Dynamics of a structured slug population model in the absence of seasonal variation

We develop a novel, nonlinear structured population model for the slug Deroceras reticulatum, a highly significant agricultural pest of great economic impact, in both organic and non-organic settings. In the absence of seasonal variations, we numerically explore the effect of life history traits that are dependent on an individual's size and measures of population biomass. We conduct a systematic exploration of parameter space and highlight the main mechanisms and implications of model design. A major conclusion of this work is that strong size dependent predation significantly adjusts the competitive balance, leading to non-monotonic steady state solutions and slowly decaying transients consisting of distinct generational cycles. Furthermore, we demonstrate how a simple ratio of adult to juvenile biomass can act as a useful diagnostic to distinguish between predated and non-predated environments, and may be useful in agricultural settings

Endovascular Stent Grafts as a Safe Secondary Option for Paraanastomotic Abdominal Aortic Aneurysm

ObjectiveTo describe our experience of endovascular repair of paraanastomotic aortic aneurysm.Methods and resultsFrom March 2001 to December 2004 we identified 6 patients with a paraanastomotic aortic aneurysms following previous open repair of abdominal aortic aneurysm. All patients were treated with endovascular surgery under epidural anaesthesia. There were no major complications, surgical conversions or deaths. Four patients received a bifurcated aortic stent-graft, and two an aorto-uniliac stent-graft followed by a femoro-femoral bypass. At follow-up (mean 26.1±10.2 months) there were no deaths, endoleaks or graft migrations observed.ConclusionEndovascular surgery, avoiding general anesthesia and re-laparotomy, is the ideal technique for treatment of this complication resulting from failed primary conventional AAA repair

Endovascular Stent Grafts as a Safe Secondary Option for Paraanastomotic Abdominal Aortic Aneurysm

Objective: To describe our experience of endovascular repair of paraanastomotic aortic aneurysm. Methods and results: From March 2001 to December 2004 we identified 6 patients with a paraanastomotic aortic aneurysms following previous open repair of abdominal aortic aneurysm. All patients were treated with endovascular surgery under epidural anaesthesia. There were no major complications, surgical conversions or deaths. Four patients received a bifurcated aortic stent-graft, and two an aorto-uniliac stent-graft followed by a femoro-femoral bypass. At follow-up (mean 26.1 ± 10.2 months) there were no deaths, endoleaks or graft migrations observed. Conclusion: Endovascular surgery, avoiding general anesthesia and re-laparotomy, is the ideal technique for treatment of this complication resulting from failed primary conventional AAA repair. © 2006 Elsevier Ltd. All rights reserved

Reentrant Melting of RNA with Quenched Sequence Randomness

The effect of quenched sequence disorder on the thermodynamics of RNA secondary structure formation is investigated for two- and four-letter alphabet models using the constrained annealing approach, from which the temperature behavior of the free energy, specific heat, and helicity is analytically obtained. For competing base pairing energies, the calculations reveal reentrant melting at low temperatures, in excellent agreement with numerical results. Our results suggest an additional mechanism for the experimental phenomenon of RNA cold denaturation

