953 research outputs found
PRINCIPLES OF WORKING WITH SOUND IN M. SHALYGIN'S ESSAY “RED BELLS OF JUAN MIRO”
The aim of the research is to establish the specifics of M. Shalygin's work with sound (using the work “Red Bells of Juan Miro" as an example), which will allow a better understanding of the originality of his music, as well as the composer's method of organizing sound and its (sound) interpretation. Thus, using the integrated method which combines the auditory and structural methods of analysis, as well as the analysis of the spectrogram of the work, the properties of the timbre elements, the principles of the organization of musical tissue, as well as the features of composer thinking and creative methods will be established od M. Shalygin.The aim of the research is to establish the specifics of M. Shalygin's work with sound (using the work “Red Bells of Juan Miro" as an example), which will allow a better understanding of the originality of his music, as well as the composer's method of organizing sound and its (sound) interpretation. Thus, using the integrated method which combines the auditory and structural methods of analysis, as well as the analysis of the spectrogram of the work, the properties of the timbre elements, the principles of the organization of musical tissue, as well as the features of composer thinking and creative methods will be established od M. Shalygin
Geometry of intensive scalar dissipation events in turbulence
Maxima of the scalar dissipation rate in turbulence appear in form of sheets
and correspond to the potentially most intensive scalar mixing events. Their
cross-section extension determines a locally varying diffusion scale of the
mixing process and extends the classical Batchelor picture of one mean
diffusion scale. The distribution of the local diffusion scales is analysed for
different Reynolds and Schmidt numbers with a fast multiscale technique applied
to very high-resolution simulation data. The scales take always values across
the whole Batchelor range and beyond. Furthermore, their distribution is traced
back to the distribution of the contractive short-time Lyapunov exponent of the
flow.Comment: 4 pages, 5 Postscript figures (2 with reduced quality
Development and performance evaluation of a tandem mass spectrometry assay for 4 adrenal steroids
Journal ArticleCongenital adrenal hyperplasia is a group of autosomal recessive disorders caused by a deficiency of 1 of 4 enzymes required for the synthesis of glucocorticoids, mineralocorticoids, and sex hormones. Analysis of 11-deoxycortisol (11DC), 17-hydroxyprogesterone (17OHP), 17-hydroxypregnenolone (17OHPr), and pregnenolone (Pr) in blood allows detection of these enzyme defects
Comparing hurricane and extratropical storm surge for the Mid- Atlantic and Northeast Coast of the United States for 1979–2013
This letter examines the magnitude, spatial footprint, and paths of hurricanes and extratropical cyclones (ETCs) that caused strong surge along the east coast of the US between 1979 and 2013. Lagrangian cyclone track information, for hurricanes and ETCs, is used to associate surge events with individual storms. First, hurricane influence is examined using ranked surged events per site. The fraction of hurricanes among storms associated with surge decreases from 20%–60% for the top 10 events to 10%–30% for the top 50 events, and a clear latitudinal gradient of hurricane influence emerges for larger sets of events. Secondly, surges on larger spatial domains are examined by focusing on storms that cause exceedance of the probabilistic 1-year surge return level at multiple stations. Results show that if the strongest events in terms of surge amplitude and spatial extent are considered, then hurricanes are most likely to create the hazards. However, when slightly less strong events that still impact multiple areas during the storm life cycle are considered, the relative importance of hurricanes shrinks as that of ETCs grows. Furthermore we find distinct paths for ETCs causing multisite surge at individual segments of the US east coast
The stability of decelerating shocks revisited
We present a new method for analyzing the global stability of the Sedov-von
Neumann-Taylor self-similar solutions, describing the asymptotic behavior of
spherical decelerating shock waves, expanding into ideal gas with density
\propto r^{-\omega}. Our method allows to overcome the difficulties associated
with the non-physical divergences of the solutions at the origin. We show that
while the growth rates of global modes derived by previous analyses are
accurate in the large wave number (small wavelength) limit, they do not
correctly describe the small wave number behavior for small values of the
adiabatic index \gamma. Our method furthermore allows to analyze the stability
properties of the flow at early times, when the flow deviates significantly
from the asymptotic self-similar behavior. We find that at this stage the
