Approximate Pricing of Derivatives Under Fractional Stochastic Volatility Model

We investigate the problem of pricing derivatives under a fractional stochastic volatility model. We obtain an approximate expression of the derivative price where the stochastic volatility can be composed of deterministic functions of time and fractional Ornstein-Uhlenbeck process. Numerical simulations are given to illustrate the feasibility and operability of the approximation, and also demonstrate the effect of long-range on derivative prices

Influence or Advertise: The Role of Social Learning in Influencer Marketing

We compare influencer marketing to targeted advertising from information aggregation and product awareness perspectives. Influencer marketing leverages network effects by allowing consumers to socially learn from each other about their experienced content utility, but consumers may not know whether to attribute promotional post popularity to high content or high product quality. If the quality of a product is uncertain (e.g., it belongs to an unknown brand), then a mega influencer with consistent content quality fosters more information aggregation than a targeted ad and thereby yields higher profits. When we compare influencer marketing to untargeted ad campaigns or if the product has low quality uncertainty (e.g., belongs to an established brand), then many micro influencers with inconsistent content quality create more consumer awareness and yield higher profits. For products with low quality uncertainty, the firm wants to avoid information aggregation as it disperses posterior beliefs of consumers and leads to fewer purchases at the optimal price. Our model can also explain why influencer campaigns either go viral or go bust, and how for niche products, micro-influencers with consistent content quality can be a valuable marketing tool

Pano-NeRF: Synthesizing High Dynamic Range Novel Views with Geometry from Sparse Low Dynamic Range Panoramic Images

Panoramic imaging research on geometry recovery and High Dynamic Range (HDR) reconstruction becomes a trend with the development of Extended Reality (XR). Neural Radiance Fields (NeRF) provide a promising scene representation for both tasks without requiring extensive prior data. However, in the case of inputting sparse Low Dynamic Range (LDR) panoramic images, NeRF often degrades with under-constrained geometry and is unable to reconstruct HDR radiance from LDR inputs. We observe that the radiance from each pixel in panoramic images can be modeled as both a signal to convey scene lighting information and a light source to illuminate other pixels. Hence, we propose the irradiance fields from sparse LDR panoramic images, which increases the observation counts for faithful geometry recovery and leverages the irradiance-radiance attenuation for HDR reconstruction. Extensive experiments demonstrate that the irradiance fields outperform state-of-the-art methods on both geometry recovery and HDR reconstruction and validate their effectiveness. Furthermore, we show a promising byproduct of spatially-varying lighting estimation. The code is available at https://github.com/Lu-Zhan/Pano-NeRF

Effect of blocking Ras signaling pathway with K-Ras siRNA on apoptosis in esophageal squamous carcinoma cells

AbstractObjectiveTo study the effect of RNAi silencing of the K-Ras gene on Ras signal pathway activity in EC9706 esophageal cancer cells.MethodsEC9706 cells were treated in the following six groups: blank group (no transfection), negative control group (transfection no-carrier), transfection group (transfected with pSilencer-siK-ras), taxol chemotherapy group, taxol chemotherapy plus no-carrier group, taxol chemotherapy plus transfection group. Immunocytochemistry, Reverse transcription-polymerase chain reaction and western blotting were used to analyze the expression of MAPK1 (mitogen-activated protein kinases 1) and cyclin D1 in response to siRNA (small interfering RNA) transfection and taxol treatment.ResultsK-Ras (K-Ras gene) siRNA transfection of EC9706 esophageal squamous carcinoma cells decreased the expression of K-Ras, MAPK1 and cyclin D1 at the mRNA and protein level. Reverse transcription-polymerase chain reaction indicated that the expression levels of MAPK1 and cyclin D1 mRNAs were significantly lower in the transfection group than in the blank group (P<0.05). Western blotting showed that 72 h after EC9706 cell transfection, the expression levels of MAPK1 and cyclin D1 proteins had decreased in all groups, and the expression levels in the transfection group were significantly inhibited as compared with the blank group. Apoptosis increased significantly in the transfection group or after addition of taxol as compared with the blank group and the no-carrier group. The degree of apoptosis in the taxol plus transfection group was more severe.ConclusionApoptosis increased significantly in EC9706 esophageal carcinoma cells after siRNA-mediated inhibition of Ras signaling, with the most obvious increase observed in the transfection plus taxol chemotherapy group. Ras knockdown therefore increased cellular sensitivity to the chemotherapeutic agent, taxol. Ras knockdown also down-regulated the expression of the downstream genes, MAPK1 and cyclin D1, thus inhibiting the growth, proliferation and metabolism of esophageal cancer cells