Museos y comunicación: algunas reflexiones y consideraciones generales

SIAM. Series Iberoamericanas de Museología. Año 3, Vol.

Papel del motivo LExE de las DNA polimerasas que inician con proteína terminal en la interacción con el nucleótido entrante. Estabilización de los sustratos en el centro activo de polimerización mediada por el subdominio TPR1

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 22-09-2017Esta tesis tiene embargado el acceso al texto completo hasta el 22-03-2019El motivo LExE se encuentra conservado en todas las DNA polimerasas del tipo eucariota, y se localiza cerca del centro activo de polimerización. Estudios previos sugieren que el segundo Glu interacciona con el tercer ion no catalítico en la DNA polimerasa de RB69. En el subgrupo de las DNA polimerasas que inician la replicación con proteína terminal (TP), el primer Glu del motivo LExE está sustituido por Phe/Trp y precedido por una Gly. Se construyeron mutantes puntuales para los residuos aminoacídicos Gly481, Trp483, Ala484 y Glu486 pertenecientes a la DNA polimerasa de ϕ29. Los resultados obtenidos junto a la resolución cristalográfica de la estructura del complejo ternario de la DNA polimerasa de ϕ29 nos permiten concluir que la Gly481 y el Trp483 podrían estar formando un bolsillo donde se acomoda la cadena lateral de la Val250, orientándola correctamente para interaccionar con el dNTP entrante. Los mutantes en el residuo Glu486 son también deficientes en polimerización y, como los mutantes en los residuos Gly481 y Trp483, en la actividad de pirofosforolisis cuando se usa el ion Mg2+, recuperando ambas actividades en presencia de Mn2+ e indicando un posible papel del Glu486 en la interacción con la fracción de pirofosfato del dNTP. La DNA polimerasa del fago ϕ29 contiene dos subdominios denominados TPR1 y TPR2 (Terminal Protein Region), específicos de las DNA polimerasas del subgrupo de Proteinpriming. Estudios previos llevados a cabo sobre la región TPR1 de la DNA polimerasa de ϕ29 revelaron que este subdominio establece las principales interacciones con la TP, además de contribuir a la correcta orientación tanto del extremo 3´-OH de una cadena iniciadora de DNA como del grupo OH- de la Ser232 de la TP en el centro activo de polimerización (Dufour et al., 2000; Dufour et al., 2003). El estudio de los residuos del subdominio TPR1 localizados en el loop y situados en la entrada del surco de unión de los sustratos de la polimerasa, DNA y TP, permiten concluir un papel en la unión y/o estabilización de la molécula iniciadora en el centro activo de polimerización para el residuo Tyr310. Además, el residuo Tyr310 es importante para la correcta estabilización de la TP iniciadora en el centro activo de polimerización de la DNA polimerasa durante los procesos de síntesis de DNA. Así mismo, los mutantes puntuales R306A y F309A presentan deficiencias en las reacciones de iniciación de la replicación y posterior elongación cuando se utiliza como iniciador la proteína terminal, a pesar de cosedimentar con esta última. Estos resultados indican que las DNA polimerasas mutantes no son capaces de situar de manera correcta el dATP iniciador en el centro activo de polimerización, sugiriendo que los residuos Arg306 y Phe309 contribuyen a la correcta orientación del grupo OH- de la Ser232 en la iniciación de la replicación del genoma del fago.The LExE motif is conserved in the eukaryotic-type DNA polymerases being located close to the polymerization active site. Previous researches suggested that the second Glu was involved in binding a third noncatalytic ion in bacteriophage RB69 DNA polymerase. In the Protein-priming DNA polymerases subgroup, the LEXE motif lacks the first Glu in most cases, but it has a conserved Phe/Trp and a Gly preceding it. To ascertain the role of those residues, we have analyzed the behavior of mutants at the corresponding ϕ29 DNA polymerase residues Gly481, Trp483, Ala484, and Glu486. We show that mutations at Gly481 and Trp483 hamper insertion of the incoming dNTP in the presence of Mg2+ ions, a reaction highly improved when Mn2+ was used as metal activator. These results, together with previous crystallographic resolution of ϕ29 DNA polymerase ternary complex, allow us to infer that Gly481 and Trp483 could form a pocket that orients Val250 to interact with the incoming dNTP. Mutants at Glu486 are also defective in polymerization and, as mutants at Gly481 and Trp483, in the pyrophosphorolytic activity with Mg2+. Recovery of both reactions with Mn2+ supports a role for Glu486 in the interaction with the pyrophosphate moiety of the dNTP. ϕ29 DNA polymerase contains two subdomains, named TPR1 and TPR2 (Terminal Protein Region), specifically present in the protein-priming DNA polymerases subgroup. Previous studies revealed an important role of the TPR1 subdomain in establishing the main interactions with TP. It also contributes to the right orientation of both, the terminal 3’-OH group of the primer DNA strand and the OH- group of the TP residue Ser232 at the polymerization active site (Dufour et al., 2000; Dufour et al., 2003). In the second part of this work we have focused on specific residues of the TPR1 subdomain loop which are localized at the entrance of the DNA and TP binding groove. Our results allow us to conclude a role for Tyr310 in the correct stabilization/orientation of the priming molecule at the polymerization active site during the DNA synthesis process. Likewise, we have shown that R306A y F309A mutants exhibit defects during initiation of replication and further elongation when using a TP as primer, despite of cosedimenting with the latter protein. Altogether, the results indicate that the mutant DNA polymerases are unable to place correctly the initiator dATP molecule at the polymerization active site, suggesting that residues Arg306 y Phe309 contribute to the correct orientation of the OH- group of TP Ser232 during the initiation of phage genome replication

