Quantitative analysis of correlations among flower traits in Gerbera hybrida Compositae : 1. Genetic and environmental correlations

Phenotypic (r p ), genetic (r g ), and environmental, (r e ) correlations were estimated for 38 flower traits in the Davis population of gerbera (Gerbera hybrida, Compositae). Fifty-two percent of r p and 38% of r g were statistically significant at P < 0.05. Significant negative r p were infrequent, but significant negative r g occurred in 10% of cases. There was a negative correlation between estimates of r g and r e , resulting in cases where r g was significant, but r p was not. Individual traits varied in their tendency to correlate phenotypically or genetically, and positively or negatively, with other traits. Traits within the same morphological category, such as disk florets or transitional florets, were more highly intercorrelated than were traits from different categories.

Quantitative analysis of correlations among flower traits in Gerbera hybrida, Compositae : 2. Direct and mean correlated response to selection

A Mean Correlation Response (MCR) model was developed to estimate the relative effectiveness of direct selection when other traits also respond to the selection. A measure of the relative effects of mean correlated response and direct response (R) and a measure of the relative efficiency of direct selection (IE) were applied to a genetic correlation matrix of 38 traits. These were measurements of inflorescence, receptacle and involucre, scape, disk florets, ray florets, and trans florets in the Davis population of Gerbera hybrida, Compositae. Generally, traits with high heritability had high direct and mean correlated response; these were often traits measuring disk and trans florets. Traits with low heritability had low direct and mean correlated response; these were often traits measuring the inflorescence. Traits of the inflorescence had the lowest efficiency of direct to mean correlated response.

Attention deficit disorder: quantitative analysis of CT

We compared the measurements of CTs in two groups of children: 35 satisfying DSM III criteria for attention deficit disorder (ADD) and 27 controls with other conditions. The groups were comparable in age, sex, and IQ. Measurements of the anterior horns of the lateral ventricles, bifrontal width, and right and left hemispheres did not differ. The ratio of ventricular size/bifrontal brain width (Evan's Index) averaged 0.237 in ADD and 0.263 in controls--results similar to those obtained in normal children by other investigators. Our findings suggest that when quantitative techniques, contrast populations, and "blind" analysis of CTs are employed, the results are indistinguishable in children with ADD and contrasts. If anatomic abnormalities are present in ADD, they are not discernible with current CT technology.

Dominant lethality in Xenopus laevis induced with triethylenemelamine (TEM)

Adult male South African clawed toads, Xenopus laevis, were injected intraperitoneally with triethylenemelamine (TEM) dissolved in water over a dose range of 13-1,300 micrograms/kg or with water (controls). Mating of the treated males with untreated females was induced seven days later by injection of human chorionic gonadotropic hormone (HCG). Accumulated lethality one week after fertilization among progeny was dose related. Morphological abnormalities among embryos that survived to hatching were similarly dose related. Because anatomically anomalous embryos may have impaired behavior, swimming capacity was tested, and anomalies in swimming behavior were also found to be dose related. Finally, short-term cell cultures were made on minced embryos to obtain chromosome spreads. Structural aberrations, rings, dicentrics, etc of somatic chromosomes were also dose related.

Preparative isolation of middle molecular weight fractions from the hemofiltrate of patients with chronic uremia

Fractions in the molecular weight range of the so-called middle molecules (500--3000 daltons) were isolated on a preparative scale from hemofiltrate of patients. Hemofiltration was performed with an RP-6 dialyzer using a predilution technique. The hemofiltrate was concentrated and desalinated by reverse osmosis with membranes with a normal cut-off of 500 daltons. The retentate was freeze-dried, redissolved in volatile buffer and fractionated on Sephadex G-15 macrocolumns. The middle molecule molecular weight range in the elution profiles (detected at 206 and 280 nm simultaneously) was marked with peptides. Isolated fractions in the middle molecule molecular weight range showed strong inhibitory activity upon 3H-thymidine incorporation into rat bone-marrow cells in vitro. The described combination of hemofiltration, reverse osmosis and gel chromatography is suggested as a useful approach to the isolation of these ninhydrin-positive substances which, according to their proved heterogeneity, are to be subfractionated by further procedures.