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Bolhas especulativas e toxicidade no mercado futuro de milho brasileiro
(Universidade Federal de São Carlos, 2020-09-03) Souza, Gabriela Beatriz de; Cruz Júnior, José César; https://lattes.cnpq.br/0086426315229286; https://lattes.cnpq.br/0012418931320572; https://orcid.org/0009-0005-2091-5405; Silva Júnior, Geraldo Edmundo; Capitani, Daniel Henrique Dario; https://lattes.cnpq.br/5138808982229139; https://lattes.cnpq.br/7108245336327043
Speculative bubbles and toxicity in the Brazilian corn market are presented as the object of research in this study. In the face of the continuous expansion in corn production in Brazil and in the world, speculators have found in the commodity futures markets an investment alternative that is unrelated to the traditional sectors of the financial market, causing a “financialization” of commodities. In view of this, this work proposed to analyze whether such movements caused speculative bubbles in the Brazilian corn futures market. For this purpose, the settlement prices of the contract with maturity in September 2019 were used, as it is the most liquid compared to the others, traded on the B3 futures and commodities exchange. The BSADF test was used to identify the moments when prices have moved away from their fundamental values. In addition, aiming to understand how the presence of informed agents cause an imbalance in the market, making the flow of business toxic, a metric based on turnover, the VPIN, was applied to intraday prices. To understand the origins of bubble formation in the corn futures market, a logit binomial model was estimated. A total of 25 days with presence of bubbles were identified in the period, concentrated in October 2018 and in the months of April and May 2019. In view of the low volume of negotiations, results for the VPIN were obtained only after the month of March. The results of the logit model indicate that the variables VPIN, risk and spread are determining factors in the emergence of rational bubbles that periodically collapse. Since the presence of bubbles combined with a toxic flow of orders reduces the efficiency of the future market in offering protection in times of high volatility, it is of great importance that agents, generally producers, can identify price disturbances and what reasons away from their fundamental values.
O processo de expansão urbana e seus impactos na Estação Ecológica de Ribeirão Preto, SP
(Universidade Federal de São Carlos, 2020-09-03) Abreu, Emanoele Lima; Saquy, Sammy Dutra; Fernandes, Pedro Henrique de Godoy; Jesus, Silvia Cristina de; Catojo, Adriana Maria Zalla; https://lattes.cnpq.br/1167798136607835; https://orcid.org/0000-0001-6177-1368
Embora os instrumentos normativos de planejamento urbano incluam a avaliação de impacto ambiental, há uma flexibilização dessas leis devido a interesses públicos e privados que têm objetivos contrários às políticas ambientais. No município de Ribeirão Preto, a produção de café e cana-de-açúcar tem contribuído para a fragmentação da vegetação nativa, reduzida a 6% da área municipal (4.200 ha). A Estação Ecológica de Ribeirão Preto (EERP) é o maior remanescente nativo (155 ha) e sofre pressões por estar localizada no meio urbano. Este trabalho investigou a pressão urbana na Zona de Amortecimento (ZA) e sua relação com as mudanças no Plano Diretor (PD) e leis complementares. Os mapas de cobertura da terra (2010 e 2017) também foram analisados com o objetivo de quantificar a conversão de florestas nativas para usos antrópicos, mostrando uma intensa expansão urbana na ZA no período analisado. Por outro lado, a legislação urbanística-ambiental municipal evoluiu, visto que a MP anterior (datada de 1995) abordou o meio ambiente de maneira específica mas foi modificada na lei de 2018, que tenta integrar o zoneamento urbano à zona de amortecimento a fim de tornar o uso do solo compatível com o Plano de Manejo da EERP.