Mass Spectral Studies of Organic Ions in the Gas Phase

A single focusing mass spectrometer (Metropolitan Tickers MS2) was adapted to energy studies by adding an electrostatic sector. The electrostatic sector, spherical and symmetric was calculated to allow focusing of the ion beam received at the end of the magnetic sector and taking into consideration the limited space available in the instrument. Diaphragms to correct for the fringing field were introduced. A plate connected to an electrometer monitored the beam between the two sectors while a channel electron multiplier was used as the final collector. All the circuits were new and the potentials and currents obtained were stable at least within 0.1%. The resolution obtained was better than 1 Volt in 1000 Volts. The performance of the instrument was studied, in particular the mass discrimination effect against the lower masses noticed when using the channel electron multiplier in the continuous current mode, Nitrogen, methane and methanol were studied. The shapes of the peaks were obtained by plotting the intensity as obtained in the "channeltron" versus the energy determined from the value of the potential applied to the electrostatic sector plates. The following energetic ions were detected: 1) two groups of energetic ions for peak m/e =14 from nitrogen; ii) a particular shape for peak m/e = 14 from methane which could be caused by an energetic ion, or by the presence of some nitrogen mixed with the methane; iii) a group of energetic ions for peak m/e = 17 from methanol. All these results are in very good agreement with others previously reported in the literature, obtained using different techniques. The following metastable transitions, occurring between the monitor and the electrostatic sector, were detected: i) for Nitrogen ii) for Methane iii) for Methanol These transitions agree with published results obtained with different instruments. For methane one metastable peak was obtained that was attributed to a transition occurring in the first field free region. An attempt was made to obtain information about the kinetic energy released in the metastable transition. A criterion, based on information theory, was developed for the matching of an unknown mass spectrum with that in a computer data bank. The use of the principle of minimum divergence proved adequate in the majority of cases. However, when the same compound is run in various mass spectrometers the divergence between the different spectra of the same compound can he greater than between different compounds on the same instrument. It was also shown that this criterion, deduced theoretically, approached some of the simpler criterions in use, if the spectra were normalised by making the sum of the ion abundances equal to a fixed value instead of, as is a common practice, making the most intense peak equal to one hundred. To test the criterion the files were reorganized, to speed the search, and in one case the file on tape was transferred on to a disc. The programmes used are included in an Appendix. A method was devised to deduce the molecular weight of a compound when the molecular ion does not appear in the spectrum. It is based on the combination of the probabilities of occurrence of the fragment ions and does not involve an a priori knowledge of the compound, except for an estimate of the range of masses that should include the molecular weight

Le «translateur» translaté : l’imaginaire et l’autorité d’un romancier médiéval à travers le cycle post-vulgate et son adaptation portugaise

