The Study of Optimal Hedge Ratios and Utility Based Approach to the Crude Oil Hedging Strategies Using Multivariate GARCH

Various GARCH models have been applied to the research of financial time series. For example, studies of Myers and Thompson (1989), Baillie and Myers (1991) and Lien et al. (2002), and Chang, McAleer, and Tansuchat (2011) apply GARCH models to improve the research of optimal hedge ratios. Although multivariate conditional volatility models are often employed in the measurement of minimum variance hedging strategy, they are rarely applied to the research which involves both the optimal hedge ratio and the preference of investors. This dissertation evaluate four different multivariate conditional volatility models, they are the Constant Conditional Correlations (CCC) model, the Dynamic Conditional Correlations (DCC), the BEKK model, and the Diagonal BEKK model. These models are applied to the calculation of the optimal hedge ratio and the utility based hedge ratio of Brent and WTI crude oil markets. The main aim of this research is to examine whether the performance of hedge ratios under different multivariate volatility models could be employed by investors who are not infinitely risk averse. It is concluded that the diagonal BEKK model exhibits as the best model in terms of the measurement of hedging effectiveness, and the BEKK model appears to be the worse one among the four models measured in terms of the Brent crude oil market. Moreover, estimates of the utility based hedge ratio suggest that the DCC model and the diagonal BEKK model exhibit a similar level of utility based hedge ratios in terms of the Brent and WTI crude oil data series that examined in this dissertation. However, the utility based hedging approach suffers from several limitations and the ex-post utility measure may fail to provide better insights to the selection of hedging strategies. It should be noted that there are still other multivariate GARCH models or different utility functions which can be applied in the future research of utility based optimal hedge ratios (OHRs). In addition, the method illustrated in this dissertation can not only be used in the estimation of crude oil data but also be applied to other financial series such as commodities or securities. This would be of particular interest to those who involved in the management or hedging strategies of portfolio investment and risk management

Cause Event Representations for Happiness and Surprise

PACLIC 23 / City University of Hong Kong / 3-5 December 200

Nursing Students’ Clinical Confidence In Caring Tuberculosis: Indonesian Version Of The U.S Tuberculosis Curriculum Consortium Survey Using Rasch Analysis

Background: Nursing students who are prepared in clinical practicums to comprehend the knowledge, reflect their beliefs about tuberculosis instruction, and perceive their abilities in caring for tuberculosis patients are also at risk. Nursing students’ clinical confidence in caring for tuberculosis patients is essential to be assessed. Knowledge, beliefs, and clinical confidence, as unidimensional constructs based on Bandura’s theory of self-efficacy, had been used in the US National Tuberculosis Curriculum Consortium (NTCC) survey for nursing students. This study's objective was to investigate the Indonesian version of the NTCC survey among nursing students' experiences caring for tuberculosis patients.   Methods: A quantitative study with cross-sectional using an online survey among 250 students 1st to 3rd-yearrd year students in one faculty of nursing in Banten, Indonesia. Prior to data collection, NTCC surveys were translated backward and forward, reviewed by experts, and tested in a pilot project.   Results: Internal consistency using Rasch analysis on each subscale showed good results and gave strong evidence that three subscales are unidimensional. There was an item separation index and reliability score, in that order: knowledge about tuberculosis (8.68 and 0.99), beliefs regarding tuberculosis instructions (6.50 and 0.98), and clinical confidence in caring for tuberculosis patients (6.29 and 0.98).   Conclusion: The Indonesian version of the NTCC survey has excellent internal consistency. This instrument might be improved since the original instrument is 13 years old and there is a cultural gap between the US and Indonesia. Moreover, this instrument might be needed for improving tuberculosis teaching in the nursing curriculum in Indonesia

Vectors for multi-color bimolecular fluorescence complementation to investigate protein-protein interactions in living plant cells

<p>Abstract</p> <p>Background</p> <p>The investigation of protein-protein interactions is important for characterizing protein function. Bimolecular fluorescence complementation (BiFC) has recently gained interest as a relatively easy and inexpensive method to visualize protein-protein interactions in living cells. BiFC uses "split YFP" tags on proteins to detect interactions: If the tagged proteins interact, they may bring the two split fluorophore components together such that they can fold and reconstitute fluorescence. The sites of interaction can be monitored using epifluorescence or confocal microscopy. However, "conventional" BiFC can investigate interactions only between two proteins at a time. There are instances when one may wish to offer a particular "bait" protein to several "prey" proteins simultaneously. Preferential interaction of the bait protein with one of the prey proteins, or different sites of interaction between the bait protein and multiple prey proteins, may thus be observed.</p> <p>Results</p> <p>We have constructed a series of gene expression vectors, based upon the pSAT series of vectors, to facilitate the practice of multi-color BiFC. The bait protein is tagged with the C-terminal portion of CFP (cCFP), and prey proteins are tagged with the N-terminal portions of either Venus (nVenus) or Cerulean (nCerulean). Interaction of cCFP-tagged proteins with nVenus-tagged proteins generates yellow fluorescence, whereas interaction of cCFP-tagged proteins with nCerulean-tagged proteins generates blue fluorescence. Additional expression of mCherry indicates transfected cells and sub-cellular structures. Using this system, we have determined in both tobacco BY-2 protoplasts and in onion epidermal cells that <it>Agrobacterium </it>VirE2 protein interacts with the <it>Arabidopsis </it>nuclear transport adapter protein importin α-1 in the cytoplasm, whereas interaction of VirE2 with a different importin α isoform, importin α-4, occurs predominantly in the nucleus.</p> <p>Conclusion</p> <p>Multi-color BiFC is a useful technique to determine interactions simultaneously between a given" bait" protein and multiple "prey" proteins in living plant cells. The vectors we have constructed and tested will facilitate the study of protein-protein interactions in many different plant systems.</p

