Poliquetos de fondos blandos en el Estrecho de Magallanes capturados durante la campaña oceanográfica italiana en febrero-marzo de 1991

Species composition, distribution and biogeography of polychaetes collected from the soft bottoms of the Straits of Magellan (South America) in February-March 1991 are reported. In 16 benthic samples, collected with different tools (Charcot and triangular dredges, van Veen grab), a total of 1132 individuals belonging to 119 taxa of polychaetes were collected; only 49 of the taxa found have been determined at species level. Eighteen species were recorded for the first time in the Straits of Magellan. Species richness was relatively high considering both the number of individuals collected, and the taxa known from previous studies on the area (182 species). The biogeographical analysis, conducted only on the 49 taxa classified at the species level, showed the dominance of Magellan-Antarctic-Subantarctic species (M-An-S 50%), followed by Magellan-American (M-Am 14%), Magellan-Antarctic (M-An 12%), Magellan-Subantarctic (M-S 6%), Cosmopolitans (C 10%), and also by a few species with disjunct distribution (D 8%). Values of the Sørensen similarity index among stations were very low (below 0.30) with a few exceptions. Both number of species and of individuals were higher in the Atlantic sector of the Straits, especially at some stations characterized by heterogeneous mixed sediments (gravels and pebbles) and biogenic debris (mollusc thanatocoenosis). The high number of species recorded, coupled with low similarity values among stations, suggests that the soft bottoms of the Straits of Magellan show, at medium scale, a highly diversified mosaic of different biotopes. This can be due to various factors which are expected to vary along the wide geographic area investigated, such as the wide bathymetric range sampled, the type of sampling gears used, and last but not least the occurrence of many different environmental situations along the Straits.En el presente trabajo se describen composición específica, distribución y biogeografía de los poliquetos recolectados en los fondos blandos del Estrecho de Magallanes (Sudamérica), durante los meses de febrero y marzo del año 1991. En 16 muestras bentónicas, recogidas con diferentes métodos (dragas Charcot, triangular y van Veen), se encontraron un total de 1132 individuos pertenecientes a 119 taxones de poliquetos. De éstos tan solo 49 han sido determinados a nivel de especie y a su vez 18 han resultado ser nuevas citas para el Estrecho de Magallanes. La riqueza específica encontrada fue relativamente alta, considerando tanto el número de individuos recolectados como los taxones conocidos gracias a estudios previos en el área (182 especies). El análisis biogeográfico, efectuado solamente sobre los taxones clasificados a nivel de especie (49), ha demostrado la dominancia de especies Magallano-Antártico- Subantárticas (M-An-S 50%), seguida por especies Magallano-Americanas (M-Am 14%), Magallano-Antárticas (M-An 12%), Magallano-Subantárticas (M-S 6%), Cosmopolitas (C 10%) y también por especies de distribución disjunta (D 8%). Los valores del índice de similaridad de Sørensen entre estaciones fueron muy bajos (inferiores a 0.3) salvo algunas excepciones. Tanto el número de especies como el número de individuos fueron más elevados en el sector atlántico del Estrecho, particularmente en algunas estaciones caracterizadas por sedimentos heterogéneos de tipo mixto (gravas y guijarros), y restos biogénicos (tanatocenosis de moluscos). El elevado número de especies descrito, combinado con los valores bajos de similaridad entre estaciones, sugieren que los fondos blandos del Estrecho de Magallanes presentan, a media escala, un mosaico altamente diversificado de biotopos diferentes. Esto puede ser debido a varios factores que son responsables de la variación a lo largo de la vasta área geográfica investigada, tales como el amplio rango batimétrico estudiado, el tipo de instrumentación de muestreo, y en último lugar pero no menos destacable, la presencia de muchas situaciones ambientales diferentes a lo largo del Estrech

Two iterative schemes for an H-system

Two iterative schemes for the solution of an H-system with Dirichlet boundary data for a revolution surface are studied: a Newton imbedding type procedure, which yields the local quadratic convergence of the iteration and a more simple scheme based on the method of upper and lower solutions.Fil: Amster, Pablo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; ArgentinaFil: Mariani, María Cristina. New Mexico State University Las Cruces; Méxic

