405 research outputs found

    Type I and type II interferons inhibit both basal and tumor necrosis factor-α-induced CXCL8 secretion in primary cultures of human thyrocytes.

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    Interferons (IFNs) and tumor necrosis factor-α (TNF-α) cooperate in activating several inflammation-related genes, which sustain chronic inflammation in autoimmune thyroid disease (AITD). Much is known about the positive signaling of IFNs to activate gene expression in AITD, while the mechanisms by which IFNs negatively regulate genes remain less studied. While IFNs inhibit CXCL8 secretion in several human cell types, their effects on thyroid cells were not evaluated. Our aim was to study the interplay between TNF-α and type I or type II IFNs on CXCL8 secretion by human thyroid cells. CXCL8 was measured in supernatants of primary cultures of thyroid cells basally and after a 24-h incubation with TNF-α. CXCL8 was detected in thyroid cell supernatants in basal conditions (96.2±23.5 pg/mL) being significantly increased (784.7±217.3 pg/mL; PIFN-β>IFN-α. This study demonstrates that type I and type II IFNs downregulate both basal and TNF-α-induced CXCL8 secretion by human thyrocytes, IFN-γ being the most powerful inhibitor. Future studies aimed at a better comprehension of the interplay between CXCL8 and thyroid diseases appear worthwhile

    Mapping the CMB Sky: The BOOMERANG experiment

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    We describe the BOOMERanG experiment, a stratospheric balloon telescope intended to measure the Cosmic Microwave Background anisotropy at angular scales between a few degrees and ten arcminutes. The experiment has been optimized for a long duration (7 to 14 days) flight circumnavigating Antarctica at the end of 1998. A test flight was performed on Aug.30, 1997 in Texas. The level of performance achieved in the test flight was satisfactory and compatible with the requirements for the long duration flight.Comment: 11 pages, 6 figure

    Foregrounds in the BOOMERANG-LDB data: a preliminary rms analysis

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    We present a preliminary analysis of the BOOMERanG LDB maps, focused on foregrounds. BOOMERanG detects dust emission at moderately low galactic latitudes (b>20ob > -20^o) in bands centered at 90, 150, 240, 410 GHz. At higher Galactic latitudes, we use the BOOMERanG data to set conservative upper limits on the level of contamination at 90 and 150 GHz. We find that the mean square signal correlated with the IRAS/DIRBE dust template is less than 3% of the mean square signal due to CMB anisotropy

    Decoherence in rf SQUID Qubits

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    We report measurements of coherence times of an rf SQUID qubit using pulsed microwaves and rapid flux pulses. The modified rf SQUID, described by an double-well potential, has independent, in situ, controls for the tilt and barrier height of the potential. The decay of coherent oscillations is dominated by the lifetime of the excited state and low frequency flux noise and is consistent with independent measurement of these quantities obtained by microwave spectroscopy, resonant tunneling between fluxoid wells and decay of the excited state. The oscillation's waveform is compared to analytical results obtained for finite decay rates and detuning and averaged over low frequency flux noise.Comment: 24 pages, 13 figures, submitted to the journal Quantum Information Processin

    Images of the Early Universe from the BOOMERanG experiment

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    The CMB is the fundamental tool to study the properties of the early universe and of the universe at large scales. In the framework of the Hot Big Bang model, when we look to the CMB we look back in time to the end of the plasma era, at a redshift ~ 1000, when the universe was ~ 50000 times younger, ~ 1000 times hotter and ~ 10^9 times denser than today. The image of the CMB can be used to study the physical processes there, to infer what happened before, and also to study the background geometry of our Universe

    Quantum dynamics of local phase differences between reservoirs of driven interacting bosons separated by simple aperture arrays

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    We present a derivation of the effective action for the relative phase of driven, aperture-coupled reservoirs of weakly-interacting condensed bosons from a (3+1)-D microscopic model with local U(1) gauge symmetry. We show that inclusion of local chemical potential and driving velocity fields as a gauge field allows derivation of the hydrodynamic equations of motion for the driven macroscopic phase differences across simple aperture arrays. For a single aperture, the current-phase equation for driven flow contains sinusoidal, linear, and current-bias contributions. We compute the renormalization group (RG) beta function of the periodic potential in the effective action for small tunneling amplitudes and use this to analyze the temperature dependence of the low-energy current-phase relation, with application to the transition from linear to sinusoidal current-phase behavior observed in experiments by Hoskinson et al. \cite{packard} for liquid 4^{4}He driven through nanoaperture arrays. Extension of the microscopic theory to a two-aperture array shows that interference between the microscopic tunneling contributions for individual apertures leads to an effective coupling between apertures which amplifies the Josephson oscillations in the array. The resulting multi-aperture current-phase equations are found to be equivalent to a set of equations for coupled pendula, with microscopically derived couplings.Comment: 16 pages, 5 figures v2: typos corrected, RG phase diagram correcte

    ℓ-space spectroscopy of the Cosmic Microwave Background with the BOOMERanG experiment

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    The BOOMERanG experiment has recently produced detailed maps of the Cosmic Microwave Background, where sub-horizon structures are resolved with good signal to noise ratio. A power spectrum (spherical harmonics) analysis of the maps detects three peaks, at multipoles ℓ = (213_(-13)^(+10)),(541_(-32)^(+20))(845_(-25)^(+12)). In this paper we discuss the data analysis and the implications of these results for cosmology

    Noise Properties of the BOOMERANG Instrument

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    In this paper we report a short description of the BOOMERANG experiment explaining his scientific goal and the technologies implied. We concentrate then on the analysis of the noise properties discussing in particular the scan synchronous noise. Finally we present the calibration technique and the sensitivity of all the channels

    First Estimations of Cosmological Parameters From BOOMERANG

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    The anisotropy of the cosmic microwave background radiation contains information about the contents and history of the universe. We report new limits on cosmological parameters derived from the angular power spectrum measured in the first Antarctic flight of the BOOMERANG experiment. Within the framework of inflation-motivated adiabatic cold dark matter models, and using only weakly restrictive prior probabilites on the age of the universe and the Hubble expansion parameter hh, we find that the curvature is consistent with flat and that the primordial fluctuation spectrum is consistent with scale invariant, in agreement with the basic inflation paradigm. We find that the data prefer a baryon density Ωbh2\Omega_b h^2 above, though similar to, the estimates from light element abundances and big bang nucleosynthesis. When combined with large scale structure observations, the BOOMERANG data provide clear detections of both dark matter and dark energy contributions to the total energy density Ωtot\Omega_{\rm {tot}}, independent of data from high redshift supernovae.Comment: As submitted to PRD, revised longer version with an additional figur
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