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Search Results: 1 - 10 of 192923 matches for " Claudio E; Pereira "
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El efecto de China en el comercio internacional de América Latina
Montenegro,Claudio E; Pereira,Mariana; Soloaga,Isidro;
Estudios de economía , 2011, DOI: 10.4067/S0718-52862011000200001
Abstract: using a gravity model, this article presents an analysis of aggregate trade flows aimed at identifying china's impact on latin america's trade. the results obtained indicate that: i) china's growth in the last years implied a growing supply of exports to this market from most countries in the world, including that of latin american countries; ii) at the aggregate level, there was no indication that chinese exports to third markets were crowding out lac exports to those countries; and iii) a positive relationship between imports from china and exports to third markets was only found for the southern cone countries.
El efecto de China en el comercio internacional de América Latina
Claudio E. Montenegro,Mariana Pereira,Isidro Soloaga
Estudios de Economia , 2011,
Abstract: Hacienda uso de modelos gravitacionales, se analizan las flujos agregados de comercio con el fin de identificar las efectos de China sobre el comercio de América Latina. Entre las principales conclusiones se encuentran las siguientes: i) El crecimiento del mercado chino no fue desaprovechado por los países de América Latina; ii) A nivel agregado no se encontró que las importaciones que los socias comerciales latinoamericanos hacen de China hayan desplazado a las importaciones que estas hacen de América Latina; iii) Sólo hay una asociación positiva entre importaciones de China y exportaciones a terceras mercados en el caso del Cono Sur.
Trypanosoma cruzi: Transporte de metabolitos esenciales obtenidos del hospedador
Pereira,Claudio A.; Carrillo,Carolina; Miranda,Mariana R.; Bouvier,León A.; Cánepa,Gaspar E.;
Medicina (Buenos Aires) , 2008,
Abstract: trypanosoma cruzi is the etiological agent of chagas disease, a disease endemic not only in argentina but also in all of latinamerica. t. cruzi presents several metabolic characteristics which are completely absent in its insect vectors and in mammalian hosts. some of these differences were acquired after millions of years of adaptation to parasitism, during which this protozoan replaced many biosynthetic routes for transport systems. in the present review, we describe the advances in the knowledge of t. cruzi transport processes and the molecules involved. in particular, we focus on aminoacid and polyamine transporters from the aaap family (amino acid/auxin permeases), because they seem to be exclusive transporters from trypanosomatids. taking into account that these permeases are completely absent in mammals, they could be considered as a potential target against trypanosoma cruzi.
Hiperaldosteronismo primário revisitado
Passos, Vanessa Quintas;Martins, Leandro Aurélio L.;Pereira, Maria Adelaide A.;Kater, Claudio E.;
Arquivos Brasileiros de Endocrinologia & Metabologia , 2001, DOI: 10.1590/S0004-27302001000300012
Abstract: esta apresenta??o tem o objetivo de discutir o tema "hiperaldosteronismo primário" (hap). inicialmente, ser?o apresentados os dados clínicos, laboratoriais, radiológicos e o resultado do estudo anátomo-patológico do tumor de uma paciente portadora de "aldosteronoma", seguindo-se uma discuss?o centrada em três pontos principais: 1) a investiga??o de hap em pacientes com hipertens?o arterial; 2) o diagnóstico etiológico do hap; e 3) o tratamento das várias formas de apresenta??o do hap.
Hiperaldosteronismo primário revisitado
Passos Vanessa Quintas,Martins Leandro Aurélio L.,Pereira Maria Adelaide A.,Kater Claudio E.
Arquivos Brasileiros de Endocrinologia & Metabologia , 2001,
Abstract: Esta apresenta o tem o objetivo de discutir o tema "hiperaldosteronismo primário" (HAP). Inicialmente, ser o apresentados os dados clínicos, laboratoriais, radiológicos e o resultado do estudo anátomo-patológico do tumor de uma paciente portadora de "aldosteronoma", seguindo-se uma discuss o centrada em três pontos principais: 1) a investiga o de HAP em pacientes com hipertens o arterial; 2) o diagnóstico etiológico do HAP; e 3) o tratamento das várias formas de apresenta o do HAP.
Dual Role of Topoisomerase II in Centromere Resolution and Aurora B Activity
Paula A. Coelho,Joana Queiroz-Machado,Alexandre M. Carmo,Sara Moutinho-Pereira,Helder Maiato,Claudio E. Sunkel
PLOS Biology , 2012, DOI: 10.1371/journal.pbio.0060207
Abstract: Chromosome segregation requires sister chromatid resolution. Condensins are essential for this process since they organize an axial structure where topoisomerase II can work. How sister chromatid separation is coordinated with chromosome condensation and decatenation activity remains unknown. We combined four-dimensional (4D) microscopy, RNA interference (RNAi), and biochemical analyses to show that topoisomerase II plays an essential role in this process. Either depletion of topoisomerase II or exposure to specific anti-topoisomerase II inhibitors causes centromere nondisjunction, associated with syntelic chromosome attachments. However, cells degrade cohesins and timely exit mitosis after satisfying the spindle assembly checkpoint. Moreover, in topoisomerase II–depleted cells, Aurora B and INCENP fail to transfer to the central spindle in late mitosis and remain tightly associated with centromeres of nondisjoined sister chromatids. Also, in topoisomerase II–depleted cells, Aurora B shows significantly reduced kinase activity both in S2 and HeLa cells. Codepletion of BubR1 in S2 cells restores Aurora B kinase activity, and consequently, most syntelic attachments are released. Taken together, our results support that topoisomerase II ensures proper sister chromatid separation through a direct role in centromere resolution and prevents incorrect microtubule–kinetochore attachments by allowing proper activation of Aurora B kinase.
