Use of polyvinyl alcohol as a stabilizer of peroxidase-antibody conjugate for enzyme immunoassay

Summary The activity of a peroxidase-antibody conjugate was greatly stabilized while in solution through the addition of polyvinyl alcohol (PVA). This stabilizing effect was dependent upon the molecular weight and degree of hydrolysis of the PVA used. The concentrations of PVA necessary for maximum stabilization had no adverse effects upon enzyme immunoassay. Thus, the conjugate stabilized by PVA can be used without dilution for enzyme immunoassay, and without need of refrigeration during transport and storage.     

A Non-Leaching Technic for Autoradiography

A paraffin ribbon is fastened on a perforated metal plate having a rectangular hole wide enough to allow the ribbon to be suspended freely. The desired section is centered over the hole and straightened by softening the paraffin over a hot plate and blowing gently on the section. The section is then cut loose on the end of a rubber stopper under a safelight and pressed against the albuminized photographic emulsion. Mayer's albumin does not affect the sensitivity or produce chemical fog in the emulsion.     

Incidence of Heart Disease in Children in the City of Toronto

A special registry of children with heart disease in the City of Toronto was set up (a) to provide for follow-up of all children with heart disease in that community, (b) to remove the “cardiac” label from children with functional murmurs, (c) to acquaint parents with facilities available for the management of children with heart disease, and (d) to record useful data regarding heart disease in children.The 1961-62 Cardiac Registry showed that 542 of 156,775 pre-school and school children had evidence of heart disease; 464 were congenital and 68 rheumatic in origin: 121 children with congenital heart defects had been treated surgically. Congenital cardiac disease ranked fifth in frequency among the causes of death in children. There was a diminution of acute rheumatic fever and rheumatic heart disease in children in 1961-62 when compared with data for previous years. Seventy-eight per cent of children in this series with a history of rheumatic fever were receiving continuous prophylaxis.     

Mating calls of three prochilodontid fish species from Brazil

Passive acoustic monitoring (PAM) of fish sounds has been used as a means of detecting the presence and abundance of fishes. Prior to PAM, bioacoustical analyses of sounds are needed to characterize species-specific characteristics of calls. With hydrophones placed in outdoor ponds, we recorded the mating calls of three species of prochilodontid fishes (Prochilodus argenteus, P. costatus, P. lineatus). Fish were induced to spawn and call by injection of carp (Cyprinus carpio) pituitary gland extract. We recorded a total of 394 pulse train calls and additional single pulse calls that were not associated with trains. The trains of all three species were similar in nature - series of low frequency pulses that lasted from 1 to 11 s, often with an initial rapid rise followed by a slow tapering of pulse amplitude. Dominant frequency of single pulses and trains was greatest in P. lineatus, with P. costatus and P. argenteus exhibiting lower single pulse dominant frequencies, and P. costatus having lower train dominant frequency. With data from the three species combined, the dominant frequency of pulses significantly increased with fish standard length. There was also a significant linear relationship between the dominant frequency of pulses and trains. Discriminant function analysis showed that differences in train dominant frequency, pulse duration, and pulse period between the three species were significant enough to discriminate between them. This study was the first to fully characterize the sounds of these three Prochilodus species, and should assist fisheries biologists monitoring spawning behavior in these species.     

The morphology and mode of formation of <Emphasis Type="Italic">Neoeione</Emphasis> igen. nov. from the Carboniferous of northern England

Samples of the burrows studied herein, originally introduced as Eione moniliformis Tate, have been collected from the heterolithic sandstone and siltstone beds of a coastal outcrop near the town of Howick, Northumberland, UK. These interbedded and hummocky cross-stratified beds, belonging to the Stainmore Formation, are Carboniferous and represent offshore marine sediment deposited between the fair wave base and storm wave base. As the name Eione was used previously to describe a genus of gastropod, Eione Tate is a junior homonym of Eione Rafinesque. Therefore, a new ichnogenus was established, Parataenidium Buckman, to accommodate burrows composed of two distinct levels, which included E. moniliformis. Using three-dimensional morphological modeling techniques, this study aims to: (1) clarify the current taxonomic status of Parataenidium moniliformis; and (2) provide an updated model for its construction. The transfer of E. moniliformis to Parataenidium was problematic, primarily because it is not composed of two distinct levels, but, instead, is composed of backfilled reniform sediment packages. These packages were created through a multistage process whereby the organism maintained a small open cavity from which it fed. Accordingly, a new ichnogenus, Neoeione, is proposed to accommodate the material originally described by Tate.