779 resultados para Lindquist, Donald


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Background: The COSMIN checklist is a tool for evaluating the methodological quality of studies on measurement properties of health-related patient-reported outcomes. The aim of this study is to determine the inter-rater agreement and reliability of each item score of the COSMIN checklist (n = 114). Methods: 75 articles evaluating measurement properties were randomly selected from the bibliographic database compiled by the Patient-Reported Outcome Measurement Group, Oxford, UK. Raters were asked to assess the methodological quality of three articles, using the COSMIN checklist. In a one-way design, percentage agreement and intraclass kappa coefficients or quadratic-weighted kappa coefficients were calculated for each item. Results: 88 raters participated. Of the 75 selected articles, 26 articles were rated by four to six participants, and 49 by two or three participants. Overall, percentage agreement was appropriate (68% was above 80% agreement), and the kappa coefficients for the COSMIN items were low (61% was below 0.40, 6% was above 0.75). Reasons for low inter-rater agreement were need for subjective judgement, and accustom to different standards, terminology and definitions.Conclusions: Results indicated that raters often choose the same response option, but that it is difficult on item level to distinguish between articles. When using the COSMIN checklist in a systematic review, we recommend getting some training and experience, completing it by two independent raters, and reaching consensus on one final rating. Instructions for using the checklist are improved.

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Background: Choosing an adequate measurement instrument depends on the proposed use of the instrument, the concept to be measured, the measurement properties (e.g. internal consistency, reproducibility, content and construct validity, responsiveness, and interpretability), the requirements, the burden for subjects, and costs of the available instruments. As far as measurement properties are concerned, there are no sufficiently specific standards for the evaluation of measurement properties of instruments to measure health status, and also no explicit criteria for what constitutes good measurement properties. In this paper we describe the protocol for the COSMIN study, the objective of which is to develop a checklist that contains COnsensus-based Standards for the selection of health Measurement INstruments, including explicit criteria for satisfying these standards. We will focus on evaluative health related patient-reported outcomes (HR-PROs), i.e. patient-reported health measurement instruments used in a longitudinal design as an outcome measure, excluding health care related PROs, such as satisfaction with care or adherence. The COSMIN standards will be made available in the form of an easily applicable checklist.Method: An international Delphi study will be performed to reach consensus on which and how measurement properties should be assessed, and on criteria for good measurement properties. Two sources of input will be used for the Delphi study: (1) a systematic review of properties, standards and criteria of measurement properties found in systematic reviews of measurement instruments, and (2) an additional literature search of methodological articles presenting a comprehensive checklist of standards and criteria. The Delphi study will consist of four (written) Delphi rounds, with approximately 30 expert panel members with different backgrounds in clinical medicine, biostatistics, psychology, and epidemiology. The final checklist will subsequently be field-tested by assessing the inter-rater reproducibility of the checklist.Discussion: Since the study will mainly be anonymous, problems that are commonly encountered in face-to-face group meetings, such as the dominance of certain persons in the communication process, will be avoided. By performing a Delphi study and involving many experts, the likelihood that the checklist will have sufficient credibility to be accepted and implemented will increase.

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We formulate performance assessment as a problem of causal analysis and outline an approach based on the missing data principle for its solution. It is particularly relevant in the context of so-called league tables for educational, health-care and other public-service institutions. The proposed solution avoids comparisons of institutions that have substantially different clientele (intake).

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Atualmente, as situações de erros e fraudes, têm ocorrido com muita frequência a nível mundial. Por exemplo em Cabo Verde estas têm vindo a ganhar espaço nos mídias, onde a todo momento aparece casos de erros e fraudes, como por exemplo, os casos da Sociedade Cabo-verdiana de Tabacos, Banco Comercial do Atlântico, Caixa Económica, Câmara Municipal da Ribeira Brava, Associação Sport Club Moreirense, Sociedade de Segurança Industrial, Marítima e Comercial, Ministério das Finanças entre outros. Essas situações desfavoráveis para qualquer empresa, são derivadas de uma gestão menos cuidada dos recursos, e dos valores e princípios éticos cultivados pelas pessoas. O triângulo de fraude criada por Donald Cressey demonstra os motivos que leva um individuo a cometer atos fraudulentos, como sendo a motivação, a pressão e a oportunidade. Neste sentido, o controlo interno surge como uma ferramenta muito importante e fundamental para mitigar os riscos advenientes da ocorrência de erros e fraudes, suscetíveis de acontecer nas empresas. O controlo interno traduz num conjunto de medidas que protegem o património da empresa e garantem o cumprimento dos seus objetivos entretanto, como qualquer outra ferramenta de gestão está possui determinadas limitações que podem ser ultrapassadas com a utilização de alguns procedimentos básicos e, ou alternativos de controlo interno. É imprescindível que um sistema de controlo interno, para além de implementado, adequado e em funcionamento, seja mantido e acompanhado. O estudo dos casos da SILMAC, SA e da SCT, SA, mostram a importância que o controlo interno tem na prevenção e deteção de erros e fraudes, pois denota-se que as fraudes cometidas aconteceram na sequência de fraquezas de controlo interno e no excesso de confiança depositada nos colaboradores. Currently, the situations of errors and fraud have occurred very often in the world. Cape Verde in these situations have gained ground in the media, where every moment appears to errors and fraud cases, such as cases of “Sociedade cabo-verdiana de tabacos, Banco Comercial do Atlântico, Caixa Económica, Câmara Municipal da Ribeira Brava, Associação Sport Club Moreirense, Sociedade de segurança industrial, marítima e comercial, Ministério de finanças” amongst others. These situations which unfavorable for any company, are derived from a less carefully management of resources and ethical principles and values cultivated by people. The fraud triangle created by Donald Cressey, demonstrates reasons that lead an individual to commit fraudulent acts, such as motivation, opportunity and pressure. In this sense, internal control emerges as a very important tool to mitigate the risks arising from situations of errors and fraud, which are likely to happen in companies. The internal control translates into a set of measures that protect the assets of the business and ensure the fulfillment of its objectives however, like any other management tool is has limitations, however these can be overcome with the use of basic procedures, or alternative internal control. It is essential that an internal control system, in addition to implemented, adequate and functioning is maintained and monitored. The case studies of SILMAC and SCT, show the importance of internal control is the prevention and detection of errors and fraud. For note that the fraud occurred following oversights in its internal control and confidence in their employees.

