Ciencia y Tecnología

La Historia del COVID 19 en tiempos del Coronavirus. Un ensayo inconcluso

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La Historia del COVID 19 en tiempos del Coronavirus. Un ensayo inconcluso; The History of COVID 19 in times of the Coronavirus. An unfinished essay Alvarez, Adriana Carlina Este trabajo realiza una mirada histórica por las diversas pandemias de gripe que impactaron enla República Argentina. La Gripe Rusa del siglo XIX, la Gripe de 1918, la influenza asiática de1957, hasta el actual COVID-19.El objetivo es capitalizar los modelos interpretativos utilizados para los estudios de epidemias,con la finalidad de hacer visibles las diferencias con la pandemia del Coronavirus (2020).Dedicamos especial atención a la gripe asiática de 1957/58, tratando de analizar las similitudesy diferencias que las atraviesan, preguntándonos cuán peculiar, terrible o hasta benigna puedeser en comparación con otras de su tipo.; This work takes a historical look at the various influenza pandemics that impacted the Argentine Republic. From the Russian Flu of the XIX century, the Flu of 1918, the Asian influenza of 1957 until the current COVID-19. The objective of this work is to take advantage of the interpretive models used for epidemic studies, in order to contrast previous pandemics with this Coronavirus. Paying special attention to the 1957/58 Asian flu, we analyze the similarities and differences between these pandemics, wondering how peculiar, terrible or even benign can the current one be compared to others of its kind.

Epizootics and sanitary regulations drive long-term changes in fledgling body condition of a threatened vulture

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Epizootics and sanitary regulations drive long-term changes in fledgling body condition of a threatened vulture Donázar, José Antonio; Cortés Avizanda, Ainara; Ceballos Ruiz, Olga; Arrondo, Eneco; Grande, Juan Manuel; Serrano, David Epizootics and deliberate changes in policies affecting the environment may affect large groups of species and the functioning of entire ecosystems. Although these effects often overlap in time, their simultaneous effect is rarely examined despite their importance as causes of current biodiversity loss. Here, based on the monitoring of an Egyptian vulture (Neophron percnopterus) population over thirty-three years (1986–2018), we increase our knowledge about the effects of anthropogenic-induced changes in food availability, both direct (sanitary policies limiting livestock carcass disposal) and indirect (a wild rabbit epizootic), on brood size and body condition of fledglings at nests. We compared the body mass of fledglings of broods with one chick (Single) and two chicks (within which we distinguished First and Second-hatched). The mass of Second-hatched chicks decreased after the plummet in rabbit populations (in the year 1990) and the regulations limiting carcass disposal (2005), reaching minimum values during the period with lowest food availability (i.e. 2005–2013). Recent sanitary legislation allowing carcass disposal by farmers coincides with a slight recovery in the observed body masses. Overall, this study shows that environmental changes of disparate origin can have synergistic effects on individual condition. Conservation of endangered vultures will require multi-targeted conservation plans aimed at ensuring nutritional requirements, in addition to detailed long-term monitoring, in order to detect obscure/masked drivers that affect body condition of fledglings.

Identificación de genes de resistencia a mancha amarilla en trigo

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Identificación de genes de resistencia a mancha amarilla en trigo Uranga, Juan Pablo; Schierenbeck, Matías; Perello, Analia Edith; Lohwasser, U.; Simon, M. R. Una de las principales limitantes bióticas que reducen la expresión de la potencialidad de los rendimientos del cultivo de trigo en la Argentina son las enfermedades. La mancha amarilla producida por Pyrenophora tritici-repentis (Died.) Drechs. (anamorph Drechslera tritici-repentis (Died.) Shoem.) es una de las enfermedades más importantes que afectan al trigo. El objetivo de este trabajo fue determinar variabilidad genética para resistencia a ambos patógenos y localizar molecularmente los factores genéticos determinantes de la resistencia frente a estos patógenos, que permitan distinguir progenitores con presencia de alelos favorables para ser utilizados en planes de mejoramiento.

