Publications

Abstract Fluorinated anilines are obtained by coupling of aryl halides with primary and secondary fluoroalkylamines using PhOK as weaker base, which is rarely used in cross‐coupling reactions to form C—N bonds.

We study exploration in stochastic multi-armed bandits when we have access to a divisible resource that can be allocated in varying amounts to arm pulls. We focus in particular on the allocation of distributed computing resources, where we may obtain results faster by allocating more resources per pull, but might have reduced throughput due to nonlinear scaling. For example, in simulation-based scientific studies, an expensive simulation can be sped up by running it on multiple cores. This speed-up however, is partly offset by the communication among cores, which results in lower throughput than if fewer cores were allocated per trial to run more trials in parallel. In this paper, we explore these trade-offs in two settings. First, in a fixed confidence setting, we need to find the best arm with a given target success probability as quickly as possible. We propose an algorithm which trades off between information accumulation and throughput and show that the time taken can be upper bounded by the solution of a dynamic program whose inputs are the gaps between the sub-optimal and optimal arms. We also prove a matching hardness result. Second, we present an algorithm for a fixed deadline setting, where we are given a time deadline and need to maximize the probability of finding the best arm. We corroborate our theoretical insights with simulation experiments that show that the algorithms consistently match or outperform baseline algorithms on a variety of problem instances.

The coordination of divalent metal cations to ZSM-5 has been investigated using gradient-corrected density functional theory (DFT). Coordination at both isolated charge-exchange sites and pairs of charge-exchange sites was considered for Co2+, Cu2+, Fe2+, Ni2+, Pd2+, Pt2+, Ru2+, Rh2+, and Zn2+. Thermodynamic calculations of the stability of M2+ to reduction to M0 and demetalation to form MOx particles were also carried out. The results indicate that Cu2+, Co2+, Fe2+, and Ni2+ are coordinated preferentially to five-membered rings containing two Al atoms, which are located on the walls of the sinusoidal channels, whereas Pd2+, Pt2+, Ru2+, Rh2+, and Zn2+ are coordinated preferentially to six-membered rings located on the walls of the sinusoidal channels. Examination of the stability of dimer cations of the form [M-O-M]2+ shows that such structures are not generally stable to hydrolysis, with the possible exception of [Cu-O-Cu]2+. The findings of these calculations are in good general agreement with experimental results.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Dr Friedman offers some interesting neurobiologic speculations regarding some of the findings in our recently published study¹and suggests potential links to particular neurobehavioral systems. Specifically, the possibility of monitoring speech hesitation and switching pauses may represent an intriguing approach to examine a potential mechanism (at a level of specific neurochemical alteration). Further, some of the neurobehavioral systems described are a focus of interest within one of the research programs conducted at the University of Pittsburgh, Pa, actively investigating serotonergically mediated inhibition of dopamine in a study examining prolactin response to a serotonergic agonist in depressed children and normal controls.^2,3We are also exploring the possibility that some sleep and mood changes relevant to affective disorders may be mediated by changes in frontal-striatal activation, as reflected by electroencephalographic frontal activity asymmetries.^4,5However, it appears less clear to our interpretation whether the increased right frontal activity is a

At the intersection of telerobotics, computer networking and human social interaction we have chosen to explore an area we identify as personal tele-embodiment. At the core of this research is an emphasis on the individual person rather than the intricate complexities of the machine. While the mechanical elements of our system are essential to its over-all functionality, our research is driven solely by the study and understanding of the social and psychological aspects of extended human-human interactions rather than the latest techno-gadgetry. In this paper we emphasize the importance of the human component and describe the development of one such simple, inexpensive, Internet-controlled, untethered telerobot or PRoP (personal roving presence) that provides several fundamental elements of personal tele-embodiment.

Abstract Keck-telescope spectrophotometry of the companion of PSR J1810+1744 shows a flat, but asymmetric light-curve maximum and a deep, narrow minimum. The maximum indicates strong gravity darkening (GD) near the L 1 point, along with a heated pole and surface winds. The minimum indicates a low underlying temperature and substantial limb darkening. The GD is a consequence of extreme pulsar heating and the near-filling of the Roche lobe. Light-curve modeling gives a binary inclination i = 65.°7 ± 0.°4. With the Keck-measured radial-velocity amplitude K c = 462.3 ± 2.2 km s −1 , this gives an accurate neutron star mass M NS = 2.13 ± 0.04 M ⊙ , with important implications for the dense-matter equation of state. A classic direct-heating model, ignoring the L 1 gravitational darkening, would predict an unphysical M NS > 3 M ⊙ . A few other “spider” pulsar binaries have similar large heating and fill factor; thus, they should be checked for such effects.