308 research outputs found

    Managing Operational Risk in Payment, Clearing, and Settlement Systems

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    Awareness of operational risk has increased greatly in recent years, both at individual financial institutions and for payment, clearing, and settlement systems (PCSS). PCSS consist of networks of interconnected elements (i.e., central operators, participants, and settlement agents); operational problems at any one of the key elements have the potential to disrupt the system as a whole and negatively affect financial stability. The author describes the key features of systemically important PCSS in Canada and the oversight role of the Bank of Canada with respect to those systems. She also describes one approach that could be used to assess and manage operational risk in Canadian PCSS. This approach relies on a consistent definition of operational risk that can be applied across all elements of a PCSS. It uses a recent methodology adapted from the management of operational risk at individual financial institutions. This methodology, called the loss-distribution approach, assesses risk in terms of the potential outcomes of operational events owing to certain risk factors (such as systems problems, human error, process problems, and external events), their likelihood, and their frequency. Once operational risk databases are developed that record the frequency and severity of operational events, it will be possible to estimate parts of the loss distributions for PCSS. In the meantime, qualitative analysis provided by operations experts associated with the various elements of PCSS will be important for judging the potential impact and frequency of events. In a changing financial environment, it is hoped that this methodology could be used to supplement core aspects of operational risk management, such as sound corporate governance, internal controls, policies and procedures, knowledgeable people, and robust contingency plans.Financial institutions; Payments, clearing and settlements systems

    Excess Collateral in the LVTS: How Much is Too Much?

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    The authors build a theoretical model that generates demand for collateral by Large Value Transfer System (LVTS) participants under the assumption that they minimize the cost of holding and managing collateral for LVTS purposes. The model predicts that the optimal amount of collateral held by each LVTS participant depends on the opportunity cost of collateral, the transactions costs of acquiring assets used as collateral and transferring them in and out of the LVTS, and the distribution of an LVTS participant's payment flows in the LVTS. The authors conclude that the aggregate amount of collateral pledged to the LVTS is quite close to that predicted by the model, when benchmark values are used for opportunity and transactions costs that are based on anecdotal evidence, despite the fact that these costs are likely to vary among participants. If one LVTS participant that appears to face a lower opportunity cost of collateral is excluded from the analysis, the model predicts an aggregate level of collateral that is within 5 per cent of the amount actually held by LVTS participants, on average, between February 1999 and May 2003. The authors also apply panel-data regressions to the level of collateral held in the LVTS. They find that the results are broadly supportive of the theoretical model. Sensitivity analysis of this model indicates that, when the opportunity cost of collateral increases, the amount of collateral that participants hold could be greatly reduced.

    Low-temperature concentration of tellurium and gold in continental red bed successions

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    Acknowledgements This research was supported by NERC grants (NE/L001764/1, NE/M010953/1). We are grateful to J. Still and A. Sandison for technical support and to the gypsum mines and C. Brolley for access and sampling. Critical comments from Cristiana Ciobanu, Eric Gloaguen and Georges Calas are gratefully acknowledged. The authors have no conflicts of interest to declare.Peer reviewedPublisher PD

    A simple high-performance matrix-free biomass molten carbonate fuel cell without CO2 recirculation

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    In previous reports, flowing CO2 at the cathode is essential for either conventional molten carbonate fuel cells (MCFCs) based on molten carbonate/LiAlO2 electrolytes or matrix-free MCFCs. For the first time, we demonstrate a high-performance matrix-free MCFC without CO2 recirculation. At 800°C, power densities of 430 and 410 mW/cm2 are achieved when biomass—bamboo charcoal and wood, respectively–is used as fuel. At 600°C, a stable performance is observed during the measured 90 hours after the initial degradation. In this MCFC, CO2 is produced at the anode when carbon-containing fuels are used. The produced CO2 then dissolves and diffuses to the cathode to react with oxygen in open air, forming the required Embedded Image or Embedded Image ions for continuous operation. The dissolved Embedded Image ions may also take part in the cell reactions. This provides a simple new fuel cell technology to directly convert carbon-containing fuels such as carbon and biomass into electricity with high efficiency

    CO2 Laser-Induced Growth of Epitaxial Graphene on 6H-SiC(0001)

