Daniel Simpson

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The INLA approach for approximate Bayesian inference for latent Gaussian models has been shown to give fast and accurate estimates of posterior marginals and also to be a valuable tool in practice via the R-package R-INLA. In this paper we formalize new developments in the R-INLA package and show how these features greatly extend the scope of models that(More)
In this work we consider a hierarchical spatio-temporal model for particulate matter (PM) concentration in the North-Italian region Piemonte. The model involves a Gaussian Field (GF), affected by a measurement error, and a state process characterized by a first order autoregressive dynamic model and spatially correlated innovations. This kind of model is(More)
A large number of statistical models are ‘doubly-intractable’: the likelihood normalising term, which is a function of the model parameters, is intractable, as well as the marginal likelihood (model evidence). This means that standard inference techniques to sample from the posterior, such as Markov chain Monte Carlo (MCMC), cannot be used. Examples(More)
Despite recent advances in novel therapies, the prognosis for patients with squamous cell carcinoma of the head and neck (SCCHN) remains poor. Progress in understanding the biology of cancer has led to the development of personalized therapy targeted at blocking defective signaling pathways of cancer cells. These drugs aim to act selectively to reduce the(More)
PURPOSE To report on the acute and late gastrointestinal (GI) and genitourinary (GU) toxicity associated with a unique technique of image-guided radiotherapy (IGRT) in patients undergoing postprostatectomy irradiation. METHODS AND MATERIALS Fifty patients were treated with intensity-modulated radiation therapy (IMRT) after radical prostatectomy. Daily(More)
BACKGROUND Stereotactic body radiotherapy (SBRT) is a technique used to deliver high, ablative doses of radiation in a limited number of fractions to ≥ 1 extracranial target(s). To the authors' knowledge, the prevalence of SBRT use among radiation oncologists in the United States is unknown. METHODS A random sample of 1600 American radiation oncologists(More)
A general scheme to exploit Exact-Approximate MCMC methodology for intractable likelihoods is suggested. By representing the intractable likelihood as an infinite Maclaurin or Geometric series expansion, unbiased estimates of the likelihood can be obtained by finite time stochastic truncations of the series via Russian Roulette sampling. Whilst the(More)
Exogenously provided NGF enhances cognitive performance in impaired rodents and humans and is currently a promising compound for the treatment of dementia. To investigate whether NGF-dependent cognitive improvement may be due in part to increased hippocampal neurogenesis, adult and aged male rats were treated with NGF or vehicle intracerebroventricularly(More)
In this paper we introduce a new method for performing computational inference on log-Gaussian Cox processes (LGCP). Contrary to current practice, we do not approximate by a counting process on a partition of the domain, but rather attack the point process likelihood directly. In order to do this, we use the continuously specified Markovian random fields(More)