Effect of Bovine leukemia virus on bovine mammary epithelial cells Martinez Cuesta, Lucia; Nieto Farías, María Victoria; Lendez, Pamela Anahí; Rowland, Raymond R. R.; Sheahan, Maureen A.; Cheuquepán Valenzuela, Felipe Andrés; Marin, Maia Solange; Dolcini, Guillermina Laura; Ceriani, Maria Carolina Bovine leukemia virus (BLV) is a retrovirus that infects cattle and is associated with an increase in secondary infections. The objective of this study was to analyze the effect of BLV infection on cell viability, apoptosis and morphology of a bovine mammary epithelial cell line (MAC-T), as well as Toll like receptors (TLR) and cytokine mRNA expression. Our findings show that BLV infection causes late syncytium formation, a decrease in cell viability, downregulation of the anti-apoptotic gene Bcl-2, and an increase in TLR9 mRNA expression. Moreover, we analyzed how this stably infected cell line respond to the exposure to Staphylococcus aureus (S. aureus), a pathogen known to cause chronic mastitis. In the presence of S. aureus, MAC-T BLV cells had decreased viability and decreased Bcl-2 and TLR2 mRNA expression. The results suggest that mammary epithelial cells infected with BLV have altered the apoptotic and immune pathways, probably affecting their response to bacteria and favoring the development of mastitis.

The role of silk in courtship and communication in mygalomorph spiders: do males regulate their courtship in response to female mating status? Copperi, Maria Sofia; Ferretti, Nelson Edgardo; Peretti, Alfredo Vicente In spiders, pheromones are known to be responsible for attracting the opposite sex, eliciting male searching and courtship behaviors, as well as for synchronizing potential mates in space and time. Most spiders are cannibalisticand aggressive. Thus, early recognition of a female as a possible mate is essential for males, who may suffer high energetic or reproductive costs to the extreme of losing all fitness opportunities. In Acanthogonatus centralis Goloboff 1995, a mygalomorph spider, what female signs might be triggering male courtship behavior remain unknown, as well as whether males can discriminate between females. The aims of the present work were (1) establishing whether males can detect the presence of females using airborne and silk-borne signals and (2) determining whether males can discriminate the reproductive status and body condition of females. We found no evidence that airborne pheromones play a role in the sexual communication of A. centralis, but silk-bound contact signals function as a female advertisement. Also, this is the first study that demonstrates that male mygalomorph spiders can discriminate between different signals on silk through direct contact, showing a preference for unmated females.

A Comparative Study of Some Central Notions of ASPIC+ and DeLP García, Alejandro Javier; Prakken, Henry; Simari, Guillermo Ricardo This paper formally compares some central notions from two well-known formalisms for rule-based argumentation, DeLP and ASPIC+. The comparisons especially focus on intuitive adequacy and inter-translatability, consistency, and closure properties. As for differences in the definitions of arguments and attack, it turns out that DeLP's definitions are intuitively appealing but that they may not fully comply with Caminada and Amgoud's rationality postulates of strict closure and indirect consistency. For some special cases, the DeLP definitions are shown to fare better than ASPIC+. Next, it is argued that there are reasons to consider a variant of DeLP with grounded semantics, since in some examples its current notion of warrant arguably has counterintuitive consequences and may lead to sets of warranted arguments that are not admissible. Finally, under some minimality and consistency assumptions on ASPIC+ arguments, a one-to-many correspondence between ASPIC+ arguments and DeLP arguments is identified in such a way that if the DeLP warranting procedure is changed to grounded semantics, then 's DeLP notion of warrant and ASPIC+ 's notion of justification are equivalent. This result is proven for three alternative definitions of attack.

