405 research outputs found
La historia de la matemática en el diseño de e-comics y recursos hipermedia
La historieta es uno de los medios de comunicación más extendidos entre todas las edades y es uno de los recursos comunicativos en continua evolución que más público tiene. Si a ello sumamos el fuerte impacto que ha producido las TIC en estos medios, (concepto de hipermedia), desarrollado un nuevo concepto de historietas, las historietas digitales, no es de dudar entonces, que tenemos un nuevo aliado que debemos llevarlo al aula. A esto hay que sumarle la serie de programas libres tale como Pixton, Powtoon, PowerPoint, etc., para diseñar e-comics con aspectos hipermediales como profesionales. Flores (2012) destaca que si somos capaces de crear un mensaje que rompa las expectativas estaremos introduciendo el mensaje matemático sin tener esa lectura amarga que generalmente se asocia a la clase de matemática
Isolation and prebiotic activity of inulin-type fructan extracted from Pfaffia glomerata (Spreng) Pedersen roots
AbstractPfaffia glomerata (Amaranthaceae) is popularly known as “Brazilian ginseng.” Previous studies have shown that fructose is the major carbohydrate component present in its roots. Inulin-type fructans, polymers of fructose, are the most widespread and researched prebiotics. Here, we isolated and chemically characterized inulin extracted from P. glomerata roots and investigated its potential prebiotic effect. Fructans were isolated and their structures were determined using colorimetric, chromatography, polarimetry, and spectroscopic analysis. The degree of polymerization (DP) was determined, and an in vitro prebiotic test was performed. The structure of inulin was confirmed by chromatography and spectroscopic analysis and through comparison with existing data. Representatives from the genera Lactobacillus and Bifidobacterium utilized inulin from P. glomerata, because growth was significantly stimulated, while this ability is strain specific. The results indicated that inulin extracted from P. glomerata roots represents a promising new source of inulin-type prebiotics
Estudo químico do chá de partes aéreas de amor-crescido (Portulaca pilosa L.) / Chemical study of love-grown aerial parts tea (Portulaca pilosa L.)
Plantas medicinais são consumidas em formas de chás pelo ser humana desde tempos remotos, nas mais diversas civilizações. Um chá de determinada planta medicinal pode ser útil no combate aos males que afligem a população, sendo, muitas vezes, o único recurso terapêutico disponível, principalmente para os integrantes das classes menos favorecidas da população, porém pode apresentar também algum malefício ao seu consumidor. Esse consumo sempre se baseou no conhecimento empírico das pessoas, sendo ainda escassos trabalhos científicos que colaborem com estudos sobre suas propriedades químicas, e, em especial, teores de metais em chás. Neste trabalho, teores dos elementos minerais Al, Ba, Ca, K, Mg, Mn, Cr, Cu, Fe, Ni, Sr e Zn foram analisados em amostras de chás das partes aéreas da espécie amor-crescido (Portulaca pilosa L.), coletadas em períodos pluviométricos diferentes. As concentrações destes minerais foram determinadas via espectrometria de emissão ótica por plasma acoplado indutivamente (ICP OES). A composição mineral do chá nos dois períodos analisados (chuvoso e seco) apresentaram valores dentro dos limites permitidos para o consumo humano, a partir da ingestão de no máximo uma xícara de chá de 200 mL por dia, levando-se em consideração fatores dietéticos e a biodisponibilidade destes minerais em cada organismo
Investigation on the Anticonvulsant Potential of Luteolin and Micronized Luteolin in Adult Zebrafish (Danio rerio)
Epilepsy affects around 50 million people worldwide, and an important number of patients (30%) fail to respond to any available antiepileptic drug. Previous studies have shown that luteolin presents a promising potential as an anticonvulsant. On the other hand, different studies showed that luteolin does not promote anticonvulsant effects. Therefore, there is a lack of consensus about the use of luteolin for seizure control. Luteolin low bioavailability could be a limiting factor to obtain better results. Attractively, micronization technology has been applied to improve flavonoids bioavailability. Thus, the present study aimed to investigate the effects of luteolin on its raw form and micronized luteolin in a PTZ-induced seizure model in adult zebrafish (Danio rerio). Our results demonstrate that luteolin and micronized luteolin did not block PTZ-induced seizures in adult zebrafish. Also, luteolin and micronized luteolin did not provoke behavioral changes. Finally, our results show that 24 h after seizure occurrence, no changes were detected for p70S6Kb, interleukin 1β, and caspase-3 transcript levels. Altogether, we failed to observe an anticonvulsant potential of luteolin in adult zebrafish, even in its micronized form. However, we recommend new studies to investigate luteolin benefits in epilepsy.Fil: Garbinato, Cristiane. No especifíca;Fil: Alves Lima Rezende, Cássia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Schneider, Sabrina Ester. No especifíca;Fil: Pedroso, Jefferson. No especifíca;Fil: dos Santos, Aline E.. Universidade Federal de Santa Catarina; BrasilFil: Petry, Fernanda. No especifíca;Fil: Aguiar, Gean Pablo S.. No especifíca;Fil: Girardi Müller, Liz. No especifíca;Fil: Lanza, Marcelo. Universidade Federal de Santa Catarina; BrasilFil: Piato, Angelo. Universidade Federal do Rio Grande do Sul; BrasilFil: Vladimir Oliveira, J.. Universidade Federal de Santa Catarina; BrasilFil: Siebel, Anna Maria. No especifíca
