Time-Dependent 2-D Vector Field Topology: An Approach Inspired by Lagrangian Coherent Structures

This paper presents an approach to a time-dependent variant of the concept of vector field topology for 2-D vector fields. Vector field topology is defined for steady vector fields and aims at discriminating the domain of a vector field into regions of qualitatively different behaviour. The presented approach represents a generalization for saddle-type critical points and their separatrices to unsteady vector fields based on generalized streak lines, with the classical vector field topology as its special case for steady vector fields. The concept is closely related to that of Lagrangian coherent structures obtained as ridges in the finite-time Lyapunov exponent field. The proposed approach is evaluated on both 2-D time-dependent synthetic and vector fields from computational fluid dynamics

Using problem-based learning during student placements to embed theory in practice

Practice placements, a prominent part of the education of health and social care professionals, are strongly validated by theories of adult learning. Being situated in authentic workplaces in contact with people in need, motivation to learn is strong. However, it is not always easy for students to realise the knowledge that practitioners are using in the setting, as it becomes tacit. Problem-based learning (PBL) is a form of student-centred university teaching deliberately structured to support development of students' theoretical understanding, critical thinking, professional reasoning and team skills. PBL is recognised world-wide for its applicability to health and social science curricula, but to date its potential as a method to activate theoretical learning during placements has not been realised.The aim of this masterclass is to inspire and encourage placement educators and students to use PBL as an effective, enjoyable way to structure knowledge development during placement. The outcomes of this paper include appreciation of the rationale and stages of the PBL cycle in a practice environment, and sufficient understanding about how PBL can be used to embed theory in practice to give it a try. Case studies and supervision sessions need to be adjusted a little to explicitly include a self-directed learning stage to develop students' knowledge, illustrated here through a case example. Students identify their own learning needs to guide their independent learning, maximising use of placement time. PBL in practice settings is a flexible approach, applicable to one-to-one situations, with pairs, groups (including inter-professional), and within work-based learning for staff development

Flux-Limited Diffusion for Multiple Scattering in Participating Media

For the rendering of multiple scattering effects in participating media, methods based on the diffusion approximation are an extremely efficient alternative to Monte Carlo path tracing. However, in sufficiently transparent regions, classical diffusion approximation suffers from non-physical radiative fluxes which leads to a poor match to correct light transport. In particular, this prevents the application of classical diffusion approximation to heterogeneous media, where opaque material is embedded within transparent regions. To address this limitation, we introduce flux-limited diffusion, a technique from the astrophysics domain. This method provides a better approximation to light transport than classical diffusion approximation, particularly when applied to heterogeneous media, and hence broadens the applicability of diffusion-based techniques. We provide an algorithm for flux-limited diffusion, which is validated using the transport theory for a point light source in an infinite homogeneous medium. We further demonstrate that our implementation of flux-limited diffusion produces more accurate renderings of multiple scattering in various heterogeneous datasets than classical diffusion approximation, by comparing both methods to ground truth renderings obtained via volumetric path tracing.Comment: Accepted in Computer Graphics Foru

Proposal for Strategic Planning for Solid Waste Management in Lewiston, ME

The city of Lewiston currently has excellent provisions for the disposal of solid waste, making waste disposal for citizens a relatively cheap and efficient process. Solid waste is picked up from residences and then sent to Mid Maine Waste Action Corporation (MMWAC). From there, it is turned into ash and then dumped into the Lewiston landfill. Now over 25 years old, municipal officials are concerned about the long term viability of these current arrangements. After being introduced to the current situation by municipal officials and local politicians, the goals of our project were three-fold: 1. Understand the history of waste management in Lewiston and overall patterns of behavior when dealing with waste 2. Understand how other cities with similar characteristics to Lewiston have implemented successful education programs 3. Create a list of suggestions or programs that address the identified complexities within the municipal solid waste system By focusing on these goals, we conducted relevant research that looked at various points of intervention within the system that would have the potential impact of reducing the amount of overall waste being sent to MMWAC and into the landfill. We talked to relevant public officials and professionals to gather the necessary information about the Lewiston waste system. The combined perspectives and knowledge from each of these informants coincided with our own research has guided us towards a number of potential solutions for improving waste practices in Lewiston. We have concluded that creating an education program in schools is the best place to start in the short term in order to begin changing waste management practices at a basic level. To this extent, we selected two primary schools in Lewiston, Geiger and McMahon, to implement programs and curriculum additions that would foster greater environmental awareness and more sustainable waste management practices. In the long term, we feel that implementing a waste reduction program based on economic incentives, such as variable rate pricing, is the best way to increase recycling habits among Lewiston residents. By proposing one short term and long term program, we aim to not only attempt to change the education system as a short term goal, but then offer a broader program that addresses the city of Lewiston as a whole. The programs in schools begin to address recycling behaviors so that when a situation emerges that does call for the implementation of incentive based recycling, Lewiston city residents will be better informed about the program’s benefits

