Experimental and theoretical constraints on amino acid formation from PAHs in asteroidal settings

Laboratory astrophysics and astrochemistr

Deep-sequencing reveals broad subtype-specific HCV resistance mutations associated with treatment failure

A percentage of hepatitis C virus (HCV)-infected patients fail direct acting antiviral (DAA)-based treatment regimens, often because of drug resistance-associated substitutions (RAS). The aim of this study was to characterize the resistance profile of a large cohort of patients failing DAA-based treatments, and investigate the relationship between HCV subtype and failure, as an aid to optimizing management of these patients. A new, standardized HCV-RAS testing protocol based on deep sequencing was designed and applied to 220 previously subtyped samples from patients failing DAA treatment, collected in 39 Spanish hospitals. The majority had received DAA-based interferon (IFN) a-free regimens; 79% had failed sofosbuvir-containing therapy. Genomic regions encoding the nonstructural protein (NS) 3, NS5A, and NS5B (DAA target regions) were analyzed using subtype-specific primers. Viral subtype distribution was as follows: genotype (G) 1, 62.7%; G3a, 21.4%; G4d, 12.3%; G2, 1.8%; and mixed infections 1.8%. Overall, 88.6% of patients carried at least 1 RAS, and 19% carried RAS at frequencies below 20% in the mutant spectrum. There were no differences in RAS selection between treatments with and without ribavirin. Regardless of the treatment received, each HCV subtype showed specific types of RAS. Of note, no RAS were detected in the target proteins of 18.6% of patients failing treatment, and 30.4% of patients had RAS in proteins that were not targets of the inhibitors they received. HCV patients failing DAA therapy showed a high diversity of RAS. Ribavirin use did not influence the type or number of RAS at failure. The subtype-specific pattern of RAS emergence underscores the importance of accurate HCV subtyping. The frequency of “extra-target” RAS suggests the need for RAS screening in all three DAA target regions

Molecular distribution and 13C isotope composition of volatile organic compounds in the Murchison and Sutter's Mill carbonaceous chondrites

Volatile organic compounds (VOCs) are carbon-containing chemicals that may evaporate rapidly at room temperature and standard pressure. Such organic compounds can be preserved inside carbonaceous chondrite matrices. However, unlike meteoritic soluble organic matter (SOM) and insoluble organic matter (IOM), VOCs are typically lost (at least in part) during sample processing (meteorite crushing) and exposure to terrestrial atmosphere and/or solvents. Like SOM and IOM, VOCs can provide valuable insights into the chemical inventory of the meteorite parent body and even the presolar cloud from which our solar system formed, as well as the composition and processes that occurred during the early formation of our solar system and the asteroidal stage. Thus, in this work, we designed and built an instrument that allowed us to access the VOCs present in samples of the carbonaceous chondrites Murchison and Sutter's Mill after mineral disaggregation by means of freeze–thaw cycling. We simultaneously evaluated the abundances and compound-specific 13C-distributions of the volatiles evolving after meteorite powdering at ~20, 60, and 100°C. Carbon monoxide (CO) and methane (CH4) were released from these meteorites as the most abundant VOCs. They were combusted together for analysis and showed positive δ13C values, indicative of their extraterrestrial origins. Carbon dioxide (CO2) was also an abundant VOC in both meteorites, and its isotopic values suggest that it was mainly formed from dissolved carbonates in the samples. We also detected aldehydes, ketones, and aromatic compounds in low amounts. Contrary to Murchison, which mostly yielded VOCs with positive δ13C values, Sutter's Mill yielded VOCs with negative δ13C values. The less enriched 13C isotope composition of the VOCs detected in Sutter's Mill suggest that they are either terrestrial contaminants, such as VOCs in compressed gas dusters and common laboratory solvents, or compounds disconnected from interstellar sources and/or formed through parent body processing. Understanding the relative abundances and determining the molecular distributions and isotopic compositions of free meteoritic VOCs are key in assessing their extraterrestrial origins and those of chondritic SOM and IOM. Our newly developed technique will be valuable in the study of the samples brought to the Earth from carbonaceous asteroid Bennu by NASA's OSIRIS-REx mission. © 2024 The Authors. Meteoritics & Planetary Science published by Wiley Periodicals LLC on behalf of The Meteoritical Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.Open access articleThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Proyecto de lucha contra las grandes endemias : informe technico final