Order-Order Phase Transitions Induced by Supercritical Carbon Dioxide in Triblock Copolymer Thin Films Abate, Anabella Angela; Vu, Giang Thi; Piqueras, Cristian Martin; del Barrio, Maria Cecilia; Gómez, Leopoldo R.; Catalini, Gabriel; Schmid, Friederike; Vega, Daniel Alberto We study the influence of supercritical carbon dioxide (scCO2) on the phase behavior of a cylinder-forming polystyrene-block-polybutadiene-b-polystyrenetriblock copolymer thin film. Solvent annealing with scCO2 can produce patterns with long-range order but these structures become unstable for thin films with small thicknesses. These results are in good agreement with self-consistent mean field calculations, which indicate that a drying transition occurs for thicknesses below the radius of gyration of the molecule.After decompression and solvent extraction, the initially swollen polymer nanostructure suffers a strong reduction in the average domain spacing, which has a deleterious effect on the degree of order in the resulting pattern. Both,experiments and Cahn-Hilliard simulations suggest that during decompression the pattern suffers an order-order instability where the collapse of the lattice constant leads to uncommon patterns with long-range orientational order but structural distortions at small-length scales.

The utility of Desmidiospora: a paradigm shift based on Paleogene fungal remains from the Ñirihuau Basin, Argentina Bianchinotti, Maria Virginia; Martínez, Marcelo A.; Cornou, Maria Elina Fungal remains similar to those described as Desmidiospora willoughbyi were found in samples from the Rıo Foyel section (El Foyel Group of Paleogene age), Nirihuau Basin, Argentina. A full description and illustrations are presented. The names D. willoughbyi and D. marginiconvoluta as defined are shown to be inadequate. The history of the names and actual affinity of taxa presently assigned tothose names are discussed. Arguments against the use of Desmidiospora for fungal remains other than the conidia of an entomopathogenic species are presented. Instead, the lobulate fossil remains should be treated as germlings or immature ascomata from epiphyllous fungi of polyphyletic origin.

Pines invasive behavior in Argentinian grasslands: lessons from adaptive management operations Brancatelli, Gabriela Ivanna Elizabeth; Amodeo, Martín Raúl; Cuevas, Yannina Andrea; Zalba, Sergio Martín Biological invasions are one of the most important challenges for protected areas around the world, both because of the seriousness of their effectsand because of the costs and difficulties associated with their control. Some features of the biology of invasive species, such as growth rate and reproduction, can be particularly important when organizing controlactions. Moreover, the control actions themselves can be used to gather information to adjust their effectiveness. In mountain habitats, understanding how topography influences recruitment, growth and reproductioncan provide key information for optimizing prevention and control efforts. In this article, we used data from 9093 cutted invasive Aleppo pines (Pinushalepensis) obtained from management operations in a natural reserve in the Southern Argentinian Pampas. Our results reveal variations in the growth rate, cone production and seed release in response to topography. The specimens that grow at higher altitudes exhibit larger diameters than those of equal age growing at lower altitudes. A greater frequency of individuals with thick trunks in the mountains tops has operative implications when selecting cutting tools and calculating effort and frequency of tools maintenance. We also found that trees located in higher environments start releasing seeds at a younger age. This could mean potential higher population growth rates in this habitatand as a consequence in greater risk of long-distance dispersal, highlighting the need to prioritize control operations in higher areas and to increase thefrequency between successive controls to avoid the release of seeds that can be dispersed over long distances.

Search for excited electrons singly produced in proton-proton collisions at 13 TeV with the ATLAS experiment at the LHC Aaboud, M.; Aad, G.; Abbott, B.; Abbott, D. C.; Abdinov, O.; Abeloos, B.; Abhayasinghe, D. K.; Abidi, S. H.; AbouZeid, O. S.; Abraham, N. L.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adachi, S.; Adam, L.; Adam Bourdarios, C.; Adamczyk, L.; Adamek, L.; Adelman, J.; Adersberger, M.; Adiguzel, A.; Adye, T.; Affolder, A. A.; Afik, Y.; Agapopoulou, C.; Agheorghiesei, C.; Aguilar Saavedra, J. A.; Ahmadov, F.; Dova, Maria Teresa A search for excited electrons produced in pp collisions at 13 TeV via a contact interaction qq¯→ee∗ is presented. The search uses 36.1 fb−1 of data collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider. Decays of the excited electron via a contact interaction into an electron and a pair of quarks (eqq¯) are targeted in final states with two electrons and two hadronic jets, and decays via a gauge interaction into a neutrino and a W boson (νW) are probed in final states with an electron, missing transverse momentum, and a large-radius jet consistent with a hadronically decaying W boson. No significant excess is observed over the expected backgrounds. Upper limits are calculated for the pp→ee∗→eeqq¯ and pp→ee∗→eνW production cross sections as a function of the excited electron mass me∗ at 95% confidence level. The limits are translated into lower bounds on the compositeness scale parameter Λ of the model as a function of me∗. For me∗<0.5 TeV, the lower bound for Λ is 11 TeV. In the special case of me∗=Λ, the values of me∗<4.8 TeV are excluded. The presented limits on Λ are more stringent than those obtained in previous searches.

