bluuebunny/crossref_metadata_2025 huggingface dataset:
A liquid flatjet system for solution phase soft-x-ray spectroscopy
Authors: Ekimova Maria , Quevedo Wilson , Faubel Manfred , Wernet Philippe , Nibbering Erik T. J.
Published: August 2015

We present a liquid flatjet system for solution phase soft-x-ray spectroscopy. The flatjet set-up utilises the phenomenon of formation of stable liquid sheets upon collision of two identical laminar jets. Colliding the two single water jets, coming out of the nozzles with 50 μm orifices, under an impact angle of 48° leads to double sheet formation, of which the first sheet is 4.6 mm long and 1.0 mm wide. The liquid flatjet operates fully functional under vacuum conditions (<10−3 mbar), allowing soft-x-ray spectroscopy of aqueous solutions in transmission mode. We analyse the liquid water flatjet thickness under atmospheric pressure using interferomeric or mid-infrared transmission measurements and under vacuum conditions by measuring the absorbance of the O K-edge of water in transmission, and comparing our results with previously published data obtained with standing cells with Si3N4 membrane windows. The thickness of the first liquid sheet is found to vary between 1.4–3 μm, depending on the transverse and longitudinal position in the liquid sheet. We observe that the derived thickness is of similar magnitude under 1 bar and under vacuum conditions. A catcher unit facilitates the recycling of the solutions, allowing measurements on small sample volumes (∼10 ml). We demonstrate the applicability of this approach by presenting measurements on the N K-edge of aqueous NH4+. Our results suggest the high potential of using liquid flatjets in steady-state and time-resolved studies in the soft-x-ray regime.
Deep traps and photo-electric properties of p-Si/MgO/n-Zn1−xMgxO heterojunction
Authors: Placzek-Popko E. , Paradowska K. M. , Pietrzyk M. A. , Gumienny Z. , Biegański P. , Kozanecki A.
Published: August 2015

In the paper, the photoluminescence (PL) measurements, current–voltage–temperature (I-V-T) measurements, space charge techniques (C-V and deep level transient spectroscopy (DLTS)), and photocurrent spectral characteristics have been applied to investigate defects in p-Si/MgO/ n-Zn1−xMgxO heterojunction (HJ). The HJ structure was grown on p-type Si (111) substrate with resistivity equal to 0.1 Ω cm by the plasma-assisted molecular beam epitaxy technique. A radio-frequency cell was used for the generation of oxygen plasma. PL spectrum let us determine the Mg content ∼10%. Besides the excitonic Zn0.9Mg0.1O line, the PL spectrum also contains green and yellow emission bands indicating the presence of defect states in the investigated structures. I-V measurements reveal the rectifying properties of the HJ and the current thermally activated with a trap with the activation energy equal to 0.42 eV. DLTS studies yield the majority trap of the activation energy 0.42 eV, confirming the result obtained from the I-V measurements. It was found that the defects related to this trap have a point like behaviour. A spectral characteristic of the photocurrent shows that the p-Si/MgO/n-Zn1−xMgxO HJ may be applied as a photodiode operating within the wavelength range of 300 nm-1100 nm. The dark current transport and photocurrent spectrum were explained using the Anderson model of a HJ.
Lamination of organic solar cells and organic light emitting devices: Models and experiments
Authors: Oyewole O. K. , Yu D. , Du J. , Asare J. , Anye V. C. , Fashina A. , Zebaze Kana M. G. , Soboyejo W. O.
Published: August 2015

In this paper, a combined experimental, computational, and analytical approach is used to provide new insights into the lamination of organic solar cells and light emitting devices at macro- and micro-scales. First, the effects of applied lamination force (on contact between the laminated layers) are studied. The crack driving forces associated with the interfacial cracks (at the bi-material interfaces) are estimated along with the critical interfacial crack driving forces associated with the separation of thin films, after layer transfer. The conditions for successful lamination are predicted using a combination of experiments and computational models. Guidelines are developed for the lamination of low-cost organic electronic structures.
Efficient and robust quantum random number generation by photon number detection
Authors: Applegate M. J. , Thomas O. , Dynes J. F. , Yuan Z. L. , Ritchie D. A. , Shields A. J.
Published: August 2015

We present an efficient and robust quantum random number generator based upon high-rate room temperature photon number detection. We employ an electric field-modulated silicon avalanche photodiode, a type of device particularly suited to high-rate photon number detection with excellent photon number resolution to detect, without an applied dead-time, up to 4 photons from the optical pulses emitted by a laser. By both measuring and modeling the response of the detector to the incident photons, we are able to determine the illumination conditions that achieve an optimal bit rate that we show is robust against variation in the photon flux. We extract random bits from the detected photon numbers with an efficiency of 99% corresponding to 1.97 bits per detected photon number yielding a bit rate of 143 Mbit/s, and verify that the extracted bits pass stringent statistical tests for randomness. Our scheme is highly scalable and has the potential of multi-Gbit/s bit rates.
Fuzzy logic based dynamic sliding mode control of boost inverter in photovoltaic application
Authors: Goldvin Sugirtha Dhas B. , Deepa S. N.
Published: August 2015

