Fast frequency estimation and tracking using Lagrange interpolation

A computationally efficient and accurate frequency estimation and tracking algorithm is proposed, based on the adaptive frequency estimator (AFE) of Etter and Hush. A Lagrange interpolator (a fractional delay filter) is used to estimate the gradient of the performance surface of the adaptation, which enables highly accurate estimation. The performance of the new algorithm is demonstrated in the context of tracking a chirp signal in noise     

Actin and fimbrin are required for the internalization step of endocytosis in yeast

In Saccharomyces cerevisiae, alpha-factor is internalized by receptor-mediated endocytosis and transported via vesicular intermediates to the vacuole where the pheromone is degraded. Using beta-tubulin and actin mutant strains, we showed that actin plays a direct role in receptor-mediated internalization of alpha-factor, but is not necessary for transport from the endocytic intermediates to the vacuole. beta-tubulin mutant strains showed no defect in these processes. In addition, cells lacking the actin-binding protein, Sac6p, which is the yeast fimbrin homologue, are defective for internalization of alpha-factor suggesting that actin filament bundling might be required for this step. The actin dependence of endocytosis shows some interesting similarities to endocytosis from the apical membrane in polarized mammalian cells.     

Westernized food habits and concentrations of serum lipids in the Japanese

It has recently been reported that there exists a new 'RING-finger' protein family among the zinc-finger (Zf) proteins. Previously, we had isolated the mouse Mel-18 cDNA (mMel-18) encoding the nuclear RING-finger protein that exhibits an ability to bind to a nonspecific DNA column. Here, we have isolated and characterized the human Mel-18 cDNA (hMel-18) using the mMel-18 cDNA as a probe. The deduced hMel-18 protein contains 344 amino acids (38 kDa) with a RING-finger motif, a helix-loop-helix (HLH)-like structure and a Pro/Ser-rich region. The hMel-18 gene is conserved among vertebrates. Its mRNA is highly expressed in placenta, lung and kidney, but the level is low in liver, pancreas and skeletal muscle. Using in situ hybridization, we mapped hMel-18 to band q22 of chromosome 12. It is possible that the Mel-18/bmi-1 gene family represents a mammalian homologue of the Drosophila polycomb gene group.     

Passive dissolution kinetics of titanium in vitro

The dissolution of titanium in simulated interstitial electrolyte (SIE), human serum in SIE (serum/SIE) and 8.0 mM ethylenediaminetetraacetic acid (EDTA) in SIE (EDTA/SIE) was measured in vitro. Titanium fibre samples were immersed in these solutions and maintained at 37°C, 10% O₂, 5% CO₂ and 97±3% relative humidity for 0–5000 h. The concentration of titanium released was quantified using electrothermal atomic absorption spectroscopy. Changes in oxide stoichiometry were determined by Auger electron spectroscopy after processing and immersion in the test solutions. The oxide became nearly stoichiometric TiO₂ after immersion, suggesting equilibration of the surface with the solutions. Solution ligands enhanced the magnitude of dissolution, with EDTA>serum/SIE>SIE. The dissolution kinetics were empirically fitted by a two-phase logarithmic relationship. The first phase of dissolution (t<300 h) was dominated by equilibration of the oxide with the solution and the second phase (t>300 h) by mass diffusion. The dissolution kinetics were similar for the EDTA/SIE and serum/SIE solutions, indicating that the mechanisms of dissolution for each solution may be the same.     

Influence of water immersion stress on peripheral nerve recovery in the rat

Previously, we have shown that embryonic day 12 thymus anlage cultured alone cannot develop into the mature organ but degenerates. In the present study, we investigated the cause of this insufficient organogenesis of embryonic day 12 thymus anlage in organ culture. We cocultured embryonic day 12 thymus anlages with various cell lines as pellets formed by centrifugation. In coculture with fibroblastic cell lines, but not with thymic epithelial cell lines, embryonic day 12 thymus anlages developed to support full T cell differentiation, and expressed mature stromal cell markers, Ia and Kb. By pellet culture of thymus anlages and fibroblastic cell lines transfected with a beta-galactosidase expression vector, we analyzed the distribution of added fibroblastic cells in pellets. The added fibroblastic cells constituted neither thymic capsule nor septa but disappeared after about 2 weeks in culture. Moreover, immunohistochemical studies indicated that added fibroblastic cells were adjacent to mesenchymal cells of thymus anlage. Our results strongly suggest that added fibroblastic cells support the development of the thymus anlage through interaction with its mesenchymal cells.     

Control of high common mode voltage during transthoracicdefibrillation

A high common mode voltage (V_cm) relative to earth ground is produced on the myocardium during the delivery of a defibrillator pulse and can generate a differential error signal when potential gradients are recorded with bipolar electrodes and isolation amplifiers. The error signal is proportional to V_cm, and therefore, a reduction in V_cm improves the accuracy of the potential gradient data. Experiments were conducted on 5 dogs to determine whether V_cm can be controlled using a bridge circuit. The bridge circuit consisted of a 5 kΩ power rheostat in parallel with the transthoracic resistance of the dog. The variable contact of the rheostat was connected to earth ground, and by adjusting the rheostat, V_cm on the myocardium could be varied. In each dog, 20 A shocks were delivered through stainless steel transthoracic electrodes. Point contact electrodes sutured to the epicardium were used to measure V_cm. It was determined that V_cm could be reduced to approximately zero at a given electrode on the heart. In addition, for the 5 dogs studied, the maximum measured V_cm on the heart was only 10% of the transthoracic voltage when the bridge circuit was balanced for an interior point in the heart     

An analysis of slow phase velocity on congenital nystagmus-asymmetrical responses of optokinetic stimulation

Persistence of the hypoglossal artery is an unusual congenital abnormality of the carotid arterial system, and the simultaneous occurrence of atheromatous disease in the internal carotid artery and persistent hypoglossal artery is even more uncommon. Carotid surgery in this situation is challenging, and the surgeon must be aware of potential inherent pitfalls. A 74-year-old woman with asymptomatic stenosis of both internal carotid and hypoglossal arteries associated with occlusion of the contralateral internal carotid artery underwent successful revascularization. The anatomy of this unusual lesion and the surgical strategies, which included cranial nerve dissection and mandibular subluxation, are reviewed.     

Transport properties of Nd1.85Ce0.15 δ single crystals: The narrow-band model

The anisotropy of the resistivity and thermoelectric power (TEP)S of Nd_1.85Ce_0.15CuO_4?δ single crystal (T _c =17 K) has been investigated. In the temperature rangeT _c <T<300 K the ratioρ _c/ρ_ab≈10⁴ and the dependencesρ _ab (T) andρ _c (T) change from quadratic to linear atT～200 K. The dependencesS _ab (T) andS _c (T) reach a maximum atT>T _c and then decrease almost linearly with increasing temperature, changing sign from positive to negative nearT～ 150 K. The features of the resistivity and TEP temperature dependences (the lawρ∝T ² changing toρ∝T, the change in the sign of S with temperature, and the low TEP anisotropy at largeρ anisotropy) have been interpreted in the framework of the narrow-band model.