bluuebunny/crossref_metadata_2025 huggingface dataset:
Invited Article: Dielectric material characterization techniques and designs of high-Q resonators for applications from micro to millimeter-waves frequencies applicable at room and cryogenic temperatures
Authors: Le Floch Jean-Michel , Fan Y. , Humbert Georges , Shan Qingxiao , Férachou Denis , Bara-Maillet Romain , Aubourg Michel , Hartnett John G. , Madrangeas Valerie , Cros Dominique , Blondy Jean-Marc , Krupka Jerzy , Tobar Michael E.
Published: March 2014

Dielectric resonators are key elements in many applications in micro to millimeter wave circuits, including ultra-narrow band filters and frequency-determining components for precision frequency synthesis. Distributed-layered and bulk low-loss crystalline and polycrystalline dielectric structures have become very important for building these devices. Proper design requires careful electromagnetic characterization of low-loss material properties. This includes exact simulation with precision numerical software and precise measurements of resonant modes. For example, we have developed the Whispering Gallery mode technique for microwave applications, which has now become the standard for characterizing low-loss structures. This paper will give some of the most common characterization techniques used in the micro to millimeter wave regime at room and cryogenic temperatures for designing high-Q dielectric loaded cavities.
Signal-to-noise ratio impact of grain-to-grain heating variation in heat assisted magnetic recording
Authors: Zhu Jian-Gang (Jimmy) , Li Hai
Published: March 2014

In this paper, we present a micromagnetic modeling study of the recording signal-to-noise performance of the heat assisted magnetic recording (HAMR) processes, focusing on the effect of possible grain-to-grain heating variation. The temperature variation is modeled by assuming a small random deviation of the steady state thermal profile for each grain. It is found that the temperature variation from grain to grain can yield significant signal-to-noise ratio degradation, enhancing transition jitter, and the limiting performance high linear densities. The degradation is characteristically the same as that caused by grain-to-grain Curie temperature, Tc, variations. Even though it is hard to distinguish in recording performance testing from Tc variation, a quantitative understanding of this grain-to-grain heating variation in practical conditions is of importance for advancing HAMR as a viable future recording technology.
Permanent polarization and charge distribution in organic light-emitting diodes (OLEDs): Insights from near-infrared charge-modulation spectroscopy of an operating OLED
Authors: Marchetti Alfred P. , Haskins Terri L. , Young Ralph H. , Rothberg Lewis J.
Published: March 2014

Vapor-deposited Alq3 layers typically possess a strong permanent electrical polarization, whereas NPB layers do not. (Alq3 is tris(8-quinolinolato)aluminum(III); NPB is 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl.) The cause is a net orientation of the Alq3 molecules with their large dipole moments. Here we report on consequences for an organic light-emitting diode (OLED) with an NPB hole-transport layer and Alq3 electron-transport layer. The discontinuous polarization at the NPB|Alq3 interface has the same effect as a sheet of immobile negative charge there. It is more than compensated by a large concentration of injected holes (NPB+) when the OLED is running. We discuss the implications and consequences for the quantum efficiency and the drive voltage of this OLED and others. We also speculate on possible consequences of permanent polarization in organic photovoltaic devices. The concentration of NPB+ was measured by charge-modulation spectroscopy (CMS) in the near infrared, where the NPB+ has a strong absorption band, supplemented by differential-capacitance and current-voltage measurements. Unlike CMS in the visible, this method avoids complications from modulation of the electroluminescence and electroabsorption.
High-speed spiral imaging technique for an atomic force microscope using a linear quadratic Gaussian controller
Authors: Habibullah H. , Pota H. R. , Petersen I. R.
Published: March 2014

This paper demonstrates a high-speed spiral imaging technique for an atomic force microscope (AFM). As an alternative to traditional raster scanning, an approach of gradient pulsing using a spiral line is implemented and spirals are generated by applying single-frequency cosine and sine waves of slowly varying amplitudes to the X and Y-axes of the AFM’s piezoelectric tube scanner (PTS). Due to these single-frequency sinusoidal input signals, the scanning process can be faster than that of conventional raster scanning. A linear quadratic Gaussian controller is designed to track the reference sinusoid and a vibration compensator is combined to damp the resonant mode of the PTS. An internal model of the reference sinusoidal signal is included in the plant model and an integrator for the system error is introduced in the proposed control scheme. As a result, the phase error between the input and output sinusoids from the X and Y-PTSs is reduced. The spirals produced have particularly narrow-band frequency measures which change slowly over time, thereby making it possible for the scanner to achieve improved tracking and continuous high-speed scanning rather than being restricted to the back and forth motion of raster scanning. As part of the post-processing of the experimental data, a fifth-order Butterworth filter is used to filter noises in the signals emanating from the position sensors and a Gaussian image filter is used to filter the images. A comparison of images scanned using the proposed controller (spiral) and the AFM PI controller (raster) shows improvement in the scanning rate using the proposed method.
Deoxyribonucleic acid-based hybrid thin films for potential application as high energy density capacitors
Authors: Joyce Donna M. , Venkat Narayanan , Ouchen Fahima , Singh Kristi M. , Smith Steven R. , Grabowski Christopher A. , Terry Murray P. , Grote James G.
Published: March 2014

