bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical study on strain induced variations in electronic properties of 2H-MoS2 bilayer sheets
Authors: Dong Liang , Dongare Avinash M. , Namburu Raju R. , O'Regan Terrance P. , Dubey Madan
Published: February 2014

The strain dependence of the electronic properties of bilayer sheets of 2H-MoS2 is studied using ab initio simulations based on density functional theory. An indirect band gap for bilayer MoS2 is observed for all variations of strain along the basal plane. Several transitions for the indirect band gap are observed for various strains for the bilayer structure. The variation of the band gap and the carrier effective masses for the holes and the electrons for the bilayer MoS2 structure under conditions of uniaxial strain, biaxial strain, as well as uniaxial stress is investigated.
Investigation of amplitude spatio-temporal couplings at the focus of a 100 TW-25 fs laser
Authors: Kahaly S. , Monchocé S. , Gallet V. , Gobert O. , Réau F. , Tcherbakoff O. , D'Oliveira P. , Martin Ph. , Quéré F.
Published: February 2014

We address the on target focal spot spatio-temporal features of an ultrashort, 100 TW class laser chain by using spectrally resolved imaging diagnostics. The observed spatio-spectral images, which we call rotating imaging spectrographs, are obtained single shot to reveal the essential information about the spatio-temporal couplings. We observe nontrivial effects in the focal plane due to compressor defects which significantly affect the maximum on target intensity. This diagnostic might become an essential tool for improving compressor alignment in many upcoming multi-petawatt short pulse laser facilities.
Spatiotemporal dynamics of a digital phase-locked loop based coupled map lattice system
Authors: Banerjee Tanmoy , Paul Bishwajit , Sarkar B. C.
Published: February 2014

We explore the spatiotemporal dynamics of a coupled map lattice (CML) system, which is realized with a one dimensional array of locally coupled digital phase-locked loops (DPLLs). DPLL is a nonlinear feedback-controlled system widely used as an important building block of electronic communication systems. We derive the phase-error equation of the spatially extended system of coupled DPLLs, which resembles a form of the equation of a CML system. We carry out stability analysis for the synchronized homogeneous solutions using the circulant matrix formalism. It is shown through extensive numerical simulations that with the variation of nonlinearity parameter and coupling strength the system shows transitions among several generic features of spatiotemporal dynamics, viz., synchronized fixed point solution, frozen random pattern, pattern selection, spatiotemporal intermittency, and fully developed spatiotemporal chaos. We quantify the spatiotemporal dynamics using quantitative measures like average quadratic deviation and spatial correlation function. We emphasize that instead of using an idealized model of CML, which is usually employed to observe the spatiotemporal behaviors, we consider a real world physical system and establish the existence of spatiotemporal chaos and other patterns in this system. We also discuss the importance of the present study in engineering application like removal of clock-skew in parallel processors.
Experimental validation of the dual positive and negative ion beam acceleration in the plasma propulsion with electronegative gases thruster
Authors: Rafalskyi Dmytro , Popelier Lara , Aanesland Ane
Published: February 2014

The PEGASES (Plasma Propulsion with Electronegative Gases) thruster is a gridded ion thruster, where both positive and negative ions are accelerated to generate thrust. In this way, additional downstream neutralization by electrons is redundant. To achieve this, the thruster accelerates alternately positive and negative ions from an ion-ion plasma where the electron density is three orders of magnitude lower than the ion densities. This paper presents a first experimental study of the alternate acceleration in PEGASES, where SF6 is used as the working gas. Various electrostatic probes are used to investigate the source plasma potential and the energy, composition, and current of the extracted beams. We show here that the plasma potential control in such system is key parameter defining success of ion extraction and is sensitive to both parasitic electron current paths in the source region and deposition of sulphur containing dielectric films on the grids. In addition, large oscillations in the ion-ion plasma potential are found in the negative ion extraction phase. The oscillation occurs when the primary plasma approaches the grounded parts of the main core via sub-millimetres technological inputs. By controlling and suppressing the various undesired effects, we achieve perfect ion-ion plasma potential control with stable oscillation-free operation in the range of the available acceleration voltages (±350 V). The measured positive and negative ion currents in the beam are about 10 mA for each component at RF power of 100 W and non-optimized extraction system. Two different energy analyzers with and without magnetic electron suppression system are used to measure and compare the negative and positive ion and electron fluxes formed by the thruster. It is found that at alternate ion-ion extraction the positive and negative ion energy peaks are similar in areas and symmetrical in position with +/− ion energy corresponding to the amplitude of the applied acceleration voltage.
Many-body effects in the spin-polarized electron transport through graphene nanoislands
Authors: Luo Kaikai , Sheng Weidong
Published: February 2014

Spin-polarized electron transport through zigzag-edged graphene nanoislands is studied within the framework of the Pariser-Parr-Pople Hamiltonian. By including both short- and long-range electron-electron interactions, the electron conductance is calculated self-consistently for the hexagonal model on various substrates from which we are able to identify the effects of the many-body interactions in the electron transport. For the system in its lowest antiferromagnetic (AFM) state, the long-range interactions are shown to have negligible effect on the electron transport in the low-energy region in which the conductance is found quenched mainly by the short-range interactions. As the system is excited to its second AFM state, the short- and long-range interactions are found to have opposite effects on the electron transmission, i.e., the electron transmission is found to increase with either the suppression of the long-range interactions or the enhancement of the short-range interactions. When the system moves further into the ferromagnetic state, the conductance becomes spin dependent and its resonance is shown to exhibit a blue shift in an environment with stronger long-range interactions. The distinct impact of short- and long-range electron-electron interactions are attributed to their different effects on the spin polarization in the model system.
A wideband vibration energy harvester based on a folded asymmetric gapped cantilever
Authors: Hu Yating , Xu Yong
Published: February 2014