The unregulated low voltage photovoltaic dc supply can be converted into regulated high-voltage ac supply in a single stage by the boost inverter. In this paper, a Fuzzy Logic based Dynamic Sliding Mode Control (FLDSMC) of the boost inverter for photovoltaic application is designed and simulated. FLDSMC essentially consists of a fuzzy knowledge base and a rule base system to develop the dynamic sliding mode law for the boost inverter. FLDSMC is designed in order to eliminate the chattering phenomenon of dynamic sliding mode controller (DSMC) and also to reduce the steady state error caused by the PI controller of DSMC. The paper also aims to improve the power quality issue which includes Total Harmonic Distortion. To evaluate and validate the performance of the FLDSMC, it is compared with the conventional DSMC method. To evaluate the effectiveness of the proposed methodology, a comprehensive assessment is carried out under extreme conditions, namely, input voltage variation and load variation. The simulation result shows that the FLDSMC possesses a fast, steady state response and robustness. Under these conditions, proposed FLDSMC is designed so that it is suitable for solar powered, stand-alone inverter system with minimal size and results in high conversion efficiency and minimal cost.
Stratified shear flow instabilities in the non-Boussinesq regime
Authors: Heifetz E. , Mak J.
Published: August 2015

Effects of the baroclinic torque on wave propagation normally neglected under the Boussinesq approximation is investigated here, with a special focus on the associated consequences for the mechanistic interpretation of shear instability arising from the interaction between a pair of vorticity-propagating waves. To illustrate and elucidate the physical effects that modify wave propagation, we consider three examples of increasing complexity: wave propagation supported by a uniform background flow; wave propagation supported on a piecewise-linear basic state possessing one jump; and an instability problem of a piecewise-linear basic state possessing two jumps, which supports the possibility of shear instability. We find that the non-Boussinesq effects introduce a preference for the direction of wave propagation that depends on the sign of the shear in the region where waves are supported. This in turn affects phase-locking of waves that is crucial for the mechanistic interpretation for shear instability, and is seen here to have an inherent tendency for stabilisation.
Forced synchronization of autonomous dynamical Boolean networks
Authors: Rivera-Durón R. R. , Campos-Cantón E. , Campos-Cantón I. , Gauthier Daniel J.
Published: August 2015

We present the design of an autonomous time-delay Boolean network realized with readily available electronic components. Through simulations and experiments that account for the detailed nonlinear response of each circuit element, we demonstrate that a network with five Boolean nodes displays complex behavior. Furthermore, we show that the dynamics of two identical networks display near-instantaneous synchronization to a periodic state when forced by a common periodic Boolean signal. A theoretical analysis of the network reveals the conditions under which complex behavior is expected in an individual network and the occurrence of synchronization in the forced networks. This research will enable future experiments on autonomous time-delay networks using readily available electronic components with dynamics on a slow enough time-scale so that inexpensive data collection systems can faithfully record the dynamics.
Synchronized states and multistability in a random network of coupled discontinuous maps
Authors: Nag Mayurakshi , Poria Swarup
Published: August 2015

The synchronization behavior of coupled chaotic discontinuous maps over a ring network with dynamic random connections is reported in this paper. It is observed that random rewiring stabilizes one of the two strongly unstable fixed points of the local map. Depending on initial conditions, the network synchronizes to different unstable fixed points, which signifies the existence of synchronized multistability in the complex network. Moreover, the length of discontinuity of the local map has an important role in generating windows of different synchronized fixed points. Synchronized fixed point and synchronized periodic orbits are found in the network depending on coupling strength and different parameter values of the local map. We have identified the existence of period subtracting bifurcation with respect to coupling strength in the network. The range of coupling strength for the occurrence of synchronized multistable spatiotemporal fixed points is determined. This range strongly depends upon the dynamic rewiring probability and also on the local map.
Hot carrier extraction using energy selective contacts and its impact on the limiting efficiency of a hot carrier solar cell
Authors: Limpert Steven C. , Bremner Stephen P.
Published: August 2015

Extraction of charge carriers from a hot carrier solar cell using energy selective contacts and the impact on limiting power conversion efficiency are analyzed. It is shown that assuming isentropic conversion of carrier heat into voltage implies zero power output at all operating points. Under conditions of power output, lower voltages than in the isentropic case are obtained due to the irreversible entropy increase associated with carrier flow. This lowers the limiting power conversion efficiency of a hot carrier solar cell.
Oscillation and collective conveyance of water-in-oil droplets by microfluidic bolus flow
Authors: Ohmura Takuya , Ichikawa Masatoshi , Kamei Ken-ichiro , Maeda Yusuke T.
Published: August 2015

Microfluidic techniques have been extensively developed to realize micro-total analysis systems in a small chip. For microanalysis, electro-magnetic forces have generally been utilized for the trapping of objects, but hydrodynamics has been little explored despite its relevance to pattern formation. Here, we report that water-in-oil (W/O) droplets can be transported in the grid of an array of other large W/O droplets. As each droplet approaches an interspace of the large droplet array, while exhibiting persistent back-and-forth motion, it is conveyed at a velocity equal to the droplet array. We confirm the appearance of closed streamlines in a numerical simulation, suggesting that a vortex-like stream is involved in trapping the droplet. Furthermore, more than one droplet is also conveyed as an ordered cluster with dynamic reposition.
Experimental validation of adding-doubling modeling of solar cells including luminescent down-shifting layers
Authors: Leyre S. , Proost K. , Cappelle J. , Durinck G. , Hofkens J. , Deconinck G. , Hanselaer P.
Published: August 2015

