Single hole doped strongly correlated ladder with a static impurity

We consider a strongly correlated ladder with diagonal hopping and exchange interactions described by $t-J$ type hamiltonian. We study the dynamics of a single hole in this model in the presence of a static non-magnetic (or magnetic) impurity. In the case of a non-magnetic (NM) impurity we solve the problem analytically both in the triplet (S=1) and singlet (S=0) sectors. In the triplet sector the hole doesn't form any bound state with the impurity. However, in the singlet sector the hole forms bound states of different symmetries with increasing $J/t$ values. Binding energies of those impurity-hole bound states are compared with the binding energy of a pair of holes in absence of any impurity. In the case of magnetic impurity the analytical eigenvalue equations are solved for a large (50 X 2) lattice. In this case also, with increasing $J/t$ values, impurity-hole bound states of different symmetries are obtained. Binding of the hole with the impurity is favoured for the case of a ferromagnetic (FM) impurity than in the case of antiferromagnetic (AFM) impurity. However binding energy is found to be maximum for the NM impurity. Comparison of binding energies and various impurity-hole correlation functions indicates a pair breaking mechanism by NM impurity.Comment: 15 Pages, 6 figure

A theoretical construction of wormhole supported by Phantom Energy

A new solution has been presented for the spherically symmetric space time describing wormholes with Phantom Energy. The model suggests that the existence of wormhole is supported by arbitrarily small quantity of Phantom Energy.Comment: 6 pages, One reference has been correcte

Nonradiative relaxation and laser action in tunable solid state laser crystals

Room-temperature pulsed laser action was obtained in chromium-activated forsterite (Cr:Mg2SiO4) for both 532 and 1064 nm pumping. Free running laser emission in both cases is centered at 1235 nm and has a bandwidth of approximately 30 nm. Slope efficiency as high as 22 percent was measured. Using different sets of output mirrors and a single birefrigent plate as the intracavity wavelength selecting element tunability over the 1167 to 1268 nm spectral range was demonstrated. Continuous wave laser operation at room temperature was obtained for 1064 nm pumping from a CW Nd:YAG laser. The output power slope efficiency is 6.8 percent. The gain cross section is estimated to be 1.1 x 10 to the 19th sq cm. Spectroscopic studies suggest that the laser action is due to a center other than the trivalent chromium (Cr 3+), presumably the tetravalent chromium (Cr 4+) in a tetrahedrally coordinated site

Time-resolved diffusion tomographic 2D and 3D imaging in highly scattering turbid media

A method for imaging objects in highly scattering turbid media. According to one embodiment of the invention, the method involves using a plurality of intersecting source/detectors sets and time-resolving equipment to generate a plurality of time-resolved intensity curves for the diffusive component of light emergent from the medium. For each of the curves, the intensities at a plurality of times are then inputted into the following inverse reconstruction algorithm to form an image of the medium: wherein W is a matrix relating output at source and detector positions r.sub.s and r.sub.d, at time t, to position r, .LAMBDA. is a regularization matrix, chosen for convenience to be diagonal, but selected in a way related to the ratio of the noise, to fluctuations in the absorption (or diffusion) X.sub.j that we are trying to determine: .LAMBDA..sub.ij =.lambda..sub.j .delta..sub.ij with .lambda..sub.j =/ Y is the data collected at the detectors, and X.sup.k is the kth iterate toward the desired absorption information. An algorithm, which combines a two dimensional (2D) matrix inversion with a one-dimensional (1D) Fourier transform inversion is used to obtain images of three dimensional hidden objects in turbid scattering media

The sucrose non-fermenting 1-related kinase 2 gene SAPK9 improves drought tolerance and grain yield in rice by modulating cellular osmotic potential, stomatal closure and stress-responsive gene expression