Relatório de estágio de qualificação profissional

Mestrado em Educação Pré-EscolarRelatório final de Estágio submetido como requisito parcial para obtenção do grau de Mestre em Educação Pré-Escolar.No seguimento do plano de ação traçado ao longo da unidade curricular (UC) de Prática Pedagógica Supervisionada, foi proposta a realização do presente relatório de estágio, o qual concretiza uma análise reflexiva do percurso de formação profissional da estagiária que, por sua vez, foi desenvolvido em contexto de creche e de educação pré-escolar, no Infantário Monfortinhos de Real e no Jardim de Infância Aurélia de Sousa, respetivamente. A experiência em contexto educativo, complementada pelas aulas teórico-práticas lecionadas no âmbito da referida UC, contribuiu para o desenvolvimento de competências profissionais intrínsecas à prática docente, como é exemplo a articulação teoria-prática; saber pensar e agir nos contextos educativos; construção de uma prática reflexiva sobre, na e para a ação; co-construir saberes profissionais junto da comunidade educativa; problematizar as exigências da prática profissional, promovendo a adequabilidade das planificações (adaptado de Ribeiro & Araújo, 2012, p.1). Ao longo de toda a prática pedagógica supervisionada, a estagiária teve em consideração a metodologia investigação-ação enquanto “processo em que os participantes analisam as suas próprias práticas educativas de uma forma sistemática e aprofundada” (Coutinho et al., 2009, p.360). Assim, a referida metodologia foi desenvolvida através do envolvimento da estagiária nas diversas etapas do processo educativo (Ministério da Educação, 1997), revelando-se facilitadora da análise reflexiva da sua prática pedagógica.Following the action plan drawn along the course (UC) Supervised Pedagogic Practice, it was proposed to write out this professional qualification report, which performs a reflective analysis of the course of training experienced by the student, which was developed in the contexts of day care and pre-school education, in Monfortinhos Real nursery and in Aurélia de Sousa kindergarten, respectively. The experience lived in an educational context, complemented by the practical classes taught under that UC, contributed to the development of professional skills intrinsic to teaching practice, as exemplified by the articulation between theory and practice, how to think and act in educational contexts; building a reflective practice on, in and for the action, co-build professional knowledge within the educational community; discuss the requirements of professional practice, promoting the suitability of daily plans (adapted from Ribeiro & Araújo, 2012, p.1). Throughout the supervised teaching practice, the student took into account the methodology of action research as "a process in which participants examine their own educational practice in a systematic and thorough manner" (Coutinho et al., 2009, p.360). Thus, this methodology has been developed through the involvement of the student in the different stages of the educational process (Ministry of Education, 1997), favoring the reflective analysis of her practice

Kinetic theory of age-structured stochastic birth-death processes

Classical age-structured mass-action models such as the McKendrick-von Foerster equation have been extensively studied but are unable to describe stochastic fluctuations or population-size-dependent birth and death rates. Stochastic theories that treat semi-Markov age-dependent processes using, e.g., the Bellman-Harris equation do not resolve a population's age structure and are unable to quantify population-size dependencies. Conversely, current theories that include size-dependent population dynamics (e.g., mathematical models that include carrying capacity such as the logistic equation) cannot be easily extended to take into account age-dependent birth and death rates. In this paper, we present a systematic derivation of a new, fully stochastic kinetic theory for interacting age-structured populations. By defining multiparticle probability density functions, we derive a hierarchy of kinetic equations for the stochastic evolution of an aging population undergoing birth and death. We show that the fully stochastic age-dependent birth-death process precludes factorization of the corresponding probability densities, which then must be solved by using a Bogoliubov-–Born–-Green–-Kirkwood-–Yvon-like hierarchy. Explicit solutions are derived in three limits: no birth, no death, and steady state. These are then compared with their corresponding mean-field results. Our results generalize both deterministic models and existing master equation approaches by providing an intuitive and efficient way to simultaneously model age- and population-dependent stochastic dynamics applicable to the study of demography, stem cell dynamics, and disease evolution

Fourth-Order Method for Numerical Integration of Age- and Size-Structured Population Models

In many applications of age- and size-structured population models, there is an interest in obtaining good approximations of total population numbers rather than of their densities. Therefore, it is reasonable in such cases to solve numerically not the PDE model equations themselves, but rather their integral equivalents. For this purpose quadrature formulae are used in place of the integrals. Because quadratures can be designed with any order of accuracy, one can obtain numerical approximations of the solutions with very fast convergence. In this article, we present a general framework and a specific example of a fourth-order method based on composite Newton-Cotes quadratures for a size-structured population model

Mitogenomics reveals two cryptic species in Ciona intestinalis

Individual mitochondrial genes or genomic features are commonly used as phylogenetic markers at many taxonomic levels. We used a mitogenomics approach to demonstrate the existence of two cryptic species in the ascidian Ciona intestinalis, a model chordate whose status as a single species has recently been questioned. Comprehensive comparative analysis of the mitochondrial genome of the two cryptic species revealed significant differences in gene order, size and number of noncoding regions, compositional features and divergence of protein-coding genes