Evolutionary Dynamics of Bertrand Duopoly

Duopolies are one of the simplest economic situations where interactions between firms determine market behavior. The standard model of a price-setting duopoly is the Bertrand model, which has the unique solution that both firms set their prices equal to their costs-a paradoxical result where both firms obtain zero profit, which is generally not observed in real market duopolies. Here we propose a new game theory model for a price-setting duopoly, which we show resolves the paradoxical behavior of the Bertrand model and provides a consistent general model for duopolies

A Bigger Splat: Rock fall impact processes in wet sediment - an example from Clachtoll, NW Scotland

At Clachtoll, in NW Scotland, an enigmatic outcrop of Lewisian gneiss is observed. This zone, ~60 m by 100 m in aerial view, contains abundant fractures filled with clastic material from the immediately adjacent and stratigraphically overlying Stoer Group. This zone also displays foliation that is misoriented by 90 degrees, relative to that in the surrounding basement. Fractures on top of this outcrop contain sedimentary structures, such as laminations, indicative of passive infilling, whilst fractures at the base and on the lateral flanks show characteristics more indicative of forceful injection. This study proposes that the aforementioned zone represents a hitherto unrecognised fallen block, termed the Clachtoll Megablock, lying on the regional scale nonconformity between the Lewisian gneiss and the Mesoproterozoic sedimentary rocks of the Stoer Group (ca. 1.2 Ga). It is proposed that vertical emplacement of a falling block onto unconsolidated and fluid laden sediment, could cause rapid over-pressuring and liquefaction of said sediment, leading to hydrofracture and sediment slurry injection into the impacting block. Fractures on the top of the block would then be passively infilled under gravity. Simple numerical modelling yields a fall height of 6 m as being sufficient for rapid liquid over-pressuring to overcome the tensile strength of the gneiss. Several models of emplacement were considered in an attempt to reconcile all of the features observed in the block. Features, including WNW-ESE oriented tensile fractures in the back of the block, and a small thrust associated with brittle folding in the front of the block, indicate an incomplete syn-emplacement disaggregation of the Clachtoll Megablock, consistent with gravity-driven transport from the NNE. Emplacement must have involved an element of sliding, and the misorientation of foliation inside vs. outside of the block can only be explained by rotation of the block. Evidence of soft sediment deformation in the basal part of the Stoer Group, along with knowledge of the active rift setting of the event suggest that emplacement of the Clachtoll Megablock was triggered by an earthquake ca. 1.2 Ga. Weathering processes, such as freeze-thaw, in an arid environment likely contributed to this

Rare Variant of Vastus Medialis Detected in vivo by Ultrasound and Confirmed by High-resolution MRI.

[Purpose] This report describes an unusual incidental finding during ultrasound investigation of the vastus medialis muscle. Volunteers underwent ultrasound scanning as part of an on-going investigation into the architecture of the vastus medialis muscle. [Subjects and Methods] The distal thighs of forty-one subjects were scanned using the Philips iU22 US system. An unusual muscle morphology was detected bilaterally in one subject, who then underwent a 3T Magnetic Resonance Imaging (MRI) scan in order to further investigate the muscle morphology. The subject in question was a 32 year-old female who suffers from recurrent bilateral patellar dislocations. [Results] The MRI scan confirmed the ultrasound findings, and indicated the presence of the vastus medialis in two layers, with the VML continuing deep, separate from the VMO. [Conclusion] Although this rare variant has been been reported in previous cadaveric studies, we believe this to be the first report in the literature of this morphology in vivo. The biomechanical implications of this muscle arrangement are unknown, but it may not be without significance that this individual suffers from recurrent patellar dislocations

Is there a dose response relationship between soft tissue manual therapy and clinical outcomes in fibromyalgia?

