4,645 research outputs found

    Peripheral Ossifying Fibroma

    Get PDF
    Peripheral ossifying fibroma is a relatively uncommon gingival growth that is considered to be reactive in nature and postulated to appear secondary to irritation or trauma. They usually occur in young adults with a female predominance and are solitary in nature. We report a case of peripheral ossifying fibroma in a 55-year old femal

    Group Manifold Reduction of Dual N=1 d=10 Supergravity

    Get PDF
    We perform a group manifold reduction of the dual version of N=1 d=10 supergravity to four dimensions. The effects of the 3- and 4-form gauge fields in the resulting gauged N=4 d=4 supergravity are studied in particular. The example of the group manifold SU(2)xSU(2) is worked out in detail, and we compare for this case the four-dimensional scalar potential with gauged N=4 supergravity.Comment: 22 pages, revised section 3, typos corrected. Published versio

    Gauging CSO groups in N=4 Supergravity

    Get PDF
    We investigate a class of CSO-gaugings of N=4 supergravity coupled to six vector multiplets. Using the CSO-gaugings we do not find a vacuum that is stable against all scalar perturbations at the point where the matter fields are turned off. However, at this point we do find a stable cosmological scaling solution.Comment: 21 page

    De Sitter solutions in N=4 matter coupled supergravity

    Get PDF
    We investigate the scalar potential of gauged N=4 supergravity with matter. The extremum in the SU(1,1)/U(1) scalars is obtained for an arbitrary number of matter multiplets. The constraints on the matter scalars are solved in terms of an explicit parametrisation of an SO(6,6+n) element. For the case of six matter multiplets we discuss both compact and noncompact gauge groups. In an example involving noncompact groups and four scalars we find a potential with an absolute minimum and a positive cosmological constant.Comment: 14 page

    Giant magnetoelectric effect in pure manganite-manganite heterostructures

    Full text link
    Obtaining strong magnetoelectric couplings in bulk materials and heterostructures is an ongoing challenge. We demonstrate that manganite heterostructures of the form (Insulator)/(LaMnO3)n/(CaMnO3)n/(Insulator){\rm (Insulator)/(LaMnO_3)_n/(CaMnO_3)_n/(Insulator)} show strong multiferroicity in magnetic manganites where ferroelectric polarization is realized by charges leaking from LaMnO3{\rm LaMnO_3} to CaMnO3{\rm CaMnO_3} due to repulsion. Here, an effective nearest-neighbor electron-electron (electron-hole) repulsion (attraction) is generated by cooperative electron-phonon interaction. Double exchange, when a particle virtually hops to its unoccupied neighboring site and back, produces magnetic polarons that polarize antiferromagnetic regions. Thus a striking giant magnetoelectric effect ensues when an external electrical field enhances the electron leakage across the interface.Comment: 13 page

    Potential and mass-matrix in gauged N=4 supergravity

    Get PDF
    We discuss the potential and mass-matrix of gauged N=4 matter coupled supergravity for the case of six matter multiplets, extending previous work by considering the dependence on all scalars. We consider all semi-simple gauge groups and analyse the potential and its first and second derivatives in the origin of the scalar manifold. Although we find in a number of cases an extremum with a positive cosmological constant, these are not stable under fluctuations of all scalar fields.Comment: 28 pages, LaTe

    Higher order corrections to Heterotic M-theory inflation

    Full text link
    We investigate inflation driven by NN dynamical five-branes in Heterotic M-theory using the scalar potential derived from the open membrane instanton sector. At leading order the resulting theory can be mapped to power law inflation, however more generally one may expect higher order corrections to be important. We consider a simple class of such corrections, which imposes tight bounds on the number of branes required for inflation.Comment: 10 pages, 2 figure

    Experimental evidence for the formation of stripe phases in Si/SiGe

    Get PDF
    We observe pronounced transport anisotropies in magneto-transport experiments performed in the two-dimensional electron system of a Si/SiGe heterostructure. They occur when an in-plane field is used to tune two Landau levels with opposite spin to energetic coincidence. The observed anisotropies disappear drastically for temperatures above 1 K. We propose that our experimental findings may be caused by the formation of a unidirectional stripe phase oriented perpendicular to the in-plane field.Comment: 4 pages, 3 figure

    Inheritance of Resistance to Sorghum Shoot Fly, Atherigona soccata in Sorghum, Sorghum bicolor (L.) Moench

    Get PDF
    Sorghum production is affected by a wide array of biotic constraints, of which sorghum shoot fly, Atherigona soccata is the most important pest, which severely damages the sorghum crop during the seedling stage. Host plant resistance is one of the major components to control sorghum shoot fly, A. soccata. To understand the nature of gene action for inheritance of shoot fly resistance, we evaluated 10 parents, 45 F(1)'s and their reciprocals in replicated trials during the rainy and postrainy seasons. The genotypes ICSV 700, Phule Anuradha, ICSV 25019, PS 35805, IS 2123, IS 2146, and IS 18551 exhibited resistance to shoot fly damage across seasons. Crosses between susceptible parents were preferred for egg laying by the shoot fly females, resulting in a susceptible reaction. ICSV 700, ICSV 25019, PS 35805, IS 2123, IS 2146, and IS 18551 exhibited significant and negative general combining ability (gca) effects for oviposition, deadheart incidence, and overall resistance score. The plant morphological traits associated with expression of resistance/susceptibility to shoot fly damage such as leaf glossiness, plant vigor, and leafsheath pigmentation also showed significant gca effects by these genotypes, suggesting the potential for use as a selection criterion to breed for resistance to shoot fly, A. soccata. ICSV 700, Phule Anuradha, IS 2146 and IS 18551 with significant positive gca effects for trichome density can also be utilized in improving sorghums for shoot fly resistance. The parents involved in hybrids with negative specific combining ability (sca) effects for shoot fly resistance traits can be used in developing sorghum hybrids with adaptation to postrainy season. The significant reciprocal effects of combining abilities for oviposition, leaf glossy score and trichome density suggested the influence of cytoplasmic factors in inheritance of shoot fly resistance. Higher values of variance due to specific combining ability (σ(2)s), dominance variance (σ(2)d), and lower predictability ratios than the variance due to general combining ability (σ(2)g) and additive variance (σ(2)a) for shoot fly resistance traits indicated the predominance of dominance type of gene action, whereas trichome density, leaf glossy score, and plant vigor score with high σ(2)g, additive variance, predictability ratio, and the ratio of general combining ability to the specific combining ability showed predominance of additive type of gene action indicating importance of heterosis breeding followed by simple selection in breeding shoot fly-resistant sorghums. Most of the traits exhibited high broadsense heritability, indicating high inheritance of shoot fly resistance traits
    corecore