Induced systemic resistance -like responses elicited by rhizobia Tonelli, Maria Laura; Figueredo, María Soledad; Rodríguez, Johan; Fabra, Adriana Isidora; Ibañez, Fernando Julio Rhizobia are soil bacteria that engage into a mutualistic symbiosis with plants and benefit the host by fixing atmospheric N. In addition, rhizobia can be considered as biocontrol agents, contributing to plant health through direct inhibition of a wide range of pathogens. More recently, it became evident that rhizobial invasion of plant roots can also trigger an increased systemic resistance state in the host, a process resembling the Induced Systemic Resistance (ISR) mechanism. However, this indirect biocontrol property of rhizobia was relatively less explored. Scope: In this review article, we present an overview of the current knowledge of ISR -like responses induced by rhizobia, considering general characteristics of this phenomenon, discussing the molecular pathways leading to this response and highlighting potential links between ISR -like responses and the nodulation signaling pathway. Conclusions: A more detailed knowledge of these responses can result in development of biotechnological tools for sustainable crop production, through optimization of the systemic protective effect conferred by rhizobia.

Role of inflammasome activation in tumor immunity triggered by immune checkpoint blockers Segovia, Alcira Mercedes; Russo, Sofia; Girotti, Maria Romina; Rabinovich, Gabriel Adrián; Hill, Marcelo Immune checkpoint blockers improve the overall survival of a limitednumber of patients among different cancers. Identifying pathways thatinfluence the immunological and clinical response to treatment is criticalto improve the therapeutic efficacy and predict clinical responses. Recently,a key role has been assigned to innate immune mechanisms in checkpointblockade-driven anti-tumor responses. However, inflammatory pathwayscan both improve and impair anti-tumor immunity. In this review, wediscuss how different inflammatory pathways, particularly inflammasomeactivation, can influence the clinical outcome of immune checkpoint blockers.Inflammasome activation may reinforce anti-tumor immunity by boostingCD8+ T cell priming as well as by enhancing T helper type 17 (Th17)responses. In particular, we focus on the modulation of the cation channeltransmembrane protein 176B (TMEM176B) and the ectonucleotidase CD39as potential targets to unleash inflammasome activation leading to reinforcedanti-tumor immunity and improved efficacy of immune checkpointblockers. Future studies should be aimed at investigating the mechanismsand cell subsets involved in inflammasome-driven anti-tumor responses.

Dendritic Cells and Immunogenic Cancer Cell Death: A Combination for Improving Antitumor Immunity Lamberti, María Julia; Nigro, Annunziata; Mentucci, Fátima María; Rumie Vittar, Natalia Belen; Casolaro, Vincenzo; Dal Col, Jessica The safety and feasibility of dendritic cell (DC)-based immunotherapies in cancer management have been well documented after more than twenty-five years of experimentation, and, by now, undeniably accepted. On the other hand, it is equally evident that DC-based vaccination as monotherapy did not achieve the clinical benefits that were predicted in a number of promising preclinical studies. The current availability of several immune modulatory and targeting approaches opens the way to many potential therapeutic combinations. In particular, the evidence that the immune-related effects that are elicited by immunogenic cell death (ICD)-inducing therapies are strictly associated with DC engagement and activation strongly support the combination of ICD-inducing and DC-based immunotherapies. In this review, we examine the data in recent studies employing tumor cells, killed through ICD induction, in the formulation of anticancer DC-based vaccines. In addition, we discuss the opportunity to combine pharmacologic or physical therapeutic approaches that can promote ICD in vivo with in situ DC vaccination.

Fat tails and black swans: Exact results for multiplicative processes with resets Zanette, Damian Horacio; Manrubia, S. We consider a class of multiplicative processes which, added with stochastic reset events, give origin to stationary distributions with power-law tails?ubiquitous in the statistics of social, economic, and ecological systems. Our main goal is to provide a series of exact results on the dynamics and asymptotic behavior of increasingly complex versions of a basic multiplicative process with resets, including discrete and continuous-time variants and several degrees of randomness in the parameters that control the process. In particular, we show how the power-law distributions are built up as time elapses, how their moments behave with time, and how their stationary profiles become quantitatively determined by those parameters. Our discussion emphasizes the connection with financial systems, but these stochastic processes are also expected to be fruitful in modeling a wide variety of social and biological phenomena.

