"Sea amable, ceda el asiento". Un análisis histórico Cultural del comportamiento de los pasajeros en el transporte Público de Buenos Aires a principios del siglo XX Zunino Singh, Dhan Sebastian Basado en un análisis cultural de fuentes textuales y visuales (un corpus que comprende desde documentos oficiales a caricaturas y literatura), este trabajo aborda la movilidad cotidiana en el Buenos Aires de principios del siglo XX en tanto práctica y relación social. Entendiendo los espacios de movilidad como espacios sociales, se reconstruyen históricamente las prácticas y representaciones de hombres y mujeres en tanto pasajeros cotidianos del transporte público. Se exploran las experiencias con respecto al viaje, pero también respecto de los “otros”; es decir, se indagan las prácticas de movilidad como experiencias significativas o modos de habitar en movimiento y, por ende, como formas de sociabilidad cotidiana en las grandes urbes. Asimismo, se aborda el modo en que se buscaba modelar los comportamientos de pasajeros y pasajeras a través de discursos sobre “urbanidad” o “civilidad” en tanto prácticas de autodisciplina social en espacios de proximidad corporal.

Sperm acrosome biogenesis and function during fertilization Buffone, Mariano Gabriel Over the last decades, acrosomal exocytosis (also called the “acrosome reaction”) has been recognized as playing an essential role in fertilization. Secretion of this granule is an absolute requirement for physiological fertilization. In recent years, the study of mammalian acrosomal exocytosis has yielded some major advances that challenge the long-held, general paradigms in the field. Principally, the idea that sperm must be acrosome-intact to bind to the zona pellucida of unfertilized eggs, based largely on in vitro fertilization studies of mouse oocytes denuded of the cumulus oophorus, has been overturned by experiments using state-of-the-art imaging of cumulus-intact oocytes and fertilization experiments where eggs were reinseminated by acrosome-reacted sperm recovered from the perivitelline space of zygotes. From a molecular point of view, acrosome exocytosis is a synchronized and tightly regulated process mediated by molecular mechanisms that are homologous to those reported in neuroendocrinal cell secretions. The authors provide a broader perspective, focusing on a limited number of important topics that are essential for understanding the molecular mechanisms governing this step in the fertilization process. They also discuss molecular aspects such as the signaling pathways leading to exocytosis, including the participation of ion channels, lipids, the fusion machinery proteins and the actin cytoskeleton as well as cellular aspects such as the site of acrosomal exocytosis and the use of gene-manipulated animals to study this process. Table of contents Front Matter Pages i-vii The Acrosome Reaction: A Historical Perspective Masaru Okabe Pages 1-13 The Acrosomal Matrix James A. Foster, George L. Gerton Pages 15-33 Role of Ion Channels in the Sperm Acrosome Reaction Carmen Beltrán, Claudia L. Treviño, Esperanza Mata-Martínez, Julio C. Chávez, Claudia Sánchez-Cárdenas, Mark Baker et al. Pages 35-69 The Molecules of Sperm Exocytosis Silvia A. Belmonte, Luis S. Mayorga, Claudia N. Tomes Pages 71-92 Sperm Capacitation and Acrosome Reaction in Mammalian Sperm Cintia Stival, Lis del C. Puga Molina, Bidur Paudel, Mariano G. Buffone, Pablo E. Visconti, Dario Krapf Pages 93-106 Lipid Regulation of Acrosome Exocytosis Roy Cohen, Chinatsu Mukai, Alexander J. Travis Pages 107-127 Role of Actin Cytoskeleton During Mammalian Sperm Acrosomal Exocytosis Ana Romarowski, Guillermina M. Luque, Florenza A. La Spina, Dario Krapf, Mariano G. Buffone Pages 129-144 Site of Mammalian Sperm Acrosome Reaction Noritaka Hirohashi Pages 145-158 Acrosome Reaction as a Preparation for Gamete Fusion Patricia S. Cuasnicú, Vanina G. Da Ros, Mariana Weigel Muñoz, Débora J. Cohen Pages 159-172

Enzimas: la velocidad de la vida Calvo, Juan Carlos Presenta el tema de la cinética enzimática en un modo sencillo y adecuado para alumnos de grado de carreras biomédicas. Abarca los análisis cinéticos, modelo de Michaelis y Menten, enzimas alostéricas, inhibidores y metodología utilizada en el laboratorio.

