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Expanding the current tacit/explicit knowledge dichotomy encompassing situated and theoretical/normative knowledge : a phenomenological perspective.
No full textPurpose – This article introduces a model of knowledge creation in consciousness, the creation of explicit
knowledge in six forms and its register and organisation in documents.
Design/methodology/approach – Assuming the premise of three realms of reference to knowledge and two
forms of reference to entities, this article, through a phenomenological perspective, deduces a model of the
creation of knowledge in consciousness and the creation of explicit knowledge in six forms and its register in
documents.
Findings – Two basic types of knowledge are introduced: situated knowledge and theoretical/normative
knowledge. Considering three realms of reference of knowledge – the space–time realm, subjectivity realm and
linguistic realm – six general types of knowledge are deduced. Finally, three layers of knowledge organisation
are presented: classification and mapping documents, theoretical/normative documents and documents of
situations.
Practical implications – This article can contribute to the development of more efficient forms of creation of
explicit knowledge, its register in documents and the development of more efficient knowledge organisation
and management systems.
Originality/value – Relying on established perspectives of the realms where subjectivity is immersed, this
article discusses how knowledge is created in consciousness and registered in documents. It also presents a
novel perspective of types of knowledge through the combination of dimensions, realms of reference and forms
of reference to entities
Discontinuities in the transition from calculus to analysis : the notions of limit and continuity of a function at a point.
No full textNeste artigo, identificamos contradições lógicas entre duas diferentes abordagens das noções de limite e continuidade de função: a dos livros de Cálculo e a dos livros de Análise na Reta. Além de explicitar essas contradições, apontamos suas origens e comentamos brevemente possíveis consequências delas para o ensino e a aprendizagem, especialmente no que concerne aos alunos dos cursos de Matemática (Bacharelado e Licenciatura), os quais têm como obrigatória, em seus respectivos currículos, a disciplina Análise na Reta. A pertinência de considerar a potencialidade de um impacto negativo dessas contradições no processo de aprendizagem de alunos do Bacharelado e da Licenciatura em Matemática diz respeito ao fato de que normalmente a Análise Real é oferecida, nesses cursos, após cerca de dois anos de um processo de ensino de várias disciplinas em que se cristaliza, na mente dos estudantes, a abordagem dos livros de Cálculo acerca das noções de limite e continuidade de funções. Por fim, destacamos que este estudo oferece, ainda, potencial contribuição ao processo de desenvolvimento profissional do formador de professores na Licenciatura e dos professores de Cálculo em geral.In this article, we identify logical contradictions between two different approaches to the notions of limit and continuity of a real function: that of Calculus books and the one usually found in Real Analysis books. In addition to pointing out these contradictions, we indicate their origin and briefly comment on possible consequences for teaching and learning university mathematics, especially in courses which have Real Analysis as a mandatory part of their curricula. The negative impact of these contradictions on students’ learning may demand a particular concern in Mathematics undergraduate courses, where Real Analysis comes after a two-year teaching/learning process that crystallizes the Calculus books approach. The way it was conceived, this study might also contribute to the professional development of mathematics teacher educators and Calculus teachers in general
Avaliação dos mecanismos associados ao efeito anti-hipertensivo de uma formulação com extrato da folha de goiabeira (Psidium guajava L.) em um modelo de hipertensão sódio-dependente.
No full textPrograma de Pós-Graduação em Ciências Biológicas. Núcleo de Pesquisas em Ciências Biológicas, Pró-Reitoria de Pesquisa de Pós Graduação, Universidade Federal de Ouro Preto.A hipertensão é um importante problema de saúde pública que requer tratamento com
medicamentos. No entanto, muitos pacientes são resistentes aos tratamentos convencionais.
As plantas medicinais têm sido utilizadas como uma alternativa para o tratamento destes
indivíduos, e a goiabeira (Psidium guajava L.) é uma delas, cujas propriedades antihipertensivas já foram descritas. O objetivo deste estudo foi verificar se o extrato de folha de
goiabeira (PsE) é eficaz em reduzir a pressão arterial em ratos hipertensos, e se isso é
resultado da sua influência sobre a atividade simpática, absorção de sódio, citocinas
inflamatórias, biomarcadores do perfil redox e microbiota intestinal. Ratos foram alimentados
com uma dieta com excesso de sódio e, posteriormente, receberam PsE ou veículo por via
oral por 4 semanas. Os resultados mostraram que PsE atenuou a absorção de sódio, aumentou
a reatividade simpática lombar e alterou a microbiota intestinal. Além disso, houve aumento
de IL-10 após o tratamento com PsE, sem alterações em biomarcadores do perfil redox.
