29 research outputs found

    Impact of a paleo-earthquake and debris flow in Pikillaqta collapse, Cusco-Perú

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    In Cusco Valley, have been highlighted the Tambomachay, Pachatusan and Cusco active faults (Cabrera, 1988 & Benavente et al., 2013). Cusco has a historical and instrumental seismic record Mw> 5, events occurred in 1650, 1950 and 1986 (Silgado, 1978, Tavera, 2002). In the same way, during pre-Inca and Inca periods, they suffered the occurrence of earthquakes, this is evidenced in myths and chronicles collected by different chroniclers in XVIth century. These records, however, are limited, due to poor instrumental seismic data. Thus, during our work on paleosismology and archaeoseismology studies in Cusco with the aim of complementing the seismic catalog, we’ve visited several archaeological sites. Among the archaeological centers visited, we were more interested in the Pikillaqta Archaeological Park (PAP), a city that was built at Wari Empire time, a culture that developed in southern Peru between 600 and 1000 AD (Bergh, 2012). The interest of studying this site is basically due to its archaeological evidence of unjustified abandonment around 900 AD (McEwan, 2015). Subsequently, our archeoseismology studies, based on the identification of Earthquake Archeological Effects (Rodriguez-Pascua et al., 2011), and post-seismic effects like new architectural elements dated by 14C in 900 AD, allowed us to observe an important seismic event at this age. In PAP we observed alluvial deposits of up to 2m in height inside the rooms and halls, evidencing a debris flow. Drone images, allowed us to observe drainages related to the entrance of a flow at PAP east, generating an alluvial cone in the PAP main square. Works in situ, allowed us find pottery and bones within the mud flow, dated also around 900 AD. On the other hand, results of paleosismology in the Tambomachay fault (Rosell, 2018), show a seismic event around 900 AD. With the previously mentioned, exist a clear relationship between archaeoseismology and paleosismological results. The event occurred at the end of the 9th century, originating its attempt at reconstruction and subsequent abandonment

    West Nile Virus Infection among the Homeless, Houston, Texas1

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    Among 397 homeless participants studied, the overall West Nile virus (WNV) seroprevalence was 6.8%. Risk factors for WNV infection included being homeless >1 year, spending >6 hours outside daily, regularly taking mosquito precautions, and current marijuana use. Public health interventions need to be directed toward this high-risk population

    Extensive Mammalian Ancestry of Pandemic (H1N1) 2009 Virus

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    We demonstrate that the novel pandemic influenza (H1N1) viruses have human virus–like receptor specificity and can no longer replicate in aquatic waterfowl, their historic natural reservoir. The biological properties of these viruses are consistent with those of their phylogenetic progenitors, indicating longstanding adaptation to mammals

    Characterization Of Inpaint Residuals In Interferometric Measurements of the Epoch Of Reionization

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    Radio Frequency Interference (RFI) is one of the systematic challenges preventing 21cm interferometric instruments from detecting the Epoch of Reionization. To mitigate the effects of RFI on data analysis pipelines, numerous inpaint techniques have been developed to restore RFI corrupted data. We examine the qualitative and quantitative errors introduced into the visibilities and power spectrum due to inpainting. We perform our analysis on simulated data as well as real data from the Hydrogen Epoch of Reionization Array (HERA) Phase 1 upper limits. We also introduce a convolutional neural network that capable of inpainting RFI corrupted data in interferometric instruments. We train our network on simulated data and show that our network is capable at inpainting real data without requiring to be retrained. We find that techniques that incorporate high wavenumbers in delay space in their modeling are best suited for inpainting over narrowband RFI. We also show that with our fiducial parameters Discrete Prolate Spheroidal Sequences (DPSS) and CLEAN provide the best performance for intermittent ``narrowband'' RFI while Gaussian Progress Regression (GPR) and Least Squares Spectral Analysis (LSSA) provide the best performance for larger RFI gaps. However we caution that these qualitative conclusions are sensitive to the chosen hyperparameters of each inpainting technique. We find these results to be consistent in both simulated and real visibilities. We show that all inpainting techniques reliably reproduce foreground dominated modes in the power spectrum. Since the inpainting techniques should not be capable of reproducing noise realizations, we find that the largest errors occur in the noise dominated delay modes. We show that in the future, as the noise level of the data comes down, CLEAN and DPSS are most capable of reproducing the fine frequency structure in the visibilities of HERA data.Comment: 26 pages, 18 figure

    Search for the Epoch of Reionisation with HERA: Upper Limits on the Closure Phase Delay Power Spectrum

