766 research outputs found
US Antidumping Petitions and Revealed Comparative Advantage of Shrimp Exporting Countries
The paper explores the trade competitiveness of seven major shrimp exporting countries,
namely Vietnam, China, Thailand, Ecuador, India, Indonesia and Mexico, to the USA.
Specifically, we investigate whether the United States (US) antidumping petitions impact upon
the bilateral revealed comparative advantage (RCA) indexes for each of the seven shrimp
exporting countries with the USA. Monthly data from January 2003 to December 2014 and the
panel data model are used to examine the determinants of the RCA for the shrimp exporting
countries. The empirical results show the shrimp exporting countries have superior
competitiveness against the shrimp market in the USA. Moreover, the RCA indexes are
significantly negatively influenced by shrimp prices, and are positively affected by US income
per capita. However, the EMS (Early Mortality Syndrome) shrimp disease, domestic US shrimp
quantity, exchange rate, and US antidumping laws are found to have no significant impacts on
the RCA indexes. In terms of policy implications, the USA should try to reduce production
costs of shrimp in the US market instead of imposing antidumping petitions, and the shrimp
exporting countries should maintain their comparative advantage and diversify into new
markets
US Antidumping Petitions and Revealed Comparative Advantage of Shrimp Exporting Countries
The paper explores the trade competitiveness of seven major shrimp exporting countries,
namely Vietnam, China, Thailand, Ecuador, India, Indonesia and Mexico, to the USA.
Specifically, we investigate whether the United States (US) antidumping petitions impact upon
the bilateral revealed comparative advantage (RCA) indexes for each of the seven shrimp
exporting countries with the USA. Monthly data from January 2003 to December 2014 and the
panel data model are used to examine the determinants of the RCA for the shrimp exporting
countries. The empirical results show the shrimp exporting countries have superior
competitiveness against the shrimp market in the USA. Moreover, the RCA indexes are
significantly negatively influenced by shrimp prices, and are positively affected by US income
per capita. However, the EMS (Early Mortality Syndrome) shrimp disease, domestic US shrimp
quantity, exchange rate, and US antidumping laws are found to have no significant impacts on
the RCA indexes. In terms of policy implications, the USA should try to reduce production
costs of shrimp in the US market instead of imposing antidumping petitions, and the shrimp
exporting countries should maintain their comparative advantage and diversify into new
markets
Clinical and molecular characterization of HER2 amplified-pancreatic cancer
<p>Background:
Pancreatic cancer is one of the most lethal and molecularly diverse malignancies. Repurposing of therapeutics that target specific molecular mechanisms in different disease types offers potential for rapid improvements in outcome. Although HER2 amplification occurs in pancreatic cancer, it is inadequately characterized to exploit the potential of anti-HER2 therapies.</p>
<p>Methods:
HER2 amplification was detected and further analyzed using multiple genomic sequencing approaches. Standardized reference laboratory assays defined HER2 amplification in a large cohort of patients (n = 469) with pancreatic ductal adenocarcinoma (PDAC).</p>
<p>Results:
An amplified inversion event (1 MB) was identified at the HER2 locus in a patient with PDAC. Using standardized laboratory assays, we established diagnostic criteria for HER2 amplification in PDAC, and observed a prevalence of 2%. Clinically, HER2- amplified PDAC was characterized by a lack of liver metastases, and a preponderance of lung and brain metastases. Excluding breast and gastric cancer, the incidence of HER2-amplified cancers in the USA is >22,000 per annum.</p>
<p>Conclusions:
HER2 amplification occurs in 2% of PDAC, and has distinct features with implications for clinical practice. The molecular heterogeneity of PDAC implies that even an incidence of 2% represents an attractive target for anti-HER2 therapies, as options for PDAC are limited. Recruiting patients based on HER2 amplification, rather than organ of origin, could make trials of anti-HER2 therapies feasible in less common cancer types.</p>
Defining the molecular pathology of pancreatic body and tail adenocarcinom
Background:
Pancreatic ductal adenocarcinoma (PDAC) remains a dismal disease, with very little improvement in survival over the past 50 years. Recent large-scale genomic studies have improved understanding of the genomic and transcriptomic landscape of the disease, yet very little is known about molecular heterogeneity according to tumour location in the pancreas; body and tail PDACs especially tend to have a significantly worse prognosis. The aim was to investigate the molecular differences between PDAC of the head and those of the body and tail of the pancreas.
Methods:
Detailed correlative analysis of clinicopathological variables, including tumour location, genomic and transcriptomic data, was performed using the Australian Pancreatic Cancer Genome Initiative (APGI) cohort, part of the International Cancer Genome Consortium study.
Results:
Clinicopathological data were available for 518 patients recruited to the APGI, of whom 421 underwent genomic analyses; 179 of these patients underwent whole-genome and 96 RNA sequencing. Patients with tumours of the body and tail had significantly worse survival than those with pancreatic head tumours (12·1 versus 22·0 months; P = 0·001). Location in the body and tail was associated with the squamous subtype of PDAC. Body and tail PDACs enriched for gene programmes involved in tumour invasion and epithelial-to-mesenchymal transition, as well as features of poor antitumour immune response. Whether this is due to a molecular predisposition from the outset, or reflects a later time point on the tumour molecular clock, requires further investigation using well designed prospective studies in pancreatic cancer.
