254 research outputs found

    Prediction of survival with second-line therapy in biliary tract cancer: Actualisation of the AGEO CT2BIL cohort and European multicentre validations

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    BACKGROUND: The benefit of second-line chemotherapy (L2) over standard first-line (L1) gemcitabine plus cisplatin (GEMCIS) or oxaliplatin (GEMOX) chemotherapy in advanced biliary tract cancer (aBTC) is unclear. Our aim was to identify and validate prognostic factors for overall survival (OS) with L2 in aBTC to guide clinical decisions in this setting. METHODS: We performed a retrospective analysis of four prospective patient cohorts: a development cohort (28 French centres) and three validation cohorts from Italy, UK and France. All consecutive patients with aBTC receiving L2 after GEMCIS/GEMOX L1 between 2003 and 2016 were included. The association of clinicobiological data with OS was investigated in univariate and multivariate Cox analyses. A simple score was derived from the multivariate model. RESULTS: The development cohort included 405 patients treated with L1 GEMOX (91%) or GEMCIS. Of them, 55.3% were men, and median age was 64.8 years. Prior surgical resection was observed in 26.7%, and 94.8% had metastatic disease. Performance status (PS) was 0, 1 and 2 in 17.8%, 52.4% and 29.7%, respectively. Among 22 clinical parameters, eight were associated with OS in univariate analysis. In multivariate analysis, four were independent prognostic factors (p < 0.05): PS, reason for L1 discontinuation, prior resection of primary tumour and peritoneal carcinomatosis. The model had the Harrell's concordance index of 0.655, a good calibration and was validated in the three external cohorts (N = 392). CONCLUSION: We validated previously reported predictive factors of OS with L2 and identified peritoneal carcinomatosis as a new pejorative factor in nearly 800 patients. Our model and score may be useful in daily practice and for future clinical trial design

    Workshop on Raising Data using the RDBES and TAF (WKRDBESRaiseTAF; outputs from 2022 meeting)

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    41 pĂĄginasThe Workshop on Raising Data using the RDBES and TAF (WKRDBES-Raise&TAF) met online (26–30 of September 2022) to evaluate the use of the Regional Database and Estimation System (RDBES) format to reproduce the 2022 InterCatch input and output, identifying a Transparent Assessment Framework (TAF) structure to organize the intermediate steps and to propose standardized output formats. The main outcomes of WKRDBES-Raise&TAF were: · RDBES provides sufficient support for current national estimation protocols. However, some minor issues were reported that hampered an exact reproduction of the estimates. Therefore, adaptations of the data model should not be excluded completely. · All the input to stock assessment that InterCatch currently provides, could be reproduced. The participants started from the current stock extracts that can be downloaded from InterCatch. · A workflow was proposed with a national TAF repository for each country, a stock estimation repository and a stock assessment repository. The intermediate output of those repositories will be stored in an ‘intermediate output database’ and depending on the user role, you will get access to the relevant stages in this workflow. · The following requirements for the standard output formats were defined: they cannot be more restrictive than the InterCatch input and output format; they should present measures of uncertainty and sample sizes (for national estimates) and should have a configurable domain definition (for national estimates). Despite those successful outcomes, the current plan for transition to an operational system was concluded to be too optimistic. WKRDBES-Raise&TAF therefore recommends to the Working Group on Governance of the Regional Database and Estimation System (WGRDBESGOV) to revise the roadmap and allow RDBES to be in a test phase also for 2023. WKRDBES-Raise&TAF felt the need to test the proposed workflow on a small scale and therefore recommends to the WGRDBESGOV to arrange a workshop where two stocks (pok.27.3a46 (Saithe (Pollachius virens) in Subareas 4, 6 and Division 3.a (North Sea, Rockall and West of Scotland, Skagerrak and Kattegat) and wit.27.3a47d (Witch (Glyptocephalus cynoglossus) in Subarea 4 and Divisions 3.a and 7.d (North Sea, Skagerrak and Kattegat, eastern English Channel)) will be set up to go through the whole flow.Peer reviewe

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð„with constraintsð ð ð„ „ ðandðŽð„ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

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    A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV

    Search for supersymmetry in events with one lepton and multiple jets in proton-proton collisions at root s=13 TeV

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    Measurement of the top quark mass using charged particles in pp collisions at root s=8 TeV

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    Modélisation statistique de distribution spatiale et temporelle d'espÚces d'invertébrés dans le Golfe du Saint Laurent.

