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Background Modern biorefineries require enzymatic cocktails of improved efficiency to generate fermentable sugars from lignocellulosic biomass. Cellulolytic fungi, among other microorganisms, have demonstrated the highest potential in terms of enzymatic productivity, complexity and efficiency. On the other hand, under cellulolytic-inducing conditions, they often produce a considerable diversity of carbohydrate-active enzymes which allow them to adapt to changing environmental conditions. However, industrial conditions are fixed and adjusted to the optimum of the whole cocktail, resulting in underperformance of individual enzymes. Results One of these cellulolytic cocktails from Myceliophthora thermophila has been analyzed here by means of LC-MS/MS. Pure GH6 family members detected have been characterized, confirming previous studies, and added to whole cocktails to compare their contribution in the hydrolysis of industrial substrates. Finally, independent deletions of two GH6 family members, as an example of the enzymatic diversity management, led to the development of a strain producing a more efficient cellulolytic cocktail. Conclusions These data indicate that the deletion of noncontributive cellulases (here EG VI) can increase the cellulolytic efficiency of the cocktail, validating the management of cellulase diversity as a strategy to obtain improved fungal cellulolytic cocktails.

The liver’s regenerative ability depends on injury extent. Minor injuries are repaired by hepatocyte self-duplication, while severe damage triggers cholangiocyte involvement in hepatocyte recovery. This paradigm is well-documented for adult animals but is less explored during rapid growth. We design two partial liver injury models in zebrafish, which were investigated during growth spurts: 1) partial ablation, killing half the hepatocytes; and 2) partial hepatectomy, removing half a liver lobe. In both injuries, de novo hepatocytes emerged alongside existing ones. Single-cell transcriptomics and lineage tracing with Cre-driver lines generated by genome editing identified cholangiocytes as the source of de novo hepatocytes. We further identify active mTORC1 signalling in the uninjured liver of growing animal to be a regulator of the enhanced plasticity of cholangiocytes. Our study suggests cholangiocyte-to-hepatocyte transdifferentiation as the primary mechanism of liver regeneration during periods of rapid growth. During partial liver injury in growing zebrafish, cholangiocytes regenerate hepatocytes through transdifferentiation, revealing a stage-specific regeneration mechanism regulated by mTORC1 signaling.

This report describes two cases of late cartilage delamination in two young adults after two different autologous cell-based techniques for cartilage restoration: 1. Matrix-assisted autologous chondrocyte implantation (MACI) and 2. Hyaluronic acid-bone marrow aspirate concentrate (HA-BMAC). Both cases demonstrate that even in patients who do not present with any ongoing symptoms after primary surgery, a cellular-based graft’s subsequent delamination can occur later. It is possible that regardless of the technique used or the time passed since the surgery, a graft failure may occur at some level, causing delamination of a previously asymptomatic cartilage restoration graft and a traumatic event with long-term follow-up. Surgeons must be alert to this injury and describe histologic findings to determine where failure occurs.

En este artículo se analizan tres novelas latinoamericanas distópicas escritas en la primera década del siglo XXI —Ygdrasil (2005) y Synco (2008) del chileno Jorge Baradit e Iris (2014) del boliviano Edmundo Paz Soldán— para mostrar cómo ellas representan el capitalismo —según las formas bio o necropolíticas, gore o farmacopornográficas que este adquiere en el presente—, como un orden cerrado, sin que se vislumbren en los textos posibilidades de exterioridad respecto al sistema.

Resumen: Este estudio se abocó a analizar la organización de un equipo multidisciplinario a cargo de la gestión de la política de convivencia escolar, en un liceo municipal de emplazamiento urbano en la ciudad de Valdivia, Chile. Se pregunta por su historia de conformación, así como por las barreras observadas en el proceso de organización e implementación de la política de convivencia escolar. Para responder estas preguntas se realizó un estudio de caso cualitativo, cuyas principales herramientas fueron 3 encuentros de taller participativo con el equipo, 4 entrevistas individuales semiestructuradas a otros actores educativos y una entrevista grupal con 3 integrantes del centro de estudiantes. La información fue sometida a análisis de contenido. Los resultados muestran la necesidad de validación para la organización interna de un emergente equipo de convivencia, en medio de tensiones y contradicciones provenientes de los niveles macro, meso y microsistémico. Los conflictos inherentes a la vida de las escuelas se manifiestan en forma de tensiones entre el orden, funcionamiento y organización del quehacer educativo del centro y los fundamentos emergentes que el equipo intenta convenir para guiar la acción, todo ello en un marco de interacciones mediadas por el ejercicio de poder.

