784 research outputs found

    Hedging Effectiveness under Conditions of Asymmetry

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    We examine whether hedging effectiveness is affected by asymmetry in the return distribution by applying tail specific metrics to compare the hedging effectiveness of short and long hedgers using crude oil futures contracts. The metrics used include Lower Partial Moments (LPM), Value at Risk (VaR) and Conditional Value at Risk (CVAR). Comparisons are applied to a number of hedging strategies including OLS and both Symmetric and Asymmetric GARCH models. Our findings show that asymmetry reduces in-sample hedging performance and that there are significant differences in hedging performance between short and long hedgers. Thus, tail specific performance metrics should be applied in evaluating hedging effectiveness. We also find that the Ordinary Least Squares (OLS) model provides consistently good performance across different measures of hedging effectiveness and estimation methods irrespective of the characteristics of the underlying distribution

    PC3 Breast and Prostate Cancer Productivity Costs: A Comparison of the Human Capital Approach and Friction Cost Approach

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    AbstractObjectivesProductivity costs constitute a substantial proportion of the total societal costs associated with cancer. We compared the results of applying two different analytical methods—the traditional human capital approach (HCA) and the emerging friction cost approach (FCA)—to estimate breast and prostate cancer productivity costs in Ireland in 2008.MethodsData from a survey of breast and prostate cancer patients were combined with population-level survival estimates and a national wage data set to calculate costs of temporary disability (cancer-related work absence), permanent disability (workforce departure, reduced working hours), and premature mortality.ResultsFor breast cancer, productivity costs per person using the HCA were €193,425 and those per person using the FCA were €8,103; for prostate cancer, the comparable estimates were €109,154 and €8,205, respectively. The HCA generated higher costs for younger patients (breast cancer) because of greater lifetime earning potential. In contrast, the FCA resulted in higher productivity costs for older male patients (prostate cancer) commensurate with higher earning capacity over a shorter time period. Reduced working hours postcancer was a key driver of total HCA productivity costs. HCA costs were sensitive to assumptions about discount and growth rates. FCA costs were sensitive to assumptions about the friction period.ConclusionsThe magnitude of the estimates obtained in this study illustrates the importance of including productivity costs when considering the economic impact of illness. Vastly different results emerge from the application of the HCA and the FCA, and this finding emphasizes the importance of choosing the study perspective carefully and being explicit about assumptions that underpin the methods

    Cancer And Premature Mortality In Ireland: An Employer's Perspective Following The Friction Cost Approach.

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    Cancer is the second leading cause of death in Ireland accounting for approximately 30% of all deaths. Of these, almost a third arise in those of working age. As well as the public health burden, cancer also imposes economic costs on society in general and employers in particular. This study measured the productivity costs associated with cancer-related premature mortality from an employer’s perspective in Ireland

    Short-term effects of deep ploughing on soil C stocks following renewal of a dairy pasture in New Zealand

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    In New Zealand’s high producing permanent pastures the topsoil constitutes a large reservoir of soil organic carbon (SOC), which shows a marked stratification with depth. As consequence, sub-surface layers can contain 10 times less carbon than the surface soil. In permanent pastures with high carbon inputs, the formation and decomposition of these surface SOC stocks are often at equilibrium and C storage shows little change over time. Pastoral based dairy systems utilising ryegrass plus clover cultivars require renewal every 7-10 years to avoid reversion to less productive grasses. This may involve spring cultivation (either no-till, shallow till or full cultivation), summer forage cropping and autumn re-grassing. It has been hypothesised that SOC stocks can be increased by inverting the soil profile at pasture renewal through infrequent (once in 25-30 years) deep mouldboard ploughing (up to 30 cm depth). Increased C sequestration occurs when the new grass quickly rebuilds SOC stocks in the new topsoil (exposed low C sub-soil) at a rate faster than the decomposition of SOC in the rich former topsoil transferred to depth (now below 15 cm). However, benefits form accelerated C storage may be offset if crop and pasture production is adversely affected by the ploughing event (e.g., as result of compaction or excessive drainage). Hence, the aim of this work was to assess the short-term effects of infrequent inversion tillage of long-term New Zealand pastoral-based dairy soils under summer crop management and autumn re-grassing. An imperfectly drained Typic Fragiaqualf under dairy grazing was deep ploughed (approx. 25 cm) and re-sown with turnip in October 2016; other treatments included were shallow (< 10 cm) cultivation and no-till. The site was core sampled (0-40 cm) before cultivation and after 5 months of turnip growth to assess changes in SOC. Plant growth, herbage quality, and nutrient leaching were monitored during the 5-month period; root growth was assessed at the end of the crop rotation. Full cultivation transferred SOC below 10 cm depth, as expected. Soil bulk density decreased whereas root mass increased (10-20 cm depth; P < 0.05) under deep cultivation only. Besides, losses of mineral N were attenuated under deep tillage, resulting in a relative increase in crop yield. The potential for infrequent inversion tillage increasing soil C sequestration as a greenhouse gas (GHG) mitigation tool is currently being tested at other sites in New Zealand

