272 research outputs found
The roles of biochar and arbuscular mycorrhizal inoculation on selected soil biological properties and tomato performance
Field experiment was conducted to investigate the effects of biochar application and arbuscular mycorrhizal (AM) inoculation on selected soil biological characteristics, shoot P and fruit yield of two tomato genotypes. Result indicated that mycorrhizal inoculation significantly (p< 0.05) increased shoot P (0.72 g P kg-1) and number of AM spores (47.90 spores / 25 g soil) compared to non-mycorrhizal plants, but no significant difference was observed in tomato fruit yield, microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN). Application of 20 t ha-1 of biochar significantly (p< 0.05) increased tomato fruit yields and number of AM spores when compared with the control. However, 10 and 15 t ha-1 of biochar rates gave comparable performance as 20 t ha-1 of biochar in most cases. No significant differences were observed in shoot P, MBC and MBN among biochar rates. Thus, AM inoculation enhanced P nutrition while biochar improved AM spores abundance as well as tomato fruit yields. The 20 t ha-1 of biochar could be used to improve AM spores abundance as well as tomato fruit yields.Keywords: Biochar; AM Fungi; Biological Properties; Tomato Performanc
Intrinsic decoherence and classical-quantum correspondence in two coupled delta-kicked rotors
We show that classical-quantum correspondence of center of mass motion in two
coupled delta-kicked rotors can be obtained from intrinsic decoherence of the
system itself which occurs due to the entanglement of the center of mass motion
to the internal degree of freedom without coupling to external environment
Improved Estimates of Cosmological Perturbations
We recently derived exact solutions for the scalar, vector and tensor mode
functions of a single, minimally coupled scalar plus gravity in an arbitrary
homogeneous and isotropic background. These solutions are applied to obtain
improved estimates for the primordial scalar and tensor power spectra of
anisotropies in the cosmic microwave background.Comment: 31 pages, 4 figures, LaTeX 2epsilon, this version corrects an
embarrasing mistake (in the published version) for the parameter q_C.
Affected eqns are 105, 109-110, 124, 148-153 and 155-15
Particle creation, classicality and related issues in quantum field theory: II. Examples from field theory
We adopt the general formalism, which was developed in Paper I
(arXiv:0708.1233) to analyze the evolution of a quantized time-dependent
oscillator, to address several questions in the context of quantum field theory
in time dependent external backgrounds. In particular, we study the question of
emergence of classicality in terms of the phase space evolution and its
relation to particle production, and clarify some conceptual issues. We
consider a quantized scalar field evolving in a constant electric field and in
FRW spacetimes which illustrate the two extreme cases of late time adiabatic
and highly non-adiabatic evolution. Using the time-dependent generalizations of
various quantities like particle number density, effective Lagrangian etc.
introduced in Paper I, we contrast the evolution in these two limits bringing
out key differences between the Schwinger effect and evolution in the de Sitter
background. Further, our examples suggest that the notion of classicality is
multifaceted and any one single criterion may not have universal applicability.
For example, the peaking of the phase space Wigner distribution on the
classical trajectory \emph{alone} does not imply transition to classical
behavior. An analysis of the behavior of the \emph{classicality parameter},
which was introduced in Paper I, leads to the conclusion that strong particle
production is necessary for the quantum state to become highly correlated in
phase space at late times.Comment: RevTeX 4; 27 pages; 18 figures; second of a series of two papers, the
first being arXiv:0708.1233 [gr-qc]; high resolution figures available from
the authors on reques
Scalar perturbation spectra from warm inflation
We present a numerical integration of the cosmological scalar perturbation
equations in warm inflation. The initial conditions are provided by a
discussion of the thermal fluctuations of an inflaton field and thermal
radiation using a combination of thermal field theory and thermodynamics. The
perturbation equations include the effects of a damping coefficient
and a thermodynamic potential . We give an analytic expression for the
spectral index of scalar fluctuations in terms of a new slow-roll parameter
constructed from . A series of toy models, inspired by spontaneous
symmetry breaking and a known form of the damping coefficient, lead to a
spectrum with on large scales and on small scales.Comment: 12 pages, 5 figures, RevTeX 4, revised with extra figure
The study on culture of rainbow trout (Oncorhynchus mykiss) by new design of foster-lucas ponds
Intensive culture of rainbow trout, usually done using several different methods. The objective of this study was to compare fish performance and welfare in a new design of Foster-lucas ponds (FLP) and a raceway ponds (RP) under field conditions. Currennt study was designed in two treatment with three repeats. Each pond was randomly stocked by rainbow trout fish with initial average weight of approximately 51±5 g. stocking density was 120n/m3 during study. After 10 months of trial, fish fed diets with commercial diet (Chineh Company). Feeding operation conducted according to the manuals by consideration of water temperature, fish weight and biomass. During the 10 months experiment, the fish survival rate was high (97.39 and 98.05%). No significant differences in growth parameters were observed between RP and FLP, but in all parameters FLP was higher than RP Final weight was 0.99% higher in FLP than in RP. Water quality factors (Dissolved oxygen, PH) was better in FLP. The results confirm that when water quality is maintained in safe level ranges, growth rate of rainbow trout attained in FLS are comparable to those in RP
Monte Carlo reconstruction of the inflationary potential
We present Monte Carlo reconstruction, a new method for ``inverting''
observational data to constrain the form of the scalar field potential
responsible for inflation. This stochastic technique is based on the flow
equation formalism and has distinct advantages over reconstruction methods
based on a Taylor expansion of the potential. The primary ansatz required for
Monte Carlo reconstruction is simply that inflation is driven by a single
scalar field. We also require a very mild slow roll constraint, which can be
made arbitrarily weak since Monte Carlo reconstruction is implemented at
arbitrary order in the slow roll expansion. While our method cannot evade
fundamental limits on the accuracy of reconstruction, it can be simply and
consistently applied to poor data sets, and it takes advantage of the attractor
properties of single-field inflation models to constrain the potential outside
the small region directly probed by observations. We show examples of Monte
Carlo reconstruction for data sets similar to that expected from the Planck
satellite, and for a hypothetical measurement with a factor of five better
parameter discrimination than Planck.Comment: 10 pages, 5 figures (RevTeX 4) Version submitted to PRD: references
added, minor clarification
Peripartum Cardiomyopathy: Facts and Figures
Peripartum cardiomyopathy (PPCM) is a rare clinical entity during pregnancy. PPCM is a diagnosis of exclusion. These patients do not have prior history of heart disease, and there are no other known possible causes of heart failure. It is more common in African countries, may be related to the consumption of kanwa, in the postpartum period. The multiparity, African descent and pregnancy-induced hypertension are a few risk factors for PPCM. The exact etiology of PPCM is not known; possible theories range from myocarditis to the maladaptation to the changes of pregnancy. The clinical manifestation varies from shortness of breath to thromboembolic phenomenon. Echocardiography is essential for diagnosis as well as differential diagnosis of PPCM. These patients preferably are managed in tertiary healthcare facilities. Anticoagulation and antiarrhythmic medications are pillars for the management of PPCM patients. If required, mechanical devices should be used temporarily. PPCM patients may need heart transplant. The beneficial role of bromocriptine and immunosuppression is not clear in PPCM patients. Subsequent pregnancies should be avoided to prevent the PPCM occurrence
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