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)

Background: Black, Asian and minority ethnic groups have a high need for organ transplantation but deceased donation is low. This restricts the availability of well-matched organs and results in relatively long waiting times for transplantation, with increased mortality risks. Objective: To identify barriers to organ donor registration and family consent among the BAME population, and to develop and evaluate a training intervention to enhance communication with ethnic minority families and identify impacts on family consent. Methods: Three-phase programme comprising community-based research (...) involving two systematic reviews examining attitudes and barriers to organ donation and effective interventions followed by 22 focus groups with minority ethnic groups; hospital-based research examining staff practices and influences on family consent through ethics discussion groups with staff, a study on intensive care units and interviews with bereaved ethnic minority families; and development and evaluation of a training package to enhance cultural competence among ICU staff. Setting: Community focus group study in eight London boroughs with high prevalence of ethnic minority populations. Hospital studies at five NHS hospital trusts. Participants: Community studies: 228 focus group participants; hospital studies: 35 nurses, 28 clinicians, 19 hospital chaplains, 25 members of local Organ Donation Committees, 17 bereaved family members; and evaluation: 66 health professionals. Data sources: Focus groups with community residents, systematic reviews, qualitative interviews and observation in ICUs, EDGs with ICU staff, bereaved family interviews and questionnaires for trial evaluation. Review methods: Systematic review and narrative synthesis. Results: Community studies: Organ Donor Register – different ethnic/faith and age groups were at varying points on the ‘pathway’ to organ donor registration, with large numbers lacking knowledge and remaining at a pre-contemplation stage. Key attitudinal barriers were uncertainties regarding religious permissibility, bodily concerns, lack of trust in health professionals and little priority given to registration, with the varying significance of these factors varying by ethnicity/faith and age. National campaigns focusing on ethnic minorities have had limited impact, whereas characteristics of effective educational interventions are being conducted in a familiar environment; addressing the groups’ particular concerns; delivery by trained members of the lay community; and providing immediate access to registration. Interventions are also required to target those at specific stages of the donation pathway. Hospital studies: family consent to donation – many ICU staff, especially junior nurses, described a lack of confidence in communication and supporting ethnic minority families, often reflecting differences in emotional expression, faith and cultural beliefs, and language difficulties. The continuing high proportion of family donation discussions that take place without the collaboration of a specialist nurse for organ donation reflected consultants’ views of their own role in family consent to donation, a lack of trust in SNODs and uncertainties surrounding controlled donations after circulatory death. Hospital chaplains differed in their involvement in ICUs, reflecting their availability/employment status, personal interests and the practices of ICU staff. Evaluation: professional development package – a digital versatile disk-based training package was developed to promote confidence and skills in cross-cultural communication. Initial evaluation produced positive feedback and significant affirmative attitudinal change but no significant difference in consent rate over the short follow-up period with requirements for longer-term evaluation. Limitations: Participants in the focus group study were mainly first-generation migrants of manual socioeconomic groups. It was not permitted to identify non-consenting families for interview with data regarding the consent process were therefore limited to consenting families. Conclusions: The research presents guidance for the effective targeting of donation campaigns focusing on minority ethnic groups and provides the first training package in cultural competence in the NHS. Future work: Greater evaluation is required of community interventions in the UK to enhance knowledge of effective practice and analysis of the experiences of non-consenting ethnic minority families. Funding: The National Institute for Health Research Programme Grants for Applied Research programme. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:A Response to David Carr, “The Significance of Music for the Promotion of Moral and Spiritual Value”Iris M. YobDavid Carr has addressed a question that has been lurking in philosophical literature for centuries and, I might add, in our collective intuition as well: Just what is the connection between music and the moral and spiritual life? And as we have come to expect from his work, he brings a (...) new perspective to this perennial question in his answer. First he traces a line of thinking since Plato about music and the ordering of the soul, he touches on the role of music and the other arts in exploring the complexities of the moral imperative as it is lived out in human lives, and returns at the end to give a new take on the old Platonic idea of ordering of the soul. Just maybe, he suggests, the detachment, however temporary, "from the trials and tribulations that beset us in the day to day rough and tumble of human practical affairs" "in the interests of some more balanced perspective" on spiritual and moral matters "might be easier to achieve in the contemplation and appreciation of great works of 'music alone.'"This conclusion does not lay claim to more than what is perfectly reasonable. Allowing oneself to be immersed in a great work of music or art or architecture or dance may very well provide that distance from every day life where one might [End Page 209] re-center and refocus, refresh and renew one's outlook on the world. Such an engagement with an artwork can interrupt the patterns of thinking and acting that might have become increasingly thoughtless and ego-centric. It can be a re-creation in the true sense of the word. Paul Tillich, one of the great twentieth century religious philosophers, tells of an experience he had during the First World War where he served as a chaplain in the German army. On a brief leave from the front he visited Kaiser Friedrich Museum in Berlin and stood entranced before Botticelli's "Madonna and Child with Singing Angels." The moment was spiritually transformative, he tells us, lifting his spirits beyond the mud and grime of the battlefield to contemplate life and meaning on a different plane altogether. The experience enabled him to return to duty with renewed inner strength and calm.1 I believe this is a rather powerful and compelling example of what Carr is talking about.In coming to his conclusion, Carr is relying on the particularly difficult case of "music alone," that is, music that does not have words, title, or any other kind of representative function. In other words his argument does not depend on any didactic nature or morally or spiritually directive intent of the music. Rather, it is centered on music that ostensibly is not about anything. This is musical sound composed and performed for the appreciation of what it is in itself. And yet, in providing distance from the every day world, according to Carr, it can give expression to "realms of spiritual experience that lie beyond the sensual and empirical." Here we enter the world of the metaphorical and symbolic, what Rudolf Otto would call the "irrational" or "superrational," or the realm of the Holy. While Carr does not state this explicitly I would go so far as to say that this realm of the wordless and sacred is where the spiritual and the moral are grounded and from where they draw their power.Against this background, I would like to ask how does "music alone," in the sense intended by Carr and Peter Kivy from whom he borrowed the term bring about this effect? We are unable now to ask Tillich what it was that gave the Botticelli its impact for him, but it is curious that what it did for him it most likely did not do for all the other soldiers from the front who happened upon it the way he did. Tillich would most likely explain its effect by resorting to his theory of symbols, because after all this painting does have a literal meaning that might very well have inspired him. But... (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)

