Exploring monsoon precipitation signal in the Peruvian tropical montane cloud forest: Andean Walnut wood anatomy plasticity Rodríguez Ramírez, Ernesto C.; Crispin DelaCruz, Doris B.; Morales, Mariano Santos; Ticse Otarola, Ginette Vilma Alicia; Ames Martínez, Fressia N.; Guerra, Anthony; Alves Ferreira, Cassiana; Requena Rojas, Edilson Jimmy Andean Walnut (Juglans neotropica Diels-Juglandaceae) is a long-lived, deciduous broadleaf Tropical Montane Cloud Forest (TMCF) tree species native to the Andes Cordillera; nevertheless, it has received limited attention for dendro-quantitative wood anatomical studies. Based on 70 increment cores from 50 Andean Walnut trees at two Peruvian TMCFs, two chronologies (from 1969 to 2020 and from 1964 to 2020) were developed. The xylem vessel parameters assessment allowed us to detect South American Monsoon System (SAMS) precipitation signals in the Andean Walnuts’ wood. Dendro-wood anatomical features can be assessed within an annual growth ring, which allows for assessing intra-annual past and present wood anatomy-function relationships and its climate vulnerability.

Archivos personales como fuente para la investigación científica. El Fondo Myriam Noemí Tarragó del Instituto de las Culturas; Personal archives as a source for scientific research. Myriam Noemí Tarragó Archive of the Instituto de las Culturas Olub, Julia; Gluzman, Geraldine Andrea En este trabajo presentamos el Fondo Documental Myriam Noemí Tarragó que se conserva en el Archivo de Investigadores del Instituto de las Culturas desde el año 2019. Myriam Tarragó es una destacada arqueóloga argentina con una prolífica carrera iniciada hacia finales de la década de 1950 y que cubrió principalmente el estudio del pasado en los Andes meridionales, fundamentalmente el noroeste argentino, norte de Chile, y también ha dejado su impronta en la arqueología ecuatoriana. Damos cuenta de algunos aspectos necesarios de abordar cuando tratamos con documentación de archivo y, en combinación con la reconstrucción de la biografía de la productora, brindamos una caracterización general del contenido del fondo. A su vez ofrecemos una serie de elementos a ser considerados a la hora de su consulta en orden de maximizar la información presente en el archivo, con el fin último de difundir y poner a disposición de investigadores y otros interesados este valioso y extenso archivo. Nos proponemos también discutir la relación entre las herramientas que ofrece la archivística y los usuarios que recurren a los Archivos como fuente para sus investigaciones, reflexionando sobre la necesidad de interdisciplinariedad para mejorar el acceso a los fondos documentales.; In this paper we present the Myriam Noemí Tarragó Archive that has been preserved in the Archivo de Investigadores of the Instituto de las Culturas since 2019. Myriam Tarragó is a prominent archaeologist from Argentina with a prolific career that began towards the end of the 1950s and covered mainly the study of the past in the southern Andes, fundamentally the Argentine Northwest, North of Chile and she has also left her mark on Ecuadorian archaeology. We point out some necessary aspects to address when dealing with archival documentation and, in combination with the reconstruction of the producer's biography, we provide a general description of the archive. In addition, we offer a series of elements to be considered at the time of consultation in order to maximize the available data in the archive, with the ultimate goal of disseminating and making this valuable and extensive archive available to researchers and other interested parties. We also intend to discuss the relationship between the instruments offered by archival science and the users who use Archives as a source for their research, reflecting on the need for interdisciplinarity to improve the access to the documents.