Deoxyribonucleic acid (DNA) based hybrid films incorporating sol-gel-derived ceramics have shown strong promise as insulating dielectrics for high voltage capacitor applications. Our studies of DNA-CTMA (cetyltrimethylammonium) complex/sol-gel ceramic hybrid thin film devices have demonstrated reproducibility and stability in temperature- and frequency-dependent dielectric properties with dielectric constant k ∼ 5.0 (1 kHz), as well as reliability in DC voltage breakdown measurements, attaining values consistently in the range of 300–350 V/μm. The electrical/dielectric characteristics of DNA-CTMA films with sol-gel-derived ceramics were examined to determine the critical energy storage parameters such as voltage breakdown and dielectric constant.
A simple algorithm for beam profile diagnostics using a thermographic camera
Authors: Katagiri Ken , Hojo Satoru , Honma Toshihiro , Suzuki Kazutoshi , Noda Akira , Noda Koji
Published: March 2014

A new algorithm for digital image processing apparatuses is developed to evaluate profiles of high-intensity DC beams from temperature images of irradiated thin foils. Numerical analyses are performed to examine the reliability of the algorithm. To simulate the temperature images acquired by a thermographic camera, temperature distributions are numerically calculated for 20 MeV proton beams with different parameters. Noise in the temperature images which is added by the camera sensor is also simulated to account for its effect. Using the algorithm, beam profiles are evaluated from the simulated temperature images and compared with exact solutions. We find that niobium is an appropriate material for the thin foil used in the diagnostic system. We also confirm that the algorithm is adaptable over a wide beam current range of 0.11–214 μA, even when employing a general-purpose thermographic camera with rather high noise (ΔTNETD ≃ 0.3 K; NETD: noise equivalent temperature difference).
Local density dependent potential for compressible mesoparticles
Authors: Faure Gérôme , Maillet Jean-Bernard , Stoltz Gabriel
Published: March 2014

This work proposes a coarse grained description of molecular systems based on mesoparticles representing several molecules, where interactions between mesoparticles are modelled by an interparticle potential of molecular type. Since strong non-equilibrium situations over a wide range of pressure and density are targeted, the internal compressibility of the mesoparticles has to be considered. This is done by introducing a dependence of the potential on the local environment of the mesoparticles. To define local densities, we resort to a three-dimensional Voronoi tessellation instead of standard local, spherical averages. As an example, a local density dependent potential is fitted to reproduce the Hugoniot curve of a model of nitromethane over a large range of pressures and densities.
Unraveling the nature of coherent beatings in chlorosomes
Authors: Dostál Jakub , Mančal Tomáš , Vácha František , Pšenčík Jakub , Zigmantas Donatas
Published: March 2014

Coherent two-dimensional (2D) spectroscopy at 80 K was used to study chlorosomes isolated from green sulfur bacterium Chlorobaculum tepidum. Two distinct processes in the evolution of the 2D spectrum are observed. The first being exciton diffusion, seen in the change of the spectral shape occurring on a 100-fs timescale, and the second being vibrational coherences, realized through coherent beatings with frequencies of 91 and 145 cm−1 that are dephased during the first 1.2 ps. The distribution of the oscillation amplitude in the 2D spectra is independent of the evolution of the 2D spectral shape. This implies that the diffusion energy transfer process does not transfer coherences within the chlorosome. Remarkably, the oscillatory pattern observed in the negative regions of the 2D spectrum (dominated by the excited state absorption) is a mirror image of the oscillations found in the positive part (originating from the stimulated emission and ground state bleach). This observation is surprising since it is expected that coherences in the electronic ground and excited states are generated with the same probability and the latter dephase faster in the presence of fast diffusion. Moreover, the relative amplitude of coherent beatings is rather high compared to non-oscillatory signal despite the reported low values of the Huang-Rhys factors. The origin of these effects is discussed in terms of the vibronic and Herzberg-Teller couplings.
Residual and intentional n-type doping of ZnO thin films grown by metal-organic vapor phase epitaxy on sapphire and ZnO substrates
Authors: Brochen Stéphane , Lafossas Matthieu , Robin Ivan-Christophe , Ferret Pierre , Gemain Frédérique , Pernot Julien , Feuillet Guy
Published: March 2014

ZnO epilayers usually exhibit high n-type residual doping which is one of the reasons behind the difficulties to dope this material p-type. In this work, we aimed at determining the nature of the involved impurities and their potential role as dopant in ZnO thin films grown by metalorganic vapor phase epitaxy (MOVPE) on sapphire and ZnO substrates. In both cases, secondary ion mass spectroscopy (SIMS) measurements give evidence for a strong diffusion of impurities from the substrate to the epilayer, especially for silicon and aluminum. In the case of samples grown on sapphire substrates, aluminum follows Fick's diffusion law on a wide growth temperature range (800−1000°C). Thus, the saturation solubility and the diffusion coefficient of aluminum in ZnO single crystals have been determined. Furthermore, the comparison between SIMS impurity and effective dopant concentrations determined by capacitance-voltage measurements highlights, on one hand a substitutional mechanism for aluminum diffusion, and on the other hand that silicon acts as a donor in ZnO and not as an amphoteric impurity. In addition, photoluminescence spectra exhibit excitonic recombinations at the same energy for aluminum and silicon, indicating that silicon behaves as an hydrogenic donor in ZnO. Based on these experimental observations, ZnO thin films with a controlled n-type doping in the 1016−1019cm−3 range have been carried out. These results show that MOVPE growth is fully compatible with the achievement of highly Al-doped n-type thin films, but also with the growth of materials with low residual doping, which is a crucial parameter to address ZnO p-type doping issues.
Impacts of surface spins and inter-particle interactions on the magnetism of hollow γ-Fe2O3 nanoparticles
Authors: Khusrhid Hafsa , Nemati Porshokouh Zohreh , Phan Manh-Huong , Mukherjee Pritish , Srikanth Hariharan
Published: March 2014

