324 research outputs found

    Monetary Policy Rules with Financial Instability

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    To provide a rigorous analysis of monetary policy in the face of financial instability, the authors extend the standard dynamic stochastic general equilibrium model to include a financial system. Their simulations suggest that if financial stability affects output and inflation with a lag, and if the central bank has privileged information about financial stability, then monetary policy responding instantly to deteriorating financial stability can trade off more output and inflation instability today for a faster return to the trend than a policy that follows the traditional Taylor rule. This augmented rule leads in some parameterizations to improved outcomes in terms of long-term welfare, but the welfare impacts of such a rule are small.DSGE models, financial instability, monetary policy rule

    Arid community responses to nitrogen and carbon addition depend on dominant species traits and are decoupled between above- and below-ground biomass

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    Questions: Arid communities are strongly limited by soil resources including water and nitrogen (N). Plants compete for N with other plants and microorganisms, which are also limited by carbon (C). We propose that above- and below-ground plant responses to soil resources are modulated by community structure (species relative abundances, “mass ratio hypothesis”) and species traits (relative growth rates — RGRs). We evaluated the single and combined effects of soil N and C addition on the above- and below-ground biomass accumulation of perennial grass patches in an arid community, and the mechanisms involved in their responses. Location: Patagonian steppe, Argentina. Methods: We added N (2 g N m−2; NH4NO3) and C (330 g C m−2; sucrose) to 1-m2 field plots in a factorial design. After two years, we harvested above-ground (n = 5 plots) and below-ground biomass (n = 10 soil cores) and sorted it by species. We measured potential soil respiration as a proxy of microbial activity. Results: Total above-ground biomass increased by 55% as a result of N and decreased by 45% as a result of C addition, in relation to controls. C addition reduced total below-ground biomass by 42%. The above-ground differences were associated with changes in the biomass of dominant species according to their RGRs. Poa ligularis (dominant, high RGR) increased by 92% as a result of N addition while Pappostipa speciosa (dominant, low RGR) decreased by 55% as a result of C addition. Intermediate and subordinate grasses did not modify their biomass, independently of their RGR. Potential soil respiration was three times higher in plots with C addition than in control plots. Conclusions: Community biomass was explained by a combination of mass ratio hypothesis and specific RGR, as dominant grasses controlled above-ground community responses to N (high-RGR species) and C addition (low-RGR species). Our findings highlight the independence between the above- and below-ground processes and the importance of considering community equitability and species characteristics to predict plant community responses to changes in soil resources.Fil: Campana, María Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Reyes, María Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Aguiar, Martin Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentin

    Concepciones sobre la ciencia y el aprendizaje en docentes de ciencias biológicas de la escuela secundaria. Un estudio en contextos de capacitación docente en el Partido de General Pueyrredón, Provincia de Buenos Aires

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    Tesis de Maestría en Educación en Ciencias Experimentales y Tecnología, Facultad de Ciencias Exactas, Físicas y Naturales de la Universidad Nacional de Córdoba. Año 2019.En esta tesis se describen las concepciones sobre ciencia y aprendizaje en docentes de Biología que acceden a los cursos de capacitación docente estatales, en uno de los distritos más importantes de la Provincia de Buenos Aires, y se han relacionado los resultados con variables como la edad, la formación de base, la antigüedad docente. Se realizaron dos estudios. En el primero se utilizaron cuestionarios de dilemas para indagar concepciones sobre ciencia y aprendizaje en 76 sujetos. A continuación, se realizaron cuatro entrevistas para profundizar sobre las concepciones de aprendizaje al indagar en cuestiones de la práctica educativa propia. En las concepciones sobre ciencia, se encontró un grupo de docentes con posiciones vinculadas a visiones más actuales de ciencia en todas las dimensiones indagadas, mientras que en un segundo grupo las posiciones se tornaban más realistas empiristas cuando se analiza la dimensión referida al método científico. En las concepciones de aprendizaje, se encontró que los docentes tienen posiciones vinculadas a la teoría constructiva del aprendizaje en cuestiones relacionadas al “qué se aprende”, sin embargo se alejan de esta posición en aquellas relacionadas al “cómo se aprende”. Se detectó un grupo menor con posiciones consistentes en la teoría constructiva en todas las dimensiones. La edad y el contexto de formación de base serían algunos de los aspectos que explicaría estas diferencias. En las entrevistas, se encontró que al indagar sobre cuestiones de la práctica educativa propia, se evidenciaban en mayor medida concepciones ligadas a la teoría directa sobre el aprendizaje.Fil: Martin, Sofía Sol. Universidad Nacional de Mar del Plata, Facultad de Ciencias Exactas y Naturales. Grupo de Investigación en Educación Científica; Argentina

    Discriminant analysis of principal components and pedigree assessment of genetic diversity and population structure in a tetraploid potato panel using SNPs

