Tuning of fiber optic surface reflectivity through graphene oxide-based Layer-by-Layer film coatings

SFRH/BD/135820/2018 UID/EEA/50014/2019 UID/FIS/00068/2019 M-ERA-NET2/0002/2016The use of graphene oxide-based coatings on optical fibers are investigated, aiming to tune the reflectivity of optical fiber surfaces for use in precision sensing devices. Graphene oxide (GO) layers are successfully deposited onto optical fiber ends, either in cleaved or hollow microspheres, by mounting combined bilayers of polyethylenimine (PEI) and GO layers using the Layer-by-Layer (LbL) technique. The reflectivity of optical fibers coated with graphene oxide layers is investigated for the telecom region allowing to both monitor layer growth kinetics and cavity characterization. Tunable reflective surfaces are successfully attained in both cleaved optical fibers and hollow microsphere fiber-based sensors by simply coating them with PEI/GO layers through the LbL film technique.publishersversionpublishe

Acoustic optical fiber sensor based on graphene oxide membrane

A Fabry–Pérot acoustic sensor based on a graphene oxide membrane was developed with the aim to achieve a faster and simpler fabrication procedure when compared to similar graphene-based acoustic sensors. In addition, the proposed sensor was fabricated using methods that reduce chemical hazards and environmental impacts. The developed sensor, with an optical cavity of around 246 µm, showed a constant reflected signal amplitude of 6.8 ± 0.1 dB for 100 nm wavelength range. The sensor attained a wideband operation range between 20 and 100 kHz, with a maximum signal-to-noise ratio (SNR) of 32.7 dB at 25 kHz. The stability and sensitivity to temperatures up to 90◦C was also studied. Moreover, the proposed sensor offers the possibility to be applied as a wideband microphone or to be applied in more complex systems for structural analysis or imaging.publishersversionpublishe

Fiber Fabry-Perot interferometer for curvature sensing

A curvature sensor based on an Fabry-Perot (FP) interferometer was proposed. A capillary silica tube was fusion spliced between two single mode fibers, producing an FP cavity. Two FP sensors with different cavity lengths were developed and subjected to curvature and temperature. The FP sensor with longer cavity showed three distinct operating regions for the curvature measurement. Namely, a linear response was shown for an intermediate curvature radius range, presenting a maximum sensitivity of 68.52 pm/m-1. When subjected to temperature, the sensing head produced a similar response for different curvature radii, with a sensitivity varying from 0.84 pm/°C to 0.89 pm/°C, which resulted in a small cross-sensitivity to temperature when the FP sensor was subjected to curvature. The FP cavity with shorter length presented low sensitivity to curvature

Trace elements in loggerhead turtles (Caretta caretta) stranded in mainland Portugal: Bioaccumulation and tissue distribution

Pollution is among the most significant threats that endanger sea turtles worldwide. Waters off the Portuguese mainland are acknowledged as important feeding grounds for juvenile loggerheads. However, there is no data on trace element concentrations in marine turtles occurring in these waters. We present the first assessment of trace element concentrations in loggerhead turtles (Caretta caretta) occurring off the coast of mainland Portugal. Also, we compare our results with those from other areas and discuss parameters that may affect element concentrations. Trace element concentrations (As, Cd, Cu, Pb, Mn, Hg, Ni, Se, Zn) were determined in kidney, liver and muscle samples from 38 loggerheads stranded between 2011 and 2013. As was the only element with higher concentrations in muscle (14.78 μg g-1ww) than in liver or kidney. Considering non-essential elements, Cd presented the highest concentrations in kidney (34.67 μg g-1) and liver (5.03 μg g-1). Only a weak positive link was found between renal Cd and turtle size. Inter-elemental correlations were observed in both liver and kidney tissues. Hepatic Hg values (0.30 ± 0.03 μg g-1) were higher than values reported in loggerheads in the Canary Islands but lower than in Mediterranean loggerheads. Cd concentrations in the present study were only exceeded by values found in turtles from the Pacific. Although many endogenous and exogenous parameters related with complex life cycle changes and wide geographic range may influence trace element accumulation, the concentrations of Cd are probably related to the importance of crustaceans in loggerhead diet in the Portuguese coast.Sociedade Portuguesa de Vida Selvagem for their assistance with data and sample collection and the staff at the Centres Científics i Tècnics of the Universitat de Barcelona. The authors also thank the Oceanário de Lisboa for their support. LN, MF and AM were supported by the Portuguese Foundation for Science and Technology (FCT) grants (SFRH/BD/51416/2011, SFRH/BD/30240/2006, SFRH/BPD/64889/2009, respectively). Also, LN, SM and CE were supported by CESAMUID/AMB/50017/2013 (FCT) co-funded by FCT/MEC and FEDER, within PT2020 and Compete 2020. Sample collection was partially supported by Project LIFE MarPro (Life09 NAT/PT/000038) co-funded by the European Commission and Project CetSenti RECI/AAG-GLO/0470/2012 (FCOMP-01-0124-FEDER- 027472), FCT/MCTES (PIDDAC) and FEDER - COMPETE (POFC)info:eu-repo/semantics/publishedVersio

