18 research outputs found

    Genetic Diversity of Newcastle Disease Virus Involved in the 2021 Outbreaks in Backyard Poultry Farms in Tanzania

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    Newcastle disease virus is a significant avian pathogen with the potential to decimate poultry populations all over the world and cause enormous economic losses. Distinct NDV genotypes are currently causing outbreaks worldwide. Due to the high genetic diversity of NDV, virulent strains that may result in a lack of vaccine protection are more likely to emerge and ultimately cause larger epidemics with massive economic losses. Thus, a more comprehensive understanding of the circulating NDV genotypes is critical to reduce Newcastle disease (ND) burden. In this study, NDV strains were isolated and characterized from backyard poultry farms from Tanzania, East Africa in 2021. Reverse-transcription polymerase chain reaction (RT-PCR) based on fusion (F) gene amplification was conducted on 79 cloacal or tracheal swabs collected from chickens during a suspected ND outbreak. Our results revealed that 50 samples out 79 (50/79; 63.3%) were NDV-positive. Sequencing and phylogenetic analyses of the selected NDV isolates showed that 39 isolates belonged to subgenotype VII.2 and only one isolate belonged to subgenotype XIII.1.1. Nucleotide sequences of the NDV F genes from Tanzania were closely related to recent NDV isolates circulating in southern Africa, suggesting that subgenotype VII.2 is the predominant subgenotype throughout Tanzania and southern Africa. Our data confirm the circulation of two NDV subgenotypes in Tanzania, providing important information to design genotype-matched vaccines and to aid ND surveillance. Furthermore, these results highlight the possibility of the spread and emergence of new NDV subgenotypes with the potential of causing future ND epizootics

    A Theoretical Code to Simulate the Behaviour of an Electro-Injector for Diesel Engines and Parametric Analysis

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    A simulation code of an innovative electro-injector for Diesel engines is presented with the preliminary analysis carried out using the code. The simulation code is based on the concentrated volume method. The energy and continuity conservation equations and dynamic equations are used for the movable parts of the system under friction. The one dimensional code simulated the propagation in the feeding pump and the control of the electro-injector. The program uses the method of characteristics to solve conservation equations, simulating the propagation in the pipe between the two chambers. To go deeply into the study of the electro-injector, main routine tests were carried out checking the exact value of diesel fuel parameters and the fuel energy losses with stationary and instationary flows. A comparison with different experimental results obtained by different types of electroinjectors, running at real conditions, has been made with good agreement. Finally, a theoretical sensitivity analysis was carried out using the Design Of Experiment method to optimize the electroinjector performances

    Genomic Diversity and Geographic Distribution of Newcastle Disease Virus Genotypes in Africa : Implications for Diagnosis, Vaccination, and Regional Collaboration

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    The emergence of new virulent genotypes and the continued genetic drift of Newcastle disease virus (NDV) implies that distinct genotypes of NDV are simultaneously evolving in different geographic locations across the globe, including throughout Africa, where NDV is an important veterinary pathogen. Expanding the genomic diversity of NDV increases the possibility of diagnostic and vaccine failures. In this review, we systematically analyzed the genetic diversity of NDV genotypes in Africa using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Information published between 1999 and 2022 were used to obtain the genetic background of different genotypes of NDV and their geographic distributions in Africa. The following genotypes were reported in Africa: I, II, III, IV, V, VI, VII, VIII, XI, XIII, XIV, XVII, XVIII, XX, and XXI. A new putative genotype has been detected in the Democratic Republic of the Congo. However, of 54 African countries, only 26 countries regularly report information on NDV outbreaks, suggesting that this number may be vastly underestimated. With eight different genotypes, Nigeria is the country with the greatest genotypic diversity of NDV among African countries. Genotype VII is the most prevalent group of NDV in Africa, which was reported in 15 countries. A phylogeographic analysis of NDV sequences revealed transboundary transmission of the virus in Eastern Africa, Western and Central Africa, and in Southern Africa. A regional and continental collaboration is recommended for improved NDV risk management in Africa

    On central spanning trees of a graph

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    Druggability profile of stilbene-derived PPAR agonists: Determination of physicochemical properties and PAMPA study

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    PPAR agonists represent a new therapeutic opportunity for the prevention and treatment of neurodegenerative disorders, but their pharmacological success depends on favourable pharmacokinetic properties and capability to cross the BBB. In this study, we assayed some PPAR agonists previously synthesized by us for their physicochemical properties, with particular references to lipophilicity, solubility and permeability profiles, using the PAMPA. Although tested compounds showed high lipophilicity and low aqueous solubility, the results revealed a good overall druggability profile, encouraging further studies in the field of neurodegenerative diseases

    Using edge-valued decision diagrams for symbolic generation of shortest paths

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    Abstract. We present a new method for the symbolic construction of shortest paths in reachability graphs. Our algorithm relies on a variant of edge–valued decision diagrams that supports efficient fixed–point iterations for the joint computation of both the reachable states and their distance from the initial states. Once the distance function is known, a shortest path from an initial state to a state satisfying a given condition can be easily obtained. Using a few representative examples, we show how our algorithm is vastly superior, in terms of both memory and space, to alternative approaches that compute the same information, such as ordinary or algebraic decision diagrams.

    Discovery of N-3-[(ethanimidoylamino)methyl]benzyl-l-prolinamide dihydrochloride: A new potent and selective inhibitor of the inducible nitric oxide synthase as a promising agent for the therapy of malignant glioma

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    In mammalian cells, aberrant iNOS induction may have detrimental consequences, and seems to be involved in the proliferation and progression of different tumors, such as malignant gliomas. Therefore, selective inhibition of iNOS could represent a feasible therapeutic strategy to treat these conditions. In this context, we have previously disclosed new acetamidines able to inhibit iNOS with a very high selectivity profile over eNOS or nNOS. Here we report the synthesis of a new series of compounds structurally related to the leading scaffold of N-[(3-aminomethyl)benzyl] acetamidine (1400 W), together with their in vitro activity and selectivity. Compound 39 emerged as the most promising molecule of this series, and it was ex vivo evaluated on isolated and perfused resistance arteries, confirming a high selectivity toward iNOS inhibition. Moreover, C6 rat glioma cell lines biological response to 39 was investigated, and preliminary MTT assay showed a significant decrease in cell metabolic activity of C6 rat glioma cells. Finally, results of a docking study shed light on the binding mode of 39 into NOS catalytic site

    A framework to decompose GSPN models

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    This paper presents a framework to decompose a single GSPN model into a set of small interacting models. This decomposition technique can be applied to any GSPN model with a finite set of tangible markings and a generalized tensor algebra (Kronecker) representation can be produced automatically. The numerical impact of all the possible decompositions obtained by our technique is discussed. To do so we draw the comparison of the results for some practical examples. Finally, we present all the computational gains achieved by our technique, as well as the future extensions of this concept for other structured formalisms.</p
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