4,310 research outputs found

    Morocco – 2017

    Get PDF

    Toxicity of Radiotherapy in Patients With Collagen Vascular Disease

    Get PDF
    Background A diagnosis of collagen vascular disease (CVD) may predispose to radiotherapy (RT) toxicity. The objective of the current study was to identify factors that influence RT toxicity in the setting of CVD. Methods A total of 86 RT courses for 73 patients with CVD were delivered between 1985 and 2005. CVD subtypes include rheumatoid arthritis (RA; 33 patients), systemic lupus erythematosus (SLE; 13 patients), scleroderma (9 patients), dermatomyositis/polymyositis (5 patients), ankylosing spondylitis (4 patients), polymyalgia rheumatica/temporal arteritis (4 patients), Wegener granulomatosis (3 patients), and mixed connective tissue disorders (MCTD)/other (2 patients). Each patient with CVD was matched to 1 to 3 controls with respect to sex, race, site irradiated, RT dose (±2 Gray), and age (±5 years). Results There was no significant difference between CVD patients (65.1%) and controls (72.5%) experiencing any acute toxicity. CVD patients had a higher incidence of any late toxicity (29.1% vs 14%; P = .001), and a trend toward an increased rate of severe late toxicity (9.3% vs 3.7%; P = .079). RT delivered to the breast had increased risk of severe acute toxicity, whereas RT to the pelvis had increased risk of severe acute and late toxicity. RT administered in the setting of scleroderma carried a higher risk of severe late toxicity, whereas RT to SLE patients carried a higher risk of severe acute and late toxicity. Conclusions Although generally well tolerated, RT in the setting of CVD appears to carry a higher risk of late toxicity. RT to the pelvis or in the setting of SLE or scleroderma may predispose to an even greater risk of severe toxicity. These issues should be considered when deciding whether to offer RT for these patients. Cancer 2008;113:648–53

    Extended Formulations in Mixed-integer Convex Programming

    Full text link
    We present a unifying framework for generating extended formulations for the polyhedral outer approximations used in algorithms for mixed-integer convex programming (MICP). Extended formulations lead to fewer iterations of outer approximation algorithms and generally faster solution times. First, we observe that all MICP instances from the MINLPLIB2 benchmark library are conic representable with standard symmetric and nonsymmetric cones. Conic reformulations are shown to be effective extended formulations themselves because they encode separability structure. For mixed-integer conic-representable problems, we provide the first outer approximation algorithm with finite-time convergence guarantees, opening a path for the use of conic solvers for continuous relaxations. We then connect the popular modeling framework of disciplined convex programming (DCP) to the existence of extended formulations independent of conic representability. We present evidence that our approach can yield significant gains in practice, with the solution of a number of open instances from the MINLPLIB2 benchmark library.Comment: To be presented at IPCO 201

    Second best toll and capacity optimisation in network: solution algorithm and policy implications

    Get PDF
    This paper looks at the first and second-best jointly optimal toll and road capacity investment problems from both policy and technical oriented perspectives. On the technical side, the paper investigates the applicability of the constraint cutting algorithm for solving the second-best problem under elastic demand which is formulated as a bilevel programming problem. The approach is shown to perform well despite several problems encountered by our previous work in Shepherd and Sumalee (2004). The paper then applies the algorithm to a small sized network to investigate the policy implications of the first and second-best cases. This policy analysis demonstrates that the joint first best structure is to invest in the most direct routes while reducing capacities elsewhere. Whilst unrealistic this acts as a useful benchmark. The results also show that certain second best policies can achieve a high proportion of the first best benefits while in general generating a revenue surplus. We also show that unless costs of capacity are known to be low then second best tolls will be affected and so should be analysed in conjunction with investments in the network