A comparative study of the static and dynamic magnetic properties of polycrystalline hollow γ-Fe2O3 nanoparticles with two distinctly different sizes of 10.3 ± 1.3 nm and 14.8 ± 0.5 nm has been performed. High-resolution TEM images confirmed the crystalline structure and the presence of the shell thickness of 2.17 ± 0.28 nm and 3.25 ± 0.24 nm for the 10 nm and 15 nm particles, respectively. Quantitative fits of the frequency dependent ac susceptibility to the Vogel-Fulcher model, τ = τo exp[Ea/k(T − To)], show stronger inter-particle interactions in the 15 nm nanoparticles than in the 10 nm nanoparticles. A systematic analysis of the room-temperature magnetic loops using the modified Langevin function indicates a stronger effect of disordered surface spins in the 10 nm hollow particles as compared to the 15 nm hollow particles. Our study suggests that while the effect of disordered surface spins dominates the magnetic behavior of the 10 nm hollow particles, both the disordered surface spins and inter-particle interactions contribute to the magnetism of the 15 nm hollow particles.
Spintronic switches for ultra low energy global interconnects
Authors: Sharad Mrigank , Roy Kaushik
Published: March 2014

We present ultra-low energy interconnect design using nano-scale spin-torque (ST) switches for global data-links. Emerging spin-torque phenomena can lead to ultra-low-voltage, high-speed current-mode magnetic-switches. ST-switches can simultaneously provide large trans-impedance gain by employing magnetic tunnel junctions, to convert current-mode signals into large-swing voltage levels. Such device-characteristics can be used in the design of energy-efficient current-mode global interconnects.
Deep sub-nanosecond reversal of vortex cores confined in a spin-wave potential well
Authors: Dong Xinwei , Wang Zhenyu , Wang Ruifang
Published: March 2014

A spin-wave potential well is created in a permalloy nanodisk by setting up a cylindrical cavity in the center of the sample. We then apply a single-harmonic external magnetic field perpendicular to the disk plane to switch the vortex polarity of the sample. Our micromagnetic numerical studies establish that the effective spin-wave confinement by the potential well leads to much stronger magnetization oscillation in the sample. Therefore, the vortex core can be reversed well below 200 ps and over a wide range of field frequency. Our findings present an additional efficient means for ultrafast switching of magnetic vortices.
Single-crystalline monolayer and multilayer graphene nano switches
Authors: Li Peng , Jing Gaoshan , Zhang Bo , Sando Shota , Cui Tianhong
Published: March 2014

Growth of monolayer, bi-layer, and tri-layer single-crystalline graphene (SCG) using chemical vapor deposition method is reported. SCG's mechanical properties and single-crystalline nature were characterized and verified by atomic force microscope and Raman spectroscopy. Electro-mechanical switches based on mono- and bi-layer SCG were fabricated, and the superb properties of SCG enable the switches to operate at pull-in voltage as low as 1 V, and high switching speed about 100 ns. These devices exhibit lifetime without a breakdown of over 5000 cycles, far more durable than any other graphene nanoelectromechanical system switches reported.
Donut wakefields generated by intense laser pulses with orbital angular momentum
Authors: Mendonça J. T. , Vieira J.
Published: March 2014

We study the wakefields produced in a plasma by intense laser pulses carrying a finite amount of orbital angular momentum. We show that these wakefields have new donut-like shapes, different from those usually considered in the literature, and could be used to accelerate hollow electron beams. Wakefields with a more general angular structure were also considered. The analytical solutions are corroborated by relativistic particle-in-cell simulations using OSIRIS.
Algebraic reconstruction combined with the signal space separation method for the inverse magnetoencephalography problem with a dipole-quadrupole source
Authors: Nara T. , Koiwa K. , Takagi S. , Oyama D. , Uehara G.
Published: March 2014

This paper presents an algebraic reconstruction method for dipole-quadrupole sources using magnetoencephalography data. Compared to the conventional methods with the equivalent current dipoles source model, our method can more accurately reconstruct two close, oppositely directed sources. Numerical simulations show that two sources on both sides of the longitudinal fissure of cerebrum are stably estimated. The method is verified using a quadrupolar source phantom, which is composed of two isosceles-triangle-coils with parallel bases.
Materials for light-induced water splitting: In situ controlled surface preparation of GaPN epilayers grown lattice-matched on Si(100)
Authors: Supplie Oliver , May Matthias M. , Stange Helena , Höhn Christian , Lewerenz Hans-Joachim , Hannappel Thomas
Published: March 2014

Energy storage is a key challenge in solar-driven renewable energy conversion. We promote a photochemical diode based on dilute nitride GaPN grown lattice-matched on Si(100), which could reach both high photovoltaic efficiencies and evolve hydrogen directly without external bias. Homoepitaxial GaP(100) surface preparation was shown to have a significant impact on the semiconductor-water interface formation. Here, we grow a thin, pseudomorphic GaP nucleation buffer on almost single-domain Si(100) prior to GaPN growth and compare the GaP0.98N0.02/Si(100) surface preparation to established P- and Ga-rich surfaces of GaP/Si(100). We apply reflection anisotropy spectroscopy to study the surface preparation of GaP0.98N0.02 in situ in vapor phase epitaxy ambient and benchmark the signals to low energy electron diffraction, photoelectron spectroscopy, and x-ray diffraction. While the preparation of the Ga-rich surface is hardly influenced by the presence of the nitrogen precursor 1,1-dimethylhydrazine (UDMH), we find that stabilization with UDMH after growth hinders well-defined formation of the V-rich GaP0.98N0.02/Si(100) surface. Additional features in the reflection anisotropy spectra are suggested to be related to nitrogen incorporation in the GaP bulk.
Cation off-stoichiometric effect on superconducting GdBa2Cu3O7-δ thin films investigated by Raman spectroscopy
Authors: Kakeshita T. , Hirose K. , Yokoyama T. , Lee S.
Published: March 2014

