9,661 research outputs found

    Impacts of Unattended Train Operations (UTO) on Productivity and Efficiency in Metropolitan Railways

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    Urban metro subway systems (metros) around the world are choosing increasing levels of automation for new and existing lines: the global length of metro lines capable of unattended train operation (UTO) is predicted to triple in the next 10 years. Despite significant investment in this technology, empirical evidence for the financial and service quality impacts of UTO in metros remains scarce. This study used questionnaires and semistructured interviews with the Community of Metros and Nova Group benchmarking groups to assemble emerging evidence of how automation affected costs, staffing, service capacity, and reliability. The results from an analysis of data from 23 lines suggested that UTO could reduce staff numbers by 30% to 70%, with the amount of wage cost reduction depending on whether staff on UTO lines were paid more. On the basis of the experience of seven metros, the capital costs of lines capable of UTO were higher, but the internal rate of return had been estimated by two metros at 10% to 15%. Automated lines were capable of operating at the highest service frequencies of up to 42 trains per hour, and the limited available data suggested that automated lines were more reliable. The findings indicated that UTO was a means to a more flexible and reliable operating model that could increase metro productivity and efficiency. The study identified important work needed to understand the impacts of UTO and identify where statistical analyses would add value once sufficiently large data sets became available

    Delivering manufacturing technology and workshop appreciation to engineering undergraduates using the flipped classroom approach

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    Delivery of manufacturing technology and practical workshop-based work, on undergraduate engineering courses that engage the learners, is challenging. The paper presents an experimental method of workshop delivery using the flipped learning approach, a pedagogical model in which the typical lecture and homework elements of a course are reversed. Video lectures are viewed by students prior to class. In-class time can be devoted to exercises, projects, or discussions as in this case. Learners were asked to observe three audiovisual clips in preparation for class. The objective was to determine whether the flipped classroom approach can enhance the learning experience, through better engagement with the students, compared to conventional classroom-based learning. The level of student participation and level of success have been established by means of feedback questionnaires from more than 100 participants and peer observation. The results are encouraging and demonstrate that this approach is favoured by the students

    Nonlinear Rheology of Unentangled Polymer Melts Reinforced with High Concentration of Rigid Nanoparticles

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    A scaling model is presented to analyze the nonlinear rheology of unentangled polymer melts filled with high concentration of small spherical particles. Assuming the majority of chains to be reversibly adsorbed to the surface of the particles, we show that the emergence of nonlinearity in the viscoelastic response of the composite system subjected to a 2D shear flow results from stretching of the adsorbed chains and increasing desorption rate of the adsorbed segments due to the imposed deformation. The steady-state shear viscosity of the mixture in nonlinear shear thinning regime follows the power lawwhereis the applied shear rate. At large strain amplitude γ 0, the storage and loss moduli in strain sweep tests scale asandrespectively

    Determining Training Needs for Cloud Infrastructure Investigations using I-STRIDE

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    As more businesses and users adopt cloud computing services, security vulnerabilities will be increasingly found and exploited. There are many technological and political challenges where investigation of potentially criminal incidents in the cloud are concerned. Security experts, however, must still be able to acquire and analyze data in a methodical, rigorous and forensically sound manner. This work applies the STRIDE asset-based risk assessment method to cloud computing infrastructure for the purpose of identifying and assessing an organization's ability to respond to and investigate breaches in cloud computing environments. An extension to the STRIDE risk assessment model is proposed to help organizations quickly respond to incidents while ensuring acquisition and integrity of the largest amount of digital evidence possible. Further, the proposed model allows organizations to assess the needs and capacity of their incident responders before an incident occurs.Comment: 13 pages, 3 figures, 3 tables, 5th International Conference on Digital Forensics and Cyber Crime; Digital Forensics and Cyber Crime, pp. 223-236, 201

    Endangered Quino checkerspot butterfly and climate change: Short-term success but long-term vulnerability?

