bluuebunny/crossref_metadata_2025 huggingface dataset:
Guenther receives 2011 Yoram J. Kaufman Unselfish Cooperation in Research Award: Citation
Authors: Robock Alan
Published: March 2012

Alex B. Guenther received the Yoram J. Kaufman Unselfish Cooperation in Research Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award recognizes “broad influence in atmospheric science through exceptional creativity, inspiration of younger scientists, mentoring, international collaborations, and unselfish cooperation in research.”
Guenther receives 2011 Yoram J. Kaufman Unselfish Cooperation in Research Award: Response
Authors: Guenther Alex B.
Published: March 2012

Alex B. Guenther received the Yoram J. Kaufman Unselfish Cooperation in Research Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award recognizes “broad influence in atmospheric science through exceptional creativity, inspiration of younger scientists, mentoring, international collaborations, and unselfish cooperation in research.
Shaw receives 2011 James R. Holton Junior Scientist Award: Response
Authors: Shaw Tiffany A.
Published: March 2012

Tiffany A. Shaw received the James R. Holton Junior Scientist Award at the 2011 AGU Fall Meeting, held 5–9 December in San Francisco, Calif. The award recognizes outstanding research contributions by a junior atmospheric scientist within 3 years of his or her Ph.D
Small dams need better management
Authors: Balcerak Ernie
Published: March 2012

Many small dams around the world are poorly maintained and represent a safety hazard, according to Pisaniello et al. Better oversight of small dams is needed, the authors argue. The researchers reviewed literature, conducted case studies in four states in Australia, and developed policy benchmarks and best practices for small‐dam management. Small dams, often just several meters high and typically privately owned by individual farmers, have historically caused major damage when they fail. For instance, in China in 1975, 230,000 people died when two large dams failed because of the cumulative failure of 60 smaller upstream dams. In the United States, in 1977 the 8‐meter‐high Kelly Barnes Lake dam failed, killing 39 people. Many other small‐dam failures around the world have resulted in casualties and severe ecological and economic damage.
Yellowstone's diverse hydrothermal activity stems from single source
Authors: Schultz Colin
Published: March 2012

Within Yellowstone National Park, the water emanating from the park's famous hot springs and geysers seems to belong to either one of two distinct types. In some areas, subterranean waters rich in chlorine and dissolved silicates burst from the ground to create the park's iconic geysers. In other areas, highly acidic mud pools form from chlorine‐deprived waters rich with sulfate ions. In the 1950s, researchers proposed that these two distinct surface features actually stem from a single type of underground water. Across Yellowstone, geysers and mud pools are often separated by defined geographic boundaries, making a test of their interrelatedness difficult. In northwestern Wyoming, however, acid‐rich and silica‐rich waters coexist within a roughly 12‐squarekilometer watershed that drains into nearby Heart Lake
Velocity space diffusion of charged particles in weak magnetostatic fields: Nonlinear effects, model constraints, and implications for simulations
Authors: Mace R. L. , Dalena S. , Matthaeus W. H.
Published: March 2012

The velocity space diffusion of charged test particles in random magnetostatic fields is re-investigated from a semi-dynamical point of view. The dynamics of charged particles in resonance with parallel propagating electromagnetic waves is investigated numerically and compared with analytical results for the trapping width in velocity space, Δv∥, and the bounce frequency, ωb. It is demonstrated how an understanding of the basic resonance phenomenon can lead to a better understanding of the validity regions of the quasi-linear theory and their implications for numerical simulations. It is shown, using established analytical expressions for Δv∥ and ωb, that the quasi-linear diffusion coefficient can be written in a new physically illuminating form. The concept of an effective trapping width in velocity space for the turbulence modified resonance structure is introduced. It is shown how this effective resonance width implies a condition on the density of wave modes in Fourier space, in the vicinity of the resonant wave number. The implications of this condition for simulations utilizing discrete fields are discussed in detail and examples of simulations violating this condition are presented. Other issues pertinent to the simulation of velocity diffusion in turbulent electromagnetic fields are discussed, paying attention to the discretization of the fields and the temporal discretization of the dynamical equations.
Three dimensional optical twisters-driven helically stacked multi-layered microrotors
Authors: Xavier Jolly , Dasgupta Raktim , Ahlawat Sunita , Joseph Joby , Kumar Gupta Pradeep
Published: March 2012

We demonstrate tunable helically stacked multi-layered microrotors realized in vortex-embedded three dimensional (3D) optical twister patterns. Intensity-tunable annular irradiance profiles with higher order vortex are generated as well as simultaneously unfolded by phase-engineered multiple plane wave interference. In the individually tunable 3D helical bright arms of these unfolded vortex structures, 2 μm silica beads are optically trapped as spiraling multilayered handles of multi-armed microrotors. Further, multiple rows of such microrotors are parallelly actuated with controllable sense of rotation. We also present our observation on helical 3D stacking of micro-particles in these longitudinally gyrating multi-armed rotor traps.
On simulations of complex interfaces: Molecular dynamics simulations of stationary phases
Authors: Hall K. , Ashtari M. , Cann N. M.
Published: March 2012

