4,955 research outputs found
A arte atlântica do Crastoeiro (Norte de Portugal) : contextos e significados
Basados en los resultados de las excavaciones arqueológicas realizadas en los complejos I y II
del arte atlántico de Crastoeiro, localizados en el Monte de la Senhora da Graça y partiendo del supuesto de
que los individuos no sólo viven en un espacio sino que también están inmersos o incorporados en el, este
trabajo tiene como objetivo establecer algunas interpretaciones no sólo sobre la biografía de cada uno de
estos loci, sino también, entender los diferentes procesos de interacción de las comunidades locales con el
Monte da Senhora da Graça, especialmente aquellos que se relacionan con la elección, la construcción, la
frecuencia y las acciones inherentes al uso de estos lugares que designamos arte rupestre
Biofilm reactor technology as an alternative to control fungal filamentous bulking caused by Galactomyces geotrichum
The present work aims to evaluate a strategy for solving fungal filamentous bulking caused by Galactomyces geotrichum. For this study, four sequencing batch reactors (SBR) fed with acetate were operated without (SBR1) and with support for biofilm growth [5 % (SBR2), 10 % (SBR3) and 20 % (SBR4) of the reactor volume]. The results demonstrated an overabundance of G. geotrichum in the SBR operating just with suspended biomass. The incorporation of an optimized amount of support for biofilm growth (10 %) seemed to suppress the overgrowth of the G. geotrichum filaments probably due to the combined effect of a decreased biomass loading and an increased shear force
Sequencing batch airlift reactors (SBAR): a suitable technology for treatment and valorization of mineral oil wastewaters towards lipids production
Produced water (PW) and spent oil-based wastewaters are some of the largest mineral oil wastewaters produced. Due to the high toxicity of hydrocarbons, several countries set stringent discharge limits and its treatment is compulsory before discharge. In this work, biological treatment of mineral oil wastewaters coupled with the production of bacterial lipids is demonstrated in sequential batch airlift reactors (SBAR). Two SBAR (2 L working volume) were used for treatment of PW and lubricant-based wastewater (LW), inoculated with Alcanivorax borkumensis SK2 (SBARAb+PW) and Rhodococcus opacus B4 (SBARR.o+LW), respectively. A total petroleum hydrocarbon removal (TPH) efficiency up to 96% and 80% were achieved for SBARAb+PW and SBARR.o+LW, respectively. Intracellular lipids production in SBARAb+PW increased when lower TPH/N ratios and higher feast stage duration were applied (up to 0.74 g g-1 cell dry weight (CDW)), whereas in SBARR.o+LW higher lipids production was observed for higher TPH/N ratios (0.94 g g-1 in CDW). Triacylglycerols (TAG) were the main intracellular lipid accumulated in both SBARAb+PW and SBARR.o+LW operations, while wax ester (WE) production was only observed extracellularly in the SBARAb+PW.This work was supported by the Portuguese Foundation for Science
and Technology (FCT) and European Regional Development Fund
(FEDER) under the scope of project SaltOil+ (POCI-01-0145-FEDER030180); the strategic programmes UIDB/04469/2020, UID/BIA/4050/
2013 (POCI-01-0145-FEDER-007569) and UID/BIA/04050/2019; and
by the BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded
by the European Regional Development Fund under the scope of
Norte2020 - Programa Operacional Regional do Norte. Research of Rita
M. Silva was supported by PhD grant SFRH/BD/116154/2016, funded
by FCT.info:eu-repo/semantics/publishedVersio
Activation of adenosine A2A receptors induces TrkB translocation and increases BDNF-mediated phospho-TrkB localization in lipid rafts : implications for neuromodulation
Copyright © 2010 the authorsBrain-derived neurotrophic factor (BDNF) signaling is critical for neuronal development and transmission. Recruitment of TrkB receptors to lipid rafts has been hown to be necessary for the activation of specific signaling pathways and modulation of neurotransmitter release by BDNF. Since TrkB receptors are known to be modulated by adenosine A2A receptor activation, we hypothesized that activation of A2A receptors could influence TrkB receptor localization among different membrane microdomains. We found that adenosine A2A receptor agonists increased the levels of TrkB receptors in the lipid raft fraction of cortical membranes and potentiated BDNF-induced augmentation of phosphorylated TrkB levels in lipid rafts. Blockade of the clathrin-mediated endocytosis with monodansylcadaverine(100µM) did not modify the effects of theA2A receptor agonists but significantly impairedBDNFeffects on TrkB recruitment to lipid rafts.
