Incidence of phenylketonuria in British Columbia, 1950-1971

The incidence of PKU in British Columbia in the 1950-1971 period is 1/18,750 which corresponds to that found in two other Canadian studies.^{2, 3} Evidence is presented which shows a trend toward a decline in incidence; however, this is not statistically significant. There is a preponderance of male cases in all age groups.     

Purification and amino acid sequence of melanocyte-stimulating hormone from the dogfish Squalus acanthias

A melanocyte-stimulating hormone (MSH) was isolated by gel filtration and ion-exchange chromatography from extracts of the pituitary glands of dogfish. Sequence studies were carried out on the hormone and its enzymically and chemically cleaved fragments. The sequence of the hormone, Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Met, shows that ten of its 11 residues are the same as ten of the 13 residues of mammalian alpha-MSH. About half of its molecules have the carboxyl group at the C-terminus free and about half are amidated; about a fifth have an extra tyrosine residue on the N-terminus, thereby making 11 residues the same as in mammalian alpha-MSH. Unlike the mammalian hormone, however, none of it was found to be N-acetylated.     

New method for assessing boron status of the oil palm

Plant and Soil - The measurement of optical density of acid hydrolysed oil palm leaves provides the basis for a quantitative determination of the cyanidin liberated. This in turn was shown to be...     

The Number and Morphology of Moss Chromosomes

The time that suitable cytological material is available can be extended by bringing mosses into the laboratory in late winter and keeping them in covered glass dishes placed in strong diffuse light. Best growth of the gametophyte occurs at 68-70° F. and at a relative humidity just high enough to prevent the leaves from curling. Fruiting plants can be maintained in the laboratory in the same way but at a slightly lower relative humidity. Tissue for the study of the gametophytic chromosome complement is obtained from the stem apex and embryonic leaves. Sporophytic mitoses are obtained from the meristematic tip of developing sporophytes. For the study of meiosis, the columella, to which the spore mother cells adhere, is removed from the capsule. The tissues are fixed in acetic alcohol for 1-3 hours and then stained and squashed. Ways in which moss tissue reacts differently to the conventional squash methods are discussed and special directions are given.     

MONITORING THE TREND OF HARBOR SEALS IN PRINCE WILLIAM SOUND,ALASKA, AFTER THE EXXON VALDEZ OIL SPILL

We used aerial counts to monitor the trend in numbers of harbor seals, Phoca vitulina richardsi, in Prince William Sound, Alaska, following the 1989 Exxon Valdez oil spill. Repetitive counts were made at 25 haul-out sites during the annual molt period each year from 1990 through 1997. A generalized linear model indicated that time of day, date, and time relative to low tide significantly affected seal counts. When Poisson regression was used to adjust counts to a standardized set of survey conditions, results showed a highly significant decline of 4.6% per year. Unadjusted counts indicated a slight, but not statistically significant, decline in the number of seals. The number of harbor seals on the trend-count route in eastern and central PWS has been declining since at least 1984, with an overall population reduction of 63% through 1997. Programs to monitor long-term changes in animal population sizes should account for factors that can cause short-term variations in indices of abundance. The inclusion of such factors as covariates in models can improve the accuracy of monitoring programs.