This paper reports a wideband multi-mass multi-spring piezoelectric vibration energy harvester (VEH) based on a folded asymmetric gapped cantilever, which enables multiple resonant modes formed by pure bending of every stage. Moreover, the heaviest proof mass is placed at the last stage of the cantilever to increase the harvested power. The VEH's energy conversion efficiency is further increased using the asymmetric gapped structure. A prototype has been developed and characterized. The experimental results match with finite element simulation well. The prototype was tested on an air conditioning unit to demonstrate its energy harvesting capability with a realistic broadband vibration source.
Tunable optical bistability at the graphene-covered nonlinear interface
Authors: Xiang Yuanjiang , Dai Xiaoyu , Guo Jun , Wen Shuangchun , Tang Dingyuan
Published: February 2014

We investigate theoretically the optical bistability of reflection at the interface between graphene and Kerr-type nonlinear substrates. We derive a simple procedure to calculate the nonlinear reflectivity with graphene, and discuss the influence of the graphene sheets on the hysteretic response of the TM-polarization reflected light. It is found that the bistable behavior of the reflected light can be electrically controlled via suitably varying the applied voltage on the graphene. In THz, the bistable thresholds can be lowered markedly by increasing the Fermi energy. However, in near-infrared frequency, it requires multiple graphene layers to exhibit significant influence on the bistable thresholds.
High quality SiC microdisk resonators fabricated from monolithic epilayer wafers
Authors: Magyar Andrew P. , Bracher David , Lee Jonathan C. , Aharonovich Igor , Hu Evelyn L.
Published: February 2014

The exquisite mechanical properties of SiC have made it an important industrial material with applications in microelectromechanical devices and high power electronics. Recently, the optical properties of SiC have garnered attention for applications in photonics, quantum information, and spintronics. This work demonstrates the fabrication of microdisks formed from a p-N SiC epilayer material. The microdisk cavities fabricated from the SiC epilayer material exhibit quality factors of as high as 9200 and the approach is easily adaptable to the fabrication of SiC-based photonic crystals and other photonic and optomechanical devices.
Grain growth, densification, and gyromagnetic properties of LiZnTi ferrites with H3BO3-Bi2O3-SiO2-ZnO glass addition
Authors: Zhou Tingchuan , Zhang Huaiwu , Jia Lijun , Li Jie , Liao Yulong , Jin LiChuan , Su Hua
Published: February 2014

LiZnTi (Li0.43Zn0.27Ti0.13Fe2.17O4) ferrites doped with 0.35 wt. %–1.5 wt. % H3BO3-Bi2O3-SiO2-ZnO (BBSZ) were synthesized through a low temperature ceramic sintering process. The grain growth of LiZnTi ferrites was discussed by using the liquid phase sintering mechanism. BBSZ promoted grain growth via liquid phase sintering, and the optimum addition of BBSZ could reduce porosity of the sample. Meanwhile, selected parameters including saturation induction (BS), coercivity (HC) and ferromagnetic resonance line width (ΔH) were measured as functions of doping content, and their relationships with ferrite porosity and microstructure were also discussed. The LiZnTi ferrite samples containing x = 0.5, 0.65, and 0.8 sintered at 920 °C, 900 °C, and 880 °C, respectively, exhibited high BS and low ΔH values at 9.3 GHz. The addition of proper content of BBSZ can not only improve BS but also reduce HC and ferromagnetic resonance line width (ΔH) by low temperature (∼900 °C) liquid phase sintering.
Predicting effective magnetoelectric response in magnetic-ferroelectric composites via phase-field modeling
Authors: Yang T. N. , Hu Jia-Mian , Nan C. W. , Chen L. Q.
Published: February 2014

A phase-field model coupled with constitutive equations is formulated to investigate the magnetoelectric cross-coupling in magnetic-ferroelectric composites. The model allows us to obtain equilibrium piezoelectric, piezomagnetic, dielectric, and magnetoelectric properties under a given magnetic or electric field, from the local distributions of polarization, magnetization, and strain in the composites. As an example, effective magnetoelectric coupling coefficient, i.e., magnetic-field-induced voltage output (or changes in polarization), of the CoFe2O4-BaTiO3 composites is numerically calculated. Influences of the phase connectivity and the phase fraction of the composites on the magnetoelectric coupling coefficient are discussed.
Electronic-state-controlled reset operation in quantum dot resonant-tunneling single-photon detectors
Authors: Weng Q. C. , An Z. H. , Zhu Z. Q. , Song J. D. , Choi W. J.
Published: February 2014

The authors present a systematic study of an introduced reset operation on quantum dot (QD) single photon detectors operating at 77 K. The detectors are based on an AlAs/GaAs/AlAs double-barrier resonant tunneling diode with an adjacent layer of self-assembled InAs QDs. Sensitive single-photon detection in high dIdV region with suppressed current fluctuations is achieved. The dynamic detection range is extended up to at least 104 photons/s for sensitive imaging applications by keeping the device far from saturation by employing an appropriate reset frequency.
Charge transfer and atomic-level pressure in metallic glasses
Authors: Ding Jun , Cheng Yongqiang
Published: February 2014

