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[Letter from Barry M. Wagner to Luis Casanova, July 29, 1992]
No full textA letter from Barry M. Wagner, Director, Media Production, Center for Instruction Services, to Luis Casanova, Producer, Nebraska ETV. The letter is in regards to prior correspondence, and the notification that the North Texas Institute for Educators on the Visual Arts had contacted the Dallas County Community College Center to produce the Getty Teleconference, October 21
RoMEO Studies 4: An analysis of Journal publishers' Copyright Agreements
No full textThis article is the fourth in a series of six emanating from the UK JISC-funded RoMEO Project (Rights Metadata for Open archiving). It describes an analysis of 80 scholarly journal publishers’ copyright agreements with a particular view to their effect on author self-archiving. 90% of agreements asked for copyright transfer and 69% asked for it prior to refereeing the paper. 75% asked authors to warrant that their work had not been previously published although only two explicitly stated that they viewed self-archiving as prior publication. 28.5% of agreements provided authors with no usage rights over their own paper. Although 42.5% allowed self-archiving in some format, there was no consensus on the conditions under which self-archiving could take place. The article concludes that author-publisher copyright agreements should be reconsidered by a working party representing the needs of both partie
Effects of nebivolol and atenolol on small arteries and microcirculatory endothelium-dependent dilation in hypertensive patients undergoing isometric stress.
No full textEffects of nebivolol and atenolol on small arteries and microcirculatory endothelium-dependent dilation in hypertensive patients undergoing isometric stress. Arosio E1, De Marchi S, Prior M, Zannoni M, Lechi A. Author information Abstract OBJECTIVE: To examine the effects on small arteries and on the cutaneous microcirculatory system of nebivolol and atenolol in hypertensive patients. DESIGN: Twenty hypertensive patients were randomly assigned to receive nebivolol or atenolol in a single-blind, placebo-controlled cross-over study. Piezoelectric plethysmography on the third finger, laser Doppler on the third finger at rest and after iontophoretic administration of acetylcholine, and pressure-heart rate monitoring, were carried out both at rest and during handgrip. The tests were performed 45 min after 5 mg nebivolol or 100 mg atenolol administration, then repeated 2 days later with a placebo and, after a further 2 days, with atenolol or nebivolol again. RESULTS: Both atenolol and nebivolol reduced diastolic blood pressure values and heart rate, as well the increase of blood pressure and heart rate during handgrip. No change was recorded after placebo. Piezoelectric plethysmography showed a significant increase in the ratio between time to peak and total time (PT/TT), calculated on the sphygmic wave, during handgrip (0.295 0.005 versus 0.231 0.015, P<0.005). After nebivolol, a decrease was recorded in rest conditions (0.185 0.008 versus 0.231 0.015, P<0.005) with no statistically significant increase during handgrip, whereas atenolol showed an increase in the PT/TT ratio at rest, with a sustained response during handgrip. Laser Doppler showed an increased response to acetylcholine only after nebivolol. CONCLUSIONS: Nebivolol and atenolol significantly reduced diastolic blood pressure and heart rate, favourably modulating response to handgrip. Nebivolol improved small artery distensibility index. Endothelium-dependent cutaneous vasodilation after acetylcholine demonstrated a lack of response with atenolol whereas nebivolol favourably acts on endothelial function
Prior elicitation and variable selection for bayesian quantile regression
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Bayesian subset selection suffers from three important difficulties: assigning priors over model space, assigning priors to all components of the regression coefficients vector given a specific model and Bayesian computational efficiency (Chen et al., 1999). These difficulties become more challenging in Bayesian quantile regression framework when one is interested in assigning priors that depend on different quantile levels. The objective of Bayesian quantile regression (BQR), which is a newly proposed tool, is to deal with unknown parameters and model uncertainty in quantile regression (QR). However, Bayesian subset selection in quantile regression models is usually a difficult issue due to the computational challenges and nonavailability of conjugate prior distributions that are dependent on the quantile level. These challenges are rarely addressed via either penalised likelihood function or stochastic search variable selection (SSVS). These methods typically use symmetric prior distributions for regression coefficients, such as the Gaussian and Laplace, which may be suitable for median regression. However, an extreme quantile regression should have different regression coefficients from the median regression, and thus the priors for quantile regression coefficients should depend on quantiles. This thesis focuses on three challenges: assigning standard quantile dependent prior distributions for the regression coefficients, assigning suitable quantile dependent priors over model space and achieving computational efficiency. The first of these challenges is studied in Chapter 2 in which a quantile dependent prior elicitation scheme is developed. In particular, an extension of the Zellners prior which allows for a conditional conjugate prior and quantile dependent prior on Bayesian quantile regression is proposed. The prior is generalised in Chapter 3 by introducing a ridge parameter