Experimental Lagrangian Acceleration Probability Density Function Measurement

We report experimental results on the acceleration component probability distribution function at $R_\lambda = 690$ to probabilities of less than $10^{-7}$. This is an improvement of more than an order of magnitude over past measurements and allows us to conclude that the fourth moment converges and the flatness is approximately 55. We compare our probability distribution to those predicted by several models inspired by non-extensive statistical mechanics. We also look at acceleration component probability distributions conditioned on a velocity component for conditioning velocities as high as 3 times the standard deviation and find them to be highly non-Gaussian.Comment: submitted for the special issue of Physica D: "Anomalous Distributions" 11 pages, 6 figures revised version: light modifications of the figures and the tex

Detection of a strong transient blue-shifted absorption component in the beta Pictoris disk

We present high-resolution spectra (1.0 km s-1 FWHM) of the circumstellar Ca K line towards ß Pictoris obtained on 1997 June 19 and 20. On the former date a strong absorption component was found at a heliocentric velocity of vhelio = +8 km s-1, that is blueshifted by 14 km s-1 with respect to the main, ‘stable’, circumstellar component at vhelio = +22 km s-1. To our knowledge, this is the first detection of a blueshifted Ca II component with a strength comparable to the more frequently observed redshifted events. On the following night a blueshifted component was still present, but its strength had decreased significantly; in addition, a strong redshifted component had appeared at vhelio = +54 km s-1 which was absent on the previous night. The implications of these observations for the evaporating ‘comet’ model of spectral variations in the ß Pictoris disc are discussed

Ultra-high-resolution observations of Ca K line variations in the β Pictoris disc

We present observations of the β Pictoris circumstellar Ca II K line, obtained with the new Ultra-High-Resolution facility (UHRF) at the Anglo-Australian Telescope. The resolving power was R≳900000⁠, and these data therefore comprise the highest resolution observations yet obtained of this object. Observations were obtained on three nights in 1993 (May 11, August 26 and August 29), and significant temporal variability was observed, including previously unobserved changes in the profile of the main circumstellar component

Alginate-based hydrogels functionalised at the nanoscale using layer-by-layer assembly for potential cartilage repair

Injuries to articular cartilage are frequently difficult to repair, in part because of the poor regenerative capacity of this tissue. To date, no successful system for complete regeneration of the most challenging cartilage defects has been demonstrated. The aim of this work was to develop functionalised hydrogels at the nanoscale by Layer-by-Layer (LbL) assembly to promote cartilage healing. Hydrogels, based on sodium alginate (NaAlg) and gelatin (G), were prepared by an external gelation method consisting of CaCl2 diffusion and genipin addition for G crosslinking. Successively, hydrogels were coated with G to obtain a positive charge on the surface, then functionalised by LbL assembly to create 16 nanolayers, based on poly(styrene sulfonate)/poly(allyl amine) (PSS/PAH), including a specific peptide sequence (CTATVHL) and transforming growth factors β1 (TGF-β1). Physico-chemical properties were evaluated by XPS, ATR-FTIR and rheological analyses while in vitro cytocompatibility was studied using bovine articular chondrocytes (BAC). XPS spectra showed N1s and S2p peaks, indicating that PAH and PSS have been introduced with success. ATR-FTIR indicated the specific PAH and PSS absorption peaks. Finally, the biomolecule incorporation influenced positively the processes of BAC adhesion and proliferation, and glycosamynoglycan secretion. The functionalised alginate-based hydrogels described here are ideally suited to chondral regeneration in terms of their integrity, stability, and cytocompatibility

Singular Potentials and Limit Cycles

We show that a central $1/r^n$ singular potential (with $n\geq 2$) is renormalized by a one-parameter square-well counterterm; low-energy observables are made independent of the square-well width by adjusting the square-well strength. We find a closed form expression for the renormalization-group evolution of the square-well counterterm.Comment: 15 pages LaTex, 5 eps figures, error in figures and text correcte

A method and tool for ‘cradle to grave’ embodied energy and carbon impacts of UK buildings in compliance with the new TC350 standards

