2,934 research outputs found

    On the relationship between pump chirp and single-photon chirp in spontaneous parametric downconversion

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    We study the chronocyclic character, i.e. the joint temporal and spectral properties, of the single-photon constituents of photon pairs generated by spontaneous parametric down conversion. In particular we study how single photon properties, including purity and single-photon chirp, depend on photon pair properties, including the type of signal-idler spectral and correlations and the level of pump chirp.Comment: 13 pages, 6 figure

    Photoplethysmographic Waveform in Hyperbaric Environment

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    The objective of this work is the identification of significant variations of morphological parameters of the photoplethysmographic (PPG) signal when the subjects are exposed to an increase in atmospheric pressure. To achieve this goal, the PPG signal of 26 subjects, exposed to a hyperbaric environment whose pressure increases up to 5 atm, has been recorded. From this record, segments of 4 minutes have been processed at 1 atm, 3 atm and 5 atm, both in the descending (D) and ascending (A) periods of the immersion. In total, four states (3D, 5, 3A and 1A) normalized to the basal state (1D) have been considered. In these segments, six morphological parameters of the PPG signal were studied. The width, the amplitude, the widths of the anacrotic and catacrotic phases, and the upward and downward slopes of each PPG pulse were extracted. The results showed significant increases in the three parameters related to the pulse width. This increase is significant in the four states analysed for the anacrotic phase width. Furthermore, a significant decrease in the amplitude and in both slopes (in the states 1A) was observed. These results show that the PPG width responds rapidly to the increase in pressure, indicating an activation of the sympathetic system, while amplitude and pulse slopes are decreased when the subjects are exposed to the hyperbaric environment for a considerable period of time

    Charcot's arthrophathy

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    Detection and genotyping of HPV DNA in a group of unvaccinated young women from Colombia : baseline measures prior to future monitoring program

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    Q2Q1In 2012, Colombia launched human papillomavirus (HPV) vaccination program for girls ages 9 to 12, and in 2013, the target age was expanded to 9 to 17 years. Monitoring the changes of HPV infection prevalence among young women has been proposed as an endpoint for early assessment of HPV vaccination programs. However, the data on HPV prevalence in young ages are very limited. The purpose of this study was to determine the prevalence of HPV infection and the distribution of genotypes in a group of nonvaccinated women ages 18 to 25 years old in three Colombian cities as baseline for the monitoring of the HPV national vaccination program. A total of 1,782 sexually active women were included. Cervical smear samples were collected to perform the Pap smear and HPV DNA detection using a Linear Array HPV assay. Of the 1,782 specimens analyzed, 60.3% were positive for any HPV type; 42.2% were positive for highrisk HPV (HR-HVP) types, and 44.4% for low-risk HPV (LR-HPV) types. Multiple and single infections were identified in 37.1% and 23.2% of samples, respectively. HR-HPV types -16, -52, and -51 were the most predominant with proportions of 11.3%, 7.92%, and 7.9%, correspondingly. The prevalence for HR-HPV 16/18 was 14.4%. HR-HPV prevalence in women with abnormal cytology (75.16%) was higher than in women with normal cytology (38.6%). In conclusion, a high prevalence of HR-HPV was observed among younger women. This HPV typespecific prevalence baseline may be used to monitor postvaccination longitudinal changes and to determine its impact on HPV-related disease incidence in Colombia population.https://orcid.org/0000-0002-0610-6477https://orcid.org/0000-0001-7187-9946https://orcid.org/0000-0002-3373-1809https://orcid.org/0000-0001-6295-7316Revista Internacional - Indexad

    Robustness of Cooperation in the Evolutionary Prisoner's Dilemma on Complex Networks

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    Recent studies on the evolutionary dynamics of the Prisoner's Dilemma game in scale-free networks have demonstrated that the heterogeneity of the network interconnections enhances the evolutionary success of cooperation. In this paper we address the issue of how the characterization of the asymptotic states of the evolutionary dynamics depends on the initial concentration of cooperators. We find that the measure and the connectedness properties of the set of nodes where cooperation reaches fixation is largely independent of initial conditions, in contrast with the behavior of both the set of nodes where defection is fixed, and the fluctuating nodes. We also check for the robustness of these results when varying the degree heterogeneity along a one-parametric family of networks interpolating between the class of Erdos-Renyi graphs and the Barabasi-Albert networks.Comment: 18 pages, 6 figures, revised version accepted for publication in New Journal of Physics (2007

    Incorporation of lippia citriodora microwave extract into total-green biogelatin-phospholipid vesicles to improve its antioxidant activity

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    Phytochemicals from Lippia citriodora leaves were extracted by applying an innovative technology based on the use of microwaves, which represents an alternative method to extract bioactive substances. The obtained extract was incorporated into phospholipid vesicles in order to promote the antioxidant effect of the bioactive molecules present in L. citriodora extract. The extract was analyzed by High Performance Liquid Chromatography coupled to Time-Of-Flight mass spectrometer by electrospray (HPLC-ESI-TOF-MS) and different phytochemicals were detected and quantified. The whole extract was incorporated in liposomes, glycerosomes (liposomes modified with glycerol) and propylene glycol-containing vesicles (PG-PEVs). Moreover, a biopolymer obtained from fish by-product, that is Thunnus albacares skin, was added to improve the bioactivity of the formulations. The in vitro biocompatibility and the antioxidant efficacy of the extract in solution or loaded in the vesicles were tested in primary mouse embryonic fibroblasts (3T3). The results showed the superior bioactivity of the vesicle formulations over the aqueous solution of the extract, which points to an interesting strategy for the treatment of skin disorders

    A Hybrid Approach to Parallel Pattern Discovery in C++

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    Funding: EU Horizon 2020 project, TeamPlay, grant number 779882, and UK EPSRC Discovery, grant number EP/P020631/1.Parallel pattern libraries offer a strong combination of abstraction and performance. However, discovering places in sequential code where parallel patterns should be introduced is still highly non-trivial, often requiring expert manual analysis and profiling. We present a hybrid discovery technique to detect instances of parallel patterns in sequential code. This employs both static and dynamic trace-based analysis, together with hotspot detection. We evaluate our pattern discovery mechanism on a number of representative benchmarks. We evaluate the performance of the resulting parallelised benchmarks on a 24-core parallel machine.Postprin
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