    A boosting method for maximizing the partial area under the ROC curve

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The receiver operating characteristic (ROC) curve is a fundamental tool to assess the discriminant performance for not only a single marker but also a score function combining multiple markers. The area under the ROC curve (AUC) for a score function measures the intrinsic ability for the score function to discriminate between the controls and cases. Recently, the partial AUC (pAUC) has been paid more attention than the AUC, because a suitable range of the false positive rate can be focused according to various clinical situations. However, existing pAUC-based methods only handle a few markers and do not take nonlinear combination of markers into consideration.</p> <p>Results</p> <p>We have developed a new statistical method that focuses on the pAUC based on a boosting technique. The markers are combined componentially for maximizing the pAUC in the boosting algorithm using natural cubic splines or decision stumps (single-level decision trees), according to the values of markers (continuous or discrete). We show that the resulting score plots are useful for understanding how each marker is associated with the outcome variable. We compare the performance of the proposed boosting method with those of other existing methods, and demonstrate the utility using real data sets. As a result, we have much better discrimination performances in the sense of the pAUC in both simulation studies and real data analysis.</p> <p>Conclusions</p> <p>The proposed method addresses how to combine the markers after a pAUC-based filtering procedure in high dimensional setting. Hence, it provides a consistent way of analyzing data based on the pAUC from maker selection to marker combination for discrimination problems. The method can capture not only linear but also nonlinear association between the outcome variable and the markers, about which the nonlinearity is known to be necessary in general for the maximization of the pAUC. The method also puts importance on the accuracy of classification performance as well as interpretability of the association, by offering simple and smooth resultant score plots for each marker.</p

    Adult Hypophosphatasia : a disease where the clinical complications could be avoided by careful evaluation of patients

    Get PDF
    This is the author accepted manuscript. The final version is available from Springer via the DOI in this recordOsteoporosis Conference 2018 Birmingham, UK 2 – 4 December 201

    Aqueous Neem Extract Versus Neem Powder on Culex quinquefasciatus: Implications for Control in Anthropogenic Habitats

    Get PDF
    Control programs using conventional insecticides to target anthropogenic mosquito habitats are very expensive because these habitats are widespread, particularly in cities of most African countries. Additionally, there are serious environmental concerns regarding large-scale application of most conventional insecticides. Clearly there is a need for alternative methods that are more effective, less expensive, and environmentally friendly. One such method would be the application of preparations made from parts of the neem tree, Azadirachta indica A. Jussieu (Sapindales: Meliaceae). In this study, aqueous crude extracts and crude powder were prepared from different parts of neem, and the efficacies of the preparations on juvenile stages of Culex quinquefasciatus Say (Diptera: Culicidae) were evaluated in the laboratory. When larvae were exposed to a concentration of 0.1 g/mL extract for 24 hours, percent mean mortality (± SE) was 72.7 plusmn; 1.8 for the bark, 68.7 ± 1.6 for fruits and 60 ± 1.6 for leaves. These means were not significantly different (χ2 = 4.12; df = 2; p = 0.127). At a concentration of 0.01 g/mL, > 95% of the larvae died within 24 hours of exposure to powdered neem leaf, but it took 120 hours to reach the same level of larval mortality in aqueous leaf extract. The crude extract slowly inhibited the growth and development of mosquitoes while the crude powder acted more as a barrier; the mosquitoes probably died from suffocation. However, both types of preparations can be made and used by local people to control mosquito breeding in anthropogenic habitats, especially in urbanized areas

    Partially Supersymmetric Composite Higgs Models

    Get PDF
    We study the idea of the Higgs as a pseudo-Goldstone boson within the framework of partial supersymmetry in Randall-Sundrum scenarios and their CFT duals. The Higgs and third generation of the MSSM are composites arising from a strongly coupled supersymmetric CFT with global symmetry SO(5) spontaneously broken to SO(4), whilst the light generations and gauge fields are elementary degrees of freedom whose couplings to the strong sector explicitly break the global symmetry as well as supersymmetry. The presence of supersymmetry in the strong sector may allow the compositeness scale to be raised to ~10 TeV without fine tuning, consistent with the bounds from precision electro-weak measurements and flavour physics. The supersymmetric flavour problem is also solved. At low energies, this scenario reduces to the "More Minimal Supersymmetric Standard Model" where only stops, Higgsinos and gauginos are light and within reach of the LHC.Comment: 28 pages. v2 minor changes and Refs. adde
    corecore