Influência da adição de cério na resistência à corrosão e efeito de memória de forma em ligas Fe-Mn-Si-Cr-Ni-(Ce)
(Universidade Federal de São Carlos, 2020-09-03) Baroni, Luis Felipe Sverzut; Sordi, Vitor Luiz; https://lattes.cnpq.br/8364164402481940; Rovere, Carlos Alberto Della; https://lattes.cnpq.br/8141224513975606; https://lattes.cnpq.br/3337645782698117
The interest in scientific and technological development of Fe-Mn-Si-Cr-Ni shape memory alloys is increasing in the last years. The improvement of key properties of theses alloys should enable its use in different applications, such as prestressing concrete structures in civil engineering area. In this context, the present work assesses the cerium (Ce) addition to determine its possible benefits in enhancing both corrosion protection in alkaline media and shape memory effect (SME). The studied experimental alloys were subjected to 0.18%, 0.42% and 0.96% (wt%) of Ce addition, and results were compared to a standard Ce-free alloy. The characterization of such alloys reveals that Ce addition is responsible for a grain size reduction as well as the increase and morphological change in second phase particles. The discussion of the results correlates these microstructural modifications with electrochemical results and SME. Regarding corrosion properties, all samples presented similar passive behaviors in simulated pore solution in absence of chloride ions. When Cl- was added, the sample with 0.18% was the only one to maintain its passivity while other samples showed a major increase in passive corrosion density, indicating a worse stability of the passive film. Pit potential and EIS results showed that the addition of 0.18% of Ce was sufficient to enhance corrosion protection by both changing MnS inclusion morphology and increasing the surface film corrosion protection properties, although it was not high enough to promote oxide, sulfides and intermetallic particles that increases localized corrosion appearance. In terms of shape recovery ratio, an increase in samples with 0.18% and 0.42% of Ce was observed, although there was a reduction in sample with 0.96%. The reduction might be explained by the inhomogeneous microstructure due to the formation of coarse inclusion particles. Finally, the sample with 0.42% presented the best SME results.
Efeito do treinamento resistido sobre o coeficiente de controle de fluxo (FCC) da cadeia respiratória mitocondrial do músculo gastrocnêmio de ratas ovariectomizadas
(Universidade Federal de São Carlos, 2020-09-03) Scarlato, Gabriel Carlos Goulart; Shiguemoto, Gilberto Eiji; https://lattes.cnpq.br/9885031162656978; https://lattes.cnpq.br/8582739519903360
Introduction: Menopause is a marked naturalistic process of female aging, resulting from the progressive decrease in the production of the main ovarian sex hormones permanently. The drop in the production of ovarian estrogens has a negative effect on the striated skeletal muscle system, making women more susceptible to developing sarcopenia. In search of knowledge about the phenomena that occur in the post-menopausal period and their mechanisms of action, models of ovarian removal in rats (OVX) are widely used as an experimental model of menopause induction, effectively reproducing the deleterious effects observed in menopause. The number of studies that have investigated the effect on the functioning of the electron transport chain (CTE) and its relationship with ANT-1 gene expression in OVX rats is limited, as well as the effects of resistance training (TR) intervention in this context. Objective: This study aims to evaluate the effects of resistance training on the functioning of protein complexes in the respiratory chain during coupled and uncoupled breathing in the experimental model of ovariectomized rats, as well as the ANT-1 gene expression. Materials and Methods: In this study, 40 adult Wistar rats were randomly assigned to 4 experimental groups: INT-SED, INT-TR, OVX-SED and OVX-TR. Ovariectomy was performed in the 13th week of life of these animals. The RT model performed was the stair climbing, lasting 22 weeks. The body tissues of interest were analyzed after euthanasia, which occurred 48 hours after the last training session. Oxygen consumption (O2) and mitochondrial respiratory parameters were performed on tissue biopsy of the Gastrocnemius muscle using the High Resolution Respirometry technique (Oroboros®). The titrations to establish the Flow Control Coefficient (FCC) were performed at ANT, at the Phosphate Exchanger and at the ATP-Synthase. Results: Ovarietomy negatively affected the functioning efficiency of ANT-1 and ATP synthase in the sedentary group (OVX-SED). Regarding oxygen consumption, in the coupled respiratory state (E3) there was a significant decrease in the consumption of the OVX-SED group compared to the other 3 groups, an effect reversed by the resistance training adopted in the study; both trained groups obtained excellent FCC values and oxygen consumption at E3. Conclusion: We conclude that ovariectomy promotes a decrease in the efficiency of the FCC of ANT and ATP-Synthase of the gastrocnemius muscle of sedentary OVX rats, as well as promoting a decrease in oxygen consumption at E3. An RT program is potentially capable of preventing these harmful responses and maintaining mitochondrial function in physiological conditions.