Methodological considerations for molecular dynamics simulations of complex interfaces are presented in this article. A slab geometry is examined in the context of stationary phases where selectivity occurs predominantly in pores within silica beads. Specifically, we examine the Whelk-O1 interface with n-hexane/2-propanol, the TMA-(Pro)2-N(CH3)-tether interface with n-hexane/2-propanol, and the C18H37Si interface with water/methanol. The following methodological issues are considered in detail: The assessment of solvent density within the confined region and excluded volume of the interface; the structural equilibration of surface-bound moieties; solvent equilibration for binary mixtures; surface size effects, and periodic boundary conditions; the treatment of electrostatic interactions; and the impact of pore size.
Effect of Si interlayers on the magnetic and mechanical properties of Fe/Ge neutron polarizing multilayer mirrors
Authors: Maruyama R. , Yamazaki D. , Okayasu S. , Takeda M. , Zettsu N. , Nagano M. , Yamamura K. , Hayashida H. , Soyama K.
Published: March 2012

The neutron polarizing supermirror is one of the most important optical devices for polarizing neutron beams. To meet a variety of research demands, neutron polarizing supermirrors need to display high polarization efficiencies at low external magnetic fields. Fe/Si and Fe/Ge multilayers are typically used in neutron polarizing supermirrors because the contrast in scattering length densities almost vanishes for spin-down neutrons. The Fe/Si/Ge/Si multilayer, obtained by adding thin interlayers of Si to an Fe/Ge multilayer, is effective in reducing the external field strength necessary to achieve efficient neutron polarization. To gain insight into the mechanism that controls the required external field strength for a neutron polarizing supermirror, we investigated the magnetic and mechanical properties of Fe/Si, Fe/Ge, and Fe/Si/Ge/Si multilayers. The external field strength required to achieve efficient neutron polarization was found to be proportional to the compressive film stress. The compressive stress of the Fe/Si/Ge/Si multilayer was smaller by a factor of 4.4 and 2.7 than that of Fe/Si and Fe/Ge multilayers, respectively. These measurements and analyses showed that a reduction in the compressive film stress in the Fe/Si/Ge/Si multilayer permits the use of lower external field strength to achieve efficient neutron polarization. X-ray photoelectron spectroscopic studies showed that the formation of a Ge-Si solid solution in the Ge layer may explain the marked reduction in compressive stress in the case of the Fe/Si/Ge/Si multilayer. This study confirmed that a reduction in compressive film stress is very important for a high-performance neutron polarizing supermirror.
Time and space resolved measurement of the electron temperature, mass density and ionization state in the ablation plasma between two exploding Al wires
Authors: Knapp P. F. , Pikuz S. A. , Shelkovenko T. A. , Hammer D. A. , Hansen S. B.
Published: March 2012

We have determined the properties of plasma around and between two exploding wires using high-resolution x-ray absorption spectroscopy. Plasma densities and temperatures ranging from ≳0.1g/cm3 and a few eV to less than 0.01 g/cm3 and 30 eV have been measured in experiments at Cornell University with two 40 μm aluminum (Al) wires spaced 1 mm apart driven by ∼150 kA peak current pulses with 100 ns rise time. The wire plasma was backlit by the 1.4–1.6 keV continuum radiation produced by a Mo wire X-pinch. The spectrometer employed two spherically bent quartz crystals to record the absorption and backlighter spectra simultaneously. The transition between the dense Al wire core and the coronal plasma is seen as a transition from cold K-edge absorption to Mg-, Na-, and finally Ne-like absorption at the boundary. In the plasma that accumulates between the wires, ionization states up to C-Like Al are observed. The spectrometer geometry and ∼2μm X-pinch source size provide 0.3 eV spectral resolution and 20 μm spatial resolution enabling us to see 1s → 2p satellite transitions as separate lines as well as O-, F-, and Ne-like 1s → 3p transitions that have not been seen before. A step wedge was used to calibrate the transmission, enabling density to be measured within a factor of two and temperature to be measured within ±25%. A genetic algorithm was developed to fit synthetic spectra calculated using the collisional-radiative code SCRAM to the experimental spectra. In order to obtain agreement it was necessary to assume multiple plasma regions with variable thicknesses, thereby allowing the inferred plasma conditions to vary along the absorption path.
Plasma flow healing of magnetic islands in stellarators
Authors: Hegna C. C.
Published: March 2012

Recent experiments from the large helical device (LHD) demonstrate a correlation between the “healing” of vacuum magnetic islands in stellarators and changes in the plasma flow. A model explaining this phenomenon is developed based on self-consistent torque balance and island evolution equations. In conventional stellarators, neoclassical flow damping physics plays an important role in establishing the flow profiles. The balance of neoclassical damping and cross-field viscosity produces a radial boundary layer for the plasma rotation profile outside the separatrix of a locked magnetic island. The width of this boundary layer decreases as the plasma becomes less collisional. Associated with these flow effects are plasma currents flowing in the island region that attempt to suppress island formation. These currents are enhanced as the collisionality drops making magnetic island healing occur more readily in high temperature conventional stellarators. The analytic theory produces a critical β for healing that scales monotonically with collisionality and is in qualitative agreement with LHD observations.
Communication: Spin-orbit splittings in degenerate open-shell states via Mukherjee's multireference coupled-cluster theory: A measure for the coupling contribution
Authors: Mück Leonie Anna , Gauss Jürgen
Published: March 2012

