752 research outputs found

    Effect of the Current-Wave Angle on the Local Scour around Circular Piles

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    This paper studies the effect of the wave front-current angle on the scour around a circular pile. An experimental study was carried out in the Coastal, Ocean and Sediment Transport (COAST) laboratory at the University of Plymouth (UK) using a single monopile of 0.125 m in diameter and an 8 m long by 1.5 m wide by 0.2 m high sand pit. The results obtained during the test campaign show the influence of the angle between waves and currents on both the maximum scour depth and the time scale of the process. Wave fronts partially aligned with current (65°) produce deeper scour holes than perpendicular forcing conditions (90°). Wave fronts partially against the current (115°) produce less scour than any of the two previous scenarios. The addition of waves reduced the maximum scour depth, compared with the current-only case. The development of the scour hole was found to be more rapid when waves are added to the current, with 50% of the final scour achieved in half the time. The results show that wave direction relative to the current is an important component in scour prediction

    Third-Line Nivolumab Monotherapy in Recurrent Small Cell Lung Cancer : CheckMate 032

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    Introduction: For patients with recurrent SCLC, topotecan remains the only approved second-line treatment, and the outcomes are poor. CheckMate 032 is a phase 1/2, multicenter, open-label study of nivolumab or nivolumab plus ipilimumab in SCLC or other advanced/metastatic solid tumors previously treated with one or more platinum-based chemotherapies. We report results of third- or later-line nivolumab monotherapy treatment in SCLC. Methods: In this analysis, patients with limited-stage or extensive-stage SCLC and disease progression after two or more chemotherapy regimens received nivolumab monotherapy, 3 mg/kg every 2 weeks, until disease progression or unacceptable toxicity. The primary end point was objective response rate. Secondary end points included duration of response, progression-free survival, overall survival, and safety. Results: Between December 4, 2013, and November 30, 2016, 109 patients began receiving third- or later-line nivolumab monotherapy. At a median follow-up of 28.3 months (from first dose to database lock), the objective response rate was 11.9% (95% confidence interval: 6.5\u201319.5) with a median duration of response of 17.9 months (range 3.0\u201342.1). At 6 months, 17.2% of patients were progression-free. The 12-month and 18-month overall survival rates were 28.3% and 20.0%, respectively. Grade 3 to 4 treatment-related adverse events occurred in 11.9% of patients. Three patients (2.8%) discontinued because of treatment-related adverse events. Conclusions: Nivolumab monotherapy provided durable responses and was well tolerated as a third- or later-line treatment for recurrent SCLC. These results suggest that nivolumab monotherapy is an effective third- or later-line treatment for this patient population

    Mathematically gifted and talented learners: Theory and practice

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    This is an Author's Accepted Manuscript of an article published in International Journal of Mathematical Education in Science and Technology, 40(2), 213-228, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/00207390802566907.There is growing recognition of the special needs of mathematically gifted learners. This article reviews policy developments and current research and theory on giftedness in mathematics. It includes a discussion of the nature of mathematical ability as well as the factors that make up giftedness in mathematics. The article is set in the context of current developments in Mathematics Education and Gifted Education in the UK and their implications for Science and Technology. It argues that early identification and appropriate provision for younger mathematically promising pupils capitalizes on an intellectual resource which could provide future mathematicans as well as specialists in Science or Technology. Drawing on a Vygotskian framework, it is suggested that the mathematically gifted require appropriate cognitive challenges as well as attitudinally and motivationally enhancing experiences. In the second half of this article we report on an initiative in which we worked with teachers to identify mathematically gifted pupils and to provide effective enrichment support for them, in a number of London Local Authorities. A number of significant issues are raised relating to the identification of mathematical talent, enrichment provision for students and teachers’ professional development

