87 research outputs found
La revolución científica y tecnológica y la sociedad postindustrial
En la literatura económica, sociológica y sobre desarrollo científico y tecnológico han aparecido desde la década de 1960 las nociones de revolución científica y tecnológica y de sociedad postindustrial, generalmente asociadas. Este artículo examina el antecedente de la revolución industrial y las diversas interpretaciones que ha tenido. Se reseñan los textos de Daniel Bell, Radovan Richta y varios autores soviéticos sobre estos temas para sugerir que abundan formulaciones confusas, las cuales han servido para promover la ideología del reformismo y de la supuesta extinción de los conflictos de clase, y para señalar que las predicciones de varios autores al respecto no se han verificado. Es probable que las dificultades para definir la supuesta revolución científica y tecnológica no sean casuales, sino que se deriven de una falta de análisis de la historia de la tecnología. Se propone plantear por separado las nociones de "revolución científica", "revolución tecnológica" y "revolución científica y tecnológica", y no hacer afirmaciones totalizadoras a priori, sino examinar la compleja relación entre ciencia y tecnología en determinados campos del conocimiento y de la producción.The literature about scientific and technological topics, explores frequently the idea that we are in the middle of a scientific and technological revolution and that capitalist society ad- vances towards a post-industrial society, characterized by an increasingly greater weight of the Service sector. The backgrounds of the scientific revolution in the xvm century are exam- ined in order to show that even if it is a widely studied topic, there is no agreement among historians about some aspects of this historie event. The literature on the scientific and technological revolution and the post-industrial society is reviewed, in particular authors such as Daniel Bell, Radovan Richta and several soviet authors to suggest that they wielded confused ideas, that they played a role to obscure the contradictions of capitalism as well as to promete the ideology of reformism. Some empirical data are also examined to show that the economic evolution of the last decades does not verify the optimistic projections offered by the authors mentioned above. It is suggested that it is necessary to examine in greater de- tail the historie experience of the scientific and technological revolutions
La revolución científica y tecnológica y la sociedad postindustrial
En la literatura económica, sociológica y sobre desarrollo científico y tecnológico han aparecido desde la década de 1960 las nociones de revolución científica y tecnológica y de sociedad postindustrial, generalmente asociadas. Este artículo examina el antecedente de la revolución industrial y las diversas interpretaciones que ha tenido. Se reseñan los textos de Daniel Bell, Radovan Richta y varios autores soviéticos sobre estos temas para sugerir que abundan formulaciones confusas, las cuales han servido para promover la ideología del reformismo y de la supuesta extinción de los conflictos de clase, y para señalar que las predicciones de varios autores al respecto no se han verificado. Es probable que las dificultades para definir la supuesta revolución científica y tecnológica no sean casuales, sino que se deriven de una falta de análisis de la historia de la tecnología. Se propone plantear por separado las nociones de "revolución científica", "revolución tecnológica" y "revolución científica y tecnológica", y no hacer afirmaciones totalizadoras a priori, sino examinar la compleja relación entre ciencia y tecnología en determinados campos del conocimiento y de la producción.The literature about scientific and technological topics, explores frequently the idea that we are in the middle of a scientific and technological revolution and that capitalist society ad- vances towards a post-industrial society, characterized by an increasingly greater weight of the Service sector. The backgrounds of the scientific revolution in the xvm century are exam- ined in order to show that even if it is a widely studied topic, there is no agreement among historians about some aspects of this historie event. The literature on the scientific and technological revolution and the post-industrial society is reviewed, in particular authors such as Daniel Bell, Radovan Richta and several soviet authors to suggest that they wielded confused ideas, that they played a role to obscure the contradictions of capitalism as well as to promete the ideology of reformism. Some empirical data are also examined to show that the economic evolution of the last decades does not verify the optimistic projections offered by the authors mentioned above. It is suggested that it is necessary to examine in greater de- tail the historie experience of the scientific and technological revolutions
Venom alkaloids against Chagas disease parasite: search for effective therapies