Restoration of antitumor immunity through anti-MICA antibodies elicited with a chimeric protein

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Restoration of antitumor immunity through anti-MICA antibodies elicited with a chimeric protein Torres, Nicolas; Regge, María Victoria; Secchiari, Florencia; Friedrich, Adrián David; Spallanzani, Raúl Germán; Raffo Iraolagoitia, Ximena Lucía; Nuñez, Sol Yanel; Sierra, Jessica Mariel; Ziblat, Andrea; Santilli, Maria Cecilia; Gilio, Nicolas; Almada, Evangelina; Lauché, Constanza Elena; Pardo, Romina Paola; Domaica, Carolina Ines; Fuertes, Mercedes Beatriz; Madauss, Kevin Patrick; Hance, Kenneth W.; Gloger, Israel S.; Zylberman, Vanesa; Goldbaum, Fernando Alberto; Zwirner, Norberto Walter Background Natural killer and cytotoxic CD8+ T cells are major players during antitumor immunity. They express NKG2D, an activating receptor that promotes tumor elimination through recognition of the MHC class I chain-related proteins A and B (MICA and MICB). Both molecules are overexpressed on a great variety of tumors from different tissues, making them attractive targets for immunotherapy. However, tumors shed MICA and MICB, and the soluble forms of both (sMICA and sMICB) mediate tumor-immune escape. Some reports indicate that anti-MICA antibodies (Ab) can promote the restoration of antitumor immunity through the induction of direct antitumor effects (antibody-dependent cell-mediated cytotoxicity, ADCC) and scavenging of sMICA. Therefore, we reasoned that an active induction of anti-MICA Ab with an immunogenic protein might represent a novel therapeutic and prophylactic alternative to restore antitumor immunity. Methods We generated a highly immunogenic chimeric protein (BLS-MICA) consisting of human MICA fused to the lumazine synthase from Brucella spp (BLS) and used it to generate anti-MICA polyclonal Ab (pAb) and to investigate if these anti-MICA Ab can reinstate antitumor immunity in mice using two different mouse tumors engineered to express MICA. We also explored the underlying mechanisms of this expected therapeutic effect. Results Immunization with BLS-MICA and administration of anti-MICA pAb elicited by BLS-MICA significantly delayed the growth of MICA-expressing mouse tumors but not of control tumors. The therapeutic effect of immunization with BLS-MICA included scavenging of sMICA and the anti-MICA Ab-mediated ADCC, promoting heightened intratumoral M1/proinflammatory macrophage and antigen-experienced CD8+ T cell recruitment. Conclusions Immunization with the chimeric protein BLS-MICA constitutes a useful way to actively induce therapeutic anti-MICA pAb that resulted in a reprogramming of the antitumor immune response towards an antitumoral/proinflammatory phenotype. Hence, the BLS-MICA chimeric protein constitutes a novel antitumor vaccine of potential application in patients with MICA-expressing tumors.

Developmentally Programmed Tankyrase Activity Upregulates β-Catenin and Licenses Progression of Embryonic Genome Activation

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Developmentally Programmed Tankyrase Activity Upregulates β-Catenin and Licenses Progression of Embryonic Genome Activation Gambini, Andres; Stein, Paula; Savy, Virginia; Grow, Edward J.; Papas, Brian N.; Zhang, Yingpei; Kenan, Anna C.; Padilla Banks, Elizabeth; Cairns, Bradley R.; Williams, Carmen J. Embryonic genome activation (EGA) is orchestrated by an intrinsic developmental program initiated during oocyte maturation with translation of stored maternal mRNAs. Here, we show that tankyrase, a poly(ADP-ribosyl) polymerase that regulates β-catenin levels, undergoes programmed translation during oocyte maturation and serves an essential role in mouse EGA. Newly translated TNKS triggers proteasomal degradation of axin, reducing targeted destruction of β-catenin and promoting β-catenin-mediated transcription of target genes, including Myc. MYC mediates ribosomal RNA transcription in 2-cell embryos, supporting global protein synthesis. Suppression of tankyrase activity using knockdown or chemical inhibition causes loss of nuclear β-catenin and global reductions in transcription and histone H3 acetylation. Chromatin and transcriptional profiling indicate that development arrests prior to the mid-2-cell stage, mediated in part by reductions in β-catenin and MYC. These findings indicate that post-transcriptional regulation of tankyrase serves as a ligand-independent developmental mechanism for post-translational β-catenin activation and is required to complete EGA.

¿Por qué pensar en la educación en cárceles en contexto de pandemia?