Large non-radial propagation of a coronal mass ejection on 2011 January 24 Cécere, Mariana Andrea; Sieyra, María Valeria; Cremades Fernandez, Maria Hebe; Mierla, M.; Sahade, Abril; Stenborg, G.; Costa, A.; West, M. J.; D'Huys, E. Understanding the deflection of coronal mass ejections (CMEs) is of great interest to the space weather community because of their implications for improving the prediction of CME. This paper aims to shed light into the effects of the coronal magnetic field environment on CME trajectories. We analyze the influence of the magnetic environment on the early development of a particular CME event. On 2011 January 24 an eruptive filament was ejected in association with a CME that suffered a large deflection from its source region and expected trajectory. We characterize the 3D evolution of the prominence material using the tie-pointing/triangulation reconstruction technique on EUV and white-light images. To estimate the coordinates in 3D space of the apex of the CME we use a forward-modeling technique that reproduces the large-scale structure of the flux rope-like CME, the Graduated Cylindrical Shell model. We found that the deflection amounts to 42° in latitude and 20° in longitude and that most of it occurs at altitudes below 4R⊙. Moreover, we found a non-negligible deflection at higher altitudes. Combining images of different wavelengths with the extrapolated magnetic field obtained from a potential field source surface model we confirm the presence of two magnetic structures near the erupting event. The magnetic field environment suggests that field lines from the southern coronal hole act as a magnetic wall that produces the large latitudinal deflection; while a nearby pseudostreamer and a northward extension of the southern coronal hole may be responsible for the eastward deflection of the CME.

Losartán y metformina previenen alteraciones en el tejido adiposo perivascular y en la liberación de prostanoides del lecho vascular mesentérico producidas por una dieta alta en grasa y sobrecarga de fructosa en ratas; Losartan and Metformin Prevent Abnormalities in Perivascular Adipose Tissue and in Mesenteric Vascular Bed Prostanoid Release Induced by High-fat High-fructose Diet in Rats Lee, Hyun Jin; Álvarez Primo, María; Allo, Miguel A.; Cantú, Silvana María; Donoso, Adriana Susana; Peredo, Horacio Angel; Choi, Marcelo Roberto; Puyó, Ana María Objetivo: El objetivo de este trabajo fue analizar los efectos del losartán (30 mg/kg/día) y de la metformina (500 mg/kg/día) sobre el índice de adiposidad y la liberación de prostanoides del lecho vascular mesentérico, así como su relación con la presión arterial sistólica en un modelo de síndrome metabólico inducido por una dieta alta en grasa y sobrecarga de fructosa en ratas Sprague-Dawley macho durante 9 semanas. Material y métodos: Los lechos vasculares mesentéricos extraídos se incubaron y los prostanoides liberados se midieron por cromatografía líquida de alta eficiencia. La presión arterial sistólica fue medida por método indirecto. Resultados: La dieta alta en grasa y la sobrecarga de fructosa produjo aumentos significativos en la presión arterial sistólica y del índice de adiposidad del lecho vascular mesentérico. Por su parte, la dieta alta en grasa y sobrecarga de fructosa incrementó la liberación de prostanoides vasoconstrictores tanto del tromboxano B2 como de la prostaglandina F2alfa; y del marcador de inflamación, la prostaglandina E2. La relación PGI2/TXA2 se redujo significativamente. La administración de losartán como de metformina previnieron todas estas alteraciones. Conclusión: Ambos fármacos ejercen efectos beneficiosos sobre el tejido adiposo perivascular del lecho mesentérico, lo que mejora la disfunción endotelial inducida por un desbalance de sustancias vasoactivas.; Objective: The aim of this study was to analyze the effects of losartan (30 mg/kg/day) and metformin (500 mg/kg/day) on the adiposity index and on mesenteric vascular bed prostanoid release, and their relationship with systolic blood pressure in a metabolic syndrome model induced by high-fat high fructose-diet in male Sprague-Dawley rats for 9 weeks. Methods: Mesenteric vascular beds were extracted and incubated and prostanoids were measured by high-performance liquid chromatography. Systolic blood pressure was measured by an indirect method. Results: High-fat high-fructose diet produced significant increase in systolic blood pressure and mesenteric vascular bed adiposity index and in the release of vasoconstricting prostanoids as thromboxane B2 and prostaglandin F2α and of prosta glandin E2, a marker of inflammation. The PGI2/TXA2 ratio was significantly reduced. The administration of losartan and metformin prevented all these changes. Conclusion: Both drugs have beneficial effects on mesenteric perivascular adipose tissue by improving endothelial dysfunction induced by an imbalance of vasoactive substances.

