Data governance: Organizing data for trustworthy Artificial Intelligence Janssen, Marijn; Brous, Paul; Estevez, Elsa Clara; Barbosa, Luís Soares; Janowski, Tomasz The rise of Big, Open and Linked Data (BOLD) enables Big Data Algorithmic Systems (BDAS) which are often based on machine learning, neural networks and other forms of Artificial Intelligence (AI). As such systems are increasingly requested to make decisions that are consequential to individuals, communities and society at large, their failures cannot be tolerated, and they are subject to stringent regulatory and ethical requirements. However, they all rely on data which is not only big, open and linked but varied, dynamic and streamed at high speeds in real-time. Managing such data is challenging. To overcome such challenges and utilize opportunities for BDAS, organizations are increasingly developing advanced data governance capabilities. This paper reviews challenges and approaches to data governance for such systems, and proposes a framework for data governance for trustworthy BDAS. The framework promotes the stewardship of data, processes and algorithms, the controlled opening of data and algorithms to enable external scrutiny, trusted information sharing within and between organizations, risk-based governance, system-level controls, and data control through shared ownership and self-sovereign identities. The framework is based on 13 design principles and is proposed incrementally, for a single organization and multiple networked organizations.

Non-polar extracts of Nicotiana glauca (Solanaceae) induce apoptosis in human rhabdomyosarcoma cells Musso, Florencia Antonella; Pronsato, Lucía; Milanesi, Lorena Magdalena; Vasconsuelo, Andrea Anahi; Faraoni, María Belén Rhabdomyosarcoma (RMS) is the most common soft-tissue tumour in children andadolescents. It originates in normal skeletal muscle from myogenic cells that have failed tofully differentiate, and it usually has a poor prognosis. Current RMS therapy has manyadverse effects. Hence, new treatments are needed. Various pharmacological properties,such as analgesic, antineoplastic, antimicrobial, and antiparasitic properties, have beendemonstrated in species of the Solanaceae family. We performed ethanolic extraction fromleaves of Nicotiana glauca (Solanaceae), and the extract was successively partitioned withn-hexane, chloroform, and ethyl acetate. We evaluated the effects of extracts on RMScells, and we found that the extracts trigger apoptosis. By bio-guided fractionation assays,we identified the apoptotic agents. Morphological assessment after apoptotic cell inductionof cultured cells, mitochondrial and nuclear morphology by Mitotracker, and 4,6-diamidino-2-phenylindole (DAPI) staining, respectively, were analysed in fluorescentmicroscopy. The capacity of the cells to migrate or proliferate was analysed by the Petitassay, followed by methylene blue staining. NMR and GC-MS spectrometry were used toidentify palmitic acid and scopoletin as the phytochemicals responsible for the observedeffects. These results indicate that these compounds are apoptotic inducers and they couldbe useful as chemotherapeutic agents against muscle tumours.; Rabdomiossarcoma (RMS) é o tumor de tecidos moles mais comum em crianças e adolescentes. Ele se origina no músculo esquelético normal a partir de las células miogênicas que no conseguiram-se diferenciar completamente e pelo general tem um prognóstico ruim. A terapia atual com RMS tem muitos efeitos adversos e portanto, novos tratamentos são necessários. Várias propriedades farmacológicas, como propriedades analgésica, antineoplásica, antimicrobiana e antiparasitária, foram demostradas em espécies da família Solanaceae. Neste trabalho, foi realizada a extração etanólica das folhas de Nicotiana glauca (Solanaceae), eo extrato foi particionado sucessivamente com n-hexano, clorofórmio y acetato de etila. Avaliamos os efeitos dos extratos nas células RMS e descobrimos que os extratos desencadeiam apoptose. Pelos ensaios de fracionamento bio-guiado, identificamos os agentes apoptóticos. Avaliação morfológica após indução da apoptose das células cultivadas ea morfologia mitocondrial e nuclear por coloração com Mitotracker e 4,6-diamidino-2-fenilindol (DAPI), respectivamente, foram analisadas com microscopia fluorescente. A capacidade das células para migrar ou proliferar foi analisada hair ensaio Petit, seguido pelacoloração com azul de metileno. Una espectrometría de RMN y GC-MS para uso utilizado para una identificación de ácido palmítico y una escopoletina como fitoquímicos responsáveis ​​pelos efeitos observados.