The superconducting properties of cation off-stoichiometric GdB2Cu3O7-δ (Gd123) thin film grown by pulsed laser deposition method show a strong dependence on target compositions and particularly get worse in case of a ratio Ba/Gd > 2. We investigated the effect of cation off-stoichiometric target sample on lattice properties of Gd123 thin films using Raman spectroscopy. In addition to five Ag modes related to ortho-I phase, some additional peaks are seen in the films of Ba/Gd > 2. The result implies that the superconducting properties of the films are strongly influenced by the cation off-stoichiometric effect and in connection with the existence of additional peaks.
Low-temperature evolution of local polarization properties of PbZr0.65Ti0.35O3 thin films probed by piezoresponse force microscopy
Authors: Andreeva N. V. , Tyunina M. , Filimonov A. V. , Rudskoy A. I. , Pertsev N. A. , Vakhrushev S. B.
Published: March 2014

The temperature evolution of local polarization properties in epitaxial PbZr0.65Ti0.35O3 films is studied by the low-temperature piezoresponse force microscopy (PFM). Pronounced changes in the film polarization state, including apparent polarization rotations and possible transitions between single-domain and polydomain states of individual ferroelectric nanocolumns, are revealed on cooling from the room temperature to 8 K using PFM imaging. More than two-fold increase in the coercive voltage extracted from the piezoresponse hysteresis loops is found on cooling from 240 to 8 K. The results are explained by the thermodynamic theory of strained epitaxial perovskite ferroelectric films.
Spin Josephson effect in topological superconductor-ferromagnet junction
Authors: Ren C. D. , Wang J.
Published: March 2014

The composite topological superconductor (TS), made of one-dimensional spin-orbit coupled nanowire with proximity-induced s-wave superconductivity, is not a pure p-wave superconductor but still has a suppressed s-wave pairing. We propose to probe the spin texture of the p-wave pairing in this composite TS by examining possible spin supercurrents in an unbiased TS/ferromagnet junction. It is found that both the exchange-coupling induced and spin-flip reflection induced spin currents exist in the setup and survive even in the topological phase. We showed that besides the nontrivial p-wave pairing state accounting for Majorana Fermions, there shall be a trivial p-wave pairing state that contributes to spin supercurrent. The trivial p-wave pairing state is diagnosed from the mixing effect between the suppressed s-wave pairing and the topologically nontrivial p-wave pairing. The d vector of the TS is proved not to be rigorously perpendicular to the spin projection of p-wave pairings. Our findings are also confirmed by the Kitaev's p-wave model with a nonzero s-wave pairing.
Physical understanding of electron mobility in asymmetrically strained InGaAs-on-insulator metal-oxide-semiconductor field-effect transistors fabricated by lateral strain relaxation
Authors: Kim SangHyeon , Yokoyama Masafumi , Ikku Yuki , Nakane Ryosho , Ichikawa Osamu , Osada Takenori , Hata Masahiko , Takenaka Mitsuru , Takagi Shinichi
Published: March 2014

In this paper, we fabricated asymmetrically tensile-strained In0.53Ga0.47As-on-insulator (-OI) metal-oxide-semiconductor field-effect transistors (MOSFETs) using a lateral strain relaxation technique. A stripe-like line structure, fabricated in biaxially strained In0.53Ga0.47As-OI can lead to the lateral strain relaxation and asymmetric strain configuration in In0.53Ga0.47As-OI with the channel width of 100 nm. We have found that the effective mobility (μeff) enhancement in In0.53Ga0.47As-OI MOSFETs with uniaxial-like asymmetric strain becomes smaller than that in In0.53Ga0.47As-OI MOSFETs with biaxial strain. We have clarified from a systematic analysis between the strain values and the μeff characteristics that this mobility behavior can be understood by the change of the energy level of the conduction band minimum due to the lateral strain relaxation.
Magnetic anisotropy of thin sputtered MgB2 films on MgO substrates in high magnetic fields
Authors: Fabretti Savio , Imort Inga-Mareen , Kuschel Timo , Dahm Thomas , Guduru Veerendra K. , Zeitler Uli , Thomas Andy
Published: March 2014

We investigated the magnetic anisotropy ratio of thin sputtered polycrystalline MgB2 films on MgO substrates. Using high magnetic field measurements, we estimated an anisotropy ratio of 1.35 for T = 0 K with an upper critical field of 31.74 T in the parallel case and 23.5 T in the perpendicular case. Direct measurements of a magnetic-field sweep at 4.2 K show a linear behavior, confirmed by a linear fit for magnetic fields perpendicular to the film plane. Furthermore, we observed a change of up to 12% of the anisotropy ratio in dependence of the film thickness.
Highly polarized photoluminescence and its dynamics in semipolar (202¯1¯) InGaN/GaN quantum well
Authors: Marcinkevičius S. , Ivanov R. , Zhao Y. , Nakamura S. , DenBaars S. P. , Speck J. S.
Published: March 2014

