Las configuraciones emergentes del consumo: Transformaciones del comercio minorista y restructuración de la centralidad en la región metropolitana de Buenos Aires; Emerging configurations of consumption: Transformations of retail trade and restructuring of centrality in the metropolitan region of Buenos Aires Vecslir, Lorena; Sciutto, Florencia Elisa En una región urbana tan compleja como la de Buenos Aires, los espacios de consumo no pueden reducirse a solo dos formatos (shopping vs. calle comercial) o emplazamientos (centro vs. periferia). Este trabajo busca explicar la estructura y transformaciones del comercio minorista en el contexto metropolitano. Específicamente, se orienta a la construcción de cartografías ilustrativas de las múltiples configuraciones que este segmento económico adquiere en los distintos corredores y coronas metropolitanas, más allá de los modelos jerárquicos y del peso de la centralidad tradicional. En base a datos de Google Maps y otras fuentes complementarias, se generan mapas de diversidad e intensidad comercial que muestran una estructuración lineal de esta actividad a lo largo de antiguas rutas y avenidas supramunicipales, y una concentración nodal en torno a las estaciones ferroviarias, con infiltración en las mallas residenciales e industriales preexistentes. Simultáneamente, se identifican algunas tendencias recientes de transformación o revitalización comercial que suman a los centros, corredores y shoppings tradicionales, nuevos productos tales como shoppings de cercanía, polos gastronómicos y operaciones de renovación de centros comerciales "a cielo abierto". Se parte de la base de que la lectura interpretativa de estas configuraciones emergentes puede servir para identificar dinámicas más amplias de reestructuración de la centralidad metropolitana y especificidades de cada contexto que han tendido a ser soslayadas por estudios urbanos enfocados en los efectos territoriales de la globalización.; In an urban region as complex as it is Buenos Aires, consumption spaces cannot be reduced to only two formats (shopping centers vs. shopping streets) or locations (downtown vs. periphery). This paper seeks to explain the structure and transformations of the retail commerce in the metropolitan context. Specifically, it is oriented towards the construction of illustrative cartographies of the multiple configurations that this economic segment acquires in the different metropolitan corridors and rings, in addition to the hierarchical models and weight of the traditional centrality. Based on data from Google Maps and other complementary sources, maps of diversity and commercial intensity are generated showing a linear structure of this activity along ancient routes and supramunicipal avenues, along with a nodal concentration around railway stations, with infiltration in the pre-existing residential and industrial fabric. Simultaneously, some recent trends of commercial transformation or revitalization have been identified, that join to the centers, corridors and traditional shopping malls, new products such as neighborhood shopping malls, gastronomic centers, and renovation operations of open-air shopping centers. It is assumed that the interpretative lecture of these emerging configurations can serve to identify broader dynamics of the restructuring of metropolitan centrality and specificities of each context that have tended to be avoided by urban studies focused on the territorial effects of globalization.

Evaluating the mapping particle filter in high-dimensional state spaces Pulido, Manuel Arturo; Van Leeuwen, Peter Jan The use of Monte Carlo techniques to represent sequentially the state of a system given a set of noisy observations are a challenge for high-dimensional systems with nongaussian statistics. A novel particle filter is introduced which aims to an efficient sampling of high-dimensional state spaces considering a limited number of particles. The filter is based on variational importance sampling and optimal transport.

Medicinal plants of ethnopharmacological relevance in Sierra de Ancasti, Catamarca, Argentina Martínez, Gustavo Javier The aim of this work is to document the knowledge, significance, and uses of medicinal plants in the rural population of Ancasti, Catamarca, Argentina, considered an area of great biodiversity. The community defines itself as criollos-serranos and its subsistence economy is associated with traditional livestock production systems and small-scale agriculture. The techniques used in ethnobiology were adopted as a methodological framework. Informants were selected intentionally based on their expertise or by snowball sampling. The specific information about the topic was gathered by records and documentation of species, open interviews and specific semi-structured surveys, participant observation and records of a rapid rural diagnosis. For quantitative analysis, two indices were applied, including: Relative Importance (RI), and Informant Consensus Factor (ICF). A total of 209 medicinal plant and 5 species of fungi belonging to 70 families were recorded. Asteraceae was dominating with 25 species. Herbs were leading with a 45% contribution, followed by shrubs. The RI index highlights species like Rosmarinus officinalis, Vachellia caven and Cestrum parqui, also others rarely referred to in previous studies, as in the case of Lithraea molleoides. The medicinal flora in Ancasti, Catamarca is highly diverse and remained scarcely explored so far. Its composition accounts for a set of species and applications that are shared with those of other regions of central and northwestern Argentina, highlighting the presence of intercultural contacts.

