975 resultados para infinite horizon
Resumo:
We explore which types of finiteness properties are possible for intersections of geometrically finite groups of isometries in negatively curved symmetric rank one spaces. Our main tool is a twist construction which takes as input a geometrically finite group containing a normal subgroup of infinite index with given finiteness properties and infinite Abelian quotient, and produces a pair of geometrically finite groups whose intersection is isomorphic to the normal subgroup.
Resumo:
We analyze the two-dimensional parabolic-elliptic Patlak-Keller-Segel model in the whole Euclidean space R2. Under the hypotheses of integrable initial data with finite second moment and entropy, we first show local in time existence for any mass of "free-energy solutions", namely weak solutions with some free energy estimates. We also prove that the solution exists as long as the entropy is controlled from above. The main result of the paper is to show the global existence of free-energy solutions with initial data as before for the critical mass 8 Π/Χ. Actually, we prove that solutions blow-up as a delta dirac at the center of mass when t→∞ keeping constant their second moment at any time. Furthermore, all moments larger than 2 blow-up as t→∞ if initially bounded.
Resumo:
In this work we introduce and analyze a linear size-structured population model with infinite states-at-birth. We model the dynamics of a population in which individuals have two distinct life-stages: an “active” phase when individuals grow, reproduce and die and a second “resting” phase when individuals only grow. Transition between these two phases depends on individuals’ size. First we show that the problem is governed by a positive quasicontractive semigroup on the biologically relevant state space. Then we investigate, in the framework of the spectral theory of linear operators, the asymptotic behavior of solutions of the model. We prove that the associated semigroup has, under biologically plausible assumptions, the property of asynchronous exponential growth.
Resumo:
Due to population aging, by 2030 Switzerland may face a demand of 24 million family practitioner visits, a growth of 13 percent from the 2005 level. This result is based on the assumption that the per capita demand for doctor visits remains what was observed in 2005 by age groups and sex. During the same period, the total number of practitioners may decrease by 14 percent whereas the female proportion of such practitioners may double. These changes may cause a 33 percent decrease in the supply of physician visits to reach only 14 millions. The comparison of the demand and supply of family doctor visits reveals that by 2030, 10 million visits may be unmet which represents 40 percent of the demand. On the supply side, a full scale implementation of task delegation may partially reduce that gap (minus 2 millions). On the demand side, improved health status may bring in a larger decrease in the needs for visits (minus 4 million).
Resumo:
This paper shows that certain quotients of entire functions are characteristic functions. Under some conditions, we provide expressions for the densities of such characteristic functions which turn out to be generalized Dirichlet series which in turn can be expressed as an infinite linear combination of exponential or Laplace densities. We apply these results to several examples.
Resumo:
The objective of this paper is to re-examine the risk-and effort attitude in the context of strategic dynamic interactions stated as a discrete-time finite-horizon Nash game. The analysis is based on the assumption that players are endogenously risk-and effort-averse. Each player is characterized by distinct risk-and effort-aversion types that are unknown to his opponent. The goal of the game is the optimal risk-and effort-sharing between the players. It generally depends on the individual strategies adopted and, implicitly, on the the players' types or characteristics.
Resumo:
"Vegeu el resum a l'inici del document del fitxer adjunt."
Des paroles bibliques qui ouvrent un horizon: place de la Bible dans l'accompagnement (1ère partie).
Resumo:
Primary brain tumours are heterogeneous in histology, genetics, and outcome. Although WHO's classification of tumours of the CNS has greatly helped to standardise diagnostic criteria worldwide, it does not consider the substantial progress that has been made in the molecular classification of many brain tumours. Recent practice-changing clinical trials have defined a role for routine assessment of MGMT promoter methylation in glioblastomas in elderly people, and 1p and 19q codeletions in anaplastic oligodendroglial tumours. Moreover, large-scale molecular profiling approaches have identified new mutations in gliomas, affecting IDH1, IDH2, H3F3, ATRX, and CIC, which has allowed subclassification of gliomas into distinct molecular subgroups with characteristic features of age, localisation, and outcome. However, these molecular approaches cannot yet predict patients' benefit from therapeutic interventions. Similarly, transcriptome-based classification of medulloblastoma has delineated four variants that might now be candidate diseases in which to explore novel targeted agents.
Resumo:
The persistence of the biocontrol agent Pseudomonas fluorescens CHA0 in the surface horizon of 12 large outdoor lysimeters planted with winter wheat, Phacelia tanacetifolia followed by spring wheat, or maize was monitored for 1 year. Soil was inoculated with a spontaneous rifampin-resistant mutant (CHA0-Rif) of CHA0, and the strain was studied by using colony counts, Kogure's direct viable counts, and total counts (immunofluorescence). The number of culturable cells of the inoculant decreased progressively from 8 to 2 log CFU/g of soil or lower. However, culturable cells of CHA0-Rif accounted for less than 1% of the total cells of the inoculant 8 months after release in autumn. Since viable but nonculturable cells represented less than a quarter of the latter, most cells of CHA0-Rif in soil were thus inactive-dormant or dead at that time. Nonculturable cells of the inoculant were predominant also in the surface horizon of the lysimeters inoculated in the spring, and a significant fraction of them were viable. Results suggest that the occurrence of nonculturable cells of CHA0-Rif was influenced by climatic factors (water availability and soil temperature) and the abundance of roots in soil. The fact that the inoculant persisted as mixed populations of cells of different physiological states, in which nonculturable cells were predominant, needs to be taken into account when assessing the autecology of wild-type or genetically modified pseudomonads released into the soil ecosystem.
Resumo:
The series of Horizon Reports is the most tangible outcome of the New Media Consortium's Horizon Project, a qualitative research endeavour launched in 2002 which identifies and describes the emergingtechnologies with the greatest potential to have an impact on teaching, learning, research and creative expression in the global education field. This volume,the 2010 Horizon Report: Iberoamerican Edition, focuses on research in countries of the iberoamerican region (including the whole of Latin America, Spainand Portugal) and in the field of higher education. The 2010 Horizon Report: Iberoamerican Edition is the first to offer this regional contextualization and hasbeen produced by the NMC and the eLearn Center of the Universitat Oberta de Catalunya (UOC).
Resumo:
La sèrie d'informes Horizon és el resultat més tangible del Projecte Horizon del New Media Consortium, un esforç de recerca qualitativa iniciat el 2002, que identifica i descriu les tecnologies emergents amb més potencial d'impacte en l'ensenyament, l'aprenentatge, la recerca i la expressió creativa en l'àmbit educatiu global. Aquest volum, l'Informe Horizon 2010: Edició Iberoamericana, se centra en la investigació en els països de la regió Iberoamericana (incloent-hi tota Llatinoamèrica, Espanya i Portugal) i en l'àmbit de l'educació superior. L'Informe Horizon 2010: Edició Iberoamericana és el primer que ofereix aquesta contextualització regional i ha estat produït per l'NMC i el eLearn Center de la Universitat Oberta de Catalunya.