Spiral strand cables subjected to high velocity fragment impact

Structural cables are widely adopted around the world in offshore construction, sports stadia, large scale bridges, Ferris wheels and suspended canopy and fabric structures. However, the robustness of such structures to blast or impact is uncertain with a particular concern related to the loss of a primary structural cable when damaged by high velocity blast fragmentation. This paper presents the first ever numerical and experimental study on commonly used high-strength steel spiral strand cables subjected to high velocity fragment impact. Spiral strand cables were impacted by 20 mm fragment simulating projectiles travelling at velocities between 200 and 1400 m/s. Complex 3D non-linear finite element models were developed and carefully compared with experimental tests. The penetration resistance of the cables and resultant damage were studied with respect to fragment impact velocity. It was found that for all the impact velocities, the fragment penetration depth was less than half of the cable diameter demonstrating a considerable amount of resilience. Considering the damage caused, the residual cable breaking strengths were estimated and found to be still higher than the minimum breaking load of an un-damaged cable. The numerical models were also able to reproduce the main features of the impact tests, including the extent of localised damage area, the fragment penetration depth and mode of individual wire failures, thus demonstrating their potential to be widely used in industry for structural resilience and robustness assessments by structural engineers

Comparison of Two Detailed Models of Aedes aegypti Population Dynamics

The success of control programs for mosquito-­borne diseases can be enhanced by crucial information provided by models of the mosquito populations. Models, however, can differ in their structure, complexity, and biological assumptions, and these differences impact their predictions. Unfortunately, it is typically difficult to determine why two complex models make different predictions because we lack structured side-­by-­side comparisons of models using comparable parameterization. Here, we present a detailed comparison of two complex, spatially explicit, stochastic models of the population dynamics of Aedes aegypti, the main vector of dengue, yellow fever, chikungunya, and Zika viruses. Both models describe the mosquito?s biological and ecological characteristics, but differ in complexity and specific assumptions. We compare the predictions of these models in two selected climatic settings: a tropical and weakly seasonal climate in Iquitos, Peru, and a temperate and strongly seasonal climate in Buenos Aires, Argentina. Both models were calibrated to operate at identical average densities in unperturbedconditions in both settings, by adjusting parameters regulating densities in each model (number of larval development sites and amount of nutritional resources). We show that the models differ in their sensitivityto environmental conditions (temperature and rainfall) and trace differences to specific model assumptions.Temporal dynamics of the Ae. aegypti populations predicted by the two models differ more markedly under strongly seasonal Buenos Aires conditions. We use both models to simulate killing of larvae and/or adults with insecticides in selected areas. We show that predictions of population recovery by the models differ substantially, an effect likely related to model assumptions regarding larval development and (director delayed) density dependence. Our methodical comparison provides important guidance for model improvement by identifying key areas of Ae. aegypti ecology that substantially affect model predictions, and revealing the impact of model assumptions on population dynamics predictions in unperturbed and perturbed conditions.Fil: Legros, Mathieu. University of North Carolina; Estados UnidosFil: Otero, Marcelo Javier. Universidad de Buenos Aires; ArgentinaFil: Romeo Aznar, Victoria Teresa. Universidad de Buenos Aires; ArgentinaFil: Solari, Hernan Gustavo. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Gould, Fred. National Institutes of Health; Estados UnidosFil: Lloyd, Alun L.. National Institutes of Health; Estados Unido

Exploring the importance of ‘sustainability principles’ for dietetic practice and how to streamline these into the dietetic curriculum- a scoping review of the possibilities

This small-scale scoping project aimed to explore how ‘sustainability’ is understood within the dietetic profession and curriculum, and how ‘sustainability principles’ can be better embedded. Background/context to project: Understanding the many complexities of the human, social and ecological implications of climate change and their impact on the food system and food security is a real challenge for the dietetic profession. The evidence base for this emerging area needs, therefore, to be strengthened to ensure the profession is fully equipped with the competencies and skills required to embrace these wider ecological issues. This small scale exploratory project provides a starting point for developing more robust research into the future. Methods used: 1. Scoping review (summer 2016) which included: a. Straw poll of Dietitians in UK via LinkedIn b. Literature review carried out by initially appointed RA c. International Congress of Dietetics interactive workshop (which included a survey of n=48 international dietitians on their views on sustainability) – this was a complementary arm of funded study so will not be outlined here (but is included in draft publication) 2. A participatory student workshop with Level 6 dietetic students at Plymouth University was run in October 2016 to ‘explore dietetic student views and ideas on the importance of sustainability principles broadly and where they should fit within the curriculum’. This workshop consisted of four complementary strands: (i) delivery of key learning materials; (ii) interactive survey; (iii) group work activity; and (iv) plenary discussion. Analysis is ongoing and involves generation of basic categories and themes

Expression of the androgen receptor and an androgen-responsive protein, apolipoprotein D, in human breast cancer.