Conclui-se que o extrato está atenuando a resposta simpatoexcitatória e absorção de sódio
intestinal em ratos HS12W e parte destes efeitos podem estar associados com a alteração da
família Ruminococaceae e processo inflamatório.Hypertension is an important public health problem that requires drug treatment. However,
many patients are resistant to conventional treatments. Medicinal plants have been used as an
alternative for the treatment of these individuals, and the guava tree (Psidium guajava L.) is
one of them, whose antihypertensive properties have already been described. The aim of this
study was to verify whether guava leaf extract (PsE) is effective in reducing blood pressure in
hypertensive rats, and whether this is a result of its influence on sympathetic activity, sodium
absorption, inflammatory cytokines, profile biomarkers redox and intestinal microbiota. Rats
were fed an excess sodium diet and subsequently received PsE or vehicle orally for 4 weeks.
The results appreciated that PsE attenuated sodium absorption, increased lumbar sympathetic
reactivity and altered the intestinal microbiota. In addition, there was an increase in IL-10
after treatment with PsE, without changes in biomarkers of the redox profile. It is concluded
that the extract is attenuating the sympathoexcitatory response and intestinal sodium
absorption in HS12W rats and part of these effects may be associated with changes in the
Ruminococcaceae family and the inflammatory process
Multidimensional characteristics of sporting potential of young handball players.
No full textINTRODUÇÃO: A avaliação do potencial de jovens atletas é uma importante tarefa dos
treinadores. A tentativa de quantificar o “olho do treinador” tem sido um grande desafio para os
pesquisadores.
OBJETIVO: Comparar indicadores multidimensionais do talento esportivo em jovens
handebolistas classificados como alto e baixo potencial esportivo, de acordo com a opinião do
treinador.
MÉTODOS: Participaram 22 atletas de handebol de 15 a 17 anos de um Instituto Federal de
Ensino. O potencial esportivo foi avaliado pelo treinador da equipe, numa escala de um a cinco,
classificando os atletas em dois grupos: alto potencial (n=11) e baixo potencial (n=11). Foram
avaliados: experiência esportiva, massa corporal, estatura, altura sentado, comprimento de
mãos, envergadura, dobras cutâneas, velocidade, agilidade, preensão manual, salto vertical,
flexibilidade, resistência aeróbica; habilidades de coping, motivação, competência percebida,
nível socioeconômico, maturação biológica, drible e habilidades táticas.
RESULTADOS: Os handebolistas de alto potencial quando comparados aos de baixo potencial
foram mais velozes (p=0,05), mais ágeis (p=0,02) e mais fortes (p=0,02), eram mais experientes
(p=0,05), apresentaram maior competência percebida (p=0,01), competitividade (p=0,02) e
melhor desempenho no drible (p=0,05) e nas habilidades táticas (p=0,03).
CONCLUSÃO: Os handebolistas avaliados pelo treinador como alto potencial esportivo foram
aqueles que tiveram melhor desempenho físico-motor, maior nível de habilidades psicológicas,
técnicas e táticas quando comparados aos atletas de baixo potencial.BACKGROUND: Assessing the sporting potential of young athletes is an important task for
coaches. The attempt to quantify the “coach’s eye” has been a major challenge for researchers.
OBJECTIVE: The aim of this study was to compare multidimensional indicators of sporting talent
in young handball players classified as high and low sporting potential, according to the coach’s
opinion.
METHODS: 22 handball athletes aged 15 to 17 from a Federal Education Institute participated.
The sporting potential was evaluated by the team coach, on a scale from one to five, classifying
the athletes into two groups: high potential (n=11) and low potential (n=11). The following were
evaluated: sports experience, body mass, height, sitting height, hands length, wingspan, skinfolds,
speed, agility, handgrip, vertical jump, flexibility, aerobic resistance, coping skills, motivation,
perceived competence, socioeconomic status, biological maturation, dribbling and tactical skills.
RESULTS: High-potential handball players, when compared to low-potential ones, were faster
(p=0.05), more agile (p=0.02) and stronger (p=0.02), more experienced (p=0.05), showed greater
perceived competence (p=0.01), competitiveness (p=0.02) and better dribbling performance
(p=0.05) and tactical skills (p=0.03).
CONCLUSION: The handball players evaluated by the coach as having high sporting potential
were those who had better physical-motor performance, higher level of psychological, technical
and tactical skills when compared to low potential athletes
Optimizing SSVEP-based BCI training through Adversarial Generative Neural Networks.