Luminescent down-shifting (LDS) layers applied on top of solar cells can potentially increase solar cell performance due to the better match of the incident irradiance spectrum reaching the cell to its spectral response. In this study, the adding-doubling tool is presented, which allows fast predictions of the influence of LDS sheets on solar cell performance. The model is validated by comparing its predictions to experimental data. Four LDS sheets including different conversion materials were investigated. The modeling tool was able to predict the external quantum efficiency with an average deviation of 0.02.
A molecular dynamics study of phase transition in strongly coupled pair-ion plasmas
Authors: Baruah Swati , Ganesh R. , Avinash K.
Published: August 2015

Existence of phase transition in strongly coupled pair-ion plasmas with soft core is investigated. Extensive Molecular Dynamics (MD) simulations are performed in the canonical ensemble, for such plasmas, at different temperatures, to analyze phase stability. Our studies show interesting phase co-existence between liquid-like and vapor-like phases. The different phases are identified by calculating the ensemble averaged density. This and the corresponding critical properties are calculated directly from MD simulation. The critical temperature of vapor-liquid coexistence is obtained, and the corresponding critical value of density is also estimated for different sizes of the soft core. We have used a novel method that allows the location of phase coexistence through a constant density simulation in which the temperature is changed in a single time-step (quenching) in order to place the system in a thermodynamically and mechanically unstable state, resulting in spontaneous separation of two coexisting phases. The results obtained from this temperature quench MD method also show the coexistence of vapor-liquid phase in pair-ion plasmas. The critical exponents obtained directly from MD simulation are found to be in close agreement with the values predicted by a mean-field theory.
Thermal expansion of rock-salt cubic AlN
Authors: Bartosik M. , Todt M. , Holec D. , Todt J. , Zhou L. , Riedl H. , Böhm H. J. , Rammerstorfer F. G. , Mayrhofer P. H.
Published: August 2015

We combine continuum mechanics modeling and wafer curvature experiments to characterize the thermal expansion coefficient of AlN in its metastable cubic rock-salt (B1) structure. The latter was stabilized as nm thin layers by coherency strains in CrN/AlN epitaxial multilayers deposited on Si (100) substrates using reactive magnetron sputtering. The extraction of the B1-AlN thermal expansion coefficient, from experimentally recorded temperature dependent wafer curvature data, is formulated as an inverse problem using continuum mechanics modeling. The results are cross-validated by density functional theory calculations.
Design of a hydroformed metal blade for vertical-axis wind turbines
Authors: Domínguez Fernández Diego , Pröhl Marco , De Troyer Tim , Werner Markus , Runacres Mark C.
Published: August 2015

Vertical-axis wind turbines (VAWTs) have experienced a renewed impulse during the last few years with important research efforts focused on them. This work explores whether the global profitability of VAWTs can be improved through improved manufacturing techniques. We studied how large-series production techniques from the sheet-metal industry can be used to create blades of H-type Darrieus turbines. Blade size and shape were determined via aerodynamic and structural analyses. The proposed solution is based on the use of hydroforming manufacturing techniques with metal sheets. Our estimations show that with the positive effects of a large-scale use and production (economies of scale), such metal blades have a 90% reduction potential in their production costs compared to fibre-reinforced ones for single turbines.
Combined Au-plasmonic nanoparticles with mesoporous carbon material (CMK-3) for photocatalytic water splitting
Authors: Hung Wei Hsuan , Lai Sz Nian , Su Cheng Yi , Yin Min , Li Dongdong , Xue Xinzhong , Tseng Chuan Ming
Published: August 2015

The conventional TiO2 photoelectrode for water splitting was integrated with ordered mesoporous carbon material (CMK-3) and Au metal nanoparticles (NPs) to improve the photocatalytic efficiency under visible light irradiation. Compared to TiO2, Au/TiO2-CMK-3 photoelectrode demonstrated over two orders of magnitude enhancement of photocurrent under 532 nm laser irradiation due to the generation of hot electron and near field from Au NPs. Furthermore, the improvement of free carrier transport and additional long-wavelength absorption can be achieved by exploiting the superior conductivity and blackbody-like property of CMK-3. This proposed enhancement mechanism was proved by the measurements of photoluminescence emission spectrum and electrochemical impedance spectroscopy.
Sub-gigahertz beam switching of vertical-cavity surface-emitting laser with transverse coupled cavity
Authors: Nakahama M. , Gu X. , Sakaguchi T. , Matsutani A. , Ahmed M. , Bakry A. , Koyama F.
Published: August 2015

We report a high-speed electrical beam switching of vertical cavity surface emitting laser with a transverse coupled cavity. A high speed (sub-gigahertz) and large deflection angle (>30°) beam switching is demonstrated by employing the transverse mode switching. The angular switching speed of 900 MHz is achieved with narrow beam divergence of below 4° and extinction ratio of 8 dB. We also measured the near- and far-field patterns to clarify the origin of the beam switching. We present a simple one-dimensional Bragg reflector waveguide model, which well predicts the beam switching characteristic.
High-performance terahertz wave absorbers made of silicon-based metamaterials
Authors: Yin Sheng , Zhu Jianfei , Xu Wendao , Jiang Wei , Yuan Jun , Yin Ge , Xie Lijuan , Ying Yibin , Ma Yungui
Published: August 2015

