In order to accomplish the transition from avascular to vascular growth, solid tumours secrete a diffusible substance known as tumour angiogenesis factor (TAF) into the surrounding tissue. Endothelial cells which form the lining of neighbouring blood vessels respond to this chemotactic stimulus in a well-ordered sequence of events comprising, at minimum, of a degradation of their basement membrane, migration and proliferation. Capillary sprouts are formed which migrate towards the tumour eventually penetrating it and permitting vascular growth to take place. It (...) is during this stage of growth that the insidious process of invasion of surrounding tissues can and does take place. A model mechanism for angiogenesis is presented which includes the diffusion of the TAF into the surrounding host tissue and the response of the endothelial cells to the chemotactic stimulus. Numerical simulations of the model are shown to compare very well with experimental observations. The subsequent vascular growth of the tumour is discussed with regard to a classical reaction-diffusion pre-pattern model. (shrink)

The primary aim of this study was to investigate the relation between self-perceived executive functions and the school achievement of young adolescents, while controlling for parental education and sex. We specifically focused on executive aspects of daily life behavior and the higher-order EFs, as measured with self-report, rather than on the more basic EFs which have been the primary focus of prior investigations. In two independent samples of sixth graders, students evaluated their EFs on a self-report questionnaire, the Amsterdam Executive (...) Functioning Inventory. School achievement in the domains of mathematics and reading comprehension were evaluated with nationally used, norm-based achievement tests. Results revealed that the self-perceived EFs of young adolescents were significantly correlated with their school achievement in both study samples. School achievement was also correlated with the level of parental education, but the factor sex did not have such influence. In study 1, self-perceived EFs explained additional variance in school achievement, while controlling for parental education and sex. In study 2, this was only the case for the most robust measure of school achievement, i.e., the end-of-primary-school final achievement test. Furthermore, besides the relation with achievement tests, we also found a relation between self-perceived EFs and teacher ratings behavioral problems in the classroom. Together, our findings imply that young students can properly reflect on the effectiveness and appropriateness of their EFs in a way that is relevant to their academic achievement and classroom behavior. The findings underscore the importance of considering the development of EFs and parental education in the evaluation of academic achievements in early adolescence. (shrink)

Is what could have happened but never did as real as what did happen? What did happen, but isn't happening now, happened at another time. Analogously, one can say that what could have happened happens in another possible world. Whatever their views about the reality of such things as possible worlds, philosophers need to take this analogy seriously. Adriane Rini and Max Cresswell exhibit, in an easy step-by-step manner, the logical structure of temporal and modal discourse, and show that every (...) temporal construction has an exact parallel that requires a language that can refer to worlds, and vice versa. They make precise, in a way which can be articulated and tested, the claim that the parallel is at work behind even ordinary talk about time and modality. The book gives metaphysicians a sturdy framework for the investigation of time and modality - one that does not presuppose any particular metaphysical view. (shrink)

Recent policy in relation to clinical research proposals in the UK has distinguished between two types of review: scientific and ethical. This distinction has been formally enshrined in the recent changes to research ethics committee structure and operating procedures, introduced as the UK response to the EU Directive on clinical trials. Recent reviews and recommendations have confirmed the place of the distinction and the separate review processes. However, serious reservations can be mounted about the science/ethics distinction and the policy of (...) separate review that has been built upon it. We argue here that, first, the science/ethics distinction is incoherent, and, second, that RECs should not only be permitted to consider a study’s science, but that they have anobligation do so. (shrink)

Background: Legislation on physician-assisted suicide is being considered in a number of states since the passage of the Oregon Death With Dignity Act in 1994. Opinion assessment surveys have historically assessed particular subsets of physicians.Objective: To determine variables predictive of physicians’ opinions on PAS in a rural state, Vermont, USA.Design: Cross-sectional mailing survey.Participants: 1052 physicians licensed by the state of Vermont.Results: Of the respondents, 38.2% believed PAS should be legalised, 16.0% believed it should be prohibited and 26.0% believed it should (...) not be legislated. 15.7% were undecided. Males were more likely than females to favour legalisation . Physicians who did not care for patients through the end of life were significantly more likely to favour legalisation of PAS than physicians who do care for patients with terminal illness . 30% of the respondents had experienced a request for assistance with suicide.Conclusions: Vermont physicians’ opinions on the legalisation of PAS is sharply polarised. Patient autonomy was a factor strongly associated with opinions in favour of legalisation, whereas the sanctity of the doctor–patient relationship was strongly associated with opinions in favour of not legislating PAS. Those in favour of making PAS illegal overwhelmingly cited moral and ethical beliefs as factors in their opinion. Although opinions on legalisation appear to be based on firmly held beliefs, approximately half of Vermont physicians who responded to the survey agree that there is a need for more education in palliative care and pain management. (shrink)

Recent studies using functional magnetic resonance imaging of patients in a vegetative state have raised the possibility that such patients retain some degree of consciousness. In this paper, the ethical implications of such findings are outlined, in particular in relation to decisions about withdrawing life-sustaining treatment. It is sometimes assumed that if there is evidence of consciousness, treatment should not be withdrawn. But, paradoxically, the discovery of consciousness in very severely brain-damaged patients may provide more reason to let them die. (...) Although functional neuroimaging is likely to play an increasing role in the assessment of patients in a vegetative state, caution is needed in the interpretation of neuroimaging findings. (shrink)

