1,721,432 research outputs found
Effects of inflationary bubbles on the sub-degree polarization and temperature anisotropies of the cosmic microwave background
No full textWe predict the imprint of linear bubbly perturbations on the polarization and temperature anisotropies of the cosmic microwave background (CMB).
We analytically model a bubbly density perturbation at the beginning of the radiation dominated era and we apply the linear theory of cosmological perturbations to compute its time evolution. At decoupling, it uniquely signs the CMB polarization and temperature anisotropy sky. During evolution the perturbation propagates beyond the size of the bubble and reaches the CMB sound horizon at the time considered. Therefore, its signal appears as a series of concentric rings, each characterized by its own amplitude and sign, on the scale of 1^{o} on the sky, even if the real seed size is much smaller. Polarization and temperature rings are strictly correlated. As expected for linear perturbations with size L and density contrast \delta at decoupling, \delta T/T is roughly \delta (L/H^{-1})^{2}; the polarization is about 10% of the temperature anisotropy.
We predict the impact of a distribution of bubbles on the CMB polarization and temperature power spectra. Considering models containing both CDM Gaussian and bubbly non-Gaussian fluctuations, we simulate and analyze 10^{o} x 10^{o} sky patches with angular resolution of about 3.5^{'}. The CMB power associated with the bubbles is entirely on sub-degree angular scales (200<= l<=1000), that will be explored by the forthcoming high resolution CMB experiments with the percent precision. Depending on the parameters of the bubbly distribution we find extra-power with respect to the ordinary CDM Gaussian fluctuations; we infer simple analytical scalings of the power induced by bubbly perturbations and we constrain our parameters with the existing data
Early time perturbations behavior in scalar field cosmologies
Full text linkWe consider the problem of the initial conditions and behavior of the perturbations in scalar field cosmology with a general potential. We use the general definition of adiabatic and isocurvature conditions to set the appropriate initial values for the perturbation in the scalar field and in the ordinary matter and radiation components. In both the cases of initial adiabaticity and isocurvature, we solve the Einstein and fluid equations at early times and on superhorizon scales to find the initial behavior of the relevant quantities. In particular, in the isocurvature case, we consider models in which the initial perturbation arises from the matter as well as from the scalar field itself, provided that the initial value of the gauge-invariant curvature is zero. We extend the standard code to include all these cases, and we show some results concerning the power spectrum of the cosmic microwave background temperature and polarization anisotropies. In particular, it turns out that the acoustic peaks follow opposite behavior in the adiabatic and isocurvature regimes: in the first case their amplitude is higher than in the corresponding pure cold dark matter model, while it is the opposite for pure isocurvature initial perturbations
The 'autism in school age: Early diagnosis for treatment
No full textAutism is a serious psychiatric disorder that limits the person first and then fit to integrate into society and then to establish relationships with others. For example, pet therapy can be important in facilitating the relationship: the one with the animal, has an immediate relationship. To help children with autism using hippotherapy or dolphin therapy. In the rehabilitation of the child sits like riding without a saddle on its back by enabling him to have resulted from stimulation of rhythm and 'support of the hoof. The treatment of the horse just counteracts the hyperactivity of children with autism. The noise given by the rhythm of the hooves, like the heartbeat of the baby in the womb of the mother felt, that causes a feeling of wellbeing. With the dolphin therapy instead of the child through a kind of return to the womb, just due all'immergersi water. The pet therapy works on many levels. The relationship established between the child and the animal, and the affection that binds them, are all elements that act positively on the affective-emotional and psychophysical realm. The pet therapy has a positive effect on three levels: 1) emotional and psychological. Pets help to ease the loneliness with their needs center around the person's attention: for example, a puppy away from negative thoughts, you feel accepted and promotes interpersonal relationships; 2) at the physical level: the animals are a stimulus to motor activity and a tool for rehabilitation; 3) at play: the animal throughout its life, always manages to have the ability to play, even causing people to play
Application and internal validation of lung ultrasound score in COVID-19 setting: The ECOVITA observational study. Authors’ reply
No full textSub-horizon perturbation behavior in extended quintessence
No full textIn 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