This paper presents a systematic study on the charge transfer and ionicity in various metallic-glass forming systems, as well as its relationship with other atomic-level structure indicators, using the Bader analysis method and molecular dynamics simulation. It is shown that in a binary or multicomponent system, the chemical effects (when more than one elements present) appear to play a more important role in setting the absolute level of the atomic-level pressure, compared to the topological fluctuation.
Controlling magnetic anisotropy in La0.7Sr0.3MnO3 nanostructures
Authors: Wahler M. , Büttner B. , Blaschek H.-H. , Homonnay N. , Wid O. , O'Shea K. J. , McGrouther D. , MacLaren D. A. , Schmidt G.
Published: February 2014

We have developed a chlorine based dry etching process for nanopatterning the ferromagnetic oxide La0.7Sr0.3MnO3 (LSMO). Large arrays of millions of identical structures have been fabricated from thin LSMO films by electron-beam lithography and reactive ion etching. SQUID magnetometry demonstrates that patterned nanostructures with lateral dimensions down to 100 nm retain their full magnetization and the Curie temperature of the bulk layer. In addition, their shape anisotropy is sufficient to overcome the crystalline anisotropy of the bulk. High resolution scanning transmission electron microscopy shows that crystallinity is preserved even at the edges of the nanostructures.
Strain-induced magnetism in MoS2 monolayer with defects
Authors: Tao Peng , Guo Huaihong , Yang Teng , Zhang Zhidong
Published: February 2014

The strain-induced magnetism is observed in single-layer MoS2 with atomic single vacancies from density functional calculations. Calculated magnetic moment is no less than 2 μB per vacancy defect. The strain-induced band gap closure is concurrent with the occurrence of the magnetism. Possible physical mechanism of the emergence of strain-induced magnetism is illustrated. We also demonstrate the possibility to test the predicted magnetism in experiment. Our study may provide an opportunity for the design of new type of memory-switching or logic devices by using earth-rich nonmagnetic materials MoS2.
Ultrafast dynamics of the dielectric functions of ZnO and BaTiO3 thin films after intense femtosecond laser excitation
Authors: Acharya S. , Chouthe S. , Graener H. , Böntgen T. , Sturm C. , Schmidt-Grund R. , Grundmann M. , Seifert G.
Published: February 2014

The ultrafast carrier dynamics of epitaxial ZnO and BaTiO3 thin films after intense excitation at 3.10 eV and 4.66 eV photon energy has been studied by femtosecond absorption spectroscopy. Modelling the transient transmission changes on the basis of spectroscopic ellipsometry data and pertinent equilibrium model dielectric functions extended by additional terms for the effects at high carrier density (P-band luminescence and stimulated emission from electron-hole-plasma), a self-consistent parameterized description was obtained for both materials. Excited carrier lifetimes in the range of ≈2 to ≈60 ps and long-lived thermal effects after several hundred ps have been identified in both materials. These findings form a reliable basis to quantitatively describe future femtosecond studies on ZnO/BaTiO3 heterolayer systems.
Magnetic behaviors in melt spun Fe52−xMn23+xGa25 (x = 0–3) ribbons
Authors: Shih C. W. , Zhao X. G. , Chang H. W. , Lee Y. I. , Ma S. C. , Chang W. C.
Published: February 2014

The effect of volume fraction of B2-type ferromagnetic (FM) phase on magnetic behavior of melt-spun Fe52−xMn23+xGa25 (x = 0, 1, 2, and 3) ribbons has been investigated. X-ray diffraction (XRD) results show that the volume fraction of the B2 phase is decreased, accompanied by the increased antiferromagnetic (AFM) fcc phase, with increasing x. The magnetization isotherms of these ribbons at different temperatures demonstrate that there exists a critical field HCR from AFM to FM state, and the HCR decreases and vanishes finally with increasing temperature. High exchange bias field (HEB) at 10 K through a cooling field at HCR from 300 K could be found and correlated to the volume fraction of B2-type FM phase. Both HCR and HEB are increased with decreasing the amount of B2-type FM phase. The HCR is increased from 20 kOe for x = 0 to 50 kOe for x = 3, and HEB is increased from 0.9 kOe for x = 0 to 2.5 kOe for x = 2. The latter phenomenon might be attributed to the change of exchange interactions at FM/AFM interfaces due to the change of proportion of FM and AFM phase at low temperature.
Field-induced confined states in graphene
Authors: Moriyama Satoshi , Morita Yoshifumi , Watanabe Eiichiro , Tsuya Daiju
Published: February 2014

We report an approach to confine the carriers in single-layer graphene, which leads to quantum devices with field-induced quantum confinement. We demonstrated that the Coulomb-blockade effect evolves under a uniform magnetic field perpendicular to the graphene device. Our experimental results show that field-induced quantum dots are realized in graphene, and a quantum confinement-deconfinement transition is switched by the magnetic field.
Hydrogen lithography for nanomagnetic domain on Co-doped ZnO using an anodic aluminum oxide template
Authors: Lee Seunghun , Kim Won-Kyung , Chan Cho Yong , Kim Bum-Su , Hun Park Ji , Lee Chang-Won , Lee YoungPak , Lee Sang Bok , Fackler Sean , Takeuchi Ichiro , Ryong Cho Chae , Jeong Se-Young
Published: February 2014

