2,644 research outputs found
Understanding the Greenspan standard
Greenspan, Alan ; Monetary policy ; Business cycles ; Economic conditions
Understanding the Greenspan Standard
Alan Greenspan was sworn in as Chairman of the Board of Governors of the Federal Reserve System almost exactly 18 years ago. At the time, the Reagan administration was being rocked by the Iran-contra scandal. The Berlin Wall was standing tall while, in the Soviet Union, Mikhail Gorbachev had just presented proposals for perestroika. The stock market had not crashed since 1929 and, probably by coincidence, Prozac had just been released on the market. The New York Mets, having won the 1986 World Series, were the reigning champions of major league baseball. A lot can change in 18 years.
METODOLOGIAS ATIVAS NO ENSINO SUPERIOR: UM MAPEAMENTO SISTEMÁTICO NO CONTEXTO DOS CURSOS DE ENGENHARIA
Active learning is all pedagogical alternatives that place the focus of learning on the students. With the mediation of competent teachers, the students learn by discovery, by investigation, and by problems. Such methodologies commonly promote more content retention and comprehension once the students are engaged in activities, whether through research, group collaborations, discussion, and problem solving. This work aimed to verify the temporal evolution of active learning methods in higher education Engineering courses, based on a systematic mapping of the literature. We observed which are the main researchers in this field, their geographic location and which methodologies are preferred in the context of these courses. From the results, we observe a growth of scientific publications on active learning methodologies and Engineering Education, especially in the last five years of the period analysed (between 2015 and 2020). We also see researchs on this field in all continents, with a predominance of studies led by American and European researchers. In the mapped studies, the inverted classroom and problem-based learning were the most identified methodologies. It demonstrates a concern of teachers in this area to promote activities with high involvement, which allow the development of personal and professional skills and competencies, even during their training period.Las metodologías activas pueden entenderse como alternativas pedagógicas que ponen el foco del aprendizaje en los alumnos. Con la mediación de profesores competentes, los alumnos aprenden a partir del descubrimiento, la investigación y los problemas. Estas metodologías suelen promover una mayor retención y comprensión de los contenidos enseñados, ya que el alumno participa en actividades, ya sea a través de la investigación, la colaboración en grupo, el debate y la resolución de problemas. Este trabajo tuvo como objetivo verificar la evolución temporal del uso de las metodologías activas en el contexto de los cursos de educación superior en Ingeniería, a partir de un mapeo sistemático de la literatura. A partir de un protocolo de investigación debidamente definido, se buscó verificar cuáles son los principales investigadores en esta área, su ubicación geográfica y cuáles son las metodologías preferidas en el contexto de estos cursos. A partir de los resultados, se pudo observar que el crecimiento en el número de publicaciones científicas sobre metodologías activas en el contexto de la Enseñanza de la Ingeniería, especialmente en los últimos cinco años del período analizado (entre 2015 y 2020). Se puede observar la realización de investigaciones en este contexto en todos los continentes, con un predominio de estudios dirigidos por investigadores americanos y europeos. En los estudios mapeados, el flipped classroom y el aprendizaje basado en problemas fueron las metodologías más identificadas. Esto demuestra una mayor preocupación entre los profesores de la zona por promover actividades con alta implicación que permitan el desarrollo de habilidades y competencias personales y profesionales durante el periodo de formación.As metodologias ativas podem ser entendidas como alternativas pedagógicas que colocam o foco do aprendizado nos estudantes. Com mediação de docentes competentes, os alunos aprendem a partir da descoberta, da investigação e por problemas. Tais metodologias comumente promovem uma maior retenção e compreensão de contéudos ensinados, uma vez que o aprendiz se encontra engajado nas atividades, seja por meio de pesquisa, colaborações em grupo, discussão e resolução de problemas. Este trabalho teve como objetivo verificar a evolução temporal do uso de metodologias ativas, no contexto dos cursos superiores de Engenharia, a partir de um mapeamento sistemático da literatura. A partir de um protocolo de pesquisa devidamente definido, buscou-se verificar quais os principais pesquisadores desta área, sua localização geográfica e quais as metodologias preferidas no contexto destes cursos. A partir dos resultados, foi possível observar que o crescimento do número de publicações científicas sobre metodologias ativas no contexto da Educação em Engenharia, em especial nos últimos cinco anos do período analisado (entre 2015 e 2020). Pode-se notar a realização de pesquisas neste contexto em todos os continentes, com predomínio de estudos liderados por pesquisadores americanos e europeus. Nos estudos mapeados, a sala de aula invertida e a aprendizagem baseada em problemas foram as metodologias mais identificadas. Isso demostra uma maior preocupação dos professores da área em promover atividades com elevado envolvimento, que permitam o desenvolvimento de habilidades e competências pessoais e profissionais, ainda no período de formação
