The Attack on the Church in St. Martin-de-Fontenay: 31 July–1 August 1944

Editor’s Note: General J.A. Dextraze, “J Dex“ to Canada’s post–war army, served as Chief of the Defence Staff from 1972 to 1975 but in 1944 he was a 24–year–old company commander in Les Fusiliers de Mont-Royal (FMR). This account of the action carried out by his company on 1 August 1944 offers a graphic description of the challenges confronting the Canadians during the battles for Verrières Ridge. This attack was conducted in the context of Montgomery’s orders to “keep up the pressure on the Caen area... to make easier the task of the American armies fighting hard on the western flank.“ (27 July 1944) The church at St. Martin–de–Fontenay had been seized by the enemy in the aftermath of Operation “Spring,“ 25 July 1944. The FMR successes on 31 July allowed 2nd Division to begin the advance of 8/9 August, Operation “Totalize,“ from a secure startline. Though written in the first person, this report was drafted by Captain Joe Engler, the historical officer assigned to 2nd Canadian Infantry Division. It was his job to collect important documents and records, as well as to conduct interviews with the fighting soldiers which would allow later historical narratives to be accurately written. Engler had the dubious distinction of being the only historical officer to be killed in action when he drove into an ambush on 1 October 1944

“A” Company on Attack on Troteval Farm by the Fusiliers Mont-Royal on 24 July 1944

General J.A. Dextraze, “J Dex” to Canada’s post-war army, served as Chief of the Defence Staff from 1972 to 1975 but in 1944 he was a 24-year-old company commander in Les Fusiliers de Mont-Royal (FMR). This account of the action carried out by his company of 24 July 1944 offers a graphic description of the challenges confronting the Canadians during the battles for Normandy. This attack was conducted to clear the start line for Operation Spring which would commence that next day. Though written in the first person, this report was drafted by Captain Joe Engler, the historical officer assigned to 2nd Canadian Infantry Division. It was his job to collect important documents and records, as well as to conduct interviews with the fighting soldiers, which would allow later historical narratives to be accurately written. Engler had the dubious distinction of being the only historical officer to be killed in action when he drove into an ambush on 1 October 1944

Étude d'un procédé de fraisage immergé applicable à une fraiseuse submersible et portable.

RÉSUMÉ L'institut de recherche d'Hydro-Quebec s'efforce de développer une fraiseuse portable et submersible dans le but de réaliser, en milieu submergé, des réparations sur des composantes de barrages hydro-électriques. Comme le fraisage en milieu immergée est très peu documenté, il a été nécessaire de réaliser des essais dans le but d'analyser le procédé à l'état immergé et de le comparer à du fraisage à sec. Les expérimentations ont porté sur l'étude de la vitesse et du mode d'usure des outils de coupe constitués de pastilles de carbures, sur la puissance requise par la broche et sur les propriétés des finis de surface obtenues lors de l'usinage d'acier ANSI1020. Lors des essais, nous avons constaté que : - L'usinage sous l'eau génère une usure des outils beaucoup plus rapide en réduisant la durée de vie des pastilles de 91%. - Il existe une très bonne corrélation entre la puissance de coupe et le niveau d'usure des outils. Cette information permet de connaître l'état d'endommagement des outils de coupe sans avoir besoin de directement les mesurer. - Le milieu de coupe influence la puissance requise à la broche. Une plus grande puissance est nécessaire lors de l'usinage sous l'eau, et ce, même en faisant abstraction de la puissance dissipée dans le fluide due à la rotation de l'outil. - Le milieu de coupe ne semble pas affecter la rugosité du fini de surface (Ra). - Les finis de surface usinés à sec montrent un profil beaucoup plus périodique que ceux usinés dans l'eau. - Les paramètres des finis de surface (kurtosis et skewness) sont très constants à sec tandis qu'ils varient en fonction des paramètres de coupe sous l'eau. À basse puissance de coupe, les surfaces usinées immergées ont des paramètres forts différents des surfaces usinées à sec. Par contre, cette différence disparaît à plus haute puissance de coupe.----------ABSTRACT Research Institute of Hydro-Quebec strives to develop a portable submersible milling machine in order to carry out, repairs on components of hydroelectric dams in submerged environments. As milling in submerged environments is very poorly documented, it was necessary to perform tests in order to analyze the process when immersed and compare it to dry milling. The experiments were carried on the rate and type cutting tools wear, on the required power by the spindle and on the surface finish properties while milling ANSI1020 steel. During testing, we found that: - Underwater milling greatly increase tool wear by reducing insert life by 91%. - There is a very good correlation between the cutting power and the level of tool wear. This information helps to know the state of damage on cutting tools without having to directly measure it. - The environment in influences the cutting power needed on spindle. More power is required when machining under water, even disregarding the power dissipated in the fluid due to tool rotation. - The milling environment does not seem to aaffect roughness (Ra) of surface finish. - The dry milled surfaces show a finish much more periodic than under water milled surfaces. - The surface finish parameters (skewness and kurtosis) are very consistent dry as they vary depending on cutting parameters under water. At high cutting power, these parameters on dry milled surfaces and under water milled surfaces are similar but quite different at lower cutting power

