Monte Carlo Simulation of Protein-Induced Lipid Demixing in a Membrane with Interactions Derived from Experiment

AbstractLipid domain formation induced by annexin was investigated in mixtures of phosphatidylcholine (PC), phosphatidylserine (PS), and cholesterol (Chol), which were selected to mimic the inner leaflet of a eukaryotic plasma membrane. Annexins are ubiquitous and abundant cytoplasmic, peripheral proteins, which bind to membranes containing PS in the presence of calcium ions (Ca2+), but whose function is unknown. Prompted by indications of interplay between the presence of cholesterol in PS/PC mixtures and the binding of annexins, we used Monte Carlo simulations to investigate protein and lipid domain formation in these mixtures. The set of interaction parameters between lipids and proteins was assigned by matching experimental observables to corresponding variables in the calculations. In the case of monounsaturated phospholipids, the PS-PC and PC-Chol interactions are weakly repulsive. The interaction between protein and PS was determined based on experiments of annexin binding to PC/PS mixtures in the presence of Ca2+. Based on the proposal that PS and cholesterol form a complex in model membranes, a favorable PS-Chol interaction was postulated. Finally, protein-protein favorable interactions were also included, which are consistent with observations of large, two-dimensional, regular arrays of annexins on membranes. Those net interactions between pairs of lipids, proteins and lipids, and between proteins are all small, of the order of the average kinetic energy. We found that annexin a5 can induce formation of large PS domains, coincident with protein domains, but only if cholesterol is present

Statistical Analysis of Peptide-Induced Graded and All-or-None Fluxes in Giant Vesicles

AbstractAntimicrobial, cytolytic, and cell-penetrating peptides induce pores or perturbations in phospholipid membranes that result in fluxes of dyes into or out of lipid vesicles. Here we examine the fluxes induced by four of these membrane-active peptides in giant unilamellar vesicles. The type of flux is determined from the modality of the distributions of vesicles as a function of their dye content using the statistical Hartigan dip test. Graded and all-or-none fluxes correspond to unimodal and bimodal distributions, respectively. To understand how these distributions arise, we perform Monte Carlo simulations of peptide-induced dye flux into vesicles using a very simple model. The modality of the distributions depends on the rate constants of pore opening and closing, and dye flux. If the rate constants of pore opening and closing are both much smaller than that of dye flux through the pore, all-or-none influx occurs. However, if one of them, especially the rate constant for pore opening, increases significantly relative to the flux rate constant, the process becomes graded. In the experiments, we find that the flux type is the same in giant and large vesicles, for all peptides except one. But this one exception indicates that the flux type cannot be used to unambiguously predict the mechanism of membrane permeabilization by the peptides

Life cycle cost optimisation in highway concrete bridges management

This study presents a life cycle cost prediction and cost minimisation methodology for a set of highway concrete bridges, during a medium or a long period of time, in order to facilitate the decision process of the structure management. This methodology takes into consideration bridge intervention costs in addition with some Markov matrices degradation model. It applies a genetic algorithm in order to identify the optimised intervention plan, considering the available budget and the desired minimum performance level. Some Portuguese direct and indirect cost parameters, associated with different types of interventions during bridges lifetime, are presented. Finally, a probabilistic sensitivity analysis is carried out using Monte Carlo simulations.5A1D-90C1-54FE | Joana Maria Martins Rosa Maia de Oliveira Almeidainfo:eu-repo/semantics/publishedVersio

Structural behaviour analysis of Faria Guimarães station

No presente estudo efectua-se a modelação e análise do comportamento estrutural da estação Faria Guimarães, do Metro do Porto. A estação é constituída por um cruzamento oblíquo de duas grandes galerias executadas através do método SEM/NATM. A obra é de elevada complexidade devido aos condicionamentos geométricos da estação e obras adjacentes, à grande heterogeneidade do maciço e à ocupação intensa da superfície. A análise do comportamento estrutural da estação foi realizada recorrendo a modelos numéricos 2D e 3D, bem como a resultados obtidos com a observação da estação.In present paper the modelling and structural behaviour analysis of the Faria Guimarães station, of Metro do Porto, is presented. The station includes the inclined intersection of two large galleries executed through SEM/NATM method. The work is highly complex due to geometric limitations of the station and adjacent works, the heterogeneity of the rock mass and the dense occupation at surface. The structural behaviour analysis of the station was performed using 2D and 3D numerical models, as well as results obtained through the observation of the station.Fundação para a Ciência e Tecnologia (FCT) - Projecto POCI/ECM/57495/2004, intitulado Geotechnical Risk in Tunnels for High Speed Trains

