Comerciantes británicos en el Rio de la Plata. En torno a la construcción de una comunidad mercantil (1810-1860) Silveira, Alina Durante la primera mitad del siglo XIX gran cantidad de británicos ingresaron al puerto de Buenos Aires. Algunos de ellos eran comerciantes y constituyeron un grupo de gran visibilidad. El objetivo del presente artículo es indagar sobre la conformación de una comunidad mercantil británica a partir del estudios de los ámbitos de sociabilidad por los cuales transitaron y las instituciones voluntarios que construyeron. A su vez, esperamos que este estudio nos permita brindar mayores elementos analíticos que nos posibiliten comprender la inserción económica de los británicos en Buenos Aires antes de 1880 así como contribuir a los estudios sobre la sociabilidad porteña previa a 1850.; During the first half of the nineteenth century many British arrived at Buenos Aires. Some of them were merchants. This article will analyze the erection of a British mercantile community. We will study the sociability sphere were they circulated and the voluntary associations they erected. Also we hope our study will help us understand the economic insertion of the British activities in Buenos Aires before 1880 and the local sociability sphere.

The antimicrobial peptide microcin J25 stabilizes the gel phase of bacterial model membranes Rintoul, Maria Regina; Morero, Roberto Dionisio; Dupuy, Fernando Gabriel The bacterial membrane interaction of the antimicrobial peptide microcin J25 was studied with the probe-free techniques Langmuir monolayers and infrared spectroscopy. Membrane model systems composed by phosphatidylethanolamine:phosphatidylglycerol 7:3, which mimic the cytoplasmic membrane of Gram negative bacteria, were used in both monolayer and bilayer approaches. The peptide reduced the transition surface pressure of the expanded-to-condensed lipid monolayer states, as well as increased the gel-to-liquid crystalline transition temperature in bilayers, indicating a stabilization of membrane ordered state. In addition, a reduction of the surface pressure at which condensed domains appeared was observed upon mixed monolayers compression after microcin J25 adsorption. The results indicate a favorable interaction of microcin J25 with bacterial membrane model systems. Also, the effects on the ordered phases stabilization are discussed in terms of the biological effects observed in membranes of sensitive cells.

Physiological, structural and molecular traits activated in strawberry plants after inoculation with the plant growth-promoting bacterium Azospirillum brasilense REC3 Guerrero Molina, María Fernanda; Lovaisa, Nadia Carolina; Salazar, Sergio Miguel; Martinez Zamora, Martin Gustavo; Diaz Ricci, Juan Carlos; Pedraza, Raúl Osvaldo The plant growth‐promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum‐colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root‐inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post‐inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plants. Other early responses activated by REC3 (at 24 hpi) were a decline of lipid peroxidation and up‐regulation of strawberry genes involved in defence (FaPR1), bacterial recognition (FaFLS2) and H2O2 depuration (FaCAT and FaAPXc). The last may explain the apparent absence of oxidative burst in leaves after bacterial inoculation. Also, REC3 inoculation induced delayed structural responses such as callose deposition and cell wall fortification (at 72 hpi). Results showed that A. brasilense REC3 is capable of exerting beneficial effects on strawberry plants, reinforcing their physiological and cellular characteristics, which in turns contribute to improve plant performance.