Based on hydrogen-mediated ferromagnetism and a selective hydrogen exposure technique, i.e., hydrogen lithography, we attempted to produce magnetic domains in a paramagnetic host. Hydrogen lithography on Co-doped ZnO with an anodic aluminum oxide template was used to produce nanomagnetic domains in paramagnetic Co-doped ZnO. The domains showed in-plane magnetization with a head-to-tail configuration at room temperature, which is consistent with the object-oriented micro-magnetic framework simulations.
The effect of fluid flow on the solidification of Ni2B from the undercooled melt
Authors: Binder S. , Galenko P. K. , Herlach D. M.
Published: February 2014

In this work, we study the effect of fluid flow on the growth dynamics during solidification of tetragonal Ni2B from the undercooled melt. Different experimental techniques are applied to generate varying fluid flow velocities in undercooled samples, electromagnetic levitation under 1 g conditions (1 g EML) and in reduced gravity (μg EML) as well as the melt-fluxing technique and electrostatic levitation. The propagation of the solid-liquid interface apparent on the surface of solidifying samples is observed by high-speed video imaging while the non-contact measurement of the undercooling prior to solidification is accomplished by IR-pyrometry. It is demonstrated that fluid flow has a substantial influence on the growth kinetics. As revealed by an extended sharp-interface model, this effect is mainly attributed to the substantial change in growth kinetics caused by a convection induced transition from dendrites to more faceted solidification structures.
Estimation of parasitic losses in a proposed mesoscale resonant engine: Experiment and model
Authors: Preetham B. S. , Anderson M. , Richards C.
Published: February 2014

A resonant engine in which the piston-cylinder assembly is replaced by a flexible cavity is realized at the mesoscale using flexible metal bellows to demonstrate the feasibility of the concept. A four stroke motoring technique is developed and measurements are performed to determine parasitic losses. A non-linear lumped parameter model is developed to evaluate the engine performance. Experimentally, the heat transfer and friction effects are separated by varying the engine speed and operating frequency. The engine energy flow diagram showing the energy distribution among various parasitic elements reveals that the friction loss in the bellows is smaller than the sliding friction loss in a typical piston-cylinder assembly.
Highly Improved Electrooxidation of Captopril on Copper Hexacyanoferrate/Ordered Mesoporous Carbon-Modified Glassy Carbon Electrode
Authors: Lu Shengjun , Lu Pan , Li Cheng , Wang Caihong , Yu Jie
Published: February 2014

Using an electrochemical polymerization process, a copper hexacyanoferrate/ordered mesoporous carbon-modified glassy carbon electrode (CuHCF/OMC/GCE) was prepared. The performance of CuHCF/OMC was compared with that of CuHCF and the properties of the new material were improved. A sensor for sensitive detection of captopril was developed based on CuHCF/OMC-modified glassy carbon electrode. The composition and morphology of the as-prepared CuHCF/OMC products were characterized by energy-dispersive X-ray spectroscopy and scanning electron microscopy. The electrochemical behaviour and electrocatalytic performance of the CuHCF/OMC-modified glassy carbon electrode towards the oxidation of captopril were evaluated by cyclic voltammetry. Results showed that the CuHCF/OMC-modified electrode exhibits two well-defined redox peaks. The linear range for the detection of captopril was from 1.0 × 10–5 to 2.7 × 10–3 M, with a correlation coefficient of 0.999, and the detection limit was 1.2 × 10–6 M based on a signal-to-noise ratio of 3.
Changes in soil total C and N contents at three chronosequences after conversion from plantation pine forest to dairy pasture on a New Zealand Pumice soil
Authors: Sparling G. P. , Lewis R. , Schipper L. A. , Mudge P. , Balks M.
Published: February 2014

The large amounts of carbon (C) and nitrogen (N) sequestered as organic matter in soils have implications for global and national C and N balances and greenhouse gas emissions. Changes in soil management can affect the amount of C and N stored in soil. We investigated the change in land use from radiata pine plantation to ryegrass–white clover dairy pasture on the total C and N content of Taupo Pumice Soil. Samples were taken at three study sites (Atiamuri, Tokoroa and Wairakei) in North Island, New Zealand. Soils were cored to 60 cm depth and subsampled by soil horizon, and bulk density cores were taken from soil pits. A chronosequence of sites was obtained after conversion from pines to pasture. Long-term pastures (40–80 years) and mature pine plantations were included for further comparison. Regression analyses were completed after logarithmic transformation of the time data. The data were highly variable, but significant (P < 0.05) increases in total C and N were found at the Atiamuri and Wairakei sites. However, there was no significant change in the total C content of the profile at the Tokoroa site. Increases in total C and N were greatest in the Ap horizon and were most rapid 1–5 years after conversion. Overall rates of increase in the first 10 years after conversion were 0.167 kg C m–2 year–1 for total C and 0.032 kg N m–2 year–1 for total N, dropping to 0.027 kg C and 0.005 kg N m–2 year–1 for the 10–50-year period. The change in land use from plantation forest to dairy pasture has resulted in a moderate increase or no change in soil storage of C. Compared with total C, increases in total N storage were proportionately greater in all three examples of this Taupo Pumice Soil.
Relationships of phosphorus fractions to organic carbon content in surface soils in mature subtropical forests, Dinghushan, China
Authors: Hou Enqing , Chen Chengrong , Wen Dazhi , Liu Xian
Published: February 2014

