4,705 research outputs found

    Build n burn: using fire as a tool to evoke, educate and entertain

    Get PDF
    The visceral nature of fire was exploited in the Neolithic and Bronze Age periods in Britain by the burning down of timber buildings and monuments, as well as the cremation of the dead. These big fires would have created memories, perhaps even ‘flashbulb memories’, and this powerful mnemonic aspect of fire was likely of significance to the social and religious lives of individuals, families and communities. This article introduces the Build N Burn concept, where fires are recreated and deployed alongside public talks, performances, experimental archaeology activities and demonstrations by craft specialists to create memorable and informative public events. Three public engagements to date, two on the island of Arran and one in Caithness, both Scotland, are described here. In each case, we constructed replica timber structures inspired by local prehistoric sites, and then burned these down in a free-to-attend public event at dusk, evoking the culmination of a prehistoric festival. Build N Burn has, at its core, the principle of delivering memorable experiences for the public inspired by prehistory, underpinned by research and experiment, using events which draw on cross-sectoral collaboration and working with local communities. This article offers a critical reflection on work to date, and discusses future potential for such activities, utilizing the mnemonic power and transformational potential of fire for public engagement and experimental archaeology

    Determining the presence of scour around bridge foundations using vehicle-induced vibrations

    Get PDF
    Bridge scour is the number one cause of failure in bridges located over waterways. Scour leads to rapid losses in foundation stiffness and can cause sudden collapse. Previous research on bridge health monitoring has used changes in natural frequency to identify damage in bridge beams. The possibility of using a similar approach to identifying scour is investigated in this paper. To assess if this approach is feasible, it is necessary to establish how scour affects the natural frequency of a bridge, and if it is possible to measure changes in frequency using the bridge dynamic response to a passing vehicle. To address these questions, a novel vehicle–bridge–soil interaction (VBSI) model was developed. By carrying out a modal study in this model, it is shown that for a wide range of possible soil states, there is a clear reduction in the natural frequency of the first mode of the bridge with scour. Moreover, it is shown that the response signals on the bridge from vehicular loading are sufficient to allow these changes in frequency to be detected

    Absence of Magnetic Fluctuations in the Ferromagnetic/Topological Heterostructure EuS/Bi2_{2}Se3_{3}

    Full text link
    Heterostructures of topological insulators and ferromagnets offer new opportunities in spintronics and a route to novel anomalous Hall states. In one such structure, EuS/Bi2_{2}Se3_{3} a dramatic enhancement of the Curie temperature was recently observed. We performed Raman spectroscopy on a similar set of thin films to investigate the magnetic and lattice excitations. Interfacial strain was monitored through its effects on the Bi2_{2}Se3_{3} phonon modes while the magnetic system was probed through the EuS Raman mode. Despite its appearance in bare EuS, the heterostructures lack the corresponding EuS Raman signal. Through numerical calculations we rule out the possibility of Fabry-Perot interference suppressing the mode. We attribute the absence of a magnetic signal in EuS to a large charge transfer with the Bi2_{2}Se3_{3}. This could provide an additional pathway for manipulating the magnetic, optical, or electronic response of topological heterostructures.Comment: 6 pages, 3 figure

    The Effect of Different Decline Angles on the Biomechanics of Double Limb Squats and the Implications to Clinical and Training Practice

    Get PDF
    Bilateral decline squatting has been well documented as a rehabilitation exercise, however, little information exists on the optimum angle of decline. The aim of this study was to determine the ankle and knee angle, moments, the patellofemoral joint load, patellar tendon load and associated muscle activity while performing a double limb squat at different decline angles and the implications to rehabilitation. Eighteen healthy subjects performed double limb squats at 6 angles of declination: 0, 5, 10, 15, 20 and 25 degrees. The range of motion of the knee and ankle joints, external moments, the patellofemoral/patellar tendon load and integrated EMG of gastrocnemius, tibialis anterior, rectus femoris and biceps femoris were evaluated. As the decline angle increased up to 20 degrees, the range of motion possible at the ankle and knee increased. The joint moments showed a decrease at the ankle up to 15 degrees and an increase at the knee up to 25 degrees, indicating a progressive reduction in loading around the ankle with a corresponding increase of the load in the patellar tendon and patellofemoral joint. These trends were supported by a decrease in tibialis anterior activity and an increase in the rectus femoris activity up to 15 degrees declination. However, gastrocnemius and biceps femoris activity increased as the decline angle increased above 15 degrees. The action of gastrocnemius and biceps femoris stabilises the knee against an anterior displacement of the femur on the tibia. These findings would suggest that there is little benefit in using a decline angle greater than 15-20 degrees unless the purpose is to offer an additional stability challenge to the knee joint

    Improving Clinical Risk Stratification at Diagnosis in Primary Prostate Cancer: A Prognostic Modelling Study.

