Emissão de aldeídos durante a combustão doméstica de biomassa

Mestrado em Engenharia do AmbienteA combustão de biomassa é uma importante fonte de poluentes gasosos e particulados para a atmosfera, os quais apresentam diversos efeitos quer a nível ambiental, quer a nível da saúde humana. O presente trabalho teve como objectivo a caracterização de emissões durante a combustão doméstica de biomassa, no que diz respeito a um conjunto de compostos a que se tem prestado pouca atenção: os compostos de carbonilo, nomeadamente os aldeídos. Estes compostos ocorrem na atmosfera e resultam de um vasto número de fontes de emissão ou de reacções químicas, e são conhecidos pelo importante papel que desempenham na química e física da atmosfera e pelos efeitos nocivos na saúde humana. No presente trabalho, foram realizadas experiências de combustão com madeira de quatro das espécies florestais mais abundantes no território nacional (carvalhonegral, pinheiro-bravo, eucalipto e sobreiro) com o propósito de se medirem emissões de formaldeído e acetaldeído, os dois compostos de carbonilo libertados para a atmosfera em maiores concentrações. Os resultados obtidos mostraram que a emissão de formaldeído foi superior à de acetaldeído, qualquer que fosse o tipo de madeira utilizada como combustível. Durante a combustão de carvalho-negral observaram-se os valores mais elevados para os factores de emissão (1725 mgHCHO/kgbiomassa, base seca e 1096 mgCH3CHO/kgbiomassa, base seca), sendo que durante a combustão de madeira de pinheiro-bravo se observaram os valores mais baixos para os factores de emissão (645 mgHCHO/kgbiomassa, base seca e 366 mgCH3CHO/kgbiomassa, base seca).Biomass combustion is an important source of gaseous and particulate pollutants to the atmosphere, which can cause a variety of environmental and human health effects. The purpose of this study was to characterize emissions during domestic biomass combustion, with a focus on a set of compounds which have received little attention: the carbonyl compounds, more specifically the aldehydes. Such compounds are present in the atmosphere through a large number of emissions sources or chemical reactions, and are well known by the important role they play in the chemistry and physics of the atmosphere and by their human health effects. Combustion experiences were performed with wood from four of the most abundant tree species growing in Portugal (pyrenean oak, maritime pine, blue gum and cork oak), in order to measure formaldehyde and acetaldehyde emissions, the two carbonyl compounds that are known to be emitted to the atmosphere in higher concentrations. Results show that formaldehyde emission was prevalent over acetaldehyde emissions whatever the type of burned wood. The highest emission factors were observed during pyrenean oak combustion experiments (1725 mgHCHO/kgbiomass, dry basis and 1096 mgCH3CHO/kgbiomass, dry basis) and the lowest emissions factors were observed during maritime pine combustion experiments (645 mgHCHO/kgbiomass, dry basis e 366 mgCH3CHO/kgbiomass, dry basis)

COOPEDU IV — Cooperação e Educação de Qualidade

O quarto Congresso Internacional de Cooperação e Educação-IV COOPEDU, organizado pelo Centro de Estudos Internacionais (CEI) do Instituto Universitário de Lisboa e pela Escola Superior de Educação e Ciências Sociais do Instituto Politécnico de Leiria decorreu nos dias 8 e 9 de novembro de 2018, subordinado à temática Cooperação e Educação de Qualidade. Este congresso insere-se numa linha de continuidade de intervenção por parte das duas instituições organizadoras e dos elementos coordenadores e este ano beneficiou do financiamento do Instituto Camões, obtido através de um procedimento concursal, que nos permitiu contar com a participação presencial de elementos dos Países Africanos de Língua Portuguesa, fortemente implicados nas problemáticas da Educação e da Formação. Contou também com a participação do Instituto Camões e da Fundação Calouste Gulbenkian, entidades que sistematizaram a sua intervenção nos domínios da cooperação na área da educação nos últimos anos. A opção pela temática da qualidade pareceu aos organizadores pertinente e actual. Com efeito os sistemas educativos dos países que constituem a Comunidade de países de língua portuguesa têm implementado várias reformas mas em vários domínios mantem-se a insatisfação de responsáveis políticos, pedagogos, técnicos sociais face aos resultados obtidos. Aliás o caminho de procura da Qualidade é interminável porque vai a par da aposta na exigência e na promoção da cidadania e responsabilidade social. As comunicações que agora se publicam estão organizadas em dois eixos: o das Políticas da Educação e Formação e o das dimensões em que se traduzem essas políticas. Neste último eixo encontramos fios condutores para agregarmos as comunicações apresentadas

SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal

Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team, IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation (https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing guidance on the implementation of the phylodynamic models; Joshua L. Cherry (National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health) for providing guidance with the subsampling strategies; and all authors, originating and submitting laboratories who have contributed genome data on GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions expressed in this article are those of the authors and do not reflect the view of the National Institutes of Health, the Department of Health and Human Services, or the United States government. This study is co-funded by Fundação para a Ciência e Tecnologia and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation (POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Chlamydia Trachomatis in vivo to in vitro transition reveals mechanisms of phase variation and down-regulation of virulence factors

