Patient centred diagnosis is best practised through shared decision making; an iterative dialogue between doctor and patient, whichrespects a patient’s needs, values, preferences, and circumstances. -/- Shared decision making for diagnostic situations differs fundamentally from that for treatment decisions. This has important implications when considering its practical application. -/- The nature of dialogue should be tailored to the specific diagnostic decision; scenarios with higher stakes or uncertainty usually require more detailed conversations.

Resumen. Se presentan los conceptos básicos de muestreo secuencial en sus cinco modalidades,incluyendo muestreo secuencial de tipo estándar, usando solo una densidad crítica, por una precisiónfija, por medio de presencia-ausencia y finalmente de tipo temporal. Se notan un ejemplo real para cadacaso. Se nota y se explica la importancia de la distribución de los datos y los pertinentes ecuaciones. Sepresentan a través de ejemplos reales las ecuaciones para estimar el tamaño óptimo de la muestra paracada uno de las cinco modalidades (...) del muestreo secuencial. Se enfatiza la ventaja económica de estetipo de muestreo.Palabras clave: Distribución de los datos, muestreo secuencial, tamaño óptimo de la muestra. Fundamental concepts of sequential sampling in all its types including standard sequentialsampling, sequential sampling using only one critical density, fixed precision sequential sampling,presence-absence sequential sampling, and time sequential sampling are highlighted. A real caseexample for each of the five sequential samplings is given. The relevance of data distribution forsequential sampling along with corresponding equations is provided and explained. Equations to assessthe optimal sample size for each case are noted and exemplified. The economic advantages of sequentialsampling in stressedKeywords: Data distribution, sample size, sequential sampling. (shrink)

Resumen. Se analizan de forma detallada las bases del muestreo multietápico, la estimación de submuestreo y el muestreo de respuesta aleatoria. Se presentan las ecuaciones pertinentes ejemplificando por medio de casos reales. También se argumentan las situaciones en donde se debe utilizar estos casos específicos. Palabras claves. Caso multietápico, muestreo de respuesta aleatoria, submuestreo.. The basics of multi-stage sampling, sub-sampling and random response sampling are analyzed. Detailed equations regarding these types of sampling are provided. The applications of these types of (...) samplings are denoted by means of real case studies. Keywords. Multi-stage sampling, sub-sampling, random response sampling. (shrink)

Palabras claves. Métodos estadísticos, pruebas de hipótesisResumen. Se presentan de forma simple, breve y por medios de los ejemplos prácticos, los métodos estadísticos que sirven para demostrar la representatividad de una, dos o varias muestras basada en los parámetros poblacionales . Se indican la manera de reducir el tamaño del error experimental para aclarar el efecto significativo de los grupos o muestras bajo el interés . Además, se demuestran la forma de eliminar el efecto de las variables auxiliares o colaterales (...) causante del ruido o error en la estadística . También se nota el uso del modelo ANOVA Anidada para indicar la forma de segmentar la ANOVA en varias partes y de esta manera poder contestar preguntas más complejas. Finalmente, se describen e explican la forma de optimizar los recursos en la conducción de los experimentos y descubrir el efecto de la interacción entre las variables .Keywords. Hypothesis testing, statistical methods. Statistical methods that serve to represent, based upon population parameters of mean and variance, for one, tow or various samples taken from study populations are discussed. Ways to reduce the amount of experimental error in order to clarify the real effect of the treatments are demonstrated . The use of Covariance Analysis to show the pure effect of treatment free from the effect of collateral variables is also indicated. Nested ANOVA that allows division of ANOVA in several parts in order to answer complex questions is described and explained. Finally, the utility of Factorial Analysis for optimization of resource use as well as the illustration of interaction effects are noted and analyzed. (shrink)

In the years 1878 and 1879 the American physicist Alfred Marshall Mayer published his experiments with floating magnets as a didactic illustration of molecular actions and forms. A number of physicists made use of this analogy of molecular structure. For William Thomson they were a mechanical illustration of the kinetic equilibrium of groups of columnar vortices revolving in circles round their common centre of gravity . A number of modifications of Mayer's experiments were described, which gave configurations which were more (...) or less analogous to Mayer's arrangements. It was Joseph John Thomson who, in publications between 1897 and 1907, used Mayer's results to obtain a good deal of insight into the general laws which govern the configuration of the electrons in his atomic model. This article is mainly concerned with Mayer's experiments with floating magnets and their use by a number of physicists. Through his experiments Mayer made a significant, although small, contribution to the theory of atomic structure. (shrink)

