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Monkeypox virus (MPXV) is a double-stranded DNA virus mostly associated with rodents and occasionally spilling over to humans, causing outbreaks of mpox (formerly monkeypox) that have been relatively short-lived and [...]

Chagas disease is a zoonotic, parasitic, vector-borne neglected tropical disease that affects the lives of over 6 million people throughout the Americas. Trypanosoma cruzi,the causative agent,presents extensive genetic diversity. Here we report the genome sequence of reference strain SC43cl1, a hybrid strain belonging to the TcV discrete typing unit (DTU). The assembled diploid genome was 79 Mbp in size, divided into 1236 con-tigs with an average coverage reaching 180 *. There was extensive synteny of SC43cl1 genome with closely related TcV and TcVI genomes, with limited sequence rearrangements. TcVI genomes included several expansions not present in TcV strains. Comparative analysis of both nuclear and kinetoplast sequences clearly separated TcV from TcVI strains, which strongly supports the current DTU classification. Key words: Chagas disease, parasite, diversity, phylogeny. La maladie de Chagas est une zoonose parasitaire tropicale transmise par un vecteur et peu étudiée qui affecte les vies de plus de 6 millions de personnes à travers les Amériques. Le Trypanosoma cruzi,l''agent causal, présente une très grande diversité génétique. Dans ce travail, les auteurs rapportent la séquence du génome de la souche de référence SC43c11, une souche hybride appartenant au groupe (ou DTU pour [beaucoup moins que] discrete typing unit [beaucoup plus grand que]) TcV. Le génome diploïde assemblé mesure 79 Mb, formé par 1236 contigs dont la couverture moyenne était de 180 *. Une grande synténie, avec peu de réarrangements, a été observée entre le génome de SC43c11 et ceux des souches apparentées des groupes TcV et TcVI. Les génomes des souches appartenant au groupe TcVI comprenaient plusieurs expansions qui sont absentes des souches du groupe TcV. Une analyse comparée des séquences nucléaires et du kinétoplaste ont permis de clairement séparer les souches des groupes TcV et TcVI, ce qui supporte fortement la classification DTU actuelle. [Traduit par la Rédaction] Mots-clés: maladie de Chagas, parasite, diversité, phylogénie., Introduction Chagas disease is a zoonotic, parasitic, vector-borne neglected tropical disease that is endemic to the Americas where it affects the lives of over 6 million people. It is caused [...]

Monte Carlo criticality simulations are widely used in nuclear safety demonstrations, as they offer an arbitrarily precise estimation of global and local tallies while making very few assumptions. However, since the inception of such numerical approaches, it is well known that bias might affect both the estimation of errors on these tallies and the tallies themselves. In particular, stochastic modeling approaches developed in the past decade have shed light on the prominent role played by spatial correlations through a phenomenon called neutron clustering. This effect is particularly of great significance when simulating loosely coupled systems (i.e., with a high dominance ratio). In order to tackle this problem, this paper proposes to recast the power iteration technique of Monte Carlo criticality codes into a variance reduction technique called Adaptive Multilevel Splitting. The central idea is that iterating over neutron generations can be seen as pushing a subpopulation of neutrons toward a generational detector (instead of a spatial detector as variance reduction techniques usually do). While both approaches allow for neutron population control, the former blindly removes or splits neutrons. In contrast, the latter optimizes the spatial, generational, and spectral attributes of neutrons when they are removed or split through an adjoint flux estimation, hence tempering both generational and spatial correlations. This is illustrated in the present paper with a simple case of a bare slab reactor in the one-speed theory on which the Adaptive Multilevel Splitting was applied and compared to variations of the Monte Carlo power iteration method used in neutron transport. Besides looking at the resulting efficiency of the methods, this work also aims to highlight the main mechanisms of the Adaptive Multilevel Splitting in criticality calculations. [ABSTRACT FROM AUTHOR]

Chagas disease by Trypanosoma cruzi (T. cruzi) infection is a leading cause of myocarditis worldwide. Chagas cardiomyopathy is presented with a wide variety of conduction abnormalities including arrhythmias, first- and second-degree atrioventricular blockade, left ventricular systolic dysfunction and some cases heart failure leading to the death. Currently, there are no effective treatments available against advanced Chagas disease. With the advance in the development of novel therapies, it is important to utilize an animal model that can effectively replicate the diverse stages of Chagas disease, including chronic asymptomatic and symptomatic infection, that are akin to those observed in humans. Therefore, to characterize the cardiac alterations during the evolution of the infection, we evaluated the progression of cardiomyopathy caused by T. cruzi H1 infection in both BALB/c and ICR mouse models by performing electrocardiogram (ECG) studies in unanesthetized mice every month until 210 days post-infection (dpi). In the late chronic phase of infection, we also performed echocardiogram (ECHO) studies to further assess cardiac function. In conclusion, we demonstrated that ICR mice were more susceptible to cardiac alterations compared to BALB/c mice and both mouse strains are suitable experimental models to study chronic T. cruzi infection and novel treatments. [ABSTRACT FROM AUTHOR]

Triatoma sanguisuga is one of the major vectors of Trypanosoma cruzi in the southeastern US, where it sustains a robust zoonotic parasite transmission cycle and occasional human infections. A better understanding of triatomine development may allow for alternative approaches to insecticide-based vector control. Indeed, the role of the gut microbiota and bacterial endosymbionts in triatomine development and in their vectorial capacity is emerging. We investigated here the differences in microbiota among nymph and adult T. sanguisuga, to shed light on the metabolomic interactions occurring during development. Microbiota composition was assessed by 16s gene amplification and deep sequencing from field-caught adult bugs and their laboratory-raised progeny. Significant differences in microbiota bacterial diversity and composition were observed between nymphs and adults. Laboratory-raised nymphs showed a higher taxonomic diversity, and at least seven families predominated. On the other hand, field-caught adults had a lower bacterial diversity and four families comprised most of the microbiota. These differences in compositions were associated with differences in predicted metabolism, with laboratory-raised nymphs microbiota metabolizing a limited diversity of carbon sources, with potential for resource competition between bacterial families, and the production of lactic acid as a predominant fermentation product. On the other hand, field-caught adult microbiota was predicted to metabolize a broader diversity of carbon sources, with complementarity rather than competition among taxa, and produced a diverse range of products in a more balanced manner. The restricted functionality of laboratory-raised nymph microbiota may be associated with their poor development in captivity, and further understanding of the metabolic interactions at play may lead to alternative vector control strategies targeting triatomine microbiota. [ABSTRACT FROM AUTHOR]