bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical modeling of artificial ionospheric layers driven by high‐power HF heating
Authors: Eliasson B. , Shao X. , Milikh G. , Mishin E. V. , Papadopoulos K.
Published: September 2012

We present a multi‐scale dynamic model for the creation and propagation of artificial plasma layers in the ionosphere observed during high‐power high‐frequency (HF) heating experiments at HAARP. Ordinary (O) mode electromagnetic (EM) waves excite parametric instabilities and strong Langmuir turbulence (SLT) near the reflection point. The coupling between high‐frequency electromagnetic and Langmuir waves and low‐frequency ion acoustic waves is numerically simulated using a generalized Zakharov equation. The acceleration of plasma electrons is described by a Fokker‐Planck model with an effective diffusion coefficient constructed using the simulated Langmuir wave spectrum. The propagation of the accelerated electrons through the non‐uniform ionosphere is simulated by a kinetic model accounting for elastic and inelastic collisions with neutrals. The resulting ionization of neutral gas increases the plasma density below the acceleration region, so that the pump wave is reflected at a lower altitude. This leads to a new turbulent layer at the lower altitude, resulting in a descending artificial ionized layer (DAIL), that moves from near 230 km to about 150 km. At the terminal altitude, ionization, recombination, and ambipolar diffusion reach equilibrium, so the descent stops. The modeling results reproduce artificial ionospheric layers produced for similar sets of parameters during the high‐power HF experiments at HAARP.
Assessing the importance and expression of the 6 year geomagnetic oscillation
Authors: Silva L. , Jackson L. , Mound J.
Published: September 2012

The first time derivative of residual length‐of‐day observations is known to contain a distinctive 6 year periodic oscillation. Here we theorize that through the flow accelerations at the top of the core the same periodicity should arise in the geomagnetic secular acceleration. We use the secular acceleration of the CHAOS‐3 and CM4 geomagnetic field models to recover frequency spectra through both a traditional Fourier analysis and an empirical mode decomposition. We identify the 6 year periodic signal in the geomagnetic secular acceleration and characterize its spatial behavior. This signal seems to be closely related to recent geomagnetic jerks. We also identify a 2.5 year periodic signal in CHAOS‐3 with unknown origin. This signal is strictly axially dipolar and is absent from other magnetic or geodetic time series.
Aviation‐induced radiative forcing and surface temperature change in dependency of the emission altitude
Authors: Frömming C. , Ponater M. , Dahlmann K. , Grewe V. , Lee D. S. , Sausen R.
Published: September 2012

The present study provides a detailed assessment of the net impact of global flight altitude changes on radiative forcing and temperature response. Changes in contrail coverage, chemical perturbations (H2O, O3, CH4) and associated radiative forcings were determined from simulations with a quasi CTM. Future development of global mean radiative forcing and temperature response was calculated by means of a linear response model. The range of possible effects arising from various future scenarios is analyzed, and tradeoffs between partially counteracting short‐ and long term effects are studied. Present‐day global mean radiative forcing of short‐lived species and CH4 is reduced when flying lower, whereas that of CO2increases. The opposite effect is found for higher flight altitudes. For increasing and sustained emissions, the climate impact changes are dominated by the effect of short‐lived species, yielding a reduction for lower flight altitudes and an increase for higher flight altitudes. For future scenarios involving a reduction or termination of emissions, radiative forcing of short‐lived species decreases immediately, that of longer lived species decreases gradually, and respective temperature responses start to decay slowly. After disappearance of the shorter lived effects, only the counteracting CO2 effect remains, resulting in an increased climate effect for lower flight altitudes and a decrease for higher flight altitudes. Incorporating knowledge about the altitude sensitivity of aviation climate impact in the route planning process offers substantial mitigation potential. Scenarios and time horizons for the evaluation of future effects of mitigation instruments must be chosen carefully depending on the mitigation aim.
Asymmetry of Io's outer atmosphere: Constraints from five Galileo flybys
Authors: Dols Vincent , Delamere Peter A. , Bagenal Fran , Kurth William S. , Paterson William R.
Published: September 2012

The Galileo spacecraft probed the Io atmosphere/torus interaction region along six flybys between 1995 and 2001. The instruments on board provided measurements of the plasma density, average ion temperature, composition, flow, and magnetic perturbations to which we compare models and from which we constrain Io's atmosphere asymmetries. We have developed a model of the local interaction at Io that couples an MHD model of the flow and magnetic perturbations around the moon with a multispecies chemistry model that includes the physical chemistry of the main species: atoms, molecules, and ions derived from Io's volcanic gases (S, O, SO2, SO). We prescribe several scenarios of the multicomponent neutral atmosphere of Io based on observations and compare our results with the plasma properties inferred from the Galileo measurements. Owing to limited data on the I25 flyby, it is excluded to make a total of five flybys for our comparisons. We show that the ion average temperature profile is a key quantity to constrain the radial extension and longitudinal asymmetries of the atmosphere of Io. We propose that the atmosphere has longitudinal asymmetries: its radial extension is limited upstream and significantly larger on the anti‐Jovian downstream side. A very extended corona of SO2and SO is present mainly downstream of Io. We discuss the possible temporal variability of Io's plasma‐atmosphere interaction by comparing two flybys at different times at approximately the same location in the wake. We also discuss the plasma composition in the wake and the O1356A auroral emissions observed on the flanks of Io.
A pore network model study of the fluid‐fluid interfacial areas measured by dynamic‐interface tracer depletion and miscible displacement water phase advective tracer methods
Authors: Kibbey Tohren C. G. , Chen Lixia
Published: September 2012

