A seasonal study of the distributions of surface state variables in Liverpool Bay. I. winter data

The physical, chemical, and biological characteristics of the surface waters of Liverpool Bay were investigated during six seasonal cruises in 1975. The winter data has been analysed to provide criteria by which spatial and temporal changes in the distributions of surface state variables during the seasonal production cycle may be judged. Surface distribution maps observed during two winter cruises (January and December) were markedly dissimilar. This temporal variability is attributed to changing circulation patterns within the Bay induced by variations in magnitude and direction of wind stress. Despite the ‘visual’ dissimilarity in spatial distributions observed on the two cruises, principal component analysis demonstrates a similar general background which is dominated by conservative physical mixing of sea and fresh waters. During winter, the spatial variability in water characteristics originated at the boundaries of the cruise path and spread internally, primarily as a consequence of the differing composition of the source waters, to the sea area. No internal sources or sinks, either anthropogenically or biologically induced, were encountered during the winter cruises.     

Proton, calcium, and magnesium binding by peptides containing gamma-carboxyglutamic acid.

gamma-Carboxyglutamic acid (Gla) is believed to bind Ca [II] ions and Mg [II] ions in prothrombin and other coagulation proteins. Binding constants for H+, Ca [II] ions, and Mg [II] ions to Gla-containing peptides are determined using pH and ion selective electrode titrations. The binding constants for peptides containing a single Gla residue are similar to the constants for malonic acid. Peptides containing two Gla residues in sequence (di-Gla peptides) bind Ca [II] ions and Mg [II] ions more strongly. KMgL for the di-Gla peptides is similar to the site-binding constant for Ca [II] ions in denatured BF1. These di-Gla peptides may be useful analogs for metal binding by the disordered Gla domain in BF1.     

Spiracular transpiration in ticks: a passive diffusion barrier in three species of Ixodidae (Metastigmata: Acarina)

In ixodid ticks the morphology of the spiracle, and in particular that of the labyrinth, differs between species. A reduction in transpiration of water vapour by the 'mutual interference' effect previously described in Ixodes ricinus (L.) is not significant in many species. Instead, transpiration is retarded by very restricted air movement within the labyrinth and by a high resistance to diffusion generated by numerous small aeropyles. These adaptations may be particularly useful in arid environments.     

The DEAD-box helicase DDX56 is a conserved stemness regulator in normal and cancer stem cells

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Multilocus markers for mouse genome analysis: PCR amplification based on single primers of arbitrary nucleotide sequence

Polymerase chain reaction (PCR) based on single primers of arbitrary nucleotide sequence provides a powerful marker system for genome analysis because each primer amplifies multiple products, and cloning, sequencing, and hybridization are not required. We have evaluated this typing system for the mouse by identifying optimal PCR conditions; characterizing effects of GC content, primer length, and multiplexed primers; demonstrating considerable variation among a panel of inbred strains; and establishing linkage for several products. Mg²⁺, primer, template, and annealing conditions were identified that optimized the number and resolution of amplified products. Primers with 40% GC content failed to amplify products readily, primers with 50% GC content resulted in reasonable amplification, and primers with 60% GC content gave the largest number of well-resolved products. Longer primers did not necessarily amplify more products than shorter primers of the same proportional GC content. Multiplexed primers yielded more products than either primer alone and usually revealed novel variants. A strain survey showed that most strains could be readily distinguished with a modest number of primers. Finally, linkage for seven products was established on five chromosomes. These characteristics establish single primer PCR as a powerful method for mouse genome analysis.     

Effects of resin swelling and substitution on solid phase synthesis.

Resins sold by several companies were examined for swelling, uniformity of beads, and substitution in the case of resins sold with the first amino acid attached. Effects of resin swelling, uniformity, and substitution on the solid phase synthesis of long, structured and/or branched peptides were evaluated.