4,459 research outputs found
Parallel algorithm with spectral convergence for nonlinear integro-differential equations
We discuss a numerical algorithm for solving nonlinear integro-differential
equations, and illustrate our findings for the particular case of Volterra type
equations. The algorithm combines a perturbation approach meant to render a
linearized version of the problem and a spectral method where unknown functions
are expanded in terms of Chebyshev polynomials (El-gendi's method). This
approach is shown to be suitable for the calculation of two-point Green
functions required in next to leading order studies of time-dependent quantum
field theory.Comment: 15 pages, 9 figure
Holographic Construction of Excited CFT States
We present a systematic construction of bulk solutions that are dual to CFT
excited states. The bulk solution is constructed perturbatively in bulk fields.
The linearised solution is universal and depends only on the conformal
dimension of the primary operator that is associated with the state via the
operator-state correspondence, while higher order terms depend on detailed
properties of the operator, such as its OPE with itself and generally involve
many bulk fields. We illustrate the discussion with the holographic
construction of the universal part of the solution for states of two
dimensional CFTs, either on or on . We compute the
1-point function both in the CFT and in the bulk, finding exact agreement. We
comment on the relation with other reconstruction approaches.Comment: 26 pages, 4 figures, v2: comments adde
A Compilation Framework for Macroprogramming Networked Sensors
Abstract. Macroprogramming—the technique of specifying the behavior of the system, as opposed to the constituent nodes—provides application developers with high level abstractions that alleviate the programming burden in develop- ing wireless sensor network (WSN) applications. However, as the semantic gap between macroprogramming abstractions and node-level code is considerably wider than in traditional programming, converting the high level specification to running code is a daunting process, and a major hurdle to the acceptance of macroprogramming.
In this paper, we propose a general compilation framework for a data-driven macroprogramming language that allows for plugging in different modules implementing various stages of compilation. We also demonstrate an actual instantiation of our framework by showing an end-to-end solution for compiling macro- programs. Our compiler provides the final code to be deployed on real nodes as well as an estimate of the costs the running system will incur, e.g., in terms of messages exchanged. We compared the auto-generated code against a hand- coded version for the same application behavior to verify the outcome of our compiler
Study of biochemical markers in iron deficiency anemia
Background: The present study was aimed to study alterations in levels of oxidants and antioxidants in iron deficiency anemia (IDA).Methods: 30 patients of IDA in age group of 20-50 and 30 healthy subjects were included for study. Serum Iron, TIBC & Hb% were estimated to diagnose IDA. Serum Malondialdehyde (MDA), Nitric oxide (NO) as an oxidants & Superoxide dismutase (SOD), vitamin E, vitamin C, Zinc (Zn) levels as antioxidants were estimated.Results: Significant decreased levels of Hb%, serum iron, SOD, Vitamin C, vitamin E, Zn were found. TIBC, MDA, NO were significantly increased as compared to controls.Conclusion: The normal adult erythrocytes can resist oxidative stress by several antioxidant defense systems. In IDA, oxidative stress causes lipid peroxidation and membrane damage. So antioxidants can be used as a marker for prevention of membrane damage due to oxidative stress
WRKY6 restricts Piriformospora indica-stimulated and phosphate-induced root development in Arabidopsis
BACKGROUND: Arabidopsis root growth is stimulated by Piriformospora indica, phosphate limitation and inactivation of the WRKY6 transcription factor. Combinations of these factors induce unexpected alterations in root and shoot growth, root architecture and root gene expression profiles. RESULTS: The results demonstrate that P. indica promotes phosphate uptake and root development under Pi limitation in wrky6 mutant. This is associated with the stimulation of PHOSPHATE1 expression and ethylene production. Expression profiles from the roots of wrky6 seedlings identified genes involved in hormone metabolism, transport, meristem, cell and plastid proliferation, and growth regulation. 25 miRNAs were also up-regulated in these roots. We generated and discuss here a list of common genes which are regulated in growing roots and which are common to all three growth stimuli investigated in this study. CONCLUSION: Since root development of wrky6 plants exposed to P. indica under phosphate limitation is strongly promoted, we propose that common genes which respond to all three growth stimuli are central for the control of root growth and architecture. They can be tested for optimizing root growth in model and agricultural plants. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12870-015-0673-4) contains supplementary material, which is available to authorized users
