98 research outputs found

    Silicon nitride interferometers for optical sensing with multi-micron dimensions

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    Increasing the size of the smallest features of Photonic Integrated Circuits (PICs) to multi-micron dimensions can be advantageous to avoid expensive and complex lithographic steps in the fabrication process. In applications where extremely reduced chip size is not a requirement, the design of devices with multi-micron dimensions is potential interesting to avoid the need for e-beam lithography. Another benefit is that making the dimensions larger reduces the effect of lithographic imperfections such as waveguide surface roughness. However, the benefits do not come without limitations. Coupling the light in and out of the circuit is more challenging since diffraction gratings are not available when designing for such large dimensions. Circuit bends must have a larger radius of curvature and the existence of multimode propagation conditions can have detrimental impact in the performance of several devices, such as interferometers. In this study we perform simulations of the coupling between a lensed multimode optical fiber and a multi-micron a-SiN:H rib waveguide. Light coupling efficiency is analyzed as a function of distance variations using the FDTD method and compared with coupling to a strip waveguide. Moreover, we use numerical simulations to study the performance of a Mach-Zehnder interferometer sensitive to refractive index variations. Both the interferometer, splitters and combiners are designed with multi-micron dimensionsinfo:eu-repo/semantics/publishedVersio

    Uncovering novel plasma membrane carboxylate transporters in the yeast Cyberlindnera jadinii

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    The yeast Cyberlindnera jadinii has great potential in the biotechnology industry due to its ability to produce a variety of compounds of interest, including carboxylic acids. In this work, we identified genes encoding carboxylate transporters from this yeast species. The functional characterization of sixteen plasma membrane carboxylate transporters belonging to the AceTr, SHS, TDT, MCT, SSS, and DASS families was performed by heterologous expression in Saccharomyces cerevisiae. The newly identified C. jadinii transporters present specificity for mono-, di-, and tricarboxylates. The transporters CjAto5, CjJen6, CjSlc5, and CjSlc13-1 display the broadest substrate specificity; CjAto2 accepts mono- and dicarboxylates; and CjAto1,3,4, CjJen1-5, CjSlc16, and CjSlc13-2 are specific for monocarboxylic acids. A detailed characterization of these transporters, including phylogenetic reconstruction, 3D structure prediction, and molecular docking analysis is presented here. The properties presented by these transporters make them interesting targets to be explored as organic acid exporters in microbial cell factories.This study was supported by the strategic program UID/BIA/04050/2019, funded by Portuguese funds through the FCT I.P.; the projects PTDC/BIAMIC/5184/2014, funded by national funds through the FCT I.P.; and the European Regional Development Fund (ERDF) through the COMPETE 2020–Programa Operacional Competitividade e Internacionalização (POCI) and EcoAgriFood: Innovative green products and processes to promote AgriFood BioEconomy (operação NORTE-01–0145-FEDER-000009), supported by Norte Portugal Regional Operational Program (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (ERDF). M.S.S. acknowledges the Norte2020 for the UMINHO/BD/25/2016 PhD grant with the reference NORTE-08–5369-FSE-000060, and J.A. acknowledges the FCT for the PD/BD/150584/2020 PhD grant. PS acknowledges FCT for contract CEECINST/0007772018. I.S-S. was supported by the program contract FCT-UMINHO/Norma transitória from the Legal Regime of Scientific Employment (RJEC)

    Probable Person-to-Person Transmission of Legionnaires’ Disease

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    Correspondence to the Editor.Legionnaires’ disease is an often severe form of pneumonia that is typically acquired by susceptible persons (e.g., elderly persons and smokers) through inhalation of aerosols that contain legionella species.1-4 A cluster of cases of this disease occurred in Vila Franca de Xira, Portugal, in 2014

    Multi-biologic group analysis for an ecosystem response to longitudinal river regulation gradients

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    This work assesses the effects of river regulation on the diversity of different instream and riparian biological communities along a relieve gradient of disturbance in regulated rivers. Two case studies in Portugal were used, with different river regulation typology (downstream of run-of-river and reservoir dams), where regulated and free-flowing river stretches were surveyed for riparian vegetation, macrophytes, bryophytes, macroalgae, diatoms and macroinvertebrates. The assessment of the regulation effects on biological communities was approached by both biological and functional diversity analysis. Results of this investigation endorse river regulation as a major factor differentiating fluvial biological communities through an artificial environmental filtering that governs species assemblages by accentuating species traits related to river regulation tolerance. Communities' response to regulation gradient seem to be similar and insensitive to river regulation typology. Biological communities respond to this regulation gradient with different sensibilities and rates of response, with riparian vegetation and macroinvertebrates being the most responsive to river regulation and its gradient. Richness appears to be the best indicator for general fluvial ecological quality facing river regulation. Nevertheless, there are high correlations between the biological and functional diversity indices of different biological groups, which denotes biological connections indicative of a cascade of effects leading to an indirect influence of river regulation even on non-responsive facets of communities' biological and functional diversities. These results highlight the necessary holistic perspective of the fluvial system when assessing the effects of river regulation and the proposal of restoration measures.publishe

