Computer used to program numerically controlled milling machine

Computer program automatically directs a numerically controlled milling machine through a series of cutting and trimming actions. It accepts engineering data points, passes smooth curve segments through the points, breaks the resulting curves into a series of closely spaced points, and transforms these points into the form required by the mechanism

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

Muskrats on tidal marshes of Dorchester County

This bulletin reports, in a non-technical manner, investigations on the Virginia muskrat, prevalent in Maryland, from July, 1949 to June, 1951

”I Speak Hip Hop”: An Informative Interview about Generation Hip Hop and the Universal Hip Hop Museum

”I Speak Hip Hop” is an interview of members of Generation Hip Hop and the Universal Hip Hop Museum. This primary source highlights two Hip Hop organizations with chapters around the world. Tasha Iglesias and Travis Harris posits that Hip Hop scholars have not fully uncovered Hip Hop\u27s history around the world. As such, in addition to being a primary source, I Speak Hip Hop reveals the need for more scholarly attention on the dynamic expansion of Hip Hop cultures

Introduction: Ain’t It Evil to Live Backwards? : A Hip Hop Perspective of Religion

Historically, Black religion has been the cornerstone of the African experience in America. Due to the peculiar institution” of slavery and the ways this institutional residue still affect the lives of slave descendants, Hip Hop provides a forum to simultaneously acknowledge similarities and highlight differences. What scholars of religion and Hip Hop studies have revealed are the ways in which the effectiveness and our very understanding of “religion” changes when we bring Hip Hop in to the mix

Demographic fluctuations in a population of anomalously diffusing individuals

The phenomenon of spatial clustering induced by death and reproduction in a population of anomalously diffusing individuals is studied analytically. The possibility of social behaviors affecting the migration strategies has been taken into exam, in the case anomalous diffusion is produced by means of a continuous time random walk (CTRW). In the case of independently diffusing individuals, the dynamics appears to coincide with that of (dying and reproducing) Brownian walkers. In the strongly social case, the dynamics coincides with that of non-migrating individuals. In both limits, the growth rate of the fluctuations becomes independent of the Hurst exponent of the CTRW. The social behaviors that arise when transport in a population is induced by a spatial distribution of random traps, have been analyzed.Comment: 10 pages, 6 figure

Look right! A retrospective study of pedestrian accidents involving overseas visitors to London

Introduction: Research within the European Union has shown international visitors to have a higher injury mortality than residents. Traffic accidents are the leading cause of injury-related death among overseas visitors and evidence suggests overseas visitors are at a greater risk of being involved in road traffic accidents than the resident population. Little information looks specifically at pedestrian injuries to overseas visitors. Pedestrian deaths account for 21% of all UK road deaths. Methods: A retrospective database review of London helicopter emergency medical service (HEMS) missions was undertaken to examine the number and type of missions to overseas visitors, specifically examining pedestrian incidents. Results: Of 121 missions to overseas visitors, 74 (61%) involved the visitor as a pedestrian struck by a vehicle. Thirty-five pedestrians (47%) were struck by a bus and 20 by a car (27%). Fourteen patients (19%) had an initial Glasgow coma scale score of 3–8, suggesting severe head injury and half of all patients required prehospital intubation (38/74, 51%). Mortality was 16% (12/74%) and 62 patients (84%) survived to hospital discharge. Of 39 patients admitted to the Royal London Hospital, the average injury severity score (ISS%) was 23.0 (ISS >15 denotes severe trauma) with a mean inpatient stay of 17.9 days. Conclusion: During the 7-year period studied, 61% of HEMS missions to overseas visitors involved a pedestrian being struck by a vehicle, compared with 16% of missions to UK residents. For HEMS missions, serious trauma to pedestrians is disproportionally more common among the visitor population to London

Ab initio quantum dynamics using coupled-cluster

The curse of dimensionality (COD) limits the current state-of-the-art {\it ab initio} propagation methods for non-relativistic quantum mechanics to relatively few particles. For stationary structure calculations, the coupled-cluster (CC) method overcomes the COD in the sense that the method scales polynomially with the number of particles while still being size-consistent and extensive. We generalize the CC method to the time domain while allowing the single-particle functions to vary in an adaptive fashion as well, thereby creating a highly flexible, polynomially scaling approximation to the time-dependent Schr\"odinger equation. The method inherits size-consistency and extensivity from the CC method. The method is dubbed orbital-adaptive time-dependent coupled-cluster (OATDCC), and is a hierarchy of approximations to the now standard multi-configurational time-dependent Hartree method for fermions. A numerical experiment is also given.Comment: 5 figure

Fourier's law on a one-dimensional optical random lattice

We study the transport properties of a one-dimensional hard-core bosonic lattice gas coupled to two particle reservoirs at different chemical potentials which generate a current flow through the system. In particular, the influence of random fluctuations of the underlying lattice on the stationary-state properties is investigated. We show analytically that the steady-state density presents a linear profile. The local steady-state current obeys the Fourier law $j=-\kappa(\tau)\nabla n$ where $\tau$ is a typical timescale of the lattice fluctuations and $\nabla n$ the density gradient imposed by the reservoirs.Comment: 9 pages, 2 figure

If I Ruled the World: Putting Hip Hop on the Atlas

“If I Ruled the World: Putting Hip Hop on the Atlas” contends for a third wave of Global Hip Hop Studies that builds on the work of the first two waves, identifies Hip Hop as an African diasporic phenomenon, and aligns with Hip Hop where there are no boundaries between Hip Hop inside and outside of the United States. Joanna Daguirane Da Sylva adds to the cipha with her examination of Didier Awadi. Da Sylva\u27s excellent work reveals the ways in which Hip Hoppa Didier Awadi elevates Pan-Africanism and uses Hip Hop as a tool to decolonize the minds of African peoples. The interview by Tasha Iglesias and myself of members of Generation Hip Hop and the Universal Hip Hop Museum provides a primary source and highlights two Hip Hop organizations with chapters around the world. Mich Yonah Nyawalo’s Negotiating French Muslim Identities through Hip Hop details Hip Hop artists Médine and Diam’s, who are both French and Muslim, and whose self-identification can be understood as political strategies in response to the French Republic’s marginalization of Muslims. In “Configurations of Space and Identity in Hip Hop: Performing ’Global South’,” Igor Johannsen adds to this special issue an examination of the spatiality of the Global South and how Hip Hoppas in the Global South oppose global hegemony. The final essay, “‘I Got the Mics On, My People Speak’: On the Rise of Aboriginal Australian Hip Hop,” by Benjamin Kelly and Rhyan Clapham, provides a thorough analysis of Aboriginal Hip Hop and situates it within postcolonialism. Overall, the collection of these essays points to the multiple identities, political economies, cultures, and scholarly fields and disciplines that Hip Hop interacts with around the world