Evaluation on the Pharmacological Effect of Traditional Chinese Medicine SiJunZiTang on Stress-Induced Peptic Ulcers

Purpose. To explore the effects of SiJunZiTang (SJZT) on central neurotransmitters and the inhibition of HCl hypersecretion, along with the role of the vagus nerve. From this, the effects of SJZT and its constituent ingredients on inhibiting stress-induced peptic ulcers will be determined. Methods. Methods used to determine SJZT's effectiveness included (1) measuring the antipeptic ulcer effects of varying combinations of the constituents of SJZT; (2) evaluations of monoamine (MA) level in the brain; and (3) measuring the effects of longer-term SJZT treatment. Results. Comparing the control and experimental groups where the rats’ vagus nerves were not cut after taking SJZT orally (500 mg/kg and 1000 mg/kg), the volume of enterogastric juice, free HCl and total acidity all reduce dose-dependently. The group administered SJZT at 1000 mg/kg showed significant reductions (P<0.05). For the experimental groups where the vagus nerves were cut, a comparison with the control group suggests that the group receiving SJZT (500 mg/kg) orally for 21 days demonstrated a cure rate of 34.53%. Conclusion. The results display a correlation between the therapeutic effects of SJZT on stress-induced peptic ulcers and central neurotransmitter levels. Further to this, SJZT can inhibit the hypersecretion of HCl in the stomach, thus inhibiting stress-induced peptic ulcers

Vitamin D level regulates serum lipids discrepantly in adults with and without dyslipidemia

Vitamin D deficiency is associated with hyperlipidemia, but it r emains unclear whether vitamin D supplementation reduces serum lipid levels. The aims of this study were to investigate the associations between increased serum 25-hydroxyvitamin D (25(OH)D) concentrations and lipid levels and identify the characteristics of people with or without lipid reduction associated with increased 25(OH)D levels. The medical records of 118 individuals (53 men; mean age, 54.4 ± 10.6 years) whose serum 25(OH)D levels increased between 2 consecutive measurements were retrospectively reviewed. People with increased 25(OH)D levels (from 22.7 (17.6–29.2) to 32.1 (25.6–36.8) mg/dL; P < 0.01) had a significant reduction in serum levels of triglycerides (TG s) (from 111.0 (80–164) to 104.5 (73–142) mg/dL; P < 0.01) and total cholesterol (TC) (from 187.5 (155–213) to 181.0 (150–210) mg/dL; P < 0.05). The individuals who responded to vitamin D (≥10% reduction in TG or TC levels) exhibited significantly higher baseline TG a nd TC levels than those who did not. Only patients with hyperlipidemia (not those without hyperlipidemia) at baseline exhibited significantly reduced TG and TC levels at fol low-up. However, increasing serum 25(OH)D concentrations were significantly correlated with decreasing lipid levels in individuals with baseline 25(OH)D levels less than 30 ng/mL and in individuals aged 50–65 years (not in patients younger than 50 years or older than 65 years). In conclusion, increasing serum 25(OH)D concentrations may be potentially helpful for the treatment of hyperlipidemia in people with vitamin D deficiency

POINeT: protein interactome with sub-network analysis and hub prioritization

<p>Abstract</p> <p>Background</p> <p>Protein-protein interactions (PPIs) are critical to every aspect of biological processes. Expansion of all PPIs from a set of given queries often results in a complex PPI network lacking spatiotemporal consideration. Moreover, the reliability of available PPI resources, which consist of low- and high-throughput data, for network construction remains a significant challenge. Even though a number of software tools are available to facilitate PPI network analysis, an integrated tool is crucial to alleviate the burden on querying across multiple web servers and software tools.</p> <p>Results</p> <p>We have constructed an integrated web service, POINeT, to simplify the process of PPI searching, analysis, and visualization. POINeT merges PPI and tissue-specific expression data from multiple resources. The tissue-specific PPIs and the numbers of research papers supporting the PPIs can be filtered with user-adjustable threshold values and are dynamically updated in the viewer. The network constructed in POINeT can be readily analyzed with, for example, the built-in centrality calculation module and an integrated network viewer. Nodes in global networks can also be ranked and filtered using various network analysis formulas, i.e., centralities. To prioritize the sub-network, we developed a ranking filtered method (S3) to uncover potential novel mediators in the midbody network. Several examples are provided to illustrate the functionality of POINeT. The network constructed from four schizophrenia risk markers suggests that EXOC4 might be a novel marker for this disease. Finally, a liver-specific PPI network has been filtered with adult and fetal liver expression profiles.</p> <p>Conclusion</p> <p>The functionalities provided by POINeT are highly improved compared to previous version of POINT. POINeT enables the identification and ranking of potential novel genes involved in a sub-network. Combining with tissue-specific gene expression profiles, PPIs specific to selected tissues can be revealed. The straightforward interface of POINeT makes PPI search and analysis just a few clicks away. The modular design permits further functional enhancement without hampering the simplicity. POINeT is available at <url>http://poinet.bioinformatics.tw/</url>.</p