Dynamical Systems on Networks: A Tutorial

We give a tutorial for the study of dynamical systems on networks. We focus especially on "simple" situations that are tractable analytically, because they can be very insightful and provide useful springboards for the study of more complicated scenarios. We briefly motivate why examining dynamical systems on networks is interesting and important, and we then give several fascinating examples and discuss some theoretical results. We also briefly discuss dynamical systems on dynamical (i.e., time-dependent) networks, overview software implementations, and give an outlook on the field.Comment: 39 pages, 1 figure, submitted, more examples and discussion than original version, some reorganization and also more pointers to interesting direction

Taking environmental engineering out of the laboratory

Environmental engineering is a core component of most construction and surveying undergraduate courses. It is generally accepted that students on these courses should have an understanding of thermal comfort, heat transfer, condensation, lighting, noise transmission and acoustics. Experiments are essential in developing students’ awareness and understanding of the underlying physical concepts which drive environmental engineering solutions. Traditionally these experiments have been conducted by students working in small groups in laboratories. However, increasing student numbers and, in particular, the growth in part time study, have placed significant additional demands on limited laboratory resources. The availability of reasonably priced, simple, hand-held equipment has made it possible for students to conduct experiments outside the confines of the laboratory. Furthermore, various professional software packages (some of which are freely available online) enable the resultant data to be further developed and analysed in conjunction with the conventional textbook approach. This paper examines these alternative approaches to the traditional laboratory experiment. An assessment is provided of the types of experiment which are both possible and appropriate, and the efficacy of these approaches is considered

Repeated exercise stress impairs volitional but not magnetically evoked electromechanical delay of the knee flexors

The effects of serial episodes of fatigue and recovery on volitional and magnetically evoked neuromuscular performance of the knee flexors were assessed in twenty female soccer players during: (i) an intervention comprising 4x35s maximal static exercise; (ii) a control condition. Volitional peak force (PFV) was impaired progressively (-16 % vs. baseline: 235.3±54.7 to 198.1±38.5 N) by the fatiguing exercise and recovered to within -97 % of baseline values following six-minutes of rest. Evoked peak twitch force (PTFE) was diminished subsequent to the fourth episode of exercise (23.3 %: 21.4±13.8 vs. 16.4±14.6 N) and remained impaired at this level throughout the recovery. Impairment of volitional electromechanical delay performance (EMDV) following the first episode of exercise (25.5 % :55.3±11.9 vs. 69.5±24.5 ms) contrasted with concurrent improvement (10.0 %: 24.5±4.7 vs. 22.1±5.0 ms) in evoked electromechanical delay (EMDE) (p <0.05) and this increased disparity between EMDE and EMDV remained during subsequent periods of intervention and recovery. The fatiguing exercise provoked substantial impairments to volitional strength and EMDV that showed differential patterns of recovery. However, improved EMDE performance might identify a dormant capability for optimal muscle responses during acute stressful exercise and an improved capacity to maintain dynamic joint stabilty during critical episodes of loading

Influence of surgery and rehabilitation conditioning on psychophysiological fitness

The purpose of this study was to assess changes in psychophysiological fitness following reconstructive knee surgery and early phase (2.5 months) physical rehabilitation. Nine patients (7 male, 2 female; mean age, 29.9 years) electing to undergo anterior cruciate ligament reconstructive surgery (central third, bone-patella tendon-bone graft) were assessed on four separate assessment occasions post-surgery. Repeated measures ANOVAs showed significant condition (injured/non-injured leg) by test occasion (2 weeks pre-surgery and 6, 8 and 10 weeks post-surgery) interactions for knee ligamentous compliance (anterior tibiofemoral displacement), peak force and electromechanical delay associated with the knee flexors of the injured and noninjured legs (F3,24 = 4.7 to 6.6; p < 0.01), together with individualized emotional profile disturbance scores that were significantly less at 10 weeks post-surgery compared to pre-surgery, 6 weeks and 8 weeks post-surgery (F3,24 = 7.6; p < 0.01). Spearman rank correlation coefficients identified significant relationships between musculoskeletal fitness and emotional profile scores at pre-surgery (r = 0.69–0.72; p < 0.05) and at 8 weeks post-surgery (r = 0.70–0.73; p < 0.05). The 6 Bi-POMS subscales and the 12 ERAIQ responses found inconsistent patterns of response and relationships across the assessment occasions. Overall, the patterning of changes and associations amongst emotional performance profile discrepancy scores in conjunction with those scores from indices of musculoskeletal fitness performance capability offered important support for the efficacy of an approach which integrates self-perceptive and objective measurements of fitness capability during rehabilitation following surgery to a synovial joint

Constitutional Law - Civil Rights Act - Title VII - Sex Discrimination - Hostile Work Environment Sexual Harassment

The United States Supreme Court held that an employer\u27s conduct need not seriously affect an employee\u27s psychological well-being or cause the employee to suffer tangible injury to be actionable as hostile work environment harassment in violation of Title VII of the Civil Rights Act of 1964. Harris v. Forklift Systems, Inc., 114 S. Ct. 367 (1993)

Using policy analysis to explore the reciprocal impact of health policy on public health nursing and public health nursing on policy.