The temporal and spatial relationship between strike-slip and reverse faulting in subduction-related orogenic system: Insights from the Western slope of the Puna Plateau Jaldín Quiroz, Diego Michel Fabián; Giambiagi, Laura Beatriz; Martínez, Fernando; Benavente, Carlos; Espinoza, Daniela; Drymoni, Kyriaki; Luengo, Karina; González, Rodrigo; Rios Contesse, Juan The relationship between parallel and oblique to the orogen faults and the magmatic evolution is key to understanding the evolution of a hot orogen, such as the Central Andes. The Andean orogenesis along the southern Central Andes, during the Neogene is characterized by regional compression and magmatic processes associated with subduction. The outcome of this dynamic interaction between plate tectonics and magmatism has generated reverse, normal and strike-slip faults, both parallel and oblique to the trench. Despite the progress made on studying these fault systems, both their relationship with the stress field and their role in magma propagation into the shallow crust are still enigmatic. In this work, geomorphological observations are coupled with kinematic and dynamic analyses, as well as with kinematic forward modeling, to reconstruct the evolution of two main faults affecting the western slope of the Puna plateau, the Barrancas Blancas fault and the Tocomar fault, during the Neogene. The obtained data reveal that, between 17 and 10 Ma, the Barrancas Blancas fault had reverse activity, while the Tocomar fault had left-lateral strike-slip movement. At 10 Ma, the area was affected by the coeval reactivation of the Volcan de Punta Negra fault and the right-lateral activity of the Tocomar fault. During the last stage, strike-slip movement along the Tocomar fault favored the rise of magma, while the hydrothermal activity evolved along the Barrancas Blancas fault. The study results reveal that the oblique-to-the-orogen faults play a role in the segmentation of the reverse parallel-to-the-trench deformation and control the position of the volcanic centers, while the parallel-to-the-orogen faults control the relief development and the evolution of hydrothermal systems. The proposed model helps in understanding how magma rises to the surface associated with movement along reverse and strike-slip faults during the thickening of the crust.

Morphometric Variability in Lizards of the Genus Teius: A Comparative Study of Species with Different Reproductive Modes Espeche, Bárbara Andrea; Brigada, Ana Maria Leonilda; Rivera, Paula Cecilia The lizard genus Teius is widely distributed in lowland areas to the east of the Andes in southern South America and includes three species: Teius teyou, T. oculatus, and T. suquiensis. All three Teius species are broadly similar in morphological characters, the dorsal coloration pattern being the best feature to distinguish them. Furthermore, T. suquiensis are parthenogenetic, whereas the other two are bisexual. We applied 2D geometric morphometric methods on head morphology to measure and compare variability between these clonally and sexually reproductive lizards and to assess form variability among populations within the parthenogenetic species. We studied 181 adult females of the three species from across a wide range of their distributions. Geometric morphometrics successfully separated them in the morphospace. The three Teius presented similar head size; hence, the differences found are related to shape. Teius teyou has a shorter snout and a narrower posterior area of the head whereas T. oculatus has a longer snout and a wider posterior area of the head, and T. suquiensis shows an intermediate phenotype. Levels of morphological variability among the species were similar and independent of reproductive mode. Differences in head size and shape among populations were observed within T. suquiensis, despite its clonal inheritance. The observed variability might be explained by populations that are composed of different clonal lineages, populations that showed different responses to varying local environmental factors, or both. Additional morphological studies considering genetic diversity and habitat characteristics may clarify the factors that promote morphological variability in the genus, especially in the parthenogenetic species.

Tiempos de retención de la semilla y efectos en la germinación de tres dispersores de la palmera Syagrus romanzoffiana Datos de tiempos de retención de semillas de la palmera Syagrus romanzoffiana en el tracto digestivo de tres dispersores (zorro de monte Cerdocyon thous, mono aullador Alouatta caraya y tapir Tapirus terrestris) y del efecto del pasaje por su tracto digestivo en la germinación de las semillas. Como controles para evaluar los efectos en la germinación, se ensayaron, además, frutos intactos que retenían la pulpa y frutos despulpados artificialmente. Los ensayos experimentales fueron realizados con ejemplares en cautiverio albergados en el Centro de Investigación de Animales Silvestres, ITAIPU BINACIONAL.