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¿Por qué pensar en la educación en cárceles en contexto de pandemia? Perez, Camila A quienes desde hace años trabajamos defendiendo el derecho a la educación en las cárceles argentinas el aislamiento social preventivo y obligatorio, promulgado el 20 de marzo del 2020, nos ha conmocionado mucho. Dejar de asistir a las cárceles donde trabajábamos semanalmente y pensar cómo vivirían esta situación nuestros estudiantes privados de su libertad modificó nuestra vida cotidiana y nos enfrentó a nuevos desafíos.En este artículo propongo una primera reflexión de un proceso personal pero también colectivo, con el intento de documentar las primeras inquietudes, intervenciones y aprendizajes emergentes. Este material deberá ser analizado cuidadosamente más adelante, cuando esta situación ?excepcional? pase y podamos visualizar su impacto en los diferentes contextos de encierro en los que nos desempeñamos como educadores, militantes e investigadores.

Preocupaciones y demandas frente a Covid-19 : encuesta al personal de salud

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Preocupaciones y demandas frente a Covid-19 : encuesta al personal de salud; Concerns and demands regarding COVID-19. Survey of health personnel Ortiz, Zulma; Antonietti, Laura; Capriati, Alejandro Jose; Ramos, Silvina; Romero, Mariana; Mariani, Javier; Ortiz, Fabián; Pecheny, Mario Martín La pandemia por COVID-19 afectó la organización de los servicios de salud y tuvo consecuencias en los equipos de salud, según las condiciones laborales y de bioseguridad pre-existentes en cada institución. Durante la primera semana de abril de 2020 se realizó un estudio de corte transversal. El objetivo fue indagar acerca de las condiciones que determinan el clima organizacional: liderazgo, comunicación, recursos institucionales, cohesión/gestión de conflictos y capacitación; y cómo éstas eran percibidas por el personal de salud para hacer frente a la pandemia. Se realizaron 5670 encuestas a trabajadores/as y 50 entrevistas a informantes clave de los tres subsectores del sistema de salud (público, privado y de seguridad social). En las encuestas, el 72.9% fueron mujeres, el 51.4% médicos/as y el grupo etario predominante fue el de menores de 40 años. El 47.8% de los/as participantes refirió pluriempleo. En las entrevistas, el 52% fueron varones, el 60% médicos/ as, la edad media 44.8 años. Se estratificaron las dimensiones y se identificaron predictores independientes de percepción: edad, género, tipo de tareas, subsector y jurisdicción. La dimensión percibida con mayor frecuencia como inadecuada fue la de recursos institucionales y la disponibilidad de equipos de protección personal fue identificada como una de las principales preocupaciones. Surgieron demandas de estrategias de contención para el personal de salud y de comunicación institucional clara y uniforme. En conclusión, al momento del estudio el personal de salud percibía serios déficits en sus organizaciones respecto de las condiciones necesarias para enfrentar la pandemia, con diferencias entre subsectores del sistema.; The COVID-19 pandemic affected the organization of health services and had consequences for health teams, according to the pre-existing safety and working conditions. During the first week of April 2020, a cross sectional study was carried out with a qualitative-quantitative approach. The aim was to explore the conditions determining the organizational climate: leadership, communication, institutional resources, cohesion/conflict management, and training; and how these were perceived by health personnel to deal with the pandemic. A total of 5670 healthcare workers participated in an online survey and 50 were interviewed, from all subsectors of the Argentinean health system (public, private and union-health insurance); 72.9% were women, 51.4% were physicians, and the predominant age group was under 40 years. In the qualitative sample (interviews), 52% were men, 62% were physicians, and the average age was 44.8 years. The dimensions of the organizational climate were stratified and five independent predictors of perception of conditions were identified: age, gender, tasks performed, health system subsector, and jurisdiction. The condition most frequently perceived as inadequate were the inaccessibility of institutional resources and the access to personal protective equipment was a major concern. Claims included the need of institutional strategies to support healthcare workers and of a clear and uniform communication. In conclusion, at the time of the study, the health personnel perceived serious deficits in their organizations regarding the conditions necessary to confront COVID-19, with differences among subsectors of the health system.

