304 research outputs found
Ambientes e vida na terra: Os primeiros 4.0 ga
O planeta Terra tem sofrido alterações ao longo do tempo geológico. Pouco tempo decorrido após a sua formação, há cerca de 4.6 Ga, era uma planeta homogéneo. Durante este longo intervalo de tempo, a Geosfera sofreu diversos processos de diferenciação geoquímica e geológica, responsáveis pelo desenvolvimento da actual estrutura interna da Terra. A formação da Atmosfera e da Hidrosfera ocorreu durante o Hadaico, aproximadamente entre 4.5 Ga e 4.4 Ga.
A evolução e interacção dos sistemas terrestres, geosfera, atmosfera e hidrosfera, permitiu que fossem reunidas condições favoráveis ao aparecimento da Vida, há pelo menos 3.8 Ga. As formas de Vida foram-se desenvolvendo em diversos ambiente, constituindo outro importante sistema terrestre, a Biosfera.
Este artigo tem como principal objectivo a compilação da informação mais relevante relacionada com os principais eventos e outros episódios significantes, que contribuíram para a origem da Vida e seu suporte, tendo como limite temporal o início do Fanerozóico.Environments and Life – the first 4.0 Ga in Earth: The planet Earth has been changing through the geologic time. The Earth was created about 4.6 Ga ago as a homogeneous planet. During this long period of time, several processes occurred originating the geochemical and geological differentiation of the Geosphere and developing the present internal Earth structure. The formation of the Atmosphere and Hydrosphere occurred during the Hadean, approximately 4.5 Ga to 4.4 Ga ago.
The evolution and interaction of these important terrestrial systems (geosphere, atmosphere and hydrosphere) allowed, during Earth history, the development of vital conditions for the emergence of Life, at least 3.8 Ga ago. The first organisms might have appeared from the most diverse environments constituting another important system, the Biosphere.
The main objective of this article is to compile the most relevant information related with major geological events and other significant episodes, which have contributed to the emergence of Life and its support throughout geological time until Early Paleozoic.Centro de Ciências da Terra (NCT/UM), do Centro de Ciências da Terra (CCT/UM) e do Centro de Geologia da Universidade do Porto (CGUP). Programa de Financiamento Plurianual da FCT, inscrito no POCTI inserido no III Quadro Comunitário de Apoio, co- financiado pelo Governo Português e pela União
Europeia (FEDER
Unravelling Pseudomonas aeruginosa and Candida albicans communication in coinfections scenarios: insights through network analysis
The Supplementary Material for this article canbe found online at: https://www.frontiersin.org/articles/10.3389/fcimb.2020.550505/
full#supplementary-materialModern medicine is currently facing huge setbacks concerning infection therapeutics as microorganisms are consistently knocking down every antimicrobial wall set before them. The situation becomes more worrying when taking into account that, in both environmental and disease scenarios, microorganisms present themselves as biofilm communities that are often polymicrobial. This comprises a competitive advantage, with interactions between different species altering host responses, antimicrobial effectiveness, microbial pathogenesis and virulence, usually augmenting the severity of the infection and contributing for the recalcitrance towards conventional therapy. Pseudomonas aeruginosa and Candida albicans are two opportunistic pathogens often co-isolated from infections, mainly from mucosal tissues like the lung. Despite the billions of years of co-existence, this pair of microorganisms is a great example on how little is known about cross-kingdom interactions, particularly within the context of coinfections.