Transport in Transitory, Three-Dimensional, Liouville Flows

We derive an action-flux formula to compute the volumes of lobes quantifying transport between past- and future-invariant Lagrangian coherent structures of n-dimensional, transitory, globally Liouville flows. A transitory system is one that is nonautonomous only on a compact time interval. This method requires relatively little Lagrangian information about the codimension-one surfaces bounding the lobes, relying only on the generalized actions of loops on the lobe boundaries. These are easily computed since the vector fields are autonomous before and after the time-dependent transition. Two examples in three-dimensions are studied: a transitory ABC flow and a model of a microdroplet moving through a microfluidic channel mixer. In both cases the action-flux computations of transport are compared to those obtained using Monte Carlo methods.Comment: 30 pages, 16 figures, 1 table, submitted to SIAM J. Appl. Dyn. Sy

From Trepidation to Transformation: Strategies Used by Occupational Therapy Students on Role-Emerging Placements

To prepare graduates for the diverse practice contexts in which they may work in the future, role-emerging placements are increasingly being used within curricula. Literature highlights the benefits and challenges of such placements but there has been little research to examine how students manage and overcome these challenges. Interpretative phenomenological analysis (IPA) was used to gain a deeper understanding of how five MSc pre-registration occupational therapy students coped with the challenges of undertaking a role-emerging placement. Interviews were carried out and analysed using IPA guidelines. The students utilised personal attributes, reflection, supervision, communities of practice, peer support and experiential learning to help them cope with, and overcome, the placement challenges. This enabled them to take ownership of their own learning and development, leading to positive placement outcomes. We conclude that students need to be encouraged to use and develop a range of strategies to overcome challenges of role-emerging placements. The findings build on existing accounts of students’ experiences of role-emerging placements by providing deeper insights into the strategies they use to help them manage such placements successfully. Recommendations for further research are highlighted. Suggestions for placement preparation to facilitate students’ coping strategies are made

Medical exercise in low-back pain

Križobolja se definira kao bol, mišićna napetost i nelagoda u području tijela između donjega rebrenog luka i donje glutealne brazde, sa širenjem u nogu ili bez. Možemo ju podijeliti na specifičnu, kojoj je uzrok neka destruktivna bolest ili neurološki deficit uzrokovan, primjerice hernijom intravertebralnog diska, i nespecifičnu, kojoj ne možemo naći uzrok. S obzirom na dužinu trajanja, križobolju možemo podijeliti na akutnu, trajanja do 3 mjeseca i kroničnu, trajanja duže od 3 mjeseca. Križobolja je pravi primjer multifaktorske bolesti, a čimbenike rizika možemo podijeliti na individualne, one povezane s opterećenjem te na psihosocijalne čimbenike. Predstavlja jedan od najučestalijih problema današnjice i veliki zdravstveni problem suvremenog svijeta. U načelu, akutna i kronična križobolja liječe se različito. Glavni je cilj liječenja akutne križobolje smanjenje boli, dok je na prvom mjestu kod kronične križobolje obnavljanje funkcije, čak i u slučaju perzistiranja boli. Medicinske su vježbe neizostavan dio prevencije i liječenja bolesnika s križoboljom. Postoje razne vrste vježbi, a sve se baziraju na određenom stupnju mišićne aktivnosti s ciljem otklanjanja bola i poboljšanja funkcije. Budući da su uzroci križobolje različiti, kao i individualne osobine svakog bolesnika, tako su i različite vježbe koje se rabe, te ne postoji univerzalni skup vježbi primjenjiv za svakog bolesnika. Cilj je ovog preglednog rada sistematizirati rezultate dosadašnjih istraživanja o razlogu, načinu i rezultatima provođenja medicinskih vježbi u bolesnika s križoboljom.Low back pain is defined as a pain, muscle tension and discomfort located between lower costal arch and lower gluteal furrow with or without eradiation in leg. It can be divided into specific, if cause is destructive process or neurological deficit, such as hernia of an intervertebral disc, and nonspecific , which cause is unknown. Considering the duration of low back pain, it can be clasiffied as acute, if it lasts up to three months and chronic, if it's duration is more than three months. Low back pain is a real example of multifactorial disease, and it's risk factors can be classified as individual, those associated with load, and psychosocial factors. Low back pain is one of the most common health problems nowadays and is the major health problem of the modern world. Acute and chronic low back pain are treated differently. The main objective of treating acute low back pain is to reduce pain, while in chronic low back pain priority is to regain function, even in case of persisting pain. Medical excercises are indispensable part of prevetion and treatment of low back pain. There are different types of medical excercises and all of them are based on muscle activity with purpose of pain reduction and improvement of function. Due to various causes of low back pain and individual characteristics of every patient, medical excercises are different for each patient and there is no unique set of excercises suitable for every patient. Aim of this review article is to systematize results of previous researches which proved benefit of medical excercises in treatment of low back pain

