Search results for "vector"
showing 10 items of 2660 documents
Transmissibility of Broad bean wilt virus 1 by aphids: influence of virus accumulation in plants, virus genotype and aphid species
2013
Broad bean wilt virus 1 (BBWV-1) is transmitted by several aphid species in a non-persistent manner. Transmission efficiency by vectors is a key factor for understanding virus epidemiology and applying disease control measures based on limiting virus spread. We evaluated the transmission rates of two genetically divergent BBWV-1 isolates (PV-132 from USA and Ben from Spain) infecting broad bean (Vicia faba L.) by isofemale lines of nine aphid species from eight different genera collected in Spain. Our analyses showed that: (a) the virus concentration in the source plant was a key factor in BBWV-1 transmissibility; (b) The Spanish isolate Ben was transmitted more efficiently than the America…
Audio-video people recognition system for an intelligent environment
2011
In this paper an audio-video system for intelligent environments with the capability to recognize people is presented. Users are tracked inside the environment and their positions and activities can be logged. Users identities are assessed through a multimodal approach by detecting and recognizing voices and faces through the different cameras and microphones installed in the environment. This approach has been chosen in order to create a flexible and cheap but reliable system, implemented using consumer electronics. Voice features are extracted by a short time cepstrum analysis, and face features are extracted using the eigenfaces technique. The recognition task is solved using the same Su…
High-resolution transmission electron microscopic investigations of molybdenum thin films on faceted α-Al2O3
2005
Epitaxially grown Mo films on a faceted corundum (α-Al2O3)mplane were investigated by transmission electron microscopy. Low- and high-resolution images were taken from a cross-section specimen cut perpendicular to the facets. It was possible to identify unambiguously the crystallographic orientation of these facets and explain the considerable deviation (∼10°) of the experimental interfacet angle, as measured with atomic force microscopy (AFM), from the expected value. For the first time, proof is given for a smooth \{10\bar{1}1\} facet and a curvy facet with orientation near to \{10\bar{1}\bar{2}\}. Moreover, the three-dimensional epitaxial relationship of an Mo film on a faceted corundumm…
Languages with mismatches and an application to approximate indexing
2005
In this paper we describe a factorial language, denoted by L(S, k,r), that contains all words that occur in a string 5 up to k mismatches every r symbols. Then we give some combinatorial properties of a parameter, called repetition index and denoted by R(S,k,r), defined as the smallest integer h ? 1 such that all strings of this length occur at most in a unique position of the text S up to k mismatches every r symbols. We prove that R(S, k, r) is a non-increasing function of r and a non-decreasing function of k and that the equation r = R(S, k, r) admits a unique solution. The repetition index plays an important role in the construction of an indexing data structure based on a trie that rep…
Fascioliasis and other plant-borne trematode zoonoses
2005
Fascioliasis and other food-borne trematodiases are included in the list of important helminthiases with a great impact on human development. Six plant-borne trematode species have been found to affect humans: Fasciola hepatica, Fasciola gigantica and Fasciolopsis buski (Fasciolidae), Gastrodiscoides hominis (Gastrodiscidae), Watsonius watsoni and Fischoederius elongatus (Paramphistomidae). Whereas F. hepatica and F. gigantica are hepatic, the other four species are intestinal parasites. The fasciolids and the gastrodiscid cause important zoonoses distributed throughout many countries, while W. watsoni and F. elongatus have been only accidentally detected in humans. Present climate and glob…
Low-altitude outbreaks of human fascioliasis related with summer rainfall in Gilan province, Iran
2011
Following human fascioliasis outbreaks in 1988 and 1999 in Gilan province, northern Iran, efforts are now made to shed light on the seasonal pattern of fascioliasis transmission in this endemic area, taking into account snail host populations, climatic conditions and human cases. Populations of the intermediate host snail (Lymnaea spp.) peak in May and November, while there is a fourfold increase in the rate of human fascioliasis in February compared to that of September. Transmission is likely to occur mainly in late autumn and sporadically in late spring. Rainfall, seasonally analysed in periods of 3 years, indicates that accumulated summer rainfall may be related with the 1988 and 1999 h…
DNA sequence characterisation and phylogeography of Lymnaea cousini and related species, vectors of fascioliasis in northern Andean countries, with d…
2011
Abstract Background Livestock fascioliasis is a problem throughout Ecuador, Colombia and Venezuela, mainly in Andean areas where the disease also appears to affect humans. Transmission patterns and epidemiological scenarios of liver fluke infection have shown to differ according to the lymnaeid vector snail species involved. These Andean countries present the vectors Lymnaea cousini, L. bogotensis and L. ubaquensis, unknown in the rest of Latin America. An exhaustive combined haplotype study of these species is performed by means of DNA sequencing of the nuclear ribosomal 18S RNA gene, ITS-2 and ITS-1, and mitochondrial DNA cox 1 gene. Results The conserved 5.8S rDNA sequence corroborated t…
Effective feature descriptor-based new framework for off-line text-independent writer identification
2018
Feature engineering is a key factor of machine learning applications. It is a fundamental process in writer identification of handwriting, which is an active and challenging field of research for many years. We propose a conceptually computationally efficient, yet simple and fast local descriptor referred to as Block Wise Local Binary Count (BW-LBC) for offline text-independent writer identification of handwritten documents. Proposed BW-LBC operator, which characterizes the writing style of each writer, is applied to a set of connected components extracted and cropped from scanned handwriting samples (documents or set of words/text lines) where each labeled component is seen as a texture im…
Adaptive Distance-Based Pooling in Convolutional Neural Networks for Audio Event Classification
2020
In the last years, deep convolutional neural networks have become a standard for the development of state-of-the-art audio classification systems, taking the lead over traditional approaches based on feature engineering. While they are capable of achieving human performance under certain scenarios, it has been shown that their accuracy is severely degraded when the systems are tested over noisy or weakly segmented events. Although better generalization could be obtained by increasing the size of the training dataset, e.g. by applying data augmentation techniques, this also leads to longer and more complex training procedures. In this article, we propose a new type of pooling layer aimed at …