Genetic characterization of interleukins (IL-1α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12A, IL-12B, IL-15 and IL-18) with relevant biological roles in lagomorphs

Disponível em: www.ncbi.nlm.nih.gov/pmc/articles/pmid/26395994/ILs, as essential innate immune modulators, are involved in an array of biological processes. In the European rabbit (Oryctolagus cuniculus) IL-1α, IL-1β, IL-2, IL-4, IL-8, IL-10, IL-12A, IL-12B, IL-15 and IL-18 have been implicated in inflammatory processes and in the immune response against rabbit hemorrhagic disease virus and myxoma virus infections. In this study we characterized these ILs in six Lagomorpha species (European rabbit, pygmy rabbit, two cottontail rabbit species, European brown hare and American pika). Overall, these ILs are conserved between lagomorphs, including in their exon/intron structure. Most differences were observed between leporids and American pika. Indeed, when comparing both, some relevant differences were observed in American pika, such as the location of the stop codon in IL-1α and IL-2, the existence of a different transcript in IL8 and the number of cysteine residues in IL-1β. Changes at N-glycosylation motifs were also detected in IL-1, IL-10, IL-12B and IL-15. IL-1α is the protein that presents the highest evolutionary distances, which is in contrast to IL-12A where the distances between lagomorphs are the lowest. For all these ILs, sequences of human and European rabbit are more closely related than between human and mouse or European rabbit and mouse.Research Subject Categories::NATURAL SCIENCES::Biology::Cell and molecular biology::ImmunologyResearch Subject Categories::NATURAL SCIENCES::Biology::Cell and molecular biology::GeneticsFCT and North Portugal Regional Operational Programme 2007/2013 (ON.2) grants supported this work

Inferring Ontological Categories of OWL Classes Using Foundational Rules

Several efforts that leverage the tools of formal ontology (such as OntoClean, OntoUML, and UFO) have demonstrated the fruitfulness of considering key metaproperties of classes in ontology engineering. These metaproperties include sortality, rigidity, and external dependence, and give rise to many fine-grained ontological categories for classes, including, among others, kinds, phases, roles, mixins, etc. Despite that, it is still common practice to apply representation schemes and approaches - such as OWL - that do not benefit from identifying these ontological categories, and simplistically treat all classes in the same manner. In this paper, we propose an approach to support the automated classification of classes into the ontological categories underlying the (g)UFO foundational ontology. We propose a set of inference rules derived from (g)UFO's axiomatization that, given an initial classification of the classes in an OWL ontology, can support the inference of the classification for the remaining classes in the ontology. We formalize these rules, implement them in a computational tool and assess them against a catalog of ontologies designed by a variety of users for a number of domains.</p

Creative Little Scientists: enabling creativity through science and mathematics in preschool and first years of primary education: guidelines and curricula for teacher training (D5.2)

One of the key objectives of the Creative Little Scientists project is to propose a set of curriculum design principles as guidelines for European initial teacher education (ITE) and continuous professional development (CPD) programmes that will foster creative approaches to science and mathematics learning in preschool and the first years of primary education in the frame of inquiry-based educational environments. Work Package 5 is based on the findings of the theoretical review (Work Package 2), comparative studies (Work Package 3), and in-depth field research (Work Package 4). In addition it has been informed by the involvement of communities of stakeholders – teachers, student teachers, school staff members, teacher educators, researchers, out-of-the box thinkers, policy makers and experts in the field of inquiry, creativity or science – in online and face-to-face focus groups. This document offers teacher education policy makers and institutions a set of curriculum design principles and accompanying conceptual recommendations in order to design and apply curricula that will foster creative approaches to science and mathematics learning in preschool and first years of primary education. Furthermore it offers teacher education institutions a related set of teacher outcomes about what teachers should know and be able to do in order to develop such creative approaches. These can be seen as concrete recommendations for teacher educators and teacher education institutions to frame their sessions, workshops and courses. They are directly linked to the implications for teacher training which arose from deliverables D2.2 Conceptual Framework, D3.2 Report on Mapping and Comparing Recorded Practices, D3.3 Report on First Survey of School Practice and D4.4 Report on Practices and their Implications (see also Figure below)