Electromagnetic (EM) wave absorbers with high efficiency in different frequency bands have been extensively investigated for various applications. In this paper, we propose an ultra-broadband and polarization-insensitive terahertz metamaterial absorber based on a patterned lossy silicon substrate. Experimentally, a large absorption efficiency more than 95% in a frequency range of 0.9–2.5 THz was obtained up to a wave incident angle as large as 70°. Much broader absorption bandwidth and excellent oblique incidence absorption performance are numerically demonstrated. The underlying mechanisms due to the combination of a waveguide cavity mode and impedance-matched diffraction are analyzed in terms of the field patterns and the scattering features. The monolithic THz absorber proposed here may find important applications in EM energy harvesting systems such as THz barometer or biosensor.
A spin-optoelectronic detector for the simultaneous measurement of the degree of circular polarization and intensity of a laser beam
Authors: Khamari Shailesh K. , Porwal S. , Oak S. M. , Sharma T. K.
Published: August 2015

Simultaneous measurement of the degree of circular polarization and intensity of a laser beam is essential in advanced photonic applications. However, it is not feasible with conventional helicity dependent detectors where an additional detector is needed to measure the intensity. Here, we report the development of a spin-optoelectronic detector that can measure the degree of circular polarization and the intensity of a laser beam simultaneously. The principle of operation of device is based on the two independent fundamental phenomena occurring in Au/InP hybrid structures, namely, Inverse Spin Hall Effect (ISHE) and the Photo-Voltaic (PV) Effect. The magnitude of ISHE and PV signals is simultaneously measured across the two pairs of contacts that are made on the top of device. No cross talk is observed between the two detectors made on the same chip. The all-electronic compact device is fast, operates at room temperature, and opens up the possibility of many applications in an integrated optoelectronic platform.
Effect of low-damage inductively coupled plasma on shallow nitrogen-vacancy centers in diamond
Authors: Fávaro de Oliveira Felipe , Momenzadeh S. Ali , Wang Ya , Konuma Mitsuharu , Markham Matthew , Edmonds Andrew M. , Denisenko Andrej , Wrachtrup Jörg
Published: August 2015

Near-surface nitrogen-vacancy (NV) centers in diamond have been successfully employed as atomic-sized magnetic field sensors for external spins over the last years. A key challenge is still to develop a method to bring NV centers at nanometer proximity to the diamond surface while preserving their optical and spin properties. To that aim we present a method of controlled diamond etching with nanometric precision using an oxygen inductively coupled plasma process. Importantly, no traces of plasma-induced damages to the etched surface could be detected by X-ray photoelectron spectroscopy and confocal photoluminescence microscopy techniques. In addition, by profiling the depth of NV centers created by 5.0 keV of nitrogen implantation energy, no plasma-induced quenching in their fluorescence could be observed. Moreover, the developed etching process allowed even the channeling tail in their depth distribution to be resolved. Furthermore, treating a 12C isotopically purified diamond revealed a threefold increase in T2 times for NV centers with <4 nm of depth (measured by nuclear magnetic resonance signal from protons at the diamond surface) in comparison to the initial oxygen-terminated surface.
Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues
Authors: Jeong Woo Chul , Wi Hun , Sajib Saurav Z. K. , Oh Tong In , Kim Hyung Joong , Kwon Oh In , Woo Eung Je
Published: August 2015

Electromagnetic fields provide fundamental data for the imaging of electrical tissue properties, such as conductivity and permittivity, in recent magnetic resonance (MR)-based tissue property mapping. The induced voltage, current density, and magnetic flux density caused by externally injected current are critical factors for determining the image quality of electrical tissue conductivity. As a useful tool to identify bio-electromagnetic phenomena, precise approaches are required to understand the exact responses inside the human body subject to an injected currents. In this study, we provide the numerical simulation results of electromagnetic field mapping of brain tissues using a MR-based conductivity imaging method. First, we implemented a realistic three-dimensional human anisotropic head model using high-resolution anatomical and diffusion tensor MR images. The voltage, current density, and magnetic flux density of brain tissues were imaged by injecting 1 mA of current through pairs of electrodes on the surface of our head model. The current density map of anisotropic brain tissues was calculated from the measured magnetic flux density based on the linear relationship between the water diffusion tensor and the electrical conductivity tensor. Comparing the current density to the previous isotropic model, the anisotropic model clearly showed the differences between the brain tissues. This originates from the enhanced signals by the inherent conductivity contrast as well as the actual tissue condition resulting from the injected currents.
Manipulation of perpendicular exchange bias effect in [Co/Ni]N/(Cu, Ta)/TbCo multilayer structures
Authors: Tang Minghong , Zhang Zongzhi , Jin Qingyuan
Published: August 2015

