Thermal Analysis of a Directly Grid-Fed Induction Machine with Floating Neutral Point, Operating under Unbalanced Voltage Conditions

Significant changes may occur in the thermal behavior of a directly grid-fed induction machine when subjected to unbalances in the voltage supply. This article studies and analyzes the thermal behavior of a low power, three-phase, squirrel-cage induction motor, connected in star configuration with floating neutral point, when subjected to different levels of unbalanced voltage. The dependence of the thermal motor behavior on the severity level of the unbalance is studied and analyzed. In addition to amplitude unbalances, this article focuses on the effects of phase unbalances, as well, which were not addressed in detail in previous published studies. Moreover, situations of mixed unbalance, where amplitude and phase unbalances occur simultaneously, are also studied. The finite element method was used to simulate the thermal behavior of the machine. The experimental setup consists of a three-phase programmable AC power supply, suitable to precisely emulate unbalanced conditions that may occur in real-scale power systems, supplying a 2.2 kW induction motor. Experimental data were acquired resorting to resistance temperature detectors PT100, placed in the machine phase whose supply current value changed the most. Finally, the simulation results are verified and critically discussed through experimentally obtained results.info:eu-repo/semantics/publishedVersio

Erratum to: Mirnacle: machine learning with SMOTE and random forest for improving selectivity in pre-miRNA ab initio prediction

MicroRNAs (miRNAs) are key gene expression regulators in plants and animals. Therefore, miRNAs are involved in several biological processes, making the study of these molecules one of the most relevant topics of molecular biology nowadays. However, characterizing miRNAs in vivo is still a complex task. As a consequence, in silico methods have been developed to predict miRNA loci. A common ab initio strategy to find miRNAs in genomic data is to search for sequences that can fold into the typical hairpin structure of miRNA precursors (pre-miRNAs). The current ab initio approaches, however, have selectivity issues, i.e., a high number of false positives is reported, which can lead to laborious and costly attempts to provide biological validation. This study presents an extension of the ab initio method miRNAFold, with the aim of improving selectivity through machine learning techniques, namely, random forest combined with the SMOTE procedure that copes with imbalance datasets. By comparing our method, termed Mirnacle, with other important approaches in the literature, we demonstrate that Mirnacle substantially improves selectivity without compromising sensitivity. For the three datasets used in our experiments, our method achieved at least 97% of sensitivity and could deliver a two-fold, 20-fold, and 6-fold increase in selectivity, respectively, compared with the best results of current computational tools. The extension of miRNAFold by the introduction of machine learning techniques, significantly increases selectivity in pre-miRNA ab initio prediction, which optimally contributes to advanced studies on miRNAs, as the need of biological validations is diminished. Hopefully, new research, such as studies of severe diseases caused by miRNA malfunction, will benefit from the proposed computational tool

Urbanismo em Minas Gerais: idealizações e realizações urbanísticas para as cidades mineiras (1895-1957)

