Histopathological disturbances in two fish species Oreochromis niloticus (Linnaeus 1758) and Labeo barbus pellegrini (Bertin et Estève 1948) from downstream mining sites in the upper Ulindi and Elila river basins, Eastern DR Congo

peer reviewedThe effect of intensive mining on the health status of fish living in the upper basins of the Ulindi and Elila rivers was investigated between June 2018 and March 2022 by comparing the reproductive, hepatic and gill systems of fish collected from sites upstream and downstream of the mining sites. Biometric indices and organ histopathology are biomarkers that were studied at two different trophic levels using two fish species Oreochromis niloticus and Labeobarbus pellegreni. Histological evaluation was performed on the liver, gonads and gills of both species. Water and sediment samples were analysed for total mercury (T-Hg) concentration by (atomic absorption spectrophotometry). Histological changes were assessed semi-quantitatively, and the results were graded according to the severity of the histological responses. The results showed that L. pellegrini accumulated more T-Hg than O. niloticus. The T-Hg level was higher in the organs of both species during the rainy season than during the dry season in the following order: Gonads > Liver > Gills and exceeded the WHO/FAO recommended limit (T-Hg = 1.0 mg/kg wet weight) only in the testes and gills of L. pellegrini collected at the downstream sites of the Ulindi and Elila rivers. This does not necessarily reflect the level in the carcass. Taken together, the results suggest that mercury accumulated downstream of gold mining operations is altering the health of fish populations and that L. pellegrini can be considered a sentinel species for monitoring this pollution. To protect fish health, it is recommended that certain mining practices such as the misuse of mercury be avoided throughout the Congo River basi

Dynamic Information Flow Based on EEG and Diffusion MRI in Stroke: A Proof-of-Principle Study

In hemiparetic stroke, functional recovery of paretic limb may occur with the reorganization of neural networks in the brain. Neuroimaging techniques, such as magnetic resonance imaging (MRI), have a high spatial resolution which can be used to reveal anatomical changes in the brain following a stroke. However, low temporal resolution of MRI provides less insight of dynamic changes of brain activity. In contrast, electro-neurophysiological techniques, such as electroencephalography (EEG), have an excellent temporal resolution to measure such transient events, however are hindered by its low spatial resolution. This proof-of-principle study assessed a novel multimodal brain imaging technique namely Variational Bayesian Multimodal Encephalography (VBMEG), which aims to improve the spatial resolution of EEG for tracking the information flow inside the brain and its changes following a stroke. The limitations of EEG are complemented by constraints derived from anatomical MRI and diffusion weighted imaging (DWI). EEG data were acquired from individuals suffering from a stroke as well as able-bodied participants while electrical stimuli were delivered sequentially at their index finger in the left and right hand, respectively. The locations of active sources related to this stimulus were precisely identified, resulting in high Variance Accounted For (VAF above 80%). An accurate estimation of dynamic information flow between sources was achieved in this study, showing a high VAF (above 90%) in the cross-validation test. The estimated dynamic information flow was compared between chronic hemiparetic stroke and able-bodied individuals. The results demonstrate the feasibility of VBMEG method in revealing the changes of information flow in the brain after stroke. This study verified the VBMEG method as an advanced computational approach to track the dynamic information flow in the brain following a stroke. This may lead to the development of a quantitative tool for monitoring functional changes of the cortical neural networks after a unilateral brain injury and therefore facilitate the research into, and the practice of stroke rehabilitation

Distinct Origin of the Y and St Genome in Elymus Species: Evidence from the Analysis of a Large Sample of St Genome Species Using Two Nuclear Genes

Previous cytological and single copy nuclear genes data suggested the St and Y genome in the StY-genomic Elymus species originated from different donors: the St from a diploid species in Pseudoroegneria and the Y from an unknown diploid species, which are now extinct or undiscovered. However, ITS data suggested that the Y and St genome shared the same progenitor although rather few St genome species were studied. In a recent analysis of many samples of St genome species Pseudoroegneria spicata (Pursh) À. Löve suggested that one accession of P. spicata species was the most likely donor of the Y genome. The present study tested whether intraspecific variation during sampling could affect the outcome of analyses to determining the origin of Y genome in allotetraploid StY species. We also explored the evolutionary dynamics of these species.Two single copy nuclear genes, the second largest subunit of RNA polymerase II (RPB2) and the translation elongation factor G (EF-G) sequences from 58 accessions of Pseudoroegneria and Elymus species, together with those from Hordeum (H), Agropyron (P), Australopyrum (W), Lophopyrum (E(e)), Thinopyrum (E(a)), Thinopyrum (E(b)), and Dasypyrum (V) were analyzed using maximum parsimony, maximum likelihood and Bayesian methods. Sequence comparisons among all these genomes revealed that the St and Y genomes are relatively dissimilar. Extensive sequence variations have been detected not only between the sequences from St and Y genome, but also among the sequences from diploid St genome species. Phylogenetic analyses separated the Y sequences from the St sequences.Our results confirmed that St and Y genome in Elymus species have originated from different donors, and demonstrated that intraspecific variation does not affect the identification of genome origin in polyploids. Moreover, sequence data showed evidence to support the suggestion of the genome convergent evolution in allopolyploid StY genome species

A prospective and double blind study on neurotopin in patients with ischemic stroke

C