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Relative effects of LDL-C on ischemic stroke and coronary disease A Mendelian randomization study
No full textObjective To examine the causal relevance of lifelong differences in low-density lipoprotein cholesterol (LDL-C) for ischemic stroke (IS) relative to that for coronary heart disease (CHD) using a Mendelian randomization approach. Methods We undertook a 2-sample Mendelian randomization, based on summary data, to estimate the causal relevance of LDL-C for risk of IS and CHD. Information from 62 independent genetic variants with genome-wide significant effects on LDL-C levels was used to estimate the causal effects of LDL-C for IS and IS subtypes (based on 12,389 IS cases from METASTROKE) and for CHD (based on 60,801 cases from CARDIoGRAMplusC4D). We then assessed the effects of LDL-C on IS and CHD for heterogeneity. Results A 1 mmol/L higher genetically determined LDL-C was associated with a 50% higher risk of CHD (odds ratio OR] 1.49, 95% confidence interval CI] 1.32-1.68, p = 1.1 x 10(-8)). By contrast, the causal effect of LDL-C was much weaker for IS (OR 1.12, 95% CI 0.96-1.30, p = 0.14; p for heterogeneity = 2.6 x 10(-3)) and, in particular, for cardioembolic stroke (OR 1.06, 95% CI 0.84-1.33, p = 0.64; p for heterogeneity = 8.6 x 10(-3)) when compared with that for CHD. Conclusions In contrast with the consistent effects of LDL-C-lowering therapies on IS and CHD, genetic variants that confer lifelong LDL-C differences show a weaker effect on IS than on CHD. The relevance of etiologically distinct IS subtypes may contribute to the differences observed
Measurement of anisotropic flow in XeXe collisions at 5.44 TeV with the CMS experiment
No full textNew measurements of anisotropic flow in XeXe collisions at a center-of-mass energy of 5.44 TeV per nucleon pair, collected by the CMS experiment at the LHC, are presented. The v(2), v(3) and v(4) Fourier coefficients of the anisotropic azimuthal distribution are obtained employing three different analysis techniques: two-particle correlations, the scalar product method, and multiparticle cumulants, which have different sensitivities to non-flow and flow fluctuation effects. The results are shown as a function of transverse momentum (P-T) for various centrality selections, and compared with corresponding results from PbPb collisions. These new measurements in a smaller nucleus-nucleus system than PbPb provide additional insights into the system-size dependence of the collective flow induced by the dominant collision geometry and its fluctuations. In particular, these results, compared to theoretical predictions and Monte Carlo generators, will provide important details on the system size dependence of the medium response in heavy ion collisions. They also offer a unique opportunity to study the onset of flow from small to large systems
Beyond nPDFs effects : Prompt J/psi and psi(2S) production in pPb and pp collisions
No full textA multi-dimensional analysis of prompt charmonia in pp and pPb collisions at root s(NN) = 5.02 TeV with the CMS detector is presented. The pPb differential cross-sections of prompt J/psi are shown in a wide kinematic region, for transverse momentum p(T) spanning from 2 to 30 GeV/c and a rapidity interval between -2.4 to 1.93 in the center of mass of the collision. The final results on prompt psi/(2S) meson production cross section in pp and pPb collisions at 5.02 TeV are also reported as a function of p(T) and rapidity, for p(T) from 4 to 30 GeV/c. The nuclear modification factor is found to be smaller than that of prompt J/psi in all measured bins, especially at low p(T) and at backward rapidity. Such a different behaviour between the ground and excited states cannot be reproduced considering nPDF effects alone
Investigation of Ta 2 O 5 as an alternative high-k dielectric for InAlN/GaN MOS-HEMT on Si
No full textWe report on the demonstration and investigation of Ta 2 O 5 as high-k dielectric for InAIN/GaN-MOS high-electron mobility transistor (HEMT)-on-Si. Ta 2 O 5 of thickness 24 nm and dielectric constant �30 was sputter deposited on InAlN/GaN HEMT and was investigated for different post deposition anneal (PDA) conditions. The gate leakage was 16 nA/mm at -15 V which was �five orders of magnitude lower compared to reference HEMT. The 2-D electron gas (2-DEG) density was found to vary with annealing temperature suggesting the presence of net charge at the Ta 2 O 5 /InAIN interface. Dispersion in the capacitance-voltage (C-V) characteristics was used to estimate the frequency-dependent interface charge, while energy band diagrams under flat band conditions were investigated to estimate fixed charge. The optimum anneal condition was found to be 500 °C which has resulted into a flat band voltage spread (�V FB ) of 0.4 V and interface fix charge (Q f ) of 3.98 � 10 13 cm -2 . X-ray photoelectron spectroscopy spectra of as-deposited and annealed Ta 2 O 5 film were analyzed for Ta and O compositions in the film. The sample annealed at 500 °C has shown Ta:0 ratio of 0.41. X-ray diffraction analysis was done to checkthe crystallization of amorphous Ta 2 O 5 film at higher annealing temperatures. © 2019 IEEE
Robust Loss Functions for Learning Multi-class Classifiers
No full textRobust learning in presence of label noise is an important problem of current interest. Training data often has label noise due to subjective biases of experts, crowd-sourced labelling or other automatic labelling processes. Recently, some sufficient conditions on a loss function are proposed so that risk minimization under such loss functions is provably tolerant to label noise. The standard loss functions such as cross-entropy or mean-squared error, used for learning neural network classifiers, do not satisfy these conditions. It was shown that a loss function based on mean absolute value of error satisfies the conditions and is also empirically seen to be robust to label noise. However, minimizing absolute value of error is a difficult optimization problem. In this paper we propose a new loss function, called robust log loss and show that it satisfies the sufficient conditions for robustness. The resulting optimization problem of minimizing empirical risk is well behaved. Through extensive empirical results we show that, in terms of accuracy and learning rate, the proposed loss function is as good as cross-entropy loss for learning neural network classifiers when there is no label noise and that it is better when the training data has label noise. © 2018 IEEE
Deformation field interaction in sequential circular indentation of a strain hardening material
