Lactate dehydrogenase isozymes of mouse epidermis

Summary Five isozymes of LDH are demonstrable in the epidermis of the ear pinnae, hind feet, trunk dorsa, and tails of adult C57BL, C57HR, and C3HB mice by polyacrylamide gel electrophoresis. LDH-5 activity predominates in electropherograms. The ratio of LDH-1 to LDH-5 is greater in the epidermis of ear pinna and trunk dorsum than in that of tail and hind foot. The region-specific patterns of epidermal LDH isozymes are not correlated with melanin pigmentation or ‘hairiness’ of the skin. Supported by PHS Research Grant No. CA-06097 from the National Cancer Institute, United States Public Health Service.     

Molecular orbital studies on the conformation of γ-aminobutyric acid and muscimol

Zusammenfassung Mit Hilfe der Molecular Orbital Theorie werden die bevorzugten Konformationen für die-Aminobuttersäure und das strukturell verwandte Muscimol, die neurologisch bedeutsam sind, berechnet.

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Supported by National Institutes of Health (US) Grant No. GM-16312.     

The effect of bisamidines of 2,6-diaminoanthraquinone onEntamoeba histolytica infections in rats and hamsters

Summary Bisamidines of 2,6-diaminoanthraquinone have demonstrated potent activity against cecal and hepaticEntamoeba histolytica infections in rats and hamsters, respectively. A number of these compounds compared favorably, in overall drug efficacy, with metronidazole and other standard agents.Acknowledgements. The authors wish to thank Dr B. Jackson and co-workers for the results in the Dominant-Lethal test and N.A. Kuck for the results in the Ames test.     

N-(t-Aminoalkynyl)-substituted pyrrolidones as oxotremorine antagonists

Zusammenfassung Eine Anzahl von Antagonisten zu Oxotremorin wurden durch kleine Modifikationen der Struktur des Oxotremorins erhalten. Die aktivste Verbindung, N-(1-Methyl-4-pyrrolidino-2-butinyl)pyrrolidon, ist mehr als sechsmal wirksamer als Atropin und hat eine grössere Spezifizität mit Bezug auf das Zentralnervensystem.     

Migration and dispersal of spermatozoa in spermathecae of queen honeybees (Apis mellifera L.)

Summary Observations of variability in the phenotypic composition of honeybee colonies through time have led to ad hoc hypotheses concerning the distribution of spermatozoa in multiply mated honeybee queens. These hypotheses are not supported by available data. Serial sections of spermathecae from honeybee queens were examined by light microscopy. No obvious physical evidence was observed of agglomerations, aggregations, clumps, layers, or wads of spermatozoa within spermathecae within 24 h of insemination. A hypothesis is proposed explaining the occurrence of fluctuations of progeny phenotypes.     

Clustering and isolation in the consensus problem for partitions

We examine the problem of aggregating several partitions of a finite set into a single consensus partition We note that the dual concepts of clustering and isolation are especially significant in this connection. The hypothesis that a consensus partition should respect unanimity with respect to either concept leads us to stress a consensus interval rather than a single partition. The extremes of this interval are characterized axiomatically. If a sufficient totality of traits has been measured, and if measurement errors are independent, then a true classifying partition can be expected to lie in the consensus interval. The structure of the partitions in the interval lends itself to partial solutions of the consensus problem Conditional entropy may be used to quantify the uncertainty inherent in the interval as a whole     

Aurora A kinase (AURKA) in normal and pathological cell division

Temporally and spatially controlled activation of the Aurora A kinase (AURKA) regulates centrosome maturation, entry into mitosis, formation and function of the bipolar spindle, and cytokinesis. Genetic amplification and mRNA and protein overexpression of Aurora A are common in many types of solid tumor, and associated with aneuploidy, supernumerary centrosomes, defective mitotic spindles, and resistance to apoptosis. These properties have led Aurora A to be considered a high-value target for development of cancer therapeutics, with multiple agents currently in early-phase clinical trials. More recently, identification of additional, non-mitotic functions and means of activation of Aurora A during interphase neurite elongation and ciliary resorption have significantly expanded our understanding of its function, and may offer insights into the clinical performance of Aurora A inhibitors. Here we review the mitotic and non-mitotic functions of Aurora A, discuss Aurora A regulation in the context of protein structural information, and evaluate progress in understanding and inhibiting Aurora A in cancer.     

Autumnal migration of Eared Grebes ( Podiceps nigricollis ) through southwestern Wyoming: a key to assessing the size of the North American population

In autumn the vast majority of the North American population of Eared Grebes ( Podiceps nigricollis ) congregates for several months at Great Salt Lake, Utah, and Mono Lake, California. Because the lakes are so large, it has not been possible to monitor grebe migration with sufficient accuracy to determine when peak numbers are reached. To clarify migration phenology, we analyzed data from 2 isolated wetland areas in southwestern Wyoming where grebes land en route between breeding areas in the interior and Great Salt Lake. Occasional birds, probably nonbreeders or failed breeders, begin moving southward as early as mid-June. Migration of postbreeding birds starts in late July, peaks in late August and September, and is largely completed by the end of October, with very small numbers arriving into November. The pattern of migration and number of birds encountered varied annually, but 95% of the migration was usually completed by 15 October. As a result, censuses at the major staging lake made on or after 15 October but before the grebes depart for wintering areas can be used to study trends in size of the North American population.     

Genetic structure and division of labor in honeybee societies

Summary Recent studies have demonstrated a genotypic component to the division of labor among worker honeybees. However, these studies used artificially-selected strains of bees or colonies derived from queens that were instrumentally inseminated with the semen from very few males. We present evidence for genotypic variability among groups of workers performing tasks in colonies with naturally-mated queens. These results demonstrate that genetic structure is a level of social organization in honeybees.