Double-jump stochastic volatility model for VIX: evidence from VVIX

The paper studies the continuous-time dynamics of VIX with stochastic volatility and jumps in VIX and volatility. Built on the general parametric affine model with stochastic volatility and jump in logarithm of VIX, we derive a linear relation between the stochastic volatility factor and VVIX index. We detect the existence of co-jump of VIX and VVIX and put forward a double-jump stochastic volatility model for VIX through its joint property with VVIX. With VVIX index as a proxy for the stochastic volatility, we use MCMC method to estimate the dynamics of VIX. Comparing nested models on VIX, we show the jump in VIX and the volatility factor is statistically significant. The jump intensity is also statedependent. We analyze the impact of jump factor on the VIX dynamics

A Review of Research on the Application of Case Teaching Method in International Chinese Language Education

In recent years, with the rapid development of International Chinese Language Education, research on its related teaching methods has become increasingly abundant. Scholars in International Chinese Language Education have found that the case teaching method, widely used in disciplines such as business and law due to its open and practical characteristics, aligns well with the features and talent development needs of International Chinese Language Education. In order to maximize the role of the case teaching method in International Chinese Language Education, research on its application in this field has gained significant attention. This paper reviews the relevant research on the application of the case teaching method in International Chinese Language Education from 2000 to 2024. Based on a review of the relevant research literature, the paper summarizes the following major research areas: the applicability of the case teaching method in International Chinese Language Education, its application in business Chinese teaching, and the construction of Case Library. The paper identifies four main shortcomings in this field: 1) teaching methods are still dominated by lecture-based instruction, which tends to be rigid; 2) Case Library construction faces challenges, such as a lack of sources and high resource acquisition costs; 3) there is a lack of case sharing; and 4) the coverage of case teaching is narrow. Based on these issues, the paper suggests the following: first, conducting training for International Chinese Language teachers to familiarize them with the case teaching process and encourage its use in classroom teaching; second, expanding case collection channels by gathering teaching cases from International Chinese Language teachers worldwide to enrich Case Library and address the limited sources problem; third, promoting the opening of resources from universities with International Chinese Language Education Case Library, sharing construction experiences, and promoting co-construction and sharing of these databases; and fourth, reflecting on the application of the case teaching method, summarizing its suitable target audience and course types, expanding its application range, and improving teaching effectiveness

Nickel pyrithione induces apoptosis in chronic myeloid leukemia cells resistant to imatinib via both Bcr/Abl-dependent and Bcr/Abl-independent mechanisms

Abstract Background Acquired imatinib (IM) resistance is frequently characterized by Bcr-Abl mutations that affect IM binding and kinase inhibition in patients with chronic myelogenous leukemia (CML). Bcr-Abl-T315I mutation is the predominant mechanism of the acquired resistance to IM. Therefore, it is urgent to search for additional approaches and targeting strategies to overcome IM resistance. We recently reported that nickel pyrithione (NiPT) potently inhibits the ubiquitin proteasome system via targeting the 19S proteasome-associated deubiquitinases (UCHL5 and USP14), without effecting on the 20S proteasome. In this present study, we investigated the effect of NiPT, a novel proteasomal deubiquitinase inhibitor, on cell survival or apoptosis in CML cells bearing Bcr-Abl-T315I or wild-type Bcr-Abl. Methods Cell viability was examined by MTS assay and trypan blue exclusion staining assay in KBM5, KBM5R, K562, BaF3-p210-WT, BaF3-p210-T315I cells, and CML patients’ bone marrow samples treated with NiPT. Cell apoptosis in CML cells was detected with Annexin V-FITC/PI and rhodamine-123 staining followed by fluorescence microscopy and flow cytometry and with western blot analyses for apoptosis-associated proteins. Expression levels of Bcr-Abl in CML cells were analyzed by using western blotting and real-time PCR. The 20S proteasome peptidase activity was measured using specific fluorogenic substrate. Active-site-directed labeling of proteasomal DUBs, as well as the phosphorylation of USP14 was used for evaluating the inhibition of the DUBs activity by NiPT. Mouse xenograft models of KBM5 and KBM5R cells were analyzed, and Bcr-Abl-related proteins and protein biomarkers related to proliferation, differentiation, and adhesion in tumor tissues were detected by western blots and/or immunohistological analyses. Results NiPT induced apoptosis in CML cells and inhibited the growth of IM-resistant Bcr-Abl-T315I xenografts in nude mice. Mechanistically, NiPT induced decreases in Bcr-Abl proteins, which were associated with downregulation of Bcr-Abl transcription and with the cleavage of Bcr-Abl protein by activated caspases. NiPT-induced ubiquitin proteasome system inhibition induced caspase activation in both IM-resistant and IM-sensitive CML cells, and the caspase activation was required for NiPT-induced Bcr-Abl downregulation and apoptotic cell death. Conclusions These findings support that NiPT can overcome IM resistance through both Bcr-Abl-dependent and Bcr-Abl-independent mechanisms, providing potentially a new option for CML treatment