    The internal brakes on violent escalation:a typology

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    Most groups do less violence than they are capable of. Yet while there is now an extensive literature on the escalation of or radicalisation towards violence, particularly by ‘extremist’ groups or actors, and while processes of de-escalation or de-radicalisation have also received significant attention, processes of non- or limited escalation have largely gone below the analytical radar. This article contributes to current efforts to address this limitation in our understanding of the dynamics of political aggression by developing a descriptive typology of the ‘internal brakes’ on violent escalation: the mechanisms through which members of the groups themselves contribute to establish and maintain limits upon their own violence. We identify five underlying logics on which the internal brakes operate: strategic, moral, ego maintenance, outgroup definition, and organisational. The typology is developed and tested using three very different case studies: the transnational and UK jihadi scene from 2005 to 2016; the British extreme right during the 1990s, and the animal liberation movement in the UK from the mid-1970s until the early 2000s

    Nivolumab Monotherapy and Nivolumab Plus Ipilimumab in Recurrent Small Cell Lung Cancer: Results From the CheckMate 032 Randomized Cohort

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    Abstract Introduction Nivolumab monotherapy is approved in the United States for third-line or later metastatic small cell lung cancer based on pooled data from nonrandomized and randomized cohorts of the multicenter, open-label, phase 1/2 trial of nivolumab ± ipilimumab (CheckMate 032; NCT01928394). We report updated results, including long-term overall survival (OS), from the randomized cohort. Methods Patients with small cell lung cancer and disease progression after one to two prior chemotherapy regimens were randomized 3:2 to nivolumab 3 mg/kg every 2 weeks or nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for four cycles followed by nivolumab 3 mg/kg every 2 weeks. Patients were stratified by number of prior chemotherapy regimens and treated until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by blinded independent central review. Results Overall, 147 patients received nivolumab and 96 nivolumab plus ipilimumab. Minimum follow-up for ORR/progression-free survival/safety was 11.9 months (nivolumab) and 11.2 months (nivolumab plus ipilimumab). ORR increased with nivolumab plus ipilimumab (21.9% versus 11.6% with nivolumab; odds ratio: 2.12; 95% confidence interval: 1.06–4.26; p = 0.03). For long-term OS, minimum follow-up was 29.0 months (nivolumab) versus 28.4 months (nivolumab plus ipilimumab); median (95% confidence interval) OS was 5.7 (3.8–7.6) versus 4.7 months (3.1–8.3). Twenty-four–month OS rates were 17.9% (nivolumab) and 16.9% (nivolumab plus ipilimumab). Grade 3 to 4 treatment-related adverse event rates were 12.9% (nivolumab) versus 37.5% (nivolumab plus ipilimumab), and treatment-related deaths were n =1 versus n = 3, respectively. Conclusions Whereas ORR (primary endpoint) was higher with nivolumab plus ipilimumab versus nivolumab, OS was similar between groups. In each group, OS remained encouraging with long-term follow-up. Toxicities were more common with combination therapy versus nivolumab monotherapy

    A Human Minor Histocompatibility Antigen Specific for B Cell Acute Lymphoblastic Leukemia

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    Human minor histocompatibility antigens (mHags) play an important role in the induction of cytotoxic T lymphocyte (CTL) reactivity against leukemia after human histocompatibility leukocyte antigen (HLA)-identical allogeneic bone marrow transplantation (BMT). As most mHags are not leukemia specific but are also expressed by normal tissues, antileukemia reactivity is often associated with life-threatening graft-versus-host disease (GVHD). Here, we describe a novel mHag, HB-1, that elicits donor-derived CTL reactivity in a B cell acute lymphoblastic leukemia (B-ALL) patient treated by HLA-matched BMT. We identified the gene encoding the antigenic peptide recognized by HB-1–specific CTLs. Interestingly, expression of the HB-1 gene was only observed in B-ALL cells and Epstein-Barr virus–transformed B cells. The HB-1 gene–encoded peptide EEKRGSLHVW is recognized by the CTL in association with HLA-B44. Further analysis reveals that a polymorphism in the HB-1 gene generates a single amino acid exchange from His to Tyr at position 8 within this peptide. This amino acid substitution is critical for recognition by HB-1–specific CTLs. The restricted expression of the polymorphic HB-1 Ag by B-ALL cells and the ability to generate HB-1–specific CTLs in vitro using peptide-loaded dendritic cells offer novel opportunities to specifically target the immune system against B-ALL without the risk of evoking GVHD

