bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ integrated tuner approach for load‐pull measurement of Si/SiGe:C HBT at 200 GHz
Authors: Hasnaoui I. , Pottrain A. , Lacave T. , Chevalier P. , Gloria D. , Gaquiere C.
Published: July 2014

Load impedance variations were obtained using an innovative integrated tuner at G‐band. The 200 GHz load‐pull measurements on a silicon–germanium (SiGe) heterojunction bipolar transistor (HBT) are presented. First, the linearity of the integrated tuner is checked. Then, the main load‐pull characteristics are extracted from a 0.13 × 3 µm2 emitter area SiGe HBT. The aim of this study is to provide a solution to avoid losses related to probes and commercial tuners. Thereby, from design to measurements, power setup architecture, calibration and performances at 200 GHz are performed in a non‐50 Ω environment. Finally, comparisons between measurements and simulation from a high current model (HICUM) show good agreement, demonstrating the capability of the measurement approach.
Numerical simulation of electromagnetic field distribution induced in brain by electrical stimulation
Authors: Kim H.J. , Meng Z.J. , Sajib S.Z.K. , Chauhan M. , Jeong W.C. , Wi H. , Kwon O.I. , Woo E.J. , Oh T.I.
Published: July 2014

Deep brain stimulation (DBS) is widely used for the treatment of various neurological diseases such as Parkinson's disease and tremors. Owing to the inherent limitations of the imaging modalities, physicians have a difficulty in the diagnosis of the exact response to the brain tissues during stimulation. Recent magnetic resonance (MR)‐based electrical impedance tomography (MREIT) enables estimation of the current density distribution from the measured magnetic flux density data. Applying MREIT to DBS, one can predict the current pathway and electric field distribution which could be useful information for proving the therapeutic effects of electrical stimulation.
Performance analysis of multi‐antenna selection policies using the golden code in multiple‐input multiple‐output systems
Authors: Ge Lu , Chen Gaojie , Gong Yu , Chambers Jonathon
Published: July 2014

In multiple‐input multiple‐output (MIMO) systems, multiple‐antenna selection has been proposed as a practical scheme for improving the signal transmission quality as well as reducing realisation cost because of minimising the number of radio‐frequency chains. In this study, the authors investigate transmit antenna selection for MIMO systems with the Golden Code. Two antenna selection schemes are considered: max‐min and max‐sum approaches. The outage and pairwise error probability performance of the proposed approaches are analysed. Simulations are also given to verify the analysis. The results show the proposed methods provide useful schemes for antenna selection.
H∞ filtering for Markovian jump delay systems with parameter uncertainties and limited communication capacity
Authors: Zhuang Guangming , Song Gongfei , Xu Shengyuan
Published: July 2014

This study investigates the problem of robust H∞ filter design for a class of Markovian jump time‐varying delay systems with parameter uncertainties and limited communication capacity. The parameter uncertainties are norm bounded and the communication limitations include measurement quantisation, signal transmission delay and data packet dropout, which appear simultaneously in a networked control system framework. The authors aim to design mode‐dependent H∞ filter in the network environment so as to ensure the filtering error system is not only exponentially mean‐square stable, but also satisfies a prescribed H∞ ‐norm level for all admissible uncertainties and the limited communication capacity. The delay system method is used to cope with signal transmission delay and data packet dropout, and the sector bound approach is introduced to treat measurement quantisation. A stochastic Lyapunov–Krasovskii function is proposed to reflect the inherent mode‐dependent state delays in the system itself, the network‐induced signal transmission delay and data packet dropout, the free‐weighting matrix technique and a set of strict linear matrix inequalities are utilised to derive novel conditions that guarantee the desired mode‐dependent H∞ filter can be constructed. A numerical example, a vertical take‐off and landing helicopter system and a mass–spring system are presented to illustrate the effectiveness and usefulness of the main results obtained.
Input‐output finite‐time stabilisation of linear systems with input constraints
Authors: Amato Francesco , Carannante Giuseppe , De Tommasi Gianmaria , Pironti Alfredo
Published: July 2014

In this study, the problem of input–output finite‐time stabilisation of linear time‐varying systems is dealt with. The classical definition of input‐output finite‐time stability (IO‐FTS) is extended to that one of structured IO‐FTS, which allows to incorporate, in the definition of the stabilisation problem, some amplitude constraints on the control input variables. A sufficient condition and a necessary and sufficient condition for structured IO finite‐time stabilisation are provided in the case of L∞ and L2 inputs, respectively. Such conditions require the existence of a solution to a certain differential linear matrix inequality. The theory is applied to design the active suspension control system for a two‐degree‐of‐freedom quarter‐car model.
Single‐image super‐resolution with total generalised variation and Shearlet regularisations
Authors: Feng Wensen , Lei Hong
Published: July 2014

In this study, the authors proposed a novel regularisation model for resolution enhancement of clean or noisy single image based on the total generalised variation (TGV) and Shearlet transform. The proposed model has two main contributions. Firstly, different from models with total variation regularisation, which assume that images consist of piecewise‐constant areas, the author's TGV‐based model is aware of higher‐order smoothness, thus eliminates the staircase‐like artefacts. Secondly, various image features including edges and fine details can be preserved by their model. This is nature since the Shearlets mathematically provide an optimally sparse approximation for the class of piecewise‐smooth functions with rich geometric information. Moreover, to solve the proposed model, an efficient numerical scheme is explicitly developed based on the Nesterov's algorithm. A series of numerical experiments validate the effectiveness of the proposed method.
Active contours with a joint and region‐scalable distribution metric for interactive natural image segmentation
Authors: Liu Xin , Peng Shu‐Juan , Cheung Yiu‐ming , Tang Yuan Yan , Du Ji‐Xiang
Published: July 2014