Creative Little Scientists: enabling creativity through science and mathematics in preschool and first years of primary education: exemplary teacher training materials (D5.3)

This report focuses on the Exemplary Teacher Training Materials. The aim of these materials is to illustrate the teacher education Curriculum Design Principles and related Teacher Outcomes, which were developed during Work Package 5 as part of D5.2 Guidelines and Curricula for Teacher Training and can also be found in this report. They are designed for teacher educators to use in Initial Teacher Education (ITE) and teacher Continuing Professional Development (CPD). They aim to extend professional understanding and enhance professional development in order to foster creativity in science and mathematics education in the early years. This report explains the methodology used to develop the materials, the nature and structure of the materials and includes suggestions for their use in all phases of teacher education. Methodology used to develop the exemplary teacher training materials In the Creative Little Scientists project, the comparative research and the in-depth fieldwork in particular identified significant issues that need to be tackled in teacher education in order to foster creativity in science and mathematics education in the early years. Based on these issues the teacher education Content Design Principles, created during the curriculum design research, were refined, and a set of Teacher Outcomes developed. To produce the Exemplary Teacher Training Materials, classroom examples of creative learning and teaching were selected using these Content Design Principles and related Teacher Outcomes. All partners re-visited their data from the in-depth fieldwork (Work Package 4) to select pertinent images, interviews or classroom extracts that evidenced one or more of the Teacher Outcomes. To support and record the selection process a grid was provided where partners could record links between the fieldwork data selected, Teacher Outcomes and factors associated with creativity in learning and teaching in science and mathematics. Templates were then used to structure the classroom materials and provide consistent information about the contexts from which they were drawn. Teacher training materials: an overview and how to use them In total 169 templates are available containing exemplary materials from fieldwork for use in teacher education. These are structured in an Excel-file and can be found on the website http://www.creative-little-scientists.eu. In order to support the full use of this diverse range of resources for teacher training, suggestions are provided in this report of selection and use of these exemplary materials in relation to particular themes and associated Content Design Principles as follows: o Suggestion 1: Use of questions and ideas of children by teachers (Principles 10 and 11) o Suggestion 2: Resources and learning environment as essential context factors for Creativity and Inquiry (Principles 10, 14, 17) o Suggestion 3: Focus on the nature of science – a link with creativity (Principle 3) o Suggestion 4: Focus on Inquiry Based Science Education – link with creativity (Principle 6) o Suggestion 5: Focus on Practical Investigations which foster creativity (Principles 2, 17) o Suggestion 6: Collaboration/group work in inquiry and creativity based approaches (Principle 15) o Suggestion 7: The role of play in inquiry and creativity based approaches (Principles 7, 8, 17) o Suggestion 8: The use of the various modes of expression and representation of science and mathematics learning to support inquiry and the development of creativity – link with assessment (Principles 7, 9) o Suggestion 9: The role of the teacher in Inquiry and Creativity approaches (Principles 1, 7, 11) o Suggestion 10: Cross curricular project work to foster inquiry and creativity (Principle 6) The suggestions above are carefully chosen since they encourage inquiry and creativity in science and mathematics education for early years, by focusing on the synergies between Inquiry-Based Science Education (IBSE) and Creative Approaches (CA): play and exploration; motivation and affect; dialogue and collaboration; problem solving and agency; questioning and curiosity; reflection and reasoning; teacher scaffolding and involvement; and assessment for learning. As noted in the Conceptual Framework (D2.2) and experienced during the in-depth fieldwork, developing contexts for inquiry and exploration which foster creative learning, and achieving a balance between teacher intervention and children collaboration, as well as teacher standing back and learner agency, represent considerable professional challenges. The provided exemplary teacher training materials and associated suggestions for their use help address these challenges

