515 research outputs found
Exploring mispricing in the term structure of CDS spreads
YesBased on a reduced-form model of credit risk, we explore mispricing in the CDS spreads of North
American companies and its economic content. Specifically, we develop a trading strategy using the
model to trade out of sample market-neutral portfolios across the term structure of CDS contracts. Our
empirical results show that the trading strategy exhibits abnormally large returns, confirming the existence
and persistence of a mispricing. The aggregate returns of the trading strategy are positively related
to the square of market-wide credit and liquidity risks, indicating that the mispricing is more pronounced
when the market is more volatile. When implemented on the Markit data, the strategy shows significant
economic value even after controlling for realistic transaction costs
Use of Ambr15 as a high throughput model to speed up perfusion bioprocess development
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Sex difference in the effect of Internet gaming disorder on the brain functions: evidence from resting-state fMRI
Objective:
Studies have shown that males are more prevalence than females in Internet gaming disorder (IGD). This study was set to explore the sex difference on the effect of IGD in resting states of the brain.
Methods:
Resting-state fMRI data were collected from 58 recreational Internet game users (RGU, male = 29) and 46 IGD subjects (male = 23). Regional homogeneity (ReHo) was used to calculate group difference between the subjects. A two-way ANOVA was used to explore the IGD-by-sex interactions. Correlations between addiction severity and the ReHo values were also calculated.
Results:
Significant sex-by-group interactions were found associated with the brain features in the right posterior cingulate (rPCC), left middle occipital gyrus (lMOG), right middle temporal gyrus (rMTG), and right postcentral gyrus (rPG). Post-hoc analysis revealed that comparing with same-sex RGUs, male IGD showed decreased ReHo in the rPCC, and the ReHo in the rPCC was also negatively associated with Internet addiction test (IAT) scores for male subjects. Moreover, male IGDs showed increased ReHo, but female ones showed decreased ReHo, in both lMOG and rMTG, when comparing with same-sex RGUs.
Conclusions:
Sex differences were observed in brain regions that are responsible for executive control, visual and auditory perception. These sex differences should be taken into consideration in future studies and the treatment of IGD
Comparative Analysis of Clinical Epidemiology and Pathological Characteristics of 908 Patients with Primary Lung Cancer of Hunan Province in 1997 and 2007
Background and objective Epidemiology of lung cancer will be changed along with time and region. The aim of this study is to acknowledge the tendency of primary lung cancer in hunan province in recent years by comparing and analyzing the distribution of gender, age, area, smoking and pathology of patients who were initial diagnosed lung cancer and ancestral or permanent residence of hunan province in 1997 and 2007. Methods Clinical data of 908 patients with primary lung cancer hospitalized in Xiangya hospital were collected and evaluated. Results Compared patients in 2007 with those in 1997, ratio between male and female dropped from 3.8:1 to 2.98:1, while the proportion of young patients who were under 40 years old raised from 4.4% to 8.6% (χ2=4.465, P=0.035), patients living in the county raised from 19.9% to 40.1% (χ2=30.670, P < 0.001), smoking rate of patients from county raised from 16.9% to 39.9% (χ2= 24.939, P < 0.01). In addition, the proportion of rare histological types of lung cancer were also increased from 1.3% to 4.5% (χ2= 5.142, P=0.023). Conclusion Female patients, young patients, rural patients and rare histological types of lung cancer may have a tendency of increase in hunan province in recent years, whereas smoking cessation education should be strengthened
(1S,3R)-3-Ammoniocyclohexanecarboxylate
The title γ-aminobutyric acid, C7H13NO2, exists as a zwitterion. The crystal structure is stabilized by a network of intermolecular N—H⋯O hydrogen bonds, forming a two-dimensional bilayer. An intermolecular C—H⋯O hydrogen bond is also observed
Sedimentation in the Three Gorges Dam and the future trend of Changjiang (Yangtze River) sediment flux to the sea
