Stationary and non-stationary fluid flow of a Bose-Einstein condensate through a penetrable barrier

We experimentally study the fluid flow induced by a broad, penetrable barrier moving through an elongated dilute gaseous Bose-Einstein condensate. The barrier is created by a laser beam swept through the condensate, and the resulting dipole potential can be either attractive or repulsive. We examine both cases and find regimes of stable and unstable fluid flow: At slow speeds of the barrier, the fluid flow is stationary due to the superfluidity of the condensate. At intermediate speeds, we observe a non-stationary regime in which the condensate gets filled with dark solitons. At faster speeds, soliton formation completely ceases and a remarkable absence of excitation in the condensate is seen again.Comment: 4 pages, 4 figure

Capital Region Climate Change Forum: Citizens' Report

The Capital Region Climate Change Forum was organised, facilitated and evaluated by the Institute for Sustainable Futures (ISF) at the University of Technology, Sydney (UTS). The NSW Greenhouse Office and the ACT Department of Territory and Municipal Services provided funding for the Forum. The Forum was held from Friday 1 December to Sunday 3 December 2006. The primary objectives of the Forum were to: * Test the use of a citizens jury as a way of helping the community to engage with the issue of climate change and develop informed recommendations on how to respond * Provide the NSW and ACT Governments with a greater understanding of how the community in the Capital Region would like to respond to climate change * Improve understanding of community perspectives on climate change more broadly. The Forum grew out of an earlier proposal for a National Conversation on Climate Change (NCCC), developed by ISF. The NCCC proposal is provided in Appendix A. The aim of the NCCC is to stimulate public debate on Australia's response to climate change by undertaking a series of high profile citizen forums in all Australian states and developing an associated website and other media outputs. It seeks to promote public deliberation on climate change response. Deliberation is an approach to decision making in which citizens consider relevant facts from multiple points of view, converse with one another to think critically about options before them and enlarge their perspectives, opinions and understandings. In a deliberative process, participants are provided with information, training, time and other resources to allow them to learn about and debate an issue and come to a considered view. A deliberative process acts as a capacity building exercise in which non expert members of the community are empowered to discuss and form valid opinions about the subject

Animal, Plant, Collagen and Blended Dietary Proteins: Effects on Musculoskeletal Outcomes

This is the final version. Available from MDPI via the DOI in this record.Dietary protein is critical for the maintenance of musculoskeletal health, whereappropriate intake (i.e., source, dose, timing) can mitigate declines in muscle and bone mass and/orfunction. Animal-derived protein is a potent anabolic source due to rapid digestion and absorptionkinetics stimulating robust increases in muscle protein synthesis and promoting bone accretion andmaintenance. However, global concerns surrounding environmental sustainability has led to anincreasing interest in plant- and collagen-derived protein as alternative or adjunct dietary sources.This is despite the lower anabolic profile of plant and collagen protein due to the inferior essentialamino acid profile (e.g., lower leucine content) and subordinate digestibility (versus animal). Thisreview evaluates the efficacy of animal-, plant- and collagen-derived proteins in isolation, and asprotein blends, for augmenting muscle and bone metabolism and health in the context of ageing,exercise and energy restriction.Medical Research Council (MRC)National Institute for Health Researc

Independent control of polar and azimuthal anchoring

Monte Carlo simulation, experiment and continuum theory are used to examine the anchoring exhibited by a nematic liquid crystal at a patterned substrate comprising a periodic array of rectangles that, respectively, promote vertical and planar alignment. It is shown that the easy axis and effective anchoring energy promoted by such surfaces can be readily controlled by adjusting the design of the pattern. The calculations reveal rich behavior: for strong anchoring, as exhibited by the simulated system, for rectangle ratios $\geq 2$ the nematic aligns in the direction of the long edge of the rectangles, the azimuthal anchoring coefficient changing with pattern shape. In weak anchoring scenarios, however, including our experimental systems, preferential anchoring is degenerate between the two rectangle diagonals. Bistability between diagonally-aligned and edge-aligned arrangement is predicted for intermediate combinations of anchoring coefficient and system length-scale.Comment: 12 pages, 12 figure

