Stationary substrates facilitate bioinvasion in Paranaguá Bay in southern Brazil

Artificial substrates in and near ports and marinas commonly have many non-indigenous species and are the first stepping stone for the establishment of bioinvasors. Substrate movement influences fouling communities and so understanding of how species assemblages are related to specific substrate conditions is crucial as a management tool. Here we describe the species assemblage of the community after six months of development on granite plates in Paranaguá Bay. Species richness was similar in the two treatments, with 12 species on floating (constant depth) plates and 15 on stationary (variable depth) plates. However, species composition differed, with the community on floating plates being dominated by the native bivalve Mytella charruana (66.1 ± 5.5% cover) and that on stationary plates dominated by the barnacles Fistulobalanus citerosum (49.8 ± 3.5% cover) and the introduced Amphibalanus reticulatus (33.9 ± 3.7% cover). Other introduced species were Garveia franciscana, on one stationary plate, and Megabalanus coccopoma also on one stationary plate and not very abundant on half of the floating plates (< 2%). Thus, stationary plates were more susceptible to introduced species that may become very abundant, suggesting that this type of substrate should be a priority in management for bioinvasion control. We also hypothesize that the native bivalve M. charruana is the dominant competitor for space on floating substrates, thereby reducing the invasiveness of that type of substrate.Substratos artificiais em regiões de portos e marinas geralmente abrigam muitas espécies introduzidas e sua colonização constitui o primeiro passo no estabelecimento de bioinvasores. O grau de movimentação do substrato influencia a comunidade incrustante e o conhecimento da assembléia de espécies associada a cada situação é crucial como ferramenta de manejo. Neste trabalho, reportamos a estrutura de comunidades de seis meses desenvolvidas em substratos de granito na baía de Paranaguá. Foram encontradas 12 espécies na condição flutuante (profundidade constante) e 15 na condição fixa (profundidade variável), mas o número médio de espécies por placa não foi diferente nos tratamentos. A comunidade das placas flutuantes foi dominada pelo bivalve nativo Mytella charruana (66.1 ± 5.5% de cobertura), enquanto as placas fixas foram dominadas pelos cirripédios Fistulobalanus citerosum (49.8 ± 3.5%) e Amphibalanus reticulatus (33.9 ± 3.7%), este último introduzido na região. Outras espécies introduzidas encontradas foram Garveia franciscana, em apenas uma placa fixa, e Megabalanus coccopoma também em uma placa fixa e em metade das placas flutuantes, mas sempre com baixa cobertura (< 2%). Em conclusão, placas fixas foram mais suscetíveis às espécies introduzidas, uma delas ocorrendo em alta abundância, o que sugere que este tipo de substrato deveria ser priorizado em ações de controle e manejo de bioinvasão. Também hipotetizamos que o bivalve nativo M. charruana é o competidor dominante por espaço na condição flutuante, reduzindo a susceptibilidade deste substrato à bioinvasão

Monoclonal antibodies production in wave and stirred tank bioreactors

The rapid increase in the number of monoclonal antibodies (mAbs) which are being regularly approved for therapeutic use results in the need of their large scale production. However, this requires the development of bioreactors and processes simple to operate and easily scaledup, that allow cultivation of mammalian cells. The Stirred Tank bioreactor is the traditional and most widely used reactor type, mainly due to the know-how acquired with microbial fermentation, its flexibility and suitability for different cell types, operation modes, products and working volumes.[1] However, recently, disposable bioreactors, such as the new Wave reactor, are becoming increasingly popular due to their low initial and lifetime costs, simplified scale-up, reduced turn-around time between runs and low risk of crosscontamination.[2] Due to the current lack of comparative studies about these different technologies, we are optimizing and comparing mAb production in both Stirred Tank and Wave bioreactors. Different modes of operation are being tested (batch and fed-batch), and the use of microcarrier technology for culture of anchorage-dependent cells will also be assayed. Furthermore, it is important to evaluate the product in terms of biological activity, assuring that it maintains full functionality, by assessing how the glycosylation pattern is affected during the process of production in both reactors

Waste-based biosorbents as cost-effective alternatives to commercial adsorbents for the retention of fluoxetine from water