Chagas disease is an important disease affecting millions of patients in the New World and is caused by a protozoan transmitted by haematophagous kissing bugs. It can be treated with drugs during the early acute phase; however, effective therapy against the chronic form of Chagas disease has yet to be discovered and developed. We herein tested the activity of solenopsin alkaloids extracted from two species of fire ants against the protozoan parasite Trypanosoma cruzi, the aetiologic agent of Chagas disease. Although IC50 determinations showed that solenopsins are more toxic to the parasite than benznidazole, the drug of choice for Chagas disease treatment, the ant alkaloids presented a lower selectivity index. As a result of exposure to the alkaloids, the parasites became swollen and rounded in shape, with hypertrophied contractile vacuoles and intense cytoplasmic vacuolization, possibly resulting in osmotic stress; no accumulation of multiple kinetoplasts and/or nuclei was detected. Overexpressing phosphatidylinositol 3-kinase—an enzyme essential for osmoregulation that is a known target of solenopsins in mammalian cells—did not prevent swelling and vacuolization, nor did it counteract the toxic effects of alkaloids on the parasites. Additional experimental results suggested that solenopsins induced a type of autophagic and programmed cell death in T. cruzi. Solenopsins also reduced the intracellular proliferation of T. cruzi amastigotes in infected macrophages in a concentration-dependent manner and demonstrated activity against Trypanosoma brucei rhodesiense bloodstream forms, which is another important aetiological kinetoplastid parasite. The results suggest the potential of solenopsins as novel natural drugs against neglected parasitic diseases caused by kinetoplastids.Fil: Silva, Rafael C. M. Costa. Universidade Federal do Rio de Janeiro; BrasilFil: Fox, Eduardo G. P.. Universidade Federal do Rio de Janeiro; Brasil. South China Agricultural University; ChinaFil: Gomes, Fabio M.. Universidade Federal do Rio de Janeiro; Brasil. National Institutes of Health; Estados UnidosFil: Feijó, Daniel F.. Universidade Federal do Rio de Janeiro; BrasilFil: Ramos, Isabela. Universidade Federal do Rio de Janeiro; BrasilFil: Koeller, Carolina M.. Universidade Federal do Rio de Janeiro; Brasil. University at Buffalo; Estados UnidosFil: Costa, Tatiana F. R.. Universidade Federal do Rio de Janeiro; BrasilFil: Rodrigues, Nathalia S.. Universidade Federal do Rio de Janeiro; BrasilFil: Lima, Ana P.. Universidade Federal do Rio de Janeiro; BrasilFil: Atella, Georgia C.. Universidade Federal do Rio de Janeiro; BrasilFil: Rocha de Miranda, Kildare. Universidade Federal do Rio de Janeiro; Brasil. Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem; BrasilFil: Schoijet, Alejandra Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Alonso, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: de Alcântara Machado, Ednildo. Universidade Federal do Rio de Janeiro; BrasilFil: Heise, Norton. Universidade Federal do Rio de Janeiro; Brasi
A versatile CRISPR/Cas9 editing approach in Trypanosoma cruzi
Development of CRISPR/Cas9 as a tool for genomic edition brought a new perspective to the study of Trypanosoma cruzi, an organism usually reluctant to other gene editing technologies. Most often, epimastigotes are co-transfected with a single plasmid bearing both the gene for Cas9-GFP expression and a sequence to be translated into a single guide RNA (sgRNA), jointly with a lineal donor DNA encompassing a selection marker flanked by sequences homologous to the target gene. Here, we tested an alternative approach for the generation of Phosphodiesterase (PDE) knockout parasites. We obtained epimastigotes from Tul II strain stably expressing Cas9-GFP in the nucleus in all parasite stages, with no detrimental effects on epimastigote growth or differentiation nor on trypomastigote infection capability. These Cas9-GFP epimastigotes were co-transfected with the sgRNA + DNA donor pair, according to the intended gene target. sgRNA were obtained by in vitro transcription using a template DNA bearing the specific + scaffold sequence under a T7 promoter. To obtain the donor DNA we designed a "pre-donor" formed by a sequence including several restriction enzyme recognition sites flanked by 30-bp arms homologous to the sequence adjacent sgRNA annealing target. This "pre-donor" allowed to easily generate a variety of donor DNAs by cloning alternative selection markers. DNA extracts (boiling-preps) from 4-day post-transfection cultures were evaluated by PCR using "mixed" primer pairs: while one of the primers annealed to the target gene, the second primer annealed to a sequence in the donor DNA, allowing assessment of its correct insertion in the gene of interest. Advantages of this take on CRISPR/Cas9 edition include its versatility for choosing and switching between alternative selection markers and a quick and affordable generation of the components of the system and analysis of the transfected cultures, while possibly facilitating complementation assays on the KO lines.Fil: Vilchez Larrea, Salomé Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Prego, Alejo Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Schoijet, Alejandra Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Llanos, Manuel. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Alberca, Lucas Nicolás. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; ArgentinaFil: Bellera, Carolina Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; ArgentinaFil: Gavernet, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; ArgentinaFil: Talevi, Alan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; ArgentinaFil: Alonso, Guillermo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaXI Congreso de la Sociedad Argentina de ProtozoologíaMendozaArgentinaSociedad Argentina de Protozoologí
Identification of Contractile Vacuole Proteins in Trypanosoma cruzi
Contractile vacuole complexes are critical components of cell volume regulation
and have been shown to have other functional roles in several free-living
protists. However, very little is known about the functions of the contractile
vacuole complex of the parasite Trypanosoma cruzi, the
etiologic agent of Chagas disease, other than a role in osmoregulation.