T1T_1- and T2T_2-spin relaxation time limitations of phosphorous donor electrons near crystalline silicon to silicon dioxide interface defects

A study of donor electron spins and spin--dependent electronic transitions involving phosphorous ($^{31}$P) atoms in proximity of the (111) oriented crystalline silicon (c-Si) to silicon dioxide (SiO$_{2}$) interface is presented for [$^{31}$P] = 10$^{15}$ $\mathrm{cm}^{-3}$ and [$^{31}$P] = 10$^{16}$ $\mathrm{cm}^{-3}$ at about liquid $^4$He temperatures ($T = 5$ $\mathrm{K} - 15$ $\mathrm{K}$). Using pulsed electrically detected magnetic resonance (pEDMR), spin--dependent transitions between the \Phos donor state and two distinguishable interface states are observed, namely (i) \Pb centers which can be identified by their characteristic anisotropy and (ii) a more isotropic center which is attributed to E$^\prime$ defects of the \sio bulk close to the interface. Correlation measurements of the dynamics of spin--dependent recombination confirm that previously proposed transitions between \Phos and the interface defects take place. The influence of these electronic near--interface transitions on the \Phos donor spin coherence time $T_2$ as well as the donor spin--lattice relaxation time $T_1$ is then investigated by comparison of spin Hahn--echo decay measurements obtained from conventional bulk sensitive pulsed electron paramagnetic resonance and surface sensitive pEDMR, as well as surface sensitive electrically detected inversion recovery experiments. The measurements reveal that both $T_2$ and $T_1$ of \Phos donor electrons spins in proximity of energetically lower interface states at $T\leq 13$ K are reduced by several orders of magnitude

Proliferation of private online healthcare companies:Should the NHS try to keep up?

With an app for just about everything, why not one for contacting your doctor? In the United Kingdom, private companies offering primary healthcare are proliferating, with Dr Morton, a website offering email or telephone consultations, and Dr Now, a smartphone app offering video consultations. Companies in the United States are offering an Uber-type experience, where instead of a car, a doctor appears at your door. These companies operate in a climate where patients want convenience, flexibility, and speed of access, features which overstretched general practitioners in the UK are struggling to provide. Meanwhile, new companies are appearing regularly, with the UK digital health market currently worth £2bn (€2.6bn; $2.8bn) and expected to grow to £2.9bn by 2018.2 What are the implications for the NHS

Mechanism, dynamics, and biological existence of multistability in a large class of bursting neurons

Multistability, the coexistence of multiple attractors in a dynamical system, is explored in bursting nerve cells. A modeling study is performed to show that a large class of bursting systems, as defined by a shared topology when represented as dynamical systems, is inherently suited to support multistability. We derive the bifurcation structure and parametric trends leading to multistability in these systems. Evidence for the existence of multirhythmic behavior in neurons of the aquatic mollusc Aplysia californica that is consistent with our proposed mechanism is presented. Although these experimental results are preliminary, they indicate that single neurons may be capable of dynamically storing information for longer time scales than typically attributed to nonsynaptic mechanisms.Comment: 24 pages, 8 figure

Surfing, sweeping, and assembly of particles by a moving liquid crystal phase boundary

Non-equilibrium transport of particles embedded in a liquid crystal host can, by cooling through a phase transition, be exploited to create a remarkable variety of structures including shells, foams, and gels. Due to the complexity of the multicomponent system and protocol-dependent experimental results, the physical mechanisms behind structure selection remain only partially understood. Here we formulate a new model coupling LC physics to a Fokker-Planck equation as is commonly used in studies of transport. The resulting model allows us to draw an analogy between the LC-nanocomposite system and chemotaxis, enriching the space of possible target structures that could be produced. We study the model in one dimension both analytically and numerically to identify different parameter regimes where soliton-like pulses of particles ``surf'' the phase boundary or where the interface ``sweeps'' particles from one domain to another. We also consider an extended model that includes agglomeration of the particles and observe formation of periodic structures as a prototypical example of hierarchical self assembly. Results are compared with experimental observations of transport by isolated phase boundaries.Comment: 11 pages, 6 figure