Evaluation of VaR calculation methods

This paper evaluates different VaR calculation methods in measuring Chinese stock market in terms of the acceptability, variability, accuracy and measurement error of VaR models. Three VaR calculation methods based on 5 different models are evaluated, namely Variance-Covariance methods (VC) based on EARCH model (VCEA), RiskMetrics (VCRM) model, Monte Carlo Simulation (MC) modified with EARCH (MCEA) model and RiskMetrics model (MCRM) and historical simulation (HS). The main findings of this paper are: First, HS method and VCRM method are unacceptable in calculating VaR in Chinese stock market based on the coverage test suggested by Christoffersen for 125-day evaluation window while only HS is unacceptable for a 50-day evaluation sample. Second, MCEA method has the lowest variability, HS has the highest variability and the variability of MCRM and VCEA are lower than MCEA but higher than VCRM for 125-day and 50-day evaluation windows based on RMSRB. Third, the accuracy of MCEA is the highest among all calculation method used in the paper for 125-day evaluation window while the accuracy of MCEA, MCRM and VCEA is high and similar for 50-day evaluation window. HS and VCRM model have relatively low accuracy for both evaluation windows. Finally, there is measurement error using HS method for 125-day evaluation window based on Hitt test. It can be conclude that, MC method performs well in calculating VaR Chinese Stock market while HS is an inappropriate method based on the results of four aspects of evaluation test, however performance of each VaR calculation method is affected by the length of evaluation window.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

The inhibitory effect against collagen-induced arthritis by Schistosoma japonicum infection is infection stage-dependent

<p>Abstract</p> <p>Background</p> <p>A long-term existing schistosome infection can aid in maintaining immuno-homeostasis, thus providing protection against various types of autoimmune diseases to the infected host. Such benefits have often been associated with acute or egg stage infection and with the egg-induced Th2 response. However, since schistosome infection undergoes different stages, each associated with a specific induction of Th responses, the requirements for the ability of the different stages of schistosome infection to protect against autoimmune disease has not been elucidated. The present study was designed to study whether different stages of schistosome infection offer unique protection in collagen-induced arthritis and its mechanisms.</p> <p>Results</p> <p>Arthritis susceptible strain DBA/1 male mice were infected with <it>Schistosoma japonicum </it>for either 2 weeks resulting in early stage infection or for 7 weeks resulting in acute or egg stage infection. Following <it>Schistosoma japonicum </it>infection, collagen II was administered to induce collagen-induced arthritis, an animal model for human rheumatoid arthritis. Infection by <it>Schistosoma japonicum </it>significantly reduced the severity and the incidence of experimental autoimmune collagen-induced arthritis. However, this beneficial effect can only be provided by a pre-established acute stage of infection but not by a pre-established early stage of the infection. The protection against collagen-induced arthritis correlated with reduced levels of anti-collagen II IgG, especially the subclass of IgG2a. Moreover, in protected mice increased levels of IL-4 were present at the time of collagen II injection together with sustained higher IL-4 levels during the course of arthritis development. In contrast, in unprotected mice minimal levels of IL-4 were present at the initial stage of collagen II challenge together with lack of IL-4 induction following <it>Schistosoma japonicum </it>infection.</p> <p>Conclusion</p> <p>The protective effect against collagen-induced arthritis provided by <it>Schistosoma japonicum </it>infection is infection stage-dependent. Furthermore, the ability of schistosomiasis to negatively regulate the onset of collagen-induced arthritis is associated with a dominant as well as long-lasting Th2 response at the initiation and development of autoimmune joint and systemic inflammation.</p

in KKAy mice

and mechanisms of resveratrol on the amelioration of oxidative stress and hepatic steatosi

Association between ambient air pollution and hospital admissions, length of hospital stay and hospital cost for patients with cardiovascular diseases and comorbid diabetes mellitus: Base on 1,969,755 cases in Beijing, China, 2014–2019

