175 research outputs found
Do gasoline prices converge in a unified Europe with non-harmonized tax rates?
price convergence, law of one price, gasoline, international taxation, European integration, panel unit roots
Do gasoline prices converge in a unified Europe with non- harmonized tax rates?
The paper presents univariate and panel unit root tests for gasoline and oil price convergence over the last decade. We test for the absolute versus relative version of the LOOP and estimate the speed of convergence as well as its development over time. Our results show that the absolute version of the LOOP cannot be supported. Constant price differences between countries remain, caused mainly by existing tax differences. The relative version of the LOOP is strongly supported by the data. The speed of convergence increased over time, but differs for gross and net-of-tax prices. We can show that national tax policy by EU member states is not (yet) threatened by arbitrage due to cross-border shopping.price convergence, law of one price, gasoline, international taxation, European integration, panel unit roots
Do gasoline prices converge in a unified Europe with non-harmonized tax rates?
The paper presents univariate and panel unit root tests for gasoline and oil price convergence over the last decade. We test for the absolute versus relative version of the LOOP and estimate the speed of convergence as well as its development over time. Our results show that the absolute version of the LOOP cannot be supported. Constant price differences between countries remain, caused mainly by existing tax differences. The relative version of the LOOP is strongly supported by the data. The speed of convergence increased over time, but differs for gross and net-of-tax prices. We can show that national tax policy by EU member states is not (yet) threatened by arbitrage due to cross-border shopping. --price convergence,law of one price,gasoline,international taxation,European integration,panel unit roots
Bevel-Tip Needle Deflection Modeling, Simulation, and Validation in Multi-Layer Tissues
Percutaneous needle insertions are commonly performed for diagnostic and
therapeutic purposes as an effective alternative to more invasive surgical
procedures. However, the outcome of needle-based approaches relies heavily on
the accuracy of needle placement, which remains a challenge even with robot
assistance and medical imaging guidance due to needle deflection caused by
contact with soft tissues. In this paper, we present a novel mechanics-based 2D
bevel-tip needle model that can account for the effect of nonlinear
strain-dependent behavior of biological soft tissues under compression.
Real-time finite element simulation allows multiple control inputs along the
length of the needle with full three-degree-of-freedom (DOF) planar needle
motions. Cross-validation studies using custom-designed multi-layer tissue
phantoms as well as heterogeneous chicken breast tissues result in less than
1mm in-plane errors for insertions reaching depths of up to 61 mm,
demonstrating the validity and generalizability of the proposed method
First-time rest-stress dynamic whole-body 82Rb-PET imaging using a long axial field-of-view PET/CT scanner.
Systolic Blood Pressure and Effects of Screening for Atrial Fibrillation With Long-Term Continuous Monitoring (a LOOP Substudy)
BACKGROUND: Hypertension is a well-known risk factor for atrial fibrillation (AF) and stoke, but data on the interaction between systolic blood pressure (SBP) and effects of AF screening are lacking. METHODS: The LOOP Study randomized AF-naïve individuals aged 70 to 90 years with additional stroke risk factors to either screening with implantable loop recorder (ILR) and anticoagulation initiation upon detection of AF episodes ≥6 minutes, or usual care. In total, 5997 participants with available baseline SBP measurements were included in this substudy. Outcomes were analyzed according to the time-to-first-event principle using cause-specific Cox models. RESULTS: The hazard ratio of stroke or systemic arterial embolism for ILR versus control decreased with increasing SBP. ILR screening yielded a 44% risk reduction of stroke or systemic arterial embolism among participants with SBP ≥150 mm Hg (adjusted hazard ratio, 0.56 [0.37–0.83]). Within the ILR group, SBP≥150 mm Hg was associated with a higher incidence of AF episodes ≥24 hours than lower SBP (adjusted hazard ratio, 1.70 [1.08–2.69]) but not with the overall occurrence of AF (adjusted P>0.05). CONCLUSIONS: The impact of AF screening on thromboembolic events increased with increasing blood pressure. SBP≥150 mm Hg was associated with a >1.5-fold increased risk of AF episodes ≥24 hours, along with an almost 50% risk reduction of stroke or systemic arterial embolism by ILR screening compared to lower blood pressure. These findings should be considered hypothesis-generating and warrant further study. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique Identifier: NCT02036450
