77 research outputs found
A teoria APOS nas teses e dissertações defendidas em programas de pós-graduação nas áreas de educação matemática ou ensino de ciências e matemática
Apresentamos nesse artigo um levantamento das teses e dissertações defendidas no Brasil que tiveram a Teoria APOS como suporte teórico. Para tanto, buscamos no catálogo de teses e dissertações da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) trabalhos que contemplassem a referida teoria em sua fundamentação teórica. O termo ‘Teoria APOS’ foi definido como chave de pesquisa, de maneira que consideramos os trabalhos desenvolvidos em Programas de Pós-Graduação vinculados à área de Educação Matemática ou Ensino de Ciências e Matemática. Nessas condições, observamos que 8 dissertações e 3 teses foram defendidas no período de 2010 a 2017. Evidenciamos que tais pesquisas foram realizadas em três instituições, sendo uma delas localizada na região sudeste, e as outras duas, na região sul do país. Os objetos de pesquisa desses trabalhos foram pautados, principalmente, na concepção de estudantes acerca de determinados conhecimentos matemáticos sob o ponto de vista da teoria APOS
Physiological and Metabolic Responses of Marine Mussels Exposed to Toxic Cyanobacteria Microcystis aeruginosa and Chrysosporum ovalisporum
Toxic cyanobacterial blooms are a major contaminant in inland aquatic ecosystems. Furthermore, toxic blooms are carried downstream by rivers and waterways to estuarine and coastal ecosystems. Concerning marine and estuarine animal species, very little is known about how these species are affected by the exposure to freshwater cyanobacteria and cyanotoxins. So far, most of the knowledge has been gathered from freshwater bivalve molluscs. This work aimed to infer the sensitivity of the marine mussel Mytilus galloprovincialis to single as well as mixed toxic cyanobacterial cultures and the underlying molecular responses mediated by toxic cyanobacteria. For this purpose, a mussel exposure experiment was outlined with two toxic cyanobacteria species, Microcystis aeruginosa and Chrysosporum ovalisporum at 1 × 105 cells/mL, resembling a natural cyanobacteria bloom. The estimated amount of toxins produced by M. aeruginosa and C. ovalisporum were respectively 0.023 pg/cell of microcystin-LR (MC-LR) and 7.854 pg/cell of cylindrospermopsin (CYN). After 15 days of exposure to single and mixed cyanobacteria, a depuration phase followed, during which mussels were fed only non-toxic microalga Parachlorella kessleri. The results showed that the marine mussel is able to filter toxic cyanobacteria at a rate equal or higher than the non-toxic microalga P. kessleri. Filtration rates observed after 15 days of feeding toxic microalgae were 1773.04 mL/ind.h (for M. aeruginosa), 2151.83 mL/ind.h (for C. ovalisporum), 1673.29 mL/ind.h (for the mixture of the 2 cyanobacteria) and 2539.25 mL/ind.h (for the non-toxic P. kessleri). Filtering toxic microalgae in combination resulted in the accumulation of 14.17 ng/g dw MC-LR and 92.08 ng/g dw CYN. Other physiological and biochemical endpoints (dry weight, byssus production, total protein and glycogen) measured in this work did not change significantly in the groups exposed to toxic cyanobacteria with regard to control group, suggesting that mussels were not affected with the toxic microalgae. Nevertheless, proteomics revealed changes in metabolism of mussels related to diet, specially evident in those fed on combined cyanobacteria. Changes in metabolic pathways related with protein folding and stabilization, cytoskeleton structure, and gene transcription/translation were observed after exposure and feeding toxic cyanobacteria. These changes occur in vital metabolic processes and may contribute to protect mussels from toxic effects of the toxins MC-LR and CYNPortuguese Science Foundation and under the Projects MOREBIVALVES (PTDC/ASP-PES/31762/2017) and UID/Multi/04423/2013NORTE 2020, Portugal 2020 and the European Union through the ERDF, and by FCT. Moreover, Project AGL2015-64558-RMINECO/FEDER, UE, and the grant FPI (BES-2016–078773
Fluorescence Behavior of Phytoplankton Blooms by Time-Correlated Single-Photon Counting (TCSPC)