Study of M23C6 precipitation in a 45Ni-35Cr-Nb alloy Sosa Lissarrague, Matías Humberto; Sepúlveda Buitrago, Alejandro; Picasso, Alberto Carlos The 45Ni-35Cr-Nb alloy, commonly known as ET45 micro, produced in the form of centrifugally cast tubes, was studied by means of optical microscopy after aging treatments at 1073 and 1173 K for different times. A description of M23C6 secondary carbides precipitation phenomenon was made as a function of time. The purpose of carrying out a kinetic study of the precipitation of this phase is to be able to calculate the activation energy required for secondary precipitation. This allows to infer what is the mechanism associated with it. Analysis after using the Johnson-Mehl-Avrami-Kolmogorov (JMAK) model showed that secondary carbide precipitation occurs in a single stage. It was found that this phenomenon, which is assisted by diffusion, has an activation energy of 196 kJ/mol. This value would indicate that the diffusion of Cr atoms in the austenitic matrix is the phenomenon that dominates the precipitation of the M23C6 secondary carbide.

Pobreza energética y exclusión en Argentina: mercados rurales dispersos y el programa PERMER; Energy poverty and exclusion in Argentina: dispersed rural markets and the PERMER program Ibañez Martín, María María; Guzowski, Carina; Maidana, María Florencia This article analyzes the relationship between energy, poverty and social exclusion. Under this conceptual framework, the situation of the dispersed rural markets in Argentina and the Renewable Energies in Rural Markets Program (PERMER) as an inclusive and palliative policy of energy poverty are evaluated from the background and results review. It is concluded that the program has generated an advance in the access of traditionally excluded populations but that their results result in rural electrification, with limitations in their incidence in the inclusion and capacity development of thetarget population.; En este artículo se analiza la relación entre energía, pobreza y exclusión social. Bajo este marco conceptual, se evalúa a partir de la revisión de antecedentes y resultados la situación de los mercados rurales dispersos en Argentina y el Programa de Energías Renovables en Mercados Rurales (PERMER) como una política inclusiva y paliativa de la pobreza energética. Se concluye que el programa ha generado un avance en el acceso de poblaciones tradicionalmente excluidas pero que sus resultados redundan en electrificación rural, con limitaciones en su incidencia en la inclusión y el desarrollo de capacidades de la población objetivo.

A new concept of Compton Scattering tomography and the development of the corresponding circular Radon transform Tarpau, Cecilia; Cebeiro, Javier; Morvidone, Marcela Alejandra; Nguyen, Mai K. A new modality of Compton Scattering Tomogra-phy is presented. This model is composed of a fixed sourceand detectors placed on a fixed ring passing through thesource. This new modality, called Circular Compton ScatteringTomography, allows to register a complete set of data and,regarding constructive features like compactness or the absenceof moving components, outperforms other existing Comptonscattering tomography designs. A bi-imaging system combiningthis new system and Fan-beam computed tomography can alsobe considered, and such system will provide both the attenuationmap and the distribution on electrons of the object under study.The modeling of the Circular Compton Scattering Tomographyleads to the Radon transform on circles passing through a fixedpoint. A reconstruction algorithm based on an exact inversionformula of the Radon transform on circles is proposed andnumerical simulations for image formation and reconstructionare carried out. The results show the viability of this new imagesystem which is particularly suitable for small objects such asbiomedical objects.

