Distinct Edge Research Articles

Does self-organized criticality drive leading edge protrusion?

Arp2/3 complex nucleates dendritic actin networks and plays a pivotal role in the formation of lamellipodia at the leading edge of motile cells. Mouse fibroblasts lacking functional Arp2/3 complex have the characteristic smooth, veil-like lamellipodial leading edge of wild-type cells replaced by a massive, bifurcating filopodia-like protrusions (FLPs) with fractal geometry. The nanometer-scale actin-network organization of these FLPs can be linked to the fractal geometry of the cell boundary by a self-organized criticality through the bifurcation behavior of cross-linked actin bundles. Despite the pivotal role of the Arp2/3 complex in cell migration, the cells lacking functional Arp2/3 complex migrate at rates similar to wild-type cells. However, these cells display defects in the persistence of a directional movement. We suggest that Arp2/3 complex suppresses the formation of FLPs by locally fine-tuning actin networks and favoring dendritic geometry over bifurcating bundles, giving cells a distinct evolutionary edge by providing the means for a directed movement.

Why Champagne's female grape‐growers have reason to celebrate

Viniculture is male‐dominated, but women have found a way to exploit a distinct edge, say Isabel Fernandez‐Mateo and Amandine Ody‐Brasier

Tunable quantum Hall edge conduction in bilayer graphene through spin-orbit interaction

Bilayer graphene, in the presence of a one-sided spin-orbit interaction (SOI) induced by a suitably chosen substrate, is predicted to exhibit unconventional quantum Hall states. The new states arise due to strong SOI-induced splittings of the eight zeroth Landau levels, which are strongly layer polarized, residing fully or partially on one of the two graphene layers. In particular, an Ising SOI on the meV scale is sufficient to invert the Landau level order between the $n=0$ and $n=1$ orbital levels under moderately weak magnetic fields $B\ensuremath{\lesssim}10$ T. Furthermore, when the Ising field opposes the $B$ field, the order of the spin-polarized levels can also be inverted. We show that, under these conditions, three different compensated electron-hole phases, with equal concentrations of electrons and holes, can occur at $\ensuremath{\nu}=0$ filling. The three phases have distinct edge conductivity values. One of the phases is especially interesting, since its edge conduction can be turned on and off by switching the sign of the interlayer bias.

Task-Based Learning in Task-Based Teaching: Training Teachers of Chinese as a Foreign Language

ABSTRACTTask-based language teaching (TBLT) is increasingly becoming known for its distinct edge in developing learners’ functional competence. Although its potential in promoting content learning has yet to be realized and explored, it should be high, given TBLT's primary attention to meaning. To what extent does the potential play out in foreign language teacher education, a domain involving much content learning, is both an intellectually stimulating and practically meaningful question. This article reports on a semester-long study investigating task-based learning in a Chinese language teacher-training program that promotes TBLT. The participants were three Chinese-speaking trainees, who, while being exposed to TBLT, performed ongoing tasks. Data from one task—writing weekly reading journals—were analyzed for both content and language, quantitatively (using robust automated tools) and qualitatively. The results show tangible gains on both counts—understanding TBLT (content) and the ability to articulate it (language). The conceptual and methodological implications of the findings are discussed for future research.

Gapless insulating edges of dirty interacting topological insulators

We demonstrate that a combination of disorder and interactions in a two-dimensional bulk topological insulator can generically drive its helical edge insulating. We establish this within the framework of helical Luttinger liquid theory and exact Emery-Luther mapping. The gapless glassy edge state spontaneously breaks time-reversal symmetry in a `spin glass' fashion, and may be viewed as a localized state of solitons which carry half integer charge. Such a qualitatively distinct edge state provides a simple explanation for heretofore puzzling experimental observations. This phase exhibits a striking non-monotonicity, with the edge growing less localized in both the weak and strong disorder limits.

Stable H-Terminated Edges, Variable Semiconducting Properties, and Solar Cell Applications of C3N Nanoribbons: A First-Principles Study.