Radiosensibilisation de l'ADN par le 5-bromodéoxyuridine : l'importance de la structure et de la séquence de l'ADN

Les dimères interbrins sont des lésions de type complexe, où les deux brins d'ADN sont pontés de façon covalente. Par conséquent, ce type de lésion est très toxique pour la cellule, car il nuit à la séparation des brins d'ADN nécessaire à des processus cruciaux pour la cellule, comme la réplication et la transcription. De plus, des expériences récentes montrent que la réparation des dimères interbrins passe par la formation d'un bris double brin, une autre lésion avec un potentiel toxique élevé. Ce n'est que tout récemment qu'on a montré que la radiation ionisante menait à la formation de dimères interbrins dans l'ADN cellulaire. On en sait donc encore très peu sur les conditions dans lesquelles se produisent les dimères et comment ils sont réparés. Récemment, à la suite d'une exposition aux radiations ionisantes, notre groupe a mis en évidence la formation de dimères interbrins dans un ADN où une thymidine avait été remplacée par le 5-bromo-2'-désoxyuridine (BrdU). Ces dimères n'étaient formés que lorsque le BrdU se trouvait au centre d'une zone mésappariée. Puisque c'était la première fois que ce type de dommage était observé lors d'une exposition de l'ADN bromé à la radiation ionisante, ma thèse a porté sur l'exploration de la formation du dimère interbrin, particulièrement sur les conditions qui favorisaient sa formation.Les trois articles présentés dans cette thèse montrent que la forme de l'ADN (forme A vs forme B), la séquence, ainsi que le type de radiation employé ont une influence importante sur le type et la fréquence du dommage produit. Ces résultats montrent qu'on en sait encore très peu sur le mécanisme réel de radiosensibilisation de l'ADN bromé dans les cellules. Cependant, ils mettent aussi en évidence la réactivité distincte des régions rnésappariées de l'ADN, ainsi que leur fort potentiel pour la formation de dimères. Or, ces régions mésappariées ne représentent qu'une fraction des structures secondaires et tertiaires de l'ADN présentes dans la cellule

Renal Cryoablation: Investigation of Periprocedural Visualization Tools and Treatment Response Quantification

Cryoablation for small renal tumors has demonstrated sufficient clinical efficacy over the past decade as a non-surgical nephron-sparing approach for treating renal masses for patients who are not surgical candidates. Minimally invasive percutaneous cryoablations have been performed with image guidance from CT, ultrasound, and MRI. During the MRI-guided cryoablation procedure, the interventional radiologist visually compares the iceball size on monitoring images with respect to the original tumor on separate planning images. The comparisons made during the monitoring step are time consuming, inefficient and sometimes lack the precision needed for decision making, requiring the radiologist to make further changes later in the procedure. This study sought to mitigate uncertainty in these visual comparisons by quantifying tissue response to cryoablation and providing visualization of the response during the procedure. Based on retrospective analysis of MR-guided cryoablation patient data, registration and segmentation algorithms were investigated and implemented for periprocedural visualization to deliver iceball position/size with respect to planning images registered within 3.3mm with at least 70% overlap and a quantitative logit model was developed to relate perfusion deficit in renal parenchyma visualized in verification images as a result of iceball size visualized in monitoring images. Through retrospective study of 20 patient cases, the relationship between likelihood of perfusion loss in renal parenchyma and distance within iceball was quantified and iteratively fit to a logit curve. Using the parameters from the logit fit, the margin for 95% perfusion loss likelihood was found to be 4.28 mm within the iceball. The observed margin corresponds well with the clinically accepted margin of 3-5mm within the iceball. In order to display the iceball position and perfusion loss likelihood to the radiologist, algorithms were implemented to create a fast segmentation and registration module which executed in under 2 minutes, within the clinically-relevant 3 minute monitoring period. Using 16 patient cases, the average Hausdorff distance was reduced from 10.1mm to 3.21 mm with average DSC increased from 46.6% to 82.6% before and after registration

