Search results for " space"
showing 10 items of 4562 documents
Characterisation of Pythium paroecandrum and its antagonism towards Botrytis cinerea, the causative agent of grey mould disease of grape.
2004
Pythium paroecandrum (B-30), an oomycete, was isolated from soil samples taken from a wheat field in Genlis in the Burgundy region of France and was found to check the growth and development of Botrytis cinerea, a serious grapevine pathogen. The oomycete is a fast-growing organism, living on vegetable debris, and can be recognised by its catenulate hyphal swellings, catenulate oogonia, and monoclinous antheridia. When grown together with B. cinerea, the causal agent of the grey mould disease of the grapevine, P. paroecandrum shows a pronounced antagonism and suppresses its growth and its aptitude to provoke the grey mould symptoms. Morphological features of this oomycete, its antagonism to …
A new mycoparasite, Pythium lycopersicum, isolated in Isparta, Turkey: morphology, molecular characteristics, and its antagonism with phytopathogenic…
2008
Pythium lycopersicum sp. nov. has been isolated from soil samples taken in an agricultural land in the Isparta region of Southern Turkey. This oomycete is characterized by its contiguous sporangia having globose to elongated elements linked with hyphal filaments, ornamented oogonia, and monoclinous antheridia with large antheridial cells. The oomycete is reminiscent of Pythium ornamentatum described by the corresponding author in 1987 from soil samples taken in Algeria. Sequence analyses of the internal transcribed spacer (ITS) regions of rRNA show a close relationship with Pythium oligandrum and other mycoparasites possessing ornamented oogonia. Morphological and molecular features of this…
On the discreet spectrum of fractional quantum hydrogen atom in two dimensions
2019
We consider a fractional generalization of two-dimensional (2D) quantum-mechanical Kepler problem corresponding to 2D hydrogen atom. Our main finding is that the solution for discreet spectrum exists only for $\mu>1$ (more specifically $1 < \mu \leq 2$, where $\mu=2$ corresponds to "ordinary" 2D hydrogenic problem), where $\mu$ is the L\'evy index. We show also that in fractional 2D hydrogen atom, the orbital momentum degeneracy is lifted so that its energy starts to depend not only on principal quantum number $n$ but also on orbital $m$. To solve the spectral problem, we pass to the momentum representation, where we apply the variational method. This permits to obtain approximate analytica…
Fractional Maximal Functions in Metric Measure Spaces
2013
Abstract We study the mapping properties of fractional maximal operators in Sobolev and Campanato spaces in metric measure spaces. We show that, under certain restrictions on the underlying metric measure space, fractional maximal operators improve the Sobolev regularity of functions and map functions in Campanato spaces to Hölder continuous functions. We also give an example of a space where fractional maximal function of a Lipschitz function fails to be continuous.
Fixed Point Theorems with Applications to the Solvability of Operator Equations and Inclusions on Function Spaces
2015
Fixed point theory is an elegant mathematical theory which is a beautiful mixture of analysis, topology, and geometry. It is an interdisciplinary theory which provides powerful tools for the solvability of central problems in many areas of current interest in mathematics and other quantitative sciences, such as physics, engineering, biology, and economy. In fact, the existence of linear and nonlinear problems is frequently transformed into fixed point problems, for example, the existence of solutions to partial differential equations, the existence of solutions to integral equations, and the existence of periodic orbits in dynamical systems. This makes fixed point theory a topical area and …
Recent Developments on Fixed Point Theory in Function Spaces and Applications to Control and Optimization Problems
2015
Nonlinear and Convex Analysis have as one of their goals solving equilibrium problems arising in applied sciences. In fact, a lot of these problems can be modelled in an abstract form of an equation (algebraic, functional, differential, integral, etc.), and this can be further transferred into a form of a fixed point problem of a certain operator. In this context, finding solutions of fixed point problems, or at least proving that such solutions exist and can be approximately computed, is a very interesting area of research. The Banach Contraction Principle is one of the cornerstones in the development of Nonlinear Analysis, in general, and metric fixed point theory, in particular. This pri…
Study on the financial performance of companies operating in the pharmaceutical industry in romania
2016
Abstract The study aims at determining the financial performance of companies in the pharmaceutical industry between 2009 and 2014 by means of the indicator of the financial return rate, using multiple linear regressions as research method. By analysing the evolution of the share of companies in the pharmaceutical industry based on the trend of the financial rate of return, we can estimate that the number of entities that resort to supporting the financial activities from loans and liabilities is growing in the period under analysis. This is due mainly to the liquidity crisis faced by entities, as a result of the high recovery duration of debts. Also, using the multiple linear regression we…
Density flow over networks: A mean-field game theoretic approach
2014
A distributed routing control algorithm for dynamic networks has recently been presented in the literature. The networks were modeled using time evolution of density at network edges and the routing control algorithm allowed edge density to converge to a Wardrop equilibrium, which was characterized by an equal traffic density on all used paths. We borrow the idea and rearrange the density model to recast the problem within the framework of mean-field games. The contribution of this paper is three-fold. First, we provide a mean-field game formulation of the problem at hand. Second, we illustrate an extended state space solution approach. Third, we study the stochastic case where the density …
Faint γ-ray sources at low redshift: the radio galaxy IC 1531
2018
We present amultiwavelength study of IC 1531 (z=0.02564), an extragalactic radio source associated with the γ -ray object 3FGL J0009.9-3206 and classified as a blazar of uncertain type in the Third Fermi-Large Area Telescope AGN catalog (3LAC). A core-jet structure, visible in radio and X-rays, is enclosed within a ~220 kpc wide radio structure. The morphology and spectral characteristics of the kiloparsec jet in radio and X-rays are typical of Fanaroff-Riley type I galaxies. The analysis of the radio data and optical spectrum and different diagnostic methods based on the optical, infrared, and γ -ray luminosities also support a classification as a low-power RG seen at moderate angles (θ = …
Contrast sensitivity perimetry tests along the cardinal directions in color space: Correlation with the properties of the neural mechanisms mediating…
2014
It is well-known the advantages of measuring chromatic and achromatic contrast sensitivity for detecting pathologies. But these measurements are rarely used in clinical practice, due the complexity of the measurements and the examinator specialization. In fact, there is not a complete characterization of the response of the visual pathways to achromatic and chromatic spatio-temporal frequency stimuli. We have designed a new experimental device that facilitates these measurements and allow us to characterize the visual response in healthy patients. In this paper, we evaluated the responses of the visual pathways in healthy patients.