Stability of cosmological deflagration fronts Membiela, Federico Agustin; Megevand, Ariel Hugo In a cosmological first-order phase transition, bubbles of the stable phase nucleate and expand in the supercooled metastable phase. In many cases, the growth of bubbles reaches a stationary state, with bubble walls propagating as detonations or deflagrations. However, these hydrodynamical solutions may be unstable under corrugation of the interface. Such instability may drastically alter some of the cosmological consequences of the phase transition. Here, we study the hydrodynamical stability of deflagration fronts. We improve upon previous studies by making a more careful and detailed analysis. In particular, we take into account the fact that the equation of motion for the phase interface depends separately on the temperature and fluid velocity on each side of the wall. Fluid variables on each side of the wall are similar for weakly first-order phase transitions, but differ significantly for stronger phase transitions. As a consequence, we find that, for large enough supercooling, any subsonic wall velocity becomes unstable. Moreover, as the velocity approaches the speed of sound, perturbations become unstable on all wavelengths. For smaller supercooling and small wall velocities, our results agree with those of previous works. Essentially, perturbations on large wavelengths are unstable, unless the wall velocity is higher than a critical value. We also find a previously unobserved range of marginally unstable wavelengths. We analyse the dynamical relevance of the instabilities, and we estimate the characteristic time and length scales associated to their growth. We discuss the implications for the electroweak phase transition and its cosmological consequences.

Stress in wild Greater Rhea populations: effects of agricultural activities on seasonal excreted glucocorticoid metabolite levels Leche, Alvina; Bazzano, Gisela del Valle; Hansen, C.; Navarro, Joaquin Luis; Marin, Raul Hector; Martella, Monica Beatriz In recent years, wild populations of Greater Rhea (Rhea americana) have declined drastically, due mainly to the conversion of grassland into cropland as a result of intensive, specialized agricultural practices. In this study we evaluate potential stressfuleffects of agricultural activities on this ratite by assessing their adrenocortical response. Specifically, we compared fecal glucocorticoid metabolite (FGM) levels of rheas living in two areas under very different land use: grasslands mainly devoted to cattle grazing and agro-ecosystems intensively used for crop production. Radioimmunoanalysis of fecal samples from 269 individuals indicated no significant differences in mean concentrations of FGM according to habitat type. In the agro-ecosystem we found no direct effect between agricultural practice and the bird´s FGM levels. However, FGM concentrations were significantly higher during the dry season, which may represent a stress response to the low availability of forage due to harvesting. In contrast, no increase in the FGM levels was registered during the dry season in the grassland, where ample forage was available throughout the year. In this environment the highest increases in FGM levels coincided with the reproductive period, likely due to the frequent agonist encounters between males at this time of the year. Our findings therefore suggest that the consequences of agricultural practices may constitute a chronic environmental stressor for Greater Rhea populations living under such conditions. The present study support earlier research showing detrimental impacts of agricultural activities on this species, whose area of distribution coincides with the most productive regions of South America.

When shape matters: Strategies of different Antarctic ascidians morphotypes to deal with sedimentation Torre, Luciana; Abele, Doris; Lagger, Cristian Fabian; Momo, Fernando; Sahade, Ricardo Jose Climate change leads to increased melting of tidewater glaciers in the Western Antarctic Peninsula region and sediment bearing glacial melt waters negatively affects filter feeding species as solitary ascidians. In previous work the erect-forms Molgula pedunculata and Cnemidocarpa verrucosa (Order Stolidobranchiata) appeared more sensitive than the flat form Ascidia challengeri (Order Phlebobranchiata). Sedimentation exposure is expected to induce up-regulation of anaerobic metabolism by obstructing the organs of gas exchange (environmental hypoxia) or causes enhanced squirting activity (functional hypoxia). In this study we evaluated the possible relationship between ascidian morphotype and their physiological response to sedimentation. Together with some behavioural observations, we analysed the response of anaerobic metabolic parameters (lactate formation and glycogen consumption) in different tissues of three Antarctic ascidians, exposed to high sediment concentrations. The results were compared to experimental hypoxia (10% pO2) and exercise (induced muscular contraction) effects, in order to discriminate the effect of sediment on each species and morpho-type (erect vs. flat forms). Our results suggest that the styled (erect) C. verrucosa increases muscular squirting activity in order to expulse excessive material, while the flat-form A. challengeri reacts more passively by down-regulating its aerobic metabolism under sediment exposure. Contrary, the erect ascidian M. pedunculata did not show any measurable response to the treatments, indicating that filtration and ingestion activities were not reduced or altered even under high sedimentation (low energetic material) which could be disadvantageous on the long-term and could explain why M. pedunculata densities decline in the study area.