Very high polarization degree of 0.98, considerably larger than theoretical predictions, has been measured in (202¯1¯) In0.24Ga0.76N/GaN quantum well by low temperature photoluminescence. With increasing temperature, the polarization degree decreases due to thermal population of the excited valence band level. This effect suggests an accurate method to determine the interlevel energy, which, for the studied well, is 32 meV. Time-resolved photoluminescence measurements set radiative recombination times between 2 and 12 ns for temperatures from 3 to 300 K. Nonradiative recombination was found to be slow, over 2 ns at 300 K, taking place via traps with activation energy of 0.19 eV.
Effect of forest fragmentation and altitude on the mating system of Eucalyptus pauciflora (Myrtaceae)
Authors: Gauli Archana , Vaillancourt René E. , Steane Dorothy A. , Bailey Tanya G. , Potts Brad M.
Published: March 2014

Habitat fragmentation is a key factor causing variation in important mating system parameters in plants, but its effect is variable. We studied mating system variation among 276 native trees from 37 populations of Eucalyptus pauciflora from Tasmania. We assayed 10 microsatellite loci from 1359 open-pollinated progeny from these trees. Across Tasmania the species’ mating system was characterised by a high outcrossing rate (tm = 0.90) but moderate bi-parental inbreeding (tm–ts = 0.16) and moderate correlated paternity (rP = 0.20) in comparison to other eucalypt species. Despite significant differences in outcrossing rate and correlated paternity among populations, this variation was not correlated with fragmentation. Nevertheless, fragmentation was inversely correlated with the number of germinants per gram of seed capsule content. Outcrossing rate had been reported previously to decrease with increasing altitude in mainland populations of E. pauciflora, but this was not the case in Tasmania. However, a small but significant decrease in correlated paternity occurred with increasing altitude and a decrease in bi-parental inbreeding with increasing altitude was evident in fragmented populations only. It is argued that strong, but incomplete self-incompatibility mechanisms may buffer the mating system from changes in population density and pollinators. While seed yields from highly fragmented populations were reduced, in most cases the seed obtained is unlikely to be more inbred than that from non-fragmented populations and, thus, is likely to be as suitable for use in local forest restoration.
Corrigendum to: Forecasting fire activity in Victoria, Australia, using antecedent climate variables and ENSO indices
Authors: Harris Sarah , Nicholls Neville , Tapper Nigel
Published: March 2014

Climatic variability alters precipitation and temperature patterns globally, and presumably has an effect on regional fire regimes, yet relationships between climate variation and bushfire activity are poorly understood in many fire-prone regions. Such relationships may facilitate forecasting of the potential fire risk for an upcoming season. This paper reviews the interaction between the El Niño–Southern Oscillation (ENSO), and the weather and fire activity in the fire-prone state of Victoria, Australia. Linear correlations were used to analyse the relationships between ENSO indices, spatially averaged climate variables and fire activity in Victoria from 1972 to 2012. Data were analysed using monthly and seasonal averages and both antecedent and concurrent relationships were explored. Significant relationships were identified between fire activity and climate variables, especially in September to November, the months immediately preceding the fire season. In order of strength, these climate variables are vapour pressure at 1500 hours, vapour pressure at 0900 hours, maximum temperature, rainfall and minimum temperature. Additionally, significant relationships between ENSO indices and fire activity were identified for this period, although these relationships were not as strong as those with climate variables. The potential exists to use ENSO indices and climate variables to forecast an upcoming season's potential bushfire activity. This is the first study to analyse the ENSO–fire relationship specifically for Victoria and also the first to use Victorian fire activity data (rather than indices of fire weather) as a basis for the comparison with climate and ENSO.
Understanding evacuation preferences and wildfire mitigations among Northwest Montana residents
Authors: Paveglio Travis , Prato Tony , Dalenberg Douglas , Venn Tyron
Published: March 2014

There is currently insufficient information in the United States about residents’ planned evacuation actions during wildfire events, including any intent to remain at or near home during fire events. This is incompatible with growing evidence that select populations at risk from wildfire are considering alternatives to evacuation. This study explores the evacuation preferences of wildland–urban interface residents in Flathead County, Montana, USA. We compare the performance of wildfire mitigation and fuel reduction actions across groups of residents with different primary evacuation preferences. We also explore what factors (e.g. actions, demographics, attitudes towards government, risk perceptions) help explain residents’ preferences for evacuation. Results suggest that relatively high proportions of residents are interested in staying and defending their homes, with smaller proportions favouring evacuation or passively sheltering in their homes during wildfire. Vegetation management behaviour differs significantly among residents with different evacuation preferences, including significantly higher rates of forest thinning among those intending to remain at home and actively defend their residence. Other results suggest that sex, part-time residency, income and attitudes towards loss from fire are statistically associated with differences in evacuation preferences.
A cyclic HSV1-TK reporter for real-time PET imaging of apoptosis
Authors: Wang Fu , Wang Zhe , Hida Naoki , Kiesewetter Dale O. , Ma Ying , Yang Kai , Rong Pengfei , Liang Jimin , Tian Jie , Niu Gang , Chen Xiaoyuan
Published: March 2014