After Jacobus Henricus van't Hoff had passed away on 1 March 1911, his pupil Charles Marinus van Deventer wrote a very personal ‘in memoriam’ in the Dutch literary periodical De Gids, pointing out that van't Hoff had merely been interested in scientific facts, not in the people discovering these facts. Van't Hoff considered the study of the history of chemistry, although by no means uncongenial, a matter of little importance. He once even said: ‘To me historical research appears to be (...) appropriate for a chemist in the decline of life, when he no longer creates professional ideas, and when the laboratory has become a burden to him’. Although van Deventer had studied physical chemistry at van't Hoff's Amsterdam laboratory and had been his assistant from 1885 until 1893, he disagreed with this verdict. Van Deventer was not only a capable physical chemist, he was also an active member of the Tachtigers, a circle of Dutch poets who around 1880 brought about a renewal in Dutch literature. He took a special interest in Greek philosophy. He did not graduate with van't Hoff, but with his colleague Jan Willem Gunning . His thesis was not based on physical-chemical, but on historical research: Schetsen uit de Geschiedenis van de Scheikunde . From 1922 to 1923 he lectured on the history of chemistry at Utrecht University. His fascinating lectures were published as Grepen uit de Historie der Chemie . This work reveals his particular interest in the development of chemical concepts. (shrink)

The Utrecht professor of physics Gerrit Moll , well-known for his defence of British science against Charles Babbage's Reflections on the Decline of Science in England , did—in co-operation with members of the Natuurkundig Gezelschap at Utrecht—important work on the reception in The Netherlands of the new electromagnetic and electrodynamic discoveries . He also carried out fundamental research into the lifting power of electromagnets, which he had seen during his visit to London in 1828. In 1830, Moll published his experiments (...) with strong electromagnets having maximum lifting powers of 38 kilograms. With the results of similar experiments performed in the United States by Joseph Henry and Philip ten Eyck in mind, Moll continued his experiments with stronger electromagnets . Furthermore; he investigated the ability of very small galvanic batteries to develop a perceptible magnetism in a great horseshoe . A practical physicist, Moll was hardly interested in theoretical explanations. In The Netherlands his experiments aroused interest in the practical applications of electro- magnetic force. In the present paper, Moll's contributions to the science of electromagnetism and electrodynamics are discussed. (shrink)

On 17 November 1820 there appeared a Dutch translation of Oersted's pamphlet concerning the discovery of the effect of an electric current on a magnetic needle suspended in the earth's magnetic field . In the Netherlands a number of physicists were immediately interested in the electromagnetic and electrodynamic discoveries made by Oersted and the French physicists. They repeated and extended the experiments, and constructed new modifications of the galvanic battery for better results. They made no fundamental discoveries in this field (...) of physics, but the fact that their work was important follows from the experiments of van Beek, which confirmed Amp`ere's theory of molecular magnetic currents. Van Beek as well as Speyert van der Eyk corresponded with Amp`ere about electromagnetic and electrodynamic phenomena. In the Utrecht Universiteitsmuseum there is an unpublished letter of Amp`ere to van Beek, which is published at the end of this article. (shrink)

This paper describes the introduction of Liebig's ideas on agricultural chemistry into the Netherlands. The aversion to Liebig held by the Utrecht professor G. J. Mulder hindered the direct influence that might have been borne by Liebig's own writings; the introduction was made principally by means of Dutch translations of the text-books of the Scottish agricultural chemist J. F. W. Johnston, who generally followed Liebig's ideas.

This paper focuses on natural dualities for varieties of bilattice-based algebras. Such varieties have been widely studied as semantic models in situations where information is incomplete or inconsistent. The most popular tool for studying bilattices-based algebras is product representation. The authors recently set up a widely applicable algebraic framework which enabled product representations over a base variety to be derived in a uniform and categorical manner. By combining this methodology with that of natural duality theory, we demonstrate how to build (...) a natural duality for any bilattice-based variety which has a suitable product representation over a dualisable base variety. This procedure allows us systematically to present economical natural dualities for many bilattice-based varieties, for most of which no dual representation has previously been given. Among our results we highlight that for bilattices with a generalised conflation operation. Here both the associated product representation and the duality are new. Finally we outline analogous procedures for pre-bilattice-based algebras. (shrink)