Generation of nonlinearity in the electrical response of yeast suspensions.

The mechanism through which nonlinearity is generated in the response waveform of the electric current obtained by applying alternating current voltage to yeast suspension has not yet been elucidated. In this paper, we showed that the response waveform depends on the applied voltage and frequency. The results showed that distortion (nonlinearity) in the waveform increases as the applied voltage increases and/or the frequency decreases. We suggest a model for the generation of nonlinearity based on the influx of potassium ions into the cell via potassium ion channels and transporters in the membrane due to the applied voltage. Furthermore, we validated this model by simulating an electrical circuit.

Subcutaneous release of trigger thumb and fingers in 210 fingers.

Subcutaneous release of the tendon sheath has been performed in 210 trigger digits of 172 patients. The follow-up period ranged from 3 to 58 months, with an average of 24 months. Based on our points system, the overall results were as follows: excellent 64.3%, good 9.5% fair 8.1%, poor 18.1%. There were no infections, no injuries of nerves or vessels and no functional insufficiency. This subcutaneous procedure can be easily, quickly and safely performed by careful hand surgeons in the out-patient clinic.

Phylogenetic relationships among fruit flies, Bactrocera (Diptera, Tephritidae), based on the mitochondrial rDNA sequences.

Nucleotide sequences of a 1.6 kb long portion of the mitochondrial DNA containing the majority of the 16S rRNA gene, the tRNAval gene, and the 5' half-region of the 12S rRNA gene were determined for forty-eight individuals of nineteen Bactrocera species and one other tephritid taxon, Anastrepha ludens. Phylogenetic analyses were performed using the consistently aligned 1.5 kb long sequences, excluding seventeen portions that could not be aligned unambiguously and were aligned inconsistently among analyses using different programs and parameters. Results of phylogenetic analyses were highly congruent among distance, unweighted parsimony, and weighted parsimony methods in terms of topology of resulting trees. Bootstrap analyses supported many of the phylogenetic relationships resolved by these analyses. Although aligned sequences showed apparent biases in nucleotide content and substitutions that differed among sites within the stem/loop structure of rRNA molecules, compensation for such factors did not greatly affect the topology. The results are discussed in relation to the taxonomic positions of species used in this study and in relation to the phylogenetic and diagnostic utility of the mitochondrial rDNA fragment.

Examination of the relationship between parameters to determine electropermeability of Saccharomyces cerevisiae.

A rectangular electric pulse was applied to Saccharomyces cerevisiae suspensions in NaCl solutions. The relationship between field strength, pulse width and conductivity of extracellular media of key--factors to determine the yield of electropermeability--was examined at the time when the same permeability occurred. The results showed that the dependence of the yield of permeability upon the width of applied pulse was mutually related with the conductivity of extracellular media. Namely at one field strength, the value of pulse width is inversely proportional to that of conductivity of media and its relationship holds true for any field strength. Further, the relationship between parameters considered bears a close resemblance to that recognized between stress amplitude and the number of cycles to failure in the fatigue fracture of materials.