The Molecular ISM in the Super Star Clusters of the Starburst NGC 253
We present submillimeter spectra of the (proto-)super star cluster (SSC)
candidates in the starbursting center of the nearby galaxy NGC 253 identified
by Leroy et al. (2018). The 2.5pc resolution of our ALMA cycle 3 observations
approach the size of the SSCs and allows the study of physical and chemical
properties of the molecular gas in these sources. In the 14 SSC sources and in
the frequency ranges 342.0-345.8 GHz and 353.9-357.7 GHz we detect 55 lines
belonging to 19 different chemical species. The SSCs differ significantly in
chemical complexity, with the richest clusters showing 19 species and the least
complex showing 4 species. We detect HCN isotopologues and isomers (HCN,
HCN, HNC), abundant HCN, SO and SO, SO, and
HCS. The gas ratios CO/HCN, CO/HCO are low, ~1-10, implying high dense
gas fractions in the SSCs. Line ratio analyses suggests chemistry consistent
with photon-dominated regions and mechanical heating. None of the SSCs near the
galaxy center show line ratios that imply an X-ray dominated region, suggesting
that heating by any (still unknown) AGN does not play a major role. The gas
temperatures are high in most sources, with an average rotational temperature
of ~130 K in SO. The widespread existence of vibrationally excited HCN and
HCN transitions implies strong IR radiation fields, potentially trapped by
a greenhouse effect due to high continuum opacities.Comment: 20 pages, 4 figures, 6 tables; accepted for publication in the
Astrophysical Journa
Long-axial field-of-view PET/CT for the assessment of inflammation in calcified coronary artery plaques with [68Â Ga]Ga-DOTA-TOC.
PURPOSE
Inflamed, prone-to-rupture coronary plaques are an important cause of myocardial infarction and their early identification is crucial. Atherosclerotic plaques are characterized by overexpression of the type-2 somatostatin receptor (SST2) in activated macrophages. SST2 ligand imaging (e.g. with [68Â Ga]Ga-DOTA-TOC) has shown promise in detecting and quantifying the inflammatory activity within atherosclerotic plaques. However, the sensitivity of standard axial field of view (SAFOV) PET scanners may be suboptimal for imaging coronary arteries. Long-axial field of view (LAFOV) PET/CT scanners may help overcome this limitation. We aim to assess the ability of [68Â Ga]Ga-DOTA-TOC LAFOV-PET/CT in detecting calcified, SST2 overexpressing coronary artery plaques.
METHODS
In this retrospective study, 108 oncological patients underwent [68 Ga]Ga-DOTA-TOC PET/CT on a LAFOV system. [68 Ga]Ga-DOTA-TOC uptake and calcifications in the coronary arteries were evaluated visually and semi-quantitatively. Data on patients' cardiac risk factors and coronary artery calcium score were also collected. Patients were followed up for 21.5 ± 3.4 months.
RESULTS
A total of 66 patients (61.1%) presented with calcified coronary artery plaques. Of these, 32 patients had increased [68 Ga]Ga-DOTA-TOC uptake in at least one coronary vessel (TBR: 1.65 ± 0.53). Patients with single-vessel calcifications showed statistically significantly lower uptake (SUVmax 1.10 ± 0.28) compared to patients with two- (SUVmax 1.31 ± 0.29, p < 0.01) or three-vessel calcifications (SUVmax 1.24 ± 0.33, p < 0.01). There was a correlation between coronary artery calcium score (CACS) and [68 Ga]Ga-DOTA-TOC uptake, especially in the LAD (p = 0.02). Stroke and all-cause death occurred more frequently in patients with increased [68 Ga]Ga-DOTA-TOC uptake (15.63% vs. 0%; p:0.001 and 21.88% vs. 6.58%; p: 0.04, respectively) during the follow-up period.
CONCLUSION
[68Â Ga]Ga-DOTA-TOC as a marker for the macrophage activity can reveal unknown cases of inflamed calcified coronary artery plaques using a LAFOV PET system. [68Â Ga]Ga-DOTA-TOC uptake increased with the degree of calcification and correlated with higher risk of stroke and all-cause death. [68Â Ga]Ga-DOTA-TOC LAFOV PET/CT may be useful to assess patients' cardiovascular risk
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