We propose a generally applicable scheme for the computation of spin-orbit (SO) splittings in degenerate open-shell systems using multireference coupled-cluster (MRCC) theory. As a specific method, Mukherjee's version of MRCC (Mk-MRCC) in conjunction with an effective mean-field SO operator is adapted for this purpose. An expression for the SO splittings is derived and implemented using Mk-MRCC analytic derivative techniques. The computed SO splittings are found to be in satisfactory agreement with experimental data. Due to the symmetry properties of the SO operator, SO splittings can be considered a quality measure for the coupling between reference determinants in Jeziorski-Monkhorst based MRCC methods. We thus provide numerical insights into the coupling problem of Mk-MRCC theory.
Optical Stark spectroscopy of the $2_0^6$26 $\tilde{A}^1A^{\prime \prime} - \tilde{X}^1A^{\prime} $Ã1A′′−X̃1A′ band of chloro-methylene, HCCl
Authors: Steimle Timothy C. , Wang Fang , Zhuang Xiujuan , Wang Zhong
Published: March 2012

The laser induced fluorescence spectra of the $2_0^6 \tilde A^1 A^{\prime \prime} - \tilde X^1 A^{\prime} $206Ã1A′′−X̃1A′ band of a rotationally cold (<20 K) molecular beam sample of chloro-methylene, HCCl, has been recorded, field-free and in the presence of a static electric field. The field-free spectrum has been analyzed to produce an improved set of spectroscopic parameters for the $\tilde {A}^1A^{\prime \prime} $Ã1A′′ (060) vibronic state. The magnitude of the a-component of the permanent electric dipole moment, μa, for the $\tilde X^1 A^{\prime} $X̃1A′ (000) vibronic state has been determined to be 0.501(1) D from the analysis of the observed electric field induced shifts. Comparisons with theoretical predictions and flouro-methylene, HCF, are presented.
La0.7Ca0.3MnO3 / Mn3O4 composites: Does an insulating secondary phase always enhance the low field magnetoresistance of manganites?
Authors: Bhame S. D. , Fagnard J.-F. , Pekala M. , Vanderbemden P. , Vertruyen B.
Published: March 2012

Composites of magnetoresistive La0.7Ca0.3MnO3 (LCMO) with insulating Mn3O4 are useful as a model system because no foreign cation is introduced in the LCMO phase by interdiffusion during the heat treatment. Here we report the magnetotransport properties as a function of sintering temperature Tsinter for a fixed LCMO/Mn3O4 ratio. Decreasing Tsinter from 1250 °C to 800 °C causes an increase in low field magnetoresistance (LFMR) that correlates with the decrease in crystallite size (CS) of the LCMO phase. When plotting LFMR at (77 K, 0.5 T) versus 1/CS, we find that the data for the LCMO/Mn3O4 composites sintered between 800 °C and 1250 °C follow the same trend line as data from the literature for pure LCMO samples with crystallite size >∼25 nm. This differs from the LFMR enhancement observed by many authors in the “usual” manganite composites, i.e., composites where the insulating phase contains cations other than La, Ca or Mn. This difference suggests that diffusion of foreign cations into the grain boundary region is a necessary ingredient for the enhanced LFMR.
On experimental sensitivity analysis of the turbulent wake from an axisymmetric blunt trailing edge
Authors: Grandemange M. , Gohlke M. , Parezanović V. , Cadot O.
Published: March 2012

The sensitivity to steady local disturbances of the turbulent wake over a 3D blunt body with an axisymmetric trailing edge is investigated at Re = 2.1 × 104. The flow presents a favored m = 2 azimuthal periodicity due to the mounting of the body. It is proved that two asymmetric flows cohabit and generate a statistically symmetric natural flow. Topology shifts are random but are visible after a large number of global mode periods. The statistical symmetry is highly sensitive to any steady antisymmetric disturbance. As a consequence, depending on its position, a small control cylinder (considered as a disturbance with m = 1 azimuthal periodicity) in the close wake fixes the flow to one asymmetric topology affecting shedding activity as well as drag. On the contrary, a thin control ring (i.e., m = 0 disturbance) preserves the mean flow symmetry and has a greater impact on global mode frequency and drag. Whatever the disturbance, the sensitivity of the wake to control devices is concentrated into the mixing layers; the observed effects seem to depend more upon their local turbulent characteristics than on the global inviscid dynamics of vorticity.
Two-dimensional moist stratified turbulence and the emergence of vertically sheared horizontal flows
Authors: Sukhatme Jai , Majda Andrew J. , Smith Leslie M.
Published: March 2012

