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)

This paper is devoted to the study of some subvarieties of the variety Qof Q-Heyting algebras, that is, Heyting algebras with a quantifier. In particular, a deeper investigation is carried out in the variety Q 3 of three-valued Q-Heyting algebras to show that the structure of the lattice of subvarieties of Qis far more complicated that the lattice of subvarieties of Heyting algebras. We determine the simple and subdirectly irreducible algebras in Q 3 and we construct the lattice of subvarieties (...) (Q 3 ) of the variety Q 3. (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)

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)

This book collects the work of leading scholars on Alain Badiou and G.W.F. Hegel, creating a dialogue between, and a critical appraisal of, these two central figures in European philosophy.

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)

Anna J Dare,1 Anthony RJ Phillips,1–3 Michael Chu,1 Anthony JR Hickey,2 Adam SJR Bartlett1–31Department of Surgery, 2Maurice Wilkins Centre for Biodiscovery, University of Auckland, Auckland, New Zealand; 3New Zealand Liver Transplant Unit, Auckland City Hospital, Auckland, New ZealandBackground: Hepatic steatosis is increasingly encountered among organ donors. Currently, there is no consensus guideline as to the type or degree of donor steatosis considered acceptable for liver transplantation, and little is known about local practices in this area. The aim of this survey (...) was to evaluate current clinical practices amongst liver transplant surgeons in Australia and New Zealand in the evaluation and use of steatotic donor livers in LT.Methods: An anonymous online twelve-question survey was emailed to all practicing LT surgeons in ANZ in January 2010.Results: The response rate was 83%. Estimated prevalence of steatosis in donor livers was between 40% and 60%. In determining suitability for LT, 90% of respondents reported rejecting organs with "severe" steatosis based on visual and palpation grounds alone. A total of 68% sought further histological assessment if the donor liver looked bad and there were risk factors for steatosis. The majority of respondents performed only one biopsy of the liver, using hematoxylin and eosin staining for fat assessment. There was wide variation in the upper limit of steatosis considered to be acceptable for LT. A total of 21% of respondents still considered microvesicular steatosis a risk factor for primary graft nonfunction.Conclusion: This survey highlights the significant variation in the appraisal and use of steatotic grafts by LT surgeons in ANZ. Accurate evaluation and judicious use of mild and moderately steatotic grafts is required if we are to utilize the available donor pool best.Keywords: liver transplantation, steatosis, fatty liver, organ donors. (shrink)