Positive Development through Technology (PTD) engagement checklist: children/children and environments/facilitators

Este artigo apresenta uma reflexão teórica sobre o contributo que a aplicação da Checklist de Envolvimento: Crianças/Criança e Ambientes/Facilitadores (Strawhacker & Bers, 2018) poderá ter para a promoção de experiências de aprendizagem com tecnologia que fomentem o desenvolvimento positivo da criança (Bers, 2018). Tendo por base um modelo de “desenvolvimento positivo pela tecnologia” (PTD) assente nos princípios de desenvolvimento da criança (Ramos, 2016), este instrumento1 foi desenvolvido e validado no âmbito dos trabalhos desenvolvidos por Marina Bers (2008, 2012, 2018). A tradução aqui disponibilizada foi realizada no âmbito do projeto KML II - Laboratório de Tecnologias e Aprendizagem de Programação para o Pré-escolar e 1.º Ciclo do Ensino Básico em Portugal, observando-se os respetivos direitos de autor2 . A partir de uma perspetiva construcionista dos processos de aprendizagem (Papert, 1999; Resnick, 2017; Bers, 2018), o presente trabalho explora como esta checklist poderá contribuir para uma maior compreensão de várias dimensões de análise de contextos de promoção do desenvolvimento positivo pela tecnologia. Pretende-se, desta forma, estimular a construção de ambientes de aprendizagem ricos em tecnologia e promotores do desenvolvimento positivo da criança, que atentem, nomeadamente, à centralidade das relações interpessoais e da qualidade dos ambientes onde estas atividades ocorrem. Ao longo do texto, serão apresentadas as caraterísticas desta checklist, designadamente os seis tipos de comportamentos positivos de utilização das tecnologias considerados e a sua distribuição por domínios e dimensões de análise. A reflexão sobre a análise da relação de dinâmicas entre crianças e contextos, bem como a compreensão de como a tecnologia pode ser concebida e utilizada para promover comportamentos positivos, poderá permitir aos profissionais da educação analisar os progressos no desenvolvimento de competências tecnológicas e na promoção do desenvolvimento cognitivo, social e moral de todas as crianças. Entendemos que a possibilidade de traduzir e utilizar este instrumento de análise trará um contributo importante para a análise das interações das crianças com tecnologias, nos seus contextos educativos. Esperamos, desta forma, possibilitar um melhor conhecimento da forma como as tecnologias digitais poderão promover o desenvolvimento positivo das crianças, designadamente no âmbito da investigação desenvolvida pelo projeto KML2, cujos resultados (Amante et al, 2019; Monteiro et al, 2021; Souza et al, 2020) poderão, assim, ser discutidos no contexto do atual quadro educativo mundial.This article presents a theoretical reflection on the contribution that the application of the Engagement Checklist: Children/Child and Environments/Facilitators (Strawhacker & Bers, 2018) may have for the promotion of learning experiences with technology that promote positive child development (Bers, 2018). Based on a model of "positive development through technology" (PTD) grounded in the principles of child development (Ramos, 2016), this instrument was developed and validated within the work developed by Marina Bers (2008, 2012, 2018). The translation provided here was carried out within the scope of the KML II project - Laboratory of Technologies and Learning Programming for Pre-school and Primary School in Portugal, with respect to the corresponding authoring rights. From a learning processes constructionist perspective (Papert, 1999; Resnick, 2017; Bers, 2018), this paper explores how this checklist can contribute to a greater understanding of several dimensions of analysis of contexts promoting positive development through technology. In this way, it aims to stimulate the construction of learning environments that are rich in technology and promote positive child development, paying particular attention to the centrality of interpersonal relationships and the quality of the environments where these activities occur. Throughout the text, the characteristics of this checklist will be presented, namely the six types of positive behaviours in the use of technologies considered and their distribution by domains and dimensions of analysis. The reflection on the analysis of the relationship of dynamics between children and contexts, as well as the understanding of how technology can be designed and used to promote positive behaviours, may allow education professionals to analyse the progress in the development of technological competences and the promotion of the cognitive, social and moral development of all children. We believe that the possibility to translate and use this analysis tool will bring an important contribution to the analysis of children's interactions with technologies, in their educational contexts. We hope, in this way, to enable a better knowledge of how digital technologies may promote children's positive development, namely within the scope of the research developed by the KML2 project, whose results (Amante et al, 2019; Monteiro et al, 2021; Souza et al, 2020) may, thus, be discussed in a worldwide educational framework.info:eu-repo/semantics/publishedVersio