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    Understanding spatial and spatio-temporal species distribution is a key aspect in a management context. Thereby, a large number of statistical approaches have been developed to study their spatio-temporal distributions. However, the modeling of species distribution raises two main difficulties: (i) typical data present an excess of zero. This large proportion of zero requires specific zero-inflated modeling approaches. (ii) variables sampled in the same area often present spatial autocorrelation. Ignoring this autocorrelation may produce to false conclusion. Two approaches, which can handle zero- inflated data are compared in terms of response to variable sampling effort. This comparison is performed by simulations and using fishery dependent data of groundfish species. Delta-distribution approaches, which are the classical tool to model such zero-inflated data in ecology, can lead to poor estimates when the variability in the sampling effort is important. On the opposite, a compound Poisson with gamma marks (CPG) is much more robust to variable sampling conditions. The second part of this work aims at developing spatial model for representing the biomass distribution of epibenthic invertebrates sampled in the southern Gulf of Saint Lawrence (sGSL) since 1989 by Fisheries and Ocean Canada. Data from such broad scale surveys are ideal for understanding spatial and temporal changes in population abundance and community structure. A Bayesian hierarchical model (HBM) based on the CPG is proposed to study the distribution of these species. The latent spatial process is modeled with an exponential variogram associated with three environmental variables (sediment, depth and temperature). Maps of quantities of interest (e.g. probability of presence, quantity of biomass) are produced, taking into account the uncertainty of the estimated parameters and observation errors. This hierarchical Bayesian modeling approach provides a useful tool for spatial management of human activities that may affect living resources. Finally, a spatio-temporal model is presented to study the evolution of the biomass of invertebrates in the sGSL. The HBM proposed previously is used again, but the variogram is replaced by a latent grid, which accounts for the spatial and temporal dependencies. The spatial structure is modeled by convolving an independent process with an exponential kernel on the grid. This grid is also controlling the temporal dependency, which is modeled with an autoregressive model of order 1. The approach allows to study the evolution of biomass quantities of the epibenthic invertebrates of the sGSL. The spatio-temporel model developed is flexible and efficient and open a whole range of perspectives.Comprendre et Ă©tudier la distribution spatiale et temporelle des espĂšces est un enjeu margeur pour leur gestion. De ce fait, de nombreuses approches statistiques ont Ă©tĂ© dĂ©veloppĂ©es pour Ă©tudier leur rĂ©partition spatio-temporelles. Cependant, modĂ©liser la distribution d'une population pose deux difficultĂ©s majeures : (i) les jeux de donnĂ©es disponibles prĂ©sentent souvent une forte quantitĂ© de zĂ©ros. Cet excĂšs de zĂ©ros implique l'utilisation d'outils statistiques spĂ©cifiques, (ii) les valeurs de variables prĂ©levĂ©es en des sites voisins sont spatialement corrĂ©lĂ©es. Ignorer cette autocorrĂ©lation peut amener Ă  de fausses conclusions. Deux approches, adaptĂ©es aux donnĂ©es continues Ă  forte proportion de zĂ©ros, sont comparĂ©es lorsque l'effort d'Ă©chantillonnage (p. ex. durĂ©e, distance) est variable. La comparaison est effectuĂ©e par simulations et avec des donnĂ©es de pĂȘches commerciales de poissons de fond au large de Vancouver. L'approche delta, la plus utilisĂ©e en Ă©cologie, ne permet pas de prendre en compte cet effort variable correctement, tandis que la seconde approche, un Poisson composĂ© Ă  marques gamma (CPG), est robuste Ă  cette variabilitĂ©. La seconde partie de ces travaux s'est intĂ©ressĂ©e Ă  la modĂ©lisation spatiale de quantitĂ©s de biomasses d'invertĂ©brĂ©s Ă©pibenthiques dans le golfe du Saint-Laurent. Chaque annĂ©e depuis 1989, PĂȘche et OcĂ©an Canada organise une campagne de pĂȘche scientifique dans cette rĂ©gion. De telles donnĂ©es sont idĂ©ales pour comprendre les changements spatio-temporels d'abondance de populations. Un modĂšle hiĂ©rarchique bayĂ©sien (HBM) basĂ© sur le modĂšle CPG est proposĂ© pour Ă©tudier la rĂ©partition spatiale de ces espĂšces d'invertĂ©brĂ©s. La structure spatiale de la biomasse est modĂ©lisĂ©e grĂące Ă  un variogramme exponentiel associĂ© Ă  trois variables environnementales (sĂ©diment, profondeur et tempĂ©rature) dans la couche latente du HBM. Cette mĂ©thode produit des cartes de quantitĂ©s d'intĂ©rĂȘt (p. ex. probabilitĂ© de prĂ©sence, biomasse moyenne) en tenant compte de l'incertitude des paramĂštres estimĂ©s ainsi que les erreurs associĂ©es aux observations. Ce HBM fournit des outils utiles pour la gestion spatiale de populations. Enfin, une approche de modĂ©lisation spatio-temporelle des quantitĂ©s de biomasses d'invertĂ©brĂ© est proposĂ©e. Le HBM basĂ© sur le modĂšle CPG est une nouvelle fois utilisĂ©, mais l'utilisation du variogramme est remplacĂ©e par une grille latente, support de la dĂ©pendance spatio-temporelle. La structure spatiale est approchĂ©e par convolution discrĂšte d'un bruit blanc Ă  l'aide d'un noyau exponentiel sur la grille latente. Cette mĂȘme grille contrĂŽle Ă©galement la dĂ©pendance temporelle qui est modĂ©lisĂ©e par un processus autorĂ©gressif d'ordre 1. Ce modĂšle permet d'Ă©tudier l'Ă©volution des quantitĂ©s de biomasses des espĂšces d'invertĂ©brĂ©s du golfe. L'approche spatio-temporelle dĂ©veloppĂ©e, flexible et performante, ouvre beaucoup de perspectives quant Ă  la modĂ©lisation spatio-temporelle de distribution d'espĂšce