Simulaciones de dinámica molecular de conductividad térmica entre dos nanopartículas en contacto

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Simulaciones de dinámica molecular de conductividad térmica entre dos nanopartículas en contacto; Molecular dynamics simulations of thermal conductivity between two particles in contact Mora Barzaga, Geraudys; Miranda, Enrique Nestor; Bringa, Eduardo Marcial The nanoscale properties of materials can have a great influence on their macroscopic behavior; for instance, the generation and accumulationof defects at the nanoscale, such as point defects, porosity, and interfaces, can change their thermal properties. In this work, we studythe role of an interface in the thermal conductivity between two nanoparticles without any external load. We consider a system subjected toa temperature gradient perpendicular to the contact surface and study the thermal conductivity, thermal conductance, thermal resistance,and contact resistance vs nanoparticle size. The thermal resistance at the interface increases linearly with nanoparticles? contact radius ac.A model based on the contact area between two nanoparticles allows us to reasonably explain the obtained numerical results for thethermal conductivity, leading to a net decrease in effective conductivity as the nanoparticle size increases, reasonably well described by a(ac/R) dependence. Simulated thermal conductance was found to be proportional to (ac/R).

Ecosystem services in urban ecological infrastructure in Latin America and the Caribbean: how do they contribute to urban planning?

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Ecosystem services in urban ecological infrastructure in Latin America and the Caribbean: how do they contribute to urban planning? Romero Duque, Luz Piedad; Trilleras, Jenny M.; Castellarini, Fabiana; Quijas, Sandra We developed a conceptual framework that describes the key role of ecosystem services in urban ecological infrastructure. From this framework we analyze how research on ecosystem services has been addressed in cities of Latin America and the Caribbean, in order to discuss their incorporation into policies of urban planning, in the context of nature-based solutions and sustainable development goals. Mexico, Brazil, Chile, Colombia and Argentina represent 90% of research in urban ecosystem services, all of them except Colombia had carried out studies considering green, blue and gray-hybrid infrastructures. However, green-hybrid infrastructure clustered most of the studies. Ecosystem service supply component and intermediate beneficiaries are the most studied. Our results show that most studies have not been developed from the perspective of the biophysical, sociocultural or economic assessment of ecosystem services, on the contrary we recognized or deduced them from proxy variables found within the studies. Our findings suggest that the study of urban ecosystem services in Latin America and the Caribbean is in development and has begun to increase in the last decade. However, we found that the incorporation of urban ecosystem services in urban planning is low, but at the same time, it is in a promising development related to the application of innovative actions such as nature-based solutions and in support of the new global urban agenda.

Continuous and discrete dynamical sampling

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Continuous and discrete dynamical sampling Díaz Martín, Rocío Patricia; Medri, Ivan Vladimir; Molter, Ursula Maria In this paper we study the continuous dynamical sampling problem at infinite time in a complex Hilbert space H. We find necessary and sufficient conditions on a bounded linear operator A∈B(H) and a set of vectors G⊂H, in order to obtain that {etAg}g∈G,t∈[0,∞) is a semi-continuous frame for H. We study if it is possible to discretize the time variable t and still have a frame for H. We also relate the continuous iteration etA on a set G to the discrete iteration (A′)n on G′ for an adequate operator A′ and set G′⊂H.