In this study, we present an efficient active contour with a joint and region‐scalable distribution metric for interactive natural image segmentation. First, the authors project a red–green–blue image into the CIELab colour space and employ independent component analysis to select two subspace channels. Then, by initialising the evolving curve interactively in terms of a polygonal curve or multiple polygonal curves, they compute a joint probability distribution associated with a region‐scalable mask to model the regional statistics and propose a simple but effective distribution metric to regularise the active contours. Subsequently, they convert the resultant level set function into binary pattern and find the larger 8‐connected regions as the desired objects. Finally, the selected regions are smoothed with a circular averaging filter such that the final segmentation results can be obtained. The proposed approach not only can deal with the complex appearance and intensity in homogeneity, but also has the advantages of fast convergence and easy implementation. The experiments have shown the precise and reliable segmentation results in comparison with the state‐of‐the‐art competing approaches.
Micromixing visualization and quantification in a microscale multi-inlet vortex nanoprecipitation reactor using confocal-based reactive micro laser-induced fluorescence
Authors: Shi Yanxiang , Fox Rodney O. , Olsen Michael G.
Published: July 2014

A technique for visualizing and quantifying reactive mixing for laminar and turbulent flow in a microscale chemical reactor using confocal-based microscopic laser induced fluorescence (confocal μ-LIF) was demonstrated in a microscale multi-inlet vortex nanoprecipitation reactor. Unlike passive scalar μ-LIF, the reactive μ-LIF technique is able to visualize and quantify micromixing effects. The confocal imaging results indicated that the flow in the reactor was laminar and steady for inlet Reynolds numbers of 10, 53, and 93. Mixing and reaction were incomplete at each of these Reynolds numbers. The results also suggested that although mixing by diffusion was enhanced near the midplane of the reactor at Rej = 53 and 93 due to very thin bands of acidic and basic fluid forming as the fluid spiraled towards the center of the reactor, near the top, and bottom walls of the reactor, the lower velocities due to fluid friction with the walls hindered the formation of these thin bands, and, thus, resulted in large regions of unmixed and unreacted fluid. At Rej = 240, the flow was turbulent and unsteady. The mixing and reaction processes were still found to be incomplete even at this highest Reynolds number. At the reactor midplane, the flow images at Rej = 240 showed unmixed base fluid near the center of the reactor, suggesting that just as in the Rej = 53 and 93 cases, lower velocities near the top and bottom walls of the reactor hinder the mixing and rection of the acidic and basic streams. Ensemble averages of line-scan profiles for the Rej = 240 were then calculated to provide statistical quantification of the microscale mixing in the reactor. These results further demonstrate that even at this highest Reynolds number investigated, mixing and reaction are incomplete. Visualization and quantification of micromixing using this reactive μ-LIF technique can prove useful in the validation of computational fluid dynamics models of micromixing within microscale chemical reactors.
Reconstruction of magnetic source images using the Wiener filter and a multichannel magnetic imaging system
Authors: Leyva-Cruz J. A. , Ferreira E. S. , Miltão M. S. R. , Andrade-Neto A. V. , Alves A. S. , Estrada J. C. , Cano M. E.
Published: July 2014

A system for imaging magnetic surfaces using a magnetoresistive sensor array is developed. The experimental setup is composed of a linear array of 12 sensors uniformly spaced, with sensitivity of 150 pT*Hz−1/2 at 1 Hz, and it is able to scan an area of (16 × 18) cm2 from a separation of 0.8 cm of the sources with a resolution of 0.3 cm. Moreover, the point spread function of the multi-sensor system is also studied, in order to characterize its transference function and to improve the quality in the restoration of images. Furthermore, the images are generated by mapping the response of the sensors due to the presence of phantoms constructed of iron oxide, which are magnetized by a pulse of 80 mT. The magnetized phantoms are linearly scanned through the sensor array and the remanent magnetic field is acquired and displayed in gray levels using a PC. The images of the magnetic sources are reconstructed using two-dimensional generalized parametric Wiener filtering. Our results exhibit a very good capability to determine the spatial distribution of magnetic field sources, which produce magnetic fields of low intensity.
How to calculate linear absorption spectra with lifetime broadening using fewest switches surface hopping trajectories: A simple generalization of ground-state Kubo theory
Authors: Petit Andrew S. , Subotnik Joseph E.
Published: July 2014

In this paper, we develop a surface hopping approach for calculating linear absorption spectra using ensembles of classical trajectories propagated on both the ground and excited potential energy surfaces. We demonstrate that our method allows the dipole-dipole correlation function to be determined exactly for the model problem of two shifted, uncoupled harmonic potentials with the same harmonic frequency. For systems where nonadiabatic dynamics and electronic relaxation are present, preliminary results show that our method produces spectra in better agreement with the results of exact quantum dynamics calculations than spectra obtained using the standard ground-state Kubo formalism. As such, our proposed surface hopping approach should find immediate use for modeling condensed phase spectra, especially for expensive calculations using ab initio potential energy surfaces.
Thermodynamically constrained correction to ab initio equations of state
Authors: French Martin , Mattsson Thomas R.
Published: July 2014

