2,129 research outputs found
Modeling the Impacts of Market Activity on Bid-Ask Spreads in the Option Market
In this paper, we examine the impact of market activity on the percentage bid-ask spreads of S&P 100 index options using transactions data. We propose a new market microstructure theory which we call derivative hedge theory, in which option market percentage spreads will be inversely related to the option market maker's ability to hedge his positions in the underlying market, as measured by the liquidity of the latter market. In a perfect hedge world, spreads arise from the illiquidity of the underlying market, rather than from inventory risk or informed trading in the option market itself. We find option market volume is not a significant determinant of option market spreads. This finding leads us to question the use of volume as a measure of liquidity and supports the derivative hedge theory. Option market spreads are positively related to spreads in the underlying market, again supporting our theory. However, option market duration does affect option market spreads, with very slow and very fast option markets both leading to bigger spreads. The fast market result would be predicted by the asymmetric information theory. Inventory model predicts big spreads in slow markets. Neither result would be observed if the underlying securities market provided a perfect hedge. We interpret these mixed results as meaning that the option market maker is able to only imperfectly hedge his positions in the underlying securities market. Our result of insignificant options volume casts doubt on the price discovery argument between stock and option market (Easley, O'Hara, and Srinivas (1998)). Asymmetric information costs in either market are naturally passed to the other market maker's hedgeing and therefore it is unimportant where the informed traders trade.
Toward Sustainable Consumption and Life Satisfaction: Understanding Apparel Consumption of Voluntary Simplifiers
The modern consumption-oriented culture not only negatively impacts an individual\u27s well-being but also damages the environment. Overconsumption often results in personal debts, overwork, losing time to spend with significant others, psychological emptiness, and general unhappiness with life. In addition, this trend significantly harms the environment, causing the depletion of energy and resources. Especially, fast fashion has contributed to consumers\u27 high rates of acquisition and disposal of apparel products, leading to the problem of unsustainable apparel consumption. Voluntary simplicity provides a solution to the problem by adjusting an individual\u27s consumption level by promoting a socially responsible consumption lifestyle. Thus, the purpose of this qualitative study is to understand apparel consumption behavior of voluntary simplifiers
HRT, Herbal Formula, Induces G 2
We have demonstrated the anticancer effect of HRT in HCT116, human colon carcinoma cells. HRT inhibited cancer cell growth by causing cell cycle arrest at G2/M and inducing apoptosis as evidenced by DNA fragmentation assay. We found that HRT induces the activation of caspase-3, -8, and -9, whereas it reduces the level of Bcl-2 protein and results in the cleavage of PARP. Further, HRT decreased the level of phosphorylation of Akt and its downstream signals such as mTOR and GSK-3β. These results indicate that HRT stimulates the apoptotic signaling pathway and represses the survival and proliferation of colon cancer cells via inhibiting Akt activity. Hence, our results suggest that HRT has a potential to be developed as a therapeutic agent against colon cancer cells
The value of chest CT for prediction of breast tumor size: comparison with pathology measurement
BACKGROUND: Little information is available on the use of chest computed tomography (CT) to predict breast tumor size in breast cancer, despite the fact that chest CT examinations are being increasingly used. The purpose of this study was to evaluate the value of chest CT for predicting breast tumor size using pathology measurements as reference standards. METHODS: Tumor sizes (defined as greatest diameter) were retrospectively measured on the preoperative chest CT images of 285 patients with surgically proven unifocal, invasive breast carcinoma. Greatest tumor diameters as determined by chest CT and pathologic examinations were compared by linear regression and Spearman’s rho correlation analysis. Concordance between CT and pathology results was defined as a diameter difference of <5 mm. Subgroup analyses were also performed with respect to tumor size (<20 mm or ≥20 mm) and histological subtype (invasive ductal carcinoma(IDC) or non-IDC). RESULTS: CT and pathology measured diameters were found to be linearly related (size at pathology = 1.086 × CT determined tumor size - 1.141; Spearman’s rho correlation coefficient = 0.84, P<0.001). Most tumors (n = 228, 80.0%) were concordant by chest CT and pathology, but 36 tumors (12.7%) were underestimated by CT (average underestimation, 11 mm; range, 6–36 mm) and 21 tumors (7.4%) were overestimated (average overestimation by CT, 10 mm; range, 6–19 mm). The concordance rate between the two sets of measurements was greater for tumor of <20 mm and for IDC (P<0.001 and P = 0.011, respectively). CONCLUSIONS: Tumor size by chest CT is well correlated with pathology determined tumor size in breast cancer patients, and the diameters of the majority of tumors by chest CT and pathology differed by <5 mm. In addition, the concordance rate was higher for breast tumors of <20 mm and for tumors of the IDC histologic subtype
