36 research outputs found

    Some don't like it hot: microhabitat-dependent thermal and water stresses in a trailing edge population

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    The distributional limits of species in response to environmental change are usually studied at large temporal and/or geographical scales. However, organismal scale habitat variation can be overlooked when investigating large-scale averages of key factors such as temperature. We examine how microhabitat thermal conditions relate to physiological limits, which may contribute to recent range shifts in an intertidal alga. We defined the onset and maximum temperatures of the heat-shock response (HSR) for a southern edge population of Fucus vesiculosus, which has subsequently become extinct. The physiological threshold for resilience (assayed using chlorophyll fluorescence) coincided with declining HSR, determined from the temperature-dependent induction of seven heat-shock protein transcripts. In intertidal habitats, temperature affects physiology directly by controlling body temperature and indirectly through evaporative water loss. We investigated the relationship between the thermal environment and in situ molecular HSR at microhabitat scales. Over cm to m scales, four distinct microhabitats were defined in algal patches (canopy surface, patch edge, subcanopy, submerged channels), revealing distinct thermal and water stress environments during low-tide emersion. The in situ HSR agreed with estimated tissue temperatures in all but one microhabitat. Remarkably, in the most thermally extreme microhabitat (canopy surface), the HSR was essentially absent in desiccated tissue, providing a potential escape from the cellular metabolic costs of thermal stress. Meteorological records, microenvironmental thermal profiles and HSR data indicate that the maximum HSR is approached or exceeded in hydrated tissue during daytime low tides for much of the year. Furthermore, present-day summer seawater temperatures are sufficient to induce HSR during high-tide immersion, preventing recovery and resulting in continuous HSR during daytime low-tide cycles over the entire summer. HSR in the field matched microhabitat temperatures more closely than local seawater or atmospheric data, suggesting that the impacts of climatic change are best understood at the microhabitat scale, particularly in intertidal areas.FCT - Portuguese Science Foundation [POCTI/MAR/61105/2004, EXCL/AAG-GLO/0661/2012, SFRH/BPD/63/03/2009, SFRH/BD/74436/2010]info:eu-repo/semantics/publishedVersio

    Sex-biased gene expression in the brown alga Fucus vesiculosus

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    Background The fucoid brown algae (Heterokontophyta, Phaeophyceae) are increasingly the focus of ecological genetics, biodiversity, biogeography and speciation research. The molecular genetics underlying mating system variation, where repeated dioecious – hermaphrodite switches during evolution are recognized, and the molecular evolution of sex-related genes are key questions currently hampered by a lack of genomic information. We therefore undertook a comparative analysis of male and female reproductive tissue transcriptomes against a vegetative background during natural reproductive cycles in Fucus vesiculosus. Results Over 300 k reads were assembled and annotated against public protein databases including a brown alga. Compared with the vegetative tissue, photosynthetic and carbohydrate metabolism pathways were under-expressed, particularly in male tissue, while several pathways involved in genetic information processing and replication were over-expressed. Estimates of sex-biased gene (SBG) expression were higher for male (14% of annotated orthologues) than female tissue (9%) relative to the vegetative background. Mean expression levels and variance were also greater in male- than female-biased genes. Major female-biased genes were carbohydrate-modifying enzymes with likely roles in zygote cell wall biogenesis and/or modification. Male-biased genes reflected distinct sperm development and function, and orthologues for signal perception (a phototropin), transduction (several kinases), and putatively flagella-localized proteins (including candidate gamete-recognition proteins) were uniquely expressed in males. Overall, the results suggest constraint on female-biased genes (possible pleiotropy), and less constrained male-biased genes, mostly associated with sperm-specific functions. Conclusions Our results support the growing contention that males possess a large array of genes regulating male fitness, broadly supporting findings in evolutionarily distant heterogametic animal models. This work identifies an annotated set of F. vesiculosus gene products that potentially regulate sexual reproduction and may contribute to prezygotic isolation, one essential step towards developing tools for a functional understanding of species isolation and differentiation.Peer Reviewe

    Driving south: a multi-gene phylogeny of the brown algal family Fucaceae reveals relationships and recent drivers of a marine radiation