Supplementary data to this article can be found online at https:// doi.org/10.1016/j.seppur.2019.116139.The goal of this study is to demonstrate that waste-based biosorbents can be cost-effective and green alternatives to commercial adsorbents for the retention of pharmaceuticals. Adsorption kinetics and equilibrium measurements allowed the determination of the adsorption capacity of commercial adsorbents (GAC - granular activated carbon and two synthetic zeolites) and waste-based biosorbents (SCG - spent coffee grounds, pine bark and cork waste) for the retention of fluoxetine from water. For commercial adsorbents, the maximum adsorption capacities followed the order GAC (233.5mg/g)>zeolite 13× (32.11mg/g)>zeolite 4A (21.86mg/g), while for low-cost biosorbents, the sequence was SCG (14.31mg/g)>pine bark (6.53mg/g)>cork waste (4.74mg/g). The economic feasibility of the adsorbents/biosorbents was examined through a detailed cost analysis. Commercial adsorbents present higher costs per gram of fluoxetine removed (6.85 /g, 3.13 /g and 1.07 /g zeolite 4 A, zeolite 13× and GAC, respectively) when compared to low-cost biosorbents (0.92 /g, 0.41 /g and 0.16 /g for pine bark, cork waste and SCG, respectively). It was found that SCG is the most economically viable option for fluoxetine removal, while cork waste, the second less expensive, is the most environmentally friendly biosorbent since its preparation does not generate any solid or liquid wastes. This manuscript demonstrates that the conversion of waste materials into adsorbents has a double environmental benefit for both improving waste management and protecting the environment.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the research project PTDC/ AAG-TEC/5269/2014, the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) 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. Bruna Silva thanks FCT for a postdoctoral grant (SFRH/BPD/112354/2015).info:eu-repo/semantics/publishedVersio

Produção de multimídia e acessibilidade em cursos de aprendizagem a distância

Estudantes online que são surdos podem encontrar diferentes barreiras em cursos baseados na Web incluindo falta de imagens relacionadas ao conteúdo em páginas tomadas por texto. As diferentes barreiras podem diminuir a compreensão para pessoas cuja primeira língua seja a linguagem de sinais ao invés da linguagem escrita, um desafio para pesquisadores e professores interessados em desenvolver conteúdo multimídia. A combinação de texto, imagem, áudio e vídeo foi potencializada devido à convergência digital e passa a caracterizar os textos virtuais. O uso de multimídia agora permite diferentes efeitos na elaboração de significados. Nesta perspectiva de mudanças constantes, este artigo busca discutir alguns dos muitos desafios para o oferecimento de Cursos de Graduação em larga escala, apresentando algumas das características dos Cursos de Graduação em Letras-Libras. Também se discute a acessibilidade de conteúdo educacional digital multimídia no contexto de um projeto em andamento na UNICAMP.Online students who are deaf may encounter different barriers on Web based courses including lack of content-related images in pages full of text. The different barriers can slow comprehension for people whose first language may be a sign language instead of a written language, a challenge for researchers and teachers interested in developing multimedia content. The intermix of text, image, audio, and video has been increased due to the digital convergence and characterize the virtual texts. Multimedia usage now brings different effects on meaning making. In this perspective, this paper intends to discuss some of the many challenges in the offer of large scale undergraduate courses presenting some characteristics of a course on the Brazilian Sign Language. The paper discusses educational digital multimedia content accessibility in the context of an ongoing project at UNICAMP

Wear and corrosion of titanium in oral simulating environments

The oral cavity can be considered as an aggressive environment to restorative materials considering that several acidic substances can be retained in the saliva and biofilms as well as loads from mastication and abrasive particles take place in the wear of oral surfaces. The objective of this work is to investigate the in-vitro corrosion and wear in fluoridated artificial saliva and in presence of biofilms. Electrochemical tests of titanium surfaces were performed in artificial saliva containing different fluoride concentrations at 37 oC. Another group of titanium surfaces were prepared to the growth of oral mixed biofilms for 9 days in a specific culture medium. Then, electrochemical tests were carried out with titanium surfaces covered with biofilms in artificial saliva without fluorides. After that, wear sliding tests were performed in the same mediums using a tribometer equipped with a test viewer software. Also, electrochemical measurements were carried during the wear sliding tests. After corrosion-wear tests, worn and unworn surfaces were analyzed by AFM and SEM. A localized corrosion of titanium was only noticed in high fluoride concentration. Therefore, there was a decrease of the corrosion resistance of titanium when the fluoride concentration was increased. Moreover, the presence of biofilms affected harmfully the corrosion resistance of titanium probably due to acids release from the biofilms. However, the wear was decreased when low loads were applied on the biofilms.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/CTM/67500/2006Programa Alban - Bolsas de Alto Nível da União Europeia para a América Latina - E06D103407BRFlemish Science Foundation. Scientific Research Community on Surface Modification of Material

