Reflexiones de Becarios y Becarias a Partir de un Programa Posdoctoral en la Post-Pandemia

El escrito propone aportes para repensar críticamente metodologías interdisciplinarias en procesos de investigaciones postdoctorales.  Se parte de la experiencia de becarios y becarias pertenecientes a Argentina, Costa de Marfil y Ecuador para comprender las características de participación a partir del Covid-19: espacio virtual-territorial, diálogo entre diversas disciplinas, cuestiones de género, organización y gestión de los tiempos. A partir de un enfoque cualitativo y un diseño narrativo, se recogen las experiencias y reflexiones de los becarios/as del programa post-doctoral, y a partir de unidades narrativas y categorías de análisis, se identifican posibilidades y limitaciones para los estudios post-doctorales, tales como el desarrollo de competencias investigativas a través de la presencialidad y la virtualidad.   This article aims to generate contributions to critically re-think interdisciplinary methodologies in postdoctoral research processes. Drawing on the experiences of fellows from Argentina, Ivory Coast, and Ecuador, this study aims to understand the characteristics of participation in postdoctoral research processes, particularly in the context of Covid-19. Employing a qualitative approach and a narrative design. This exploration provides insights into the nuances of postdoctoral studies, shedding light on both possibilities and limitations through the examination of narrative units and categories of analysis, as the hybrid development of research skills

Reflexiones a Partir de un Programa Posdoctoral en la Post-Pandemia

El escrito propone aportes para repensar críticamente metodologías interdisciplinarias en procesos de investigaciones postdoctorales.  Se parte de la experiencia de becarios y becarias pertenecientes a Argentina, Costa de Marfil y Ecuador para comprender las características de participación a partir del Covid-19: espacio virtual-territorial, diálogo entre diversas disciplinas, cuestiones de género, organización y gestión de los tiempos. A partir de un enfoque cualitativo y un diseño narrativo, se recogen las experiencias y reflexiones de los becarios/as del programa post-doctoral, y a partir de unidades narrativas y categorías de análisis, se identifican posibilidades y limitaciones para los estudios post-doctorales.   This article aims to generate contributions to critically rethink interdisciplinary methodologies in postdoctoral research processes. It starts from the experience of fellows belonging to Argentina, Ivory Coast, and Ecuador to understand the participation characteristics based on Covid-19: virtual-territorial space, dialogue between diverse disciplines, gender issues, organization, and time management. Using a qualitative approach and a narrative design, the experiences and reflections of postdoctoral program fellows are collected, and possibilities and limitations for postdoctoral studies are identified through narrative units and categories of analysis

Reflexiones a Partir de un Programa Posdoctoral en la Post-Pandemia

El escrito propone aportes para repensar críticamente metodologías interdisciplinarias en procesos de investigaciones postdoctorales.  Se parte de la experiencia de becarios y becarias pertenecientes a Argentina, Costa de Marfil y Ecuador para comprender las características de participación a partir del Covid-19: espacio virtual-territorial, diálogo entre diversas disciplinas, cuestiones de género, organización y gestión de los tiempos. A partir de un enfoque cualitativo y un diseño narrativo, se recogen las experiencias y reflexiones de los becarios/as del programa post-doctoral, y a partir de unidades narrativas y categorías de análisis, se identifican posibilidades y limitaciones para los estudios post-doctorales.   This article aims to generate contributions to critically rethink interdisciplinary methodologies in postdoctoral research processes. It starts from the experience of fellows belonging to Argentina, Ivory Coast, and Ecuador to understand the participation characteristics based on Covid-19: virtual-territorial space, dialogue between diverse disciplines, gender issues, organization, and time management. Using a qualitative approach and a narrative design, the experiences and reflections of postdoctoral program fellows are collected, and possibilities and limitations for postdoctoral studies are identified through narrative units and categories of analysis

Three Generations Under One Roof? Bayesian Modeling of Radiocarbon Data from Nunalleq, Yukon-Kuskokwim Delta, Alaska

Acknowledgments. This research was funded through an Arts and Humanities Research Council grant (AH/K006029/1) awarded to Drs. Rick Knecht, Charlotta Hillerdal, and Kate Britton, and two NERC Radiocarbon Facility grants (NF/2015/1/6 and NF/2015/2/3) awarded to Drs. Rick Knecht and Paul Ledger. Véronique Forbes received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement number 703322. Excavations at Nunalleq have also benefited from the support of the local community who have made us all feel at home in Quinhagak. In particular, we wish to thank Qanirtuuq Incorporated and Warren Jones for logistical support and their consistently warm hospitality. Thanks also to Philip Ashlock who took the aerial image presented in Figure 3. We also wish to acknowledge the contribution of all of the students and researchers who have excavated at Nunalleq between 2009 and 2015. Without their hard work and dedication, in sometimes challenging conditions, this article would not have been possible. Finally, we wish to thank three anonymous reviewers and Robert Kelly for constructive criticism that has helped improved this manuscript. Permission for excavations at Nunalleq was granted by Qanirtuuq Incorporated.Peer reviewedPublisher PD

