Coherent phase and frequency detection by using sum-frequency mixing in nonlinear waveguides

We demonstrate a novel optical phase detector that uses sum-frequency mixing in a nonlinear waveguide. By monitoring the near-field pattern of the sum-frequency light radiated from the waveguide surface, the relative phase of two input light beams can be measured. By using an Al(x)Ga(1-x)As waveguide optimized for sum-frequency generation with lambda = 1.06 microm input light, we demonstrate a simple phase detector capable of resolving phase shifts of less than 0.2 rad. This phase detector is also used in an interferometer configuration as a gigahertz-resolution frequency monitor.

Auditory intensity perception: successive versus simultaneous, across-channel discriminations

This study measures the ability of observers to compare the intensities of two stimuli occupying different frequency regions. It includes three experiments, each experiment having two conditions. In one condition, the two stimuli to be compared were presented simultaneously within each interval; this condition has been called profile analysis. In the other condition, the two stimuli were presented successively within each interval. Because the overall level of the stimuli was randomized between intervals, the observers were encouraged to compare the intensities of the two stimuli within each observation interval rather than between intervals. The stimuli were two simple tones in experiment 1 and two tonal complexes in both experiments 2 and 3. The stimuli used in experiments 2 and 3 differed in frequency. The results show that simultaneous comparisons are superior to successive comparisons. For simple tones, the difference in threshold is about 8 dB; for complexes with 10 to 11 components, the difference in threshold is about 15 dB. These differences can be explained by assuming that internal noises in different channels were partially correlated when stimuli in those channels were presented simultaneously and were independent when the stimuli were presented successively. Cancellation of the correlated noise is therefore possible with simultaneous comparisons, making such discrimination better than that achievable with successive comparisons.

[RFLPs study of parental origin and mechanism of 3 cases with X chromosome structural abnormality]

In this study, we analysed the parental origin and mechanism of X chromosome abnormalities in 3 cases by using RFLPs on short or long arm of X chromosome as genetic markers. Their karyotypes were 46,X,dup(X)(p21); 46,X,del(X)(p11); 46,X,i(Xq). The results demonstrated that the dup(X)(p21) and the del(X)(p11) were of paternal origin and i(Xq) was of maternal origin. The dup(X)(p21) arose from an unequal sister chromatid exchange. The del(X) (p11) occurred through X chromosome breakage and deletion mechanism. The i(Xq) resulted from X chromosome centromere misdivision in oocyte.

Measurement of stimulated emission cross section and fluorescence branching ratio for Nd(3+) in sodium-beta'' alumina

Room-temperature measurements of laser emission cross sections of Nd(3+) ion in sodium-beta" alumina at 1.06 and 1.35 microm as well as the fluorescence branching ratios of (4)F(3/2) to (4)I(j) manifolds are reported. A theoretical calculation based on absolute absorption measurements when a modified Judd-Ofelt phenomenological intensity analysis was used is reported. The cross sections thus determined are sigma(1.06) = 3.1 +/- 0.3 x 10(-20) cm(2) and sigma(1.35) = 0.6 +/- 0.1 x 10(-20) cm(2), respectively. The emission cross section at 1.06 microm was also determined by small-signal-gain measurements and was found to be in good agreement with the above value.

Protein Synthesis in Isolated Mitochondria of Rice (Oryza sativa L.) Seedlings

For studies of in organello mitochondrial protein synthesis in rice, Oryza sativa L., conventional surface-sterilization procedures were demonstrated to be ineffective. Because of the over-whelmingly efficient [(35)S]methionine utilization by contaminating bacteria, even "essentially bacteria-free" rice mitochondria were shown to be unsuitable for the study of in organello protein synthesis. We developed a procedure to obtain a bacteria-free preparation of rice mitochondria. Such mitochondria favored a membrane-dependent ATP-generating system over an external ATP-generating system as the energy supplement for in organello protein synthesis. Two distinct classes of [(35)S]methionine-labeled, cycloheximide-insensitive products were detected: an electrophoretically unresolved population and a set of some 22 to 27 discrete polypeptide species, each with a characteristic electrophoretic mobility and relative abundance.

A prospective, controlled, double-blind, cross-over study of tripterygium wilfodii hook F in treatment of rheumatoid arthritis

A polyglycosides of Tripterygium wilfodii hook F (TWH) preparation with a code name of T2 is used in the present double-blind, controlled, cross-over study on the treatment of 70 cases of rheumatoid arthritis (RA). An impressive curative effect of T2 is confirmed much more convincingly by the present study than that by the previously reported clinical open trials. The adverse reactions and the probable pharmacological mechanism of T2 are also discussed.

Nucleotide sequences involved in the neolysogenic insertion of filamentous phage Cf16-v1 into the Xanthomonas campestris pv. citri chromosome

Following a protracted carrier state in the infected cell, filamentous bacteriophage Cf16-v1 neolysogenizes Xanthomonas campestris pv. citri by inserting the phage genome into the host chromosome. The integration region in the phage and the host chromosome, respectively, and the two junctions in the lysogen chromosome were isolated and their nucleotide sequence was determined. The phage and host attachment sites shared an identical 15-bp "core," 5'-TATACATTATGCGAA-3'. Located on either side of each core were two unique arm sequences. Each of the two phage-host junctions contained an intact core flanked by a hybrid combination of phage and host arm sequences. A 10-bp symmetrical sequence arranged as inverted repeats with 1-bp spacing straddled the core sequence. A 10-bp repeated sequence, 5'-GCGCTATGGC-3', was found distal to the core in opposite orientation at the phage attachment site, while an abbreviated form of this sequence was present in the host attachment site. These sequence characteristics indicate that neolysogenic insertion of Cf16-v1 was accomplished by a site-specific recombination mechanism similar to lambda integration. However, in contrast to lambda, the phage and the host attachment sites in the Cf16-v1 system contained a high G + C nucleotide bias (except for the core sequence itself).

Transformation of psi- Saccharomyces cerevisiae to psi+ with DNA co-purified with 3 micron circles

DNA enriched for supercoiled plasmids prepared from the 3 micron plasmid-enriched, [psi+], [2 micron degrees] strain 6-1G-P188 and from the [2 micron+] [psi+] strain LL20 can be used to transform a psi- recipient strain to psi+. Fractionation of the former preparation by electrophoresis showed that the 3 micron plasmid band contained the transforming activity.

[Transfer of plasmid RP4 into some phytopathogenic bacteria and its relation to their virulence]

Plasmid RP4 were transferred from Escherichia coli into Pseudomonas solanacerum, Xanthomonas campestris pv. oryzae, X. campestris pv. campestris, and X. campestris pv. citri at the frequencies of 1.8 X 10(-6), 2.8 X 10(-6), 1.4 X 10(-2) and 2.0 X 10(-3), respectively. The frequencies of transfer depended on bacterial species and conjugation conditions. Treatment of bromide at the concentration of 2 micrograms/ml and acridine orange at 100 micrograms/ml for 32 hrs the plasmid RP4 could be cured from the transconjugant of P. solanacerum at the frequencies of 75% and 95%, respectively. When transconjugant of P. solanacearum was inoculated into tomato plants, the decrease in virulence was observed, furthermore, no plasmids were detected both in the wild-type strain and the cured transconjugant. It thus appears that the virulence may not be related to plasmids.