Interactions of equatorial winds in super-Eddington stellar sources Abaroa, Leandro; Sotomayor Checa, Pablo Omar; Romero, Gustavo Esteban Compact objects accreting at super-Eddington rates launch powerful winds and jets. The jet interacts with the wind of the disk. A powerful jet pushes the wind sidewards producing a supersonic equatorial outflow. Such a situation might be the case in the well-known super-accreting Galactic microquasar SS433, where theexistence of an equatorial wind has been revealed by high-resolution radio observations. In this work, we present preliminary results of quantitative estimates of the expected radiation from the interaction between a jet-induced equatorial wind and a very luminous donor star with weak or null winds (e.g. a PopIII star). The results are of interest for understanding ultraluminous X-ray sources and other super-Eddington accretors in the early universe.

Sulfur fertilization in soybean: A meta-analysis on yield and seed composition Fróes de Borja Reis, André; Moro Rosso, Luiz H.; Davidson, Dan; Kovács, Péter; Purcell, Larry C.; Below, Frederick E.; Casteel, Shaun N.; Knott, Carrie; Kandel, Hans; Naeve, Seth L.; Carciochi, Walter Daniel; Ross, Willian J.; Rampazzo Favoretto, Vitor; Archontoulis, Sotirios; Ciampitti, Ignacio Antonio Sulfur (S) deficiency has been recently reported in soybean [Glycine max (L.) Merr.] producing regions across the United States. However, field studies have often failed to demonstrate a strong relationship between yield and S fertilization and generally attributing the lack of yield response to unfavorable weather and high soil S supply. In addition, only a few reports described seed composition changes due to S availability under contrasting field conditions. Therefore, our goals were (i) to implement a meta-analytic model to quantify the effect of S application at different growth stages on yield and seed concentration of protein, oil, essential non-S amino acids, and S amino acids (SAA, cysteine and methionine); ii) identify environmental factors underpinning the response of S to these plant traits. Field experiments were carried out from 2017 to 2019 growing seasons with a total of 44 unique site-years conditions across 18 locations in 8 states. Mineral S fertilizer (sulfate/ elemental S) was supplied depending on the study at sowing, vegetative and/or reproductive stages. A random-effects multilevel meta-analysis was conducted. The effect sizes compared yield and seed composition responses relative to the unfertilized control. A principal component analysis (PCA) separated distinctive environmental conditions and a sub-grouped meta-analysis with the main environmental factors was later executed to understand the response of the plant traits with those factors. Seed protein concentration increased by 0.3 % when S was applied at sowing. The concentration of SAA increased by ca. 1% regardless of the fertilization timing. Sites exposed to drought stress (18–29% reduction of potential transpiration) neither presented changes in yield nor seed composition due to S fertilization. Soils with organic matter between 25 and 32 g kg-1 (medium cluster) displayed significant responses to S application. This research brings extensive data and provides a comprehensive analysis of weather and soil attributes influencing soybean yield and seed composition responses to S availability.