Identification of the protein composition of these organelles is important for
understanding their physiological roles. We applied a combined proteomic and
bioinfomatic approach to identify proteins localized to the contractile vacuole.
Proteomic analysis of a T. cruzi fraction enriched for
contractile vacuoles and analyzed by one-dimensional gel electrophoresis and
LC-MS/MS resulted in the addition of 109 newly detected proteins to the group of
expressed proteins of epimastigotes. We also identified different peptides that
map to at least 39 members of the dispersed gene family 1 (DGF-1) providing
evidence that many members of this family are simultaneously expressed in
epimastigotes. Of the proteins present in the fraction we selected several
homologues with known localizations in contractile vacuoles of other organisms
and others that we expected to be present in these vacuoles on the basis of
their potential roles. We determined the localization of each by expression as
GFP-fusion proteins or with specific antibodies. Six of these putative proteins
(Rab11, Rab32, AP180, ATPase subunit B, VAMP1, and phosphate transporter)
predominantly localized to the vacuole bladder. TcSNARE2.1, TcSNARE2.2, and
calmodulin localized to the spongiome. Calmodulin was also cytosolic. Our
results demonstrate the utility of combining subcellular fractionation,
proteomic analysis, and bioinformatic approaches for localization of organellar
proteins that are difficult to detect with whole cell methodologies. The CV
localization of the proteins investigated revealed potential novel roles of
these organelles in phosphate metabolism and provided information on the
potential participation of adaptor protein complexes in their biogenesis
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field
La recepción e impacto de las ideas de Malthus sobre la población
En este artículo se analizan varios elementos de la obra de Thomas Malthus sobre población, en particular la recepción de su teoría y su posición política. Se resumen las críticas políticas, ideológicas y científicas que ha recibido, y se examinan asuntos hasta ahora no tratados por otros comentaristas, como es el caso de las excepciones admitidas por Malthus respecto al papel de las relaciones sociales feudales en la agricultura de Polonia y Rusia. Se sugiere que pese a que su teoría tendía a reforzar la pesada represión social y sexual existente, Malthus no fue apoyado por la burguesía británica (contrariamente a la apreciación de Marx). Se deduce que Malthus no percibió cabalmente los avances de la agricultura, y se refuta la tesis de Donald Winch de que habría sido un liberal de izquierda en política pues si bien en algunos aspectos se le puede considerar progresista, en otros, esenciales, conservador extremadamente represivo o protofascista, incluso precursor de la teoría de los golpes de Estado
Ciencia y religión: de la persecución de la iglesia católica contra Galileo a los reconciliacionistas actuales
Este trabajo es un intento de hacer una historia rápida de la relación entre ciencia y religión de Isaac Newton y los defensores de la reconciliación inglesa del siglo XVII hasta nuestros días, incluida la reacción de las iglesias, las sociedades científicas y las universidades ante la teoría De la evolución de especies por Charles Darwin y los conflictos más recientes con respecto a la enseñanza de la teoría de la evolución. También se menciona el papel de la ciencia en la explosión de los textos religiosos y algunos problemas históricos, como la interpretación de la condena de la iglesia católica contra Galileo. La conclusión es que la ciencia y la religión, al menos en la forma en que este último ha operado durante la mayor parte de la historia, son mutuamente excluyentes ya que la ciencia se inclina y se desarrolla durante una larga lucha donde su progreso socava todas las ideologías
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