Moist stratified turbulence is studied in a two-dimensional Boussinesq system influenced by condensation and evaporation. The problem is set in a periodic domain and employs simple evaporation and condensation schemes, wherein both the processes push parcels towards saturation. Numerical simulations demonstrate the emergence of a moist turbulent state consisting of ordered structures with a clear power-law type spectral scaling from initially spatially uncorrelated conditions. An asymptotic analysis in the limit of rapid condensation and strong stratification shows that, for initial conditions with enough water substance to saturate the domain, the equations support a straightforward state of moist balance characterized by a hydrostatic, saturated, vertically sheared horizontal flow (VSHF). For such initial conditions, by means of long time numerical simulations, the emergence of moist balance is verified. Specifically, starting from uncorrelated data, subsequent to the development of a moist turbulent state, the system experiences a rather abrupt transition to a regime which is close to saturation and dominated by a strong VSHF. On the other hand, initial conditions which do not have enough water substance to saturate the domain, do not attain moist balance. Rather, the system is observed to remain in a turbulent state and oscillates about moist balance. Even though balance is not achieved with these general initial conditions, the time scale of oscillation about moist balance is much larger than the imposed time scale of condensation and evaporation, thus indicating a distinct dominant slow component in the moist stratified two-dimensional turbulent system.
Methods and instrumentation for piezoelectric motors
Authors: Drevniok B. , Paul W. M. P. , Hairsine K. R. , McLean A. B.
Published: March 2012

Because of their compact form factor and rigidity, piezoelectric motors are used in scanning probe microscopes that operate at low temperature and high magnetic field. Here we present detailed information to facilitate the assembly, operation, and characterization of inertial motors. Specifically, a model of the motor is developed and used to identify different regions of operation. Drive electronics with high slew rate and large output current are described and a step-by-step procedure for assembling piezoelectric shear stacks is detailed. Additionally, a novel reflective object sensor is described and used to characterize a Pan-style inertial motor that was designed and assembled using the concepts presented in this paper.
Construction of nanostructured electrodes on flexible substrates using pre-treated building blocks
Authors: Huang Fuzhi , Chen Dehong , Li Qi , Caruso Rachel A. , Cheng Yi-Bing
Published: March 2012

A “building block” concept is introduced for the construction of electrodes for dye-sensitized solar cells (DSCs). The building blocks are prefabricated submicrometer- to micrometer-sized clusters, such as nanostructured mesoporous TiO2 spheres. This concept makes a number of approaches possible that are difficult to achieve through the conventional nanoparticle route for the preparation of flexible DSCs. Significantly, the building blocks can be physically and chemically pre-treated prior to electrode fabrication. Thus some of the intrinsic limitations of using plastic substrates can be overcome, such as applying heat treatment and TiCl4 treatment, affording a high power conversion efficiency of 7.5%.
Multiple Andreev reflection in MgB2/MgO/MgB2 Josephson junctions
Authors: Chen Ke , Cunnane Daniel , Shen Yi , Xi X. X. , Kleinsasser Alan W. , Rowell John M.
Published: March 2012

The current-voltage and conductance-voltage characteristics of MgB2/MgO/MgB2 junctions made with MgB2 electrodes grown by hybrid physical-chemical vapor deposition were systematically analyzed. In the junctions with different sizes and critical current densities, we found excess current and subharmonic gap structure indicative of multiple Andreev reflection. An apparent link between multiple Andreev reflection and substantial Josephson current at high temperatures suggests that the barrier is dominated by high-transparency channels.
Electrical control of Curie temperature in cobalt using an ionic liquid film
Authors: Shimamura K. , Chiba D. , Ono S. , Fukami S. , Ishiwata N. , Kawaguchi M. , Kobayashi K. , Ono T.
Published: March 2012

The electric field effect on magnetization properties and Curie temperature of Co ultra-thin films has been investigated. An electric field is applied to a Co film by using an electric double layer (EDL) formed in a polymer film containing an ionic liquid. The change in the Curie temperature is ∼100 K by applying the gate voltage of ±2 V, suggesting that the observed large modifications of magnetization properties are attributed to the significant change in the Curie temperature, which is induced by a large amount of carrier density control due to the formation of the EDL.
Flow visualization of a vortex ring interaction with porous surfaces
Authors: Hrynuk John T. , Van Luipen Jason , Bohl Douglas
Published: March 2012

The interaction of vortex rings of constant Reynolds number with porous surfaces composed of wire meshes of constant open area, i.e., surface porosity, but variable wire diameter is studied using flow visualization. The results indicate that several regimes of flow behavior exist in the parameter space investigated. The vortex ring passes through and immediately reforms downstream of the surface for porous surfaces with small wire mesh diameters. The transmitted vortex ring has the same diameter, but lower convection speed and circulation than the pre-interaction vortex ring. For these cases, secondary vortex rings are formed on the upstream side of the porous surface that convect upstream away from the screen. As the wire diameter of the porous surface is increased, smaller sub-scale vortical structures are formed on the transmitted vortex ring as it passes through the surface. The spatial scale of these structures is dependent on the diameter of the mesh wire. The vortex ring is disrupted but is able to reform downstream when these structures are small compared to the scale of the vortex ring. When these structures are large enough the transmitted vortex ring is disrupted and does not reform. The results indicate that the dynamics governing the vortex ring/mesh surface interaction are dependent not only on the strength of the vortex ring and the porosity of the surface, as previously thought, but also on the length scales (i.e., the diameter and spacing of the wire mesh) of the porous surface.
Thermal rectification in a fluid reservoir
Authors: Murad Sohail , Puri Ishwar K.
Published: March 2012

