Second Welland Canal - Book 2, Survey Map 4 - Locks 11, 12, 13, 14 and 15 in Grantham

Survey map of the Second Welland Canal created by the Welland Canal Company showing the Grantham Township along the outskirts of Merritton. Identified structures associated with the Canal include Locks 11, 12, 13, 14, and 15, Lock House Lot, and the towing path. The surveyors' measurements and notes can be seen in red and black ink and pencil. Several stones likely used in the measurements are identified on the map. Local area landmarks are also identified and include streets and roads(ex. Hartzel Road and Macadamized Road), the Great Western Railroad, Swing Bridge, Thorold Station and its structures (ex. freight house, office, water tank, and wood house), Gordon and Mackay Houses, Gordon and Mackay's Cotton Mill, hydraulic race, a wharf, pond, and an unnamed bridge. Properties and property owners of note are: Concession 9 Lots 12 and 13, A. Bradley, John O'Coner, G. Grant, J. Bradley, J. Vanderburgh, O. Clifford and a parcel of land leased Gordon and Mackay.

Illustration - Unit no. 9 File no. 2-R1-H21.4

An illustration dated 10 November 1948 of Unit No. 9. The description reads "Sketch Showing Field Notes taken before unit dismantled Nov. 1948 - Runner and shaft were hanging from the thrust bearing when these measurements were taken. The thrust bearing was 3/32" thinner than a full size bearing."

Amplification of the DFR1 gene in Saccaromyces cerevisiae

A new system was employed to study amplification of t,he DHF'R gene DFB,1 ) in Sa<,:;charoillYCB§. .Q~~Yi...S!i<;1~. . This system consists of a series of yeast strains containing a casset,te which encodes t he yeast, D..ERl gene ttghtly linked tjO a f usion of the yeast 1EU2. regulat,ory region wi tJ1 the LAQZ str ctural gene from E. cO.1-1 (,) . M. Clement , unpubl i,::;hed) . Th's casset;t e was shown t.o be integrat,ed int o a unj que chromosomal l ocati on in each strain . Yeast cells were se l ected for MTX-resistance and overproduction of ~ galac t osi d se ( B-gal ). Since the inserted DF'Rl and ~ACZ genes are independently regulated, it was thought that cel l s with this phenotype probably contain e d ampl if ications of the cassette. A lar ge variat ion in the f requn y o f MTX-resistance was found between the di ff e r ent str ains. These freqlen c ~ es r anged from about 2 x 10 - 7 fo r a population of cells containing the cassette integrated at, the BI J2.l gene in t,he middle of the long arm of chromosome V, to about 5 x 10-4 for a strain with the cassette i nserted in the r DNA cluster Abo It 85% of the MTX- res i stcmt iso l ates examined showed enhanced B·-gal act i v ity rel a t ive t o the parental strain . For the ma jorit y of strains, the mean B- gal activity in drug-r sistant clones was about 3 times that o f the parent following a single se l ect i on step . I n con t r ast, primary MTX-resistant derivat~ves of cells with the cassette inserted 3 at the rDNA cluster showed inc r eases in B- gal activity ranging from 9 - 14 f old r elative to the parent. Analysis of the latte r s train by Southe rn hybr idization indicated that the cassette was inde e d amplified several fold in MTX-re sistant derivatives. A sing l e strain, in which the cassette was inserted at the !lEA;], loc u.s , was used to examine in more detai 1 , the parameters affecting DFRl gene amplificat~ion in yeast . The mean B- gal activity in drug-resistant derivatives of this strain could be increased from 3 to 6 or 7 fold relative to the parent, by stepwise sel ection using increasing MTX concentrations. B-gal overproduction was found to be un stable in all primary and highly -resistant isolates examined. There was no indication, h owever, of a decrease i n growth r a t e in MTX-res i s tant cells which overproduced B - gal.