342 research outputs found
DNA Content, Karyotype Structure Analysis and Karyotype Symmetry in Ranunculus L. (Ranunculaceae). Italian Species Belonging to Sections Flammula (Webb) Benson and Micranthus (Ovcz.) Nyarady
SUMMARYDNA microdensitometric measurements and karyotype analysis show that in spite of variable ploidy level (2x—16x) and mean chromosome size (0.37—0.83 pg), genomic structure is remarkably constant throughout both the examined Sections. Karyotype symmetry, defined numerically for each species, has been compared with that of other species of Ranunculus (Subgen. Ranunculus). Such comparison confirms that both the examined Sections include relatively advanced species as suggested by DAVIS (1960) on the grounds of macromorphic and ecological elements
Recommended from our members
The pgip family in soybean and three other legume species: evidence for a birth-and-death model of evolution
Polygalacturonase-inhibiting proteins (PGIPs) are leucine-rich repeat (LRR) plant cell wall glycoproteins involved in plant immunity. They are typically encoded by gene families with a small number of gene copies whose evolutionary origin has been poorly investigated. Here we report the complete characterization of the full complement of the pgip family in soybean (Glycine max [L.] Merr.) and the characterization of the genomic region surrounding the pgip family in four legume species. Results: BAC clone and genome sequence analyses showed that the soybean genome contains two pgip loci. Each locus is composed of three clustered genes that are induced following infection with the fungal pathogen Sclerotinia sclerotiorum (Lib.) de Bary, and remnant sequences of pgip genes. The analyzed homeologous soybean genomic regions (about 126 Kb) that include the pgip loci are strongly conserved and this conservation extends also to the genomes of the legume species Phaseolus vulgaris L., Medicago truncatula Gaertn. and Cicer arietinum L., each containing a single pgip locus. Maximum likelihood-based gene trees suggest that the genes within the pgip clusters have independently undergone tandem duplication in each species. Conclusions: The paleopolyploid soybean genome contains two pgip loci comprised in large and highly conserved duplicated regions, which are also conserved in bean, M. truncatula and C. arietinum. The genomic features of these legume pgip families suggest that the forces driving the evolution of pgip genes follow the birth-and-death model, similar to that proposed for the evolution of resistance (R) genes of NBS-LRR-type
Age representation of Levy walks: partial density waves, relaxation and first passage time statistics
LĂ©vy walks (LWs) define a fundamental class of finite velocity stochastic processes that can be introduced as a special case of continuous time random walks. Alternatively, there is a hyperbolic representation of them in terms of partial probability density waves. Using the latter framework we explore the impact of aging on LWs, which can be viewed as a specific initial preparation of the particle ensemble with respect to an age distribution. We show that the hyperbolic age formulation is suitable for a simple integral representation in terms of linear Volterra equations for any initial preparation. On this basis relaxation properties, i.e. the convergence towards equilibrium of a generic thermodynamic function dependent on the spatial particle distribution, and first passage time statistics in bounded domains are studied by connecting the latter problem with solute release kinetics. We find that even normal diffusive LWs, where the long-term mean square displacement increases linearly with time, may display anomalous relaxation properties such as stretched exponential decay. We then discuss the impact of aging on the first passage time statistics of LWs by developing the corresponding Volterra integral representation. As a further natural generalization the concept of LWs with wearing is introduced to account for mobility losses
Recommended from our members
Creative and cultural industries and global production network approaches so far
Digital work-flow
The project presents a clinical case in which the digital work-flow procedure was applied for a prosthetic rehabilitation in natural teeth and implants. Digital
work-flow uses patient’s photo for the aesthetic’s planning, digital smile technology for the simulation of
the final restoration and real time scanning to register the two arches. Than the scanning are sent to the laboratory that proceed with CAD-CAM production. Digital work-flow offers the opportunities to easily speak with laboratory and patients, gives better clinical results
and demonstrated to be a less invasiveness method for the patient. Intra-oral scanner, digital smile design, preview using digital wax-up, CAD-CAM production, are new predictable opportunities for prosthetic team. This
work-flow, compared with traditional methods, is faster, more precise and predictable
Wheat glutenin subunits and dough elasticity: findings of the EUROWHEAT project
Detailed studies of wheat glutenin subunits have provided novel details of their molecular structures and interactions which allow the development of a model to explain their role in determining the visco-elastic properties of gluten and dough. The construction and analysis of near-isogenic and transgenic lines expressing novel subunit combinations or increased amounts of specific subunits allows differences in gluten properties to be related to the structures and properties of individual subunits, with potential benefits for the production of cultivars with improved properties for food processing or novel end user
- …