A novel prestack sparse azimuthal AVO inversion

In this paper we demonstrate a new algorithm for sparse prestack azimuthal AVO inversion. A novel Euclidean prior model is developed to at once respect sparseness in the layered earth and smoothness in the model of reflectivity. Recognizing that methods of artificial intelligence and Bayesian computation are finding an every increasing role in augmenting the process of interpretation and analysis of geophysical data, we derive a generalized matrix-variate model of reflectivity in terms of orthogonal basis functions, subject to sparse constraints. This supports a direct application of machine learning methods, in a way that can be mapped back onto the physical principles known to govern reflection seismology. As a demonstration we present an application of these methods to the Marcellus shale. Attributes extracted using the azimuthal inversion are clustered using an unsupervised learning algorithm. Interpretation of the clusters is performed in the context of the Ruger model of azimuthal AVO

Loss of 5-Hydroxymethylcytosine Is an Independent Unfavorable Prognostic Factor for Esophageal Squamous Cell Carcinoma

<div><p>Ten-eleven translocation (TET) enzymes catalyze the oxidation of 5-methylcytosine (5-mC) to 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine and 5-carboxylcytosine, which result in genomic DNA demethylation. It was reported that 5-hmC levels were decreased in a variety of cancers and could be regarded as an epigenetic hallmark of cancer. In the present study, 5-hmC levels were detected by immunohistochemistry (IHC) in 173 esophageal squamous cell carcinoma (ESCC) tissues and 91 corresponding adjacent non-tumor tissues; DNA dot blot assays were used to detect the 5-hmC level in another 50 pairs of ESCC tissues and adjacent non-tumor tissues. In addition, the mRNA level of <i>TET1</i>, <i>TET2</i> and <i>TET3</i> in these 50 pairs of ESCC tissues was detected by real-time PCR. The IHC and DNA dot blot results showed that 5-hmC levels were significantly lower in ESCC tissues compared with corresponding adjacent non-tumor tissues (P = 0.029). <i>TET2</i> and <i>TET3</i> expression was also significantly decreased in tumor tissues compared with paired non-tumor tissues (<i>TET2</i>, P < 0.0001; <i>TET3</i>, P = 0.009), and the decrease in 5-hmC was significantly associated with the downregulation of <i>TET2</i> expression (r = 0.405, P = 0.004). Moreover, the loss of 5-hmC in ESCC tissues was significantly associated with poor overall survival among patients with ESCC (P = 0.043); multivariate Cox regression analysis showed that the loss of 5-hmC in ESCC tissues was an independent unfavorable prognostic indicator for patients with ESCC (HR = 1.569, P = 0.029). In conclusion, 5-hmC levels were decreased in ESCC tissues, and the loss of 5-hmC in tumor tissues was an independent unfavorable prognostic factor for patients with ESCC.</p></div

Associations between clinical parameters and overall survival.

<p>Kaplan-Meier analysis showed that older age (A), poor differentiation (B), lymph node metastasis (C), advanced pTNM stage (D) and negative 5-hmC expression (E) were significantly associated with poor overall survival among patients with ESCC.</p

Expression of 5-hmC was decreased in ESCC tissues.

<p>Detection of 5-hmC expression in 173 ESCC tissues and 91 corresponding non-tumor tissues using IHC. Representative images are shown (left panel, 100×; right panel, 400×).</p

The mutation of <i>TET</i> and <i>IDH1</i>gene in 105 ESCC tissues.

<p>The mutation of <i>TET</i> and <i>IDH1</i>gene in 105 ESCC tissues.</p

Univariate and multivariate analyses of overall survival among patients with ESCC.

<p>Univariate and multivariate analyses of overall survival among patients with ESCC.</p

Clinicopathological characteristics of patients with ESCC.

<p>Clinicopathological characteristics of patients with ESCC.</p

Decreased 5-hmC expression was associated with <i>TET2</i> downregulation.

<p>(A, B and C) <i>TET1/2/3</i> mRNA levels in 50 matched ESCC tissues and non-tumor tissues were compared. 2^−ΔΔCt method was used to calculate the relative expression of <i>TET</i>, and <i>GAPDH</i> was used as an internal control, the sample with the median value of <i>TET1/2/3</i> among 100 samples were used for normalization. The data were presented on a logarithmic scale. (D, E and F) Associations between <i>TET</i> level and 5-hmC levels in ESCC were analyzed. The relative 5-hmC level were calculated by N/T. The relative <i>TET</i> expression were calculated by 2^{−ΔΔCt (N-T)} and converted to a logarithmic scale on X axis.</p

Correlations between <i>TET2</i> levels in ESCC tissues and clinicopathological characteristics of patients with ESCC.

<p>Correlations between <i>TET2</i> levels in ESCC tissues and clinicopathological characteristics of patients with ESCC.</p

The correlation between <i>TET</i> or <i>IDH1</i> gene mutations and 5-hmC expression.

<p>The correlation between <i>TET</i> or <i>IDH1</i> gene mutations and 5-hmC expression.</p