1,301 research outputs found
Granger inspired testing the ISDs for possible causal relationships
Arjan de Haan and his co-authors are keen to use the ISS Indicators of Social Development (hereafter the ISDs) to show how institutional structuration processes can cause improvements in human well-being, including economic growth (de Haan et al, 2011). Developing this aspiration, though not uncritically, this paper explores how the ISS ISDs might be used to stimulate thinking about causal relationships by linking the ISDs to each other and conventional measures of country-level development status.
But before undertaking the task of attributing causality, it is necessary to reflect on the nature of the data being used. The challenges in using the ISDs’ data can be summarised into six problems which need diagnostic reflection before interpretation of causal relationships can be convincingly undertaken ....
Effect of alloying elements on magnesium alloy damping capacities at room temperature
Alloying is a good approach to increasing its strength but leads to a reduction of damping to pure magnesium. Classifying the alloying characteristics of various alloying elements in magnesium alloys and their combined effects on the damping and mechanical properties of magnesium alloys is important. In this paper, the properties of the Mg-0.6wt%X binary alloys were analyzed through strength measurements and dynamic mechanical analysis. The effects of foreign atoms on solid-solution strengthening and dislocation damping were studied comprehensively. The effect of solid solubility on damping capacity can be considered from two perspectives: the effect of single solid-solution atoms on the damping capacities of the alloy, and the effect of solubility on the damping capacities of the alloy. The results provide significant information that is useful in developing high-strength, high-damping magnesium alloys. This study will provide scientific guidance regarding the development of new types of damping magnesium alloys
Experimental and Numerical Analysis of Normal and Lateral High-Velocity Impacts on Carbon Fiber-Reinforced Polymer Laminates
This paper examines the effects of normal and lateral high-speed impacts on carbon fiber-reinforced polymer laminates. Experimental tests were conducted at varying velocities (120–200 m/s), and the differing damage modes between normal and lateral impacts were analyzed. Dynamic finite element analysis was performed to simulate the damage process using the finite element software ABAQUS. The simulation shows a good correlation with the experimental results
Bis (1Z,3Z)-1,3-bis(4-fluorophenyl)-N,N '-diphenylpropanediiminato magnesium(II)
In the title complex, [Mg(C27H19F2N2)(2)], the Mg-II atom, lying on a crystallographic twofold rotation axis, is tetrahedrally coordinated by four N atoms from two diiminate ligands
B --> rho l nu Decay and |V_{ub}|
B --> rho l nu decay is analyzed in the effective theory of heavy quark with
infinite mass limit. The matrix element relevant to the heavy to light vector
meson semileptonic decays is parametrized by a set of four heavy flavor-spin
independent universal wave functions at the leading order of effective theory.
The form factors are calculated at the leading 1/m_Q order using the light cone
sum rule method in the framework of effective theory. |V_{ub}| is then
extracted via B --> rho l nu decay mode.Comment: 10 pages, ReVtex, 2 figures, corrected signs in some formula
Development of potency assays for a plasmid containing vascular endothelial growth factor 2
We have developed analytical methods to measure the biological
functions of pVGI.1(VEGF2), a naked plasmid DNA product containing
vascular endothelial growth factor 2 used in clinical trials for
coronary artery diseases (CAD) and peripheral artery diseases (PAD).