Siempre me ha gustado mucho el teatro Conde, Laura Gabriela Estas notas intentan aproximarse al pensamiento de Barthes respecto del teatro, a partir de la lectura de textos publicados en Lettres nouvelles, France observateur y Théatre populaire en la década del 50, reunidos por Jean-Loup Riviére en Escritos sobre el teatro de 2002, que resuenan en escrituras (contemporáneas y posteriores) centrales en la producción del autor, donde —a pesar de que el objeto de reflexión no sea el teatro— se observa la huella de una experiencia teatral siempre contradictoria, condensada en la figura del Barthes actor, lector de teatro y espectador. Interesa aquí especialmente el “deslumbramiento” que le provoca la vanguardia y el contacto con la obra de Brecht, así como su decisión de no volver a ver teatro. Lo que sigue, entonces, es un registro de algunas señales que ponen de manifiesto la trascendencia de su escritura respecto de lo anecdótico o contingente, es decir, el tenor crítico-teórico de lo que conceptualiza más allá del carácter inmediato de estos escritos en torno del acontecimiento teatral específico de su tiempo.; These notes intend to systematize the thought of Barthes about theater, from the study of texts published in Lettres nouvelles, France Observateur and Théatre populaire in the 50s, gathered by Jean-Loup Rivière Writings on Theater of 2002. These ideas can also be found in the later works of the author, despite the fact that their object is not theater but other forms of art such as literature —the trace of theatrical experience, always contradictory, is gathered in the figure of Barthes actor, spectator and reader of theatre. We are interested in Barthes's “fascination” with avant-garde theatre, especially Bretch, as well as his decision to stop going to the theatre. Our aim is to stress Barthes's writings concerning the anecdotal and contingent of theatre, taking into account that his conceptualizations go beyond the theatrical event he refers to.

Structure and dynamics of the Crystalline Stable Phase of 2-Chlorothiophene Romanini, Michela; Negrier, Philippe; Barrio, María; Mondieig, Denise; Serra, Pablo; Zuriaga, Mariano Jose; Macovez, Roberto; Tamarit, Josep-Lluís The dynamics of a simple and rigid molecule (2-chlorothiophene) has been studied by means of broadband dielectric spectroscopy (BDS) within the low-temperature stable crystalline phase, whose structure has been determined by means of powder X-ray diffraction (PXRD) measurements. The triclinic P1 structure consists of two molecules per asymmetric unit (Z′ = 2) with site occupancies of 80:20 and 60:40 for each molecule of the asymmetric unit. Such a statistical intrinsic disorder is associated with two dynamical relaxation processes corresponding respectively to out-of-plane relaxations around the C-Cl 2-fold molecular axis and in-plane reorientational motions as proposed previously (Fujiromi and Oguni, J. Phys. Chem. Solids 1993, 54, 437-612). The PXRD and BDS measurements allow rationalizing published nuclear quadrupole resonance data. We show that only the concurrent use of different experimental techniques provides the answer to a complicated case of orientational molecular dynamics in the solid state.

Un devenir excéntrico: El nonsense en las invitadas, de Silvina Ocampo; An eccentric becoming: The nonsense in lasinvitadas, by silvina ocampo Biancotto, Natalia Este trabajo propone leer las formas del nonsense en Las invitadas (1961), de Silvina Ocampo, siguiendo la hipótesis de que estos relatos se organizan según las mismas preocupaciones que alientan la producción inicial y tardía de la autora. Se discute el consenso crítico que define a este momento de su narrativa como una etapa de madurez, determinada por relatos acabados y una lógica compositiva alejada del efecto de fugacidad, tontería y dispersión del sentido de sus primeros y últimos libros. Para ello, se analiza estos cuentos como retratos del momento en que una vida se torsiona en un devenir excéntrico. El resultado expone el modo en que Las invitadas se ubica a mitad de camino entre la precariedad de un relato que se acaba en el rasgo idiota del personaje y el despropósito de la ficción como registro de la idiotez. Estos cuentos manifiestan una preocupación insistente por las formas de la rareza, ambigüedad e inconclusividad propias del nonsense.; This work proposes to read Las invitadas (1961), by Silvina Ocampo, according to the hypothesis that these stories are organized by the same concerns that encourage the author’s initial and late production. It is proposed to discuss the critical consensus that defines this moment of his narrative as a stage of maturity, determined by finished stories and by a compositional logic away from the effect of transience, foolishness and dispersion of their first and last books. The stories are read as portraits of the moment in which a life twists into an eccentric becoming. The result exposes the way in which Las invitadas is located halfway between the precariousness of a story that ends in the character’s idiotic trait is made and the nonsense of a fiction as a record of idiocy. These stories show an insistent concern about the nonsensical forms of rarity, ambiguity and inconclusivity.

