Requirement of a Plasmid-Encoded Catalase for Survival of \u3cem\u3eRhizobium etli\u3c/em\u3e CFN42 in a Polyphenol-Rich Environment

Nitrogen-fixing bacteria collectively called rhizobia are adapted to live in polyphenol-rich environments. The mechanisms that allow these bacteria to overcome toxic concentrations of plant polyphenols have not been clearly elucidated. We used a crude extract of polyphenols released from the seed coat of the black bean to simulate a polyphenol-rich environment and analyze the response of the bean-nodulating strain Rhizobium etli CFN42. Our results showed that the viability of the wild type as well as that of derivative strains cured of plasmids p42a, p42b, p42c, and p42d or lacking 200 kb of plasmid p42e was not affected in this environment. In contrast, survival of the mutant lacking plasmid p42f was severely diminished. Complementation analysis revealed that the katG gene located on this plasmid, encoding the only catalase present in this bacterium, restored full resistance to testa polyphenols. Our results indicate that oxidation of polyphenols due to interaction with bacterial cells results in the production of a high quantity of H2O2, whose removal by the katG-encoded catalase plays a key role for cell survival in a polyphenol-rich environment

Imaging properties of the light sword optical element used as a contact lens in a presbyopic eye model

The paper analyzes the imaging properties of the light sword optical element (LSOE) applied as a contact lens to the presbyopic human eye. We performed our studies with a human eye model based on the Gullstrand parameterization. In order to quantify the discussion concerning imaging with extended depth of focus, we introduced quantitative parameters characterizing output images of optotypes obtained in numerical simulations. The quality of the images formed by the LSOE were compared with those created by a presbyopic human eye, reading glasses and a quartic inverse axicon. Then we complemented the numerical results by an experiment where a 3D scene was imaged by means of the refractive LSOE correcting an artificial eye based on the Gullstrand model. According to performed simulations and experiments the LSOE exhibits abilities for presbyopia correction in a wide range of functional vision distances.This work was supported by the Polish Ministry of Science and Higher Education under grant N N 514 149038 and by the Spanish Ministerio de Ciencia e Innovación (MICINN), grant FIS2008-03884 with complementary support from the European Social Fund implemented under the Human Capital Programme (POKL), project, “Preparation and Realization of Medical Physics Specialty.”S

Fiber Laser Microcutting of AISI 316L Stainless Steel Tubes- influence of Pulse Energy and Spot Overlap on Back Wall Dross

AbstractThe design of coronary stents imposes high demands in terms of dimensional tolerance and surface finish. These devices are manufactured by laser microcutting of miniature tubes in materials such as stainless steel, cobalt chromium alloys and Nitinol. The work presented here is focused on fiber laser microcutting for coronary struts in AISI 316L stainless steel. This work studies the influence of gases such compressed air and argon passing through the tube in order to drag molten material while laser microcutting is performed. The experimental work studies the influence of beam spot overlap and pulse energy on back wall dross and average surface roughness, using response surface methodology. The results indicate that the introduction of compressed air or argon gas is a relevant method to reduce the amount of dross adhered in the back wall of the miniature tube

Cambios en la actividad enzimática en duodeno y yeyuno de cerdos durante varios periodos posdestete

Objetivos: evaluar los cambios en la actividad enzimática intestinal de algunos cerdos durante varios periodos posdestete. Materiales y métodos: el trabajo de campo se realizó en el Centro San Pablo, perteneciente a la Universidad Nacional de Colombia, sede Medellín. El estudio se realizó con 16 cerdos destetados a los 21 días de edad. Los animales experimentales fueron alimentados durante 10 días con una dieta basal (DB) que tuvo como componentes leche y algunos de sus derivados y que además cumplía con los requerimientos nutricionales. Luego, los cerdos fueron sacrificados escalonadamente los días uno, cinco, siete y diez posdestete, y se realizó extracción completa del intestino delgado, el cual fue dividido en dos secciones (duodeno y yeyuno) de igual tamaño. El análisis de la actividad enzimática (APN, DPP-IV, LPH, MGA y SI) se realizó mediante el método de velocidades iniciales y el diseño estadístico que se empleó fue completamente al azar, no obstante, los datos se analizaron mediante la aplicación de los modelos lineales generales (GLM) y de la prueba de duncan. Resultados: se evidencia que las enzimas presentaron diferencias (P and lt; 0,01) durante los periodos posdestete. En el día cinco se observaron cambios negativos en todas las enzimas en comparación con su estado durante el primer día posdestete; sin embargo, entre el día uno y diez posdestete se presentaron diferencias entre APN, DPP-IV y LPH (P and lt; 0,01). Además, se encontró que la sección proximal (duodeno) presentó las mayores actividades enzimáticas (P and lt; 0,01). Conclusiones: el destete temprano disminuye la actividad enzimática a nivel intestinal, provocando la subutilización de los nutrientes de la dieta y, por ende, alta incidencia de diarreas durante esta etapa

Contrast transfer characteristics of the light sword optical element designed for presbyopia compensation