Fundacao para a Ciencia e a Tecnologia (FCT) (SFRH/BD/68527/2010); Wellcome Trust ISSF grant (097831/Z/11/Z); FCT (SFRH/BD/68532/2010; SFRH/BPD/75295/2010)Research on the obligate intracellular bacterium Chlamydia trachomatis demands culture in cell-lines, but the adaptive process behind the in vivo to in vitro transition is not understood. We assessed the genomic and transcriptomic dynamics underlying C.Trachomatis in vitro adaptation of strains representing the three disease groups (ocular, epithelial-genital and lymphogranuloma venereum) propagated in epithelial cells over multiple passages.We found genetic features potentially underlying phase variation mechanisms mediating the regulation of a lipid A biosynthesis enzyme (CT533/LpxC), and the functionality of the cytotoxin (CT166) through an ON/OFF mechanism. We detected inactivating mutations in CT713/porB, a scenario suggesting metabolic adaptation to the available carbon source. CT135 was inactivated in a tropism-specific manner, with CT135-negative clones emerging for all epithelial-genital populations (but not for LGV and ocular populations) and rapidly increasing in frequency (~23%mutants per10 passages). RNA-sequencing analyses revealed that a deletion event involving CT135 impacted the expression of multiple virulence factors, namely effectors known to play a role in the C.Trachomatis host-cell invasion or subversion (e.g., CT456/Tarp, CT694, CT875/TepP and CT868/ChlaDub1). This reflects a scenario of attenuation of C.Trachomatis virulence in vitro, which may take place independently or in a cumulative fashion with the also observed down-regulation of plasmid-related virulence factors. This issue may be relevant on behalf of the recent advances in Chlamydia mutagenesis and transformation where culture propagation for selecting mutants/transformants is mandatory. Finally, there was an increase in the growth rate for all strains, reflecting gradual fitness enhancement over time. In general, these data shed light on the adaptive process underlying the C.Trachomatis in vivo to in vitro transition, and indicates that it would be prudent to restrict culture propagation to minimal passages and check the status of the CT135 genotype in order to avoid the selection of CT135-negative mutants, likely originating less virulent strains.publishersversionpublishe

Phase variation mediated by variable homopolymeric tracts.

<p>Panel A. The graph shows the evolution throughout passaging of the percentage of sequence reads with different ‘A’ counts in the homopolymeric tract upstream from CT533/<i>lpxC</i> for the strain E/CS1025/11. The poly(A) tract corresponds to poly(T) in the annotated leading strand. Panel B. Schematic view of the putative promoter region of CT533/<i>lpxC</i>. The predicted transcription start site [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133420#pone.0133420.ref126" target="_blank">126</a>] is labeled by +1. The variable poly(A) tract (in bold) falls between the predicted -35 and -10 hexamers (underlined). BLAST analyses revealed the existence of variable number of ‘A’ counts in <i>C</i>. <i>trachomatis</i> genomes, and also that the nucleotide indicated with an arrow is deleted exclusively in all LGV strains. Panel C. The graph shows the percentage of sequence reads with different ‘G’ counts in the variable homopolymeric tract of CT166 found in the initial populations of the epithelial-genital strains. “G” counts of nine correspond to an “ON” protein. Panel D. Schematic view of the four positions (numbers 1 to 4) relative to a gene at which contingency loci (e.g., homopolymeric tracts) can cause phase variation (adapted from van der Woude MW and Bäumler AJ, Clin Microbiol Rev <b>17</b>:581–611, 2004 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0133420#pone.0133420.ref152" target="_blank">152</a>]). Whereas positions 1 and 2 are associated with transcription initiation and position 4 with translation (ON/OFF), the mechanism regarding the position 3 is not completely disclosed. We found heterogeneity in length within homopolymeric tracts located in positions 2 (for CT533/<i>lpxC</i>) (blue), 3 (for CT043/<i>slc1</i> and the operon CT134-CT135), and 4 (for CT166—cytotoxin) (red).</p

Impact of <i>in vitro</i> passaging on the <i>C</i>. <i>trachomatis</i> growth kinetics.

<p>Panels A and B. Comparison of the growth rates and doubling times between ancestral (grey) and evolved populations (black). The percentage values above the bars correspond to the growth rate increment of the evolved population relatively to the ancestral. Panel C. Comparison of the one-step growth curve between D/CS637/11 CT135-positive and CT135-negative strains. Cells grown in the same conditions were infected at a MOI of 1, and cell scrapings were collected over time after infection for analysis of inclusion-forming units (IFUs). The black line represents the evolved CT135-negative D/CS637/11 strain, whereas the grey line represents the ancestor CT135-positive strain. The shaded area indicates the time points chosen for RNA-seq differential expression comparative analyses.</p

Comparative analysis of global gene expression (RNA-seq) between D/CT135-positive and D/CT135-negative populations.

<p>Panels A-B. Comparison of gene expression between biological replicates for the D/CT135-positive (A) and D/CT135-negative (B) populations. Pearson correlation coefficients are shown. Panel C. Comparison of gene expression between the D/CT135-negative and D/CT135-positive populations. The red points mark genes and the non-coding RNA for which the fold change of expression exceeds two-fold and the FDR-corrected <i>P</i>-values were below 0.05. For panels A to C, axes are log₁₀-transformed normalized expression levels (FPKM). Panel D. Volcano plot of –log₂ fold change (D/CT135-positive <i>versus</i> D/CT135-negative) <i>versus</i> –log₁₀ adjusted <i>P</i>-values. In order to better fit the scale to data, corrected <i>P</i>-values ≤10⁻³ were set as 10⁻³. Points in red indicate genes and the non-coding RNA for which the fold change of expression exceeds two-fold and the FDR-corrected <i>P</i>-values were below 0.05.</p