The Feldenkrais method

In this short article I discuss some strategies in the educational method focused on learning and movement known as the Feldenkrais Method. This was created by the engineer and physicist (also a judo teacher), Mosche Feldenkrais (1904-1984). I will show how this Method can impact upon creative practice referring to the ways in which this was articulated at two conferences held at the University of West London in 2016 and 2017

Diagnosing space telescope misalignment and jitter using stellar images

Accurate knowledge of the telescope's point spread function (PSF) is essential for the weak gravitational lensing measurements that hold great promise for cosmological constraints. For space telescopes, the PSF may vary with time due to thermal drifts in the telescope structure, and/or due to jitter in the spacecraft pointing (ground-based telescopes have additional sources of variation). We describe and simulate a procedure for using the images of the stars in each exposure to determine the misalignment and jitter parameters, and reconstruct the PSF at any point in that exposure's field of view. The simulation uses the design of the SNAP (http://snap.lbl.gov) telescope. Stellar-image data in a typical exposure determines secondary-mirror positions as precisely as $20 {\rm nm}$. The PSF ellipticities and size, which are the quantities of interest for weak lensing are determined to $4.0 \times 10^{-4}$ and $2.2 \times 10^{-4}$ accuracies respectively in each exposure, sufficient to meet weak-lensing requirements. We show that, for the case of a space telescope, the PSF estimation errors scale inversely with the square root of the total number of photons collected from all the usable stars in the exposure.Comment: 20 pages, 6 figs, submitted to PAS

Microscopic mechanisms of thermal and driven diffusion of non rigid molecules on surfaces

The motion of molecules on solid surfaces is of interest for technological applications such as catalysis and lubrication, but it is also a theoretical challenge at a more fundamental level. The concept of activation barriers is very convenient for the interpretation of experiments and as input for Monte Carlo simulations but may become inadequate when mismatch with the substrate and molecular vibrations are considered. We study the simplest objects diffusing on a substrate at finite temperature $T$, namely an adatom and a diatomic molecule (dimer), using the Langevin approach. In the driven case, we analyse the characteristic curves, comparing the motion for different values of the intramolecular spacing, both for T=0 and $T\ne 0$. The mobility of the dimer is higher than that of the monomer when the drift velocity is less than the natural stretching frequency. The role of intramolecular excitations is crucial in this respect. In the undriven case, the diffusive dynamics is considered as a function of temperature. Contrary to atomic diffusion, for the dimer it is not possible to define a single, temperature independent, activation barrier. Our results suggest that vibrations can account for drastic variations of the activation barrier. This reveals a complex behaviour determined by the interplay between vibrations and a temperature dependent intramolecular equilibrium length.Comment: 6 pages, 5 figures, Proceeding of the EMRS 2002 Conference, to be published in Thin Solid Film

Emerging Evidence for MicroRNAs as Regulators of Cancer Stem Cells

Cancer stem cells are defined as a subpopulation of cells within a tumor that are capable of self-renewal and differentiation into the heterogeneous cell lineages that comprise the tumor. Many studies indicate that cancer stem cells may be responsible for treatment failure and relapse in cancer patients. The factors that regulate cancer stem cells are not well defined. MicroRNAs (miRNAs) are small non-coding RNAs that regulate translational repression and transcript degradation. miRNAs play a critical role in embryonic and inducible pluripotent stem cell regulation and emerging evidence supports their role in cancer stem cell evolution. To date, miRNAs have been shown to act either as tumor suppressor genes or oncogenes in driving critical gene expression pathways in cancer stem cells in a wide range of human malignancies, including hematopoietic and epithelial tumors and sarcomas. miRNAs involved in cancer stem cell regulation provide attractive, novel therapeutic targets for cancer treatment. This review attempts to summarize progress to date in defining the role of miRNAs in cancer stem cells

Ewald methods for inverse power-law interactions in tridimensional and quasi-two dimensional systems

In this paper, we derive the Ewald method for inverse power-law interactions in quasi-two dimensional systems. The derivation is done by using two different analytical methods. The first uses the Parry's limit, that considers the Ewald methods for quasi-two dimensional systems as a limit of the Ewald methods for tridimensional systems, the second uses Poisson-Jacobi identities for lattice sums. Taking into account the equivalence of both derivations, we obtain a new analytical Fourier transform intregral involving incomplete gamma function. Energies of the generalized restrictive primitive model of electrolytes ($\eta$-RPM) and of the generalized one component plasma model ($\eta$-OCP) are given for the tridimensional, quasi-two dimensional and monolayers systems. Few numerical results, using Monte-Carlo simulations, for $\eta$-RPM and $\eta$-OCP monolayers systems are reported.Comment: to be published in Journal of Physics A: Mathematical and Theoretical (19 pages, 2 figures and 3 tables

Exact results for the reactivity of a single-file system

We derive analytical expressions for the reactivity of a Single-File System with fast diffusion and adsorption and desorption at one end. If the conversion reaction is fast, then the reactivity depends only very weakly on the system size, and the conversion is about 100%. If the reaction is slow, then the reactivity becomes proportional to the system size, the loading, and the reaction rate constant. If the system size increases the reactivity goes to the geometric mean of the reaction rate constant and the rate of adsorption and desorption. For large systems the number of nonconverted particles decreases exponentially with distance from the adsorption/desorption end.Comment: 4 pages, 2 figure

Southern Cross Soloists 2017 Concert Season

Ensemble in Residence at the Queensland Performing Arts Centre, the Southern Cross Soloists present three concerts with guest performers Damien Beaumont (presenter) and Alexandra Flood (soprano). Featuring music of all periods from the history of Western art music up to today, with new works by Australian composers Elena Kats-Chernin and John Rotar

Fast diffusion of a Lennard-Jones cluster on a crystalline surface

We present a Molecular Dynamics study of large Lennard-Jones clusters evolving on a crystalline surface. The static and the dynamic properties of the cluster are described. We find that large clusters can diffuse rapidly, as experimentally observed. The role of the mismatch between the lattice parameters of the cluster and the substrate is emphasized to explain the diffusion of the cluster. This diffusion can be described as a Brownian motion induced by the vibrationnal coupling to the substrate, a mechanism that has not been previously considered for cluster diffusion.Comment: latex, 5 pages with figure

Southern Cross Soloists Season 2016

Ensemble in Residence at the Queensland Performing Arts Centre, Southern Cross Soloists present three concerts: Forbidden Love (with Jack Liebeck, Violin)– 20th March 2016 at 3pm Visions of Earth (with William Barton, Didjeridu)– 19th June 2016 at 3pm Heavenly Voice (with Sara Macliver, Soprano)– 27th November 2016 at 3p