117 research outputs found
Generalized Poisson sigma models
A general master action in terms of superfields is given which generates
generalized Poisson sigma models by means of a natural ghost number
prescription. The simplest representation is the sigma model considered by
Cattaneo and Felder. For Dirac brackets considerably more general models are
generated.Comment: 8 pages, Latexfile, added comment and reference
Selection for resistance to oseltamivir in seasonal and pandemic H1N1 influenza and widespread co-circulation of the lineages
Background:
In Spring 2009, a novel reassortant strain of H1N1 influenza A emerged as a lineage distinct from seasonal H1N1. On June 11, the World Heath Organization declared a pandemic - the first since 1968. There are currently two main branches of H1N1 circulating in humans, a seasonal branch and a pandemic branch. The primary treatment method for pandemic and seasonal H1N1 is the antiviral drug Tamiflu® (oseltamivir). Although many seasonal H1N1 strains around the world are resistant to oseltamivir, initially, pandemic H1N1 strains have been susceptible to oseltamivir. As of February 3, 2010, there have been reports of resistance to oseltamivir in 225 cases of H1N1 pandemic influenza. The evolution of resistance to oseltamivir in pandemic H1N1 could be due to point mutations in the neuraminidase or a reassortment event between seasonal H1N1 and pandemic H1N1 viruses that provide a neuraminidase carrying an oseltamivir-resistant genotype to pandemic H1N1.
Results:
Using phylogenetic analysis of neuraminidase sequences, we show that both seasonal and pandemic lineages of H1N1 are evolving to direct selective pressure for resistance to oseltamivir. Moreover, seasonal lineages of H1N1 that are resistant to oseltamivir co-circulate with pandemic H1N1 throughout the globe. By combining phylogenetic and geographic data we have thus far identified 53 areas of co-circulation where reassortment can occur. At our website POINTMAP, http://pointmap.osu.edu webcite we make available a visualization and an application for updating these results as more data are released.
Conclusions:
As oseltamivir is a keystone of preparedness and treatment for pandemic H1N1, the potential for resistance to oseltamivir is an ongoing concern. Reassortment and, more likely, point mutation have the potential to create a strain of pandemic H1N1 against which we have a reduced number of treatment options
Supplementary material for the article: Milenković, M.; Shcherbakov, I. N.; Popov, L. D.; Levchenkov, S. I.; Borodkin, S. A.; Alexandrov, G. G. Synthesis, Characterization and Crystal Structures of Ni(II) and Cu(I) Complexes with the Condensation Product of 2-(Diphenylphosphino)Benzaldehyde and 1-Hydrazinophthalazine. Polyhedron 2017, 121, 278–284. https://doi.org/10.1016/j.poly.2016.10.020
Supplementary material for: [https://doi.org/10.1016/j.poly.2016.10.020]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2368]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3256
Analysis of Machine Learning Methods for Wildfire Security Monitoring with an Unmanned Aerial Vehicles
The article is about the methods of machine learning, designed for the detection of wildfires using unmanned aerial vehicles. In the article presented the review of machine learning methods, described the motivation part of machine learning usage and comparison of fire and smoke detection is made. The research was focused on machine learning application for monitoring task with a restrictions according to scenarios of a real monitoring. The results of experiments with demonstration of effectiveness of detection are presented in the conclusion part
Nagymértékű képlékeny alakítással előállított ultrafinom szemcséjű anyagok mikroszerkezetének és makroszkopikus tulajdonságainak kapcsolata = Relationship between microstructure and macroscopic properties of ultra-fine grained materials made by severe plastic deformation
a. Tömbi nanoszerkezetű anyagok vizsgálata során kísérleti és gyártási tapasztalatot szereztünk fémekkel és ötvözeteikkel kapcsolatban. b. A nanoszerkezet előállítása során mechanikai, finomszerkezeti röntgen és elektronmikroszkópos vizsgálatokkal meghatároztuk az anyag makroszkópikus és mikroszkópikus jellemzőit. Konstitutív egyenletet dolgoztunk ki az anizotróp viselkedés leírására. c. A nanoszerkezetű anyagok előállítását követően vizsgáltuk a technológiai feldolgozhatóságukat a továbbalakítás, a forgácsolás és a hegesztés területén. d. A gyártási folyamatok mechanikai sémájának feltárása érdekében végeselemes modelleket készítettünk a különböző intenzív képlékenyalakítási eljárásokról. Kontinuumechanikai alapon elemeztük a nanoszerkezet kialakulásának feltételeit. e. A kutatások megalapozták a