Stochastic group selection model for the evolution of altruism

We study numerically and analytically a stochastic group selection model in which a population of asexually reproducing individuals, each of which can be either altruist or non-altruist, is subdivided into $M$ reproductively isolated groups (demes) of size $N$. The cost associated with being altruistic is modelled by assigning the fitness $1- \tau$, with $\tau \in [0,1]$, to the altruists and the fitness 1 to the non-altruists. In the case that the altruistic disadvantage $\tau$ is not too large, we show that the finite $M$ fluctuations are small and practically do not alter the deterministic results obtained for $M \to \infty$. However, for large $\tau$ these fluctuations greatly increase the instability of the altruistic demes to mutations. These results may be relevant to the dynamics of parasite-host systems and, in particular, to explain the importance of mutation in the evolution of parasite virulence.Comment: 12 pages, 7 figure

A avaliação do conhecimento gramatical 'oficial': estudo dos exames nacionais de Português de 2010

Na última década e a nível nacional, as provas de aferição e os exames nacionais vêm sendo objecto de polémicas, vindas de distintos quadrantes e de que é exemplo o editorial do jornal Público de 22/6/2009: “Exames 2009: como se prepara o ‘sucesso’ fácil”. Em termos da avaliação educacional, se aceitarmos que “a avaliação é sinónimo de sucesso” (Pacheco & Zabalza, 1995: 7), tal significará que, ao estudar a avaliação externa, poderemos contribuir para uma compreensão sustentada da educação em línguas. Além disso, entendendo a avaliação do conhecimento gramatical “oficial” como um factor constitutivo das disciplinas de Português, será possível descrever como são representados e avaliados os conhecimentos explícitos sobre o ensino da língua materna. Neste quadro, pretende-se, neste estudo, aprofundar a análise do domínio da gramática em provas de avaliação externa, comparando as provas de aferição de Língua Portuguesa do 4º e do 6º anos de escolaridade e os exames do 9º e do 12º anos, todos realizados no ano lectivo de 2009/2010. Com esta finalidade, o trabalho desenvolver-se-á de acordo com as seguintes dimensões de análise: a) delimitação da estrutura das diferentes provas de avaliação em Português, de acordo com domínios correntes como a leitura, a escrita ou a gramática; b) identificação dos tipos de pergunta e dos conteúdos implicados na avaliação do saber gramatical; c) categorização das questões segundo três níveis - reconhecimento, produção e explicitação dos conhecimentos sobre a língua. Para além de compreender melhor o papel da regulação externa dos saberes relativos ao conhecimento explícito da língua, deste estudo retirar-se-ão conclusões acerca das novas formas de (re)configuração da gramática escolar

Supercritical CO2-assisted spray drying of strawberry-like gold-coated magnetite nanocomposites in chitosan powders for inhalation

Associate Laboratory Research Unit for Green Chemistry Clean Processes and Technologies-LAQV - (UID/QUI/50006/2013) ; UCIBIO from FCT/MEC - UID/Multi/04378/2013 ; ERDF - POCI-01-0145-FEDER-007265; FCT/MEC - SFRH/BD/51584/2011; SFRH/BPD/93982/2013 ; FCT-Lisbon - IF/00915/2014Lung cancer is one of the leading causes of death worldwide. Therefore, it is of extreme importance to develop new systems that can deliver anticancer drugs into the site of action when initiating a treatment. Recently, the use of nanotechnology and particle engineering has enabled the development of new drug delivery platforms for pulmonary delivery. In this work, POXylated strawberry-like gold-coated magnetite nanocomposites and ibuprofen (IBP) were encapsulated into a chitosan matrix using Supercritical Assisted Spray Drying (SASD). The dry powder formulations showed adequate morphology and aerodynamic performances (fine particle fraction 48%-55% and aerodynamic diameter of 2.6-2.8 μm) for deep lung deposition through the pulmonary route. Moreover, the release kinetics of IBP was also investigated showing a faster release of the drug at pH 6.8, the pH of lung cancer. POXylated strawberry-like gold-coated magnetite nanocomposites proved to have suitable sizes for cellular internalization and their fluorescent capabilities enable their future use in in vitro cell based assays. As a proof-of-concept, the reported results show that these nano-in-micro formulations could be potential drug vehicles for pulmonary administration. © 2017 by the authors.publishersversionpublishe

Generating asymmetries in the early vertebrate embryo: the role of the Cerberus-like family

One fundamental aspect of vertebrate embryonic development is the formation of the body plan. For this process, asymmetries have to be generated during early stages of development along the three main body axes: Anterior-Posterior, Dorso-Ventral and Left-Right. We have been studying the role of a novel class of molecules,the Cerberus/Dan gene family. These are dedicated secreted antagonists of three major signaling pathways: Nodal, BMP and Wnt. Our studies contribute to the current view that the fine tuning of signaling is controlled by a set of inhibitory molecules rather than by activators. In this context, the Cerberus-like molecules emerge as key players in the regulation and generation of asymmetries in the early vertebrate embryo.C.R.U.P; F.C.T.; IGC/Fundação Calouste Gulbenkia

P9 - Antimicrobial properties and bioactivity potential of smart nanoparticles for dental applications