Given the described scenario, this study aimed to collect, curate, and analyze all published experimental information on the molecular basis of P. aeruginosa and C. albicans interactions in biofilms, in order to shed light into key mechanisms that may affect infection prognosis, increasing this area of knowledge. Publications were optimally retrieved from PubMed and Web of Science and classified as to their relevance. Data was then systematically and manually curated, analyzed, and further reconstructed as networks. A total of 641 interactions between the two pathogens were annotated, outputting knowledge on important molecular players affecting key virulence mechanisms, such as hyphal growth, and related genes and proteins, constituting potential therapeutic targets for infections related to these bacterial-fungal consortia. Contrasting interactions were also analyzed, and quorum-sensing inhibition approaches were highlighted. All annotated data was made publicly available at www.ceb.uminho.pt/ISCTD, a database already containing similar data for P. aeruginosa and Staphylococcus aureus communication. This will allow researchers to cut on time and effort when studying this particular subject, facilitating the understanding of the basis of the inter-species and inter-kingdom interactions and how it can be modulated to help design alternative and more effective tailored therapies. Finally, data deposition will serve as base for future dataset integration, whose analysis will hopefully give insights into communications in more complex and varied biofilm communities.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/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 COMPETE2020 and FCT for the
project POCI-01-0145-FEDER-029841 and FCT for the PhD Grant of TG [grant number SFRH/BD/136544/2018].info:eu-repo/semantics/publishedVersio
Technological feasibility of couscous-algae-supplemented formulae : process description, nutritional properties and in vitro digestibility
Research Areas: Food Science & TechnologyThe aim of this work was to develop functional couscous in a traditional Tunisian manner
(hand rolling), enriched in algae biomass (6% w/w). Four Chlorella vulgaris (C. vulgaris) biomasses
and one mixture of C. vulgaris and two macroalgae biomasses (Ulva rigida and Fucus vesiculosus)
were used. The C. vulgaris strain was subjected to random mutagenesis and different culture conditions (Allmicroalgae), resulting in different pigmentations and biochemical compositions. Couscous
samples were characterized in terms of nutritional properties, oscillatory rheology properties and
digestibility. All biomasses provided a significant supplementation of nutrients and excellent acceptance. The enrichment resulted in lower firmness, higher viscoelastic functions (G0 and G”) and a
significant improvement in the cooking quality. Major differences between couscous samples with
different microalgae were observed in protein and mineral contents, fully meeting Regulation (EC)
No. 1924/2006 requirements for health claims made on foodstuffs. The amount of digested proteins
was also higher in algae-containing samples. The fatty acid profile of the enriched couscous varied
in a biomass-specific way, with a marked increase in linolenic acid (18:3 ω3) and a decrease in the
ω6/ω3 ratio. Sensory analysis revealed that microalgae-containing products could compete with
conventional goods with an added advantage, that is, having an ameliorated nutritional value using
algae as a “trendy” and sustainable ingredient.info:eu-repo/semantics/publishedVersio
A comparison between the quality of eggs from indigenous chicken breeds and that from commercial layers
There is an increased interest in animal
products from more sustainable farming practices, which
may include using local breeds. In addition, maintaining
biodiversity is important, and naturally, indigenous
breeds of chickens are well adapted to the local environmental
conditions. In the current study, 286 eggs
from 4 Portuguese breeds of chickens (Branca, Amarela,
Pedr^es Portuguesa, and Preta Lusit^anica) and from a
commercial hybrid laying hen were used. Chemical and
physical characteristics of the eggs and the egg components
such as weights, Haugh units, yolk color, albumen
protein content, yolk fatty acid content, and mineral
content in the albumen and yolk were analyzed. The
Branca breed produced eggs with a lighter brown shell
color and lower Haugh unit values than the remaining
native breeds (P,0.05). The commercial hens produced
eggs that were found to be more rounded shape than the ideal and with a darker colored shell and yolk than eggs
from the 4 local breeds. In addition, the commercial hens
also produced heavier eggs but with lower Haugh units
than the Amarela, Pedr^es Portuguesa, and Preta
Lusit^anica breeds (P , 0.05). The range of saturated
fatty acids, monounsaturated fatty acids, and total
polyunsaturated fatty acids between eggs from the 4
breeds was small and not significantly different. No differences
were found in the percentage of albumen protein
between breeds. Albumen and yolk ash content was not
different between breeds. The overall analysis indicated
that eggs from these native genotypes match the quality
of a commercial product in many characteristics. In
markets where eggs from local breeds are available,
