37 research outputs found

    Echoes from a long time ago: Chewbacca inflation

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    The cosmic microwave background (CMB) radiation offers a unique avenue for exploring the early Universe's dynamics and evolution. In this paper, we delve into the fascinating realm of slow-roll inflation, contextualizing the primordial acoustic perturbations as the resonant echoes akin to the iconic sound of Chewbacca from the Star Wars universe. By extrapolating polynomial potentials for these primordial sounds, we illuminate their role in shaping the inflationary landscape. Leveraging this framework, we calculate the scalar spectral index (nsn_s) and tensor-to-scalar ratio (rr), providing insights into the underlying physics governing the inflationary epoch. Employing a rigorous chi-square (χ2\chi^2) analysis, we meticulously scrutinize the Planck data combined with that offered by the BICEP/Keck collaboration to identify the Chewbacca sound profile that best aligns with observational constraints. Our findings not only shed light on the intricate interplay between sound and cosmology but also unveil intriguing parallels between the cosmic symphony of the early universe and beloved cultural icons.Comment: 8 pages + references, 5 figures. Prepared for submission to the Annals of Improbable Research on April 1st 2024. Find "The Sound of the Big Bang" in the audio folder of the source fil

    Seroprevalence of five neglected parasitic diseases among immigrants accessing five infectious and tropical diseases units in Italy: a cross-sectional study.

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    : This multicentre cross-sectional study aims to estimate the prevalence of five neglected tropical diseases (Chagas disease, filariasis, schistosomiasis, strongyloidiasis, toxocariasis) among immigrants accessing health care facilities in five Italian cities (Bologna, Brescia, Florence, Rome, Verona). : Individuals underwent a different set of serological tests, according to country of origin and presence of eosinophilia. Seropositive patients were treated and further followed up. : A total of 930 adult immigrants were enrolled: 477 men (51.3%), 445 women (47.9%), 8 transgender (0.8%); median age was 37.81 years (range 18-80). Most of them were coming from the African continent (405/930, 43.5%), the rest from East Europe, South America and Asia. A portion of 9.6% (89/930) were diagnosed with at least one of the infections under study. Seroprevalence of each specific infection varied from 3.9% (7/180) for Chagas diseases to 9.7% (11/113) for toxocariasis. Seropositive people were more likely to be 35 to 40 years-old male and to come from South East Asia, Sub-Saharan Africa or South America. : The results of our study confirm that neglected tropical diseases represent a substantial health problem among immigrants and highlight the need for addressing this emerging public health issue.<br/

    Enzymatic synthesis of 2’-O-acyl-prodrugs of 1-(beta-D-arabinofuranosyl)-5(E)-(2-bromovinyl)uracil (sorivudine, BV-araU) and of 2’-O-acyl-araU, -araC and -araA.

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    Pig liver esterase (EC 3.1.1.1) catalysed regioselective hydrolysis of 1-(2,3,5-tri-O-acyl-beta-D-arabinofuranosyl)uracil, -cytosine and -adenine to give the corresponding 2'-monoesters effectively and in high yield. This methodology enabled the preparation of 1-(2-O-acyl-beta-D-arabinofuranosyl)-5-[(E)-(2-bromovinyl)]uracil prodrugs which, although slightly less active than the parent 1-(beta-D-arabinofuranosyl)-5-(E)-(2 bromovinyl)uracil (sorivudine; BV-araU), were strongly active in vitro against varicella-zoster virus (ED50 2.4-45 ng/ml). The retarded rates of enzymatic hydrolysis of the 2'-esters imply that they might function as lipophilic prodrugs, leading to increased plasma and cellular concentrations. In view of the marked in vitro activity, they represent an interesting approach to arabinofuranosyl nucleoside prodrugs with improved pharmacokinetics and enzymatic stability

    Distribution of the number of peaks within a long gamma-ray burst

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    The variety and complexity of long duration gamma–ray burst (LGRB) light curves (LCs) encode a wealth of information on the way LGRB engines release their energy following the collapse of the progenitor massive star. Thus far, attempts to characterise GRB LCs focused on a number of properties, such as the minimum variability timescale, power density spectra (both ensemble average and individual), or through different definitions of variability. In parallel, a characterisation as a stochastic process was pursued by studying the distributions of waiting times, peak flux, fluence of individual peaks that can be identified within GRB time profiles. Yet, the question remains as to whether the diversity of GRB profiles can be described in terms of a common stochastic process. Here we address this issue by extracting and modelling for the first time the distribution of the number of peaks within a GRB profile. We analysed four different GRB catalogues: CGRO/BATSE, Swift/BAT, BeppoSAX/GRBM, and Insight-HXMT. The statistically significant peaks were identified by means of well tested and calibrated algorithm mepsa and further selected by applying a set of thresholds on signal-to-noise ratio. We then extracted the corresponding distributions of number of peaks per GRB. Among the different models considered (power-law, simple or stretched exponential) only a mixture of two exponentials turned out to model all the observed distributions, suggesting the existence of two distinct behaviours: (i) an average number of 2.1 ± 0.1 peaks per GRB (“peak poor”) and accounting for about 80% of the observed population of GRBs; (ii) an average number of 8.3 ± 1.0 peaks per GRB (“peak rich”) and accounting for the remaining 20% of the observed population. We associate the class of peak-rich GRBs with the presence of sub-second variability, which instead appears to be absent among peak-poor GRBs. The two classes could result from two different regimes through which GRB inner engines release energy or through which energy is dissipated into gamma-rays
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