The paper discusses the abilities of the light sword optical element (LSOE) for presbyopia compensation. The imaging properties are analyzed by means of the modulation transfer functions and output images of the star resolution test. All numerical calculations are performed assuming an optical set-up simulating the presbyopic human eye and based on the Gullstrand model. In order to have a meaningful comparison we expand our study and present adequate analysis for other elements potentially useful in ophthalmology as reading glasses, bifocal lenses and axicons. According to the obtained results the LSOE can successfully realize vision with an extended depth of field. The element makes possible the compensation of an assumed defocus up to 4 dioptres. The output images formed by the LSOE are well recognizable and have acceptable qualities for near as well as far object distances

III. Systematic uncertainties in atomic data

Acknowledgements. SRON is supported financially by NWO, the Netherlands Organization for Scientific Research. C.S. acknowledges the support by an appointment to the NASA Postdoctoral Program at the NASA Goddard Space Flight Center, administered by Oak Ridge Associated Universities under contract with NASA and by Max-Planck-Gesellschaft (MPG). J.M. acknowledges the support from STFC (UK) through the University of Strathclyde UK APAP network grant ST/R000743/1. P.A. acknowledges the support from Fundação para a Ciência e a Tecnologia (FCT), Portugal, under Grant No. UID/FIS/04559/2020(LIBPhys). N.W. is supported by the GACR grant 21-13491X. The research leading to these results has received funding from the European Union’s Horizon 2020 Programme under the AHEAD2020 project (grant agreement n. 871158).There has been a growing request from the X-ray astronomy community for a quantitative estimate of systematic uncertainties originating from the atomic data used in plasma codes. Though there have been several studies looking into atomic data uncertainties using theoretical calculations, in general, there is no commonly accepted solution for this task. We present a new approach for estimating uncertainties in the line emissivities for the current models of collisional plasma, mainly based upon a dedicated analysis of observed high resolution spectra of stellar coronae and galaxy clusters. We find that the systematic uncertainties of the observed lines consistently show an anticorrelation with the model line fluxes, after properly accounting for the additional uncertainties from the ion concentration calculation. The strong lines in the spectra are in general better reproduced, indicating that the atomic data and modeling of the main transitions are more accurate than those for the minor ones. This underlying anticorrelation is found to be roughly independent of source properties, line positions, ion species, and the line formation processes. We further applied our method to the simulated XRISM and Athena observations of collisional plasma sources and discuss the impact of uncertainties on the interpretation of these spectra. The typical uncertainties are 1-2% on temperature and 3-20% on abundances of O, Ne, Fe, Mg, and Ni.publishersversionpublishe

Histone H2A (H2A.X and H2A.Z) Variants in Molluscs: Molecular Characterization and Potential Implications For Chromatin Dynamics

Histone variants are used by the cell to build specialized nucleosomes, replacing canonical histones and generating functionally specialized chromatin domains. Among many other processes, the specialization imparted by histone H2A (H2A.X and H2A.Z) variants to the nucleosome core particle constitutes the earliest response to DNA damage in the cell. Consequently, chromatin-based genotoxicity tests have been developed in those cases where enough information pertaining chromatin structure and dynamics is available (i.e., human and mouse). However, detailed chromatin knowledge is almost absent in most organisms, specially protostome animals. Molluscs (which represent sentinel organisms for the study of pollution) are not an exception to this lack of knowledge. In the present work we first identified the existence of functionally differentiated histone H2A.X and H2A.Z variants in the mussel Mytilus galloprovincialis (MgH2A.X and MgH2A.Z), a marine organism widely used in biomonitoring programs. Our results support the functional specialization of these variants based on: a) their active expression in different tissues, as revealed by the isolation of native MgH2A.X and MgH2A.Z proteins in gonad and hepatopancreas; b) the evolutionary conservation of different residues encompassing functional relevance; and c) their ability to confer specialization to nucleosomes, as revealed by nucleosome reconstitution experiments using recombinant MgH2A.X and MgH2A.Z histones. Given the seminal role of these variants in maintaining genomic integrity and regulating gene expression, their preliminary characterization opens up new potential applications for the future development of chromatin-based genotoxicity tests in pollution biomonitoring programs