Background Parrots (Psittacidae Family) are one of the most colorful groups of birds in the world, their colors produced both structurally and via unusual pigments (psittacofulvins). Most species are considered to be monogamous, and many have been viewed historically as sexually monomorphic and monochromatic. However, studies using morphometric analysis and spectrophotometric techniques have revealed sexual size dimorphism and also sexual plumage color dimorphism among some species. The Monk Parakeet ( Myiopsitta monachus ), a native parrot of South America, is an interesting species for the study of plumage coloration and size since it is considered sexually monochromatic and monomorphic. Furthermore, recent studies show that the Monk Parakeet has extra-bond paternity behavior and even breeding trios, which suggests that sexual selection may play an important role in this species, and that it might have sexually dimorphic plumage (albeit imperceptible by humans) and be dimorphic in size. Methods For the determination of plumage color we used spectrophotometry in the range of avian vision (300‒700 nm) and performed a morphological analysis. Results Our spectrophotometric results indicate that the Monk Parakeet shows subtle sexual plumage color dimorphism in three (crown, nape and wing) out of twelve body regions. Similarly, our morphometric analysis showed that there are subtle sex differences in body size (bill and weight). Conclusions Although the Monk Parakeet shows extra-bond paternity and breeding trio behaviors which could increase sexual dimorphism, these behaviors occur among highly related individuals; perhaps the high rate of inbreeding is responsible for the attenuation of sexual plumage color dimorphism and sex differences in body size observed.

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Starvation causes the accumulation of lipid droplets in the liver, a somewhat counterintuitive phenomenon that is nevertheless conserved from flies to humans. Much like fatty liver resulting from overfeeding, hepatic lipid accumulation (steatosis) during undernourishment can lead to lipotoxicity and atrophy of the liver. Here, we found that although surface populations of Astyanax mexicanus undergo this evolutionarily conserved response to starvation, the starvation-resistant cavefish larvae of the same species do not display an accumulation of lipid droplets upon starvation. Moreover, cavefish are resistant to liver atrophy during starvation, providing a unique system to explore strategies for liver protection. Using comparative transcriptomics between zebrafish, surface fish, and cavefish, we identified the fatty acid transporter slc27a2a/fatp2 to be correlated with the development of fatty liver. Pharmacological inhibition of slc27a2a in zebrafish rescues steatosis and atrophy of the liver upon starvation. Furthermore, down-regulation of FATP2 in Drosophila larvae inhibits the development of starvation-induced steatosis, suggesting the evolutionarily conserved importance of the gene in regulating fatty liver upon nutrition deprivation. Overall, our study identifies a conserved, druggable target to protect the liver from atrophy during starvation.

This paper analyzes the important presence of the archive in four Latin American science fiction novels, by two Argentine and two Chilean authors respectively: Jorge Baradit's Ygdrasil (2005), Pola Oloixarac's Las constelaciones oscuras (2015), Sergio Missana's Entremuros (2019), and Martin Caparros's Sinfin (2020. In these narratives, the archive appears as a central technology, either in the plane of enunciation or in that of the enunciated. The archive is at the service of power: while it sometimes seems to enable a possibility of Utopia and memory, it eventually does not manage to influence the future dystopia. In this framework, neoliberalism appears as an omnipresent imaginary, in some cases corresponding to its current manifestations and, in others, stretching towards extreme versions, such as the enslavement and massacre of millions of human beings.

This study focused on analyzing the organization of a multidisciplinary team in charge of managing the school social climate policy, in a municipal high school located in an urban setting in Valdivia, Chile. The study addresses its conformation, as well as the barriers observed in the process of organizing and implementing the school social climate policy. To answer these questions a qualitative case study was carried out, which main tools were 3 participatory workshop meetings with the team, 4 semi-structured individual interviews with other educational actors and a group interview with 3 members of the student council. The information was subjected to content analysis. Results show the need for validation within the internal organization of an emerging school social climate team, in the midst of tensions and contradictions coming from the macro, meso, and microsystemic levels. The conflicts, inherent to the schools life, are manifested in the form of tensions between the order, functioning and organization of the school’s educational practice and the emerging fundamentals that the team tries to agree upon to guide the action, all this in a framework of interactions mediated by the exercise of power.