Zircon dissolution in a ductile shear zone, Monte Rosa granite gneiss, northern Italy

The sizes, distributions and shapes of zircon grains within variably deformed granite gneiss from the western Alps have been studied. Zircon shows numerous indicators of a metamorphic response in both the host gneiss and a 5 cm wide continuous ductile shear zone, within which the zircon grain sizes range from <1 µm to >50 µm. However, the very fine grain sizes are virtually absent from grain boundaries. Within this zone, zircons consistently have more rounded and embayed margins, which are interpreted as evidence of dissolution in response to fluid influx during shearing. Zircons are preferentially located near metamorphic muscovite in both the host gneiss and the shear zone and tend to show the poorest crystal shape, indicating that fluids linked to the formation and presence of muscovite may enhance both the crystallization of zircon and its subsequent dissolution. Larger zircon crystals typically show a brittle response to deformation when adjacent to phyllosilicates, with fractures consistently perpendicular to the (001) mica cleavage. The variety of metamorphic behaviour observed for zircon indicates that it may be highly reactive in sub-solidus mid-crustal metamorphic environments

Produção de eletricidade nuclear e resistência social: três décadas de demandas por uma «Córdoba não nuclear»

In this paper we study the actions of resistance to nuclear technology in the province of Córdoba, Argentina. We describe and analyze contentious episodes that emerge around the production process of nuclear power from the return to democracy in 1983 to the present. Actors, arguments and ways in which resistance to the development of nuclear technology are implemented are identified, as well as the consequences and results it has produced. It is argued that the actions of resistance to nuclear technology in Córdoba have developed with various levels of citizen participation and visibility in the public sphere for more than three decades. During this period, resistance has promoted controversies over energy production, the environmental issue and promoted impacts on technological processes and collective claims.En este trabajo se estudian las acciones de resistencia a la tecnología nuclear en la provincia de Córdoba, Argentina, a partir de la descripción y el análisis de episodios contenciosos que emergen en torno al proceso productivo de la nucleoelectricidad desde el retorno a la democracia en 1983 hasta la actualidad. Se identifican actores, argumentos y formas en que se implementa la resistencia al desarrollo de la tecnología nuclear, así como también las consecuencias y resultados que ha producido. Se sostiene que las acciones de resistencia a la tecnología nuclear en Córdoba se han desarrollado con diversos niveles de participación ciudadana y visibilidad en la esfera pública durante más tres décadas. Durante este período, han impulsado controversias por la producción de energía, la cuestión ambiental y promovido impactos sobre procesos tecnológicos y el hacer colectivo de reclamos.Este trabalho estuda as ações de resistência à tecnologia nuclear na província de Córdoba, Argentina, a partir da descrição e análise de episódios contenciosos que emergem em torno do processo de produção da nucleoeletricidade desde o retorno à democracia até a atualidade. São identificados atores, argumentos e formas de implementação da resistência ao processo de produção da nucleoeletricidade, bem como as consequências e resultados que tem produzido. Argumenta-se que as ações de resistência à tecnologianuclear em Córdoba têm sido desenvolvidas com diferentes níveis de participação cidadã e visibilidade na esfera pública por mais de três décadas. Durante esse período, elas têm impulsionado controvérsias sobre a produção de energia, a questão ambiental e promoveram impactos nos processos tecnológicos e na reivindicação coletiva

Hacia un discurso antinuclear: procesos de refutación y re-significación en la polémica pública por la producción de nucleoelectricidad en Argentina

