402 research outputs found
Popular Support for Trade Agreements and Partner Country Characteristics â Evidence from an Unexpected Election Outcome
Using quasiâexperimental data from a survey that was conducted immediately before and after the November 2016 presidential election, we analyze how the election of Donald Trump affected the willingness of Europeans to sign a trade and investment agreement with the United States. We find that the election outcome lead to an immediate and sizable negative effect on Europeans' image of the United States. But we do not find that, at the same time, there was a negative reaction in the willingness of Europeans to sign an agreement with the United States
X-ray He-like ions diagnostics: New Computations for Photoionized Plasmas: I. preliminary considerations
Using the new version of the photoionization code Titan designed for
plane-parallel photoionized thick hot media, which is unprecedented from the
point of view of line transfer, we have undertaken a study of the influence of
different parameters on the He-like and H-like emission of a medium
photoionized by an X-ray source. We explain why in modelling the emitting
medium it is important to solve in a self-consistent way the thermal and
ionization equilibria and to take into account the interconnection between the
different ions. We give the equivalent widths of the sum of the He-like
triplets and the triplet intensity ratios and , for the most important
He-like ions, for a range of density, column density, and ionization parameter,
in the case of constant density media. We show that the line intensities from a
given ion can be accounted for, either by small values of both the column
density and of the ionization parameter, or by large values of both quantities,
and it is necessary to take into account several ions to disentangle these
possibilities. We show also that a "pure recombination spectrum" almost never
exists in a photoionized medium: either it is thin, and resonance lines are
formed by radiative excitation, or it is thick, and free-bound absorption
destroys the resonance photons as they undergo resonant diffusion.Comment: 19 pages, 14 figures, accepted in A &
SoLid : Search for Oscillations with Lithium-6 Detector at the SCK-CEN BR2 reactor
Sterile neutrinos have been considered as a possible explanation for the recent reactor and Gallium anomalies arising from reanalysis of reactor flux and calibration data of previous neutrino experiments. A way to test this hypothesis is to look for distortions of the anti-neutrino energy caused by oscillation from active to sterile neutrino at close stand-off (similar to 6-8m) of a compact reactor core. Due to the low rate of anti-neutrino interactions the main challenge in such measurement is to control the high level of gamma rays and neutron background.
The SoLid experiment is a proposal to search for active-to-sterile anti-neutrino oscillation at very short baseline of the SCK center dot CEN BR2 research reactor.
This experiment uses a novel approach to detect anti-neutrino with a highly segmented detector based on Lithium-6. With the combination of high granularity, high neutron-gamma discrimination using 6LiF:ZnS(Ag) and precise localization of the Inverse Beta Decay products, a better experimental sensitivity can be achieved compared to other state-of-the-art technology. This compact system requires minimum passive shielding allowing for very close stand off to the reactor. The experimental set up of the SoLid experiment and the BR2 reactor will be presented. The new principle of neutrino detection and the detector design with expected performance will be described. The expected sensitivity to new oscillations of the SoLid detector as well as the first measurements made with the 8 kg prototype detector deployed at the BR2 reactor in 2013-2014 will be reported
Evolution of the X-ray spectrum in the flare model of Active Galactic Nuclei
Nayakshin & Kazanas (2002) have considered the time-dependent illumination of
an accretion disc in Active Galactic Nuclei, in the lamppost model. We extend
their study to the flare model, which postulates the release of a large X-ray
flux above a small region of the accretion disc. A fundamental difference with
the lamppost model is that the region of the disc below the flare is not
illuminated before the onset of the flare.