Long-term survival analysis of masitinib in amyotrophic lateral sclerosis Mora, Jesus S.; Bradley, Walter G.; Chaverri, Delia; Hernández Barral, María; Mascias, Javier; Gamez, Josep; Gargiulo Monachelli, Gisella Mariana; Moussy, Alain; Mansfield, Colin D.; Hermine, Olivier; Ludolph, Albert C. Background: A randomized, placebo-controlled phase III study (AB10015) previously demonstrated that orally administered masitinib (4.5 mg/kg/day) slowed rate of functional decline, with acceptable safety, in amyotrophic lateral sclerosis (ALS) patients having an ALS Functional Rating Scale-revised (ALSFRS-R) progression rate from disease onset to baseline of <1.1 points/month. Here we assess long-term overall survival (OS) data of all participants from study AB10015 and test whether a signal in OS is evident in an enriched patient population similar to that prospectively defined for confirmatory study AB19001. Methods: Survival status of all patients originally randomized in AB10015 was collected from participating investigational sites. Survival analysis (using the multivariate log-rank test and Cox proportional hazards model, with stratification factors as covariates) was performed on the intention-to-treat population and enriched subgroups, which were defined according to initial randomization, baseline ALSFRS-R progression rate and baseline disease severity. Results: A significant survival benefit of 25 months (p = 0.037) and 47% reduced risk of death (p = 0.025) was observed for patients receiving 4.5 mg/kg/day masitinib (n = 45) versus placebo (n = 62) in an enriched cohort with ⩾2 on each baseline ALSFRS-R individual component score (i.e. prior to any complete loss or severe impairment of functionality) and post-onset ALSFRS-R progression rate <1.1 (i.e. exclusion of very fast progressors) [median OS of 69 versus 44 months, respectively; hazard ratio, 0.53 [95% CI (0.31–0.92)]]. This corresponds to the population enrolled in confirmatory phase III study, AB19001. Conclusions: Analysis of long-term OS (75 months average follow-up from diagnosis) indicates that oral masitinib (4.5 mg/kg/day) could prolong survival by over 2 years as compared with placebo, provided that treatment starts prior to severe impairment of functionality.

Supervisión y Gestión de Datos de Código Abierto de una Microrred Aislada en una Escuela Rural; Open Source Data Management and Supervision System of an Isolated Microgrid in a Rural School Catuogno, Guillermo Ricardo; Acosta, Guillermo; Catuogno, Carlos Gustavo En este trabajo se presenta la implementación de un sistema de gestión de datos recolectados de una microrred eólica-solar instalado en una escuela rural de ubicación remota. Este sistema fue realizado utilizando software libre, y consiste en la adquisición de los datos del sistema eólico-solar, el almacenamiento de la información en una base de datos relacional y la visualización de la información procesada a través del servidor y visualizada por medio de un navegador web. El sistema desarrollado fue instalado en el paraje Puerta del Sol, ubicado al norte de la provincia de San Luis y consta de un controlador lógico programable (PLC) que recolecta la información del proceso, una pantalla interface hombre-máquina (HMI) para visualización local de los datos procesados, y una computadora que contiene un servidor web y un gestor de base de datos (ubicada en las instalaciones de la Universidad). La computadora ejecuta una aplicación programada en Python que periódicamente consulta al PLC vía internet sobre la información del proceso y guarda esta información en una base de datos MariaDB (compatible MySQL). Paralelamente el servidor web responde mediante aplicaciones programadas en lenguaje PHP a las consultas que, desde un cliente externo remoto, sean solicitadas mediante una página HTML. El comportamiento del sistema de gestión propuesto se ha validado con los resultados experimentales obtenidos.; This paper presents the implementation of a data management system. The data is colleted from a wind-solar microgrid installed in a remote rural school. This system was made using free software, and consists of the acquisition of data from the wind-solar generator, the storage of the information in a relational database and the visualization of the information processed through the internet by means of a web browser. The developed system was installed in the Puerta del Sol area, located in the north of the province of San Luis and consists of a programmable logic controller (PLC) that collects the information of the process, a human-machine interface (HMI) screen for local visualization process data, and a computer that contains a web server and a database manager (located at the University facilities). An application programmed in Python runs in the computer and periodically queries the PLC via the internet about the process information and saves this information in a MariaDB database (MySQL compatible). At the same time, the web server responds through applications programmed in PHP language to the queries that, from a remote external client, are requested through an HTML page. The behavior of the proposed management system has been validated with the experimental results obtained.

