Methods for suspensions of passive and active filaments

Flexible filaments and fibres are essential components of important complex fluids that appear in many biological and industrial settings. Direct simulations of these systems that capture the motion and deformation of many immersed filaments in suspension remain a formidable computational challenge due to the complex, coupled fluid--structure interactions of all filaments, the numerical stiffness associated with filament bending, and the various constraints that must be maintained as the filaments deform. In this paper, we address these challenges by describing filament kinematics using quaternions to resolve both bending and twisting, applying implicit time-integration to alleviate numerical stiffness, and using quasi-Newton methods to obtain solutions to the resulting system of nonlinear equations. In particular, we employ geometric time integration to ensure that the quaternions remain unit as the filaments move. We also show that our framework can be used with a variety of models and methods, including matrix-free fast methods, that resolve low Reynolds number hydrodynamic interactions. We provide a series of tests and example simulations to demonstrate the performance and possible applications of our method. Finally, we provide a link to a MATLAB/Octave implementation of our framework that can be used to learn more about our approach and as a tool for filament simulation

COMPARISON OF THE INFLUENCE OF THREE TYPES OF MILITARY BOOT INSOLE UPON THE FORCE AND LOADING RATES EXPERIENCED IN DROP JUMP LANDING

Eight male subjects performed drop jumps from a 0.8 m high platform onto a force plate and landing forces were sampled at 1000Hz. Six jumps were completed wearing military boots fitted with three different insoles (Saran, Poron and Sorbathane), and also when barefoot. Comparison of the last five jumps in each case showed that mean peak forces were similar (7.5 BW) for all insoles, though the forefoot impact mean (±SE) loading rate was higher for Sorbathane (754 ± 77 BWs-1) than for Saran (552 ± 58 BWs-1) or Poron (636 ± 77BWs-1). Mean peak loading rates for Poron, Saran and Sorbathane from forefoot to heel contact were similar for Saran (249 BWs-1) and Poron (254 BWs-1) and slightly higher for Sorbathane (300 BWs-1). Barefoot peak forces and both forefoot impact and peak loading rate were less than when a boot was worn with an insole

Ruchazie Family Centre - Evaluation, Year 1 Report 2015-2016

In 2014 the Quarriers were funded by the Big Lottery Fund (BLF) to extend their work at the Ruchazie family centre to engage more widely with parents/carers and their children. The University of Stirling was commissioned in 2015 to evaluate the programme between 2015-2019. This report is based on our initial findings from our work in the first year of the evaluation programme

“Any d*** can make a baby, but it takes a real man to be a dad”: group work for fathers

This article contributes to debates about fathers in social work by examining a group work intervention for fathers in Scotland. We present findings from observations of the ‘dad’s group’ and interviews with seven fathers and staff members. Participating in the dad’s group was found to be an expanded perception and expression of masculinity and fatherhood. The group provided a platform for the men to define and challenge understandings of fatherhood in which they developed a sense of expertise and self-belief as individuals and as fathers. We provide examples of the way that the men manoeuvre against societal barriers, in the context of disadvantage, unemployment and persistent mental health difficulties and prevailing gendered stereotypes and allow the fluid expression of manhood through engaging with non-masculine activities. In consideration of policy and practice implications, we argue that parenting support such as group work for fathers are crucial to improve parenting skills and wellbeing and positive outcomes for children. Acknowledgments. This research was funded by the Big Lottery. Thanks go to the men, staff and other users of the Family Centre for their willingness to participate in this project. Thanks to Andressa Gadda for her role in data collection, analysis and writing. Thank you to the reviewers for their very helpful and detailed comments

What senior academics can do to support reproducible and open research: a short, three-step guide

Increasingly, policies are being introduced to reward and recognise open research practices, while the adoption of such practices into research routines is being facilitated by many grassroots initiatives. However, despite this widespread endorsement and support, open research is yet to be widely adopted, with early career researchers being the notable exception. For open research to become the norm, initiatives should engage academics from all career stages, particularly senior academics (namely senior lecturers, readers, professors) given their routine involvement in determining the quality of research. Senior academics, however, face unique challenges in implementing policy change and supporting grassroots initiatives. Given that - like all researchers - senior academics are in part motivated by self-interest, this paper lays out three feasible steps that senior academics can take to improve the quality and productivity of their research, that also serve to engender open research. These steps include a) change hiring criteria, b) change how scholarly outputs are credited, and c) change to funding and publishing with open research. The guidance we provide is accompanied by live, crowd-sourced material for further reading

Use of magnetic resonance angiography to select candidates with recently symptomatic carotid stenosis for surgery: systematic review

Objective To determine if sufficient evidence exists to support the use of magnetic resonance angiography as a means of selecting patients with recently symptomatic high grade carotid stenosis for surgery. Design Systematic review of published research on the diagnostic performance of magnetic resonance angiography, 1990-9. Main outcome measures Performance characteristics of diagnostic test. Results 126 potentially relevant articles were identified, but many articles failed to examine die performance of magnetic resonance angiography as a diagnostic test at the surgical decision thresholds used in major clinical trials on endarterectomy. 26 articles were included in a meta-analysis that showed a maximal joint sensitivity and specificity of 99% (95% confidence interval 98% to 100%) for identifying 70-99% stenosis and 90% (81% to 99%) for identifying 50-99% stenosis. Only four articles evaluated contrast enhanced magnetic resonance angiography. Conclusions Magnetic resonance angiography is accurate for selecting patients for carotid endarterectomy at the surgical decision thresholds established in the major endarterectomy trials, but the evidence is not very robust because of the heterogeneity of the studies included. Research is to determine the diagnostic performance of the most recent developments in magnetic resonance angiography, including contrast enhanced techniques, as well as to assess the impact of magnetic resonance angiography on surgical decision making and outcomes

Complement and cytokine response in acute Thrombotic Thrombocytopenic Purpura

Complement dysregulation is key in the pathogenesis of atypical Haemolytic Uraemic Syndrome (aHUS), but no clear role for complement has been identified in Thrombotic Thrombocytopenic Purpura (TTP). We aimed to assess complement activation and cytokine response in acute antibody-mediated TTP. Complement C3a and C5a and cytokines (interleukin (IL)-2, IL-4, IL-6, IL-10, tumour necrosis factor, interferon-γ and IL-17a) were measured in 20 acute TTP patients and 49 remission cases. Anti-ADAMTS13 immunoglobulin G (IgG) subtypes were measured in acute patients in order to study the association with complement activation. In acute TTP, median C3a and C5a were significantly elevated compared to remission, C3a 63·9 ng/ml vs. 38·2 ng/ml (P < 0·001) and C5a 16·4 ng/ml vs. 9·29 ng/ml (P < 0·001), respectively. Median IL-6 and IL-10 levels were significantly higher in the acute vs. remission groups, IL-6: 8 pg/ml vs. 2 pg/ml (P = 0·003), IL-10: 6 pg/ml vs. 2 pg/ml (P < 0·001). C3a levels correlated with both anti-ADAMTS13 IgG (rs  = 0·604, P = 0·017) and IL-10 (rs  = 0·692, P = 0·006). No anti-ADAMTS13 IgG subtype was associated with higher complement activation, but patients with the highest C3a levels had 3 or 4 IgG subtypes present. These results suggest complement anaphylatoxin levels are higher in acute TTP cases than in remission, and the complement response seen acutely may relate to anti-ADAMTS13 IgG antibody and IL-10 levels