különleges tulajdonsággal rendelkező tömbi nanoszerkezetű anyagok laboratóriumot meghaladó, félüzemi előállítását. | a. During the investigation of bulk nanostructured materials we have got experiences in experimental and production methods for metals and alloys. b. Using X-ray diffraction, electron microscopy and mechanical measurements, the macro- and microscopical properties have been evaluated. New constitutive equation has been formulated to describe the anisotropic behavior of the materials. c. After production of nanostructured materials, the further deformation, cutting and welding was tested . d. A FEM method was developed for modeling the technological process of severe plastic deformation. Continuum mechanical methods have been used to describe the conditions necessary for processing nanostructured materials. e. These researches made possible to produce nanostructured materials not only in laboratory conditions but even with real semi-production methods
Odd Scalar Curvature in Anti-Poisson Geometry
Recent works have revealed that the recipe for field-antifield quantization
of Lagrangian gauge theories can be considerably relaxed when it comes to
choosing a path integral measure \rho if a zero-order term \nu_{\rho} is added
to the \Delta operator. The effects of this odd scalar term \nu_{\rho} become
relevant at two-loop order. We prove that \nu_{\rho} is essentially the odd
scalar curvature of an arbitrary torsion-free connection that is compatible
with both the anti-Poisson structure E and the density \rho. This extends a
previous result for non-degenerate antisymplectic manifolds to degenerate
anti-Poisson manifolds that admit a compatible two-form.Comment: 9 pages, LaTeX. v2: Minor changes. v3: Published versio
Sea-ice production over the Laptev Sea shelf inferred from historical summer-to-winter hydrographic observations of 1960s-1990s
The winter net sea-ice production (NSIP) over the Laptev Sea shelf is inferred from continuous summer-to-winter historical salinity records of 1960s–1990s. While the NSIP strongly depends on the assumed salinity of newly formed ice, the NSIP quasi-decadal variability can be linked to the wind-driven circulation anomalies in the Laptev Sea region. The increased wind-driven advection of ice away from the Laptev Sea coast when the Arctic Oscillation (AO) is positive implies enhanced coastal polynya sea-ice production and brine release in the shelf water. When the AO is negative, the NSIP and seasonal salinity amplitude tends to weaken. These results are in reasonable agreement with sea-ice observations and modeling
Supplementary material for the article: Milenković, M.; Shcherbakov, I. N.; Popov, L. D.; Levchenkov, S. I.; Borodkin, S. A.; Alexandrov, G. G. Synthesis, Characterization and Crystal Structures of Ni(II) and Cu(I) Complexes with the Condensation Product of 2-(Diphenylphosphino)Benzaldehyde and 1-Hydrazinophthalazine. Polyhedron 2017, 121, 278–284. https://doi.org/10.1016/j.poly.2016.10.020
Supplementary material for: [https://doi.org/10.1016/j.poly.2016.10.020]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2368]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3256
The ATLAS EventIndex: a BigData catalogue for all ATLAS experiment events
The ATLAS EventIndex system comprises the catalogue of all events collected,
processed or generated by the ATLAS experiment at the CERN LHC accelerator, and
all associated software tools to collect, store and query this information.
ATLAS records several billion particle interactions every year of operation,
processes them for analysis and generates even larger simulated data samples; a
global catalogue is needed to keep track of the location of each event record
and be able to search and retrieve specific events for in-depth investigations.
Each EventIndex record includes summary information on the event itself and the
pointers to the files containing the full event. Most components of the
EventIndex system are implemented using BigData open-source tools. This paper
describes the architectural choices and their evolution in time, as well as the
past, current and foreseen future implementations of all EventIndex components.Comment: 21 page
Search for the Phi(1860) Pentaquark at COMPASS
Narrow Xi-pi+- and Xi-bar+pi+- resonances produced by quasi-real photons have
been searched for by the COMPASS experiment at CERN. The study was stimulated
by the recent observation of an exotic baryonic state decaying into Xi-pi-, at
a mass of 1862 MeV, interpreted as a pentaquark. While the ordinary hyperon
states Xi(1530)^0 and Xi-bar(1530)^0 are clearly seen, no exotic baryon is
observed in the data taken in 2002 and 2003.Comment: 10 pages, 5 figure
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