Molecular and Functional Characterization of a Trypanosoma cruzi Nuclear Adenylate Kinase Isoform
María de los Milagros Cámara,León A. Bouvier,Gaspar E. Canepa,Mariana R. Miranda,Claudio A. Pereira
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002044
Abstract: Trypanosoma cruzi, the etiological agent of Chagas' disease, is an early divergent eukaryote in which control of gene expression relies mainly in post-transcriptional mechanisms. Transcription levels are globally up and down regulated during the transition between proliferating and non-proliferating life-cycle stages. In this work we characterized a nuclear adenylate kinase isoform (TcADKn) that is involved in ribosome biogenesis. Nuclear adenylate kinases have been recently described in a few organisms, being all related to RNA metabolism. Depending on active transcription and translation, TcADKn localizes in the nucleolus or the cytoplasm. A non-canonical nuclear localization signal was mapped towards the N-terminal of the protein, being the phosphate-binding loop essential for its localization. In addition, TcADKn nuclear exportation depends on the nuclear exportation adapter CRM1. TcADKn nuclear shuttling is governed by nutrient availability, oxidative stress and by the equivalent in T. cruzi of the mammalian TOR (Target of Rapamycin) pathway. One of the biological functions of TcADKn is ribosomal 18S RNA processing by direct interaction with ribosomal protein TcRps14. Finally, TcADKn expression is regulated by its 3′ UTR mRNA. Depending on extracellular conditions, cells modulate protein translation rates regulating ribosome biogenesis and nuclear adenylate kinases are probably key components in these processes.
Dual Role of Topoisomerase II in Centromere Resolution and Aurora B Activity
Paula A Coelho,Joana Queiroz-Machado,Alexandre M Carmo,Sara Moutinho-Pereira,Helder Maiato,Claudio E Sunkel
PLOS Biology , 2008, DOI: 10.1371/journal.pbio.0060207
Abstract: Chromosome segregation requires sister chromatid resolution. Condensins are essential for this process since they organize an axial structure where topoisomerase II can work. How sister chromatid separation is coordinated with chromosome condensation and decatenation activity remains unknown. We combined four-dimensional (4D) microscopy, RNA interference (RNAi), and biochemical analyses to show that topoisomerase II plays an essential role in this process. Either depletion of topoisomerase II or exposure to specific anti-topoisomerase II inhibitors causes centromere nondisjunction, associated with syntelic chromosome attachments. However, cells degrade cohesins and timely exit mitosis after satisfying the spindle assembly checkpoint. Moreover, in topoisomerase II–depleted cells, Aurora B and INCENP fail to transfer to the central spindle in late mitosis and remain tightly associated with centromeres of nondisjoined sister chromatids. Also, in topoisomerase II–depleted cells, Aurora B shows significantly reduced kinase activity both in S2 and HeLa cells. Codepletion of BubR1 in S2 cells restores Aurora B kinase activity, and consequently, most syntelic attachments are released. Taken together, our results support that topoisomerase II ensures proper sister chromatid separation through a direct role in centromere resolution and prevents incorrect microtubule–kinetochore attachments by allowing proper activation of Aurora B kinase.
Plasmid Vectors and Molecular Building Blocks for the Development of Genetic Manipulation Tools for Trypanosoma cruzi
León A. Bouvier, María de los Milagros Cámara, Gaspar E. Canepa, Mariana R. Miranda, Claudio A. Pereira
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080217
Abstract: The post genomic era revealed the need for developing better performing, easier to use and more sophisticated genetic manipulation tools for the study of Trypanosoma cruzi, the etiological agent of Chagas disease. In this work a series of plasmids that allow genetic manipulation of this protozoan parasite were developed. First of all we focused on useful tools to establish selection strategies for different strains and which can be employed as expression vectors. On the other hand molecular building blocks in the form of diverse selectable markers, modifiable fluorescent protein and epitope-tag coding sequences were produced. Both types of modules were harboured in backbone molecules conceived to offer multiple construction and sub-cloning strategies. These can be used to confer new properties to already available genetic manipulation tools or as starting points for whole novel designs. The performance of each plasmid and building block was determined independently. For illustration purposes, some simple direct practical applications were conducted.
The galactic unclassified B[e] star HD 50138 III. The short-term line profile variability of its photospheric lines
Marcelo Borges Fernandes,Michaela Kraus,Dieter H. Nickeler,Peter De Cat,Patricia Lampens,Claudio Bastos Pereira,Mary E. Oksala
Physics , 2012, DOI: 10.1051/0004-6361/201220166
Abstract: HD 50138 presents the B[e] phenomenon, but its nature is not clear yet. This star is known to present spectral variations, which have been associated with outbursts and shell phases. We analyze the line profile variability of HD 50138 and its possible origin, which provide possible hints to its evolutionary stage, so far said to be close to the end of (or slightly beyond) the main sequence. New high-resolution spectra of HD 50138 obtained with the HERMES spectrograph over several nights (five of them consecutively) were analyzed, allowing us to confirm short-term line profile variability. Our new data show short-term variations in the photospheric lines. On the other hand, purely circumstellar lines (such as [O I] lines) do not show such rapid variability. The rotational velocity of HD 50138, V_rot = 90.3 +- 4.3 km/s, and the rotation period, P = 3.64 +- 1.16 d, were derived from the He II 4026A photospheric line. Based on the moment method, we confirm that the origin of this short-term line profile variability is not stellar spots, and it may be caused by pulsations. In addition, we show that macroturbulence may affect the profiles of photospheric lines, as is seen for B supergiants. The location of HD 50138 at the end of (or slightly beyond) the main sequence, the newly detected presence of line profile variability resembling pulsating stars, and macroturbulence make this star a fascinating object.
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