Development of a hyperimmune equine serum therapy for COVID-19 in Argentina

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Development of a hyperimmune equine serum therapy for COVID-19 in Argentina; Desarrollo de un suero equino hiperinmune para el tratamiento de COVID-19 en Argentina Zylberman, Vanesa; Sanguineti, Santiago; Pontoriero, Andrea; Higa, Sandra V.; Cerutti, Maria Laura; Morrone Seijo, Susana María; Pardo, Romina Paola; Muñoz, Luciana; Acuña Intieri, María Eugenia; Alzogaray, Vanina Andrea; Avaro, Martín M.; Benedetti, Estefanía; Berguer, Paula Mercedes; Bocanera, Laura; Bukata, Lucas; Bustelo, Marina S.; Campos, Ana M.; Colonna, Mariana; Correa, Elisa; Cragnaz, Lucí­a; Dattero, María E.; Dellafiore, María Andrea; Foscaldi, Sabrina Andrea; González, Joaquí­n V.; Guerra, Luciano Lucas; Klinke, Sebastian; Labanda, María Soledad; Lauché, Constanza Elena; López, Juan C.; Martínez, Anabela M.; Otero, Lisandro Horacio; Peyric, Elías H.; Ponziani, Pablo F.; Ramondino, Romina; Rinaldi, Jimena Julieta; Rodrí­guez, Santiago; Russo, Javier E.; Russo, Mara Laura; Saavedra, Soledad Lorena; Seigelchifer, Mauricio; Sosa, Santiago; Vilariño, Claudio; López Biscayart, Patricia; Corley, Esteban; Spatz, Linus; Baumeister, Elsa; Goldbaum, Fernando Alberto La enfermedad denominada COVID-19 es causada por el coronavirus SARS-CoV-2 y es actualmente considerada una pandemia a nivel global. El desarrollo de vacunas es sin duda la mejor estrategia a largo plazo, pero debido a la emergencia sanitaria, existe una necesidad urgente de encontrar soluciones rápidas y efectivas para el tratamiento de la enfermedad. Hasta la fecha, el uso de plasma de convalecientes es la única inmunoterapia disponible para pacientes hospitalizados con COVID-19. El uso de anticuerpos policlonales equinos (EpAbs) es otra alternativa terapéutica interesante. La nueva generación de EpAbs incluyen el procesamiento y purificación de los mismos y la obtención de fragmentos F(ab’)2 con alta pureza y un excelente perfil de seguridad en humanos. Los EpAbs son fáciles de producir, lo cual permite el desarrollo rápido y la elaboración a gran escala de un producto terapéutico. En este trabajo mostramos el desarrollo de un suero terapéutico obtenido luego de la inmunización de caballos utilizando el receptor-binding domain de la glicoproteína Spike del virus. Nuestro producto mostró ser alrededor de 50 veces más potente en ensayos de seroneutralización in vitro que el promedio de los plasmas de convalecientes. Estos resultados nos permitirían testear la seguridad y eficacia de nuestro producto en ensayos clínicos de fase 2/3 a realizarse a partir de julio de 2020 en la zona metropolitana de Buenos Aires, Argentina.; The disease named COVID-19, caused by the SARS-CoV-2 coronavirus, is currently generating a global pandemic. Vaccine development is no doubt the best long-term immunological approach, but in the current epidemiologic and health emergency there is a need for rapid and effective solutions. Convalescent plasma is the only antibody-based therapy available for COVID-19 patients to date. Equine polyclonal antibodies (EpAbs) put forward a sound alternative. The new generation of processed and purified EpAbs containing highly purified F(ab’)2 fragments demonstrated to be safe and well tolerated. EpAbs are easy to manufacture allowing a fast development and scaling up for a treatment. Based on these ideas, we present a new therapeutic product obtained after immunization of horses with the receptor-binding domain of the viral Spike glycoprotein. Our product shows around 50 times more potency in in vitro seroneutralization assays than the average of convalescent plasma. This result may allow us to test the safety and efficacy of this product in a phase 2/3 clinical trial to be conducted in July 2020 in the metropolitan area of Buenos Aires, Argentina.

Migrantes senegaleses frente a la pandemia. Una comunidad que se organiza

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Migrantes senegaleses frente a la pandemia. Una comunidad que se organiza Murguia Cruz, Nelida Abril; Kleidermacher, Gisele Paola Un recorrido sobre las acciones que ha realizado la comunidad senegalesa para atravesar esta particular situación en la Ciudad Autónoma de Buenos Aires, desencadenada por la pandemia. Realizado a través de conversaciones telefónicas y mediante el trabajo directo con organizaciones en las que participan, o bien, con las que se relacionan, ya sea institucionales o de la sociedad civil, ya sea argentinas o de la propia comunidad senegalesa.

Land-use changes in the periurban interface: Hydrologic consequences on a flatland-watershed scale

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Land-use changes in the periurban interface: Hydrologic consequences on a flatland-watershed scale Delgado, María Isabel; Carol, Eleonora Silvina; Casco, Maria Adela The aim of this work was to analyze the hydrologic effects on surface runoff and infiltration of changes in land use and land coverage. The periurban-flatland watershed of El Pescado Creek (Argentina) was the study site investigated. We used Geographic-Information-System techniques together with the curve-number method (CN) to estimate the surface runoff in five land-use scenarios having increasing levels of anthropic impact (years 1986, 1996, 2006, 2016, and 2026) considering two rainfalls and the antecedent-runoff conditions (ARC) defined by that methodology. We identified three hydrologic-soil Groups (B, C, and D) and five land uses (grassland, forest, urbanization, greenhouses, and poultry farms). Land use and land coverage change process increased CN values, and consequently the estimated surface runoff, especially in the upper watershed. Changes towards impervious (687 ha with greenhouses and poultry farms) or semi-impervious land coverage (800 ha with urbanizations) affected infiltration. The most contrasting results were related to the ARC I, II, and III weighted-average infiltration of the watershed that diminished from above 93.0%, down to 88.5% and finally to 50.4%, respectively (calculated with data from the 55.8-mm rainfall), and from 86.6%, to 58.3%, and to finally 28.8% (calculated with data from the 117.8 mm rainfall). Simulating a near-future land-use scenario (year 2026) enabled us to estimate the watershed pattern by adding new area containing semi-impervious and impervious land coverage. The estimated weighted-average infiltrations (ARC II) were 81.3% and 54.9%, for the above 55.8-mm and 117.8-mm rainfalls, respectively. Changes concerning infiltration might be disturbing the natural recharging process of aquifers, carrying out modifications in the hydrodynamics of the watershed, and also affecting water supply for human activities in the territory.