Molecular mechanisms of 33-mer gliadin peptide oligomerisation Amundarain, María Julia; Herrera, Maria Georgina; Zamarreño, Fernando; Viso, Juan Francisco; Costabel, Marcelo Daniel; Dodero, Veronica Isabel The proteolytic resistant 33-mer gliadin peptide is an immunodominant fragment in gluten and responsible for the celiac disease and other gluten-related disorders. Meanwhile, the primary structure of the 33-mer is associated with the adaptive immune response in celiac patients, and the structural transformation of the 33-mer into protofilaments activates a primordial innate immune response in human macrophages. This means that accumulation, oligomerisation and structural transformation of the 33-mer could be the unknown first event that triggers the disease. Herein, we reveal the early stepwise mechanism of 33-mer oligomerisation by combining multiple computational simulations, tyrosine cross-linking, fluorescence spectroscopy and circular dichroism experiments. Our theoretical findings demonstrated that the partial charge distribution along the 33-mer molecule and the presence of glutamine that favours H-bonds between the oligomers are the driving forces that trigger oligomerisation. The high content of proline is critical for the formation of the flexible PPII secondary structure that led to a β structure transition upon oligomerisation. Experimentally, we stabilised the 33-mer small oligomers by dityrosine cross-linking, detecting from dimers to higher molecular weight oligomers, which confirmed our simulations. The relevance of 33-mer oligomers as a trigger of the disease as well as its inhibition may be a novel therapeutic strategy for the treatment of gluten-related disorders.

How to Valorize Peanut Shells by a Simple Thermal-Catalytic Method Fermanelli, Carla Soledad; Galarza, Emilce Daniela; Pierella, Liliana Beatriz; Renzini, Maria Soledad; Saux, Clara In this work, a simple thermal-catalytic system was used to valorize peanut shells (Arachis hypogaea), the residual biomass from the peanut industry. To accomplish this purpose, tin modified MEL zeolites were synthesized to catalyze pyrolysis vapors reactions in order to improve bio-oil quality. The processes were conducted at 500 °C for 10 min, with biomass-to-catalyst ratio of 1:1. Proximate, ultimate and elemental analyses of the peanut shells were carried out. Biopolymer composition and HHV were also determined. Thermal decomposition behavior of the raw material was assessed by TGA/DTG analysis. Tin was incorporated to the zeolite matrix by the wet impregnation method to obtain loads of 2, 5, 7 and 10 wt%. All the catalysts were characterized by XRD, TPR, FTIR and BET surface area. Liquid products composition was determined by GC–MS. The material with 5 wt% of tin showed the best results. The optimal combination of Lewis and Brönsted acid sites in this catalyst promoted the necessary reactions to enhance bio-oil quality. In this sense, hydrocarbons selectivity in the presence of the 5 wt% tin zeolite was ten times the one reached in the absence of catalysts. Likewise, 5-hydroxymethyl-furfural formation was favored, obtaining the highest selectivity with the same metal load on the catalyst.