La traduction portugaise de la version post-vulgate française de la Quête du Graal achevée vers la fin du XIIIe siècle et intitulée A Demanda do Santo Graal, offre un prisme intéressant pour saisir, en contexte et à travers les jeux de déplacements et de reconfiguration, l’imaginaire caractéristique du cycle Post-Vulgate, autrement difficilement accessible. La Demanda do Santo Graal permet de mieux comprendre l’imaginaire du roman français et d’accompagner son évolution en dehors de ses frontières linguistiques à une époque où le romancier n’est plus traducteur, mais devient lui-même une figure d’autorité. Ce travail consiste essentiellement à voir comment la Queste Post-Vulgate lue en parallèle avec la traduction/adaptation portugaise permet de comprendre l’évolution du roman vers la fin du Moyen Âge et la notion d’auteur en faisant la distinction entre le translateur, le créateur et le romancier dans le récit médiéval tout en faisant témoin de l’évolution de leur subjectivité littéraire du roman des origines à celui du Moyen Âge tardif.The Portuguese translation of the Post-Vulgate Cycle completed towards the end of the 13th century and entitled A Demanda do Santo Graal offers an interesting prism to grasp, within the context and through a set of displacement and of reconfiguration, the characteristics of the Queste Post-Vulgate’s imagination, otherwise difficult to access. The Demanda do Santo Grail gives the reader access to the imagination of the Medieval French novel while tracing the different aspects of its evolution outside of its linguistic borders in an era where the writer is no longer a translator, but becomes an auctor. This work mainly shows how the Queste Post-Vulgate, read in conjunction with the Portuguese translation/adaptation, illustrates the evolution of the novel and the concept of author while distinguishing between the translator, the creator and the writer. This important distinction between the different representations of the writer during the medieval period allows one to understand their literary subjectivity in the narrative from the beginning to the end of the Middle Ages

Pronunciamentos de Posse de Michel Temer antes e depois do impeachment: uma análise discursiva e microtextual

O presente trabalho tem por objetivo fazer uma análise crítica de dois discursos proferidos pelo Presidente da República, Michel Temer, por ocasião de sua posse, em dois momentos: como interino, e como presidente de fato, após confirmação do impeachment da Presidenta Dilma Rousseff. Por meio de conceitos importantes do gênero textual discurso (MARCUSCHI, 2008) e de ideologia (THOMPSON, 1995), chegando à Análise de Discurso Crítica – ADC (FAIRCLOUGH, 2001), evidenciam-se modificações encontradas na fala quanto aos objetivos anunciados pelo presidente entre o primeiro e o segundo discursos e, por meio da linguagem utilizada e escolha de vocabulário, é possível avaliar se houve clareza nas propostas apresentadas aos cidadãos

Isolation and characterization of plant growth promoting bacteria isolated from andean soil as potential inoculants of soybean seeds

Argentina is the leading exporter of soybean oil and flour, and the third largest producer of grain. Since, the crop isa matter of great importance to the national economy. Their production depends on the soil as their main resourceto ensure a good productive capacity, so it is necessary to preserve the physical, chemical and biological propertiesof the soil. Although, the indiscriminate use of chemical fertilizers, disturb them. In recent years, there has been atrend towards cleaner production to reduce the use of chemical. One of the alternatives involves biological meansthrough the use of plant growth promoting bacteria. These group of bacteria colonize the rhizosphere of plants andstimulate the plant growth by several mechanisms.The objective of this work was to characterize, identify and evaluate the growth promoting effect of 13 strainsisolated from the Andean vegetation rhizosphere. The bacterial isolates were Enterobacteria, Stenotrophomonas,Pseudomonas, Nocardiodes, Bacillus, Exiguobacterium, Acinetobacter and Lactococcus genera. The results of thebiochemical characterization determined that from the 13 bacterial strains, which produce siderophores, 11possess the catalase enzyme, 10 fixate nitrogen, 12 produce the protease enzyme, 12 solubilize phosphorus, and 11produce indoleacetic acid.The application of different inoculums to the seeds, allowed to obtain plants with longer stem length, moredeveloped roots, larger and more intense coloration leaves than the control plants. The results encourage deeperstudies to achieve the formulation of inoculums to use as a biofertilizer, which would replace chemical fertilizersor reduce their doses.Fil: Belfiore, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Santos, Ana Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; Argentin