With the demand for increasing storage density in spintronic applications, extensive work has been devoted to searching for perpendicular magnetic material systems with strong exchange bias effect. In this study we have investigated the exchange bias effect in perpendicular magnetized heterostructures of [Co/Ni]N/(Cu, Ta)/TbCo. An interlayer of 0.8 nm Cu is capable of achieving separate magnetization switching, showing a quite large exchange bias field over 2.9 kOe. With increasing the interlayer thickness, both the Co/Ni bias field and TbCo switching field decrease much more rapidly for the samples with a Ta interlayer as compared to the Cu case, due to the better coverage ability of the amorphous nature. The influence of layer thickness and composition of the FM and FI layers has also been investigated and the variation tendencies are well interpreted.
Comparison of nuclear electric resonance and nuclear magnetic resonance in integer and fractional quantum Hall states
Authors: Tomimatsu Toru , Shirai Shota , Hashimoto Katsushi , Sato Ken , Hirayama Yoshiro
Published: August 2015

Electric-field-induced nuclear resonance (NER: nuclear electric resonance) involving quantum Hall states (QHSs) was studied at various filling factors by exploiting changes in nuclear spins polarized at quantum Hall breakdown. Distinct from the magnetic dipole interaction in nuclear magnetic resonance, the interaction of the electric-field gradient with the electric quadrupole moment plays the dominant role in the NER mechanism. The magnitude of the NER signal strongly depends on whether electronic states are localized or extended. This indicates that NER is sensitive to the screening capability of the electric field associated with QHSs.
Flow and heat transfer to modified second grade fluid over a non-linear stretching sheet
Authors: Khan Masood , Rahman Masood ur
Published: August 2015

The objective of the present work is to analyze the two-dimensional boundary layer flow and heat transfer of a modified second grade fluid over a non-linear stretching sheet of constant surface temperature. The modelled momentum and energy equations are deduced to a system of ordinary differential equations by employing suitable transformations in boundary layer region and integrated numerically by fourth and fifth order Runge-Kutta Fehlberg method. Additionally, the analytic solutions of the governing problem are presented for some special cases. The secured results make it clear that the power-law index reduces both the momentum and thermal boundary layers. While the incremented values of the generalized second grade parameter leads to an increase in the momentum boundary layer and a decrease in the thermal boundary layer. To see the validity of the present results we have made a comparison with the previously published results as a special case with an outstanding compatibility.
Effect of previous reproductive performance on current reproductive rate in South Australian Merino ewes
Authors: Kleemann David O. , Walker Simon K. , Ponzoni Raul W. , Gifford Dennis R. , Walkley James R. W. , Smith Darryl H. , Grimson Richard J. , Jaensch Kaylene S. , Walkom Samuel F. , Brien Forbes D.
Published: August 2015

Reproductive performance of ewes in the current year may be influenced by their performance in the previous year and by the ability of seasonal and management conditions to facilitate full recovery before the next breeding cycle. This possibility was tested by analysing reproductive data from 2100 South Australian Merino ewes mated to Merino rams annually from 1991 to 1997. The model fitted to the data included the fixed effects of previous reproductive performance (PRP) (no lambs born; single or multiple lambs born, none reared; single lambs born, singles reared; multiples born, singles reared; multiples born, multiples reared), age of ewe (2.5, 3.5, 4.5 years), year (1992–1997), bloodline (A, B, L, X) and all two-way interactions. Current-year parameters were net reproduction rate (NRR, lambs weaned of ewes joined) and its components of fertility (ewes lambing of ewes joined), fecundity (lambs born of ewes lambing) and lamb survival (lambs weaned of lambs born). Other parameters were lamb liveweight at weaning per ewe joined and pre-mating liveweight. In addition, repeatability values were calculated across ages for these parameters. NRR was higher in the current year for those groups of ewes that reared lambs in the previous year; this was associated with the highly productive multiple-bearing and -rearing groups having a liveweight at the next mating similar compared to that of groups that did not rear lambs. Repeatability values of 0.27 for NRR and 0.40 for fertility suggest there are genetic and permanent environmental components contributing to the differences observed among the PRP groups for NRR, particularly so for fertility. Selecting ewes after their first lambing opportunity on fertility alone at a rate of 90% would give a non-cumulative increase in fertility of 3.4% at subsequent lambing opportunities. Hence, improvements in the current ewe flock for NRR by graziers managing flocks of the South Australian Merino strain are likely to come from (1) identifying and selecting those ewes of high fertility from early records and (2) attending to management factors impacting on fecundity and lamb survival.
Risks in extrapolating habitat preferences over the geographical range of threatened taxa: a case study of the quokka (Setonix brachyurus) in the southern forests of Western Australia
Authors: Bain Karlene , Wayne Adrian , Bencini Roberta
Published: August 2015

Context
Extrapolation of knowledge for threatened taxa between parts of their range that are disconnected and/or ecologically diverse can result in significant sources of error that undermine the effectiveness of conservation efforts.

Aims
We investigated the risks associated with extrapolation of ecological information across environmental gradients, using the quokka (Setonix brachyurus) as a case study. Information documented in the northern part of its range is currently used to manage this species across its range in south-western Australia. We examined the suitability of this approach by developing a habitat suitability model (HSM) for the quokka in the southernmost areas of its range and comparing this with existing knowledge for the species.

