Perron-Frobenius operators and the Klein-Gordon equation

We study the non-uniqueness sets for solutions to the Klein-Gordon equation in 1 space dimension, for solutions whose Fourier transform is a finite complex measure absolutely continuous with respect to arc length. We show that generally, in the non-unique case for lattice-crosses, the space of solutions that vanish there is infinite-dimensional.Comment: 27 page

Understanding the Radio Emission from ϵ\epsilon Eridani

Some solar-type stars are known to present faint, time-variable radio continuum emission whose nature is not clearly established. We report on Jansky Very Large Array observations of the nearby star $\epsilon$ Eridani at 10.0 and 33.0 GHz. We find that this star has flux density variations on scales down to days, hours and minutes. On 2020 Apr 15 it exhibited a radio pulse at 10.0 GHz with a total duration of about 20 minutes and a peak four times larger than the plateau of 40 $\mu$Jy present in that epoch. We were able to model the time behavior of this radio pulse in terms of the radiation from shocks ramming into the stellar wind. Such shocks can be produced by the wind interaction of violently expanding gas heated suddenly by energetic electrons from a stellar flare, similar to the observed solar flares. Because of the large temperature needed in the working surface to produce the observed emission, this has to be non thermal. It could be gyrosynchrotron or synchrotron emission. Unfortunately, the spectral index or polarization measurements from the radio pulse do not have enough signal-to-noise ratio to determine its nature.Comment: 7 pages, 4 figures. To appear in Astronomy & Astrophysic

Hydrodynamical Models of Outflow Collimation in YSOs

We explore the physics of time-dependent hydrodynamic collimation of jets from Young Stellar Objects (YSOs). Using parameters appropriate to YSOs we have carried out high resolution hydrodynamic simulations modeling the interaction of a central wind with an environment characterized by a moderate opening angle toroidal density distribution. The results show that the the wind/environment interaction produces strongly collimated supersonic jets. The jet is composed of shocked wind gas. Using analytical models of wind blown bubble evolution we show that the scenario studied here should be applicable to YSOs and can, in principle, initiate collimation on the correct scales (R ~ 100 AU). The simulations reveal a number of time-dependent non-linear features not anticipated in previous analytical studies including: a prolate wind shock; a chimney of cold swept-up ambient material dragged into the bubble cavity; a plug of dense material between the jet and bow shocks. We find that the collimation of the jet occurs through both de Laval nozzles and focusing of the wind via the prolate wind shock. Using an analytical model for shock focusing we demonstrate that a prolate wind shock can, by itself, produce highly collimated supersonic jets.Comment: Accepted by ApJ, 31 pages with 12 figures (3 JPEG's) now included, using aasms.sty, Also available in postscript via a gzipped tar file at ftp://s1.msi.umn.edu/pub/afrank/SFIC1/SFIC.tar.g

Virtual Learning During the COVID-19 Pandemic: The Opening for the Implementation of a Blended Learning Modality in the Chemistry Class at High School Level

The pandemic caused by the SARS-COV2 virus, known as COVID-19 brought with it a series of challenges for educational and teaching institutions, since, from one moment to the next, the need for a massive migration from face-to-face education to online education, using educational technological tools, however, is considered that it is necessary to restructure teaching and implement a blenden learning model, which is characterized by the integration of various pedagogical and didactic resources in face-to-face and virtual environments to achieve meaningful learning through the construction of knowledge in subjects that are the basis for many careers in the health sciences such as Chemistry. The objective of this study was to analyze the relevance of implementing a hybrid model in education at the high school level in the Chemistry class, through the incorporation of Information and Communication Technologies as educational tools. According to the results, the implementation of a b-learning model is an alternative strategy for the teaching-learning of Chemistry and, at the same time, makes it possible to reduce the health risk that situations such as contagion by COVID-19 or other potentially communicable diseases, since this model allows students to take classes virtually, and simultaneously in person, following contingency measures

Recovery of active pathogenesis-related enzymes from the apoplast of Musa acuminata infected by Mycosphaerella fijiensis