The origin of matter at the base of relativistic jets in active galactic nuclei Romero, Gustavo Esteban; Gutiérrez, Eduardo Mario The generation of relativistic jets in active sources such as blazars is a complex problem with many aspects, most of them still not fully understood. Relativistic jets are likely produced by the accretion of matter and magnetic fields onto spinning black holes. Ergospheric dragging effects launch a Poynting-dominated outflow in the polar directions of these systems. Observations with very high resolution of the jet in the nearby radio galaxy M87 and evidence of extremely fast variability in the non-thermal radiation of several other objects indicate that charged particles produce synchrotron emission and gamma rays very close to the base of the jet. How these particles are injected into the magnetically shielded outflow is a mystery. Here we explore the effects of various processes in the hot accretion inflow close to the black hole that might result in the copious production of neutral particles which, through annihilation and decay in the jet´s funnel, might load the outflow with mass and charged particles on scales of a few Schwarzschild radii.

On some graph classes related to perfect graphs: A survey Bonomo-Braberman, Flavia; Durán, Guillermo; Safe, Martin Dario; Wagler, Annegret K. Perfect graphs form a well-known class of graphs introduced by Berge in the 1960s in terms of a min–max type equality involving two famous graph parameters. In this work, we survey certain variants and subclasses of perfect graphs defined by means of min–max relations of other graph parameters; namely: clique-perfect, coordinated, and neighborhood-perfect graphs. We show the connection between graph classes and both hypergraph theory, the clique graph operator, and some other graph classes. We review different partial characterizations of them by forbidden induced subgraphs, present the previous results, and the main open problems. Computational complexity problems are also discussed.

Acute glyphosate exposure does not condition the response of microbial communities to a dry-rewetting disturbance in a soil with long history of glyphosate-based herbicides Allegrini, Marco; Gomez, Elena del Valle; Zabaloy, Maria Celina Dry-rewetting perturbations are natural disturbances in the edaphic environment and particularly in dryland cultivation areas. The interaction of this disturbance with glyphosate-based herbicides (GBHs) deserves special attention in the soil environment due to the intensification of agricultural practices and the acceleration of climate change with an intensified water cycle. The objective of this study was to assess the response of microbial communities in a soil with long history of GBHs to a secondary imposed perturbation (a single dry-rewetting event). A factorial microcosm study was conducted to evaluate the potential conditioning effect of an acute glyphosate exposure on the response to a following dry-rewetting event. A Respiratory Quotient (RQ) based on an ecologically relevant substrate (p-coumaric acid) and basal respiration was used as physiological indicator. Similarly, DNA-based analyses were considered, including quantitative PCR (qPCR) of functional sensitive microbial groups linked to cycles of carbon (Actinobacteria) and nitrogen (ammonia-oxidizing microorganisms), qPCR of total bacteria and denaturing gradient gel electrophoresis (DGGE) of ammonia-oxidizing bacteria (AOB). Significant effects of Herbicide and of Dry-rewetting perturbations were observed in the RQ and in the copy number of amoA gene of AOB, respectively. However, no significant interaction was observed between them when analyzing the physiological indicator and the copy number of the evaluated genes. PCR-DGGE results were not conclusive regarding a potential effect of Dry-rewetting × Herbicide interaction on AOB community structure, suggesting further analysis by deep sequencing of amoA gene. The results of this study indicate that the perturbation of an acute glyphosate exposure in a soil with long-history of this herbicide does not have a conditioning effect on the response to a subsequent dry-rewetting disturbance according to a physiological indicator or the quantified bacterial/archaeal genes. This is particularly relevant for the sustainability of soils in rainfed agriculture, where frequent exposure to GBHs along with intensification of hydrological cycles are expected to occur. Further studies considering multiple dry-rewetting disturbances and in different soil types should be conducted to simulate those conditions and to validate our results.