The diversity of microbial extremophiles Rasuk, Maria Cecilia; Ferrer, Gabriela Mónica; Farias, Maria Eugenia; Albarracín, Virginia Helena Extreme environments are defined as those habitats in which human life is not possible. Thus, from a human point of view, those forms of life thriving in those conditions will be called as "extremophiles". Environments that harbor this kind of life are widespread around the globe, including hot springs, hydrothermal vents, deep ocean, deserts, high-altitude environments, brines and soda lakes, nuclear reactors, ice sheets, and toxic wastes (Stetter 1999; Miroshnichenko and Bonch-Osmolovskaya 2006; Raymond et al. 2008; Dib et al. 2009; Albarracín et al. 2011, 2012; Albarracín and Farías 2012). Including representatives of all three domains of life, that is, Bacteria, Archaea, and Eukaryote, extremophiles are denoted by a descriptive term, usually a word with Greek or Latin roots followed by the combining form phile Greek term for "loving." Their names are given depending on the physicochemical factor they withstand, such as thermophiles, psychrophiles (organisms growingbest at high or low temperatures), acidophiles, alkaliphiles (organisms optimally adapted to acidic or basic pH values), barophiles (organisms that grow best under pressure), xerophiles (resistant to desiccation), or halophiles (organisms that require high salt concentrations for growth). In addition, a much larger diversity of organisms can tolerate extreme conditions and grow, but not necessarily optimally in extreme habitats; these organisms are defined as extremotrophs or extreme tolerant(Stojanović et al. 2008; Madigan et al. 2014).The discovery of extremophiles has drastically changed our understanding toward the diversity of life itself and the conditions under which it can be sustained. Thus, extremophiles are of interest for both basic and applied science. Indeed, these "superbugs" hold many interesting biological secrets, such as the biochemical limits on the stability of macromolecules and the genetic instructions for constructingstable macromolecules to one or another extreme. They are very important in the study of origins of life; many extremophiles, in particular the hyperthermophiles, lie close to the "universal ancestor" of all existent life on Earth. This exciting realization has fueled much research on these organisms to understand the nature of primitive life forms, how the first cells "made a living" in Earth's early days, and how early organisms set the stage for the evolution of modern life forms (Madigan 2000). Also, astrobiologists are particularly interested in studying extremophiles, as many organisms of this type are capable of surviving in environments similar to those from other planets; Mars may have regions in its deep subsurface that could harbor extremophiles. Likewise, the subsurface water ocean of Jupiter's moon Europa may harbor a similar "extreme" life (Westall et al. 2002; Edwards et al. 2005).Extremophiles are also the focus of biotechnological processes. Due to their amazing array of enzymes and other chemical compounds, they have provided products to be used under extreme conditions in applications as diverse as laundry detergent additives and the genetic identification of criminals (Ito et al. 1998).The aim of this work is to offer a short, but comprehensive report on the biology and biodiversity of extremophilic microbes thriving in particular environments around the globe together with a description on their importance for basic research and common biotechnological applications.

Valoración productiva del conocimiento científico Rintoul, Ignacio Este capítulo relata el proceso de creación de una EBT. La estrategia de accionesconsistió en el desarrollo sincronizado de la tecnología, la financiación, lapropiedad intelectual, la comunicación social, la investigación de mercado, eldesarrollo de socios estratégicos, la negociación con empresas licenciantes y lavisión dinámica del negocio de innovación durante todas las etapas del proyecto.Se exponen además, los roles del investigador responsable, el equipo de trabajo,las instituciones y los entes de financiación. Así mismo de describen los aciertos,los fracasos, los incentivos personales, la psicología emprendedora y laspropuestas de mejora que deberían implementarse para multiplicar lasexperiencias exitosas de creación de EBTs. El lenguaje utilizado es muy sencilloy los análisis y ejemplos expuestos son extremadamente simplistas y apelan másal sentido común del lector que a la rigurosidad documental. Esto seguramenteatenta contra la exactitud y prolijidad del trabajo pero sin dudas aumenta lacomprensión del público en general.; This chapter describes the generation of a technology-based Enterprise (TBE). The strategy consisted in the synchronized development of technology, financing, intellectual property, social communication, market research, choose of strategical partners, licensing negotiation, and dynamic vision of the innovation process along every step of the project. The roles of the leader, the team, the institution and the financing organizations, is highlighted. Successes and failures are described as well as personal abilities needed to generate a TBE. The description is made with a very simple language to improve a general access to the public.