Optical spectroscopic classification of 35 hard X-ray sources from the Swift-BAT 70-month catalogue Marchesini, Ezequiel Joaquín; Masetti, N; Palazzi, E.; Chavushyan, V.; Jiménez Bailón, E.; Patiño Álvarez, V. M.; Reynaldi, María Victoria; Rojas, A. F.; Saviane, I.; Andruchow, Ileana; Bassani, L.; Bazzano, A.; Bird, A. J.; Malizia, A.; Minniti, D.; Monaco, L.; Stephen, J. B.; Ubertini, P. The nature of a substantial percentage (about one fifth) of hard X-ray sources discovered with the BAT instrument onboard the Neil Gehrels Swift Observatory (hereafter Swift) is unknown because of the lack of an identified longer-wavelength counterpart. Without such follow-up, an X-ray catalogue is of limited astrophysical value: we therefore embarked, since 2009, on a long-term project to uncover the optical properties of sources identified by Swift by using a large suite of ground-based telescopes and instruments. In this work, we continue our programme of characterization of unidentified or poorly studied hard X-ray sources by presenting the results of an optical spectroscopic campaign aimed at pinpointing and classifying the optical counterparts of 35 hard X-ray sources taken from the 70-month BAT catalogue. This sample was selected out of the available information about the chosen objects: either they are completely unidentified sources, or their association with a longer-wavelength counterpart is still ambiguous. With the use of optical spectra taken at six different telescopes we were able to identify the main spectral characteristics (continuum type, redshift, and emission or absorption lines) of the observed objects, and determined their nature. We identify and characterize a total of 41 optical candidate counterparts corresponding to 35 hard X-ray sources given that, because of positional uncertainties, multiple lower energy counterparts can sometimes be associated with higher energy detections. We discuss which ones are the actual (or at least most likely) counterparts based on our observational results. In particular, 31 sources in our sample are active galactic nuclei: 16 are classified as Type 1 (with broad and narrow emission lines) and 13 are classified as Type 2 (with narrow emission lines only); two more are BL Lac-type objects. We also identify one LINER, one starburst, and 3 elliptical galaxies. The remaining 5 objects are galactic sources: we identify 4 of them as cataclysmic variables, whereas one is a low mass X-ray binary.

Hurgando en el arcón de los tiempos perdidos en los confines de la ecúmene. Las etnias selk'nam, yámana y halakwulup según el registro somatométrico de Martín Gusinde (1989 [1937]); Rummaging in the chest of lost time at the edges of the inhabited world: the selk’nam, yámana and halakwulup ethnic groups according to gusinde’s (1989 [1937]) somatometry Cocilovo, Jose Alberto; Varela, Hector Hugo; Valdano, Silvia Durante el siglo pasado, investigaciones realizadas sobre las etnias del extremo austral del continente americano proporcionaron abundante información sobre la etnografía y las características físicas que reflejan la composición de los fenotipos locales relacionados con selk'nam, yámana y halakwulup, entre las que se destaca la contribución de Martín Gusinde. En este trabajo se explora la estructura de la población nativa y las relaciones de parentesco sobre la base de rasgos fenotípicos con la evaluación de 18 variables cefalométricas en 110 individuos. El análisis estadístico multivariado confirma la existencia de diferencias significativas entre grupos y entre sexos por grupos. Se comprobó una marcada estructura de la población y un balance diferente entre grupos con relación a los efectos de la deriva genética y la migración. Halakwulup presentó una varianza fenotípica mayor que la esperada comparada con selk'nam y yámana. Las varianzas observadas de ambos sexos halakwulup y hombres selk'nam revelan su interacción en un circuito territorial mayor, mientras que las varianzas de ambos sexos yámana y mujeres selk'nam indican menor tamaño efectivo y su interacción en un ámbito más restringido. Se destaca el valor de la información recuperada pues refleja la condición humana en el límite de la supervivencia después de 10.000 años de historia.; During twentieth century, research on ethnic groups in the far south of the American continent provided much information on the ethnography and physical characteristics that reflect the composition of local phenotypes related to the Selk’nam, Yámana and Halakwulup, in which the contribution of Martín Gusinde stands out. This paper explores the structure of the native population and kinship relationships based on phenotypic traits resulting from the evaluation of 18 cephalometric variables in 110 individuals. Multivariate statistical analysis confirms the existence of significant differences between groups and between sexes by group. A marked population structure and a balance between genetic drift and different migration between groups were found. Halakwulup presented a higher phenotypic variance than expected compared with Selk’nam and Yámana. The observed variances of both sexes among the Halakwulup and Selk’nam men reveal their interaction in a larger territorial circuit, while the variances of both sexes among the Yámana and Selk’nam women indicate a smaller effective size and their interaction in a more restricted environment. The value of the study is that it highlights the human condition at the limit of survival after 10,000 years of history.