    Evaluation des impacts de mesures de gestion pour la sole du golfe de Gascogne (8ab)

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    Une baisse de captures de sole du Golfe de Gascogne est recommandĂ©e par le CIEM pour 2022. Pour y rĂ©pondre, un certain nombre de mesures de gestion peuvent ĂȘtre envisagĂ©es et leur impact estimĂ© par simulations. Ces mesures doivent conduire Ă  une diminution effective des captures (pas seulement des dĂ©barquements), nĂ©cessaire pour rĂ©tablir le stock, quel que soit le niveau auquel sera fixĂ© le TAC. L’amĂ©lioration de l’état d’un stock passe par une diminution de la mortalitĂ© par pĂȘche globale et donc des volumes capturĂ©s, mais peut Ă©galement impliquer une amĂ©lioration du diagramme d’exploitation, par exemple en capturant moins de petits individus. La diminution de la mortalitĂ© par pĂȘche globale implique une rĂ©duction d’effort de pĂȘche (arrĂȘt temporaire, diminution de la taille des filets
) ; l’amĂ©lioration du diagramme d’exploitation peut, elle, nĂ©cessiter des augmentations de maillages et/ou des modifications de pratiques de pĂȘche comme la diminution de l’effort de pĂȘche dans des zones ou Ă  des pĂ©riodes oĂč les captures de petits individus sont importantes. Dans un contexte oĂč le recrutement est faible, toute mesure permettant d’en tirer le meilleur parti, en permettant aux petits individus de grandir, devrait ĂȘtre encouragĂ©e. La pertinence des rĂ©sultats de ces diverses simulations repose sur la qualitĂ© des donnĂ©es utilisĂ©es. Ainsi des donnĂ©es non exhaustives de capture de petits individus conduira Ă  une sous-estimation des impacts d’une amĂ©lioration de la sĂ©lectivitĂ© (au sens large). L’impact de chacun des scĂ©narios sur le chiffre d’affaires est estimĂ© pour chaque flottille en supposant que la diminution du chiffre d’affaire (CA) est proportionnelle Ă  la diminution d’effort de pĂȘche. Cependant, l’impact sur les autres espĂšces que la sole d’une modification des maillages ne peut ĂȘtre estimĂ©, en l’absence de paramĂštres de sĂ©lectivitĂ©. De mĂȘme, l’impact d’une fermeture spatiale ne peut ĂȘtre quantifiĂ© en l’absence d’information sur l’activitĂ© dans ces zones des navires non soumis Ă  la gĂ©olocalisation (VMS). Les fileyeurs de plus de 12 mĂštres Ă©tant les plus gros contributeurs Ă  la mortalitĂ© par pĂȘche de la sole, principalement au 1er trimestre, il peut ĂȘtre logique de faire porter une grande part de l’effort de rĂ©duction Ă  cette flottille, ou Ă  ce trimestre. NĂ©anmoins, cela reste une option, pas une recommandation, comme le sont tous les scĂ©narios prĂ©sentĂ©s dans ce document
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