    Projecting productivity losses for cancer-related mortality 2011 - 2030

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    © 2016 The Author(s). Background: When individuals stop working due to cancer this represents a loss to society - the loss of productivity. The aim of this analysis was to estimate productivity losses associated with premature mortality from all adult cancers and from the 20 highest mortality adult cancers in Ireland in 2011, and project these losses until 2030. Methods: An incidence-based method was used to estimate the cost of cancer deaths between 2011 and 2030 using the Human Capital Approach. National data were used for cancer, population and economic inputs. Both paid work and unpaid household activities were included. Sensitivity analyses estimated the impact of assumptions around future cancer mortality rates, retirement ages, value of unpaid work, wage growth and discounting. Results: The 233,000 projected deaths from all invasive cancers in Ireland between 2011 and 2030 will result in lost productivity valued at €73 billion; €13 billion in paid work and €60 billion in household activities. These losses represent approximately 1.4 % of Ireland's GDP annually. The most costly cancers are lung (€14.4 billion), colorectal and breast cancer (€8.3 billion each). However, when viewed as productivity losses per cancer death, testis (€364,000 per death), cervix (€155,000 per death) and brain cancer (€136,000 per death) are most costly because they affect working age individuals. An annual 1 % reduction in mortality reduces productivity losses due to all invasive cancers by €8.5 billion over 20 years. Conclusions: Society incurs substantial losses in productivity as a result of cancer-related mortality, particularly when household production is included. These estimates provide valuable evidence to inform resource allocation decisions in cancer prevention and control

    Collaborative Gaze Channelling for Improved Cooperation During Robotic Assisted Surgery

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    The use of multiple robots for performing complex tasks is becoming a common practice for many robot applications. When different operators are involved, effective cooperation with anticipated manoeuvres is important for seamless, synergistic control of all the end-effectors. In this paper, the concept of Collaborative Gaze Channelling (CGC) is presented for improved control of surgical robots for a shared task. Through eye tracking, the fixations of each operator are monitored and presented in a shared surgical workspace. CGC permits remote or physically separated collaborators to share their intention by visualising the eye gaze of their counterparts, and thus recovers, to a certain extent, the information of mutual intent that we rely upon in a vis-à-vis working setting. In this study, the efficiency of surgical manipulation with and without CGC for controlling a pair of bimanual surgical robots is evaluated by analysing the level of coordination of two independent operators. Fitts' law is used to compare the quality of movement with or without CGC. A total of 40 subjects have been recruited for this study and the results show that the proposed CGC framework exhibits significant improvement (p<0.05) on all the motion indices used for quality assessment. This study demonstrates that visual guidance is an implicit yet effective way of communication during collaborative tasks for robotic surgery. Detailed experimental validation results demonstrate the potential clinical value of the proposed CGC framework. © 2012 Biomedical Engineering Society.link_to_subscribed_fulltex

    Policy challenges for the pediatric rheumatology workforce: Part III. the international situation

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    Survival dominates current pediatric global health priorities. Diseases of poverty largely contribute to overall mortality in children under 5 years of age. Infectious diseases and injuries account for 75% of cause-specific mortality among children ages 5-14 years. Twenty percent of the world's population lives in extreme poverty (income below US $1.25/day). Within this population, essential services and basic needs are not met, including clean water, sanitation, adequate nutrition, shelter, access to health care, medicines and education. In this context, musculoskeletal disease comprises 0.1% of all-cause mortality in children ages 5-14 years. Worldwide morbidity from musculoskeletal disease remains generally unknown in the pediatric age group. This epidemiologic data is not routinely surveyed by international agencies, including the World Health Organization. The prevalence of pediatric rheumatic diseases based on data from developed nations is in the range of 2,500 - 3,000 cases per million children. Developing countries' needs for musculoskeletal morbidity are undergoing an epidemiologic shift to chronic conditions, as leading causes of pediatric mortality are slowly quelled
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