Catalogue d'une... collection de tableaux... du cabinet de feu M. Boulanger... Vente 8 janv. 1827,...

[Vente (Art). 1827-01-08. Paris]

Conferencia de competitividad Doctor Michael Porter

Gestión del conocimiento

Dr. Michael Hornyansky

Professor of English Language and Literatre, Michael Hornyansky, in 1989. Dr. Hornyansky was one of the original Brock faculty members.

Dr. Michael Hornyansky

Professor of English Language and Literatre, Michael Hornyansky, in 1989. Dr. Hornyansky was one of the original Brock faculty members.

Michael Hornyansky

Michael Hornyansky was head of the Department of English at Brock and was one of the first 7 faculty members.

Ecological interactions between zooplankton and photosynthetic bacteria in Crawford Lake, Ontario

The present study was carried out to test the hypothesis that photosynthetic bacteria contribute a large portion of the food of filter feeding zooplankton populations in Crawford Lake, Ontario. The temporal and spatial variations of both groups of organisms are strongly dependent on one another. 14 By using C-Iabelled photosynthetic bacteria. the ingestion and clearance rates of Daphnia pulex, ~. rosea, and Keratella spp were estimated during summer and fall of 1982. These quantitative estimations of zooplankton ingestion and clearence rates on photosynthetic bacteria comprised an original addition to the literature. Photosynthetic bacteria comprised a substantial portion of the diet of all four dominant zooplankton species. The evidence for this is based on the ingestion and clearance rates of the dominant zooplankton species. Ingestion rates of D. pulex and D. rosea ranged 5 5 -1 -1 - -- 5 - -- 5 from 8.3X10 -1 to 14.6XlO -1 cells.ind. hr and 8.1X10 to 13.9X10 cells.ind. hr • Their clearance rates ranged from 0.400 to 1.000 -1 -1 -1 -1 ml.ind. hr. and 0.380 to 0.930 ml.ind. hr • The ingestion and clearance -1 -1 -1 -1 rates of Keratella spp were 600 cell.ind. hr and 0.40 ul.ind. hr respectively. Clearance rates were inversely proportional to the concentration of food cells and directly proportional to the body size of the animals. It is believed that despite the very short reg~neration times of photosynthetic bacteria (3-8 hours) their population densities were controlled in part by the feeding rates of the dominant zooplankton in Crawford Lake. By considering the regeneration times of photosynthetic bacteria and the population clearance rates of zooplankton, it was estimated that between 16 to 52% and 11 to 35% of the PHotosynthetic bacteria were' consumed· by Daphnia· pulex. and Q.. rosea per day. The temporal and spatial distribution of Daphnia pulex, !.. rosea, Keratella quadrata, K. coChlearis and photosynthetic bacteria in Crawford Lake were also investigated during the period of October, 1981 to December, 1982. The photosynthetic bacteria in the lake, constituted a major food source for only those zooplankton Which tolerate anaerobic conditions. Changes in temperature and food appeared to correlate with the seasonal changes in zooplankton density. All four dominant species of zooplankton were abundant at the lake's surface (O-4m) during winter and spring and moved downwards with the thermocline as summer stratification proceeded. Photosynthetic bacteria formed a 2 m thick layer at the chemocline. The position of this photosynthetic bacterial J-ayer changed seasonally. In the summer, the bacterial plate moved upwards and following fall mixing it moved downwards. A vertical shift of O.8m (14.5 to 15.3m) was recorded during the period of June to December. The upper limit of the photosynthetic bacteria in the water column was controlled by dissolved oxygen, and sulfide concentrations While their lower limit was controlled by light intensity. A maximum bacterio- 1 chlorophyll concentration of 81 mg Bchl.l was recorded on August 9, 1981. The seasonal distribution of photosynthetic bacteria was controlledinpart' by ·theg.-"z1ai'_.Q;~.zoopl. ank:tCm;-.Qther -ciactors associated with zooplankton grazing were oxygen and sulfide concentrations.