Judges face difficult choices when the birth and genetic mothers of a child are separate people who dispute maternal access; the views of the general population may help them. Fifty women were asked whether, if they were infertile and could have only one child, they would prefer to be birth mothers (to carry a baby which was not genetically theirs) or genetic mothers (to have another woman carry their genetic baby). Similarly, fifty men were asked about their preference for a (...) partner's child. In both groups the strength of preferences was measured using a lottery technique. The direction and strength of preferences was similar between men and women, and approximately equally divided between birth and genetic motherhood. These attitudes should be taken into account by those adjudicating custody disputes between such mothers. (shrink)

Residency training in the Netherlands is to be restructured over the coming years. To this end a general competence profile for medical specialists has been introduced. This profile is nearly the same as the Canadian CanMEDS 2000 model, which describes seven general areas of medical specialist competence, one of which is professionalism. In order to establish a training programme for residents and their instructors based on this competence, it is necessary to develop a vision that does justice to everyday medical (...) practice. The two most prevailing views of professionalism—as personal, or as a behavioural characteristic—fall short of this. Only when professionalism is understood as reflective professionalism does it encompass the fundamental contextuality of medical treatment. This means that the focus of training and assessment must be shifted to accountability for treatment. (shrink)

We describe a novel computational theory of how individuals segment perceptual information into representations of events. The theory is inspired by recent findings in the cognitive science and cognitive neuroscience of event segmentation. In line with recent theories, it holds that online event segmentation is automatic, and that event segmentation yields mental simulations of events. But it posits two novel principles as well: first, discrete episodic markers track perceptual and conceptual changes, and can be retrieved to construct event models. Second, (...) the process of retrieving and reconstructing those episodic markers is constrained and prioritized. We describe a computational implementation of the theory, as well as a robotic extension of the theory that demonstrates the processes of online event segmentation and event model construction. The theory is the first unified computational account of event segmentation and temporal inference. We conclude by demonstrating now neuroimaging data can constrain and inspire the construction of process-level theories of human reasoning. (shrink)

The traditional Dung networks depict arguments as atomic and study the relationships of attack between them. This can be generalised in two ways. One is to consider various forms of attack, support, feedback, etc. Another is to add content to nodes and put there not just atomic arguments but more structure, e.g. proofs in some logic or simply just formulas from a richer language. This paper offers to use temporal and modal language formulas to represent arguments in the nodes of (...) a network. The suitable semantics for such networks is Kripke semantics. We also introduce a new key concept of usability of an argument. This is the beginning of a continuing research for adding contents to the nodes of an argumentation network. This research will allow us to address notions like ?what does it exactly mean for a node to attack another? or ?what does it mean for a network to be consistent? or ?can we give proper proof rules to manipulate networks?, and more. (shrink)

At the turn of the century Idealism was perhaps the leading school of philosophy in the English-speaking world. By the 1960s the situation was very different. There had occurred during the previous two generations what has been described as 'a revolution in philosophy', one consequence of which had been the almost total eclipse of Idealism. Originally published in 1962, this book is a critical study of certain aspects of the work of four Idealist philosophers: F. H. Bradley, T. H. Green, (...) Bernard Bosanquet and Josiah Royce. It deals mainly with their social philosophy, but some consideration is also given to their metaphysics. It is the thesis of this book that there is a valid and significant form of Idealism to be found in the work of these philosophers, but that they did not succeed in developing it fully and consistently. (shrink)

Objectives: To study the consent process experienced by participants who are enrolled in a molecular genetic research study that aims to find new genetic mutations responsible for an apparently inherited disorder.Design: Semi-structured interviews and analysis/description of main themes.Participants: 78 members of 52 families who had been recruited to a molecular genetic study.Results: People were well informed about the goals, risks and benefits of the genetic research study but could not remember the consent process. They had mostly been recruited to take (...) part by trusted clinicians or their relatives but had little memory of, or concern about signing consent forms. Families appeared to regard the research as a continuation of their, or their relatives’, clinical care.Conclusions: Ethical review should be more flexible in its attitude to consent forms and written information sheets for some sorts of research. For rare genetic disease studies where research has been discussed fully within the clinical setting then the consent obtained at that time could suffice rather than needing extra consent at a later stage. However, clinician-researchers will need to ensure that their duty of care extends for the duration of the research and beyond. (shrink)

Introduction: The decision of “do not attempt resuscitation” in the event of cardiopulmonary arrest is usually made when the patients are critically ill and cannot make an informed choice. Although, various professional bodies have published guidelines, little is know about the patients’ own views regarding DNAR discussion.Aim: The aim of this study was to determine patients’ attitudes regarding discussing DNAR before they are critically ill.Methods: A prospective study was performed in a general out patients department. A questionnaire was distributed to (...) consecutive outpatients along with an explanatory leaflet in the adult outpatient clinic.Results: 364 patients completed the questionnaire . 90% of respondents wanted all patients to be asked regarding DNAR decision at some point during a hospital admission. The majority would not find a DNAR discussion distressing. Only 10% would find it upsetting, however, 48% of these still wanted a discussion. 37% of respondents wanted to discuss DNAR decisions on admission; 32% in outpatients; 17% at consent for surgery, 14% when they are critically ill. 87% of respondents would not object to their relatives being involved in making decisions about their resuscitation status. However, only 12% of the subjects in the study had been involved in discussing the resuscitation status of a relative and 21% would not be comfortable to discuss a relative’s resuscitation status. Although 33% of patients preferred their resuscitation status to simply be documented within their clinical notes, 77% wanted it to be more easily accessible.Conclusions: This study suggests that contrary to current practice most patients want to discuss their DNAR status prior to becoming critically ill. This includes half of the small number that find it distressing to discuss. Although most patients are comfortable with relatives being involved in discussing DNAR, a significant proportion do not want their relatives to be asked. Furthermore, once a decision has been made, the majority of patients want it to be more accessible than current practice allows. (shrink)