Interface solitons in two-dimensional photonic lattices

We analyze localization of light at the interface separating square and hexagonal photonic lattices, as recently realized experimentally in two-dimensional laser-written waveguide arrays in silica glass with self-focusing nonlinearity [A. Szameit {\em et al.}, Opt. Lett. {\bf 33}, 663 (2008)]. We reveal the conditions for the existence of {\em linear} and {\em nonlinear} surface states substantially influenced by the lattice topology, and study the effect of the different symmetries and couplings on the stability of two-dimensional interface solitons.Comment: 3 pages, 4 figures, submitted to Opt. Let

Nonlinear localized modes at phase-slip defects in waveguide arrays

We study light localization at a phase-slip defect created by two semi-infinite mismatched identical arrays of coupled optical waveguides. We demonstrate that the nonlinear defect modes possess the specific properties of both nonlinear surface modes and discrete solitons. We analyze stability of the localized modes and their generation in both linear and nonlinear regimes.Comment: 3 pages, 6 figures, submitted to Opt. Let

Implicit preference towards slim bodies and weight-stigma modulate the understanding of observed familiar actions

Mounting research evidence suggests that motor resonance (MR, i.e., the mapping of others’ actions onto one’s own motor repertoire) can be influenced by diverse factors related to individual differences. However, no evidence has been reported so far on the effects of physical appearance and negative attitudes toward obesity to the mechanism of MR. Thirty-six participants (18 normal-weight and 18 overweight) performed a weight discrimination task, in which they were observing amateur actors reaching and grasping a light or heavy cube with or without deception (true vs. fake actions). At the end of each video clip, participants were instructed to indicate the correct cube size (light or heavy). Importantly, body similarity between observers and actors was manipulated by presenting videos of normal-weight or overweight actors. Fat phobic attitudes and automatic preference for normal-weight than obese people were also examined. Signal detection analysis (d′) on the acquired accuracy data has shown that both normal- and overweight participants were able to better discriminate truthful actions when performed by the normal-weight as compared to overweight actors. Furthermore, this finding was negatively correlated with increased scores of fat phobic attitudes in both groups. Hence, for the first time, we provide experimental evidence of action simulation being modulated by an implicit visual sensitivity towards slim bodies

Vision-Based Production of Personalized Video

In this paper we present a novel vision-based system for the automated production of personalised video souvenirs for visitors in leisure and cultural heritage venues. Visitors are visually identified and tracked through a camera network. The system produces a personalized DVD souvenir at the end of a visitor’s stay allowing visitors to relive their experiences. We analyze how we identify visitors by fusing facial and body features, how we track visitors, how the tracker recovers from failures due to occlusions, as well as how we annotate and compile the final product. Our experiments demonstrate the feasibility of the proposed approach

Discrete surface solitons in two-dimensional anisotropic photonic lattices

We study nonlinear surface modes in two-dimensional {\em anisotropic} periodic photonic lattices and demonstrate that, in a sharp contrast to one-dimensional discrete surface solitons, the mode threshold power is lower at the surface, and two-dimensional discrete solitons can be generated easier near the lattice corners and edges. We analyze the crossover between effectively one- and two-dimensional regimes of the surface-mediated beam localization in the lattice.Comment: 3 pages, 4 figure

Discrete and surface solitons in photonic graphene nanoribbons

We analyze localization of light in honeycomb photonic lattices restricted in one dimension which can be regarded as an optical analog of (``armchair'' and ``zigzag'') graphene nanoribbons. We find the conditions for the existence of spatially localized states and discuss the effect of lattice topology on the properties of discrete solitons excited inside the lattice and at its edges. In particular, we discover a novel type of soliton bistability, the so-called geometry-induced bistability, in the lattices of a finite extent.Comment: three double-column pages, 5 figures, submitted for publicatio

Scale‐Dependent Processes and Runout in Bidisperse Granular Flows:Insights From Laboratory Experiments and Implications for Rock/Debris Avalanches

