Right-side dominance for song control in the zebra finch.

Adult male zebra finches underwent unilateral denervation of the syrinx or unilateral lesion of the forebrain nucleus HVC known to be important for song control. Disruptive effects on song were greater after right-side than after left-side operations. After denervation of the right half of the syrinx, the fundamental frequencies of all syllables within a song converged on a value near 500 Hz, and nearly all syllables were altered in type. In contrast, the syllables produced after denervation of the left side of the syrinx largely maintained their preoperative frequencies, and fewer syllables changed in type. Unlike nerve sections, HVC lesions did not result in strikingly lateralized effects on syllable phonology; however, HVC lesions did affect the temporal patterning of a bird's song, whereas nerve sections did not, and changes in temporal patterning were more marked after right than after left HVC lesions. Right-side dominance for zebra finch song control is the reverse of that described in other songbird species with lateral asymmetry for vocal communication. We suggest that the need for a dominant side is more important than the side of dominance.     

Precision of the all-glass impinger and the andersen microbial impactor for air sampling in solid-waste handling facilities.

A method was devised to determine the precision of the all-glass impinger and the Andersen six-stage microbial impactor over a wide range of aerosol concentrations like those found in facilities which process solid waste. Simultaneous samples were collected inside a municipal solid-waste recovery system, and the data were treated statistically to estimate the precision of each air-sampling device. All-glass impingers yielded colony counts which indicated a linear relationship between samplers over an observed aerosol concentration of 1.1 X 10(3) to 2.8 X 10(7) colony-forming units per m3 of air. Impactors also yielded colony counts which indicated a linear relationship over an observed aerosol concentration range of 3.9 X 10(3) to 1.9 X 10(5) colony-forming units per m3 of air. The coefficients of variation for the all-glass impinger and the six-stage impactor in an environment with a high and variable dust level were determined to be 0.38 and 0.23, respectively.     

Innervation of the synovial membrane of the cats joint capsule

Summary Results of investigations on the occurrence of nerve fibres and endings in the synovial membrane of the knee and elbow joint in the cat are reported. The stratum synoviale contains only autonomic fibres, running in the adventitia of arteries.Free nerve endings are lacking in the stratum synoviale. Simple Pacinian corpuscles with an inner core are occasionally observed in the border zone between the stratum synoviale and fibrosum. The ultrastructure of these endorgans resembles that of Pacinian corpuscles in the hairless and hairy skin of the cat.     

Hydrolase and serum treatment of normal chick embryo cells: effects on hexose transport.

We have asked whether treatment of normal cultured cells with proteases, other hydrolytic enzymes, or serum can convert them into transient phenocopies of transformed cells with respect to the very high rate of hexose transport characteristic of transformed cells. Treatment of density-inhibited cultures of normal chick embryo fibroblasts with trypsin, plasmin, neuraminidase, or hyaluronidase stimulated their rate of 2-deoxyglucose uptake to a level only marginally higher than that seen in normal exponentially growing cultures, and only 35-45% of that seen in transformed cultures. Addition of the hydrolytic enzymes to growing cell cultures had little effect on 2-deoxyglucose uptake. Serum, however, could stimulate 2-deoxyglucose uptake all the way up to the transformed level. Even though the hydrolases and serum differed in their ability to stimulate 2-deoxyglucose uptake, both reagents were capable of stimulating cell division equally well. Evidence is presented suggesting that the hexose transport rate is controlled by serum factors, and that proteolysis can affect the response of the cells of these factors.     

Induction of term labor with intravenous prostaglandin F2α (a comparison of two dosage schedules)

The efficacy of intravenous Prostaglandin F_2α (PGF_2α) infusion for induction of labor in two different dosage schedules was studied in 90 women between 36 and 43 weeks of gestation. The rate of PGF_2α infusion was increased at four-hour intervals in 36 women in the low dosage group and every hour in 54 women in the high dosage group, never exceeding an infusion rate of 20 μg/min. in either group. Labor was successfully induced in approximately 90% of the patients in each group. There was no statistically significant difference in the mean induction-delivery interval between the two groups at the 5 percent level. Intravenous PGF_2α was found to be effective and safe for both mother and infant in the dosage schedules used in this study for induction of labor.