A phenomenological approach to the simulation of metabolism and proliferation dynamics of large tumour cell populations

A major goal of modern computational biology is to simulate the collective behaviour of large cell populations starting from the intricate web of molecular interactions occurring at the microscopic level. In this paper we describe a simplified model of cell metabolism, growth and proliferation, suitable for inclusion in a multicell simulator, now under development (Chignola R and Milotti E 2004 Physica A 338 261-6). Nutrients regulate the proliferation dynamics of tumor cells which adapt their behaviour to respond to changes in the biochemical composition of the environment. This modeling of nutrient metabolism and cell cycle at a mesoscopic scale level leads to a continuous flow of information between the two disparate spatiotemporal scales of molecular and cellular dynamics that can be simulated with modern computers and tested experimentally.Comment: 58 pages, 7 figures, 3 tables, pdf onl

Adverse childhood experiences and suicide attempts in morbidly obese adults

Introdução: As tentativas de suicídio surgem frequentemente associadas a problemas alimentares, tanto anorexia quanto bulimia. Do mesmo modo, tem-se verifi cado uma elevada ocorrência de suicídio entre obesos. Investigações têm mostrado que a adversidade na infância pode ser um fator de risco para as tentativas de suicídio. Objetivos: Caracterizar e compreender a relação entre experiências de adversidade na infância e tentativas de suicídio em 100 obesos mórbidos candidatos a cirurgia bariátrica. Métodos: Um total de 100 pacientes foram selecionados de setembro de 2007 a outubro de 2007 e de janeiro de 2008 a janeiro de 2009, sendo que 20 pacientes eram do sexo feminino. A média de idade era de 38,89±9,87 anos, e a média do peso máximo era de 136,43±14 kg. O Questionário da História de Adversidade na Infância foi utilizado para avaliar experiências adversas. Resultados: 88% dos pacientes relataram a existência de pelo menos uma experiência de adversidade na infância, e 25% relataram já ter realizado pelo menos uma tentativa de suicídio. A adversidade na infância esteve associada a um risco aumentado para realizar tentativas de suicídio (odds ratio = 2,026). Conclusão: Esses dados devem ser levados em consideração na avaliação e no acompanhamento desses pacientes.Introduction: Suicide attempts are often associated with eating disorders, both anorexia and bulimia. Likewise, a high incidence of suicide has been observed among obese patients. Previous studies have shown that adverse experiences in childhood may be a risk factor for suicide attempts. Objectives: To characterize and to understand the relationship between adverse experiences and suicide attempts in 100 morbidly obese patients referred for bariatric surgery. Methods: A total of 100 patients were selected from September 2007 to October 2007 and from January 2008 to January 2009. Of these, 20 patients were females. Mean age was 38.89±9.87 years, and mean maximum weight was 136.43±14 kg. The Portuguese version of the Family ACE (Adverse Childhood Experiences) Questionnaire was used to assess the occurrence of adverse events. Results: 88% of the patients reported the existence of at least one adverse experience in childhood, and 25% reported at least one previous suicide attempt. Adversity in childhood was associated with an increased risk for suicide attempts (odds ratio = 2.026). Conclusion: These data should be taken into account in the assessment and monitoring of these patients.Fundação para a Ciência e a Tecnologia (FCT); (SFRH/BD/37069/2007)

Radiative corrections to polarization observables in elastic electron-deuteron scattering in leptonic variables

The model--independent QED radiative corrections to polarization observables in elastic scattering of unpolarized and longitudinally--polarized electron beam by the deuteron target have been calculated in leptonic variables. The experimental setup when the deuteron target is arbitrarily polarized is considered and the procedure for applying derived results to the vector or tensor polarization of the recoil deuteron is discussed. The basis of the calculations consists of the account for all essential Feynman diagrams which results in the form of the Drell-Yan representation for the cross-section and use of the covariant parametrization of the deuteron polarization state. The numerical estimates of the radiative corrections are given for the case when event selection allows the undetected particles (photons and electron-positron pairs) and the restriction on the lost invariant mass is used.Comment: 43 pages,3 figures. To be published in ZhTEF. revised 14.02.2012. arXiv admin note: text overlap with arXiv:nucl-ex/0002003 by other author

The yield of head CT in syncope: a pilot study

Although head CT is often routinely performed in emergency department (ED) patients with syncope, few studies have assessed its value

Factors contributing to posttraumatic growth and its buffering effect in adult chidren of cancer patients undergoing treatment

This study examined relationships among demographic, clinical, and psychosocial variables in adult children of cancer patients. Two hundred and fourteen participants completed measures of posttraumatic growth (PTG), distress, posttraumatic stress disorder (PTSD) symptoms, social support, and family functioning. Significant gender differences in all PTG dimensions were found, as well as associations among PTG, gender, parental dependency, distress, PTSD, and family functioning. Social support was not a mediator in the relationship between gender and PTG. Gender, education, disease duration, dependency, distress, and family flexibility predicted PTG. Finally, PTG had amoderating effect in the relationship between distress and PTSD/social support. These results may guide psychosocial interventions in this population.Fundação para a Ciência e Tecnologia (FCT