Dryinidae of the Neotropical region (Hymenoptera: Chrysidoidea) Olmi, Massimo; Virla, Eduardo Gabriel An updated revision of Neotropical Dryinidae is presented. Seven subfamilies, 23 genera and 502 species are treated. Descriptions, geographic distribution, known hosts, natural enemies and type material of each species are presented, together with illustrations of the main morphological characters and keys to the subfamilies, genera and species. Complete lists of references concerning the Neotropical Dryinidae and their hosts are given. The following new genus is described: Peckius Olmi & Virla, gen. nov. (Apodryininae). The following new species are described: Anteon xochipalense Olmi & Virla, sp. nov. (Mexico, Guerrero), Deinodryinus levigatus Olmi & Virla, sp. nov. (Peru, Lamabayeque), Deinodryinus xanthonotatus Olmi & Virla, sp. nov. (French Guiana), Dryinus semiruber Olmi & Virla, sp. nov. (Argentina, Corrientes), Dryinus valens Olmi & Virla, sp. nov. (Dominican Republic, Pedernales), Dryinus xanthopus Olmi & Virla, sp. nov. (French Guiana), Megadryinus cacaonis Olmi & Virla, sp. nov. (Brazil, São Paulo), Gonatopus isabelensis Olmi & Virla, sp. nov. (Ecuador, Galapagos Islands), Gonatopus villamilensis Olmi & Virla, sp. nov. (Ecuador, Galapagos Islands), Neodryinus mayanus Olmi & Virla, sp. nov. (Honduras), and Peckius insularis Olmi & Virla, sp. nov. (Ecuador, Galapagos Islands). The following new synonymies are presented: Deinodryinus kawensis Olmi 2011b (April) (=D. caxiuana Coelho, Aguiar & Engel, 2011 (June), syn. nov.); Dryinus gibbosus Olmi, 1984 (=D. multicarinatus Coelho, Aguiar & Engel, 2011, syn. nov.); Dryinus striatus (Fenton, 1927), (=D. sinopensis Olmi, 1984, syn. nov.; = D. cerrensis Olmi, 2004a, syn. nov.); Gonatopus Ljungh, 1810 (=Trichogonatopus Kieffer, 1909, syn. nov.); Eucamptonyx dromedarius (Cameron 1888) (=E. hansoni Olmi, 1991, syn. nov.); Haplogonatopus hernandezae Olmi, 1984 (=H. crucianus Olmi, 1986, syn. nov.). The following new combinations are established: Eucamptonyx dromedarius (Cameron, 1888), comb. nov. (from Gonatopus); Gonatopus goiasensis (Olmi 1991), comb. nov. (from Trichogonatopus); G. hispidus (Olmi 1984), comb. nov. (from Trichogonatopus); G. longinoi (Olmi, 1998d), comb. nov. (from Trichogonatopus); G. marinoae (Virla, 1997), comb. nov. (from Trichogonatopus); G. neotropicus (Olmi, 1984), comb. nov. (from Trichogonatopus); G. raptor (Fenton, 1927), comb. nov. (from Chalcogonatopus); G. rubriceps (Kieffer, 1909), comb. nov. (from Trichogonatopus); G. stellaris (Virla, 1997), comb. nov. (from Trichogonatopus). The male of Crovettia brasiliana Olmi 1984, is described for the first time.

