125 research outputs found
Reconnaissance observations by CIGIDEN after the 2015 Illapel, Chile earthquake and tsunami
This paper describes the reconnaissance work conducted by researchers from the National Research Center for Integrated
Natural Disaster Management (CIGIDEN) between September 23rd and October 2nd in the area affected by the Mw 8.3
Illapel megathrust earthquake, which struck offshore the coast of the Coquimbo Region in central Chile on September 16th
,
2015. A first team focused on the seismic performance and effects of the tsunami on public hospitals and on reinforced
concrete (RC) buildings. A second team focused on the road network infrastructure. Field work included: (i) a survey on the
physical and functional damages of the public hospitals in the Region; (ii) a visual inspection and preliminary damage
assessment of 20 RC buildings in the largest cities of the region and an aftershock instrumentation of the Coquimbo
hospital; and (iii) the inspection of bridges, pedestrian bridges, and rockfall along overstepped cut slopes of the road
network. The overall limited impact of this megathrust earthquake may be explained in part by the long-term efforts made
by the country to prepare for such events. Learnings from the 2010 Maule earthquake were evidenced in the successful
evacuation along the coast of the country, and the overall good performance of engineered masonry structures, and of RC
buildings designed after 2010
The Interspersed Spin Boson Lattice Model
We describe a family of lattice models that support a new class of quantum
magnetism characterized by correlated spin and bosonic ordering [Phys. Rev.
Lett. 112, 180405 (2014)]. We explore the full phase diagram of the model using
Matrix-Product-State methods. Guided by these numerical results, we describe a
modified variational ansatz to improve our analytic description of the
groundstate at low boson frequencies. Additionally, we introduce an
experimental protocol capable of inferring the low-energy excitations of the
system by means of Fano scattering spectroscopy. Finally, we discuss the
implementation and characterization of this model with current circuit-QED
technology.Comment: Submitted to EPJ ST issue on "Novel Quantum Phases and Mesoscopic
Physics in Quantum Gases
Global conformal anomaly in N=2 string
We show the existence of a global anomaly in the one-loop graphs of N=2
string theory, defined by sewing tree amplitudes, unless spacetime
supersymmetry is imposed. The anomaly is responsible for the non-vanishing
maximally helicity violating amplitudes. The supersymmetric completion of the
N=2 string spectrum is formulated by extending the previous cohomological
analysis with an external spin factor; the target space-time spin-statistics of
these individual fields in a selfdual background are compatible with previous
cohomological analysis as fields of arbitrary spin may be bosonized into one
another. We further analyze duality relations between the open and closed
string amplitudes and demonstrate this in the supersymmetric extension of the
target space-time theory through the insertion of zero-momentum operators.Comment: 29 pages, LaTeX, one figur
microRNA-122 stimulates translation of hepatitis C virus RNA
Hepatitis C virus (HCV) is a positive strand RNA virus that propagates primarily in the liver. We show here that the liver-specific microRNA-122 (miR-122), a member of a class of small cellular RNAs that mediate post-transcriptional gene regulation usually by repressing the translation of mRNAs through interaction with their 3′-untranslated regions (UTRs), stimulates the translation of HCV. Sequestration of miR-122 in liver cell lines strongly reduces HCV translation, whereas addition of miR-122 stimulates HCV translation in liver cell lines as well as in the non-liver HeLa cells and in rabbit reticulocyte lysate. The stimulation is conferred by direct interaction of miR-122 with two target sites in the 5′-UTR of the HCV genome. With a replication-defective NS5B polymerase mutant genome, we show that the translation stimulation is independent of viral RNA synthesis. miR-122 stimulates HCV translation by enhancing the association of ribosomes with the viral RNA at an early initiation stage. In conclusion, the liver-specific miR-122 may contribute to HCV liver tropism at the level of translation
Comparative and Joint Analysis of Two Metagenomic Datasets from a Biogas Fermenter Obtained by 454-Pyrosequencing
Biogas production from renewable resources is attracting increased attention as an alternative energy source due to the limited availability of traditional fossil fuels. Many countries are promoting the use of alternative energy sources for sustainable energy production. In this study, a metagenome from a production-scale biogas fermenter was analysed employing Roche's GS FLX Titanium technology and compared to a previous dataset obtained from the same community DNA sample that was sequenced on the GS FLX platform. Taxonomic profiling based on 16S rRNA-specific sequences and an Environmental Gene Tag (EGT) analysis employing CARMA demonstrated that both approaches benefit from the longer read lengths obtained on the Titanium platform. Results confirmed Clostridia as the most prevalent taxonomic class, whereas species of the order Methanomicrobiales are dominant among methanogenic Archaea. However, the analyses also identified additional taxa that were missed by the previous study, including members of the genera Streptococcus, Acetivibrio, Garciella, Tissierella, and Gelria, which might also play a role in the fermentation process leading to the formation of methane. Taking advantage of the CARMA feature to correlate taxonomic information of sequences with their assigned functions, it appeared that Firmicutes, followed by Bacteroidetes and Proteobacteria, dominate within the functional context of polysaccharide degradation whereas Methanomicrobiales represent the most abundant taxonomic group responsible for methane production. Clostridia is the most important class involved in the reductive CoA pathway (Wood-Ljungdahl pathway) that is characteristic for acetogenesis. Based on binning of 16S rRNA-specific sequences allocated to the dominant genus Methanoculleus, it could be shown that this genus is represented by several different species. Phylogenetic analysis of these sequences placed them in close proximity to the hydrogenotrophic methanogen Methanoculleus bourgensis. While rarefaction analyses still indicate incomplete coverage, examination of the GS FLX Titanium dataset resulted in the identification of additional genera and functional elements, providing a far more complete coverage of the community involved in anaerobic fermentative pathways leading to methane formation
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