Plant Antifungal Lectins: Mechanism of Action and Targets on Human Pathogenic Fungi del Rio, Marianela Victoria; de la Canal, Laura; Regente, Mariana Clelia Lectins are proteins characterized by their ability to specifically bind different carbohydrate motifs. This feature is associated with their endogenous biological function as well as with multiple applications. Plants are important natural sources of these proteins; however, only a reduced group was shown to display antifungal activity. Although it is hypothesized that the target of lectins is the fungal cell wall, the mechanism through which they exert the antifungal action is poorly understood. This topic is relevant to improve treatment against pathogens of importance for human health. In this context, mechanisms pointing to essential attributes for virulence instead of the viability of the pathogen emerge as a promising approach. This review provides the current knowledge on the action mechanism of plant antifungal lectins and their putative use for the development of novel active principles against fungal infections.

Key to cranial and mandibular remains of non-flying small mammals from southern South America Udrizar Sauthier, Daniel Edgardo; Formoso, Anahí Elizabeth; Andrade, Analia; Podestá, Darío; Teta, Pablo Vicente Reliable identification of small mammal bone remains is crucial for several disciplines, including archaeology, biogeography, ecology, paleontology, taxonomy, and taphonomy. However, this issue is usually a challenging task, often complicated by the fragmentary nature of bone accumulations and/or by the taphonomic processes involved in the genesis of some assemblages. In this work, we provide dichotomous artificial keys for crania and mandibles of non-flying small mammal (<1000 g) genera of southern South America (i.e., southern Argentina and Chile). Keys are complemented with separate accounts for species identification, based on the cranial and dental features better preserved on fragmentary materials.

Plant oil-based waterborne polyurethanes: A brief review Mucci, Veronica Lujan; Hormaiztegui, M. E. Victoria; Aranguren, Mirta Ines The increasing pressure from consumers and policy makers to reduce the use of synthetic polymers, whose production contributes to the depletion of non-renewable resources and are usually non-biodegradable, has prompted the efforts to find suitable bio-based sources for the production of polymers. Vegetable oils have been a frequently spotted in this search because they are versatile, highly available and a low cost liquid biosource, which can be used in the synthesis of a wide plethora of different polymers and reactive monomers. Following the same idea of reducing the environmental stress, the traditional polyurethanes that are soluble in organic solvents have been targeted for replacement, particu-larly in applications such as adhesives and coatings, in which the solvent is released to the atmosphere increasing the air pollution. Instead, waterborne poly-urethanes (WBPU), which are polyurethane dispersions (PUD) prepared in aqueous media, release benign water to the atmosphere during use as supported or self-standing films for different applications. In this brief review, the contributions to the development of WBPUs based on vegetable oils are discussed, focusing mainly on the contributions of the last decade. The synthesis of ionic and non-ionic PUDs, their characterization and the properties of the resulting dried mate-rials, as well as derived composite materials are considered.