Conclusion:
PDACs of the body and tail demonstrate aggressive tumour biology that may explain worse clinical outcomes
CP--violating Chargino Contributions to the Higgs Coupling to Photon Pairs in the Decoupling Regime of Higgs Sector
In most supersymmetric theories, charginos belong to
the class of the lightest supersymmetric particles and the couplings of Higgs
bosons to charginos are in general complex so that the CP--violating chargino
contributions to the loop--induced coupling of the lightest Higgs boson to
photon pairs can be sizable even in the decoupling limit of large pseudoscalar
mass with only the lightest Higgs boson kinematically accessible at
future high energy colliders. We introduce a specific benchmark scenario of CP
violation consistent with the electric dipole moment constraints and with a
commonly accepted baryogenesis mechanism in the minimal supersymmetric Standard
Model. Based on the benchmark scenario of CP violation, we demonstrate that the
fusion of the lightest Higgs boson in linearly polarized photon--photon
collisions can allow us to confirm the existence of the CP--violating chargino
contributions {\it even in the decoupling regime of the Higgs sector} for
nearly degenerate SU(2) gaugino and higgsino mass parameters of about the
electroweak scale.Comment: 1+13 pages, 3 eps figure
Dynamical Chiral Symmetry Breaking on the Light Front I. DLCQ Approach
Dynamical chiral symmetry breaking in the DLCQ method is investigated in
detail using a chiral Yukawa model closely related to the Nambu-Jona-Lasinio
model. By classically solving three constraints characteristic of the
light-front formalism, we show that the chiral transformation defined on the
light front is equivalent to the usual one when bare mass is absent. A quantum
analysis demonstrates that a nonperturbative mean-field solution to the
``zero-mode constraint'' for a scalar boson (sigma) can develop a nonzero
condensate while a perturbative solution cannot. This description is due to our
identification of the ``zero-mode constraint'' with the gap equation. The
mean-field calculation clarifies unusual chiral transformation properties of
fermionic field, which resolves a seemingly inconsistency between triviality of
the null-plane chiral charge Q_5|0>=0 and nonzero condensate. We also calculate
masses of scalar and pseudoscalar bosons for both symmetric and broken phases,
and eventually derive the PCAC relation and nonconservation of Q_5 in the
broken phase.Comment: Revised version to appear in Phys. Rev. D. 19 pages, 4 figures,
REVTEX. Derivation of the PCAC relation is given. Its relation to the
nonconservation of chiral charge is clarified. 1 figure and some references
adde
Mapping the energy landscape of biomolecules using single molecule force correlation spectroscopy (FCS): Theory and applications
In the current AFM experiments the distribution of unfolding times, P(t), is
measured by applying a constant stretching force f_s from which the apparent
unfolding rate is obtained. To describe the complexity of the underlying energy
landscape requires additional probes that can incorporate the dynamics of
tension propagation and relaxation of the polypeptide chain upon force quench.
We introduce a theory of force correlation spectroscopy (FCS) to map the
parameters of the energy landscape of proteins. In the FCS the joint
distribution, P(T,t) of folding and unfolding times is constructed by repeated
application of cycles of stretching at constant fs, separated by release
periods T during which the force is quenched to f_q<f_s. During the release
period, the protein can collapse to a manifold of compact states or refold. We
show that P(T,t) can be used to resolve the kinetics of unfolding as well as
formation of native contacts and to extract the parameters of the energy
landscape using chain extension as the reaction coordinate and P(T,t). We
illustrate the utility of the proposed formalism by analyzing simulations of
unfolding-refolding trajectories of a coarse-grained protein S1 with beta-sheet
architecture for several values of f_s, T and f_q=0. The simulations of
stretch-relax trajectories are used to map many of the parameters that
characterize the energy landscape of S1.Comment: 23 pages, 9 figures; accepted to Biophysical Journa
Doping dependence of the resonance peak and incommensuration in high- superconductors
The doping and frequency evolutions of the incommensurate spin response and
the resonance mode are studied based on the scenario of the Fermi surface
topology. We use the slave-boson mean-field approach to the
model and including the antiferromagnetic fluctuation correction in the
random-phase approximation. We find that the equality between the
incommensurability and the hole concentration is reproduced at low frequencies
in the underdoped regime. This equality observed in experiments was explained
{\it only} based on the stripe model before. We also obtain the downward
dispersion for the spin response and predict its doping dependence for further
experimental testing, as well as a proportionality between the low-energy
incommensurability and the resonance energy. Our results suggest a common
origin for the incommensuration and the resonance peak based on the Fermi
surface topology and the d-wave symmetry.Comment: 5 pages, 4 PS figure
PRECISION-Panc: the next generation therapeutic development platform for pancreatic cancer
No abstract available
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