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    The butterfly Euphydryas editha is known to be vulnerable to climate events that exacerbate natural phenological asynchrony between insect and hosts. In prior work, populations of E. editha have been more persistent at high latitudes and high elevations than in the south and at low elevations, consistent with response to observed warming climate. However, poleward range shifts by the endangered subspecies E. e. quino are blocked by urbanization and range shifts to higher elevation may require host shifts. Prior studies were inconclusive as to whether elevational and host shifts were already occurring. Here, we re-evaluate this scenario with new evidence from molecular genetics, host-choice behaviour and field recording of butterfly distribution. We found a statistically significant upward shift in population distribution since 2009. Insects in the expanding region were neither genomic outliers within Quino nor specifically adapted to their principal local host genus, Collinsia. These diverse data collectively support the hypothesis that an elevational range expansion is already in progress, accompanied and facilitated by a shift of principal host from Plantago to Collinsia. Quino appears resilient to warming climate. However, projections indicate that most or all of Quino’s current range in the USA, including the new high elevation expansion, will become uninhabitable. Our most frequent projected future range (circa 2050) is c. 400 km northward from current populations, hence conservation of Quino may eventually require assisted colonization. For now, Critical Habitat (sensu Endangered Species Act) has been designated at sites around the new upper elevational limit that were not known to be occupied. Designating Critical Habitat outside the historic range is a pioneering response to climate change. This politically challenging, non-traditional, climate change-oriented conservation effort exemplifies flexible thinking needed for species vulnerable to climate change

    Breast cancer risk reduction:is it feasible to initiate a randomised controlled trial of a lifestyle intervention programme (ActWell) within a national breast screening programme?

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    BackgroundBreast cancer is the most commonly diagnosed cancer and the second cause of cancer deaths amongst women in the UK. The incidence of the disease is increasing and is highest in women from least deprived areas. It is estimated that around 42% of the disease in post-menopausal women could be prevented by increased physical activity and reductions in alcohol intake and body fatness. Breast cancer control endeavours focus on national screening programmes but these do not include communications or interventions for risk reductionThis study aimed to assess the feasibility of delivery, indicative effects and acceptability of a lifestyle intervention programme initiated within the NHS Scottish Breast Screening Programme (NHSSBSP).MethodsA 1:1 randomised controlled trial (RCT) of the 3 month ActWell programme (focussing on body weight, physical activity and alcohol) versus usual care conducted in two NHSSBSP sites between June 2013 and January 2014. Feasibility assessments included recruitment, retention, and fidelity to protocol. Indicative outcomes were measured at baseline and 3 month follow-up (body weight, waist circumference, eating and alcohol habits and physical activity. At study end, a questionnaire assessed participant satisfaction and qualitative interviews elicited women¿s, coaches and radiographers¿ experiences. Statistical analysis used Chi squared tests for comparisons in proportions and paired t tests for comparisons of means. Linear regression analyses were performed, adjusted for baseline values, with group allocation as a fixed effectResultsA pre-set recruitment target of 80 women was achieved within 12 weeks and 65 (81%) participants (29 intervention, 36 control) completed 3 month assessments. Mean age was 58¿±¿5.6 years, mean BMI was 29.2¿±¿7.0 kg/m2 and many (44%) reported a family history of breast cancer.The primary analysis (baseline body weight adjusted) showed a significant between group difference favouring the intervention group of 2.04 kg (95%CI ¿3.24 kg to ¿0.85 kg). Significant, favourable between group differences were also detected for BMI, waist circumference, physical activity and sitting time. Women rated the programme highly and 70% said they would recommend it to others.ConclusionsRecruitment, retention, indicative results and participant acceptability support the development of a definitive RCT to measure long term effects.Trial registrationThe trial was registered with Current Controlled Trials (ISRCTN56223933)

    A gender-sensitised weight loss and healthy living programme for overweight and obese men delivered by Scottish Premier League football clubs (FFIT): a pragmatic randomised controlled trial.