Motivated by the recent synthesis of the graphene-like C3N nanosheet, the geometrical structures and electronic properties of its ribbon form, that is, C3N nanoribbons (C3NNRs), are investigated by first-principles calculations. It is found that there are five types of energetically favorable H-terminated edges in the C3NNRs. Different from graphene nanoribbons, the corresponding stable C3NNRs are all nonmagnetic semiconductors regardless of the edge shape and termination. However, their band feature and gap size can be modulated by the ribbon width and edge termination, which brings direct-, quasi-direct-, and indirect-band-gap semiconducting behaviors in the nanoribbons. Comparing to the C3N nanosheet, the work function is reduced in the C3NNRs with fully di- and monohydrogenated edges, which results in a type-II band alignment with SiC and silicane nanosheets. More interestingly, the combined hetero-nanostructures will be promising excitonic solar cell materials with high power conversion efficiencies up to 17–21%. Our study demonstrates that the C3NNRs have distinct edge stabilities and variable semiconducting behaviors, which endow fascinating potential applications in the fields of solar energy and nanodevices.

Experimental investigations on wiper inserts’ edge preparation, workpiece hardness and operating parameters in hard turning of AISI D2 steel

Review of the available literature indicates that hard part turning requires tailored cutting edge for specific tool workpiece combination. Incidentally, much work could not be found that evaluates the role of wiper insert’s cutting edge while hard turning. The objective of presented work is to evaluate the effect of wiper inserts’ micro geometry for critical hardness regime of the material. The work employs two distinct edge geometries namely chamfer (0.15 mm × 25°) and chamfer plus hone (0.15 mm × 25°–25 μm) for wiper inserts in finish hard turning of AISI D2 steel without cutting fluid. Taguchi L18 array is used for tool wear/life, material removed and surface roughness and comparison has been done with a conventional insert (chamfered plus honed edge geometry). Three levels of feed rate and depth of cut have been used while machining workpieces of two different hardness (55HRC and 60HRC). Contrary to the influence of edge preparation typically reported for conventional inserts, here, it is found that its role is somewhat suppressed in the presence of wiper macro-geometry for both the output parameters namely tool wear/life and surface roughness. More specifically, workpiece hardness is found to play most significant role (with PCR of 70.11%) for tool life whereas for surface roughness, insert type (wiper inserts are seen to clearly outperform conventional tools) and feed rate are found to be more dominant. Interestingly, maximum wear scar has been observed at the minor cutting edge with “Notching” being the prevalent wear mode. Oxidation and seizure pull-out seem to be principal wear mechanisms. Microhardness is seen to be increased beneath the machined surface for both new and worn tools up to a depth of 200 μm. At highest feed (0.281 mm/rev) and depth of cut (0.20 mm) combination, material pull-out was revealed as the major microstructural damage.

Distinct edge effects and reproductive periods of sympatric litter-dwelling scorpions (Arachnida: Scorpiones) in a Brazilian Atlantic forest

Edge effects have drastically affected species living in tropical forests. However, understanding how species respond to edge effects remains a challenge, owing to the many factors involved and different responses of each species thereto. Here, we analyzed how the abundance of two sympatric scorpion species (Tityus pusillus and Ananteris mauryi) and their potential prey varied as a function of microhabitat changes (litter depth, dry mass, and leaf shape) from edge to interior forest habitats. We further analyzed the contribution of potential prey to scorpion abundance and reproductive periods. Data were collected monthly at three 300-m² transects/site at distances of 10, 100, and 200m from the forest edge in a fragment of the Atlantic forest in northeastern Brazil, between April 2016 and March 2017. Scorpions responded differentially to edge effects, with A. mauryi abundance being similar along the edge-interior gradient, whereas T. pusillus had a higher abundance in the interior. As T. pusillus inhabit the top layer of the leaf litter, this species will possibly be more influenced by edge effects. In contrast, being a humicolous scorpion and inhabiting the bottom layers of leaf litter, A. mauryi would not be influenced by edge effects as much as T. pusillus. The reproductive period also was distinct between the two species, with T. pusillus reproducing in the dry season and A. mauryi in the rainy season. The oscillation in the abundance of different groups of prey at different periods maintained the overall prey abundance at a relatively constant level throughout the year, mitigating the effects of prey availability on the abundance and reproductive period of the scorpions. These results suggest that microhabitat exploitation is a key factor to sustain litter-dwelling scorpions in disturbed forest remnants and that T. pusillus can be an ecological indicator of edge effects.