Temperature Stable Dielectric Properties in BaTiO3–Bi(Mg2/3Nb1/3)O3–NaNbO3 Solid Solution Raz, Muhammad; Ali, Asif; Camargo, Javier Eduardo; Castro, Miriam Susana 0.5BaTiO3–(0.5–x)Bi(Mg2/3Nb1/3)O3–xNaNbO3 (x=0.1, 0.2 and 0.3) samples were processed via solid-state sintering route. Phase identification of the samples showed the formation of a single-phase cubic perovskite-structure (space group Pm-3 m) which was further confirmed using Raman spectroscopy. Microstructural analysis of the samples revealed some voids in the samples while grain size was observed to decrease with increasing NaNbO3 concentration. The addition of NaNbO3 shifted Tm to below room temperature and the stability range of 0.5BaTiO3–0.5Bi(Mg2/3Nb1/3)O3 ceramics was enhanced. The sample with x=0.20 exhibited ϵr(mid) = 400 ±15% stable over a wide temperature range from −85 to 500 °C and most importantly a low dielectric loss of < 0.05 stable across a wide temperature range −100 to 426 °C was maintained. The thermally stable dielectric properties of sample x=0.2 suggests that it could be useful candidate material for capacitor applications in both low (X9R) as well as harsh environment applications.

Ureide permease 5 (AtUPS5) connects cell compartments involved in UREIDE metabolism Lescano López, Ignacio; Bogino, María Florencia; Martini, Carolina; Tessi, Tomás María; González, Claudio Alejandro; Schumacher, Karin; Desimone, Marcelo Allantoin is a purine oxidative product involved in long distance transport of organic nitrogen in nodulating legumes and was recently shown to play a role in stress tolerance in other plants. The subcellular localization of enzymes that catalyze allantoin synthesis and degradation indicates that allantoin is produced in peroxisomes and degraded in the endoplasmic reticulum (ER). Although it has been determined that allantoin is mostly synthesized in roots and transported to shoots either for organic nitrogen translocation in legumes or for plant protection during stress in Arabidopsis (Arabidopsis thaliana), the mechanism and molecular components of allantoin export from root cells are still unknown. AtUPS5 (Arabidopsis UREIDE PERMEASE 5) is a transmembrane protein that transports allantoin with high affinity when expressed in yeast. The subcellular fate of splicing variants AtUPS5L (long) and AtUPS5S (short) was studied by tagging them with fluorescent proteins in their cytosolic loops. The capability of these fusion proteins to complement the function of the native proteins was demonstrated by nutritional and salt stress experiments. Both variants localized to the ER, but the AtUPS5L variant was also detected in the trans-Golgi network/early endosome and at the plasma membrane. AtUPS5L and AtUPS5S localization indicates that they could have different roles in allantoin distribution between subcellular compartments. Our data suggest that under nonstress conditions UPS5L and UPS5S may function in allantoin degradation for nutrient recycling, whereas under stress, both genes may be involved in vesicular export allowing allantoin translocation from roots to shoots.

Checklist of the nematode parasites of wild birds of Argentina Drago, Fabiana Beatriz; Nuñez, Maria Veronica; Dueñas Díaz, Mariano A commented checklist of the nematodes parasites of Argentinean wild birds is presented. This is the first compilation of parasitological papers about nematodes of Argentinean birds published between 1873 and November 2019. This review includes information about 64 nematode nominal species and 13 taxa identified at generic level, belonging to five orders, 16 superfamilies, 20 families, and 44 genera. Five species were considered incertae sedis, because they were described based only on larval stages, and one species was maintained as species inquirenda. The highest number of taxa of nematodes was recorded in the family Acuariidae with 20 nominal species and two taxa identified at generic level, followed by Anisakidae with eight nominal species and one taxon identified at generic level, and Tetrarneridae with eight nominal species and two taxa identified at generic level. Of the 1042 species of birds reported in Argentina, only 65 (6.24%) were reported as hosts of adult nematodes. The families of birds with the highest number of reported taxa were Tinamidae (12 nematode taxa), Laridae (11), Anatidae (8) and Phalacrocoracidae (7). The present review provides data on hosts, geographical distribution, sites of infection, location of material deposited in Helminthologicaj Collections, references, and taxonomic comments. A host/parasite list is also provided.

