5,904 research outputs found
Response-dependent two-phase sampling designs for biomarker studies
No full textTwo‐phase sampling designs are developed and investigated for use in the context of a rheumatology study where interest lies in the association between a biomarker with an expensive assay and disease progression. We derive optimal phase‐II stratum‐specific sampling probabilities for analyses from parametric maximum likelihood (ML), mean score (MS), inverse probability weighted (IPW) and augmented inverse probability weighted estimating equations (AIPW). The easy‐to‐implement optimally efficient design for the MS estimator is found to be asymptotically optimal for the IPW and AIPW estimators we consider, and is shown to result in efficiency gains over balanced and simple random sampling even when analyses are likelihood‐based. We further demonstrate the robustness of this optimal design and show that it results in very efficient estimation even when the model or parameters used in its derivation are misspecified. This is the peer-reviewed version of the following article: McIsaac, M. A., & Cook, R. J. (2014). Response-dependent two-phase sampling designs for biomarker studies. Canadian Journal Of Statistics, 42(2), 268-284. doi:10.1002/cjs.11207, which has been published in final form at http://doi.org/10.1002/cjs.11207. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Version
β-Catenin is a useful adjunct immunohistochemical marker for the diagnosis of pulmonary lymphangioleiomyomatosis
No full textLymphangioleiomyomatosis (LAM) is a rare multisystem disease leading to cystic destruction of the lung parenchyma and is associated with abnormal smooth muscle proliferation affecting airways, lymphatics, and blood vessels. LAM occurs sporadically or in association with the tuberous sclerosis complex (TSC). Recent evidence demonstrates the role of aberrant β-catenin signaling in TSC. To further understand the pathogenesis of LAM and to examine the diagnostic usefulness of β-catenin, we examined protein expression in 28 pulmonary LAM cases and 10 cases of renal angiomyolipoma resected from patients with sporadic LAM. Immunohistochemical analysis was performed for established markers of LAM cells (HMB45, estrogen receptor [ER]-α, and progesterone receptor [PR]) and β-catenin. All LAM cases were positive for β-catenin and demonstrated high specificity with overall immunoreactivity superior to HMB45, ER-α, and PR. Similar expression was demonstrated in renal angiomyolipoma. Our results indicate that β-catenin is a useful marker of LAM and may be clinically useful in the diagnostic setting
Reformulating the rj-McMC Algorithm for 3D Inversion of Passive Seismic Data for Near-Surface Characterization
No full textGeophysical subsurface characterization techniques could, due to their non-invasive nature, play a crucial role in the design and subsequent construction of infrastructure in urban & industrial environ- ments. Geo-data specialist company Fugro sees potential in upgrading their current ambient-seismic- noise-tomography workflow, to make use of state-of-the-art inversion schemes with the main goal of increasing the quality and accuracy of the initial-site characterization delivered to clients. In this thesis I explore the feasibility of utilizing the reverse-jump Markov chain Monte Carlo (rj-McMC) algorithm for the inversion of ambient seismic noise for characterization in urban & industrial environments. Specif- ically, testing the potential of scaling down this inversion algorithm to fit in a small scale, near-surface framework. To achieve this, I first carried out analyses to evaluate the appropriate Rayleigh wave frequency range, after which realistic noise hyperparameters, suited for this reduced scale problem, were obtained. Because of the potential exploitation of in-situ borehole measurements, I reformulated the Bayesian prior within the rj-McMC algorithm to implement these constraining shear wave velocity values appropriately. I conducted extensive synthetic experiments to gain insight into the behavior of this adapted algorithm, from which it was concluded that the inherent dynamic discretization partially prevents these constraints from being implemented to their full extent. Nevertheless, promising results lead me to conclude that the use of the rj-McMC algorithm for application in near-surface urban & industrial environments is feasible.Applied Geophysics | IDEA Leagu
Ballads, Tudor Vagabonds and Roundhead Reputations: the Restoration After-Life of Cook Laurel
No full textThis essay examines how ballad song was appropriated to present the demise of the Rump Parliament and commemorate the Restoration of the monarchy. Songs not only provide a tune through which words could be performed, but also weave together disparate texts through memory of past utterances and performances. The tune “Cook Laurel” establishes a mnemonic connection between Parliamentarian figures and ubiquitous rascals in Elizabethan folklore and in Ben Jonson’s Gipsies Metmorphos’d (performed 1621). The use of song emphasizes and consolidates representations of Parliamentarians as rogues, offering royalists a way to lament the regicide and to celebrate the Restoration
Systematic review: efficacy and safety of rituximab for adults with idiopathic thrombocytopenic purpura.
No full textComprehensive sequencing of dilated cardiomyopathy genes reveals additive effects of multiple genes on disease risk and severity
No full textTransition to Adult Services – What Can the Paediatric Teams and Adult Teams Learn From Each Other?
No full textCLINICAL AND GENETIC CHARACTERISTICS OF FAMILIAL DILATED CARDIOMYOPATHY IN A LARGE UK PROSPECTIVE COHORT
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