Significance

Apoptosis, or programmed cell death, is critical for maintaining tissue homeostasis and development in multicellular organisms. This article describes a unique molecularly engineered cyclic herpes simplex virus type 1–thymidine kinase (cTK) reporter for real-time apoptosis PET imaging. This reporter enables quantitative and real-time monitoring of caspase-3 activity in response to extracellular stimuli. As a PET reporter, cTK shows low background and high sensitivity in response to caspase-3 activation. The application of this particular caspase reporter system would be of significance in assisting preclinical high-throughput screening of different apoptosis-inducing drugs and monitoring their therapeutic efficacy in a noninvasive and quantitative manner.
Joseph Merlin in London, 1760–1803: the Man behind the Mask. New Documentary Sources
Authors: Debenham Margaret
Published: March 2014

Joseph Merlin (1735–1803), ‘Ingenious Mechanick’, musical-instrument maker and flamboyant showman, is perhaps best remembered for his Museum in Princes Street, London, with its scintillating displays of automata and extraordinary inventions. Two newly identified sets of Court documents, Nicholl v. Merlin, 1779 and Merlin v. Celsson, 1779–81, now provide insights into previously unknown aspects of his business dealings and personal life. The former concerns a dispute over a house that Merlin commissioned to be built in 1776, the latter a violation of his 1774 combined harpsichord-pianoforte patent rights. Material relating to Lavigne Verel, his musical instrument foreman from 1773 to 1781, is also reported. Amongst other novel findings, perhaps the most surprising is Merlin's marriage in 1783. Contemporary primary-source material consulted includes original manuscripts held at The National Archives, UK, the Scone Palace Archives, Parish Registers, Land Tax and Apprenticeship records and numerous contemporary newspaper advertisements and notices.
The State of Babel After the Fall: Philo Judaeus and the Possibility of Rhetoric
Authors: Reeves Joshua
Published: March 2014

This article contextualizes Philo Judaeus’s treatise De Confusione Linguarum in rhetorical and intellectual history. While most interpretations of the Tower of Babel legend have found that its primary function is to explain the dispersion of the world’s diverse nations and languages, Philo argues that the “confusion of tongues” signifies a more basic existential condition. For Philo, this confusion disrupted humankind’s capacity for perfect communication, helping us value rhetorical action as an essential element of the confused, ongoing process of struggle that characterizes our everyday sociality. The confusion of tongues, therefore, simultaneously gave rise to rhetoric and the masses, as it imposed a principle of difference in language and discordant heterogeneity in the social order.
DETERMINING INCLINATIONS OF ACTIVE GALACTIC NUCLEI VIA THEIR NARROW-LINE REGION KINEMATICS. II. CORRELATION WITH OBSERVED PROPERTIES*
Authors: Fischer T. C. , Crenshaw D. M. , Kraemer S. B. , Schmitt H. R. , Turner T. J.
Published: March 2014

Active galactic nuclei (AGNs) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight, yet the specific inclinations of all but a few AGNs are generally unknown. By determining the inclinations and geometries of nearby Seyfert galaxies using the kinematics of their narrow-line regions (NLRs) and comparing them with observed properties, we find strong correlations between inclination and total hydrogen column density, infrared color, and Hβ FWHM. These correlations provide evidence that the orientation of AGNs with respect to our line of sight affects how we perceive them beyond the Seyfert 1/2 dichotomy. They can also be used to constrain three-dimensional models of AGN components such as the broad-line region and torus. Additionally, we find weak correlations between AGN luminosity and several modeled NLR parameters, which suggests that the NLR geometry and kinematics are dependent to some degree on the AGN's radiation field.
tqDist: a library for computing the quartet and triplet distances between binary or general trees
Authors: Sand Andreas , Holt Morten K. , Johansen Jens , Brodal Gerth Stølting , Mailund Thomas , Pedersen Christian N. S.
Published: March 2014

Summary: tqDist is a software package for computing the triplet and quartet distances between general rooted or unrooted trees, respectively. The program is based on algorithms with running time for the triplet distance calculation and for the quartet distance calculation, where n is the number of leaves in the trees and d is the degree of the tree with minimum degree. These are currently the fastest algorithms both in theory and in practice.

Availability and implementation: tqDist can be installed on Windows, Linux and Mac OS X. Doing this will install a set of command-line tools together with a Python module and an R package for scripting in Python or R. The software package is freely available under the GNU LGPL licence at http://birc.au.dk/software/tqDist .

Contact:  cstorm@birc.au.dk

Supplementary information:  Supplementary data are available at Bioinformatics online
An ATP-Binding Cassette Pleiotropic Drug Transporter Protein Is Required for Xenobiotic Tolerance and Antagonism in the Fungal Biocontrol Agent Clonostachys rosea
Authors: Dubey Mukesh K. , Jensen Dan Funck , Karlsson Magnus
Published: March 2014