BackgroundCurrent clinical guidelines do not support the use of manual therapy (MT) interventions for Fibromyalgia (FM) patients, despite evidence of positive biochemical, mechanical and psychological effects, and the popularity of hands-on treatments amongst patients. An optimal dose for MT has not been established; this may explain the discrepancies found within the published literature. The aim of this systematic review was to determine whether there is a dose response relationship for MT leading to improvements in core domains of FM symptomology; Pain, Mood, Sleep, Global Measure of Impact (Functional Status & Quality of Life).MethodsWe searched six databases from 1990 to January 2018; studies were evaluated using the PEDro scale. Within-group (ES d) and between-group (ES g) Effect Sizes were calculated.ResultsWe identified and screened 4012 articles, 12 articles were critically appraised. Overall, there is moderate evidence that MT has positive effects on the four clinical outcomes investigated. However, there was no consistent dose response relationship observed across all studies.ConclusionsA dose of approximately 45 min MT, three to five times per week, for three to five weeks, totalling 11 h 15 min, should be considered a baseline generic protocol for treatment delivery and research trials. Further research is necessary to confirm domain specific, or patient specific optimal doses. Moderator variables such as treatment time, frequency, duration; and MT type also need to be explored to ensure optimal delivery of MT in future research and clinical care provision

What factors influence physical activity participation in people with rheumatoid arthritis?

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by periods of inflammation and remission. Physical activity can reduce disease activity and lower the risks of associated co-morbidities such as cardiovascular disease. Despite the benefits, a high percentage of people with RA do not participate in regular physical activity.Objective: The purpose of this qualitative literature review was to explore and synthesize the experiences of people with RA to develop better insight of the factors that influence physical activity participation.Method: A systematic search was conducted across five online databases; MEDLINE, CINAHL, ScienceDirect, PsycINFO, Web of Science. Studies were assessed for quality, data were extracted and analyzed using thematic synthesis.Results: A total of 186 articles were identified and screened against inclusion/exclusion criteria. Seven studies met the criteria and were included in this review. Five key themes were identified as the most significant factors to physical activity participation: professional knowledge and guidance; part of a community; knowing me, knowing RA; what’s in it for me; and where, when, how much? Professional knowledge and guidance was the underpinning factor influencing physical activity participation.Conclusion: The results identify several internal and external factors that affect physical activity participation. To engage, facilitate and motivate patients to participate in physical activity, ongoing education and support from health care professionals is required. This will promote better symptom management and maintain functional independence. Additionally, health care professionals need to consider individual preferences and abilities when recommending physical activity

Holonomies of Intersecting Branes

We discuss the geometry of string and M-theory gauge fields in Deligne cohomology. In particular, we show how requiring string structure (or loop space Spin-C structure) on the five-brane leads to topological conditions on the flux in the relative Deligne cohomology of the bulk - brain pair.Comment: 8 pages, LaTeX, talk given in the RTN Workshop "The quantum structure of spacetime and the geometric nature of fundamental interactions," (Kolymbari, Greece, September 2004

Experiences of a student with a visual impairment transitioning to higher education: A narrative inquiry

Transition to higher education is a considerable period of change for students, and can be a particularly challenging time for students with a visual impairment. The aim of this study was to understand the transition experiences of an undergraduate student in Sport Rehabilitation with a visual impairment. A narrative inquiry was conducted with one participant purposively sampled due to being certified severely sight impaired. Data were collected using a semi-structured interview, and analysed by creating narrative threads within Clandinin and Connelly’s three-dimensional framework. The social influence of role models, peers, and staff were noted in relation to their impact on confidence and feeling of fitting in. Navigating the campus, teaching spaces, and demonstrations were all highlighted as spatial factors that affected independence and participation during transition. Time-related aspects such a personal development, proactivity, and pre-, during, and post-teaching session experiences were identified as key considerations. The narratives uncovered should serve as a tool to trigger reflection on previous teaching practice, and inform future direction. The findings and recommendations within this study will benefit transition and inclusivity for students with a visual impairment, particularly on Sport Rehabilitation or other healthcare programmes, allowing them to study and practice effectively

An Application of Evolutionary Game Theory to Social Dilemmas: The Traveler's Dilemma and the Minimum Effort Coordination Game

The Traveler's Dilemma game and the Minimum Effort Coordination game are two social dilemmas that have attracted considerable attention due to the fact that the predictions of classical game theory are at odds with the results found when the games are studied experimentally. Moreover, a direct application of deterministic evolutionary game theory, as embodied in the replicator dynamics, to these games does not explain the observed behavior. In this work, we formulate natural variants of these two games as smoothed continuous-strategy games. We study the evolutionary dynamics of these continuous-strategy games, both analytically and through agent-based simulations, and show that the behavior predicted theoretically is in accord with that observed experimentally. Thus, these variants of the Traveler's Dilemma and the Minimum Effort Coordination games provide a simple resolution of the paradoxical behavior associated with the original games