Extraction of jojoba oil with liquid CO2 + propane solvent mixtures Palla, Camila Andrea; Hegel, Pablo Ezequiel; Pereda, Selva; Bottini, Susana Beatriz In this work liquid CO2/propane mixtures were used to extract jojoba oil from oilseeds. First, experiments at 313 K and pressures of 70 bar and 200 bars were carried out on jojoba oil deposited on glass spheres, using different solvent concentrations (30 wt%, 50 wt% and 70 wt% CO2), to assess the influence of the solvent composition and phase behavior on the extraction rate. Then, jojoba oil was extracted from the milled seeds under homogeneous liquid conditions, using solvent mixtures containing 30 wt% and 50 wt% CO2 at 70 bar and 313 K. A solvent mixture with 30 wt% CO2 exhibited good solvent power. Oil extraction yields of 98 % were obtained using a minimum solvent to oilseed mass ratio of 5 g solvent / g oilseed and operating the extractor at 313 K and 70 bar.

A potent combination microbicide that Targets SHIV-RT, HSV-2 and HPV Kizima, Larisa; Rodríguez, Aixa Inés; Kenney, Jessica; Derby, Nina; Mizenina, Olga; Menon, Radhika; Seidorm, Samantha; Zhang, Shimin; Levendosky, Keith; Ninochka, Jean-Pierre; Pugach, Pavel; Villegas, Guillermo; Ford, Brian E.; Gettie, Agegnehu; Blanchard, James; Piatak, Michael Jr.; Lifson, Jeffrey D.; Paglini, Maria Gabriela; Teleshova, Natalia; Zydowsky, Thomas M.; Robbiani, Melissa; Fernández Romero, José Prevalent infection with human herpes simplex 2 (HSV-2) or human papillomavirus (HPV) is associated with increased human immunodeficiency virus (HIV) acquisition. Microbicides that target HIV as well as these sexually transmitted infections (STIs) may more effectively limit HIV incidence. Previously, we showed that a microbicide gel (MZC) containing MIV-150, zinc acetate (ZA) and carrageenan (CG) protected macaques against simian-human immunodeficiency virus (SHIV-RT) infection and that a ZC gel protected mice against HSV-2 infection. Here we evaluated a modified MZC gel (containing different buffers, co-solvents, and preservatives suitable for clinical testing) against both vaginal and rectal challenge of animals with SHIV-RT, HSV-2 or HPV. MZC was stable and safe in vitro (cell viability and monolayer integrity) and in vivo (histology). MZC protected macaques against vaginal (p<0.0001) SHIV-RT infection when applied up to 8 hours (h) prior to challenge. When used close to the time of challenge, MZC prevented rectal SHIV-RT infection of macaques similar to the CG control. MZC significantly reduced vaginal (p<0.0001) and anorectal (p = 0.0187) infection of mice when 106 pfu HSV-2 were applied immediately after vaginal challenge and also when 5×103 pfu were applied between 8 h before and 4 h after vaginal challenge (p<0.0248). Protection of mice against 8×106 HPV16 pseudovirus particles (HPV16 PsV) was significant for MZC applied up to 24 h before and 2 h after vaginal challenge (p<0.0001) and also if applied 2 h before or after anorectal challenge (p<0.0006). MZC provides a durable window of protection against vaginal infection with these three viruses and, against HSV-2 and HPV making it an excellent candidate microbicide for clinical use.

¿Y si el Papa fuera una mujer? Sucksdorf, Cristián La enorme presencia de mujeres en las más altas esferas del poder no puede ser un dato ignorado al momento de analizar la vitalidad del modo de vida patriarcal. Es más, se ha llegado a escuchar: si el Papa fuera mujer el aborto sería ley. Ciertamente una meta lejana. Pero esta tendencia podría prometer acercarla mediante, por ejemplo, la incorporación de mujeres al sacerdocio y a las instancias de decisión del Estado Vaticano. Es cierto que leer sólo de este modo esa consigna del Encuentro Nacional de Mujeres de 2012 sería un olvido imperdonable de la ironía en que se sostiene. Pero a los efectos de estas líneas no interesa la consigna en sí misma (transitoria, como toda consigna), sino una posible lectura (quizás no la del Encuentro) que ella tolera, a saber: ese camino amarillo del progreso que se nos propone como una salida de emergencia a los males del patriarcado. Estaríamos entonces frente a un debilitamiento o crisis del patriarcado; el esperado síntoma sería ese lugar de poder ganado para las mujeres.

