454 research outputs found
Approximate controllability for some integrodifferential measure driven system with nonlocal conditions
In this work, we focus on a specific category of nonlocal integrodifferential equations. The development of a few new sufficient postulates that guarantee solvability and approxi- mative controllability is described here. We apply the theory of the resolvent operator in the sense of Grimmer, as well as the fixed point strategy and the theory of the Lebesgue-Stieljes integral, in the context of the space of regulated functions. In light of this, the prevalence of our findings is greater than that which is found in the literature. At last, and example is comprised that exhibits the significance of developed theory
Improving the depth sensitivity of time-resolved measurements by extracting the distribution of times-of-flight
Time-resolved (TR) techniques provide a means of discriminating photons based on their time-of-flight. Since early arriving photons have a lower probability of probing deeper tissue than photons with long time-of-flight, time-windowing has been suggested as a method for improving depth sensitivity. However, TR measurements also contain instrument contributions (instrument-response-function, IRF), which cause temporal broadening of the measured temporal point-spread function (TPSF) compared to the true distribution of times-of-flight (DTOF). The purpose of this study was to investigate the influence of the IRF on the depth sensitivity of TR measurements. TPSFs were acquired on homogeneous and two-layer tissue-mimicking phantoms with varying optical properties. The measured IRF and TPSFs were deconvolved using a stable algorithm to recover the DTOFs. The microscopic Beer-Lambert law was applied to the TPSFs and DTOFs to obtain depth-resolved absorption changes. In contrast to the DTOF, the latest part of the TPSF was not the most sensitive to absorption changes in the lower layer, which was confirmed by computer simulations. The improved depth sensitivity of the DTOF was illustrated in a pig model of the adult human head. Specifically, it was shown that dynamic absorption changes obtained from the late part of the DTOFs recovered from TPSFs acquired by probes positioned on the scalp were similar to absorption changes measured directly on the brain. These results collectively demonstrate that this method improves the depth sensitivity of TR measurements by removing the effects of the IRF. Ā© 2013 Optical Society of America
DĆ©veloppement dāun algorithme pour la surveillance de lāincidence du cancer colorectal Ć MontrĆ©al avec les banques donnĆ©es mĆ©dico-administratives de la RAMQ
Contexte : Les meĢthodes actuelles, dāidentification des cas de cancer, utiliseĢes au QueĢbec et ailleurs sont connues pour sous-estimer le fardeau du cancer, en particulier pour certains sous- groupes de population. Les algorithmes utilisant des donneĢes de facturation constituent des options peu couĢteuses pour ameĢliorer la qualiteĢ de la surveillance du cancer, mais nāont pas eĢteĢ mis en place au niveau populationnel.
Objectifs : Nos objectifs eĢtaient de : 1) deĢvelopper un algorithme permettant lāidentification des cas de cancer colorectal (CCR) en utilisant, au niveau populationnel, les donneĢes des hospitalisations et de facturation ; 2) valider lāalgorithme ; et 3) deĢcrire les caracteĢristiques des cas nouvellement captureĢs.
MeĢthodes : Nous avons jumeleĢ les donneĢes de facturation des meĢdecins, des hospitalisations et du fichier des tumeurs (FiTQ) pour 2 013 430 reĢsidents montreĢalais aĢgeĢs de 20 et plus entre le 1er avril 2000 et le 31 mars 2010. Nous avons compareĢ les performances de trois algorithmes baseĢs sur des codes de diagnostics et diffeĢrentes sources de donneĢes. Nous avons valideĢ les cas de CCR identifieĢs en utilisant les codes dāacte de traitement, la reĢpartition par site et les tendances temporelles. Nous avons deĢcrit les cas identifieĢs selon lāaĢge, le sexe, le statut socioeĢconomique et les types de traitement.
ReĢsultats : Notre algorithme baseĢ sur les codes de diagnostics et de traitement identifie 11 476 des 12 933 cas incidents de CCR contenus dans le FiTQ ainsi que 2 317 cas nouvellement captureĢs. Nos cas ont des tendances globales dans le temps et des distributions par site similaires aux donneĢes existantes, ce qui augmente notre confiance en lāalgorithme. Notre algorithme a captureĢ, en termes de pourcentage, plus dāindividus aĢgeĢs de 50 ans et moins chez les cas de CCR nouvellement captureĢs : 8,2 % contre 5,3 %. De plus, les cas nouvellement captureĢs sont plus susceptibles de vivre dans des zones favoriseĢes socioeĢconomiquement.
Conclusions : Notre algorithme fournit un portrait plus complet de lāincidence du CCR aĢ lāeĢchelle de la population que les meĢthodes actuelles dāidentification. Il pourrait eĢtre utiliseĢ pour estimer les tendances de lāincidence aĢ long terme, aider aĢ la surveillance en temps opportun et supporter les interventions, au QueĢbec et dans dāautres provinces ou pays ayant des donneĢes similaires.Background: Cancer case ascertainment methods used in Quebec and elsewhere are known to underestimate the burden of cancer, particularly for certain subgroups. Algorithms using claims data are a low-cost option to improve the quality of cancer surveillance but have not been implemented at the population-level.
Objectives: Our objectives were to 1) develop a colorectal cancer (CRC) case ascertainment algorithm using population-level hospitalization and physician billing data, 2) validate the algorithm, and 3) describe the characteristics of newly-captured cases.
Methods: We linked physician billing, hospitalization, and tumour registry data for 2,013,430 Montreal residents aged 20 + (2000ā2010). We compared the performance of three algorithms based on diagnostic codes and different data sources. We validated cases using receipt of treatment, site distribution, and time trends. We described identified cases according to age, sex, socioeconomic status, and treatment patterns.
Results: Our algorithm based on diagnosis and treatment codes identified 11,476 of the 12,933 incident CRC cases contained in the tumour registry as well as 2,317 newly-captured cases. Our cases share similar overall time trends and site distributions to existing data, which increases our confidence in the algorithm. Our algorithm captured, proportionally more individuals aged 50 and younger among newly captured CRC cases: 8.2% vs. 5.3%. Additionally, newly captured cases were more likely to live in socioeconomically advantaged areas.
Conclusions: Our algorithm provides a more complete picture of population-wide CRC incidence than existing case ascertainment methods. It could be used to estimate long-term incidence trends, aid in timely surveillance, and to inform interventions, in both Quebec and other jurisdictions
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