No full textBrain-computer interfaces (BCIs) based on steady-state visually evoked potential (SSVEP) use brain activity to control external devices, with applications ranging from assistive technologies to gaming. Typically, BCI systems are developed using supervised learning techniques that require labelled brain signals. However, acquiring these labelled signals can be tiring and time-consuming, especially for subjects with disabilities. In this study, we evaluated the performance impact of using synthetic brain signals to train and calibrate an SSVEP-based BCI system. Specifically, we used generative adversarial networks (GANs) to synthesize brain signals with SSVEP information, considering cases with two and four visual stimuli. Four scenarios with different proportions of real vs. synthetic brain signals were evaluated: Scenario 1 (baseline) using only real data and Scenarios 2-4 with 10%, 20% and 30% of real data replaced by synthetic data, respectively. Our results reveal that synthetic data can be used to train the BCI without a performance loss across the tested scenarios when two visual stimuli are used and with an average performance reduction compared to baseline of 7% (Scenario 2), 10,3% (Scenario 3) and 9,3% (Scenario 4) for four stimuli. Furthermore, considering each recording has duration of 2 seconds, by replacing 30% of real data with synthetic data, there is an immediate time-saving of 48 s and 96 s in the cases with two and four visual stimuli, respectively. This trade-off between accuracy and efficiency has significant implications for improving the usability and accessibility of SSVEP-based BCI, especially for assistive applications
Obra de arte : Dasein e fenomenologia.
No full textPrograma de Pós-Graduação em Filosofia. Departamento de Filosofia, Instituto de Filosofia, Arte e Cultura, Universidade Federal de Ouro Preto.O presente trabalho tem por objetivo compreender o pensamento de Martin Heidegger
e sua visão da obra de arte a partir do ensaio A origem da obra de arte (1936), assim como o
desdobramento de seu pensamento em relação aos parâmetros de Ser e Tempo (1927). Para isso,
pretende-se evidenciar as bases para a reflexão ontológico-fenomenológica que se iniciam em
ST e se realizam no ensaio de 1936. O objetivo da pesquisa é contribuir para a viabilização de
acesso ao pensamento heideggeriano a respeito da temática do artístico.The present work aims to understand Martin Heidegger’s thought and his vision of the work of
art through the essay The origin of the work of art (1936), as well as the unfolding of his thought
compared to the parameters of Being and Time (1927). Thus, we intend to establish the basis
for the ontological-phenomenological reflection that takes place in the 1936 essay. This
research aimed to elucidate and make the Heideggerian thought about the thematic of the artistic
more accessible for readers
Roteamento de comboios de combustível para abastecimento de equipamentos de mina.
No full textPrograma de Pós-Graduação em Instrumentação, Controle e Automação de Processos de Mineração. Departamento de Engenharia de Controle e Automação, Escola de Minas, Universidade Federal de Ouro Preto.Em complexos mineradores de grande porte, os equipamentos em operação estado dispostos em
uma extensa região geográfica e alguns destes equipamentos possuem restrições de locomoção,
como escavadeiras, tratores e perfuratrizes. Por conta destas limitações, estes equipamentos
necessitam de abastecimento nos seus locais de operação, por meio de caminhões tanque com
infraestrutura de abastecimento, chamados comboios de combustível. Neste estudo, é tratado
o problema de roteamento destes comboios de combustível com o objetivo de minimizar a
maior rota. Para resolvê-lo em instâncias de pequeno porte, foi proposta uma formulação de
programação linear inteira mista. Para tratar instâncias de grande porte foi proposto um algoritmo
meta-heurístico baseado no Iterated Local Search, que utiliza um algoritmo, chamado
TPA, para a alocação e posicionamento de viagens. O algoritmo meta-heurístico foi validado
através de um estudo de caso real do Complexo de Carajás, coletado em maio de 2023, com 61
equipamentos de mina a serem abastecidos e 8 comboios de combustível. O algoritmo metaheurístico encontrou uma boa solução rapidamente, mostrando-se uma ferramenta valiosa para
apoio na tomada de decisão.In large-scale mining complexes, operational equipment is allocated across a vast geographic
region, and some of these equipment mobility restrictions as excavators, tractors, and drills. Due
to these limitations, these mining equipment require refueling at their operation sites through
fuel trucks equipped with refueling infrastructure, known as fuel convoys. This study addresses
the problem of routing these fuel convoys to minimize the longest route. To find a solution to this
problem, a mixed-integer linear programming formulation was proposed to address a simplified
version of the problem. To handle large instances, a metaheuristic algorithm based on Iterated
Local Search was proposed, along with a new algorithm for trip allocation and positioning.
These approaches were validated using a case study from Carajas Complex, collected in May ́
2023, involving up to 61 mining equipment and eight fuel convoys. The metaheuristic algorithm
quickly found a good solution, proving to be an efficient tool for decision-making
Neuroserpin : a potential biomarker for early-onset severe preeclampsia.