Structural-functional approach to identify post-disturbance recovery indicators in forests from northwestern Patagonia: a tool to prevent state transitions Cavallero, Laura; López, Dardo Rubén; Raffaele, Estela; Aizen, Marcelo Adrian The disruption of the natural post-disturbance recovery process, either by changes in disturbance regime or by another disturbance, can trigger transitions to alternative degraded states. In a scenario of high disturbance pressure on ecological systems, it is essential to detect recovery indicators to define the period when the system needs more protection as well as the period when the system supports certain use pressure without affecting its resilience. Recovery indicators can be identified by non-linear changes in structural and functional variables. Fire largely modulates the dynamic and stability of plant communities worldwide, and is this the case in northwestern (NW) Patagonia. The ultimate goal of this study is to propose a structural-functional approach based on a reference system (i.e. chronosequence) as a tool to detect post-disturbance recovery indicators in forests from NW Patagonia. In NW Patagonia (40-42°S), we sampled 25 Austrocedrus chilensis and Nothofagus spp communities differing in post-fire age (0.3-180 yr). In each community we recorded structural (woody species cover and height, solar radiation, air temperature, relative humidity) and functional (annual recruitment of woody and tree species) attributes. We modelled these attributes in function of post-fire age and analized the relationship between a functional attribute and a Structural Recovery Index (SRI). Communities varying in time-since-last-fire were structurally and functionally different. Moreover, response variables showed non-linear changes along the chronosequence, allowing the selection of recovery indicators. We suggest to use vegetation variables instead of environmental variables as structural recovery indicators. Horizontal and Vertical Vegetation Heterogeneity indices provided the information necessary to describe vegetation spatial reorganization after fire. Tree species annual recruitment was a good indicator of the functional recovery of forest communities. The relationship between a functional attribute and SRI allowed us to detect phases with high- and low-risk of degradation during post-fire succession. High-risk phases (< 36 yr old) had the highest horizontal vegetation heterogeneity and scarce tree seedling density (< 7,000 seedlings.ha-1.yr-1). Whereas, low-risk phases (> 36 yr old) had the highest vertical vegetation heterogeneity and tree species seedling density (> 10,000 seedlings.ha-1.yr-1). Due to the low structural-functional levels, communities at high-risk phases would be more vulnerable to antropic pressure (e.g. livestock raising, logging) than communities at low-risk phases. The proposed approach contributes to the sustainable management of forest communities because it allows to estimate the minimum structural-functional levels from which forest communities could be harvested.

La prensa y el impacto de las Cortes de Cádiz en el Perú; The press and the impact of the Cortes de Cádiz in Perú Morán Ramos, Luis Daniel; Aguirre, María Las independencias en Iberoamérica y particularmente la coyuntura de las Cortes de Cádiz han marcado profundamente el proceso revolucionario y la configuración política de las actuales naciones hispanoamericanas. El virreinato peruano vivió durante aquel contexto de cambios una profusión de impresos que pusieron en evidencia la importancia de la difusión de la información y su lectura en la convulsionada vida política peruana. Ésta investigación busca explicar, a través del análisis de la prensa y otros impresos, el impacto que las reformas de las Cortes ocasionaron en el Perú y la imagen que la prensa construyó de aquel proceso.; Independence in Latin America and particularly the situation of the Cortes of Cádiz have deeply marked the revolutionary process and the political configuration of the current Latin American Nations. The Peruvian Viceroyalty lived during that context of changes a vast profusion of forms that put in evidence the importance of the dissemination of information and reading in the tumultuous Peruvian political life. This research seeks to explain, through the analysis of the press and other printed material, the impact of the reforms in Peru and the image that the press built from the process.

Philornis downsi (Diptera: Muscidae), an avian nest parasite invasive to the Galápagos Islands, in Mainland Ecuador Bulgarella, Mariana; Quiroga, Martin Anibal; Brito Vera, Gabriel A.; Dregni, Jonathan S.; Cunninghame, Francesca; Mosquera Muñoz, Denis A.; Monje, Lucas Daniel; Causton, Charlotte E.; Heimpel, George E. Philornis downsi (Dodge and Aitken) is a bird-parasitic muscid fly native to mainland South America that recently invaded the Galápagos Islands where it is parasitizing Darwin's finches and other land birds. This parasite was previously known only from Argentina, Brazil, and Trinidad and Tobago. The first report of P. downsi from mainland Ecuador is provided, supporting the hypothesis that the invasion route of P. downsi from its native range to the Galápagos Islands includes mainland Ecuador. Four different morphologies of pupal exuviae, which belong to different fly species, were uncovered. Dipteran puparia were found in 20% of naturally occurring nests collected in 2013 and in 27% of nests in 2014 at the two sites in western Ecuador. P. downsi accounted for 74% and 40% of the puparia in 2013 and 2014, respectively. Two new bird host species for the genus Philornis were recorded: the streak-headed woodcreeper (Lepidocolaptes souleyetii) and the fasciated wren (Campylorhynchus fasciatus). The levels of nest parasitism found were much lower than levels reported for the Galápagos Islands. Finally, parasitism of P. downsi by a parasitoid in the genus Brachymeria (Hymenoptera, Chalcididae) is documented. Overall, 9% of fly puparia collected in 2013, and 19% of those collected in 2014, had parasitoid emergence holes.