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El proyecto se inició en mayo de 1978 y se terminó en diciembre de 1981. Sus objetivos principales con establecer las bases científicas para la administración racional de las pesquerías peruanas de aguas continentales y para su óptima utilización.

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A software for the calculation of unsaturated soil hydraulic conductivity K(theta) is presented for commonly used methods found in the literature, based on field experiments in which a soil profile is submitted to water infiltration followed by internal drainage. The software is available at: dourado@esalq.usp.br.

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Artikkelin tekijämerkintönä virheellisesti Johan Lindqvist

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The estimation of non available soil variables through the knowledge of other related measured variables can be achieved through pedotransfer functions (PTF) mainly saving time and reducing cost. Great differences among soils, however, can yield non desirable results when applying this method. This study discusses the application of developed PTFs by several authors using a variety of soils of different characteristics, to evaluate soil water contents of two Brazilian lowland soils. Comparisons are made between PTF evaluated data and field measured data, using statistical and geostatistical tools, like mean error, root mean square error, semivariogram, cross-validation, and regression coefficient. The eight tested PTFs to evaluate gravimetric soil water contents (Ug) at the tensions of 33 kPa and 1,500 kPa presented a tendency to overestimate Ug 33 kPa and underestimate Ug1,500 kPa. The PTFs were ranked according to their performance and also with respect to their potential in describing the structure of the spatial variability of the set of measured values. Although none of the PTFs have changed the distribution pattern of the data, all resulted in mean and variance statistically different from those observed for all measured values. The PTFs that presented the best predictive values of Ug33 kPa and Ug1,500 kPa were not the same that had the best performance to reproduce the structure of spatial variability of these variables.

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The symmetrical two-dimensional quantum wire with two straight leads joined to an arbitrarily shaped interior cavity is studied with emphasis on the single-mode approximation. It is found that for both transmission and bound-state problems the solution is equivalent to that for an energy-dependent one-dimensional square well. Quantum wires with a circular bend, and with single and double right-angle bends, are examined as examples. We also indicate a possible way to detect bound states in a double bend based on the experimental setup of Wu et al.

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Systematic trends in the properties of a linear split-gate heterojunction are studied by solving iteratively the Poisson and Schrödinger equations for different gate potentials and temperatures. A two-dimensional approximation is presented that is much simpler in the numerical implementation and that accurately reproduces all significant trends. In deriving this approximation, we provide a rigorous and quantitative basis for the formulation of models that assumes a two-dimensional character for the electron gas at the junction.

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An efficient method is developed for an iterative solution of the Poisson and Schro¿dinger equations, which allows systematic studies of the properties of the electron gas in linear deep-etched quantum wires. A much simpler two-dimensional (2D) approximation is developed that accurately reproduces the results of the 3D calculations. A 2D Thomas-Fermi approximation is then derived, and shown to give a good account of average properties. Further, we prove that an analytic form due to Shikin et al. is a good approximation to the electron density given by the self-consistent methods.

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Electron wave motion in a quantum wire with periodic structure is treated by direct solution of the Schrödinger equation as a mode-matching problem. Our method is particularly useful for a wire consisting of several distinct units, where the total transfer matrix for wave propagation is just the product of those for its basic units. It is generally applicable to any linearly connected serial device, and it can be implemented on a small computer. The one-dimensional mesoscopic crystal recently considered by Ulloa, Castaño, and Kirczenow [Phys. Rev. B 41, 12 350 (1990)] is discussed with our method, and is shown to be a strictly one-dimensional problem. Electron motion in the multiple-stub T-shaped potential well considered by Sols et al. [J. Appl. Phys. 66, 3892 (1989)] is also treated. A structure combining features of both of these is investigated

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Recent measurements of electron escape from a nonequilibrium charged quantum dot are interpreted within a two-dimensional (2D) separable model. The confining potential is derived from 3D self-consistent Poisson-Thomas-Fermi calculations. It is found that the sequence of decay lifetimes provides a sensitive test of the confining potential and its dependence on electron occupation