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Due to the significant role of non‐profit organizations in the development of modern societies, these organizations must adjust their boardrooms. Since traditional theories of corporate governance appear to be limited in explaining the changing non‐profit world, we propose an extended model of governance that integrates the traditional arguments of agency theory with a cognitive dimension. Based on a sample of Spanish foundations, we present evidence on the effect of the board composition on foundations' organizational efficiency. We show that board size and independence do not have a definitive effect on the entity's efficiency. Instead, the knowledge diversity inside the boardroom and the active character of trustees have a positive influence on resource allocation. The cognitive dimension of the extended model of governance is critical to explaining how boards impact on organizational performance. 相似文献
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M.P. Frías F.J. Alonso M.D. Ruiz-Medina J.M. Angulo 《Journal of statistical planning and inference》2008
Estimation of the long-range dependence parameter in spatial processes using a semiparametric approach is studied. An extended formulation of the averaged periodogram method proposed in Robinson [1994. Semiparametric analysis of long memory time series. Ann. Statist. 22, 515–539] is derived, considering a certain homogeneous and isotropic behaviour of the spectral distribution in the low frequencies. The weak consistency of the estimator proposed is proved. 相似文献
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Impact of selection bias on the evaluation of clusters of chemical compounds in the drug discovery process
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Ariel Alonso Elasma Milanzi Geert Molenberghs Christophe Buyck Luc Bijnens 《Pharmaceutical statistics》2015,14(2):129-138
Expert opinion plays an important role when selecting promising clusters of chemical compounds in the drug discovery process. Indeed, experts can qualitatively assess the potential of each cluster, and with appropriate statistical methods, these qualitative assessments can be quantified into a success probability for each of them. However, one crucial element often overlooked is the procedure by which the clusters are assigned to/selected by the experts for evaluation. In the present work, the impact such a procedure may have on the statistical analysis and the entire evaluation process is studied. It has been shown that some implementations of the selection procedure may seriously compromise the validity of the evaluation even when the rating and selection processes are independent. Consequently, the fully random allocation of the clusters to the experts is strongly advocated. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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In epidemiological surveillance it is important that any unusual increase of reported cases be detected as rapidly as possible. Reliable forecasting based on a suitable time series model for an epidemiological indicator is necessary for estimating the expected non-epidemic indicator and to elaborate an alert threshold. Time series analyses of acute diseases often use Gaussian autoregressive integrated moving average models. However, these approaches can be adversely affected by departures from the true underlying distribution. The objective of this paper is to introduce a bootstrap procedure for obtaining prediction intervals in linear models in order to avoid the normality assumption. We present a Monte Carlo study comparing the finite sample properties of bootstrap prediction intervals with those of alternative methods. Finally, we illustrate the performance of the proposed method with a meningococcal disease incidence series. 相似文献
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Over the last decades, the evaluation of potential surrogate endpoints in clinical trials has steadily been growing in importance,
not only thanks to the availability of ever more potential markers and surrogate endpoints, also because more methodological
development has become available. While early work has been devoted, to a large extent, to Gaussian, binary, and longitudinal
endpoints, the case of time-to-event endpoints is in need of careful scrutiny as well, owing to the strong presence of such
endpoints in oncology and beyond. While work had been done in the past, it was often cumbersome to use such tools in practice,
because of the need for fitting copula or frailty models that were further embedded in a hierarchical or two-stage modeling
approach. In this paper, we present a methodologically elegant and easy-to-use approach based on information theory. We resolve
essential issues, including the quantification of “surrogacy” based on such an approach. Our results are put to the test in
a simulation study and are applied to data from clinical trials in oncology. The methodology has been implemented in R. 相似文献
16.
Annouschka Laenen Ariel Alonso Geert Molenberghs Tony Vangeneugden 《Journal of the Royal Statistical Society. Series A, (Statistics in Society)》2009,172(1):237-253
Summary. The concept of reliability denotes one of the most important psychometric properties of a measurement scale. Reliability refers to the capacity of the scale to discriminate between subjects in a given population. In classical test theory, it is often estimated by using the intraclass correlation coefficient based on two replicate measurements. However, the modelling framework that is used in this theory is often too narrow when applied in practical situations. Generalizability theory has extended reliability theory to a much broader framework but is confronted with some limitations when applied in a longitudinal setting. We explore how the definition of reliability can be generalized to a setting where subjects are measured repeatedly over time. On the basis of four defining properties for the concept of reliability, we propose a family of reliability measures which circumscribes the area in which reliability measures should be sought. It is shown how different members assess different aspects of the problem and that the reliability of the instrument can depend on the way that it is used. The methodology is motivated by and illustrated on data from a clinical study on schizophrenia. On the basis of this study, we estimate and compare the reliabilities of two different rating scales to evaluate the severity of the disorder. 相似文献
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Juan Manuel Moreno Manso Mª. Elena García-Baamonde SánchezMacarena Blázquez Alonso 《Children and youth services review》2012,34(1):311-315
This research analyses the morpho-syntactical competence of children in care and the educational style of their parents. The studies from the literature give no specific data concerning how the morphological and syntactic components are affected in children suffering from neglect. These studies point to important deficiencies in language development, but do not specify what such difficulties actually are. This research is carried out within the framework of the residential care children's homes in the region of Extremadura (Spain). The morpho-syntactic competence of the children and the parental educational style of a total of 74 children in residential care are analysed. The subjects are 41 males and 33 females, between 6 and 18 years of age. We apply the ‘Objective Language Criteria Test’ (BLOCScreening) to evaluate their linguistic development and the ‘Autoevaluative Multifactorial Child Adaptation Test’ (TAMAI) to determine educational style. The presence of difficulties in morphosyntaxis is evident. The children with a low dominion of morphology and syntax perceive a more punitive style in the parents. The difficulties in morphosyntax are manifested both expressive and receptive. Use short sentences to frequent omission of morphological markers. Comprehension problems are lower than those of expression, but it shows a erroneous understanding of some grammatical structures, and grammatical errors in spontaneous speech. Use fewer morphologically complex words in their narratives. Have difficulty in organising the content of the speech and the use of cohesive devices (using the precision and accuracy of the conjunctions used in compound sentences). We must stress the need to carry out early prevention and intervention programmes in order to promote an increase in both the quantity and the quality of language stimulation. From there, the need to set up intervention programmes that influence the linguistic competence of children who have suffered abuse. 相似文献
18.
Juan Manuel Moreno Manso Mª. Elena García-BaamondeMacarena Blázquez Alonso 《Children and youth services review》2011,33(7):1325-1331
This article proposes an intervention program, designed specifically for children in residential care who suffer institutionalized abuse, aimed at stimulating their use of language. The objective of the intervention procedure is to improve children's linguistic competence and their socio-affective development, as well as to enable parents to communicate and interact effectively with their children. Several studies have focused on the difficulties children suffering from abuse have with verbal expression and other areas of development. The research stresses the need to set up intervention programs that can improve the linguistic and social competence of children suffering from abuse. With such children, there is a fundamental need to develop a competence that will encourage their adaptive social skills, which are basic skills for interacting socially and which encourage the pragmatic language function, a skill needed for relating to adults and solving interpersonal problems. 相似文献
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