Aprender y enseñar a través de imágenes. Desafío educativo Rigo, Daiana Yamila El presente trabajo muestra la experiencia de la puesta en práctica de un diseño instructivo definido a partir del uso de recursos educativos icónicos con el objetivo de conocer cómo los alumnos valoran la realización de actividades académicas definidas a partir de imágenes, fotografías y obras de arte, e indagar la percepción de los estudiantes sobre las posibilidades que este medio ofrece para una comprensión y motivación mayor. La experiencia se desarrolla con alumnos de sexto grado, educación primaria, área Ciencias Sociales a través de dos actividades centrales. Los resultados revelan que el uso de la imagen como recurso didáctico debería ser tenido en cuenta como una estrategia de enseñanza-aprendizaje para planificar las tareas académicas.; This paper shows the experiences of the implementation of instructional design, defined from the use of iconic educational resources with the aim of knowing how students value the academic activities defined from images, pictures and artwork, as well as explore the perception of the students about the possibilities offered this medium for a greater understanding and motivation. The experience is developed with sixth graders, elementary education, social sciences area, through two core activities. The results reveal that the use of the image as a teaching resource should be considered as a teaching-learning strategy to plan academic tasks.

DNA Repair Activity of Ilex paraguariensis in Human Cells In Vitro Erben, Melina; Poletta, Gisela Laura; Simoniello, Maria Fernanda Yerba mate (Ilex paraguariensis) has been consumed as popular infusions in South America for centuries, with potential beneficial effects on health. The aim of this study was to evaluate yerba mate antioxidant properties in human leucocytes exposed in vitro to oxidative damage, using the Comet assay. Human cells were exposed to 10 μM H2O2 and then allowed to repair with increasing concentrations of two different yerba mate infusions: 10 μl/mL, 100 μl/mL and 1000 μl/mL. Damage Index (DI) and the percentage of damage reduction (%DR) were calculated. DI showed that both infusions produced similar protective effects (p > 0.05) and the %DR indicated a decreased in oxidative damage as infusion concentration increases (p < 0.05). The greatest protective effects were found using the highest concentration of mate (1000 μl/mL). Thus, we conclude that the regular ingestion of Ilex paraguariensis infusions could contribute to antioxidant defense on humans.; La yerba mate (Ilex paraguariensis) se consume como infusión popular en América del Sur desde hace siglos, con potenciales efectos beneficiosos sobre la salud. El objetivo de este estudio fue evaluar las propiedades antioxidantes de la yerba mate en leucocitos humanos expuestos in vitro a un daño oxidativo, utilizando el ensayo cometa. Células humanas fueron expuestas a 10 μM de H2O2 y luego reparadas con concentraciones crecientes de dos diferentes infusiones de yerba mate: 10, 100 y 1.000 μL/mL. Se calculó el índice de daño (DI) y el porcentaje de reducción de daño (% DR). El DI mostro que ambas infusiones producen efectos protectores similares (p > 0,05) y el % DR indicó una disminución en el daño oxidativo al aumentar la concentración de la infusión (p < 0,05). Los mayores efectos protectores fueron encontrados con la concentración más alta de mate (1.000 μl/mL). Por lo tanto, concluimos que la ingestión regular de infusiones de Ilex paraguariensis podría contribuir a la defensa antioxidante en seres humanos.

Predictive value of direct nitrate reductase assay and its clinical performance in the detection of multi- and extensively drug-resistant tuberculosis Imperiale, Belén Rocío; Morcillo, Nora Susana; Palomino, Juan Carlos; Vandamme, Peter; Martin, Anandi Conventional culture and drug susceptibility testing (DST) methods for Mycobacterium tuberculosis are laborious and time consuming. For this reason alternative rapid culture and DST techniques are urgently needed to shorten the time for drug-resistance detection. A total of 222 smear-positive sputum samples were evaluated by the direct nitrate reductase assay (D-NRA) on Lowenstein-Jensen medium, for the rapid and simultaneous detection of resistance to isoniazid, rifampicin, kanamycin and ofloxacin. p-Nitrobenzoic acid was also included for identification of the M. tuberculosis complex. Results were compared with the BACTEC MGIT 960 as gold standard. The general performance of the D-NRA was very good, reaching a global value of 97 %. D-NRA had a turn-around time of 16.9 days to obtain results while that of the indirect MGIT 960 system was 29 days. D-NRA is a low-cost technology, easy to set up in clinical laboratories and suitable to be used for DST of M. tuberculosis in all smear-positive samples. © 2014 SGM.