Exploring the relationship between the accumulation of soil organic carbon (C) and the form and availability of soil phosphorus (P) is important for improved understanding of soil P availability and its regulation of C storage in forest ecosystems. Here, we investigated the relationships among soil organic C, sequentially extracted P fractions and P sorption index in 32 surface soils (0–0.15 m depth) across eight mature subtropical forests (80–400 years) in Dinghushan, China. Results showed that soil organic P (Po) accounted for 40–63% (mean 54%) of soil total P. Soil organic C was significantly positively correlated with both the content and the percentage of soluble inorganic P (Pi), Al-Po and Fe-Po fractions and the content of the Al-Pi fraction. The content of soil total Po increased significantly with soil organic C, whereas the percentage of soil total Po tended to increase with soil organic C only when soil organic C was low (<30 Mg/ha) but was relatively stable when soil organic C was high (≥30 Mg/ha). Moreover, soil organic C was highly correlated with P sorption index. Our results suggest that accumulation of organic C may increase, rather than decrease, the availability of P in surface soil in mature subtropical forests.
Biological quality of a podzolic soil after 19 years of irrigated minimum-till kikuyu–ryegrass pasture
Authors: Swanepoel P. A. , Habig J. , du Preez C. C. , Botha P. R. , Snyman H. A.
Published: February 2014

Conversion of natural rangeland to minimum-tillage kikuyu (Pennisetum clandestinum) based pastures for dairy production in the southern Cape of South Africa, may be beneficial to soil biological quality. The objective was to evaluate whether 19 years of minimum-till kikuyu-ryegrass pasture had altered the distribution and quality of biological properties formerly developed under natural rangeland. An irrigated minimum-till kikuyu-ryegrass pasture soil was compared to virgin soil with natural rangeland. Soil organic matter, soil organic C, active C, microbial biomass C, total N and enzymatic activities (β-glucosidase, urease and alkaline phosphatase) behaved similarly by having higher values in the surface layers of the cultivated pasture soil than in virgin soil, decreased with depth until they become similar at the 200–300 mm depth. Acid phosphatase activity was similar (P > 0.05) between soils. Vertical distribution of potentially mineralizable N was similar (P > 0.05) at 0–100 mm soil depth, but higher (P ≤ 0.01) in the cultivated pasture soil than in the virgin soil. The microbial indicated along with stratification ratios for different biological indicators that the cultivated pasture soil’s ecosystem functionality improved. Soil microbial functional diversity and carbon source utilisation patterns of the cultivated pasture soil and virgin soil was influenced by plant species present and root exudate composition. The soil microbial diversity, as shown by the Shannon-Weaver and Enrichment Indices, was significantly altered between cultivated pasture and the virgin soil, especially at different soil depths. A general appraisal of biological soil properties indicated that conversion of natural fynbos vegetation to irrigated minimum-till kikuyu-ryegrass pasture after 19 years of cultivation on a podzolic soil beneficial.
Distribution, habitat preferences and management of the yellow-bellied glider, Petaurus australis, on the Bago Plateau, New South Wales: a reassessment of the population and its status
Authors: Kambouris Peter J. , Kavanagh Rodney P. , Rowley Kelly A.
Published: February 2014

Context A population of yellow-bellied glider on the Bago Plateau, near Tumbarumba, was listed as an Endangered Population in 2008 under the New South Wales (NSW) Threatened Species Conservation Act 1995. The listing was based on limited data that suggested that the population is geographically and genetically distinct and its habitat in decline. Aims To review the validity of the endangered-population listing following the collection of new data on its distribution, habitat preferences and responses to logging. Methods Surveys for the yellow-bellied glider were conducted at a subset of sites established in 1995 on the Bago Plateau as well as across parts of the neighbouring Kosciuszko National Park, which had not been surveyed previously. The distribution of suitable habitat throughout these areas was evaluated. Key results The yellow-bellied glider was recorded at 29% of 48 sites resurveyed in 2010, 54% of which were previously occupied in 1995. Most changes in glider occupancy occurred at sites that had not been logged during the intervening period. The gliders preferred forest types dominated by montane gums (Eucalyptus dalrympleana, E. viminalis, E. camphora, E. pauciflora and E. stellulata) and used forest types of montane gums mixed with E. robertsonii or E. delegatensis in proportion to their availability across the landscape. The gliders were not observed to use monospecific stands of E. delegatensis. The yellow-bellied glider was also recorded frequently in Kosciuszko National Park. E. dalrympleana was consistently represented in the distribution of this species across the NSW Snowy Mountains. Conclusions Yellow-bellied glider site occupancy was not related to timber harvesting. Its habitat was not restricted by elevation or confined within Bago and Maragle State Forests by the Tumut River Gorge, Blowering and Talbingo Dams, as previously thought. We estimated that there is a large population of the gliders occupying up to 440 000 ha of contiguous habitat across the broader Snowy Mountains region of NSW, extending also into ACT and Victoria. Implications The listing of the Bago Plateau portion of this population as an endangered population appears inconsistent with relevant listing criteria and requires review.
GAP, an aequorin-based fluorescent indicator for imaging Ca
2+
in organelles
Authors: Rodriguez-Garcia Arancha , Rojo-Ruiz Jonathan , Navas-Navarro Paloma , Aulestia Francisco Javier , Gallego-Sandin Sonia , Garcia-Sancho Javier , Alonso Maria Teresa
Published: February 2014

