Does certification work in emerging markets? evidence from the Indian IPO market

There is inconclusive evidence regarding the economic value of certification in the context of IPOs in developed markets. Using a natural experiment of regulator mandated IPO grading requirement, we examine the effects of third-party certification in the Indian IPO market. We summarize our empirical results below. First, underpricing is unaffected by the grading process. Second, stock price informativeness as proxied by idiosyncratic volatility increases significantly due to IPO grading process. Third, retail and institutional subscription levels are significantly positively associated with IPO grades after controlling for other certification mechanisms such as underwriter reputation, group affiliation, analyst recommendation and venture capital backing. Finally, using a pseudo grading process we conclude that IPO grades are not mechanically derivable from publicly available information. In a nutshell, we use our unique setting to examine the usefulness of certification in emerging markets with institutional voids

Theory of birefringence of nematic liquid crystals

A theory of the birefringence of nematic liquid crystals is developed taking into account the intermolecular potential energy arising from dipole-dipole, anisotropic dispersion, induction and repulsion interactions. The potential energy exhibits a dependence on molecular orientation and is expressible as - (u0 + u1 cosθ + u2 cos2θ + u4 cos4θ + u4 cos4θ + ...) where Theta is the angle which the long axis of the molecule makes with the uniaxial direction of the liquid crystal. The birefringence of the medium is evaluated in terms of the Boltzmann distribution of the oriented molecules. The theory explains the experimentally observed result that the temperature coefficient of the extraordinary index is large and negative whereas that of the ordinary index is small and positive. Analysis of the data on p-azoxyanisole and p-azoxyphenetole shows that dispersion and repulsion forces play a predominant role in determining the temperature variation of the birefringence. Assuming that the molecular librations in the liquid crystal can be represented by a system of harmonic oscillators, the rms librational amplitude is evaluated for p-azoxyanisole from recent measurements of the ultrasonic velocity. The increase in the rms amplitude with temperature in the nematic range is found to be in good agreement with that obtained directly from the experimental data on birefringence

Evaluation of several different planetary boundary layer schemes within a single model, a unified model and a multimodel superensemble

This paper addresses the forecasts of latent heat fluxes from five different formulations of the planetary boundary layer (PBL). Different formulations are deployed within the Florida State University global spectral model. Hundreds of short range forecast experiments are carried out using daily data sets for summer 2002 with each model. The primary goal of this study is to compare the performance of the diverse family of PBL algorithms for the latent heat fluxes within the PBL. Benchmark fluxes are calculated from the vertical integrals of Yanai's formulation of the apparent moisture sink and a precipitation using Physical Initialization. This provides indirectly observed estimates of the vertical fluxes of latent heat in the PBL. This comparison reveals that no single scheme shows a global spread of improvement over other models for forecasts of latent heat fluxes in the PBL. Among these diverse models the turbulent kinetic energy based closure provides somewhat better results. The construction of a multimodel superensemble provides a synthesis of these different PBL formulations and shows improved forecasts of the surface fluxes. A single unified model utilizing weighted PBL algorithms where all the five schemes are retained within a single model shows some promise for improving a single model

Wind reversals in turbulent Rayleigh-Benard convection

The phenomenon of irregular cessation and subsequent reversal of the large-scale circulation in turbulent Rayleigh-B\'enard convection is theoretically analysed. The force and thermal balance on a single plume detached from the thermal boundary layer yields a set of coupled nonlinear equations, whose dynamics is related to the Lorenz equations. For Prandtl and Rayleigh numbers in the range $10^{-2} \leq \Pr \leq 10^{3}$ and 10^{7} \leq \Ra \leq 10^{12}, the model has the following features: (i) chaotic reversals may be exhibited at Ra $\geq 10^{7}$; (ii) the Reynolds number based on the root mean square velocity scales as \Re_{rms} \sim \Ra^{[0.41 ... 0.47]} (depending on Pr), and as $\Re_{rms} \sim \Pr^{-[0.66 ... 0.76]}$ (depending on Ra); and (iii) the mean reversal frequency follows an effective scaling law \omega / (\nu L^{-2}) \sim \Pr^{-(0.64 \pm 0.01)} \Ra^{0.44 \pm 0.01}. The phase diagram of the model is sketched, and the observed transitions are discussed.Comment: 4 pages, 5 figure

Hurricane Forecasts with a Mesoscale Suite of Models

A suite of mesoscale models are being used in the present study to examine experimental forecast performance for tracks and intensity of hurricanes covering the years 2004, 2005 and 2006. Fifty-eight storm cases are being considered in the present study. Most of the mesoscale models are being run at a horizontal resolution at around 9 km. This includes the WRF (two versions), MM5, HWRF, GFDL and DSHP. The performances of forecasts are evaluated using absolute errors for storm track and intensity. Our consensus forecasts utilize ensemble mean and a bias corrected ensemble mean for these member models on the mesoscale and the large-scale model suites. Comparing the forecast statistics for the mesoscale suite, the large-scale suite and the combined suite we find that the mesoscale suite provided the best track forecasts for 60 and 72 h. However, the forecast from the combined suite of model were also very close to the track errors of the mesoscale at 60 and 72 h. Overall track forecast errors were least for the combined suite. The intensity forecasts of the bias corrected ensemble mean of the mesoscale suite were comparable to DSHP and GFDL at the later part of the forecast periods

Impact of CAMEX-4 Data Sets for Hurricane Forecasts using a Global Model

This study explores the impact on hurricane data assimilation and forecasts from the use of dropsondes and remote-sensed moisture profiles from the airborne Lidar Atmospheric Sensing Experiment (LASE) system. We show that the use of these additional data sets, above those from the conventional world weather watch, has a positive impact on hurricane predictions. The forecast tracks and intensity from the experiments show a marked improvement compared to the control experiment where such data sets were excluded. A study of the moisture budget in these hurricanes showed enhanced evaporation and precipitation over the storm area. This resulted in these data sets making a large impact on the estimate of mass convergence and moisture fluxes, which were much smaller in the control runs. Overall this study points to the importance of high vertical resolution humidity data sets for improved model results. We note that the forecast impact from the moisture profiling data sets for some of the storms is even larger than the impact from the use of dropwindsonde based winds

Effect of supplementation with tamarind and chilli on the growth of young rats on a poor-South-Indian-rice diet

This article does not have an abstract

Hydroxyurea therapy for children with sickle cell disease: Describing how caregivers make this decision

Background: Hydroxyurea (HU) is underutilized in children with sickle cell disease (SCD) because caregivers frequently decline HU when it is offered. This study explores what impacts this decision. Results: Caregivers of children with clinically severe SCD whose children were offered HU previously were interviewed. We used a qualitative analytical approach to analyze their telephone interview transcripts. Caregivers who chose HU (n = 9) reported their children had severe SCD, sought detailed information about HU, and accepted HU as a preventative therapy. In contrast, caregivers who did not choose HU (n = 10) did not perceive their children as having severe SCD and did not question their child's provider about HU. Conclusions: This study identifies specific areas that providers should address to when they discuss HU with families so that they can make informed decisions. Our study also uncovered factors that are important to consider when designing future interventions to improve hydroxyurea acceptance and when developing decision-aid tools to assist caregivers of children with SCD who are considering disease modifying therapies