The bidispersity observed in the particle‐size distribution of rock avalanches and volcanic debris avalanches (rock/debris avalanches) has been proposed as a factor contributing to their long runout. This has been supported by small‐scale analog experimental studies, which observe that a small proportion of fine particles mixed with coarser particles enhances granular avalanche runout. However, the mechanisms enabling this phenomenon and their resemblance to rock/debris avalanches have not been directly evaluated. Here, binary mixture granular avalanche experiments are employed to constrain the processes and conditions under which bidispersity enhances the runout of granular avalanches in experiments. Structure‐from‐motion photogrammetry is used to measure center of mass displacement and assess energy dissipation. Subsequently, this study evaluates the dynamic scaling and flow regimes in the lab and field to assess whether the runout‐enhancing mechanism is applicable to rock/debris avalanches. In small‐scale experiments, the granular mass propagates under a collisional regime, enabling kinetic sieving and size segregation. Fine particles migrate to the base where they reduce frictional areas between coarse particles and the substrate and encourage rolling. The reduced energy dissipation increases the kinetic energy conversion and avalanche mobility. However, rock/debris avalanches are unlikely to acquire a purely collisional regime; instead, they propagate under a frictional regime. The size segregation which is essential for the process observed at the lab‐scale is prohibited by the frictional regime, as evident by the sedimentology of rock/debris avalanche deposits. The proposal of bidispersity as a runout‐enhancing mechanism overlooks that scale‐dependent behaviors of natural events are often omitted in small‐scale experiments

Music Teachers’ Perceptions of, and approaches to,Creativity in the Greek-Cypriot Primary Education

TThe purpose of this study was to explore music teachers' perceptions of, and approaches to, creativity in Primary education. Even though teachers' perceptions on creativity have been investigated broadly and extensively, qualitative research on music teachers' beliefs nurturing the students' creativity in Primary education are less common. In the present paper, data were collected through in-depth interviews with 10 individuals in the Greek-Cypriot Primary Education. The results of this exploratory study indicated that activities should include the promotion of the students' self-action and autonomy, and the pedagogical initiatives that enable students to come up with original outputs in order to be creative. This understanding, in turn, provided the researchers with access to the teacher participants' perceptions of creativity: a multifaceted concept related to students' autonomy, initiative, and the application of imagination and unrestrained thinking to any musical activity. These findings offer some initial insights and are discussed with respect to their implications for policy and practice. Suggestions for future research are also made

Cathodal transcranial direct current stimulation of the extrastriate visual cortex modulates implicit anti-fat bias in male, but not female, participants.

Explicit negative attitudes towards obese individuals are well documented and seem to modulate the activity of perceptual areas, such as the Extrastriate Body Area (EBA) in the lateral occipito-temporal cortex, which is critical for body-shape perception. Nevertheless, it is still unclear whether EBA serves a role in implicit weight-stereotypical bias, thus reflecting stereotypical trait attribution on the basis of perceptual cues. Here, we used an Implicit Association Test (IAT) to investigate whether applying transcranial direct current stimulation (tDCS) over bilateral extrastriate visual cortex reduces pre-existing implicit weight stereotypical associations (i.e. "Bad" with Fat and "Good" with Slim, valence-IAT). Furthermore, an aesthetic-IAT, which focused on body-concepts related to aesthetic dimensions (i.e. "Ugly" and "Beauty"), was developed as a control condition. Anodal, cathodal, or sham tDCS (2 mA, 10min) over the right and left lateral occipito-temporal (extrastriate visual) cortex was administered to 13 female and 12 male participants, before performing the IATs. Results showed that cathodal stimulation over the left extrastriate visual cortex reduced weight-bias for the evaluative dimensions (Bad vs. Good) as compared to sham stimulation over the same hemisphere. Furthermore, the effect was specific for the polarity and hemisphere of stimulation. Importantly, tDCS affected the responses only in male participants, who presented a reliable weight-bias during sham condition, but not in female participants, who did not show reliable weight-bias at sham condition. The present results suggest that negative attitudes towards obese individuals may reflect neural signals from the extrastriate visual cortex

The Spider Boot: An Effective Foot Protection System Against Anti-Personnel Mine Blasts

It is estimated that about 70 million AP landmines are deployed worldwide, slowing down the economic recovery of war torn countries and causing indiscriminate injuries to returning civilian populations long after the end of a conflict. Several military and non-military organizations are currently engaged in mine clearance, either in support of peacekeeping operations or for humanitarian demining