We show how equations of state generated by density functional theory methods can be augmented to match experimental data without distorting the correct behavior in the high- and low-density limits. The technique is thermodynamically consistent and relies on knowledge of the density and bulk modulus at a reference state and an estimation of the critical density of the liquid phase. We apply the method to four materials representing different classes of solids: carbon, molybdenum, lithium, and lithium fluoride. It is demonstrated that the corrected equations of state for both the liquid and solid phases show a significantly reduced dependence of the exchange-correlation functional used.
Determination of the ReA Electron Beam Ion Trap electron beam radius and current density with an X-ray pinhole camera
Authors: Baumann Thomas M. , Lapierre Alain , Kittimanapun Kritsada , Schwarz Stefan , Leitner Daniela , Bollen Georg
Published: July 2014

The Electron Beam Ion Trap (EBIT) of the National Superconducting Cyclotron Laboratory at Michigan State University is used as a charge booster and injector for the currently commissioned rare isotope re-accelerator facility ReA. This EBIT charge breeder is equipped with a unique superconducting magnet configuration, a combination of a solenoid and a pair of Helmholtz coils, allowing for a direct observation of the ion cloud while maintaining the advantages of a long ion trapping region. The current density of its electron beam is a key factor for efficient capture and fast charge breeding of continuously injected, short-lived isotope beams. It depends on the radius of the magnetically compressed electron beam. This radius is measured by imaging the highly charged ion cloud trapped within the electron beam with a pinhole camera, which is sensitive to X-rays emitted by the ions with photon energies between 2 keV and 10 keV. The 80%-radius of a cylindrical 800 mA electron beam with an energy of 15 keV is determined to be \documentclass[12pt]{minimal}\begin{document}$r_{80\%}=(212\pm 19)\mu$\end{document}r80%=(212±19)μm in a 4 T magnetic field. From this, a current density of j = (454 ± 83)A/cm2 is derived. These results are in good agreement with electron beam trajectory simulations performed with TriComp and serve as a test for future electron gun design developments.
Yukawa particles in a confining potential
Authors: Girotto Matheus , dos Santos Alexandre P. , Colla Thiago , Levin Yan
Published: July 2014

We study the density distribution of repulsive Yukawa particles confined by an external potential. In the weak coupling limit, we show that the mean-field theory is able to accurately account for the particle distribution. In the strong coupling limit, the correlations between the particles become important and the mean-field theory fails. For strongly correlated systems, we construct a density functional theory which provides an excellent description of the particle distribution, without any adjustable parameters.
Dynamic disorder and the energetic costs of information transduction
Authors: Thill Peter
Published: July 2014

We study a model of dynamic disorder relevant for signal transduction pathways in which enzymatic reaction rates fluctuate over several orders of magnitude. For the simple networks we consider, dynamic disorder drives the system far from equilibrium and imposes an energetic burden for high fidelity signaling capability. We study how the dynamics of the underlying stochastic behavior in the reaction rate process is related to the energetic cost of transmitting information through the network.
Silicon photovoltaic cells coupled with solar-pumped fiber lasers emitting at 1064 nm
Authors: Takeda Yasuhiko , Iizuka Hideo , Mizuno Shintaro , Hasegawa Kazuo , Ichikawa Tadashi , Ito Hiroshi , Kajino Tsutomu , Ichiki Akihisa , Motohiro Tomoyoshi
Published: July 2014

We have designed silicon (Si) photovoltaic (PV) cells coupled with solar-pumped fiber lasers (SPFLs), by considering the unique illumination conditions for PV cells: (1) monochromatic (1064 nm) and normal incidence, (2) large intensity, and (3) small area. We have revealed that a multilayered bandpass filter formed on the front surface of a PV cell equipped with a diffuse reflector on the back surface sufficiently traps the illumination. This, in turn, allows us to use a thin Si wafer to eliminate the detrimental effect of the series resistance in the cell under intense illumination, along with a small lateral size that is suitable for direct connection with an SPFL. Simulated conversion efficiency of the newly designed 20 μm-thick Si PV cell with the 14-layerd bandpass filter and Lambertian back reflector is 61% under normally incident 1064 nm illumination at 1 kW/cm2, which is twice as high as that of a conventional surface-textured Si solar cell of 75 μm in thickness.
Understanding the many-body expansion for large systems. I. Precision considerations
Authors: Richard Ryan M. , Lao Ka Un , Herbert John M.
Published: July 2014

Electronic structure methods based on low-order “n-body” expansions are an increasingly popular means to defeat the highly nonlinear scaling of ab initio quantum chemistry calculations, taking advantage of the inherently distributable nature of the numerous subsystem calculations. Here, we examine how the finite precision of these subsystem calculations manifests in applications to large systems, in this case, a sequence of water clusters ranging in size up to \documentclass[12pt]{minimal}\begin{document}$\rm (H_2O)_{47}$\end{document}(H2O)47. Using two different computer implementations of the n-body expansion, one fully integrated into a quantum chemistry program and the other written as a separate driver routine for the same program, we examine the reproducibility of total binding energies as a function of cluster size. The combinatorial nature of the n-body expansion amplifies subtle differences between the two implementations, especially for n ⩾ 4, leading to total energies that differ by as much as several kcal/mol between two implementations of what is ostensibly the same method. This behavior can be understood based on a propagation-of-errors analysis applied to a closed-form expression for the n-body expansion, which is derived here for the first time. Discrepancies between the two implementations arise primarily from the Coulomb self-energy correction that is required when electrostatic embedding charges are implemented by means of an external driver program. For reliable results in large systems, our analysis suggests that script- or driver-based implementations should read binary output files from an electronic structure program, in full double precision, or better yet be fully integrated in a way that avoids the need to compute the aforementioned self-energy. Moreover, four-body and higher-order expansions may be too sensitive to numerical thresholds to be of practical use in large systems.
Influence of surface coverage on the chemical desorption process
Authors: Minissale M. , Dulieu F.
Published: July 2014

