Polarization of the Charge-Exchange X-Rays Induced in the Heliosphere

We report results of a theoretical investigation of polarization of the X-ray emissions induced in charge-exchange collisions of fully stripped solar wind ions C6+and O8+ with the heliospheric hydrogen atoms. The polarization of X-ray emissions has been computed for line-of-sight observations within the ecliptic plane as a function of solar wind ion velocities, including a range of velocities corresponding to the slow and fast solar wind, and Coronal Mass Ejections. To determine the variability of polarization of heliospheric X-ray emissions, the polarization has been computed for solar minimum conditions with self-consistent parameters of the solar wind plasma and heliospheric gas and compared with the polarization calculated for an averaged solar activity. We predict the polarization of charge-exchange X-rays to be between 3% and 8%, depending on the line-of-sight geometry, solar wind ion velocity, and the selected emission lines

Sistemática molecular de los géneros Laurencia, Osmundea y Palisada (Rhodophyta) de las Islas Canarias, basadas en la secuencia espaciadora del RUBISCO y del rDNA

The molecular systematics of Laurencia, Osmundea and Palisada (Rhodomelaceae, Ceramiales) species from the Canary Islands has been determined by analysis sequences of the ribulose,1-5, bisphosphate carboxylase (RUBISCO) spacer from the plastid genome and the internal transcribed spacers (ITS1 and ITS2) and the rDNA 5.8S coding region from the nuclear genome. Comparison of sequence data showed an identity of 72-83 % between the species. Three taxonomic group were identified that correspond to established phylogenetic taxons. Phylogenetic trees using both parsimony and maximum-likelihood methods were derived from the sequence data; the trees indicate that O. pinnatifida appears to be the most distantly related species from the Laurencia and Palisada species. The exact phylogenetic position of Laurencia sp. A (“amarilla”) need additional studies.Se aportan datos filogenéticos de algunas especies de Laurencia, Osmundea y Palisada (Rhodomelaceae, Ceramiales) de las Islas Canarias mediante el análisis de secuencias de la región espaciadora de ribulose,1-5, bisfosfato carboxilasa (RUBISCO) del genoma plastídico y las regiones espaciadoras internas (ITS1, ITS2) y de la región codificadora del rDNA en el genoma nuclear. Los tres géneros analizados, Laurencia, Osmundea y Palisada muestran las correspondientes identidades moleculares con una identidad del 72-83% entre ellas. Empleando métodos de parsimonia y máxima similitud, los correspondientes árboles filogenéticos ponen de manifiesto que O. pinnatifida es el taxon más distante entre las especies de Laurencia y Palisada analizadas. La posición exacta del taxon mencionado como Laurencia sp. A “amarilla”) precisa de estudio adicional

Donor tobacco smoking is associated with postoperative thrombosis after primary liver transplantation

Background: Thrombosis after liver transplantation is a leading cause of graft loss, morbidity, and mortality. Several known recipient- and surgery-related characteristics have been associated with increased risk of thrombosis after transplantation. Potential donor-related risk factors, however, remain largely undefined. Objectives: We aimed to identify risk factors for early post-transplantation thrombosis ('90 days) and to determine the impact of early postoperative thrombosis on long-term graft and patient survival. Patients/Methods: A post hoc analysis was performed of an observational cohort study including all primary, adult liver transplantations performed between 1993 and 2018. Donor-, recipient-, and surgery-related characteristics were collected. Competing risk model analyses and multivariable regression analyses were performed to identify risk factors for developing early post-transplant thrombosis and graft failure. Results: From a total of 748 adult liver transplantations, 58 recipients (7.8%) developed a thrombosis after a median of 7 days. Post-transplantation thrombotic events included 25 hepatic artery thromboses, 13 portal vein thromboses, and 22 other thrombotic complications. Donor history of smoking was independently associated with early postoperative thrombosis (odds ratio [OR] 2.42; 95% confidence interval [CI], 1.29-4.52). Development of early post-transplant thrombosis was independently associated with patient mortality (hazard ratio [HR] 3.61; 95% CI 1.54-8.46) and graft failure (HR 5.80, 95% CI 3.26-10.33), respectively. Conclusion: Donor history of smoking conveys a more than two-fold increased risk of thrombosis after liver transplantation, independent of other factors. Post-transplant thrombosis was independently associated with decreased patient and graft survival

Anti-inflammatory Gut Microbial Pathways Are Decreased During Crohn's Disease Exacerbations

