DNA polymerase activity in trophoblast giant cells in the mouse /

In the developing mouse embryo, the diploid trophectoderm is known to undergo a diploid to giant cell transformation. These cells arise by a process of endoreduplication, characterized by replication of the entire genome without subsequent mitosis or cell division, leading to polyploidy and the formation of giant nuclei. Studies of 13.5 day rat trophoblast derived from the parietal yolk sac have indicated a relatively low rate of DNA polymerase a activity, the noinnal eukaryotic replicase, in comparison to that of DNA polymerase g. These results have suggested that endoreduplication in trophoblast giant cells may not employ the normal replicase enzyme, DNA polymerase a. In order to determine whether a 'switch' from DNA polymerase to DNA polymerase is a necessary concomitant of the diploid to giant cell transformation, two distinct populations of trophoblast giant cells, the primary giant cell derived from the mural trophectoderm and the secondary giant cell derived from the polar trophoectoderm were used. These two populations of trophoblast giant cells can be obtained from the tissue outgrowths of 3.5da blastocysts and the extraembryonic ectoderm (EX) and ectoplacental cone (EPC) of 7.5 day embryos respectively. Tissue outgrowths were treated with aphidicolin, a specific reversible inhibitor of eukaryotic DNA polymerase a, on various days after explantation. The effect of aphidicolin treatment was assessed both qualitatively, using autoradiography and quantitatively by scintillation counting and Feulgen staining. 3 DNA synthesis was measured in control and treated cultures after a Hthymidine pulse. Scintillation counts of the embryo proper revealed that DNA synthesis was consistently inhibited by greater than 907. in the presence of aphidicolin. Inhibition of DNA synthesis in the EX and EPC varied between 81-957. and 82-987. respectively, indicating that most DNA synthesis was mediated by DNA polymerase a, but that a small but significant amount of residual synthesis was indicated. A qualitative approach was then applied to determine whether the apparent residual DNA synthesis was restricted to a subpopulation of giant cells or whether all giant cells displayed a low level of DNA synthesis. Autoradiographs of the ICM of blastocysts and the embryo proper of 7.5da embryos, which acted as diploid control population, was completely inhibited regardless of duration in explant culture. In contrast, primary trophoblast giant cells derived from blastocysts and secondary giant cells derived from the EX and EPC were observed to possess some heavily labelled cells after aphidicolin treatment. These results suggest that although DNA polymerase a is the primary replicating enzyme responsible for endoreduplication in mouse trophoblast giant cells, some nonactivity is also observed. A DNA polymerase assay employing tissue lysates of outgrown 7.5da embryo, EX and EPC tissues was used to attempt to confirm the presence of higher nonactivity in tissues possessing trophoblast giant cells. Employing a series of inhibitors of DNA polymerases, it would appear that DNA polymerase a is the major polymerase active in all tissues of the 7.5da mouse embryo. The nature of the putative residual DNA synthetic activity could not be unequivically determined in this study. Therefore, these results suggest that both primary and secondary trophoblast giant cells possess and use DNA polymerase a in endoreduplicative DNA synthesis. It would appear that the high levels of DNA polymerase g activity reported in trophoblast tissue derived from the 13.5 da rat yolk sac was not a general feature of all endoreduplication.

Colonel John Butler (Niagara)/St. Catharines District Branch of the United Empire Loyalists fonds

United Empire Loyalist is an honour given to American Loyalists who came to British North America and the British Colonies to show their loyalty to King George III after the British defeat in the American Revolution. The Loyalists settled in Quebec, Ontario, Nova Scotia and modern day New Brunswick. The Colonel John Butler (Niagara) Branch (formerly the St. Catharines and District Branch) has origins which date as far back as 1898. A branch was organized in Virgil by Captain John D. Servos, but was unsuccessful. In 1905 there was another attempt to form a branch, but the war of 1914-1918 resulted in this branch becoming inactive. In 1914, an Act of Parliament incorporated the United Empire Loyalists’ Association of Canada. The St. Catharines and District Branch was formed in 1921. This branch remained active, and in 1992 they changed their name to The Colonel John Butler (Niagara) Branch. The Loyalists also have a strong focus on genealogy. All descendants are eligible to use UE (which stands for Unity of the Empire) after their names. source: http://www.coljohnbutleruel.com

Retired Women Teachers of Ontario—St. Catharines branch fonds, 1970-2013.

The Retired Women Teachers of Ontario (RWTO) was founded in Toronto by a small group of retired women teachers known as the Rendezvous Club. This group brought together several branches in 1956 to form the Ontario Association of Superannuated Teachers (OAWST), which was changed to the RWTO in 1999. The group was initially formed in order to provide retired women teachers with the same pension that was received by their male colleagues. The group came to the realization that they would have a better chance of success if they had a larger group of supporters. As a result, new branches were formed throughout Ontario. In 1967, the government concurred that the pension should be raised, and the minimum pension level was increased to $1200 a year. The following year the Retired Teachers of Ontario was formed, representing both male and female retired teachers. This new group was now responsible for communicating and negotiating with the government concerning pension matters. However, the RWTO continued to exist with a focus on the special interests and well-being of retired women teachers. There are currently 53 branches throughout Ontario.

Wrestling Card - Cardiff Giant

The wrestler's name is Cardiff Giant and the number stamped on the reverse is 649.

Preparing Students with ASD for Inclusive Classrooms: A Case Study of Giant Steps

Giant Steps is a therapeutic school for children with Autism Spectrum Disorder (ASD) founded in 1995 by a group of parents who felt that the public school system was not fully able to meet the needs of their children. While the education system has progressed through the years to offer all students with access to public education, many educators still are not adequately prepared to provide inclusive learning environments for students with ASD. Given the prevalence of ASD in southern Ontario (1 in every 42 boys and 1 in every 189 girls), research on ASD and inclusive practices is both vital and timely. The purpose of this qualitative case study is to understand how the Giant Steps program prepares and transitions students with ASD for inclusive classrooms. Data was collected through two rounds of in-depth interviews, and was subsequently analyzed and interpreted into research findings that are presented through three major themes (i.e., unique program aspects, holistic approach, inclusion not integration). Collectively, the themes provide insights about how students at Giant Steps are prepared for inclusion, as well as how different stakeholders within the Giant Steps program perceive inclusion and their role in preparing students for inclusive classrooms.

Memoranda booklet (soft cover) compliments of the Canadian Bank of Commerce, St. Catharines Branch

Memoranda booklet (soft cover) compliments of the Canadian Bank of Commerce, St. Catharines Branch. Only one page has writing on it. It appears to be a shopping list, n.d.

Certificate from the Accounts Branch of Crown Lands, Ontario

Certificate from the Accounts Branch of Crown Lands, Ontario in receipt of $72 for renewal of license made out to S.D. Woodruff and signed by Thomas H. Johnson, Assistant Commissioner, May 23, 1881.

List (4 pages, handwritten) of titles on the Sarnia Branch subject to mortgages

List (4 pages, handwritten) of titles on the Sarnia Branch subject to mortgages, n.d.

List (1 page, handwritten) of Sarnia Branch for which no abstract of the title has been furnished

List (1 page, handwritten) of Sarnia Branch for which no abstract of the title has been furnished. This was signed by H. [illegible] in 1839 and a note was added to this list on Nov. 15, 1859.

List (1 page, handwritten) of taxes paid for lands on the Sarnia Branch

List (1 page, handwritten) of taxes paid for lands on the Sarnia Branch, n.d.