Effect of oral biofilms on the biotribocorrosion of titanium

The oral cavity is a complex environment where corrosive substances from dietary, human saliva and oral biofilms may accumulate in retentive areas of implant-supported prostheses promoting a corrosion of their surfaces. On the other side, during mastication, micro-movements may occur in artificial joints causing a relative contact motion between surfaces. Both processes result in a tribocorrosion system. The objective of this work is to investigate the in-vitro tribocorrosion behavior of titanium covered by biofilms and immersed in artificial saliva. Reciprocating sliding wear tests coupled with electrochemical techniques were performed at 25 o C on titanium samples covered or not with biofilms. Mixed biofilms of Candida albicans and Streptococcus mutans were grown at 37 oC on titanium surfaces for 9 days in Tryptic Soy Broth medium, containing mucin, yeast extract, peptone and sucrose. The open-circuit potential (OCP) was measured until stabilization in artificial saliva. After that, electrochemical impedance spectroscopy (EIS) measurements were carried out at open circuit potential. Subsequently, sliding tests were performed at normal loads of 0.1, 0.2 and 3 N, at a sliding frequency of 1 Hz, and linear displacement amplitudes of 0.5 and 2 mm using a tribometer equipped with a test viewer software. During the sliding tests, the OCP was constantly monitored. At the end of the sliding test, the OCP was further monitored until stabilization, and another series of EIS measurements was made. Worn and unworn surfaces were inspected by SEM. The detachment of the biofilms was not noticed when low loads were applied, and biofilms appear to have some lubricating effect. However, it was found that acidic substances released from Streptococcus mutans and external substances accumulated into the biofilm might corrode surfaces located below and around the biofilms. At a normal load of 3 N, the biofilms were removed from the contact region by the sliding action, and it was observed that the repassivation rate of titanium covered with biofilms was lower than without biofilms.Fundação para a Ciência e a Tecnologia (FCT)ALBANFlemish Science Foundation. Scientific Research Community on Surface Modification of MaterialsPrograma Alban - Bolsas de Alto Nível da União Europeia para a América Latin

Tribocorrosion of commercially pure titanium in oral simulating environments

According to several studies, commercially pure (cp) titanium presents the required properties for dental applications such as mechanical resistance, low density, corrosion resistance and biocompatibility [1-3]. Also, it is widely accepted that the surface properties of the metallic material will play an essential role in the interaction between implanted materials and tissue. Whatever Ti is used in crowns or implants, a relative displacement between the implant and the adjacent material (gum, bone, porcelain…) might occur, always in the presence of an environment constituted by inorganic and organic species. Therefore, a tribocorrosion system may be formed, and the synergistic effect of wear and corrosion may lead to accelerated failure of the system. Nevertheless, few studies have focused on the tribocorrosion behavior of titanium in oral simulating environments, considering the presence of fluoride solutions and/or bacterial biofilms [4-8]. The aim of this work was to study the effect of sliding wear of cp titanium in the presence of artificial saliva containing different amounts of fluoride. Also, the behavior of the tribocorrosion system when a biofilm is present at the surface of the metallic materials was evaluated. Samples of grade 2 Ti were prepared by grinding using SiC sandpapers till 1200 mesh. Tribocorrosion tests were accomplished in Fusayama’s artificial saliva (AS) containing two different fluoride concentrations: 30 and 227 ppmF-. Open-circuit potential (OCP) was monitored during the entire experiment and electrochemical impedance spectroscopy tests (EIS) were carried out at 50 mV above corrosion potential (Ecorr) at frequencies from 100 KHz to 15.8 mHz, before and after sliding. The sliding tests were carried out using an alumina sphere as counterbody under a normal load of 3 N, an amplitude of 2 mm for 20 min. Results were statistically analyzed at significance level of p < 0.05. Samples were inspected by SEM-EDS and AFM. As shown in fig. 1, the addition of 227 ppmF- to the AS resulted in a higher Ecorr during sliding. However, in the same solution, Ti presents a significantly higher passive current density in the absence of mechanical action. During sliding, third-body particles were produced, and chemical analysis of the solution revealed a significant release of Ti ions. The influence of the presence of bacterial cultures of S.mutans on the corrosion and tribocorrosion behavior of titanium is also discussed.Fundação para a Ciência e a Tecnologia (FCT)Programa Alban - Bolsas de Alto Nível da União Europeia para a América LatinaFlemish Science Foundation.Scientific Research Community on Surface Modification of Material