Los indicadores de la contaminación de las aguas monitoreo químico y biomonitoreo Sabatini, Sebastian Eduardo; Ruíz, María D.; Calcagno, Javier Ángel Durante gran parte de la historia deldesarrollo humano los ambientes acuáticos han sido considerados como meras fuentes de abastecimiento de aguay eliminación de residuos. La creenciade que todo lo que se vertía en el medio acuático se diluiría debido a la inmensidad de los océanos (algo más delas dos terceras parte de la superficie denuestro planeta), hizo que la idea de lacontaminación acuática resultara algoimpensado. Hoy en día se sabe que tanto las actividades humanas como cierLos indicadores de lacontaminación de lastos procesos naturales pueden afectarla calidad de las aguas superficiales ysubterráneas. Es un tema complejo deenorme importancia ambiental, económica y científica, que ha sido objeto dedebate en los últimos años.

Refugios de fuego de Austrocedrus chilensis y su función en la expansión del bosque sobre el matorral en el noroeste de la Patagonia; Austrocedrus chilensis fire refuges and their role in the expansion of forest over shrubland in northwest Patagonia Landesmann, Jennifer Brenda El fuego modula la dinámica de la vegetación, favoreciendo distintas estrategias de persistencia y recolonización. Especies de reproducción obligada por semilla dependen de características ambientales para persistir, como de refugios los cuales tienen atributos biofísicos que disminuyen la severidad del fuego, permitiendo su supervivencia y dispersión post-fuego. Mientras que hay especies que mediante órganos de reserva pueden persistir y rebrotar. El objetivo de esta tesis es desarrollar y validar un modelo conceptual de dinámica sucesional entre comunidades vegetales de distinta historia de vida en paisajes propensos al fuego. En el noroeste de Patagonia, matorrales rebrotantes y bosques de Austrocedrus chilensis (ciprés) responden diferencialmente al fuego generando un ciclo sucesional. Estudié características de remanentes de ciprés, su potencial de dispersión hacia la matriz y las interacciones entre rebrotantes y ciprés en el tiempo. Encontré que los remanentes de ciprés ocurren en refugios donde la alta relación roca/vegetación disminuiría la severidad del fuego. Los cipreses revelaron mayor crecimiento en refugios que en la matriz, aunque exhibieron severas reducciones durante años secos. Este compromiso entre supervivencia al fuego y vulnerabilidad a la sequía implicaría que la funcionalidad de los refugios podría reducirse ante incrementos en la severidad de estos eventos. La dispersión de semillas de ciprés desde refugios presentó un kernel de cola gorda, indicando posibilidad de dispersión a largas distancias y rápida expansión. Aunque el establecimiento de plántulas de ciprés incrementó ante la presencia de rebrotantes, el posterior crecimiento del ciprés estuvo suprimido por al menos 15 años hasta que superaron la competencia de las rebrotantes. Los refugios de fuego son clave para la persistencia y recolonización del ciprés, pero la competencia con las rebrotantes en la matriz estaría enlenteciendo el proceso sucesional, lo que podría aumentar la probabilidad de incendio y modificar el curso sucesional hacia un estadio dominado por rebrotantes.; Fire shapes vegetation dynamics favoring different persistence and recolonization strategies. Obligate seeders depend on environmental characteristics to persist, like fire refuges which are characterized by byophisical attributes that reduce fire severity, thus allowing their survivorship and post-fire seed dispersal. On the other hand, resprouters rely on belowground storage structures to persist and recover after fire. The general aim of this thesis is to develop and validate a conceptual model of succesional dynamics of plant communities with different life-history traits in fire-prone landscapes. In northwest Patagonia, resprouting shrubs and Austrocedrus chilensis trees (obligate seeders) respond differently to fire and take part in a succesional cycle. I studied attributes of A. chilensis remnants that survived fire, their seed dispersal potential to the surrounding matrix and the interaction between A. chilensis and resprouter shrub species along time. I found that A. chilensis remnants are the result of fire refuges where high rock to vegetation ratios may reduce fire severity, allowing survivorship. A. chilensis within refuges showed higher growth rates than those growing within the matrix, but displayed severe reductions in growth during dry years. This trade-off between fire survival and vulnerability to drought may imply that fire refuges could reduce their functionality under increasing drought and fire severity. A. chilensis seed dispersal from refuges presented a fat tailed kernel, meaning long distance dispersal probability and high expansion rates. Although A. chilensis seedling establishment was increased by resprouters’ presence, obligate seeders’ growth was suppressed for at least 15 years until they overcome competition by resprouters and ended suppressing resprouters’ growth. Fire refuges play a key role for A. chilensis persistence and recolonization; however, competition with resprouters in the matrix may be slowing down the successional process, which may probably increase fire probability and modify the course of succession to a resprouters dominated stage.