    Get PDF
    INTRODUCTION: Over 80% of the nearly 1 million men diagnosed with prostate cancer annually worldwide present with localised or locally advanced non-metastatic disease. Risk stratification is the cornerstone for clinical decision making and treatment selection for these men. The most widely applied stratification systems use presenting prostate-specific antigen (PSA) concentration, biopsy Gleason grade, and clinical stage to classify patients as low, intermediate, or high risk. There is, however, significant heterogeneity in outcomes within these standard groupings. The International Society of Urological Pathology (ISUP) has recently adopted a prognosis-based pathological classification that has yet to be included within a risk stratification system. Here we developed and tested a new stratification system based on the number of individual risk factors and incorporating the new ISUP prognostic score. METHODS AND FINDINGS: Diagnostic clinicopathological data from 10,139 men with non-metastatic prostate cancer were available for this study from the Public Health England National Cancer Registration Service Eastern Office. This cohort was divided into a training set (n = 6,026; 1,557 total deaths, with 462 from prostate cancer) and a testing set (n = 4,113; 1,053 total deaths, with 327 from prostate cancer). The median follow-up was 6.9 y, and the primary outcome measure was prostate-cancer-specific mortality (PCSM). An external validation cohort (n = 1,706) was also used. Patients were first categorised as low, intermediate, or high risk using the current three-stratum stratification system endorsed by the National Institute for Health and Care Excellence (NICE) guidelines. The variables used to define the groups (PSA concentration, Gleason grading, and clinical stage) were then used to sub-stratify within each risk category by testing the individual and then combined number of risk factors. In addition, we incorporated the new ISUP prognostic score as a discriminator. Using this approach, a new five-stratum risk stratification system was produced, and its prognostic power was compared against the current system, with PCSM as the outcome. The results were analysed using a Cox hazards model, the log-rank test, Kaplan-Meier curves, competing-risks regression, and concordance indices. In the training set, the new risk stratification system identified distinct subgroups with different risks of PCSM in pair-wise comparison (p < 0.0001). Specifically, the new classification identified a very low-risk group (Group 1), a subgroup of intermediate-risk cancers with a low PCSM risk (Group 2, hazard ratio [HR] 1.62 [95% CI 0.96-2.75]), and a subgroup of intermediate-risk cancers with an increased PCSM risk (Group 3, HR 3.35 [95% CI 2.04-5.49]) (p < 0.0001). High-risk cancers were also sub-classified by the new system into subgroups with lower and higher PCSM risk: Group 4 (HR 5.03 [95% CI 3.25-7.80]) and Group 5 (HR 17.28 [95% CI 11.2-26.67]) (p < 0.0001), respectively. These results were recapitulated in the testing set and remained robust after inclusion of competing risks. In comparison to the current risk stratification system, the new system demonstrated improved prognostic performance, with a concordance index of 0.75 (95% CI 0.72-0.77) versus 0.69 (95% CI 0.66-0.71) (p < 0.0001). In an external cohort, the new system achieved a concordance index of 0.79 (95% CI 0.75-0.84) for predicting PCSM versus 0.66 (95% CI 0.63-0.69) (p < 0.0001) for the current NICE risk stratification system. The main limitations of the study were that it was registry based and that follow-up was relatively short. CONCLUSIONS: A novel and simple five-stratum risk stratification system outperforms the standard three-stratum risk stratification system in predicting the risk of PCSM at diagnosis in men with primary non-metastatic prostate cancer, even when accounting for competing risks. This model also allows delineation of new clinically relevant subgroups of men who might potentially receive more appropriate therapy for their disease. Future research will seek to validate our results in external datasets and will explore the value of including additional variables in the system in order in improve prognostic performance.This is the final version of the article. It first appeared from PLOS via http://dx.doi.org/10.1371/journal.pmed.100206
    corecore