1,287 research outputs found
BELIEVING FACTS IN THE FOG OF WAR:Identity, Media, and Hot Cognition in Ukraineâs 2014 Odesa Tragedy
Die Entwicklung des russischen DemokratieverstÀndnisses 2008-2012: Gab es einen demokratischen Aufbruch?
Aufgrund der ĂŒberraschend ausgebrochenen gröĂten Demonstrationen der Wladimir Putin-Ăra, welche einen Protest gegen die weitgehend als Betrug wahrgenommenen Duma-Wahlen vom Dezember 2011 darstellten, spekulierten viele Beobachter, dass es in Russland zu einem demokratischen Aufbruch kommen könnte. Ein Vergleich der unmittelbar nach den Parlaments- und PrĂ€sidentschaftswahlen in den Jahren 2008 und 2012 in Russland durchgefĂŒhrten Meinungsumfragen offenbart jedoch nur wenige Anzeichen eines solchen Aufbruchs und zeigt, dass die UnterstĂŒtzung fĂŒr die Demokratie gleich geblieben ist. Die Meinungsumfragen zeigen auch, dass die Idee des "Aufbruchs" unpassend sein könnte, weil die "Demokratie", die von vielen Russen unterstĂŒtzt wird, gleichzeitig mit einem "starken AnfĂŒhrer" vereinbar ist, der ohne "Checks and Balances" herrscht. Sie unterstĂŒtzen das, was Guillermo O'Donnell bekanntermaĂen eine "delegative Demokratie" nannte, in der die Menschen frei und regelmĂ€Ăig StaatsoberhĂ€upter wĂ€hlen, von welchen dann erwartet wird, dass sie ihre breite Macht ohne EinschrĂ€nkungen ausĂŒben, um Probleme zu lösen und Weiterentwicklung zu fördern
Rotation periods of exoplanet host stars
The stellar rotation periods of ten exoplanet host stars have been determined
using newly analysed Ca II H & K flux records from Mount Wilson Observatory and
Stromgren b, y photometric measurements from Tennessee State University's
automatic photometric telescopes (APTs) at Fairborn Observatory. Five of the
rotation periods have not previously been reported, with that of HD 130322 very
strongly detected at Prot = 26.1 \pm 3.5 d. The rotation periods of five other
stars have been updated using new data. We use the rotation periods to derive
the line-of-sight inclinations of the stellar rotation axes, which may be used
to probe theories of planet formation and evolution when combined with the
planetary orbital inclination found from other methods. Finally, we estimate
the masses of fourteen exoplanets under the assumption that the stellar
rotation axis is aligned with the orbital axis. We calculate the mass of HD
92788 b (28 MJ) to be within the low-mass brown dwarf regime and suggest that
this object warrants further investigation to confirm its true nature.Comment: Accepted for publication in MNRAS. 15 pages, 11 figure
Report of the Astronomy Committee
The present report relates only to the scientific needs of Astronomy. Its applications to the possible services that astronomers can render in the war, as a part of the work done by the National Research Council in connection with the Council of National Defense, will be made the subject of a separate study
A striking correspondence between the dynamics generated by the vector fields and by the scalar parabolic equations
The purpose of this paper is to enhance a correspondence between the dynamics
of the differential equations on and those
of the parabolic equations on a bounded
domain . We give details on the similarities of these dynamics in the
cases , and and in the corresponding cases ,
and dim() respectively. In addition to
the beauty of such a correspondence, this could serve as a guideline for future
research on the dynamics of parabolic equations
The resistive state in a superconducting wire: Bifurcation from the normal state
We study formally and rigorously the bifurcation to steady and time-periodic
states in a model for a thin superconducting wire in the presence of an imposed
current. Exploiting the PT-symmetry of the equations at both the linearized and
nonlinear levels, and taking advantage of the collision of real eigenvalues
leading to complex spectrum, we obtain explicit asymptotic formulas for the
stationary solutions, for the amplitude and period of the bifurcating periodic
solutions and for the location of their zeros or "phase slip centers" as they
are known in the physics literature. In so doing, we construct a center
manifold for the flow and give a complete description of the associated
finite-dimensional dynamics
Instability of the steady states of some GinzburgâLandau-like equations with real coefficients
The instability of the steady states with nonconstant amplitude is analysed for a nonlocal GinzburgâLandau equation with real coefficients and quasiperiodic boundary conditions. The results are obtained in terms of easily recognized, qualitative properties of the steady states. Some of the results are new, even for the standard (local) GinzburgâLandau equation with real coefficients. A related GinzburgâLandau equation coupled to a mean field is also considered that appears in the analyses of counter-propagating waves in extended systems, nonoscillatory instabilities with a conservation law, and viscous Faraday waves in large aspect ratio containers
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Ecohydrological consequences of droughtâ and infestationâtriggered tree dieâoff: insights and hypotheses
Widespread, rapid, drought-, and infestation-triggered tree mortality is emerging as a phenomenon affecting forests globally and may be linked to increasing temperatures and drought frequency and severity. The ecohydrological consequences of forest die-off have been little studied and remain highly uncertain. To explore this knowledge gap, we apply the extensive literature on the ecohydrological effects of tree harvest in combination with the limited existing die-off ecohydrology research to develop new, relevant hypotheses. Tree mortality results in loss of canopy cover, which directly alters evaporation, transpiration, and canopy interception and indirectly alters other watershed hydrologic processes, including infiltration, runoff, groundwater recharge, and streamflow. Both die-off and harvest research suggest that for most forests, water yield can be expected to increase following substantial loss of tree cover by die-off. We hypothesize that where annual precipitation exceeds 500 mm or water yield is dominated by snowmelt, watersheds will experience significantly decreased evapotranspiration and increased flows if absolute canopy cover loss from die-off exceeds 20%. However, recent observations suggest that water yield following die-off can potentially decrease rather than increase in drier forests. To reliably predict die-off responses, more research is needed to test these hypotheses, including observations of multiple water budget components and the persistence of ecohydrological effects with the post-die-off successional dynamics of tree recruitment, understorey growth, and interactions with additional disturbances. With die-off, mitigation and restoration options are limited and costly, necessitating societal adaptation; therefore, die-off ecohydrology should be a high priority for future research. Published in 2011. This article is a US Government work and is in the public domain in the USA.Keywords: bark beetle, Evapotranspiration, Recharge, Die-off, Ecohydrology, Forest mortality, Tree mortality, Water yield, Tree pestsKeywords: bark beetle, Evapotranspiration, Recharge, Die-off, Ecohydrology, Forest mortality, Tree mortality, Water yield, Tree pest
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