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Oxalates as Activating Groups for Alcohols in Visible Light Photoredox Catalysis: Formation of Quaternary Centers by Redox-Neutral Fragment Coupling.
Alkyl oxalates are new bench-stable alcohol-activating groups for radical generation under visible light photoredox conditions. Using these precursors, the first net redox-neutral coupling of tertiary and secondary alcohols with electron-deficient alkenes is achieved
Nature and Nurture in Dark Matter Halos
Cosmological simulations consistently predict specific properties of dark
matter halos, but these have not yet led to a physical understanding that is
generally accepted. This is especially true for the central regions of these
structures. Recently two major themes have emerged. In one, the dark matter
halo is primarily a result of the sequential accretion of primordial structure
(ie `Nature'); while in the other, dynamical relaxation (ie `Nurture')
dominates at least in the central regions. Some relaxation is however required
in either mechanism. In this paper we accept the recently established
scale-free sub-structure of halos as an essential part of both mechanisms.
Consequently; a simple model for the central relaxation based on a self-similar
cascade of tidal interactions, is contrasted with a model based on the
accretion of adiabatically self-similar, primordial structure. We conclude that
a weak form of this relaxation is present in the simulations, but that is
normally described as the radial orbit instability.Comment: 25 pages, 3 figures, fig with parts 1 to d, fig 3 with parts a to
Exploring the use of strategic frameworks in dental practice
This paper explores the use of strategic frameworks in NHS and private dental practice. It reviews the policy context of dentistry and suggests the challenges in this context will require dental practices to prioritise understanding and engagement with a strategic approach. A strategic approach will be required in order to enhance and improve performance. Two specific strategic frameworks will be explored in terms of their relevance to NHS and private dental practic
Black holes and Galactic density cusps -- I. Radial orbit cusps and bulges
In this paper, we study the distribution functions that arise naturally
during self-similar radial infall of collisionless matter. Such matter may be
thought of either as stars or as dark matter particles. If a rigorous steady
state is assumed, then the system is infinite and is described by a universal
distribution function given the self-similar index. The steady logarithmic
potential case is exceptional and yields the familiar Gaussian for an infinite
system with an inverse-square density profile. We show subsequently that for
time-dependent radial self-similar infall, the logarithmic case is accurately
described by the Fridmann and Polyachenko distribution function. The system in
this case is finite but growing. We are able to embed a central mass in the
universal steady distribution only by iteration, except in the case of massless
particles. The iteration yields logarithmic corrections to the massless
particle case and requires a `renormalization' of the central mass. A central
spherical mass may be accurately embedded in the Fridmann and Polyachenko
growing distribution however. Some speculation is given concerning the
importance of radial collisionless infall in actual galaxy formation.Comment: 10 pp, 3 fig
Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) PARM tape user's guide
The Scanning Multichannel Microwave Radiometer (SMMR) instrument, onboard the Nimbus-7 spacecraft, collected data from Oct. 1978 until Jun. 1986. The data were processed to physical parameter level products. Geophysical parameters retrieved include the following: sea-surface temperatures, sea-surface windspeed, total column water vapor, and sea-ice parameters. These products are stored on PARM-LO, PARM-SS, and PARM-30 tapes. The geophysical parameter retrieval algorithms and the quality of these products are described for the period between Nov. 1978 and Oct 1985. Additionally, data formats and data availability are included
The International Mass Loading Service
The International Mass Loading Service computes four loadings: a) atmospheric
pressure loading; b) land water storage loading; c) oceanic tidal loading; and
d) non-tidal oceanic loading. The service provides to users the mass loading
time series in three forms: 1) pre-computed time series for a list of 849 space
geodesy stations; 2) pre-computed time series on the global 1deg x 1deg grid;
and 3) on-demand Internet service for a list of stations and a time range
specified by the user. The loading displacements are provided for the time
period from 1979.01.01 through present, updated on an hourly basis, and have
latencies 8-20 hours.Comment: 8 pages, 3 figures, to appear in the Proceedings of the Reference
Frames for Applications in Geosciences Simposium, held in Luxemboug in
October 201
Exploring glass as a novel method for hands-free data entry in flexible cystoscopy
We present a way to annotate cystoscopy finding on Google Glass in a reproducible and hands free manner for use by surgeons during operations in the sterile environment inspired by the current practice of hand-drawn sketches. We developed three data entry variants based on speech and head movements. We assessed the feasibility, benefits and drawbacks of the system with 8 surgeons and Foundation Doctors having up to 30 years' cystoscopy experience at a UK hospital in laboratory trials. We report data entry speed and error rate of input modalities and contrast it with the participants' feedback on their perception of usability, acceptance, and suitability for deployment. The results are supportive of new data entry technologies and point out directions for future improvement of eyewear computers. The findings can be generalised to other endoscopic procedures (e.g. OGD/laryngoscopy) and could be included within hospital IT in the future
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