An organized nonuniform mass distribution in solids leads to a monotonically varying thermal conductivity in a nanomaterial so that the heat flux is directionally dependent. We investigate through molecular dynamics simulations if the influence of an organized mass distribution in a fluid also leads to thermal rectification. Heat transfer is monitored in a water reservoir placed between two (hot and cold) silicon walls. The distribution of the fluid in the reservoirs is organized by applying an external force to each water molecule in a specified direction, creating a density gradient. This external force is smaller than the intermolecular forces in water, in most cases by much more than an order of magnitude. The simulations reveal that mass graded fluid-containing nanosystems can be engineered to possess an asymmetric axial thermal conductance that leads to greater heat flow in the direction of decreasing mass density. The rectification improves as the thermal conductivity is enhanced by increasing the fluid density adjacent to a hot wall, since doing so decreases the interfacial resistance and increases the heat flux.
Blue monolithic II-VI-based vertical-cavity surface-emitting laser
Authors: Klembt S. , Seyfried M. , Aschenbrenner T. , Sebald K. , Gutowski J. , Hommel D. , Kruse C.
Published: March 2012

We report on laser operation of optically pumped, fully epitaxial blue vertical-cavity surface-emitting lasers. The ZnSe-based structures posses a bottom and top distributed Bragg reflector consisting of ZnMgSSe as high-index material and a short-period superlattice of MgS/ZnCdSe as low-index material. The cavity has an optical thickness of λ and contains three ZnSe quantum wells surrounded by ZnMgSSe barriers. To illustrate the specific issues related to this demanding material combination, we compare two epitaxial structures of different crystalline quality. A minimum threshold of 5 pJ is observed for laser emission at 443 nm comparable to values reported for nitride based vertical-cavity surface-emitting lasers.
Implications of quantum metabolism and natural selection for the origin of cancer cells and tumor progression
Authors: Davies Paul , Demetrius Lloyd A. , Tuszynski Jack A.
Published: March 2012

Empirical studies give increased support for the hypothesis that the sporadic form of cancer is an age-related metabolic disease characterized by: (a) metabolic dysregulation with random abnormalities in mitochondrial DNA, and (b) metabolic alteration – the compensatory upregulation of glycolysis to offset mitochondrial impairments. This paper appeals to the theory of Quantum Metabolism and the principles of natural selection to formulate a conceptual framework for a quantitative analysis of the origin and proliferation of the disease. Quantum Metabolism, an analytical theory of energy transduction in cells inspired by the methodology of the quantum theory of solids, elucidates the molecular basis for differences in metabolic rate between normal cells, utilizing predominantly oxidative phosphorylation, and cancer cells utilizing predominantly glycolysis. The principles of natural selection account for the outcome of competition between the two classes of cells. Quantum Metabolism and the principles of natural selection give an ontogenic and evolutionary rationale for cancer proliferation and furnish a framework for effective therapeutic strategies to impede the spread of the disease.
Association between melatonin receptor 1A (MTNR1A) gene polymorphism and the reproductive performance of Mediterranean Italian buffaloes
Authors: Luridiana S. , Mura M. C. , Pazzola M. , Paludo M. , Cosso G. , Dettori M. L. , Bua S. , Vacca G. M. , Carcangiu V.
Published: March 2012

A melatonin receptor 1A (MTNR1A) gene polymorphism in adult buffaloes has been reported to affect reproductive seasonality. Consequently, the aim of the present study was to assess whether this polymorphism can affect age at first conception and the interval between first and second calving in Mediterranean Italian buffaloes. The allelic frequency of the C and T alleles was 0.44 and 0.56, respectively, whereas the genotypic frequency was 26% for C/C, 40% for C/T and 34% for T/T. The average age at first mating was approximately 20 months, whereas that at calving was approximately 32 months. The largest number of calvings of primiparous buffaloes was recorded between June and October. No associations between genotype, first mating and subsequent calving date were found. The duration from first to second calving was longer in buffaloes with the C/C genotype compared with those with the T/T and C/T genotypes (P < 0.01). The period of calving for buffaloes with the C/C genotype was mainly from July to September, whereas that for buffaloes with the T/T genotype was largely from March to May. The MTNR1A gene had no effect on the age of first conception in Mediterranean Italian buffaloes. Rather, the association between the T/T genotype and reproductive activity during days with a long photoperiod indicates that this polymorphism may be considered a genetic marker to identify buffaloes that are able to reproduce out of the breeding season.
Corrigendum to: Factors influencing large wildland fire suppression expenditures
Authors: Liang Jingjing , Calkin Dave E. , Gebert Krista M. , Venn Tyron J. , Silverstein Robin P.
Published: March 2012