Methods
We surveyed 327 sites, representative of a range of ecotypes, for presence/absence of quokkas. Occupancy models were applied to select a subset of habitat variables that best predicted occupancy patterns.

Key results
Occupancy patterns were influenced by complex vegetation structure, low levels of woody debris and habitat patchiness. HSMs developed for quokkas in the north could not predict occupancy patterns in the south. Significant fragmentation of subpopulations was observed due to patchiness in the availability of suitable habitat.

Conclusions
The choice of predictor variables in HSMs that are not transferrable between regions could contribute to inappropriate management of habitat for quokkas and an increased risk of local extinctions. In addition, failure to consider processes that affect preferred habitat variables could contribute to the segregation of habitat patches and intervening distances that are too great for successful dispersal, immigration and recolonisation processes.

Implications
The extrapolation of HSMs between geographical areas can increase the risk of outcomes that are detrimental to the conservation of threatened species. Where such extrapolation is necessary, actions guided by the HSMs should be implemented in a management framework that can detect adverse effects, allow for inclusion of new ecological information and explicitly consider the limitations and assumptions of this approach. In addition, perceptions of habitat fragmentation need to include processes such as fire regimes and feral animals that affect the availability and connectivity of habitat and have the potential to adversely affect population viability.
Impacts of thermal limitation on thermoregulatory behaviour and reproductive success in a lizard
Authors: Halstead Jennifer E. , Schwanz Lisa E.
Published: August 2015

Climatic variation can impact populations of ectotherms by altering reproduction, development, and survival. While a warm climate can provide additional thermal opportunities for ectotherms, excessively warm conditions can restrict activity in avoidance of lethal temperatures. However, ectotherms are not necessarily passive to thermal conditions, and often employ flexible thermoregulatory behaviour to accommodate environmental variation. Here, we examine whether the Australian jacky dragon lizard, Amphibolurus muricatus, can compensate for reduced basking opportunity by basking with greater intensity, and how the thermal environment influences reproductive success in females. Overall, there was no compelling evidence for compensatory thermoregulatory behaviour in response to reduced basking opportunity. Moreover, females with reduced thermal opportunities did not produce eggs, although reproductive success was quite low for both groups, so additional factors may have limited reproduction in the colony. This study allows insight into the links between climate and population persistence in wild animals by providing crucial and rare data on how thermal environment impacts reproduction in an egg-laying lizard.
IL-22 regulates lymphoid chemokine production and assembly of tertiary lymphoid organs
Authors: Barone Francesca , Nayar Saba , Campos Joana , Cloake Thomas , Withers David R. , Toellner Kai-Michael , Zhang Yang , Fouser Lynette , Fisher Benjamin , Bowman Simon , Rangel-Moreno Javier , Garcia-Hernandez Maria de la Luz , Randall Troy D. , Lucchesi Davide , Bombardieri Michele , Pitzalis Costantino , Luther Sanjiv A. , Buckley Christopher D.
Published: August 2015

Significance

Ectopic clusters of immune cells that mimic the structure and function of secondary lymphoid organs are defined as tertiary lymphoid organs (TLOs). They have been observed at sites of chronic inflammation for decades, but their formation and function have remained enigmatic. TLOs are thought to contribute to disease pathogenesis by promoting autoreactive lymphocyte survival and autoantibody production. In this study we identify a novel role for the cytokine IL-22 in TLO development and biology. We provide evidence that IL-22 expression within TLOs is instrumental for the production of the lymphoid chemokines, chemokine (C-X-C motif) ligand 13 and chemokine (C-X-C motif) ligand 12, which in turn orchestrate B-cell clustering, lymphoid aggregation, and autoantibody production. Our data provide a strong rationale for targeting IL-22 in TLO-associated autoimmune diseases.
Phylogenetic analyses of melanoma reveal complex patterns of metastatic dissemination
Authors: Sanborn J. Zachary , Chung Jongsuk , Purdom Elizabeth , Wang Nicholas J. , Kakavand Hojabr , Wilmott James S. , Butler Timothy , Thompson John F. , Mann Graham J. , Haydu Lauren E. , Saw Robyn P. M. , Busam Klaus J. , Lo Roger S. , Collisson Eric A. , Hur Joe S. , Spellman Paul T. , Cleaver James E. , Gray Joe W. , Huh Nam , Murali Rajmohan , Scolyer Richard A. , Bastian Boris C. , Cho Raymond J.
Published: August 2015

Significance

Subpopulations of cells in a primary melanoma sometimes disseminate and establish metastases, which usually cause mortality. By sequencing tumor samples from patients with metastatic melanoma never subjected to targeted therapies, we were able to trace the genetic evolution of cells in the primary that seed metastases. We show that distinct cells in the primary depart multiple times in parallel to seed metastases, often after evolving from a common, parental cell subpopulation. Intriguingly, we also determine that single metastases can be founded by more than one cell population found in the primary cancer. These mechanisms show how profound genetic diversity arises naturally among multiple metastases, driving growth and drug resistance, but also indicate that certain mutations may distinguish cells destined to metastasize.
NH4+ triggers the release of astrocytic lactate via mitochondrial pyruvate shunting
Authors: Lerchundi Rodrigo , Fernández-Moncada Ignacio , Contreras-Baeza Yasna , Sotelo-Hitschfeld Tamara , Mächler Philipp , Wyss Matthias T. , Stobart Jillian , Baeza-Lehnert Felipe , Alegría Karin , Weber Bruno , Barros L. Felipe
Published: August 2015

Significance

Aerobic glycolysis is important for synaptic growth, neuronal excitability, memory formation, and behavior and is also involved in neurodegeneration. Here we present evidence, obtained with novel optical tools, to show that

N

H
4
+

contributes to aerobic glycolysis by specifically inhibiting the mitochondrial consumption of pyruvate in astrocytes.