Fluid‐fluid interfacial areas in porous media are of considerable interest due to the impact they have on a wide range of practical applications involving mass transfer between phases, as well as for their importance in understanding unsaturated and multiphase flow behaviors in porous media. Tracer methods provide a low‐cost experimental approach for determining interfacial areas in porous media. Although a number of different tracer methods have been developed, uncertainty remains as to exactly what areas they measure. The work presented here uses pore network model simulations to study the behavior of tracers during simulated tracer measurements for two different specific water‐phase tracer methods: the dynamic‐interface tracer depletion method and the miscible displacement tracer method. The hypothesis driving this work was that different tracer methods likely measure different areas as a result of the very different ways tracers are used. Experimental data sets for six different porous media were used to validate the model and provide comparison with model‐simulated tracer‐based area measurements. Results of the work suggest that areas measured using the dynamic‐interface tracer depletion method closely match total fluid‐fluid interfacial areas, as long as the extent of tracer depletion during the method is relatively small. However, areas measured with the miscible displacement method likely fall somewhere between capillary and total fluid‐fluid areas. Calculations conducted with realistic diffusion coefficients and film thicknesses indicate that diffusion and head‐driven flow in films are insufficient to allow significant tracer access to film area, suggesting the potential importance of other mechanisms. Calculations conducted as a part of the work suggest that Leverett estimates of maximum area formed during drainage may be closer to total areas than previously reported.
Experimental and theoretical investigation of the effect of SiO2 content in gate dielectrics on work function shift induced by nanoscale capping layers
Authors: Caraveo-Frescas J. A. , Wang H. , Schwingenschlögl U. , Alshareef H. N.
Published: September 2012

The impact of SiO2 content in ultrathin gate dielectrics on the magnitude of the effective work function (EWF) shift induced by nanoscale capping layers has been investigated experimentally and theoretically. The magnitude of the effective work function shift for four different capping layers (AlN, Al2O3, La2O3, and Gd2O3) is measured as a function of SiO2 content in the gate dielectric. A nearly linear increase of this shift with SiO2 content is observed for all capping layers. The origin of this dependence is explained using density functional theory simulations.
Atomic gas temperature in a nonequilibrium high-intensity discharge lamp determined from the red wing of the resonance mercury line 254 nm
Authors: Drakakis E. , Karabourniotis D.
Published: September 2012

For developing low-wattage high intensity discharge (HID) lamps, a better understanding of the relatively unexplored nonequilibrium phenomena is essential. This needs interpretation of diagnostic results by methods free from equilibrium assumptions. In this paper, the atomic temperature is determined from the simulation of a quasistatic broadened resonance line by distinguishing between atomic temperature and excitation temperature in the equation of radiative transfer. The proposed method is applied to the red wing of the resonance mercury line 254 nm emitted from a HID lamp working on ac. The experimental results show severe deviation from local thermodynamic equilibrium. More than one thousand degrees difference was obtained between atomic and electron temperatures at the maximum current phase.
Analytical solutions to a class of non-Newtonian fluids with free boundaries
Authors: Fang Li , Guo Zhenhua
Published: September 2012

We study analytical solutions to a class of non-Newtonian fluids with free boundaries. For suitable non-Newtonian fluids, we construct a class of analytical solutions in \documentclass[12pt]{minimal}\begin{document}${\mathbb R}$\end{document}R with both continuous density condition and the stress free condition across the free boundaries separating the fluid from vacuum. Such solutions exhibit interesting new information such as the formation of vacuum as time tends to infinitely and explicit regularities and large time decay estimates of the velocity field.
Effect of nanoparticle polydispersity on the self-assembly of polymer tethered nanospheres
Authors: Phillips Carolyn L. , Glotzer Sharon C.
Published: September 2012

Recent simulations predict that aggregating nanospheres functionalized with polymer “tethers” can self-assemble to form a cylinder, perforated lamellae, lamellae, and even the double gyroid phase, which are phases also seen in block copolymer and surfactant systems. Nanoparticle size polydispersity is likely to be a characteristic of these systems. If too high, polydispersity may destabilize a phase. Using multiple thermodynamic paths to explore the phase diagram as a function of temperature and polydispersity, we explore the effect of nanosphere size polydispersity on the phase diagram. We show that in the portions of the phase diagram characterized by an icosahedral local nanoparticle packing motif, a low amount of polydispersity lowers the energy and a large amount of polydispersity raises the energy of the system by disrupting the icosahedral packing. In general, regions of the phase diagram characterized by liquid-like icosahedral packing have high terminal polydispersities from 15% to more than 30%. In the regions of the phase diagram characterized by crystalline local packing, polydispersity raises the energy of the system and induces a phase transition from crystalline to liquid-like ordering within the nanosphere rich regions of the microphase. We find the bilayer crystalline lamellae phase has a terminal polydispersity of 6%, but may still be partially crystalline up to 12%.
Spectroscopy and dynamics of the predissociated, quasi-linear S2 state of chlorocarbene
Authors: Tao Chong , Richmond Craig A. , Mukarakate Calvin , Kable Scott H. , Bacskay George B. , Brown Eric C. , Dawes Richard , Lolur Phalgun , Reid Scott A.
Published: September 2012