Post-transcriptional regulation of seed dormancy and germination: Current understanding and future directions Tognacca, Rocío Soledad; Botto, Javier Francisco Seed dormancy is a developmental checkpoint that prevents mature seeds from germinating under conditions that are otherwise favorable for germination. Temperature and light are the most relevant environmental factors that regulate seed dormancy and germination. These environmental cues can trigger molecular and physiological responses including hormone signaling, particularly that of abscisic acid and gibberellin. The balance between the content and sensitivity of these hormones is the key to the regulation of seed dormancy. Temperature and light tightly regulate the transcription of thousands of genes, as well as other aspects of gene expression such as mRNA splicing, translation, and stability. Chromatin remodeling determines specific transcriptional outputs, and alternative splicing leads to different outcomes and produces transcripts that encode proteins with altered or lost functions. Proper regulation of chromatin remodeling and alternative splicing may be highly relevant to seed germination. Moreover, microRNAs are also critical for the control of gene expression in seeds. This review aims to discuss recent updates on post-transcriptional regulation during seed maturation, dormancy, germination, and post-germination events. We propose future prospects for understanding how different post-transcriptional processes in crop seeds can contribute to the design of genotypes with better performance and higher productivity.

QSAR-3D como herramienta abstracción en la enseñanza de la Química Medicinal; QSAR-3D as an abstraction tool in the education of medical chemistry Torres, Dimas Ignacio Este trabajo busca analizar los beneficios y dificultades de la implementación del QSAR-3D en la enseñanza de la química medicinal. Se tratará el contexto teórico tanto del método de QSAR-3D como de las bases pedagógicas que fundamentan esta intervención educativa. Los ejes más importantes son las limitaciones actuales en la capacidad de abstracción de los alumnos y las nuevas tecnologías que habilitan plantear un enfoque novedoso en un área de suma relevancia en la química medicinal. En particular se evalúa la factibilidad de realizar un experimento computacional de forma remota. También se revelan conexiones con otras subdisciplinas de la química para remarcar su valor como contenido transversal.; This work seeks to analyze the benefits and difficulties of implementing QSAR-3D in the teaching of medicinal chemistry. The theoretical context of both the QSAR-3D method and the pedagogical bases that underlie this educational intervention will be discussed. The most important axes are the current limitations in the students' capacity for abstraction and the new technologies that make it possible to propose a novel approach in an area of great relevance in medicinal chemistry. In particular, the feasibility of conducting a computational experiment remotely is evaluated. Connections with other chemistry sub-disciplines are also revealed to highlight their value as cross-sectional content.

Exports "brother-boost": the trade-creation and skill-upgrading effect of Venezuelan forced migration on Colombian manufacturing firms Lombardo, Carlo Ignazio; Peñaloza Pacheco, Leonardo José This paper studies the impact of a massive skilled labor supply shock on Colombian manufacturing firms’ exports, the Venezuelan exodus. We exploit crosssectional and time variability of Venezuelan forced migrants’ settlements in Colombian sub-national areas through an enclave instrumental variables approach to account for the selection of immigrants’ location. Using yearly customs data from 2013 to 2019, we find that the Venezuelan migration improved Colombian manufacturing firms’ export performance, particularly to high-income countries of the OECD located in North America and low-income countries. This effect was stronger for firms that exported less prior to the exodus (2012). Furthermore, using a detailed yearly panel of manufacturing firms from 2013 to 2019 we identify the potential labor market driving mechanism of the trade-creation effect: immigrants lowered exporting firms’ blue-collar wages, and allowed them to upgrade their labor force skill composition, namely firms were able to hire workers more compatible with exports to developed destinations.