We provide a mathematical study of a model of energy metabolism and hemodynamics of glioma allowing a better understanding of metabolic modifications leading to anaplastic transformation from low grade glioma.This mathematical analysis allows ultimately to unveil the solution to a viability problem which seems quite pertinent for applications to medecine.

Cancer is a complex disease, necessitating research on many different levels; at the subcellular level to identify genes, proteins and signaling pathways associated with the disease; at the cellular level to identify, for example, cell-cell adhesion and communication mechanisms; at the tissue level to investigate disruption of homeostasis and interaction with the tissue of origin or settlement of metastasis; and finally at the systems level to explore its global impact, e.g. through the mechanism of cachexia. Mathematical models have been proposed (...) to identify key mechanisms that underlie dynamics and events at every scale of interest, and increasing effort is now being paid to multi-scale models that bridge the different scales. With more biological data becoming available and with increased interdisciplinary efforts, theoretical models are rendering suitable tools to predict the origin and course of the disease. The ultimate aims of cancer models, however, are to enlighten our concept of the carcinogenesis process and to assist in the designing of treatment protocols that can reduce mortality and improve patient quality of life. Conventional treatment of cancer is surgery combined with radiotherapy or chemotherapy for localized tumors or systemic treatment of advanced cancers, respectively. Although radiation is widely used as treatment, most scheduling is based on empirical knowledge and less on the predictions of sophisticated growth dynamical models of treatment response. Part of the failure to translate modeling research to the clinic may stem from language barriers, exacerbated by often esoteric model renderings with inaccessible parameterization. Here we discuss some ideas for combining tractable dynamical tumor growth models with radiation response models using biologically accessible parameters to provide a more intuitive and exploitable framework for understanding the complexity of radiotherapy treatment and failure. (shrink)

We consider the simple case of a nonrelativistic charged harmonic oscillator in one dimension, to investigate how to take into account the radiation reaction and vacuum fluctuation forces within the Schrödinger equation. The effects of both zero-point and thermal classical electromagnetic vacuum fields, characteristic of stochastic electrodynamics, are separately considered. Our study confirms that the zero-point electromagnetic fluctuations are dynamically related to the momentum operator p=−i ℏ ∂/∂ x used in the Schrödinger equation.