Significance

Genetically encoded calcium indicators are excellent tools to monitor subcellular Ca
2+
signals inside organelles. We describe here a novel family of fluorescent Ca
2+
sensors based on the fusion of an improved GFP variant and aequorin, named GFP–Aequorin Protein (GAP). Since GFP and aequorin are both from jellyfish, with no mammalian homologues, the possibility of interactions between GAP and mammalian partners is minimized. This makes GAP a truly orthogonal calcium indicator in contrast to the widely used calmodulin-based indicators. GAP displays many advantages over other existing Ca
2+
probes, including its ability to be targeted to multiple organelles and its functionality in vivo. This Ca
2+
biosensor opens an avenue for studies of Ca
2+
dynamics in vivo.
DNMT3A Arg882 mutation drives chronic myelomonocytic leukemia through disturbing gene expression/DNA methylation in hematopoietic cells
Authors: Xu Jie , Wang Yue-Ying , Dai Yu-Jun , Zhang Wu , Zhang Wei-Na , Xiong Shu-Min , Gu Zhao-Hui , Wang Kan-Kan , Zeng Rong , Chen Zhu , Chen Sai-Juan
Published: February 2014

Significance

Epigenetic modifications are required for the regulation of hematopoiesis. DNA methyltransferase 3A (DNMT3A), a critical epigenetic modifier responsible for de novo DNA methylation, was reported recently to be a frequently mutated gene in hematopoietic malignancies. However, the role of mutated DNMT3A in hematopoiesis remains largely unknown. Here we show that the Arg882 (R882) mutation of DNMT3A disrupts the normal function of this enzyme and results in chronic myelomonocytic leukemia (CMML) in mice. Meanwhile, the gene expression, DNA methylation, and protein–protein interaction assays suggest that DNMT3A R882 mutation drives CMML by disturbing the transcriptional expression/DNA methylation program and cell-cycle regulation of hematopoietic cells. This study may shed light on the function of DNMT3A mutant in myeloid leukemogenesis.
Curriculum and assessment reform gone wrong: the perfect storm of GCSE English
Authors: Isaacs Tina
Published: February 2014

Curriculum and its associated assessment are at the heart of educational systems worldwide. In light of perceived national educational stagnation or decline, as well as of performance in international league tables such as Programme for International Student Assessment (PISA), countries have embarked on curriculum and assessment reforms. This is particularly true in England, where currently wholesale changes are being introduced throughout the system. The curriculum and qualification system in England privileges that which is tested over any other expression of knowledge, which leads teachers to concentrate on teaching what is assessed, either externally through examination papers or internally through coursework. In the summer of 2012, following curriculum and assessment reforms to General Certificate of Secondary Education (GCSE) qualifications, serious concerns were raised about the marking and awarding processes for GCSE English, culminating in legal action. Using that experience as an example of assessment policy and practice gone awry, this article explores the ramifications of rapid qualifications changes and posits that some of the problems that plagued GCSE English in 2012 could be repeated, albeit in different guises, after revised qualifications are introduced in 2015.
InCandida albicans, phosphorylation of Exo84 by Cdk1-Hgc1 is necessary for efficient hyphal extension
Authors: Caballero-Lima David , Sudbery Peter E.
Published: February 2014

The exocyst, a conserved multiprotein complex, tethers secretory vesicles before fusion with the plasma membrane; thus it is essential for cell surface expansion. In both Saccharomyces cerevisiae and mammalian cells, cell surface expansion is halted during mitosis. In S. cerevisiae, phosphorylation of the exocyst component Exo84 by Cdk1-Clb2 during mitosis causes the exocyst to disassemble. Here we show that the hyphae of the human fungal pathogen Candida albicans continue to extend throughout the whole of mitosis. We show that CaExo84 is phosphorylated by Cdk1, which is necessary for efficient hyphal extension. This action of Cdk1 depends on the hyphal-specific cyclin Hgc1, the homologue of G1 cyclins in budding yeast. Phosphorylation of CaExo84 does not alter its localization but does alter its affinity for phosphatidylserine, allowing it to recycle at the plasma membrane. The different action of Cdk1 on CaExo84 and ScExo84 is consistent with the different locations of the Cdk1 target sites in the two proteins. Thus this conserved component of polarized growth has evolved so that its phosphoregulation mediates the dramatically different patterns of growth shown by these two organisms.
Sociology of Human Rights
Authors: Turner Bryan S.
Published: February 2014

This article examines the role of sociology in international human rights law. It discusses the relevant views of German sociologist Max Weber and considers the issues of human rights and citizenship rights. It describes the emergence of the sociology of human rights as a consequence of taking globalization seriously and highlights the failure of sociologists to address long-standing philosophical problems surrounding human rights. This article identifies a number of legitimate sociological areas of inquiry which include the social and political conditions that have produced the entitlements or juridical revolutions and the social movements that have fostered human rights developments.
What Outcomes for Victims?
Authors: McKay Fiona
Published: February 2014