The overall aim of this study was to explore the reciprocal impact of health policy on public health nursing and public health nursing on policy. This study uses a new approach to considering public health nurses’ engagement in policy: one which puts public health nurses, as actors in the policy process, at the centre of the investigation. The overall philosophical lens through which the research was conducted was critical social theory and the methodology was a grounded theory influenced research design. The study adopted a three stage data collection and analysis process: primary data (questionnaires and interviews), detailed policy analyses of two specific White Papers and secondary data (extant documents). The data were collected and analysed through a grounded theory approach in order to answer four research questions: 1. What do public health nurses know about policy, specifically in relation to two English Department of Health White Papers: Creating A Patient-Led NHS (DOH 2005) and Our Health, Our Care, Our Say (DOH 2006)? 2. How do they engage in the policy process? 3. What affects their implementation of policy? 4. Is there a policy-practice gap? A triangulated approach to data collection and analysis was used. Primary data were collected through questionnaires and follow up telephone interviews with public health nurses (health visitors and school nurses) in four PCTs and one social enterprise in five different geographical areas of England. Further data from detailed policy analyses using frameworks by Popple and Leighninger (2008) and Walt and Gilson (1994) were also considered. Finally, secondary data from extant documents including newspapers, websites and organisational documents were reviewed. At the end of the research process, it was possible to answer the four research questions. In addition to this, new knowledge and theory emerged around three main themes: i) A proposal for a new combined framework for policy analysis which leads to a comprehensive and analytical account of policy content and context combined with a detailed consideration of the role of public health nurses as actors in the policy process. ii) Theories as to why and how public health nurses lack influence in the policy process. iii) Analysis of the effect of lack of resources on inhibiting practice innovation in response to policy agendas. Consideration of these theories led to several recommendations for practice. Throughout the research process, there was continued interaction between the three phases of data collection, analysis and theory development

Nonstandard electroconvection in a bent-core oxadiazole material

Electroconvection (EC) phenomena have been investigated in the nematic phase of a bent-core oxadiazole material with negative dielectric anisotropy and a frequency dependent conductivity anisotropy. The formation of longitudinal roll (LR) patterns is one of the predominant features observed in the complete frequency and voltage range studied. At voltages much above the LR threshold, various complex patterns such as the "crisscrossed" pattern, bimodal varicose, and turbulence are observed. Unusually, the nonstandard EC (ns-EC) instability in this material, is observed in a regime in which we measure the dielectric and conductivity anisotropies to be negative and positive respectively. A further significant observation is that the EC displays distinct features in the high and low temperature regimes of the nematic phase, supporting an earlier report that EC patterns could distinguish between regions that have been reported as uniaxial and biaxial nematic phases

Control of Ship capsize in stern quartering seas.

A non-linear mathematical model for the roll-yaw behaviour of a ship is used to predict capsize of a small tanker which sank in the North Sea some years ago. This capsize problem was initially simulated on an analogue computer by the Danish Maritime Authorities as well as being tank tested. The problem was simulated using the digital package SIMULINK, which produced comparable results indicating instability in waves of just less than 3 m in height. Validation of the results is attempted and a discussion of possible improvements to the model is given. Simulated responses of the tanker with simple hydrodynamic fin stabilisers show that capsize could have been prevented by this means in waves up to 7 m in height. Active PID control using a simple full span elevon is used to show a factor of ten reduction in roll angle to much greater waves. This work is of use to ship designers illustrating that stability can be enhanced for a fraction of the cost of major redesign of the ship hull and can be tailored to load conditions

Learning to become evidence based social workers: student views on research education and implementation in practice

Professional guidelines for social workers in relation to research use in practice, present social workers as consumers, rather than producers of research evidence. This approach aligns with a growing emphasis on the use of evidence-based practice within social work. This paper reports on a small mixed methods study with a cohort of BA social work students (N = 38) with two aims: 1) to understand the experiences of students learning research at undergraduate level and 2) to explore how their learning and placement experiences interact and influence their development as ‘research-minded’ practitioners of the future. Descriptive statistics of the quantitative data and thematic analysis of focus groups are presented. Our findings support the existing literature relating to social work students attitudes to research, including feelings of anxiety and perceptions of difficulty, while also viewing it as important to their careers. We also found that within placement settings, students encounter negative, often dismissive views of research and experience little in the way of role-modelling of evidence-based practice. We consider these findings in light of the promotion of EBP in UK social work, and how this may influence our teaching of research and evidence use to future student cohorts