Síntese, caracterização e uso de nanodispositivo magnético para remoção de poluentes químicos e microbiológicos de ambientes aquáticos
Magnetite (Fe3O4) is a spinel-type iron oxide of the general formula MFe2O4, where M may be a divalent or trivalent cations. Such compounds may be combined with polymers to give rise composite materials. An interesting polymer that can be combined with magnetite is the water-soluble carbomer, carboxylic groups rich called carbopol. In the present study, we produce in a pilot scale, a nanodevice resulting from the association of the magnetite with different carbopol polymer concentrations, obtaining pure Fe3O4 (C0), Fe3O4/Carbopol-0.1% (C1), Fe3O4/Carbopol-0.25% (C2) and Fe3O4/Carbopol-0.5% (C3), for directed magnetically decontamination of chemical and microbiological pollutants in aquatic environments. FTIR and DRX data confirmed the structure of magnetite (C0). In addition, the chemical bonding of carbopol with magnetite was confirmed, since after exhaustive washing of the compounds, the spectra showed bands of both magnetite and carbopol. The magneto-rheology assays showed that samples C1 and C2 were dragged by the applied magnetic field. Methylene Blue (AM) adsorption studies showed adsorption capacity in the following order: C3>C2>C1>C0. Also, experiments to evaluate the ability to remove microorganisms from water using Escherichia coli strain ATCC 25922 showed that the removal capacity was the inverse of the adsorption capacity: C0>C1>C2≈C3. These data suggest that pure magnetite has a greater ability to eliminate microorganisms from water, probably due to its catalytic effect on the bacterial cell wall, which is minimized by polymer coating. The cell viability assay with the culture of murine macrophages J774A.1showed tolerable levels of cytotoxicity at low concentrations, for all compounds (except C0, which showed cell viability below 70% at all concentrations) and cell viability levels below 70% for all compounds in concentrations greater than 400 µg/mL. A significant ability of C1 to remove microorganisms in water was observed, suggesting that this material can be used simultaneously to eliminate chemical and microbiological pollutants in an aqueous environment.A magnetita (Fe3O4) é um óxido de ferro do tipo espinélio de fórmula geral MFe2O4, onde M pode ser um cátion divalente ou trivalente. Esses compostos podem ser combinados com polímeros dando origem a compósitos. Um interessante polímero para ser combinado com a magnetita é o carbômero sintético hidrossolúvel, rico em carboxilatos, denominado carbopol. No presente trabalho, produzimos em escala piloto, nanodispositivos resultantes da associação da magnetita com diferentes concentrações de carbopol, obtendo os compostos Fe3O4 pura (C0), Fe3O4/Carbopol0,1% (C1), Fe3O4/Carbopol-0,25% (C2) e Fe3O4/Carbopol-0,5% (C3), objetivando a descontaminação magneticamente dirigida de poluentes químicos e microbiológicos em ambientes aquáticos. Os dados de FTIR e DRX confirmaram a estrutura da magnetita (C0). Além disso, a vinculação química do carbopol com a magnetita foi confirmada, uma vez que após exaustiva lavagem dos compostos, os espectros mostraram bandas tanto do Fe3O4 quanto do carbopol. Os ensaios de magnetoreologia mostraram que as amostras C1 e C2 sofreram arraste na presença de campo magnético. Os estudos de adsorção de Azul de Metileno (AM) mostraram capacidade de adsorção na seguinte ordem: C3 > C2 > C1 > C0. Adicionalmente, os experimentos de avaliação da habilidade de eliminação de micro-organismos em água, usando como modelo a cepa ATCC 25922 de Escherichia coli, mostraram que a capacidade de remoção foi o inverso da capacidade de adsorção: C0 > C1 > C2 ≈ C3. Os dados sugerem que a magnetita pura tem uma maior capacidade de eliminar microorganismos de água, provavelmente devido ao seu efeito catalítico sobre a parede celular bacteriana, que é minimizado pelo recobrimento com o polímero. O ensaio de viabilidade celular com cultura de macrófagos murinos J774A.1 mostrou níveis toleráveis de citotoxicidade em baixas concentrações, para todos os compostos (exceto C0, que apresentou viabilidade celular inferior a 70% em todas as concentrações) e níveis de viabilidade inferiores a 70% para todos os compostos em concentrações maiores que 400 µg/mL. Como C1 apresentou baixa toxicidade e significativa capacidade em remover micro-organismos e matéria inorgânica em água, associada à sua resposta magnética, sugere-se que este material possa ser simultaneamente usado como agente de descontaminação magneticamente dirigido
Monotongação: um fenômeno fonético-fonológico na variável.