In cold astrophysical environments, some molecules are observed in the gas phase whereas they should have been depleted, frozen on dust grains. In order to solve this problem, astrochemists have proposed that a fraction of molecules synthesized on the surface of dust grains could desorb just after their formation. Recently the chemical desorption process has been demonstrated experimentally, but the key parameters at play have not yet been fully understood. In this article, we propose a new procedure to analyze the ratio of di-oxygen and ozone synthesized after O atoms adsorption on oxidized graphite. We demonstrate that the chemical desorption efficiency of the two reaction paths (O+O and O+O2) is different by one order of magnitude. We show the importance of the surface coverage: for the O+O reaction, the chemical desorption efficiency is close to 80% at zero coverage and tends to zero at one monolayer coverage. The coverage dependence of O+O chemical desorption is proved by varying the amount of pre-adsorbed N2 on the substrate from 0 to 1.5 ML. Finally, we discuss the relevance of the different physical parameters that could play a role in the chemical desorption process: binding energy, enthalpy of formation, and energy transfer from the new molecule to the surface or to other adsorbates.
Hard wear-resistant coatings with anisotropic thermal conductivity for high thermal load applications
Authors: Böttger P. H. Michael , Braginsky Leonid , Shklover Valery , Lewin Erik , Patscheider Jörg , Cahill David G. , Sobiech Matthias
Published: July 2014

High thermal load applications such as high speed dry cutting lead to high temperatures in the coated tool substrate that can soften the tool and high temperature gradients that can put stress on the coating/tool interface. In this work, theoretical considerations are presented for multilayer and graded protective coatings that can induce a significant anisotropy in their thermal conductivity. Solution of the heat equation shows that anisotropy of thermal conductivity has the potential to reduce temperatures and temperature gradients arising due to brief, localized heat at the coating surface (“hot-spots”). Experimental realization of high anisotropy is demonstrated in TiN/AlCrN multilayer coatings with variable layer thickness. In the coating with 50 nm bilayer periodicity, the highest anisotropy was obtained with a value of κ||/κ⊥=3.0±0.9. Time-domain thermoreflectance is used to measure in-plane and cross-plane thermal conductivity of fabricated coatings. The observed high values of anisotropy of thermal conductivity are compared with theoretical predictions and its realisation is discussed with regard to the coating microstructure.
Near infrared emission from molecule-like silver clusters confined in zeolite A assisted by thermal activation
Authors: Lin Hui , Imakita Kenji , Rong Gui Sa Chu , Fujii Minoru
Published: July 2014

Strong and broad near infrared (NIR) emission peaked at ∼855 nm upon optimal excitation at 342 nm has been observed from molecule-like silver clusters (MLSCs) confined in zeolite A assisted by thermal activation. To the best of our knowledge, this is the first observation of NIR emission peaked at longer than 800 nm from MLSCs confined in solid matrices. The decay time of the NIR emission is over 10 μs, which indicates that it is a spin-forbidden transition. The ∼855 nm NIR emission shows strong dependence on the silver loading concentration and the thermal activation temperature.
The ejection threshold of molten aluminum induced by millisecond pulsed laser
Authors: Zang Y. N. , Ni X. W. , Han B.
Published: July 2014

The laser pulse energy density threshold of melt ejection induced by millisecond pulsed laser can vary widely due to the variation of focused laser spot area. An axisymmetric model of the flow of liquid Aluminum under the effect of recoil force from evaporation is built up to analyze the threshold of ejection through the temporal evolution of the temperature of melted pool. Temperature of the central point of focused laser spot, drag force induced by surface tension in melted pool, and recoil force of evaporation on molten liquid surface could be obtained through resolving heat conduction equation analytically and numerically with assumed Gaussian temperature distribution function. The relationship of laser pulse energy density threshold of the ejection and area of the focused laser spot is obtained through the theoretical calculation. The shape of the melted pool will be different when the relative magnitude of recoil force and drag force is varied. The validity of the obtained threshold is verified through comparison of melted pool shape with the experimental result reported in literature. The criterion proposed in this paper provides a reliable fast-diagnostic method for laser processing.
Surface stoichiometry of pulsed ultraviolet laser treated polycrystalline CdTe
Authors: Simonds Brian J. , Palekis Vasilios , Van Devener Brian , Ferekides Christos , Scarpulla Michael A.
Published: July 2014