Mercado relevante: Un concepto jurídico con fundamento económico. Desafíos y divergencias en la economía digital; Relevant market: A legal concept with an economic rationale. Challenges and divergences in the digital economy Greco, Esteban Manuel; Viecens, María Fernanda El funcionamiento de la economía digital está sometiendo a revisión tanto los instrumentos como los objetivos de las políticas de competencia. La definición de mercado relevante, como herramienta analítica clave en el derecho de la competencia, no escapa a esta tendencia. En este artículo se presentan los principales desafíos que los antecedentes en las agencias de competencia y la literatura muestran al respecto. También se analizan las definiciones de mercado relevante adoptadas por agencias de competencia en dos fusiones recientes que involucran actores de la economía digital: Walmart-Cornershop y Visa-Plaid. La comparativa sobre estas decisiones evidencia la falta de convergencia en los resultados, explicada, en parte, por diferencias en las definiciones de mercado.; The functioning of the digital economy is subjecting both the instruments and the objectives of competition policies to review. The definition of the relevant market, as a key analytical tool in competition law, does not escape this trend. This article presents the main challenges that the antecedents in competition agencies and the literature show in this regard. It also analyses the relevant market definitions adopted by competition agencies in two recent mergers involving players in the digital economy: Walmart-Cornershop and Visa-Plaid. The comparative analysis of these decisions shows a lack of convergence in the results, partly explained by differences in market definitions.

La tercera misión de la universidad y sus múltiples sentidos en debate: extensión, transferencia, vinculación, compromiso, coproducción e impacto social de las prácticas académicas y los modos de producción de conocimiento; The third mission of the university and its multiple meanings in debate: transfer, “extension”, community engagement, coproduction and social impact of academic practices Alonso, Mauro Ricardo; Cuschnir, Melisa Sol; Napoli, Mariángela Este trabajo revisa algunas de las conceptualizaciones que dan cuenta de los mecanismos por los que, en sentido amplio, la universidad como institución productora de conocimiento ha interactuado con la sociedad a lo largo de su historia reciente: cuáles son los sentidos posibles de esa interacción, qué tipo de conceptualizaciones teóricas se han consolidado para comprender estas dinámicas y cuáles son las dimensiones en las que cada una pone el acento. El trabajo se divide en cuatro secciones, en las que presentamos una revisión de conceptos y modelos teórico-analíticos y aborda, desde múltiples sentidos, “la cuestión de la tercera misión” de la universidad en dos niveles de análisis. Las primeras dos secciones se centran en un recorrido histórico de su surgimiento, desarrollo y gobernanza. La tercera sección se ocupa de un segundo nivel en el que revisitamos más en detalle las posibles dimensiones y componentes de la tercera misión de la universidad, con foco en las conceptualizaciones respecto de la noción de conocimiento como parte del proceso clásico de producción, transferencia y uso desde la universidad hacia la sociedad. Finalmente, en la cuarta sección, se presentamos cinco enfoques sistematizados, agrupados a partir de una elaboración propia, que analizan la relación universidad-sociedad y de los que se derivan enfoques analíticos. Discutimos el concepto de extensión universitaria para el contexto latinoamericano, la noción de compromiso social (community engagement en el inglés original) de la universidad, la noción de apropiación social del conocimiento e hibridación de las actividades de extensión recuperando la literatura que observa la relación expertos-legos; y las consideraciones teórico-prácticas del “idioma de la coproducción”. Finalmente, nos detenemos en una conceptualización reciente que observa la cuestión de la tercera misión: la noción de impacto social del conocimiento.; Our work displays a review of some of the conceptualizations that account for the mechanisms by which, in a broad sense, the university as an institution that produces knowledge has interacted with society throughout its recent history: what are the possible meanings of this interaction, what kind of theoretical conceptualizations have been consolidated to understand these dynamics and what are the dimensions in which each one emphasizes. The work is divided into five sections, in which we present a literature review that we consider relevant and addresses, from multiple senses, “the question of the third mission” of the university at two levels of analysis. The first two sections focus on a first level linked to a historical journey of its emergence, development and governance. The third section deals with a second level in which we revisit in more detail the possible dimensions and components of the third mission of the university, focusing on the conceptualizations regarding the notion of knowledge as part of the classical process of production, transfer and use from the university to society. Finally, the fourth section presents a review that we propose from five approaches, grouped from our own elaboration, which deal with analyzing the university-society relationship and from which analytical approaches are derived. We discuss the concept of university extension for the Latin American context, secondly the notion of social commitment (community engagement in the original English) of the university, thirdly, the notion of social appropriation of knowledge and hybridization of outreach activities recovering the literature that observes the expert-lay relationship; fourth, we present the theoretical-practical considerations of the “language of co-production” and finally, we will stop at one of the most recent conceptualizations that propose to observe the question of the third mission: the notion of the social impact of knowledge.

