2,427 research outputs found
Derived categories of Burniat surfaces and exceptional collections
We construct an exceptional collection of maximal possible length
6 on any of the Burniat surfaces with , a 4-dimensional family of
surfaces of general type with . We also calculate the DG algebra of
endomorphisms of this collection and show that the subcategory generated by
this collection is the same for all Burniat surfaces.
The semiorthogonal complement of is an "almost
phantom" category: it has trivial Hochschild homology, and K_0(\mathcal
A)=\bZ_2^6.Comment: 15 pages, 1 figure; further remarks expande
Is there a bidirectional association between rheumatoid arthritis and periodontitis? A systematic review and meta-analysis
BACKGROUND
Several lines of evidence suggest a bi-directional association between Rheumatoid Arthritis (RA) and Periodontitis (PD). Our aim was to systematically appraise the evidence on the association between RA and PD in terms of clinical and laboratory outcomes.
METHODS
An electronic search of several databases (PubMed, EMBASE, MEDLINE, LILACS, CINHL, Scopus, Web of Science, The Cochrane Library, OpenGrey and Google Scholar) was conducted up to March 2019 (PROSPERO CRD42018107817) by two independent reviewers. Observational studies included in the review were quality-appraised using the Newcastle-Ottawa Scale (NOS) tool. Random effects models were used for quantitative analyses.
RESULTS
A total of 8 case-control studies were identified after the final search of 1491 titles. Following quality assessment, 2 studies were excluded due to the high risk of bias, while the remaining 6 were further analysed. Meta-analyses revealed no substantial effect of RA on the Probing Pocket Depth (PPD) and Clinical Attachment Level (CAL) of patients with PD when compared to controls but high degree of study heterogeneity was found. To the contrary, PD was associated with substantially worse RA disease activity as assessed by an increase in the DAS28 score of 0.74 (0.25–1.24, 95%CI, p < 0.001).
CONCLUSION
There is consistent evidence suggesting that PD is associated with worse RA clinical activity as assessed by DAS28 scores whereas, RA patients do not have worsen PD clinical outcomes
Periodontitis and circulating blood cell profiles: a systematic review and meta-analysis
Periodontitis is a chronic inflammatory disease with local and systemic implications. Evidence suggests consistent hematologic changes associated with periodontitis. Our aim was to critically appraise the available evidence on hemogram, leukogram, and thrombogram alterations in otherwise healthy patients suffering from periodontitis when compared with controls. For this systematic review (SR), we searched MEDLINE, Web of Science, EMBASE, and the Cochrane Library (CENTRAL) for studies published up to June 2020. Both observational and interventional studies with baseline standard hematologic levels were included. Outcomes of interest were baseline hemogram, leukogram, and thrombogram values and the impact of periodontitis treatment on these outcomes. Upon risk of bias assessment, data extraction and both qualitative and quantitative (standardized mean differences) analyses were performed. Random-effects meta-analyses were performed to provide pooled estimates. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed (PROSPERO Reg. No. CRD42020164531). A total of 45 studies, eight intervention and 37 case–control studies, were identified after the final search of 3,012 titles. Following quality assessment, 43 articles were deemed to have low risk of bias, and two articles moderate risk. Meta-analyses confirmed that periodontitis was associated with both white and red cell lineages. Severe chronic periodontitis was associated with greater white blood cell counts (mean difference [MD] = 0.53, 95% confidence interval [CI]: 0.26–0.79) when compared with controls. Periodontitis was associated with a larger number of neutrophils (MD = 7.16%, 95% CI: 5.96–8.37) and lower mean platelet volume (MD = 0.30 fL, 95% CI: 0.49 to −0.10) compared with healthy participants. Nonsurgical periodontal treatment was associated with a decrease in white blood cell (WBC) levels (MD = 0.28 10 9/L, 95% CI: −0.47 to −0.08) in patients with chronic periodontitis. Periodontitis is associated with hematologic changes (Strength of Recommendation Taxonomy [SORT] A recommendation). Higher WBC levels, higher neutrophil levels, higher erythrocyte sedimentation rate, and lower mean platelet volumes are the most common blood count findings. The association between periodontitis and WBC could be causal in nature. Further assessment to determine whether periodontitis causes changes in circulating blood cells and to identify the molecular mechanisms underlying these associations is warranted
Using artificial intelligence methods to assess academic achievement in public high schools of a European Union country
Cruz-Jesus, F., Castelli, M., Oliveira, T., Mendes, R., Nunes, C., Sa-Velho, M., & Rosa-Louro, A. (2020). Using artificial intelligence methods to assess academic achievement in public high schools of a European Union country. Heliyon, 6(6), [e04081]. https://doi.org/10.1016/j.heliyon.2020.e04081Understanding academic achievement (AA) is one of the most global challenges, as there is evidence that it is deeply intertwined with economic development, employment, and countries’ wellbeing. However, the research conducted on this topic grounds in traditional (statistical) methods employed in survey (sample) data. This paper presents a novel approach, using state-of-the-art artificial intelligence (AI) techniques to predict the academic achievement of virtually every public high school student in Portugal, i.e., 110,627 students in the academic year of 2014/2015. Different AI and non-AI methods are developed and compared in terms of performance. Moreover, important insights to policymakers are addressed.publishersversionpublishersversionpublishe
Capacidade competitiva de estirpes efetivas de Rhizobium na nodulação do feijoeiro nos cerrados.