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    <p>Abstract</p> <p>Background</p> <p>Understanding the processes driving speciation in marine ecosystems remained a challenge until recently, due to the unclear nature of dispersal boundaries. However, recent evidence for marine adaptive radiations and ecological speciation, as well as previously undetected patterns of cryptic speciation is overturning this view. Here, we use multi-gene phylogenetics to infer the family-level evolutionary history of Fucaceae (intertidal brown algae of the northern Pacific and Atlantic) in order to investigate recent and unique patterns of radiative speciation in the genus <it>Fucus </it>in the Atlantic, in contrast with the mainly monospecific extant genera.</p> <p>Results</p> <p>We developed a set of markers from 13 protein coding genes based on polymorphic cDNA from EST libraries, which provided novel resolution allowing estimation of ancestral character states and a detailed reconstruction of the recent radiative history. Phylogenetic reconstructions yielded similar topologies and revealed four independent trans-Arctic colonization events by Fucaceae lineages, two of which also involved transitions from hermaphroditism to dioecy associated with Atlantic invasions. More recently, reversion of dioecious ancestral lineages towards hermaphroditism has occurred in the genus <it>Fucus</it>, particularly coinciding with colonization of more extreme habitats. Novel lineages in the genus <it>Fucus </it>were also revealed in association with southern habitats. These most recent speciation events occurred during the Pleistocene glaciations and coincided with a shift towards selfing mating systems, generally southward shifts in distribution, and invasion of novel habitats.</p> <p>Conclusions</p> <p>Diversification of the family occurred in the Late-Mid Miocene, with at least four independent trans-Artic lineage crossings coincident with two reproductive mode transitions. The genus <it>Fucus </it>arose in the Pliocene but radiated within a relatively short time frame about 2.5 million years ago. Current species distributions of <it>Fucus </it>suggest that climatic factors promoted differentiation between the two major clades, while the recent and rapid species radiation in the temperate clade during Pleistocene glacial cycles coincided with several potential speciation drivers.</p

    Anaesthesia - related fears - a cross - sectional survey among the portuguese population

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    Introduction: Patients experience preoperative anxiety. The objective of this study was to assess patients’ fears concerning anaesthesia and evaluate possible associations with sociodemographic background and previous anaesthesia. Methods: A survey was filled preoperatively, for 6 months, including anaesthesia-related fears, sociodemographic data, previous anaesthesia and surgery, current surgical and anaesthetic procedure, and preferred anaesthesia technique. Descriptive statistics, principal component analysis, Chi-square test, t-test and ANOVA were used for statistical analysis. Results: 153 questionnaires were collected. The mean age was 58 years, 61.4% were female and 59.5% employed. 47.1% had an anaesthesia consultation before. 49.7% were ASA II. 78.4% had been submitted to surgery before, 81.7% to anaesthesia and 14.5% had regional anaesthesia. In 73.5% general anaesthesia preferred. Half of patients with previous regional anaesthesia favoured this technique. The most relevant fears were “being paralysed because of anaesthesia”, “not waking up” and “waking up during surgery”. The least relevant were “fasting incapacity”, “having nightmares” and “speaking of personal matters”. A statistically significant relation was observed between the fear of “feeling pain after surgery” and having a previous anaesthetic experience. Female and unemployed patients were more concerned with general complications, while male patients gave more importance to awareness and paralysis. Conclusion: Paralysis after anaesthesia, intraoperative awareness and death were the main concerns of our inquiries.info:eu-repo/semantics/publishedVersio

    Bacterial cellulose production: valorization of wastewater and life cycle assessment

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    Low-cost substrates, most from agro-industrial wastes, have increasingly been exploited as nutrient sources for the fermentation of bacterial cellulose (BC), an appealing approach from an economical and environmental point of view. However, these wastes carry a very high organic load, which, while advantageous for the fermentation, generate high organic load wastewaters as well, which require proper treatment before the release or recycling of the treated water, which may have a significant impact in the economic and environmental sustainability of the BC production. Anaerobic digestion (AD), a process that produces biogas (primarily a mixture of methane and CO2) typically used for lighting and heating, is one of the most appropriate and promising treatments for high loaded industrial wastewaters. In this work, wastewaters from BC fermentation were characterized, as well as their biochemical methane potential and anaerobic biodegradability. The performance of an upflow anaerobic sludge blanket reactor (UASB) for the treatment of these wastewaters was also evaluated. Briefly, A relevant among of biogas could be produced from AD, while reducing the chemical oxygen demand (COD, an indirect measure the amount of organic compounds) of the treated waters [1]. The Life Cycle Assessment (LCA) is a methodology used to quantify the environmental, health and resource depletion impacts related to products, processes, and services. A LCA was used to a projected production of BC under static culture, including wastewater treatment, following a cradle-to-gate approach. From this study, a considerable amount of water is consumed, most of which being treated and emitted to the environment (to fresh water). The BC production facility itself had a small contribution to the consumption of resources and environmental impact of the global life cycle, most of which were associated with the production and transport of materials. Further, a comparative LCIA was made against plant celluloses. Briefly, with the increasing environmental awareness, BC production may be a strong candidate towards the reductions of environmental impacts and risks, concerning climate change and fossil resource depletion, while providing a viable, economically and environmentally sustainable bioproduct, with unique properties for a wide range of market applications [2].info:eu-repo/semantics/publishedVersio