A few test models show that the spectrum which follows immediately the
increase in continuum flux should display the characteristics of a highly
illuminated but dense gas, i.e. very intense X-ray emission lines and
ionization edges in the soft X-ray range. The behaviour of the iron line is
different in the case of a "moderate" and a ``strong'' flare: for a moderate
flare, the spectrum displays a neutral component of the Fe K line at
6.4 keV, gradually leading to more highly ionized lines. For a strong flare,
the lines are already emitted by FeXXV (around 6.7 keV) after the onset, and
have an equivalent width of several hundreds of eV. We find that the observed
correlations between , , and the X-ray flux, are well accounted by a
combination of flares having not achieved pressure equilibrium, strongly
suggesting that the observed spectrum is dominated by regions in non-pressure
equilibrium, typical of the onset of the flares. Finally a flare being confined
to a small region of the disc, the spectral lines should be narrow (except for
a weak Compton broadening), Doppler shifted, and moving.Comment: 14 pages, 13 figures, accepted in A & A, english corrected versio
Exploring the Cost Effectiveness of a Whole-Genome Sequencing-Based Biomarker for Treatment Selection in Patients with Advanced Lung Cancer Ineligible for Targeted Therapy
Objective: We aimed to perform an early cost-effectiveness analysis of using a whole-genome sequencing-based tumor mutation burden (WGS-TMB), instead of programmed death-ligand 1 (PD-L1), for immunotherapy treatment selection in patients with non-squamous advanced/metastatic non-small cell lung cancer ineligible for targeted therapy, from a Dutch healthcare perspective. Methods: A decision-model simulating individual patients with metastatic non-small cell lung cancer was used to evaluate diagnostic strategies to select first-line immunotherapy only or the immunotherapy plus chemotherapy combination. Treatment was selected using PD-L1 [A, current practice], WGS-TMB [B], and both PD-L1 and WGS-TMB [C]. Strategies D, E, and F take into account a patientâs disease burden, in addition to PD-L1, WGS-TMB, and both PD-L1 and WGS-TMB, respectively. Disease burden was defined as a fast-growing tumor, a high number of metastases, and/or weight loss. A threshold of 10 mutations per mega-base was used to classify patients into TMB-high and TMB-low groups. Outcomes were discounted quality-adjusted life-years (QALYs) and healthcare costs measured from the start of first-line treatment to death. Healthcare costs includes drug acquisition, follow-up costs, and molecular diagnostic tests (i.e., standard diagnostic techniques and/or WGS for strategies involving TMB). Results were reported using the net monetary benefit at a willingness-to-pay threshold of âŹ80,000/QALY. Additional scenario and threshold analyses were performed. Results: Strategy B had the lowest QALYs (1.84) and lowest healthcare costs (âŹ120,800). The highest QALYs and healthcare costs were 2.00 and âŹ140,400 in strategy F. In the base-case analysis, strategy A was cost effective with the highest net monetary benefit (âŹ27,300), followed by strategy B (âŹ26,700). Strategy B was cost effective when the cost of WGS testing was decreased by at least 24% or when immunotherapy results in an additional 0.5 year of life gained or more for TMB high compared with TMB low. Strategies C and F, which combined TMB and PD-L1 had the highest net monetary benefit (â„ âŹ76,900) when the cost of WGS testing, immunotherapy, and chemotherapy acquisition were simultaneously reduced by at least 47%, 39%, and 43%, respectively. Furthermore, strategy C resulted in the highest net monetary benefit (â„ âŹ39,900) in a scenario where patients with both PD-L1 low and TMB low were treated with chemotherapy instead of immunotherapy plus chemotherapy. Conclusions: The use of WGS-TMB is not cost effective compared to PD-L1 for immunotherapy treatment selection in non-squamous metastatic non-small cell lung cancer in the Netherlands. WGS-TMB could become cost effective provided there is a reduction in the cost of WGS testing or there is an increase in the predictive value of WGS-TMB for immunotherapy effectiveness. Alternatively, a combination strategy of PD-L1 testing with WGS-TMB would be cost effective if used to support the choice to withhold immunotherapy in patients with a low expected benefit of immunotherapy.</p
Exploring the Cost Effectiveness of a Whole-Genome Sequencing-Based Biomarker for Treatment Selection in Patients with Advanced Lung Cancer Ineligible for Targeted Therapy