In this work, we report on the spectroscopy and dynamics of the quasi-linear S2 state of chlorocarbene, CHCl, and its deuterated isotopologue using optical-optical double resonance (OODR) spectroscopy through selected rovibronic levels of the S1 state. This study, which represents the first observation of the S2 state in CHCl, builds upon our recent examination of the corresponding state in CHF, where pronounced mode specificity was observed in the dynamics, with predissociation rates larger for levels containing bending excitation. In the present work, a total of 14 S2 state vibrational levels with angular momentum ℓ = 1 were observed for CHCl, and 34 levels for CDCl. The range of ℓ in this case was restricted by the pronounced Renner-Teller effect in the low-lying S1 levels, which severely reduces the fluorescence lifetime for levels with Ka > 0. Nonetheless, by exploiting different intermediate S1 levels, we observed progressions involving all three fundamental vibrations. For levels with long predissociation lifetimes, rotational constants were determined by measuring spectra through different intermediate J levels of the S1 state. Plots of the predissociation linewidth (lifetime) vs. energy for various S2 levels show an abrupt onset, which lies near the calculated threshold for elimination to form C(3P) + HCl on the triplet surface. Our experimental results are compared with a series of high level ab initio calculations, which included the use of a dynamically weighted full-valence CASSCF procedure, focusing maximum weight on the state of interest (the singlet and triplet states were computed separately). This was used as the reference for subsequent Davidson-corrected MRCI(+Q) calculations. These calculations reveal the presence of multiple conical intersections in the singlet manifold.
Theoretical and experimental approach on dielectric properties of ZnO nanoparticles and polyurethane/ZnO nanocomposites
Authors: Velayutham T. S. , Abd Majid W. H. , Gan W. C. , Khorsand Zak A. , Gan S. N.
Published: September 2012

ZnO nanoparticles (ZnO-NPs) were synthesized by a new, simple sol-gel method in gelatin media (particle size of ZnO ≈ 30 to 60 nm). Polyurethane/ZnO nanocomposites thin films (PU/ZnO-NPs) were prepared by mixing the ZnO-NPs into PU prepolymer. The nanocomposites were structurally characterized using Fourier transmission infrared (FTIR) spectroscopy. The interaction between ZnO-NPs and PU matrix is studied by analyzing the differences in C=O region and N-H region of FTIR spectra. The morphology of ZnO and PU/ZnO nanocomposites were assessed using transmission electron micrograph, TEM, and field emission scanning electron microscope, FESEM, respectively. The dielectric properties of ZnO-NPs were attributed to the interfacial and orientation polarization. Measurement is reported for the real and imaginary parts of the ac conductivity of ZnO-NPs in the frequency range of 10 to 106 Hz in the temperature range 298–478 K. The experimental results are interpreted in terms of the classical correlated-barrier hopping theory. In addition, the dielectric properties of PU/ZnO nanocomposites (0–15 vol. % filler concentration) were analyzed with respect to frequency. Quantitative analysis based on mixing laws for two-phase spherical dispersion system such as Lichtenecker, Maxwell, Jayasundere and Smith, and Yamada equations was used to predict the effective permittivity accurately up to 15 vol. % of ZnO in PU matrix.
Band gap enhancement of glancing angle deposited TiO2 nanowire array
Authors: Chinnamuthu P. , Mondal A. , Singh N. K. , Dhar J. C. , Chattopadhyay K. K. , Bhattacharya Sekhar
Published: September 2012

Vertically oriented TiO2 nanowire (NW) arrays were fabricated by glancing angle deposition technique. Field emission-scanning electron microscopy shows the formation of two different diameters ∼80 nm and ∼40 nm TiO2 NW for 120 and 460 rpm azimuthal rotation of the substrate. The x-ray diffraction and Raman scattering depicted the presence of rutile and anatase phase TiO2. The overall Raman scattering intensity decreased with nanowire diameter. The role of phonon confinement in anatase and rutile peaks has been discussed. The red (7.9 cm−1 of anatase Eg) and blue (7.4 cm−1 of rutile Eg, 7.8 cm−1 of rutile A1g) shifts of Raman frequencies were observed. UV-vis absorption measurements show the main band absorption at 3.42 eV, 3.48 eV, and ∼3.51 eV for thin film and NW prepared at 120 and 460 rpm, respectively. Three fold enhance photon absorption and intense light emission were observed for NW assembly. The photoluminescence emission from the NW assembly revealed blue shift in main band transition due to quantum confinement in NW structures.
Refined theoretical study of radiative association: Cross sections and rate constants for the formation of SiN
Authors: Gustafsson Magnus , Antipov Sergey V. , Franz Jan , Nyman Gunnar
Published: September 2012

