Report on the Bombing of Our Own Troops during Operation “Tractable”: 14 August 1944

Editor’s Note: Operation “Tractable“ was the second major Canadian operation in Normandy designed to break through the German defensive perimeter to reach Falaise. Like its predecessor, Operation “Totalize,“ “Tractable“ was to employ heavy bombers to augment the firepower available to the troops. The use of heavy bombers in a tactical role was a relatively new tasking for the strategic force and required precise targetting to destroy and disrupt enemy positions. The strategic bomber force, British and American, had made significant contributions to the land battle in Normandy, but there had been mistakes, most notably during Operation “Cobra” when the American 8th Air Force had twice bombed their own troops on 24–25 July causing 136 deaths and an additional 621 casualties. For Operation “Tractable,” the medium bombers of 2 Group, 2nd Tactical Air Force were to bomb German gun, mortar and tank positions along the startline immediately prior to H-Hour. This was to be followed by a large attack by Bomber Command hours after the start of the advance. This bombing was intended “to destroy or neutralize enemy guns, harbours, and defended lacalities on the right flank and to prevent any enemy movement from this area to the area of attack.” (First Canadian Army Op Instruction No. 14, August 1944). Though the air support was largely a success, a number of aircraft mistakenly bombed short hitting units of First Canadian Army. In total, over 150 Allied soldiers were killed and 241 wounded by the short bombing. Though it had little impact on the outcome of “Tractable,” there were a number of investigations launched to understand why the short bombing occurred. The report which follows, dated 25 August 1944 and written by Air Chief Marshal Arthur Harris, Air Officer Commanding-in-Chief of Bomber Command, contains the official RAF post–mortem on the reasons for the accidental bombing of First Canadian Army

Narrative of Chain cruise #17, phase I : St. George, Bermuda, to Freetown, Sierra Leone, 19 February - 22 March 1961

The journal of a cruise of R/V CHAIN from Bermuda to Freetown, Sierra Leone during February and March, 1961, is the basis of this report. Location of observations are given. The portion of the Mid- Atlantic Ridge lying along the equator was surveyed from 10° to 19°W, and new information concerning the slope and orientation of rift zones was obtained. A detailed bathymetric survey of the Romanche Trench was made. A continuous temperature-depth profile, from the surface to 100 meters, was made along the ship 's track with a thermistor chain. Surface shear was measured with pitotmeters mounted on the chain (surface water velocity relative to the water velocity at the depth of the pitotmeter), to determine the strength and direction of the equatorial undercurrent.The Office of Naval Research under Contract Nonr-, 2196 (00

Turbomachinery technology for high-speed civil flight

NASA Lewis' research and technology efforts applicable to turbomachinery for high-speed flight are discussed. The potential benefits and cycle requirements for advanced variable cycle engines and the supersonic throughflow fan engine for a high-speed civil transport application are presented. The supersonic throughflow fan technology program is discussed. Technology efforts in the basic discipline areas addressing the severe operating conditions associated with high-speed flight turbomachinery are reviewed. Included are examples of work in internal fluid mechanics, high-temperature materials, structural analysis, instrumentation and controls

Moving an incisor across the midline: A treatment alternative in an adolescent patient

A 13-year-old sought treatment for a severely compromised maxillary left central incisor and an impacted fully developed left canine. Extraction of both teeth became necessary. As the key component of the revised comprehensive treatment plan, the right maxillary central incisor was moved into the position of the left central incisor. All other maxillary teeth were moved mesially to close any gaps. Active orthodontic treatment was completed after 34 months. Frenectomy, minor periodontal surgeries, and bonded lingual retainers were used to improve aesthetics and stabilize the tooth positions. The patient was pleased with the treatment outcome. Cone-beam computed tomography provided evidence that the tooth movement was accompanied by a deviation of the most anterior portion of the median palatine suture. This observation may make relapse more likely if long-term retention cannot be ensured. Root resorption was not observed as a consequence of the major tooth movement. (Am J Orthod Dentofacial Orthop 2011;139:533-43

Web archives: the future

T his report is structured first, to engage in some speculative thought about the possible futures of the web as an exercise in prom pting us to think about what we need to do now in order to make sure that we can reliably and fruitfully use archives of the w eb in the future. Next, we turn to considering the methods and tools being used to research the live web, as a pointer to the types of things that can be developed to help unde rstand the archived web. Then , we turn to a series of topics and questions that researchers want or may want to address using the archived web. In this final section, we i dentify some of the challenges individuals, organizations, and international bodies can target to increase our ability to explore these topi cs and answer these quest ions. We end the report with some conclusions based on what we have learned from this exercise

Factors Affecting Residential Property Development Patterns

The pattern of residential development within the context of metropolitan growth and development has been the subject of an extensive literature. Among the streams of literature have been monocentric and policentric models, rent gradients and population density, and spatial mismatch and jobs/housing balance. Less explored have been the factors determining the specific location of development from within a larger set of suitable locations. This paper uses a disaggregated data set, county property appraiser data, to track the number of new single-family housing units built in each section (square mile) of Alachua County, Florida by the year built over a twenty- year period. The paper explores the role of transportation, large-scale development, employment nodes, existing patterns of development, and regulation on the spatial pattern of development. As discussions turn to smart growth, compact development, and the alleviation of sprawl, it is important to understand the forces that contribute to observed development patterns.

How does insect resistance to phosphine affect insect control costs of stored-grain?

Crop Production/Industries,