El estatuto de lo valorativo en psicoanálisis: Aproximaciones entre el psicoanálisis argentino y el feminismo (1983-1995); The status of values in psychoanalysis: Approaches between argentine psychoanalysis and feminism (1983-1995) Gonzalez Oddera, Mariela En el presente artículo se reflexiona sobre el estatuto de la dimensión valorativa en psicoanálisis, desde los aportes de la historia de la psicología, en particular, de la historia crítica. Por un lado, se ubica brevemente la contribución de la epistemología feminista a la consideración de la relación entre valores y ciencia. Luego, se analiza el caso concreto de recepción de los Estudios de la Mujer en la psicología y el psicoanálisis argentino y su proyecto de reflexión crítica sobre los sesgos ideológicos presentes en la empresa freudiana. Al final, se plasma la interrogación por las potencialidades y límites de dicho proyecto.; This article reflects on the status of values in psychoanalysis, trough the contributions of the history of psychology, in particular, the critical history. The contribution of feminist epistemology to the evaluation of the relationship between values and science is briefly included. Then, it´s analized the reception of Women's Studies in the argentine psychology and psychoanalysis, and its project of critical reflection on the ideological biases present in the freudian work. Finally, the potential and limits of this project is boarded.

Evaluation of errors in the distribution system and control of drugs: The case of a private hospital Diaz, Lourdes; Maidana, Mabel; Marin, Lupe; Samaniego, Lourdes; Maciel, Olga; Vera, Zully; Lugo, Gladys; Marin, Gustavo Horacio Introduction: Medication errors may arise during the process of prescribing, transcribing, dispensing, preparation, and administration of any drug. The objective of this study was to quantify the detectable incidence of medication errors that occur in the distribution system and control of drugs administration. Methods: A descriptive non-experimental crosssectional investigation was performed. The data collection instrument consisted on a system of voluntary and anonymous reporting methods. Results: The particularity of the study was that of the total number of tickets under study, only 25 had errors (0.56%). The error incidence rate obtained in this institution result much lower than a previous study conducted by us, in the subsector of Social Security of Paraguay (6.3% vs. 0.56%). The most prevalent error was due to incorrect business name (64%), while the one with the lowest prevalence was referred to the wrong patient and medication unsolicited (4%). Most of the errors detected occurred during transcription (56%). 80% of the errors were detected by pharmacy technicians, 12% bynurses, and 8% by attendees. The particular organization of the hospital and the control carried out in different instances keep a relatively low level of medication errors. The consequences of the errors and the importance of the pharmacist’s role in the detection, prevention, and resolution of these problems were crucial factors in the case studied. Conclusion: Determining the incidence and type of medication error in the different parts of an interaction chain process, allows to analyze its causes, and to make changes where these errors are detected, in order to provide the users of the health system a better care service. Since the commitment of the different health actors involved is decisive to avoid medical errors, it is important to encourage them to support surveillance actions to strengthen good prescription practices.

Estimations of rooting depths and sources of plant-available water (PAW) in flatland petrocalcic soils under different land uses Mujica, Claudio Ramon; Bea, Sergio Andrés Plant-available water (PAW) is one of the most important issues in productive landscapes around the world. Besides climatic conditions, it depends on several factors, among them, land uses, the rooting and water table depths, and the presence of soil heterogeneities (e.g., petrocalcic horizons). In the present work, PAW evolution was assessed over 441 days in a vertical 1D domain of a monitored Pampean petrocalcic soil under two different land uses and contrasted water demand (i.e., natural and afforested grasslands). For this purpose, rooting depths were estimated using a process-based numerical model of the aquifer-soil-plant-atmosphere continuum constrained by both in situ measured atmospheric demand and water table fluctuations. This model was calibrated against soil water content measurements at different depths and finally, as validation, computed transpiration rates were compared with the sap flow measurements. Modeling results, and calibrated rooting depths, suggest that petrocalcic horizons induce a limited hydraulic connection between the shallow soil portions and the phreatic aquifer. Thus, water storage is enhanced above the petrocalcic horizon in the natural grassland plot particularly during the periods of low atmospheric demand, whereas it is immediately consumed by forest to soil wilting point below the afforested grassland (hydric stress). The numerical methodology followed here appears as an alternative to estimate the forest groundwater usage in afforested grasslands, a key issue in soil salinization research in great plain areas.