Objective: We aimed to perform an early cost-effectiveness analysis of using a whole-genome sequencing-based tumor mutation burden (WGS-TMB), instead of programmed death-ligand 1 (PD-L1), for immunotherapy treatment selection in patients with non-squamous advanced/metastatic non-small cell lung cancer ineligible for targeted therapy, from a Dutch healthcare perspective. Methods: A decision-model simulating individual patients with metastatic non-small cell lung cancer was used to evaluate diagnostic strategies to select first-line immunotherapy only or the immunotherapy plus chemotherapy combination. Treatment was selected using PD-L1 [A, current practice], WGS-TMB [B], and both PD-L1 and WGS-TMB [C]. Strategies D, E, and F take into account a patientâs disease burden, in addition to PD-L1, WGS-TMB, and both PD-L1 and WGS-TMB, respectively. Disease burden was defined as a fast-growing tumor, a high number of metastases, and/or weight loss. A threshold of 10 mutations per mega-base was used to classify patients into TMB-high and TMB-low groups. Outcomes were discounted quality-adjusted life-years (QALYs) and healthcare costs measured from the start of first-line treatment to death. Healthcare costs includes drug acquisition, follow-up costs, and molecular diagnostic tests (i.e., standard diagnostic techniques and/or WGS for strategies involving TMB). Results were reported using the net monetary benefit at a willingness-to-pay threshold of âŹ80,000/QALY. Additional scenario and threshold analyses were performed. Results: Strategy B had the lowest QALYs (1.84) and lowest healthcare costs (âŹ120,800). The highest QALYs and healthcare costs were 2.00 and âŹ140,400 in strategy F. In the base-case analysis, strategy A was cost effective with the highest net monetary benefit (âŹ27,300), followed by strategy B (âŹ26,700). Strategy B was cost effective when the cost of WGS testing was decreased by at least 24% or when immunotherapy results in an additional 0.5 year of life gained or more for TMB high compared with TMB low. Strategies C and F, which combined TMB and PD-L1 had the highest net monetary benefit (â„ âŹ76,900) when the cost of WGS testing, immunotherapy, and chemotherapy acquisition were simultaneously reduced by at least 47%, 39%, and 43%, respectively. Furthermore, strategy C resulted in the highest net monetary benefit (â„ âŹ39,900) in a scenario where patients with both PD-L1 low and TMB low were treated with chemotherapy instead of immunotherapy plus chemotherapy. Conclusions: The use of WGS-TMB is not cost effective compared to PD-L1 for immunotherapy treatment selection in non-squamous metastatic non-small cell lung cancer in the Netherlands. WGS-TMB could become cost effective provided there is a reduction in the cost of WGS testing or there is an increase in the predictive value of WGS-TMB for immunotherapy effectiveness. Alternatively, a combination strategy of PD-L1 testing with WGS-TMB would be cost effective if used to support the choice to withhold immunotherapy in patients with a low expected benefit of immunotherapy.</p
Mixed-Model Noise Removal in 3D MRI via Rotation-and-Scale Invariant Non-Local Means
Mixed noise is a major issue influencing quantitative analysis in different forms of magnetic resonance image (MRI), such as T1 and diffusion image like DWI and DTI. Using different filters sequentially to remove mixed noise will severely deteriorate such medical images. We present a novel algorithm called rotation-and-scale invariant nonlocal means filter (RSNLM) to simultaneously remove mixed noise from different kinds of three-dimensional (3D) MRI images. First, we design a new similarity weights, including rank-ordered absolute difference (ROAD), coming from a trilateral filter (TriF) that is obtained to detect the mixed and high-level noise. Then, we present a shape view to consider the MRI data as a 3D operator, with which the similarity between the patches is calculated with the rigid transformation. The translation, rotation and scale have no influence on the similarity. Finally, the adaptive parameter estimation method of ROAD is illustrated, and the effective proof that validates the proposed algorithm is presented. Experiments using synthetic data with impulse noise, Rician noise, and the real MRI data confirm that the proposed method yields superior performance compared with current state-of-the-art methods
Postnatal Growth after Intrauterine Growth Restriction Alters Central Leptin Signal and Energy Homeostasis
Intrauterine growth restriction (IUGR) is closely linked with metabolic diseases, appetite disorders and obesity at adulthood. Leptin, a major adipokine secreted by adipose tissue, circulates in direct proportion to body fat stores, enters the brain and regulates food intake and energy expenditure. Deficient leptin neuronal signalling favours weight gain by affecting central homeostatic circuitry. The aim of this study was to determine if leptin resistance was programmed by perinatal nutritional environment and to decipher potential cellular mechanisms underneath
The X-ray spectrum of NGC 7213 and the Seyfert--LINER connection
We present an XMM-Newton observation of the Seyfert-LINER galaxy NGC 7213.
The RGS soft X-ray spectrum is well fitted with a power law plus soft X-ray
collisionally ionised thermal plasma (kT = 0.18 +0.03/-0.01 keV). We confirm
the presence of Fe I, XXV and XXVI K-alpha emission in the EPIC spectrum and
set tighter constraints on their equivalent widths of 82 +10/-13, 24 +9/-11 and
24 +10/-13 eV respectively. We compare the observed properties together with
the inferred mass accretion rate of NGC 7213, to those of other Seyfert and
LINER galaxies. We find that NGC 7213 has intermediate X-ray spectral
properties lying between those of the weak AGN found in the LINER M81 and
higher luminosity Seyfert galaxies. There appears to be a continuous sequence
of X-ray properties from the Galactic Centre through LINER galaxies to
Seyferts, likely determined by the amount of material available for accretion
in the central regions.Comment: 8 pages, 3 figures. Accepted for MNRA
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