Background: Evidence on the effects of the air pollutants on the hospital admissions, hospital cost and length of stay (LOS) among patients with comorbidities remains limited in China, particularly for patients with cardiovascular diseases and comorbid diabetes mellitus (CVD-DM). Methods: We collected daily data on CVD-DM patients from 242 hospitals in Beijing between 2014 and 2019. Generalized additive model was employed to quantify the associations between admissions, LOS, and hospital cost for CVD-DM patients and air pollutants. We further evaluated the attributable risk posed by air pollutants to CVD-DM patients, using both Chinese and WHO air quality guidelines as reference. Results: Per 10 ug/m3 increase of particles with an aerodynamic diameter \u3c 2.5 μm (PM2.5), particles with an aerodynamic diameter \u3c 10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), carbonic oxide (CO) and ozone (O3) corresponded to a 0.64% (95% CI: 0.57 to 0.71), 0.52% (95% CI: 0.46 to 0.57), 0.93% (95% CI: 0.67 to 1.20), 0.98% (95% CI: 0.81 to 1.16), 1.66% (95% CI: 1.18 to 2.14) and 0.53% (95% CI: 0.45 to 0.61) increment for CVD-DM patients’ admissions. Among the six pollutants, particulate pollutants (PM2.5 and PM10) in most lag days exhibited adverse effects on LOS and hospital cost. For every 10 ug/m3 increase in PM2.5 and PM10, the absolute increase with LOS will increase 62.08 days (95% CI: 28.93 to 95.23) and 51.77 days (95% CI:22.88 to 80.66), respectively. The absolute increase with hospital cost will increase 105.04 Chinese Yuan (CNY) (95% CI: 49.27 to 160.81) and 81.76 CNY (95% CI: 42.01 to 121.51) in PM2.5 and PM10, respectively. Given WHO 2021 air quality guideline as the reference, PM2.5 had the maximum attributable fraction of 3.34% (95% CI: 2.94% to 3.75%), corresponding to an avoidable of 65,845 (95% CI: 57,953 to 73,812) patients with CVD-DM. Conclusion: PM2.5 and PM10 are positively associated with hospital admissions, hospital cost and LOS for patients with CVD-DM. Policy changes to reduce air pollutants exposure may reduce CVD-DM admissions and substantial savings in health care spending and LOS

A novel lytic phage potentially effective for phage therapy against Burkholderia pseudomallei in the tropics.

BACKGROUND: Burkholderia pseudomallei is a tropical pathogen that causes melioidosis. Its intrinsic drug-resistance is a leading cause of treatment failure, and the few available antibiotics require prolonged use to be effective. This study aimed to assess the clinical potential of B. pseudomallei phages isolated from Hainan, China. METHODS: Burkholderia pseudomallei strain (HNBP001) was used as the isolation host, and phages were recovered from domestic environmental sources, which were submitted to the host range determination, lytic property assays, and stability tests. The best candidate was examined via the transmission electron microscope for classification. With its genome sequenced and analyzed, its protective efficacy against B. pseudomallei infection in A549 cells and Caenorhabditis elegans was evaluated, in which cell viability and survival rates were compared using the one-way ANOVA method and the log-rank test. RESULTS: A phage able to lyse 24/25 clinical isolates was recovered. It was classified in the Podoviridae family and was found to be amenable to propagation. Under the optimal multiplicity of infection (MOI) of 0.1, an eclipse period of around 20 min and a high titer (1012 PFU/ml) produced within 1 h were demonstrated. This phage was found stabile at a wide range of temperatures (24, 37, 40, 50, and 60 °C) and pH values (3-12). After being designated as vB_BpP_HN01, it was fully sequenced, and the 71,398 bp linear genome, containing 93 open reading frames and a tRNA-Asn, displayed a low sequence similarity with known viruses. Additionally, protective effects of applications of vB_BpP_HN01 (MOI = 0.1 and MOI = 1) alone or in combination with antibiotics were found to improve viability of infected cells (70.6 ± 6.8%, 85.8 ± 5.7%, 91.9 ± 1.8%, and 96.8 ± 1.8%, respectively). A significantly reduced mortality (10%) and a decreased pathogen load were demonstrated in infected C. elegans following the addition of this phage. CONCLUSIONS: As the first B. pseudomallei phage was isolated in Hainan, China, phage vB_BpP_HN01 was characterized by promising lytic property, stability, and efficiency of bacterial elimination during the in vitro/vivo experiments. Therefore, we can conclude that it is a potential alternative agent for combating melioidosis

Transgene Expression Is Associated with Copy Number and Cytomegalovirus Promoter Methylation in Transgenic Pigs