There is an urgent and immediate need to address the excessive cost of large fires. Here, we studied large wildland fire suppression expenditures by the US Department of Agriculture Forest Service. Among 16 potential non-managerial factors, which represented fire size and shape, private properties, public land attributes, forest and fuel conditions, and geographic settings, we found only fire size and private land had a strong effect on suppression expenditures. When both were accounted for, all the other variables had no significant effect. A parsimonious model to predict suppression expenditures was suggested, in which fire size and private land explained 58% of variation in expenditures. Other things being equal, suppression expenditures monotonically increased with fire size. For the average fire size, expenditures first increased with the percentage of private land within burned area, but as the percentage exceeded 20%, expenditures slowly declined until they stabilised when private land reached 50% of burned area. The results suggested that efforts to contain federal suppression expenditures need to focus on the highly complex, politically sensitive topic of wildfires on private land.
Assessing the lexical evidence for a Central Solomons Papuan family using the Oswalt Monte Carlo Test
Authors: Dunn Michael , Terrill Angela
Published: March 2012

In the absence of comparative method reconstruction, high rate of lexical cognate candidates is often used as evidence for relationships between languages. This paper uses the Oswalt Monte Carlo Shift test (a variant of Oswalt 1970) to explore the statistical basis of the claim that the four Papuan languages of the Solomon Islands have greater than chance levels of lexical similarity. The results of this test initially appear to show that the lexical similarities between the Central Solomons Papuan languages are statistically significant, but the effect disappears when known Oceanic loanwords are removed. The Oswalt Monte Carlo test is a useful technique to test a claim of greater than chance similarity between any two word lists — with the proviso that undetected loanwords strongly increase the chance of spurious identification.
The effect of active teaching and subject content coverage on students' achievement: evidence from primary schools in Kenya
Authors: Oketch Moses , Mutisya Maurice , Sagwe Jackline , Musyoka Peter , Ngware Moses W.
Published: March 2012

There is a growing public concern in Kenya over the persistent gap between those schools that are consistently ranked at the top and those ranked at the bottom of the annual Kenya Certificate of Primary Education (KCPE) examination league tables. This has raised the issue of inequality
in educational opportunity. Our primary concern in this paper is to understand some of the classroom–school factors that may explain the persistent differences in achievement between the top and bottom schools. We focus on time-on-task (the length of exposure to any particular teaching
and learning task) and curriculum content, and ask whether this explains the difference in performance. We test the following hypotheses: differences exist on teachers' time-on-task between low and high performing schools; greater teacher time-on-task has a positive effect on student gain
score; and greater content coverage has a positive effect on student achievement. For the student achievement gains, we use item response theory test scores of 1889 Grade 6 pupils from 70 schools in Kenya. Data on time-on-task were generated from 70 maths lessons observed in these schools,
while content coverage was developed from students' maths note books for the entire period they were in Grade 6. The study was conducted by a team of researchers at the African Population and Health Research Center (APHRC) with funding from Google.org. Using two level hierarchical modelling,
we control for pupil, teacher and school factors. Results show that exposure to content is positively correlated with pupil gain scores (gain score is the difference in score between test at time t1 and test at time t2 of the same pupil taught by the same teacher). Maths teachers
in both bottom and top performing schools spend the same proportion of time-on-task. However, we do not find that time-on-task is related to achievement in this sample.
Transformation, trust and the 'importance of teaching': continuities and discontinuities in the Coalition government's discourse of education reform
Authors: Bates Agnieszka
Published: March 2012

The imperative of transforming education continues to permeate the discourse of UK education reform. Although the Coalition government's publications herald a 'new school system', they reveal the same neo-liberal thinking as their New Labour predecessors. The context of the national
budget deficit is now being brought to bear to promote greater effectiveness of the education system. Inherent in the Coalition strategy is a diminution of the vital role of teachers in bringing about profound change. This paper examines the notion of transformative change through the lens
of George Herbert Mead's philosophy of evolution. Within this framework, transformation is a complex, emergent and unpredictable process that resists centralised control. Consequently, profound social change needs to be predicated on trust, conceptualised as a reciprocal relationship rooted
in the acceptance of phenomena beyond our control.
Effect of Stocking Density on Walleye Performance in Ponds Lined with Ethylene Propylene Diene Monomer
Authors: Ward Matthew J , Stane Justin , Schrock Garret , Funk Clayton
Published: March 2012

A prior study suggested that the yield of walleyes Sander vitreus from ponds lined with ethylene propylene diene monomer (EPDM) exceeds the yield from earthen (substrate) ponds. To evaluate production potential in an EPDM pond, walleye performance was compared between two stocking densities, low (187,500 fry/ha) and high (375,000 fry/ha). Stocking density did not significantly affect walleye survival (low density = 88%, high = 82%). At harvest, walleyes were 6 mm longer for the low-density treatment but yield was greater in the high-density treatment (low density = 72 kg/ha, high = 88 kg/ha). Depending on size of walleyes desired, a pond stocking density of 375,000 fry/ha may be excessive, particularly during years when fry survival is high (>80%). To reassess the prior findings that walleye growth in EPDM ponds exceeds that in earthen substrate ponds, growth was compared between earthen and EPDM ponds provided a standard stocking density of 187,500 fry/ha. Similar findings were experienced, with walleyes being 11 mm longer at harvest in EPDM ponds.
Physical match performance of youth football players in relation to physical capacity
Authors: Rebelo António , Brito João , Seabra André , Oliveira José , Krustrup Peter
Published: March 2012