This work focuses on the public polemic over nuclear power in Argentina. We identify and analyze processes of rebuttal and re-signification of arguments held by promoting sectors of nuclear power in the article The nuclear crack. Departing from an instrumental use of discourse analysis, and paying particular attention to the argumentative function of the topoi, we study a key dimension of the dichotomization mechanism conformed by the processes of rebuttal and re-signification of arguments that constitute the `nuclear speech´. We argued that the rebuttal and re-signification of the conceptualizations of nuclear technology as clean, safe and cheap in the case study makes possibly to identify the emergence of a counter-discourse that we propose to define as an antinuclear discourse.En este trabajo se aborda la polémica pública por la producción de nucleoelectricidad en Argentina a partir de la identificación, descripción y análisis de procesos de refutación y resignificación de argumentos sostenidos por sectores promotores de la energía atómica en el artículo periodístico La grieta nuclear. Implementando un uso instrumental del análisis del discurso, y prestando especial atención a la función argumentativa de los topoi, se estudia una dimensión central del mecanismo de dicotomización conformada por los procesos de refutación y resignificación de argumentos que constituyen la denominada “monserga nuclear”. En este sentido, se sostiene que la refutación y resignificación de las conceptualizaciones de la tecnología nuclear como limpia, segura y barata en el caso de estudio permite identificar la emergencia de un “discurso contra” que proponemos denominar en términos de antinuclear

Structural characterization of the M* partly folded intermediate of wild-type and P138A EcAspAT

A combination of spectroscopic techniques, hydrogen/deuterium exchange, and limited proteolysis experiments coupled to mass spectrometry analysis was used to depict the topology of the monomeric M*partly folded intermediate of aspartate aminotransferase from Escherichia coli in wild type (WT) as well as in a mutant form in which the highly conserved cis-proline at position 138 was replaced by a trans-alanine (P138A). Fluorescence analysis indicates that, although M* is an off-pathway intermediate in the folding of WT aspartate aminotransferase from E. coli, it seems to coincide with an on-pathway folding intermediate for the P138A mutant. Spectroscopic data, hydrogen/deuterium exchange, and limited proteolysis experiments demonstrated the occurrence of conformational differences between the two M*intermediates, with P138A-M* being conceivably more compact than WT-M*. Limited proteolysis data suggested that these conformational differences might be related to a different relative orientation of the small and large domains of the protein induced by the presence of the cis-proline residue at position 138. These differences between the two M* species indicated that in WT-M* Pro138 is in the cis conformation at this stage of the folding process. Moreover, hydrogen/deuterium exchange results showed the occurrence of few differences in the native N2 forms of WT and P138A, the spectroscopic features and crystallographic structures of which are almost superimposabl

Risk, Nuclear Technology and Resistance in Formosa, Argentina: The Controversy around the CAREM Project and the NPUO2

En el marco del renovado interés por el desarrollo nuclear en Argentina y el mundo, y de la nueva ola de oposición a esta tecnología registrada tras el accidente de Fukushima en 2011, se abordan en este artículo las acciones de resistencia a la tecnología nuclear en la provincia argentina de Formosa. Se implementa el estudio de un caso representativo, conformado por los proyectos de construcción de un reactor CAREM y una nueva planta productora de dióxido de uranio en territorio provincial. Más específicamente, se describe y analiza el proceso de construcción de la percepción social de la tecnología nuclear como una amenaza para el ambiente y la salud de las personas; las formas en que se lleva a cabo la resistencia en el espacio y la esfera pública; y las continuidades y rupturas que presenta el caso con otras acciones de protesta en contra de esta tecnología. Se argumenta que las acciones de resistencia a la energía atómica en Formosa emergen como parte de procesos democráticos e históricos de discusión en la esfera pública, sostenidos por actores que poseen diversos tipos de conocimientos y experticias acerca del desarrollo y la implementación de la tecnología nuclear en Argentina.No âmbito do renovado interesse pelo desenvolvimento nuclear na Argentina e no mundo, e a nova onda de oposição a essa tecnologia registrada após o acidente de Fukushima em 2011, este artigo aborda as ações de resistência à tecnologia nuclear na província argentina de Formosa. O estudo de um caso representativo é implementado, consistindo nos projetos de construção de um reator CAREM e uma nova planta de produção de dióxido de urânio no território provincial. Mais especificamente, é descrito e analisado o processo de construção da percepção social da tecnologia nuclear como uma ameaça ao meio ambiente e à saúde das pessoas; as formas pelas quais a resistência é realizada no espaço e na esfera pública; e as continuidades e rupturas que o caso apresenta com outras ações de protesto contra essa tecnologia. Argumenta-se que as ações de resistência à energia atômica em Formosa surgem como parte de processos democráticos e históricos de discussão na esfera pública, sustentados por atores que possuem diversos tipos de conhecimento e experiência sobre o desenvolvimento e implementação da tecnologia nuclear na Argentina.Within the context of a renewed interest in the development of nuclear power in Argentina and the world, and the new wave of opposition to this technology that has arisen after the Fukushima accident in 2011, this paper focuses on the actions of resistance against nuclear technology in the Argentine Province of Formosa. We analyze a representative case study of the construction projects of a CAREM reactor and a new uranium dioxide production plant within the province’s territory. More specifically, we describe and analyze the process of the construction of the public perception of nuclear technology as a threat to the environment and people’s health, the ways in which resistance is performed in the public arena, and the continuities and ruptures between this case and other collective actions against this technology. We argue that resistance against nuclear power in Formosa has emerged as part of democratic and historical processes of discussion in the public sphere, and are supported by parties that possess diverse types of knowledge and expertise in the development and implementation of nuclear technology in Argentina.Fil: Piaz, Agustín Gabriel. Universidad Nacional de San Martín. Escuela de Humanidades. Centro de Estudios de Historia de la Ciencia y de la Técnica "José Babini"; Argentina. Universidad Nacional de San Martín. Escuela de Humanidades. Laboratorio de Investigación en Ciencias Humanas - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Laboratorio de Investigación en Ciencias Humanas; Argentin