Identification of Large Equivalent Width Dusty Galaxies at 4 << z << 6 from Sub-mm Colours

Infrared (IR), sub-millimetre (sub-mm) and millimetre (mm) databases contain a huge quantity of high quality data. However, a large part of these data are photometric, and are thought not to be useful to derive a quantitative information on the nebular emission of galaxies. The aim of this project is first to identify galaxies at z > 4-6, and in the epoch of reionization from their sub-mm colours. We also aim at showing that the colours can be used to try and derive physical constraints from photometric bands, when accounting for the contribution from the IR fine structure lines to these photometric bands. We model the flux of IR fine structure lines with CLOUDY, and add them to the dust continuum emission with CIGALE. Including or not emission lines in the simulated spectral energy distribution (SED) modifies the broad band emission and colours. The introduction of the lines allows to identify strong star forming galaxies at z > 4 - 6 from the log10 (PSW_250um/PMW_350um) versus log10 (LABOCA_870um/PLW_500um) colour-colour diagramme. By comparing the relevant models to each observed galaxy colour, we are able to roughly estimate the fluxes of the lines, and the associated nebular parameters. This method allows to identify a double sequence in a plot built from the ionization parameter and the gas metallicity. The HII and photodissociation region (PDR) fine structure lines are an essential part of the SEDs. It is important to add them when modelling the spectra, especially at z > 4 - 6 where their equivalent widths can be large. Conversely, we show that we can extract some information on strong IR fine structure lines and on the physical parameters related to the nebular emission from IR colour-colour diagrams.Comment: Paper accepted in Astronomy and Astrophysics on 10 November 202

High prevalence of anti-C1q antibodies in biopsy-proven active lupus nephritis

Background. Anti-C1q antibodies (anti-C1q) have been shown to correlate positively with systemic lupus erythematosus (SLE) nephritis. Several clinical studies indicated a high negative predictive value, suggesting that active lupus nephritis is rarely seen in patients with no anti-C1q. However, the true prevalence of anti-C1q at the time of active lupus nephritis has not been well established. The aim of this study was to determine prospectively the prevalence of anti-C1q in proven active lupus nephritis at the time of the renal biopsy. Methods. In this prospective multi-centre study, we investigated adult SLE patients undergoing renal biopsy for suspected active lupus nephritis. Serum samples were taken at the time of the biopsy and analysed for the presence of anti-C1q in a standardized way. The activity of lupus nephritis was classified according to the renal histology. Biopsies were also analysed for the presence of glomerular IgG, C1q and C3 deposition. Results. A total of 38 patients fulfilling at least 4/11 American College of Rheumatology (ACR) criteria for the diagnosis of SLE were included. Out of this, 36 patients had proliferative (class II, III or IV) and two had class V lupus nephritis. All but one patient with proliferative lupus nephritis were positive for anti-C1q (97.2%) compared with the 35% of control SLE patients with inactive lupus nephritis and 25% of SLE patients without lupus nephritis ever. All patients were positive for glomerular C1q (36/36) and 37/38 patients had glomerular IgG deposits. Anti-C1q strongly decreased during successful treatment. Conclusions. Anti-C1q have a very high prevalence in biopsy-proven active lupus nephritis, thus a negative test result almost excludes active nephritis. The data support the hypothesis of a pathogenic role of anti-C1q in lupus nephriti

The obscure events contributing to the evolution of an incipient sex chromosome in Populus: a retrospective working hypothesis

