101 research outputs found
Atom interferometry with fermionic and bosonic isotopes of strontium for precision gravity measurements and test of the Equivalence Principle
Bragg gravity-gradiometer using the S-P intercombination transition of Sr
We present a gradiometer based on matter-wave interference of
alkaline-earth-metal atoms, namely Sr. The coherent manipulation of the
atomic external degrees of freedom is obtained by large-momentum-transfer Bragg
diffraction, driven by laser fields detuned away from the narrow
S-P intercombination transition. We use a well-controlled
artificial gradient, realized by changing the relative frequencies of the Bragg
pulses during the interferometer sequence, in order to characterize the
sensitivity of the gradiometer. The sensitivity reaches
s for an interferometer time of 20 ms, limited only by geometrical
constraints. We observed extremely low sensitivity of the gradiometric phase to
magnetic field gradients, approaching a value 10 times lower than the
sensitivity of alkali-atom based gradiometers. An efficient double-launch
technique employing accelerated red vertical lattices from a single
magneto-optical trap cloud is also demonstrated. These results highlight
strontium as an ideal candidate for precision measurements of gravity
gradients, with potential application in future precision tests of fundamental
physics.Comment: 10 pages, 7 figure
Gallbladder polyps in association with metachromatic leukodystrophy
Polypoid lesions of the gallbladder (PLG) are rare in the paediatric population. Growth in technology with the availability of high-quality ultrasonography and in the experience of radiologists in detecting such lesions, has led to an increase in incidental detection of PLG. In children, the occur either as a primary disorder or in association with other conditions, including metachromatic leukodystrophy, Peutz- Jeghers syndrome, or pancreatobiliary malunion [1]. Due the rarity of these lesions in the paediatric age group, accurate management algorithms are inherited from the adult population. In these, PLG is a more common pathology, occurring in 4\u20137% of patients undergoing ultrasonography, with clinical significance relating largely to their malignant potential [2,3]
Atmospheric turbulence profiling using the SLODAR technique with ARGOS at LBT
ARGOS is the Ground Layer Adaptive Optics system of the Large Binocular Telescope, it uses three Laser Guide Stars, generated by Rayleigh backscattered light of pulsed lasers. Three Shack-Hartmann WFS measure the wavefront distortion in the Ground Layer. The SLOpe Detection And Ranging (SLODAR) is a method used to measure the turbulence profiles. Cross correlation of wavefronts gradient from multiple stars is used to estimate the relative strengths of turbulent layers at different altitudes. We present here the results on sky of the SLODAR profile on ARGOS
A Moderate Walking Test Predicts Survival in Women With Cardiovascular Disease
Introduction: Cardiovascular disease (CVD) is the principal cause of death in U.S. women. Peak oxygen uptake is strongly related to mortality and CVD. This study aimed to investigate the association between estimated peak oxygen uptake, determined using a moderate 1-km walking test, and all-cause mortality in female patients with stable CVD. Methods: Of the 482 women in our registry between 1997 and 2020, we included 430 participants in the analysis (aged 67 [34-88] years). A Cox proportional hazard model was used to determine the variables significantly associated with mortality. On the basis of the peak oxygen uptake estimated using the 1-km walking test, the sample was subdivided into tertiles, and mortality risk was calculated. The discriminatory accuracy of peak oxygen uptake in estimating survival was assessed by receiver operating characteristic curves. All results were adjusted for demographic and clinical covariates. Results: A total of 135 deaths from any cause occurred over a median of 10.4 years (IQR=4.4-16.4), with an average annual mortality of 4.2%. Estimated peak oxygen uptake was a stronger predictor of all-cause mortality than demographic and clinical variables (c-statistic-0.767; 95% CI=0.72, 0.81; p<0.0001). The survival rate decreased from the highest tertile of fitness to the lowest. Compared with the lowest group, hazard ratios (95% CIs) for the second and third tertiles were 0.55 (0.37, 0.83) and 0.29 (0.16, 0.51), respectively (p for trend <0.0001). Conclusions: Higher peak oxygen uptake levels were associated with a lower risk of all-cause mortality. The indirect estimation of peak oxygen uptake using the 1-km walking test is feasible and can be applied for risk stratification among female patients undergoing secondary prevention programs
Performance and First Science Observations with ARGOS
