Postnatally, heart muscle cells almost completely lose their ability to divide, which makes their loss after trauma irreversible. Potential repair by cell grafting or mobilizing endogenous cells is of particular interest for possible treatments for heart disease, where the poor capacity for cardiomyocyte proliferation probably contributes to the irreversibility of heart failure. Knowledge of the molecular mechanisms that underly formation of heart muscle cells might provide opportunities to repair the diseased heart by induction of (trans) differentiation of endogenous or exogenous (...) cells into heart muscle cells. We briefly review the molecular mechanisms involved in early development of the linear heart tube by differentiation of mesodermal cells into heart muscle cells. Because the initial heart tube does not comprise all the cardiac compartments present in the adult heart, heart muscle cells are added to the distal borders of the tube and within the tube. At both distal borders, mesodermal cell are recruited into the cardiac lineage and, within the heart tube, muscular septa are formed. In this review, the relative late additions of heart muscle cells to the linear heart tube are described and the potential underlying molecular mechanisms are discussed. BioEssays 26:248–261, 2004. Wiley Periodicals, Inc. (shrink)

The objective of the new series, "Molecular Biology, Biochemistry and Biophysics", of which this brochure forms the first volume, is to produce more than another compilation of data. It is hoped that the new series will help the individual "specialist" keep abreast of important developments in the natural sciences at the molecular and subcellular level in fields complementary to his own. The predominant aim is not so much to increase the ever-growing body of information in an encyclopedic fashion but rather (...) to give, in addition to a well rounded factual presentation of subjects which have reached a degree of maturation, a leitmotiv developed by the individual authors from a more personal point of view. The reader should thus be able to use these mono graphs not only for acquisition of knowledge but as a source of further motiva tion in his own work. This latter and more consequential aim of the monograph series is one of the reasons for presenting here a most unusual talk which should enable the reader to sit back and view his own efforts in the context of science and creative attempts as a whole. The lecture is the virtually unknown inaugural address of the Dutch physical chemist JACOBUS HENRICUS VAN'T HOFF. As is shown in his short biography presented on pages 3 and 4 the principal thoughts of the molecular biologist of today are akin to his own and he clearly recognized the universality of molecular life processes. (shrink)

Causal eliminativists maintain that all causal talk is false. The prospects for such a view seem to be stymied by an indispensability argument, charging that any agent must distinguish between effective and ineffective strategies, and that such a distinction must commit that agent to causal notions. However, this argument has been under-explored. The contributions of this paper are twofold: first, I provide a thorough explication of the indispensability argument and the various ways it might be defended. Second, I point to (...) an important limitation in the argument and suggest that it does not give us sufficient reason to reject eliminativism. In support of this last claim, I show that the distinction between effective and ineffective strategies could perfectly well be grounded in a counterfactual rather than a causal decision theory and argue that there are fully adequate explanations of how we could come to make the requisite counterfactual judgments that need not invoke causal concepts. (shrink)

J. H. van 't Hoff's 1874 Dutch pamphlet, in which he proposed the spatial arrangement of atoms in a molecule, is one of the most significant documents in the history of chemistry. This essay presents a new narrative of Van 't Hoff's early life and places the appearance of the pamphlet within the context of the 'second golden age' of Dutch science. We argue that the combination of the reformed educational system in The Netherlands, the emergence of graphical (...) molecular modelling within the theoretical and practical culture of chemistry during the 1860s and 1870s, as well as Van 't Hoff's own personal research trajectory, formed the background to his unprecedented attribution of spatial meaning to the traditional concept of atomic 'arrangement'. We also present a new English translation of the pamphlet, for we have found that the existing translation, published by G. M. Richardson in 1901, contains many errors, changes and omissions. The new version offers a more accurate rendition in English of Van 't Hoff's style and argument. (shrink)

Palliative sedation is an option of last resort to control refractory suffering. In order to better understand palliative-care nurses’ attitudes to palliative sedation, an anonymous questionnaire was sent to all nurses (589) employed in palliative care in Flanders (Belgium). In all, 70.5% of the nurses (n = 415) responded. A large majority did not agree that euthanasia is preferable to palliative sedation, were against non-voluntary euthanasia in the case of a deeply and continuously sedated patient and considered it generally better (...) not to administer artificial floods or fluids to such a patient. Two clusters were found: 58.5% belonged to the cluster of advocates of deep and continuous sedation and 41.5% belonged to the cluster of nurses restricting the application of deep and continuous sedation. These differences notwithstanding, overall the attitudes of the nurses are in accordance with the practice and policy of palliative sedation in Flemish palliative-care units. (shrink)