Invasion of fluvial ecosystems by red swamp crayfish, Procambarus clarkii

Trabajo presentado en el International Symposium on Conservation of Native European Freshwater Crayfish, celebrado en Olot (Girona) del 23 al 25 de septiembre de 2015.Biological invasions are one of the biggest threats to biodiversity and conservation of native species, playing a key role in global change. To try to control them, it is important to understand two types of phenomena: mechanisms that allow a species to successfully establish in a new environment, and the ecological, evolutionary and socio-economic consequences of an invasion. We will address both types of phenomena using a multidisciplinary approach and multi-scale research, employing as study model an invasive species of global importance, which has invaded many inland waters: the red swamp crayfish, Procambarus clarkii. In its native area, this species mainly lives in marshes; nevertheless, it has been able to invade a new environment, streams, in invaded areas (in our case: West Andalusia in South Western Spain). Since its introduction over 40 years ago, this invasion is causing serious damage to native species like the European freshwater crayfish, Austropotamobius pallipes. We have five main objectives in this study: (1) to compare the genetic diversity of invasive populations with the native area, identifying patterns of introduction, propagation and gene flow; (2) to determine what mechanisms (at the level of gene expression in different tissues) allow P. clarkii to adapt to new conditions or environmental stress: identify genes and loci responsible for local adaptation; (3) to explore the ecological effects of P. clarkii in streams, in terms of structure and ecosystem functioning, and interactions with populations of native crayfish (A. pallipes) and native amphibians and fishes. To do this, we will compare the ecological effects of stream populations (which have potentially evolved in response to the new environment) with those of founding populations from marshes; (4) to compare the ecological effects of P. clarkii with those of A. pallipes and determine whether the invasive species is occupying the same ecological niche as the native species which has displaced; and (5) to examine the prevalence of Aphanomyces astaci in the red swamp crayfish, given that this invasive species is a chronic carrier of the crayfish plague, aphanomycosis, causing the death of European freshwater crayfish; and that of the fungus that causes chytridiomycosis in amphibians. In this project, we expect to find mechanisms that allow the red swamp crayfish to successfully establish in a new environment and the consequences that this entails for native species.Peer reviewe

Invasión de ecosistemas fluviales por cangrejo rojo americano, Procambarus clarkii

Trabajo presentado en las Jornadas españolas sobre conservación del cangrejo de río autóctono, celebradas el 21 y 22 de septiembre de 2015.Las invasiones biológicas son una de las mayores amenazas para la biodiversidad y conservación de las especies autóctonas, jugando un papel clave en el cambio global. Para intentar controlarlas, es importante entender dos tipos de fenómenos: los mecanismos que permiten a una especie establecerse con éxito en un nuevo ambiente, y las consecuencias ecológicas, evolutivas y económicas de una invasión. Nosotros abordaremos ambos tipos de fenómenos usando un enfoque multidisciplinar y un estudio multiescala, empleando como modelo de estudio una de las especies invasoras con mayor importancia global, la cual ya ha invadido la mayoría de aguas continentales: el cangrejo rojo americano, Procambarus clarkii. En su área nativa, esta especie vive principalmente en marismas; sin embargo, en las áreas invadidas ha sido capaz de invadir un nuevo ambiente, los arroyos, (en nuestro caso: el oeste de Andalucía en el suroeste de España). Desde su introducción hace unos 40 años, esta invasión está causando importantes daños a las especies autóctonas como el cangrejo de río, Austropotamobius pallipes. En este estudio, nos planteamos los siguientes cinco objetivos: (1) comparar la diversidad genética de las poblaciones invasoras con las de las áreas nativas, identificando patrones de introducción, propagación y flujo génico; (2) determinar qué mecanismos (a nivel de expresión de genes en diferentes tejidos) permiten que P. clarkii se adapte a nuevas condiciones o estrés ambiental: identificando genes y loci responsables para la adaptación local; (3) explorar los efectos ecológicos de P. clarkii en arroyos, en términos de estructura y funcionamiento del ecosistema, además de las interacciones con poblaciones nativas, tanto de cangrejo de río (A. pallipes) como de anfibios y peces autóctonos. Para hacer esto, compararemos los efectos ecológicos de las poblaciones de arroyo (las cuales potencialmente han evolucionado en respuesta a nuevos ambientes) con aquellas de poblaciones fundadoras desde las marismas; (4) comparar los efectos ecológicos de P. clarkii con aquellos de A. pallipes y determinar si la especie invasora está ocupando el mismo nicho ecológico que la especie nativa a la cual ha desplazado; y (5) examinar la prevalencia de Aphanomyces astaci en el cangrejo rojo americano, dado que esta especie invasora es portadora de la peste del cangrejo, afanomicosis, causando la muerte del cangrejo de río autóctono; y también la del hongo que causa la quitridiomicosis en anfibios. Con este proyecto, pretendemos dilucidar los mecanismos que permiten al cangrejo rojo americano establecerse exitosamente en un nuevo ambiente y las consecuencias que esto conlleva para las especies autóctonas.Peer reviewe

An integrated cell atlas of the lung in health and disease

Single-cell technologies have transformed our understanding of human tissues. Yet, studies typically capture only a limited number of donors and disagree on cell type definitions. Integrating many single-cell datasets can address these limitations of individual studies and capture the variability present in the population. Here we present the integrated Human Lung Cell Atlas (HLCA), combining 49 datasets of the human respiratory system into a single atlas spanning over 2.4 million cells from 486 individuals. The HLCA presents a consensus cell type re-annotation with matching marker genes, including annotations of rare and previously undescribed cell types. Leveraging the number and diversity of individuals in the HLCA, we identify gene modules that are associated with demographic covariates such as age, sex and body mass index, as well as gene modules changing expression along the proximal-to-distal axis of the bronchial tree. Mapping new data to the HLCA enables rapid data annotation and interpretation. Using the HLCA as a reference for the study of disease, we identify shared cell states across multiple lung diseases, including SPP1+ profibrotic monocyte-derived macrophages in COVID-19, pulmonary fibrosis and lung carcinoma. Overall, the HLCA serves as an example for the development and use of large-scale, cross-dataset organ atlases within the Human Cell Atlas