This paper studies contemporaneous relationship between S&P 500 index returns and logincrements of the market volatility index (VIX) via a nonparametric copula method. Specifically, we propose a conditional dependence index to investigate how the dependence between the two series varies across different segments of the market return distribution. We observe the following findings: (a) the two s...

Conspecific negative density dependence (CNDD) is an important driver of stand-level tree diversity in temperate forests. CNDD can occur via two main processes. First, soil pathogens and herbivores form a halo high enemy surrounding established trees at local spatial scales. As result, seedlings saplings residing within this experience reduced growth survival. Second, intraspecific competition ...

conclusions low onset age of smoking cigarettes, high novelty seeking and low cooperativeness in opiate dependents are among the important personality traits in future use of drugs that can predict the subsequent onset of using opiate drugs. results opiate addicts had higher scores in novelty seeking dimension and lower scores in cooperativeness compared to nicotine addicts. the onset age of sm...

conclusions results showed that sexual dysfunction is a prevalent disorder in opioid-dependent males. addiction withdrawal centers should be warned about the dysfunction caused by opioids and, from a clinical perspective, it is imperative that patients misusing opiates and those treated with methadone are routinely asked about their sexual functioning so that, if indicated, appropriate investig...

background :impact of substance abuse on outcome of hospitalized patients with acute myocardial infarction (mi) is a frequent question. available studies show disagreements over its impact, thus we performed this study to find a clear answer.   methods : in a cross sectional study, 304 patients (include 152 consecutive opium dependents and equal number of independents) with acute mi admitted to...

glutathione s-transferases (gsts; ec: 2.5.1.18) are ubiquitous multifunctional enzymes, which play a key role in cellular detoxification. functional genetic polymorphisms in genes encoding gstm1 (a member of gst class mu; omim: 138350), and gstt1 (a member of gst class theta; omim: 600436) have been well defined. the functional null alleles of gstm1 and gstt1 represent deletions of gstm1 and gs...