Understanding pretence and understanding action

Two studies were carried out in an attempt to replicate an earlier but controversial set of findings that suggested that young children are able to understand pretence in a mentalistic sense (Hickling, Wellman, & Gottfried, 1997). In Study 1, 65 three-year-olds and 77 four-year-olds were asked to either judge the thoughts of an absent teddy bear, who had not witnessed a change in the original pretence stipulation, or were asked to complete a similar, standard false-belief task. Study 2 repeated the experimental procedures of the first study with 24 three-year-olds and 16 four-year-olds, with the difference that all children had to complete both tasks in a single session. The results obtained across both studies showed that 3-year-olds were unable to correctly judge the discrepant thoughts of the teddy bear, suggesting that young children do not attribute a false belief to another actor during pretend play, and that instead they view pretence in terms of overt action

Endotaxial Si nanolines in Si(001):H

We present a detailed study of the structural and electronic properties of a self-assembled silicon nanoline embedded in the H-terminated silicon (001) surface, known as the Haiku stripe. The nanoline is a perfectly straight and defect free endotaxial structure of huge aspect ratio; it can grow micrometre long at a constant width of exactly four Si dimers (1.54nm). Another remarkable property is its capacity to be exposed to air without suffering any degradation. The nanoline grows independently of any step edges at tunable densities, from isolated nanolines to a dense array of nanolines. In addition to these unique structural characteristics, scanning tunnelling microscopy and density functional theory reveal a one-dimensional state confined along the Haiku core. This nanoline is a promising candidate for the long sought after electronic solid-state one-dimensional model system to explore the fascinating quantum properties emerging in such reduced dimensionality.Comment: 8 pages, 6 figure

Stress relief as the driving force for self-assembled Bi nanolines

Stress resulting from mismatch between a substrate and an adsorbed material has often been thought to be the driving force for the self-assembly of nanoscale structures. Bi nanolines self-assemble on Si(001), and are remarkable for their straightness and length -- they are often more than 400 nm long, and a kink in a nanoline has never been observed. Through electronic structure calculations, we have found an energetically favourable structure for these nanolines that agrees with our scanning tunneling microscopy and photoemission experiments; the structure has an extremely unusual subsurface structure, comprising a double core of 7-membered rings of silicon. Our proposed structure explains all the observed features of the nanolines, and shows that surface stress resulting from the mismatch between the Bi and the Si substrate are responsible for their self-assembly. This has wider implications for the controlled growth of nanostructures on semiconductor surfaces.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

A clinical algorithm for wound biofilm identication

Broj publiciranih referenci koje ukazuju na prisutnost biofi lma u kroničnim ranama je u porastu. Sve je veći broj dokaza koji potvrđuju da biofilm značajno sudjeluje u nezacijeljivanju rane i u bakterijskim infekcijama. Iz navedenih razloga postavlja se pitanje nedostatka postupnika o dokazima prisutnosti biofilma u rani. Namjera je ovog rada specifi cirati vidljive dokaze i indirektno dati kliničke smjernice tretmana biofilma u rani, te predložiti određeni postupnik za olakšanje kliničkog prepoznavanja biofi lma da bi se potom promijenilo ciljano liječenje vrijeda.Recognition of the existence of biofilm in chronic wounds is increasing among wound care practitioners, and a growing body of evidence indicates that biofilm contributes significantly to wound recalcitrance. While clinical guidelines regarding the involvement of biofilm in human bacterial infections have been proposed, there remains uncertainty and lack of guidance towards biofilm presence in wounds. The intention of this report is to collate knowledge and evidence of the visual and indirect clinical indicators of wound biofilm, and propose an algorithm designed to facilitate clinical recognition of biofilm and subsequent wound management practices

One dimensional Si-in-Si(001) template for single-atom wire growth

Single atom metallic wires of arbitrary length are of immense technological and scientific interest. We describe a novel silicon-only template enabling the self-organised growth of isolated micrometer long surface and subsurface single-atom chains. It consists of a one dimensional, defect-free reconstruction - the Haiku core, here revealed for the first time in details - self-assembled on hydrogenated Si(001) terraces, independent of any step edges. We discuss the potential of this Si-in-Si template as an appealing alternative to vicinal surfaces for nanoscale patterning.Comment: 3 pages, 2 figure

Understanding the Mind or Predicting Signal-Dependent Action? Performance of Children With and Without Autism on Analogues of the False-Belief Task

To evaluate the claim that correct performance on unexpected transfer false-belief tasks specifically involves mental-state understanding, two experiments were carried out with children with autism, intellectual disabilities, and typical development. In both experiments, children were given a standard unexpected transfer false-belief task and a mental-state-free, mechanical analogue task in which participants had to predict the destination of a train based on true or false signal information. In both experiments, performance on the mechanical task was found to correlate with that on the false-belief task for all groups of children. Logistic regression showed that performance on the mechanical analogue significantly predicted performance on the false-belief task even after accounting for the effects of verbal mental age. The findings are discussed in relation to possible common mechanisms underlying correct performance on the two tasks

B Physics on the Lattice: Present and Future

Recent experimental measurements and lattice QCD calculations are now reaching the precision (and accuracy) needed to over-constrain the CKM parameters $\bar\rho$ and $\bar\eta$. In this brief review, I discuss the current status of lattice QCD calculations needed to connect the experimental measurements of $B$ meson properties to quark flavor-changing parameters. Special attention is given to $B\to\pi\ell\nu$, which is becoming a competitive way to determine $|V_{ub}|$, and to $B^0-\bar{B^0}$ mixings, which now include reliable extrapolation to the physical light quark mass. The combination of the recent measurement of the $B_s$ mass difference and current lattice calculations dramatically reduces the uncertainty in $|V_{td}|$. I present an outlook for reducing dominant lattice QCD uncertainties entering CKM fits, and I remark on lattice calculations for other decay channels.Comment: Invited brief review for Mod. Phys. Lett. A. 15 pages. v2: typos corrected, references adde

Soliton effects in dangling-bond wires on Si(001)

Dangling bond wires on Si(001) are prototypical one dimensional wires, which are expected to show polaronic and solitonic effects. We present electronic structure calculations, using the tight binding model, of solitons in dangling-bond wires, and demonstrate that these defects are stable in even-length wires, although approximately 0.1 eV higher in energy than a perfect wire. We also note that in contrast to conjugated polymer systems, there are two types of soliton and that the type of soliton has strong effects on the energetics of the bandgap edges, with formation of intra-gap states between 0.1 eV and 0.2 eV from the band edges. These intra-gap states are localised on the atoms comprising the soliton.Comment: 6 pages, 3 figures, 3 tables, submitted to Phys. Rev.