Corrosion behaviour of titanium in the presence of Streptococcus mutans

Objective The main aim of this in vitro study was to evaluate the influence of Streptococcus mutans on the corrosion of titanium. Methods S. mutans biofilms were formed on commercially pure titanium (CP-Ti) square samples (10 mm × 10 mm × 1 mm) using a culture medium enriched with sucrose. Open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) measurements were used to evaluate the corrosion behaviour of CP-Ti in the presence of S. mutans in Fusayama's artificial saliva. The corrosion of biofilm-free CP-Ti samples was also evaluated in artificial saliva. Biofilms biomass was measured by spectrophotometry, using crystal violet staining, after 1, 2 and 7 days. Results The OCP values recorded on CP-Ti in the presence of S. mutans (−0.3 ± 0.02 V vs. SCE) was lower than those on biofilm-free CP-Ti (−0.1 ± 0.01 V vs. SCE) after 2 h of immersion in artificial saliva (p < 0.05). That reveals a high reactivity of titanium in presence of S. mutans. Impedance spectra revealed the formation of a compact passive film on titanium in artificial saliva or in the presence of a 2 days old S. mutans biofilm even though the corrosion resistance of CP-Ti has decreased in presence of a S. mutans biofilm. Conclusion The presence of bacterial colonies, such as S. mutans, negatively affected the corrosion resistance of the titanium.The authors acknowledge the financial support provided by Alban Programme (cod. E06D103407BR), the Erasmus Student Exchange Programme of the CEC, FCT (PTDC/CTM/67500/2006) and the Scientific Research Community on Surface Modification of Materials funded by the Flemish Science Foundation (WOG-FWO-Vlaanderen)

Formação continuada de professores de Matemática: o desenvolvimento de comunidades de prática baseadas na tecnologia

O presente artigo aborda discussões teóricometodológicas sobre o processo de constituição de uma Comunidade de Prática, constituída por uma comunidade virtual, na qual se assume uma postura problematizadora e se articulam interesses e objetivos comuns, ações, diálogos, experiências, discursos reflexivos e histórias compartilhadas, possibilitando implicações para uma possível re-significação da prática docente de professores de Matemática. Os participantes dessa comunidade são alunos da disciplina de PósGraduação: "Didática Aplicada ao Ensino da Matemática", do IGCE / Unesp / Rio Claro-SP - Brasil, que se constituem profissionalmente como professores de escolas e universidades públicas e particulares, que discutem, refletem e compartilham experiências sobre a prática docente, em uma comunidade interativa, virtual, permeada por características computacionais e pedagógicas, na qual a prática compartilhada torna-se objeto de reflexão e possível re-significação.Facultad de Informátic

Formação continuada de professores de Matemática: o desenvolvimento de comunidades de prática baseadas na tecnologia

O presente artigo aborda discussões teóricometodológicas sobre o processo de constituição de uma Comunidade de Prática, constituída por uma comunidade virtual, na qual se assume uma postura problematizadora e se articulam interesses e objetivos comuns, ações, diálogos, experiências, discursos reflexivos e histórias compartilhadas, possibilitando implicações para uma possível re-significação da prática docente de professores de Matemática. Os participantes dessa comunidade são alunos da disciplina de PósGraduação: "Didática Aplicada ao Ensino da Matemática", do IGCE / Unesp / Rio Claro-SP - Brasil, que se constituem profissionalmente como professores de escolas e universidades públicas e particulares, que discutem, refletem e compartilham experiências sobre a prática docente, em uma comunidade interativa, virtual, permeada por características computacionais e pedagógicas, na qual a prática compartilhada torna-se objeto de reflexão e possível re-significação.Facultad de Informátic