Comprehensive database on Induan (Lower Triassic) to Sinemurian (Lower Jurassic) marine bivalve genera and their paleobiogeographic record Ros Franch, Sonia; Márquez Aliaga, Ana; Damborenea, Susana Ester Marine bivalve genera that were described or mentioned for Triassic and Lower Jurassic deposits worldwide are reviewed in terms of their validity, stratigraphic range, paleogeographic distribution, paleoautoecology and shell mineralogy. Data were originally compiled at species level and are arranged systematically. A brief discussion for each genus includes synonymy, taxonomic status and included subgenera, as well as current uncertainties about their validity and range. The distribution of each genus is also shown on paleogeographic maps. Type species and first and last appearances of each genus are also mentioned. We recognize as valid 280 genera and their included subgenera, and we further discurss 148 genera (arranged alphabetically) which were mentioned for the study interval but are not included for different reasons. The purpose of this paper is to provide an updated critical assessment of all available basic information for each genus, in order to obtain a sound database to study the generic paleodiversity of marine bivalves in the time interval from Induan (Early Triassic) to Sinemurian (Early Jurassic). This was a critical time for bivalve evolution and diversification, which began with the recovery from the Permian-Triassic extinction and ended with the recovery from the Triassic-Jurassic extinction.

Biocatalysed acidification and metal leaching processes in sediments of polluted urban streams Porzionato, Natalia Florencia; Candal, Roberto Jorge; Curutchet, Gustavo Andres Sediments of fluvial streams are a sink for pollutants such as heavy metals and organic recalcitrant compounds. In anoxic conditions, sulphide generation and alkalinisation cause precipitation of heavy metals. The redox potential of the system could change to higher values, mainly owing to oxygen exposition generated by anthropogenic disturbances of the sediment such as dredging operations. Knowledge about the mechanisms involved is fundamental to assess the risk of acid generation and rise in heavy metals bioavailability. In this paper, the characterisation and assessment of acidification risk of sediments of a contaminated stream near Buenos Aires was carried out by static and kinetic assays. Speciation of heavy metals was determined after metal sequential extraction procedure. Also, re-suspension of sediments assay in batch mode, with and without Acidithiobacillus ferrooxidans inoculum, was carried out to assess the chemical changes that occur at oxygen exposure, verifying the acidification and heavy metal release processes.

Taphonomic analysis of archaeomalacological assemblages: shell middens on the northern coast of Santa Cruz (Patagonia, Argentina); Análisis tafonómicos de conjuntos arqueomalacológicos: concheros en la costa norte de Santa Cruz (Patagonia, Argentina) Hammond, Heidi En este trabajo se presenta una propuesta metodológica para el estudio de conjuntos arqueomalacológicos de concheros y su aplicación en el análisis de restos recuperados a partir de excavaciones sistemáticas en sitios ubicados al sur de la ría Deseado, en la costa norte de Santa Cruz, Patagonia argentina. Esta metodología se focaliza en el estudio de diferentes variables tafonómicas que afectan el registro arqueomalacológico para avanzar en la interpretación de los agentes y procesos involucrados en la formación de las estructuras de concheros y sobre las actividades humanas desarrolladas en los sitios. Además estos análisis son significativos para realizar interpretaciones paleoambientales, paleoecológicas, así como para evaluar la integridad de los conjuntos, interpretar las características estructurales y la variabilidad de los sitios.; This paper proposes a method of studying archaeomalacological assemblages from shell middens, and describes an application of this method in the analysis of remains recovered from systematic excavations at sites located south of the Ría Deseado estuary (northern coast of Santa Cruz Province, Argentina). This methodology aims to isolate taphonomic variables affecting archaeomalacological records to aid identification of the agents and processes involved in shell midden formation and to improve interpretations of the human activities performed at the sites. These analyses are also relevant to paleoenvironmental and paleoecological reconstructions, and to interpretations of site variability through assessments of assemblage integrity and structure.