    Diet and helminth parasites of freshwater turtles Mesoclemmys tuberculata, Phrynops geoffroanus (Pleurodira: Chelidae) and Kinosternon scorpioides (Criptodyra: Kinosternidae) in a semiarid region, Northeast of Brazil

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    In this study, the Kinosternon scorpioides, Mesoclemmys tuberculata and Phrynops geoffroanus freshwater turtles collected in the Cariús River, State of Ceará, were analysed as to their diet composition and presence of helminths. Among the 63 examined turtles 55 (87.3%) were parasitized. We found three Nematoda species (Physaloptera retusa, Serpinema monospiculatus and Spiroxys figueiredoi) and one Trematoda species (Gorgoderina sp.). Phrynops geoffroanus had the highest indexes of prevalence (97.56%) and mean intensity of infection (33.5), followed by M. tuberculata (70% and 12.64, respectively) and K. scorpioides (50% and three, respectively). Host body size was positively related to helminths abundance in both male and female Chelidae species. A significant difference in helminths abundance between the sexes was found only in P. geoffroanus, where females had more parasites than males. Regarding diet, the main food items ingested by M. tuberculata were Odonata nymphs (Aeshnidae and Libellulidae), whilst P. geoffroanus feeds mainly on Diptera larvae (Chironomidae), Odonata nymph (Aeshnidae) and Notonectidae, and only seeds were found in the stomach contents of K. scorpioides. Here, we present the first record of S. monospiculatus parasitizing K. scorpioides, Gorgoderina sp. and P. retusa were reported for the first time in P. geoffroanus, and M. tuberculata represents a new host to P. retusa and S. figueiredoi

    Comparative Effectiveness of COVID-19 Vaccines in Preventing Infections and Disease Progression from SARS-CoV-2 Omicron BA.5 and BA.2, Portugal

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    We estimated comparative primary and booster vaccine effectiveness (VE) of SARS-CoV-2 Omicron BA.5 and BA.2 lineages against infection and disease progression. During April-June 2022, we implemented a case-case and cohort study and classified lineages using whole-genome sequencing or spike gene target failure. For the case-case study, we estimated the adjusted odds ratios (aORs) of vaccination using a logistic regression. For the cohort study, we estimated VE against disease progression using a penalized logistic regression. We observed no reduced VE for primary (aOR 1.07 [95% CI 0.93-1.23]) or booster (aOR 0.96 [95% CI 0.84-1.09]) vaccination against BA.5 infection. Among BA.5 case-patients, booster VE against progression to hospitalization was lower than that among BA.2 case-patients (VE 77% [95% CI 49%-90%] vs. VE 93% [95% CI 86%-97%]). Although booster vaccination is less effective against BA.5 than against BA.2, it offers substantial protection against progression from BA.5 infection to severe disease.The acquisition of sequencing equipment and reagents used in this study by the Instituto Nacional de Saúde Doutor Ricardo Jorge was partially funded by the HERA project (grant no. 2021/PHF/23776) supported by the European Commission through the European Centre for Disease Control, and also partially funded by the GenomePT project (grant no. POCI-01-0145-FEDER-022184), supported by COMPETE 2020–Operational Programme for Competitiveness and Internationalisation, Lisboa Portugal Regional Operational Programme, Algarve Portugal Regional Operational, under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund, and by the Portuguese Science and Technology Foundation. Algarve Biomedical Center Laboratory received public funding through the Project ALG-D2-2021-06 Variants Screen in Southern Portugal– Monitoring Variants of Concern in Southern Portugal and the Portuguese Science and Technology Foundation national support through the Comprehensive Health Research Center (grant no. UIDP/04923/2020)info:eu-repo/semantics/publishedVersio

    Práticas artísticas no ensino básico e secundário

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    A mediação entre os conteúdos culturais e a Educação Artística formal tem emergido como uma distinta área de inovação e de intervenção, como o mostram os 18 artigos selecionados nesta nona edição da revista Matéria-Prima.Entre a identidade, fundada nos focos de conhecimento local, e uma inserção integrada nos problemas e conteúdos globais joga-se a problematização da Educação Artística. As propostas articulam quer discursos curatoriais (museu, bienal, exposição), como ações de mediação visando uma expansão das atividades, a que se juntam as reflexões sobre a realidade da formação de professores, nas suas diversas modalidades, em diversas realidades sociais.Propiciam-se oportunidades de ações de intervenção, concertadas ou não, entre os agentes artísticos e os educadores. O resultado pode ser potenciado se se conseguir uma perspetiva informada e integrada das realidades artísticas: pede-se a todos os intervenientes mais integração e disponibilidade para um conhecimento mútuo consequente.info:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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