consumers are purchasing a high-quality product while
aiding in the expansion of local genetic resources and
investing in local farmersinfo:eu-repo/semantics/publishedVersio
Effects of increasing doses of condensed tannins extract from Cistus ladanifer L. on In Vitro ruminal fermentation and biohydrogenation
Research Areas: Agriculture ; Veterinary Sciences ; ZoologyCistus ladanifer (rockrose) is a perennial shrub quite abundant in the Mediterranean region, and it is a rich source in secondary compounds such as condensed tannins (CTs). Condensed tannins from C. ladanifer were able to change the ruminal biohydrogenation (BH), increasing the t11–18:1 and c9,t11–18:2 production. However, the adequate conditions of the C. ladanifer CTs used to optimize the production of t11–18:1 and c9,t11–18:2 is not yet known. Thus, we tested the effect of increasing the doses of C. ladanifer CT extract (0, 25, 50, 75 and 100 g/kg dry matter (DM)) on in vitro rumen BH. Five in vitro batch incubations replicates were conducted using an oil supplemented high-concentrate substrate, incubated for 24 h with 6 mL of buffered ruminal fluid. Volatile fatty acids (VFAs) and long chain fatty acids (FA) were analyzed at 0 h and 24 h, and BH of c9–18:1, c9, c12–18:2 and c9, c12, c15–18:3, and BH products yield were computed. Increasing doses of C. ladanifer CTs led to a moderate linear decrease (p < 0.001) of the VFA production (a reduction of 27% with the highest dose compared to control). The disappearance of c9–18:1 and c9,c12–18:2 as well as the production of t11–18:1 and c9, t11:18:2 was not affected by increasing doses of C. ladanifer CTs, and only the disappearance of c9, c12, c15–18:3 suffered a mild linear decrease (a reduction of 24% with the highest dose compared to control). Nevertheless, increasing the C. ladanifer CT dose led to a strong depression of microbial odd and branched fatty acids and of dimethyl acetals production (less than 65% with the highest dose compared to control), which indicates that microbial growth was more inhibited than fermentative and biohydrogenation activities, in a possible adaptative response of microbial population to stress induced to CTs and polyunsaturated fatty acids. The ability of C. ladanifer to modulate the ruminal BH was not verified in the current in vitro experimental conditions, emphasizing the inconsistent BH response to CTs and highlighting the need to continue seeking the optimal conditions for using CTs to improve the fatty acid profile of ruminant fat.info:eu-repo/semantics/publishedVersio
Technological Feasibility of Couscous-Algae-Supplemented Formulae: Process Description, Nutritional Properties and In Vitro Digestibility
The aim of this work was to develop functional couscous in a traditional Tunisian manner
(hand rolling), enriched in algae biomass (6% w/w). Four Chlorella vulgaris (C. vulgaris) biomasses
and one mixture of C. vulgaris and two macroalgae biomasses (Ulva rigida and Fucus vesiculosus)
were used. The C. vulgaris strain was subjected to random mutagenesis and different culture conditions
(Allmicroalgae), resulting in different pigmentations and biochemical compositions. Couscous
samples were characterized in terms of nutritional properties, oscillatory rheology properties and
digestibility. All biomasses provided a significant supplementation of nutrients and excellent acceptance.
The enrichment resulted in lower firmness, higher viscoelastic functions (G0 and G”) and a
significant improvement in the cooking quality. Major differences between couscous samples with
different microalgae were observed in protein and mineral contents, fully meeting Regulation (EC)
No. 1924/2006 requirements for health claims made on foodstuffs. The amount of digested proteins
was also higher in algae-containing samples. The fatty acid profile of the enriched couscous varied
in a biomass-specific way, with a marked increase in linolenic acid (18:3 !3) and a decrease in the
!6/!3 ratio. Sensory analysis revealed that microalgae-containing products could compete with
conventional goods with an added advantage, that is, having an ameliorated nutritional value using
algae as a “trendy” and sustainable ingredientinfo:eu-repo/semantics/publishedVersio
Fatty Acid Composition of M. Biceps Femoris of Edible Dormouse (Glis glis L.)
This study aimed to investigate the fatty acid (FA) composition of edible dormouse m. biceps
femoris in both sexes. More than 20 FA were identified in the muscle, with the 18:1cis-9 (oleic acid)
being the most abundant in both sexes, comprising more than 50% of total FA in muscle. The most
dominated FA were monounsaturated (MUFA), followed by saturated FA (SFA) and polyunsaturated
FA (PUFA), reaching 54.8%, 25.43% and 19.8% of total FA, respectively. Sums of PUFA and n-3
PUFA tended (p > 0.05) to be higher in males than in females. There were no significant differences
between sexes on the FA composition. Nevertheless, the 18:2n-6 tended to differ between sexes
(p = 0.063). Several long-chain PUFA (LC-PUFA) were detected in dormouse muscle, with the 20:4
n-6 (arachidonic acid, AA) and the 22:6 n-3 (docosahexaenoic acid, DHA) being the most abundant in
both sexes. The relatively high stearoyl-CoA desaturase (SCD) indexes and the large concentration
of 18:1cis-9 in dormouse muscle tissues might point to a low mobilization of the SCD products.