N

H
4
+

, a waste product of excitatory neurotransmission, is therefore proposed to behave as an intercellular signal in brain tissue.
Review: Inhibition of bacterial quorum sensing by plant extracts
Authors: Yarmolinsky Ludmila , Bronstein Moshe , Gorelick Jonathan
Published: August 2015

Bacterial quorum sensing (QS) is a form of cell-to-cell communication which is vital to the pathogenicity of many bacteria, and therefore a promising target for the development of new treatments for microbial infections. While many medicinal plants possess antibacterial activity, only a few plants have been shown to target quorum sensing. In the face of increased microbial resistance to existing antibiotics coupled with the decline in novel antibiotic development, QS inhibitors from medicinal plants is a promising direction for new antibacterial treatments,. The purpose of this review is to summarize the verified data on the anti-QS properties of medicinal plants and the various mechanisms of their actions.
Purification and characterization of enantioselective N-acetyl-β-Phe acylases from Burkholderia sp. AJ110349
Authors: Imabayashi Yuki , Suzuki Shun’ichi , Kawasaki Hisashi , Nakamatsu Tsuyoshi
Published: August 2015

For the production of enantiopure β-amino acids, enantioselective resolution of N-acyl β-amino acids using acylases, especially those recognizing N-acetyl-β-amino acids, is one of the most attractive methods. Burkholderia sp. AJ110349 had been reported to exhibit either (R)- or (S)-enantiomer selective N-acetyl-β-Phe amidohydrolyzing activity, and in this study, both (R)- and (S)-enantioselective N-acetyl-β-Phe acylases were purified to be electrophoretically pure and determined the sequences, respectively. They were quite different in terms of enantioselectivities and in their amino acids sequences and molecular weights. Although both the purified acylases were confirmed to catalyze N-acetyl hydrolyzing activities, neither of them show sequence similarities to the N-acetyl-α-amino acid acylases reported thus far. Both (R)- and (S)-enantioselective N-acetyl-β-Phe acylase were expressed in Escherichia coli. Using these recombinant strains, enantiomerically pure (R)-β-Phe (>99% ee) and (S)-β-Phe (>99% ee) were obtained from the racemic substrate.
Biocatalytic synthesis of 3,4,5,3′,5′-pentahydroxy-trans-stilbene from piceatannol by two-component flavin-dependent monooxygenase HpaBC
Authors: Furuya Toshiki , Sai Masahiko , Kino Kuniki
Published: August 2015

HpaBC monooxygenase was previously reported to hydroxylate resveratrol to piceatannol. In this article, we report a novel catalytic activity of HpaBC for the synthesis of a pentahydroxylated stilbene. When Escherichia coli cells expressing HpaBC were incubated with resveratrol, the resulting piceatannol was further converted to a new product. This product was identified by mass spectrometry and NMR spectroscopy as a 5-hydroxylated piceatannol, 3,4,5,3′,5′-pentahydroxy-trans-stilbene (PHS), which is a reportedly valuable biologically active stilbene derivative. We attempted to produce PHS from piceatannol on a flask scale. After examining the effects of detergents and buffers on PHS production, E. coli cells expressing HpaBC efficiently hydroxylated piceatannol to PHS in a reaction mixture containing 1.5% (v/v) Tween 80 and 100 mM 3-morpholinopropanesulfonic acid-NaOH buffer at pH 7.5. Under the optimized conditions, the whole cells regioselectively hydroxylated piceatannol, and the production of PHS reached 6.9 mM (1.8 g L−1) in 48 h.
Preferential binding of E. coli with type 1 fimbria to d-mannobiose with the Manα1→2Man structure
Authors: Ajisaka Katsumi , Yuki Kaoru , Sato Kaori , Ishii Nozomi , Matsuo Ichiro , Kuji Ryo , Miyazaki Tatsuo , Furukawa Kiyoshi
Published: August 2015

Manα1→2Man, Manα1→3Man, Manα1→4Man, and Manα1→6Man were converted to the glycosylamine derivatives. Then, they were mixed with monobenzyl succinic acid to obtain their amide derivatives. After removing the benzyl group by hydrogenation, the succinylamide derivatives were coupled with the hydrazino groups on BlotGlyco™ beads in the presence of water-soluble carbodiimide. d-Mannobiose-linked beads were incubated with fluorescence-labeled Escherichia coli with type 1 fimbria, and the number of the fluorescent dots associated with the beads was counted in order to determine the binding preference among d-mannobiose isomers. The results showed that the bacteria bind strongly to Manα1→2Man1→beads, Manα1→3Man1→beads, Manα1→4Man1→beads, and Manα1→6Man1→beads, in order. In the presence of 0.1 M methyl α-d-mannopyranoside, most of the bacteria failed to bind to these beads. These results indicate that E. coli with type 1 fimbria binds to all types of d-mannobiose isomers but preferentially to Manα1→2Man disaccharide.
The effects of Chamaecyparis obtusa essential oil on pain-related behavior and expression of pro-inflammatory cytokines in carrageenan-induced arthritis in rats
Authors: Suh Hye Rim , Chung Hyun Joo , Park Eui Ho , Moon Sun Wook , Park Su Jin , Park Chan Woo , Kim Yang In , Han Hee Chul
Published: August 2015