Little is known regarding the activity and function of the androgen receptor (AR) in human breast cancer. In the present study AR was evaluated in untreated primary breast cancers using antisera to the amino- and carboxy-termini of the receptor and quantitated using colour video image analysis. A strong correlation between tissue concentration and percentage AR-positive cells was observed for each antiserum. However, comparison of percentage positive cells using the amino- and carboxy-terminal AR antisera in individual breast cancer specimens revealed a subset of tumours with discordantly increased staining for the carboxy terminus. These findings suggest the presence of amino-terminal-truncated AR in a proportion of breast cancer cells or presence of AR mutations or associated protein alterations that affect binding of the amino-terminal AR antiserum. Immunohistochemical expression of the androgen-regulated glycoprotein, apolipoprotein D (apo-D), was also evaluated in the breast cancer specimens. Focal positivity of apo-D staining, which did not always co-localise with AR-positive cells, was observed within breast tumours. Furthermore, no correlation was evident between percentage positive cells stained for AR and apo-D in breast cancer specimens. These findings indicate that, although apo-D expression is androgen regulated in human breast cancer cell lines in vitro, its expression in primary breast cancers may be regulated by other factors. The expression of AR in primary breast cancers also suggests that the receptor may be involved in tumour responsiveness or in abnormal responses to endocrine therapies

Linear perturbative theory of the discrete cosmological N-body problem

We present a perturbative treatment of the evolution under their mutual self-gravity of particles displaced off an infinite perfect lattice, both for a static space and for a homogeneously expanding space as in cosmological N-body simulations. The treatment, analogous to that of perturbations to a crystal in solid state physics, can be seen as a discrete (i.e. particle) generalization of the perturbative solution in the Lagrangian formalism of a self-gravitating fluid. Working to linear order, we show explicitly that this fluid evolution is recovered in the limit that the initial perturbations are restricted to modes of wavelength much larger than the lattice spacing. The full spectrum of eigenvalues of the simple cubic lattice contains both oscillatory modes and unstable modes which grow slightly faster than in the fluid limit. A detailed comparison of our perturbative treatment, at linear order, with full numerical simulations is presented, for two very different classes of initial perturbation spectra. We find that the range of validity is similar to that of the perturbative fluid approximation (i.e. up to close to ``shell-crossing''), but that the accuracy in tracing the evolution is superior. The formalism provides a powerful tool to systematically calculate discreteness effects at early times in cosmological N-body simulations.Comment: 25 pages, 21 figure

Generating operative workflows for vestibular schwannoma resection: a two-stage Delphi consensus in collaboration with British Skull Base Society. Part 1: the retrosigmoid approach

Objective: An operative workflow systematically compartmentalises operations into hierarchal components of phases, steps, instrument, technique errors and event errors. Operative workflow provides a foundation for education, training, and understanding of surgical variation. In Part 1 we present a codified operative workflow for the retrosigmoid approach to vestibular schwannoma resection. / Methods: A mixed-method consensus process of literature review, small group Delphi consensus, followed by a national Delphi consensus was performed in collaboration with British Skull Base Society (BSBS). Each Delphi round was repeated until data saturation and over 90% consensus was reached. / Results: Eighteen consultant skull base surgeons (10 neurosurgeons; 8 ENT) with median 17.9 years of experience (IQR 17.5 years) of independent practice participated. There was a 100% response rate across both Delphi rounds. The operative workflow for the retrosigmoid approach contained 3 phases and 40 unique steps: Phase 1: approach and exposure; Phase 2: tumour debulking and excision; Phase 3: closure. For the retrosigmoid approach, technique and event error for each operative step was also described. / Conclusions: We present Part 1 of a national, multi-centre, consensus-derived codified operative workflow for the retrosigmoid and approach to vestibular schwannomas that encompasses phases, steps, instruments, technique errors, and event errors. The codified retrosigmoid approach presented in this manuscript can serve as foundational research for future work, such as operative workflow analysis or neurosurgical simulation and education

TRPV4 receptor as a functional sensory molecule in bladder urothelium: Stretch‐independent, tissue‐specific actions and pathological implications

The newly recognized sensory role of bladder urothelium has generated intense interest in identifying its novel sensory molecules. Sensory receptor TRPV4 may serve such function. However, specific and physiologically relevant tissue actions of TRPV4, stretch‐independent responses, and underlying mechanisms are unknown and its role in human conditions has not been examined. Here we showed TRPV4 expression in guinea‐pig urothelium, suburothelium, and bladder smooth muscle, with urothelial predominance. Selective TRPV4 activation without stretch evoked significant ATP release—key urothelial sensory process, from live mucosa tissue, full‐thickness bladder but not smooth muscle, and sustained muscle contractions. ATP release was mediated by Ca2+‐dependent, pannexin/connexin‐conductive pathway involving protein tyrosine kinase, but independent from vesicular transport and chloride channels. TRPV4 activation generated greater Ca2+ rise than purinergic activation in urothelial cells. There was intrinsic TRPV4 activity without exogeneous stimulus, causing ATP release. TRPV4 contributed to 50% stretch‐induced ATP release. TRPV4 activation also triggered superoxide release. TRPV4 expression was increased with aging. Human bladder mucosa presented similarities to guinea pigs. Overactive bladders exhibited greater TRPV4‐induced ATP release with age dependence. These data provide the first evidence in humans for the key functional role of TRPV4 in urothelium with specific mechanisms and identify TRPV4 up‐regulation in aging and overactive bladders