24 research outputs found

    Chemical composition and release in situ due to injury of the invasive coral tubastraea (Cnidaria, Scleractinia)

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    Substâncias químicas de defesa contra consumidores e competidores podem ser usadas por espécies invasoras marinhas como estratégia de colonização e perpetuação em novo ambiente. Entretanto, há poucos estudos experimentais que demonstrem as possíveis interações negativas entre corais escleractínios. Este trabalho tem como objetivo caracterizar os metabólitos secundários dos corais invasores Tubastraea tagusensis e T. coccinea; avaliar através da técnica de amostragem in situ quais são as substâncias de T. tagusensis liberadas na água do mar, com o auxílio de aparelho subaquático com colunas Sep-Paks®. Colônias dos corais invasores Tubastraea spp foram coletadas na Baía de Ilha Grande, RJ, e extraídas com MeOH. Os extratos foram submetidos à eluições com hexano, DCM e MeOH, e analisados por CG-EM. Estearato de metila e palmitato de metila foram as substâncias majoritárias das frações hexânicas e hexano: DCM, enquanto o colesterol foi a substância mais abundante das frações DCM e DCM:MeOH de Tubastraea spp. O material orgânico retido nas colunas Sep-Paks® foi identificado como hidrocarbonetos. Diferenças significativas entre controle e tratamento foram relacionadas a diferentes quantidades de 1-hexadeceno, n-hexadecano e n-eicosano. A produção de substâncias de defesas em Tubastraea spp permite especular sobre a ameaça que estes corais invasores representam para as comunidades bentônicas da Ilha Grande.Defensive chemistry may be used against consumers and competitors by invasive species as a strategy for colonization and perpetuation in a new area. There are relatively few studies of negative chemical interactions between scleratinian corals. This study characterizes the secondary metabolites in the invasive corals Tubastraea tagusensis and T. coccinea and relates these to an in situ experiment using a submersible apparatus with Sep-Paks® cartridges to trap substances released by T. tagusensis directly from the sea-water. Colonies of Tubastraea spp were collected in Ilha Grande Bay, RJ, extracted with methanol (MeOH), and the extracts washed with hexane, dichloromethane (DCM) and methanol, and analyzed by GC/MS. Methyl stearate and methyl palmitate were the major components of the hexane and hexane:MeOH fractions, while cholesterol was the most abundant in the DCM and DCM:MeOH fractions from Tubastraea spp. The organic material retained in Sep-Paks® cartridges was tentatively identified as hydrocarbons. There was a significant difference between treatments and controls for 1-hexadecene, n-hexadecane and n-eicosane contents. The production of defensive substances by the invasive corals may be a threat to the benthic communities of the region, which include endemic species

    Effect of mesograzer and nutrient levels on the induction of defenses in several Brazilian acroalgae

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    Herbivory can greatly modify benthic community structure by affecting the distribution of algal species. To deter herbivores, algae have developed several mechanisms, including the induction of chemical and morphological defenses, which may be influenced by nutrient availability. We tested 4 red (Chondrophycus flagellifera, Cryptonemia seminervis, Osmundaria obtusiloba, Pterocladiella capillacea), 4 brown (Dictyota menstrualis, Lobophora variegata, Sargassum vulgare, Stypopodium zonale), and 1 green (Codium decorticatum) algae for inducible defenses following exposure to direct consumption by an amphipod community dominated by Elasmopus brasiliensis. In addition, the effects of water-borne cues from nearby grazed conspecifics and non-grazing consumers on the induction of defenses were examined in C. decorticatum under natural and enhanced (200% natural) nutrient levels. Induction of defense was assessed in choice-feeding assays, using live algae or artificial food containing non-polar extracts of amphipod-exposed (treated) and non-exposed (control) algae. Palatability levels, estimated as the relative difference in wet mass due to consumption in feeding assays between grazer-exposed and control plants, declined significantly in 3 species after the acclimatization period. Tissue from the directly consumed red alga P. capillacea (live alga) was significantly less palatable than tissue from the control plants. Likewise, a significant effect was observed in the brown alga L. variegata. Similar, although not statistically significant, trends were observed in 6 other species. For the green alga C. decorticatum, nutrient enrichment did not affect induction of defenses by herbivores, yet unfertilized plants were more palatable than fertilized conspecifics