Potential threat of plastic waste during the navigation of ships through the Turkish straits Kaptan, Mehmet; Sivri, Nüket; Blettler, Martin Cesar Maria; Ugurlu, Özkan The Turkish Straits System (TSS) is a dangerous and narrow waterway extending between the Black Sea and the Aegean Sea, including the Bosphorus, the Dardanelles, and the Marmara Sea and the Gulf of Izmit. The western banks of the TSS constitute the geographic starting point of the European continent, while the banks to the east are the beginnings of the Asia. TSS is considered one of the most strategically significant waterways of the world. This waterway is the main trading routes linking the Black Sea riparian countries to the world markets. As a result, the density in marine traffic through the TSS has recently reached alarmingly high levels. The aim of this study was to estimate the amount of plastic waste generated aboard merchant ships during their passage through the TSS during the period 2006?2017. This potential resource of waste would potentially impact on the Marmara Sea and its natural environment. The results of this study revealed that merchant ships crossing the TSS generated an average of 187.6 m3 of plastic waste per year. This result suggests that the threat given by the ships crossing this strait is approximately 1% of the total amount of waste recorded in the TSS coastals.

Persistencia de los efectos de la descompactación del suelo con paratill Perdomo, Luis Ignacio; Rollhauser, Martin; Melani, Esteban Miguel; Guilino, Facundo Daniel; Draghi, Laura Monica; Jorajuria Collazo, Daniel; Sarli, Guillermo Oliverio; Villarreal, Rafael; Lozano, Luis Alberto; Soracco, Carlos Germán; García, Mirta; Palancar, Telmo Cecilio En la Argentina predomina como sistema productivo la siembra directa donde la ausencia de remoción y el tránsito de máquinas cada vez más pesadas han incrementado los problemas de compactación. Para revertir este fenómeno se utilizan descompactadores. Existen datos dispares de cuán prolongada es la duración del efecto de descompactación. Se realizó un ensayo utilizando un descompactador angulado lateral (Paratill) en un suelo Hapludol Thapto Árgico. A los dos años se evaluó la resistencia a la penetración, la densidad aparente, la infiltración y la producción de materia seca comparando el tratamiento descompactado con el testigo (sin descompactar). No se encontraron diferencias en densidad aparente ni en infiltración entre ambos tratamientos. Hubo diferencias en la resistencia a la penetración donde el tratamiento testigo alcanzó valores mayores al descompactado en parte del perfil trabajado y aún debajo de la profundidad máxima alcanzada. La materia seca producida en el tratamiento descompactado duplicó a la del testigo evidenciando que el efecto de la descompactación se mantiene dos años después de realizada. Se concluye que el efecto de la descompactación se evidencia aún dos años después de efectuada en el parámetro resistencia a la penetración y que el cultivo percibe estos efectos.; In Argentina, no-tillage is the main management system where the absence of soil disturbance and the traffic of heavy machine has increased the problems of soil compaction. In order to reverse this phenomenon, decompaction is used, with contradictory results on the duration of the effect of soil loosing. The study was performed using a lateral angled decompactor (Paratill) in a Thapto Argic Hapludol. After two years, penetration resistance, bulk density, infiltration and dry matter production was evaluated under two treatments: decompacted; and control (without decompaction). No differences were found in bulk density or infiltration between treatments. Along the studied soil profile, the control treatment showed higher values of penetration resistance in comparison with the decompacted only between 7 and 30 cm, even below the maximum depth reached. Dry matter was higher under decompaction treatment, showing that the effect of decompaction was maintained two years after its application. In conclusion, the effect of decompaction is still evident after two years, improving the penetration resistance parameter and crop biomass production.