ATP-binding cassette (ABC) transporters mediate active efflux of natural and synthetic toxicants and are considered to be important for drug tolerance in microorganisms. In biological control agents (BCA), ABC transporters can play important roles in antagonism by providing protection against toxins derived from the fungal prey and by mediating the secretion of endogenous toxins. In the present study, we generated deletion and complementation strains of the ABC transporter abcG5 in the fungal BCA Clonostachys rosea to study its role in xenobiotic tolerance and antagonism. Gene expression analysis shows induced expression of abcG5 in the presence of the Fusarium mycotoxin zearalenone (ZEA), secreted metabolites of F. graminearum, and different classes of fungicides. Phenotypic analysis of abcG5 deletion and complementation strains showed that the deletion strains were more sensitive towards F. graminearum culture filtrates, ZEA, and iprodione- and mefenoxam-based fungicides, thus suggesting the involvement of abcG5 in cell protection. The ΔabcG5 strains displayed reduced antagonism towards F. graminearum in a plate confrontation assay. Furthermore, the ΔabcG5 strains failed to protect barley seedlings from F. graminearium foot rot disease. These data show that the abcG5 ABC transporter is important for xenobiotic tolerance and biocontrol traits in C. rosea.
A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring
Authors: Sikora E. J. , Allen T. W. , Wise K. A. , Bergstrom G. , Bradley C. A. , Bond J. , Brown-Rytlewski D. , Chilvers M. , Damicone J. , DeWolf E. , Dorrance A. , Dufault N. , Esker P. , Faske T. R. , Giesler L. , Goldberg N. , Golod J. , Gómez I. R. G. , Grau C. , Grybauskas A. , Franc G. , Hammerschmidt R. , Hartman G. L. , Henn R. A. , Hershman D. , Hollier C. , Isakeit T. , Isard S. , Jacobsen B. , Jardine D. , Kemerait R. , Koenning S. , Langham M. , Malvick D. , Markell S. , Marois J. J. , Monfort S. , Mueller D. , Mueller J. , Mulrooney R. , Newman M. , Osborne L. , Padgett G. B. , Ruden B. E. , Rupe J. , Schneider R. , Schwartz H. , Shaner G. , Singh S. , Stromberg E. , Sweets L. , Tenuta A. , Vaiciunas S. , Yang X. B. , Young-Kelly H. , Zidek J.
Published: March 2014

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss. Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses. Successful monitoring programs have been developed for several plant diseases, including downy mildew of cucurbits, Fusarium head blight of wheat, potato late blight, and rusts of cereal crops. A recent example of a successful disease-monitoring program for an economically important crop is the soybean rust (SBR) monitoring effort within North America. SBR, caused by the fungus Phakopsora pachyrhizi, was first identified in the continental United States in November 2004. SBR causes moderate to severe yield losses globally. The fungus produces foliar lesions on soybean (Glycine max) and other legume hosts. P. pachyrhizi diverts nutrients from the host to its own growth and reproduction. The lesions also reduce photosynthetic area. Uredinia rupture the host epidermis and diminish stomatal regulation of transpiration to cause tissue desiccation and premature defoliation. Severe soybean yield losses can occur if plants defoliate during the mid-reproductive growth stages. The rapid response to the threat of SBR in North America resulted in an unprecedented amount of information dissemination and the development of a real-time, publicly available monitoring and prediction system known as the Soybean Rust-Pest Information Platform for Extension and Education (SBR-PIPE). The objectives of this article are (i) to highlight the successful response effort to SBR in North America, and (ii) to introduce researchers to the quantity and type of data generated by SBR-PIPE. Data from this system may now be used to answer questions about the biology, ecology, and epidemiology of an important pathogen and disease of soybean.
Pyramiding B Genes in Cotton Achieves Broader But Not Always Higher Resistance to Bacterial Blight
Authors: Essenberg Margaret , Bayles Melanie B. , Pierce Margaret L. , Verhalen Laval M.
Published: March 2014

Near-isogenic lines of upland cotton (Gossypium hirsutum) carrying single, race-specific genes B4, BIn, and b7 for resistance to bacterial blight were used to develop a pyramid of lines with all possible combinations of two and three genes to learn whether the pyramid could achieve broad and high resistance approaching that of L. A. Brinkerhoff's exceptional line Im216. Isogenic strains of Xanthomonas axonopodis pv. malvacearum carrying single avirulence (avr) genes were used to identify plants carrying specific resistance (B) genes. Under field conditions in north-central Oklahoma, pyramid lines exhibited broader resistance to individual races and, consequently, higher resistance to a race mixture. It was predicted that lines carrying two or three B genes would also exhibit higher resistance to race 1, which possesses many avr genes. Although some enhancements were observed, they did not approach the level of resistance of Im216. In a growth chamber, bacterial populations attained by race 1 in and on leaves of the pyramid lines decreased significantly with increasing number of B genes in only one of four experiments. The older lines, Im216 and AcHR, exhibited considerably lower bacterial populations than any of the one-, two-, or three-B-gene lines. A spreading collapse of spray-inoculated AcBIn and AcBInb7 leaves appears to be a defense response (conditioned by BIn) that is out of control.
Polymorphobacter multimanifer gen. nov., sp. nov., a polymorphic bacterium isolated from antarctic white rock
Authors: Fukuda Wakao , Chino Yohzo , Araki Shigeo , Kondo Yuka , Imanaka Hiroyuki , Kanai Tamotsu , Atomi Haruyuki , Imanaka Tadayuki
Published: March 2014

A Gram-stain-negative, non-spore-forming, aerobic, oligotrophic bacterium (strain 262-7T) was isolated from a crack of white rock collected in the Skallen region of Antarctica. Strain 262-7T grew at temperatures between −4 and 30 °C, with optimal growth at 25 °C. The pH range for growth was between pH 6.0 and 9.0, with optimal growth at approximately pH 7.0. The NaCl concentration range allowing growth was between 0.0 and 1.0 %, with an optimum of 0.5 %. Strain 262-7T showed an unprecedented range of morphological diversity in response to growth conditions. Cells grown in liquid medium were circular or ovoid with smooth surfaces in the lag phase. In the exponential phase, ovoid cells with short projections were observed. Cells in the stationary phase possessed long tentacle-like projections intertwined intricately. By contrast, cells grown on agar plate medium or in liquid media containing organic compounds at low concentration exhibited short- and long-rod-shaped morphology. These projections and morphological variations clearly differ from those of previously described bacteria. Ubiquinone 10 was the major respiratory quinone. The major fatty acids were C17 : 1ω6c (28.2 %), C16 : 1ω7c (22.6 %), C18 : 1ω7c (12.9 %) and C15 : 0 2-OH (12.3 %). The G+C content of genomic DNA was 68.0 mol%. Carotenoids were detected from the cells. Comparative analyses of 16S rRNA gene sequences indicated that strain 262-7T belongs to the family