Tendencias en la percepción de los consumidores y adquirientes sobre los aditivos alimentarios López, Paloma Lucía; Reinante, Rocío Denisse; Grosso, Nelson; Olmedo, Rubén Horacio Una multiplicidad de factores influencia la percepción sobre los alimentos por parte de los consumidores y adquirientes siendo el conocimiento o información un factor clave en su percepción. Actualmente, la mayoría de los alimentos que encontramos en el mercado contienen aditivos en su composición y se utilizan con el objetivo de mejorar las características del alimento, ya sean organolépticas, de procesamiento o de conservación. El Laboratorio de Tecnología de Alimentos de la Facultad de Ciencias Agropecuarias de la Universidad Nacional de Córdoba (LabTA-FCA-UNC) se encuentra abocado a la tarea de evaluar la percepción de los consumidores sobre los aditivos por medio de la realización de encuestas. Las respuestas apuntaron a que los consumidores prefieren alimentos con aditivos de origen natural en lugar de los aditivos sintéticos, esto es debido a que perciben a los sintéticos como más tóxicos. Es decir, relacionan lo natural con lo saludable, y lo sintético con daños a la salud sin tener un criterio basado en información al respecto. Es por esta razón, que se torna fundamental la necesidad de brindar educación alimentaria con el fin de mejorar el conocimiento en la sociedad.; A multiplicity of factors influences the perception of food by consumers and acquirers, knowledge or information being a key factor in their perception. Currently, most of the foods that we find on the market contain additives in their composition and are used with the aim of improving the characteristics of the food, whether they are organoleptic, processing or preservation. The Laboratorio de Tecnologia de Alimentos at the Facultad de Ciencias Agropecuarias of the Universidad Nacional de Córdoba (LabTA-FCA-UNC) is dedicated to the task of evaluating the perception of consumers about additives by conducting surveys. The responses pointed out that consumers prefer foods with additives of natural origin instead of synthetic additives, this is because they perceive synthetics as more toxic. That is, they relate the natural with the healthy, and the synthetic with damage to health without having a criterion based on information in this regard. It is for this reason that the need to provide food education in order to improve knowledge in society becomes fundamental.

Primeros registros de Playerito Enano (Calidris pusilla) para la provincia de Santa Fe, Argentina; First records of Semipalmated Sandpiper (Calidris pusilla) for the province of Santa Fe, Argentina del Castillo, María; Oscar, Diego; La Grotteria, Jorge; Juani, Marcelo Miguel; Ornstein, Ulises; Galimberti, Adrián; Terán, Andrés; Lorenzón, Rodrigo Ezequiel Presentamos los primeros registros de Playerito Enano (Calidris pusilla) para la provincia de Santa Fe, Argentina, ocurridos en la Laguna Añapiré de la localidad Campo Andino. Comentamos la importancia de dicho humedal, que no se encuentra protegido debidamente, y que alberga a especies migradoras raras para el país.; We present the first records of Semipalmated Sandpiper (Calidris pusilla) for the province of Santa Fe, Argentina. Occurred in the Añapiré Lagoon in Campo Andino. We commented on the importance of this wetland, which is not properly protected, and which harbors scarce migratory species for the country.