    Valorization of sugarcane by-products through synthesis of biogenic amorphous silica microspheres for sustainable cosmetics

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    Ashes from sugarcane by-product incineration were used to synthesize silica powders through alkaline hot extraction, followed by ethanol/acid precipitation or the sol–gel method. Both production methods allowed amorphous spherical silica microparticles with sizes ranging from 1–15 μm and 97% purity to be obtained. Water absorption ranged from 135–155 mL/100 g and 150–250 mL/100 g for precipitated silica and silica gel, respectively, while oil absorption ranged from 305 to 390 and from 250 to 350 mL/100 g. The precipitation with ethanol allowed the recovery of 178 g silica/kg ash, with a lab process cost of EUR 28.95/kg, while the sol-gel process showed a yield of 198 g silica/kg ash with a cost of EUR 10.89/kg. The experimental data suggest that ash from sugarcane by-products is a promising source to be converted into a competitive value-added product, minimizing the environmental impact of disposal problems.info:eu-repo/semantics/publishedVersio

    Severe COVID-19 recovery is associated with timely acquisition of a myeloid cell immune-regulatory phenotype

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    Copyright © 2021 Trombetta, Farias, Gomes, Godinho-Santos, Rosmaninho, Conceição, Laia, Santos, Almeida, Mota, Gomes, Serrano, Veldhoen, Sousa and Fernandes. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.After more than one year since the COVID-19 outbreak, patients with severe disease still constitute the bottleneck of the pandemic management. Aberrant inflammatory responses, ranging from cytokine storm to immune-suppression, were described in COVID-19 and no treatment was demonstrated to change the prognosis significantly. Therefore, there is an urgent need for understanding the underlying pathogenic mechanisms to guide therapeutic interventions. This study was designed to assess myeloid cell activation and phenotype leading to recovery in patients surviving severe COVID-19. We evaluated longitudinally patients with COVID-19 related respiratory insufficiency, stratified according to the need of intensive care unit admission (ICU, n = 11, and No-ICU, n = 9), and age and sex matched healthy controls (HCs, n = 11), by flow cytometry and a wide array of serum inflammatory/immune-regulatory mediators. All patients featured systemic immune-regulatory myeloid cell phenotype as assessed by both unsupervised and supervised analysis of circulating monocyte and dendritic cell subsets. Specifically, we observed a reduction of CD14lowCD16+ monocytes, and reduced expression of CD80, CD86, and Slan. Moreover, mDCs, pDCs, and basophils were significantly reduced, in comparison to healthy subjects. Contemporaneously, both monocytes and DCs showed increased expression of CD163, CD204, CD206, and PD-L1 immune-regulatory markers. The expansion of M2-like monocytes was significantly higher at admission in patients featuring detectable SARS-CoV-2 plasma viral load and it was positively correlated with the levels of specific antibodies. In No-ICU patients, we observed a peak of the alterations at admission and a progressive regression to a phenotype similar to HCs at discharge. Interestingly, in ICU patients, the expression of immuno-suppressive markers progressively increased until discharge. Notably, an increase of M2-like HLA-DRhighPD-L1+ cells in CD14++CD16- monocytes and in dendritic cell subsets was observed at ICU discharge. Furthermore, IFN-γ and IL-12p40 showed a decline over time in ICU patients, while high values of IL1RA and IL-10 were maintained. In conclusion, these results support that timely acquisition of a myeloid cell immune-regulatory phenotype might contribute to recovery in severe systemic SARS-CoV-2 infection and suggest that therapeutic agents favoring an innate immune system regulatory shift may represent the best strategy to be implemented at this stage.The Research was funded by Fundação para a Ciência e Tecnologia (FCT), “APOIO ESPECIAL RESEARCH 4COVID-19” projects 803, 125, 231_596873172, and 729. AMCG and GF received fellowships funded by FCT (DOCTORATES4COVID-19, 2020.10202.BD), and JANSSEN- CILAG FARMACÊUTICA, respectively. The funder was not involved in the study design, collection, analysis, interpretation of data, writing of the article or decision to submit it for publication. MV was supported by the European Union H2020 ERA project (No 667824 – EXCELLtoINNOV). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 667824.info:eu-repo/semantics/publishedVersio

