9 research outputs found
Extreme Limit Theory of Competing Risks under Power Normalization
Advanced science and technology provide a wealth of big data from different
sources for extreme value analysis.Classic extreme value theory was extended to
obtain an accelerated max-stable distribution family for modelling competing
risk-based extreme data in Cao and Zhang (2021). In this paper, we establish
probability models for power normalized maxima and minima from competing risks.
The limit distributions consist of an extensional new accelerated max-stable
and min-stable distribution family (termed as the accelerated p-max/p-min
stable distribution), and its left-truncated version. The limit types of
distributions are determined principally by the sample generating process and
the interplay among the competing risks, which are illustrated by common
examples. Further, the statistical inference concerning the maximum likelihood
estimation and model diagnosis of this model was investigated. Numerical
studies show first the efficient approximation of all limit scenarios as well
as its comparable convergence rate in contrast with those under linear
normalization, and then present the maximum likelihood estimation and diagnosis
of accelerated p-max/p-min stable models for simulated data sets. Finally, two
real datasets concerning annual maximum of ground level ozone and survival
times of Stanford heart plant demonstrate the performance of our accelerated
p-max and accelerated p-min stable models
Extreme analysis of typhoons disaster in mainland China with insurance management
Due to climate change, typhoons, especially extreme typhoons, are becoming more intense and causing ascending financial losses. A majority of previous studies on typhoon economic losses over a period of time considered all types of typhoon rather than the extreme typhoons. This study focuses on the risk management of extreme typhoons by establishing the compensation mechanism and a typhoon-specific insurance product. The annual maximum losses of typhoons is first modelled by generalized extreme value distribution (GEV) under the Extreme Value Theory (EVT). The prediction of unexpected economic losses is then obtained via VaR and CVaR for the compensation mechanism among individual, insurance company and government. To analyse the typhoon vulnerability of 11 Chinese coastal provinces (or municipalities), the Multiple-Criteria Decision Making (MCDM) method, combining Analytic Hierarchy Process (AHP) based Grey Rational Analysis (GRA) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), is applied for evaluating the typhoon vulnerability of these regions for 2022. The nationwide best estimates for typhoon reserves on the basis of insurance compensation mechanism is therefore calculated and will be allocated to these 11 provinces according to the vulnerability ranking obtained via MCDM method. The findings indicate that the top three provinces (Guangdong, Fujian and Zhejiang) in typhoon vulnerability rankings are also with the highest losses and frequency in practice, while Hebei has the highest insurance premium
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HDAC1 and 2 regulate endothelial VCAM-1 expression and atherogenesis by suppressing methylation of the GATA6 promoter.
Increased expression of vascular cell adhesion molecule (VCAM)-1 on the activated arterial endothelial cell (EC) surface critically contributes to atherosclerosis which may in part be regulated by epigenetic mechanisms. This study investigated whether and how the clinically available histone deacetylases 1 and 2 (HDAC1/2) inhibitor drug Romidepsin epigenetically modulates VCAM-1 expression to suppress atherosclerosis. Methods: VCAM-1 expression was analyzed in primary human aortic EC (HAEC) treated with Romidepsin or transfected with HDAC1/2-targeting siRNA. Methylation of GATA6 promoter region was examined with methylation-specific PCR assay. Enrichment of STAT3 to GATA6 promoter was detected with chromatin immunoprecipitation. Lys685Arg mutation was constructed to block STAT3 acetylation. The potential therapeutic effect of Romidepsin on atherosclerosis was evaluated in Apoe -/- mice fed with a high-fat diet. Results: Romidepsin significantly attenuated TNFα-induced VCAM-1 expression on HAEC surface and monocyte adhesion through simultaneous inhibition of HDAC1/2. This downregulation of VCAM-1 was attributable to reduced expression of transcription factor GATA6. Romidepsin enhanced STAT3 acetylation and its binding to DNA methyltransferase 1 (DNMT1), leading to hypermethylation of the GATA6 promoter CpG-rich region at +140/+255. Blocking STAT3 acetylation at Lys685 disrupted DNMT1-STAT3 interaction, decreased GATA6 promoter methylation, and reversed the suppressive effects of HDAC1/2 inhibition on GATA6 and VCAM-1 expression. Finally, intraperitoneal administration of Romidepsin reduced diet-induced atherosclerotic lesion development in Apoe -/- mice, accompanied by a reduction in GATA6/VCAM-1 expression in the aorta. Conclusions: HDAC1/2 contributes to VCAM-1 expression and atherosclerosis by suppressing STAT3 acetylation-dependent GATA6 promoter methylation. These findings may provide a rationale for HDAC1/2-targeting therapy in atherosclerotic heart disease
Wide-Range Linear Iontronic Pressure Sensor with Two-Scale Random Microstructured Film for Underwater Detection
A broad linear range
of ionic flexible sensors (IFSs) with high
sensitivity is vital to guarantee accurate pressure acquisition and
simplify back-end circuits. However, the issue that sensitivity gradually
decreases as the applied pressure increases hinders the linearity
over the whole working range and limits its wide-ranging application.