    Diversity and ethics in trauma and acute care surgery teams: results from an international survey

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    Background Investigating the context of trauma and acute care surgery, the article aims at understanding the factors that can enhance some ethical aspects, namely the importance of patient consent, the perceptiveness of the ethical role of the trauma leader, and the perceived importance of ethics as an educational subject. Methods The article employs an international questionnaire promoted by the World Society of Emergency Surgery. Results Through the analysis of 402 fully filled questionnaires by surgeons from 72 different countries, the three main ethical topics are investigated through the lens of gender, membership of an academic or non-academic institution, an official trauma team, and a diverse group. In general terms, results highlight greater attention paid by surgeons belonging to academic institutions, official trauma teams, and diverse groups. Conclusions Our results underline that some organizational factors (e.g., the fact that the team belongs to a university context or is more diverse) might lead to the development of a higher sensibility on ethical matters. Embracing cultural diversity forces trauma teams to deal with different mindsets. Organizations should, therefore, consider those elements in defining their organizational procedures. Level of evidence Trauma and acute care teams work under tremendous pressure and complex circumstances, with their members needing to make ethical decisions quickly. The international survey allowed to shed light on how team assembly decisions might represent an opportunity to coordinate team member actions and increase performance

    Conditions promoting effective very high gravity sugarcane juice fermentation

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    Abstract Background: Applying very high gravity (VHG) fermentation conditions to the sugarcane juice (SCJ) bioethanol industry would improve its environmental and economic sustainability without the need for major infrastructure changes or investments. It could enable a decrease in the consumption of biological and natural resources (cane/ land, water and energy) while maintaining acceptable production parameters. The present study attempts to demonstrate and characterise an efective industrially relevant SCJ-VHG fermentation process. Results: An industry-like SCJ-VHG bioethanol production process with 30 and 35 °Bx broth was employed to investigate the efects of both the yeast strain used and nitrogen source supplementation on process yield, process productivity, biomass viability, glycerol concentration and retention-associated gene expression. Process performance was shown to be variably afected by the diferent process conditions investigated. Highest process efciency, with a 17% (w/v) ethanol yield and only 0.2% (w/v) sugar remaining unfermented, was observed with the Saccharomyces cerevisiae industrial strain CAT-1 in 30 °Bx broth with urea supplementation. In addition, efcient retention of glycerol by the yeast strain was identifed as a requisite for better fermentation and was consistent with a higher expression of glycerol permease STL1 and channel FPS1. Urea was shown to promote the deregulation of STL1 expression, overcoming glucose repression. The consistency between Fps1-mediated ethanol secretion and ethanol in the extracellular media reinforces previous suggestions that ethanol might exit the cell through the Fps1 channel. Conclusions: This work brings solid evidence in favour of the utilisation of VHG conditions in SCJ fermentations, bringing it a step closer to industrial application. SCJ concentrated up to 30 °Bx maintains industrially relevant ethanol production yield and productivity, provided the broth is supplemented with a suitable nitrogen source and an appropriate industrial bioethanol-producing yeast strain is used. In addition, the work contributes to a better understanding of the VHG-SCJ process and the variable efects of process parameters on process efciency and yeast strain response. Keywords: Biofuel, Bioethanol, Sugarcane, Saccharomyces cerevisiae, CAT-1, Very high gravity, Process optimisation, Process sustainabilityB. Monteiro was supported by the Ph.D. Grant 2011/12185-0 from the Fundação de Amparo à Pesquisa do Estado de São Paulo-FAPESP. P. Ferraz and M. Barroca are supported by the Doctoral Programme in Applied and Environmental Microbiology (DP-AEM) and the FCT by Ph.D. Grants PD/ BD/113814/2015 and PD/BD/113810/2015, respectively. T. Collins thanks the FCT for support through the Investigador FCT Programme (IF/01635/2014). T. Collins and C. Lucas are supported by the strategic programme UID/ BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and the ERDF through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI). P. Ferraz, T. Collins and C. Lucas were further funded by the project EcoAgriFood (NORTE-01- 0145-FEDER-000009), supported by the Norte Portugal Regional Operational Programme (NORTE 2020) under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (ERDF).info:eu-repo/semantics/publishedVersio
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