Cosmic microwave background constraints on dark energy dynamics: Analysis beyond the power spectrum
No full textWe consider the distribution of the non-Gaussian signal induced by weak lensing on the primary total intensity cosmic microwave background (CMB) anisotropies. Our study focuses on the three point statistics exploiting a harmonic analysis based on the CMB bispectrum. By considering the three multipoles as independent variables, we reveal a complex structure of peaks and valleys determined by the reprojection of the primordial acoustic oscillations through the lensing mechanism. We study the dependence of this system on the expansion rate at the epoch in which the weak lensing power injection is relevant, probing the dark energy equation of state at redshift corresponding to the equivalence with matter or higher (w(infinity)). The variation of the latter quantity induces a geometrical feature affecting distances and growth rate of linear perturbations, acting coherently on the whole set of bispectrum coefficients, regardless of the configuration of the three multipoles. We evaluate the impact of the bispectrum observable on the CMB capability of constraining the dark energy dynamics. We perform a maximum likelihood analysis by varying the dark energy abundance, the present equation of state w(0) and w(infinity). We show that the projection degeneracy affecting a pure power spectrum analysis in total intensity is broken if the bispectrum is taken into account. For a Planck-like experiment, assuming nominal performance, no foregrounds or systematics, and fixing all the parameters except w(0), w(infinity) and the dark energy abundance, a percent and ten percent precision measure of w(0) and w(infinity) is achievable from CMB data only. The reason is the enhanced sensitivity of the weak lensing signal to the behavior of the dark energy at high redshifts, which compensates the reduced signal to noise ratio with respect to the primary anisotropies. These results indicate that the detection of the weak lensing signal by the forthcoming CMB probes may be relevant to gain insight into the dark energy dynamics at the onset of cosmic acceleration
Circulating endothelial progenitor cells biology and regenerative medicine in pulmonary vascular diseases
No full textPulmonary vascular disorders (PVDs) include primary or secondary diseases who ultimately influence the right heart function. Several researches showed that stem and progenitor cells may represent a novel approach in treating pulmonary hypertension. In particular, circulating endothelial progenitor cells (EPCs) are mobilized either from the bone marrow and/or arteries to replace dysfunctional endothelial cells and restore blood perfusion to ischemic tissues. They may deliver paracrine signals to stimulate local angiogenesis or may be physically incorporated within neovessels. Understanding the molecular mechanisms utilized by vascular endothelial growth factor (VEGF) to stimulate EPC might shed light on novel targets for regenerative medicine. Ca2+ machinery regulates proliferation, migration, tube formation, and, therefore, differentiation of EPCs may give valuable insights into the biology of these cells; the Ca2+ machinery in these cells is extremely plastic and may vary depending on their origin. In this paper, we review EPCs subtypes, their sources, biological properties, functional mechanisms and of course involvement in pulmonary vascular diseases
A possible value in terms of education with action inclusive
No full textToday in the Italian school there is an increasingly widespread presence of pupils with special educational needs (BES). According to the OECD pupils with Special Educational Needs are: students DISABLED (ex L.104/92), pupils with DIFFICULTY (emotional, behavioral, learning, DSA, etc.), pupils with DISADVANTAGE (cultural, socio-economic, socio-linguistic, etc.). The special educational needs may arise from poor physical condition (chronic diseases, allergies, etc.) in the structures and bodily functions (sensory impairment, motor, cognitive, etc.)., From personal activities (deficits in learning, communication, language, autonomy, interaction, etc.), social participation (difficulty playing the role of student and follow the curriculum and class activities, difficulty of tracking the opportunities for social participation of the classroom, such as field trips or other informal occasions), by contextual factors and environmental factors (barriers, prejudices, overprotective family, deviant social contexts, etc.).; personal contextual factors (low self-esteem, poor motivation, behavior problems, etc.). We speak not only then deficits or pathologies, but situations of need which, if neglected, can cause school failure and exclusion from the educational process. The tendency of the current guidelines in the field of European integration will propose the aims to welcome in the school environment for pupils with difficulties. However, integration between the system and that there are considerable differences inclusive, whose depth can be useful in order to better understand the phenomenon. © JPES
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