Paleoindicators of meromixis

This study was undertaken to ascertain whether meromictic lakes could be differentiated from holomictic lakes on the basis of their surficial profundal sediments. Surface sediment cores (15 cm long) were collected from both the littoral and profundal zones of four meromictic and six holomictic lakes and analyzed for total number of fossil chironomid headcapsu~es, chlorophyll and carotenoid degradation products as well as \ iron and manganese concentrations. Littoral and profundal comparisons of the surface sediments were made between the two lake types using the Mann-Whitney U test. Iron, manganese and the iron to manganese ratio in the littoral sediments of meromictic lakes were significantly lower than those found in the littoral sediments of holomictic lakes. The observed differences are believed to represent an artifact of the significantly higher carbonate concentrations found in three of the four meromictic lakes studied. Profundal and littoral to profundal ratio comparison between holomictic and meromictic lakes suggest that the significantly lower iron and higher carotenoid concentrations in meromictic profundal sediments were a con~equence of meromixis. However, the overlap in distribution exhibited by both iron and carotenoid degradation products between the two lake types was sufficiently large in this study to nullify their use as a means of differentiating meromictic from holomictic lakes. A long core (4.25 m) was removed from the deepest part of the meromictic Crawford Lake (Ontario), sectioned at 5 cm intervals, and analyzed to assess when meromixis occurred, based on its fossil record. Temporal changes in the total number of chironomid headcapsules, and chlorophyll and carotenoid sediment degradation products were closely correlated with organic matter, indicating in my opinion that extensive redeposition of littoral chironomid headcapsules in the profundal zone has occurred. Temporal variations in carotenoid degradation products, in response to changes in organic matter, obscured increased preservation that may have occurred as a consequence of meromixis. Temporal variations in iron and manganese suggest that relatively stable redox conditions have existed throughout most of the lake's history. Therefore it would appear that Crawford Lake has been meromictic since its inception.

Bowslaugh Family fonds, 1860-1861, 1868, 1876-1877, 1880-1882, 1886-1890, 1892-1893, 1895, 1898-1899, n.d.

Edward W. Bowslaugh (1843-1923) was the son of Jacob and Anna (Beamer) Bowslaugh. Edward Bowslaugh married Mary Southward, and the couple had six children, Edgar Morley, Edward Freeman, twins Alfred Malcolm and Alice Mary, Annie Olivia, John Jacob and Mabel Florence. Edward W. Bowslaugh was a farmer, contractor and owner of the Grimsby Planing Mills in Grimsby, Ont. and Bowslaugh’s Planing Mill in Kingsville, Ont. The mills manufactured door and sash trim and other wood related products. Some customers contracted the firm to provide wood products for cottages being built at Grimsby Park, the Methodist camp ground. Some time before 1885 Edward Bowslaugh and his family moved to Kingsville, Ont. to open up a new planing mill and door and sash manufactory. He later sold the Grimsby Planing Mills to Daniel Marsh. The diaries and account books include many names of workers as well as friends and family members residing in the Grimsby and Kingsville areas. James M. Bowslaugh (1841-1882) was the son of Jacob and Anna (Beamer) Bowslaugh. James married first Anna Catharine Merritt and after her death in 1875 he married Mary Gee in 1877. James and Anna had three children, Eliza, James Herbert, George Hiram, all died very young. James and Mary Gee had one son, Charles Leopold Kenneth Frederich Bowslaugh, b. 1881. James Bowslaugh was a farmer and lumberman, much like his younger brother Edward. James’ early diaries often note the activities of himself and his brother Edward. Both Edward and James were heavily involved in the Methodist church, teaching or leading Sunday school and attending prayer meetings. Alfred M. Bowslaugh b. 1873 was the son of Edward W. Bowslaugh and his wife Mary Southward. The school notebook is from his days as a student in Kingsville, Ont.

Copies of two dispatches upon the subject of the Welland Canal, 1827-1828

The material is a printed record of two dispatches sent by Sir Peregrine Maitland, Lieutenant Governor of Upper Canada to secretary of state for the colonies, the first in 1827 to Earl Bathurst, the second in 1828 to Right Hon. W. Huskisson. The dispatches concern funding for the canal as well as an introduction of William Hamilton Merritt as managing agent of the Welland Canal Company. It was the intention of the Welland Canal Company to send Mr. Merritt to England to gain further assistance from the government and private investors.