266 research outputs found
Dispersive estimates and NLS on product manifolds
We prove a general dispersive estimate for a Schroedinger type equation on a
product manifold, under the assumption that the equation restricted to each
factor satisfies suitable dispersive estimates. Among the applications are the
two-particle Schroedinger equations on Euclidean spaces, and the nonlinear
Schroedinger equation on the product of two real hyperbolic spaces
The wave equation on hyperbolic spaces
In this paper, we study the dispersive properties of the wave equation
associated with the shifted Laplace-Beltrami operator on real hyperbolic
spaces, and deduce Strichartz estimates for a large family of admissible pairs.
As an application, we obtain local well-posedness results for the nonlinear
wave equation
Nonlinear Schrödinger equation on four-dimensional compact manifolds
International audienc
Italy's image as a tourism destination in the Chinese leisure travel market.
This study aims to measure the image of Italy as a tourism destination on the Chinese leisure traveller market. To this end, Echtner & Ritchie’s model (1991) is applied; however, compared to its original formulation, it is implemented with greater consideration of the experiential dimension and potential travel constraints affecting the perception of the range of tourism goods and services on offer. This enables not just a denotative, but also and above all a connotative measurement of the image, thereby reducing the risk of ambiguity in the interpretation of the most significant attributes that emerged during the analysis. Adopting a hypothetical segmentation of the market in question, it was also possible to the elements that act as encouraging and discouraging factors regarding a holiday in Italy are highlight, identifying tailor-made approaches to the construction and promotion/commercialisation of tourism products designed to be attractive to the specific segment of interest
Nonlinear Schr\"odinger equation on real hyperbolic spaces
We consider the Schr\"odinger equation with no radial assumption on real
hyperbolic spaces. We obtain sharp dispersive and Strichartz estimates for a
large family of admissible pairs. As a first consequence, we get strong
well-posedness results for NLS. Specifically, for small intial data, we prove
and global well-posedness for any subcritical nonlinearity (in
contrast with the Euclidean case) and with no gauge invariance assumption on
the nonlinearity . On the other hand, if is gauge invariant,
charge is conserved and hence, as in the Euclidean case, it is possible to
extend local solutions to global ones. The corresponding argument in
requires the conservation of energy, which holds under the stronger
condition that is defocusing. Recall that global well-posedness in the
gauge invariant case was already proved by Banica, Carles & Staffilani, for
small radial data and for large radial data. The second important
application of our global Strichartz estimates is "scattering" for NLS both in
and in , with no radial or gauge invariance assumption. Notice that,
in the Euclidean case, this is only possible for the critical power
and can be false for subcritical powers while, on hyperbolic
spaces, global existence and scattering of small solutions holds for all
powers . If we restrict to defocusing nonlinearities ,
we can extend the scattering results of Banica, Carles & Staffilani to
the nonradial case. Also there is no distinction anymore between short range
and long range nonlinearity : the geometry of hyperbolic spaces makes every
power-like nonlinearity short range.Comment: Version 1 : 18 January 2008. Version 2 : 29 February 200
Ultrasound-Guided Microinjection into the Mouse Forebrain In Utero at E9.5
In utero survival surgery in mice permits the molecular manipulation of gene expression during development. However, because the uterine wall is opaque during early embryogenesis, the ability to target specific parts of the embryo for microinjection is greatly limited. Fortunately, high-frequency ultrasound imaging permits the generation of images that can be used in real time to guide a microinjection needle into the embryonic region of interest. Here we describe the use of such imaging to guide the injection of retroviral vectors into the ventricular system of the mouse forebrain at embryonic day (E) 9.5. This method uses a laparotomy to permit access to the uterine horns, and a specially designed plate that permits host embryos to be bathed in saline while they are imaged and injected. Successful surgeries often result in most or all of the injected embryos surviving to any subsequent time point of interest (embryonically or postnatally). The principles described here can be used with slight modifications to perform injections into the amnionic fluid of E8.5 embryos (thereby permitting infection along the anterior posterior extent of the neural tube, which has not yet closed), or into the ventricular system of the brain at E10.5/11.5. Furthermore, at mid-neurogenic ages (~E13.5), ultrasound imaging can be used direct injection into specific brain regions for viral infection or cell transplantation. The use of ultrasound imaging to guide in utero injections in mice is a very powerful technique that permits the molecular and cellular manipulation of mouse embryos in ways that would otherwise be exceptionally difficult if not impossible
Wine Experiences: A Review from a Multisensory Perspective
The existing multisensory literature suggests that the combination of the different human senses in a controlled fashion during food/drink experiences can provide more enjoyment to consumers. The present research reviews recent literature relating multisensory perception with wine experiences, focusing on the interaction of the five basic senses (taste, smell, vision, touch, and sound). This is mostly being assessed from a perceptual and behavioral consumer perspective. Here, the authors report different ways in which such interactions across these senses can affect the way a wine is experienced, prior to, during, and even after tasting. The authors finish this literature review by providing some insights in the context of wine and food pairing, while also generally reflecting on potential future work. These insights may be inspirational for a diverse group of organizations working with wine. Based on such multisensory approaches, it may be possible to bring unforeseen sensations to the different wine experiences, while at the same time stressing particular sensory and/or emotional attributes
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