Chamaecyparis obtusa essential oil (COE) has been widely used to treat allergic diseases and was suggested to exert anti-inflammatory, antioxidant, and antimicrobial effects. This study evaluated the effects of COE on pain-related behavior and pro-inflammatory cytokines in rats with carrageenan (CGN)-induced arthritis. Reduced dynamic weight load on inflamed joint in voluntarily walking rats was used as the behavior test for arthritic pain; 10% COE-treated group was significantly attenuated pain (6–8 h post-CGN injection) compared to VEH (mineral oil)-treated group. In addition, the protein levels of interleukin (IL)-1β, tumor necrosis factor-α, IL-6 (6–8 h), and cyclooxygenase (COX)-2 (8 h) within the synovial membrane, as well as IL-1β, COX-2 (6–8 h), and IL-6 (5–7 h) within the meniscus, of 10% COE-treated group were significantly reduced. The current results implicate that COE has anti-inflammatory and anti-nociceptive effects on arthritis in rats.
The elicitor-responsive gene for a GRAS family protein, CIGR2, suppresses cell death in rice inoculated with rice blast fungus via activation of a heat shock transcription factor, OsHsf23
Authors: Tanabe Shigeru , Onodera Haruko , Hara Naho , Ishii-Minami Naoko , Day Brad , Fujisawa Yukiko , Hagio Takashi , Toki Seiichi , Shibuya Naoto , Nishizawa Yoko , Minami Eiichi
Published: August 2015

We show that a rice GRAS family protein, CIGR2, is a bonafide transcriptional activator, and through this function, targets the B-type heat shock protein-encoding gene OsHsf23 (Os09g0456800). CIGR2 (Os07g0583600) is an N-acetylchitooligosaccharide elicitor-responsive gene whose activity, through the direct transcriptional control of OsHsf23, is required for mediating hypersensitive cell death activation during pathogen infection. RNAi lines of CIGR2 and OsHsf23 similarly exhibited the higher level of granulation in the epidermal cells of leaf sheath inoculated with an avirulent isolate of rice blast fungus. Interestingly, we did not observe altered levels of resistance, suggesting that CIGR2 suppresses excessive cell death in the incompatible interaction with blast fungus via activation of OsHsf23.
Influence of warmth and competence on the promotion of safe in-group selection: Stereotype content model and social categorization of faces
Authors: Ponsi G. , Panasiti M. S. , Scandola M. , Aglioti S. M.
Published: August 2015

Categorizing an individual as a friend or foe plays a pivotal role in navigating the social world. According to the stereotype content model (SCM), social perception relies on two fundamental dimensions, warmth and competence, which allow us to process the intentions of others and their ability to enact those intentions, respectively. Social cognition research indicates that, in categorization tasks, people tend to classify other individuals as more likely to belong to the out-group than the in-group ( in-group overexclusion effect, IOE) when lacking diagnostic information, probably with the aim of protecting in-group integrity. Here, we explored the role of warmth and competence in group-membership decisions by testing 62 participants in a social-categorization task consisting of 150 neutral faces. We assessed whether (a) warmth and competence ratings could predict the in-group/out-group categorization, and (b) the reliance on these two dimensions differed in low-IOE versus high-IOE participants. Data showed that high ratings of warmth and competence were necessary to categorize a face as in-group. Moreover, while low-IOE participants relied on warmth, high-IOE participants relied on competence. This finding suggests that the proneness to include/exclude unknown identities in/from one's own in-group is related to individual differences in the reliance on SCM social dimensions. Furthermore, the primacy of the warmth effect seems not to represent a universal phenomenon adopted in the context of social evaluation.
Photometric study and period variation investigation of the W UMa-type binary EQ UMa
Authors: Hu Shao Ming , Li Kai , Guo D.-F. , Jiang Yunguo , Gao Dongyang , Chen Xu
Published: August 2015

Four-color light curves of EQ UMa were obtained with the 1.0 m telescope at Weihai Observatory, Shandong University. The light variability of EQ UMa is typical of a W UMa-type binary. By analyzing the four-color light curves simultaneously, we found that EQ UMa is a semi-detached binary with the less massive component filling its inner Roche lobe. The very short period and the Algol-type configuration make EQ UMa a very good target to challenge the formation and evolution theory of low-mass Algols. We investigated the orbital period change of EQ UMa by all available times of minimum light. It is shown that the orbital period of EQ UMa displays a cyclic oscillation with a period of 12.1 yr superimposed on long-term increase with a rate of dp/dt = 1.77 × 10−7 d yr−1. The long-term period increase should be caused by the mass transfer from the less massive component to the more massive one. The cyclic modulation is very probably produced by the light travel time effect of a third component.