Objective: Data on the epidemiology of the Teniasis/Cysticercosis complex in the Department of a Paz, Bolivia, are very scarce, even if #Taenia solium is known to be endemic in the area. Thus, in the present study, we tried to identify the way of contamination of the human by the larvae of #Taenia solium, and to evaluate the prevalence of teniasis in several communities located in the Altiplano. Methods: A cross-sectional survey has been concluted in three rural communities located in the privince of Los Andes. the prevalence of taeniasis has been measured through coprological examinations including a direct microscopic examination and examination using Ritchie's concentration methods. A questionnaire has been aplied to collect information on the socio-economic environment, the displacements and the nutritional habits of each person. Another questionnaire, elaborated by the IENT, will be applied to identify people who suffer of epilepsy and to characterize the clinical presentation of the latter. The a CT-scan examination and a serodetection of antigens of #T. solium$will be performed on people with epilepsy in order to identify those patients with neurocysticercosis. The study of the contaminant potential in order to identify those patients with neurocysticercosis. The study of the contaminant potential of food was realized in a rural community, as well as in the cities of La Paz and El Alto. Samples of cooked ig meat had been bought, dissected (thickness 0.5 cm wide) and the viability of the cysticerci present in the pieces of meat has been analyzed. The infective potential of the parasite was assessed by the capacity of evagination of the cysticerci preciously washed with a saline solution and left to incubate in a Petri box containing a saline solution at 20$ sp. was found neither by direct examination of stools nor by te Ritchie's concentration techniques. Three cases of infection by helminth parasites have been recorded: two cases with #Hymenolepis nana$(1,!$ (0,4%). In addition, the patients showed high rates of infection by protozoan parasites: #Entamoeba coli$(59,8$ (49,8%), #Blastocystis hominis$(47,6$ (14,1%), #Giardia lamblia$(10,8$ (10,8%) and #Iodamoeba butschlii$ (9,7%). A rigorous disection of the 120 food samples was made. 75 samples were bought in La Paz, 38 in El Alto and 7 in the village of Batallas on the Altiplano. Cysticerci were found in only one of the 75 samples which represents 0,8% of all the samples. The 10 cysticerci found were incubated during 24h in bovine bile diluted in physiological serum for testing their viability. None of them started to evaginate, thus they were al non-viable. Conclusion: According to our results, the prevalence of teniasis is very low in this part of the Bolivian Altiplano. A decrease of the prevalence of taeniasis probably occurred durging this last years, thanks to the National Programme for the Prevention and Control of Teniasis-Cysticercosis started in 1994. The apparent low rate of porcine infection by cysticercosis in this region may be due to changes in the husbandry practices or to an improvement in hygiene habits (90% of the population have latrines). No contaminating food was found during the study. the contamination of the human by infectious food may occur at Chrstmas when the marketing of pork meat increases dramatically in the city. (résumé d'auteur

A Classification System for Colombian Wetlands: an Essential Step Forward in Open Environmental Policy-Making

Knowledge about the distribution and diversity of wetlands has become an essential tool for environmental management and policy-making. Yet, while recent estimates indicate that 27% of the area of Colombia is covered by wetlands and despite a number of regional studies, information about the diversity of wetlands nationally is scarce. In response, we present a national wetland classification system that is based on an ecological approach, from the perspective of wetland scientists, and which builds upon the assumptions underlying the flood pulse concept and hydrogeomorphic approach. Thus, the approach and structure of the Brazilian wetland classification system are used, with geomorphological adjustments made according to Colombia’s topography. The classification is hierarchical, multi-scale, functional, and organized according to four levels (system, macroregion, subsystem, and class), with the wetland diversity of Colombia represented nationally by 89 macrohabitats across marine-coastal, inland, and anthropogenic systems. The primary purpose of this classification is to provide integrated and organized information on the distribution and diversity of Colombian wetlands that will serve as a baseline for transparent environmental policy-making. © 2019, Society of Wetland Scientists

Low-frequency and rare exome chip variants associate with fasting glucose and type 2 diabetes susceptibility

Fasting glucose and insulin are intermediate traits for type 2 diabetes. Here we explore the role of coding variation on these traits by analysis of variants on the HumanExome BeadChip in 60,564 non-diabetic individuals and in 16,491 T2D cases and 81,877 controls. We identify a novel association of a low-frequency nonsynonymous SNV in GLP1R (A316T; rs10305492; MAF=1.4%) with lower FG (β=-0.09±0.01mmoll-1, P=3.4 × 10-12), T2D risk (OR[95%CI]=0.86[0.76-0.96], P=0.010), early insulin secretion (β=-0.07±0.035pmolinsulin mmolglucose-1, P=0.048), but higher 2-h glucose (β=0.16±0.05mmoll-1, P=4.3 × 10-4). We identify a gene-based association with FG at G6PC2 (p SKAT =6.8 × 10-6) driven by four rare protein-coding SNVs (H177Y, Y207S, R283X and S324P). We identify rs651007 (MAF=20%) in the first intron of ABO at the putative promoter of an antisense lncRNA, associating with higher FG (β=0.02±0.004mmoll-1, P=1.3 × 10-8). Our approach identifies novel coding variant associations and extends the allelic spectrum of variation underlying diabetes-related quantitative traits and T2D susceptibility. © 2015 Macmillan Publishers Limited. All rights reserved