Análisis espacial de la seropositividad de leptospirosis humana en un espacio rururbano del partido de Tandil mediante Sistemas de Información Geográfica Silva, Julia Analia; Rivero, Mariana Alejandra; Scialfa, Exequiel Alejandro; Linares, Santiago La leptospirosis es la zoonosis de mayor distribución mundial, endémica en Argentina. Las herramientas de análisis espacial contenidas en los Sistemas de Información Geográfica permiten evaluar las correlaciones entre determinantes socioeconómicos y ambientales de la leptospirosis, conocer sus posibles causas y tomar decisiones aplicables en base a información precisa y confiable. En este trabajo se tomó como caso de estudio la localidad de María Ignacia Vela, en el partido de Tandil, la cual presenta una dinámica social y configuración territorial con estrecha vinculación rural y urbana. El trabajo persiguió dos objetivos, en primera instancia, detectar la existencia de patrones de distribución espacial de la seropositividad a leptospirosis y en segundo lugar, modelar un escenario predictivo de la probabilidad de infección por Leptospira spp. en el área de estudio. Para detectar positividad a Leptospira spp. se realizó el diagnóstico serológico a través de la técnica de microaglutinación (MAT). Con los resultados de laboratorio, la información obtenida a partir de encuestas y la georreferencia de los participantes se aplicaron técnicas de análisis estadísticos y espaciales aplicando los softwares EpiInfo versión 3.5.3, InfoStat versión 2018 y ArcGIS 10.6. Las relaciones espaciales halladas entre los determinantes estudiados y la seropositividad a Leptospira spp. facilitarán la definición de estrategias específicas que contribuyan a mejorar la toma de decisiones territoriales en cuestiones de salud en las áreas rururbanas.

Deficiency of CD73 activity promotes protective cardiac immunity against Trypanosoma cruzi infection but permissive environment in visceral adipose tissue Eberhardt, Natalia; Sanmarco, Liliana Maria; Bergero, Gastón; Theumer, Martín Gustavo; García, Mónica Cristina; Ponce, Nicolás Eric; Cano, Roxana Carolina; Aoki, Maria del Pilar Damaged cells release the pro-inflammatory signal ATP, which is degraded by the ectonucleotidases CD39 and CD73 to the anti-inflammatory mediator adenosine (ADO). The balance between ATP/ADO is known to determine the outcome of inflammation/infection. However, modulation of the local immune response in different tissues due to changes in the balance of purinergic metabolites has yet to be investigated. Here, we explored the contribution of CD73-derived ADO on the acute immune response against Trypanosoma cruzi parasite, which invades and proliferates within different target tissues. Deficiency of CD73 activity led to an enhanced cardiac microbicidal immune response with an augmented frequency of macrophages with inflammatory phenotype and increased CD8+ T cell effector functions. The increment of local inducible nitric oxide (NO) synthase (iNOS)+ macrophages and the consequent rise of myocardial NO production in association with reduced ADO levels induced protection against T. cruzi infection as observed by the diminished cardiac parasite burden compared to their wild-type (WT) counterpart. Unexpectedly, parasitemia was substantially raised in CD73KO mice in comparison with WT mice, suggesting the existence of tissue reservoir/s outside myocardium. Indeed, CD73KO liver and visceral adipose tissue (VAT) showed increased parasite burden associated with a reduced ATP/ADO ratio and the lack of substantial microbicidal immune response. These data reveal that the purinergic system has a tissue-dependent impact on the host immune response against T. cruzi infection.