Towards an antinuclear discourse: rebuttal and re-signification processes in the public polemic over nuclear power in Argentina

En este trabajo se aborda la polémica pública por la producción de nucleoelectricidad en Argentina a partir de la identificación, descripción y análisis de procesos de refutación y resignificación de argumentos sostenidos por sectores promotores de la energía atómica en el artículo periodístico La grieta nuclear. Implementando un uso instrumental del análisis del discurso, y prestando especial atención a la función argumentativa de los topoi, se estudia una dimensión central del mecanismo de dicotomización conformada por los procesos de refutación y resignificación de argumentos que constituyen la denominada “monserga nuclear”. En este sentido, se sostiene que la refutación y resignificación de las conceptualizaciones de la tecnología nuclear como limpia, segura y barata en el caso de estudio permite identificar la emergencia de un “discurso contra” que proponemos denominar en términos de antinuclear.This work focuses on the public polemic over nuclear power in Argentina. We identify and analyze processes of rebuttal and re-signification of arguments held by promoting sectors of nuclear power in the article The nuclear crack. Departing from an instrumental use of discourse analysis, and paying particular attention to the argumentative function of the topoi, we study a key dimension of the dichotomization mechanism conformed by the processes of rebuttal and resignification of arguments that constitute the `nuclear speech´. We argued that the rebuttal and re-signification of the conceptualizations of nuclear technology as clean, safe and cheap in the case study makes possibly to identify the emergence of a counter-discourse that we propose to define as an antinuclear discourse.Fil: Piaz, Agustín Gabriel. Universidad Nacional de San Martin. Escuela de Humanidades. Laboratorio de Investigacion En Ciencias Humanas. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Laboratorio de Investigacion En Ciencias Humanas.; Argentin

High-yield production in Escherichia coli and convenient purification of a candidate vaccine against SARS-CoV-2

Objectives: The aim of the present work was to identify a time-saving, effective, and low-cost strategy to produce in Escherichia coli a protein chimera representing a fusion anti-SARS-CoV-2 candidate vaccine, consisting of immunogenic and antigenic moieties. Results: We overexpressed in E. coli BL21(DE3) a synthetic gene coding for CRM197-RBD, and the target protein was detected in inclusion bodies. CRM197-RBD was solubilized with 1 % (w/v) of the anionic detergent N-lauroylsarcosine (sarkosyl), the removal of which from the protein solution was conveniently accomplished with Amberlite XAD-4. The detergent-free CRM197-RBD was then separated from contaminating DNA using polyethylenimine (PEI), and finally purified from PEI by salting out with ammonium sulfate. Structural (CD spectrum) and functional (DNase activity) assays revealed that the CRM197-RBD chimera featured a native and active conformation. Remarkably, we determined a yield of purified CRM197-RBD equal to 23 mg per litre of culture. Conclusions: To produce CRM197-RBD, we devised the use of sarkosyl as an alternative to urea to solubilize the target protein from E. coli inclusion bodies, and the easy removal of sarkosyl by means of Amberlite XAD-4

