7,362 research outputs found
Impact on the Higgs Production Cross Section and Decay Branching Fractions of Heavy Quarks and Leptons in a Fourth Generation Model
In a fourth generation model with heavy quarks, the production cross section
of the Higgs boson in the gluon-gluon fusion process is significantly increased
due to additional quark loops. In a similar way, the partial decay width of the
decay channels and is modified.
These changes and their impact on the Higgs search are discussed.Comment: 9 pages, 6 figures, minor changes with a few more references adde
Full Daytime Sub-Ambient Radiative Cooling in Commercial-like Paints with High Figure of Merit
Radiative cooling is a passive cooling technology that acts by reflecting sunlight and emitting radiation in the sky window. Although highly desirable, full daytime sub-ambient radiative cooling in commercial-like single-layer particle-matrix paints has not been achieved. Here, we demonstrate full daytime sub-ambient radiative cooling in CaCO3-acrylic paint by using large band gap CaCO3 fillers, a high particle concentration of 60%, and a broad size distribution. Our paint shows a high solar reflectance of 95.5% and a high normal emissivity of 0.94 in the sky window. Field tests show cooling power exceeding 37 W/m2 and a surface temperature of \u3e1.7 degrees C below ambient at noon. A figure of merit RC is proposed to compare the cooling performance independent of weather conditions. The standard RC of our paint is 0.49, among the best radiative cooling performances, while offering the benefits of convenient paint form, low cost, and compatibility with commercial paint fabrication processes
Review of data-driven methods used to control the normalization of the top quark background contribution in the H --> WW(*) --> {\ellν\ellν} analyses at the LHC
A few data-driven methods used in deriving the normalization of the dominant top quark background contribution in the analyses by the ATLAS and CMS experiments at the LHC are reviewed and compared. Additional information, justi fication or modi fication to some of the methods is provided. These methods have also been or can be applied to other analyses such as cross section measurements of the Standard Model WW process and searches for new physics in channels with similar final states
A Learning-Based Steganalytic Method against LSB Matching Steganography
This paper considers the detection of spatial domain least significant bit (LSB) matching steganography in gray images. Natural images hold some inherent properties, such as histogram, dependence between neighboring pixels, and dependence among pixels that are not adjacent to each other. These properties are likely to be disturbed by LSB matching. Firstly, histogram will become smoother after LSB matching. Secondly, the two kinds of dependence will be weakened by the message embedding. Accordingly, three features, which are respectively based on image histogram, neighborhood degree histogram and run-length histogram, are extracted at first. Then, support vector machine is utilized to learn and discriminate the difference of features between cover and stego images. Experimental results prove that the proposed method possesses reliable detection ability and outperforms the two previous state-of-the-art methods. Further more, the conclusions are drawn by analyzing the individual performance of three features and their fused feature
Measurement of the c-axis optical reflectance of AFeAs (A=Ba, Sr) single crystals: Evidence of different mechanisms for the formation of two energy gaps
We present the c-axis optical reflectance measurement on single crystals of
BaFeAs and SrFeAs, the parent compounds of FeAs based
superconductors. Different from the ab-plane optical response where two
distinct energy gaps were observed in the SDW state, only the smaller energy
gap could be seen clearly for \textbf{E}c-axis. The very pronounced
energy gap structure seen at a higher energy scale for
\textbf{E}ab-plane is almost invisible. We propose a novel picture
for the band structure evolution across the SDW transition and suggest
different driving mechanisms for the formation of the two energy gaps.Comment: 4 page
A Sequential Circuit-Based IP Watermarking Algorithm for Multiple Scan Chains in Design-for-Test
In Very Large Scale Integrated Circuits (VLSI) design, the existing Design-for-Test(DFT) based watermarking techniques usually insert watermark through reordering scan cells, which causes large resource overhead, low security and coverage rate of watermark detection. A novel scheme was proposed to watermark multiple scan chains in DFT for solving the problems. The proposed scheme adopts DFT scan test model of VLSI design, and uses a Linear Feedback Shift Register (LFSR) for pseudo random test vector generation. All of the test vectors are shifted in scan input for the construction of multiple scan chains with minimum correlation. Specific registers in multiple scan chains will be changed by the watermark circuit for watermarking the design. The watermark can be effectively detected without interference with normal function of the circuit, even after the chip is packaged. The experimental results on several ISCAS benchmarks show that the proposed scheme has lower resource overhead, probability of coincidence and higher coverage rate of watermark detection by comparing with the existing methods
Association of Exposure to Particular Matter and Carotid Intima-Media Thickness: A Systematic Review and Meta-Analysis