Evaluation of SnO2 for sunlight photocatalytic decontamination of water

The broad bandgap tin (IV) oxide (SnO2) is the least investigated semiconductor material for photocatalytic water decontamination in sunlight exposure. A detailed study covering the synthesis, characterization and the evaluation of photocatalytic activity of SnO2, in the natural sunlight exposure, is presented. The structural characterization by XRD revealed the formation of phase pure tetragonal SnO2 with the average crystallite size of ∼41.5 nm whereas minor Sn2+ states in the material were identified by XPS analysis. As explored by diffuse reflectance (DR) and photoluminescence (PL) spectroscopy, the material exhibited a distinct absorption edge at ∼3.4 eV. The morphological and microstructure analysis of the synthesized SnO2 was carried out by FESEM and HRTEM. The electrochemical impedance spectroscopy (EIS) and chronopotentiometry (CP) predicted the better charge transport and retention ability of the material under illumination whereas the Mott-Schottky extrapolation prophesied the n-type behavior with the flat-band potential of −0.60 V. The photocatalytic activity of SnO2 was assessed in the exposure of complete spectrum natural sunlight for the removal of 2,4,6-trichlorophenol. The HPLC and TOC analysis monitored the progress of degradation and mineralization whereas the released chloride ions were evaluated by ion chromatography. The effect of the transition metal ions (Fe3+, Cu2+, Ni2+, and Zn2+) as electron capture agents and H2O2 as ROS generator was explored during the degradation process. The utility of the material for the simultaneous removal of chlorophenols in the mixture was also investigated. The SnO2 exhibited sustained activity in the repeated use. Based on experimental evidence congregated, the mechanism of the removal process and the efficacy of SnO2 for sunlight photocatalytic decontamination of water was established.

Imaging the Topology of Grounding Grids Based on Wavelet Edge Detection

A wavelet edge detection method is introduced to image the topology of grounding grids and locate the grounding conductors from measured magnetic induction. Theoretical analysis of the magnetic field and calculation method of discrete wavelet transform are described. Since the sharpest variation of the magnetic field perpendicular to the ground surface occurs right above a conductor, the gradient vector modulus maximum of the vertical component can be calculated to extract the position information about the conductor. This scheme is derived from the Canny edge detection. A 2-D discrete à trous algorithm is used to perform equivalent edge detection as the wavelet transform avoids partial derivative. The method is robust to noise and would extract more stable and distinct edge. Extensive simulation and experimental examples demonstrate that the proposed method can accurately draw the topology of grounding grids and locate the conductors.

Agronomic performance of Indian wheat varieties and genetic stocks known for outstanding chapati quality characteristics

The aim of the present study was to evaluate set of wheat genotypes in one location for their agronomic performance and chapati quality. The cultivars included the tall traditional wheat of the pre-dwarfing era, which were known to excel for chapati quality. This set also included varieties known to have good chapati quality, commercially grown wheats, advanced lines and genetic stocks excelling in one or other quality attribute. All these genotypes developed for different component traits were evaluated along with the recently released high yielding varieties to assess their quality. The mean chapati score of these genotypes revealed that the tall varieties had a distinct edge over others and are the best resource available for this trait. C306 had a high mean chapati score of 8.17 followed by C518, C591 and C273. The released varieties WG357, HD2733 and PBW343 were intermediate in chapati quality whereas the genetic stocks WH1103 and WH712 had lowest score in the group. Among other agronomic traits recorded the traditional varieties were tall and had lower yields than the recently released varieties. The tall varieties had a slightly higher test weight. The environmental conditions and the quantitative nature of the chapati quality did not auger well with the set of genotypes tested however, better and stable performance of the tall traditional varieties. C306 the wheat variety released in 1965 for cultivation has remained the best quality genotype over the years and was also established from this study.

Distinct edge states and optical conductivities in the zigzag and armchair silicene nanoribbons under exchange and electric fields**Project supported by the National Natural Science Foundation of China (Grant Nos. 11347127, 61404044, and 11347111).

Based on the tight binding model, we investigate the low energy bandstructures, edge states, and optical absorptions for the silicene nanoribbons (SiNRs) with different terminations under an in-plane exchange field and/or a perpendicular electric field. We find that the zigzag SiNRs are gapped by the exchange field, but they could reenter the metallic state after the application of the electric field. Contrarily, a certain kind of armchair SiNRs remain gapless even if a weak exchange field is present. Furthermore, the combination of the exchange and electric fields could effectively modulate the penetration length and the components of the edge states in the SiNRs. The corresponding optical conductivities for the SiNRs are also calculated, which show remarkable dependence on the edge types of the SiNRs and the two external fields.