Phenotypic plasticity in leaf traits in response to experimental precipitation increase: Wettability, foliar water uptake and gas exchange Cavallaro, Agustin; Carbonell Silletta, Luisina Marta; Askenazi Vera, Javier Oscar; Goldstein, Guillermo Hernan; Bucci, Sandra Janet; Scholz, Fabian Gustavo Water availability is one of the factors affecting plant growth and development, especially in arid and semiarid environments. Changes in precipitation due climate change alter water availability to plants impacting on plant physiology. Numerous studies have focused on plant response to reduced precipitation and less on the effects of increased precipitation. The main objective of this study was to evaluate biophysical and physiological leaf traits in response to experimental water addition in four dominant shrubs and one grass species in a Patagonian steppe, during the dry season. The experiment consisted of two treatments: control and water addition, increasing the average annual rainfall by 25% during 6 years. We measured leaf wettability, water status, transpiration, photosynthesis, stomatal conductance, water use efficiency and foliar water uptake (FWU). In addition, we determined the phenotypic plasticity index of these evaluated traits. We expected lower FWU and higher transpiration and photosynthesis rates due changes in leaf surface properties under water addition treatment. All study species responded significantly to treatment with higher loss of water per transpiration and lower FWU. Also, all species increased photosynthesis rate and water use efficiency (WUE). However, water potential and leaf wettability did not change with higher precipitation. Thus, higher phenotypic plasticity was observed in functional than in morphological traits. Since functional traits were more sensitive than leaf surface traits, plants may quickly take advantage when environmental conditions tend to be more favourable to growth. Our findings suggest that plants of Patagonian steppe have adaptive ability to respond to environmental changes through plastic responses.

QSAR Study of Biologically Active Essential Oils against Beetles infesting the Walnut in Catamarca, Argentine Repellent and contact toxicity activity of the essential oils of Laurus nobilis (Lauraceae), Lippia integrifolia (Verbenaceae), Aloysia polystachya (Verbenaceae), Tagetes minuta (Asteraceae), Pimpinella anisum (Apiaceae) and Cuminum cyminum (Apiaceae) growing in Catamarca, Argentina against weevils of the genus Carpophilus and Oryzaephilus that infesting the production of walnuts were evaluated. Yields of essential oils obtained by hydrodistillation range from 1.0 to 4 % (v/w). Analysis by gas chromatography-mass spectrometry of the EOs led the identification of their major constituents and their relative proportions. Repellence/toxicity test assayed by impregnation on filter paper discs were performed using different doses. Experimental data were analysed using Generalized Estimating Equations (GEE; IBM SPSS Statistics 23.0) with normal distribution and the identity link function. The dependent variables were the mean repellency values of 5 repetitions. Predictors entered into the model were oil treatment, employed doses, the time points and all 2-way interactions between them. The working correlation matrix was assumed to be unstructured. From the tested essential oils spectral information, we work their molecular modeling as mixtures from the development of one descriptor combining the molecular descriptors of each component in the mixture and its molar fraction , i.e. . The application of chemoinformatic approaches determined that a combination of mixture descriptors related with molecular size, branchedness, charge distribution and electronegativity is useful to explain the repellent activity profile against Carpophilus spp and Orizaephilus spp. According PCA calculations, while repellency against Carpophilus spp increase with EOs containing molecules composed of flexible substructures formed by saturate aliphatic carbon chains and a number reduced of non-hydrogen substituents, the activity profile against Orizaephilus spp appears to be favored by aliphatic hydrophobic functions linked to one hydrogen bond acceptor function. These models were validated with 9 and 4 EOs (test sets) reported with repellent activity against weevils of the Nitidulidae and Silvanidae family. Each PCA model confirm to each EOs as repellent with a comparable performance to the experimental reports.