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    BACKGROUND: The prevalence of male obesity is increasing but few men take part in weight loss programmes. We assessed the effect of a weight loss and healthy living programme on weight loss in football (soccer) fans. METHODS: We did a two-group, pragmatic, randomised controlled trial of 747 male football fans aged 35-65 years with a body-mass index (BMI) of 28 kg/m(2) or higher from 13 Scottish professional football clubs. Participants were randomly assigned with SAS (version 9·2, block size 2-9) in a 1:1 ratio, stratified by club, to a weight loss programme delivered by community coaching staff in 12 sessions held every week. The intervention group started a weight loss programme within 3 weeks, and the comparison group were put on a 12 month waiting list. All participants received a weight management booklet. Primary outcome was mean difference in weight loss between groups at 12 months, expressed as absolute weight and a percentage of their baseline weight. Primary outcome assessment was masked. Analyses were based on intention to treat. The trial is registered with Current Controlled Trials, number ISRCTN32677491. FINDINGS: 374 men were allocated to the intervention group and 374 to the comparison group. 333 (89%) of the intervention group and 355 (95%) of the comparison group completed 12 month assessments. At 12 months the mean difference in weight loss between groups, adjusted for baseline weight and club, was 4·94 kg (95% CI 3·95-5·94) and percentage weight loss, similarly adjusted, was 4·36% (3·64-5·08), both in favour of the intervention (p<0·0001). Eight serious adverse events were reported, five in the intervention group (lost consciousness due to drugs for pre-existing angina, gallbladder removal, hospital admission with suspected heart attack, ruptured gut, and ruptured Achilles tendon) and three in the comparison group (transient ischaemic attack, and two deaths). Of these, two adverse events were reported as related to participation in the programme (gallbladder removal and ruptured Achilles tendon). INTERPRETATION: The FFIT programme can help a large proportion of men to lose a clinically important amount of weight; it offers one effective strategy to challenge male obesity. FUNDING: Scottish Government and The UK Football Pools funded delivery of the programme through a grant to the Scottish Premier League Trust. The National Institute for Health Research Public Health Research Programme funded the assessment (09/3010/06)

    Conjugate addition nitro-Mannich reaction of carbon and heteroatom nucleophiles to nitroalkenes

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    The conjugate addition nitro-Mannich reactions of ethyl-β-nitroacrylate (1) and β-nitrostyrene (2) with electron rich aromatic nucleophiles, stabilized carbanions, alcohols, amines, thiols, and diphenyl phosphine oxide were investigated. The one pot conjugate addition nitro-Mannich reaction was unsuccessful except for the addition of alkoxides to 2 in alcohol as solvent. Isolation of the conjugate addition products followed by deprotonation with nBuLi and treatment with a simple imine in the presence of TFA led to β-nitroamine derived products. Products derived from 1 spontaneously cyclised in only a few examples and on the whole led to inherently unstable products. Products derived from 2 were isolated as their trifluoroacetamides, gave good yields of single diastereoisomers for aromatic and alkoxide nucleophiles and the structures were verified by single crystal X-ray crystallography. Products derived from amine nucleophiles were isolated in low yields while sulfur nucleophiles gave poor diastereoselectivities

    Phytotherapics in tissue healing and its interface with professionals of health in Brazil / Fitoterápicos na cicatrização de tecidos e sua interface com profissionais de saúde no Brasil

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    The World Health Organization and many other national health conferences have stimulated the use of phytotherapeutics and medicinal plants in primary health care in Brazil. Phytotherapeutics and the use of medicinal plants are part of the folk medicine practice, which complements the treatment that is usually employed by lower income population. There is a growing interest in researches about improving the knowledge of plants’ medicinal properties used in tissue healing. This process occurs as a biological response after injury, where uncountable signaling pathways are stimulated to restore the homeostasis of the affected structure. It is observed that Brazil has been developing important researches to improve the knowledge of plants’ medicinal properties favoring a greater prescription by the health professionals and also a better use by the population. Phototherapeutics act in tissue repair in different ways, and the present review describes the use of these in healing in experimental researches and its interface with professionals of health. In this research, we checked scientific articles (Medline, Scielo, Lilacs, Coordination of Superior Level Staff Improvement (CAPES), PubMed and Google Scholar) published between years 2000 and 2018. Companies, researchers, professionals of health and the general population have shown an interest in phytotherapeutics compounds as alternatives for the treatment of various conditions and the healing of injuries. This is due to the lower side effects, easy access and low cost of herbal medicines compared to allopathic medicines and the rich biodiversity from the Brazilian flora. However, it is necessary for the health professionals training and motivation, aiming at a correct and safe prescription and the use of herbal medicines in tissue healing, as well as the insertion of this practice into their professional qualification.
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