Search results for "Vector"
showing 10 items of 2660 documents
Microbiota Variation Across Life Stages of European Field-Caught Anopheles atroparvus and During Laboratory Colonization: New Insights for Malaria Re…
2021
The potential use of bacteria for developing novel vector control approaches has awakened new interests in the study of the microbiota associated with vector species. To set a baseline for future malaria research, a high-throughput sequencing of the bacterial 16S ribosomal gene V3-V4 region was used to profile the microbiota associated with late-instar larvae, newly emerged females, and wild-caught females of a sylvan Anopheles atroparvus population from a former malaria transmission area of Spain. Field-acquired microbiota was then assessed in non-blood-fed laboratory-reared females from the second, sixth, and 10th generations. Diversity analyses revealed that bacterial communities varied …
Visceral leishmaniasis: host-parasite interactions and clinical presentation in the immunocompetent and in the immunocompromised host.
2013
SummaryVisceral leishmaniases are vector-borne parasitic diseases caused by protozoa belonging to the genus Leishmania. The heterogeneity of clinical manifestations and epidemiological characteristics of the disease reflect the complex interplay between the infecting Leishmania species and the genetic and immunologic characteristics of the infected host. The clinical presentation of visceral leishmaniasis depends strictly on the immunocompetency of the host and ranges from asymptomatic to severe forms. Conditions of depression of the immune system, such as HIV infection or immunosuppressive treatments, impair the capability of the immune response to resolve the infection and allow reactivat…
Systematics of Mepraia (Hemiptera-Reduviidae): cytogenetic and molecular variation.
2009
The haematophagous insects of the subfamily Triatominae (Hemiptera-Reduviidae) have great epidemiological importance as vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Mepraia was originally described as a monotypic genus comprised of Mepraia spinolai, distributed along coastal areas of northern Chile (from Region I to the Metropolitan Region). Recently, some M. spinolai populations have been ranked as a new species named Mepraia gajardoi. Several populations along the distribution range of the genus were sampled, and genetic differentiation was studied based upon the analysis of three molecular markers: cytogenetics (karyotype and chromosome behaviour during meiosis us…
Nuclear rDNA pseudogenes in Chagas disease vectors: Evolutionary implications of a new 5.8S+ITS-2 paralogous sequence marker in triatomines of North,…
2013
A pseudogene, paralogous to rDNA 5.8S and ITS-2, is described in Meccus dimidiata dimidiata, M. d. capitata, M. d. maculippenis, M. d. hegneri, M. sp. aff. dimidiata, M. p. phyllosoma, M. p. longipennis, M. p. pallidipennis, M. p. picturata, M. p. mazzottii, Triatoma mexicana, Triatoma nitida and Triatoma sanguisuga, covering North America, Central America and northern South America. Such a nuclear rDNA pseudogene is very rare. In the 5.8S gene, criteria for pseudogene identification included length variability, lower GC content, mutations regarding the functional uniform sequence, and relatively high base substitutions in evolutionary conserved sites. At ITS-2 level, criteria were the shor…
Honey Bee Suppresses the Parasitic Mite Vitellogenin by Antimicrobial Peptide
2020
AbstractThe negative effects of honey bee parasitic mites and deformed wing virus (DWV) on honey bee and colony health have been well characterized. However, the relationship between DWV and mites, particularly viral replication inside the mites, remains unclear. Furthermore, the physiological outcomes of honey bee immune responses stimulated by DWV and the mite to the host (honey bee) and perhaps the pathogen/parasite (DWV/mite) are not yet understood. To answer these questions, we studied the tripartite interactions between the honey bee,Tropilaelaps mercedesae, and DWV as the model.T. mercedesaefunctioned as a vector for DWV without supporting active viral replication. Thus, DWV negligib…
The eigen-structure of the Jacobian in multi-class Lighthill-Whitham-Richards traffic flow models
2007
Characteristic-based High Resolution Shock Capturing schemes for hyperbolic systems of conservation laws require, in their basic design structure, knowledge on the complete eigen-decomposition of the Jacobian matrix of the system. For the Multi-Class Lighthill-Witham-Richards (MCLWR) Traffic flow model considered in [4], there is no explicit formula for the eigenvalues of the Jacobian matrix, which can only be determined numerically. However, once they are determined, the eigen-vectors are easily computed and straightforward formulas can be obtained by exploiting the specific structure of the Jacobian matrix in these models. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterisation of Lymnaea cubensis, L. viatrix and L. neotropica n. sp., the main vectors of Fasciola hepatica in Latin America, by analysis of the…
2007
Although, in the endemic areas throughout the world, human fascioliasis presents varying patterns in its epidemiology, the species of lymnaeid snail that act as intermediate hosts and vectors are always crucial in the transmission of the causative parasites. Species in the Galba/Fossaria group of snails, such as Lymnaea cubensis, L. viatrix var. A ventricosa, L. viatrix var. B elongata and Galba truncatula, appear to be frequently involved in the transmission of Fasciola hepatica in Central and South America, although specific classification within this morphologically and anatomically confusing group is often very difficult. To explore the potential use of molecular analyses in the identif…
DNA Multi-Marker Genotyping and CIAS Morphometric Phenotyping of Fasciola gigantica-Sized Flukes from Ecuador, with an Analysis of the Radix Absence …
2021
Simple Summary Fasciolid flukes collected from sheep and cattle in Ecuador showed a high diversity in DNA sequences whose analyses indicated introductions from South America, European and North American countries. These results agree with the numerous livestock importations performed by Ecuador. Abnormally big-sized liver flukes were found in Ecuadorian sheep. The morphometric phenotypic CIAS study showed that its size maximum and mean very pronouncedly and significantly surpassed those of the Fasciola hepatica populations from South America and Spain and proved to be intermediate between standard F. hepatica and F. gigantica populations. Such a feature is only known in intermediate fasciol…
State Estimation of a Mobile Manipulator via Non-uniformly Sampled Position Measurements
2011
Abstract We derive an exact deterministic nonlinear estimator to compute the continuous state of a nonlinear time-varying system based on discrete, non uniformly time spaced, state measurements. The system consists of a robot arm mounted on a mobile non holonomic vehicle. The paper also discusses the effect on the estimation error of a bounded input additive noise.
Detecting global and local hippocampal shape changes in Alzheimer's disease using statistical shape models.
2012
Item does not contain fulltext The hippocampus is affected at an early stage in the development of Alzheimer's disease (AD). With the use of structural magnetic resonance (MR) imaging, we can investigate the effect of AD on the morphology of the hippocampus. The hippocampal shape variations among a population can be usually described using statistical shape models (SSMs). Conventional SSMs model the modes of variations among the population via principal component analysis (PCA). Although these modes are representative of variations within the training data, they are not necessarily discriminative on labeled data or relevant to the differences between the subpopulations. We use the shape des…