-A pesquisa envolve a continuidade de trabalhos anteriores e em andamento, voltados para a compreensão da história do urbanismo em MinasGerais, particularmente, relacionados com a formação das cidades mineiras. Buscamos ampliar a compreensão sobre as propostas urbanísticasdesenvolvidas para as cidades do estado elaboradas por profissionais, como engenheiros, arquitetos e outros planejadores. Assim, temos eixos deabordagem diferenciados, com enfoque sobre processos históricos que conjugam passado e presente. Abordamos a formação das cidades doEstado de Minas Gerais, nos ciclos de modernização, desde a metade do século XIX, até a metade do século XX. Além disso, buscamos entender atrajetória profissional dos urbanistas envolvidos nas proposições e realizações para estas cidades. Esta continuidade pretendida busca tambémconsolidar a integração de trabalhos de pesquisa já delineada através da Rede Urbanismo.br, coordenada pela Profª Maria Cristina da Silva Leme,envolvendo instituições como a FAUUSP, a UFBA, a UFPE, a UFF, a UFRGS e a UFES, sendo que esta Rede conta com o apoio do CNPq desde oseu inicio. Nesta abordagem sobre a formação das cidades mineiras e os urbanistas que ali atuaram, temos a própria capital do Estado de MinasGerais, Belo Horizonte, cujas transformações se deram com rapidez e intensidade, alterando, nestes últimos cem anos, a paisagem bucólica pensadapelos seus idealizadores, Aarão Reis e Francisco Bicalho, que estiveram à frente da Comissão Construtora da Nova Capital. Outras cidades,inúmeras localidades, com as suas especificidades, planejadas ou não, distribuídas pelas várias regiões do Estado. Trabalhamos com a organizaçãogeo-política definida nos anos 60, a saber, a Zona da Mata Mineira, com as cidades de Além Paraíba, Cataguazes, Juiz de Fora, Leopoldina, Mar deEspanha, Muriaé, Ponte Nova, Rio Casca, Rio Preto, Viçosa, Visconde do Rio Branco e Ubá. A Zona Sul, com as cidades de Alfenas, Baependi,Cambuquira, Campanha, Caxambú, Itajubá, Passos, Poços de Caldas, Varginha, Lambari, Lavras, Pouso Alegre, Sao Lourenço e Três Corações. AZona Metalúrgica, com a Capital do Estado, Belo Horizonte, e outras cidades como Betim, Caeté, Contagem, Congonhas do Campo, Divinópolis,Itabira, Mariana, Nova Lima, Ouro Preto, Itaúna, Lagoa Santa, Sabará, Santa Barbara, Santa Luzia e Sete Lagoas. O Rio Doce, com as cidades deCaratinga, Coronel Fabriciano, Governador Valadares, Ipatinga, João Monlevade, Manhuaçu, Manhumirim, Mantena, Conselheiro Pena e Timoteo. OAlto São Francisco com Curvelo, Divinópolis, Itaúna, Pitangui, Dores do Indaiá, S. Gotardo, Nova Ponte, Furnas, Pará de Minas e Três Marias. OMédio São Francisco, com as cidades de Januária, Pirapora, São Francisco e Manga. O Triângulo com Uberaba; Uberlândia, Araguari, Ituiutaba ePrata. O Mucuri com Teófilo Ottoni, Nanuque, Ataléia e Carlos Chagas. O Alto Paranaíba com Araxá, Carmo do Paranaíba, Ibiá, Patos de Minas ePatrocínio. A Zona do Campos das Vertentes com Barbacena, Conselheiro Lafayette, Formiga, Oliveira, Santos Dumont e São João del Rey. O AltoJequitinhonha com Diamantina, Serro, Gouveia, Itamarandiba e Passa Quatro. O Médio Jequitinhonha com Almenara, Pedra Azul, Araçuaí eJequitinhonha. A Zona de Itacambira com Grão-Mogol, Espinosa, Monte Azul, Salinas e Itaobim. O Paracatu com Paracatu, Unaí, João Ribeiro ePresidente Olegário. Por fim a Zona de Montes Claros com Montes Claros, Bocaiúva, Coração de Jesus e Janaúba. Pretendemos avançar osestudos sobre este rol de cidades, que compõem as várias regiões do Estado, com base nos levantamentos e dados já sistematizados

Research Blogging: Indexing and Registering the Change in Science 2.0

Increasing public interest in science information in a digital and 2.0 science era promotes a dramatically, rapid and deep change in science itself. The emergence and expansion of new technologies and internet-based tools is leading to new means to improve scientific methodology and communication, assessment, promotion and certification. It allows methods of acquisition, manipulation and storage, generating vast quantities of data that can further facilitate the research process. It also improves access to scientific results through information sharing and discussion. Content previously restricted only to specialists is now available to a wider audience. This context requires new management systems to make scientific knowledge more accessible and useable, including new measures to evaluate the reach of scientific information. The new science and research quality measures are strongly related to the new online technologies and services based in social media. Tools such as blogs, social bookmarks and online reference managers, Twitter and others offer alternative, transparent and more comprehensive information about the active interest, usage and reach of scientific publications. Another of these new filters is the Research Blogging platform, which was created in 2007 and now has over 1,230 active blogs, with over 26,960 entries posted about peer-reviewed research on subjects ranging from Anthropology to Zoology. This study takes a closer look at RB, in order to get insights into its contribution to the rapidly changing landscape of scientific communication

Cosmological dynamics of the tachyon with an inverse power-law potential

We investigate tachyon dynamics with an inverse power-law potential $V(\phi) \propto \phi^{-\alpha}$. We find global attractors of the dynamics leading to a dust behaviour for $\alpha > 2$ and to an accelerating universe for $0 < \alpha \le 2$. We study linear cosmological perturbations and we show that metric fluctuations are constant on large scales in both cases. In presence of an additional perfect fluid, the tachyon with this potential behaves as dust or dark energy.Comment: 10 pages, 1 figur