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    The reported narrow genetic base of cultivated potato (Solanum tuberosum) can be expanded by the introgression of many related species with large genetic diversity. The analysis of the genetic structure of a potato population is important to broaden the genetic base of breeding programs by the identification of different genetic pools. A panel composed by 231 diverse genotypes was characterized using single nucleotide polymorphism (SNP) markers of the Illumina Infinium Potato SNP Array V2 to identify population structure and assess genetic diversity using discriminant analysis of principal components (DAPC) and pedigree analysis. Results revealed the presence of five clusters within the populations differentiated principally by ploidy, taxonomy, origin and breeding program. The information obtained in this work could be readily used as a guide for parental introduction in new breeding programs that want to maximize variability by combination of contrasting variability sources such as those presented here.Fil: Deperi, Sofía Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Tagliotti, Martin Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Bedogni, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Manrique Carpintero, Norma C.. Michigan State University; Estados UnidosFil: Coombs, Joseph. Michigan State University; Estados UnidosFil: Zhang, Ruofang. Inner Mongolia University; ChinaFil: Douches, David. Michigan State University; Estados UnidosFil: Huarte, Marcelo Atilio. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentin

    Use of easy measurable phenotypic traits as a complementary approach to evaluate the population structure and diversity in a high heterozygous panel of tetraploid clones and cultivars

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    Diversity in crops is fundamental for plant breeding efforts. An accurate assessment of genetic diversity, using molecular markers, such as single nucleotide polymorphism (SNP), must be able to reveal the structure of the population under study. A characterization of population structure using easy measurable phenotypic traits could be a preliminary and low-cost approach to elucidate the genetic structure of a population. A potato population of 183 genotypes was evaluated using 4859 high-quality SNPs and 19 phenotypic traits commonly recorded in potato breeding programs. A Bayesian approach, Minimum Spanning Tree (MST) and diversity estimator, as well as multivariate analysis based on phenotypic traits, were adopted to assess the population structure. Results: Analysis based on molecular markers showed groups linked to the phylogenetic relationship among the germplasm as well as the link with the breeding program that provided the material. Diversity estimators consistently structured the population according to a priori group estimation. The phenotypic traits only discriminated main groups with contrasting characteristics, as different subspecies, ploidy level or membership in a breeding program, but were not able to discriminate within groups. A joint molecular and phenotypic characterization analysis discriminated groups based on phenotypic classification, taxonomic category, provenance source of genotypes and genetic background. Conclusions: This paper shows the significant level of diversity existing in a parental population of potato as well as the putative phylogenetic relationships among the genotypes. The use of easily measurable phenotypic traits among highly contrasting genotypes could be a reasonable approach to estimate population structure in the initial phases of a potato breeding program.Fil: Tagliotti, Martin Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Deperi, Sofía Irene. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Bedogni, María Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Zhang, Ruofang. Inner Mongolia University; ChileFil: Manrique Carpintero, Norma C.. Michigan State University; Estados UnidosFil: Coombs, Joseph. Michigan State University; Estados UnidosFil: Douches, David. Michigan State University; Estados UnidosFil: Huarte, Marcelo Atilio. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentin

    Design of a New 3D Gelatin—Alginate Scaffold Loaded with Cannabis sativa Oil

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    There is an increasing medical need for the development of new materials that could replace damaged organs, improve healing of critical wounds or provide the environment required for the formation of a new healthy tissue. The three-dimensional (3D) printing approach has emerged to overcome several of the major deficiencies of tissue engineering. The use of Cannabis sativa as a therapy for some diseases has spread throughout the world thanks to its benefits for patients. In this work, we developed a bioink made with gelatin and alginate that was able to be printed using an extrusion 3D bioprinter. The scaffolds obtained were lyophilized, characterized and the swelling was assessed. In addition, the scaffolds were loaded with Cannabis sativa oil extract. The presence of the extract provided antimicrobial and antioxidant activity to the 3D scaffolds. Altogether, our results suggest that the new biocompatible material printed with 3D technology and with the addition of Cannabis sativa oil could become an attractive alternative to common treatments of soft-tissue infections and wound repair.Pablo E. Antezana is grateful for his postdoctoral fellowship granted by the CONICET. The authors would like to acknowledge grants from the Universidad de Buenos Aires, UBACYT 20020150100056BA and PIDAE 2022 (Martín F. Desimone), which supported this work. Gorka Orive wishes to thank the Spanish Ministry of Economy, Industry and Competitiveness (PID2019-106094RB-I00/AEI/10.13039/501100011033) and to acknowledge technical assistance from the ICTS NANBIOSIS (Drug Formulation Unit, U10) at the University of the Basque Country. We also appreciate the support from the Basque Country Government (Grupos Consolidados, No ref: IT1448-22)

    Efecto de la estirpe y del tratamiento de muda en la interrupción de la puesta y la recuperación productiva posterior