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    Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to separate the weak signal from overwhelming foreground emissions. Calibration inaccuracies can compromise the sensitivity of these measurements to the effect that a detection of the EoR is precluded. An alternative to standard analysis techniques makes use of the closure phase, which allows one to bypass antenna-based direction-independent calibration. Similarly to standard approaches, we use a delay spectrum technique to search for the EoR signal. Using 94 nights of data observed with Phase I of the Hydrogen Epoch of Reionization Array (HERA), we place approximate constraints on the 21 cm power spectrum at z=7.7z=7.7. We find at 95% confidence that the 21 cm EoR brightness temperature is \le(372)2^2 "pseudo" mK2^2 at 1.14 "pseudo" hh Mpc1^{-1}, where the "pseudo" emphasises that these limits are to be interpreted as approximations to the actual distance scales and brightness temperatures. Using a fiducial EoR model, we demonstrate the feasibility of detecting the EoR with the full array. Compared to standard methods, the closure phase processing is relatively simple, thereby providing an important independent check on results derived using visibility intensities, or related.Comment: 16 pages, 14 figures, accepted for publication by MNRA

    Whole-genome sequencing of chronic lymphocytic leukemia identifies subgroups with distinct biological and clinical features

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    The value of genome-wide over targeted driver analyses for predicting clinical outcomes of cancer patients is debated. Here, we report the whole-genome sequencing of 485 chronic lymphocytic leukemia patients enrolled in clinical trials as part of the United Kingdom's 100,000 Genomes Project. We identify an extended catalog of recurrent coding and noncoding genetic mutations that represents a source for future studies and provide the most complete high-resolution map of structural variants, copy number changes and global genome features including telomere length, mutational signatures and genomic complexity. We demonstrate the relationship of these features with clinical outcome and show that integration of 186 distinct recurrent genomic alterations defines five genomic subgroups that associate with response to therapy, refining conventional outcome prediction. While requiring independent validation, our findings highlight the potential of whole-genome sequencing to inform future risk stratification in chronic lymphocytic leukemia

    Validation of the HERA Phase I Epoch of Reionization 21 cm Power Spectrum Software Pipeline

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    We describe the validation of the HERA Phase I software pipeline by a series of modular tests, building up to an end-to-end simulation. The philosophy of this approach is to validate the software and algorithms used in the Phase I upper-limit analysis on wholly synthetic data satisfying the assumptions of that analysis, not addressing whether the actual data meet these assumptions. We discuss the organization of this validation approach, the specific modular tests performed, and the construction of the end-to-end simulations. We explicitly discuss the limitations in scope of the current simulation effort. With mock visibility data generated from a known analytic power spectrum and a wide range of realistic instrumental effects and foregrounds, we demonstrate that the current pipeline produces power spectrum estimates that are consistent with known analytic inputs to within thermal noise levels (at the 2σ level) for k > 0.2h Mpc-1 for both bands and fields considered. Our input spectrum is intentionally amplified to enable a strong "detection" at k ~ 0.2 h Mpc-1-at the level of ~25σ-with foregrounds dominating on larger scales and thermal noise dominating at smaller scales. Our pipeline is able to detect this amplified input signal after suppressing foregrounds with a dynamic range (foreground to noise ratio) of ≳107. Our validation test suite uncovered several sources of scale-independent signal loss throughout the pipeline, whose amplitude is well-characterized and accounted for in the final estimates. We conclude with a discussion of the steps required for the next round of data analysis

    Competitive Fitness of Influenza B Viruses Possessing E119A and H274Y Neuraminidase Inhibitor Resistance-Associated Substitutions in Ferrets.

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    Neuraminidase (NA) inhibitors (NAIs) are the only antiviral drugs recommended for influenza treatment and prophylaxis. Although NAI-resistant influenza B viruses that could pose a threat to public health have been reported in the field, their fitness is poorly understood. We evaluated in ferrets the pathogenicity and relative fitness of reverse genetics (rg)-generated influenza B/Yamanashi/166/1998-like viruses containing E119A or H274Y NA substitutions (N2 numbering). Ferrets inoculated with NAI-susceptible rg-wild-type (rg-WT) or NAI-resistant (rg-E119A or rg-H274Y) viruses developed mild infections. Growth of rg-E119A virus in the nasal cavities was delayed, but the high titers at 3 days post-inoculation (dpi) were comparable to those of the rg-WT and rg-H274Y viruses (3.6-4.1 log10TCID50/mL). No virus persisted beyond 5 dpi and replication did not extend to the trachea or lungs. Positive virus antigen-staining of the nasal turbinate epithelium was intermittent with the rg-WT and rg-H274Y viruses; whereas antigen-staining for the rg-E119A virus was more diffuse. Virus populations in ferrets coinoculated with NAI-susceptible and -resistant viruses (1:1 mixture) remained heterogeneous at 5 dpi but were predominantly rg-WT (>70%). Although the E119A substitution was associated with delayed replication in ferrets, the H274Y substitution did not measurably affect viral growth properties. These data suggest that rg-H274Y has undiminished fitness in single virus inoculations, but neither rg-E119A nor rg-H274Y gained a fitness advantage over rg-WT in direct competition experiments without antiviral drug pressure. Taken together, our data suggest the following order of relative fitness in a ferret animal model: rg-WT > rg-H274Y > rg-E119A
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