Improved Bound on the Maximum Number of Clique-Free Colorings with Two and Three Colors

Given integers $r, k \geq2$ let $\kappa_{r,k+1}(G)$ denote the number of distinct edge colorings of $G$ with $r$ colors, which are $K_{k+1}$-free, i.e., which contain no monochromatic clique on $k+...

Exploring HR practitioners’ perspective on employer branding and its role in organisational attractiveness and talent management

PurposeThe latest research in the field of employer branding highlights a mix of marketing principles and recruitment practices, based on the concept that, just as customers have perceptions of an organisation’s brand, then so do other stakeholders including employees. However, the emphasis has been on organisations, which predominantly operate in developed countries typically with Westernised-individualistic cultures. This paper aims to investigate employer branding for service organisations’ image and attraction as an employer in a non-Western culture.Design/methodology/approachThis study examines the perceptions of human resources’ professionals and practitioners on the role of employer branding in employer attractiveness and talent management, within Mauritian banking sector. The data collection for this qualitative study involved semi-structured interviews with senior managers from Mauritian banking organisations, including multinational enterprises, small business unit banks and Mauritian banks.FindingsAnalysis of the findings showed that organisations, and banks in this case, are increasingly competing to attract highly skilled personnel in various professional areas; therefore, those organisations that attract the best talent will have a distinct edge in the marketplace. Furthermore, findings from the semi-structured interviews with senior managers suggest that employer branding remains at the embryonic stage within the Mauritian banking sector; therefore, a clear need exists for a more developed strategy.Research limitations/implicationsThe outcomes of this study call for re-engineering with regards to managerial collaboration in organisations for the successful design and implementation of the employer branding strategy. The empirical findings from the Mauritian banking sector show that the strategic position occupied by the human resource function is still at an embryonic stage as regards with the competitiveness of banks as service organisations.Practical implicationsThe study presents a need for the development and maintenance of long-term collaborative and trust-based relationships between the human resource and marketing functions.Originality/valueThe insights provided through this study addresses the dearth of academic research on employer branding on the African continent while providing invaluable information from a human resource professional perspective.

Reduction of defect states in atomic-layered HfO2 film on SiC substrate using post-nitridation annealing

The changes of the defect states below the conduction band in atomic-layered HfO2 film grown on SiC substrate were examined as a function of the post-nitridation annealing temperature in an NH3 ambient. As the post-nitridation annealing temperature increased up to 600°C, the incorporated nitrogen into the HfO2/SiC interface was gradually increased. The band gap and valence band offset were mostly increased as a function of the post-nitridation annealing temperature and the band alignment of HfO2 films changed. O K-edge absorption features revealed two distinct band edge states below the conduction band edge in HfO2 films, and these defect states were dramatically reduced with increasing of the post-nitridation annealing temperature. The reduction of defect states in HfO2/SiC improved the electrical properties such as the leakage current density, breakdown voltage, and trap charge density in the HfO2 film and interface of HfO2/SiC.

Combined retrieval of Arctic liquid water cloud and surface snow properties using airborne spectral solar remote sensing

Abstract. The passive solar remote sensing of cloud properties over highly reflecting ground is challenging, mostly due to the low contrast between the cloud reflectivity and that of the underlying surfaces (sea ice and snow). Uncertainties in the retrieved cloud optical thickness τ and cloud droplet effective radius reff, C may arise from uncertainties in the assumed spectral surface albedo, which is mainly determined by the generally unknown effective snow grain size reff, S. Therefore, in a first step the effects of the assumed snow grain size are systematically quantified for the conventional bispectral retrieval technique of τ and reff, C for liquid water clouds. In general, the impact of uncertainties of reff, S is largest for small snow grain sizes. While the uncertainties of retrieved τ are independent of the cloud optical thickness and solar zenith angle, the bias of retrieved reff, C increases for optically thin clouds and high Sun. The largest deviations between the retrieved and true original values are found with 83 % for τ and 62 % for reff, C. In the second part of the paper a retrieval method is presented that simultaneously derives all three parameters (τ, reff, C, reff, S) and therefore accounts for changes in the snow grain size. Ratios of spectral cloud reflectivity measurements at the three wavelengths λ1 = 1040 nm (sensitive to reff, S), λ2 = 1650 nm (sensitive to τ), and λ3 = 2100 nm (sensitive to reff, C) are combined in a trispectral retrieval algorithm. In a feasibility study, spectral cloud reflectivity measurements collected by the Spectral Modular Airborne Radiation measurement sysTem (SMART) during the research campaign Vertical Distribution of Ice in Arctic Mixed-Phase Clouds (VERDI, April/May 2012) were used to test the retrieval procedure. Two cases of observations above the Canadian Beaufort Sea, one with dense snow-covered sea ice and another with a distinct snow-covered sea ice edge are analysed. The retrieved values of τ, reff, C, and reff, S show a continuous transition of cloud properties across snow-covered sea ice and open water and are consistent with estimates based on satellite data. It is shown that the uncertainties of the trispectral retrieval increase for high values of τ, and low reff, S but nevertheless allow the effective snow grain size in cloud-covered areas to be estimated.