Fiebre hemorrágica Argentina. Conflictos y desafíos para la ciencia en el ámbito rural

First detected in 1955, the Argentine hemorrhagic fever (AHF) is a serious acute viral illness located in an area of intensive agricultural activity. This article enquires into some of the recent lines of investigation with the purpose of analyzing how medical practices have continued or ceased to be implemented as well as determining whether the social groups identified as main risk groups of the AHF have seen any variation. In order to do this, a summary of the disease’s history has been made in addition to an investigation on the trajectory of the viral research laboratory that monopolized the research, production and distribution of the vaccine: the Maiztegui National Human Viral Disease Institute (INEVH). Based on primary as well as secondary sources and interviews with researchers and staff from the INEVH, we have studied its institutional career along with the conflicts that appeared in its development. These are associated with social and economic issues of the rural area where physicians, scientists and the affected population live and work.La fiebre hemorrágica argentina (FHA) es una enfermedad viral aguda grave, detectada en 1955, que está radicada en una zona de intensiva actividad agrícola. Este artículo indaga algunas de las líneas de investigación recientes, con el objetivo de analizar continuidades y rupturas en las prácticas médicas y en los grupos sociales identificados como principales grupos de riesgo de la FHA. Para ello, se realiza un somero recorrido por la historia de la enfermedad, y se explora la trayectoria del centro de salud que concentra las investigaciones, la producción y la distribución de la vacuna, el Instituto Nacional de Enfermedades Virales Humanas “Dr. Julio I. Maiztegui” (INEVH). A partir de literatura secundaria especializada, fuentes primarias y entrevistas a investigadores y personal del INEVH, se estudia esta trayectoria institucional y los conflictos presentes en su desarrollo, asociados a problemáticas sociales y económicas del medio rural en el que viven y trabajan tanto los médicos y científicos involucrados como la población afectada

Inhibition of bone resorption by Tanshinone VI isolated from Salvia miltiorrhiza Bunge

During the last decade, a more detailed knowledge of molecular mechanisms involved in osteoclastogenesis has driven research efforts in the development and screening of compound libraries of several small molecules that specifically inhibit the pathway involved in the commitment of the osteoclast precursor cells. Natural compounds that suppress osteoclast differentiation may have therapeutic value in treating osteoporosis and other bone erosive diseases such as rheumatoid arthritis or metastasis associated with bone loss. In ongoing investigation into anti-osteoporotic compounds from natural products we have analyzed the effect of Tanshinone VI on osteoclasts differentiation, using a physiologic three-dimensional osteoblast/bone marrow model of cell co-culture. Tanshinone VI is an abietane diterpene extracted from the root of Salvia miltiorrhiza Bunge (Labiatae), a Chinese traditional crude drug, “Tan-Shen”. Tashinone has been widely used in clinical practice for the prevention of cardiac diseases, arthritis and other inflammation-related disorders based on its pharmacological actions in multiple tissues. Although Tanshinone VI A has been used as a medicinal agent in the treatment of many diseases, its role in osteoclast-related bone diseases remains unknown. We showed previously that Tanshinone VI greatly inhibits osteoclast differentiation and suppresses bone resorption through disruption of the actin ring; subsequently, we intended to examine the precise inhibitory mechanism of Tanshinone VI on osteoclast differentiating factor. This study shows, for the first time, that Tanshinone VI prevents osteoclast differentiation by inhibiting RANKL expression and NFkB induction