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    The thermal decomposition of SiC surface provides, perhaps, the most promising method for the epitaxial growth of graphene on a material useful in the electronics platform. Currently, efforts are focused on a reliable method for the growth of large-area, low-strain epitaxial graphene that is still lacking. We report here a novel method for the fast, single-step epitaxial growth of large-area homogeneous graphene film on the surface of SiC(0001) using an infrared CO2 laser (10.6 {\mu}m) as the heating source. Apart from enabling extreme heating and cooling rates, which can control the stacking order of epitaxial graphene, this method is cost-effective in that it does not necessitate SiC pre-treatment and/or high vacuum, it operates at low temperature and proceeds in the second time scale, thus providing a green solution to EG fabrication and a means to engineering graphene patterns on SiC by focused laser beams. Uniform, low-strain graphene film is demonstrated by scanning electron microscopy and x-ray photoelectron, secondary ion mass, and Raman spectroscopies. Scalability to industrial level of the method described here appears to be realistic, in view of the high rate of CO2-laser induced graphene growth and the lack of strict sample-environment conditions.Comment: 32 pages, 5 figures, includes Supporting Informatio

    The sarcoma diagnostic interval: a systematic review on length, contributing factors and patient outcomes

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    Sarcomas are rare and heterogeneous mesenchymal tumours of soft tissue or bone, making them prone to late diagnosis. In other malignancies, early diagnosis has an impact on stage of disease, complexity of therapeutic procedures, survival and health-related quality of life (HRQoL). Little is known about what length of diagnostic interval should be considered as delay in patients with bone (BS) or soft tissue sarcomas (STS). To quantify total interval (defined as time from first symptom to histological diagnosis) and its components, identify contributing factors to its length and determine the impact on patients’ outcome in terms of mortality and HRQoL. A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Seventy-six articles out of 2310 met the predefined inclusion criteria. Total intervals, varied broadly; 9–120.4 weeks for BS and 4.3–614.9 weeks for STS. Older age and no initial radiological examinations were contributing factors for a long interval in BS, while in STS results were conflicting. The impact of length of total interval on clinical outcomes in terms of survival and morbidity remains ambiguous; no clear relation could be identified for both BS and STS. No study examined the impact on HRQoL. The length of total interval is variable in BS as well as STS. Its effect on outcomes is contradictory. There is no definition of a clinically relevant cut-off point that discriminates between a short or long total interval. Prospero: CRD42017062492

    Immunohistochemical assessment of intrinsic and extrinsic markers of hypoxia in reproductive tissue: differential expression of HIF1α and HIF2α in rat oviduct and endometrium

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    Hypoxia is thought to be critical in regulating physiological processes within the female reproductive system, including ovulation, composition of the fluid in the oviductal/uterine lumens and ovarian follicle development. This study examined the localisation of exogenous (pimonidazole) and endogenous [hypoxia inducible factor 1α and 2α (HIF1α, -2α), glucose transporter type 1 (GLUT1) and carbonic anhydrase 9 (CAIX)] hypoxia-related antigens within the oviduct and uterus of the rat reproductive tract. The extent to which each endogenous antigen co-compartmentalised with pimonidazole was also assessed. Female Wistar Furth rats (n = 10) were injected intraperitoneally with pimonidazole (60 mg/kg) 1 h prior to death. Reproductive tissues were removed immediately following death and fixed in 4% paraformaldehyde before being embedded in paraffin. Serial sections were cut (6–7 μm thick) and antigens of interest identified using standard immunohistochemical procedures. The mucosal epithelia of the ampulla, isthmus and uterus were immunopositive for pimonidazole in most sections. Co-compartmentalisation of pimonidazole with HIF1α was only expressed in the mucosa of the uterus whilst co-compartmentalisation with HIF2α was observed in the mucosa of the ampulla, isthmus and uterus. Both GLUT1 and CAIX were co-compartmentalised with pimonidazole in mucosa of the isthmus and uterus. This study confirms that mucosal regions of the rat oviduct and uterus frequently experience severe hypoxia and there are compartment specific variations in expression of endogenous hypoxia-related antigens, including the HIF isoforms. The latter observation may relate to target gene specificity of HIF isoforms or perhaps HIF2α’s responsiveness to non-hypoxic stimuli such as hypoglycaemia independently of HIF1α

    Residence, income and cancer hospitalizations in British Columbia during a decade of policy change