Radiative association of silicon mononitride (SiN) in its two lowest molecular electronic states is studied through quantum and classical dynamics. Special attention is paid to the behavior of the cross section at high collision energies. A modified expression for the semiclassical cross section is presented which excludes transitions to continuum states. This gives improved agreement with quantum mechanical perturbation theory at high energies. The high energy cross section is overestimated if conventional semiclassical theory is used. The modified semiclassical theory should be valid in general for radiative association transitions from an upper to a lower electronic state. We also implement a quantum dynamical optical potential method with the same type of modification. The rate coefficient is calculated using Breit–Wigner theory and the modified semiclassical formula for the resonance and direct contributions, respectively, for temperatures from 10 K to 20 000 K. A rapid decrease in the rate constant for formation of ground state SiN is observed above 2000 K which was not seen previously.
Secondary nontwist phenomena in area-preserving maps
Authors: Vieira Abud C. , Caldas I. L.
Published: September 2012

Phenomena as reconnection scenarios, periodic-orbit collisions, and primary shearless tori have been recognized as features of nontwist maps. Recently, these phenomena and secondary shearless tori were analytically predicted for generic maps in the neighborhood of the tripling bifurcation of an elliptic fixed point. In this paper, we apply a numerical procedure to find internal rotation number profiles that highlight the creation of periodic orbits within islands of stability by a saddle-center bifurcation that emerges out a secondary shearless torus. In addition to the analytical predictions, our numerical procedure applied to the twist and nontwist standard maps reveals that the atypical secondary shearless torus occurs not only near a tripling bifurcation of the fixed point but also near a quadrupling bifurcation.
Effect of light Si-doping on the near-band-edge emissions in high quality GaN
Authors: Le L. C. , Zhao D. G. , Jiang D. S. , Wu L. L. , Li L. , Chen P. , Liu Z. S. , Zhu J. J. , Wang H. , Zhang S. M. , Yang H.
Published: September 2012

We have investigated the effect of light Si-doping on the optical properties of high quality GaN films with the method of low temperature photoluminescence. It is found that the peak (Ix) at 3.473 eV always appears in the photoluminescence spectra of lightly Si-doped GaN. The relative intensity of peak Ix to heavy-hole free exciton peak increases linearly with the increasing concentration of Si doping, providing a strong support to the assignment that Ix originates from inelastic scattering of free excitons by Si donors. In addition, a rarely reported peak (Px) at 3.365 eV can only be clearly observed in the PL spectrum of unintentionally doped GaN sample. Its intensity is found to reduce dramatically with the decrease of residual carbon concentration based on the secondary ion mass spectrometry analysis. Px is attributed to the excitons bound to carbon-related complex defects.
Infrared spectroscopy of hydrated naphthalene cluster anions
Authors: Knurr Benjamin J. , Adams Christopher L. , Weber J. Mathias
Published: September 2012

We present infrared spectra of mass-selected C10H8−·(H2O)n·Arm cluster anions (n = 1–6) obtained by Ar predissociation spectroscopy. The experimental spectra are compared with predicted spectra from density functional theory calculations. The OH groups of the water ligands are involved in H-bonds to other water molecules or to the π system of the naphthalene anion, which accommodates the excess electron. The interactions in the water network are generally found to be more important than those between water molecules and the ion. For 2 ≤ n ≤ 4 the water molecules form single layer water networks on one side of the naphthalene anion, while for n = 5 and 6, cage and multilayer structures become more energetically favorable. For cluster sizes with more than 3 water molecules, multiple conformers are likely to be responsible for the experimental spectra.
First-principles study of O-BN: A sp3-bonding boron nitride allotrope
Authors: Huang Quan , Yu Dongli , Zhao Zhisheng , Fu Siwei , Xiong Mei , Wang Qianqian , Gao Yufei , Luo Kun , He Julong , Tian Yongjun
Published: September 2012

A fully tetrahedrally bonded boron nitride (BN) allotrope with an orthorhombic structure (O-BN) was investigated through first-principles calculations. O-BN has a bulk modulus of 371.8 GPa and a hardness of 66.4 GPa, thereby making it a superhard material with potential technological and industrial applications. O-BN becomes thermodynamically more stable than layered hexagonal BN (h-BN) at pressure above 1.5 GPa and is more favorable than the recently reported Pct-BN at any pressure. The phase transformations from h-BN and BN nanotubes to O-BN were respectively simulated, indicating the feasible synthesis of this superhard phase.
Fiber-optic Raman sensing of cell proliferation probes and molecular vibrations: Brain-imaging perspective
Authors: Doronina-Amitonova Lyubov V. , Fedotov Il'ya V. , Ivashkina Olga I. , Zots Marina A. , Fedotov Andrei B. , Anokhin Konstantin V. , Zheltikov Aleksei M.
Published: September 2012

Optical fibers are employed to sense fingerprint molecular vibrations in ex vivo experiments on the whole brain and detect cell proliferation probes in a model study on a quantitatively controlled solution. A specifically adapted spectral filtering procedure is shown to allow the Raman signal from molecular vibrations of interest to be discriminated against the background from the fiber, allowing a highly sensitive Raman detection of the recently demonstrated EdU (5-ethynyl-2′-deoxyuridine) labels of DNA synthesis in cells.
Generation of high-frequency terahertz waves in periodically poled LiNbO3 based on backward parametric interaction
Authors: Chen Ruolin , Sun Guan , Xu Guibao , Ding Yujie J. , Zotova Ioulia B.
Published: September 2012