A long noncoding RNA promotes parasite differentiation in African trypanosomes

Copyright © 2022 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC)The parasite Trypanosoma brucei causes African sleeping sickness that is fatal to patients if untreated. Parasite differentiation from a replicative slender form into a quiescent stumpy form promotes host survival and parasite transmission. Long noncoding RNAs (lncRNAs) are known to regulate cell differentiation in other eukaryotes. To determine whether lncRNAs are also involved in parasite differentiation, we used RNA sequencing to survey the T. brucei genome, identifying 1428 previously uncharacterized lncRNA genes. We find that grumpy lncRNA is a key regulator that promotes parasite differentiation into the quiescent stumpy form. This function is promoted by a small nucleolar RNA encoded within the grumpy lncRNA. snoGRUMPY binds to messenger RNAs of at least two stumpy regulatory genes, promoting their expression. grumpy overexpression reduces parasitemia in infected mice. Our analyses suggest that T. brucei lncRNAs modulate parasite-host interactions and provide a mechanism by which grumpy regulates cell differentiation in trypanosomes.This work was supported in part by Fundação para a Ciência e Tecnologia (FCT) grant, awarded to F.G. and entitled “Long noncoding RNAs as new diagnostic biomarkers for African Sleeping sickness” (PTDC/DTPEPI/7099/2014, start date: 1 January 2016, end date: 31 December 2018); also by Howard Hughes Medical Institute International Early Career Scientist Program (project title: “How parasites use epigenetics to evade host defenses,” project no. 55007419, start date: 1 February 2012, end date: 31 January 2017); and by the European Research Council (project title: “Exploring the hidden life of African trypanosomes: parasite fat tropism and implications for the disease,” project no. 771714, start date: 1 August 2018, end date: 31 January 2024), both awarded to L.M.F. The project leading to these results have received funding from “la Caixa” Foundation under the agreement LCF/PR/HR20/52400019 [project title: “Mechanism and function of epitranscriptomic poly(A) tail modifications in African trypanosomes,” project no. HR20-00361, start date: 1 March 2021, end date: 29 February 2024]. L.M.F. is supported by FCT (IF/01050/2014, project title: “Molecular basis for the efficient biology of trypanossome parasitism,” start date: 1 January 2015, end date: 31 December 2019) and by CEEC institutional program (CEECINST/00110/2018, start date: 1 January 2020, end date: 14 December 2020). C.N. acknowledges the support of the Spanish Ministry of Economy, Industry and Competitiveness (MEIC) to the EMBL partnership, the Centro de Excelencia Severo Ochoa and the CERCA Programme/Generalitat de Catalunya. S. Michaeli acknowledges the support of the Israel Science Foundation (ref. 1959/20) from October 2020 to October 2025, entitled “Functional analysis of rRNA processing and the role of rRNA modification for specialized translation in the two life stages of trypanosomes” and U.S. Binational Science Foundation (ref. 2015/219) from October 2015 to October 2019, entitled “The role and mechanism of RNA pseudo-uridylation and sugar methylation (Nm) during the developmental cycle of trypanosomes.” The work done in A.D.’s laboratory was supported by National Science Center SONATA BIS grant, entitled “Non-canonical RNA tailing and other post-transcriptional regulatory mechanisms in T cell-mediated adaptive immunity” (proposal ID: 492777, agreement no: UMO-2020/38/E/NZ2/00372, start date: 22 March 2021, end date: 21 March 2026); National Science Center OPUS grant, entitled “Analysis of the role of cytoplasmic polyadenylation in the regulation of the innate immune response” (proposal ID: 443521, agreement no.: UMO-2019/33/B/NZ2/01773, start date: 2 March 2020, end date: 1 March 2023); and European Union’s Horizon 2020 (H2020-WIDESPREAD-03-2017)–ERAChair, entitled “MOlecular Signaling in Health and Disease - Interdisciplinary Centre of Excellence” (acronym: MOSaIC, agreement no.: 810425, implementation period: start date: 1 November 2018, end date: 31 October 2023).info:eu-repo/semantics/publishedVersio

Trypanosoma brucei parasites occupy and functionally adapt to the adipose tissue in mice

This work was supported by 55007419 (HHMI) and 2151 (EMBO) to L.M.F., D.P.-N., F.B., and F.G.; FCT fellowships to S.T., F.R.-F., and F.A.-B. (SFRH/BPD/89833/2012, SFRH/BD/51286/2010, and SFRH/BD/80718/2011, respectively); Wellcome Trust grant (093228), MRC MR/M020118/1, and European Community Seventh Framework Programme under grant agreement No. 602773 (Project KINDRED) to S.A.Y. and T.K.S.; and PAI 7/41 (Belspo) and ERC-NANOSYM to J.V.D.A.Trypanosoma brucei is an extracellular parasite that causes sleeping sickness. In mammalian hosts, trypanosomes are thought to exist in two major niches: early in infection, they populate the blood; later, they breach the blood-brain barrier. Working with a well-established mouse model, we discovered that adipose tissue constitutes a third major reservoir for T. brucei. Parasites from adipose tissue, here termed adipose tissue forms (ATFs), can replicate and were capable of infecting a naive animal. ATFs were transcriptionally distinct from bloodstream forms, and the genes upregulated included putative fatty acid β-oxidation enzymes. Consistent with this, ATFs were able to utilize exogenous myristate and form β-oxidation intermediates, suggesting that ATF parasites can use fatty acids as an external carbon source. These findings identify the adipose tissue as a niche for T. brucei during its mammalian life cycle and could potentially explain the weight loss associated with sleeping sickness.Publisher PDFPeer reviewe