Validation of a Statistical Forecast Model for Zonda Wind in West Argentina Based on the Vertical Atmospheric Structure Norte, Federico Augusto; Simonelli, Silvia Carmen Zonda is a strong, warm, very dry wind associated with adiabatic compression upon descending the eastern slopes of the Andes Cordillera in western-central Argentina. This research seeks, first, to validate the skill of a statistical forecast of zonda based on the behavior of the vertical structure of the atmosphere and, second, to describe the climatology of the vertical profile leeward of the Andes. The forecast was built for May-August 1974/1983, and was verified against a series of cases recorded in the Mendoza Aero and San Juan Aero weather stations for May-August 2005/2014.It made use of the Stepwise Discriminant Analysis (SDA) and rawinsonde data from Mendoza Aero as predictors, with the following input variables: surface pressure, temperature, dew point, and the zonal and meridional components of the wind on surface and of the fixed levels up to 200 hPa.The variables selected as predictors by the SDA were: surface pressure, dew point depression at 850 hPa, meridional wind component at 850 hPa, and zonal wind component at 400 hPa. Climatology of the vertical profile of the atmosphere leeward of the Andes was built from daily rawinsonde data from Mendoza Aero for May-August 1974/1983. Zonda markedly influences the atmospheric structure leeward of the Andes in western-central Argentina. Its maximum impact occurs at850 to 800 hPa, with significant heating and decrease of humidity. Validation of the prediction program considered deterministic and probabilistic forecasts. Contingency tables show that probability of zonda occurrence in the plains is generally overestimated, and false alarm cases are far more frequent than surprise events. The main contribution of this paper is precisely the validation of the prediction model, which ensures forecasters one more tool to improve zonda forecasting; this, in turn, will aid decision-makers when taking steps to ameliorate zonda wind impact.

Psychometric properties of the Attitudes Toward Gay men scale in Argentinian context: The influence of sex, authoritarianism, and social dominance orientation; Propiedades psicométricas de la escala de Actitudes hacia la Homosexualidad Masculina en el contexto argentino. La influencia del sexo, el autoritarismo y la orientación a la dominancia Etchezahart, Edgardo; Ungaretti, Joaquín; Prado-Gasco, Vicente; Brussino, Silvina Alejandra Even though prejudice toward male homosexuality is one of the main reasons for discrimination in Argentina, there is no valid measure to assess it. The aim of this study was to analyze the psychometric properties of the Attitudes Toward Gay Men Scale (ATG) and to examine the influence of sex, right wing authoritarianism, and social dominance orientation on anti-gay attitudes. Data were collected with a convenience sample of 436 undergraduate students from University of Buenos Aires. Analysis of the data showed adequate psychometric properties for the ATG Scale and the moderating effect of sex, right wing authoritarianism and social dominance orientation on anti-gay attitudes. Implications of these findings were discussed.  ; A pesar de que el prejuicio hacia la homosexualidad masculina constituye una de las principales causas de discriminación en Argentina, no existen instrumentos válidos para evaluar dicho constructo. El objetivo del presente trabajo fue analizar las propiedades psicométricas de la escala de Actitudes hacia la Homosexualidad Masculina (ATG) y examinar la influencia del sexo de los participantes, el autoritarismo del ala de derechas y la orientación a la dominancia social en las actitudes anti-gay. La muestra fue intencional y estuvo compuesta por 436 estudiantes de la Universidad de Buenos Aires. El análisis de los datos indicó adecuadas propiedades psicométricas para la escala ATG, así como el efecto moderador del sexo en las relaciones entre el autoritarismo del ala de derechas y la orientación a la dominancia social en las actitudes anti-gay. Se discuten las implicancias del presente estudio.

