Inertial manifolds in biological systems

The focus of this thesis is biological systems whose dynamics present an interesting feature: only some dimensions drive the whole system. In our examples, the dynamics is expressed as ODEs, such that the ith equation depends on all the variables xi = f (x1,...,xi,xi+1,...), so that they cannot be solved by classical methods. The authors in the literature found that one could express the variable of order bigger than N as a function of the first N variables, thus closing the differential equations; the approximations obtained were exponentially close to the nonapproximated result. In Nonlinear Dynamics, such functions are called Inertial Manifolds. They are defined as manifolds that are invariant under the flow of the dynamical system, and attract all trajectories exponentially. The first example gives rise to a generalisation of a theorem which, in the literature, is proved for the PDE u= -Au + V(u). We prove existence for the most general case u= -A(u)u + V(u) and consider the validity of the results for the biological parameters. We also present a theoretical discussion, by providing examples. The second example arises from Statistics applied to population biology. The infinite number of differential equations for the moments are approximated using a Moment Closure technique, that is expressing moments of order higher than N as a function of the first moments, generally using the function valid for the normal distribution. The example shows exceptional approximation. Though this technique is often used, there is no complete mathematical justification. We examine the relation between the Moment Closure technique and Inertial Manifolds. We prove that the approximated system can be seen as a perturbation of the original system, that it admits an Inertial Manifold, which is close to the original one for \epsilon \rightarrow 0 and t \rightarrow \infty

Age influenced cattle serum antigen detected by autoantibodies

International audienc

Microbiota–Liver Diseases Interactions

: Gut microbiota regulates essential processes of host metabolism and physiology: synthesis of vitamins, digestion of foods non-digestible by the host (such as fibers), and-most important-protects the digestive tract from pathogens. In this study, we focus on the CRISPR/Cas9 technology, which is extensively used to correct multiple diseases, including liver diseases. Then, we discuss the non-alcoholic fatty liver disease (NAFLD), affecting more than 25% of the global population; colorectal cancer (CRC) is second in mortality. We give space to rarely discussed topics, such as pathobionts and multiple mutations. Pathobionts help to understand the origin and complexity of the microbiota. Since several types of cancers have as target the gut, it is vital extending the research of multiple mutations to the type of cancers affecting the gut-liver axis

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

Polyacetylenes Bearing Chiral-Substituted Fluorene and Terfluorene Pendant Groups: Synthesis and Properties

The synthesis of the first polyacetylenes bearing chiral fluorene-based pendant groups is described. Poly{9,9-bis[(S)-3,7-dimethyloctyl]fluoren-2-ylacetylene} (PFA1), poly{9,9-bis[(S)-2-methylbutyl]- fluoren-2-ylacetylene} (PFA2), and poly{9,9,9′,9′,9′′,9′′-hexakis[(S)-2-methylbutyl]-7,2′;7′,2′′-terfluoren- 2-ylacetylene} (PFA3) have been obtained by Rh(I)-catalyzed polymerization of the corresponding terminal acetylene monomers 2-ethynyl-9,9-bis[(S)-3,7-dimethyloctyl]fluorene (2a), 2-ethynyl-9,9-bis[(S)-2-methylbutyl]fluorene (2b), and 2-ethynyl-9,9,9′,9′,9′′,9′′-hexakis[(S)-2-methylbutyl]-7,2′;7′,2′′-terfluorene (10). The effect of the alkyl chain length at the C-9 position of fluorene on the structural and conformational aspects of the polymers PFA1 and PFA2 as well as on their chiroptical properties was studied by XRD, DSC, TGA, GPC, UV-vis, and CD. A more planar conformation of the polyenic backbone of PFA1 with respect to PFA2 can be inferred by a red shift of the ð-ð* transition in the UV-vis spectra. Their photoluminescence properties are those typical of fluorene systems. CD measurements evidenced Cotton effects of opposite signs in correspondence of the backbone absorption region, ascribable to an excess of a screw sense of the helical conformations assumed by the two polymers. PFA3 revealed an amorphous structure and exhibited peculiar thermal stability features (as indicated by TGA and DSC). Its emission spectra interest the violet-blue region and do not show any substantial red shift passing from solution to solid state, thus pointing out an aggregation prevention of terfluorene groups by means of the polyacetylene backbone

New Oral Anticoagulants Versus Warfarin in Atrial Fibrillation After Early Postoperative Period in Patients With Bioprosthetic Aortic Valve

Background: The efficacy of novel nonvitamin K antagonist oral anticoagulants (NOACs) in nonvalvular atrial fibrillation (AF) to prevent stroke is well assessed, but NOACs use in AF that occurs after bioprosthetic aortic valve replacement (AVR) is not endorsed. This retrospective real-world study evaluated the efficacy and safety of NOACs prescribed no earlier than 4 months after AVR as an alternative to warfarin in patients with AF. Methods: We pooled 1032 patients from the databases of 5 centers. Ischemic/embolic events and major bleeding rates were compared between 340 patients assuming NOACs and 692 prescribed warfarin. Propensity score matching was performed to avoid the bias between groups. Results: The NOACs vs warfarin embolic/ischemic rate was 13.5% (46 of 340) vs 22.7% (157 of 692), respectively, (hazard ratio [HR], 0.5; 95% confidence interval [CI], 0.37-0.75; P < .001), and the incidence rate was 3.7% vs 6.9% patients/year, respectively (log-rank test P = .009). The major bleeding rate was 7.3% (25 of 340) vs 13% (90 of 692) (HR, 0.5; 95% CI, 0.33-0.84; P = .007), and the incidence rate was 2% vs 4% patients/year (log-rank test P = .002.) After propensity score matching, the NOACs vs warfarin embolic/ischemic rate was 13.1% (42 of 321) vs 21.8% (70 of 321) (HR, 0.6; 95% CI, 0.4-0.9; P = .02), and the incidence rate was 4.1% vs 6.7% patients/year (log rank test P = .01). The major bleeding rate was 7.8% (25 of /321) vs 13.7% (44 of 321) (HR, 0.5; 95% CI, 0.31-0.86; P = .01), and the incidence rate was 2.4% vs 4.2% patients/year (log-rank P = .01). Conclusions: In a real-word study, NOACs use overcomes the indications provided by guidelines. This study evidenced that NOACs use in patients who developed AF after bioprosthetic AVR was more effective in prevention of thromboembolism and safe in reduction of major bleeding events compared with warfarin

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