Ciencia y tecnología en la provincia de Buenos Aires: Capacidades y propuestas

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Ciencia y tecnología en la provincia de Buenos Aires: Capacidades y propuestas; Science and technology in the province of Buenos Aires: Capabilities and proposals; Ciência e tecnologia na província de Buenos Aires: Capacidades e propostas Bilmes, Gabriel Mario; Liaudat, Santiago; Ranea Sandoval, Ignacio Francisco; Bilmes, Julián; Baum, Gabriel : La provincia de Buenos Aires (PBA) reúne poco más del 30% de la inversión pública y privada total en I+D de Argentina. Su magnitud es tal que, si fuese un país, podría ocupar el cuarto lugar en inversión en este rubro, después de Brasil, México y Argentina. Es el distrito que produce la mayor cantidad de publicaciones científicas y el que tiene mayor número de personas dedicadas a actividades de I+D. Sin embargo, no ha logrado organizar toda esta potencialidad, ni articularla a su desarrollo productivo y social. El presente artículo busca poner de relieve la importancia y necesidad de contar con una política provincial de CyT que responda a las demandas socioproductivas de la PBA. Para ello se muestra, por un lado, las capacidades CyT con las que cuenta. Por otro lado, se presenta un conjunto de propuestas para que el complejo de instituciones CyT que trabajan en el territorio de la PBA pueda colaborar en la resolución de los graves problemas que afectan a la región.; The Province of Buenos Aires (PBA) gathers just over 30% of total public and private investment in R&D in Argentina. Its magnitude is such that, if it were a country, it could occupy the fourth place in investment in this area, after Brazil, Mexico and Argentina. It is the district that produces the most scientific publications and the one with the largest number of people dedicated to R&D activities. However, it has not managed to organize all this potential, nor to articulate it to its productive and social development. This article seeks to highlight the importance and need of having a provincial S&T policy that responds to the socio-productive demands of the PBA. For this, it shows, on the one hand, the S&T capabilities that it has. On the other hand, a set of proposals is presented so that the complex of S&T institutions working in the PBA territory can collaborate in solving the serious problems that affect the region.; A Província de Buenos Aires (PBA) reúne pouco mais de 30% do investimento público e privado total em P&D na Argentina. Sua magnitude é tal que, se fosse um país, poderia ocupar o quarto lugar em investimentos nessa área, depois do Brasil, México e Argentina. É o distrito que produz mais publicações científicas e aquele com o maior número de pessoas dedicadas às atividades de P&D. No entanto, não conseguiu organizar todo esse potencial nem articulá-lo ao seu desenvolvimento produtivo e social. Este artigo procura destacar a importância e a necessidade de uma política provincial de C&T que responda às demandas sócio-produtivas do PBA. Para isso, mostra, primeiramente, os recursos de C&T que possui. Em segundo lugar, é apresentado um conjunto de propostas para que o complexo de instituições de C&T, que trabalham no território do PBA, possa colaborar na solução dos graves problemas que afetam a região.

Routh reduction of palatini gravity in vacuum

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Routh reduction of palatini gravity in vacuum Capriotti, Santiago An interpretation of Einstein-Hilbert gravity equations as Lagrangian reduction of Palatini gravity is made. The main technique involved in this task consists in representing the equations of motion as a set of differential forms on a suitable bundle. In this setting Einstein-Hilbert gravity can be considered as a kind of Routh reduction of the underlying field theory for Palatini gravity. As a byproduct of this approach, a novel set of conditions for the existence of a vielbein for a given metric is found.