Global environmental implications of atmospheric methane removal through chlorine-mediated chemistry-climate interactions Li, Qinyi; Meidan, Daphne; Hess, Peter Otto; Añel, Juan A.; Cuevas, Carlos Alberto; Doney, Scott; Fernandez, Rafael Pedro; van Herpen, Maarten; Höglund Isaksson, Lena; Johnson, Matthew S.; Kinnison, Douglas E.; Lamarque, Jean Francoise; Röckmann, Thomas; Mahowald, Natalie M.; Saiz López, Alfonso Atmospheric methane is both a potent greenhouse gas and photochemically active, with approximately equal anthropogenic and natural sources. The addition of chlorine to the atmosphere has been proposed to mitigate global warming through methane reduction by increasing its chemical loss. However, the potential environmental impacts of such climate mitigation remainunexplored. Here, sensitivity studies are conducted to evaluate the possible effects of increasing reactive chlorine emissions on the methane budget, atmospheric composition and radiative forcing. Because of non-linear chemistry, in order to achieve a reduction in methane burden (instead of anincrease), the chlorine atom burden needs to be a minimum of three times the estimated present-day burden. If the methane removal target is set to 20%, 45%, or 70% less global methane by 2050 compared to the levels in the Representative Concentration Pathway 8.5 scenario (RCP8.5), our modeling results suggest that additional chlorine fluxes of 630, 1250, and 1880 Tg Cl/year, respectively, are needed. The results show that increasing chlorine emissions also induces significant changes in other important climate forcers. Remarkably, the tropospheric ozone decrease is large enough that the magnitude of radiative forcing decrease is similar to that of methane. Adding 630, 1250, and 1880 Tg Cl/year to the RCP8.5 scenario, chosen to have the mostconsistent current-day trends of methane, will decrease the surface temperature by 0.2, 0.4, and 0.6 °C by 2050, respectively. The quantity and method in which the chlorine is added, its interactions with climate pathways, and the potential environmental impacts on air quality and ocean acidity, must be carefully considered before any action is taken.

Base de datos de ocurrencia de Leptochloa crinita y L. pluriflora en Argentina Base de datos de ocurrencia de las especies nativas de argentina de interés forrajero, Leptochloa crinita y L. pluriflora. La presente base de datos fue creada para el artículo Marinoni et al. (2015) y actualizada para Marinoni et al. (2021).

Ensayos en cámara de crecimiento en condiciones controladas, ensayos a campo y datos del clima en la región Estudios de la adición de prolina (Pro) al medio de cultivo de inoculantes de maní, para evaluar si la aplicación de Pro a inoculantes para semillas de maní optimiza el desarrollo de la leguminosa expuesta a estrés hídrico (EH), contribuyendo a mejorar el rendimiento de los cultivos. Para ello, se estudió el efecto de la aplicación de Pro en inoculantes para semillas de maní sobre el crecimiento de plantas en interacción con Bradyrhizobium sp. en condiciones controladas de EH; y se evaluó el rendimiento de cultivos de maní provenientes de semillas tratadas con inoculantes suplementados con Pro en ensayos a campo.