Backward terahertz pulses at high frequencies are generated in multi-period periodically poled LiNbO3 using ultrafast pulses of a regenerative amplifier. The highest frequencies generated by us are centered at 4.8 THz at the poling period of 7.1 μm, corresponding to the output wavelength of 62.5 μm. Enhancement factors as large as 61 in the output powers are achieved and analyzed due to resonance-enhanced nonlinear optical coefficients.
Effect of bulk electric field reversal on the bounce resonance heating in dual-frequency capacitively coupled electronegative plasmas
Authors: Liu Yong-Xin , Zhang Quan-Zhi , Liu Jia , Song Yuan-Hong , Bogaerts Annemie , Wang You-Nian
Published: September 2012

The electron bounce resonance heating (BRH) in dual-frequency capacitively coupled plasmas operated in oxygen and argon has been studied by different experimental methods. In comparison with the electropositive argon discharge, the BRH in an electronegative discharge occurs at larger electrode gaps. Kinetic particle simulations reveal that in the oxygen discharge, the bulk electric field becomes quite strong and is out of phase with the sheath field. Therefore, it retards the resonant electrons when traversing the bulk, resulting in a suppressed BRH. This effect becomes more pronounced at lower high-frequency power, when the discharge mode changes from electropositive to electronegative.
Total energy loss to fast ablator-ions and target capacitance of direct-drive implosions on OMEGA
Authors: Sinenian N. , Zylstra A. B. , Manuel M. J.-E. , Rinderknecht H. G. , Frenje J. A. , Séguin F. H. , Li C. K. , Petrasso R. D. , Goncharov V. , Delettrez J. , Igumenshchev I. V. , Froula D. H. , Stoeckl C. , Sangster T. C. , Meyerhofer D. D. , Cobble J. A. , Hicks D. G.
Published: September 2012

Measurements of the total energy carried by fast ablator-ions in direct-drive implosions on OMEGA have been conducted using magnetic and Thomson Parabola spectrometers. It is shown that the total laser energy lost to fast ablator-ions for plastic and glass targets is comparable and that it is a modest fraction of the incident laser energy (≲1%). These measurements have been used to infer a non-linear, voltage-dependent target capacitance (∼0.1 nF) associated with the space-charge that accelerates the fast-ions.
Communication: From graphite to diamond: Reaction pathways of the phase transition
Authors: Xiao Penghao , Henkelman Graeme
Published: September 2012

Phase transitions between carbon allotropes are calculated using the generalized solid-state nudged elastic band method. We find a new reaction mechanism between graphite and diamond with nucleation characteristics that has a lower activation energy than the concerted mechanism. The calculated barrier from graphite to hexagonal diamond is lower than to cubic diamond, resolving a conflict between theory and experiment. Transitions are calculated to three structures of cold compressed graphite: bct C4, M, and Z-carbon, which are accessible at the experimentally relevant pressures near 17 GPa.
Ultra-high cooling rate utilizing thin film evaporation
Authors: Su Fengmin , Ma Hongbin , Han Xu , Chen Hsiu-hung , Tian Bohan
Published: September 2012

This research introduces a cell cryopreservation method, which utilizes thin film evaporation and provides an ultra-high cooling rate. The microstructured surface forming the thin film evaporation was fabricated from copper microparticles with an average diameter of 50 μm. Experimental results showed that a cooling rate of approximately 5×104 °C/min was achieved in a temperature range from 10 °C to −187 °C. The current investigation will give birth to a cell cryopreservation method through vitrification with relatively low concentrations of cryoprotectants.
Multifetal pregnancies: preterm admissions and outcomes
Authors: Badgery-Parker Tim , Shand Antonia W. , Ford Jane B. , Jenkins Mary G. , Morris Jonathan M. , Roberts Christine L.
Published: September 2012

Objective.
To describe the rates of antenatal hospital admission during twin or higher order multifetal pregnancies, and the admission outcomes as discharge undelivered, transfer to higher care, or spontaneous or elective delivery.

Methods.
Cohort study using linked birth and hospital data. The cohort comprised women who gave birth to twins or higher order multiple infants of ≥ 24 weeks gestation in 2001–2008 and who were admitted to hospital in weeks 20–36 of the pregnancy.

Results.
In 63.4% of 10 779 twin pregnancies and 99.5% of 197 triplet and quadruplet pregnancies, the woman was admitted to hospital at least once in weeks 20–36 of the pregnancy, for a total 10 985 admissions. Almost half the admissions (46.3%) ended in discharge without delivery, 10.7% in transfer to higher care, 21.1% in spontaneous labour and birth, and 21.8% in elective delivery (induction or prelabour Caesarean section). The reason for admission was preterm labour in 34.2% of admissions.

Conclusions.
Hospital admission during pregnancy is common for women with multifetal pregnancies, with many of these admissions resulting in preterm birth. This is the first study to report the rate of pregnancy admissions for women with multifetal pregnancies, and provides a baseline for future studies of hospital use in this population.

