Is Cash Flow a Proxy for Financing Constraints in the Investment Equation? The Case of Unlisted Japanese Firms

The literature maintains the statistical significance of cash flow in the investment equation. One criticism against the financing constraint interpretation of cash flow is that cash flow may be picking up information on the future profitability of a firm which Tobinfs Q fails to capture. We confine ourselves to the investment behavior of unlisted automobile parts suppliers, and use the sales of large automobile makers as an exogenous instrument. Despite the various criticisms against the financing constraint interpretation of cash flow, our statistical evidence does not disagree with the hypothesis.Tobinfs Q, Investment Equation, Cash Flow, Financing Constraint, Japanese Unlisted Firms

THE SIGMOIDAL INVESTMENT FUNCTION

Based on the investment theory of Abel and Eberly (1994), we develop an analytical model of adjustment costs, which produces a sigmoidal investment function. We also estimate the piecewise linear investment function, which includes as special cases linear models, models with one threshold, the original model of Abel and Eberly, which has two thresholds, and sigmoidal models. Empirical evidence clearly supports the sigmoidal model. The threshold estimate of Tobinfs q is 0.91. The investment ratio does not respond at value of Tobinfs q below 0.91, but begins to react sensitively as Tobinfs q passes 0.91.Tobinfs q, financial constraints, irreversibility of investment, unlisted, Japanese firms, piecewise linear function

Fabrication of Ni-B alloy coated vapor-grown carbon nanofibers by electroless deposition

Ni-B alloy coated vapor-grown carbon nanofibers (VGCNFs) were fabricated by electroless deposition and their microstructures were investigated. The effects of heat treatment on the coated VGCNFs were also studied. VGCNFs could be coated with a homogeneous Ni-B alloy film using a plating bath containing dimethylaminoborane (DMAB) as a reducing agent. The boron content of the Ni-B alloy film could be varied from 14 to 24 atom% B by varying the DMAB concentration of the plating bath. The VGCNFs were uniformly coated with a Ni-B alloy layer that was only several nanometers thick. The coating thickness on the VGCNFs could be controlled by varying the reaction time. The Ni-B alloy coatings formed in this study were semicrystalline or amorphous depending on the boron content of the alloy film. After heat treatment, the phase structure of the Ni-B alloy coatings changed to a stable crystalline structure consisting of a face-centered-cubic nickel phase and a Ni3B phase. No cracks or exfoliation of the coatings were observed, even after heat treatment.ArticleCARBON 49: 1484-1490(2011)journal articl

Imprinting spatial helicity structure of vector vortex beam on spin texture in semiconductors

We present the transfer of the spatially variant polarization of topologically structured light to the spatial spin texture in a semiconductor quantum well. The electron spin texture, which is a circular pattern with repeating spin-up and spin-down states whose repetition rate is determined by the topological charge, is directly excited by a vector vortex beam with a spatial helicity structure. The generated spin texture efficiently evolves into a helical spin wave pattern owing to the spin-orbit effective magnetic fields in the persistent spin helix state by controlling the spatial wave number of the excited spin mode. By tuning the repetition length and azimuthal angle, we simultaneously generate helical spin waves with opposite phases by a single beam.Comment: 6 pages, 4 figure

Mechanical stability of orthodontic miniscrew depends on a thread shape

Background/purpose: Primary stability of orthodontic miniscrew system is of great importance in maintaining stable anchorage during a treatment period. Thus, this study aimed to examine whether the thread shape of orthodontic miniscrew had an effect on its mechanical stability in bone. Materials and methods: Three different types of miniscrews (type A and B with a regular thread shape; type C with a novel thread shape) were placed in artificial bone block with different artificial cortical bone thickness of 1.5, 2.0 and 3.0 mm. Values of maximum insertion torque (MIT), removal torque (RT), torque ratio (TR), screw mobility, static stiffness (K), dynamic stiffness (K∗) and energy dissipation (tan δ) ability were assessed for each miniscrew system. Results: The MIT, RT, TR and K of type C miniscrew were significantly greater than those of type A and B miniscrews when the miniscrews were placed in the thinner artificial bone. Furthermore, the TR value of type C miniscrew was more than 1, indicating the MRT value was larger than the MIT value in the novel miniscrew. The values of K∗ and tan δ were almost similar among the three types of miniscrews. Conclusion: The miniscrew with a novel thread shape showed a higher initial stability compared to those with a regular thread shape. Thus, in order to obtain a sufficient initial stability, it is important to select the type of screw thread that is appropriate for the thickness of the cortical bone

Resuscitation of Preterm Infants with Reduced Oxygen Results in Less Oxidative Stress than Resuscitation with 100% Oxygen

The objective of this study was to determine the effects of the level of inhaled oxygen during resuscitation on the levels of free radicals and anti-oxidative capacity in the heparinized venous blood of preterm infants. Forty four preterm infants <35 weeks of gestation with mild to moderate neonatal asphyxia were randomized into two groups. The first group of infants were resuscitated with 100% oxygen (100% O2 group), while in the other group (reduced O2 group), the oxygen concentration was titrated according to pulse oximeter readings. We measured total hydroperoxide (TH) and redox potential (RP) in the plasma within 60 min of birth. The integrated excessive oxygen (∑(FiO2-0.21) × Time(min)) was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). TH was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). RP was not different between the 100% O2 and reduced O2 groups (p = 0.399). RP/TH ratio was lower in the 100% O2 group than in the reduced O2 group (p<0.01). We conclude that in the resuscitation of preterm infants with mild to moderate asphyxia, oxidative stress can be reduced by lowering the inspired oxygen concentration using a pulse oximeter