General recursive solution for one dimensional quantum potentials: a simple tool for applied physics

A revision of the recursive method proposed by S.A. Shakir [Am. J.Phys. \textbf{52}, 845 (1984)] to solve bound eigenvalues of the Schr\"odinger equation is presented. Equations are further simplified and generalized for computing wave functions of any given one-dimensional potential, providing accurate solutions not only for bound states but also for scattering and resonant states, as demonstrated here for a few examples.Comment: Final version to appear in the Brazilian Magazine of Physics Teaching (http://www.sbfisica.org.br/noticias/publicacoes.shtml

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

Winds as the origin of radio emission in z=2.5z=2.5 radio-quiet extremely red quasars

Most active galactic nuclei (AGNs) are radio-quiet, and the origin of their radio emission is not well-understood. One hypothesis is that this radio emission is a by-product of quasar-driven winds. In this paper, we present the radio properties of 108 extremely red quasars (ERQs) at $z=2-4$. ERQs are among the most luminous quasars ($L_{bol} \sim 10^{47-48}$ erg/s) in the Universe, with signatures of extreme ($\gg 1000$ km/s) outflows in their [OIII]$\lambda$5007 \AA\ emission, making them the best subjects to seek the connection between radio and outflow activity. All ERQs but one are unresolved in the radio on $\sim 10$ kpc scales, and the median radio luminosity of ERQs is $\nu L_\nu [{\rm 6\,GHz}] = 10^{41.0}$ erg/s, in the radio-quiet regime, but one to two orders of magnitude higher than that of other quasar samples. The radio spectra are steep, with a mean spectral index $\langle \alpha \rangle = -1.0$. In addition, ERQs neatly follow the extrapolation of the low-redshift correlation between radio luminosity and the velocity dispersion of [OIII]-emitting ionized gas. Uncollimated winds, with a power of one per cent of the bolometric luminosity, can account for all these observations. Such winds would interact with and shock the gas around the quasar and in the host galaxy, resulting in acceleration of relativistic particles and the consequent synchrotron emission observed in the radio. Our observations support the picture in which ERQs are signposts of extremely powerful episodes of quasar feedback, and quasar-driven winds as a contributor of the radio emission in the intermediate regime of radio luminosity $\nu L_\nu = 10^{39}-10^{42}$ erg/s.Comment: accepted by MNRA

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

The active optics software for the VST telescope

The VST (VLT Survey Telescope) active optics software must basically provide the analysis of the image coming from the wavefront sensor (a 10x10 subpupils Shack Hartmann device) and the calculation of primary mirror forces and secondary mirror displacements to correct the aberrations of the optical system, instrinsic or originated for thermal and gravity reasons. After the telescope commissioning the VST will be operated by ESO. In this framework, INAF-OAC staff was committed to design and realize the software in a VLT-compliant way. This will smoothen the integration, operation and maintenance of the telescope in the Paranal observatory

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

Renal hypoplasia without optic coloboma associated with PAX2 gene deletion

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On the potential of regenerative braking of electric buses as a function of their itinerary

This paper proposes a mathematical model for an electric bus powertrain, implemented in a simulation platform. We intend to analyze the consumption of energy according to the route specifications and other performance measures. The potential for regenerative braking will be evaluated for different routes, since it depends significantly on them. It is expected that a "pattern" can be observed in that concerning the potential of the system to recover back some of the energy spent in its operation. Moreover, the use of supercapacitors to make this braking energy absorption is investigated.This work is financed by FEDER Funds, through the Operational Programme for Competitiveness Factors COMPETE, and by Portuguese Funds through FCT - Foundation for Science and Technology, under the project 13844. The first author would like to thank FCT (Fundacao para a Cincia e Tecnologia) for the PhD scholarship SFRH/BD/51256/2010, and to the MIT- Portugal Program in Engineering Design and Advanced Manufacturing Leaders for Technical Industries focus area

Electrical bus performance modeling for urban environments

Electric vehicles are seen as a key driver to address the issue of global warming, mainly through their zero tailpipeemissions operation and energy efficiency improvements. However, this does not solve the problem of urban chaos, relatedto traffic congestion and parking space cluttering, which contribute to increase human stress and overall economicproductivity decrease. To address all these issues, electric urban buses come as an obvious solution, and they also have theadvantages of being quieter than regular buses and of promoting a better travel experience to passengers.Nowadays there are already electric buses operating in some parts of the world and one of the main concerns is theirhigh weight, which is mainly due to the amount of batteries they carry in order to have an adequate range. Severalstrategies are possible and are being tested to provide buses with adequate operability in terms of range: battery swappingat central stations, battery charging at central stations on slow or fast charge rates and sizing the battery pack to the route ofthe electric bus using fast charge on bus stops.This paper intends to provide a mathematical model for the electric bus powertrain and its routes, based on a createddriving cycle that simulates an acceleration and deceleration period between two stops of a bus. The main objective is toverify how much of the energy recovered from regenerative braking can be absorbed by lithium-ion batteries and to verifywhether the supercapacitors can excel the batteries for this purpose. The intent is to reduce the amount of batteries carried,in the attempt to increase the bus efficiency by optimizing regenerative braking capabilities and possibly reduce overallsystem weight.This work is financed by FEDER Funds, through the Operational Programme for Competitiveness Factors - COMPETE under the project 13844. Deborah Perrotta thanks FCT (Fundaço para a Cincia e Tecnologia) for PhD scholarship (SFRH / BD / 51256 / 2010) under the scope of the MIT Portugal Program in Engineering Design and Advanced Manufacturing - Leaders for Technical Industries focus area