Leverage and productivity growth in emerging economies: Is there a threshold effect?

While credit is essential for investment, innovation and economic growth, there are risks to unfettered credit booms. The present paper provides an innovative micro-economic approach to identify the threshold leverage beyond which corporate indebtedness becomes “excessive”. In particular, the paper hypothesizes a non-linear relationship in that moderate leverage could boost growth while very high leverage could restrict total factor productivity growth, through increased likelihood of financial distress and bankruptcy. Estimates of a threshold model for a group of emerging CEE countries confirm the non-linear relationship, after controlling for various firm, industry and financial market characteristics.Financial support from ESRC grant RES-062-23-0986 is gratefully acknowledge

Determination of cloud microphysical properties by laser backscattering and extinction measurements

The extinction and backscattering of 514 nm laser radiation in polydisperse water droplet clouds was studied in the laboratory. Three cloud size distributions with modal diameters of 0.02, 5.0, and 12.0 microns were investigated. The relationships between the cloud optical parameters (attentuation coefficient, sigma and volume backscattering coefficient, Beta (sub pi)) and the cloud water content, C, were measured for each size distribution. It was found that a linear relationship exists between sigma and C and between beta (sub pi) and C for cloud water content values up to 3gm/cubic m. The linear relationships obtained, however, have slopes which depend on the droplet size distribution. For a given water content both sigma and beta (sub pi) increase as the modal diameter decreases. The measured data are compared with existing theoretical analyses and discussed in terms of thie application to lidar measurements of atmospheric clouds. It is concluded that the empirical information obtained can serve as a basis for quantitative lidar measurements

Topological bands and localized vibration modes in quasiperiodic beams

We investigate a family of quasiperiodic continuous elastic beams, the topological properties of their vibrational spectra, and their relation to the existence of localized modes. We specifically consider beams featuring arrays of ground springs at locations determined by projecting from a circle onto an underlying periodic system. A family of periodic and quasiperiodic structures is obtained by smoothly varying a parameter defining such projection. Numerical simulations show the existence of vibration modes that first localize at a boundary, and then migrate into the bulk as the projection parameter is varied. Explicit expressions predicting the change in the density of states of the bulk define topological invariants that quantify the number of modes spanning a gap of a finite structure. We further demonstrate how modulating the phase of the ground springs distribution causes the topological states to undergo an edge-to-edge transition. The considered configurations and topological studies provide a framework for inducing localized modes in continuous elastic structural components through globally spanning, deterministic perturbations of periodic patterns defined by the considered projection operations

Basal Cell Adenoma‑Clinicopathological, Immunohistochemical Analysis and Surgical Considerations of a Rare Salivary Gland Tumor with Review of Literature

Introduction: Basal cell adenoma (BCA) of the salivary glands is a rare benign salivary gland tumour. Differentiation of BCA from varied entities involving maxillofacial area is mandatory. Aim: To analyze the clinicopathological, histopathologic features, immunohistochemcal analysis and surgical considerations of this rare entity. Materials and Methods: This study included 12 cases of BCA from archives of department reported over the period of 13 years. All the pertaining clinicopathologic features such as incidence, age, sex and site of lesions were assessed. Tissue sections were stained by using panel of immunohistochemical markers, i.e. Pan CK, CK 5/6 and S100, Calponin, p63, CD 117 and smooth muscle actin. Results: BCA was observed in 26-52 years age group (mean age, 38.75 years) with female propensity of 7:5 male to female ratio. It is seen more commonly in parotid gland, followed by upper lip, buccal mucosa and palate. Solid type is the most common histopathologic type followed by tubular, membranous and trabecular. Only one case of membranous type of BCA showed recurrence. Pan CK, CK 5/6 showed strong immunoreactivity, calponin showed moderate staining, p63 and Ki‑67 mild staining, whereas CD 117 and SMA showed negative immunostaining. Conclusion: Vigilant comprehensive analysis of all the pertaining clinicopathologic and histopathologic features and immunohistochemical analysis are required for differentiating from other lesions with basaloid differentiation having varying prognosis.Keywords: Basal cell adenoma, basal cell adenocarcinoma, monomorphic adenom

New limit for the half-life of double beta decay of 94^{94}Zr to the first excited state of 94^{94}Mo

Neutrinoless Double Beta Decay is a phenomenon of fundamental interest in particle physics. The decay rates of double beta decay transitions to the excited states can provide input for Nuclear Transition Matrix Element calculations for the relevant two neutrino double beta decay process. It can be useful as supplementary information for the calculation of Nuclear Transition Matrix Element for the neutrinoless double beta decay process. In the present work, double beta decay of $^{94}$Zr to the $2^{+}_{1}$ excited state of $^{94}$Mo at 871.1 keV is studied using a low background $\sim$ 230 cm$^3$ HPGe detector. No evidence of this decay was found with a 232 g.y exposure of natural Zirconium. The lower half-life limit obtained for the double beta decay of $\rm^{94}Zr$ to the $2^{+}_{1}$ excited state of $\rm^{94}Mo$ is $T_{1/2} (0\nu + 2\nu)> 3.4 \times 10^{19}$ y at 90% C.L., an improvement by a factor of $\sim$ 4 over the existing experimental limit at 90\% C.L. The sensitivity is estimated to be $T_{1/2} (0\nu + 2\nu) > 2.0\times10^{19}$ y at 90% C.L. using the Feldman-Cousins method.Comment: 11 pages, 7 figures, Accepted in Eur. Phys. J.

Necessary and sufficient condition for longitudinal magnetoresistance

Since the Lorentz force is perpendicular to the magnetic field, it should not affect the motion of a charge along the field. This argument seems to imply absence of longitudinal magnetoresistance (LMR) which is, however, observed in many materials and reproduced by standard semiclassical transport theory applied to particular metals. We derive a necessary and sufficient condition on the shape of the Fermi surface for non-zero LMR. Although an anisotropic spectrum is a pre-requisite for LMR, not all types of anisotropy can give rise to the effect: a spectrum should not be separable in any sense. More precisely, the combination $k_{\rho}v_{\phi}/v_{\rho}$, where $k_\rho$ is the radial component of the momentum in a cylindrical system with the z-axis along the magnetic field and $v_{\rho} (v_{\phi}$) is the radial (tangential) component of the velocity, should depend on the momentum along the field. For some lattice types, this condition is satisfied already at the level of nearest-neighbor hopping; for others, the required non-separabality occurs only if next-to-nearest-neighbor hopping is taken into account.Comment: 7 pages, 2 figure