This article describes the various imaginaries and practices that underlie the contemporary building boom in Phnom Penh, Cambodia. One such imaginary is of a city of absence. In part, this relates to a discourse of the city in ruin, the result of material-historical processes that destroyed Phnom Penh’s urban fabric and society in the 1970s. Yet idioms of ruin and absence have been markedly resilient in Phnom Penh; indeed, they were widely appropriated during the colonial and postcolonial eras to justify experiments in city-making and urban-planning interventions. The article thus aims to relate these older representations of absence to contemporary invocations of the city as tabula rasa — but an explicitly Asian one. Such representations, which organize perceptions of the city and govern the logics of its space, are key to current planning experiments that are seeking to remake it as the city of the future. With Phnom Penh an emerging space of circulation and a field of intervention, these efforts include a shift to building vertically, with highrise towers, in a town once acclaimed for its French provincial charm.

Abstract A unified strategy for enantioselective total synthesis of all stereoisomers of the [2+2] family of quadrigemine alkaloids is reported. In this approach, two enantioselective intramolecular Heck reactions are carried out at the same time on precursors fashioned in four steps from either meso- or (+)-chimonanthine to form the two critical quaternary carbons of the peripheral cyclotryptamine rings of these products. Useful levels of catalyst control are realized in either desymmetrizing a meso precursor or controlling diastereoselectivity in elaborating C2-symmetric intermediates. None of the synthetic quadrigemines are identical with alkaloids isolated previously and referred to as quadrigemines A and E. In addition, we report improvements in our previous total syntheses of (+)- or (-)-quadrigemine C that shortened the synthetic sequence to 10 steps and provided these products in 2.2% overall yield from tryptamine.

We report a measurement of e+e- pairs from semileptonic heavy-flavor decays in d+Au collisions at sNN=200 GeV. By exploring the mass and transverse-momentum dependence of the yield, the bottom decay contribution can be isolated from charm, and quantified by comparison to pythia and mc@nlo simulations. The resulting bb¯-production cross section is σbb¯dAu=1.37±0.28(stat)±0.46(syst) mb, which is equivalent to a nucleon-nucleon cross section of σbbNN=3.4±0.8(stat)±1.1(syst)μb.

The PHENIX collaboration presents first measurements of low-momentum (0.41  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.