An activity prediction model for steroidal and triterpenoidal inhibitors of acetylcholinesterase enzyme Borioni, José Luis; Cavallaro, Valeria; Pierini, Adriana Beatriz; Murray, Ana Paula; Peñeñory, Alicia Beatriz; Puiatti, Marcelo; García, Manuela Emila Nowadays, the importance of computational methods in the design of therapeutic agents in a more efficient way is indisputable. Particularly, these methods have been important in the design of novel acetylcholinesterase enzyme inhibitors related to Alzheimer’s disease. In this sense, in this report a computational model of linear prediction of acetylcholinesterase inhibitory activity of steroids and triterpenes is presented. The model is based in a correlation between binding energies obtained from molecular dynamic simulations (after docking studies) and IC50 values of a training set. This set includes a family of natural and semi-synthetic structurally related alkaloids reported in bibliography. These types of compounds, with some structural complexity, could be used as building blocks for the synthesis of many important biologically active compounds Therefore, the present study proposes an alternative based on the use of conventional and easily accessible tools to make progress on the rational design of molecules with biological activity.

Genomic differentiation of Deschampsia antarctica and D. cespitosa (Poaceae) based on satellite DNA González, María Laura; Chiapella, Jorge Oscar; Topalian, Juliana; Urdampilleta, Juan Domingo Repetitive DNA is a rapidly evolving component of vascular plant genomes, which can account for genomic differentiation in plant lineages. Satellite DNA (satDNA) is tandem repetitive DNA for which array size and disposition on chromosomes may vary between reproductively isolated groups, such as different populations or closely related species. Deschampsia is a cosmopolitan grass genus growing in temperate and cold regions; D. cespitosa is widespread all over the world, whereas D. antarctica is restricted to Antarctica and southern Patagonia. The present work aims to the identification, isolation and comparison of satDNA from the genomes of two Deschampsia spp. with bioinformatics tools and their subsequent analysis and cytological study. The genomic analysis of TAREAN found 34 families of satDNA included on 21 superfamilies, most of them shared between the two species. Some of these satDNAs presented homology with others previously reported for grasses. A few satDNA families were found exclusively in one of the species. Most satDNAs were found in both species and showed high sequence homology, but their distribution on chromosomes was different between species. This highlights the importance of changes in the genomic disposition of satDNA in the evolution of species. Based on the 'satDNA library hypothesis' the differential amplification of satDNAs between independent lineages may be the cause of such differences.

Organización del trabajo, salud y estrategias gremiales de cajeras de supermercados en Rosario, Argentina; Work Organization, health and union strategies in supermarket cashiers in Rosario, Argentina Guiamet, Jaime El presente estudio indagó sobre los procesos de salud-enfermedad en el sector servicios. Enparticular, se abordó el trabajo en una empresa multinacional de supermercados ubicada en laciudad de Rosario, Argentina. El objetivo del estudio fue analizar el vínculo entre la organización del trabajo y los procesos de salud-enfermedad en el puesto de trabajo de cajera de supermercados. El estudio se inspiró en la corriente teórica de la Antropología del Trabajo. Este campo entiende a los procesos productivos a partir de su condición sociohistórica y a los procesos de salud-enfermedad como expresión del conflicto entre capital y trabajo. Se privilegió metodológicamente el desarrollo de un enfoque etnográfico, optando por estrategias intensivas de construcción de la información,tales como la observación participante y las entrevistas semiestructuradas. Los resultados revelaron que las trabajadoras de cajas experimentaron malestares asociados con la organización laboral, situaciones conflictivas con personal jerárquico y clientes y situaciones de padecimientos como casos de estrés laboral. Además, se analizó la dificultad de la organización gremial en el sector, lo cual también incidió en las posibilidades de las cajeras para transformar los procesos de salud enfermedad.

