Myosin-5 varies its steps along the irregular F-actin track

Molecular motors employ chemical energy to generate unidirectional mechanical output against a track. By contrast to the majority of macroscopic machines, they need to navigate a chaotic cellular environment, potential disorder in the track and Brownian motion. Nevertheless, decades of nanometer-precise optical studies suggest that myosin-5a, one of the prototypical molecular motors, takes uniform steps spanning 13 subunits (36 nm) along its F-actin track. Here, we use high-resolution interferometric scattering (iSCAT) microscopy to reveal that myosin takes strides spanning 22 to 34 actin subunits, despite walking straight along the helical actin filament. We show that cumulative angular disorder in F-actin accounts for the observed proportion of each stride length, akin to crossing a river on variably-spaced stepping stones. Electron microscopy revealed the structure of the stepping molecule. Our results indicate that both motor and track are soft materials that can adapt to function in complex cellular conditions

Lot sizing and furnace scheduling in small foundries

A lot sizing and scheduling problem prevalent in small market-driven foundries is studied. There are two related decision levels: (1) the furnace scheduling of metal alloy production, and (2) moulding machine planning which specifies the type and size of production lots. A mixed integer programming (MIP) formulation of the problem is proposed, but is impractical to solve in reasonable computing time for non-small instances. As a result, a faster relax-and-fix (RF) approach is developed that can also be used on a rolling horizon basis where only immediate-term schedules are implemented. As well as a MIP method to solve the basic RF approach, three variants of a local search method are also developed and tested using instances based on the literature. Finally, foundry-based tests with a real-order book resulted in a very substantial reduction of delivery delays and finished inventory, better use of capacity, and much faster schedule definition compared to the foundry's own practice. © 2006 Elsevier Ltd. All rights reserved

From tradition to innovation: a comparison of the traditional 4-step approach versus a blended learning modification for technical skills teaching

Bergmans E, Billington A, Thies K-C. From tradition to innovation: a comparison of the traditional 4-step approach versus a blended learning modification for technical skills teaching. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine . 2023;31(1): 80.BACKGROUND: This experimental study was performed to evaluate the role of blended learning for technical skill teaching on the European Trauma Course (ETC). While online modules are extensively used for theoretical teaching, their role in skills training remains less well explored. The ETC currently relies on the established 4-step technique for teaching technical skills. However, the required large cohort of skilled instructors and the time intensity prove increasingly challenging in a current climate of staff shortages and funding constraints. This study assesses if blended learning, combining pre-course online elements with face-to-face training matches the effectiveness of the traditional 4-step approach whilst being more time-efficient.; METHODS: In a randomised, multi-centre trial, the conventional face-to-face 4-step technique for teaching a skill of medium complexity, the application of a pelvic binder, was compared with an innovative blended approach. It was hypothesised that the blended approach was non-inferior for skill performance measured after the teaching session and after two days (skill retention) with the time needed for teaching and student/teacher satisfaction as secondary outcomes.; RESULTS: Ninety participants, divided into 44 traditional and 46 blended method students, were analysed. Independent-samples t-test showed no significant difference in performance scores and non-inferiority of the blended approach with a half of one standard deviation margin. A statistically significant difference in mean retention scores favored the blended approach. A Mann-Whitney U Test revealed no significant difference in candidate satisfaction levels but a statistically significant difference in instructors' satisfaction levels in favour of the blended approach. Analysis with Welch' t-test demonstrated that the face-to-face teaching time needed for the blended approach was significantly shorter (by 6 min).; CONCLUSIONS: The integration of a blended approach with the 4-step technique for teaching pelvic binder application in the ETC streamlined teaching without compromising skill acquisition quality. This innovative approach addresses traditional limitations and shows promise in adapting medical education to modern learning and teaching demands. We suggest that blended learning could also be applied for other skills taught on life support courses.; TRIAL REGISTRATION: University of Dundee (Schools of Medicine and Life sciences Research Ethics Committee, REC number 22/59, 28th June 2022). © 2023. The Author(s)

The European Trauma Course: Transforming systems through training

The European Trauma Course (ETC) exemplifies an innovative approach to multispecialty trauma education. This initiative was started as a collaborative effort among the European Society for Emergency Medicine, the European Society for Trauma and Emergency Surgery, and the European Society of Anaesthesiology under the auspices of the European Resuscitation Council. With the robust support of these societies, the project has evolved into the independent European Trauma Course Organisation. Over the past 15 years, the ETC has transcended traditional training by integrating team dynamics and non-technical skills into a scenario-based simulation course, helping to shape trauma care practice and education. A distinctive feature of the ETC is its training of doctors and allied healthcare professionals, fostering a collaborative and holistic approach to trauma care. The ETC stands out for its unique team-teaching approach, which has gained widespread recognition as the standard for in-hospital trauma care training not only in Europe but also beyond. Since its inception ETC has expanded geographically from Finland to Sudan and from Brazil to the Emirates, training nearly 20,000 healthcare professionals and shaping trauma care practice and education across 25 countries. Experiencing exponential growth, the ETC continues to evolve, reflecting its unmet demand in trauma team education. This review examines the evolution of the ETC, its innovative team-teaching methodology, national implementation strategies, current status, and future challenges. It highlights its impact on trauma care, team training, and the effect on other life support courses in various countrie

Running to stand still: adaptation and the response of plants to rapid climate change

Climate is a potent selective force in natural populations, yet the importance of adaptation in the response of plant species to past climate change has been questioned. As many species are unlikely to migrate fast enough to track the rapidly changing climate of the future, adaptation must play an increasingly important role in their response. In this paper we review recent work that has documented climate-related genetic diversity within populations or on the microgeographical scale. We then describe studies that have looked at the potential evolutionary responses of plant populations to future climate change. We argue that in fragmented landscapes, rapid climate change has the potential to overwhelm the capacity for adaptation in many plant populations and dramatically alter their genetic composition. The consequences are likely to include unpredictable changes in the presence and abundance of species within communities and a reduction in their ability to resist and recover from further environmental perturbations, such as pest and disease outbreaks and extreme climatic events. Overall, a range-wide increase in extinction risk is likely to result. We call for further research into understanding the causes and consequences of the maintenance and loss of climate-related genetic diversity within populations