Left ventricle segmentation using a Bayesian approach with distance dependent shape priors

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Left ventricle segmentation using a Bayesian approach with distance dependent shape priors Cardenas, Rodrigo; Curiale, Ariel Hernán; Mato, German We propose a method for segmentation of the left ventricle in magnetic resonance cardiac images. The framework consists of an initial Bayesian segmentation of the central slice of the volume. This segmentation is used to locate a shape prior for the LV myocardial tissue. This shape prior is determined using the fact that the myocardium is approximately annular as seen in the short-axis. Then a second Bayesian segmentation is performed to obtain the final result. This procedure is repeated for the rest of the slices. An extrapolation of the area of the LV is used to determine a stopping criterion. The method was evaluated on the databases of the Cardiac Atlas project. Our results demonstrate a suitable accuracy for myocardial segmentation (≈0.8 Dice’s coefficient). For the endocardium and the epicardium the Dice’s coefficients are 0.94 and 0.9 respectively. The accuracy was also evaluated in terms of the Hausdorff distance and the average distance. For the myocardium we obtain 8 mm and 2 mm respectively. Our results demonstrate the capability and merits of the proposed method to estimate the structure of the LV. The method requires minimal user input and generates results with quality comparable to more complex approaches. This paper suggests a new efficient approach for automatic LV quantification based on a Bayesian technique with shape priors with errors comparable to state-of-the-art techniques.

Giro neoliberal en Argentina y Brasil en los últimos años: Periferialización, dependencia y desigualdad

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Giro neoliberal en Argentina y Brasil en los últimos años: Periferialización, dependencia y desigualdad; Neoliberal turn in Argentina and Brazil in recent years: Peripheralization, dependency and inequality Merino, Gabriel Esteban América Latina es conocida como la región más desigual del mundo en términos de ingresos, y también resalta por su carácter “subdesarrollado” o sus niveles de pobreza. Las visiones dominantes invisibilizan que estos fenómenos están estrechamente relacionados con el hecho de que la región se ubica desde los orígenes del capitalismo y del sistema mundial moderno como periferia (fundante), envuelta en la lógica del desarrollo desigual y combinado. es una región en donde se expresan con claridad, y también con ciertas particularidades, las consecuencias económico-sociales de la situación de dependencia, del lugar subordinado en la división internacional del trabajo y en el sistema interestatal. sin embargo, esto no es una situación constante e inmodificable. Así como a partir de ciertos momentos se observan giros políticos –“progresistas”, de “izquierda”, “populistas”, “posneoliberales”, o nacionales populares desde nuestra perspectiva– que tienden a revertir o al menos a matizar las condiciones señaladas, también se observan giros que las refuerzan. en este sentido, en el presente trabajo se analiza el giro político estratégico que se produjo a partir de 2015-2016 en argentina y Brasil, a favor de un programa neoliberal-periférico que desplazó al programa nacional neodesarrollista y a la articulación político-social que lo sostenía. Ello impactó en el rápido aumento de la desigualdad de riquezas e ingresos, de la pobreza, del desempleo y de la brecha con respecto del centro y de otros territorios semiperiféricos. Desde esta perspectiva, argentina y Brasil se encuentran en una encrucijada fundamental: profundizar su retroceso bajo un programa de neoliberalismo periférico y la subordinación a una potencia en declive, o producir un nuevo giro político y desarrollar una estrategia regional para terminar con las condiciones de subordinación y dependencia.; Latin America is known as the most unequal region in the world in terms of income, and it also stands out for its “underdeveloped” nature or its poverty levels. The dominant perspectives make invisible that these phenomena are closely related to the fact that the region is located in the origins of capitalism and the modern world system as a periphery (founding), wrapped in the logic of unequal and combined development. It is a region where the socio-economic consequences of the situation of dependency, of the subordinate place in the international division of labor and in the interstate system are expressed clearly and with certain particularities. However, it is not a constant and unchangeable situation. Just as from certain moments we observe political turns -"progressive","left","populist","post-neoliberal", or popular nationals from our perspective - which tend to reverse or at least moderate the indicated conditions, we also observe turns that reinforce them. In this sense, this paper analyzes the strategic political turn that took place from 2015-2016 in argentina and Brazil, in favor of a neoliberal-peripheral program that displaced the national neo-developmental program and the socio-political articulation that sustained it. This had an impact on the rapid increase in wealth and income inequality, poverty, unemployment and the gap respecting the center and other semi-peripheral territories. From this perspective, argentina and Brazil are at a fundamental crossroad: deepening their setback under a program of peripheral neoliberalism and subordination to a declining power, or gene- rating a new political turn and developing a regional strategy to end the conditions of subordination and dependency.