The effect of A2A receptor activation in TrkB localization was mimicked by 5 µM forskolin, an adenylyl cyclase activator. Also, it was blocked by the PKA inhibitors Rp-cAMPs and PKI-(14 –22), and by the Src-family kinase inhibitor PP2. Moreover, removal of endogenous adenosine or disruption of lipid rafts reduced BDNF stimulatory effects on glutamate release from cortical synaptosomes.
Lipid raft integrity was also required for the effects of BDNF on hippocampal long-term potentiation at CA1 synapses. Our data
demonstrate, for the first time, a BDNF-independent recruitment of TrkB receptors to lipid rafts induced by activation of adenosine A2A receptors, with functional consequences for TrkB phosphorylation and BDNF-induced modulation of neurotransmitter
release and hippocampal plasticity.Supported by Fundacão para a Ciência e a Tecnologia (SFRH/BD/21374/2005 for N.A.L., SFRH/BD/21359/2005 for V.C.S., and SFRH/BPD/11528/2002 for D.B.P.) and by the European Union [European Cooperation in Science and Technology (COST) COST B30 concerted action, Neural Regeneration and Plasticity (NEREPLAS)]
Os artrópodes auxiliares generalistas associados aos citrinos na ilha Terceira (Açores)
A fauna de artrópodes dos Açores, que foi recentemente listada, é composta por cerca de 2.209 espécies e subespécies (Borges et al., 2005a). Uma fracção importante da fauna de artrópodes dos Açores é constituída por espécies de predadores, incluindo predadores generalistas (e.g. Araneae – aranhas, Hemiptera‑Heteroptera, Neuroptera, Staphylinidae, Diptera‑Syphidae etc.) e parasitoides (Hymenoptera – Parasitica). Os ecossistemas agrícolas são aqueles que mais poderão beneficiar da acção dos predadores generalistas, geralmente designados por auxiliares. No entanto, a densidade dos insectos fitófagos, muitos dos quais constituem pragas, só pode ser controlada pelos auxiliares quando não é muito elevada. Apesar do elevado número de pomares existentes na ilha Terceira (Açores), a superfície ocupada por culturas frutícolas é pequena comparativamente à área coberta por pastagens (as pastagens ocupam 44% da área total; Borges 1999a). No ano 2003, iniciou‑se o projecto INTERFRUTA (projecto de cooperação entre Açores, Madeira e Canárias), que contribuiu para o maior conhecimento dos artrópodes associados a quatro culturas frutícolas (bananeiras, citrinos, macieiras e pessegueiros) da ilha Terceira (ver Santos et al., 2005a, b). Neste trabalho apresenta‑se uma lista comentada e a distribuição das espécies de artrópodes auxiliares encontradas nos pomares de Citrinos. [da Introdução
Exploring syntrophic relationships in the anaerobic biodegradation of lipids and long chain fatty acids
ICBM-3 - 3rd International Conference on Biogas Microbiology (Abstract Book)[Excerpt] Practical knowledge on anaerobic digestion of waste lipids has been improving for several decades, but the microbiology of these processes remains partially undisclosed, with non-cultivated taxonomic groups often detected in anaerobic communities degrading lipids. This work studies the diversity and physiology of anaerobic microorganisms involved in the metabolism of lipids and long chain fatty acids. Anaerobic culturing procedures were applied for the development of enrichment cultures, and combined with next generation sequencing techniques. Enriched microbial communities specialized in the degradation of triolein (0.3 mmol·L-1) and oleate (1 mmol·L-1) were obtained under methanogenic conditions. Oleatedegrading cultures were also developed in the presence of the external electron acceptors ferric hydroxide (75 mmol·L-1) or sulfate (15 mmol·L-1). Three mesophilic sludges from different origins were used as inocula. [...]info:eu-repo/semantics/publishedVersio
Garden and food waste co-fermentation for biohydrogen and biomethane production in a two-step hyperthermophilic-mesophilic process
Co-fermentation of garden waste (GW) and food waste (FW) was assessed in a two-stage process coupling hyperthermophilic dark-fermentation and mesophilic anaerobic digestion (AD). In the first stage, biohydrogen production from individual substrates was tested at different volatile solids (VS) concentrations, using a pure culture of Caldicellulosiruptor saccharolyticus as inoculum. FW concentrations (in VS) above 2.9 g L-1 caused a lag phase of 5 days on biohydrogen production. No lag phase was observed for GW concentrations up to 25.6 g L-1. In the co-fermentation experiments, the highest hydrogen yield (46±1 L kg-1) was achieved for GW:FW 90:10% (w/w). In the second stage, a biomethane yield of 682±14 L kg-1 was obtained using the end-products of GW:FW 90:10% co-fermentation. The energy generation predictable from co-fermentation and AD of GW:FW 90:10% is 0.5 MJ kg-1 and 24.4 MJ kg-1, respectively, which represents an interesting alternative for valorisation of wastes produced locally in communities.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER006684), Project SAICTPAC/0040/2015 (POCI-01-0145-FEDER016403) 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 the financial support of FCT and European Social Fund through the grant attributed to A.A. Abreu (SFRH/BPD/82000/2011). Research of A.J. Cavaleiro was supported by the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement No 323009.info:eu-repo/semantics/publishedVersio
