Biflavones of Dacrydium sensu lato

A survey of the biflavonyls in the leaves and branchlets of all three sections of the genus Dacrydium s.l. revealed a complex mixture of amentoflavone and its partial methyl ethers and hinokiflavone in most species. A group of three species in section C, however, were characterised by cupressuflavone derivatives as the major biflavone constituents. The results are used to discuss proposals for revised generic boundaries.     

Taxonomy of nonfermentative bacilli: The IIk-2 group

Twenty-two strains of the Center for Disease Control’s IIk-2 group of nonfermentative Gram-negative, weakly pigmented (yellow) bacteria were examined in respect to phenotypic features, DNA base composition, and both intra-and extra-group DNA-DNA hybridizations. Eighteen of the 22 strains appeared to be members of one taxon. This taxon is phenotypically not similar to two genera,Acinetobacter andMoraxella, which have similar base compositions. It does, however, have phenotypic features and base composition compatible with those of the genusFlavobacterium.     

Thermoregulatory behavior of juvenile cromileptes altivelis (serranidae), a tropical marine fish

Ten juvenile Cromileptes altivelis were tested individually for 3-day periods in electronic shuttleboxes to measure their thermoregulatory behavior. The fish voluntarily occupied a 21–27°C span, out of a potentially available 0–50°C range. The mean final thermal preferendum was 24.5°C for all individuals. The thermoregulatory performance of this species is similar to that of cool temperate freshwater fishes.     

RNA levels in colchicine-resistant mutants of Chlamydomonas reinhardi

A colchicine-resistant mutant of Chlamydomonas reinhardi (col⁻_{10, 12}) which appears blocked in the final stages of the cell division cycle is shown to have an RNA: protein ratio over four times that which is observed in wild-type cultures. This does not appear to be simply a consequence of reduced overall growth rate, because a comparable reduction in the overall growth rate of wild type by caffeine inhibition did not produce such a large rise in RNA content. The RNA levels in six other colchicine-resistant mutants, which have various abnormalities in colchicine-binding activity, has also been investigated. Two of them have elevated RNA levels.     

Effect of temperature on locomotor activity in the goldfish (Carassius auratus) and the bluegill (Lepomis macrochirus): Presence of an ‘activity well’ in the region of the final preferendum

Goldfish (Carassius auratus) and bluegill sunfish (Lepomis macrochirus) were placed in aquaria where their locomotor activity was monitored by photocells, and tested at various acclimation temperatures over a range encompassing their final thermal preferenda. Activity was pooled over 24-hour periods to eliminate any circadian rhythm effects. Both species exhibited an activity well of reduced locomotor activity in the region of the final preferendum. Goldfish, tested either singly or in groups of 2–5 individuals, exhibited a social-interaction effect which became more pronounced at higher temperatures. These results are discussed in relation to a thermokinetic interpretation of thermo-regulatory behavior in fishes, and to the correspondence between thermal preferenda and thermal optima.     

Thermoregulatory behavior of the bluespotted sunfish,Enneacanthus Gloriousus

Twenty bluespotted sunfish, Enneacanthus gloriosus, were individually tested for thermoregulatory behavior in an electronic shuttlebox. The first fishes of this genus to be tested for thermoregulatory behavior, these individuals were captured near the northern limit of their zoogeographic range, in northeastern Pennsylvania. The mean final preferendum from pooled data of all 20 fish was 28.5°C; there were no significant differences between day and night.     

Multigenic regulation of the primary immune response to ovalbumin in mice

At least four genes regulate the primary immune response to ovalbumin in mice. The ability to be sensitized to transfer delayed type hypersensitivity to ovalbumin is controlled by two genes. One gene,OVA-, is linked to theH-2 complex and maps to the left ofI-E. The linkage of the other gene,OVA-Bg1, has not been determined, but it segregates independently of theLy M locus, of the heavy chain allotype genes and of certain genes controlling coat color. At least two genes regulate the ability to respond with a primary antiovalbumin antibody response. One gene,OVA-, is linked to theH-2 complex and maps to the right ofI-E. Discordance of the minimum dose of antigen needed to elicit delayed type hypersensitivity response and antibody suggests that non-H-2 gene(s) regulating the primary antibody response are different fromOVA-Bg1.Abbreviations used in this paper BSA bovine serum albumin - DTH delayed type hypersensitivity - H-2 major histocompatibility complex of mouse - Ir gene — immune response gene - OVA ovalbumin - SRBC sheep red blood cells