This article examines the redress processes for victims of human rights violations. It explores the outcomes of human rights law from the point of view of victims of human rights violations and evaluates what outcome may be satisfactory for victims. The analysis reveals that while efforts to redress human rights violations have produced a considerable volume of legal instruments, reports, recommendations and programs, what victims have actually received at the end of the day is less impressive. This article highlights the fact that many victims of human rights violations are not able to access any avenue of redress. It also stressed the need for procedural justice and victim-centred approaches in the reparations processes.
First gravitational lensing mass estimate of a damped Lyman α galaxy at z = 2.2
Authors: Grillo C. , Fynbo J. P. U.
Published: February 2014

We present the first lensing total mass estimate of a galaxy, at redshift 2.207, that acts as a gravitational deflector and damped Lyman α absorber on the background QSO SDSS J1135−0010, at redshift 2.888. The remarkably small projected distance, or impact parameter, between the lens and the source has been estimated to be 0.8 ± 0.1 kpc in a recent work. By exploiting the Sloan Digital Sky Survey data base, we establish a likely lensing magnification signal in the photometry of the QSO. This is determined to be 2.2 mag brighter (or eight times more luminous) than the median QSO at comparable redshifts. We describe the total mass distribution of the lens galaxy with a one-component singular isothermal sphere model and contrast the values of the observed and model-predicted magnification factors. For the former, we use conservatively the photometric data of the 95 per cent of the available distant QSO population. We estimate that the values of the lens effective velocity dispersion and two-dimensional total mass, projected within a cylinder with radius equal to the impact parameter, are included between 60 and 170 km s−1 and 2.1 × 109 and 1.8 × 1010 M⊙, respectively. We conclude by remarking that analyses of this kind are crucial to exploring the relation between the luminous and dark-matter components of galaxies in the high-redshift Universe.
The transcript elongation factor SPT4/SPT5 is involved in auxin-related gene expression in Arabidopsis
Authors: Dürr Julius , Lolas Ihab B. , Sørensen Brian B. , Schubert Veit , Houben Andreas , Melzer Michael , Deutzmann Rainer , Grasser Marion , Grasser Klaus D.
Published: February 2014

The heterodimeric complex SPT4/SPT5 is a transcript elongation factor (TEF) that directly interacts with RNA polymerase II (RNAPII) to regulate messenger RNA synthesis in the chromatin context. We provide biochemical evidence that in Arabidopsis, SPT4 occurs in a complex with SPT5, demonstrating that the SPT4/SPT5 complex is conserved in plants. Each subunit is encoded by two genes SPT4-1/2 and SPT5-1/2. A mutant affected in the tissue-specifically expressed SPT5-1 is viable, whereas inactivation of the generally expressed SPT5-2 is homozygous lethal. RNAi-mediated downregulation of SPT4 decreases cell proliferation and causes growth reduction and developmental defects. These plants display especially auxin signalling phenotypes. Consistently, auxin-related genes, most strikingly AUX/IAA genes, are downregulated in SPT4–RNAi plants that exhibit an enhanced auxin response. In Arabidopsis nuclei, SPT5 clearly localizes to the transcriptionally active euchromatin, and essentially co-localizes with transcribing RNAPII. Typical for TEFs, SPT5 is found over the entire transcription unit of RNAPII-transcribed genes. In SPT4–RNAi plants, elevated levels of RNAPII and SPT5 are detected within transcribed regions (including those of downregulated genes), indicating transcript elongation defects in these plants. Therefore, SPT4/SPT5 acts as a TEF in Arabidopsis, regulating transcription during the elongation stage with particular impact on the expression of certain auxin-related genes.
Structure-function analysis of the Yhc1 subunit of yeast U1 snRNP and genetic interactions of Yhc1 with Mud2, Nam8, Mud1, Tgs1, U1 snRNA, SmD3 and Prp28
Authors: Schwer Beate , Shuman Stewart
Published: February 2014

Yhc1 and U1C are homologous essential subunits of the yeast and human U1 snRNP, respectively, that are implicated in the establishment and stability of the complex of U1 bound to the pre-mRNA 5′ splice site (5′SS). Here, we conducted a mutational analysis of Yhc1, guided by the U1C NMR structure and low-resolution crystal structure of human U1 snRNP. The N-terminal 170-amino acid segment of the 231-amino acid Yhc1 polypeptide sufficed for vegetative growth. Although changing the zinc-binding residue Cys6 to alanine was lethal, alanines at zinc-binding residues Cys9, His24 and His30 were not. Benign alanine substitutions at conserved surface residues elicited mutational synergies with other splicing components. YHC1-R21A was synthetically lethal in the absence of Mud2 and synthetically sick in the absence of Nam8, Mud1 and Tgs1 or in the presence of variant U1 snRNAs. YHC1 alleles K28A, Y12A, T14A, K22A and H15A displayed a progressively narrower range of synergies. R21A and K28A bypassed the essentiality of DEAD-box protein Prp28, suggesting that they affected U1•5′SS complex stability. Yhc1 Arg21 fortifies the U1•5′SS complex via contacts with SmD3 residues Glu37/Asp38, mutations of which synergized with mud2Δ and bypassed prp28Δ. YHC1-(1-170) was synthetically lethal with mutations of all components interrogated, with the exception of Nam8.
Dance as a Way of Being Religious
Authors: Gaston Anne-Marie (Anjali) , Gaston Tony
Published: February 2014