Diversity of mammals and birds recorded with camera-traps in the Paraguayan Humid Chaco; Diversidad de mamíferos y aves registrados con cámaras trampa en el Chaco Húmedo Paraguayo Caballero Gini, Andrea Natalia; Bueno Villafañe, Diego; Laino, Rafaela; Musálem, Karim A pesar de su vasta extensión y la rica fauna que alberga, el Chaco Húmedo es una de las ecorregiones menos estudiadas en el país. En este estudio proporcionamos una lista de aves y mamíferos registrados con cámaras trampa en la Estancia Playada, una propiedad privada ubicada al sur de la región Occidental en la ecorregión del Chaco Húmedo de Paraguay. Los muestreos se llevaron a cabo entre noviembre de 2016 y abril de 2017 con un esfuerzo total de 485 días-cámara. Registramos 15 especies de mamíferos y 20 de aves, entre ellas el muitú (Crax fasciolata), el oso hormiguero gigante (Myrmecophaga tridactyla) y la nutria neotropical (Lontra longicaudis) que están globalmente amenazadas a diferentes grados. Nuestros resultados sugieren que la Estancia Playada es un sitio con potencial para la conservación de aves y mamíferos en el Chaco Húmedo de Paraguay.; Despite its vast extension and the rich fauna that it hosts, the Paraguayan Humid Chaco is one of the least studied ecoregions in the country. In this study, we provide a list of birds and medium-sized and large mammals recorded with camera traps in Estancia Playada, a private property located south of Occidental region in the Humid Chaco ecoregion of Paraguay. The survey was carried out from November 2016 to April 2017 with a total effort of 485 camera-days. We recorded 15 mammal and 20 bird species, among them the bare-faced curassow (Crax fasciolata), the giant anteater (Myrmecophaga tridactyla), and the neotropical otter (Lontra longicaudis); species that are globally threatened in different dregrees. Our results suggest that Estancia Playada is a site with the potential for the conservation of birds and mammals in the Humid Chaco of Paraguay.

Modulation of the mTOR pathway plays a central role in dendritic cell functions after Echinococcus granulosus antigen recognition Rodríguez Rodrígues, Christian Fernando Ariel; Nicolao, María Celeste; Chop, Maia; Plá, Natalia; Massaro, Mora; Loos, Julia Alexandra; Cumino, Andrea Carina Immune evasion is a hallmark of persistent echinococcal infection, comprising modulation of innate immune cells and antigen-specific T cell responses. However, recognition of Echinococcus granulosus by dendritic cells (DCs) is a key determinant of the host?s response to this parasite. Given that mTOR signaling pathway has been described as a regulator linking metabolism and immune function in DCs, we reported for the first time in these cells, global translation levels, antigen uptake, phenotype, cytokine transcriptional levels, and splenocyte priming activity upon recognition of the hydatid fluid (HF) and the highly glycosylated laminar layer (LL). We found that LL induced a slight up-regulation of CD86 and MHC II in DCs and also stimulated the production of IL-6 and TNF-α. By contrast, HF did not increase the expression of any co-stimulatory molecules, but also down-modulated CD40 and stimulated the expression of the anti-inflammatory cytokine IL-10. Both parasitic antigens promoted protein synthesis through mTOR activation. The use of rapamycin decreased the expression of the cytokines tested, empowered the down-modulation of CD40 and also reduced splenocyte proliferation. Finally, we showed that E. granulosus antigens increase the amounts of LC3-positive structures in DCs which play critical roles in the presentation of these antigens to T cells.

