Nesterov smoothing for sampling without smoothness

We study the problem of sampling from a target distribution in $\mathbb{R}^d$ whose potential is not smooth. Compared with the sampling problem with smooth potentials, this problem is much less well-understood due to the lack of smoothness. In this paper, we propose a novel sampling algorithm for a class of non-smooth potentials by first approximating them by smooth potentials using a technique that is akin to Nesterov smoothing. We then utilize sampling algorithms on the smooth potentials to generate approximate samples from the original non-smooth potentials. We select an appropriate smoothing intensity to ensure that the distance between the smoothed and un-smoothed distributions is minimal, thereby guaranteeing the algorithm's accuracy. Hence we obtain non-asymptotic convergence results based on existing analysis of smooth sampling. We verify our convergence result on a synthetic example and apply our method to improve the worst-case performance of Bayesian inference on a real-world example

Nonreciprocal entanglement in cavity-magnon optomechanics

Cavity optomechanics, a promising platform to investigate macroscopic quantum effects, has been widely used to study nonreciprocal entanglement with Sagnec effect. Here we propose an alternative way to realize nonreciprocal entanglemment among magnons, photons, and phonons in a hybrid cavity-magnon optomechanics, where magnon Kerr effect is used. We show that the Kerr effect gives rise to a magnon frequency shift and an additional two-magnon effect. Both of them can be tuned from positive to negative via tuning the magectic field direction, leading to nonreciprocity. By tuning system parameters such as magnon frequency detuning or the coefficient of the two-magnon effect, bipartite and tripartite entanglements can be nonreciprocally enhanced. By further studying the defined bidirectional contrast ratio, we find that nonreciprocity in our system can be switch on and off, and can be engineered by the bath temperature. Our proposal not only provides a potential path to demonstrate nonreciprocal entanglement with the magnon Kerr effect, but also opens a direction to engineer and design diverse nonreciprocal devices in hybrid cavity-magnon optomechanics with nonlinear effects.Comment: 8 pages,4 figures. Accepted by Phys. Rev.

Experimental and analytic study of a hybrid solar/biomass rural heating system

© 2019 Elsevier Ltd This paper presents a dedicated analytic and experimental study of a hybrid solar/biomass space heating system incorporating a micro-channel solar thermal panels-array, a biomass boiler and a dedicated control algorithm. This system enables the smart and joint use of solar and biomass energies to provide a comfortable indoor environment. The in-situ testing of the system was undertaken and the data obtained from the testing were analysed using Grubbs method to formulate the experimental thermal efficiency equation for the solar panels-array and the heat conversion factor equation for the combined heat storage/exchanging water tank. The annual energy performance of the hybrid system was investigated using a professional building energy simulation program (EnergyPlus), which can predict the heat load profile of house, the ratio of energy usage from solar/biomass sources and the primary energy/exergy efficiencies. The thermal efficiency of the solar thermal panels-array is in the range of 60%–70%. The heat storage water tank has a heat conversion factor in the range of 0.94–0.98. The heat load index per unit area is 46.86 W/m2 and cumulative heating energy consumption with 100 m2 house is 24.3 GJ during a heating season. The total annual energy demand of the solar/biomass heating system is around 35.91 GJ, of which the sun provides 63.31% and biomass provides 36.69%. The primary energy and exergy efficiencies of the solar/biomass rural heating system are 67.66% and 16.17% respectively. However, when the total input electrical exergy is traced back to its primary energy source, i.e. a coal-fired power plant, the exergy efficiency falls from 23.14% to 7.27%. Compared to the traditional primary energy supply system, the energy conversion effect and effective utilization degree of the solar/biomass heating system are relatively higher

Marek’s Disease Virus Activates the PI3K/Akt Pathway Through Interaction of Its Protein Meq With the P85 Subunit of PI3K to Promote Viral Replication