La cuestión del Interior en el juego político provincial Campos, Hernán El federalismo Argentino con sus tres niveles de gobierno (nacional, provincial y municipal) y las disputas políticas que se suceden en cada uno de los niveles es complejo y con una rica gradación de escenarios empíricos posibles de ser analizados (1). Un elemento a distinguir del proceso abierto en Santiago del Estero después de la Intervención Federal del 2004 y del ascenso del Frente Cívico es que la coalición provincial de gobierno en la disputa política al interior de la provincia tiende a comportarse como un sistema político en sí mismo, es decir, a actuar simultáneamente como oficialismo y oposición. Hay que advertir como elemento para el análisis, que los gobiernos locales en la provincia son altamente dependientes de las transferencias del gobierno provincial, ya que en promedio, sus ingresos municipales propios representan el 14%, que está muy por debajo de la media nacional que se ubica en el 48% (2). A partir de esto, aparece una de las principales hipótesis en relación a lo político: los actores juegan dentro del Frente Cívico sabiendo que su principal competidor se encuentra dentro del mismo espacio. El Interior de la provincia se presenta para el Frente Cívico como una sólida base de organización territorial, de movilización instituyente y de legitimidad a la autoridad política. Lejos de una postura racionalista y de un “yo acuso”, las reflexiones y estas primeras aproximaciones giran en torno a cómo se construyen sólidas bases de mayorías electorales en el Interior santiagueño.

Building a Fab on a Chip Imboden, Matthias; Han, Han; Stark, Thomas; Lowell, Evan; Chang, Jackson; Pardo, Flavio; Bolle, Cristian; del Corro, Pablo Guillermo; Bishop, David J. Semiconductor fabs are large, complex industrial sites with costs for a single facility approaching $10B. In this paper we discuss the possibility of putting the entire functionality of such a fab onto a single silicon chip. We demonstrate a path forward where, for certain applications, especially at the nanometer scale, one can consider using a single chip approach for building devices with significant potential cost savings. In our approach, we build micro versions of the macro machines one typically finds in a fab, and integrating all the components together. We argue that the technology now exists to allow one to build a Fab on a Chip.

Crime as social excess: Reconstructing Gabriel Tarde’s criminal sociology Tonkonoff, Sergio Esteban Gabriel Tarde, along with Durkheim and others, set the foundations for what is today a common-sense statement in social science: crime is a social phenomenon. However, the questions about what social is and what kind of social phenomenon crime is remain alive. Tarde’s writings have answers for both of these capital and interdependent problems and serve to renew our view of them. The aim of this article is to reconstruct Tarde’s definition of crime in terms of genus and specific difference, exploring his criminology as a case of his general sociology. This procedure shows that Tarde succeeded in creating a comprehensive theory of crime and criminals founded not only on his most well-known concept, imitation, but also on his equally important concepts of invention, opposition, social logic and social teleology. For Tarde, crime is a complex phenomenon related to criminal inventions, criminal propagations, the production of penal laws, the execution of controls and punishments, and the collective reactions to all these.

Scaleup of Batch Reactors Using Phenomenological-Based Models Monsalve Bravo, Gloria Milena; Moscoso Vásquez, Hilda Marcela; Alvarez Zapata, Hernán This work presents a methodology for scaling up Batch Processes (BPs). First, a review of the most popular scale-up methods differentiating batch from continuous processing is made, finding that traditional scale-up approaches do not consider BPs characteristics and that many particular successful cases are reported, but no formal procedure has been developed for scaling up these processes. Considering these facts, a novel scale-up procedure is presented, in which a process Phenomenological-Based Semiphysical Model PBSM and its Hankel matrix are used for computing the State Impactability Index (SII) that allows to determine: (i) the process main dynamics at each stage of the batch and (ii) the critical point of the Operating Trajectory (OT) at which the batch must be scaled-up. Finally, the methodology is applied to a batch suspension polymerization reactor, comparing the scaled unit design when using this approximation and a traditional method.