TecnologÃas digitales y enseñanza de inglés:
Este estudo tem por objetivo analisar as contribuições da utilização das TDIC no processo de desenvolvimento das habilidades de speaking e writting em aprendizes de inglês, partindo da proposta de produção de um vÃdeo e da escrita colaborativa de um e-book. Trata-se de uma pesquisa qualitativa, configurada como estudo de caso, que teve como participantes 6 licenciandos em lÃngua inglesa (LI). Os dados foram coletados por meio de questionários e foi realizado ao longo do Componente Curricular LÃngua Inglesa Avançada I. Os resultados alcançados permitiram perceber que as TDIC auxiliaram eficazmente na aprendizagem dos discentes, estimulando a percepção dos próprios erros e incitando a autonomia, levando os participantes a revisarem aspectos linguÃsticos fundamentais para suas produções.
PALAVRAS-CHAVE: Tecnologias; LÃngua inglesa; Aprendizagem.
ABSTRACT
This study aims to analyze the contributions of the use of ICDT in the developing process of speaking and writing skills with English learners, starting from the proposal of a video production and the collaborative writing of an e-book. It is a qualitative research, configured as a case study, which had as participants 6 English-language students (EL). The data were collected through questionnaires and was conducted during the Subject Advanced English Language I. The results obtained allowed to realize that the ICDT helped effectively in the students’ learning, stimulating the perception of their own errors and inciting the autonomy, taking the participants to review linguistic aspects that were fundamental to their productions.
KEYWORDS: Technologies; English language; Learning.
RESUMEN
Este estudio tiene por objetivo analizar las contribuciones de la utilización de las TDIC en el proceso de desarrollo de las habilidades de hablar y escribir en aprendices de inglés, partiendo de la propuesta de producción de un vÃdeo y de la escritura colaborativa de un ebook. Se trata de una investigación cualitativa, configurada como estudio de caso, que tuvo como participantes 6 licenciandos en lengua inglesa (LI). Los datos fueron recolectados por medio de cuestionarios y fue realizado a lo largo del Componente Curricular de la Lengua Inglesa Avanzada I. Los resultados alcanzados permitieron percibir que las TDIC ayudaron eficazmente en el aprendizaje de los discentes, estimulando la percepción de los propios errores e incitando la autonomÃa, llevando a los participantes a revisar aspectos lingüÃsticos fundamentales para sus producciones.
PALABRAS CLAVE: TecnologÃas; Idioma Inglés; Aprendizaje.This study aims to analyze the contributions of the use of ICDT in the developing process of speaking and writing skills with English learners, starting from the proposal of a video production and the collaborative writing of an e-book. It is a qualitative research, configured as a case study, which had as participants 6 English-language students (EL). The data were collected through questionnaires and was conducted during the Subject Advanced English Language I. The results obtained allowed to realize that the ICDT helped effectively in the students’ learning, stimulating the perception of their own errors and inciting the autonomy, taking the participants to review linguistic aspects that were fundamental to their productions.Este estudio tiene por objetivo analizar las contribuciones de la utilización de las TDIC en el proceso de desarrollo de las habilidades de hablar y escribir en aprendices de inglés, partiendo de la propuesta de producción de un vÃdeo y de la escritura colaborativa de un ebook. Se trata de una investigación cualitativa, configurada como estudio de caso, que tuvo como participantes 6 licenciandos en lengua inglesa (LI). Los datos fueron recolectados por medio de cuestionarios y fue realizado a lo largo del Componente Curricular de la Lengua Inglesa Avanzada I. Los resultados alcanzados permitieron percibir que las TDIC ayudaron eficazmente en el aprendizaje de los discentes, estimulando la percepción de los propios errores e incitando la autonomÃa, llevando a los participantes a revisar aspectos lingüÃsticos fundamentales para sus producciones
The parasitoid Psyllaephagus blastopsyllae (Hymenoptera: Encyrtidae), as potential control of the eucalypt psyllid Blastopsylla occidentalis (Hemiptera: Psylloidea), in Brazil.