Efficient CRISPR/Cas9 Genome Editing in Alfalfa Using a Public Germplasm Bottero, Ana Emilia; Massa, Gabriela Alejandra; Gonzalez, Matías Nicolás; Stritzler, Margarita; Tajima, Hiromi; Gómez, Cristina; Frare, Romina Alejandra; Feingold, Sergio; Blumwald, Eduardo; Ayub, Nicolás Daniel; Soto, Gabriela Cynthia Because its ability to acquire large amounts of nitrogen by symbiosis, tetraploid alfalfa is the main source of vegetable proteins in meat and milk production systems in temperate regions. Alfalfa cultivation also adds fixed nitrogen to the soil, improving the production of non-legumes in crop rotation and reducing the use of nitrogen fertilizers derived from fossil fuel. Despite its economic and ecological relevance, alfalfa genetics remains poorly understood, limiting the development of public elite germplasm. In this brief article, we reported the high-efficiency of alfalfa mutagenesis by using the public clone C23 and the CRISPR/Cas9 system. Around half of the GUS overexpressing plants (35S-GUS under C23 genomic background) transformed with an editing plasmid containing two sgRNAs against the GUS gene and the Cas9 nuclease exhibited absence of GUS activity. Nucleotide analysis showed that the inactivation of GUS in CRISPR/Cas9-editing events were produced via different modifications in the GUS gene, including frameshift and non-sense mutations. Using the CRISPR/Cas9 system and two sgRNAs, we have also edited the alfalfa gene NOD26, generating plants with different doses of alleles at this locus, including complete gene knockout at high efficiency (11%). Finally, we discuss the potential applications of genome-editing technologies to polyploid research and to alfalfa improvement public programs.

Biomarkers of geno- and cytotoxicity in the native broad-snouted caiman (Caiman latirostris): Chromosomal aberrations and mitotic index Chacón, Camila Felisa; López González, Evelyn Cecilia; Poletta, Gisela Laura We evaluated the sensitivity of the chromosomal aberration (CA) and mitotic index (MI) assays on peripheral blood lymphocytes (PBLs) of Caiman latirostris, following ex vivo exposure to the alkylating agent, MMS. Two concentrations of MMS were tested in cultured peripheral blood. Relative to controls, MMS exposure reduced the number of metaphases observed, but both the numbers of cells with MN and the percentages of aberrant metaphases increased. The types of CA identified were chromosome and chromatid breaks, chromosomal rearrangements, monosomies, and nullisomies, with significantly higher values in the MMS-exposed groups. The incorporation of the MI and CA tests in C. latirostris can provide information on damage caused by xenobiotic exposures.

El estudio del impacto de la sequía en pequeñas comunidades rurales de México: Una revisión de la bibliografía; The study of drought impact in small rural communities in Mexico: a bibliography revision Bocco, Gerardo; Orozco Ramírez, Quetzalcóatl; Alvarez Larrain, Alina; Solís, Berenice; Dobler Morales, Carlos La sequía afecta severamente a sociedades campesinas, dedicadas a la agricultura de temporal o pequeña ganadería, en países intertropicales, de economías emergentes. En comparación con otros fenómenos extremos de índole climática, tales como las inundaciones, la sequía es difícil de definir y precisar en cuanto a su ocurrencia en el tiempo y el espacio. Pero la disminución o falta de precipitación impactan de manera decisiva en los calendarios agrícolas de temporal y representan una amenaza a la seguridad alimentaria de familias campesinas. La investigación y las revisiones bibliográficas sobre la sequía han sido numerosas, tanto a nivel disciplinario o interdisciplinario. El tema del impacto de la sequía en pequeñas comunidades campesinas, en cambio, ha recibido menor atención. En este trabajo presentamos una revisión sobre el impacto de la sequía en, y la respuesta de, pequeñas comunidades campesinas en México. Consideramos que existe un acervo de teoría y de experiencias documentadas que demuestran que las comunidades campesinas en México, han tenido, históricamente, una gran capacidad de manejo de las crisis sociales derivadas de los impactos de la variabilidad climática en general y de la sequía en particular. Sugerimos que la investigación sobre estos temas, de manera participativa y a partir del conocimiento ambiental tradicional, es una alternativa importante en el aporte científico para la gestión del riesgo a nivel local.; Drought can severely affect small farmer communities whose livelihoods depend on rainfed agriculture or small-scale livestock ranching in tropical developing countries. Compared with other climatic extremes such as floods, drought is harder to define and characterize across space and time. Yet, the reduction or lack of precipitation can affect agricultural calendars in meaningful ways and threaten households’ food security. Extensive research and literature reviews have focused on drought, both from mono- and inter-disciplinary perspectives. How drought can impact small rural communities, however, has received less attention. Here, we conduct a review of literature on drought impacts and responses in a context of small rural communities in Mexico. We find that there is an existing body of theoretical and empirical work, which demonstrates the historical capacity of small rural communities in Mexico to manage social crises triggered by climatic variability, in general, and drought, in particular. We suggest that research in this field, enriched by participatory approaches and traditional knowledge, can provide valuable insights for managing climatic risks at the local level.