Many aquatic ecosystems, such as lagoons or lakes, are increasingly vulnerable to climate changes and human pressure. The environmental and economic costs of anthropogenic eutrophication are high as well as the applied methods to counteract eutrophication This chapter analyzes the variation in abundance (and biomass) of several phytoplankton families in one of the most well-known volcanic lagoons in the Archipelago of the Azores-Portugal (Furnas Lagoon) and the dynamic correlation between groups of different types of algae that have been established seasonally between 2003 and 2018. For that purpose, the principal component analysis (PCA) technique was used in data series on biomass and abundance of phytoplankton and chlorophyll a, in the time interval considered. The application of PCA techniques in natural phytoplankton populations offers the possibility of making rapid qualitative diagnoses of the trophic state in natural lakes. On the other hand, the fluorescence properties of phytoplankton microorganisms are strongly affected by the physicochemical properties of natural waters. The fluorescence emission and the lifetime of the different water samples were obtained by photon counting with time correlation (TCSPC), allowing to establish the fluorescent signature of these phytoplankton groups under certain conditions
Patient-physician discordance in assessment of adherence to inhaled controller medication: a cross-sectional analysis of two cohorts
We aimed to compare patient's and physician's ratings of inhaled medication adherence and to identify predictors of patient-physician discordance.(SFRH/BPD/115169/2016) funded by Fundação
para a Ciência e Tecnologia (FCT); ERDF (European Regional
Development Fund) through the operations: POCI-01-0145-FEDER-029130
('mINSPIRERS—mHealth to measure and improve adherence to medication
in chronic obstructive respiratory diseases—generalisation and evaluation
of gamification, peer support and advanced image processing technologies')
cofunded by the COMPETE2020 (Programa Operacional Competitividade e
Internacionalização), Portugal 2020 and by Portuguese Funds through FCT
(Fundação para a Ciência e a Tecnologia).info:eu-repo/semantics/publishedVersio
Broadened T-cell Repertoire Diversity in ivIg-treated SLE Patients is Also Related to the Individual Status of Regulatory T-cells
Intravenous IgG (ivIg) is a therapeutic alternative for lupus erythematosus, the mechanism of which remains to be fully understood. Here we investigated whether ivIg affects two established sub-phenotypes of SLE, namely relative oligoclonality of circulating T-cells and reduced activity of CD4 + Foxp3+ regulatory T-cells (Tregs) reflected by lower CD25 surface density.Octapharma research funding; Fundação para a Ciência e a Tecnologia postdoctoral fellowships: (SFRH/BPD/20806/2004, SFRH/BPD/34648/2007); FCT Programa Pessoa travel grant
Broadened T-cell Repertoire Diversity in ivIg-treated SLE Patients is Also Related to the Individual Status of Regulatory T-cells
Burden of injury along the development spectrum : associations between the Socio-demographic Index and disability-adjusted life year estimates from the Global Burden of Disease Study 2017
Background The epidemiological transition of non-communicable diseases replacing infectious diseases as the main contributors to disease burden has been well documented in global health literature. Less focus, however, has been given to the relationship between sociodemographic changes and injury. The aim of this study was to examine the association between disability-adjusted life years (DALYs) from injury for 195 countries and territories at different levels along the development spectrum between 1990 and 2017 based on the Global Burden of Disease (GBD) 2017 estimates. Methods Injury mortality was estimated using the GBD mortality database, corrections for garbage coding and CODEm-the cause of death ensemble modelling tool. Morbidity estimation was based on surveys and inpatient and outpatient data sets for 30 cause-of-injury with 47 nature-of-injury categories each. The Socio-demographic Index (SDI) is a composite indicator that includes lagged income per capita, average educational attainment over age 15 years and total fertility rate. Results For many causes of injury, age-standardised DALY rates declined with increasing SDI, although road injury, interpersonal violence and self-harm did not follow this pattern. Particularly for self-harm opposing patterns were observed in regions with similar SDI levels. For road injuries, this effect was less pronounced. Conclusions The overall global pattern is that of declining injury burden with increasing SDI. However, not all injuries follow this pattern, which suggests multiple underlying mechanisms influencing injury DALYs. There is a need for a detailed understanding of these patterns to help to inform national and global efforts to address injury-related health outcomes across the development spectrum.Peer reviewe
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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