After being injected into muscles, vascular endothelial growth factor 2
(VEGF-2), presumably expressed in muscle tissues, binds to the
endothelial cell receptors VEGFR2 or VEGFR3, triggering the downstream
responses including cell proliferation and vascularization. As it is
important to make sure clinical material is biological active, we
developed a quantitative assay first to measure the receptor binding
activity of the pVGI.1(VEGF2) gene product expressed by the transfected
host cells, and then a qualitative assay to confirm the cell
proliferation promoting activity of the expressed protein. In both
assays the signals were plotted directly against input DNA
concentrations used to transfect the host cells. We confirmed
specificity for both assays. In addition, we demonstrated acceptable
levels of spike recovery (86.7-116%), precision (largest relative
standard deviation (RSD)=19.3%), linearity and range (60-140% relative
potency, 15 - 35 \ub5g/mL) for the quantitative assay. We intend to
use the potency assays for routine lot release and stability studies
Magnetic phase diagram in EuLaFeAs single crystals
We have systematically measured resistivity, susceptibility and specific heat
under different magnetic fields (H) in EuLaFeAs single
crystals. It is found that a metamagnetic transition from A-type
antiferromagnetism to ferromagnetism occurs at a critical field for magnetic
sublattice of . The jump of specific heat is suppressed and shifts to
low temperature with increasing H up to the critical value, then shifts to high
temperature with further increasing H. Such behavior supports the metamagnetic
transition. Detailed H-T phase diagrams for x=0 and 0.15 crystals are given,
and possible magnetic structure is proposed. Magnetoresistance measurements
indicate that there exists a strong coupling between local moment of
and charge in Fe-As layer. These results are very significant to understand the
underlying physics of FeAs superconductors.Comment: 5 pages, 4 figure
Further investigations of linear trirhodium complexes: experimental and theoretical studies of Rh-3(dpa)(4)Cl-2 and Rh-3(dpa)(4)Cl-2 (BF4) dpa = bis(2-pyridyl)amido anion
The linear trirhodium compound, Rh-3(dpa)(4)Cl-2 (1), and its one-electron oxidation product, [Rh-3(dpa)(4)Cl-2]BF4 (2), have been synthesized and studied extensively. The magnetic measurement for compound 1 shows that it possesses one unpaired electron that is assigned to occupy the sigma(nb) orbital ((2)A(2)) by DFT calculations. Upon oxidation, a beta-spin electron of 1 is removed, that causes compound 2 to exhibit a triplet ground state. DFT calculations indicate that the two unpaired electrons of 2 occupy sigma(nb) and delta* orbitals (B-3(1)), which is supported by H-1 NMR spectrum. Unlike their isoelectronic analogues [Co-3(dpa)(4)Cl-2] (3) and [Co-3(dpa)(4)(Cl)(2)]BF4 (4), both compound 1 and 2 do not display the spin-crossover phenomenon. The reason may be attributed to the relative large energy gap between B-3(1) and open-shell singlet B-1(1) states
The association between distal findings and proximal colorectal neoplasia: a systematic review and meta-analysis
Objectives:
Whether screening participants with distal hyperplastic polyps (HPs) detected by flexible sigmoidoscopy (FS) should be followed by subsequent colonoscopy is controversial. We evaluated the association between distal HPs and proximal neoplasia (PN)/advanced proximal neoplasia (APN) in asymptomatic, average-risk patients.
Methods:
We searched Ovid Medline, EMBASE, and the Cochrane Library from inception to 30 June 2016 and included all screening studies that examined the relationship between different distal findings and PN/APN. Data were independently extracted by two reviewers with disagreements resolved by a third reviewer. We pooled absolute risks and odds ratios (ORs) with a random effects meta-analysis. Seven subgroup analyses were performed according to study characteristics. Heterogeneity was characterized with theI2 statistics.
Results:
We analyzed 28 studies (104,961 subjects). When compared with normal distal findings, distal HP was not associated with PN (OR=1.16, 95% confidence interval (CI)=0.89–1.51,P=0.14,I2=40%) or APN (OR=1.09, 95% CI=0.87–1.36,P=0.39,I2=5%), while subjects with distal non-advanced or advanced adenoma had higher odds of PN/APN. Higher odds of PN/APN were observed for more severe distal lesions. Weaker association between distal and proximal findings was noticed in studies with higher quality, larger sample size, population-based design, and more stringent endoscopy quality-control measures. The Egger’s regression tests showed allP>0.05.
Conclusions:
Distal HP is not associated with PN/APN in asymptomatic screening population when compared with normal distal findings. Hence, the presence of distal HP alone detected by FS does not automatically indicate colonoscopy referral for all screening participants, as other risk factors of PN/APN should be considered
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