Generalized Ginzburg-Landau approach to inhomogeneous phases in nonlocal chiral quark models Carlomagno, Juan Pablo; Gomez Dumm, Daniel Alberto; Scoccola, Norberto Nerio We analyze the presence of inhomogeneous phases in the QCD phase diagram within the framework of nonlocal chiral quark models. We concentrate in particular in the positions of the tricritical (TCP) and Lifshitz (LP) points, which are studied in a general context using a generalized Ginzburg-Landau approach. We find that for all the phenomenologically acceptable model parametrizations considered the TCP is located at a higher temperature and a lower chemical potential in comparison with the LP. Consequently, these models seem to favor a scenario in which the onset of the first order transition between homogeneous phases is not covered by an inhomogeneous, energetically favored phase.

Peces marinos, peces fluviales: explotación diferencial por grupos cazadores-recolectores del noreste de Chubut (Patagonia central, Argentina) Svoboda, Ariadna; Gomez Otero, Julieta La incorporación de peces a la dieta de grupos cazadores-recolectores puede evaluarse en función de su densidad, la disponibilidad de recursos de mayor tamaño corporal, la tecnología disponible, entre otros. En este trabajo se aborda la variabilidad en el registro ictiofaunístico durante el Holoceno tardío en dos áreas: el valle inferior del río Chubut y su desembocadura y costa adyacente. De acuerdo a la productividad ambiental, la disponibilidad de recursos de alta jerarquía y las oportunidades de captura de peces, se genera un modelo de subsistencia que evalúa la diversidad e importancia relativa de los peces para las dos áreas. Las expectativas zooarqueológicas derivadas son discutidas a partir de los muestreos faunísticos de las localidades Barranca Norte y Los Cangrejales Sur (desembocadura y costa) y los sitios Loma Grande 1 y Cinco Esquinas 1 (valle inferior), ubicados a unos 30 y 18 km del mar respectivamente. Los resultados arrojan diferencias en la riqueza taxonómica de peces: en el valle predominan las percas, mientras que en la desembocadura y costa se explotó una amplia variedad. Se registró una importante contribución de peces en ambas áreas; sin embargo, en los campamentos residenciales de la desembocadura los restos de peces son menos frecuentes.; The incorporation of fish into the diet of hunter-gatherers can be evaluated on the basis of their densities, the abundance of high-ranked resources and available technology. This paper examines the variability of the late Holocene ichthyoarchaeological record in two environ- mental areas: the lower valley of the Chubut River, along with its mouth and adjacent marine coast. According to environmental productivity, high-ranked resources availability and capture opportunities, a subsistence model is generated. This model evaluates diversity and relative impor- tance of fish for the two areas. Zooarchaeological expectations inferred are discussed on account of faunal samples taken from different archaeological sites, such as Barranca Norte and Los Can- grejales Sur (located at the river mouth and marine coast), Loma Grande 1 and Cinco Esquinas 1 (located on the valley, at 30 and 18 km distance from sea). Results show differences in fish taxo- nomic richness with perch dominant in the valley sites, whereas a high range of fish was found at the river mouth and marine coast sites. Although an important contribution of fish registered in both areas was recorded; in residential camps at the river mouth fish remains were scarce.