Striped dolphins as trace element biomonitoring tools in oceanic waters: accounting for health-related variables

In Europe, monitoring contaminant concentrations and their effects in the marine environment is required under the Marine Strategy Framework Directive (MSFD, 2008/56/EC). The striped dolphin (Stenella coeruleoalba) is the most abundant small cetacean species in Portuguese oceanic waters, representing a potential biomonitoring tool of contaminant levels in offshore waters. Concentrations of nine trace elements were evaluated by ICP-MS in kidney, liver and muscle samples of 31 striped dolphins stranded in the Portuguese continental coast. The mean renal Cd concentration was high (19.3 μg.g-1 wet weight, range 0.1-69.3 μg.g-1 wet weight) comparing to striped dolphins from other locations. Therefore, the present study reports a possibly concerning level of Cd in the oceanic food chain in Portuguese offshore areas. This study also aimed at evaluating potential relationships between trace element concentrations and striped dolphins' biological and health-related variables. Individual length was related with some of the trace element concentrations detected in striped dolphins. Indeed, Cd, Hg and Se bioaccumulated in larger animals, whereas the reverse was observed for Mn and Zn. Striped dolphins with high parasite burdens showed higher levels of Hg, while animals showing gross pathologies presented higher concentrations of Cd and Se. This study reported relationships between trace element concentrations and health-related variables for the first time in striped dolphins and it also provided information on the relative contamination status of Portuguese oceanic waters in comparison to other regions in the world.publishe

Major Histocompatibility Complex (MHC) Class II sequence polymorphism in long-finned pilot whale (Globicephala melas) from the North Atlantic

Funding Silvia S. Monteiro and Marisa Ferreira were supported by a Ph.D. grant from Fundação para a Ciência e Tecnologia (ref SFRH/BD/38735/2007 and SFRH/BD/30240/2006, respectively). Alfredo López was supported by a postdoctoral grant from Fundação para a Ciência e Tecnologia (ref SFRH/BPD/82407/2011). Catarina Eira is supported by CESAM (UID/AMB/50017), from FCT/MEC through national funds and FEDER (PT2020, Compete 2020). The work related with strandings and tissue collection in Portugal was partially supported by the SafeSea Project EEAGrants PT 0039 (supported by Iceland, Liechtenstein and Norway through the EEA Financial Mechanism), by the Project MarPro–Life09 NAT/PT/000038 (funded by the European Union–Program Life+) and by the project CetSenti FCT RECI/AAG-GLO/0470/2012; FCOMP-01-0124-FEDER-027472 (Funded by the Program COMPETE and Fundação para a Ciência e Tecnologia).Peer reviewedPostprin