As operational impacts from buildings are reduced, embodied impacts are increasing. However, the latter are seldom calculated in the UK; when they are, they tend to be calculated after the building has been constructed, or are underestimated by considering only the initial materials stage. In 2010, the UK Government recommended that a standard methodology for calculating embodied impacts of buildings be developed for early stage design decisions. This was followed in 2011–12 by the publication of the European TC350 standards defining the ‘cradle to grave’ impact of buildings and products through a process Life Cycle Analysis. This paper describes a new whole life embodied carbon and energy of buildings (ECEB) tool, designed as a usable empirical-based approach for early stage design decisions for UK buildings. The tool complies where possible with the TC350 standards. Initial results for a simple masonry construction dwelling are given in terms of the percentage contribution of each life cycle stage. The main difficulty in obtaining these results is found to be the lack of data, and the paper suggests that the construction and manufacturing industries now have a responsibility to develop new data in order to support this task

Distinctive diets of eutherian predators in Australia

Introduction of the domestic cat and red fox has devastated Australian native fauna. We synthesized Australian diet analyses to identify traits of prey species in cat, fox and dingo diets, which prey were more frequent or distinctive to the diet of each predator, and quantified dietary overlap. Nearly half (45%) of all Australian terrestrial mammal, bird and reptile species occurred in the diets of one or more predators. Cat and dingo diets overlapped least (0.64 ± 0.27, n = 24 location/time points) and cat diet changed little over 55 years of study. Cats were more likely to have eaten birds, reptiles and small mammals than foxes or dingoes. Dingo diet remained constant over 53 years and constituted the largest mammal, bird and reptile prey species, including more macropods/potoroids, wombats, monotremes and bandicoots/bilbies than cats or foxes. Fox diet had greater overlap with both cats (0.79 ± 0.20, n = 37) and dingoes (0.73 ± 0.21, n = 42), fewer distinctive items (plant material, possums/gliders) and significant spatial and temporal heterogeneity over 69 years, suggesting the opportunity for prey switching (especially of mammal prey) to mitigate competition. Our study reinforced concerns about mesopredator impacts upon scarce/threatened species and the need to control foxes and cats for fauna conservation. However, extensive dietary overlap and opportunism, as well as low incidence of mesopredators in dingo diets, precluded resolution of the debate about possible dingo suppression of foxes and cats

“I wouldn’t know what to do with the breasts”: the impact of patient gender on medical student confidence and comfort in clinical skills

Background: Previous research has found a relationship between students’ gender and attitudes surrounding peer physical examination, but relationship between patient gender and confidence/comfort is less clear. We explored whether patient gender affects medical students’ levels of confidence and comfort in clinical examination skills. Methods: An electronic survey and focus groups were conducted with medical students from one UK institution. Students reported levels of confidence/comfort when carrying out clinical examinations on men/women. An inductive thematic analysis was performed. Results:    Of a total of 1500 students provided with the opportunity to participate, ninety (6%) responded. For cardiovascular and respiratory examinations, confidence/comfort were higher when examining male-presenting patients. The opposite was true for mental state examinations. Barriers to confidence/comfort included perceiving males as a norm, difficulty navigating breasts, tutors’ internalised gendered attitudes and a wider sociocultural issue. Facilitators of confidence/comfort included students relating to patients, embodying a professional role, gender blindness, and authentic clinical environments. Fewer than 20% (n = 18) of students felt they had enough opportunity to practice clinical skills on women, versus 90% (n = 82) on men. Conclusion: Our study identified an area where students’ confidence and comfort in clinical examinations could be enhanced within medical education. Changes were implemented in the institution under study’s vocational skills teaching, which is rooted in general practice. Information on gender and clinical skills was provided within course handbooks, time was scheduled to discuss gender and clinical skills in small group settings, and equitable gender representation was ensured in clinical assessment

Optical emission line nebulae in galaxy cluster cores 1: the morphological, kinematic and spectral properties of the sample

We present an Integral Field Unit survey of 73 galaxy clusters and groups with the VIsible Multi Object Spectrograph on the Very Large Telescope. We exploit the data to determine the H α gas dynamics on kpc scales to study the feedback processes occurring within the dense cluster cores. We determine the kinematic state of the ionized gas and show that the majority of systems (∼2/3) have relatively ordered velocity fields on kpc scales that are similar to the kinematics of rotating discs and are decoupled from the stellar kinematics of the brightest cluster galaxy. The majority of the H α flux (>50 per cent) is typically associated with these ordered kinematics and most systems show relatively simple morphologies suggesting they have not been disturbed by a recent merger or interaction. Approximately 20 per cent of the sample (13/73) have disturbed morphologies which can typically be attributed to active galactic nuclei activity disrupting the gas. Only one system shows any evidence of an interaction with another cluster member. A spectral analysis of the gas suggests that the ionization of the gas within cluster cores is dominated by non-stellar processes, possibly originating from the intracluster medium itself