Increased chromosomal radiosensitivity in asymptomatic carriers of a heterozygous BRCA1 mutation

Background: Breast cancer risk increases drastically in individuals carrying a germline BRCA1 mutation. The exposure to ionizing radiation for diagnostic or therapeutic purposes of BRCA1 mutation carriers is counterintuitive, since BRCA1 is active in the DNA damage response pathway. The aim of this study was to investigate whether healthy BRCA1 mutations carriers demonstrate an increased radiosensitivity compared with healthy individuals. Methods: We defined a novel radiosensitivity indicator (RIND) based on two endpoints measured by the G2 micronucleus assay, reflecting defects in DNA repair and G2 arrest capacity after exposure to doses of 2 or 4 Gy. We investigated if a correlation between the RIND score and nonsense-mediated decay (NMD) could be established. Results: We found significantly increased radiosensitivity in the cohort of healthy BRCA1 mutation carriers compared with healthy controls. In addition, our analysis showed a significantly different distribution over the RIND scores (p = 0.034, Fisher’s exact test) for healthy BRCA1 mutation carriers compared with non-carriers: 72 % of mutation carriers showed a radiosensitive phenotype (RIND score 1–4), whereas 72 % of the healthy volunteers showed no radiosensitivity (RIND score 0). Furthermore, 28 % of BRCA1 mutation carriers had a RIND score of 3 or 4 (not observed in control subjects). The radiosensitive phenotype was similar for relatives within several families, but not for unrelated individuals carrying the same mutation. The median RIND score was higher in patients with a mutation leading to a premature termination codon (PTC) located in the central part of the gene than in patients with a germline mutation in the 5′ end of the gene. Conclusions: We show that BRCA1 mutations are associated with a radiosensitive phenotype related to a compromised DNA repair and G2 arrest capacity after exposure to either 2 or 4 Gy. Our study confirms that haploinsufficiency is the mechanism involved in radiosensitivity in patients with a PTC allele, but it suggests that further research is needed to evaluate alternative mechanisms for mutations not subjected to NMD

Monitoring the reversible B to A-like transition of DNA in eukaryotic cells using Fourier transform infrared spectroscopy

The ability to detect DNA conformation in eukaryotic cells is of paramount importance in understanding how some cells retain functionality in response to environmental stress. It is anticipated that the B to A transition might play a role in resistance to DNA damage such as heat, desiccation and toxic damage. To this end, conformational detail about the molecular structure of DNA has been derived primarily from in vitro experiments on extracted or synthetic DNA. Here, we report that a B- to A-like DNA conformational change can occur in the nuclei of intact cells in response to dehydration. This transition is reversible upon rehydration in air-dried cells. By systematically monitoring the dehydration and rehydration of single and double-stranded DNA, RNA, extracted nuclei and three types of eukaryotic cells including chicken erythrocytes, mammalian lymphocytes and cancerous rodent fibroblasts using Fourier transform infrared (FTIR) spectroscopy, we unequivocally assign the important DNA conformation marker bands within these cells. We also demonstrate that by applying FTIR spectroscopy to hydrated samples, the DNA bands become sharper and more intense. This is anticipated to provide a methodology enabling differentiation of cancerous from non-cancerous cells based on the increased DNA content inherent to dysplastic and neoplastic tissue

Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94846/1/palo900.pd