Fiscalidad y petróleo: un análisis tributarioambiental a partir de gravámenes concretos; Taxation and petroleum: an environmental-taxation analysis from specific taxes Salassa Boix, Rodolfo Rubén Este trabajo es un artículo de investigación científica que a partir de gravámenes concretos pretende demostrar el papel que los tributos pueden jugar ante los riesgos y daños ecológicos derivados del petróleo. Este análisis se construyó con base en una visión esencialmente dogmática del Derecho; de esta manera, la meta fue comprender primero y explicar después el significado de las normas positivas vigentes sobre los tributos ambientales. La principal conclusión afirma que si de prevenir y mitigar se trata, proponemos la regulación de tributos ambientales cuya presión fiscal no deje indiferente a los sujetos vinculados con las actividades petroleras. Si de obtener fondos para limpiar, recomponer o compensar se trata, proponemos la regulación de tributos, que más allá de la presión fiscal afecte a los sujetos vinculados con las actividades petroleras y destine la totalidad o mayoría de su recaudación a la limpieza, recomposición o compensación por la contaminación del petróleo.REVISTA INDEXADA:- ERIH PLUS- SCIELO- PUBLINDEX (Índice bibliográfico oficial de Colombia, Categoría B)- REDALYC- BASE DE DATOS LEXBASE- EBSCO- LATINDEX (En catálogo, con Doble referato ? evaluadores externos)- DIALNET; This paper is a scientific research that aims to demonstrate the role that taxes can play against the risks and ecological damages linked with petroleum activities. The work was essentially plannedfrom a dogmatic legal vision. Thus, the goals were first to understand and then to explain the meaning of the current positive regulation on ecological taxes. The main conclusion asserts that if we need to prevent and mitigate is desirable to regulate ecological taxes whose fiscal burden do not be insignificantfor subjects linked to petroleum activities. If we need to get funds to clean, rebuild or compensate is desirable to impose taxes that, beyond the degree of their fiscal burden, affect all subjects linked to any oil activity and allocate all or most of their collection to clean, restructure or compensate damages derived from petroleum pollution.

Conflict in Pre-Hispanic Northwest Argentina: Implications Arising From Human Bone Trauma Patterns Gheggi, María Soledad The time span ranging from ca. 900 to 1450A.D. in the South-Central Andes has been traditionally posited as a period of social unrest, political disintegration and large-scale conflict due to, primarily, environmental causes. However, the osteological record of traumatic injuries in a sample of 223 adult and subadult crania from different areas of Northwest Argentina does not clearly correspond to the expected scenario of pervasive and formalized armed attacks. Cranial trauma prevalence in the sample is low (17.48%), and no statistically significant differences were met between the sexes. No differences were found when comparing trauma prevalence between settlements or regions, suggesting that location or function of the sites may not have influenced in trauma frequencies. This information more comfortably agrees with a scenario of conflict where several sources of violence may have caused the record of traumatic injuries (i.e. raids, ambushes, etc). These results serve to problematize how conflict is expected to be expressed in the archaeological record, especially in osseous human remains, what sources of violence may have generated the traumatic patterns observed and the intensity of conflict in this region in particular and in the pre-Hispanic Andes in general.

The Einstein Nanocrystal Bertoldi, Dalía Surena; Fernandez Guillermet, Armando Jorge; Miranda, Enrique Nestor We study the simplest possible model of nanocrystal consisting in a simple cubic lattice with a small number of atoms (NA ~ 10-10^3), where each atom is linked to its nearest neighbor by a quantum harmonic potential. Some properties (entropy, temperature, specific heat) of the nanocrystal are calculated numerically but exactly within the framework of the microcanonical ensemble. We find that the presence of a surface in the nanocrystal modifies the thermostatistic properties to a greater extent than the small number of atoms in the system. The specific heat Cv behaves similarly to the Einstein solid, with an asymptotic value for high temperatures that differs from that of the Dulong-Petit law by a term of the order of NA^(-1/3) and that can be explained easily in terms of the surface. The entropy is non-additive, but this is due to the presence of the surface and we show that the additivity is recovered in the thermodynamic limit. Finally, we find that, when calculations follow the canonical ensemble, results differ little for small systems (NA = 27) and are inexistent for larger systems (NA = 1000).