Background: Long time exposure to particular matter has been linked to myocardial infarction, stroke and blood pressure, but its association with atherosclerosis is not clear. This meta-analysis was aimed at assessing whether PM2.5 and PM10 have an effect on subclinical atherosclerosis measured by carotid intima-media thickness (CIMT). Methods: Pubmed, Ovid Medline, Embase and NICK between 1948 and 31 March 2015 were searched by combining the keywords about exposure to the outcome related words. The random-effects model was applied in computing the change of CIMT and their corresponding 95% confidence interval (95% CI). The effect of potential confounding factors was assessed by stratified analysis and the impact of traffic proximity was also estimated. Results: Among 56 identified studies, 11 articles satisfied the inclusion criteria. In overall analysis increments of 10 μg/m3 in PM2.5 and PM10 were associated with an increase of CIMT (16.79 μm; 95% CI, 4.95–28.63 μm and 4.13 μm; 95% CI, −5.79–14.04 μm, respectively). Results shown in subgroup analysis had reference value for comparing with those of the overall analysis. The impact of traffic proximity on CIMT was uncertain. Conclusions: Exposure to PM2.5 had a significant association with CIMT and for women the effect may be more obvious
Autophagy Protects against Palmitic Acid-Induced Apoptosis in Podocytes in vitro
Autophagy is a highly conserved degradation process that is involved in the clearance of proteins and damaged organelles to maintain intracellular homeostasis and cell integrity. Type 2 diabetes is often accompanied by dyslipidemia with elevated levels of free fatty acids (FFAs). Podocytes, as an important component of the filtration barrier, are susceptible to lipid disorders. The loss of podocytes causes proteinuria, which is involved in the pathogenesis of diabetic nephropathy. In the present study, we demonstrated that palmitic acid (PA) promoted autophagy in podocytes. We further found that PA increased the production of reactive oxygen species (ROS) in podocytes and that NAC (N-acetyl-cysteine), a potent antioxidant, significantly eliminated the excessive ROS and suppressed autophagy, indicating that the increased generation of ROS was associated with the palmitic acid-induced autophagy in podocytes. Moreover, we also found that PA stimulation decreased the mitochondrial membrane potential in podocytes and induced podocyte apoptosis, while the inhibition of autophagy by chloroquine (CQ) enhanced palmitic acid-induced apoptosis accompanied by increased ROS generation, and the stimulation of autophagy by rapamycin (Rap) remarkably suppressed palmitic acid-induced ROS generation and apoptosis. Taken together, these in vitro findings suggest that PA-induced autophagy in podocytes is mediated by ROS production and that autophagy plays a protective role against PA-induced podocyte apoptosis
Anisotropic superconducting properties of aligned SmLaFeAsOF microcrystalline powder
The SmLaFeAsOF compound is a quasi-2D
layered superconductor with a superconducting transition temperature T = 52
K. Due to the Fe spin-orbital related anisotropic exchange coupling
(antiferromagnetic or ferromagnetic fluctuation), the tetragonal
microcrystalline powder can be aligned at room temperature using the
field-rotation method where the tetragonal -plane is parallel to the
aligned magnetic field B and -axis along the rotation axis.
Anisotropic superconducting properties with anisotropic diamagnetic ratio
2.4 + 0.6 was observed from low field susceptibility
(T) and magnetization M(B). The anisotropic low-field phase diagram
with the variation of lower critical field gives a zero-temperature penetration
depth (0) = 280 nm and (0) = 120 nm. The magnetic
fluctuation used for powder alignment at 300 K may be related with the pairing
mechanism of superconductivity at lower temperature.Comment: 4 pages, 6 figure
Accurate and affordable detection of rifampicin and isoniazid resistance in <em>Tuberculosis </em>sputum specimens by multiplex PCR-multiple probes melting analysis
\ua9 Springer-Verlag GmbH Germany, part of Springer Nature 2024.Background: Escalating cases of multidrug-resistant tuberculosis (MDR-TB) pose a major challenge to global TB control efforts, necessitating innovative diagnostics to empower decentralized detection of gene mutations associated with resistance to rifampicin (RIF) and isoniazid (INH) in Mycobacterium tuberculosis (M. tuberculosis) in resource-constrained settings. Methods: Combining multiplex fluorescent PCR and Multiple Probes Melting Analysis, we identified mutations in the rpoB, katG, ahpC and inhA genes from sputum specimens. We first constructed a reference plasmid library comprising 40 prevalent mutations in the target genes’ resistance determining regions and promoters, serving as positive controls. Our assay utilizes a four-tube asymmetric PCR method with specifically designed molecular beacon probes, enabling simultaneous detection of all 40 mutations. We evaluated the assay’s effectiveness using DNA isolated from 50 clinically confirmed M. tuberculosis sputum specimens, comparing our results with those obtained from Sanger sequencing and retrospective validation involving bacteriological culture and phenotypic drug susceptibility testing (pDST). We also included the commercial Xpert MTB/RIF assay for accuracy comparison. Results: Our data demonstrated remarkable sensitivity in detecting resistance to RIF and INH, achieving values of 93.33% and 95.24%, respectively, with a specificity of 100%. The concordance between our assay and pDST was 98.00%. Furthermore, the accuracy of our assay was comparable to both Sanger sequencing and the Xpert assay. Importantly, our assay boasts a 4.2-h turnaround time and costs only $10 per test, making it an optimal choice for peripheral healthcare settings. Conclusion: These findings highlight our assay’s potential as a promising tool for rapidly, accurately, and affordably detecting MDR-TB
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