Differential effect of corn oil-based low trans structured fat on the plasma and hepatic lipid profile in an atherogenic mouse model: comparison to hydrogenated trans fat
<p>Abstract</p> <p>Background</p> <p><it>Trans </it>fat are not desirable in many aspects on health maintenance. Low <it>trans </it>structured fats have been reported to be relatively more safe than <it>trans </it>fats.</p> <p>Methods</p> <p>We examined the effects of low <it>trans </it>structured fat from corn oil (LC), compared with high <it>trans </it>fat shortening, on cholesterol and fatty acid metabolism in apo E deficient mice which is an atherogenic animal model. The animals were fed a high <it>trans </it>fat (10% fat: commercial shortening (CS)) or a low <it>trans </it>fat (LC) diet for 12 weeks.</p> <p>Results</p> <p>LC decreased apo B and hepatic cholesterol and triglyceride concentration compared to the CS group but significantly increased plasma total cholesterol and triglyceride concentration and fecal lipids with a simultaneous increase in HDL-cholesterol level, apo A-I, and the ratio of HDL-cholesterol to total cholesterol (HTR). Reduction of hepatic lipid levels by inclusion of LC intake was observed alongside modulation of hepatic enzyme activities related to cholesterol esterification, fatty acid metabolism and fecal lipids level compared to the CS group. The differential effects of LC intake on the plasma and hepatic lipid profile seemed to be partly due to the fatty acid composition of LC which contains higher MUFA, PUFA and SFA content as well as lower content of <it>trans </it>fatty acids compared to CS.</p> <p>Conclusions</p> <p>We suggest that LC may exert a dual effect on plasma and hepatic lipid metabolism in an atherogenic animal model. Accordingly, LC, supplemented at 10% in diet, had an anti-atherogenic effect on these <it>apo E</it><sup><it>-/- </it></sup>mice, and increased fecal lipids, decreased hepatic steatosis, but elevated plasma lipids. Further studies are needed to verify the exact mode of action regarding the complex physiological changes and alteration in lipid metabolism caused by LC.</p
Prevalence and socio-economic burden of heart failure in an aging society of South Korea
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Background
Heart failure (HF) is one of the leading causes of morbidity and mortality in South Korea. With the rapidly aging population in the country, the prevalence of HF and its associated costs are expected to rise continuously. This study was carried out to estimate the prevalence and economic burden of HF in order to understand its impact on our society.
Methods
A prevalence-based, cost-of-illness study was conducted using the 2014 Health Insurance Review and Assessment Service-National Patients Sample (HIRA-NPS) data. Adult HF patients were defined as those aged ≥19 years who had at least one insurance claim record with a primary or secondary diagnosis of HF (ICD-10 codes of I11.0, I13.0, I13.2, and I50.x). The costs consist of direct costs (i.e., medical and non-medical costs) and indirect costs (i.e., productivity loss cost due to morbidity and premature death). Subgroup analyses were conducted by age group, history of HF hospitalization, and type of universal health security program enrolled in.
Results
A total of 475,019 adults were identified to have HF in 2014. The estimated prevalence rate of HF was 12.4 persons per 1,000 adults. According to the base cases and the extended definition of the cases, the annual economic burden of HF from a societal perspective ranges from USD 1,414.0 to 1,560.5 for individual patients, and from USD 752.8 million to 1,085.6 million for the country. A high percentage (68.5 %) of this socioeconomic burden consist of medical costs, followed by caregivers cost (13.2 %), productivity loss costs due to premature death (10.8 %) and morbidity (4.2 %), and transportation costs (3.4 %). The HF patients with prior hospitalization due to HF annually spent 9.7 times more for National-Health-Insurance-covered medical costs compared to HF patients who were not previously hospitalized.
Conclusions
In the present study, HF patients who were older and had a history of prior hospitalization for HF as well as an indigent status were shown at high risk of spending more for healthcare to treat their HF. An effective disease management protocol should be employed to target this patient group
Pulmonary Venous Malformation in a 4-Year-Old Boy: a Case Report
We report a case of a pulmonary venous malformation in a 4-year-old boy who presented with recurrent pneumonia. A radiograph revealed a right infrahilar mass and a hyperlucent right lung. Computed tomography (CT) demonstrated a mass containing intensely enhancing areas and multiple phleboliths located in the right lower lobe and encasing the right bronchus and right inferior pulmonary vein. Magnetic resonance imaging (MRI) precisely revealed the mass demarcation. A right lower lobectomy was performed and a pathological examination confirmed the diagnosis of a venous malformation. To the best of our knowledge, a venous malformation in pulmonary tissue has not been reported in the English literature. Herein, we report a case of a pulmonary venous malformation, with the radiograph, CT, MRI, and blood pool scan findings, along with its pathologic correlation
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