Mode Shape Description and Model Updating of Axisymmetric Structures Using Radial Tchebichef Moment Descriptors

A novel approach for mode shape feature extraction and model updating of axisymmetric structures based on radial Tchebichef moment (RTM) descriptors is proposed in this study. The mode shape features extracted by RTM descriptors can effectively compress the full-field modal vibration data and retain the most important information. The reconstruction of mode shapes using RTM descriptors can accurately describe the mode shapes, and the simulation shows that the RTM function is superior to Zernike moment function in terms of its mathematical properties and its shape reconstruction ability. In addition, the proposed modal correlation coefficient of the RTM amplitude can overcome the main disadvantage of using the modal assurance criterion (MAC), which has difficulty in identifying double or close modes of symmetric structures. Furthermore, the model updating of axisymmetric structures based on RTM descriptors appears to be more efficient and effective than the normal model updating method directly using modal vibration data, avoids manipulating large amounts of mode shape data, and speeds up the convergence of updating parameters. The RTM descriptors used in correlation analysis and model updating are demonstrated with a cover of an aeroengine rig. The frequency deviation between the test and the FE model was reduced from 17.13% to 1.23% for the first 13 modes via the model updating process. It verified the potential to industrial application with the proposed method

Urea based fuel cells and electrocatalysts for urea oxidation

Urea is a new member of hydrogen-storage materials for low-temperature fuel cells. It avoids issues of toxicity and safety compared to ammonia and hydrazine. The main limitation of urea fuel cells is the relative low power density due to the sluggish anode reaction. Rapid advances in nano-catalysts for urea electrooxidation have been achieved in order to lower overpotential and improve activity. Urine, as a natural resource of urea, is also an environmental pollutant. Most technologies of treating urine with self-generation electricity are based on microbial fuel cells. However, microbes are only able to utilize the organic substrates rather than urea in urine. Chemical fuel cells in contrast directly oxidize urea to nitrogen gas and removed from urine. Thus urea fuel cells have been used as an alternative method to treat urine. In the paper, the progress in urea based fuel cells and electrocatalysts for urea oxidation is reviewed

Staircase Band Gap Si \u3csub\u3e1-x\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3e/Si Photodectectors

We fabricated Si 1-xGex/Si photodetectors by using a staircase band gap Si 1-xGex/Si structure. These devices exhibit a high optical response with a peak responsive wavelength at 0.96 μm and a responsivity of 27.8 A/W at -5 V bias. Excellent electrical characteristics evidenced by good diode rectification are also demonstrated. The dark current density is 0.1 pA/μm2 at V bias, and the breakdown voltage is -27 V. The high response is explained as the result of a staircase band gap by theoretical analysis

Room-Temperature Blue Luminescence of Thermally Oxidized Si\u3csub\u3e1-x-y\u3c/sub\u3eGe\u3csub\u3ex\u3c/sub\u3eC\u3csub\u3ey\u3c/sub\u3e Thin Films on Si (100) Substrates

