Fixed-domain asymptotic properties of tapered maximum likelihood estimators

When the spatial sample size is extremely large, which occurs in many environmental and ecological studies, operations on the large covariance matrix are a numerical challenge. Covariance tapering is a technique to alleviate the numerical challenges. Under the assumption that data are collected along a line in a bounded region, we investigate how the tapering affects the asymptotic efficiency of the maximum likelihood estimator (MLE) for the microergodic parameter in the Mat\'ern covariance function by establishing the fixed-domain asymptotic distribution of the exact MLE and that of the tapered MLE. Our results imply that, under some conditions on the taper, the tapered MLE is asymptotically as efficient as the true MLE for the microergodic parameter in the Mat\'ern model.Comment: Published in at http://dx.doi.org/10.1214/08-AOS676 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Targeting Epigenetic Mechanisms to Alleviate Alcoholic Steatosis

Alcohol-related liver disease (ALD) is a major health concern and recent studies have reported nearly 1 million alcohol-related deaths from 1999 to 2017 in the United States.1 ALD is a spectrum of conditions that ranges from early steatosis or fatty liver to inflammation or alcoholic steatohepatitis progressing to fibrosis and cirrhosis. Approximately 8%–20% of alcoholic steatohepatitis patients develop cirrhosis and, in some, alcoholic steatohepatitis can present in the form of acute-on-chronic liver failure, termed alcoholic hepatitis, owing to excessive drinking episodes. Corticosteroids are the first line of therapy for ALD, however, only marginal short-term survival benefit in patients with severe alcoholic hepatitis has been reported.2 Studies from the National Institute on Alcohol Abuse and Alcoholism consortia have focused on preclinical or early clinical testing of drugs classified on the basis of pathogenic mechanisms such as targeting the gut–liver axis, anti-inflammatory agents, antioxidants, and drugs that promotes liver regeneration.3 Despite several efforts, the treatment for alcoholic hepatitis remains suboptimal and there is an urgent need to develop new, safe, and effective therapies. Uncovering new targets directly involved in regulatory processes that influence gene expression and cellular phenotype could be an attractive strategy

Alcohol and Cancer: Mechanisms and Therapies

Several scientific and clinical studies have shown an association between chronic alcohol consumption and the occurrence of cancer in humans. The mechanism for alcohol-induced carcinogenesis has not been fully understood, although plausible events include genotoxic effects of acetaldehyde, cytochrome P450 2E1 (CYP2E1)-mediated generation of reactive oxygen species, aberrant metabolism of folate and retinoids, increased estrogen, and genetic polymorphisms. Here, we summarize the impact of alcohol drinking on the risk of cancer development and potential underlying molecular mechanisms. The interactions between alcohol abuse, anti-tumor immune response, tumor growth, and metastasis are complex. However, multiple studies have linked the immunosuppressive effects of alcohol with tumor progression and metastasis. The influence of alcohol on the host immune system and the development of possible effective immunotherapy for cancer in alcoholics are also discussed here. The conclusive biological effects of alcohol on tumor progression and malignancy have not been investigated extensively using an animal model that mimics the human disease. This review provides insights into cancer pathogenesis in alcoholics, alcohol and immune interactions in different cancers, and scope and future of targeted immunotherapeutic modalities in patients with alcohol abuse

Spectral theory of stationary H-valued processes

AbstractFor weakly stationary stochastic processes taking values in a Hilbert space, spectral representation and Cramér decomposition are studied. Using these ideas and the moving average representation for such processes established earlier by the authors, some necessary and sufficient spectral conditions for such stochastic processes to be purely nondeterministic are given in both discrete and continuous parameter cases

Quasi-invariance of analytic measures on compact groups

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On the existence of weak variational solutions to stochastic differential equations

We study the existence of weak variational solutions in a Gelfand triplet of real separable Hilbert spaces, under continuity, growth, and coercivity conditions on the coefficients of the stochastic differential equation. The laws of finite dimensional approximations are proved to weakly converge to the limit which is identified as a weak solution. The solution is an H– valued continuous process in L2 (Ω, C([0, T], H)) ∩ L2([0, T] × Ω, V ). Under the assumption of monotonicity the solution is strong and unique