Mapa de restricciones ambientales al cambio de uso del suelo El presente trabajo tiene la finalidad de aportar bases conceptuales y una metodología estandarizada para el ordenamiento ambiental y territorial de los departamentos de Pocho, San Alberto y San Javier. El Ordenamiento Ambiental se basó en los criterios de sustentabilidad ambiental (CSA) establecidos en la Ley Nacional Nº 26.331. Específicamente, para realizar el Ordenamiento Ambiental de Traslasierra se priorizaron y adaptaron 7 CSA. Los CSA fueron adaptados para categorizar no sólo los bosques, sino que, también, toda la superficie correspondiente al área de estudio, que incluye otros ecosistemas naturales, agro-ecosistemas y/o áreas bajo otro tipo de uso. Estos 7 criterios se asocian con la capacidad de los ecosistemas de proveer servicios ecosistémicos clave de soporte, regulación y provisión. Los criterios de superficie de bosque y de estado de conservación se relacionan principalmente con servicios de soporte (ej. capacidad de brindar hábitat para las especies y de stock de carbono) y de regulación (ej. a mayor tamaño del parche de bosque, y mejor estado de conservación, mayor capacidad de fijar carbono, de regulación eco-hidrológica y micro-climática). Además, los bosques proveen bienes madereros (leña y madera) y no madereros (ej. miel, frutos del monte y especies aromáticas). En el caso de ‘sitios ecológicos’ de pastizales naturales, estos proveen forraje para la producción ganadera. Los criterios de vinculación de comunidades y ecorregiones se asocian directamente con el servicio de soporte de hábitat para la biodiversidad, pero también con el de regulación ya que promueven el flujo génico entre ecosistemas, dado que se relaciona con la conectividad y regulación de meta-poblaciones. El criterio de valores sobresalientes se asocia específicamente con la provisión de hábitat para la biodiversidad (ej. especies clave y/o endémicas). Por su parte el criterio de potencial de conservación de cuencas se asocia esencialmente con la capacidad de regulación eco-hidrológica de los ecosistemas (ej. regulación de sequías e inundaciones, purificación de agua, control de erosión), pero también con la capacidad de brindar servicios de agua dulce para tanto consumo humano como para la producción agropecuaria (ej. para ganado y riego). La aplicación de estos 7 criterios nos permitió zonificar la región en base a las restricciones que impone el ambiente frente a la intensificación agropecuaria y/o al cambio de uso del suelo, en base a su fragilidad (o susceptibilidad a ser degradados) y capacidad de proveer servicios ecosistémicos. Finalmente, se generó un Sistema de Información Geográfica (SIG) que incluye un mapa ‘indicador’ para cada criterio (i.e., 7 mapas indicadores de CSA). Cada mapa indicador se generó como resultado de la integración de información proveniente de distintas fuentes.

Abstract Extraction and purification of enzymes from the Southern eagle ray (Myliobatis goodei) by-products and their compatibility with detergents: A practical approach towards circular economy; Extraction and purification of enzymes from the Southern eagle ray (Myliobatis goodei) by-products and their compatibility with detergents: A practical approach towards circular economy Lamas, Daniela Lorena; Massa, Agueda Elena Nowadays, the need to simultaneously achieve the valorization and recovery of fishing waste is critical for addressing environmental challenges and promoting resource sustainability. Fishing waste hosts enzymes that hold the potential for extraction and utilization in various industries. In this sense, the aim of this work was to extract and purify enzymes from the gastrointestinal tract of Myliobatis goodei using low-cost processes. The proteolytic and lipolytic activities of the extracted enzymes were also investigated. In addition, the detergent compatibility of the purified enzyme extract was evaluated to determine its potential application as an additive in laundry soaps. The crude extract was obtained by homogenization of 100g gastrointestinal tract in buffer Tris-HCl(pH=8.0). Then, it was precipitated with ammonium sulfate and purified by filtration Finally, it was subjected to centrifugation at 10,000 ×g for 30 min at 4°C in an ultrafilters membrane with a 100 kDa cut-off. This purification protocol showed good performance for proteases and lipases as their activity was recovered at each step. The proteolytic activity was assayed using azocasein as substrate at pH 8.0 and 40°C, while trypsin activity was analyzed against the specific substrate benzoyl-arginine-p-nitroanilide. The lipolytic activity was carried out by p-nitrophenol production through the reaction of pnitrophenylacetate dissolved in 2-propanol at pH 7.0 and 37°C. The compatibility of the enzyme activity with some commercial detergents was evaluated. Additionally, proteolytic and lipolytic activities were tested on spiruline and soybean oil stains andshowed a strong ability to remove them from cotton fabrics. Due to its promising properties, the purified enzymes isolated from the gastrointestinal tract of M. goodei may be considered as a potential effective active ingredient for its use in the detergents industry.

