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Continued fractions which match power series expansions at two points
Efficiency, equity, and NICE clinical guidelines
The stated purpose of clinical guidelines from the United Kingdom's National Institute for Clinical Excellence (NICE) is to "help healthcare professionals and patients make the right decisions about healthcare in specific clinical circumstances." However, what constitutes "the right decisions" depends on your point of view. For individual patients the right decision is that which maximises their wellbeing, and this is properly the concern of the clinician. Yet in resource constrained healthcare systems this will not always coincide with the right decisions for patients in general or society as a whole, thereby leading to some understandable tensions. NICE is a national policy making body whose responsibility is clearly broader than the individual patient. This wider viewpoint is reflected in NICE's technology appraisals by the central role afforded to cost effectiveness. We argue that the methods currently used by the NICE clinical guideline programme confuse these two viewpoints
Directly detecting sub-GeV dark matter with electrons from nuclear scattering
Dark matter (DM) particles with mass in the sub-GeV range are an attractive
alternative to heavier weakly-interacting massive particles, but direct
detection of such light particles is challenging. If however DM-nucleus
scattering leads to ionisation of the recoiling atom, the resulting electron
may be detected even if the nuclear recoil is unobservable. We demonstrate that
including this effect significantly enhances direct detection sensitivity to
sub-GeV DM. Existing experiments set world-leading limits, and future
experiments may probe the cross sections relevant for thermal freeze-out.Comment: 8 pages revtex4, 5 figures; v2: analysis updated to include
constraints from XENON1T; accepted for publication in PR
A weighty interpretation of the Galactic Centre excess
Previous attempts at explaining the gamma-ray excess near the Galactic Centre
have focussed on dark matter annihilation directly into Standard Model
particles. This results in a preferred dark matter mass of 30-40 GeV (if the
annihilation is into b quarks) or 10 GeV (if it is into leptons). Here we show
that the gamma-ray excess is also consistent with heavier dark matter
particles; in models of secluded dark matter, dark matter with mass up to 76
GeV provides a good fit to the data. This occurs if the dark matter first
annihilates to an on-shell particle that subsequently decays to Standard Model
particles through a portal interaction. This is a generic process that works in
models with annihilation, semi-annihilation or both. We explicitly demonstrate
this in a model of hidden vector dark matter with an SU(2) gauge group in the
hidden sector.Comment: 5 pages, 4 figures. v2: Matches PRD version. Note: title of PRD
version is "Interpretation of the Galactic Center excess of gamma rays with
heavier dark matter particles
Disk Evolution in Young Binaries: from Observations to Theory
The formation of a binary system surrounded by disks is the most common
outcome of stellar formation. Hence studying and understanding the formation
and the evolution of binary systems and associated disks is a cornerstone of
star formation science. Moreover, since the components within binary systems
are coeval and the sizes of their disks are fixed by the tidal truncation of
their companion, binary systems provide an ideal "laboratory" in which to study
disk evolution under well defined boundary conditions.
In this paper, we review observations of several inner disk diagnostics in
multiple systems, including hydrogen emission lines (indicative of ongoing
accretion), and color excesses (evidence of warm inner disks), and
polarization (indicative of the relative orientations of the disks around each
component). We examine to what degree these properties are correlated within
binary systems and how this degree of correlation depends on parameters such as
separation and binary mass ratio. These findings will be interpreted both in
terms of models that treat each disk as an isolated reservoir and those in
which the disks are subject to re-supply from some form of circumbinary
reservoir, the observational evidence for which we will also critically review.
The planet forming potential of multiple star systems is discussed in terms of
the relative lifetimes of disks around single stars, binary primaries and
binary secondaries. Finally, we summarize several potentially revealing
observational problems and future projects that could provide further insight
into disk evolution in the coming decadeComment: 16 pages, 7 figures, chapter in Protostars and Planets
Drugs for exceptionally rare diseases: a commentary on Hughes et al
Recently in this journal, Hughes and colleagues discussed special funding status to ultra-orphan drugs. They concluded that there should be a uniform policy for the provision of orphan drugs across Europe; that complete restriction was impractical, and that UK policy should aspire to the values of the EU directive on orphan drugs. We critically assess these arguments, demonstrating that they failed to justify special status for treatments for rare diseases
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