to address important challenges that may arise in some applications, such as multicollinearity and overfitting problems. The proposed prior is also used in Chapter 4 for subset selection of the fixed and random coefficients in a linear mixedeffects QR model. In Chapter 5 we specify normal-exponential prior distributions for the regression coefficients which can provide adaptive shrinkage and represent an alternative model to the Bayesian Lasso quantile regression model. For the second challenge, we assign a quantile dependent prior over model space in Chapter 2. The prior is based on the percentage bend correlation which depends on the quantile level. This prior is novel and is used in Bayesian regression for the first time. For the third challenge of computational efficiency, Gibbs samplers are derived and setup to facilitate the computation of the proposed methods. In addition to the three major aforementioned challenges this thesis also addresses other important issues such as the regularisation in quantile regression and selecting both random and fixed effects in mixed quantile regression models
Sensitivity to prior independence via Farlie-Gumbel-Morgenstern model
No full textStatistical Methods
Including design in e-manufacturing
No full textThis paper reviews major issues in the implementation of e-manufacturing, particularly the design aspects. It will examine recent progress, drawing out particular issues that are being addressed. Use will be made of the work by the author and colleagues to devise rule-based design and Internet-based control of machines to illustrate how these developments affect the integrated e-manufacturing environment. A dynamic Simulink model of the way e-manufacture is affected by overall design delays is used to evaluate general solutions for partial and complete e-based companies. These models show how changing to improved designs reduces WI
Generators for decompositions of tensor products of modules associated with standard Jordan partitions.
No full textIf K is a field of finite characteristic p, G is a cyclic group of order q = p(alpha), U and W are indecomposable KG-modules with dim U = m and dim W = n, and lambda(m,n,p) is a standard Jordan partition of mn, we describe how to find a generator for each of the indecomposable components of the KG-module U circle times W.Original manuscript prior to peer review (preprint
Insights into the influence of priors in posterior mapping of discrete morphological characters: a case study in Annonaceae
No full textBackground - Posterior mapping is an increasingly popular hierarchical Bayesian based method used to infer character histories and reconstruct ancestral states at nodes of molecular phylogenies, notably of morphological characters. As for all Bayesian analyses specification of prior values is an integrative and important part of the analysis. He we provide an example of how alternative prior choices can seriously influence results and mislead interpretations. Methods/Principal Findings - For two contrasting discrete morphological characters, namely a slow and a fast evolving character found in the plant family Annonaceae, we specified a total of eight different prior distributions per character. We investigated how these prior settings affected important summary statistics. Our analyses showed that the different prior distributions had marked effects on the results in terms of average number of character state changes. These differences arise because priors play a crucial role in determining which areas of parameter space the values of the simulation will be drawn from, independent of the data at hand. However, priors seemed to fit the data better if they would result in a more even sampling of parameter space (normal posterior distribution), in which case alternative standard deviation values had little effect on the results. The most probable character history for each character was affected differently by the prior. For the slower evolving character, the same character history always had the highest posterior probability independent of the priors used. In contrast, the faster evolving character showed different most probable character histories depending on the prior. These differences could be related to the level of homoplasy exhibited by each character. Conclusions - Although our analyses were restricted to two morphological characters within a single family, our results underline the importance of carefully choosing prior values for posterior mapping. Prior specification will be of crucial importance when interpreting the results in a meaningful way. It is hard to suggest a statistically sound method for prior specification without more detailed studies. Meanwhile, we propose that the data could be used to estimate the prior value of the gamma distribution placed on the transformation rate in posterior mappin
Self-archiving practice and the influence of publisher policies in the social sciences
No full textAuthors in different disciplines exhibit very different behaviours on the so-called ‘green’ road to open access, i.e. self-archiving. This study looks at the self-archiving behaviour of authors publishing in leading journals in six social science disciplines. It tests the hypothesis that authors are self-archiving according to the norms of their respective disciplines rather than following self-archiving policies of publishers, and that, as a result, they are self-archiving significant numbers of publisher PDF versions. It finds significant levels of
self-archiving, as well as significant self-archiving of
the publisher PDF version, in all the disciplines
investigated. Publishers’ self-archiving policies have
no influence on author self-archiving practice
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