Geodynamic controls on the contamination of Cenozoic arc magmas in the southern Central Andes: Insights from the O and Hf isotopic composition of zircon Jones, Rosemary E.; Kirstein, Linda; Kasemann, Simone A.; Dhuime, Bruno; Elliott, Tim; Litvak, Vanesa Dafne; Alonso, Ricardo Narciso; Hinton, Richard; Edinburgh Ion Microprobe Facility Subduction zones, such as the Andean convergent margin of South America, are sites of active continental growth and crustal recycling. The composition of arc magmas, and therefore new continental crust, reflects variable contributions from mantle, crustal and subducted reservoirs. Temporal (Ma) and spatial (km) variations in these contributions to southern Central Andean arc magmas are investigated in relation to the changing plate geometry and geodynamic setting of the southern Central Andes (28–32 S) during the Cenozoic. The in-situ analysis of O and Hf isotopes in zircon, from both intrusive (granitoids) and extrusive (basaltic andesites to rhyolites) Late Cretaceous – Late Miocene arc magmatic rocks, combined with high resolution U–Pb dating, demonstrates distinct across-arc variations. Mantle-like d18O(zircon) values (+5.4& to +5.7& (±0.4 (2r))) and juvenile initial eHf(zircon) values (+8.3 (±0.8 (2r)) to +10.0 (±0.9 (2r))), combined with a lack of zircon inheritance suggests that the Late Cretaceous (73 Ma) to Eocene (39 Ma) granitoids emplaced in the Principal Cordillera of Chile formed from mantle-derived melts with very limited interaction with continental crustal material, therefore representing a sustained period of upper crustal growth. Late Eocene (36 Ma) to Early Miocene (17 Ma) volcanic arc rocks present in the Frontal Cordillera have ‘mantle-like’ d18O(zircon) values (+4.8& (±0.2 (2r) to +5.8& (±0.5 (2r))), but less radiogenic initial eHf(zircon) values (+1.0 (±1.1 (2r)) to +4.0 (±0.6 (2r))) providing evidence for mixing of mantle-derived melts with the Late Paleozoic – Early Mesozoic basement (up to 20%). The assimilation of both Late Paleozoic – Early Mesozoic Andean crust and a Grenville-aged basement is required to produce the higher than ‘mantle-like’ d18O(zircon) values (+5.5& (±0.6 (2r) to +7.2& (±0.4 (2r))) and unradiogenic, initial eHf(zircon) values (3.9 (±1.0 (2r)) to +1.6 (±4.4 (2r))), obtained for the Late Oligocene (23 Ma) to Late Miocene (9 Ma) magmatic rocks located in the Argentinean Precordillera, and the Late Miocene (6 Ma) volcanic rocks present in the Frontal Cordillera. The observed isotopic variability demonstrates that the assimilation of pre-existing continental crust, which varies in both age and composition over the Andean Cordillera, plays a dominant role in modifying the isotopic composition of Late Eocene to Late Miocene mantle-derived magmas, implying significant crustal recycling. The interaction of arc magmas with distinct basement terranes is controlled by the migration of the magmatic arc due to the changing geodynamic setting, as well as by the tectonic shortening and thickening of the Central Andean crust over the latter part of the Cenozoic.

Late Cenozoic contractional evolution of the current arc-volcanic region along the southern Central Andes (35°20′S) Tapia, Felipe; Farías, Marcelo; Naipauer, Maximiliano; Puratich, Jacqueline The Andean internal zone records deformation, uplift and erosion that serve as proxies of variations on mountain building dynamics. Hence, the study of this region would give keys to understand the factors controlling the orogenic evolution. Structural, stratigraphic and geochronological data in the Andean internal zone at 35°20′S evidence that this region has only underwent contractional deformation since the late Miocene up to present, differing from coeval Pleistocene extensional tectonics affecting the retro-arc. Contractional deformation was characterized by the development of a piggy-back basin in the latest Miocene filled by synorogenic deposits. Afterward, an out-of-sequence thrusting event affected the region since at least the Pliocene until the Present. Shortening in the inner part of the Andean orogen would be favored by both the high orthogonality of the out-sequence structures with respect to the plate convergence vector and by the minor resistance to shortening produced by the southward decrease of the orogen height and by the removal of material via erosion of the uplifted mountain belt. In contrast, oblique structures, as those described farther north, accommodate strike-slip displacement. Likewise, we propose that erosion from the inner orogen favored the prolongation of the out-of-sequence thrusting event until the Present, differing from the situation north of the 34°S where this event ended by the Pliocene.