According to ontological nihilism nothing exists. A recent argument purports to show that this view is indefensible, since its most plausible formulations are tacitly committed to quantificational claims that are inconsistent with the nihilist's view that there aren't any existents. I show that this objection begs the question against the nihilist. The objector's argument relies on an equivalence principle implying that claims which nihilists regard as non-quantificational should nonetheless be interpreted as equivalent to quantified claims, given that both kinds of (...) assertion are assertible in the same contexts. This style of reasoning is supported by considerations of charity, which suggest that similarities in inter-personal patterns of language use provide evidence of similarity in the semantic content of speakers' utterances. However, related considerations also suggest that intra-personal patterns of language use constitute significant semantic evidence of the same kind. When we appreciate this and further recognize that nihilists are disposed to assert the negation of any positive, quantified claim, we see that it is too much to expect principles of semantic interpretation based on considerations of charity to decisively refute nihilism. This result has interesting metametaphysical implications concerning the role and scope of analogous arguments based on principles of interpretive charity. (shrink)

Despite societal concerns about the welfare of commercial laying hens, little attention has been paid to the welfare implications of the choices made by the genetics companies involved with their breeding. These choices regarding trait selection and other aspects of breeding significantly affect living conditions for the more than 7 billion laying hens in the world. However, these companies must consider a number of different commercial and societal interests, beyond animal welfare concerns. In this article we map some of the (...) relevant dilemmas faced by genetics companies in order to outline the scope of opportunities to improve welfare under current market conditions. This includes identifying cases where different animal welfare concerns conflict. We discuss the moral responsibility of laying hen genetics companies and the welfare implications that derive from the choices they make and the policies they follow. In addition to evaluating a selection of predominant current practices and breeding goals, we outline different angles from where to assess the moral legitimacy of various industry practices and policies. We discuss specific issues such as injurious pecking, bone health, induced moulting, chick culling and the circumstances of breeding stock. (shrink)

Previous research has shown that uncertainty communication by scientists (i. e., expressing reservations towards their own research) increases the public’s trust in their work. The reasons for this have not been elucidated, however. In the present study, we provide a theoretical explanation for this phenomenon. Specifically, we expected that attributed communicator bias would mediate the effect of uncertainty communication on trust. Results from a mixed-design experiment (N = 88), using modified science news articles, revealed support for this hypothesis. Positive effects (...) of uncertainty communication on trust and donation intention were both mediated by attributed communicator bias. (shrink)

Summary In 1874, the Dutch chemist and Nobel prizewinner Jacobus Henricus van 't Hoff (1852?1911) laid the foundations for stereochemistry with a publication in which he openly suggested that molecules were real physical entities with a three-dimensional structure. He visualized this new spatial concept with illustrations, but also with the help of small cardboard molecular models, which he made himself. Some of these models have survived the ravages of time and are among the oldest molecular models in the world (...) still in existence. What is more, they are the first material models of a three-dimensional molecular structure ever made. This article describes the surviving Van 't Hoff models, kept in Museum Boerhaave in Leiden and in the Deutsches Museum in Munich. Special attention is paid to the use of these models and the specific purposes they served. A closer examination of the models and their context reveals that they had an essential part to play in the early development and spread of Van 't Hoff's stereochemistry theory: he put his molecular models not only to versatile use as didactic tools, scientific instruments, and precursors to experimental proof, but also as devices to persuade other scientists of the usefulness of his theory. (shrink)

There are many ways to assess face perception skills. In this study, we describe a novel task battery FEAST (Facial Expression Action Stimulus Test) developed to test recognition of identity and expressions of human faces as well as stimulus control categories. The FEAST consists of a neutral and emotional face memory task, a face and object identity matching task, a face and house part-to-whole matching task, and a human and animal facial expression matching task. The identity and part-to-whole matching tasks (...) contain both upright and inverted conditions. The results provide reference data of a healthy sample of controls in two age groups for future users of the FEAST. (shrink)

Both the concept of a Darwinian tree of life (TOL) and the possibility of its accurate reconstruction have been much criticized. Criticisms mostly revolve around the extensive occurrence of lateral gene transfer (LGT), instances of uptake of complete organisms to become organelles (with the associated subsequent gene transfer to the nucleus), as well as the implications of more subtle aspects of the biological species concept. Here we argue that none of these criticisms are sufficient to abandon the valuable TOL concept (...) and the biological realities it captures. Especially important is the need to conceptually distinguish between organismal trees and gene trees, which necessitates incorporating insights of widely occurring LGT into modern evolutionary theory. We demonstrate that all criticisms, while based on important new findings, do not invalidate the TOL. After considering the implications of these new insights, we find that the contours of evolution are best represented by a TOL. (shrink)

Inleiding in de wetenschapsfilosofie, bedoeld voor filosofiestudenten.