1,828 research outputs found
Hacia un cambio en la concepción de movimiento de estudiantes de la secundaria: un experimento en clase Primera Parte
The main objective of this work was to investigate the effectivinees and the didactic implications arising from the utilization of a constructivist approach to the teaching of the inertial conception of movement to a regular class of a brazilian secondary school.</p
Quanto De Inusitado Guarda Uma Sala De Aula De Matemática? Aprendizagens E Erro
A mathematics class in a public school: a usual school, a usual classroom. Everything flows as normal. However, an accurate attention to a small and trivial situation may constitute a watchful eye to simplicities in this mathematics class. As the homework was corrected, a student has doubts, the teacher explains... How consequent is this episode? In this quiet mathematics class a "mistake" is opened as production. A plot like a mathematics class, with the minimum of its potency. A deviation is taken as learning along with mathematics. An escape to reproduction of a model that stands, as a way that leads, to the correct result. The invention of an operation method that disquiet a thought, idealizing a thinking that breaks with the previous abordation. This article appears next to a master's dissertation in Education. In the research that generates the dissertation, there is a place beside the mathematics class in opening up to happening that there will giving.305692693
O gênero Strombomonas (Euglenophyceae pigmentadas) em ambientes lênticos na Planície Costeira do Rio Grande do Sul, Brasil
Effect of hyperosmotic shock on phosphoenolpyruvate carboxykinase gene expression and gluconeogenic activity in the crab muscle
AbstractChasmagnathus granulata phosphoenolpyruvate carboxykinase (PEPCK) cDNA from jaw muscle was cloned and sequenced, showing a specific domain to bind phosphoenolpyruvate in addition to the kinase-1 and kinase-2 motifs to bind guanosine triphosphate (GTP) and Mg2+, respectively, specific for all PEPCKs. In the kinase-1 motifs the GK was changed to RK. The first 19 amino acids of the putative enzyme contain hydrophobic amino acids and hydroxylated residues specific to a mitochondrial type signal. The PEPCK is expressed in hepatopancreas, muscles, nervous system, heart, and gills. Hyperosmotic stress for 24 h increased the PEPCK mRNA level, gluconeogenic and PEPCK activities in muscle
Effect Of Fixative Type And Fixation Time On The Morphology Of Equine Preantral Ovarian Follicles
The aim of this study was to investigate the efficacy of the tissue fixatives Bouin, Carnoy and 10% Formaldehyde in equine ovarian fragments. Ovaries (n=4) from mares of mixed breeds were obtained at a local slaughterhouse and transported at 20 oC in a thermo container. Immediately after collection, the ovaries were washed with a modified PBS solution (CultilabR, Campinas-SP, Brazil) and divided into nine fragments with approximately 5x5x1 mm, removed from the parenchyma of each ovary. The ovarian fragments were then immersed in three different fixatives, Bouin (B) Carnoy (C) or 10% Formaldehyde (F) for 6, 12 or 24 hours. Each fragment was individually immersed in a 20 mL tube containing 20 times the volume of fixative solution. After this period, the fragments were held in 70% ethanol for 24 hours. Each procedure was performed in four replicates. For histological analysis, the specimens were dehydrated in increasing concentrations of alcohol, submitted to diaphanization in xylol and embedded in paraffin. Serial sections of 5 'Êm were made with the use of a rotating microtome (LeicaR type, Wetzlar, Germany), followed by slide mounting and staining with periodic acid-Schiff (PAS) and hematoxylin. A total of 540 slides with 1,620 sections were evaluated, which contained 465 preantral follicles that were classified as normal or degenerated. Follicles were considered as degenerated when presented at least one of the following aspects: cytoplasm retraction, pyknotic nucleus, cytoplasmic vacuoles, displacement of granulosa cells and/or disruption of the basal membrane. A logistic regression test was used for statistical analysis, and differences were considered significant when P<0.05. The Carnoy fixative, when used for 24 hours, provided the best conditions of morphological integrity (53.3%; 32/60) compared to all others, and the use of Boiun for 24 hours was considered the worst treatment (19.1%; 9/47). The other treatments lead to the following results: C12h 50% (30/60), C6 H 40% (24/60), F24h 37.8% (17/45), F12h 35.1% (13/37), F6h 32% (16/50), B12h 30.5% (18/59) and B6h 24.4% (11/45). Therefore, we suggest that fixation of equine ovarian tissue with Carnoy for 24 hours is the most suitable protocol for morphological preservation of pre-antral follicles.37124325
Alkaloids: Therapeutic Potential against Human Coronaviruses
Alkaloids are a class of natural products known to have wide pharmacological activity and have great potential for the development of new drugs to treat a wide array of pathologies. Some alkaloids have antiviral activity and/or have been used as prototypes in the development of synthetic antiviral drugs. In this study, eleven anti-coronavirus alkaloids were identified from the scientific literature and their potential therapeutic value against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is discussed. In this study, in silico studies showed an affinity of the alkaloids for binding to the receptor-binding domain of the SARS-CoV-2 spike protein, putatively preventing it from binding to the host cell. Lastly, several mechanisms for the known anti-coronavirus activity of alkaloids were discussed, showing that the alkaloids are interesting compounds with potential use as bioactive agents against SARS-CoV-2
Интеллектуалы в дискурсе власти постсовременности
Background: It is suggested that allergic immune activation, combined with a genetic predisposition, may contribute to the expression of aberrant social behaviour relevant to autism. We have previously shown that a food allergic response reduced social behaviour in mice, which was associated with altered dopaminergic activity in brain regions relevant for social and emotional behaviour. Dietary fatty acid composition has been shown to affect both the immune system and neurological processes and may therefore contribute to the prevention of food allergy-induced abnormalities in social behaviour. Method: The aim of this study was to assess whether dietary supplementation with fish oil rich in long chain omega-3 polyunsaturated fatty acids (n-3 LCPUFA) prevents food allergy-induced abnormalities in social behaviour and associated deficits of the dopaminergic system in the prefrontal cortex of whey-sensitised mice. Results: The n-3 LCPUFA-enriched fish oil diet decreased the acute allergic skin response and was able to prevent the disturbance in social behaviour of whey-sensitised mice. N-3 LCPUFA supplementation increased docosahexaenoic acid (DHA) incorporation in the brain and restored levels of dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT) and homovanillic acid (HVA) in the prefrontal cortex of allergic mice. Moreover, reduced levels of 5-HIAA, metabolite of serotonin, in intestines of allergic mice was also restored by the n-3 LCPUFA-enriched diet. Conclusion: In addition to its effects on the allergic skin response, n-3 LCPUFA restored allergy-induced deficits in social behaviour and in prefrontal dopamine and metabolite levels. Therefore, n-3 LCPUFA may exert its beneficial effect on behaviour via modulation of the dopaminergic system in the prefrontal cortex and may therefore be an interesting target in the use of dietary interventions for immune-mediated psychiatric disorders such as ASD
An Assessment of Inter‑Observer Agreement in Water Source Classification and Sanitary Risk Observations
O gênero Phacus (Euglenophyceae) em sistemas lênticos da Planície Costeira do Rio Grande do Sul, sul do Brasil
Novos e raros registros de Euglenophyta incolores na Planície Costeira do Rio Grande do Sul, Brasil
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