Coming online for scientific operations, the ARGOS facility is boosting the imaging and spectroscopic capabilities at the LBT. With six Rayleigh laser guide stars and the corresponding wavefront sensing, ARGOS corrects the ground layer distortions for both LBT 8.4 m telescopes with its adaptive secondary mirrors. Under most conditions this setup delivers a PSF size reduction by a factor ~2-3. With the two LUCI infrared imaging and MOS spectroscopy instruments receiving the corrected images, observations in the near infrared can be performed at high spatial and spectral resolution. We will briefly discuss the final ARGOS technical setup and the adaptive optics performances. With first scientific observations been conducted, we will show that imaging cases with GLAO are nicely boosting several science programs from cluster CMD, Milky Way embedded star formation and Cepheids, BHs in nearby galaxies to extragalactic deep fields. In the unique combination of ARGOS with the multi-object NIR spectroscopy available in LUCI, first scientific observations have been performed on local and high-z objects. Those high spatial and spectral resolution observations nicely demonstrate the capabilities now at hand with ARGOS at the LBT. Inhere we describe briefly the system and show examples of science observations from nearby clusters to high redshift gravitationally lensed objects
Arquitectura futurista
Presenta los siguientes textos: Antonio Sant'Elia, "La Arquitectura Futurista. Manifiesto; Umberto Boccioni, "Arquitectura futurista. Manifiesto"; Volt (Vicenzo Fani), "Del funanbulismo obligatorio o: suprimamos las plantas de las casas"; Enrico Prampolini, "La "Atmosferastruttura" - Bases para la arquitectura futurista"; Vincenzo Fani (Volt), "La Casa Futurista independiente-movil-desmontable-mecánica-divertida"; Virgilio Marchi, "Manifiesto de la arquitectura futurista dinámica, estado de ánimo y dramática"; Enrico Prampolini, "Arquitectura Futurista"; Cesar Augusto Poggi, "Arquitectura Futursita (sic) Poggi"; F.T. Marinetti, Angiolo Mazzoni, Mino Somenzi, "Manifiesto Futurista de la arquitectura aérea"Presenta una serie de manifiestos y textos sobre Arquitectura futurista. Dossier elaborado por Juan AgustÃn Mancebo. Traducción: Marta Morcill
Long term nucleotide and nucleoside analogs treatment in chronic hepatitis B HBeAg negative genotype D patients and risk for hepatocellular carcinoma
Background and rationale of the study. Effect of Long-term nucleoside/nucleotide (NUC) on hepatocellular carcinoma (HCC) incidence in a population of HBeAg-negative genotype D patients has not been adequately studied in real-life cohorts. Our aim was to evaluate the impact of liver fibrosis and other variables on HCC incidence in this population of patients. Of 745 patients with chronic hepatitis B (CHB), 306 HBeAg-negative genotype D were selected and included in this study. All patients received treatment with NUC for at least 18 months. Patients with CHB or compensated cirrhosis were included. Patients with HCC diagnosed before or during the first 18 months of NUC therapy were excluded. Results. HCC was diagnosed in 2 CHB patients (1.0%) and 23 cirrhosis patients (20%) (OR = 24.41, 95% CI 5.40 < OR < 153.2; p < 0.0001). Multivariate analysis revealed that HCC risk was independently associated with age ≥ 60 years (OR = 6.45, 95% CI 1.22 to 34.0; p = 0.02) and liver cirrhosis (OR = 12.1, 95% CI 1.39 to 106.2; p = 0.02), but not with virological response (VR), and previous resistance to NUC, or rescue therapy. Multivariate analysis in cirrhosis patients revealed that only age ≥ 60 years was an independent risk factor associated with HCC (p = 0.003). Conclusions. Liver cirrhosis and age ≥ 60 years are the stronger risk factors for HCC in genotype D HBeAgnegative patients. Previous resistance to NUC in patients that achieved a VR after rescue therapy was not a predictive factor regarding HCC. VR does not appear to significantly reduce the overall incidence of HCC when a patient has already progressed to liver cirrhosis
SOUL at LBT: commissioning results, science and future
The SOUL systems at the Large Bincoular Telescope can be seen such as
precursor for the ELT SCAO systems, combining together key technologies such as
EMCCD, Pyramid WFS and adaptive telescopes. After the first light of the first
upgraded system on September 2018, going through COVID and technical stops, we
now have all the 4 systems working on-sky. Here, we report about some key
control improvements and the system performance characterized during the
commissioning. The upgrade allows us to correct more modes (500) in the bright
end and increases the sky coverage providing SR(K)>20% with reference stars
G<17, opening to extragalcatic targets with NGS systems. Finally, we
review the first astrophysical results, looking forward to the next generation
instruments (SHARK-NIR, SHARK-Vis and iLocater), to be fed by the SOUL AO
correction.Comment: 13 pages, 10 figures, Adaptive Optics for Extremely Large Telescopes
7th Edition, 25-30 Jun 2023 Avignon (France
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