Exploring the use of nuclear alterations, motility and ecological guilds in epipelic diatoms as biomonitoring tools for water quality improvement in urban impacted lowland streams Nicolosi Gelis, María Mercedes; Cochero, Joaquin; Donadelli, Jorge Luis; Gomez, Nora In this study we explored the use of less conventional diatom metrics (motility, nuclear abnormalities and ecological guilds) to measure changes in diatom assemblages related to the transfer of epipelic communities from urban impacted streams to less impacted sites. Three lowland streams in the Argentine Pampean plain were selected, and two sites were established per stream for a total of six sites. Three sites were referenced as low urban impact (LI), as they run through peri-urban areas, and three downstream sites were referenced as high impact sites (HI), since they run through a dense urban area. Six germination trays filled with stream sediment were placed at each HI site, and three at each LI site, and left to be colonized for 30 days before transferring three trays from the HI sites to their respective LI site upstream. Samples were collected at days 0, 15, 30 and 45 days from each tray, and diatom species were identified and classified into ecological guilds. Motility variables were measure per individual of the genera Nitzschia (path length, velocity and maximum velocity) through video recording. Also, the frequency of abnormal nuclear locations and nuclear membrane breakage were determined. Results showed that there were no significant differences in any motility metrics, while the nuclei variables exhibited higher proportion of abnormally positioned nuclei and nuclear membrane breakage at the HI sites. The proportion of nuclear membrane breakage decreased over time in the translocated assemblage, indicating that it could be a sensitive indicator of water quality improvement, while the ecological guilds showed significant differences on the proportion of high profile and motile diatoms. The improvement in water quality produced a significative increase in the proportion of the high profile guild in the translocated biofilm. Despite the motile forms being the dominant group, the water quality improvement allowed the high profile forms, to colonize the substrate. These results emphasize the possible use of the ecological guilds as a suitable indicator of water quality improvement in Pampean streams, especially in nutrient rich environment. These tools can provide a rapid assessment of diatom condition and could be considered supplementary to biomonitoring protocols in lowland streams.

Photo-double-ionization of water at 20 eV above threshold Randazzo, Juan Martin; Turri, G.; Bolognesi, P.; Mathis, J.; Ancarani, L. U.; Avaldi, L. The photodouble ionization of the water molecule is studied at 20 eV excess energy in a combined experimental and theoretical investigation. In the experiments, two photoelectrons of equal kinetic energy are detected in coincidence after energy and angular selection. On the theoretical side, a generalized Sturmian function approach is implemented to describe accurately the correlated two-electron continuum, while separable products of Moccia orbitals [J. Chem. Phys. 40, 2164 (1964)JCPSA60021-960610.1063/1.1725489] are used for the initial electronic state of the water molecule. The theoretical triple-differential cross sections (TDCSs) are averaged over all possible molecular orientations in order to be compared with the experiments. The measured TDCSs display rich angular distributions that are in large part well reproduced by the adopted first-order treatment of the interaction with a two-active-electron target.

Geo-climatic hazards in the eastern subtropical Andes: Distribution, Climate Drivers and Trends Vergara Dal Pont, Iván Pablo; Moreiras, Stella Maris; Araneo, Diego Christian; Garreaud, René Detecting and understanding historical changes in the frequency of geo-climatic hazards (G-CHs) is crucial for the quantification of current hazards and project them into the future. Here we focus in the eastern subtropical Andes (32-33° S), using meteorological data and a century-long inventory of 553 G-CHs triggered by rainfall or snowfall. We first analyse their spatio-temporal distributions and the role of climate variability on the year-to-year changes in the number of days per season with G-CHs. Precipitation is positively correlated with the number of G-CHs across the region and year-round; mean temperature is negatively correlated with snowfall-driven hazards in the western (higher) half of the study region during winter and with rainfall-driven hazards in the eastern zone during summer. The trends of the G-CHs frequency since the mid-20th century were calculated taking cautions for their non-systematic monitoring. The G-CHs series for the different triggers, zones and seasons were generally stationary. Nonetheless, there is a small positive trend in rainfall-driven G-CHs in the eastern zone during summer congruent with a rainfall increase there. We also found a decrease in snowfall-driven G-CHs in the western zone since the late 1990?s onwards, most likely due to a reduction in winter precipitation rather than to an increase in temperature.