Inserción desigual de inmigrantes bolivianos en un mercado de trabajo segmentado : un estudio en municipios del este salteño; Unequal insertion of bolivian immigrants in a segmented labor market : a study in municipalities in eastern salta Ataide, Soraya En este trabajo nos proponemos aportar a los estudios sobre migración y movilidad social, analizando las trayectorias y redes migratorias de bolivianos vinculados a un mercado de trabajo agrícola. Nuestro objetivo entonces es explicar la conformación de un mercado de trabajo segmentado por la etnia nacionalidad boliviana. Partimos de la necesidad de discutir la idea de “colectividad boliviana” como un grupo homogéneo y de relativizar el éxito socio económico de ciertos inmigrantes laborales. También destacamos la importancia de observar las trayectorias y redes migratorias que conforman, atravesadas por distintas desigualdades y ancladas en diferentes contextos espacio - temporales. Nuestro referente empírico se ubica en dos municipios del este salteño, Apolinario Saravia y Gral. Pizarro, donde actualmente se desarrolla una producción hortícola de frescos, orientada al mercado interno, con una fuerte presencia de trabajadores y productores de origen boliviano, que fueron llegando, desde hace por lo menos cinco décadas, en distintos contextos espacio – temporales, nacional, regional provincial y local. Utilizamos una estrategia metodológica de tipo longitudinal cualitativa y nuestra herramienta metodológica es la trayectoria migratoria, a la vez que la utilizamos como unidad de análisis.; The aim of this paper is to contribute to studies on migration and social mobility by analysing the migratory tracks of Bolivian migrants in a horticultural labor market. Our purpose is to explain the formation of a labor market segmented by the Bolivian nationality and ethnicity. Our starting point is the need to discuss the idea of the “Bolivian community” as a homogeneous group and to relativize the socio-economic success of a small group of these immigrants. We also emphasize the importance of observing their migratory tracks and networks, crossed by different inequalities and anchored in different spatio - temporal contexts. Two municipalities of eastern Salta, Apolinario Saravia and Gral. Pizarro, constitute our empirical references. There, a horticultural production of fresh produce is being developed, oriented to the domestic market, with a strong presence of workers and producers of Bolivian origin for at least five decades in different spatio - temporal, national, regional and local contexts. We use a longitudinal qualitative methodological strategy and our methodological device and also unit of analysis is the “migratory track”.

Synergetic interplay between metal (Pt) and nonmetal (C) species in codoped TiO2: A DFT+U study Morgade, Cecilia Ines Nora; Cabeza, Gabriela Fernanda The structural, energetic, magnetic and electronic properties of Pt-C-doped and Pt/C-codoped TiO2 have been studied using first-principle calculations to elucidate the effect of the metal-nonmetal interactions. Compared with other non-metals, C-doping induces the formation of complex structures on titania. From the analysis of the electronic structures of the C-doping system, band gap narrowing as well as the formation of localized gap states are observed in it. The calculated results are in agreement with the experimental absorptions observed in the UV-visible diffuse reflectance spectroscopy spectra. Based on our results, the main findings relating to Pt/C codoping are the formation of highly symmetric coordination-like compounds and the formation of impurity states in the band gap that could be propitious for the separation of photoexcited electron-hole pairs. Is especially remarkable the case of Pt/C@Ti-codoped TiO2 which could be the most effective for the redox reaction of H2O to produce H2 and O2 because it presents the greatest narrowing of the band gap, the lower shift of the conduction band and it is the only one that favorably modifies the position of valence band. All are necessary conditions for the reaction mentioned.

New national and regional bryophyte records, 46 Ellis, L.T.; Asthana, A.K.; Srivastava, P.; Omar, I.; Rawat, K.K.; Sahu, V.; Cano, M.J.; Costa, D.P.; Dias, E.M.; Dias dos Santos, N.; Silva, J.B.; Fedosov, V.E.; Kozhin, M.N.; Ignatova, E.A.; Germano, S.R.; Golovina, E.O.; Gremmen, N.J.M.; Ion, R.; Ştefǎnuţ, S.; von Konrat, M.; Jimenez, Maria Soledad; Suarez, Guillermo Martin; Kiebacher, T.; Lebouvier, M.; Long, D.G.; Maity, D.; Ochyra, R.; Parnikoza, I.; Plášek, V.; Fialová, L.; Skoupá, Z.; Poponessi, S.; Aleffi, M.; Sabovljević, M.S.; Sabovljević, A.D.; Saha, P.; Aziz, M.N.; Sawicki, J.; Suleiman, M.; Sun, B.-Y.; Vá?a, J.; Wójcik, T.; Yoon, Y.-J.; Żarnowiec, J.; Larraín, J.