A Pleistocene freshwater ichthyofaunal assemblage from central Argentina: What kind of fishes lived in the Pampean lagoons before the extinction of the megafauna? Bogan, Sergio; Agnolin, Federico; Cenizo, Marcos Martín; Tassara, Daniel Adrian; Giacchino, Adrián This study contributes to the knowledge of continental fishes recovered from sedimentary successions corresponding to the Bonaerean Stage/Age (late mid-Pleistocene) in the locality of Centinela del Mar, General Alvarado County, Buenos Aires province, Argentina. At this site we describe fossil fishes from a palaeolagoon, including Corydoras sp., Pimelodella sp., Rhamdia sp., Oligosarcus sp., small undetermined characids, Jenynsia sp. and Odontesthes sp. The recovered ichthyofaunal assemblage comprises at least seven taxa of Paranaean lineage. The taxonomic composition of the palaeoichthyofauna is quite comparable to that presently found in Bonaerean Watercourses of the Atlantic Drainage ecoregion. This suggests that local ichthyofaunal communities have remained relatively stable since the late mid-Pleistocene.

Winding modes and the reflection symmetry in AdS3 Iguri, Sergio Manuel; Kovensky, Nicolas; Maestri, Leila; Martín, Lucas Emilio We compute the contact term of the two-point function for the SL (2, ℝ)- WZNW model in the winding sector. After reviewing some generalities of the model and its Euclidean counterpart, we discuss the reflection symmetry for the spectral flowed sector. We define the corresponding intertwining operator and use it to find the explicit form of the contact term of the propagator for a vertex carrying an arbitrary amount of spectral flow. Finally, we enhance the already known integral expression of a singly flowed vertex in order to reproduce such contact term directly in the space-time picture.

Photoexcited energy relaxation and vibronic couplings in π-conjugated carbon nanorings Rodríguez Hernández, Beatriz; Oldani, Andres Nicolas; Martinez Mesa, Aliezer; Uranga Pina, Llinersy; Tretiak, Sergei; Fernández Alberti, Sebastián Conjugated carbon nanorings exhibit unique photophysical properties that, combined with their tunable sizes and conformations, make them suitable for a variety of practical applications. These properties are intimately associated to their strained, bent and sterically hindered cyclic structures. Herein we perform a comparative analysis of the photoinduced dynamics in carbon nanorings composed of nine phenyl units([9]CPP) and nine naphthyl units ([9]CN) respectively. The sterically demanding naphthyl units lead to large dihedral angles between neighboring units. Nevertheless, the ultrafast electronic and vibrational energy relaxation and redistribution is found to be similar for both systems. We observe that vibronic couplings, introduced by nonadiabatic energy transfer between electronic excited states, ensure the intramolecular vibrational energy redistribution through specific vibrational modes. The comparative impact of the internal conversion process on the exciton spatial localization and intra-ring migration indicates that naphthyl units in [9]CN achieve more efficient but less dynamical self-trapping compared to that of phenyl units in [9]CPP. That is, during the photoinduced process, the exciton in [9]CN is more static and localized than the exciton in [9]CPP. The internal conversion processes take place through a specific set of middle- to high-frequency normal modes, which directly influence the spatial exciton redistribution during the internal conversion, self-trapping and intra-ring migration.

Vicuñas y humanos en el pasado reciente (siglos XIX y XX) del oeste tinogasteño (Catamarca, Argentina); Vicuñas and Humans in the Recent Past (Nineteenth and Twentieth Centuries) of Western Tinogasta (Catamarca, Argentina) Miyano, Juan Pablo; Ratto, Norma Rosa Este trabajo explora la percepción sobre las vicuñas de los pobladores del oeste tinogasteño (Catamarca, Argentina) del pasado reciente (siglos XIX y XX). Para ello se analizan las manifestaciones orales tradicionales recopiladas en la Colección de Folklore que corresponden a distintas localidades de la región de estudio (La Ramadita, Medanitos y Fiambalá). Los resultados se integran y discuten con los sistemas simbólicos de la cosmovisión andina, la información proveniente de fuentes orales y escritas de otros sectores de los Andes centro-sur y la información arqueológica y zooarqueológica del oeste tinogasteño que da cuenta de la relación humano-animal entre los siglos V a. C. y XV d. C.; This paper examines the perception of the vicuñas by the habitants of western Tinogasta (Catamarca, Argentina) during the recent past (Nineteenth and Twentieth Centuries). For this purpose, we analyzed traditional oral manifestations compiled in the Colección de Folklore belonging to different localities of the region of study (La Ramadita, Medanitos y Fiambalá). The results were integrated and discussed with the symbolic systems of the Andean cosmovision, information from oral and written sources of other sectors of the south-central Andes, and archaeological and zooarchaeological information of the western Tinogasta, which accounts for human-animal relationships during the V BC and XV AD centuries

