94,078 research outputs found
Spatial-temporal rainfall simulation using generalized linear models
We consider the problem of simulating sequences of daily rainfall at a network of sites in such a way as to reproduce a variety of properties realistically over a range of spatial scales. The properties of interest will vary between applications but typically will include some measures of "extreme'' rainfall in addition to means, variances, proportions of wet days, and autocorrelation structure. Our approach is to fit a generalized linear model (GLM) to rain gauge data and, with appropriate incorporation of intersite dependence structure, to use the GLM to generate simulated sequences. We illustrate the methodology using a data set from southern England and show that the GLM is able to reproduce many properties at spatial scales ranging from a single site to 2000 km 2 ( the limit of the available data)
3D beam-column finite element under non-uniform shear stress distribution due to shear and torsion
The paper discusses the application of a 2-node, three-dimensional (3D) beam-column finite element with an enhanced fiber cross-section model to the inelastic response analysis of concrete members. The element accounts for the local distribution of strains and stresses under the coupling of axial, flexural, shear, and torsional effects with an enriched kinematic description that accounts for the out-of-plane deformations of the cross-section. To this end the warping displacements are interpolated with the addition of a variable number of local degrees of freedom. The material response is governed by a 3D nonlinear stress-strain relation with damage that describes the degrading mechanisms of typical engineering materials under the coupling of normal and shear stresses. The element formulation is validated by comparing the numerical results with measured data from the response of two prismatic concrete beams under torsional loading and with standard beam formulations
Erythema nodosum as a result of estrogen patch therapy for prostate cancer: a case report.
© 2015 Coyle et al.Introduction: Erythema nodosum is often associated with a distressing symptomatology, including painful subcutaneous nodules, polyarthropathy, and significant fatigue. Whilst it is a well-documented side-effect of estrogen therapy in females, we describe what we believe to be the first report in the literature of erythema nodosum as a result of estrogen therapy in a male. Case presentation: A 64-year-old Afro-Caribbean man with locally advanced carcinoma of the prostate agreed to participate in a randomized controlled trial comparing estrogen patches with luteinizing hormone-releasing hormone analogs to achieve androgen deprivation, and was allocated to the group receiving estrogen patches. One month later he presented with tender lesions on his shins and painful swelling of his ankles, wrists, and left shoulder. This was followed by progressive severe fatigue that required hospital admission, where he was diagnosed with erythema nodosum by a rheumatologist. Two months after discontinuing the estrogen patches the erythema nodosum, and associated symptoms, had fully resolved, and to date he remains well with no further recurrence. Conclusion: Trial results may establish transdermal estrogen as an alternative to luteinizing hormone-releasing hormone analogs in the management of prostate cancer, and has already been established as a therapy for male to female transsexuals. It is essential to record the toxicity profile of transdermal estrogen in men to ensure accurate safety information. This case report highlights a previously undocumented toxicity of estrogen therapy in men, of which oncologists, urologists, and endocrinologists need to be aware. Rheumatologists and dermatologists should add estrogen therapy to their differential diagnosis of men presenting with erythema nodosum
Software for cut-generating functions in the Gomory--Johnson model and beyond
We present software for investigations with cut generating functions in the
Gomory-Johnson model and extensions, implemented in the computer algebra system
SageMath.Comment: 8 pages, 3 figures; to appear in Proc. International Congress on
Mathematical Software 201
The Stratigraphic Record of Pre-breakup Geodynamics: Evidence from the Barrow Delta, offshore Northwest Australia
The structural and stratigraphic evolution of rift basins and passive margins has been widely studied, with many analyses demonstrating that delta systems can provide important records of post-rift geodynamic processes. However, the apparent lack of ancient syn-breakup delta systems and the paucity of seismic imaging across continent-ocean boundaries means the transition from continental rifting to oceanic spreading remains poorly understood. The Early Cretaceous Barrow Group of the North Carnarvon Basin, offshore NW Australia was a major deltaic system that formed during the latter stages of continental rifting, and represents a rich sedimentary archive, documenting uplift, subsidence and erosion of the margin. We use a regional database of 2D and 3D seismic and well data to constrain the internal architecture of the Barrow Group. Our results highlight three major depocentres: the Exmouth and Barrow sub-basins, and southern Exmouth Plateau. Over-compaction of pre-Cretaceous sedimentary rocks in the South Carnarvon Basin, and pervasive reworking of Permian and Triassic palynomorphs in the offshore Barrow Group, suggests that the onshore South Carnarvon Basin originally contained a thicker sedimentary succession, which was uplifted and eroded prior to breakup. Backstripping of sedimentary successions encountered in wells in the Exmouth Plateau depocentre indicate anomalously rapid tectonic subsidence (≤0.24 mm yr-1) accommodated Barrow Group deposition, despite evidence for minimal, contemporaneous upper crustal extension. Our results suggest that classic models of uniform extension cannot account for the observations of uplift and subsidence in the North Carnarvon Basin, and may indicate a period of depth-dependent extension or dynamic topography preceding breakup
Duration of untreated psychosis and social function: 1-year follow-up study of first-episode schizophrenia.
BACKGROUND: In first-episode schizophrenia, longer duration of untreated psychosis (DUP) predicts poorer outcomes. AIMS: To address whether the relationship between DUP and outcome is a direct causal one or the result of association between symptoms and/or cognitive functioning and social functioning at the same time point. METHOD: Symptoms, social function and cognitive function were assessed in 98 patients with first-episode schizphrenia at presentation and 1 year later. RESULTS: There was no significant clinical difference between participants with short and long DUP at presentation. Linear regression analyses revealed that longer DUP significantly predicted more severe positive and negative symptoms and poorer social function at 1 year, independent of scores at presentation. Path analyses revealed independent direct relationships between DUP and social function, core negative symptoms and positive symptoms. There was no significant association between DUP and cognition. CONCLUSIONS: Longer DUP predicts poor social function independently of symptoms. The findings underline the importance of taking account of the phenomenological overlap between measures of negative symptoms and social function when investigating the effects of DUP
Z2SAL: a translation-based model checker for Z
Despite being widely known and accepted in industry, the Z formal specification language has not so far been well supported by automated verification tools, mostly because of the challenges in handling the abstraction of the language. In this paper we discuss a novel approach to building a model-checker for Z, which involves implementing a translation from Z into SAL, the input language for the Symbolic Analysis Laboratory, a toolset which includes a number of model-checkers and a simulator. The Z2SAL translation deals with a number of important issues, including: mapping unbounded, abstract specifications into bounded, finite models amenable to a BDD-based symbolic checker; converting a non-constructive and piecemeal style of functional specification into a deterministic, automaton-based style of specification; and supporting the rich set-based vocabulary of the Z mathematical toolkit. This paper discusses progress made towards implementing as complete and faithful a translation as possible, while highlighting certain assumptions, respecting certain limitations and making use of available optimisations. The translation is illustrated throughout with examples; and a complete working example is presented, together with performance data
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