We measured at room temperature the photoluminescence spectra of the thermally oxidized Si1-x-yGexCy thin films which were grown on silicon substrates by plasma-enhanced chemical vapor deposition and the wet oxidized at 1100 °C for 20 min. The photoluminescence band with a peak at ~393 nm under the exciting radiation of λ = 241 nm was observed. Possible mechanism of this photoluminescence is discussed

Tissue Inhibitor of Metalloproteinases-1 Interacts with CD74 to Promote AKT Signaling, Monocyte Recruitment Responses, and Vascular Smooth Muscle Cell Proliferation

Tissue inhibitor of metalloproteinases-1 (TIMP-1), an important regulator of matrix metalloproteinases (MMPs), has recently been shown to interact with CD74, a receptor for macrophage migration inhibitory factor (MIF). However, the biological effects mediated by TIMP-1 through CD74 remain largely unexplored. Using sequence alignment and in silico protein-protein docking analysis, we demonstrated that TIMP-1 shares residues with both MIF and MIF-2, crucial for CD74 binding, but not for CXCR4. Subcellular colocalization, immunoprecipitation, and internalization experiments supported these findings, demonstrating that TIMP-1 interacts with surface-expressed CD74, resulting in its internalization in a dose-dependent manner, as well as with a soluble CD74 ectodomain fragment (sCD74). This prompted us to study the effects of the TIMP-1-CD74 axis on monocytes and vascular smooth muscle cells (VSCMs) to assess its impact on vascular inflammation. A phospho-kinase array revealed the activation of serine/threonine kinases by TIMP-1 in THP-1 pre-monocytes, in particular AKT. Similarly, TIMP-1 dose-dependently triggered the phosphorylation of AKT and ERK1/2 in primary human monocytes. Importantly, Transwell migration, 3D-based Chemotaxis, and flow adhesion assays demonstrated that TIMP-1 engagement of CD74 strongly promotes the recruitment response of primary human monocytes, while live cell imaging studies revealed a profound activating effect on VSMC proliferation. Finally, re-analysis of scRNA-seq data highlighted the expression patterns of TIMP-1 and CD74 in human atherosclerotic lesions, thus, together with our experimental data, indicating a role for the TIMP-1-CD74 axis in vascular inflammation and atherosclerosis

Genetic variations in the sheep <i>SIRT7</i> gene and their correlation with body size traits

As a nicotinamide adenine dinucleotide (NAD)-dependent histone deacetylase and ADP ribosyl transferase, the silent information regulator 7 (Sirtuin 7, SIRT7) plays a crucial role in regulating the differentiation of adipocytes and myoblasts, lipid metabolism, glucose metabolism, and cellular growth in mammals. It has been hypothesized that SIRT7 affects growth traits in animals; therefore, in this study, the potential insertion/deletion (indel) of genetic variations within the ovine SIRT7 gene and their correlation with sheep growth traits were explored. A total of 709 individuals from five Chinese and Mongolian sheep breeds were analyzed. Two novel indel loci of the sheep SIRT7 gene were detected and were named 5′ promoter region-insertion-7&thinsp;bp (5′ promoter region-7&thinsp;bp) and 3′ UTR-insertion-17&thinsp;bp (3′ UTR-17&thinsp;bp), respectively. In all of the sheep breeds, frequencies of the 5′ promoter region-7&thinsp;bp mutation were low, whereas mutations of 3′ UTR-17&thinsp;bp were high in Tong sheep and Lanzhou fat-tail sheep (LFTS). Furthermore, both indel polymorphisms had significant associations with different growth characteristics (P&lt;0.05). Among these associations, the 3′ UTR-17&thinsp;bp was highly correlated with rump width in small-tail Han sheep (STHS, rams; P&lt;0.01), and individuals with the ID genotype had better chest depth values than those with the II genotype. In this paper, two novel indels within the sheep SIRT7 gene were identified, and genetic diversity and its effects on body size traits were explored. These findings will potentially provide useful DNA markers for the improvement of economic traits in sheep genetic breeding.</p