in the osteoblast lineage
Authors: Berman Seth D. , Calo Eliezer , Landman Allison S. , Danielian Paul S. , Miller Emily S. , West Julie C. , Fonhoue Borel Djouedjong , Caron Alicia , Bronson Roderick , Bouxsein Mary L. , Mukherjee Siddhartha , Lees Jacqueline A.
Published: August 2008

Mutation of the
RB-1
and
p53
tumor suppressors is associated with the development of human osteosarcoma. With the goal of generating a mouse model of this disease, we used conditional and transgenic mouse strains to inactivate
Rb
and/or
p53
specifically in osteoblast precursors. The resulting
Rb;p53
double mutant (DKO) animals are viable but develop early onset osteosarcomas with complete penetrance. These tumors display many of the characteristics of human osteosarcomas, including being highly metastatic. We established cell lines from the DKO osteosarcomas to further investigate their properties. These immortalized cell lines are highly proliferative and they retain their tumorigenic potential, as judged by their ability to form metastatic tumors in immunocompromised mice. Moreover, they can be induced to differentiate and, depending on the inductive signal, will adopt either the osteogenic or adipogenic fate. Consistent with this multipotency, a significant portion of these tumor cells express Sca-1, a marker that is typically associated with stem cells/uncommitted progenitors. By assaying sorted cells in transplant assays, we demonstrate that the tumorigenicity of the osteosarcoma cell lines correlates with the presence of the Sca-1 marker. Finally, we show that loss of
Rb
and
p53
in Sca-1-positive mesenchymal stem/progenitor cells is sufficient to yield transformed cells that can initiate osteosarcoma formation
in vivo
.
Gestures and some key issues in the study of language development
Authors: Gullberg Marianne , de Bot Kees , Volterra Virginia
Published: August 2008

The purpose of the current paper is to outline how gestures can contribute to the study of some key issues in language development. Specifically, we (1) briefly summarise what is already known about gesture in the domains of first and second language development, and development or changes over the life span more generally; (2) highlight theoretical and empirical issues in these domains where gestures can contribute in important ways to further our understanding; and (3) summarise some common themes in all strands of research on language development that could be the target of concentrated research efforts.
Before L1
Authors: Liszkowski Ulf
Published: August 2008

This paper investigates the social-cognitive and motivational complexities underlying prelinguistic infants’ gestural communication. With regard to deictic referential gestures, new and recent experimental evidence shows that infant pointing is a complex communicative act based on social-cognitive skills and cooperative motives. With regard to infant representational gestures, findings suggest the need to re-interpret these gestures as initially non-symbolic gestural social acts. Based on the available empirical evidence, the paper argues that deictic referential communication emerges as a foundation of human communication first in gestures, already before language. Representational symbolic communication, instead, emerges as a transformation of deictic communication first in the vocal modality and, perhaps, in gestures through non-symbolic, socially situated routines.
The relationship between spontaneous gesture production and spoken lexical ability in children with Down syndrome in a naming task
Authors: Stefanini Silvia , Recchia Martina , Caselli Maria Cristina
Published: August 2008

We examined the relationship between spontaneous gesture production and spoken lexical ability in children with Down syndrome (DS) in a naming task. Fifteen children with DS (3;8–8;3 years) were compared to 15 typically developing (TD) children matched for developmental age (DATD) (2;6–4;3 years of chronological age) and 15 matched for lexical ability identified by the MacArthur-Bates CDI questionnaire (LATD) (1;9–2;6 years of chronological age). Children of the DATD group displayed a larger number of correct spoken answers compared to other groups, while DS and LATD groups showed a similar naming accuracy. In comparison to both groups of TD children, a higher number of unintelligible answers was produced by children with DS, indicating that their spoken language is characterized by serious phono-articulatory difficulties. Although children with DS did not differ from DATD and LATD controls on the total number of gestures, they produced a significantly higher percentage of representational gestures. Furthermore, DATD children produced more spoken answers without gestures, LATD children produced more bimodal answers, while children with DS gestured more without speech. Results suggest that representational gestures may serve to express meanings when children’s cognitive abilities outstrip their productive spoken language skills.
Gesture and information structure in first and second language
Authors: Yoshioka Keiko
Published: August 2008

This study investigates the frequency of gestural marking of pre-introduced referents in discourse by Dutch learners of Japanese with native data as baseline. Of interest is whether learners’ over-explicit marking of referents in speech and gesture reported in the literature is a phenomenon related specifically to the acquisition process of pronominal systems or a general phenomenon related to learning to structure information in a target-like manner irrespective of target languages. The data were analyzed in terms of referential expressions used (lexical NP, pronoun, zero-anaphora) and of the rate of gestures accompanying mentions of referents. The results reveal that even when the target language does not have an active use of pronouns, learners overtly specify referents in two modalities. Cross-linguistic variations in discourse-related gestures and possible accounts of the frequent gestural marking of referents in L2 are discussed.
Gesture viewpoint in Japanese and English
Authors: Brown Amanda
Published: August 2008

Abundant evidence across languages, structures, proficiencies, and modalities shows that properties of first languages influence performance in second languages. This paper presents an alternative perspective on the interaction between established and emerging languages within second language speakers by arguing that an L2 can influence an L1, even at relatively low proficiency levels. Analyses of the gesture viewpoint employed in English and Japanese descriptions of motion events revealed systematic between-language and within-language differences. Monolingual Japanese speakers used significantly more Character Viewpoint than monolingual English speakers, who predominantly employed Observer Viewpoint. In their L1 and their L2, however, native Japanese speakers with intermediate knowledge of English patterned more like the monolingual English speakers than their monolingual Japanese counterparts. After controlling for effects of cultural exposure, these results offer valuable insights into both the nature of cross-linguistic interactions within individuals and potential factors underlying gesture viewpoint.