Sphingomonadaceae

, and that 262-7T should be distinguished from known genera in the family

Sphingomonadaceae

. According to the phylogenetic position, physiological characteristics and unique morphology variations, strain 262-7T should be classified as a representative of a novel genus of the family

Sphingomonadaceae

. Here, a novel genus and species with the name Polymorphobacter multimanifer gen. nov., sp. nov. is proposed (type strain 262-7T = JCM 18140T = ATCC BAA-2413T). The novel species was named after its morphological diversity and formation of unique projections.
Extreme HOT regions are CpG-dense promoters in C. elegans and humans
Authors: Chen Ron A.-J. , Stempor Przemyslaw , Down Thomas A. , Zeiser Eva , Feuer Sky K. , Ahringer Julie
Published: March 2014

Most vertebrate promoters lie in unmethylated CpG-dense islands, whereas methylation of the more sparsely distributed CpGs in the remainder of the genome is thought to contribute to transcriptional repression. Nonmethylated CG dinucleotides are recognized by CXXC finger protein 1 (CXXC1, also known as CFP1), which recruits SETD1A (also known as Set1) methyltransferase for trimethylation of histone H3 lysine 4, an active promoter mark. Genomic regions enriched for CpGs are thought to be either absent or irrelevant in invertebrates that lack DNA methylation, such as C. elegans; however, a CXXC1 ortholog (CFP-1) is present. Here we demonstrate that C. elegans CFP-1 targets promoters with high CpG density, and these promoters are marked by high levels of H3K4me3. Furthermore, as for mammalian promoters, high CpG content is associated with nucleosome depletion irrespective of transcriptional activity. We further show that highly occupied target (HOT) regions identified by the binding of a large number of transcription factors are CpG-rich promoters in C. elegans and human genomes, suggesting that the unusually high factor association at HOT regions may be a consequence of CpG-linked chromatin accessibility. Our results indicate that nonmethylated CpG-dense sequence is a conserved genomic signal that promotes an open chromatin state, targeting by a CXXC1 ortholog, and H3K4me3 modification in both C. elegans and human genomes.
1-Phenylpiperazine-1,4-diium tetrachloridocobalt(II)
Authors: Dhieb Abdelhamid Chiheb , Janzen Daron E. , Rzaigui Mohamed , Smirani Sta Wajda
Published: March 2014

In the title molecular salt, (C10H16N2)[CoCl4], the piperazine ring of the phenylpiperazine dication adopts a chair conformation and the phenyl ring occupies an equatorial orientation. In the tetrachloridocobaltate(II) dianion, the Co—Cl bond lengths for the chloride ions not accepting hydrogen bonds are significantly shorter than those for the chloride ions accepting such bonds. In the crystal, the components are linked by N—H...Cl hydrogen bonds, generating [001] chains.
N-(2-Chloroethyl)morpholine-4-carboxamide
Authors: Ujam Oguejiofo T. , Asegbeloyin Jonnie N. , Nicholson Brian K. , Ukoha Pius O. , Ukwueze Nkechi N.
Published: March 2014

The title compound, C7H13ClN2O2, synthesized by the reaction of 2-chloroethyl isocyanate and morpholine, crystallizes with four molecules in the asymmetric unit, which have similar conformations and comprise two pairs each related by approximate non-crystallographic inversion centres. Two of them have a modest orientational disorder of the 2-chloroethyl fragments [occupancy ratio of 0.778 (4):0.222 (4)]. In the crystal, molecules are linked by N—H...O=C hydrogen bonds, forming three crystallographically different kinds of infinite hydrogen-bonded chains extending along [001].
Poly[diammonium [diaqua(μ7-benzene-1,2,3,4,5,6-hexacarboxylato)tetraoxidodiuranium(VI)]]
Authors: Cantos Paula M. , Cahill Christopher L.
Published: March 2014

Uranyl-carboxylate hybrid materials dominate the catalog of uranyl compounds owing in part to the affinity between COO−functional groups and UO22+. Polycarboxylate organic ligands may present a degree of steric hindrance and could thus influence the resulting uranyl topology. Single crystals of the title compound, {(NH4)2[(UO2)2(C12O12)(H2O)2]}n, were synthesized hydrothermally as a result of reacting uranyl nitrate with benzene-1,2,3,4,5,6-hexacarboxylic acid (mellitic acid). The structure is comprised of a single unique monomeric uranyl cation adopting a pentagonal bipyramidal geometry. The uranyl coordination sphere is composed of four O atoms originating from one half of a fully deprotonated mellitic acid ligand and a single water molecule. The observed axial U—O bonds display an average distance of 1.765 (8) Å, whereas equatorial O atoms are found at an average distance of 2.40 (5) Å. All uranium–oxygen bond lengths are in good agreement with literature values. Furthermore, the coordination between the uranyl pentagonal bipyramids and the mellitic acid anion constructs a three-dimensional anionic framework which is charge-balanced with ammonium cations. Additional stabilization of the structure is provided by O—H...O and N—H...O hydrogen bonding interactions between the components.