Natamycin and nisin supported on starch edible films for controlling mixed culture growth on model systems and Port Salut cheese Ollé Resa, Carolina Patricia; Gerschenson, Lia Noemi; Jagus, Rosa Juana Consumer demand for natural food additives has increased and, as a consequence, the use of natural antimicrobials like natamycin and nisin is being investigated. In the case of cheese, surface colonization by microorganisms constitutes a significant risk to consumer's health. In this study, the effectiveness of natamycin and nisin supported in tapioca starch films against Saccharomyces cerevisiae and Listeria innocua in a mixed culture present on the surface of a model system and of Port Salut cheese was evaluated. It was observed that the preservatives incorporated in starch films, controlled growth of both microorganisms present together on the surface of the cheese during storage. Additionally, the joint presence of nisin and natamycin was effective as a barrier against a mixed culture preventing an external contamination of cheese and of a model system, during storage. Hence, this film has great potential to be used as antimicrobial edible packaging.

Stellar scattering and the formation of hot Jupiters in binary systems Marti, Javier Guillermo; Beauge, Cristian Hot Jupiters (HJs) are usually defined as giant Jovian-size planets with orbital periods P⩽10 days. Although they lie close to the star, several have finite eccentricities and significant misalignment angle with respect to the stellar equator, leading to ~20% of HJs in retrograde orbits. More than half, however, seem consistent with near-circular and planar orbits. In recent years, two mechanisms have been proposed to explain the excited and misaligned subpopulation of HJs: Lidov–Kozai migration and planet–planet scattering. Although both are based on completely different dynamical phenomena, at first hand they appear to be equally effective in generating hot planets. Nevertheless, there has been no detailed analysis comparing the predictions of both mechanisms, especially with respect to the final distribution of orbital characteristics. In this paper, we present a series of numerical simulations of Lidov–Kozai trapping of single planets in compact binary systems that suffered a close fly-by of a background star. Both the planet and the binary component are initially placed in coplanar orbits, although the inclination of the impactor is assumed random. After the passage of the third star, we follow the orbital and spin evolution of the planet using analytical models based on the octupole expansion of the secular Hamiltonian. We also include tidal effects, stellar oblateness and post-Newtonian perturbations. The present work aims at the comparison of the two mechanisms (Lidov–Kozai and planet–planet scattering) as an explanation for the excited and inclined HJs in binary systems. We compare the results obtained through this paper with results in Beaugé & Nesvorný (2012), where the authors analyse how the planet–planet scattering mechanisms works in order to form this hot Jovian-size planets. We find that several of the orbital characteristics of the simulated HJs are caused by tidal trapping from quasi-parabolic orbits, independent of the driving mechanism (planet–planet scattering or Lidov–Kozai migration). These include both the 3-day pile-up and the distribution in the eccentricity versus semimajor axis plane. However, the distribution of the inclinations shows significant differences. While Lidov–Kozai trapping favours a more random distribution (or even a preference for near polar orbits), planet–planet scattering shows a large portion of bodies nearly aligned with the equator of the central star. This is more consistent with the distribution of known hot planets, perhaps indicating that scattering may be a more efficient mechanism for producing these bodies.

Histological Changes in the Retina Provoked by Lithium Treatment in a Nocturnal Rodent (Lagostomus maximus maximus) Calderón, Claudia Patricia; Filippa, Veronica Palmira; Fogal, Teresa Hilda; Piezzi, Ramon Salvador; Pelzer, Lilian Eugenia; Mohamed, Fabian Heber Daily morphological variations have been previously described in the viscacha (Lagostomus maximus maximus) retina. The aim of this work was to determine the effects of lithium administration on the histology of retinas from this nocturnal rodent since lithium is a drug that has been shown to affect different parameters of circadian rhythms. Adult male viscachas were divided into 2 groups, injected daily with lithium chloride or vehicle for 35 days, and sacrificed at 08:00, 16:00, and 24:00 h for light and electron microscopy studies. The following morphometric parameters were analyzed: the thickness of the photoreceptor layer, the rod outer and inner segments, and the outer nuclear layer. The control group displayed a true daily cycle of photoreceptor renewal similar to that previously reported by us for (untreated) viscachas in their normal habitat. In all lithium-treated groups, we did not observe histological changes in the thickness measurement of the retinal layers. In these groups, the retinas presented ultrastructural characteristics similar to those observed in control animals sacrificed at 24:00 h. In conclusion, chronic lithium administration abolished the daily histological rhythm in the viscacha retina, probably via inhibition of the phagocytosis process in pigment epithelial cells.