Edição especial dos resumos do IUFRO World Congress, 25., 2019, Curitiba
Deriving phytoplankton size classes from satellite data: Validation along a trophic gradient in the eastern Atlantic Ocean
In recent years, the global distribution of phytoplankton functional types (PFT) and phytoplankton size classes (PSC) has been determined by remote sensing. Many of these methods rely on interpretation of phytoplankton size or type from pigment data, but independent validation has been difficult due to lack of appropriate in situ data on cell size.
This work uses in situ data (photosynthetic pigments concentration and cell abundances) from the north-east Atlantic, along a trophic gradient, sampled from 2005 to 2010, as well as Atlantic Meridional Transect (AMT) data for the same region, to test a previously developed conceptual model, which calculates the fractional contributions of pico-, nano- and micro-plankton to total phytoplankton chlorophyll biomass (Brewin et al., 2010). The application of the model proved to be successful, as shown by low mean absolute error between data and model fit. However, regional values obtained for the model parameters had some effect on the relative distribution of size classes as a function of chlorophyll-a, compared with the results according to the original model. The regional parameterisation yielded a dominance of micro-plankton contribution for chlorophyll-a concentrations greater than 0.5 mg m− 3, rather than from 1.3 mg m− 3 in the original model. Intracellular chlorophyll-a (Chla) per cell, for each size class, was computed from the cell enumeration results (microscope counts and flow cytometry) and the chlorophyll-a concentration for that size class given by the model. The median intracellular chlorophyll-a values computed were 0.004, 0.224 and 26.78 pg Chla cell− 1 for pico-, nano-, and micro-plankton respectively. This is generally consistent with the literature, thereby providing an indirect validation of the method based on pigments to assign size classes. Using a satellite-derived composite image of chlorophyll-a for the study area, a map of cell abundance was generated based on the computed intracellular chlorophyll-a for each size-class, thus extending the remote-sensing method for mapping size classes of phytoplankton from chlorophyll-a concentration to mapping cell numbers in each class. The map reveals the ubiquitous presence of pico-plankton, and shows that all size classes are more abundant in more productive areas
Infections with Avian Pathogenic and Fecal Escherichia coli Strains Display Similar Lung Histopathology and Macrophage Apoptosis
The purpose of this study was to compare histopathological changes in the lungs of chickens infected with avian
pathogenic (APEC) and avian fecal (Afecal) Escherichia coli strains, and to analyze how the interaction of the bacteria with
avian macrophages relates to the outcome of the infection. Chickens were infected intratracheally with three APEC strains,
MT78, IMT5155, and UEL17, and one non-pathogenic Afecal strain, IMT5104. The pathogenicity of the strains was assessed by
isolating bacteria from lungs, kidneys, and spleens at 24 h post-infection (p.i.). Lungs were examined for histopathological
changes at 12, 18, and 24 h p.i. Serial lung sections were stained with hematoxylin and eosin (HE), terminal deoxynucleotidyl
dUTP nick end labeling (TUNEL) for detection of apoptotic cells, and an anti-O2 antibody for detection of MT78 and
IMT5155. UEL17 and IMT5104 did not cause systemic infections and the extents of lung colonization were two orders of
magnitude lower than for the septicemic strains MT78 and IMT5155, yet all four strains caused the same extent of
inflammation in the lungs. The inflammation was localized; there were some congested areas next to unaffected areas. Only
the inflamed regions became labeled with anti-O2 antibody. TUNEL labeling revealed the presence of apoptotic cells at 12 h
p.i in the inflamed regions only, and before any necrotic foci could be seen. The TUNEL-positive cells were very likely dying
heterophils, as evidenced by the purulent inflammation. Some of the dying cells observed in avian lungs in situ may also be
macrophages, since all four avian E. coli induced caspase 3/7 activation in monolayers of HD11 avian macrophages. In
summary, both pathogenic and non-pathogenic fecal strains of avian E. coli produce focal infections in the avian lung, and
these are accompanied by inflammation and cell death in the infected areas
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