A unique maternal and placental galectin signature upon SARS-CoV-2 infection suggests galectin-1 as a key alarmin at the maternal–fetal interface Zhao, Fangqi; Tallarek, Ann Christin; Wang, Yiru; Xie, Yiran; Diemert, Anke; Lu Culligan, Alice; Vijayakumar, Pavithra; Kittmann, Enrico; Urbschat, Christopher; Bayo Fina, Juan Miguel; Arck, Petra Clara; Farhadian, Shelli F.; Dveksler, Gabriela S.; Garcia, Mariana; Blois, Sandra M. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic imposed a risk of infection and disease in pregnant women and neonates. Successful pregnancy requires a fine-tuned regulation of the maternal immune system to accommodate the growing fetus and to protect the mother from infection. Galectins, a family of β-galactoside–binding proteins, modulate immune and inflammatory processes and have been recognized as critical factors in reproductive orchestration, including maternal immune adaptation in pregnancy. Pregnancy-specific glycoprotein 1 (PSG1) is a recently identified gal-1 ligand at the maternal–fetal interface, which may facilitate a successful pregnancy. Several studies suggest that galectins are involved in the immune response in SARS-CoV-2–infected patients. However, the galectins and PSG1 signature upon SARS-CoV-2 infection and vaccination during pregnancy remain unclear. In the present study, we examined the maternal circulating levels of galectins (gal-1, gal-3, gal-7, and gal-9) and PSG1 in pregnant women infected with SARS-CoV-2 before vaccination or uninfected women who were vaccinated against SARS-CoV-2 and correlated their expression with different pregnancy parameters. SARS-CoV-2 infection or vaccination during pregnancy provoked an increase in maternal gal-1 circulating levels. On the other hand, levels of PSG1 were only augmented upon SARS-CoV-2 infection. A healthy pregnancy is associated with a positive correlation between gal-1 concentrations and gal-3 or gal-9; however, no correlation was observed between these lectins during SARS-CoV-2 infection. Transcriptome analysis of the placenta showed that gal-1, gal-3, and several PSG and glycoenzymes responsible for the synthesis of gal-1-binding glycotopes (such as linkage-specific N-acetyl-glucosaminyltransferases (MGATs)) are upregulated in pregnant women infected with SARS-CoV-2. Collectively, our findings identify a dynamically regulated “galectin-specific signature” that accompanies the SARS-CoV-2 infection and vaccination in pregnancy, and they highlight a potentially significant role for gal-1 as a key pregnancy protective alarmin during virus infection.

Photo-induced protein modifications: a range of biological consequences and applications Vera, Claudia Cecilia; Borsarelli, Claudio Darío Proteins are the most abundant biomolecules in living organisms and tissues and are also present in many natural and processed foods and beverages, as well as in pharmaceuticals and therapeutics. When exposed to UV?visible light, proteins containing endogenous or exogenous chromophores can undergo direct and indirect photochemical processes, resulting in protein modifications including oxidation of residues, cross-linking, proteolysis, covalent binding to molecules and interfaces, and conformational changes. When these modifications occur in an uncontrolled manner in a physiological context, they can lead to biological dysfunctions that ultimately result in cell death. However, rational design strategies involving light-activated protein modification have proven to be a valuable tool for the modulation of protein function or even for the construction of new biomaterials. This mini-review describes the fundamentals of photochemical processes in proteins and explores some of their emerging biomedical and nanobiotechnological applications, such as photodynamic therapy (PDT), photobonding for wound healing, photobioprinting, photoimmobilization of biosensors and enzymes for sensing, and biocatalysis, among others.

Information transfer during mobbing: call rate is more important than the number of callers in a southern temperate passerine Fernandez, Gustavo Javier; Dutour, Mylène; Carro, Mariana Emilia Many bird species vary their alarm calls according to the level of risk they face and this information can be used by receivers to respond to the mobbing event. Recent studies have also found that the number of callers can play an important role in the decision of subsequent individuals to join a mobbing event. We conducted a playback experiment to assess if differences in calling rate and number of callers elicit different behavioural responses in the house wren (Troglodytes aedon chilensis). We broadcast the alarm call of either one or two individuals, at different calling rates along the breeding season. We found that house wrens responded more frequently during playback of alarm calls at higher rates than during playback of calls at lower rates. However, focal individuals moved closer to the speaker when calls were played back at lower rates. There were no differences in the response of house wrens when we broadcast the calls of one or two individuals. These results suggest that call rates are an important element in the communication of danger in the house wren, rather than caller number. Significance statement: Mobbing is an anti-predator strategy observed in many species, and often involves the use of calls that can communicate to conspecifics and heterospecifics about the threat of the predator. Understanding the factors and cues that receivers use to respond is an important element in understanding communication between individuals. We studied the role of call rate and number of callers in the behavioural response to mobbing calls of individuals in the house wren during the breeding season. Using a playback experiment, we show that individuals respond more often to calls played at a high rate, regardless of the number of callers. House wrens´ call rates vary according to the level of perceived risk, so our results show that receivers use this information to respond to mobbing calls.