Furthermore, finding the unusual FA 20:3 D5,D11,D14, suggests feeding on leaf and wood lipids of
Coniferophytes. We demonstrated sexual size monomorphism in edible dormouse. The literature
regarding the composition of dormouse meat is scarce and no studies reported the FA composition of
muscle, thus, this work can contribute to increasing the knowledge on edible dormouse physiology
and nutritional traitsinfo:eu-repo/semantics/publishedVersio
Antimicrobial resistance three ways: healthcare crisis, major concepts, and the relevance of biofilms
Worldwide, infections are resuming their role as highly effective killing diseases, as current treatments are failing to respond to the growing problem that is antimicrobial resistance (AMR). The social and economical burden of AMR seems ever rising, with health- and research-related organizations rushing to collaborate on a worldwide scale to find effective solutions. Resistant bacteria are spreading even in first-world nations, being found not only in healthcare-related settings, but also in food and in the environment. In this mini-review, the impact of AMR in healthcare systems and the major bacteria behind it are highlighted. Ecological aspects of AMR evolution and the complexity of its molecular mechanisms are explained. Major concepts, such as intrinsic, acquired, and adaptive resistance, as well as tolerance and heteroresistance, are also clarified. More importantly, the problematic of biofilms and their role in AMR, namely its main resistance and tolerance mechanisms, is elucidated. Finally, some of the most promising anti-biofilm strategies being investigated are reviewed. Much is still to be done regarding the study of AMR and the discovery of new anti-biofilm strategies. Gladly, considerable research on this topic is generated every day and increasingly concerted actions are being engaged globally to try and tackle this problem.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 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. The authors also acknowledge COMPETE2020 and FCT for the project POCI-01-0145-FEDER-029841, and FCT for the PhD Grants of Andreia Magalhães [grant number SFRH/BD/132165/2017] and Tânia Grainha [grant number SFRH/BD/136544/2018].info:eu-repo/semantics/publishedVersio
The influence of patterned nanofiber meshes on human mesenchymal stem cell osteogenesis
A specially designed electroconductive collector enables the electrospinning of P-NFM composed of areas of parallel/uniaxially aligned fibers and areas of random/orthogonal nanofiber distribution. The biological relevance of P-NFM is demonstrated using hBMSCs as an autologous cell source. The structures induce cell orientation along the uniaxially aligned fibers, mainly during earlier culturing periods under basal and osteogenic differentiation conditions. The microtopography of the P-NFM also controls the deposition of mineralized extracellular matrix along the pre-defined fiber direction. Genotypic characterization confirms the successful differentiation into the osteogenic lineage.European Integrated Project GENOSTEM (LSH-STREP-CT-2003-503161); European Network of Excellence EXPERTISSUES (NMP3-CT-2004-500283); Portuguese Foundation for Science and Technology for the project Naturally Nano (POCI/EME/58982/2004) and the PhD grant SFRH/BD/24382/2005
Avaliação de alternativas aos revestimentos com alcatrão de hulha para estruturas de aço total ou parcialmente imersas em estuário e água do mar
Na procura de revestimentos anticorrosivos para protecção de estruturas de aço total ou parcialmente imersas em estuário e água do mar, que sejam alternativas mais ecológicas aos revestimentos com alcatrão de hulha ainda utilizados, foi desenvolvido um projecto no qual se comparam revestimentos epoxídicos comerciais com um revestimento de alcatrão de hulha epoxídico de referência, também comercial. Este trabalho inclui, para além da avaliação da protecção anticorrosiva dos revestimentos envolvidos no projecto, quer em laboratório, quer em exposição natural em estuário (rios Sado e Tejo) e em mar (Sines) durante quatro anos, a caracterização laboratorial das tintas integradas nos diferentes esquemas de pintura que deram origem aos revestimentos em estudo. Os resultados da avaliação no fim de dois anos de exposição natural, complementados com os ensaios em laborató permitiram concluir que dois dos quatro revestimentos alternativos estudados apresentaram melhor comportamento anticorrosivo do que o revestimento com alcatrão de hulha epoxídico usado como referência
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