1,102 research outputs found
In search of genetic diversity in Rosa foetida Hermann in Iran
Rosa foetida is a dense, erect shrub with bright yellow or scarlet flowers with a yellowish reverse petal. It is most abundant in South West Asia. In Iran R. foetida occurs mainly in the mountainous North and West regions. The species is the origin of the strong yellow color in hybrid roses, which was introduced into modern cultivars in 1900 through a single species hybridization event. In this study we have used 10 microsatellite markers to determine diversity in Rosa foetida accessions collected across Iran. To our surprise, nearly all samples collected were of the same genotype, even when collected at different sites. Only four different genotypes have been detected in total. The results are discussed in relation to breeding system, human influence and overall gene pool statu
Geometric approach to nonlinear coherent states using the Higgs model for harmonic oscillator
In this paper, we investigate the relation between the curvature of the
physical space and the deformation function of the deformed oscillator algebra
using non-linear coherent states approach. For this purpose, we study
two-dimensional harmonic oscillators on the flat surface and on a sphere by
applying the Higgs modell. With the use of their algebras, we show that the
two-dimensional oscillator algebra on a surface can be considered as a deformed
one-dimensional oscillator algebra where the effect of the curvature of the
surface is appeared as a deformation function. We also show that the curvature
of the physical space plays the role of deformation parameter. Then we
construct the associated coherent states on the flat surface and on a sphere
and compare their quantum statistical properties, including quadrature
squeezing and antibunching effect.Comment: 12 pages, 7 figs. To be appeared in J. Phys.
Influence of phonons on exciton-photon interaction and photon statistics of a quantum dot
In this paper, we investigate, phonon effects on the optical properties of a
spherical quantum dot. For this purpose, we consider the interaction of a
spherical quantum dot with classical and quantum fields while the exciton of
quantum dot interacts with a solid state reservoir. We show that phonons
strongly affect the Rabi oscillations and optical coherence on first
picoseconds of dynamics. We consider the quantum statistics of emitted photons
by quantum dot and we show that these photons are anti-bunched and obey the
sub-Poissonian statistics. In addition, we examine the effects of detuning and
interaction of quantum dot with the cavity mode on optical coherence of energy
levels. The effects of detuning and interaction of quantum dot with cavity mode
on optical coherence of energy levels are compared to the effects of its
interaction with classical pulse
Two-scale modelling of fracture of magnesium phosphate cement under bending using X-ray computed tomography characterisation
This paper presents an efficient experimental-numerical analysis of fracture mechanics in magnesium phosphate cement (MPC) based on the structural and mechanical properties of its constituents including potassium magnesium phosphate hexahydrate (MKP), magnesium oxide (MgO) and pores. At micro-scale, the fracture energy and material strength of solid phases were obtained relying on the combination of nanoindentation experiments and simulation. The X-ray computed tomography (XCT) image-based 3D meso-structure model of MPC beam was generated and incorporated with the finite element cohesive zone model to analyse the fracture process of MPC beam under three-point bending. The unknown fracture parameters of cohesive elements at the interface between MKP and MgO were determined via the model calibration process conditional to the experimental data in terms of relationship between macro-load and crack mouth opening displacement. The cohesive strengths obtained for MKP, MgO and MKP-MgO were found to be 5.8, 106 and 24 MPa, respectively. In the same order, the fracture energies were0.02, 0.08 and 0.04 N/mm, respectively
Effects of post-anthesis heat stress and nitrogen levels on grain yield and grain growth of wheat ( T. durum and T. aestivum) genotypes
Influence of gravitational field on quantum-nondemolition measurement of atomic momentum in the dispersive Jaynes-Cummings model
We present a theoretical scheme based on su(2) algebra to investigate the
influence of homogeneous gravitational field on the quantum nondemolition
measurement of atomic momentum in dispersive Jaynes-Cummings model. In the
dispersive Jaynes-Cummings model, when detuning is large and the atomic motion
is in a propagating light wave, we consider a two-level atom with quantized
cavity-field in the presence of a homogeneous gravitational field. We derive an
effective Hamiltonian describing the dispersive atom-field interaction in the
presence of gravitational field. We can see gravitational influence both on the
momentum filter and momentum distribution. Moreover, gravitational field
decreases both tooth spacing of momentum and the width of teeth of momentum.Comment: 21 pages, 8 figure
Oblique projection for scalable rank-adaptive reduced-order modeling of nonlinear stochastic PDEs with time-dependent bases
Time-dependent basis reduced order models (TDB ROMs) have successfully been
used for approximating the solution to nonlinear stochastic partial
differential equations (PDEs). For many practical problems of interest,
discretizing these PDEs results in massive matrix differential equations (MDEs)
that are too expensive to solve using conventional methods. While TDB ROMs have
the potential to significantly reduce this computational burden, they still
suffer from the following challenges: (i) inefficient for general
nonlinearities, (ii) intrusive implementation, (iii) ill-conditioned in the
presence of small singular values, and (iv) error accumulation due to fixed
rank. To this end, we present a scalable method based on oblique projections
for solving TDB ROMs that is computationally efficient, minimally intrusive,
robust in the presence of small singular values, rank-adaptive, and highly
parallelizable. These favorable properties are achieved via low-rank
approximation of the time discrete MDE. Using the discrete empirical
interpolation method (DEIM), a low-rank decomposition is computed at each
iteration of the time stepping scheme, enabling a near-optimal approximation at
a fraction of the cost. We coin the new approach TDB-CUR since it is equivalent
to a CUR decomposition based on sparse row and column samples of the MDE. We
also propose a rank-adaptive procedure to control the error on-the-fly.
Numerical results demonstrate the accuracy, efficiency, and robustness of the
new method for a diverse set of problems
A Comparison between Recombinant Activated Factor VII (Aryoseven) and Novoseven in Patients with Congenital Factor VII Deficiency
In order to establish the efficacy and biosimilar nature of AryoSeven to NovoSeven in the treatment of congenital factor VII (FVII) deficiency, patients received either agent at 30 1/4g/kg, intravenously per week for 4 weeks, in a randomized fashion. The primary aim was to compare FVII:coagulation activity (FVII:C), 20 minutes after recombinant activated FVII (rFVIIa) injection, in the 2 groups. A secondary measure was self-reported bleeding. The median interquartile baseline range of the plasma level of activated FVII (FVIIa) activity in the 2 groups was 1.6 (1.1-14.0) IU/dL and 5.0 (1.1-25.5) IU/dL. All patients achieved levels of FVIIa (FVII:C) >30 IU/dL, 20 minutes after the injection of rFVIIa. Bleeding was similar between the 2 groups, with a comparable decrease in severity and frequency compared to the last month prior to treatment. AryoSeven is similar to NovoSeven in increasing postinjection FVIIa activity as well as in clinical safety and efficacy. © The Author(s) 2014
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