Non-forking w-good frames

We introduce the notion of a w-good $\lambda$-frame which is a weakening of Shelah's notion of a good $\lambda$-frame. Existence of a w-good $\lambda$-frame implies existence of a model of size $\lambda^{++}$. Tameness and amalgamation imply extension of a w-good $\lambda$-frame to larger models. As an application we show: $\textbf{Theorem}$ Suppose $2^{\lambda}< 2^{\lambda^{+}} < 2^{\lambda^{++}}$ and $2^{\lambda^{+}} > \lambda^{++}$. If $I(K, \lambda) = I(K, \lambda^{+}) = 1 \leq I(K, \lambda^{++}) < 2^{\lambda^{++}}$ and $K$ is $(\lambda, \lambda^+)$-tame, then $K_{\lambda^{+++}} \neq \emptyset$. The proof presented clarifies some of the details of the main theorem of [Sh576] and avoids using the heavy set-theoretic machinery of [Sh: h \S VII] by replacing it with tameness.Comment: 22 pages; 2 figures; fixed a few typo

Las ruinas de Santo Domingo de Pontevedra

Esta obra nace como resultado de las investigaciones llevadas a cabo por un equipo interdisciplinar que ha trabajado conjuntamente en sucesivos proyectos de investigación. Estos proyectos se enmarcan dentro de la Cátedra de Investigación “Filgueira Valverde”, constituida en 1997 con el fin de fomentar las actividades de investigación en el Campus de Pontevedra, cofinanciada por Caixanova y la Universidad de Vigo y gestionados por el Vicerrectorado de Relaciones Institucionales. El primer proyecto, Identificación de la flora colonizadora de los escudos del centro histórico de Pontevedra. Limpieza y conservación, fue llevado a cabo en el año 1998. El segundo, Colonización vegetal, estado de alteración y pautas de conservación en elementos pétreos representativos de las Ruinas de Santo Domingo se materializó a lo largo del año 2004 y el tercero, Estudio de los factores de deterioro en el conjunto de las Ruinas de Santo Domingo (Pontevedra) Propuesta de las medidas de limpieza, restauración y conservación, se desarrolló durante el año 2008. La dirección de dichos proyectos ha corrido a cargo de la Profesora Titular de Universidad Mª Eugenia López de Silanes

Sarcomatoid Spermatocytic Tumour: Report of a Rare Case and Literature Review

okSpermatocytic tumour (ST) accounts for 1% of testicular germ cell tumours. It is an indolent neoplasm with good prognosis. In approximately 6% of STs, sarcomatous dedifferentiation may occur, portending an aggressive behaviour and representing a significant diagnostic challenge that can lead to its misdiagnosis. Herein, we report the clinicopathological features of a patient with a sarcomatoid spermatocytic tumor, initially diagnosed as mixed germ cell tumour, who was referred to our institution with lung metastases mainly composed of rhabdomyosarcomatous elements. This case report illustrates the importance of recognizing this entity for adequate management of these patients.publishersversionepub_ahead_of_prin

Manifestaciones de la desigualdad en la niñez, adolescencia y juventud : el caso de los trabajadores callejeros de la ciudad de La Plata

Background of INCASI Project H2020-MSCA-RISE-2015 GA 691004. WP1: CompilationEsta ponencia tiene como propósito compartir los primeros resultados de un censo sobre niños/as, adolescentes y jóvenes que trabajan y/o viven en la calle en el casco urbano de la ciudad de La Plata (capital de la provincia de Buenos Aires), llevado adelante en noviembre de 2014. El trabajo se enmarca en una investigación más amplia que tiene como objetivo reconocer la magnitud y las particularidades del fenómeno en cuestión. Las preguntas más importantes que orientan dicha investigación refieren a una búsqueda por reconocer cuántos sujetos se encuentran bajo esta condición ,qué actividades desarrollan, cómo se han constituido sus trayectorias vitales (laborales, educativas, familiares, etc.), qué tipos de usos hacen del espacio público, qué vínculos tejen allí, qué diferencias aparecen entre quienes viven y trabajan en la calle y entre quienes sólo trabajan allí, entre otras