No full textAn experimental study was made to characterise and model the deformation field in sequential circular indentation of a model strain hardening material. Digital image correlation was used to measure the evolving subsurface deformation field in terms of displacement, strain rate and strain as a function of indentation spacing and depth. These measurements were used to validate a finite element model for complementary simulations. The results identify relationships between sequential indentation parameters and overlap of subsurface strain distributions, maximum subsurface strains and indentation loads. Maximum strain and the degree of strain field overlap in the deformed subsurface were maximised when the ratio of indentation spacing (S) to projected indentation contact length (L) was approximately S/L = 1.1, 1.2. Also discussed are the implications for understanding process-scale considerations for indentation-based mechanical surface treatments, including energy dissipation and relationship of surface coverage measures to subsurface strain overlap. Relative differences in energy expended were found for conditions that produce similar levels of subsurface plastic strain and strain field overlap. Finally, the role of sequential indentation parameters on strain path changes and path reversals in the deformed subsurface is investigated and discussed in the context of heterogeneous mechanics and corresponding effects on subsurface microstructure evolution. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group
Measurement of radiation heat transfer in supercritical carbon dioxide medium
No full textIn this work, a novel experimental method for measurement of radiation emitted by supercritical carbon dioxide (s-CO 2 ) at high pressure and high temperature is presented. Due to high pressure conditions, use of conventional spectroscopic methods to measure radiative properties of s-CO 2 is challenging. In the present method, supercritical conditions are created in a shock tube by using carbon dioxide (CO 2 ) as the driven gas. The radiative emission by s-CO 2 is measured using a platinum based thin film sensor. The total emissivity for s-CO 2 is estimated and the value compares favourably with that predicted theoretically using a standard method available in literature. It is estimated that the total emissivity value of supercritical conditions is nearly 0.2 for the conditions studied, implying that s-CO 2 acts as a participating medium for radiation heat transfer. The outcome of this study will have significant impact on the design of heat transfer equipment such as solar thermal receivers and heat exchangers typically used in s-CO 2 based closed Brayton cycle, for which participating medium radiation heat transfer has been neglected traditionally. © 2019 Elsevier Lt
Collision Avoidance of Arbitrarily Shaped Deforming Objects Using Collision Cones
No full textIn this letter, the problem of collision avoidance of objects, which can deform by changing their shape as a function of time, is considered. There are several scenarios involving such deforming objects - examples include environments with shape-shifting robots, such as snake robots, boundaries of swarms of vehicles, and boundaries of oil spills. There is very limited work in the literature that considers dynamic environments comprising such shape changing entities. To develop conditions that predict the onset of collision for deformable objects, this letter uses the notion of collision cones in environments involving engagements between a point object and a deforming object, a circular object and a deforming object, and finally, an arbitrarily shaped object and a deforming object. The collision cone equations are subsequently embedded in a Lyapunov framework and used to develop nonlinear analytical guidance laws for collision avoidance in such environments. Simulations are performed to demonstrate the efficacy of the guidance laws
Electronic nose: a non-invasive technology for breath analysis of diabetes and lung cancer patients
No full textIn human exhaled breath, more than 3000 volatile organic compounds (VOCs) are found, which are directly or indirectly related to internal biochemical processes in the body. Electronic noses (E-noses) could play a potential role in screening/analyzing various respiratory and systemic diseases by studying breath signatures. An E-nose integrates a sensor array and an artificial neural network that responds to specific patterns of VOCs, and thus can act as a non-invasive technology for disease monitoring. The gold standard blood glucose monitoring test for diabetes diagnostics is invasive and highly uncomfortable. This contributes to the massive need for technologies which are non-invasive and can be used as an alternative to blood measurements for glucose detection. While lung cancer is one of the deadliest cancers with the highest death rate and an extremely high yearly global burden, the conventional diagnosis means, such as sputum cytology, chest radiography, or computed tomography, do not support wide-range population screening. A few standard non-invasive techniques, such as mass spectrometry and gas chromatography, are expensive, non-portable, and require skilled personnel for operation and are again not suitable for large-scale screening. Breath contains markers for both diabetes and lung cancer along with markers for several diseases and thus, a non-invasive technique such as the E-nose would greatly improve analysis procedures over existing invasive methods. This review shows the state-of-the-art technologies for VOC detection and machine learning approaches for two clinical models: diabetes and lung cancer detection
Decreasing Trend in Black Carbon Aerosols Over the Indian Region
No full textWe examine long-term trends in the near-surface black carbon mass concentration, using multiyear primary data obtained from a dense network (ARFINET) of observatories over the Indian region. We report for the first time the statistically significant decreasing trend in black carbon mass concentration, based on primary data from this region, at an average rate of ~242 ± 53 ng · m �3  · year �1 during the period 2007�2016. This finding contrasts with the generally increasing trend in the columnar aerosol optical depth, reported earlier, and the steadily increasing trend in anthropogenic activities over this region. The roles of different possible mechanisms, including possible changes in the vertical redistribution of aerosols, are discussed. Over the period 2007�2015, a significant though weak, increasing trend is seen in the contribution from aerosols above 1 km to the columnar aerosol optical depth. These observations imply possible long-term climate consequences. ©2019. American Geophysical Union. All Rights Reserved