It is known that viruses can active the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway in host cells to support cell survival and viral replication; however, the role of PI3K/Akt signaling in the pathogenic mechanisms induced by Marek’s disease virus (MDV) which causes a neoplastic Marek’s disease in poultry, remains unknown. In this study, we showed that MDV activated the PI3K/Akt pathway in chicken embryo fibroblasts (CEFs) at the early phase of infection, whereas treatment with a PI3K inhibitor LY294002 prior to MDV infection decreased viral replication and DNA synthesis. Flow cytometry analysis showed that inhibition of the PI3K/Akt pathway could significantly increase apoptosis in MDV-infected host cells, indicating that activation of PI3K/Akt signaling could facilitate viral replication through support of cell survival during infection. Evaluation of the underlying molecular mechanism by co-immunoprecipitation and laser confocal microscopy revealed that a viral protein Meq interacted with both p85α and p85β regulatory subunits of PI3K and could induce PI3K/Akt signaling in Meq-overexpressing chicken fibroblasts. Our results showed, for the first time, that MDV activated PI3K/Akt signaling in host cells through interaction of its Meq protein with the regulatory p85 subunit of PI3K to delay cell apoptosis and promote viral replication. This study provides clues for further studies of the molecular mechanisms underlying MDV infection and pathogenicity for the host

GSKJ4 Protects Mice Against Early Sepsis via Reducing Proinflammatory Factors and Up-Regulating MiR-146a

Sepsis, defined as life-threatening organ dysfunction, is one of the most common causes of mortality in intensive care units with limited therapeutic options. However, the mechanism underlying the regulation of epigenetics on sepsis remains largely undefined. Here we showed that JMJD3, the histone lysine demethylase, played a critical role in the epigenetic regulation of innate immunity during early sepsis. Pharmacological inhibition of JMJD3 by GSKJ4 protected mice against early septic death and reduced pro-inflammatory cytokine interleukin-1β (IL-1β) production as well as IL-6, tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) expression. Interestingly, GSKJ4 up-regulated the transcription of anti-inflammatory microRNA-146a (miR-146a) in peritoneal macrophages from septic mice. Mechanistically, JMJD3 negatively regulated the transcription of miR-146a via its demethylation of H3K27me3 on the promoter of miR-146a. Moreover, the transcription of miR-146a was positively regulated by nuclear factor-κB (NF-κB) p65. Inhibition of NF-κB p65 promoted JMJD3 binding to miR-146a promoter and decreased the tri-methylation level of H3K27, while the inhibition of JMJD3 did not affect the recruitment of NF-κB p65 to miR-146a promoter. These results highlight an epigenetic mechanism by which JMJD3 was inhibited by NF-κB p65 from binding to miR-146a promoter to promote the anti-inflammatory response. Taken together, our findings uncover a key role for JMJD3 in modulating the miR-146a transcription and shed light on the JMJD3 inhibitors could be potential therapeutic agents for early sepsis therapy

Economic Effects of Ecological Compensation Policy in Shiyang River Basin: Empirical Research Based on DID and RDD Models

In order to achieve the sustainable development of ecological resources and social economy in the Shiyang River Basin, a series of Ecological Compensation policies have been implemented in the basin. This study takes these policies as an opportunity to design an experiment. The nine counties (districts) affected by these policies are used as the experimental samples, and the period from 2000 to 2019 is the experimental period. The difference-in-differences method is used to study the effect of the series of Ecological Compensation policies in the Shiyang River Basin on the economic development of the basin. Furthermore, the regression discontinuity design was used to estimate the time and mechanism of this effect. The research found that the early start of phase I of the Key Governance Planning Project in 2006 played a significant and continuous promotive role in the economic development of the river basin; the Water Resources Allocation and Regulation Plan significantly promoted the development of tertiary industry in 2005–2007; the Key Governance Planning significantly promoted the development of primary industry in 2007–2010. The results suggest that to optimize the industrial structure to the maximum extent in the future and promote the sustainable development of ecological resources and social economy in the Shiyang River Basin, economic changes, such as water-saving green agriculture and eco-tourism, should be developed