Tooth decay is one of the greatest causes of tooth loss in the world. This not only afects the patient’s quality of life but also carries an economic burden associated with the need for multiple reinterventions. Endodontic treatment aims to preserve teeth by cleaning, disinfecting and flling/sealing the root canal. Despite the high success rate of endodontic treatment, failures do occur in a large number of cases. Several new biomaterials for dentistry have been developed, however their bioactivity is often misunderstood. Our work focuses on the biological characterization of novel bioactive glass nanoparticles, including the evaluation of their antimicrobial and biocompatibility properties. Candida albicans (ATCC 11225) and Enterococcus faecalis (ATCC 29212) were included to evaluate the antimicrobial potential by the drop plate method [1]. The cytotoxicity was tested using the MC3T3-E1 cell line, through the resazurin reduction assay. The novel bioactive glass nanoparticles demonstrated antimicrobial activity against C. albicans and E. faecalis, being able to inhibit their growth but also, in some incubation times, decreased the survival of these microorganisms. After 24 h of incubation of MC3T3-E1 osteoblast cells with bioactive glass nanoparticles conditioned medium, around 48% cell viability was achieved. These novel bioactive glass nanoparticles have shown promising properties which may fnd applications on diferent areas of clinical dentistry.info:eu-repo/semantics/publishedVersio

Solving a capacitated waste collection problem using an open-source tool

Increasing complexity in municipal solid waste streams worldwide is pressing Solid Waste Management Systems (SWMS), which need solutions to manage the waste properly. Waste collection and transport is the first task, traditionally carried out by countries/municipalities responsible for waste management. In this approach, drivers are responsible for decision-making regarding collection routes, leading to inefficient resource expenses. In this sense, strategies to optimize waste collection routes are receiving increasing interest from authorities, companies and the scientific community. Works in this strand usually focus on waste collection route optimization in big cities, but small towns could also benefit from technological development to improve their SWMS. Waste collection is related to combinatorial optimization that can be modeled as the capacitated vehicle routing problem. In this paper, a Capacitated Waste Collection Problem will be considered to evaluate the performance of metaheuristic approaches in waste collection optimization in the city of Bragança, Portugal. The algorithms used are available on Google OR-tools, an open-source tool with modules for solving routing problems. The Guided Local Search obtained the best results in optimizing waste collection planning. Furthermore, a comparison with real waste collection data showed that the results obtained with the application of OR-Tools are promising to save resources in waste collection.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the R &D Units Project Scope: UIDB/05757/2020, UIDB/00690/2020, UIDB/50020/2020, and UIDB/00319/2020. Adriano Silva was supported by FCT-MIT Portugal PhD grant SFRH/BD/151346/2021, and Filipe Alves was supported by FCT PhD grant SFRH/BD/143745/2019

Determining factors of functioning in hemodialysis patients using the international classification of functioning, disability and health

Background: Hemodialysis (HD) treatment affects functioning, physical activity level, clinical biomarkers, and body composition. However, the association between these variables with functioning, considering International Classification of Functioning, Disability and Health (ICF) domains remains unclear. Thus, the aim of this study was to investigate the possible association between physical activity, biomarkers, and body composition with functioning in HD patients in reference to the ICF. Methods: Eighty HD patients performed different tests grouped according to ICF domain: Body structure and function – handgrip strength (HS), 5-repetition sit-to-stand test, and 60-s sit-to-stand test (5-STS, 60-STS, respectively); Activity – short physical performance battery (SPPB); and Participation – participation scale questionnaire. Physical activity [Human Activity Profile questionnaire (HAP)], body composition (Dual-energy X-ray absorptiometry), Parathormone (PTH), and alkaline phosphatase were analyzed as possible variables associated with ICF domains. Data analyses were performed using simple and multiple regression models adjusted for age, duration of HD, and diuresis volume. Results: In the body structure and function domain, appendicular lean mass, PTH level, and age were associated with HS ( R2 = 0.558); HAP and PTH were associated with 5-STS ( R2 = 0.263); and HAP, PTH, duration of HD, and age were associated with 60-STS ( R2 = 0.337). In the activity domain, HAP, PTH, alkaline phosphatase, duration of HD, age, and body fat were associated with SPPB ( R2 = 0.689). Finally, only HAP was associated with the participation scale ( R2 = 0.067). Conclusion: Physical activity and PTH levels are determinant protagonists of functioning in all ICF domains in hemodialysis patients

Public perceptions of hazards associated with Brazil nuts (Bertholletia excelsa) : evaluation of risk within an European context

One of the most important economic plants of the Amazon is the Brazil nut (Bertholletia excelsa). Brazil nuts for international trade are mainly obtained from wild collection rather than from plantations, often cited as one of the most important products of extractive reserves in Amazonia. The European Commission (2003/493/EC) has imposed strict regulations on the import from Brazil of Brazil nuts in their shells, as the shells have been found to contain high levels of aflatoxins, which can lead to liver cancer. This may have a negative impact on the Brazilian exports of shelled Brazil nuts, due to possible public awareness. The aim of the present research is to assess public perceptions regarding Brazil nuts and to contrast these with other nuts in general through the use of the Portuguese version of the Perceived Food Risk Index (PFRI). A sample of 418 consumers was drawn through a door-to-door interview using a random route walk procedure and following a quota sampling controlled for sex, age and location. Consumers were asked to choose the most relevant quality and preservation characteristics and to identify their consumption patterns for Brazil nuts and for nuts in general. Risk perception was evaluated over ten risk characteristics, for each of the following hazards: i) aflatoxins; ii) biological contaminants; iii) organoleptic changes; iv) fragments and strange bodies and v) microbial contamination. Additionally, subjects were asked to rate the probability of each hazard occurring in Brazil nuts or in nuts in general. Results show high consumptions of nuts in general, and a reduced consumption of Brazil nuts, although with low differences on the dimensions of risk perception. Concluding, this work adds to knowledge about the perceptions of risk connected to Brazil nuts consumption, namely that consumers perceive Brazil nuts as safe as nuts in general