Enseñar a argumentar en la escuela secundaria: el caso de la Filosofía; Teaching how to argue in high school: the case of Philosophy Majorel, Cecilia; Padilla Sabate, Constanza; Rosconi, María Gabriela; Moisés, Fabiana María Diversas investigaciones en diferentes contextos educativos han evidenciado las dificultades de los estudiantes de escuelas secundarias para comprender textos de cierta complejidad y para fundamentar la propia postura ante diversos contenidos disciplinares. En Argentina, los estudios se han focalizado en estudios diagnósticos sobre la comprensión de textos narrativos y expositivos, pero no en los efectos de la implementación de propuestas didácticas que favorezcan la comprensión y producción de textos argumentativos. En este artículo, se sintetizan los resultados de una investigación colaborativa, realizada en una escuela secundaria pública del noroeste argentino, cuyo objetivo fue el diseño, implementación y evaluación de estrategias didácticas que priorizan el desarrollo de prácticas argumentativas dialógicas para promover el pensamiento crítico-en sentido amplio- (Paul y Elder, 2003), en el aprendizaje de la Filosofía. Se triangularon resultados obtenidos de tres fuentes de datos: producciones estudiantiles, perspectivas de los estudiantes y del docente, y las secuencias didácticas implementadas; Research in different educational contexts has shown the difficulties that high school students have understanding texts of a certain complexity and substantiating their own positions regarding several disciplinary contents. In Argentina, studies have focused on diagnostic studies on the understanding of narrative and expositive texts, but not on the effects of the implementation of teaching initiatives that favor the understanding and production of argumentative texts. In this article, we synthesise the results of a collaborative research, carried out in a public high school in the northwest of Argentina, whose objective was the design, implementation and evaluation of teaching strategies that prioritise the development of dialogical argumentative practices in order to promote critical thinking - in a broad sense- (Paul and Elder, 2003), when learning Philosophy. Results were triangulated from three data sources: students’ productions, students and teachers’ perspectives, and the implemented teaching sequences.

Two new species of Acanthobothrium Blanchard, 1848 (Cestoda: Onchoproteocephalidea) from rajiform batoids off Argentina Franzese, Sebastián; Ivanov, Veronica Adriana Two new species of Acanthobothrium Blanchard, 1848 were collected from rajiform batoids along the coast of Argentina. They are Acanthobothrium carolinae sp. n. from Bathyraja magellanica (Philippi) and Acanthobothrium domingae sp. n. from Dipturus brevicaudatus (Marini). Both belong to category 1 and 2 because their total length is lower than 15 mm, they have fewer than 50 proglottids, fewer than 80 testes and a  symmetric or asymmetric ovary. Acanthobothrium carolinae sp. n. differs from all congeners by the following combination of features: proglottid apolysis, hook morphology, microthrix pattern on the cephalic peduncle and distribution of the vitelline follicles. Acanthobothrium domingae sp. n. is unique in the combination of proglottid apolysis, total length, number of proglottids, hook and septal morphology, microthrix pattern on the cephalic peduncle, number and distribution of testes, cirrus sac length, distribution of the vitelline follicles and genital pore position. The discovery of these species increases the number of species of Acanthobothrium parasitising rajiform batoids off Argentina from one to three. All three species have a  unique pattern of distribution of the gladiate spinitriches along the length of the cephalic peduncle, i.e., gladiate spinitriches being interrupted in a  medial line both dorsally and ventrally.