The Three Gorges Dam (TGD) on the upper Changjiang (Yangtze River), China, disrupts the continuity of Changjiang sediment delivery to downstream and coastal areas. In this study, which was based on 54 years of annual water and sediment data from the mainstream and major tributaries of Changjiang, sediment deposition induced by the TGD in 2003–2008 was quantified. Furthermore, we determined the theoretical trapping efficiency of the cascade reservoir upstream of the TGD. Its impact on Changjiang sediment flux in the coming decades is discussed. Results show that about 172 million tons (Mt) of sediment was trapped annually by the TGD in 2003–2008, with an averaged trapping efficiency of 75%. Most of the total sediment deposition, as induced by the TGD (88%), accumulated within the region between the TGD site and Cuntan. However, significant siltation (12% of the total sediment deposition) also occurred upstream of Cuntan as a consequence of the upstream extended backwater region of the TGD. Additionally, the Changjiang sediment flux entered a third downward step in 2001, prior to operation of the TGD. This mainly resulted from sediment reduction in the Jinshajiang tributary since the late 1990s. As the cascade reservoir is put into full operation, it could potentially trap 91% of the Jinshajiang sediment discharge and, therefore, the Jinshajiang sediment discharge would most likely further decrease to 14 Mt/yr in the coming decades. Consequently, the Changjiang sediment flux to the sea is expected to continuously decrease to below 90 Mt/yr in the near future, or only 18% of the amount observed in the 1950s. In the presence of low sediment discharge, profound impacts on the morphology of estuary, delta and coastal waters are expected
Altered brain functional networks in Internet gaming disorder: independent component and graph theoretical analysis under a probability-discounting task
Internet gaming disorder (IGD) is becoming a matter of concern around the world. However, the neural mechanism underlying IGD remains unclear. In present study, we used independent component analysis (ICA) and graph theoretical analysis (GTA) to explore the potential changed networks in IGD subjects compared to recreational game user (RGU) under a probability-discounting task. Imaging and behavioral data were collected from 18 IGD and 20 RGU subjects. Behavioral results showed the IGD subjects, comparing to RGU, prefer risky options to the fixed ones and spent less time in making risky decisions. In imaging results, the ICA analysis revealed that the IGD showed stronger functional connectivity (FC) in reward circuits and executive control network, as well as lower FC in anterior salience network (ASN) than RGU; for the GTA results, the IGD showed impaired FC in reward circuits and ASN compared to RGU. Taken all, these results suggest that IGD subjects were more sensitive to rewards and, at the same time, they usually neglect the potential punishment under a risky circumstance. Besides this, they were more impulsive in decision-making as they could not control their impulsivity effectively. This might explain why IGD subjects cannot stop their gaming behaviors even facing serve negative consequences
1,2-Di-tert-butylethane-1,2-diyl bis(tert-butanesulfinamide)
In the title compound, C18H40N2O2S2, a vicinal diamine derivative, the crystal structure is stabilized by two intramolecular N—H⋯O hydrogen bonds. The distance between the two kernel chiral C atoms is 1.580 (2) Å
Meta-analyses of the functional neural alterations in subjects with Internet gaming disorder: similarities and differences across different paradigms
Internet gaming disorder (IGD) has become a global public health concern due to its increasing prevalence and potential negative consequences. Researchers have sought to identify which brain regions are associated with this disorder. However, inconsistent results have been reported among studies due to the heterogeneity of paradigms and subjects.
The present research aimed to combine the results of individual studies to provide a more coherent and powerful explanation. By selecting 40 studies utilizing a qualified whole-brain analysis, we performed a comprehensive series of meta-analyses that employed seed-based d mapping. We divided the existing experimental paradigms into 3 categories: game-related cue-reactivity, executive control, and risk-reward-related decision-making tasks.
We divided all studies into three subgroups according to their paradigms. In cue-reactivity tasks, patients with IGD exhibited significant hyperactivation in the bilateral precuneus and bilateral cingulate and significant hypoactivation in the insula, but there were no differences in the striatum. In executive control tasks, patients with IGD displayed significant hyperactivation in the right superior temporal gyrus, bilateral precuneus, bilateral cingulate, and insula and hypoactivation in the left inferior frontal gyrus. In risky decision-making paradigms, IGD patients exhibited significant hyperactivation in the left striatum, right inferior frontal gyrus, and insula and hypoactivation in the left superior frontal gyrus, left inferior frontal gyrus, and right precentral gyrus.
Our study aimed to discover the similarities among all studies and to explore the uniqueness of the different paradigms. This study further confirmed the critical role of reward circuitry and executive control circuitry in IGD but not under all conditions
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