The aims of the study were to (1) analyse the activity profile of youth football players during competitive matches, and (2) examine the relationship between physical match performance and intermittent exercise performance as well as . Thirty youth male football players, aged 14–17 years, carried out a laboratory treadmill test for determination of as well as the Yo‐Yo intermittent recovery level 1 (Yo‐Yo IR1) and Yo‐Yo intermittent endurance level 2 (Yo‐Yo IE2) tests. Time–motion analysis and heart rate (HR) recordings were performed during two competitive matches per player. Distance covered during the match was 6311±948 (range: 4435–8098) m, of which 12% were high‐intensity activities (HIA; 759±437 [374–2062] m), and 5% was backwards running (309±205 [12–776] m). Mean match HR was 168±12 (140–187) bpm, corresponding to 85% (69–91) of maximum HR. The total distance covered in the last 13.3‐min period of the match was 40%, 26% and 17% lower than in the first, second and fourth 13.3‐min periods of the match, respectively (P<0.05). The distance covered in backwards running decreased by 31% and 37% from the first to the last 13.3‐min periods of the first and second half, respectively (P<0.05). The Yo‐Yo IR1 was significantly associated with the time spent with sprinting during the match (r=0.63; P=0.002) and during the last 13.3‐min period (r=0.63; P=0.022). Both Yo‐Yo IR1 and Yo‐Yo IE2 were correlated with the time spent with match HIA (r=0.56 and r=0.57, respectively; P<0.05). No significant relationship was observed between and match time–motion variables (r=−0.13–0.25; P>0.05) or Yo‐Yo test performances (r=0.09–0.26; P>0.05). In conclusion, youth football players have a high heart‐rate loading during match play and a decreased running performance towards the end of the game. The intermittent exercise capacity, as determined in the Yo‐Yo IR1 test, appears to be a valid indicator of high‐intensity exercise performance in youth matches.
MicroRNA-30c-2* limits expression of proadaptive factor XBP1 in the unfolded protein response
Authors: Byrd Andrew E. , Aragon Ileana V. , Brewer Joseph W.
Published: March 2012

Stress in the endoplasmic reticulum (ER) triggers the unfolded protein response (UPR), a multifaceted signaling system coordinating translational control and gene transcription to promote cellular adaptation and survival. Microribonucleic acids (RNAs; miRNAs), single-stranded RNAs that typically function as posttranscriptional modulators of gene activity, have been shown to inhibit translation of certain secretory pathway proteins during the UPR. However, it remains unclear whether miRNAs regulate UPR signaling effectors directly. In this paper, we report that a star strand miRNA, miR-30c-2* (recently designated miR-30c-2-3p), is induced by the protein kinase RNA activated–like ER kinase (PERK) pathway of the UPR and governs expression of XBP1 (X-box binding protein 1), a key transcription factor that augments secretory capacity and promotes cell survival in the adaptive UPR. These data provide the first link between an miRNA and direct regulation of the ER stress response and reveal a novel molecular mechanism by which the PERK pathway, via miR-30c-2*, influences the scale of XBP1-mediated gene expression and cell fate in the UPR.
Open access central funds in UK universities
Authors: PINFIELD Stephen , MIDDLETON Christine
Published: March 2012

This paper reports on the extent to which higher education institutions in the UK have set up central funds and similar institutionally co‐ordinated approaches to the payment of open access article‐processing charges. It presents data demonstrating that central funds have only been set up by a minority of institutions and that the number of institutions has not changed significantly between 2009 and 2011. It then explores the barriers to the establishment of such funds and discusses recent developments that might lower these barriers. Finally, it provides a case study of the development of the central fund at the University of Nottingham in the UK and considers the sustainability of such an approach.
Selling to the BRIC: China — understanding and improving your footprint
Authors: STANLEY Adrian
Published: March 2012

This article starts with a consideration of the demographic and economic background to China's development. It then goes on to clarify and explain unique factors of the Chinese academic journals market which publishers need to know about and consider. It looks at this from a sales market perspective and also from that of authorship and content creation. It helps give a roadmap and outline to publishers who want to understand and improve their local footprint.
Identification of the ubiquitous Coriolis momentum pinch in JET tokamak plasmas
Authors: Weisen H. , Camenen Y. , Salmi A. , Versloot T.W. , de Vries P.C. , Maslov M. , Tala T. , Beurskens M. , Giroud C.
Published: March 2012

A broad survey of the experimental database of neutral beam heated plasmas in the JET tokamak has established the theoretically expected ubiquity, in rotating plasmas, of a convective transport mechanism which has its origin in the vertical particle drift resulting from the Coriolis force. This inward convection, or pinch, leads to inward transport of toroidal angular momentum and is characterized by pinch numbers RV/χϕ, which rise from near unity at r/a ≈ 0.25 to around 5 at r/a ≈ 0.85. Linear gyrokinetic calculations of the Coriolis pinch number and the Prandtl number χϕ/χi are in good agreement with the experimental observations, with similar dependences on plasma parameters. The data, however, do not rule out contributions from different processes, such as residual stresses.
Modelling of hydrogen isotope inventory in mixed materials including porous deposited layers in fusion devices
Authors: Sang Chaofeng , Bonnin Xavier , Warrier Manoj , Rai Abha , Schneider Ralf , Sun Jizhong , Wang Dezhen
Published: March 2012