Upstream logistic transport planning in the oil-industry: a case study Rossit, Diego Gabriel; Gonzalez, Mauro Ehulech; Tohmé, Fernando Abel; Frutos, Mariano Nowadays, oil companies have to deal with an increasingly competitive environment. In this sense, the optimization of operational processes to enhance efficiency is crucial. This article addresses the design of a decision support tool for the inland upstream transport logistics in the oil industry based on a case of study in Argentina. This problem is traditionally difficult to solve for managers due to the large number of demand facilities scattered on a large geographic area that have to be served and the consideration of several operational requirements, such as maximum allowable travel times for vehicles, availability of a limited fleet size with a small number of drivers, plus the usual demand constraints as well as those arising from security risks derived from the incompatibility of chemical products. A novel mathematical formulation and a constructive heuristic are proposed in order to address this problem. The results allow to reduce the time that the company spends for obtaining a feasible distribution plan that minimizes the time horizon of the distribution schedule provided to the clients and enhances customer satisfaction.

Trophic ecology of a corymorphid hydroid population in the Bahía Blanca Estuary, Southwestern Atlantic Dutto, María Sofía; Carcedo, Maria Cecilia; Nahuelhual, Eugenia Gabriela; Conte, Alberto Fabian; Berasategui, Anabela Anhi; Garcia, Maximiliano Darío; Puente Tapia, Francisco Alejandro; Genzano, Gabriel Nestor; Hoffmeyer, Monica Susana Solitary macroscopic polyps are rare, and ecological information about them, such as diet and feeding rates is scarce worldwide. Here we describe the population of the solitary and seasonal polyps of Corymorpha januarii found in the Bahía Blanca Estuary, Argentina, and provide one of the first approaches to define their feeding ecology by gut content analysis. We analyzed the substrate and the accompanying benthic components, and provided in situ observations as well as observations on polyps kept in aquarium. A mean of 4 types of trophic items per polyp and 13.33 consumed prey items per polyp were obtained, representing a daily carbon consumption of 1.8 mg C per polyp per day and 75 mg C per square meter per day when considering polyp densities. The daily mass-specific ingestion rate was 20.5 % of polyp biomass. Polyps of C. januarii showed a variable diet composed mainly of organic matter and zooplanktonic prey, and probably selected copepods, mysids, and other zooplanktonic prey of lower or no swimming capacity (e.g., barnacle larvae and invertebrates, and fish eggs). The diversity of the prey ingested indicates that C. januarii is highly adaptable to changing environmental conditions, and this organism may have a significant role in energy transfer in estuarine waters.

Phylogenetic Relationships in Arjona (Schoepfiaceae), a Hemiparasitic Herb from Southern South America Vidal Russell, Romina Arjona is a small genus of hemiparasitic herbs distributed in southern South America. Most species are found in dry open areas in rocky and sandy soils whereas A. pusilla is found in humid places such as wet meadows. Regional treatments recognize five species and two varieties. The species are not clearly defined, and leaf shape and pubescence are the main differentiating taxonomic characters. In this study individuals from four of the five recognized species were examined to reconstruct the evolutionary history of the genus and to test the monophyly of recognized species. Samples covered the range of morphological variability and geographical distributional. The nuclear ribosomal internal transcribed spacer (ITS) regions and two chloroplast spacers (atpB-rbcL and trnL-F) were used to reconstruct the molecular phylogeny of the genus using Bayesian inference and maximum likelihood criteria. The molecular data show that geography better explains phylogenetic groupings than species assignment. This suggests that morphological variation among populations, in the context of the genetic lineages, should be studied in more detail to test the hypothesis that different ecotypes exist in Arjona.