The effects of nanosecond pulsed ultraviolet laser annealing on the surface stoichiometry of close-space sublimated polycrystalline thin films are investigated using angle-resolved x-ray photoemission spectroscopy (XPS). The raw data suggest the formation of a Cd-rich surface layer, but this is counter to the expectation based on Cd and Te vapor pressures above CdTe that predicts a Te-rich layer and to direct observation of elemental Te at the surface. In order to explain this apparent discrepancy, we analyze our XPS data in the context of prior reports of lateral segregation of Cd and Te at the surface after pulsed laser treatments with a simple model of angular dependent XPS in the presence of surface roughness. This analysis reveals that a uniform Te layer cannot explain our results. Instead, our analysis suggests that Te enrichment occurs near grain boundaries and that a sub-monolayer Cd layer exists elsewhere. These complex yet repeatable results underscore the challenges in measuring surface stoichiometry to high precision on films relevant for polycrystalline CdTe devices. It also suggests that the Cd and Te vapor pressures above grain boundaries may differ from those above grain interiors and that ohmic contact may be made preferentially at the grain boundaries after pulsed laser annealing.
Investigation of the GaN-on-GaAs interface for vertical power device applications
Authors: Möreke Janina , Uren Michael J. , Novikov Sergei V. , Foxon C. Thomas , Hosseini Vajargah Shahrzad , Wallis David J. , Humphreys Colin J. , Haigh Sarah J. , Al-Khalidi Abdullah , Wasige Edward , Thayne Iain , Kuball Martin
Published: July 2014

GaN layers were grown onto (111) GaAs by molecular beam epitaxy. Minimal band offset between the conduction bands for GaN and GaAs materials has been suggested in the literature raising the possibility of using GaN-on-GaAs for vertical power device applications. I-V and C-V measurements of the GaN/GaAs heterostructures however yielded a rectifying junction, even when both sides of the junction were heavily doped with an n-type dopant. Transmission electron microscopy analysis further confirmed the challenge in creating a GaN/GaAs Ohmic interface by showing a large density of dislocations in the GaN layer and suggesting roughening of the GaN/GaAs interface due to etching of the GaAs by the nitrogen plasma, diffusion of nitrogen or melting of Ga into the GaAs substrate.
Direct synthesis of highly textured Ge on flexible polyimide films by metal-induced crystallization
Authors: Oya N. , Toko K. , Saitoh N. , Yoshizawa N. , Suemasu T.
Published: July 2014

The highly (111)-textured Ge thin film (50-nm thickness) is demonstrated on a flexible polyimide film via the low-temperature crystallization (325 °C) of amorphous Ge using Al as a catalyst. Covering the polyimide with insulators significantly improved the crystal quality of the resulting Ge layer. In particular, SiN covering led to 97% (111)-oriented Ge with grains 200 μm in size, two orders larger than the grain size of polycrystalline Ge directly formed on the polyimide film. This achievement will give a way to realize advanced electronic and optical devices simultaneously allowing for high performance, inexpensiveness, and flexibility.
The Barn
Authors: Lingelbach Bernd
Published: July 2014

A short history of the Barn is given, including the description of a few objects. The Barn is a well-known ‘hands-on’ museum; two examples are given to show that from time to time something new is presented. Prior to the 2009 European Conference on Visual Perception in Regensburg, a conference called ‘3-Dillusions’ was held in the Barn. Owing to the success of that meeting the conference, ‘Illusions and Delusions’ was held in August 2013.
Selecting priority conservation areas based on zooplankton diversity: the case of Mediterranean wetlands
Authors: Gilbert Juan Diego , de Vicente Inmaculada , Jiménez-Melero Raquel , Parra Gema , Guerrero Francisco
Published: July 2014

A set of Mediterranean wetlands has been studied in order to identify priority areas for conservation using zooplankton assemblages. We also measure the degree of nestedness to determine the best strategy for conservation of zooplankton diversity. The present study was conducted in 29 wetlands located in the south-east of the Iberian Peninsula (Spain). Two complementary approaches were used, cluster analysis and parsimony analysis of endemicity (PAE), with a presence–absence data matrix, in order to group wetlands as a function of zooplankton composition. To select conservation areas, four different criteria were used: species richness; exclusive species occurrences; the number of wetlands in which species appeared; and phylogenetic diversity. The results showed the existence of three different zones (subgroups of wetlands). Using the same method, a significant nestedness among wetlands was also observed independently of the method used to group them. The conservation proposal included 98% of the total species and 41.4% of the studied wetlands. This work confirms that zooplankton assemblages are essential for making wetland conservation decisions and for the identification of areas with connectivity (fluxes of species) in which efforts should be more intense to preserve their biodiversity.
Allometric growth and condition factor of West African shrimp, Macrobrachium vollenhovenii (Herklots, 1857), in the rivers of Côte d'Ivoire
Authors: Konan Koffi Mexmin , Ouattara Allassane , Da Costa Kouassi Sébastino , Adépo-Gourène Abouo Béatrice , Gourène Germain
Published: July 2014

The length–length and length–weight relationships and condition factor for Macrobrachium vollenhovenii are described using samples collected from the rivers of Côte d’Ivoire. The maximum carapace lengths (CLs) registered for males and females were 63.00 and 53.60 mm, respectively. All relationships between body length and CL and weight and CL were found to be highly significant, with r2 > 0.76 (P < 0.001). In the length–length relation, the allometry coefficient (b) ranged from 0.75 to 1.46 and varied according to the considered length and groups. The value of b of the length–weight relationship varied from 2.55 to 3.30. Although the three allometry types were observed, overall, M. vollenhovenii exhibited negative allometry. The condition factor (K) did not significantly vary among males and females. The K value decreased from the eastern to western Côte d’Ivoire. The present study presents, for the first time, results on the allometric growth and condition factors of M. vollenhovenii from the rivers of Côte d’Ivoire. Further, a biological database is established for use by fishery managers and in further research on the ecology, reproductive biology and aquaculture potentialities of this species.
Unravelling the impact of anthropogenic pressure on plant communities in Mediterranean temporary ponds
Authors: Bouahim Siham , Rhazi Laila , Amami Btissam , Waterkeyn Aline , Rhazi Mouhssine , Saber Er-Riyahi , Zouahri Abdelmjid , Van den Broeck Maarten , Muller Serge D. , Brendonck Luc , Grillas Patrick
Published: July 2014

