158 research outputs found

    Response of kelps from different latitudes to consecutive heat shock

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    Although extensive work has focused on kelp responses to constant temperature, little is known about their response to the consecutive temperature shocks they are often exposed to in the shallow subtidal and intertidal pools. Here we characterized the responses of the two southernmost forest-forming kelp species in the Northeast Atlantic, Laminaria ochroleuca De La Pylaie and Saccorhiza polyschides (Lightf.) Batt. to multiple cycles of thermal stress. Individuals from the upper vertical limit of the geographical distribution edges where the two species co-occur forming forests, France and Portugal, were exposed to 4 consecutive cycles of thermal shock simulating a spring tide. A 24 h cycle consisted of culture at 15 degrees C, plus 1 h heat shock at one of five levels (20, 22.5, 25, 27.5 or 30 degrees C). The maximum quantum yield (Fv/Fm) of chlorophyll fluorescence of photosystem 2 (PS2) was used to detect impaired reaction center function, as a proxy for individual fitness costs, during recovery from heat shock. Both species showed resilience to temperatures from 20 to 25 degrees C. While exposure to 27.5 degrees C caused no inhibition to Fv/Fm of S. polyschides, a threshold was met above this temperature and exposure to 30 degrees C caused the death of all individuals. In contrast, L ochroleuca from France was damaged but able to survive 30 degrees C shocks and individuals from Portugal showed complete resilience to this treatment. In both species, blade elongation decreased with increasing temperature, with necrosis surpassing growth at higher temperatures. Resilience to high temperature exposure may confer an advantage to L ochroleuca to colonize intertidal pools on the Portuguese coast, in agreement with the observation that both species recruit in tide pools but only L ochroleuca reach adulthood. Our results indicate that as summer temperatures increase with climate change, the disappearance of S. polyschides from intertidal pools and a decrease in the density of L ochroleuca can be expected. (C) 2014 Elsevier B.V. All rights reserved.ASSEMBLE (ASSociation of European Marine Biological Laboratories) [227799]; Portuguese Science and Technology Foundation (FCT); FCT [PTDC/AAC-CLI/109108/2008, EXCL/AAG-GLO/0661/2012]info:eu-repo/semantics/publishedVersio

    "My Child has Cerebral Palsy": Parental Involvement and Children's School Engagement

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    Engaged students tend to show school-committed behaviors (e.g., attend classes, get involved with the learning process), high achievement, and sense of belonging. However, students with disabilities are prone to show a lack of engagement with school due to the specific difficulties they have to handle. In fact, children with disabilities are likely to show poor participation in school when compared with children without disabilities. This poor involvement is related to their low autonomy to participate in the school activities, which, in turn, results in low school engagement. Parents play a crucial role in their childrens education. Parental involvement in school activities promotes autonomous behaviors and, consequently, school engagement. In fact, extant literature has shown close relationships between parental involvement, school engagement, and academic performance. Yet, parental involvement in school activities of children with Cerebral Palsy (CP) has received little direct attention from researchers. These children tend to display lower participation due to the motor, or cognitive, impairments that compromise their autonomy, and have a high likelihood to develop learning disabilities, with special incidences in reading and arithmetic. Therefore, our aim is twofold, to understand the parental styles; and how the perceived parental involvement in school activities is related to their children school engagement. Hence, 19 interviews were conducted with one of the parents of 19 children with CP. These interviews explored the school routines of children and the perceived involvement of parents in those routines. Additionally, children filled out a questionnaire on school engagement. Results show that the majority of the parents were clustered in the Autonomy Allowance and Acceptance and Support parental style, and the majority of their children were perceived as autonomous. Moreover, about a half of the children reported a high level of school engagement. Finally, neither childrens autonomous behaviors reportedThis study was conducted at Psychology Research Centre (UID/PSI/01662/2013), University of Minho, and supported by the Portuguese Foundation for Science and Technology and the Portuguese Ministry of Science, Technology and higher Education through national funds and co-financed by FEDER through COMPETE2020 under the PT2020 Partnership Agreement (FOCI-01-0145-FEDER-007653). AP was supported by a PhD fellowship from the Portuguese Foundation for Science and Technology (FCT - SFRH/BD/95104/2013). PM was supported by a Post-Doctoral fellowship from the Research Center on Psychology (CIPsi), School of Psychology, University of Minho.info:eu-repo/semantics/publishedVersio

    Antibody response against plasmid-encoded toxin (Pet) and the protein involved in intestinal colonization (Pic) in children with diarrhea produced by enteroaggregative Escherichia coli

