A SIMPLE STOCHASTIC MODEL FOR THE SARS-COV-2 EPIDEMIC CURVE

An epidemic curve is a graphic depiction of the number of outbreak cases by date of illness onset, ordinarily constructed after the disease outbreak is over. However, a good estimate of the epidemic curve early in an outbreak would be invaluable to health care officials. On the other hand, from the end of February, the SARS-CoV-2 epidemic in Brazil seems to not following the Europe, or in particular, Italy or Spain. Even if less tests have been applied, there are less deaths occurring in Brazil than in both cited countries. However, due to the few applied tests, there is no certain planning on the real number of active cases. To estimate the number of future cases, epidemiologists make an educated guess as to how many people might become affected. We have proposed a simple fitting model using a simulated annealing technique, testing it with the South Korea data. We have tested and discussed the uncertainties of the model. We also have analyzed the trends in the confirmed cases using this model for the five most affected countries plus Brazil along several epidemic weeks

A PROPOSAL FOR A HYBRID POWER TRAIN FOR A TRUCK

Aiming at reducing the emission of pollutants from automotive vehicles, international commissions indicate, at each given period, a target of admissible values for these pollutants, to be implemented by the automakers. A case like the future implementation of EuroVII, from 2025, in European regions. In parallel to these conditions, there are many studies with the objective of seeking alternatives for the propulsion of these combustion vehicles, for example, the application of fully electric or hybrid vehicles. This article aims to develop and implement a mathematical model for a proposal for a hybrid engine, in a low-power truck, resulting in a small diesel engine, powering the vehicle's alternator and battery, generating the charging for use in a main electric motor, that is, to develop with a focus on energy conservation and the environment, with a reduction in the size of a combustion engine and its emissions

Generalized squeezing operators, bipartite Wigner functions and entanglement via Wehrl's entropy functionals

We introduce a new class of unitary transformations based on the su(1,1) Lie algebra that generalizes, for certain particular representations of its generators, well-known squeezing transformations in quantum optics. To illustrate our results, we focus on the two-mode bosonic representation and show how the parametric amplifier model can be modified in order to generate such a generalized squeezing operator. Furthermore, we obtain a general expression for the bipartite Wigner function which allows us to identify two distinct sources of entanglement, here labelled by dynamical and kinematical entanglement. We also establish a quantitative estimate of entanglement for bipartite systems through some basic definitions of entropy functionals in continuous phase-space representations.Comment: 16 page

Vaginal cytology as a tool to predict the time of ovulation in goats and sheep.

The detection of ovulation is of great importance for the use of reproductive biotechnologies in small ruminants. The ovulation is efficiently determined by ultrasound (US), equipment that is not always available and of relatively high cost. Therefore, the aim of this study was to identify the efficacy of vaginal cytology as a tool to determine the ovulation time in these species. The study was carried out during the non-breeding season, in Coronel Pacheco, Minas Gerais (21°35'S and 43°15'W). In sheep, the standard chosen was anucleated, but it had a high CV (23.7%), which led to non-high accuracy (66.7%). Therefore, PPV and NPV were 26% and 88%, respectively; the specificity was 45% and 64% at 24 h and 12 h before ovulation respectively; and finally, the sensitivity at the moment of ovulation was 55%. It can be concluded that the vaginal cytology may be an efficient tool to determine the moment of ovulation in goats, however it is less accurate in sheep

Adenosine A2A receptor modulation of hippocampal CA3-CA1 synapse plasticity during associative learning in behaving mice