BACKGROUND AND AIMS: Crohn's disease [CD] is a chronic inflammatory disorder of the gastrointestinal tract characterised by alternating periods of exacerbation and remission. We hypothesised that changes in the gut microbiome are associated with CD exacerbations, and therefore aimed to correlate multiple gut microbiome features to CD disease activity. METHODS: Faecal microbiome data generated using whole-genome metagenomic shotgun sequencing of 196 CD patients were of obtained from the 1000IBD cohort [one sample per patient]. Patient disease activity status at time of sampling was determined by re-assessing clinical records 3 years after faecal sample production. Faecal samples were designated as taken 'in an exacerbation' or 'in remission'. Samples taken 'in remission' were further categorised as 'before the next exacerbation' or 'after the last exacerbation', based on the exacerbation closest in time to the faecal production date. CD activity was correlated with gut microbial composition and predicted functional pathways via logistic regressions using MaAsLin software. RESULTS: In total, 105 bacterial pathways were decreased during CD exacerbation (false-discovery rate [FDR] <0.1) in comparison with the gut microbiome of patients both before and after an exacerbation. Most of these decreased pathways exert anti-inflammatory properties facilitating the biosynthesis and fermentation of various amino acids [tryptophan, methionine, and arginine], vitamins [riboflavin and thiamine], and short-chain fatty acids [SCFAs]. CONCLUSIONS: CD exacerbations are associated with a decrease in microbial genes involved in the biosynthesis of the anti-inflammatory mediators riboflavin, thiamine, and folate, and SCFAs, suggesting that increasing the intestinal abundances of these mediators might provide new treatment opportunities. These results were generated using bioinformatic analyses of cross-sectional data and need to be replicated using time-series and wet lab experiments

A combination of fecal calprotectin and human beta-defensin 2 facilitates diagnosis and monitoring of inflammatory bowel disease

Inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS) show a large overlap in clinical presentation, which presents diagnostic challenges. As a consequence, invasive and burdensome endoscopies are often used to distinguish between IBD and IBS. Here, we aimed to develop a noninvasive fecal test that can distinguish between IBD and IBS and reduce the number of endoscopies. We used shotgun metagenomic sequencing to analyze the composition and function of gut microbiota of 169 IBS patients, 447 IBD patients and 1044 population controls and measured fecal Calprotectin (FCal), human beta defensin 2 (HBD2), and chromogranin A (CgA) in these samples. These measurements were used to construct training sets (75% of data) for logistic regression and machine learning models to differentiate IBS from IBD and inactive from active IBD. The results were replicated on test sets (remaining 25% of the data) and microbiome data obtained using 16S sequencing. Fecal HBD2 showed high sensitivity and specificity for differentiating between IBD and IBS (sensitivity = 0.89, specificity = 0.76), while the inclusion of microbiome data with biomarkers (HBD2 and FCal) showed a potential for improvement in predictive power (optimal sensitivity = 0.87, specificity = 0.93). Shotgun sequencing-based models produced comparable results using 16S-sequencing data. HBD2 and FCal were found to have predictive power for IBD disease activity (AUC approximate to 0.7). HBD2 is a novel biomarker for IBD in patients with gastro-intestinal complaints, especially when used in combination with FCal and potentially in combination with gut microbiome data

Mucosal microbiota modulate host intestinal immune signatures in Inflammatory Bowel Disease

BackgroundHost intestinal immune gene signatures and microbial dysregulations expose potential mechanisms in the pathogenesis of inflammatory bowel diseases (IBD). Profiling of mucosa-attached microbiota allows the understanding of locally present microbial communities and their immediate impact on the host. This study evaluated interactions between host mucosal gene expression and intestinal mucosa-attached microbiota in IBD.MethodsIntestinal mucosal bulk RNA-sequencing data was combined with mucosal 16S rRNA gene sequencing data from 696 intestinal biopsies derived from 337 patients with IBD (181 with Crohn’s disease [CD] and 156 with ulcerative colitis [UC]) and 16 non-IBD controls. Hierarchical all-against-all associations testing (HAllA) was used to assess factors affecting host gene expressions and microbiota. Mucosal cell enrichments were predicted by deconvolution. Linear mixed interaction models were used to investigate host-microbiota interactions, adjusting for age, sex, BMI and batch effects. Variation explanation analysis was performed by Lasso regression.ResultsIn total, 15,934 intestinal genes and 113 microbial taxa were identified and included in subsequent analyses. Host intestinal gene expressions were characterized by tissue- and inflammation-specificity, whereas intraindividual variability of the mucosal microbiota dominated over disease location and inflammation effects. We observed forty associations between the mucosal expression of genes and the abundance of specific microbes independent of dysbiosis (FDR&lt;0.05). Examples include a positive association between aryl hydrocarbon receptor (AHR) and Bifidobacterium, and a negative association between interleukin 18 receptor 1 (IL18R1) and Lachnoclostridium. Furthermore, 112 gene-microbiota interactions changed in patients with microbial dysbiosis compared to non-dysbiosis (FDR&lt;0.05). These interactions were enriched in immune-related and extracellular matrix organization pathways. For example, the IL1R1 gene was positively associated with Collinsella abundance in non-dysbiotic patients, whereas an inverse association was observed in high dysbiosis. Finally, the presence of mucosal microbial taxa explained up to 10% of the variation in cell type enrichment, affecting epithelial cells, macrophages and regulatory T-cells.ConclusionInteractions between host intestinal gene expressions and mucosa-attached microbiota are disrupted in patients with IBD. Furthermore, mucosal microbiota are highly personalized and potentially contribute to intestinal cell type alterations. Our study unravels key immune-mediated molecular pathways and relevant bacteria in intestinal tissue, which may guide drug development and precision medicine in IBD