Mead production: Fermentative performance of yeasts entrapped in different concentrations of alginate
Mead is an alcoholic drink known since ancient times, produced by yeast fermenting diluted honey. However, the production of mead has suffered in recent years, partially owing to the lack of scientific progress in this field. In this study, two strains of Saccharomyces cerevisiae, QA23 and ICVD47, were immobilized in 2 or 4% (w/v) alginate beads to assess the most effective alginate concentration for yeast immobilization to produce mead. Neither of the alginate concentrations was able to prevent cell leakage from the beads. The fermentation length was 120h for both yeast strains. In all cases, at the end of the fermentation, the number of cells entrapped in the beads was higher than the number of free cells, and the total 4% alginate bead wet weight was significantly higher than the 2% alginate bead wet weight. In addition, the evaluation of mead quality showed that the yeast strain had significantly more influence on the physicochemical characteristics than the alginate concentration. Although the yeasts immobilized in the two alginate concentrations were able to perform the fermentation, further research is needed in order to understand the evolution of the yeast population inside the beads throughout the fermentative process.The research presented in this paper was partially funded by the
Fundação para a Ciência e Tecnologia, and by the PTDC project
(contract PTDC/AGR-ALI/68284/2006). A.P.P. is the recipient of a
PhD grant from FCT (SFRH/BD/45820/2008).info:eu-repo/semantics/publishedVersio
Effects of atopy and rhinitis on exhaled nitric oxide values - a systematic review
<p>Abstract</p> <p>Background</p> <p>Atopy and rhinitis are among the factors affecting exhaled nitric oxide (FeNO) values and may contribute to difficulties in the clinical interpretation of FeNO measurements. However, data assessing their effects on FeNO values had never been summarized. This review aims to evaluate the effect of atopy and rhinitis in FeNO values in otherwise healthy individuals.</p> <p>Methods</p> <p>A systematic review was performed in Pubmed, Scopus and ISI Web of Knowledge. A two-step selection process was completed, and from 2357 references 19 were included. The inclusion criteria were: participants without known diseases other than rhinitis; atopy assessement by SPT or Specific IgE; and FeNO measurements according to ATS/ERS recommendations.</p> <p>Results</p> <p>The 8 articles measuring FeNO in children showed higher values in both allergic rhinitis and atopic children when compared with healthy children. The 11 articles performed in adults observed higher FeNO in AR patients comparatively with either healthy or atopic individuals. However, adult healthy and atopic individuals had similar FeNO values.</p> <p>Conclusions</p> <p>FeNO values are higher in individuals with rhinitis and/or atopy without other health problems. These effects are small, seem to be independent and should be further studied using multivariate models. The effect of atopy was observed only in children. The combined effect of atopy and rhinitis produced higher FeNO values in adults. These results support that both atopy and rhinitis should be considered when interpreting or when defining FeNO reference values.</p
Troubleshooting of filamentous bulking using hybdrid systems
The present work aims to evaluate filamentous bulking
control in hybrid systems. For this study, four
sequencing batch reactors (SBR) fed with acetate were
operated without (SBR1) and with support for biofilm
growth [5 % (SBR2), 10 % (SBR3) and 20 % (SBR4) of
the reactor volume]. The results demonstrated an
overabundance of a filamentous fungi-like
microorganism in the SBR operating just with
suspended biomass. The incorporation of an optimized
amount of support for biofilm growth (10 % and 20 %)
seemed to suppress the overgrowth of this filamentous
microorganism probably due to the combined effect of a
decreased biomass loading rate and the physical cut or
breakdown of filaments induced by support-to-support
collisions
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