Connecting Regional Development to Environmental Education

&lt;p&gt;In this study we investigate how environmental education can be connected with the regional sustainable development We perceive that the dialogues surrounding Environmental Education in formal education have been dividing opinions over the last two decades. This does not happen only in relation to the conceptual precepts, but mainly in relation to the field of activity. Our theoretical support comes from authors engaged with the Critical Environmental Education, signaling for the construction of what we call Reference Framework. Our research is developed from a qualitative perspective, having as a strategy the exploratory case study. For the analysis of the documents we make reference to the methodology of content analysis proposed by Bardin (2011) and reflective application of the Reference Framework. We argue that so far in Brazil, environmental education is divided into two major theoretical trends that reflect the practices of environmental educators. On the one hand, supporting a behaviorist / liberal / conservative tendency of Environmental Education (CARVALHO, 2001; GUIMAR&amp;Atilde;ES, 2000; LOUREIRO, 2008), understand environmental practices from its immediate resolution dimension, focusing actions that situate environmental practices through changes in social behaviors, mostly promoted by environmental activism. On the other hand, we have the opposite, that is, the popular / critical / emancipatory tendency which situates its argumentative and practical content situates in the significant assumption of a new societal posture in relation to the economic models adopted. It establishes the connection between environmental education and local / regional development, delineating a perception of reality, forming a dimension of creating other ways of relating human and non-human, including the emergence of a rationality that impresses ethical socio-environmental values, other forms of understanding of the world and the concept of environmental rationality.&lt;/p&gt

Síntese e caracterização de um superplastificante para betão

A maior parte das estruturas da construção civil exigem um betão fresco com elevados níveis de trabalhabilidade. Estes níveis são conseguidos com a adição de uma quantidade de água várias vezes superior à teoricamente necessária, limitando as propriedades físicas do betão resultante. A solução para este problema consiste na adição, na mistura inicial, de substâncias fluidificantes, que proporcionem uma diminuição da quantidade de água. Estas substâncias são conhecidas por superplastificantes ou agentes redutores de água de alta gama. Estes aditivos são compostos químicos à base de polímeros orgânicos solúveis em água, que contêm grupos sulfito ligados às cadeias poliméricas em intervalos regulares. A maior parte das formulações comerciais pertencem às seguintes famílias: condensados de melamina-formaldeído sulfonados (SMF), condensados de naftaleno-formaldeído sulfonados (SNF) e linhosulfonatos modificados (MLS). Mais recentemente, surgiram no mercado produtos de natureza diferente conhecidos por polímeros de éter carboxílico (CE). Na prática, as partículas de cimento aderem umas às outras, delimitando água no seu interior. Deste modo, parte da superfície das partículas de cimento não fica disponível para a hidratação, nem mesmo a água que permanece no interior. Como consequência, a mistura toma-se muito viscosa e origina betões com baixas resistências mecânicas. Os superplastificantes vão provocar a dispersão dos aglomerados de partículas, reduzindo assim a viscosidade da pasta, aumentando a trabalhabilidade e as resistências mecânicas. No presente trabalho foram sintetizados condensados SMF em três etapas reaccionais consecutivas: metilolação, sulfonação e polimerização. O processo foi desenvolvido em meio aquoso, onde o pH do meio é o parâmetro operatório mais importante. Outras condições operatórias, nomeadamente a temperatura e a proporção de reagentes, têm também que ser tomadas em consideração. As condições processuais foram ajustadas por forma a melhorar as propriedades mecânicas do betão. Procedeu-se à caracterização do produto final por espectroscopia FTIR (Fourier Transform Infrared) e cromatografia GFC (Gel Filtration Chromatography). O mecanismo de actuação dos superplastificantes foi identificado e estudado recorrendo a técnicas de microscopia óptica