The fungus Mycosphaerella fijiensis causes black Sigatoka (BS) disease, a major pathogen in the banana industry worldwide. Numerous molecular and biochemical studies have been done for the M. fijiensis, Musa acuminata interaction, but this is the first study describing the zymographic behavior of β-1,3-glucanase, chitinase and protease in the apoplast and symplast of healthy, BS-infected but asymptomatic and BS diseased banana leaves. In BS-infected tissues, β-1,3-glucanase enzymatic activity was associated with two polypeptides with retention index (Ri) values of 0.43 and 0.56. These were more notable in the apoplast than in the symplast. Chitinase activity in BS-infected tissue in both the apoplast and symplast was mainly associated with a single polypeptide (Ri = 0.89). Both β-1,3-glucanase and chitinase activities were apparently more intense in BS-infected leaves than in healthy leaves. Protease activity was associated with two polypeptides (Ri = 0.04 and 0.14). In both the apoplast and symplast, the Ri 0.04 polypeptide increased in intensity with disease progression, whereas Ri 0.14 polypeptide intensity decreased. Overall protease activity intensity was higher in the symplast. Maximum symplast contamination of the apoplast was 2% as estimated by glucose 6-phosphate dehydrogenase activity, a biochemical marker for symplast. Accumulation of pathogenesis-related enzymatic activities in the apoplast of M. acuminata leaf tissue was caused by hostcontrolled enzyme downloading in response to M. fijiensis infection. Clear differences were identified in the electrophoretic profiles of healthy and diseased banana plants. The results further support a putative role of these enzymes in the extracellular defense repertoire of banana and, more importantly, suggest that M. fijiensis possesses a mechanism for suppression and delay of defense response in M. acuminata.Key words: Black Sigatoka, glucose 6-phosphate dehydrogenase, pathogenesis-related (PR) proteins, polyacrylamide gel electrophoresis (PAGE), retention index (Ri), sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)

Gestão da informação na controladoria do Ministério Público: um estudo de caso

Dissertação apresentada ao programa de Pós-Graduação – PPGMAD, do Núcleo de Ciências Sociais Aplicadas – NUCSA, da Universidade Federal de Rondônia – UNIR, como requisito fundamental para obtenção do título de Mestre em Administração, no Programa de Pós-Graduação: Mestrado em Administração. Orientador: Prof. Dr. Tomás Daniel Menéndez RodriguezEsta dissertação analisa os resultados obtidos com a utilização das técnicas de gestão da informação na controladoria do setor público, a partir de um estudo de caso realizado no Ministério Público do Estado de Rondônia para a composição e acompanhamento da execução de um ciclo do Plano Geral de Atuação do órgão. Apoiada em métodos quantitativo-computacionais, a pesquisa realiza uma análise comparativa de dois ciclos consecutivos de planejamento em que o primeiro não utilizou tais ferramentas. As soluções propostas são compostas a partir do referencial teórico, associadas a outras mais que foram desenvolvidas de modo a conferir maior adequabilidade aos métodos empregados diante da realidade organizacional. Os resultados obtidos são confrontados com os do ciclo anterior de planejamento permitindo assim aferir a validade dos instrumentos de gestão empregados tendo em vista as mudanças culturais ocorridas internamente e os progressos sociais advindos das ferramentas de controle utilizadas para o acompanhamento da execução

Highly efficient system for the micropropagation and acclimatization of pineapple in vitro plants (Ananas comosus L. Merr, var. MD2)

The low acclimatization efficiency of pineapple seedlings obtained by in vitro culture has been one of the main limitations to massively scale micropropagation protocols. Various factors may be affecting the successful establishment of in vitro plants to ex vitro conditions, related to the plant and/or the environment and the management of seedlings. The objective of this study was to establish an efficient micropropagation and acclimatization system for the MD2 variety, with a high in vitro multiplication rate and a high greenhouse and field survival of pineapple in vitro plants. In the multiplication phase, the axillary buds were isolated and placed on a semisolid medium and three induction treatments with different concentrations of BAP (1.0, 3.0, 5.0 mg/L) and ANA (2.0 mg/L), were evaluated. After the third subculture, multiple shoots were transferred to a temporary immersion system (BIOMINT). During acclimatization and nursery phases, six treatments with different substrate compositions wereevaluated. The induction treatment IT3 (BAP 5.0 mg/L and ANA 2.0 mg/L) was selected for a significantly high multiplication rate. AT4 treatment (Soil + Coconut fiber + perlite 1:1:1) showed the highest survival rate (95%) and allowed the obtaining of well-developed plants. This system constitutes a valuable technology to introduce in vitro plants to the pineapple production scheme on a commercial scale