Contribuição para o estudo das plantas vasculares da ilha de Santa Maria, Açores.

V Expedição Científica do Departamento de Biologia – Santa Maria e Formigas 1990.Integrada na expedição científica Santa Maria - 1990, foi realizada uma incursão a esta ilha com os objectivos principais de: aumentar a colecção do herbário da Universidade dos Açores e angariar informação sobre a localização e fenologia das espécies endémicas da Macaronésia

Effects of the interactions between glutaraldehyde and the polymeric matrix on the efficacy of the biocide against pseudomonas fluorescens biofilms

Glutaraldehyde (GTA) is a widely used biocide due to its high effectiveness. The experimental work reported here was carried out to assess the effectiveness of GTA in controlling biofilms formed by Pseudomonas fluorescens on stainless steel slides, and to compare efficacy against both planktonic and sessile microrganisms. The tests were performed using two concentrations of GTA (50 and 100mg L-1), biofilms of two ages (7 and 15 d), several pH values (5, 7 and 9) and a range of exposure times (from 0 (control) to 1, 3, 7 and 24 h). The action of GTA on biofilm and planktonic populations was assessed by means of activity tests, zeta potential, and the wet weight of the biofilms. Biofilms were not completely removed after treatment with GTA in any of the conditions studied. The higher GTA concentration was more effective in reducing the bacterial activity of the biofilm. The biocide proved to be more effective for longer exposure times. GTA showed good antimicrobial activity against P. fluorescens in suspension, with higher activity at pH 9. The findings of this study suggest that when GTA is used to control biofilms, it reacts with one of the components of the matrix, the proteins, thereby reducing its antimicrobial action.Instituto de Biotecnologia e Química Fina (IBQF)

Role of the polymeric matrix constituents on the performance of a biocide against pseudomonas fluorescens biofilms

The effectiveness of glutaraldehyde – a very common biocide – to control biofilms formed by Pseudomonas fluorescens on stainless steel slides, was investigated. The tests were performed using two concentrations of the biocide (50 and 100 mg Lˉ¹), biofilms of two ages (7 and 15 days), several pH values (5, 7 and 9) and a range of exposure times (from 0 to 1, 3, 7 and 24 hours). The GTA action on biofilm and planktonic populations was assessed by means of activity tests and wet weight of the biofilms. The results showed that biofilms were not completely removed after the treatment with biocide, in all the situations studied. The higher concentration was more effective in reducing the bacterial activity of the biofilm. The biocide proved to be more effective for longer exposure times. GTA showed good antimicrobial activity against P. fluorescens in suspension, with higher activity for pH 9. The findings of this study suggest that when GTA is used to control biofilms, it reacts with one of the components of the matrix – the proteins – thereby reducing its antimicrobial action.Instituto de Biotecnologia e Química Fina (IBQF)

LoCuSS: Exploring the selection of faint blue background galaxies for cluster weak-lensing

Cosmological constraints from galaxy clusters rely on accurate measurements of the mass and internal structure of clusters. An important source of systematic uncertainty in cluster mass and structure measurements is the secure selection of background galaxies that are gravitationally lensed by clusters. This issue has been shown to be particular severe for faint blue galaxies. We therefore explore the selection of faint blue background galaxies, by reference to photometric redshift catalogs derived from the COSMOS survey and our own observations of massive galaxy clusters at z~0.2. We show that methods relying on photometric redshifts of galaxies in/behind clusters based on observations through five filters, and on deep 30-band COSMOS photometric redshifts are both inadequate to identify safely faint blue background galaxies. This is due to the small number of filters used by the former, and absence of massive galaxy clusters at redshifts of interest in the latter. We therefore develop a pragmatic method to combine both sets of photometric redshifts to select a population of blue galaxies based purely on photometric analysis. This sample yields stacked weak-lensing results consistent with our previously published results based on red galaxies. We also show that the stacked clustercentric number density profile of these faint blue galaxies is consistent with expectations from consideration of the lens magnification signal of the clusters. Indeed, the observed number density of blue background galaxies changes by ~10-30 per cent across the radial range over which other surveys assume it to be flat.Comment: submitted to MNRA

The LSTS open-source communication and autonomy software: enabling networked vehicle systems to find track, and sample dynamic features of the ocean

Peer Reviewe

Nanoparticles for Delivery of Vitamin D: Challenges and Opportunities

In addition to the traditional role of calcium homeostasis and bone mineralization, calcitriol, the active metabolite of vitamin D, also displays other metabolic activities as antiproliferative, pro-differentiating, anti-inflammatory, immunomodulatory, and antineoplastic effects. Thus, the awareness that vitamin D insufficiency/deficiency may be associated with various diseases has grown. Also nowadays, vitamin D is recognized as a potential therapeutic agent in anticancer therapy. However, its administration presents some drawbacks such as high toxicity and low bioavailability. Thus, the use of nanotechnology may overcome these problems associated with vitamin D administration, allowing to decrease its toxicity in healthy tissues and increasing its bioavailability. In this chapter, an overview on vitamin D and its metabolic activity is presented, as well as a review of nanosystems for the encapsulation of vitamin D for different applications, such as food and pharmaceutical industries

Detection of Vulnerabilities in Smart Contracts Specifications in Ethereum Platforms

Ethereum is the principal ecosystem based on blockchain that provides a suitable environment for coding and executing smart contracts, which have been receiving great attention due to the commercial apps and among the scientific community. The process of writing secure and well performing contracts in the Ethereum platform is a major challenge for developers. It consists of the application of non-conventional programming paradigms due to the inherent characteristics of the execution of distributed computing programs. Furthermore, the errors in the deployed contracts could have serious consequences because of the immediate linkage between the contract code and the financial transactions. The direct handling of the assets means that the errors can be more relevant for security and have greater economic consequences than a mistake in the conventional apps. In this paper, we propose a tool for the detection of vulnerabilities in high-level languages based on automatized static analysis

Trace elements accumulation in the sea lamprey along the major hydrographic basins of Portugal

Trace elements accumulation in the sea lamprey along the major hydrographic basins of Portuga

Sociolinguistic Correlates of Negative Evaluation: Variable Concord in Rio de Janeiro

Variable agreement in Brazilian Portuguese is subject to social stigma, under strongly negative evaluation, brought to the public’s attention in 2011 in a heated nation-wide sociolinguistic debate triggered by TV Globo, the principal national television network. In order to isolate objective factors underlying this debate, we examine the variable ‘years of schooling’ in a trend study of Rio de Janeiro speech from 1980 and 2000. Analysis of relative weights and their corresponding ranges reveals that distance between effects of each level of education has increased over time. Polarization of the education variable in 1980 was moderate, while in 2000 polarization becomes extreme in an increasingly uneven social distribution of marked forms. The results reveal massive exacerbation of sociolinguistic apartheid, showing that nothing has changed in human interaction with respect to language despite many years of language studies. For this reason, we suggest that our sociolinguistic studies ought to trigger legal action, with creation of laws against linguistic prejudice, modeled on laws against other forms of prejudice, so that society can profit from results of sociolinguistic research in a humanistic and emancipatory way