Obtenção de biodiesel por transesterificação em dois estágios e sua caracterização por cromatografia gasosa: óleos e gorduras em laboratório de química orgânica
Methanolic transesterification of oils and fats was carried out in a two steps procedure, under basic and acidic catalysis. Palm, soybean, canola, corn, rice, grapeseed, sunflower, peanut, pequi and olive oils, besides tallow and lard were used as feedstock. Specific gravity, relative viscosity, thin layer chromatography and gas chromatography were used to characterize the biodiesel. Biodiesel was obtained in high yield and purity. Results were used to discuss the following key-concepts: 1 - triglycerides, composition and properties; 2 - nucleophilic acyl substitution under basic and acid conditions, 3 - thin layer chromatography, 4 - gas chromatography and its quantitative methods
Universidad comprometida : Rescatando PYMES durante la crisis de Covid-19
Efeitos econômicos das políticas de isolamento da pandemia da Covid-19 levaram pequenas e médias empresas (PMEs) a buscar alternativas para sobreviver. Em cenários de crise, uma universidade engajada tem um papel importante ao abordar não apenas questões de saúde, mas também problemas sociais e econômicos em contextos regionais. Neste artigo, um projeto de universidade-comunidade é analisado com o intuito de apontar os elementos necessários para promover uma universidade regional engajada: a Rede de Assessoria SOS-PME, originalmente projetada para apoiar PMEs durante a crise. Uma universidade engajada entrega conhecimento para a sociedade, além de educação e pesquisa. Como resultado, identificam-se elementos para promover a terceira missão da universidade engajada – engajamento social: equipe engajada, multidisciplinaridade, gerenciamento de projetos, agilidade, alianças, estratégia de comunicação, e suporte e reputação da instituiçãoThe economic effects of isolation policies resulting from the COVID-19 pandemic have led small and medium-sized enterprises (SMEs) to look for alternatives to survive. Within this crisis scenario, an engaged university has an important role to play in a regional context in addressing not only health issues, but also any resultant social and economic problems. An engaged university needs to take actions that go beyond its traditional missions of education and research - it has to deliver knowledge to society. This paper analyzes a university-community project in Brazil to identify the necessary elements that help promote a regionally- -engaged university: the SOS-PME Advisory Network project, which was originally designed to assist SMEs during the crisis. As a result, we identified elements necessary for promoting the university’s third mission - social engagement by way of a university-community project: an engaged team, multidisciplinarity, project management, agility, alliances, a communication strategy, institutional support, and reputation.Los efectos económicos de las políticas de aislamiento de la pandemia de COVID-19 han llevado a las pequeñas y medianas empresas (PYMEs) a buscar alternativas para sobrevivir. En un escenario de crisis, una universidad comprometida desempeña un papel importante para abordar, no solo los problemas de salud, sino también los problemas sociales y económicos en un contexto regional. En este artículo, se analiza un proyecto universidad-comunidad con la intención de señalar los elementos necesarios para promover una universidad regional comprometida: la Red de Asesoramiento SOS-PME, originalmente diseñado para apoyar a las PYMEs durante la crisis. Una universidad comprometida necesita llevar adelante acciones más allá de sus misiones tradicionales de educación e investigación; debe transferir conocimiento a la sociedad. Como resultado, identificamos cuáles son los elementos necesarios para promover la tercera misión de una universidad con compromiso social: equipo comprometido, gestión de proyectos, agilidad, alianzas, multidisciplinariedad, estrategia de comunicación y apoyo, y reputación de la institución
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Produção e composição bromatológica de forrageiras em sistema de integração lavoura-pecuária em diferentes épocas de semeadura
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