5,509 research outputs found
The hidden burden of adult allergic rhinitis : UK healthcare resource utilisation survey
Funding Funding for this survey was provided by Meda Pharma.Peer reviewedPublisher PD
Intranasal corticosteroids in allergic rhinitis in COVID-19 infected patients: An ARIA-EAACI statement
A novel strain of human coronaviruses, named by the International Committee on Taxonomy of Viruses (ICTV)1 as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged and caused an infectious disease. This disease has recently been referred to by the World Health Organisation (WHO) as the “coronavirus disease 2019” (COVID-19). Since the first report of this disease in December 2019 in Wuhan, China,2, 3 COVID-19 has aggressively spread across the globe. WHO declared it a pandemic on March 11
Density functional perturbation theory within non-collinear magnetism
We extend the density functional perturbation theory formalism to the case of
non-collinear magnetism. The main problem comes with the exchange-correlation
(XC) potential derivatives, which are the only ones that are affected by the
non-collinearity of the system. Most of the present XC functionals are
constructed at the collinear level, such that the off-diagonal (containing
magnetization densities along and directions) derivatives cannot be
calculated simply in the non-collinear framework. To solve this problem, we
consider here possibilities to transform the non-collinear XC derivatives to a
local collinear basis, where the axis is aligned with the local
magnetization at each point. The two methods we explore are i) expanding the
spin rotation matrix as a Taylor series, ii) evaluating explicitly the XC for
the local density approximation through an analytical expression of the
expansion terms. We compare the two methods and describe their practical
implementation. We show their application for atomic displacement and electric
field perturbations at the second order, within the norm-conserving
pseudopotential methods
Combinatorics of Hard Particles on Planar Graphs
We revisit the problem of hard particles on planar random tetravalent graphs
in view of recent combinatorial techniques relating planar diagrams to
decorated trees. We show how to recover the two-matrix model solution to this
problem in this purely combinatorial language.Comment: 35 pages, 20 figures, tex, harvmac, eps
Becoming war: towards a martial empiricism
Under the banner of martial empiricism, we advance a distinctive set of theoretical and methodological commitments for the study of war. Previous efforts to wrestle with this most recalcitrant of phenomena have sought to ground research upon primary definitions or foundational ontologies of war. By contrast, we propose to embrace war’s incessant becoming, making its creativity, mutability, and polyvalence central to our enquiry. Leaving behind the interminable quest for its essence, we embrace war as mystery. We draw on a tradition of radical empiricism to devise a conceptual and contextual mode of enquiry that can follow the processes and operations of war wherever they lead us. Moving beyond the instrumental appropriations of strategic thought and the normative strictures typical of critical approaches, martial empiricism calls for an unbounded investigation into the emergent and generative character of war. Framing the accompanying special issue, we outline three domains around which to orient future research: mobilization, design, and encounter. Martial empiricism is no idle exercise in philosophical speculation. It is the promise of a research agenda apposite to the task of fully contending with the momentous possibilities and dangers of war in our time
The PseudoDojo: Training and grading a 85 element optimized norm-conserving pseudopotential table
First-principles calculations in crystalline structures are often performed
with a planewave basis set. To make the number of basis functions tractable two
approximations are usually introduced: core electrons are frozen and the
diverging Coulomb potential near the nucleus is replaced by a smoother
expression. The norm-conserving pseudopotential was the first successful method
to apply these approximations in a fully ab initio way. Later on, more
efficient and more exact approaches were developed based on the ultrasoft and
the projector augmented wave formalisms. These formalisms are however more
complex and developing new features in these frameworks is usually more
difficult than in the norm-conserving framework. Most of the existing tables of
norm- conserving pseudopotentials, generated long ago, do not include the
latest developments, are not systematically tested or are not designed
primarily for high accuracy. In this paper, we present our PseudoDojo framework
for developing and testing full tables of pseudopotentials, and demonstrate it
with a new table generated with the ONCVPSP approach. The PseudoDojo is an open
source project, building on the AbiPy package, for developing and
systematically testing pseudopotentials. At present it contains 7 different
batteries of tests executed with ABINIT, which are performed as a function of
the energy cutoff. The results of these tests are then used to provide hints
for the energy cutoff for actual production calculations. Our final set
contains 141 pseudopotentials split into a standard and a stringent accuracy
table. In total around 70.000 calculations were performed to test the
pseudopotentials. The process of developing the final table led to new insights
into the effects of both the core-valence partitioning and the non-linear core
corrections on the stability, convergence, and transferability of
norm-conserving pseudopotentials. ...Comment: abstract truncated, 17 pages, 25 figures, 8 table
Series expansions of the percolation probability on the directed triangular lattice
We have derived long series expansions of the percolation probability for
site, bond and site-bond percolation on the directed triangular lattice. For
the bond problem we have extended the series from order 12 to 51 and for the
site problem from order 12 to 35. For the site-bond problem, which has not been
studied before, we have derived the series to order 32. Our estimates of the
critical exponent are in full agreement with results for similar
problems on the square lattice, confirming expectations of universality. For
the critical probability and exponent we find in the site case: and ; in the bond case:
and ; and in the site-bond
case: and . In
addition we have obtained accurate estimates for the critical amplitudes. In
all cases we find that the leading correction to scaling term is analytic,
i.e., the confluent exponent .Comment: 26 pages, LaTeX. To appear in J. Phys.
Asymptotic behaviour of convex and column-convex lattice polygons with fixed area and varying perimeter
We study the inflated phase of two dimensional lattice polygons, both convex
and column-convex, with fixed area A and variable perimeter, when a weight
\mu^t \exp[- Jb] is associated to a polygon with perimeter t and b bends. The
mean perimeter is calculated as a function of the fugacity \mu and the bending
rigidity J. In the limit \mu -> 0, the mean perimeter has the asymptotic
behaviour \avg{t}/4 \sqrt{A} \simeq 1 - K(J)/(\ln \mu)^2 + O (\mu/ \ln \mu) .
The constant K(J) is found to be the same for both types of polygons,
suggesting that self-avoiding polygons should also exhibit the same asymptotic
behaviour.Comment: 10 pages, 3 figure
- …