Herein, we design a two-scale random microstructure ionic gel film
with rich porosity and a rough surface. It increases the buffer space
during compression, enabling the stress deformation to be more uniform,
which makes sure that the sensitivity maintains steady as the pressure
loading. In addition, we develop electrodes with multilayer graphene
produced by a roll-to-roll process, utilizing its large interlayer
spacing and ion-accessible surface area. It benefits the migration
and diffusion of ions inside the electrolyte, which increases the
unit area capacitance and sensitivity, respectively. The IFS shows
ultra-high linearity and a linear range (correlation coefficient ∼
0.9931) over 0–1 MPa, an excellent sensitivity (∼12.8
kPa–1), a fast response and relaxation time (∼20
and ∼30 ms, respectively), a low detection limit (∼2.5
Pa), and outstanding mechanical stability. This work offers an available
path to achieve wide-range linear response, which has potential applications
for attaching to soft robots, followed with sensing slight disturbances
induced by ships or submersibles
Wide-Range Linear Iontronic Pressure Sensor with Two-Scale Random Microstructured Film for Underwater Detection
A broad linear range
of ionic flexible sensors (IFSs) with high
sensitivity is vital to guarantee accurate pressure acquisition and
simplify back-end circuits. However, the issue that sensitivity gradually
decreases as the applied pressure increases hinders the linearity
over the whole working range and limits its wide-ranging application.
Herein, we design a two-scale random microstructure ionic gel film
with rich porosity and a rough surface. It increases the buffer space
during compression, enabling the stress deformation to be more uniform,
which makes sure that the sensitivity maintains steady as the pressure
loading. In addition, we develop electrodes with multilayer graphene
produced by a roll-to-roll process, utilizing its large interlayer
spacing and ion-accessible surface area. It benefits the migration
and diffusion of ions inside the electrolyte, which increases the
unit area capacitance and sensitivity, respectively. The IFS shows
ultra-high linearity and a linear range (correlation coefficient ∼
0.9931) over 0–1 MPa, an excellent sensitivity (∼12.8
kPa–1), a fast response and relaxation time (∼20
and ∼30 ms, respectively), a low detection limit (∼2.5
Pa), and outstanding mechanical stability. This work offers an available
path to achieve wide-range linear response, which has potential applications
for attaching to soft robots, followed with sensing slight disturbances
induced by ships or submersibles
Wide-Range Linear Iontronic Pressure Sensor with Two-Scale Random Microstructured Film for Underwater Detection
A broad linear range
of ionic flexible sensors (IFSs) with high
sensitivity is vital to guarantee accurate pressure acquisition and
simplify back-end circuits. However, the issue that sensitivity gradually
decreases as the applied pressure increases hinders the linearity
over the whole working range and limits its wide-ranging application.
Herein, we design a two-scale random microstructure ionic gel film
with rich porosity and a rough surface. It increases the buffer space
during compression, enabling the stress deformation to be more uniform,
which makes sure that the sensitivity maintains steady as the pressure
loading. In addition, we develop electrodes with multilayer graphene
produced by a roll-to-roll process, utilizing its large interlayer
spacing and ion-accessible surface area. It benefits the migration
and diffusion of ions inside the electrolyte, which increases the
unit area capacitance and sensitivity, respectively. The IFS shows
ultra-high linearity and a linear range (correlation coefficient ∼
0.9931) over 0–1 MPa, an excellent sensitivity (∼12.8
kPa–1), a fast response and relaxation time (∼20
and ∼30 ms, respectively), a low detection limit (∼2.5
Pa), and outstanding mechanical stability. This work offers an available
path to achieve wide-range linear response, which has potential applications
for attaching to soft robots, followed with sensing slight disturbances
induced by ships or submersibles