Genetic diversity, population structure, and immigration, in a partially hunted puma population of south-central Argentina

CONICET Digital -

Genetic diversity, population structure, and immigration, in a partially hunted puma population of south-central Argentina Gallo, Orlando; Castillo, Diego Fabián; Barata Godinho, Maria Raquel; Casanave, Emma Beatriz Los carnívoros están disminuyendo a nivel mundial debido en parte a los disturbios ecológicos de origen antrópico. En Argentina, las actividades humanas han fragmentado el hábitat natural, lo cual ha intensificado el conflicto puma-ganadería llevando al control local de las poblaciones mediante la caza. En este trabajo se investigó la variabilidad genética y la estructura poblacional de pumas (Puma concolor) de tres provincias del centro-sur de Argentina con dos diferentes políticas de manejo para la especie: protección versus caza legal. Las estimaciones se basaron en 83 individuos genotipados utilizando 25 loci microsatélites especie específicos. La diversidad genética general resultó ser alta (heterocigosidad observada = 0,63) pero más baja que la de otras poblaciones sudamericanas. Los análisis espaciales revelaron la presencia de dos grupos genéticos con signos de cuello de botella, diversidad muy similar y un flujo génico bajo (3% por generación) entre ellos. Sin embargo, los análisis basados en grupos definidos a priori mostraron que el patrón del flujo de genes sigue valores crecientes de la presión de caza, convergiendo en el área con el mayor número de individuos cazados. Nuestros resultados sugieren que la presión de caza probablemente está contribuyendo al patrón de flujo génico, limitando los movimientos de los pumas y creando una dinámica meta-poblacional entre las subpoblaciones geográficas. Es necesario realizar estudios integrando aspectos demográficos y genéticos para una mejor compresión de los movimientos de los pumas a través del paisaje, y adoptar planes de manejo exitosos para la conservación de la población a largo plazo.; Carnivores are decreasing globally due in part to anthropogenic ecological disturbances. In Argentina, human activities have fragmented wildlife habitat, thereby intensifying puma–livestock conflict and leading to population control of the predator species by hunting. We investigated genetic variability and population structure of pumas (Puma concolor) from three south-central Argentine provinces with two different management policies for the species: full protection versus legal hunting. All genetic estimates were based on 83 individuals genotyped at 25 species-specific microsatellite loci. The overall genetic diversity was high (observed heterozygosity = 0.63), but lower than in other South American populations. Spatial analyses revealed the presence of two bottlenecked genetic clusters with very similar diversity and low gene flow (3% per generation) between them. However, analyses based on a priori separated groups showed that gene flow follows increasing values of hunting pressure, converging to the area with the greatest number of individuals harvested. Our results suggest that hunting pressure likely is contributing to the gene flow pattern, limiting pumas’ movements and creating a metapopulation dynamic among geographic subpopulations. Integrated demographic and genetic approaches are needed to better understand pumas’ movements across the landscape and adopt successful management plans to achieve long-term population viability.

16S rRNA gene diversity in the salt crust of Salar de Uyuni, Bolivia, the World’s Largest Salt Flat

CONICET Digital -

16S rRNA gene diversity in the salt crust of Salar de Uyuni, Bolivia, the World’s Largest Salt Flat Pecher, Wolf T.; Martínez, Fabiana Lilian; DasSarma, Priya; Guzmán, Daniel; DasSarma, Shiladitya Salar de Uyuni is a vast, high-altitude salt flat in Bolivia with extreme physico-geochemical properties approaching multiple limits of life. Evidence for diverse halophilic bacteria and archaea was found in its surface and near-surface salt crust using 16S amplicon analysis, providing a snapshot of prokaryotic life.

Complete Genome Sequence of the Lignocellulose-Degrading Actinomycete Streptomyces albus CAS922

CONICET Digital -

Complete Genome Sequence of the Lignocellulose-Degrading Actinomycete Streptomyces albus CAS922 Tippelt, Anna; Nett, Markus; Vela Gurovic, Maria Soledad Streptomyces albus CAS922 was isolated from sunflower seed hulls. Its fully sequenced genome harbors a multitude of genes for carbohydrate-active enzymes, which likely facilitate growth on lignocellulosic biomass. Furthermore, the presence of 27 predicted biosynthetic gene clusters indicates a significant potential for the production of bioactive secondary metabolites.

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