The N-terminal pre-A region of Mycobacterium tuberculosis 2/2HbN promotes NO-dioxygenase activity Pesce, Alessandra; Bustamante, Juan Pablo; Bidon Chanal, Axel; Boechi, Leonardo; Estrin, Dario Ariel; Luque, Francisco Javier; Sebilo, Anne; Guertin, Michel; Bolognesi, Martino; Ascenzi, Paolo; Nardini, Marco A unique defense mechanisms by which Mycobacterium tuberculosis protects itself from nitrosative stress is based on the O2-dependent NO-dioxygenase (NOD) activity of truncated hemoglobin 2/2HbN (Mt2/2HbN). The NOD activity largely depends on the efficiency of ligand migration to the heme cavity through a two-tunnel (long and short) system; recently, it was also correlated with the presence at the Mt2/2HbN N-terminus of a short pre-A region, not conserved in most 2/2HbNs, whose deletion results in a drastic reduction of NO scavenging. In the present study, we report the crystal structure of Mt2/2HbN-ΔpreA, lacking the pre-A region, at a resolution of 1.53 Å. We show that removal of the pre-A region results in long range effects on the protein C-terminus, promoting the assembly of a stable dimer, both in the crystals and in solution. In the Mt2/2HbN-ΔpreA dimer, access of heme ligands to the short tunnel is hindered. Molecular dynamics simulations show that the long tunnel branch is the only accessible pathway for O2-ligand migration to/from the heme, and that the gating residue Phe(62)E15 partly restricts the diameter of the tunnel. Accordingly, kinetic measurements indicate that the kon value for peroxynitrite isomerization by Mt2/2HbN-ΔpreA-Fe(III) is four-fold lower relative to the full-length protein, and that NO scavenging by Mt2/2HbN-ΔpreA-Fe(II)-O2 is reduced by 35-fold. Therefore, we speculate that Mt2/2HbN evolved to host the pre-A region as a mechanism for preventing dimerization, thus reinforcing the survival of the microorganism against the reactive nitrosative stress in macrophages. Database Coordinates and structure factors have been deposited in the Protein Data Bank under accession number 5AB8. Removal of the pre-A region in M. tuberculosis 2/2HbN (Mt2/2HbN-ΔpreA) results in dimerization and in a reduced access to the heme pocket. Kinetic measurements indicate a 4-fold decrease in kon for peroxynitrite isomerization and a 35-fold decrease in NO-scavenging relative to full-length Mt2/2HbN. Thus, the pre-A region might be involved in reinforcing survival of the microorganism against nitrosative stress in macrophages.

Eprinomectin accumulation in Rhipicephalus (Boophilus) microplus: Pharmacokinetic and efficacy assessment Lifschitz, Adrian Luis; Nava, Santiago; Mangold, Atilio Jose; Imperiale, Fernanda Andrea; Ballent, Mariana; Canevari, J.; Lanusse, Carlos Edmundo Eprinomectin (EPM) is a macrocyclic lactone used against endo-ectoparasites without withdrawal time in milk and meat after its pour-on administration at 0.5 mg/kg. Previous experiments evaluated the efficacy of EPM against Rhipicephalus (Boophilus) microplus in cattle. This study assessed EPM efficacy against R. (B.) microplus after topical administration at two dose rates and investigated the relationship between EPM systemic exposure in the host and drug concentrations accumulated in ticks recovered from treated animals. A standardized pharmaco-parasitological study was performed in two phases. In phase 1 eighteen Braford cattle naturally infected with R. (B.) microplus were divided into three experimental groups with a similar level of infestation (Kruskal-Wallis test, P > 0.05): control group and treated groups with EPM pour-on (1 and 1.5 mg/kg). Samples of heparinized blood and ticks at different life stages were taken between 0 and 21 days (d) post-administration to measure EPM concentrations by HPLC. The efficacy trial (phase 2) included eighteen Braford calves naturally infected with R. (B.) microplus divided into control group and 1 mg/kg and 1.5 mg/kg EPM treated groups. Female ticks (4.5-8 mm) on cattle were counted between 1 and 23 days post-treatment to evaluate the efficacy of EPM. The reproductive efficiency index (REI) and the fertility efficiency index (FEI) were evaluated. Plasma concentrations of EPM showed a linear relationship with the level of dose rate administered. Peak plasma concentrations were within a range between 13.8 and 90 ng/ml, which guarantee milk drug concentrations below the maximum residues level. High EPM concentrations were detected in ticks. EPM concentrations in R. (B.) microplus were correlated to plasma concentrations between 1.25 days and 21 days post-administration (r 0.84; P < 0.05). EPM efficacy calculated using the Henderson-Tilton formula was 98.9% and 99.1% (7 days post-administration) and 100% (23 days post-administration) after EPM treatment at 1 and 1.5 mg/kg, respectively. EPM administered at 1.5 mg/kg also showed a significantly higher deleterious effect on tick fertility as measured by FEI (P < 0.01). Therefore, treatment with EPM may be useful for controlling ticks in cattle, particularly in dairy production systems.