Genetic determination of gender is a fundamental developmental and evolutionary process in plants. Although it appears that dioecy in [i]Populus[/i] is genetically controlled, the precise gender-determining systems remain unclear. The recently released second draft assembly and annotated gene set of the [i]Populus[/i] genome provided an opportunity to revisit this topic. We hypothesized that over evolutionary time, selective pressure has reformed the genome structure and gene composition in the peritelomeric region of the chromosome XIX, which has resulted in a distinctive genome structure and cluster of genes contributing to gender determination in [i]Populus trichocarpa[/i]. Multiple lines of evidence support this working hypothesis. First, the peritelomeric region of the chromosome XIX contains significantly fewer single nucleotide polymorphisms than the rest of [i]Populus[/i] genome and has a distinct evolutionary history. Second, the peritelomeric end of chromosome XIX contains the largest cluster of the nucleotide-binding site–leucine-rich repeat (NBS–LRR) class of disease resistance genes in the entire [i]Populus[/i] genome. Third, there is a high occurrence of small microRNAs on chromosome XIX, which is coincident to the region containing the putative gender-determining locus and the major cluster of NBS–LRR genes. Further, by analyzing the metabolomic profiles of floral bud in male and female [i]Populus[/i] trees using a gas chromatography-mass spectrometry, we found that there are gender-specific accumulations of phenolic glycosides. Taken together, these findings led to the hypothesis that resistance to and regulation of a floral pathogen and gender determination coevolved, and that these events triggered the emergence of a nascent sex chromosome. Further studies of chromosome XIX will provide new insights into the genetic control of gender determination in [i]Populus[/i]

In vitro evaluation of the aryl hydrocarbon receptor transactivity induced by human intestinal metabolites

The gastrointestinal tract is directly exposed to the environment and constitutes one of the first lines of defense against harmful antigens in the diet or the microbiota. Highly expressed in intestinal cells, the aryl hydrocarbon receptor (AhR) plays a crucial role in gut mucosal integrity and in intestinal immune function. Substances derived from food and the microbiota in the intestinal lumen can induce AhR transcriptional activity and thus maintain intestinal barrier homeostasis. We suggested the combination of a simulator of the human gut microbial ecosystem (SHIME) with cell based AhR transactivity bioassays. Thereby, the effects of human gut microbiota metabolism on the AhR signaling pathways could be evaluated. Three AhR reporter gene cell lines (T47D, HepG2, HT29) from human mammary, hepatic, and intestinal tissues, respectively, were used to test mixtures of microbiota-derived metabolites that were generated in a 3-days experiment on a SHIME system. The SHIME samples induced an AhR agonist activation in the different cell lines, with slightly tissue-dependent effects. Microbiota produced metabolites, such as short-chain fatty acids (SCFA) and tryptophan catabolites were quantified chromatographically in the SHIME samples, and they might be causing the AhR agonist activity of the mixture. However, more detailed investigations are needed to identify the contribution of individual metabolites to AhR activation. This is an innovative suggestion to study in vitro the AhR modulation caused by the human intestinal metabolism.GutTransit Projec

Sucralose and maltodextrin affect differently the gut microbiota of healthy individuals and IBD patients

editorial reviewedIntestinal fibrosis is a long–term complication of inflammatory bowel diseases (IBD). Changes in microbial populations have been linked with the onset of fibrosis and some food additives are known to promote intestinal inflammation facilitating fibrosis induction. Most of these studies have been performed using murine models or healthy donors while the effects of food additives on intestinal microbiota of patients suffering from IBD is less understood. The aim of this work was therefore to determine how food additives affect intestinal microbiota of both healthy and “IBD” donors. Two food additives, sucralose (SUC) and maltodextrin (MDX), were tested in a short–term (72h) in vitro model of the human intestinal microbiota. Three groups of donors were investigated: healthy persons (H), patients in remission of IBD (R) and patients with an active period of IBD (A). Short-chain fatty acid production was assessed using SPME-GC/MS while the evolution of microbial populations positively or negatively correlated with health, inflammation and/or fibrosis was assessed using qPCR. MDX and SUC increased propionate and butyrate production in H and R donors. In addition, MDX increased butyrate in A donors and decreased the butyrate–producer genus Roseburia in H and R donors. Both, SUC and MDX decreased the beneficial bacteria F. prausnitzii in A donors. Moreover, in R and A donors, SUC and MDX decreased A. muciniphila. MDX promoted the growth of Enterococcus in H and R groups and Streptococcus in the three groups of donors, both genus being associated with intestinal inflammation. SUC induced increases of Escherichia/Shigella in H and Enterococcus in H and R groups. Ruminococcus, correlated with higher risk of fibrosis, was increased in the three groups of donors treated with MDX while SUC increased Ruminococcus only in IBD donors. Oscillospira, correlated with reduced risk of fibrosis, was decreased in the three groups of donors with MDX and in H and A donors with SUC. This study demonstrates how strongly the human microbiota can be affected by some food additives. In addition, to our knowledge, this is the first human in vitro study focusing on the impact of food additives on microbiota of IBD patients