7,477 research outputs found
A global inter-country economic model based on linked input-output models
We present a new, flexible and extensible alternative to multi-regional
input-output (MRIO) for modelling the global economy. The limited coefficient set of MRIO (technical coefficients only) is extended to include two
new sets of coefficients, import ratios and import propensities. These new
coefficient sets assist in the interaction of the new model with other social
science models such as those of trade, migration, international security
and development aid. The model uses input-output models as descriptions of the internal workings of countries’ economies, and couples these
more loosely than in MRIO using trade data for commodities and services from the UN. The model is constructed using a minimal number
of assumptions, seeks to be as parsimonious as possible in terms of the
number of coefficients, and is based to a great extent on empirical observation. Two new metrics are introduced, measuring sectors’ economic
significance and economic self-reliance per country. The Chinese vehicles sector is shown to be the world’s most significant, and self-reliance is
shown to be strongly correlated with population. The new model is shown
to be equivalent to an MRIO under an additional assumption, allowing
existing analysis techniques to be applied
Recommended from our members
Resonances in coupled πk,ηK scattering from lattice QCD
Coupled-channel and scattering amplitudes are determined by
studying the finite-volume energy spectra obtained from dynamical lattice QCD
calculations. Using a large basis of interpolating operators, including both
those resembling a construction and those resembling a pair of
mesons with relative momentum, a reliable excited-state spectrum can be
obtained. Working at , we find a gradual increase in
the phase-shift which may be identified with a broad scalar
resonance that couples strongly to and weakly to . The
low-energy behavior of this amplitude suggests a virtual bound-state that may
be related to the resonance. A bound state with is found
very close to the threshold energy, whose coupling to the
channel is compatible with that of the experimental . Evidence is
found for a narrow resonance in . Isospin--3/2 scattering is
also studied and non-resonant phase-shifts spanning the whole elastic
scattering region are obtained.We thank our colleagues within the Hadron Spectrum
Collaboration. We also thank R. Briceno, M.R. Pennington,
C.J.Shultz and A.P. Szczepaniak for fruitful discussions.
Chroma [63] and QUDA [64, 65] were used to perform
this work on clusters at Jefferson Laboratory under the
USQCD Initiative and the LQCD ARRA project. Gauge
configurations were generated using resources awarded
from the U.S. Department of Energy INCITE program
at Oak Ridge National Lab, the NSF Teragrid at the
Texas Advanced Computer Center and the Pittsburgh
Supercomputer Center, as well as at Jefferson Lab. RGE
and JJD acknowledge support from U.S. Department of
Energy contract DE-AC05-06OR23177, under which Jefferson
Science Associates, LLC, manages and operates
Jefferson Laboratory. JJD acknowledges support from
the U.S. Department of Energy Early Career award contract
DE-SC0006765. CET acknowledges partial support
from the Science and Technology Facilities Council
(U.K.) [grant number ST/L000385/1].This is the accepted manuscript. The final version is available at http://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.054008
Recommended from our members
B1 resonance in coupled πω, πφ scattering from lattice QCD
We present the first lattice QCD calculation of coupled and
scattering, incorporating coupled and -wave in
. Finite-volume spectra in three volumes are determined via a
variational analysis of matrices of two-point correlation functions, computed
using large bases of operators resembling single-meson, two-meson and
three-meson structures, with the light-quark mass corresponding to a pion mass
of MeV. Utilizing the relationship between the discrete
spectrum of finite-volume energies and infinite-volume scattering amplitudes,
we find a narrow axial-vector resonance (), the analogue of the
meson, with mass MeV and width
MeV. The resonance is found to couple dominantly to -wave , with
a much-suppressed coupling to -wave , and a negligible coupling
to consistent with the `OZI rule'. No resonant behavior is observed
in , indicating the absence of a putative low-mass analogue of
the claimed in . In order to minimally present the contents
of a unitary three-channel scattering matrix, we introduce an -channel
generalization of the traditional two-channel Stapp parameterization
Decays of an exotic 1-+ hybrid meson resonance in QCD
We present the first determination of the hadronic decays of the lightest
exotic resonance in lattice QCD. Working with SU(3) flavor
symmetry, where the up, down and strange quark masses approximately match the
physical strange-quark mass giving MeV, we compute
finite-volume spectra on six lattice volumes which constrain a scattering
system featuring eight coupled channels. Analytically continuing the scattering
amplitudes into the complex energy plane, we find a pole singularity
corresponding to a narrow resonance which shows relatively weak coupling to the
open pseudoscalar--pseudoscalar, vector--pseudoscalar and vector--vector decay
channels, but large couplings to at least one kinematically-closed
axial-vector--pseudoscalar channel. Attempting a simple extrapolation of the
couplings to physical light-quark mass suggests a broad resonance
decaying dominantly through the mode with much smaller decays into
, , and . A large total width is
potentially in agreement with the experimental candidate state,