Dance has accompanied religious ceremonies and sacred rites since prehistoric times. Most religions have included dance as part of worship at some period or in some places. However, because of its association with fertility and its celebration of the body, dance has equally been proscribed at times in different religions. Historical data on the use of dance in Christian rites indicate wide fluctuations in acceptance over the centuries. The presentation of dance as part of worship was highly developed in India, where dancers were employed by Hindu temples for many centuries. Such dances were highly formalized and required long training, and were largely the preserve of a specific community (caste) of dancers and dance-associated musicians. In the last century the movement for Sacred Dance has sought to revive and promote religious dances, creating a diversity of hybrid and innovative movement styles. Dance as a form of sacred art continues to evolve and diversify.
Buddhism—Image as Icon, Image as Art
Authors: Lachman Charles
Published: February 2014

Buddhism is characterized by considerable geographical and doctrinal diversity, but one feature shared by its many disparate strands is an emphasis on the ritual importance of images. These images constitute the core of the category of “Buddhist art” as it is commonly understood, but there is a significant difference between how such objects are viewed by Buddhist practitioners and how they are viewed by art historians and scholars of religion. This chapter investigates the role and status of images in Buddhism (beginning with the so-called “aniconic controversy”), the various critical approaches that have been used to interpret them, and the inherent tension between these two perspectives: the tension, that is, between images as “icons” and images as “art.” It also considers some of the ways in which such contemporary artists as Atta Kim and Montien Boonma have engaged Buddhist ideas and themes in their practice.
Alteration and Persistence: Form and Matter in thePhysicsandDe Generatione et Corruptione
Authors: Cohen S. Marc
Published: February 2014

Aristotle's Physics is a study of nature (phusis) and of natural objects (ta phusei). According to him, these objects—either all of them or at least some of them—are in motion. That is, they are kinoumena, things that are subject to change. The first book of the Physics is largely devoted to this task. The account of substantial change in the Physics is devoid of any commitment to prime matter. Aristotle also takes up the topics of alteration and coming-to-be in De Generatione et Corruptione. He adopts a kind of conservation principle: “the corruption of one thing is the generation of another, and vice versa.” In addition, Aristotle points out that all changes involve both a subject (hupokeimenon) and an attribute (pathos) of a sort which can be predicated of the subject, and says that either one of these is capable of “change” (metabolê).
Gender and The Christian Traditions
Authors: Elliott Dyan
Published: February 2014

Classical and medieval thinkers had much to say about gendered topics, including proper social roles and relationships for men and women, differing physical and psychological make-ups, and behaviors that might cause blurring between characteristics understood to belong to each sex. The theological arguments and pastoral direction of the Middle Ages relied heavily on precedents drawn from early Christianity, making an understanding of the apostolic and patristic periods essential when examining gender issues. This essay, therefore, addresses debates from both early Christianity and the central Middle Ages, concentrating primarily on discussions about the merits of virginity versus celibacy, but also treating discourse on "virile" women and the effects of the rediscovery of Aristotelian thought on ideas about procreation and the female body. Since these discussions often took place as their authors addressed contemporary crises, they offer an opportunity to examine Christian society's shifting, and often competing, values, especially those pertaining women.
Ideology and the Intellectuals
Authors: Berry Craig , Kenny Michael
Published: February 2014

The question of how intellectuals ought to relate to the ideological traditions of the political cultures of modern societies has been a recurrent theme of European social and political thought over the last two centuries. This chapter explores earlier traditions of European thinking, associated with the work of Karl Mannheim, Julien Benda, and Antonio Gramsci, which established the major lines of debate about the relationship of intellectuals to a sense of nationhood and the political traditions of the polities they inhabited. These ideas form the backdrop to the analysis of the drift towards post-national thinking among important groups of intellectual practitioners in the UK towards the end of the twentieth century. Cosmopolitan thinking, the article suggests, has tended to obscure the ideological character of the main lines of political thinking associated with globalization, and ensured that progressive intellectuals tended to abandon the ‘national-popular’ to their counterparts on the political right, with fateful consequences.
Nationalism
Authors: Vincent Andrew
Published: February 2014

The chapter focuses on nationalism as an ideology. It reviews the largely unresolved debates over the background, genealogy, and development of nationalism, many of which oscillate between primordial, pre-modern, and modernist accounts. It scrutinizes debates over ethnicity, culture, race, self-determination, and democracy, in relation to nationalism; critically appraises the theoretical paradoxes implicit within nationalist argument; and finally turns to an overview of some of the main themes pervading nationalist discourse. These themes are viewed, in themselves, as largely vacuous. What makes them significant is the entry of other thicker ideologies (conservatism, liberalism, authoritarianism, and fascism), which carry the nationalist argument forward.
Republicanism
Authors: Laborde Cécile
Published: February 2014

After presenting the recent republican revival, focusing in particular on the neo-republican school of thought, this chapter assesses the exact nature of the differences between liberalism and republicanism, and notably the republicanism of freedom as non-domination associated with Philip Pettit. Drawing on the tools of ideological analysis, as laid out by Michael Freeden, it shows that some of these disagreements are conceptual; others are normative; and yet others are strategic. In particular, republicans have a distinctive understanding of the concept of liberty; their focus on non-domination and ‘anti-power’ shapes a more comprehensive, progressive political agenda; and their language is more effective as a critique of real-world neoliberal politics.