Some dimensions of commonsense reasoning about the physical world : an empirical study of the structure of students' conceptualisations

Abstract Research in the area of alternative conceptions in Science has been suggesting that students hold conceptualisations which are different from those learned at school. This thesis aims to investigate possible structured patterns of commonsense reasoning about the physical world present in the way students (ranging from 8-9 year old to undergraduate students of Physics) conceptualise entities in Science. The theoretical framework was developed mainly from previous Piagetian studies (see Mariani and Ogborn 1990, 1991) about the child's construction of reality (Piaget 1937), particularly in what concerns the fundamental role of actions in this construction, and also with a basis in some more recent studies on the representation of knowledge in the area of the cognitive sciences. With a basis in this theoretical framework some very fundamental 'ontological' questions were addressed to the students about a selected group of entities (Can you touch it? or Can you create it? etc.). Also students were asked to compare entities and to locate them in a given number of 'ontological' dimensions (static or dynamic, cause or effect, etc.) The empirical data was collected with the use of questionnaires and interviews. The sample consisted of five different agelinstructional groups of Brazilian students. Multidimensional scaling was used to analyse the quantitative data. The qualitative data was analysed using a systemic network with which different answers given by students could be classified. The general result of the quantitative analysis was a common fourdimensional 'ontological' space for all five groups, with the dimensions being interpreted in the same way as in a previous published pilot study (Mariani and Ogborn, 1991), and being fundamentally related to the distinctions static or dynamic, place or localized, cause or motion and immaterial fluid (continuous) or action (discrete). In these spaces entities can be located and may change their positions with different agelinstructional groups. The results of the qualitative analysis give some more support to these quantitative results

The effects of fibers on the performance of bituminous mastics for road pavements

The experimental investigation herein described is aimed at understanding the effects of cellulose-based fibers on the mechanical properties of bituminous mastics for paving applications. Three bitumen (two of which modified with SBS polymers), a calcareous filler and four different types of fiber with varying content were used to prepare the investigated mastics. The filler to bitumen ratio was maintained constant. The laboratory investigations were focused on empirical tests (Needle Penetration and Ring and Ball – R&B – Temperature) and dynamic-mechanical tests, the latter performed in a wide range of temperatures. Results suggest that fibers improve the behavior of mastics for hot mix asphalts, particularly with respect to the prevention of rutting phenomena at high service temperatures

Primer registro de Cecilioides Acicula (Müller, 1774) Ferussaciidae, en la Provincia de Buenos Aires

Cecilioides acicula (Müller, 1774) es una especie perteneciente a la familia Ferussaciidae, nativa del centro y oeste de Europa, Mediterráneo, Arabia, norte de África y centro de Asia. La acción humana contribuyó a su dispersión por diferentes partes del planeta, Norte de Europa, Isla de Mallorca, Azores, islas Canarias, África del Sur, Australia, Nueva Zelanda. En América del Norte fue citada en Canadá y Bermuda, Estados Unidos de América Pennsylvania, Florida, California, Virginia, New Jersey, New México y Hawaii. América Central en Barbados. En América del Sur hasta la fecha en Uruguay: Punta Ballena (Maldonado) y Argentina: Rosario (Santa Fe). El objetivo de este trabajo es comunicar la presencia de esta especie introducida en la provincia de Buenos Aires, específicamente en la ciudad de La Plata. Es una especie de hábitos subterráneos, en los estratos inferiores de suelos húmedos entre hojarasca, piedras y raíces, apareciendo raramente en la superficie. Es común hallarla entre restos óseos de sepulturas antiguas. Los cinco ejemplares de Cecilioides acicula fueron obtenidos de muestras de sedimento asociadas a restos humanos y envolturas proveniente de exhumaciones legales realizadas en el Cementerio Municipal de La Plata, los cuales fueron inhumados a 40 cm de profundidad y posteriormente donados a la Facultad de Ciencias Médicas –UNLP-. La dispersión de esta especie como la de muchos otros gasterópodos terrestres fue debido al traslado de plantas ornamentales con su sustrato. Este nuevo aporte amplía su distribución geográfica en la Argentina para la provincia de Buenos Aires. Cabe mencionar que la forma de vida subterránea, su preferencia por sustratos calcáreos y el hecho de ser hallada en suelos de cementerios que actúan como refugios, podría ser el motivo de la escasez de registros. Agradecimientos: PIP0796-2014; Proyectos de Investigación y Desarrollo UNLP- FCNyM - N727 y N783

¿La gobernanza guiada por pautas de gobierno abierto mejora el valor público de los programas gubernamentales?