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    BACKGROUND: Through the 1990s, governments across Canada shifted health care funding allocation and organizational foci toward a community-based population health model. Major concerns of reform based on this model include ensuring equitable access to health and health care, and enhancing preventive and community-based resources for care. Reforms may act differentially relative to specific conditions and services, including those geared to chronic versus acute conditions. The present study therefore focuses on health service utilization, specifically cancer hospitalizations, in British Columbia during a decade of health system reform. METHODS: Data were drawn from the British Columbia Linked Health Data resource; income measures were derived from Statistics Canada 1996 Census public use enumeration area income files. Records with a discharge (separation) date between 1 January 1991 and 31 December 1998 were selected. All hospitalizations with ICD-9 codes 140 through 208 (except skin cancer, code 173) as principal diagnosis were included. Specific cancers analyzed include lung; colorectal; female breast; and prostate. Hospitalizations were examined in total (all separations), and as divided into first and all other hospitalizations attributed to any given individual. Annual trends in age-sex adjusted rates were analyzed by joinpoint regression; longitudinal multivariate analyses assessing association of residence and income with hospitalizations utilized generalised estimating equations. Results are evaluated in relation to cancer incidence trends, health policy reform and access to care. RESULTS: Age-sex adjusted hospitalization rates for all separations for all cancers, and lung, breast and prostate cancers, decreased significantly over the study period; colorectal cancer separations did not change significantly. Rates for first and other hospitalizations remained stationary or gradually declined over the study period. Area of residence and income were not significantly associated with first hospitalizations; effects were less consistent for all and other hospitalizations. No interactions were observed for any category of separations. CONCLUSIONS: No discontinuities were observed with respect to total hospitalizations that could be associated temporally with health policy reform; observed changes were primarily gradual. These results do not indicate whether equity was present prior to health care reform. However, findings concur with previous reports indicating no change in access to health care across income or residence consequent on health care reform

    Clinical manifestations of colorectal cancer patients from a large multicenter study in Colombia

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    Colorectal cancer (CRC) is a major public health problem, and its incidence is rising in developing countries. However, studies characterizing CRC clinicopathological features in cases from developing countries are still lacking. The goal of this study was to evaluate clinicopathological and demographic features in one of the largest CRC studies in Latin America. The study involved over 1525 CRC cases recruited in a multicenter study in Colombia between 2005 and 2014 as part of ongoing genetic and epidemiological studies. We gathered clinicopathological data such as age at diagnosis, sex, body mass index, tobacco and alcohol consumption, family history of cancer, and tumor features including location, histological type, and stage. Statistical analyses were performed to test the association between age of onset, sex, and clinical manifestations. The average age at CRC diagnosis was 57.4 years, with 26.5% of cases having early-onset CRC (diagnosed by age 50 years). Most cases were women (53.2%;P=0.009), 49.2% were overweight or obese, 49.1% were regular alcohol drinkers, 52% were smokers/former smokers, and 12.2% reported relatives with cancer. Most tumors in the study were located in the rectum (42.7%), were adenocarcinomas (91.5%), and had advanced stage (T3–T4, 79.8%). Comparisons by sex found that male cases were more likely to be obese (36.5% vs 31.1%; P=0.001), less likely to have a family history of cancer (9.7% vs 15.3%;P=0.016), and more likely to have advanced-stage tumors (83.9% vs 76.1%; P=0.036). Comparisons by age of onset found that early-onset cases were more likely to be women (59.3% vs 51.0%;P=0.005) and report a family history of cancer (17.4% vs 10.2%;P=0.001). To our knowledge, our study is the largest report of clinicopathological characterization of Hispanic CRC cases, and we suggest that further studies are needed to understand CRC etiology in diverse Hispanic populations.</p

    The evidence base for circulating tumour DNA blood-based biomarkers for the early detection of cancer: a systematic mapping review

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    Background: The presence of circulating cell-free DNA from tumours in blood (ctDNA) is of major importance to those interested in early cancer detection, as well as to those wishing to monitor tumour progression or diagnose the presence of activating mutations to guide treatment. In 2014, the UK Early Cancer Detection Consortium undertook a systematic mapping review of the literature to identify blood-based biomarkers with potential for the development of a non-invasive blood test for cancer screening, and which identified this as a major area of interest. This review builds on the mapping review to expand the ctDNA dataset to examine the best options for the detection of multiple cancer types. Methods: The original mapping review was based on comprehensive searches of the electronic databases Medline, Embase, CINAHL, the Cochrane library, and Biosis to obtain relevant literature on blood-based biomarkers for cancer detection in humans (PROSPERO no. CRD42014010827). The abstracts for each paper were reviewed to determine whether validation data were reported, and then examined in full. Publications concentrating on monitoring of disease burden or mutations were excluded. Results: The search identified 94 ctDNA studies meeting the criteria for review. All but 5 studies examined one cancer type, with breast, colorectal and lung cancers representing 60% of studies. The size and design of the studies varied widely. Controls were included in 77% of publications. The largest study included 640 patients, but the median study size was 65 cases and 35 controls, and the bulk of studies (71%) included less than 100 patients. Studies either estimated cfDNA levels non-specifically or tested for cancer-specific mutations or methylation changes (the majority using PCR-based methods). Conclusion: We have systematically reviewed ctDNA blood biomarkers for the early detection of cancer. Pre-analytical, analytical, and post-analytical considerations were identified which need to be addressed before such biomarkers enter clinical practice. The value of small studies with no comparison between methods, or even the inclusion of controls is highly questionable, and larger validation studies will be required before such methods can be considered for early cancer detection
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