Medical exercise in low-back pain

Križobolja se definira kao bol, mišićna napetost i nelagoda u području tijela između donjega rebrenog luka i donje glutealne brazde, sa širenjem u nogu ili bez. Možemo ju podijeliti na specifičnu, kojoj je uzrok neka destruktivna bolest ili neurološki deficit uzrokovan, primjerice hernijom intravertebralnog diska, i nespecifičnu, kojoj ne možemo naći uzrok. S obzirom na dužinu trajanja, križobolju možemo podijeliti na akutnu, trajanja do 3 mjeseca i kroničnu, trajanja duže od 3 mjeseca. Križobolja je pravi primjer multifaktorske bolesti, a čimbenike rizika možemo podijeliti na individualne, one povezane s opterećenjem te na psihosocijalne čimbenike. Predstavlja jedan od najučestalijih problema današnjice i veliki zdravstveni problem suvremenog svijeta. U načelu, akutna i kronična križobolja liječe se različito. Glavni je cilj liječenja akutne križobolje smanjenje boli, dok je na prvom mjestu kod kronične križobolje obnavljanje funkcije, čak i u slučaju perzistiranja boli. Medicinske su vježbe neizostavan dio prevencije i liječenja bolesnika s križoboljom. Postoje razne vrste vježbi, a sve se baziraju na određenom stupnju mišićne aktivnosti s ciljem otklanjanja bola i poboljšanja funkcije. Budući da su uzroci križobolje različiti, kao i individualne osobine svakog bolesnika, tako su i različite vježbe koje se rabe, te ne postoji univerzalni skup vježbi primjenjiv za svakog bolesnika. Cilj je ovog preglednog rada sistematizirati rezultate dosadašnjih istraživanja o razlogu, načinu i rezultatima provođenja medicinskih vježbi u bolesnika s križoboljom.Low back pain is defined as a pain, muscle tension and discomfort located between lower costal arch and lower gluteal furrow with or without eradiation in leg. It can be divided into specific, if cause is destructive process or neurological deficit, such as hernia of an intervertebral disc, and nonspecific , which cause is unknown. Considering the duration of low back pain, it can be clasiffied as acute, if it lasts up to three months and chronic, if it's duration is more than three months. Low back pain is a real example of multifactorial disease, and it's risk factors can be classified as individual, those associated with load, and psychosocial factors. Low back pain is one of the most common health problems nowadays and is the major health problem of the modern world. Acute and chronic low back pain are treated differently. The main objective of treating acute low back pain is to reduce pain, while in chronic low back pain priority is to regain function, even in case of persisting pain. Medical excercises are indispensable part of prevetion and treatment of low back pain. There are different types of medical excercises and all of them are based on muscle activity with purpose of pain reduction and improvement of function. Due to various causes of low back pain and individual characteristics of every patient, medical excercises are different for each patient and there is no unique set of excercises suitable for every patient. Aim of this review article is to systematize results of previous researches which proved benefit of medical excercises in treatment of low back pain