observed in , , which we suggest may be heavily suppressed
decay channels
Calcitization of aragonitic bryozoans in Cenozoic tropical carbonates from East Kalimantan, Indonesia
© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The file attached is the published version of the article
Categorical dilemmas: challenges for HIV prevention among men who have sex with men and transgender women in Vietnam
In Vietnam, HIV continues disproportionately to affect men who have sex with men and transgender women, and the increase in HIV prevalence in these populations may be related to a lack of tailoring of current prevention approaches, which often fail to address social diversity within these populations. To effectively respond to HIV in Vietnam, it is imperative to identify sub-populations within the broad category of ‘men who have sex with men’ (MSM), a term which in Vietnam as in many other sites frequently subsumes transgender women. In this paper, we document the different categories used to describe people who engage in same-sex sexual practices and/or non-normative gender performances drawing on data collected via in-depth interviews and focus groups with a total of 79 participants in Hanoi. We identified over 40 different categories used to describe men who have sex with men and/or transgender women. These categories could be described as behaviourally-based, identity-based, or emic, and each carried different meanings, uses (based on age and geography) and levels of stigma. The categories shine light on the complexity of identities among men who have sex with men and transgender women and have utility for future research and programming to more comprehensively address HIV in Vietnam
Recommended from our members
An a0 resonance in strongly coupled πη, K K scattering from lattice QCD a0 RESONANCE in STRONGLY COUPLED ⋯ DUDEK, EDWARDS, and WILSON
We present the first calculation of coupled-channel meson-meson scattering in
the isospin , -parity negative sector, with channels ,
and , in a first-principles approach to QCD. From
the discrete spectrum of eigenstates in three volumes extracted from lattice
QCD correlation functions we determine the energy dependence of the -matrix,
and find that the -wave features a prominent cusp-like structure in close to threshold coupled with a rapid turn
on of amplitudes leading to the final-state. This behavior is
traced to an -like resonance, strongly coupled to both and
, which is identified with a pole in the complex energy plane,
appearing on only a single unphysical Riemann sheet. Consideration of -wave
scattering suggests a narrow tensor resonance at higher energy.This is the author accepted manuscript. The final version is available from the American Physical Society via http://dx.doi.org/10.1103/PhysRevD.93.09450
Optimized Atmospheric-Pressure Chemical Vapor Deposition Thermochromic VO2 Thin Films for Intelligent Window Applications
Monoclinic vanadium(IV) oxide (VO2) has been widely studied for energy-efficient glazing applications because of its thermochromic properties, displaying a large change in transmission of near-IR wavelengths between the hot and cold states. The optimization of the reaction between VCl4 and ethyl acetate via atmospheric-pressure chemical vapor deposition (APCVD) was shown to produce thin films of monoclinic VO2 with excellent thermochromic properties (ΔTsol = 12%). The tailoring of the thermochromic and visible light transmission was shown to be possible by altering the density and morphology of the deposited films. The films were characterized by X-ray diffraction, atomic-force microscopy, scanning electron microscopy, ellipsometry, and UV–vis spectrometry. This article provides useful design rules for the synthesis of high-quality VO2 thin films by APCVD
The early inflorescence of Arabidopsis thaliana demonstrates positional effects in floral organ growth and meristem patterning.
Linear modelling approaches detected significant gradients in organ growth and patterning across early flowers of the Arabidopsis inflorescence and uncovered evidence of new roles for gibberellin in floral development. Most flowering plants, including the genetic model Arabidopsis thaliana, produce multiple flowers in sequence from a reproductive shoot apex to form a flower spike (inflorescence). The development of individual flowers on an Arabidopsis inflorescence has typically been considered as highly stereotypical and uniform, but this assumption is contradicted by the existence of mutants with phenotypes visible in early flowers only. This phenomenon is demonstrated by mutants partially impaired in the biosynthesis of the phytohormone gibberellin (GA), in which floral organ growth is retarded in the first flowers to be produced but has recovered spontaneously by the 10th flower. We presently lack systematic data from multiple flowers across the Arabidopsis inflorescence to explain such changes. Using mutants of the GA 20-OXIDASE (GA20ox) GA biosynthesis gene family to manipulate endogenous GA levels, we investigated the dynamics of changing floral organ growth across the early Arabidopsis inflorescence (flowers 1-10). Modelling of floral organ lengths identified a significant, GA-independent gradient of increasing stamen length relative to the pistil in the wild-type inflorescence that was separable from other, GA-dependent effects. It was also found that the first flowers exhibited unstable organ patterning in contrast to later flowers and that this instability was prolonged by exogenous GA treatment. These findings indicate that the development of individual flowers is influenced by hitherto unknown factors acting across the inflorescence and also suggest novel functions for GA in floral patterning
- …