Search results for "vector"
showing 10 items of 2660 documents
Malaria en España: aspectos entomológicos y perspectivas de futuro
2008
Rubén Bueno Marí (ruben.bueno@uv.es) y Ricardo Jiménez Peydró (Ricardo.Jimenez@uv.es) La malaria fue erradicada de España oficialmente en 1964. Sin embargo, en la actualidad en nuestro país se registran anualmente cientos de casos importados. En este sentido, el estudio del vector se postula de gran importancia para inferir posibles escenarios de transmisión, ya sea de tipo esporádico o regular. Si bien el nivel socio-económico del país no parece secundar una posible reemergencia de la enfermedad a corto o medio plazo, la presencia de poblaciones de anofelinos bien establecidas y gametocitos de plasmodios circulando entre cierto porcentaje de la población humana parecen avalar, con suficien…
Assessing the performance of GIS- based machine learning models with different accuracy measures for determining susceptibility to gully erosion
2019
Assessing the performance of GIS- based machine learning models withdifferent accuracy measures for determining susceptibility togully erosionYounes Garosia, Mohsen Sheklabadia,⁎, Christian Conoscentib, Hamid Reza Pourghasemic,d, Kristof Van Ooste,faFaculty of Agriculture, Department of Soil Science, Bu Ali Sina University, Ahmadi Roshan Avenue, 6517838695 Hamedan, IranbDepartment of Earth and Sea Sciences (DISTEM), University of Palermo, Via Archirafi22, 90123 Palermo, ItalycCollege of Marine Sciences and Engineering, Nanjing Normal University, Nanjing, 210023, ChinadDepartment of Natural Resources and Environmental Engineering, College of Agriculture, Shiraz University, Shiraz, IraneA- Fo…
Remaining useful life estimation of HMPE rope during CBOS testing through machine learning
2021
Fibre rope used in cranes for offshore deployment and recovery has significant potential to perform lifts with smaller cranes and vessels to reach depths limited by weight of steel wire rope. Current condition monitoring methods based on manual inspection and time-based and reactive maintenance have significant potential for improvement coupled with more accurate remaining useful life (RUL) prediction. Machine learning has found use as a condition monitoring approach, coupled with vast improvements in data acquisition methods. This paper details data-driven RUL prediction methods based on machine learning algorithms applied on cyclic-bend-over-sheave (CBOS) tests performed on two fibre rope…
Performance assessment of individual and ensemble data-mining techniques for gully erosion modeling
2017
Gully erosion is identified as an important sediment source in a range of environments and plays a conclusive role in redistribution of eroded soils on a slope. Hence, addressing spatial occurrence pattern of this phenomenon is very important. Different ensemble models and their single counterparts, mostly data mining methods, have been used for gully erosion susceptibility mapping; however, their calibration and validation procedures need to be thoroughly addressed. The current study presents a series of individual and ensemble data mining methods including artificial neural network (ANN), support vector machine (SVM), maximum entropy (ME), ANN-SVM, ANN-ME, and SVM-ME to map gully erosion …
A Wickerhamomyces anomalus Killer Strain in the Malaria Vector Anopheles stephensi
2013
The yeast Wickerhamomyces anomalus has been investigated for several years for its wide biotechnological potential, especially for applications in the food industry. Specifically, the antimicrobial activity of this yeast, associated with the production of Killer Toxins (KTs), has attracted a great deal of attention. The strains of W. anomalus able to produce KTs, called "killer" yeasts, have been shown to be highly competitive in the environment. Different W. anomalus strains have been isolated from diverse habitats and recently even from insects. In the malaria mosquito vector Anopheles stephensi these yeasts have been detected in the midgut and gonads. Here we show that the strain of W. a…
Applications of alignment-free methods in epigenomics
2013
Epigenetic mechanisms play an important role in the regulation of cell type-specific gene activities, yet how epigenetic patterns are established and maintained remains poorly understood. Recent studies have supported a role of DNA sequences in recruitment of epigenetic regulators. Alignment-free methods have been applied to identify distinct sequence features that are associated with epigenetic patterns and to predict epigenomic profiles. Here, we review recent advances in such applications, including the methods to map DNA sequence to feature space, sequence comparison and prediction models. Computational studies using these methods have provided important insights into the epigenetic reg…
An upper bound of the index of an equilibrium point in the plane
2012
Abstract We give an upper bound of the index of an isolated equilibrium point of a C 1 vector field in the plane. The vector field is decomposed in gradient and Hamiltonian components. This decomposition is related with the Loewner vector field. Associated to this decomposition we consider the set Π where the gradient and Hamiltonian components are linearly dependent. The number of branches of Π starting at the equilibrium point determines the upper bound of the index.
Desychronization of one-parameter families of stable vector fields
2005
Given a one-parameter family of vector fields on , Fλ(x), , such that for each λ, Fλ has a global asymptotically stable equilibrium point xλ, we construct a vector field on of the form G(λ, x) = (g(λ, x), Fλ(x)) which exhibits chaotic behaviour. This result is an incursion in the inverse problem of master–slave synchronization.This paper discusses self-disorganization of parameter dependent stable vector fields. Motivations are found in applications to drug design: one way to lead an unfriendly organism to death is to destabilize its metabolism. In this paper we envisage the mathematical aspect of the question. We show that for a very stable system (one globally attracting equilibrium state…
Agent's actions as a classification criteria for the state space in a learning from rewards system
2008
We focus in this paper on the problem of learning an autonomous agent's policy when the state space is very large and the set of actions available is comparatively short. To this end, we use a non-parametric decision rule (concretely, a nearest-neighbour strategy) in order to cluster the state space by means of the action that leads to a successful situation. Using an exploration strategy to avoid greedy behaviour, the agent builds clusters of positively-classified states through trial and error learning. In this paper, we implement a 3D synthetic agent which plays an 'avoid the asteroid' game that suits our assumptions. Using as the state space a feature vector space extracted from a visua…
New pegylated polyaspartamide-based polyplexes as gene delivery vectors
2010
Aims: To synthesize novel polyhydroxyethylaspartamide (PHEA) copolymers containing spermine (Spm) and polyethylene glycol (PEG) moieties in high yields, with the expectation that this material would show stealth properties and the ability to complex DNA by electrostatic interactions. Materials & methods: PHEA–PEG–Spm copolymer was prepared with a two-step reaction. Chemical, physicochemical and biological characterizations of PHEA–PEG–Spm copolymers and their obtained polyplexes with pDNA were performed. Results: The introduction of spermine in PHEA structure allows to obtain a copolymer bearing in the side chains polyamine moieties capable to interact with DNA. On the other hand, the …