Respuesta cardiovascular a la administración crónica de péptido natriurético tipo C en ratas espontáneamente hipertensas; Cardiovascular response to chronic administration of c-type natriuretic peptide in spontaneously hypertensive rats Caniffi, Carolina Cecilia; Sueiro, Laura; Bouchet, Gonzalo; Romero, Mariana; Barrionuevo, Emiliano; Arranz, Cristina Teresa; Costa, Maria de Los Angeles Introducción: El péptido natriurético tipo C (CNP) ha cobrado relevancia por sus efectos sobre la regulación de la función y la morfología del corazón y los vasos sanguíneos. Previamente demostramos in vitro que el CNP incrementa la actividad del sistema del óxido nítrico (NO) en ratas espontáneamente hipertensas (SHR). Objetivo: Estudiar el efecto del tratamiento crónico con CNP sobre la presión arterial sistólica (PAS), la función cardíaca y vascular y el sistema del NO en ratas espontáneamente hipertensas y normotensas. Material y métodos: Se emplearon ratas Wistar macho de 12 semanas de edad normotensas y espontáneamente hipertensas. Los animales recibieron infusión crónica de solución salina o CNP (0,75 mg/hora/rata) durante 14 días mediante la implantación de bombas osmóticas subcutáneas. Se midió la PAS y se realizaron un electrocardiograma y un ecocardiograma. Se extrajeron el ventrículo izquierdo y la arteria aorta torácica y se determinó la actividad, con L-[U14C]-arginina, de la óxido nítrico sintasa (NOS) y se realizaron estudios de reactividad vascular. Resultados: La administración crónica de CNP disminuyó la PAS en las SHR. Se observó menor volumen minuto en las SHR y el CNP incrementó dicho volumen, en tanto que no indujo cambios en las ratas normotensas. En las SHR se observó un desequilibrio en las respuestas vasodilatadora y vasoconstrictora en la arteria aorta y el tratamiento con CNP mejoró la función vascular respecto de las ratas normotensas. En ambos tejidos, la actividad de la NOS fue mayor en las SHR y se incrementó con la infusión durante 14 días de CNP. Sin embargo, dicho incremento fue menor en las SHR. Conclusión: El CNP induce cambios a nivel cardiovascular y en el sistema del NO que podrían resultar beneficiosos en este modelo de hipertensión arterial.; Background: C-type natriuretic peptide (CNP) plays an important role in the regulation of cardiovascular function and morphology. We have previously demonstrated that CNP increases nitric oxide (NO) system activity in vivo in spontaneously hypertensive rats (SHR). Objective: The goal of this study is to evaluate the effect of chronic CNP administration on systolic blood pressure (SBP), cardiovascular function and the NO system in spontaneously hypertensive and normotensive rats. Methods: Twelve-week-old normotensive male Wistar rats and SHR were used. They received chronic infusion of saline or CNP (0.75 mg/h/rat) for 14 days via subcutaneously implanted osmotic pumps. Systolic blood pressure was measured and an electrocardiogram and echocardiogram were performed. The left ventricle and the thoracic aorta were resected; nitric oxide synthase (NOS) activity was determined using L-[U14C]-arginine and vascular reactivity was assessed. Results: Chronic administration of CNP decreased SBP in SHR. Cardiac output was lower in SHR and increased with CNP; however, CNP had no effect in normotensive rats. Spontaneously hypertensive rats had unbalanced aortic vasodilation and vasoconstriction responses, and CNP improved the vascular function. Nitric oxide synthase activity was greater in SHR and increased with the 14-day CNP infusion, but this increase was lower than in normotensive rats. Conclusion: C-type natriuretic peptide induces cardiovascular and NO system changes which may be beneficial in this model of hypertension.