What is known about the topic?
Multifetal pregnancies are high risk and require greater medical care than singleton pregnancies. However, few studies specifically examine multifetal pregnancies, and most pregnancy studies exclude them, so there is little known about the resource use of this group.

What does this paper add?
This is the first paper to report population rates of hospital admission during pregnancy for women with multifetal pregnancies. We report the admission rates, and the admission outcomes as discharge undelivered, transfer to higher care or spontaneous or elective delivery.

What are the implications for practitioners?
Most women with multifetal pregnancies are admitted to hospital at least once during the pregnancy, with 51% of these admissions resulting in preterm delivery. Of those discharged undelivered, 60% were admitted for 1 day or less. This has implications for resource use, proposed place of birth and for practitioners advising pregnant women.
The epidemiology of anal cancer
Authors: Grulich Andrew E. , Poynten I. Mary , Machalek Dorothy A. , Jin Fengyi , Templeton David J. , Hillman Richard J.
Published: September 2012

Anal cancer comprises malignancies of the anal canal principally of two morphologic variants: squamous cell carcinoma (SCC) and adenocarcinoma. In most settings, SCC compromises more than 70% of cases. In the general population, anal cancer is uncommon, with age-standardised incidence rates mostly between 1 and 2 per 100 000 per year. However, incidence of anal SCC is increasing by 1–3% per year in developed country settings. High-risk human papillomavirus (HPV) types can be detected in 80–90% of all anal SCC cases, making it second only to cervical cancer in the closeness of its association with this virus. HPV-16 can be detected in ~90% of HPV-positive cases of anal SCC. Case–control studies have demonstrated that sexual risk factors (homosexuality in men and multiple sexual partners in women) are strongly associated with anal cancer risk. Other risk factors include immune deficiency and tobacco exposure. Anal cancer rates are highest in homosexual men, particularly in those who are HIV-positive, in whom anal cancer is among the most common of all cancers. Vaccination against HPV holds great promise for anal cancer prevention for those not already HPV-infected. For the current generation of adult high-risk populations, screening programs to allow early detection and treatment are under investigation.
Gesture-plus-word combinations, transitional forms, and language development
Authors: Fasolo Mirco , D'Odorico Laura
Published: September 2012

The aim of the present study was to evaluate relationships between early production of gesture, gesture-plus-word combinations and transitional forms on successive lexical and syntactic skills. Twenty-four children interacting with their mothers were observed. We found that complementary gesture-plus-word combinations and transitional forms use at 18 months were related with lexical skill and MLU — but not with utterance complexity — at 24 months; supplementary gesture-plus-word combinations use at 18 months, instead, was related with utterance complexity, but not with lexical skill and MLU. These relationships are explained in terms of increasing communicative competence in the child and also in terms of the adult’s contribution to linguistic development.
Gestural-vocal coordination
Authors: Murillo Eva , Belinchón Mercedes
Published: September 2012

The aim of this study was to examine longitudinally gestural and vocal coordination in multimodal communicative patterns during the period of transition to first words, and its role in early lexical development. Eleven monolingual Spanish children were observed from 9 to 12 and 15 months of age in a semi-structured play situation. We obtained three main findings: (1) the use of multimodal patterns of communication increases significantly with age during the period studied; (2) the rate of use of those multimodal patterns at 12 months predicts lexical development at 15 months; and (3) the use of the pointing gesture at 12 months, especially when it is accompanied with vocalization and social use of gaze, is the best predictor of lexical outcome at 15 months. Our findings support the idea that gestures, gazes and vocalizations are part of an integrated and developing system that children use flexibly to communicate from early on. The coordination of these three types of elements, especially when a pointing gesture is involved, has a predictive value on early lexical development and appears as a key for progress in language development.
Cross-linguistic comparison of representations of motion in language and gesture
Authors: Chui Kawai
Published: September 2012

In the linguistic-gestural representation of motion events, the past studies showed that manner and path in English are mentioned within one clause, and the two components can be represented together in one gesture. In Turkish and Japanese, they are expressed separately in two clauses, and two separate gestures — one for manner and one for path — are produced accordingly. The present study investigates the linguistic-gestural expression of motion in Mandarin Chinese discourse, and finds that Mandarin speakers predominantly use simple manner verbs to express manner and serial verbs and prepositional phrases to convey path within a clause. In gestural representation, speakers prefer to depict path information only within a clause, be it carrying new or given information. The cross-linguistic differences demonstrate language specificity in linguistic encodings and manual depictions of motion. Such variation in how speech and gesture are used can further suggest language specificity in the conceptualization of motion events.
Resting hand postures
Authors: Dosso Jill A. , Whishaw Ian Q.
Published: September 2012