Transgenic animals have been used for years to study gene function, produce important proteins, and generate models for the study of human diseases. However, inheritance and expression instability of the transgene in transgenic animals is a major limitation. Copy number and promoter methylation are known to regulate gene expression, but no report has systematically examined their effect on transgene expression. In the study, we generated two transgenic pigs by somatic cell nuclear transfer (SCNT) that express green fluorescent protein (GFP) driven by cytomegalovirus (CMV). Absolute quantitative real-time PCR and bisulfite sequencing were performed to determine transgene copy number and promoter methylation level. The correlation of transgene expression with copy number and promoter methylation was analyzed in individual development, fibroblast cells, various tissues, and offspring of the transgenic pigs. Our results demonstrate that transgene expression is associated with copy number and CMV promoter methylation in transgenic pigs

Enabling family business resilience – The role of female leadership: Evidence from a Chinese family business

This is an accepted manuscript of a chapter published by Emerald in Family Business Debates: Multidimensional Perspectives Across Countries, Continents and Geo-political Frontiers, published on 28/11/2022, available online: https://doi.org/10.1108/978-1-80117-666-820221014 The accepted version of the publication may differ from the final published version.Research on what makes family business resilient and why resilience matters in family businesses is in development. Drawing on the upper echelon theory, we examine the impact of female leadership on resilience development. Semi-structured interviews were performed in the selected family business. This was complemented by secondary data available from online publications. Results suggest that resilience consists of abilities to prepare for, control, adapt to, and absorb change. Evidence further indicates female-embodied attributes, female-enabled family cohesion, female-empowered governance, and female-characterised resource orchestration lead to the development of resilience

Labview-based design and realization of virtual oscilloscope

Conference Name:2012 International Conference on Mechanical and Electronic Engineering, ICMEE 2012. Conference Address: Hefei, China. Time:June 23, 2012 - June 24, 2012.International Science and Education Researcher Association; VIP Information Conference Center; Beijing Gireda Research CenterOscilloscope is an electronic measuring instrument which is used in production practice and scientific research widely. Ordinary oscilloscope have heavy exterior and single function, and we can't measure the signal amplitude and frequency characteristics accurately. This article uses the method of programming LabVIEW to design virtual oscilloscope. The virtual oscilloscope realized the real-time data acquisition, waveform display, and measuring parameters and other functions. Its various performance indicators are much better than that of a traditional oscilloscope. 漏 2012 Springer-Verlag Berlin Heidelberg

Labview-based design and realization of virtual oscilloscope

Conference Name:2012 International Conference on Mechanical and Electronic Engineering, ICMEE 2012. Conference Address: Hefei, China. Time:June 23, 2012 - June 24, 2012.International Science and Education Researcher Association; VIP Information Conference Center; Beijing Gireda Research CenterOscilloscope is an electronic measuring instrument which is used in production practice and scientific research widely. Ordinary oscilloscope have heavy exterior and single function, and we can't measure the signal amplitude and frequency characteristics accurately. This article uses the method of programming LabVIEW to design virtual oscilloscope. The virtual oscilloscope realized the real-time data acquisition, waveform display, and measuring parameters and other functions. Its various performance indicators are much better than that of a traditional oscilloscope. 漏 2012 Springer-Verlag Berlin Heidelberg

Sentinel lymph node biopsy mapped with methylene blue dye alone in patients with breast cancer: A systematic review and meta-analysis.

BACKGROUND:Methylene blue dye is easy to obtain in developing countries and can be used in sentinel lymph node mapping for breast cancer. However, the accuracy of methylene blue alone for sentinel lymph node mapping in breast cancer has not been well defined. In this study, we collected data to assess the feasibility and accuracy of sentinel lymph node biopsy mapped with methylene blue alone in patients with breast cancer. METHODS:We searched the PubMed, EMBASE, and Cochrane Library databases from January 1, 1993, to March 31, 2018. Selected studies had to have a defined group of patients with breast cancer in which MBD alone was used as the mapping technique for SNB. RESULTS:18 studies were included in this study. The combined identification rate was 91% [95% confidence interval (CI): 88%-94%, I2 = 68.3%], and the false negative rate was 13% (95% CI: 9%-18%, I2 = 36.7%). The pooled sensitivity, negative predictive value, and accuracy rate were 87% (95% CI: 82%-91%, I2 = 37.5%), 91% (95% CI: 87%-93%, I2 = 32.4%) and 94% (95% CI: 92%-96%, I2 = 29%), respectively. CONCLUSIONS:This meta-analysis found that mapping sentinel lymph node locations with methylene blue dye alone results in an acceptable identification rate but an excessive false negative rate according to the American Society of Breast Surgeons' recommendations. Caution is warranted when using methylene blue dye alone as the mapping method for sentinel lymph node biopsy