    SARS‐CoV2 pneumonia recovery is linked to expansion of innate lymphoid cells type 2 expressing CCR10

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    © 2021 The Authors. European Journal of Immunology published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Accelerate lung repair in SARS-CoV-2 pneumonia is essential for pandemic handling. Innate lymphoid cells (ILCs) are likely players, given their role in mucosal protection and tissue homeostasis. We studied ILC subpopulations at two time points in a cohort of patients admitted in the hospital due to SARS-CoV-2 infection. COVID-19 patients with moderate/severe respiratory failure featured profound depletion of circulating ILCs at hospital admission, in agreement with overall lymphocyte depletion. However, ILCs recovered in direct correlation with lung function improvement as measured by oxygenation index and in negative association with inflammatory and lung/endothelial damage markers like RAGE. While both ILC1 and ILC2 expanded, ILC2 showed the most striking phenotype changes, with CCR10 upregulation in strong correlation with these parameters. Overall, CCR10+ ILC2 emerge as relevant contributors to SARS-CoV-2 pneumonia recovery.This work was funded by the following grants from Fundação para a Ciência e a Tecnologia (FCT), Portugal, through “APOIO ESPECIAL RESEARCH4COVID-19,” project numbers 125 to SMF and 803 to ACT. AMCG and GBF received fellowships funded by FCT (DOCTORATES4COVID-19, 2020.10202.BD) and JANSSEN- CILAG FARMACÊUTICA, respectively.info:eu-repo/semantics/publishedVersio

    Targeting Glutathione and Cystathionine β-Synthase in Ovarian Cancer Treatment by Selenium-Chrysin Polyurea Dendrimer Nanoformulation

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    The research was funded by iNOVA4Health UID/Multi/04462, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Educação e Ciência (FCT-MCTES), through national funds, and co-funded by FEDER under the PT2020 Partnership Agreement. We also acknowledge funding from FCT-MCTES through project DREAM PTDC/MEC-ONC/29327/2017.Ovarian cancer is the main cause of death from gynecological cancer, with its poor prognosis mainly related to late diagnosis and chemoresistance (acquired or intrinsic) to conventional alkylating and reactive oxygen species (ROS)-generating drugs. We and others reported that the availability of cysteine and glutathione (GSH) impacts the mechanisms of resistance to carboplatin in ovarian cancer. Different players in cysteine metabolism can be crucial in chemoresistance, such as the cystine/glutamate antiporter system Xc (xCT) and the H2S-synthesizing enzyme cystathionine β-synthase (CBS) in the pathway of cysteine catabolism. We hypothesized that, by disrupting cysteine metabolic flux, chemoresistance would be reverted. Since the xCT transporter is also able to take up selenium, we used selenium-containing chrysin (SeChry) as a plausible competitive inhibitor of xCT. For that, we tested the effects of SeChry on three different ovarian cancer cell lines (ES2, OVCAR3, and OVCAR8) and in two non-malignant cell lines (HaCaT and HK2). Results showed that, in addition to being highly cytotoxic, SeChry does not affect the uptake of cysteine, although it increases GSH depletion, indicating that SeChry might induce oxidative stress. However, enzymatic assays revealed an inhibitory effect of SeChry toward CBS, thus preventing production of the antioxidant H2S. Notably, our data showed that SeChry and folate-targeted polyurea dendrimer generation four (SeChry@PUREG4-FA) nanoparticles increased the specificity for SeChry delivery to ovarian cancer cells, reducing significantly the toxicity against non-malignant cells. Collectively, our data support SeChry@PUREG4-FA nanoparticles as a targeted strategy to improve ovarian cancer treatment, where GSH depletion and CBS inhibition underlie SeChry cytotoxicity.publishersversionpublishe
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