    Specific gene expression profiles and chromosomal abnormalities are associated with infant disseminated neuroblastoma

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    Background: Neuroblastoma (NB) tumours have the highest incidence of spontaneous remission, especially among the stage 4s NB subgroup affecting infants. Clinical distinction of stage 4s from lethal stage 4 can be difficult, but critical for therapeutic decisions. The aim of this study was to investigate chromosomal alterations and differential gene expression amongst infant disseminated NB subgroups. Methods: Thirty-five NB tumours from patients diagnosed at < 18 months (25 stage 4 and 10 stage 4s), were evaluated by allelic and gene expression analyses. Results: All stage 4s patients underwent spontaneous remission, only 48% stage 4 patients survived despite combined modality therapy. Stage 4 tumours were 90% near-diploid/tetraploid, 44% MYCN amplified, 77% had 1p LOH (50% 1p36), 23% 11q and/or 14q LOH (27%) and 47% had 17q gain. Stage 4s were 90% near-triploid, none MYCN amplified and LOH was restricted to 11q. Initial comparison analyses between stage 4s and 4 < 12 months tumours revealed distinct gene expression profiles. A significant portion of genes mapped to chromosome 1 (P < 0.0001), 90% with higher expression in stage 4s, and chromosome 11 (P = 0.0054), 91% with higher expression in stage 4. Less definite expression profiles were observed between stage 4s and 4 < 18m, yet, association with chromosomes 1 (P < 0.0001) and 11 (P = 0.005) was maintained. Distinct gene expression profiles but no significant association with specific chromosomal region localization was observed between stage 4s and stage 4 < 18 months without MYCN amplification. Conclusion: Specific chromosomal aberrations are associated with distinct gene expression profiles which characterize spontaneously regressing or aggressive infant NB, providing the biological basis for the distinct clinical behaviour

    Predicting Infectious ComplicatioNs in Children with Cancer : an external validation study

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    Background:The aim of this study was to validate the 'Predicting Infectious ComplicatioNs in Children with Cancer' (PICNICC) clinical decision rule (CDR) that predicts microbiologically documented infection (MDI) in children with cancer and fever and neutropenia (FN). We also investigated costs associated with current FN management strategies in Australia.Methods:Demographic, episode, outcome and cost data were retrospectively collected on 650 episodes of FN. We assessed the discrimination, calibration, sensitivity and specificity of the PICNICC CDR in our cohort compared with the derivation data set.Results:Using the original variable coefficients, the CDR performed poorly. After recalibration the PICNICC CDR had an area under the receiver operating characteristic (AUC-ROC) curve of 0.638 (95% CI 0.590-0.685) and calibration slope of 0.24. The sensitivity, specificity, positive predictive value and negative predictive value of the PICNICC CDR at presentation was 78.4%, 39.8%, 28.6% and 85.7%, respectively. For bacteraemia, the sensitivity improved to 85.2% and AUC-ROC to 0.71. Application at day 2, taking into consideration the proportion of MDI known (43%), further improved the sensitivity to 87.7%. Length of stay is the main contributor to cost of FN treatment, with an average cost per day of AUD 2183 in the low-risk group.Conclusions:For prediction of any MDI, the PICNICC rule did not perform as well at presentation in our cohort as compared with the derivation study. However, for bacteraemia, the predictive ability was similar to that of the derivation study, highlighting the importance of recalibration using local data. Performance also improved after an overnight period of observation. Implementation of a low-risk pathway, using the PICNICC CDR after a short period of inpatient observation, is likely to be safe and has the potential to reduce health-care expenditure
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