Time evolution of the chiral phase transition during a spherical expansion
We examine the non-equilibrium time evolution of the hadronic plasma produced
in a relativistic heavy ion collision, assuming a spherical expansion into the
vacuum. We study the linear sigma model to leading order in a large-
expansion. Starting at a temperature above the phase transition, the system
expands and cools, finally settling into the broken symmetry vacuum state. We
consider the proper time evolution of the effective pion mass, the order
parameter , and the particle number distribution. We
examine several different initial conditions and look for instabilities
(exponentially growing long wavelength modes) which can lead to the formation
of disoriented chiral condensates (DCCs). We find that instabilities exist for
proper times which are less than 3 fm/c. We also show that an experimental
signature of domain growth is an increase in the low momentum spectrum of
outgoing pions when compared to an expansion in thermal equilibrium. In
comparison to particle production during a longitudinal expansion, we find that
in a spherical expansion the system reaches the ``out'' regime much faster and
more particles get produced. However the size of the unstable region, which is
related to the domain size of DCCs, is not enhanced.Comment: REVTex, 20 pages, 8 postscript figures embedded with eps
Influence of shape of quantum dots on their far-infrared absorption
We investigate the effects of the shape of quantum dots on their far-infrared
absorption in an external magnetic field by a model calculation. We focus our
attention on dots with a parabolic confinement potential deviating from the
common circular symmetry, and dots having circular doughnut shape. For a
confinement where the generalized Kohn theorem does not hold we are able to
interprete the results in terms of a mixture of a center-of-mass mode and
collective modes reflecting an excitation of relative motion of the electrons.
The calculations are performed within the time-dependent Hartree approximation
and the results are compared to available experimental results.Comment: RevTeX, 16 pages with 10 postscript figures included. Submitted to
Phys. Rev.
Shear viscosity of hot scalar field theory in the real-time formalism
Within the closed time path formalism a general nonperturbative expression is
derived which resums through the Bethe-Salpter equation all leading order
contributions to the shear viscosity in hot scalar field theory. Using a
previously derived generalized fluctuation-dissipation theorem for nonlinear
response functions in the real-time formalism, it is shown that the
Bethe-Salpeter equation decouples in the so-called (r,a) basis. The general
result is applied to scalar field theory with pure lambda*phi**4 and mixed
g*phi**3+lambda*phi**4 interactions. In both cases our calculation confirms the
leading order expression for the shear viscosity previously obtained in the
imaginary time formalism.Comment: Expanded introduction and conclusions. Several references and a
footnote added. Fig.5 and its discussion in the text modified to avoid double
counting. Signs in Eqs. (45) and (53) correcte
Co 15002: A potential fifth generation inbred derivative developed through inbreeding followed by hybridization and selection for sugarcane improvement
Among 129 clones evaluated along with standard varieties CoC 671 and Co 86032 in Pre-zonal varietal trial (PZVT) during 2014-15, the clone PZVT 13-175 recorded the highest cane yield of 143.52 t/ha which was significantly superior to both the standards. Consequently the clone was given Co status i.e. Co 15002 and was included in Initial Varietal Trial of All India Co-ordinated research Project on Sugarcane in Peninsular Zone along with 25 other test entries and four standards at 15 test locations during the year 2018-19. Co 15002 registered significantly higher sucrose content (19.43%) than the commercially released sugarcane variety CoSnk 05103 (18.96 %) and on par with the ruling variety Co 86032 (19.63 %) at 10th month crop maturity. Cane yield of Co 15002 (96.27 t/ha) was found to be on par with the recently released CoSnk 05103 (97.23 t/ha) and CoC 671 (99.30 t/ha). Co 15002 was screened for red rot, smut and yellow leaf diseases under natural and artificially inoculated conditions at Coimbatore, Pune, Kolhapur and Navsari. Under natural conditions, smut and yellow leaf diseases were not observed. Co 15002 was resistant or moderately resistant to red rot by both plug and nodal methods in all the test locations. In artificial inoculated conditions, Co 15002 showed resistance to moderately resistant reaction to smut. It recorded 20 % flowering intensity and low pollen fertility of 30 % with peak flowering during the first fortnight of November and can be used as a pistil parent in hybridization programmes
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