15,320 research outputs found
Nonlinear Response of Inertial Tracers in Steady Laminar Flows: Differential and Absolute Negative Mobility
We study the mobility and the diffusion coefficient of an inertial tracer advected by a two-dimensional incompressible laminar flow, in the presence ofthermal noise and under the actionof an external force. We show, with extensive numerical simulations, that the force-velocity rela-tion for the tracer, in the nonlinear regime, displays complex and rich behaviors, including negativedifferential and absolute mobility. These effects rely upon asubtle coupling between inertia andapplied force which induce the tracer to persist in particular regions of phase space with a velocityopposite to the force. The relevance of this coupling is revisited in the framework of non-equilibriumresponse theory, applying a generalized Einstein relationto our system. The possibility of experi-mental observation of these results is also discussed
Noise versus chaos in a causal Fisher-Shannon plane
We revisit the Fisher-Shannon representation plane , evaluated using the Bandt and Pompe recipe to assign a
probability distribution to a time series. Several stochastic dynamical (noises
with , , power spectrum) and chaotic processes (27 chaotic
maps) are analyzed so as to illustrate the approach. Our main achievement is
uncovering the informational properties of the planar location.Comment: 6 pages, 1 figure. arXiv admin note: text overlap with
arXiv:1401.213
A preliminary transcriptomic approach to elucidate post harvest ripening of plum fruit
The aim of the present study was to dissect common and/or diverse mechanisms regulating plum (Prunus salicina) fruit ripening in genotypes characterized by different patterns of ethylene production. Fruit of an ethylenesuppressed cultivar ('Shiro') and a cultivar characterized by the typical increase of ethylene production during fruit ripening ('Santa Rosa') were harvested at commercial maturity stage and allowed to further ripen at room temperature (23°C) up to 4 days. While non-detectable amounts of ethylene were recorded in 'Shiro' fruit, a typical climacteric behavior was observed in 'Santa Rosa' plums. For comparative purposes, the peach microarray μPEACH 1.0 containing 4,806 oligonucleotides corresponding to an equal number of genes expressed in peach fruit was employed for transcript profiling during postharvest ripening of both cultivars. Intriguingly, transcript levels of genes involved in ethylene biosynthesis, primarily 1-aminocyclopropane-1-carboxylate synthase, appeared to increase during the progress of 'Shiro' fruit ripening, following the same pattern as in 'Santa Rosa' plums. These data suggest that an induction of the ethylene biosynthetic pathway is present also in plum cultivars in which the burst of ethylene is not detectable. Expression levels of other genes implicated in auxin metabolism, antioxidant system and stress response followed the same pattern in both cultivars. Overall, this preliminary transcriptomic approach tried to elucidate the flow of events that accompany postharvest ripening of plum cultivars with diverse properties in relation to ethylene evolutio
How are topics born? Understanding the research dynamics preceding the emergence of new areas
The ability to promptly recognise new research trends is strategic for many stake- holders, including universities, institutional funding bodies, academic publishers and companies. While the literature describes several approaches which aim to identify the emergence of new research topics early in their lifecycle, these rely on the assumption that the topic in question is already associated with a number of publications and consistently referred to by a community of researchers. Hence, detecting the emergence of a new research area at an embryonic stage, i.e., before the topic has been consistently labelled by a community of researchers and associated with a number of publications, is still an open challenge. In this paper, we begin to address this challenge by performing a study of the dynamics preceding the creation of new topics. This study indicates that the emergence of a new topic is anticipated by a significant increase in the pace of collaboration between relevant research areas, which can be seen as the ‘parents’ of the new topic. These initial findings (i) confirm our hypothesis that it is possible in principle to detect the emergence of a new topic at the embryonic stage, (ii) provide new empirical evidence supporting relevant theories in Philosophy of Science, and also (iii) suggest that new topics tend to emerge in an environment in which weakly interconnected research areas begin to cross-fertilise
U.S. Investors’ Response to Philippine Capital Market Liberalization: Evidence from the First Philippine Fund
This paper investigates the impact of liberalization of international investment restrictions in the Philippines on the discounts of the First Philippine Fund (FPF) closed-end country fund. In particular, it investigates whether such restrictions are binding and how U.S. investors see the announced relaxation of restrictions. The overall results suggest evidence supporting the hypothesis that changes in the FPF’s discounts are associated with the announcements of changes in restrictions in international investment.capital markets, liberalization, investment
Space Time Defects as a Source of Curvature and Torsion
Space time is described as a continuum four-dimensional medium similar to
ordinary elastic continua. Exploiting the analogy internal stress states are
considered. The internal ''stress'' is originated by the presence of defects.
The defects are described according to the typical Volterra process. The case
of a point defect in an otherwise isotropic four-dimensional medium is
discussed showing that the resulting metric tensor corresponds to an expanding
(or contracting) universe filled up with a non-zero energy-momentum density.Comment: Presentation at the Sixth Friedman seminar in Cargese 28/6-3/7/2004.
Submitted for the proceedings of the seminar to appear in the International
Journal of Modern Physics
Has Foreign Entry Made Domestic Banks More Efficient?
Has foreign entry indeed made domestic banks more efficient? Unite's and Sullivan's study, based on a sample of 16 expanded commercial banks (ECBs) and general macroeconomic data for the Philippines for the period 1990-1998, on the whole, supports the view of a general weakening of relationship-style banking brought about by the liberalization of foreign presence in the Philippine banking sector. This has consequences, of course, to the practices in the domestic banking industry. Read more in this Policy Notes.financial liberalization, foreign bank entry, domestic banks, expanded commercial banks
Automated technologies needed to prevent radioactive materials from reentering the atmosphere
Project SIREN (Search, Intercept, Retrieve, Expulsion Nuclear) was created to identify and evaluate the technologies and operational strategies needed to rendezvous with and capture aerospace radioactive materials (e.g., a distressed or spent space reactor core) before such materials can reenter the terrestrial atmosphere and then to safely move these captured materials to an acceptable space destination for proper disposal. A major component of the current project SIREN effort is the development of an interactive technology model (including a computerized data base) that explores, in building-block fashion, the interaction of the technologies and procedures needed to successfully accomplish a SIREN mission. The SIREN model will include appropriate national and international technology elements--both contemporary and projected into the next century. To obtain maximum flexibility and use, the SIREN technology data base is being programmed for use on 286-class PC's. The major technical elements for a successful SIREN mission include: ground and space-based tracking, launch vehicles of needed payload capacity, telerobotic systems, sensors, capture technologies, and space transport and disposal. However, Project SIREN also will impose specialized requirements including the use of dextrous aerospace systems capable of properly functioning in intense radiation and thermal environments
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