Juventudes, cooperativismo y plataformas digitales: Una experiencia argentina en construcción; Youth, cooperativism and digital platforms: An argentine experience in construction Otero, Analia Los desafíos sociales y económicos en la postpandemia serán múltiples, en el caso argentino, el impacto del Covid-19 en las juventudes tendrá consecuencias severas de cara al mundo del trabajo, sobre todo con relación a la agudización de la precarización, el deterioro de la condición laboral, la expansión del precariado digital, etc. Este trabajo desde una perspectiva cualitativa indaga sobre un proyecto de cooperativismo de plataforma, impulsado desde una cooperativa de base tecnológica en argentina. En el texto se debate sobre las intersecciones complejas entre cooperativismo y plataformasdigitales; se exponen relatos de la experiencia, dando cuenta de sus raíces, causas y gestación, al tiempo que se plantea la singularidad de esta construcción colectiva innovadora como fuente de futuras indagaciones.; The social and economic challenges in the post-pandemic will be multiple. In the Argentine case, the impact of Covid-19 on youth will have severe consequences for the world of work, especially in relation to the worsening of precariousness; the deterioration of the labor condition; the expansion of the digital precariat. etc. This work from a qualitative perspective investigates a platform cooperative project, promoted from a technology-based cooperative in Argentina. The text discusses the complex intersections between cooperatives and digital platforms; Stories of the experience are exposed, giving an account of its roots, causes and gestation, at the same time that the uniqueness of this innovative collective construction is raised as a source of future investigations.

Cambios en el agua disponible de Patagonia Norte: Transición climática hacia condiciones más cálidas y secas Adduca, Santino; Hurtado, Santiago Ignacio; Calianno, Martin Helene J; Easdale, Marcos Horacio El clima y el agua en la producción agrícola y ganadera cumplen un rolfundamental. Por este motivo,en este artículo describimos la disminuciónobservada del agua disponible en Patagonia Norte,asociada a una transición climática hacia condiciones más cálidas y secas. Las consecuencias de estos cambios agravan la problemática del acceso al agua en una región árida como la Patagonia.

Evaluación del potencial de ventilación natural de distintas localidades de la Argentina; Evaluation of the potential of natural ventilation of several Argentinean locations González, Silvina Mariana; Valdez, Marcelo Federico; Flores Larsen, Silvana Elinor La ventilación natural en edificios residenciales es una estrategia bioclimática fundamental para reducir los consumos de energía eléctrica destinados a la climatización para garantizar el confort térmico de los habitantes de una vivienda. Además del diseño y orientación adecuados de las aberturas (puertas y ventanas) de una vivienda o edificio, la efectividad de la ventilación natural como estrategia de climatización pasiva depende de las condiciones ambientales del lugar. En este trabajo se analizan las condiciones meteorológicas típicas y se determina el potencial de ventilación natural de ochenta y siete (87) ubicaciones a lo largo del territorio argentino, distribuidas en todas las provincias y en prácticamente todas las regiones climáticas del país. En base al año meteorológico típico de cada ubicación se computa una hora de ventilación natural cada vez que la temperatura del aire exterior, la temperatura de punto de rocío y la velocidad del viento se encuentran entre los valores establecidos por las condiciones de confort de los habitantes. Los resultados indican que el territorio argentino posee un excelente potencial (por encima de las 2190 h o del 25% de las horas anuales) para aprovechar la ventilación natural como estrategia pasiva de climatización durante prácticamente todo el año. De acuerdo a los resultados obtenidos, las regiones con climas templado pampeano, templado serrano, árido de sierras y campos, y árido de la estepa patagónica son las más favorables para el aprovechamiento de las estrategias de ventilación natural.; Natural ventilation in residential buildings is a key bioclimatic strategy to help reduce the electrical energy consumption associated with air conditioning to ensure the thermal comfort of the occupants of a building. Apart from an adequate design and orientation of the openings (doors and windows), the effectiveness of natural ventilation as a passive cooling strategy depends on the environmental conditions of the area. In this effort, the typical meteorological conditions are analyzed and the natural ventilation potentials are determined for eighty-seven (87) locations throughout the Argentinean territory. These sites are located in each of the provinces of the country and are inserted in practically all the climatic regions. Using the typical meteorological year of each location, the natural ventilation potential is computed by adding up all the hours of the year in which the dry bulb temperature, the dew point and the wind speed are within the values required for the thermal comfort of the occupants. The results show that the Argentinean territory has excellent potential (above 2190h during the year, or 25%) to exploit natural ventilation as a passive cooling strategy throughout most of the year. The tempered (templado pampeano and templado serrano), and arid (de sierras y campos y de la estepa patagónica) climates where found to be the most proper to leverage natural ventilation strategies.