Primary productivity determinants of different land uses in humid subtropical ecosystems: from native forests to tree plantations Diaz Villa, Maria Virginia Eva; Cristiano, Piedad María; de Diego, María Soledad; Rodríguez, Sabrina Andrea; Bucci, Sandra Janet; Scholz, Fabian Gustavo; Goldstein, Guillermo Hernan Land-use changes in forest ecosystems may alter the amount of carbon sequestration. The main objective of this study was to characterize the impact of different land-use practices on structure and functioning of humid subtropical forests that are under severe threat. We emphasize the characterization of canopy photosynthetic activity, assessed by the Enhanced Vegetation Index (EVI), the Leaf Area Index (LAI) and the fraction of Absorbed Photosynthetically Active Radiation (fPAR), using a combination of ground base measurements and remote sensing data on native well-preserved forests, impacted forests by selective logging and pine plantations in NE Argentina. Even though selective timber extraction resulted in a substantial decrease in stand’s tree density, EVI values were as high as those from preserved forests. In these forests, an increase in the understory cover appears to compensate the response of stand’s EVI to timber extraction. Removal of canopy trees enhances incoming solar radiation, allowing active growth of understory vegetation. The pine plantations exhibited the lowest values of LAI, fPAR and EVI. However, when EVI was normalized by LAI, the pine plantations exhibited the highest EVI/LAI values. Our results suggest that after 15 years of forest recovery from selective timber extraction, photosynthetic capacity was similar to that of preserved forests. Increases in the understory cover may compensate the potential decrease in the canopy photosynthetic activity. Pine plantations resulted in substantially lower productivity as depicted by lower EVI and LAI but exhibited higher growth efficiency than native forests.

Representaciones morales y grados de participación en el conflicto de 2007 en la industria pesquera de Mar del Plata, Buenos Aires, Argentina; Moral representations and degrees of participation in the 2007 conflict in the fishing industry of Mar del Plata, Buenos Aires, Argentina Schulze, Maria Soledad El presente artículo tiene como objetivo analizar las representaciones sobre la conflictividad laboral durante el año 2007 en un grupo de trabajadores de la industria de procesamiento de pescado de la ciudad puerto de Mar del Plata (Pcia. de Buenos Aires, Argentina). La atracción se dirige a este grupo de trabajadores/as que histórica y generacionalmente ha sufrido los efectos devastadores de la precariedad y la flexibilización laboral en la rama del filet. Específicamente, pretendemos explorar el grado de participación de nuestros entrevistados en un conflicto particular acontecido en el año 2007 en la industria pesquera de Mar del Plata. Consideramos sustantivo indagar dichas representaciones con relación a las trayectorias laborales, las condiciones laborales involucradas en dichas trayectorias y las relaciones de producción. Para lograr los objetivos planteados se utilizaron principalmente fuentes primarias, construidas a partir de una entrevista semiestructurada aplicada en terreno a 161 trabajadores y trabajadoras.; The objective of this article is to analyze representations of labor conflict in a group of workers in the fish processing industry of the port city of Mar del Plata (Province of Buenos Aires, Argentina). The attraction is addressed to this group of workers who, historically and generationally, have suffered the devastating effects of precariousness and labor flexibilization in the filet branch. Specifically, we intend to explore the degree of participation, of our interviewees, in a conflict that occurred in 2007 in the fishing industry of Mar del Plata. We consider substantive to investigate such representations in relation to work trajectories, the working conditions involved in these trajectories and the production relations. To achieve the proposed objectives, primary sources constructed from a semistructured interview applied in the field to 161 workers were used.