Using presence-absence data to establish reserve selection procedures that are robust to temporal species turnover

Previous studies suggest that a network of nature reserves with maximum efficiency (obtained by selecting the minimum area such that each species is represented once) is likely to be insufficient to maintain species in the network over time. Here, we test the performance of three selection strategies which require presence-absence data, two of them previously proposed (multiple representations and selecting an increasing percentage of each species' range) and a novel one based on selecting the site where each species has exhibited a higher permanence rate in the past. Multiple representations appear to be a safer strategy than selecting a percentage of range because the former gives priority to rarer species while the latter favours the most widespread. The most effective strategy was the one based on the permanence rate, indicating that the robustness of reserve networks can be improved by adopting reserve selection procedures that integrate information about the relative value of sites. This strategy was also very efficient, suggesting that the investment made in the monitoring schemes may be compensated for by a lower cost in reserve acquisition

Robustness of reserve selection procedures under temporal species turnover

Complementarity-based algorithms for the selection of reserve networks emphasize the need to represent biodiversity features efficiently, but this may not be sufficient to maintain those features in the long term. Here, we use data from the Common Birds Census in Britain as an exemplar data set to determine guidelines for the selection of reserve networks which are more robust to temporal turnover in features. The extinction patterns found over the 1981-1991 interval suggest that two such guidelines are to represent species in the best sites where they occur (higher local abundance) and to give priority to the rarer species. We tested five reserve selection strategies, one which finds the minimum representation set and others which incorporate the first or both guidelines proposed. Strategies were tested in terms of their efficiency (inversely related to the total area selected) and effectiveness (inversely related to the percentage of species lost) using data on eight pairs of ten-year intervals. The minimum set strategy was always the most efficient, but suffered higher species loss than the others, suggesting that there is a trade-off between efficiency and effectiveness. A desirable compromise can be achieved by embedding the concerns about the long-term maintenance of the biodiversity features of interest in the complementarity-based algorithms

Biosurfactants: production, applications and future potential

Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Surfactants are one of the most important classes of industrial chemicals in terms of production volume. These compounds exhibit a wide variety of applications in several industries and are present in nearly every product and aspect of our daily life. They can be found in detergents, laundry formulations, household cleaning products, cosmetics, herbicides or pesticides, and are also used in bioremediation, agriculture, food, pharmaceutical, textile, paper or the petroleum industries, among others. Most conventional surfactants available nowadays are derived from non-renewable resources and their use may lead to significant ecological problems due to their toxicity and low biodegradability. In the recent years, an increase in environmental awareness has led to much more interest in the use of renewablebased, biodegradable and more environmentally friendly surfactants. Among them biosurfactants, surface-active compounds synthesized by microorganisms, are attracting a pronounced interest due to their potential advantages over their synthetic counterparts, and to the fact that they could replace some of the synthetics in many environmental and industrial applications. [...]info:eu-repo/semantics/publishedVersio

Sodium chloride effect on the aggregation behaviour of rhamnolipids and their antifungal activity

In this work, the antifungal activity of rhamnolipids produced by Pseudomonas aeruginosa #112 was evaluated against Aspergillus niger MUM 92.13 and Aspergillus carbonarius MUM 05.18. It was demonstrated that the di-rhamnolipid congeners were responsible for the antifungal activity exhibited by the crude rhamnolipid mixture, whereas mono-rhamnolipids showed a weak inhibitory activity. Furthermore, in the presence of NaCl (from 375 mM to 875 mM), the antifungal activity of the crude rhamnolipid mixture and the purified di-rhamnolipids was considerably increased. Dynamic Light Scattering studies showed that the size of the structures formed by the rhamnolipids increased as the NaCl concentration increased, being this effect more pronounced in the case of di-rhamnolipids. These results were confirmed by Confocal Scanning Laser Microscopy, which revealed the formation of giant vesicle-like structures (in the µm range) by self-assembling of the crude rhamnolipid mixture in the presence of 875 mM NaCl. In the case of the purified mono- and di-rhamnolipids, spherical structures (also in the µm range) were observed at the same conditions. The results herein obtained demonstrated a direct relationship between the rhamnolipids antifungal activity and their aggregation behaviour, opening the possibility to improve their biological activities for application in different fields.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01–0145-FEDER-006684) and the project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462). The authors also acknowledge financial support from BioTecNorte operation (NORTE-01-0145-FEDER-000004) and the project MultiBiorefinery (POCI-01-0145-FEDER-016403) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. A. I. Rodrigues was supported by the doctoral Grant SFRH/111600/2015 provided by FCT. E. J. Gudiña was supported by the Post-Doctoral grant CEBBPD/01/2015/07 from the project UID/BIO/04469/2013, funded by FCT.info:eu-repo/semantics/publishedVersio

Automatic tracking of red blood cells in micro channels using OpenCV

The present study aims to developan automatic method able to track red blood cells (RBCs) trajectories flowing through a microchannel using the Open Source Computer Vision (OpenCV). The developed method is based on optical flux calculation assisted by the maximization of the template-matching product. The experimental results show a good functional performance of this method.(undefined

Processamento de imagem digital com MatLab : uma aplicação em ambiente industrial