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    La inducción de la muda en gallinas ponedoras, mediante la supresión total del alimento sólido, está prohibida en la UE. Por ello, es necesario estudiar sistemas alternativos que, logrando los mismos efectos, no causen en el ave una sensación de hambre que perjudique significativamente su bienestar. El objetivo es conseguir que la gallina experimente una adecuada pérdida de peso vivo para que la puesta cese rápidamente, su tracto reproductor se "rejuvenezca", restableciéndose la producción de huevos lo más rápida y satisfactoriamente posible, con una mínima mortalidad. En este trabajo se han utilizado 216 gallinas de una estirpe ligera (Hy-Line) y otras 216 gallinas semipesadas (Lohmann Brown), induciéndoles la muda con 3 alimentos diferentes: salvado de trigo, cebada y un pienso comercial suministrado en cantidad restringida. Las gallinas se alojaron en grupos de 4 aves por jaula, con 18 réplicas por estirpe y alimento. El salvado y cebada causaron el cese de la puesta más rápidamente (días 7 y 9 desde el inicio de la muda; respectivamente), que el pienso restringido (día14) (P<0,001). La intensidad de puesta en el día 30 desde el inicio de la inducción a la muda fue similar entre tratamientos (33,3%), pero mayor (P < 0,001) en las semipesadas (42,6%) que en las ligeras (23,9%). La mortalidad fue nula durante la muda y sólo en el segundo ciclo de puesta la estirpe tuvo un efecto significativo sobre este parámetro (19,04% en ligeras vs 5,09 en semipesadas; P<0,001

    Reviews of the genera Schaefferia Absolon, 1900, Deuteraphorura Absolon, 1901, Plutomurus Yosii, 1956 and the Anurida Laboulbène, 1865 species group without eyes, with the description of four new species of cave springtails (Collembola) from Krubera-Voronya cave, Arabika Massif, Abkhazia

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    Krubera-Voronya cave and other deep systems in Arabika Massif are being explored during many speleological expeditions. A recent Ibero-Russian exploration expedition (summer of 2010) took place in this cave with the aim of providing a study of the biocenosis of the deepest known cave in the world. Four new species of Collembola were found at different depths: Schaefferia profundissima n. sp., Anurida stereoodorata n. sp., Deuteraphorura kruberaensis n. sp., and Plutomurus ortobalaganensis n. sp., the last one at -1980 m deep. The identification and description of the new species have required the careful study of all congeneric species, implying a revision of each genus. As a result of this work tables and keys to all significant characters for each species are presented

    Efectos de la administración crónica de carvedilol sobre la variabilidad de la presión arterial y el daño de órgano blanco en ratas con desnervación sinoaórtica

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    Background: Increased blood pressure variability is a novel risk factor for the development of target organ injury both in hypertensive and normotensive subjects, so its reduction should be considered as a new therapeutic goal. Objective: The aim of this study was to evaluate the effect of long-term oral carvedilol treatment on blood pressure, blood pressure variability and target organ injury in the left ventricle and thoracic aorta in a model of blood pressure liability. Methods: Twelve male Wistar rats submitted to sinoaortic denervation were treated during 8 weeks with a single dose of carvedilol 30 mg/kg or vehicle. At the end of treatment, echocardiographic evaluation and blood pressure and short-term variability measurements were performed. Left ventricular and thoracic aortic weights were determined and histological samples were prepared from both tissues. Metalloproteinase MMP-2 and transforming growth factor β (TGF-β) were quantified in the left ventricle and thoracic aorta. Results: Carvedilol reduced systolic blood pressure and its variability in sinoaortic-denervated rats compared with the control group (126±5 vs. 142±11 mmHg, p<0.05; SD: 2.9±0.5 vs. 6.0±0.5 mmHg; p<0.05). A lower amount of connective tissue was found in carvedilol-treated animals. The expression of TGF-β decreased in both organs after carvedilol treatment. Conclusions: Chronic carvedilol treatment significantly reduces systolic blood pressure and its short-term variability in sinoaorticdenervated rats, decreasing the degree of left ventricular fibrosis.Fil: del Mauro, Julieta Sofía. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Santander Plantamura, Yanina Alejandra. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Bertera, Facundo Martin. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Carranza, Maria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Donato, Pablo Martín. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gorzalczany, Susana Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; ArgentinaFil: Gelpi, Ricardo Jorge. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Taira, Carlos Alberto. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Höcht, Christian. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Farmacología; Argentin

    ¿Es posible realizar una distinción estricta entre estructuralismo y posestructuralismo en el campo de los estudios literarios?

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    In the paper we propose to review the fundamental concepts of structuralism, to see how they delineated a whole form of analysis in the field of literary theory and finally to discuss the theoretical division between structuralism and post-structuralism. For this purpose, we will briefly talk about structuralism at a general level and especially in literary theory, to finally observe which were the specific methodological developments derived from this epistemological conception. Finally, a comparison will be made with the developments of the so-called post-structuralism, in order to discuss whether the differences between the two terms in the field of literary theory-criticism justify a real division.En el siguiente trabajo nos proponemos hacer una revisión de los conceptos fundamentales del estructuralismo, ver cómo estos delinearon toda una forma de análisis en el campo de la teoría literaria y finalmente discutir la división teórica entre estructuralismo y post-estructuralismo. Para dicho propósito, hablaremos brevemente del estructuralismo a nivel general y, en particular, de su impacto en la teoría literaria, para finalmente observar cuáles fueron los desarrollos metodológicos específicos derivados de dicha concepción epistemológica. Por último, se compararán con los desarrollos del llamado post-estructuralismo para discutir si las diferencias entre ambos términos en el campo de la teoría y la crítica literaria justifican una división real
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