Payloads development for European land mobile satellites: A technical and economical assessment

The European Space Agency (ESA) has defined two payloads for Mobile Communication; one payload is for pre-operational use, the European Land Mobile System (EMS), and one payload is for promoting the development of technologies for future mobile communication systems, the L-band Land Mobile Payload (LLM). A summary of the two payloads and a description of their capabilities is provided. Additionally, an economic assessment of the potential mobile communication market in Europe is provided

Sub-horizon Perturbation Behavior in Extended Quintessence

In the general context of scalar-tensor theories, we consider a model in which a scalar field coupled to the Ricci scalar in the gravitational sector of the Lagrangian, is also playing the role of an ``Extended Quintessence'' field, dominating the energy content of the Universe at the present time. In this framework, we study the linear evolution of the perturbations in the Quintessence energy density, showing that a new phenomenon, named here ``gravitational dragging'', can enhance the scalar field density perturbations as much as they reach the non-linear regime. The possibility of dark energy clumps formation is thus discussed.Comment: Proceedings of the 5th International UCLA Symposium on Sources and Detection of Dark Matter and Dark Energy in the Universe (Dark Matter 2002), Marina del Rey, California, USA, 20-22 February 200

Neodymium: Yttrium-Aluminum-Garnet Long Impulse Laser for the Elimination of Superfluous Hair: Experiences and Considerations from 3 Years of Activity

This study examined the results obtained with a modern apparatus for laser hair removal (neodymium: yttrium-aluminum-garnet [Nd:YAG] laser at long impulses with a wave-length of 1,064 nm; Q-switched laser) over a follow-up period of 3 years. A large heterogeneous group of 480 patients was taken into consideration. These patients were treated according to a standard protocol with monthly checkups and a personalized protocol at deferred appointments. The results, discovered by means of the most objective procedure possible, were retrieved and put into a graph showing two different curves for the repopulation of hair. In their clinical travels, the authors observed an average variable regrowth of 40% to 65%, allowing them to affirm that laser hair removal using Nd:YAG at long impulses is decisively efficient in obtaining long-term results. The use of a protocol (denominated "prolonged monthly checkup") with laser sessions at ever-decreasing periods permits, among other things, more outstanding and advantageous results for the patient. Thanks to more efficiently synchronized phases of the biologic hair cycle, this shortens and moves the telegenic phases closer and also renders the anagenic phases (those in which the selective photoermolysis on the pilipheric follicle proves to be efficient) more efficient. Personalization of the treatment relative to the monthly health checkup sessions is of fundamental importance to the scope of obtaining the best results in terms of cost-benefit rate, provided submassimal fluxes are (i.e., those well-tolerated by the patient) used. All this allows hair removal that is not definitive, but which becomes progressively permanent (i.e., characterized by ever-growing periods of lack of hair sustained by sporadic maintenance laser sessions based on the individual's necessity). © 2004 Springer Science+Business Media, Inc

Scalar field dark energy and Cosmic Microwave Background

A dynamical scalar field represents the simplest generalization of a pure Cosmological Constant as a candidate to explain the recent evidence in favour of the accelerated cosmic expansion. We review the dynamical properties of such a component, and argue that, even if the background expectation value of this field is fixed and the equation of state is the same as a Cosmological Constant, scalar field fluctuations can still be used to distinguish the two components. We compare predicted spectra of Cosmic Microvave Background (CMB) anisotropies in tracking scalar field cosmologies with the present CMB data, in order to get constraints on the amount and equation of state of dark energy. High precision experiments like SNAP, {\sc Planck} and {\sc SNfactory}, together with the data on Large Scale Structure, are needed to probe this issue with the necessary accuracy. Here we show the intriguing result that, with a strong prior on the value of the Hubble constant today, the assumption of a flat universe, and consistency relations between amplitude and spectral index of primordial gravitational waves, the present CMB data at $1\sigma$ give indication of a dark energy equation of state larger than -1, while the ordinary Cosmological Constant is recovered at $2\sigma$.Comment: 4 pages including 2 figures, Dark Matter 2002 proceedings, Nucl.Phys.B in pres

Celiac vagus nerve stimulation recapitulates angiotensin II-induced splenic noradrenergic activation, driving egress of CD8 effector cells

Angiotensin II (AngII) is a peptide hormone that affects the cardiovascular system, not only through typical effects on the vasculature, kidneys, and heart, but also through less understood roles mediated by the brain and the immune system. Here, we address the hard-wired neural connections within the autonomic nervous system that modulate splenic immunity. Chronic AngII infusion triggers burst firing of the vagus nerve celiac efferent, an effect correlated with noradrenergic activation in the spleen and T cell egress. Bioelectronic stimulation of the celiac vagus nerve, in the absence of other challenges and independently from afferent signals to the brain, evokes the noradrenergic splenic pathway to promote release of a growth factor mediating neuroimmune crosstalk, placental growth factor (PlGF), and egress of CD8 effector T cells. Our findings also indicate that the neuroimmune interface mediated by PlGF and necessary for transducing the neural signal into an effective immune response is dependent on α-adrenergic receptor signaling

Numerical study of halo concentrations in dark-energy cosmologies

We study the concentration parameters, their mass dependence and redshift evolution, of dark-matter halos in different dark-energy cosmologies with constant and time-variable equation of state, and compare them with "standard'' Lambda-CDM and OCDM models. We find that previously proposed algorithms for predicting halo concentrations can be well adapted to dark-energy models. When centred on the analytically expected values, halo concentrations show a log-normal distribution with a uniform standard deviation of ~0.2. The dependence of averaged halo concentrations on mass and redshift permits a simple fit of the form (1+z) c=c0 (M/M0)^a, with a~-0.1 throughout. We find that the cluster concentration depends on the dark energy equation of state at the cluster formation redshift z_{coll} through the linear growth factor D_+(z_{coll}). As a simple correction accounting for dark-energy cosmologies, we propose scaling c0 from Lambda-CDM with the ratio of linear growth factors, c0 -> c0 D_+(z_{coll})/D_{+,Lambda-CDM}(z_{coll}).Comment: 11 pages, submitted to Astronomy & Astrophysic

Astrophysical and Cosmological Information from Large-scale sub-mm Surveys of Extragalactic Sources

We present a quantitative analysis of the astrophysical and cosmological information that can be extracted from the many important wide-area, shallow surveys that will be carried out in the next few years. Our calculations combine the predictions of the physical model by Granato et al. (2004) for the formation and evolution of spheroidal galaxies with up-to-date phenomenological models for the evolution of starburst and normal late-type galaxies and of radio sources. We compute the expected number counts and the redshift distributions of these source populations separately and then focus on proto-spheroidal galaxies. For the latter objects we predict the counts and redshift distributions of strongly lensed sources at 250, 350, 500, and 850 micron, the angular correlation function of sources detected in the surveys considered, the angular power spectra due to clustering of sources below the detection limit in Herschel and Planck surveys. An optimal survey for selecting strongly lensed proto-spheroidal galaxies is described, and it is shown how they can be easily distinguished from the other source populations. We also discuss the detectability of the imprints of the 1-halo and 2-halo regimes on angular correlation functions and clustering power spectra, as well as the constraints on cosmological parameters that can be obtained from the determinations of these quantities. The novel data relevant to derive the first sub-millimeter estimates of the local luminosity functions of starburst and late-type galaxies, and the constraints on the properties of rare source populations, such as blazars, are also briefly described.Comment: 16 pages, 10 figures. Accepted for publication on MNRA