The Distribution of Quasars and Galaxies in Radio Color-Color and Morphology Diagrams

We positionally match the 6 cm GB6, 20 cm FIRST and NVSS, and 92 cm WENSS radio catalogs and find 16,500 matches in ~3,000 deg2 of sky. Using this unified radio database, we construct radio "color-magnitude-morphology" diagrams and find that they display a clear structure, rather than a random scatter. We propose a simple, yet powerful, method for morphological classification of radio sources based on FIRST and NVSS measurements. For a subset of matched sources, we find optical identifications using the SDSS Data Release 1 catalogs, and separate them into quasars and galaxies. Compact radio sources with flat radio spectra are dominated by quasars, while compact sources with steep spectra, and resolved radio sources, contain substantial numbers of both quasars and galaxies.Comment: 4 pages, 2 figures, to be published in the Proceedings of "Multiwavelength AGN Surveys", Cozumel, Dec 8 - 12, 200

Long-Term Dietary Patterns Are Reflected in the Plasma Inflammatory Proteome of Patients with Inflammatory Bowel Disease

Diet plays an important role in the development and progression of inflammatory bowel disease (IBD, comprising Crohn's disease (CD) and ulcerative colitis (UC)). However, little is known about the extent to which different diets reflect inflammation in IBD beyond measures such as faecal calprotectin or C-reactive protein. In this study, we aimed to unravel associations between dietary patterns and circulating inflammatory proteins in patients with IBD. Plasma concentrations of 73 different inflammation-related proteins were measured in 454 patients with IBD by proximity extension assay (PEA) technology. Food frequency questionnaires (FFQ) were used to assess habitual diet. Principal component analysis (PCA) was performed to extract data-driven dietary patterns. To identify associations between dietary patterns and plasma proteins, we used general linear models adjusting for age, sex, BMI, plasma storage time, smoking, surgical history and medication use. Stratified analyses were performed for IBD type, disease activity and protein intake. A high-sugar diet was strongly inversely associated with fibroblast growth factor-19 (FGF-19) independent of IBD type, disease activity, surgical history and deviance from recommended protein intake (false discovery rate (FDR) &lt; 0.05). Conversely, a Mediterranean-style pattern was associated with higher FGF-19 levels (FDR &lt; 0.05). A pattern characterised by high alcohol and coffee intake was positively associated with CCL11 (eotaxin-1) levels and with lower levels of IL-12B (FDR &lt; 0.05). All results were replicated in CD, whereas only the association with FGF-19 was significant in UC. Our study suggests that dietary habits influence distinct circulating inflammatory proteins implicated in IBD and supports the pro- and anti-inflammatory role of diet. Longitudinal measurements of inflammatory markers, also postprandial, are needed to further elucidate the diet-inflammation relationship

Non-thermal escape of molecular hydrogen from Mars

We present a detailed theoretical analysis of a non-thermal escape of molecular hydrogen from Mars induced by collisions with hot atomic oxygen from martian corona. To accurately describe the energy transfer in O + H$_2(v,j)$ collisions, we performed extensive quantum-mechanical calculations of state-to-state elastic, inelastic, and reactive cross sections. The escape flux of H$_2$ molecules was evaluated using a simplified 1D column model of the martian atmosphere with realistic densities of atmospheric gases and hot oxygen production rates for the low solar activity conditions. An average density of the non-thermal escape flux of H$_2$ of $1.9\times10^5$ cm$^{-2}$s$^{-1}$ was obtained considering energetic O atoms produced in dissociative recombinations of O$_{2}^{+}$ ions. Predicted rovibrational distribution of the escaping H$_2$ was found to contain a significant fraction of higher rotational states. While the non-thermal escape rate was found to be lower than Jeans flux for H$_2$ molecules, the non-thermal escape rates of HD and D$_2$ are significantly higher than their respective Jeans rates. The accurate values of non-thermal escape fluxes of different molecular isotopes of H$_2$ may be important in analyses of evolution of the martian atmosphere. The described molecular ejection mechanism is general and expected to contribute to atmospheric escape of H$_2$ and other light molecules from planets, satellites, and exoplanetary bodies.Comment: submitted to Geophys. Res. Let