Pharmacological mechanism underlying the antinociceptive activity of vanillic acid Yrbas, Maria de Los Angeles; Morucci, Florencia; Alonso, Maria del Rosario; Gorzalczany, Susana Beatriz Vanillic acid is found at high concentrations in many plants used in traditional medicine. It has been associated with a variety of pharmacologic activities such as carcinogenesis inhibition, apoptosis and inflammation; however, it has become most popular for its pleasant creamy odor. Since there are few reports concerning the antinociceptive activity of this phenolic compound, the aim of this work was to study this activity in in vivo animal models. Vanillic acid was administered by the intraperitoneal route producing a dose-dependent inhibition of the acetic acid-induced writhing response (ED50: 9.3 mg/kg). The antinociceptive activity was inhibited by the pretreatment with ondansetron and yohimbine, indicating that the serotoninergic and adrenergic systems could participate in the mechanism underlying the analgesic activity of vanillic acid. This compound was also demonstrated to interact with ASICs (Acid-sensing Ion Channels) as well as with TPRV1, TRPA1, and TRPM8 receptors in vivo. Furthermore, vanillic acid did not interfere with the locomotor function or motor coordination. The plasmatic phenolic content, analyzed by HPLC, showed that its t1/2 and AUC were 0.123 h and 1.38 μg·h/mL; respectively. In conclusion, vanillic acid might represent a potential therapeutic option for the treatment of pain.

Influence of the projectile charge state on electron emission spectra from a Cu(111) surface Archubi, Claudio Darío; Silkin, V. M.; Gravielle, Maria Silvia Double differential electron emission distributions produced by grazing impact of fast dressed ions on a Cu(111) surface are investigated focusing on the effects of the electronic band structure. The process is described within the Band-Structure-Based approximation, which is a perturbative method that includes an accurate representation of the electron-surface interaction, incorporating information of the electronic band structure of the solid. Differences in the behaviour of the emission spectra for He+q, Li+q, Be+q and C+q projectiles with different charge states q are explained by the combined effect of the projectile trajectory and the projectile charge distribution.

Oil extraction kinetics of hydrothermally pretreated canola seeds Zárate, Valeria; Perez, Ethel; Crapiste, Guillermo Hector; Nolasco, Susana M.; Fernández, María Belén In this work the kinetics of oil extraction from spring canola seeds subjected to a hydrothermal pretreatment with direct steam (393 K, 5 min) was studied. The differences between the seed internal structure generated by the application of this pretreatment and that of the untreated sample (ground sample) were observed by scanning electron microscopy. Oil from both samples was extracted with hexane at different times and temperatures using a stirred batch system. Oil yield increased up to 46 % due to the hydrothermal treatment. A model was proposed to explain the oil extraction process from hydrothermally pretreated and untreated canola seeds, taking into account two main mechanisms: a washing process of the surface oil from the seed, and a diffusion process. Parameters of the model were fitted, and values of the oil fraction extracted during the washing step (0.27 and 0.50 for untreated and hydrothermally treated canola seeds, respectively) and the effective diffusion coefficient (3.1–9.4.10- 12 m2 s 1 ) were obtained. The latter value showed an Arrhenius-type temperature dependence in the untreated sample, but the diffusion coefficient did not vary with temperature when oil diffusion was analyzed using hydrothermally pretreated seeds.

