In the active control of noise in ducts, it is common practice to locate an error microphone far from the control source to avoid the near-field effects by evanescent waves. Such a distance between the control source and the error microphone makes a certain level of time delay inevitable and, hence, may yield undesirable effects on the convergence properties of control algorithms such as filtered-x and filtered-u least-mean-square (LMS). This paper discusses the dependence of the convergence rate on the acoustic error path in these popular algorithms and introduces new algorithms "constraint filtered-x and constraint filtered-u LMS," which increase the convergence region regardless of the time delay in the acoustic error path. In the algorithms, coefficients of the controller are adapted using modified residuals that are defined in such a way that the control process become stationary. Performances of the new LMS algorithms are presented in comparison with those by the conventional algorithms based on computer simulations.

The presence of protein kinase activity in the purified phytochrome preparations [Wong, et al. (1986) J. Biol. Chem. 261, 12089-12097] has been re-examined. The phytochrome preparations having SAR (specific absorbance ratio, A668/A280 for the Pr form as a measure of phytochrome purity) values of greater than 0.95 were homogeneous on SDS gel, but could be further purified to a SAR value of 1.07 by repeated gel filtrations on a Bio-Gel A-0.5 m column. The protein kinase activity remained in the phytochrome preparations having SAR values less than 1.05, but it became undetectable in the phytochrome preparation with a SAR value of 1.07. Two dimensional gel electrophoresis of the phytochrome preparation (SAR, 0.89) showed that a phytochrome band with pl 5.8 had no kinase activity. Phosphorylating activity of the protein kinase was enhanced to some extent by polycations, polylysine and histone. Phytochrome served as a good substrate for this enzyme. The present data indicate that phytochrome has no intrinsic protein kinase activity, but a protein kinase is present in highly purified phytochrome preparations.

Introduction This study aimed to elucidate the relationship between premature ventricular complexes (PVCs) and right ventricular (RV) dysfunction, and the effects of radiofrequency catheter ablation (RFCA) on RV function. Methods A total of 110 patients (age, 50.8 ± 14.4 years; 30 men) without structural heart disease who had undergone RFCA for RV outflow tract (RVOT) PVCs were retrospectively included. RV function was assessed using fractional area change (FAC) and global longitudinal strain (GLS) before and after RFCA. Clinical data were compared between the RV dysfunction (n = 63) and preserved RV function (n = 47) groups. The relationship between PVC burden and RV function was analyzed. Change in RV function before and after RFCA was compared between patients with successful and failed RFCA. Results PVC burden was significantly higher in the RV dysfunction group than in the preserved RV function group (p < .001). FAC and GLS were significantly worse in proportion to PVC burden (p < .001 and p < .001, respectively). The risk factor associated with RV dysfunction was PVC burden [odds ratio (95% confidence interval), 1.092 (1.052–1.134); p < .001]. Improvement in FAC (13.0 ± 8.7% and –2.5 ± 5.6%, respectively; p < .001) and GLS (–6.8 ± 5.7% and 2.1 ± 4.2%, respectively; p < .001) was significant in the patients with successful RFCA, compared to the patients in whom RFCA failed. Conclusions Frequent RVOT PVCs are associated with RV dysfunction. RV dysfunction is reversible by successful RFCA.

A protein factor and its binding site involved in light-responsive gene expression of Arabidopsis thaliana cab1 were investigated. Mobility shift assays were performed to identify a nuclear protein factor and its binding sites on the cab1 promoter. For the binding assay, the Arabidopsis cab1 promoter was cleaved with endonucleases into small fragments (65-200 bp) and end-labeled with Klenow fragments. Nuclei were prepared from the light-grown plants and nuclear proteins were prepared by extracting the purified nuclei with 0.5 M ammonium sulfate. The binding site of the nuclear protein factor was scattered throughout the whole promoter region from the transcription start site to the far upstream region of the promoter. To identify the binding sites that are involved in the light responsiveness, mobility shift assays were performed between the cab1 promoter fragments and the nuclear extracts prepared from the 2 day dark-adapted sample. The mobility shift assay of the 65 bp (-318/ -254) fragment with nuclear extract from the dark-adapted sample showed an additional band, not seen with the light-grown sample. Because the new band was present only in the dark-adapted sample that repressed cab1 expression, it may represent a negative regulatory factor (NRF). The NRF was separable on a heparin-Sepharose column from the other factor present in both the light-grown and dark-adapted samples. The implications of the presence of the NRF have been discussed with respect to gene products of the photosignal transduction Arabidopsis mutants.