Bell's theorem is expounded as an analysis in Bayesian inference. Assuming the result of a spin measurement on a particle is governed by a causal variable internal (hidden, “local”) to the particle, one learns about it by making a spin measurement; thence about the internal variable of a second particle correlated with the first; and from there predicts the probabilistic result of spin measurements on the second particle. Such predictions are violated by experiment: locality/causality fails. The statistical nature of the (...) observations rules out signalling; acausal, superluminal, or otherwise. Quantum mechanics is irrelevant to this reasoning, although its correct predictions of experiment imply that it has a nonlocal/acausal interpretation. Cramer's newtransactional interpretation, which incorporates this feature by adapting the Wheeler-Feynman idea of advanced and retarded processes to the quantum laws, is advocated. It leads to an invaluable way of envisaging quantum processes. The usual paradoxes melt before this, and one, the “delayed choice” experiment, is chosen for detailed inspection. Nonlocality implies practical difficulties in influencing hidden variables, which provides a very plausible explanation for why they have not yet been found; from this standpoint, Bell's theoremreinforces arguments in favor of hidden variables. (shrink)

ObjectiveTest anxiety (TA) is a construct that has scarcely been studied based on Lang’s three-dimensional model of anxiety. The objective of this article is to investigate the repercussion of sociodemographic and academic variables on different responses for each component of anxiety and for the type of test in adolescent students.MethodA total of 1181 students from 12 to 18 years old (M= 14.7 and SD = 1.8) participated, of whom 569 were boys (48.2%) and 612 girls (51.8%). A sociodemographic questionnaire and (...) theCuestionario de Ansiedad ante los examenes-Adaptado (CAEX-A)[Test Anxiety Questionnaire-Adapted] an adaptation for Spanish secondary school levels (ESO) and Bachillerato were administered.ResultsGirls scored higher on the cognitive and physiological components of TA than boys, the intensity of the physiological response increasing with age. Bachillerato level students reported more physiological anxiety than those of ESO level. Students with better marks in the previous year presented more anxiety in the cognitive component, while those who obtained the lower mark presented higher anxiety values in the behavioral component. Participants reported that the types of tests that cause them more anxiety were oral tests in front of the class, oral presentation in front of a panel, and mathematics tests.ConclusionAdolescents show a differential response of TA based on the physiological, cognitive and motor components, mediated by the variables of gender, age, grade, academic performance and type of exam. These results serve to design specific intervention programs to manage anxiety in situations of academic assessment. (shrink)

A guide for everyone involved in medical decision making to plot a clear course through complex and conflicting benefits and risks.

Bell's theorem is expounded as an analysis in Bayesian probabilistic inference. Assume that the result of a spin measurement on a spin-1/2 particle is governed by a variable internal to the particle (local, “hidden”), and examine pairs of particles having zero combined angular momentum so that their internal variables are correlated: knowing something about the internal variable of one tells us something about that of the other. By measuring the spin of one particle, we infer something about its internal variable; (...) through the correlation, about the internal variable of the second particle, which may be arbitrarily distant and is by hypothesis unchanged by this measurement (locality); and make (probabilistic) prediction of spin observations on the second particle. Each link in this chain has a counterpart in the Bayesian analysis of the situation. Irrespective of the details of the internal variable description, such prediction is violated by measurements on many particle pairs, so that locality—effectively the only physics invoked—fails. The time ordering of the two measurements is not Lorentz-invariant, implying acausality. Quantum mechanics is irrelevant to this reasoning, although its correct predictions of the statistics of the results imply it has a nonlocal—acausal interpretation; one such, the “transactional” interpretation, is presented to demonstrable advantage, and some misconceptions about quantum theory are pursued. The “unobservability” loophole in photonic Bell experiments is proven to be closed. It is shown that this mechanism cannot be used for signalling; signalling would become possible only if the hidden variables, which we insist must underlie the statistical character of the observations (the alternative is to give up), are uncovered in deviations from quantum predictions. Their reticence is understood as a consequence of their nonlocality: it is not easy to isolate and measure something nonlocal. Once the hidden variables are found, all the problems of quantum field theory and of quantum gravity might melt away. (shrink)