Investigation of the impact of high liquid viscosity on jet atomization in crossflow via high-fidelity simulations

Atomization of extremely high viscosity liquid can be of interest for many applications in aerospace, automotive, pharmaceutical, and food industries. While detailed atomization measurements usually face grand challenges, high-fidelity numerical simulations offer the advantage to comprehensively explore the atomization details. In this work, a previously validated high-fidelity first-principle simulation code HiMIST is utilized to simulate high-viscosity liquid jet atomization in crossflow. The code is used to perform a parametric study of the atomization process in a wide range of Ohnesorge numbers (Oh = 0.004–2) and Weber numbers (We = 10–160). Direct comparisons between the present study and previously published low-viscosity jet in crossflow results are performed. The effects of viscous damping and slowing on jet penetration, liquid surface instabilities, ligament formation/breakup, and subsequent droplet formation are investigated. Complex variations in near-field and far-field jet penetrations with increasing Oh at different We are observed and linked with the underlying jet deformation and breakup physics. Transition in breakup regimes and increase in droplet size with increasing Oh are observed, mostly consistent with the literature reports. The detailed simulations elucidate a distinctive edge-ligament-breakup dominated process with long surviving ligaments for the higher Oh cases, as opposed to a two-stage edge-stripping/column-fracture process for the lower Oh counterparts. The trend of decreasing column deflection with increasing We is reversed as Oh increases. A predominantly unimodal droplet size distribution is predicted at higher Oh, in contrast to the bimodal distribution at lower Oh. It has been found that both Rayleigh-Taylor and Kelvin-Helmholtz linear stability theories cannot be easily applied to interpret the distinct edge breakup process and further study of the underlying physics is needed.

One new species of the genus Xizicus (Orthoptera: Tettigoniidae: Meconematinae) from Chongqing, China

The paper described one new species from Chongqing, China, i.e. Xizicus (Eoxizicus) simianshanensis sp. nov., it resembles Xizicus (Eoxizicus) divergentis (Liu & Zhang, 2000) and Xizicus (Eoxizicus) xiai (Liu & Zhang, 2000), but differs from the latter in: posterior processes of male tenth abdominal tergite straight; inner margin of base area of cerci with a notch, the other area of ventral surface after it enlarged inwards, with distinct edge; subgenital plate with posterior margin narrow, with styli stout and short.

Synergistic effects of grain boundaries and edges on fatigue deformations of sub-5 nm graphene nanoribbons

Polycrystalline graphene nanoribbons usually experience a brittle rupture before failure, and the irreversible breaking occurs in grain boundaries (GBs). In this paper, molecular dynamic simulations are conducted to study the fatigue properties of bi-crystal graphene nanoribbons under a periodic in-plane compression. It is found that ribbon edges rather than GBs dominate the dynamic stability when the ribbon width is smaller than 5 nm. The fatigue failure is closely related to the misorientation angle between two grains because of the distinct edge energy. It always starts from the edges with higher energy and results in a localized damage at the edges.

Global production sharing: Exploring Australia's competitive edge

AbstractCross‐border dispersion of production processes within vertically integrated global industries (“global production sharing”) has been an increasingly important structural feature of economic globalisation in the recent decades. This paper examines patterns and determinants of global production sharing with an emphasis on how Australian manufacturing fits into global production networks (GPNs). Though Australia is a minor player in GPNs, there is evidence that Australian manufacturing has a distinct competitive edge in specialised, skill‐intensive tasks in several industries such as aircraft, medical devices, machine tools, measuring and scientific equipment and photographic equipment. Specialisation in high‐value‐to‐weight components and final goods within GPNs, which are suitable for air transport, helps Australian manufacturing to overcome the “tyranny of distance” in world trade. Being predominantly “relationship specific,” Australian GPN exports are not significantly susceptible to real exchange rate appreciation.