Persons engaged in talking often make manual gestures. When a gesture or a sequence of such gestures ends, the hands are brought to a rest position. In previous work it has been observed that in such rest positions the hands tend to assume one of two poses: Collection, in which the digits are lightly semi-flexed and closed, and Stationing, in which the digits are open and the digits and palm contact the body or a surface. In previous work it has also been observed that in practical actions such as reaching, Collection occurs when advancing the hand to grasp something. This has also been observed when the hand is lifted in preparation for a gesture. Stationing has been observed to occur once the hand ends a reaching action or when the hand returns to a rest position after engaging in gesture. In light of this, it was proposed that in conversations where speakers are engaging in gesturing, hands in a rest position of Collection might reflect an intention to continue discourse, and hands in a rest position of Stationing an intention to discontinue it. Accordingly, the occurrence of Collection and Stationing was noted in video recordings of pairs of subjects in conversations in which they were trying to agree about some topic given to them for debate. A Collected hand posture was frequently associated with continuation of an argument. A Stationed hand posture was frequently associated with a speaker’s concluding statements. Listeners were also observed to show Collection and Stationed hand shapes when speakers were engaged in continuing and concluding discourse, respectively. The relationship between speech intention and resting hand postures is discussed in relation to the possible meaningful roles that resting hand shape may have in discourse.
Variación conceptual y formal del término educación bilingüe intercultural (ebi) en distintos tipos de discursos
Authors: Messineo Cristina
Published: September 2012

This paper studies the use of the term educación bilingüe intercultural (ebi) (‘intercultural bilingual education’) both in specialized discourse as well as in non-specialized documents from the perspective of a proposal for a terminology which is at variance with the traditional point of view, oriented towards terminology normalization and prescription. The focus here is on communication: according to this approach, terms are considered as units of natural language with a capacity for reference, but, like words, they can also have other functions (expressive, conative, etc.), and can be used in different communicative settings. This analysis allows us to explain the term intercultural bilingual education in discourses produced in different socio-cultural situations, to observe the degree of competence the producers of such discourses have of such a term and to describe the formal and conceptual variation of the term according to the users and the type of text.
Relationship between Fish Size and Upper Thermal Tolerance
Authors: Recsetar Matthew S. , Zeigler Matthew P. , Ward David L. , Bonar Scott A. , Caldwell Colleen A.
Published: September 2012

Using critical thermal maximum (CTMax) tests, we examined the relationship between upper temperature tolerances and fish size (fry–adult or subadult lengths) of rainbow trout Oncorhynchus mykiss (41–200‐mm TL), Apache trout O. gilae apache (40–220‐mm TL), largemouth bass Micropterus salmoides (72–266‐mm TL), Nile tilapia Oreochromis niloticus (35–206‐mm TL), channel catfish Ictalurus punctatus (62–264 mm‐TL), and Rio Grande cutthroat trout O. clarkii virginalis (36–181‐mm TL). Rainbow trout and Apache trout were acclimated at 18°C, Rio Grande cutthroat trout were acclimated at 14°C, and Nile tilapia, largemouth bass, and channel catfish were acclimated at 25°C, all for 14 d. Critical thermal maximum temperatures were estimated and data were analyzed using simple linear regression. There was no significant relationship (P > 0.05) between thermal tolerance and length for Nile tilapia (P = 0.33), channel catfish (P = 0.55), rainbow trout (P = 0.76), or largemouth bass (P = 0.93) for the length ranges we tested. There was a significant negative relationship between thermal tolerance and length for Rio Grande cutthroat trout (R2 = 0.412, P < 0.001) and Apache trout (R2 = 0.1374, P = 0.028); however, the difference was less than 1°C across all lengths of Apache trout tested and about 1.3°C across all lengths of Rio Grande cutthroat trout tested. Because there was either no or at most a slight relationship between upper thermal tolerance and size, management and research decisions based on upper thermal tolerance should be similar for the range of sizes within each species we tested. However, the different sizes we tested only encompassed life stages ranging from fry to adult/subadult, so thermal tolerance of eggs, alevins, and larger adults should also be considered before making management decisions affecting an entire species.
Iran's “Twenty-Year Vision Document”: An Outlook on Science and Technology
Authors: Madarshahi Monir Sadat
Published: September 2012

In 2005, Iran outlined its goals in economic, science and technology for the next twenty years, Sanad-e- Cheshm Andaz-e Bist Saleh (The Twenty-Year Vision Document), a working plan to raise the country's ranking to that of the first in the region. This article aims to map Iran's scientific and technological performance over five years since the ratification of the plan. Three main areas of science and technology—the percentage of GDP invested in knowledge, scientific performance and technological performance—were used to compare Iran's scientific output with a set of regional countries. The study revealed that Iran's investment in science to inspire technology (the linear model) has been able to nourish scientific performance in the form of rising publication, whereas the neighboring countries followed a more diversified pathway and inspired science from technological advances. Thus, the number of countries in the region capable of competing with and even outstripping Iran in terms of technological and hence scientific performance has increased.
The term “Macedonian(s)” in Ottoman Macedonia: on the map and in the mind
Authors: Pandevska Maria
Published: September 2012

In this article I analyze the term “Macedonian(s)” based on the discourse of the Macedonian Revolutionary Organization (1893–1908) from the aspect of the internal understanding of the term as a supra-local and supra-church identity. Another matter for analysis in this article is that of the stereotypes in the interpretation of Macedonian historical processes inherited from the nineteenth century, still present in some contemporary historiographies. Hence, the article makes an attempt to bring down the stereotype about the existence of some unique Macedonian ethnic phenomenon known as the “Macedonian salad.” This article also deals with the significance of the geopolitical position of Ottoman Macedonia within the empire. More specifically, the emphasis is placed on the change of its position after the Great Eastern Crisis (1875–1881). Namely, for the first time since the Ottoman conquests in the Middle Ages, Macedonia's position within the empire changed from being a central to a peripheral Ottoman province, with all the advantages and disadvantages that this change brought about. This aspect of Macedonian historical reality is often neglected in the historiography.
Effects of Tournament Compared with Catch and Release Angling on Nest Abandonment of Largemouth Bass
Authors: Diana Matthew J. , Larsen Aaron L. , Siepker Michael J. , Wahl David H.
Published: September 2012