perturbation growth rates are larger than those obtained for unstable
asymptotic solutions at similar [\gamma,\omega]. Our results reduce the
discrepancy that exists between theoretical predictions and experimental
results.Comment: 10 pages, 9 figures. Accepted to ApJ; Expanded discussion of boundary
condition
Enzyme-Directed Mutasynthesis: A Combined Experimental and Theoretical Approach to Substrate Recognition of a Polyketide Synthase
Acyltransferase domains control the extender unit recognition in Polyketide Synthases (PKS) and thereby the side-chain diversity of the resulting natural products. The enzyme engineering strategy presented here allows the alteration of the acyltransferase substrate profile to enable an engineered biosynthesis of natural product derivatives through the incorporation of a synthetic malonic acid thioester. Experimental sequence−function correlations combined with computational modeling revealed the origins of substrate recognition in these PKS domains and enabled a targeted mutagenesis. We show how a single point mutation was able to direct the incorporation of a malonic acid building block with a non-native functional group into erythromycin. This approach, introduced here as enzyme-directed mutasynthesis, opens a new field of possibilities beyond the state of the art for the combination of organic chemistry and biosynthesis toward natural product analogues
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Tropical Oceanic Causes of Interannual to Multidecadal Precipitation Variability in Southeast South America over the Past Century
Observations, atmosphere models forced by historical SSTs, and idealized simulations are used to determine the causes and mechanisms of interannual to multidecadal precipitation anomalies over southeast South America (SESA) since 1901. About 40% of SESA precipitation variability over this period can be accounted for by global SST forcing. Both the tropical Pacific and Atlantic Oceans share the driving of SESA precipitation, with the latter contributing the most on multidecadal time scales and explaining a wetting trend from the early midcentury until the end of the last century. Cold tropical Atlantic SST anomalies are shown to drive wet conditions in SESA. The dynamics that link SESA precipitation to tropical Atlantic SST anomalies are explored. Cold tropical Atlantic SST anomalies force equatorward-flowing upper-tropospheric flow to the southeast of the tropical heating anomaly, and the vorticity advection by this flow is balanced by vortex stretching and ascent, which drives the increased precipitation. The 1930s Pampas Dust Bowl drought occurred, via this mechanism, in response to warm tropical Atlantic SST anomalies. The atmospheric response to cold tropical Pacific SSTs also contributed. The tropical Atlantic SST anomalies linked to SESA precipitation are the tropical components of the Atlantic multidecadal oscillation. There is little evidence that the large trends over past decades are related to anthropogenic radiative forcing, although models project that this will cause a modest wetting of the climate of SESA. As such, and if the Atlantic multidecadal oscillation has shifted toward a warm phase, it should not be assumed that the long-term wetting trend in SESA will continue. Any reversal to a drier climate more typical of earlier decades would have clear consequences for regional agriculture and water resources
Mesoscopic scattering of spin s particles
Quantum effects in weakly disordered systems are governed by the properties
of the elementary interaction between propagating particles and impurities.
Long range mesoscopic effects due to multiple scattering are derived by
iterating the single scattering vertex, which has to be appropriately
diagonalized. In the present contribution, we present a systematic and detailed
diagonalisation of the diffuson and cooperon vertices responsible for weak
localisation effects. We obtain general expressions for eigenvalues and
projectors onto eigenmodes, for any spin and arbitrary elementary interaction
with impurities. This description provides a common frame for a unified theory
of mesoscopic spin physics for electrons, photons, and other quantum particles.
We treat in detail the case of spin-flip scattering of electrons by freely
orientable magnetic impurities and briefly review the case of photon scattering
from degenerate dipole transitions in cold atomic gases.Comment: published version, with a new figure and new section
CHARGE TRANSFER BETWEEN POSITIVE ALKALI IONS AND ATOMS
The total cross sections for resonant charge exchange have been measured as a function of energy in the range from 10 to 500 eV for the Cs{sup +}-Cs, Rb{sup +}-Rb, and K{sup +}-K systems. The agreement with certain data obtained at higher energies for these systems, and with theoretical cross sections of Smirnov is satisfactory
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