No full textPreeclampsia is a hypertensive disease of pregnancy associated with intense inflammatory and pro-coagulant
responses. Neuroserpin is a serine protease inhibitor that has been involved in neurological and immune pro-
cesses and has not yet been investigated in preeclampsia. Herein, we evaluated neuroserpin levels in association
with other inflammatory mediators (IL-17A, IL-33, and CXCL-16) during severe preeclampsia. The mediators’
plasma levels were measured by immunoassays in 24 pregnant women with severe preeclampsia (early pre-
eclampsia: N = 17, late preeclampsia: N = 7), 34 normotensive pregnant women, and 32 non-pregnant women.
In general, pregnancy was associated with higher levels of neuroserpin, IL-17A, IL-33, and CXCL-16 than the non-
pregnant state. However, this increase was attenuated in pregnancies complicated by severe preeclampsia.
Although neuroserpin levels did not differ between normotensive pregnant women and pregnant women with
severe preeclampsia, neuroserpin levels tended to be lower in early-onset than in late-onset severe preeclampsia.
There were positive correlations between neuroserpin and IL-17A, neuroserpin and CXCL-16, and IL-17A and
CXCL-16 levels in women with severe preeclampsia. In addition, although the risk for developing severe pre-
eclampsia was higher in older women in this study, maternal age did not significantly influence the mediators’
levels, nor their correlations in the preeclampsia group. In summary, our data suggest that neuroserpin might be
a potential biomarker for early-onset severe preeclampsia and, that the imbalance among neuroserpin, IL-17A,
IL-33, and CXCL-16 levels may be associated with the pathogenesis of preeclampsia, regardless of the
maternal age
Optically stimulated luminescence dating : applicability in rudaceous facies from alluvial fans in the Quadrilátero Ferrífero, Minas Gerais.
No full textEste artigo apresenta dados da luminescência opticamente estimulada de sedimentos rudáceos de leques aluviais da região do Quadrilátero Ferrífero. Tais dados foram obtidos através de 12 datações cujas amostras foram coletadas com um amostrador e alavanca específicos e eficientes para inserção e retirada dos tubos do pacote sedimentar. O objetivo desse trabalho é discutir as características da luminescência do quartzo presente em depósitos de leques aluviais e verificar se o método é eficiente em sedimentos de granulometria caracterizada por grânulos, seixos, calhaus e matacões. No que se refere a taxa de dose anual, o percentual de água foi definido levando-se em conta o histórico de cada amostra. Após estimativa da radiação cósmica, os valores obtidos entre 0,2328 e 0,2509 mGy/ano foram insignificantes com relação as concentrações de 232Th, 238U e 40K. Em todo ciclo de medição, para normalizar os sinais de LOE, foi administrada dose teste de 31,8 Gy na amostra do leque do Complexo Bonfim Meridional, 1,78 Gy na da fácies Gmm do leque 1 do Complexo Bonfim Setentrional e 2,67 Gy nas demais amostras. A eficácia da dose teste foi comprovada durante os testes de reciclagem, sempre entre 0,9 e 1,10, e de recuperação, inferiores a 5%, indicando completo fotoesvaziamento e ausência de transferência térmica significativa. Os valores da dispersão, entre 0 e 16%, e a ausência de bimodalidade nos gráficos de densidade indicam que os grãos estiveram expostos à luz solar por pelo menos 16 horas antes do soterramento, acarretando no seu fotoesvaziamento completo. Este estudo demonstra que depósitos rudáceos podem ser datados por LOE com eficiência.This paper presents data of the optically stimulated luminescence of rudaceous sediments from alluvial fans in the Quadrilátero Ferrífero region. Those data were obtained through the dating of 12 samples collected with a sampler and a lever that proved to be efficient for removing the metal tubes from the sedimentary package. This work aims to discuss the characteristics of the luminescence of the quartz present in deposits of alluvial fans and to check that the referred dating method is also efficient in deposits of granulometry mainly characterized by granules, cobbles, pebbles and boulders. Regarding the annual dose rate, the percentage of water was defined by considering the climatic period in which each sample was collected. After estimating the cosmic radiation, the values obtained between 0,2328 and 0,2509 mGy/year encompassed an insignificant percentage in relation to the concentrations of 232Th, 238U and 40K. During the acquisition of the equivalent dose, a test dose of 31,8 Gy was administered in the sample of alluvial fan of Bonfim Meridional Complex, 1,78 Gy in the sample of the Gmm facies of alluvial fan 1 in the Bonfim Setentrional Complex and 2,67 Gy in the other samples. The effectiveness of the test dose was verified during recycling tests, always between 0,9 and 1,10, and recovery tests, below 5%, indicating good bleaching and absence of significant thermal transfer. Moreover, the dispersion values obtained, between 0 and 16%, as well as the absence of bimodality in the density graphs, indicate that the grains were exposed to sunlight for at least 16 hours before the burial, resulting in their complete bleaching. This study demonstrates that rudaceous deposits can be efficiently dated by OSL