Role of Hydration in Biomembranes as a Challenge for Current Biophysics Disalvo, Edgardo Anibal; Cejas, Jimena del Pilar; Rosa, Antonio Sebastián; Frias, Maria de Los Angeles The consideration of water as a structural component gives biological membranes specific thermodynamic properties that explain its responsive behavior when chased by physical and chemical perturbations. These properties are derived from the peculiar surface tension of pure water and its variation due to the presence of hydrogen bonds arrangements between water and membrane components that determine a complex surface free energy profile. A completer and more realistic picture should consider how the hydration properties are linked to mechanical forces with relevance in osmotic stress of cells and in the behavior lipid monolayers. In the present work, the mechano-chemical coupling of surface pressure with water activity in a lipid interphase is explored as a way to mimic the thermodynamic response of the lipid interphase to bioactive compounds. As a result, the relaxation processes during the action of bio effectors are described in terms of water organization around the lipid residues such as acyl chains and polar head groups.

Color Properties of Silver Nanoparticle Composites D'ambrosio, Christian Nahuel; Inchaussandague, Marina Elizabeth; Skigin, Diana Carina In order to investigate tunable color materials comprising metallic nanospheres, we investigated the color response of structures formed by periodic arrangements of silver nanoparticles. We use different approaches to model the dielectric function of silver in order to analyze the differences introduced in the reflection and transmission spectra and, consequently, in the obtained color. To calculate the spectral response, we use the KKR method, widely used to model structures comprising layers of periodically arranged spheres. The results obtained show the relevance of the model used for the dielectric function of silver for an accurate prediction of the color produced by systems composed of nanoparticles of different sizes and filling fractions.

Opechona chloroscombri and Opechona corkumi n. sp. (Digenea: Lepocreadiidae) from the Northern Gulf of Mexico with Phylogenetic Analysis Based on 28S RDNA Curran, Stephen S.; Ksepka, Steven P.; Martorelli, Sergio Roberto; Overstreet, Robin M.; Warren, Micah B.; Bullard, Stephen Ash This study investigated the identity of 2 lepocreadiid digenean species belonging in the genus Opechona Looss, 1907 that infect littoral fishes of the northern Gulf of Mexico. Opechona chloroscombri , a species previously known only from the Caribbean Sea and the Atlantic Ocean off Brazil, is reported herein from the Atlantic bumper, Chloroscombrus chrysurus (L.), in the northern Gulf of Mexico. A second species infects the gulf butterfish, Peprilus burti Fowler, and the American harvestfish, Peprilus paru (L.), and it is described as a new species that occurs in coastal waters of the north-central and northeastern Gulf of Mexico. Metacercariae infecting the mesoglea of pelagic jellyfishes (Bougainvillia carolinensis [McCady], Chrysaora quinquecirrha [Desor], and Stomolophus meleagris Agassiz) and pelagic comb jellies (Mnemiopsis leidyi Agassiz and Beroe ovata Bruguière) were collected that resemble the new species but require further study to identify. Newly generated sequence fragments (28S rDNA) from both species of Opechona plus 2 other lepocreadiids collected during the study were aligned with publicly available sequences from 18 other lepocreadiids, 6 species of Aephnidiogenidae , and 2 species of Gorgocephalidae Manter, 1966. The alignment was subjected to Bayesian inference analysis rooted using a gorgocephalid. The resulting tree estimated the positions of both Opechona spp. as being unresolved within a group of taxa that included all available species of Opechona plus available species from the morphologically similar genera Prodistomum , Preptetos Pritchard, 1960, and Clavogalea Bray, 1985. Although relatively similar in morphology, the 2 studied species of Opechona were surprisingly not closely related. Opechona cablei () is herein considered to be a junior synonym of Opechona pyriformis () .