Identifying the respective role of environmental, landscape and management factors in explaining the patterns in community composition is an important goal in ecology. Using a set of 32 temporary ponds in northern Morocco we studied the respective importance of local (within the pond) and regional (density of ponds in landscape) factors and the impacts of different land uses on the plant species assemblages, separating pond and terrestrial species. The main hypotheses tested were that (1) species assemblages respond to both local and regional environmental factors, (2) anthropogenic pressure has a negative influence on the number of pond species, and that (3) human activities differ in their impact on pond biodiversity. The results showed that (1) local factors explain most of the variation in plant community composition, and (2) land use impacts the communities through changing local environmental conditions, leading to a loss of typical pond species. Aside from recreation, all other activities (grazing, drainage, agriculture and partial urbanisation) significantly reduced the number of pond species. The conservation strategy for rare pond species should focus on maintaining networks of oligotrophic ponds, while allowing only low-impact activities.
A rod-like bacterium is responsible for high molybdenum concentrations in the tropical sponge Halichondria phakellioides
Authors: Buccella Constanza , Alvarez Belinda , Gibb Karen , Padovan Anna
Published: July 2014

The tropical marine sponge, Halichondria phakellioides, from Darwin Harbour contains high concentrations of molybdenum. A rod-like bacterium extracellular in sponge tissue was observed using transmission electron microscopy. Molybdenum was located within these bacteria, but not in sponge cells. This is the first report of the trace element molybdenum localised in a sponge bacterial symbiont. Many different bacterial symbionts were identified in the sponge by sequence analysis so the identity of the molybdenum-accumulating bacterium could only be inferred.
25-Hydroxycholesterol acts as an amplifier of inflammatory signaling
Authors: Gold Elizabeth S. , Diercks Alan H. , Podolsky Irina , Podyminogin Rebecca L. , Askovich Peter S. , Treuting Piper M. , Aderem Alan
Published: July 2014

Significance

The lipid 25-hydroxycholesterol (25HC) is produced by immune cells in response to infection. We demonstrate that in addition to interfering with viral entry and replication, 25HC also amplifies the activation of immune cells and increases the production of immune mediators. Furthermore, we show that the presence of 25HC is actually harmful in the setting of infection with influenza because the production of these immune mediators leads to damage to the host. These observations might have particular relevance for understanding the mechanisms behind the high pathogenicity of several recently emerged influenza strains, including the H5N1 “bird flu,” and might have implications for the protection of the host from these virulent strains.
Alteration of the lipid profile in lymphomas induced by MYC overexpression
Authors: Eberlin Livia S. , Gabay Meital , Fan Alice C. , Gouw Arvin M. , Tibshirani Robert J. , Felsher Dean W. , Zare Richard N.
Published: July 2014

Significance

Desorption electrospray ionization mass spectrometric imaging (DESI-MSI) has been shown to be particularly powerful for identifying lipids and metabolites directly from tissue sections and providing a chemical map of their distribution. We applied DESI-MSI to investigate changes in lipid profiles that occur in animal and human lymphomas associated with the overexpression of the v-myc avian myelocytomatosis viral oncogene homolog (MYC). Using statistical analysis, we found 86 lipids that were either increased or decreased in MYC-induced transgenic mouse models of lymphoma. Most of the increased lipids were glycerophosphoglycerols and cardiolipins with a higher content of monounsaturated fatty acids when compared with control tissue. The lipid profiles of MYC associated human lymphomas with overexpression of MYC resemble closely those observed in MYC-induced transgenic mouse models.
Structure of a new DNA-binding domain which regulates pathogenesis in a wide variety of fungi
Authors: Lohse Matthew B. , Rosenberg Oren S. , Cox Jeffery S. , Stroud Robert M. , Finer-Moore Janet S. , Johnson Alexander D.
Published: July 2014

Significance

The WOPR-domain family of transcriptional regulators is deeply conserved in the fungal kingdom where the members function as master transcriptional regulators of cell morphology and pathogenesis. Despite the critical biological roles of WOPR-domain proteins, previous bioinformatic and structural prediction did not provide any significant matches between these proteins and any other type of protein. We describe a 2.6-Å–resolution structure of a WOPR domain in complex with its preferred DNA sequence. We also describe a set of biochemical experiments that confirms and rationalizes the importance of the protein–DNA contacts observed in the structure. Based on the structure, we conclude that the WOPR domain represents a new family of DNA-binding proteins, one with key roles for fungal morphogenesis and pathogenesis.
The Pussy Riot affair and Putin's démarche from sovereign democracy to sovereign morality
Authors: Sharafutdinova Gulnaz
Published: July 2014

