(Table, page 500) Geochemistry of a pancake-shaped concretion from lake Charlotte, Canada

A pancake-shaped concretion from Ship Harbour Lake, a small freshwater lake in eastern Nova Scotia (now named Lake Charlotte) is part of collection sent to the National Museum of Canada by Mr. R. A. Logan, of the Pan American Airvays. These concretions are of similar to the well-known marine concretions with a composition similar to wad. These are known only from abyssmal depths of the sea in the red clay deposits, while the present concretions occur in very shallow lake waters. They should be of interest to geologists, who may be concerned with the rather difficult problem which some concretions raise of distinguishing between concretions of syngenitic and epigenetic origin.

The two single-strand cleavages at each end of Tn10 occur in a specific order during transposition.

During Tn10 transposition, the element is excised from the donor site by double-strand cleavages at the two transposon ends. Double-strand cleavage is a central step in the nonreplicative transposition reaction of many transposons in both prokaryotes and eukaryotes. Evidence is presented to show that the Tn10 double-strand cut is made by an ordered, sequential cleavage of the two strands. The transferred strand is cut first, and then the nontransferred strand is cleaved. The single-strand nicked intermediate is seen to accumulate when Mn2+ is substituted for Mg2+ in the reaction or when certain mutant transposases are used. The fact that the transferred strand is cleaved before the non-transferred strand implies that the order of strand cleavages is not the determining factor that precludes a replicative mechanism of transposition.

Mechanisms underlying the sensitivity of songbird forebrain neurons to temporal order.

Neurons in the songbird forebrain area HVc (hyperstriatum ventrale pars caudale or high vocal center) are sensitive to the temporal structure of the bird's own song and are capable of integrating auditory information over a period of several hundred milliseconds. Extracellular studies have shown that the responses of some HVc neurons depend on the combination and temporal order of syllables from the bird's own song, but little is known about the mechanisms underlying these response properties. To investigate these mechanisms, we recorded intracellular responses to a set of auditory stimuli designed to assess the degree of dependence of the responses on temporal context. This report provides evidence that HVc neurons encode information about temporal structure by using a variety of mechanisms including syllable-specific inhibition, excitatory postsynaptic potentials with a range of different time courses, and burst-firing nonlinearity. The data suggest that the sensitivity of HVc neurons to temporal combinations of syllables results from the interactions of several cells and does not arise in a single step from afferent inputs alone.

Abstract of statements of insurance companies in Canada.

Some years issued in the series of Sessional papers of the Parliament of Canada.

Dominion aid to agricultural instruction in Canada; a review of the work performed by the provinces with the moneys granted under the agricultural instruction act during the four year period, 1913-1917.

At head of title: Dominion of Canada. Dept. of agriculture. Office of the agricultural insturction act ..

The congress guide and scientific programme [of the] 5th Pacific Science Congress, Victoria, B. C., June 1-4; Vancouver, B. C., June 5-14; Canada, 1933.

Mode of access: Internet.

Report of the Superintendent of Insurance for Canada. : Rapport du Surintendant des assurances du Canada.

English title only, 1945-1954.

Titles and documents relative to the seigniorial tenure, required by an address of the Legislative Assembly, 1851.

Another compilation with similar title was also published in 1852. The contents of the two volumes are different.

Capital investments in Canada; some facts and figures respecting one of the most attractive investment fields in the world.

Mode of access: Internet.

Report of the Proceedings of the Annual Convention of the Western Canada Irrigation Association.

At head of title: Dept. of the Interior of Canada ... Irrigation Branch.

Report of the commissioners of the Intercolonial railway.

Printed by order of Parliament.

Biennial survey of education in Canada.

At head of title: Dominion of Canada. Dominion bureau of statistics. Education statistics branch.

The cattle trade of western Canada; special report

At head of title: Dominion of Canada. Department of agriculture. Branch of the live stock commissioner