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    Enteroaggregative Escherichia eoli (EAEC) is an emerging cause of pediatric and adult travellers diarrhea. the mechanism by which EAEC induce diarrhea is not completely known. Two serine protease autotransporter proteins, named Pet and Pic have been identified in EAEC strains. Pet has enterotoxic and cytotoxic activities, while the role of Pic in pathogenesis may lie on its mucinolytic activity. Little is known about Pet and Pic biological activities in vivo. in this study the antibody responses against these autotransporter proteins in convalescent children is investigated. Fifteen (83%) children showed specific antibodies against Pet or Pic in their sera. IgG and IgM antibodies were the main isotype found. Specific antibodies against Pic, but not against Pet, were detected in sera from age-matched control group. These data show that specific anti-Pet and anti-Pic antibodies are produced during the course of a natural EAEC infection in children. (C) 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.Univ São Paulo, Dept Microbiol, Inst Ciencias Biomed, São Paulo, BrazilInst Butantan, Lab Especial Microbiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniv São Paulo, Fac Ciencias Farmaceut, Dept Anal Clin & Toxicol, BR-05508900 São Paulo, BrazilCINVESTAV, IPN, Dept Cell Biol, Mexico City 14000, DF, MexicoUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc

    Biochemical and histopathological impacts of rutile and anatase (TiO2 forms) in Mytilus galloprovincialis

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    Titanium dioxide (TiO2) particles have been widely used in various industrial applications and consumer products. Due to their large production and use, they will eventually enter into aquatic environments. Once in the aquatic environment TiO2 particles may interact with the organisms and induce toxic effects. Since the most common crystallographic forms of TiO2 are rutile and anatase, the present study evaluated the effect of these two forms of TiO2 particles in Mytilus galloprovincialis. For this, mussels were exposed to different concentrations of rutile and anatase particles (0, 5, 50, 100 µg/L) for twenty-eight days. Ti concentrations, histopathological alterations and biochemical effects were evaluated. Similar Ti concentrations were found in mussels exposed to rutile and anatase, with the highest values in mussels exposed to the highest exposure concentration. Histopathological results demonstrated that both forms of TiO2 induced alterations on gills and digestive glands along the increasing exposure gradient. Biochemical markers showed that mussels exposed to rutile maintained their metabolic capacity (assessed by the activity of the Electron Transport System, ETS), while anatase increased the metabolism of mussels. Mussels exposed to rutile increased their detoxifying defences which, due to the low tested concentrations, were sufficient to avoid cellular damage. On the other hand, mussels exposed to anatase suffered cellular damages despite the increase of the antioxidant defences which may be related to the high ETS activity. Both rutile and anatase particles were toxic to M. galloprovincialis, being the highest oxidative stress exerted by the crystalline form anatase.publishe

    Highly conducting bombyx mori silk fibroin-based electrolytes incorporating glycerol, dimethyl sulfoxide and [Bmim]PF6

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    Green, transparent and flexible electrolyte films composed of a Bombyx mori silk fibroin (SF) host biopolymer doped with glycerol (G), dimethyl sulfoxide (DMSO, D) and 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) ionic liquid (IL), were synthesized. The materials were represented by the notation SF@GD@ILx (x = 15, 20 and 30 is the mass ratio of SF/[Bmim]PF6 in %). SF@, SF@G, SF@D and SF@GD samples were also prepared. DMSO was found to play a dual-role, acting as solvent of [Bmim]PF6, and enhancing ionic conductivity. DMSO, alone or combined with [Bmim]PF6, led to the increase of the mean roughness and induced the formation of more ordered Silk II conformations (beta-sheets). No structural modifications were detected in the SF@GD@ILx samples upon increasing the temperature up to 100 degrees C. The highest ionic conductivity was exhibited by the IL-rich sample SF@GD@IL30 (1.07 and 4.61 mS cm(-1), at 22 and 100 degrees C, respectively). In the [Bmim]PF6-doped electrolytes "free" and coordinated PF6- ions coexist. The weight losses occurring below 200 degrees C involved essentially the release of adsorbed water and DMSO. The suitable mechanical properties, high ionic conductivity and good electrochemical stability suggest that these electrolytes are attractive candidates for application in electrochemical devices.Veronica de Zea Bermudez would like to express her gratitude to Professor Michel Armand who, during her PhD thesis at Grenoble (1989-1992), was an endless source of ideas that made her work productive and stimulating. His qualities, as an inspiring and extraordinary scientist, equal his kindness, generosity and great heart. This work was supported by National funds by Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/QUI/00686/2018, UID/QUI/00686/2019, UID/QUI/50006/2019 and UID/QUI/00313/2020. The authors thank FEDER funds through the COMPETE 2020 Program and National Funds through FCT under the projects PEst-OE/QUI/UI0616/2014, LUMECD (POCI-01-0145-FEDER-016884 and PTDC/CTMNAN/0956/2014), UniRCell (POCI-01-0145-FEDER-016422 and SAICTPAC/0032/2015), PORPLANTSURF (POCI-01-0145FEDER-029785 and PTDC/CTM-REF/29785/2017), and NORTE01-0145-FEDER-030858. R.F.P.P thanks FCT-UM for the researcher contract in the scope of Decreto-Lei 57/2016 and 57/2017. H.M.R. Goncalves was funded by PTDC/BTM-MAT/30858/2017
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