This essay brings attention to the recent discursive turn in Russian politics that is reflected in the Kremlin's turn to issues of traditional values and morality. Expressed in Russia's domestic and foreign policies, this new “morality politics” is dated by the Pussy Riot trial in 2012 that the Kremlin used to advance its new discursive frame in the public sphere. Although not entirely new in its orientation, this new stage of “morality politics” differs from the earlier policy initiatives in its intensity, scope and political significance for the regime. The moralizing stance taken by the regime is accompanied by a divide and rule political tactic, whereby the establishment has tried to marginalize the protesters from the rest of the Russian public that the regime is attempting to reconsolidate based on traditional, conservative values. The essay interprets this recent morality turn as a strategy selected by the Kremlin to restore the regime's legitimacy that has been shaken by the protests of 2011–2012 and looks at the social and political consequences of the selected strategy.
Excited States of the Double sine-Gordon Model1
Authors: Lu Wen-Fa , Xu Bo-Wei , Zhang Yu-Mei
Published: July 2014

Using the Gaussian wave functional as variational ground state, we study the excited states of the double sine-Gordon model in

dimensions. We find, i) for

there exist two particle bound states, their energy decreases with increasing coupling; ii) also for

, the phase shift of the two-particle scattering state is always positive; iii) for

the investigation on the interaction between the particles shows that the theory is trivial.
Targeted delivery of antisense oligonucleotides to hepatocytes using triantennary N-acetyl galactosamine improves potency 10-fold in mice
Authors: Prakash Thazha P. , Graham Mark J. , Yu Jinghua , Carty Rick , Low Audrey , Chappell Alfred , Schmidt Karsten , Zhao Chenguang , Aghajan Mariam , Murray Heather F. , Riney Stan , Booten Sheri L. , Murray Susan F. , Gaus Hans , Crosby Jeff , Lima Walt F. , Guo Shuling , Monia Brett P. , Swayze Eric E. , Seth Punit P.
Published: July 2014

Triantennary N-acetyl galactosamine (GalNAc, GN3), a high-affinity ligand for the hepatocyte-specific asialoglycoprotein receptor (ASGPR), enhances the potency of second-generation gapmer antisense oligonucleotides (ASOs) 6–10-fold in mouse liver. When combined with next-generation ASO designs comprised of short S-cEt (S-2′-O-Et-2′,4′-bridged nucleic acid) gapmer ASOs, ∼60-fold enhancement in potency relative to the parent MOE (2′-O-methoxyethyl RNA) ASO was observed. GN3-conjugated ASOs showed high affinity for mouse ASGPR, which results in enhanced ASO delivery to hepatocytes versus non-parenchymal cells. After internalization into cells, the GN3-ASO conjugate is metabolized to liberate the parent ASO in the liver. No metabolism of the GN3-ASO conjugate was detected in plasma suggesting that GN3 acts as a hepatocyte targeting prodrug that is detached from the ASO by metabolism after internalization into the liver. GalNAc conjugation also enhanced potency and duration of the effect of two ASOs targeting human apolipoprotein C-III and human transthyretin (TTR) in transgenic mice. The unconjugated ASOs are currently in late stage clinical trials for the treatment of familial chylomicronemia and TTR-mediated polyneuropathy. The ability to translate these observations in humans offers the potential to improve therapeutic index, reduce cost of therapy and support a monthly dosing schedule for therapeutic suppression of gene expression in the liver using ASOs.
Iron-based high transition temperature superconductors
Authors: Chen Xianhui , Dai Pengcheng , Feng Donglai , Xiang Tao , Zhang Fu-Chun
Published: July 2014

In a superconductor electrons form pairs and electric transport becomes dissipation-less at low temperatures. Recently discovered iron-based superconductors have the highest superconducting transition temperature next to copper oxides. In this article, we review material aspects and physical properties of iron-based superconductors. We discuss the dependence of transition temperature on the crystal structure, the interplay between antiferromagnetism and superconductivity by examining neutron scattering experiments, and the electronic properties of these compounds obtained by angle-resolved photoemission spectroscopy in link with some results from scanning tunneling microscopy/spectroscopy measurements. Possible microscopic model for this class of compounds is discussed from a strong coupling point of view.
Flaviflexus salsibiostraticola sp. nov., an actinobacterium isolated from a biofilm reactor
Authors: Jin Long , Ko So-Ra , Lee Hyung-Gwan , Kim Byung-Hyuk , Kim Hee-Sik , Ahn Chi-Yong , Oh Hee-Mock
Published: July 2014

A Gram-stain-positive, aerobic, non-motile, non-spore-forming, cocci-shaped actinobacterium, designated strain EBR4-1-2T, was isolated from a biofilm reactor in Korea. Comparative 16S rRNA gene sequence studies showed the isolate was clearly affiliated with the class

Actinobacteria

, and was related most closely to

Flaviflexus huanghaiensis

H5T, showing 98.9 % similarity. Cells of strain EBR4-1-2T formed yellow colonies on R2A agar, contained MK-9(H4) as the predominant menaquinone, and included C18 : 1ω9c, C16 : 0, C16 : 1ω9c and C14 : 0 as the major fatty acids. The cell-wall peptidoglycan type was A5α (l-Lys–l-Ala–l-Lys–d-Glu). The G+C content of the genomic DNA of strain EBR4-1-2T was 65.6 mol%. Thus, the combined genotypic and phenotypic data supported the conclusion that strain EBR4-1-2T represents a novel species of the genus