This work has as main objective to propose activities about the phonological-phonological phenomenon of monotongation, that can help the teachers and students in the writing of the diphthongs that can monotongar. The phonetic process of monotongation, by nature, occurs by transforming the encounter of a vowel, followed by a semivowel or glide (decreasing diphthong) on the same syllable, in a simple vowel. Thus, the work will bring activities aimed at directing teachers and students around the phenomenon of monotongation in the writing of Brazilian Portuguese, allowing reflections around the various situations of use of language variants applied in the use of language in daily life. For this, the research starts from brief reflections of the studies of Variationist Sociolinguistics, having as central point the eminent figure of this subject, the student Labov. Then, we will take a look at the phenomenon of monotongation, from the works of Câmara Jr (2004); Time (2009); Coelho (2010) and Machado (2012), and finally, according to the presented theory, we will carry out a series of activities, aiming at a didactic and methodological understanding of the theme. The role of the activities proposed to ratify the phenomenon of monotongation in writing and became available as a source of research and references, to be used in another possible research.Este trabalho tem por objetivo principal propor atividades acerca do fenômeno fonético-fonológico da monotongação, que possam auxiliar aos docentes e discentes na escrita dos ditongos que podem monotongar. O processo fonético da monotongação, por natureza, ocorre através da transformação do encontro de uma vogal, seguida de uma semivogal ou glide (ditongo decrescente) na mesma sílaba, em vogal simples. Diante disso, o trabalho trará atividades voltadas a direcionar os docentes e discentes em torno do fenômeno da monotongação na escrita do português brasileiro, possibilitando reflexões em torno das diversas situações de uso de variantes linguísticas aplicadas no uso da língua no cotidiano. Para tanto, a pesquisa parte de breves reflexões dos estudos da Sociolinguística Variacionista, tendo como ponto central a figura eminente desse tema, o estudioso Labov. Em seguida, traçaremos um olhar sobre o fenômeno da monotongação, a partir dos trabalhos de Câmara Jr (2004); Hora (2009); Coelho (2010) e Machado (2012), e por fim, de acordo com a teoria apresentada, efetivaremos uma série de atividades, visando uma compreensão didática e metodológica do tema. O rol das atividades propostas para ratificar o fenômeno da monotongação na escrita e ficaram disponíveis como fonte de pesquisa e referências, para serem utilizadas em outra eventual pesquisa
Granulosa cell tumor associated with occult hyperadrenocorticism in a Yorkshire Terrier bitch
Background: Hyperadrenocorticism (HAC), is considered a set of symptoms due to excessive exposure to cortisol. Naturally occurring HAC is most often related to pituitary tumors (pituitary-dependent HAC - PDH). Occult HAC, is referred as a clinical picture highly consistent with HAC; however, routine screening tests are negative. In addition, one or more steroids are elevated following administration of adrenocorticotrophic hormone (ACTH). Ovarian granulosa cell tumors, can produce steroids leading to paraneoplastic syndromes. The objective of this study was to report an unpublished case of ovarian granulosa cell tumor associated with occult hyperadrenocorticism in a Yorkshire Terrier. Case: A 13-year-old intact female dog, Yorkshire Terrier, was brought for consultation with slight weight loss, polyuria, polydipsia, irregular estrous cycles, increased abdominal volume and thin coat. On physical examination the animal was gasping and presented severe periodontal disease, bulging abdomen, alopecia and skin hyperpigmentation. Complete blood count presented no changes; however, serum biochemistry evaluation highlighted hyperalbuminemia, hypertriglyceridemia, alkaline phosphatase increased activity, and urinary specific gravity and creatinine below reference values. On abdominal ultrasonography left adrenal gland measured 2.08 cm x 1.08 cm and the right adrenal gland measured 2.11 cm x 0.84 cm, indicating bilateral adrenomegaly compatible with PDH. In the hypogastric abdomen, a large heterogeneous hypoechogenic mass was also observed, with areas of cystic cavities, measuring 5.80 cm x 7.30 cm A low dose dexamethasone suppression test (LDDST) was performed, due to PDH suspicion. The test did not confirm HAC, suspecting, then, to be a case of occult/atypical HAC. Due to the strong clinical suspicion, and owner financial problems for further investigated occult HAC, trilostane treatment was initiated. Approximately one month after starting treatment, an ACTH stimulation test (AST) for cortisol and 17-hydroxyprogesterone (17-OHP) determination was performed, revealing high values for both hormones. Exploratory laparotomy was indicated due to the tumor image on hypogastric region visualized on abdominal ultrasonography. A cranial pole mass of the left ovary measuring 8.5 x 7.0 x 4.5 cm, of friable consistency and brownish color, was removed through ovariohysterectomy. A granulosa cell tumor on left ovary, as well as leiomyoma and cystic endometrial hyperplasia in the uterus, became clear through histopathological examination. Trilostane treatment was sustained after surgery. Few weeks later, the patient presented a clinical picture suggestive of hypoadrenocorticism, associated with a low sodium:potassium ratio (25:1), and AST results (basal and post-ACTH cortisol) below reference range, confirming Addisonian´ crises. The patient deceives within two days Discussion: Granulosa cell tumors can produce estrogen and progesterone, as well as other steroids, leading to paraneoplastic syndromes with peculiar clinical presentations. Steroids transport in plasma occurs via specific carrier proteins. Increased production of other steroid hormones may result in higher concentration of free cortisol, thus leading to clinical manifestations of hypercortisolism. As 17-OHP is one of the precursors in cortisol synthesis and has been shown elevated on AST, it can be assumed that altered steroid hormone levels due to the granulosa cell tumor interfered on cortisol biodisponibility, leading to HAC signs. Dexamethasone suppression test results indicated that pituitary-adrenal axis was responsive to negative feedback. The Addisonian crises after tumor removal indicate that the main source for systemic excessive cortisol effects was the eminent steroid secretion by the granulosa cell tumor
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