Fundação para a Ciência e a Tecnologia (FCT

Dimensões Pedagógicas da Sala de Aula Virtual: Teoria e Prática

Este artigo aborda a sala de aula virtual enquanto espaço intencionalmente concebido com o objetivo de promover experiências de aprendizagem relevantes. Centramo-nos nas dimensões pedagógicas integradas e mobilizadas neste espaço, nomeadamente informativa, prática, comunicativa, tutorial e de avaliação, de forma a estabelecer um diálogo entre a teoria e a prática de um docente do ensino superior. Os dados apresentados foram obtidos através da observação direta da organização de salas de aula virtuais e da entrevista ao respetivo docente. A análise destes dados permitem-nos a!rmar que o professor atribuiu uma importância signi!cativa às dimensões em questão, preocupando-se em criar um ambiente on4 — | line estimulante com diferentes recursos (tecnológicos), privilegiando um design centrado no desenvolvimento de competências (com atividades individuais e em grupo) e num modelo pedagógico próprio para ambientes online - e-moderating - baseado nos princípios do construtivismo, da autonomia e da interação

Ligadura de traquéia no período pré-natal ou administração intra-amniótica de surfactante ou dexametasona evitam algumas alterações estruturais nas artérias pulmonares de fetos de coelho com hérnia diafragmática congênita produzida com cirurgia

PURPOSE: Characterization of the structural changes occurring in the pulmonary arteries resulting from surgically produced congenital diaphragmatic hernia in rabbits, with particular emphasis on the preventive effects of prenatal tracheal ligation or administration of intra-amniotic dexamethasone or surfactant. METHODS: Twenty rabbit fetuses underwent surgical creation of a left-sided congenital diaphragmatic hernia on the 24th or 25th gestational day. They were divided according to the following procedures: congenital diaphragmatic hernia (n = 5), congenital diaphragmatic hernia plus tracheal ligation (n = 5), congenital diaphragmatic hernia plus intra-amniotic administration of dexamethasone 0.4 mg (n = 5) or surfactant (Curosurf 40 mg, n = 5). On gestational day 30, all the fetuses were delivered by caesarean section and killed. A control group consisted of five nonoperated fetuses. Histomorphometric analysis of medial thickness, cell nuclei density, and elastic fiber density of pulmonary arterial walls was performed. RESULTS: Arteries with an external diameter >; 100 mum have a decreased medial thickness, lower cell nuclei density, and greater elastic fiber density when compared with arteries with external diameter ; 100 mum. Prenatal treatments with tracheal ligation or intra-amniotic administration of dexamethasone or surfactant prevented these changes. In arteries with external diameterOBJETIVO: Caracterização das alterações estruturais que ocorrem nas artérias pulmonares de fetos de coelho com hérnia diafragmática congênita produzida com cirurgia, com destaque especial aos efeitos preventivos da ligadura de traquéia ou administração intra-amniótica de dexametasona ou surfactante. MÉTODOS: Vinte fetos de coelho foram submetidos a cirurgia para produção de hérnia diafragmática no 24º ou 25º dia de gestação. Os animais foram divididos de acordo com os procedimentos: hérnia diafragmática congênita (n = 5), hérnia diafragmática congênita com ligadura de traquéia (n = 5), hérnia diafragmática congênita com administração intraamniótica de 0,4mg de dexametasona (n = 5) ou surfactante (40mg de Curosurf, n = 5). No 30º dia de gestação, todos os fetos foram retirados por cesariana e mortos. O grupo controle consistiu de 5 fetos normais não operados. Foram realizadas análises histomorfométricas da parede das artérias pulmonares: espessura da camada média, contagem do número de núcleos celulares e densidade de fibras elásticas. RESULTADOS: As artérias com diâmetro externo >; 100 mim apresentaram diminuição da espessura da camada média, menor número de núcleos celulares por micrômetro quadrado e maior densidade de fibras elásticas em comparação com as artérias com diâmetro externo diâmetro externo ; 100 mim. Os métodos terapêuticos, ligadura de traquéia e administração intraamniótica de drogas promoveram reversão destas alterações. Nas artérias com diâmetro extern

Rhamnolipids inhibit aflatoxins production in Aspergillus flavus by causing structural damages in the fungal hyphae and down-regulating the expression of their biosynthetic genes

Aflatoxins are hepatotoxic and carcinogenic fungal secondary metabolites that usually contaminate crops and represent a serious health hazard for humans and animals worldwide. In this work, the effect of rhamnolipids (RLs) produced by Pseudomonas aeruginosa #112 on the growth and aflatoxins production by Aspergillus flavus MUM 17.14 was studied in vitro. At concentrations between 45 and 1500 mg/L, RLs reduced the mycelial growth of A. flavus by 2340% and the production of aflatoxins by 93.999.5%. Purified mono-RLs and di-RLs exhibited a similar inhibitory activity on fungal growth. However, the RL mixture had a stronger inhibitory effect on aflatoxins production at concentrations up to 190 mg/L, probably due to a synergistic effect resulting from the combination of both congeners. Using transmission electron microscopy, it was demonstrated that RLs damaged the cell wall and the cytoplasmic membrane of the fungus, leading to the loss of intracellular content. This disruptive phenomenon explains the growth inhibition observed. Furthermore, RLs down-regulated the expression of genes aflC, aflE, aflP and aflQ involved in the aflatoxins biosynthetic pathway (6.4, 44.3, 38.1 and 2.0-fold, respectively), which is in agreement with the almost complete inhibition of aflatoxins production. Overall, the results herein gathered demonstrate for the first time that RLs could be used against aflatoxigenic fungi to attenuate the production of aflatoxins, and unraveled some of their mechanisms of action.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER 000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also acknowledge the support of the i3S Scientific Platform Histology and Electron Microscopy (HEMS), member of the PPBI (PPBI POCI-01-0145-FEDER-022122). A.I. Rodrigues and L. Abrunhosa acknowledge FCT for the grant SFRH/BD/111600/2015 and the Assistant Research contract CEECIND/00728/2017, respectively.info:eu-repo/semantics/publishedVersio