Dibujando la nación desdibujando al enemigo: Imágenes de movilización bélica en la prensa de guerra paraguaya, 1867-1868 Johansson, Maria Lucrecia Between 1864 and 1870, the Paraguayan forces clashed with the armies of Argentina, Brazil and Uruguay, in what was called the War of the Triple Alliance (1864-1870). During that war, the Paraguayan government revolutionized journalism by the creation of two illustrated newspapers: El Centinela and Cabichuí (1867-1868). The engravings of these newspapers created a system of opposition we/they that rested on opposite values and in the opposition between negative and positive images. The aim of this paper is to analyse how the press built negative images of the enemy and how those images were the basis for creating a positive representation of Paraguay.

Defining the HLA class I-associated viral antigen repertoire from HIV-1-infected human cells Ternette, Nicola; Yang, Hongbing; Partridge, Thomas; Llano, Anuska; Cedeño, Samandhy; Fischer, Roman; Charles, Philip D.; Dudek, Nadine L.; Mothe, Beatriz; Crespo, Manuel; Fischer, William M.; Korber, Bette T. M.; Nielsen, Morten; Borrow, Persephone; Purcell, Anthony W.; Brander, Christian; Dorrell, Lucy; Kessler, Benedikt M.; Hanke, Tomáš Recognition and eradication of infected cells by cytotoxic T lymphocytes is a key defense mechanism against intracellular pathogens. High-throughput definition of HLA class I-associated immunopeptidomes by mass spectrometry is an increasingly important analytical tool to advance our understanding of the induction of T-cell responses against pathogens such as HIV-1. We utilized a liquid chromatography tandem mass spectrometry workflow including de novo-assisted database searching to define the HLA class I-associated immunopeptidome of HIV-1-infected human cells. We here report for the first time the identification of 75 HIV-1-derived peptides bound to HLA class I complexes that were purified directly from HIV-1-infected human primary CD4+ T cells and the C8166 human T-cell line. Importantly, one-third of eluted HIV-1 peptides had not been previously known to be presented by HLA class I. Over 82% of the identified sequences originated from viral protein regions for which T-cell responses have previously been reported but for which the precise HLA class I-binding sequences have not yet been defined. These results validate and expand the current knowledge of virus-specific antigenic peptide presentation during HIV-1 infection and provide novel targets for T-cell vaccine development.

Esfera pública y redes sociales en Internet: ¿Qué es lo nuevo en Facebook?; Public sphere and social networks resources on Internet: What's new in Facebook? Raimondo Anselmino, Natalia; Reviglio, María Cecilia; Diviani, Ricardo Habitamos en sociedades altamente mediatizadas ya no sólo completamente atravesadas por la acción de los medios masivos de comunicación sino, también, por las nuevas tensiones que asume el proceso de mediatización a partir del desarrollo de las redes sociales en Internet. Al reconocer la naturaleza ambiental y constructiva de los medios masivos de comunicación es posible, también, considerar a la mediatización como modalidad nuclear de construcción de la esfera pública. En dicho contexto, este escrito inquiere sobre los modos en que el funcionamiento de Facebook y los discursos allí expuestos participan en la configuración de la esfera pública contemporánea, así como, además, sobre el grado de novedad que presenta dicha intervención respecto de la ejercida por los tradicionales medios masivos de comunicación. En función de articular las reflexiones expuestas con algunos de los ejes que ha asumido el debate teórico suscitado por el análisis que realizó Habermas sobre la génesis y las transformaciones estructurales de la vida pública, este texto se concentra en los siguientes tres aspectos: la gestión de la visibilidad, de la puesta en público o publicación; el lugar que ocupan el diálogo, la deliberación y el disenso; la condición múltiple y móvil de la esfera pública actual.; We live in highly mediatizated societies and not only completely traversed by the action of the mass media but also by new tensions that assumes the mediatization process from the development of social networks resources on Internet. Recognizing the environmental and constructive nature of the mass media, it is also possible to consider mediatization as nuclear mode of construction of the public sphere. In this context, this paper asks about the ways in which the operation of Facebook and discourses posted there shape contemporary public sphere, and also the degree of novelty of such intervention with respect to that exerted by the traditional mass media. For the purpose of joint thinkings reflections exposed with some of the areas that has taken the theoretical debate surrounding the Habermas's analysis about the genesis and structural transformations of public life, this text focuses on the following three aspects: the management of visibility, of commissioning public or publication; the place of dialogue, deliberation and dissent; the multiple and mobile status of the current public sphere.