Sobre la literatura de animales: apuntes para una crítica indisciplinada Yelin, Julieta Rebeca El trabajo tiene como objetivo inicial analizar algunas ideas nodales dentro del campo de los estudios animales para, a partir de esos lineamientos de carácter general, abordar el discurso de la crítica literaria, inmersa en un significativo proceso de reconfiguración conceptual. El acento será puesto sobre algunas apropiaciones de la noción de “vida”, un núcleo relevante en la mayor parte de los estudios críticos que examinan la productividad del vínculo literatura-animalidad. Dicho núcleo entraña una transformación de los juicios acerca de las formas que asumen las relaciones entre vida y literatura, así como también una revisión de las concepciones que intentan aprehender un sujeto de la experiencia.; O trabalho tem como objetivo inicial analisar algumas ideias nodais dentro do campo dos estudos animais para, a partir destas orientações de caráter geral, abordar o discurso da crítica literária, imersa em um significativo processo de reconfiguração conceitual. O acento será posto sobre algumas apropriações da noção de “vida”, um núcleo relevante na maior parte dos estudos críticos que examinam a produtividade do vínculo literatura-animalidade. Tal núcleo acarreta em uma transformação dos juízos acerca das formas que assumem as relações entre vida e literatura, assim como uma revisão das concepções que tentam apreender um objeto da experiência.; The work has as the initial objective to analyze some nodal points in the field of animal studies and, starting from these general guidelines, address the discourse of literary criticism undergoing a significant process of conceptual reconfiguration. The accent will be placed on some appropriations of the notion of "life", an important core in most critical studies examining the productivity of the literature-animality link. Suh core involves a transformation of the judgments about the forms taken by the relations between life and literature, as well as a revision of concepts trying to apprehend a subject of experience.

Physicochemical characterization of aqueous micellar systems formed by environmentally friendly salts Cordisco, Estefanía; Haidar, Carla; Goñi, Rocío; Nerli, Bibiana Beatriz; Pellegrini Malpiedi, Luciana In this work, environmentally friendly aqueous micellar two-phase systems containing nonionic surfactants (Triton X-114, Triton X-100 and Genapol X080) and organic salts (sodium citrate and sodium tartrate) were characterized. In order to accomplish this objective, the binodal diagrams (cloud point vs. surfactant concentration) were obtained for each condition. Additionally, critical micelle concentration (CMC) and micellar hydrodynamic diameter (DH) were determined for each system. According to the obtained results, it was found that the presence of salts lowered the CMC (ΔCMC up to 0.15 mM) and cloud point values (ΔCP up to 18 °C) following the sequence: sodium citrate > sodium tartrate. In addition, the hydrodynamic diameters of the micelles were notoriously increased in presence of the studied salts, showing the high sensitivity of the described aqueous micellar two-phase systems to the medium condition. These results open perspectives for the use of greener aqueous micellar two-phase systems for bioseparation purposes.

Carbohydrate metabolization in late stages in the recalcitrant pollen of pumpkin (Cucurbita pepo L.) Carrizo Garcia, Carolina; Guarnieri, M.; Pacini, E. Pumpkin (Cucurbita pepo L.) pollen is starchy, sucrose-poor and recalcitrant, features opposite to those of several model species; therefore, some differences in carbohydrate metabolism could be expected in this species. By studying pumpkin recalcitrant pollen, the objective was to provide new biochemical evidence to improve understanding of how carbohydrate metabolism might be involved in pollen functioning in advanced stages. Four stages were analysed: immature pollen from 1 day before anthesis, mature pollen, mature pollen exposed to the environment for 7 h, and pollen rehydrated in a culture medium. Pollen viability, water and carbohydrate content and activity of enzymes involved in carbohydrate metabolism were quantified in each stage. Pollen viability and water content dropped quickly after dehiscence, as expected. The slight changes in carbohydrate concentration and enzyme activity during pollen maturation contrast with major changes recorded with ageing and rehydration. Pumpkin pollen seems highly active and closely related to its surrounding environment in all the stages
analysed; the latter is particularly evident among insoluble sucrolytic enzymes, mainly wall-bound acid invertase, which would be the most relevant for sucrose cleavage. Each stage was characterised by a particular metabolic/enzymatic profile; some particular features, such as the minor changes during  maturation, fast sucrolysis upon rehydration or sharp decrease in insoluble sucrolytic activity with ageing seem to be related to the lack of dormancy and recalcitrant nature of pumpkin pollen.

