Primordial power spectrum from WMAP

The observed angular power spectrum of the cosmic microwave background temperature anisotropy, $C_l$, is a convolution of a cosmological radiative transport kernel with an assumed primordial power spectrum of inhomogeneities. Exquisite measurements of $C_l$ over a wide range of multipoles from the Wilkinson Microwave Anisotropy Probe (WMAP) has opened up the possibility to deconvolve the primordial power spectrum for a given set of cosmological parameters (base model). We implement an improved (error sensitive) Richardson-Lucy deconvolution algorithm on the measured angular power spectrum from WMAP assuming a concordance cosmological model. The most prominent feature of the recovered $P(k)$ is a sharp, infra-red cut off on the horizon scale. The resultant $C_l$ spectrum using the recovered spectrum has a likelihood far better than a scale invariant, or, `best fit' scale free spectra ($\Delta\ln{\cal L}=25$ {\it w.r.t.} Harrison Zeldovich, and, $\Delta\ln{\cal L}=11$ {\it w.r.t.} power law with $n_s=0.95$). The recovered $P(k)$ has a localized excess just below the cut-off which leads to great improvement of likelihood over the simple monotonic forms of model infra-red cut-off spectra considered in the post WMAP literature. The recovered $P(k)$, in particular, the form of infra-red cut-off is robust to small changes in the cosmological parameters. We show that remarkably similar form of infra-red cutoff is known to arise in very reasonable extensions and refinements of the predictions from simple inflationary scenarios. Our method can be extended to other cosmological observations such as the measured matter power spectrum and, in particular, the much awaited polarization spectrum from WMAP.Comment: 20 pages, 12 figures, uses Revtex4, Matches version accepted to Phys. Rev. D. More extensive discussion of the method in the appendix, references added and typos correcte

Internal representations of smell in the Drosophila brain

Recent advances in sensory neuroscience using Drosophila olfaction as a model system have revealed brain maps representing the external world. Once we understand how the brain's built-in capability generates the internal olfactory maps, we can then elaborate how the brain computes and makes decision to elicit complex behaviors. Here, we review current progress in mapping Drosophila olfactory circuits and discuss their relationships with innate olfactory behaviors

Trasmissione dell\u2019attaccamento e Modello Dinamico-Maturativo.

Nel loro complesso, le ricerche sulle SS e le AAI, comprese quelle svolte nella prospettiva del DMM, sembrano confermare l\u2019ipotesi di una trasmissione intergenerazionale dell\u2019attaccamento: l\u2019attaccamento dei figli sembra influenzato da quello di entrambi genitori, ma l\u2019interpretazione dei dati \ue8 ancora poco chiara e alcuni problemi rimangono irrisolti. I risultati della maggior parte delle ricerche svolte nel passato provengono da campioni di famiglie europee o nordamericane di classe media e a basso rischio psicosociale. Nelle famiglie ad alto rischio i cui membri manifestano disturbi comportamentali o psichiatrici e in quelle che vivono in condizioni di grave pericolo (guerra, povert\ue0, carestia, regimi dittatoriali, emigrazione clandestina) i dati relativi alla trasmissione dell\u2019attaccamento non sono cos\uec lineari. In condizioni di pericolo, infatti, sembra manifestarsi una maggiore discontinuit\ue0 (oppure un\u2019inversione) dell\u2019attaccamento tra genitori e figli e una maggiore influenza da parte dell\u2019ambiente