© 2009 Nature Publishing Group All rights reservedPrevious in vitro studies have characterized the electrophysiological and molecular signaling pathways of adenosine tonic modulation on long-lasting synaptic plasticity events, particularly for hippocampal long-term potentiation(LTP). However, it remains to be elucidated whether the long-term changes produced by endogenous adenosine in the efficiency of synapses are related to those required for learning and memory formation. Our goal was to understand how endogenous activation of adenosine excitatory A2A receptors modulates the associative learning evolution in conscious behaving mice. We have studied here the effects of the application of a highly selective A2A receptor antagonist, SCH58261, upon a well-known associative learning paradigm - classical eyeblink conditioning. We used a trace paradigm, with a tone as the conditioned stimulus (CS) and an electric shock presented to the supraorbital nerve as the unconditioned stimulus(US). A single electrical pulse was presented to the Schaffer collateral–commissural pathway to evoke field EPSPs (fEPSPs) in the pyramidal CA1 area during the CS–US interval. In vehicle-injected animals, there was a progressive increase in the percentage of conditioning responses (CRs) and in the slope of fEPSPs through conditioning sessions, an effect that was completely prevented (and lost) in SCH58261 (0.5 mg/kg, i.p.)-injected animals. Moreover, experimentally evoked LTP was impaired in SCH58261- injected mice. In conclusion, the endogenous activation of adenosine A2A receptors plays a pivotal effect on the associative learning process and its relevant hippocampal circuits, including activity-dependent changes at the CA3-CA1 synapse.This study was supported by grants from the Spanish Ministry of Education and Research (BFU2005-01024 and BFU2005-02512), Spanish Junta de Andalucía (BIO-122 and CVI-02487), and the Fundación Conocimiento y Cultura of the Pablo de Olavide University (Seville, Spain).B. Fontinha was in receipt of a studentship from a project grant (POCI/SAU-NEU/56332/2004) supported by Fundação para a Ciência e Tecnologia (FCT, Portugal), and of an STSM from Cost B30 concerted action of the EU

Cenário histórico da transferência de embriões de caprinos no Brasil: relatos técnicos científicos.

Resumo: A caprinocultura é uma atividade relevante na pecuária brasileira, de grande importância em todo mundo e o uso de biotecnologias da reprodução pode contribuir para aumentar a eficiência produtiva e reprodutiva dos rebanhos. As técnicas de superovulação (SOV) e transferência de embriões (TE) são utilizadas na multiplicação de material genético superior nessa espécie, porém, a carência de informações estatísticas limita a estimativa do impacto potencial das mesmas. Diante disso, o objetivo do presente estudo foi realizar um levantamento de trabalhos científicos relacionados à produção de embriões de caprinos produzidos no Brasil entre os anos de 1985 e 2018 e identificar tendências no desenvolvimento dessa biotecnologia no país. Observa-se que, no período avaliado, havia grupos de pesquisa trabalhando ativamente no desenvolvimento da produção e transferência de embriões em caprinos no Brasil preferencialmente com raças leiteiras e com coletas de embriões pela via transcervical. Espera-se com este tipo de levantamento contribuir com o diagnóstico da atividade Brasil. [Historical scenario of the goat embryo transfer in Brazil: scientific technical reports].Edição dos resumos do XXIII Congresso Brasileiro de Reprodução Animal, Gramado, RS, Brasil, 15 a 17 de maio 2019

Avaliação das percepções dos discentes EJA em relação aos docentes e a vivência no âmbito escolar/ Evaluation of the perceptions of the EJA discents in relation to teachers and experience school scope

As relações interpessoais entre discentes e docentes, na modalidade EJA, são necessárias e fundamentais para que a aprendizagem aconteça. De modo geral, esta pesquisa tem como objetivo: avaliar as percepções dos discentes EJA em relação aos docentes quanto às contribuições da aprendizagem e à vivência no âmbito escolar. E como objetivos específicos: analisar a vivência dos discentes EJA com todos que compõem a escola; e, delinear as considerações expostas pelos discentes EJA em analogia a (in)disciplina e a vivência familiar. Este estudo pauta-se na problemática: como os discentes EJA avaliam o trabalho docente em sua vivência escolar? Hipoteticamente, verifica-se que os docentes fomentam uma vivência escolar agradável e colaborativa com os discentes, de modo que estes entendam que a educação é uma porta de acesso a melhorias, principalmente na vida profissional e emocional. Este artigo fundamenta-se na LDB nº 9.394/96 e nos pressupostos teóricos de Zampin (2017), Silva (2014), Silva e Moura (2013), Martins e Silva (2011) e Cury (2004). Em termos estruturais, iniciou-se por meio do levantamento bibliográfico, tendo como metodologia exploratória descritiva e abordagem quantitativa e qualitativa, mediante pesquisa de campo e levantamento de dados por questionário semiestruturado que será respondido por 23 discentes que estudam em uma escola pública municipal localizada no interior do Estado de Pernambuco. Diante do que foi apurado, percebe-se que os discentes EJA sentem-se acolhidos pelos docentes, e estes sempre procuram trabalhar de forma que a aprendizagem significativa aconteça.