Flaviflexus

, for which the name Flaviflexus
salsibiostraticola sp. nov. is proposed. The type strain is EBR4-1-2T ( = KCTC 33148T = JCM 19016T).
Characterization of meticillin-resistant and meticillin-susceptible isolates of Staphylococcus pseudintermedius from cases of canine pyoderma in Australia
Authors: Siak Meng , Burrows Amanda K. , Coombs Geoffrey W. , Khazandi Manouchehr , Abraham Sam , Norris Jacqueline M. , Weese J. Scott , Trott Darren J.
Published: July 2014

Meticillin-resistantStaphylococcus pseudintermedius(MRSP) has recently emerged as a worldwide cause of canine pyoderma. In this study, we characterized 22S. pseudintermediusisolates cultured from 19 dogs with pyoderma that attended a veterinary dermatology referral clinic in Australia in 2011 and 2012. Twelve isolates were identified as MRSP bymecAreal-time PCR and phenotypic resistance to oxacillin. In addition to β-lactam resistance, MRSP isolates were resistant to erythromycin (91.6 %), gentamicin (83.3 %), ciprofloxacin (83.3 %), chloramphenicol (75 %), clindamycin (66 %), oxytetracycline (66 %) and tetracycline (50 %), as shown by disc-diffusion susceptibility testing. Meticillin-susceptibleS. pseudintermediusisolates only showed resistance to penicillin/ampicillin (90 %) and tetracycline (10 %). PFGE using theSmaI restriction enzyme was unable to type nine of the 12 MRSP isolates. However the nine isolates provided the same PFGE pulsotype using theCfr91 restriction enzyme. Application of themec-associated direct repeat unit (dru) typing method identified the nineSmaI PFGE-untypable isolates as dt11cb, adrutype that has only previously been associated with MRSP sequence type (ST)45 isolates that possess a unique SCCmecelement. The dt11cb isolates shared a similar multidrug-resistant antibiogram phenotype profile, whereas the other MRSP isolates, dt11a, dt11af (dt11a-associated) and dt10h, were resistant to fewer antibiotic classes and had distinct PFGE profiles. This is the first report of MRSP causing pyoderma in dogs from Australia. The rapid intercontinental emergence and spread of multidrug-resistant MRSP strains confirms the urgent need for new treatment modalities for recurrent canine pyoderma in veterinary practice.
Poly[[tri-μ-aqua-dodecaaquatris(μ3-1-hydroxyethylidene-1,1-diphosphonato)tricalcium(II)tripalladium(II)] pentahydrate]
Authors: Kutsenko Irina P. , Kozachkova Alexandra N. , Tsaryk Natalia V. , Pekhnyo Vasily I. , Rusanova Julia A.
Published: July 2014

The asymmetric unit of the title compound, {[CaPd{CH3OHC(PO3)2}(H2O)5]·5/3H2O}n, consists of one half of the complex [Pd{CH3OHC(PO3)2}]2−anion (point group symmetrym..), one Ca2+cation [site symmetry (.2.)] that is surrounded by three water molecules (one of which is on the same rotation axis) and by three disordered lattice water molecules. The anions form a trinuclear metallocycle around a crystallographic threefold rotation axis. The cations are related by a twofold rotation axis to form a [Ca2(H2O)10]2+dimer. The slightly distorted square-planar coordination environment of the PdIIatoms in the complex anions is formed by O atoms of the bidentate chelating phosphonate groups of the 1-hydroxyethylidene-1,1-diphosphonate ligands. In the crystal, cations are bound to anions through —Ca—O—P—O— bonds, as well as through O—H...O hydrogen bonds, resulting in a three-dimensional polymer. The structure is completed by five disordered solvent molecules localized in cavities within the framework.
Isopropyl 1-benzoyl-4-benzoyloxy-2,6-diphenyl-1,2,3,6-tetrahydropyridine-3-carboxylate
Authors: Govindan E. , Murugavel K. , Amirthaganesan S. , SubbiahPandi A.
Published: July 2014

In the title compound, C35H31NO5, the piperidine ring has an envelope conformation, with the phenyl-substituted C atom adjacent to the methylene C atom as the flap. This flap atom deviates by 0.633 (2) Å from the mean plane of the other five essentially coplanar atoms in the ring (r.m.s. deviation = 0.044 Å). Intramolecular C—H...O hydrogen bonds formS(7) andS(9) ring motifs. In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers withR22(16) loops.
(2E)-1-(4-Chlorophenyl)-3-[4-(propan-2-yl)phenyl]prop-2-en-1-one
Authors: Narayana Badiadka , Salian Vinutha V. , Sarojini Balladka K. , Jasinski Jerry P.
Published: July 2014

In the title compound, C18H17ClO, the dihedral angle between the benzene rings is 53.5 (1)°. The mean plane of the prop-2-en-1-one group is twisted by 24.5 (8) and 33.5 (3)° from the chloro- and propanyl-substituted rings, respectively.
Ethyl 2,6-bis(4-bromophenyl)-1-isocyano-4-oxocyclohexanecarboxylate
Authors: Zhang Dawei , Hao Linlin , Li Jing
Published: July 2014

In the title compound, C22H19Br2NO3, the central oxocyclohexane ring is in a twist-boat conformation; all the substituents (one ethoxycarbonyl and two aryl groups) are located in equatorial orientations. One of the –CH2– groups and the opposite –CH– group bearing a bromobenzene substituent form the flagpoles of the twist-boat. The dihedral angle between the aromatic rings is 76.4 (4)°. In the crystal, weak C—H...O interactions link the molecules intoC(5) chains propagating in the [010] direction. A short Br...O contact of 3.254 (4) Å is observed.