The popularity of tournament angling for largemouth bass Micropterus salmoides remains high, leading to concerns about the effects on populations. Catch-and-release angling and its effects on nest abandonment have been well documented, but few studies have examined the effects of competitive angling on nest abandonment. Nest-guarding male largemouth bass were subjected to one of three treatments: no angling (controls), catch-and-release angling, and simulated tournament angling. Abandonment rates were assessed at 24 h following angling. Both angling treatments experienced higher abandonment rates than the control group (3%) with tournament-angled males abandoning their nests at a higher rate (90%) than catch-and-release males (33%). Additional research will be required to determine the population-level consequences of these angling practices. Until then, a conservative recommendation would be for organizers to consider alternative tournament formats during the reproductive season for largemouth bass.

Received November 30, 2011; accepted May 9, 2012
A Retrospective Evaluation of Sustainable Yields for Australia's Northern Prawn Fishery
Authors: Wang You-Gan , Wang Na
Published: September 2012

The fundamental aim in fisheries management is to determine an optimal fishing effort for sustainably harvesting from a replenishable resource. The current management objective of Australia's Northern Prawn Fishery is to maximize the long-term net economic return following Australian government policy, resulting in an average recent catch of tiger prawn species of about 1,250 tons only. However, the maximum sustainable catch stated from different studies is around 3,000–4,700 tons. We also evaluated the net profit assuming that there was no buyback scheme in 2005 and the fishing fleet was kept at 89 vessels since 2005 and concluded that 40% more catch on average (2006–2009) and an additional total profit of A$17 million (excluding crew cost) could have been gained in addition to the many millions of dollars of savings in the buyback scheme. These findings have great implications for future management in Australia and elsewhere because there is a grave concern of overfishing worldwide.

RESUMEN

El objetivo principal del manejo pesquero es determinar el esfuerzo óptimo que produzca la captura sostenible de un recurso renovable. El objetivo actual de manejo de la pesquería de camarón del norte de Australia es maximizar el retorno económico neto en el largo plazo bajo los términos de la política del gobierno australiano, tomando en cuenta que los niveles actuales de captura de camarón ascienden a 1,250 toneladas, cuando la máxima captura sostenible, de acuerdo a varios estudios, es de 3,000 a 4,700 toneladas. También se evalúa la ganancia neta bajo la suposición de que no existió un esquema de recompra en 2005 y que la flota pesquera se mantuvo en 89 embarcaciones desde 2005. Se concluye que se pudo haber ganado, en promedio, un 40% más de captura (2006–2009) y una ganancia adicional total de A$17 millones (excluyendo el gastos de la tripulación) con respecto a los muchos millones de dólares que se ahorraron con el esquema de recompra. Estos resultados tienen implicaciones importantes para el futuro manejo en Australia y en otros lugares dado que existe una preocupación a nivel mundial por la sobrex-plotación pesquera.
The Cocaine Trail: Levamisole-Induced Leukocytoclastic Vasculitis in a Cocaine User
Authors: Metwally Omar , Hamidi Massihullah , Townsend Leilani , Abualula Hasan , Zaitoun Anwar , Lall Thomas
Published: September 2012

Two million Americans use cocaine on a regular basis. Sixty-nine percent of cocaine in the United States is adulterated with levamisole, a veterinary antihelminthic drug. In 2008, the first cases of levamisole-induced agranulocytosis and vasculopathy associated with adulterated cocaine were reported in the southwestern United States. Since then, reports of levamisole-associated toxicity have become increasingly common. The authors present the case of a 47-year-old woman from Michigan with purpuric lesions likely secondary to levamisole-induced leukocytoclastic vasculitis.
‘You Kick the Bucket; We Do the Rest!’: Jokes and the Culture of Reprinting in the Transatlantic Press1
Authors: Nicholson Bob
Published: September 2012

In December 1893 the Conservative candidate for Flintshire addressed an audience at Mold Constitutional Club. After he had finished attacking Gladstone and the local Liberal incumbent, he ended his speech with a joke. He advised the Conservative party to adopt, with regard to the government, the sign of an American undertaker: ‘You kick the bucket; we do the rest’. How did a sign belonging to a Nevadan undertaker become the subject of a joke told at a political meeting in North Wales? This unlikely question forms the basis of this article. Using new digital archives, it tracks the journey of the gag from its origins in New York, its travels around America, its trip across the Atlantic, its circulation throughout Britain and its eventual leap into political discourse. The article uses the joke to illuminate the workings of a broader culture of transatlantic reprinting. During the final quarter of the nineteenth century miscellaneous ‘snippets’ cut from the pages of the American press became a staple feature of Britain's bestselling newspapers and magazines. This article explores how these texts were imported, circulated and continually rewritten in dynamic partnership between authors, editors and their readers.