O artigo analisa em que medida a introdução de princípios de governo aberto, ao promover mudanças na governança das políticas públicas, favorece a geração de valor público em programas governamentais. A partir de estudo de caso do programa Bolsa Família, com triangulação de métodos, é feito o rastreamento das alterações na governança do programa que estiveram alinhadas a princípios de governo aberto, aferindo até que ponto houve ou não uma maior geração de valor público pelo programa. O estudo conclui que o Bolsa Família, mais do que atender a normativos e adotar uma governança orientada por padrões genéricos, construiu seu próprio modelo (ou referencial) de governança aberta. Alguns aspectos cruciais desse modelo já coincidiam com princípios e diretrizes de governo aberto que só seriam consagrados posteriormente. As evidências são de que isso ocorreu pela necessidade prática de encontrar soluções que trouxessem agilidade e facilidades operacionais à implementação e à prestação de contas do programa, materializadas na forma de algumas de suas ferramentas de política, como o Cadastro Único. A pesquisa oferece ainda uma contribuição aplicada de operacionalização do conceito de valor público por meio, entre outras, da análise do acesso e do uso de dados abertos.The article analyzes the extent to which the introduction of open government principles, by promoting changes in the governance of public policies, favors the generation of public value for government programs. Based on a case study of the Bolsa Família program, with a triangulation of methods, changes in the governance of the program that were aligned with the principles of open government are tracked and the measurement of the extent to which, or not, there was a greater generation of public value by the program. The study concludes that Bolsa Família – which is more than just meeting norms and adopting governance guided by generic standards – has built its own open governance model. Some crucial aspects of this model already coincided with open government principles and guidelines that would only be enshrined later. The evidence is that this occurred due to the practical need to find solutions that would bring agility and operational facilities to the implementation and accountability of the program, materialized in the form of some of its policy tools, such as the Single Registry. The research also offers an applied contribution to operationalize the concept of public value through, among others, the analysis of access and use of open dataEl artículo analiza en qué medida la introducción de principios de gobierno abierto, al promover cambios en la gobernanza de las políticas públicas, favorece la generación de valor público. Basado en un estudio de caso del programa Bolsa Família, con triangulación de métodos, se investigan los cambios en la gobernanza del programa que están en línea con los principios de gobierno abierto y se verifica en qué medida hubo una mayor generación de valor público por el programa. El estudio concluye que Bolsa Familia, más que cumplir normas y adoptar una gobernanza guiada por estándares genéricos, ha construido su propio modelo de gobernanza abierta. Algunos aspectos cruciales de este modelo ya coincidían con principios y lineamientos de gobierno abierto que solo serían consagrados más adelante. La evidencia es que esto ocurrió por la necesidad práctica de encontrar soluciones que aportaran agilidad y facilidades operativas a la implementación y rendición de cuentas del programa, materializado en la forma de algunas de sus herramientas de política, como el Registro Único de beneficiarios del programa. La investigación también ofrece una contribución aplicada para operacionalizar el concepto de valor público por medio del análisis del acceso y del uso de datos abiertos, entre otros mecanismos.Revista do Serviço Público - RSP, v. 71, Edição Especial, p. 34-56Análise e Ciência de DadosGestão PúblicaGovernançaISSN Eletrônico: 2357-8017ISSN Impresso: 0034-924

Effect of a cytoprotective dose of dehydroleucodine, xanthatin, and 3-benzyloxymethyl-5h-furan-2-one on gastric mucosal lesions induced by mast cell activation