Abstract Background Family members of sucrose non-fermenting 1-related kinase 2 (SnRK2), being plant-specific serine/threonine protein kinases, constitute the central core of abscisic acid (ABA)-dependent and ABA-independent signaling pathways, and are key regulators of abiotic stress adaptation in plants. We report here the functional characterization of SAPK9 gene, one of the 10 SnRK2s of rice, through developing gain-of-function and loss-of-function phenotypes by transgenesis. Results The gene expression profiling revealed that the abundance of single gene-derived SAPK9 transcript was significantly higher in drought-tolerant rice genotypes than the drought-sensitive ones, and its expression was comparatively greater in reproductive stage than the vegetative stage. The highest expression of SAPK9 gene in drought-tolerant Oryza rufipogon prompted us to clone and characterise the CDS of this allele in details. The SAPK9 transcript expression was found to be highest in leaf and upregulated during drought stress and ABA treatment. In silico homology modelling of SAPK9 with Arabidopsis OST1 protein showed the bilobal kinase fold structure of SAPK9, which upon bacterial expression was able to phosphorylate itself, histone III and OsbZIP23 as substrates in vitro. Transgenic overexpression (OE) of SAPK9 CDS from O. rufipogon in a drought-sensitive indica rice genotype exhibited significantly improved drought tolerance in comparison to transgenic silencing (RNAi) lines and non-transgenic (NT) plants. In contrast to RNAi and NT plants, the enhanced drought tolerance of OE lines was concurrently supported by the upgraded physiological indices with respect to water retention capacity, soluble sugar and proline content, stomatal closure, membrane stability, and cellular detoxification. Upregulated transcript expressions of six ABA-dependent stress-responsive genes and increased sensitivity to exogenous ABA of OE lines indicate that the SAPK9 is a positive regulator of ABA-mediated stress signaling pathways in rice. The yield-related traits of OE lines were augmented significantly, which resulted from the highest percentage of fertile pollens in OE lines when compared with RNAi and NT plants. Conclusion The present study establishes the functional role of SAPK9 as transactivating kinase and potential transcriptional activator in drought stress adaptation of rice plant. The SAPK9 gene has potential usefulness in transgenic breeding for improving drought tolerance and grain yield in crop plants.http://deepblue.lib.umich.edu/bitstream/2027.42/134605/1/12870_2016_Article_845.pd

INFLUENCE OF ORGANIC MANURES AND GIBBERELLIC ACID ON GROWTH AND YIELD OF STRAWBERRY (Fragaria X ananassa DUCH.)

A field experiment was conducted to study the effect of organic manures and growth regulators on the growth and yield of two varieties of strawberry namely ‘Sweet Charlie’ and ‘Winter Dawn’. Six treatments were taken combining three organic manures viz. Vermicompost @ 3.0 t/ha, Mustard oil cake @ 1.0 t/ha and Neem cake @ 1.0 t/ha and two concentrations of gibberellic acid (GA3) viz. 75 ppm and 100 ppm along with a control. Foliar application of GA3 was carried out at 40 and 60 days after planting whereas organic manures were applied as basal dose. Results of the study suggested that higher doses i.e. 100 ppm of GA3 along with vermicompost exhibited more vegetative growth whereas 75 ppm GA3 resulted in higher fruit set and yield in both the varieties. It was found that vermicompost @ 3.0 t/ha combined with 100 ppm GA3 recorded the highest plant height (24.7 cm and 21.4 cm) and numbers of leaves per plant (46.0 and 68.7) in both Sweet Charlie and Winter Dawn varieties, respectively. Whereas, highest fruit diameter (3.3cm and 3.4cm), fruit length (4.6cm and 4.8cm), fruit weight (18.2 g and 17.9 g), number of fruits per plant (24.6 and 32.0), yield per plant (447.8 g and 572.1 g) and yield per hectare (18.80 t and 24.03 t) were recorded under vermicompost @ 3.0 t/ha in combination with 75 ppm GA3 in both Sweet Charlie and Winter Dawn varieties, respectively. It was observed that Winter Dawn variety produced a 28.0% higher yield as compared to Sweet Charlie under the best treatment i.e. vermicompost @ 3.0 t/ha in combination with 75 ppm GA3