Hydrogen isotope inventory (HII) is a key issue for fusion devices such as ITER. Simultaneous use of Be, W and C as the wall material for different parts of plasma-facing components (PFCs) will bring in material mixing issues, which compound that of hydrogen isotope retention. To simulate the hydrogen inventory in the PFCs, we have developed a flexible standalone model called HIIPC (Hydrogen Isotope Inventory Processes Code). The particle-balance-based model for reaction–diffusion and HII in metal and porous media (mainly carbon and co-deposited layers) is presented, coupled with a heating model which can calculate the temperature distribution. Some sample results are given to illustrate the model's capabilities and show good qualitative agreement with the experiment.
Effects of imperfections on localized bulging in inflated membrane tubes
Authors: Fu Y. B. , Xie Y. X.
Published: March 2012

The problem of localized bulging in inflated membrane tubes shares the same features with a variety of other localization problems such as formation of kink bands in fibre-reinforced composites and layered structures. This type of localization is known to be very sensitive to imperfections, but the precise nature of such sensitivity has not so far been quantified. In this paper, we study effects of localized wall thinning/thickening on the onset of localized bulging in inflated membrane tubes as a prototypical example. It is shown that localized wall thinning may reduce the critical pressure or circumferential stretch by an amount of the order of the square root of maximum wall thickness reduction. As a typical example, a 10 per cent maximum wall thinning may reduce the critical circumferential stretch by 19 per cent. This square root law complements the well-known Koiter's two-thirds power law for subcritical periodic bifurcations. The relevance of our results to mathematical modelling of aneurysm formation in human arteries is also discussed.
Bending strength of delaminated aerospace composites
Authors: Kinawy Moustafa , Butler Richard , Hunt Giles W.
Published: March 2012

Buckling-driven delamination is considered among the most critical failure modes in composite laminates. This paper examines the propagation of delaminations in a beam under pure bending. A pre-developed analytical model to predict the critical buckling moment of a thin sub-laminate is extended to account for propagation prediction, using mixed-mode fracture analysis. Fractography analysis is performed to distinguish between mode I and mode II contributions to the final failure of specimens. Comparison between experimental results and analysis shows agreement to within 5 per cent in static propagation moment for two different materials. It is concluded that static fracture is almost entirely driven by mode II effects. This result was unexpected because it arises from a buckling mode that opens the delamination. For this reason, and because of the excellent repeatability of the experiments, the method of testing may be a promising means of establishing the critical value of mode II fracture toughness,
G
IIC
, of the material. Fatigue testing on similar samples showed that buckled delamination resulted in a fatigue threshold that was over 80 per cent lower than the static propagation moment. Such an outcome highlights the significance of predicting snap-buckling moment and subsequent propagation for design purposes.
Non-smooth mode I fracture of fibre-reinforced composites: an experimental, numerical and analytical study
Authors: Davidson Paul , Waas Anthony M.
Published: March 2012

We present a novel approach to analyse the fracture of fibre-reinforced composites. Experimental results on mode I fracture of glass fibre and carbon fibre unidirectional laminates presented here and published by others in the open literature formed the basis for the analytical and numerical results presented. When details of the external loading rate are explicitly accounted for, a new picture of fracture emerges, which encompasses the possibility for non-smooth crack growth and the necessity to relax the use of a critical strain energy release rate as a criterion for crack advancement. Results predicted by adopting the analytical model presented here are seen to capture a wide variety of fracture responses that have been observed previously.
On longitudinal compressive failure of carbon-fibre-reinforced polymer: from unidirectional to woven, and from virgin to recycled
Authors: Pinho S. T. , Gutkin R. , Pimenta S. , De Carvalho N. V. , Robinson P.
Published: March 2012

Modelling the longitudinal compressive failure of carbon-fibre-reinforced composites has been attempted for decades. Despite many developments, no single model has surfaced to provide simultaneously a definitive explanation for the micromechanics of failure as well as validated predictions for a generic stress state. This paper explores the reasons for this, by presenting experimental data (including scanning electron microscopic observations of loaded kink bands during propagation, and brittle shear fracture at 45
°
to the fibres) and reviewing previously proposed micromechanical analytical and numerical models. The paper focuses mainly on virgin unidirectional (UD) composites, but studies for woven and recycled composites are also presented, highlighting similarities and differences between these cases. It is found that, while kink-band formation (also referred to in the literature as microbuckling) is predominant in UD composites under longitudinal compression, another failure mode related to the failure of the fibres can be observed experimentally. It is also shown that the micromechanics of the failure process observed in UD composites is similar to that in other fibre architectures, hence encouraging the adaptation and application of models developed for the former to the latter.