The Carnegie Supernova Project I Holmbo, S.; Stritzinger, Maximilian; Karamehmetoglu, E.; Burns, Christopher R.; Morrell, Nidia Irene; Ashall, Chris; Hsiao, Eric; Galbany, Lluís; Folatelli, Gaston; Phillips, M. M.; Baron, E.; Gutiérrez, C. P.; Leloudas, G.; Müller Bravo, T. E.; Hoeflich, Peter; Taddia, F.; Suntzeff, Nicholas B. An analysis leveraging 170 optical spectra of 35 stripped-envelope (SE) core-collapse supernovae (SNe) observed by the Carnegie Supernova Project I and published in a companion paper is presented. Mean template spectra were constructed for the SNe IIb, Ib, and Ic subtypes, and parent ions associated with designated spectral features are identified with the aid of the spectral synthesis code SYNAPPS. Our modeled mean spectra suggest the ∼6150 Å feature in SNe IIb may have an underlying contribution due to silicon, while the same feature in some SNe Ib may have an underlying contribution due to hydrogen. Standard spectral line diagnostics consisting of pseudo-equivalent widths (pEWs) and blue-shifted Doppler velocity were measured for each of the spectral features. Correlation matrices and rolling mean values of both spectral diagnostics were constructed. A principle component analysis (PCA) was applied to various wavelength ranges of the entire dataset and suggests clear separation among the different SE SN subtypes, which follows from trends previously identified in the literature. In addition, our findings reveal the presence of two SNe IIb subtypes, a select number of SNe Ib displaying signatures of weak, high-velocity hydrogen, and a single SN Ic with evidence of weak helium features. Our PCA results can be leveraged to obtain robust subtyping of SE SNe based on a single spectrum taken during the so-called photospheric phase, separating SNe IIb from SNe Ib with ∼80% completion.

Ultra-peripheral collisions of charged hadrons in extensive air showers Masip, Manuel; Rosario, Ivan; Sciutto, Sergio Juan We discuss the electromagnetic collisions of high energy protons, pions and kaons with atmospheric nuclei. In particular, we use the equivalent photon approximation to estimate (i) the diffractive collisions where the projectile scatters inelastically off a nucleus, and (ii) the usual radiative processes (bremsstrahlung, pair production and photonuclear interactions) of these charged hadrons in the air. We then include the processes in the simulator AIRES and study how they affect the longitudinal development of extensive air showers. For 109-11 GeV proton primaries we find that they introduce a very small reduction (below 1%) in the average value of both X max and ΔX max. At a given shower age (relative slant depth from X max), these electromagnetic processes slightly increase the number of charged particles at the shower maximum and reduce the number of muons when it is old, decreasing by 1% the muon-to-(γ + e) near the ground level.