The aim of this study was to determine whether the lactones dehydroleucodine, xanthatin and 3-benzyloxymethyl-5H-furan-2-one, would be effective in an animal model of gastric ulcer induced by mast cell activation. Rats were divided into ten groups. Treatments were repeated for four days. The degree of gastric erosion was assessed with a scoring system and histological preparations. Gastric mast cell morphology was analyzed by histological procedures. Serum serotonin levels were determined as markers of mast cell activation. Statistical analyses were done using ANOVA and Tukey–Kramer test. We demonstrated that the repeated administration of compound 48/80 results in extensive mucosal lesions in the gastric mucosa and that such lesions occurred in association with mast cell degranulation and a significant increase of serum serotonin. We showed that these lesions were prevented by dehydroleucodine, xanthatin, and 3-benzyloxymethyl-5H-furan-2-one and that this effect was similar to that obtained with sodium cromoglycate. In conclusion, the results of the present study indicate that the optimal gastric cytoprotective dose of dehydroleucodine, xanthatin, and 3-benzyloxymethyl-5H-furan-2-one is efficacious in an animal model of gastric ulcer induced by mast cell activation. Our findings suggest that these lactones could be valuable tools for designing novel therapeutic agents for digestive disorders associated with inappropriate mast cell activation.Fil: Vera, Mariano Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Mariani, María Laura Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Aguilera, Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Penissi, Alicia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Instituto de Histología y Embriología de Mendoza Dr. Mario H. Burgos; Argentin

Ecological traits, genetic diversity and regional distribution of the macroalga Treptacantha elegans along the Catalan coast (NW Mediterranean Sea)

The widespread decline of canopy-forming macroalgal assemblages has been documented in many regions during the last decades. This pattern is often followed by the replacement of structurally complex algal canopies by more simplified habitats (e.g., turfs or sea urchin barren grounds). Against all odds, the fucoid Treptacantha elegans, a large Mediterranean brown macroalga, broadened its depth range to deeper and exposed environments and displayed an unexpected range expansion along the northern coast of Catalonia over the last two decades. Here, we reconstruct the spread of T. elegans in time and space and unravel ecological and demographic traits such as population dynamics and genetic patterns to provide a comprehensive and integrated view of the current status and geographical expansion for this species. Fast-growing dynamics, early fertile maturity, and high turnover rate are the main competitive advantages that allow the exposed populations of T. elegans to colonize available substrata and maintain dense and patchy populations. We also provided evidence that the deeper and exposed populations of T. elegans constitute a single group across the Catalan coast, with little genetic differentiation among populations. This seems to support the hypothesis of a unique source of spread in the last decades from the Medes Islands No-Take Zone towards both southern and northern waters.CCMAR was funded by FCT—Foundation for Science and Technology (Portugal) UID/Multi/04326/2019, PTDC/MAR-EST/6053/2014,Biodiversa/0004/2015, (DL 57/2016/CP1361/CT0010), SFRH/BSAB/150485/2019info:eu-repo/semantics/publishedVersio

QUASILINEAR ELLIPTIC SYSTEMS OF RESONANT TYPE AND NONLINEAR EIGENVALUE PROBLEMS

This work is devoted to the study of a quasilinear elliptic system of resonant type. We prove the existence of infinitely many solutions of a related nonlinear eigenvalue problem. Applying an abstract minimax theorem, we obtain a solution of the quasilinear system (x, u, v), under conditions involving the first and the second eigenvalues

Look What I Am Doing: Does Observational Learning Take Place in Evocative Task-Sharing Situations?

Two experiments were conducted to investigate whether physical and observational practice in task-sharing entail comparable implicit motor learning. To this end, the social-transfer-of-learning (SToL) effect was assessed when both participants performed the joint practice task (Experiment 1 \u2013 complete task-sharing), or when one participant observed the other performing half of the practice task (Experiment 2 \u2013 evocative task-sharing). Since the inversion of the spatial relations between responding agent and stimulus position has been shown to prevent SToL, in the present study we assessed it in both complete and evocative task-sharing conditions either when spatial relations were kept constant or changed from the practice to the transfer session. The same pattern of results was found for both complete and evocative task-sharing, thus suggesting that implicit motor learning in evocative task-sharing is equivalent to that obtained in complete task-sharing. We conclude that this motor learning originates from the simulation of the complementary (rather than the imitative) action