A single ectomycorrhizal fungal species can enable a Pinus invasion Hayward, Jeremy; Horton, Thomas R.; Pauchard, Aníbal; Nuñez, Martin Andres Like all obligately ectomycorrhizal plants, pines require ectomycorrhizal fungal symbionts to complete their life cycle. Pines introduced into regions far from their native range are typically incompatible with local ectomycorrhizal fungi, and, when they invade, coinvade with fungi from their native range. While the identities and distributions of coinvasive fungal symbionts of pine invasions are poorly known, communities that have been studied are notably depauperate. However, it is not yet clear whether any number of fungal coinvaders is able to support a Pinaceae invasion, or whether very depauperate communities are unable to invade. Here, we ask whether there is evidence for a minimum species richness of fungal symbionts necessary to support a pine/ectomycorrhizal fungus coinvasion. We sampled a Pinus contorta invasion front near Coyhaique, Chile, using molecular barcoding to identify ectomycorrhizal fungi. We report that the site has a total richness of four species, and that many invasive trees appear to be supported by only a single ectomycorrhizal fungus, Suillus luteus. We conclude that a single ectomycorrhizal (ECM) fungus can suffice to enable a pine invasion.

Trifluoroacetic acid as excipient destabilizes melittin causing the selective aggregation of melittin within the centrin-melittin-trifluoroacetic acid complex Pastrana Rios, Belinda; Sosa, Liliana del Valle; Santiago, Jorge Trifluoroacetic acid (TFA) may be the cause of the bottleneck in high resolution structure determination for protein-peptide complexes. Fragment based drug design often involves the use of synthetic peptides which contain TFA (excipient). Our goal was to explore the effects of this excipient on a model complex: centrin-melittin-TFA. We performed Fourier transform infrared, two-dimensional infrared correlation spectroscopies and spectral simulations to analyze the amide I’/I’* band for the components and the ternary complex. Melittin (MLT) was observed to have increased helicity upon its interaction with centrin, followed by the thermally induced aggregation of MLT within the ternary complex in the TFA presence.

Indígenas y misioneros: génesis y representaciones de una misión evangélica en el ingenio La Esperanza; Indigenes and missionaries: genesis and representations of an evangelical mission in the sugar mill La Esperanza Espinosa, Mariana Esther En la primera década del siglo XX el misionero británico de los Hermanos Libres John Linton organizó una misión entre indígenas guaraníes -o “chiriguanos”- que se llamó Cherenta. El asentamiento se creó al interior de La Esperanza, el ingenio azucarero de la familia inglesa Leach ubicado en el piedemonte andino del noroeste argentino. El artículo busca desentrañar algunos aspectos sobre la génesis y las actuales representaciones de esta misión evangélica. En el fenómeno social que significa la misión confluyen al menos tres procesos con sus propias temporalidades y dinámicas: la etno-historia y etnografía sobre los grupos guaraní-hablantes; los ingenios azucareros, especialmente como espacios interétnicos; y las experiencias de misionalización. El trabajo se propone observar en estos ejes variables significativas que nos orienten hacia una interpretación del vínculo religión y etnicidad entre los actuales creyentes.; In the first decade of the twentieth century the British missionary John Linton of the Free Brethren organized a mission among “chiriguanos” indigenes called "Cherenta". The establishment was built within La Esperanza, the sugar mill of the British Leach family located in the Andean foothills in Argentine northwestern. The article seeks to reveal some aspects of the genesis and current representations of this evangelical mission. In the social phenomenon that means the mission converge at least three processes with their own temporality and dynamic: the ethno-history and ethnography of the “chiriguanos”; sugar mills, especially as interethnic spaces; and the experiences of misionalization. The paper aims to observe significant variables into these axes to guide us towards an interpretation of the link between religion and ethnicity of the believers at the present time.