The Extremophile Endolithella mcmurdoensis gen. et sp. nov. (Trebouxiophyceae, Chlorellaceae), a new Chlorella-like Endolithic alga from Antarctica

The McMurdo Dry Valleys constitute the largest ice-free region of Antarctica and one of the most extreme deserts on Earth. Despite the low temperatures, dry and poor soils and katabatic winds, some microbes are able to take advantage of endolithic microenvironments, inhabiting the pore spaces of soil and constituting photosynthesis-based communities. We isolated a green microalga, Endolithella mcmurdoensis gen. et sp. nov, from an endolithic sandstone sample collected in the McMurdo Dry Valleys (Victoria Land, East Antarctica) during the K020 expedition, in January 2013. The single non-axenic isolate (E. mcmurdoensis LEGE Z-009) exhibits cup-shaped chloroplasts, electron-dense bodies, and polyphosphate granules but our analysis did not reveal any diagnostic morphological characters. On the basis of phylogenetic analysis of the 18S rRNA (SSU) gene, the isolate was found to represent a new genus within the family Chlorellaceae.We are sincerely grateful to Antarctica New Zealand for providing logistics support during K020 event. This campaign was conducted as part of the New Zealand Terrestrial Antarctic Biocomplexity Survey (nzTABS) through awards (UOWX0710 and UOWX1401) from the New Zealand Foundation for Research and Technology (FRST), Antarctica New Zealand, and the New Zealand Ministry of Business, Innovation and Employment to SCC. The work was also supported by the Portuguese Science and Technology Foundation (FCT) through grants UID/Multi/04423/2019 to CIIMAR, IF/01358/2014 and PTDC/MAR-BIO/2818/2012 to PNL, PTDC/CTA-AMB/30997/2017 to CM, and PhD scholarships to AR (SFRH/BD/140567/2018).info:eu-repo/semantics/publishedVersio

The use of comet assay to assess global DNA methylation in human biomonitoring studies

The Comet assay is a valuable tool for the detection of DNA damage in genotoxicity and human biomonitoring studies. Throughout the years, this biomarker has undergone several adaptations in their protocol in order to increase its sensitivity and the possible outcomes. By including an additional step of DNA digestion with lesion-specific endonucleases, the comet assay can provide information regarding the type of DNA damage detected in cells. The use of these enzymes has also allowed the development of a methylation-sensitive modified version of the comet assay. This version enables the routine measurement of global methylation, as well as CpG island DNA methylation in a variety of cells while simultaneously determining the genetic integrity of examined cells (Wentzel, 2012). Briefly, it makes use of isochizomeric restriction enzymes HpaII and MspI (that display differential sensitivity to DNA methylation) to characterize methylation outside CpG islands and restriction enzyme NotI to determine DNA methylation in CpG islands. The technique has been recently adapted to a medium-throughput version (Lewies, 2014) that allows the simultaneous analysis of a larger number of samples and overcomes some technical problems. Nevertheless, this technique has not yet been carried out in human biomonitoring studies. In this context, the aim of this work was to make use of this version of the comet assay to characterize global DNA methylation in approximately 50 human samples. Samples were analysed by the methylation-sensitive modified version of the comet assay (medium-throughput) and by ELISA based assay. Data obtained with both methods were compared and reproducibility of the methylation-sensitive modified version of the comet assay determined. Results obtained contribute to knowledge on the feasibility of this version of the comet assay and its possible usage in human biomonitoring studies as an epigenetic biomarker.This work was supported by The Portuguese Science Foundation (FCT) through CESAM (UID/AMB/50017/2013) and CNRS/INEE - National Center for Scientific Research/Institute of Ecology and Environment, via OHMI – International Observatory Hommes-Millieux. Carla Costa and Marta S. Monteiro are supported by the grants SFRH/BPD/96196/2013 and SFRH/BPD/45911/2008, respectively, funded by FCT (QREN – POPH – Type 4.1 – Advanced training, subsidized by the European Social Fund and national funds of MEC)