SMAD7 rs12953717 polymorphism contributes to increased risk of colorectal cancer.

Mothers against decapentaplegic homolog 7 (SMAD7) rs12953717 polymorphism has been implicated to alter the risk of colorectal cancer (CRC), but the results are controversial. The objective of this study was to quantitatively evaluate the association between SMAD7 rs12953717 polymorphism and CRC susceptibility. A comprehensive search was conducted to identify all eligible studies of SMAD7 rs12953717 polymorphism and CRC risk. Pooled odds ratio and 95% confidence interval were calculated using a fixed or random effects model. Statistical analysis was performed with Review Manager 5.0 and Stata 11. A total of 11 case-control studies, including 12,058 cases and 11,444 controls, were identified. The combined results based on all studies suggested that rs12953717 was associated with CRC risk under all genetic models. When stratifying for race, the data showed that the rs12953717 was associated with a significantly increased CRC risk under all genetic models in Caucasians. Statistically significant association was found in all genetic models except in recessive model comparison in the subgroup of Asians. After stratifying the studies by study design, there was a significant association between rs12953717 polymorphism and CRC risk under all genetic models in the subgroup of population-based studies. Our study suggests that rs12953717 polymorphism is associated with an increased CRC risk.

[Black soil organic matter predicting model based on field hyperspectral reflectance].

To develop soil organic matter (OM) quick measuring methods, deepen the application of remote sensing in agriculture, improve agricultural production and management way, and promote the development of quantitative remote sensing studies relating to terrestrial ecosystem, field hyperspectral reflectance in the visible/near infrared bands of black soil in Hailun city, northeast China, was collected and analyzed with spectral analysis methods to discover the spectral characteristics of field reflectance and its influencing factors, and the spectral indices were derived, then black soil organic matter predicting model based on the correlation between OM content and spectral indices was built. Root mean squared error (RMSE) was introduced to validate the predictability and precision of the models, and coefficient of the determination (R2) was used to evaluate stability of the models. The results are as follows: the main spectral region of remarkable differences between field black soil reflectance curves is less than 1 250 nm, especially less than 1 000 nm; OM is the main factor determining the curve shape of field black soil reflectance, anc there are single or double spectral wave troughs for different soil samples because of varying OM content at the spectral region less 1 100 nm; correlation between OM and differential coefficient of logarithmic reflectance reciprocal (DCLRR) is much more significant than that between OM and other reflectance or its transforms, and the maximum coefficient of correlation is at 1 260 nm; the predicting model for black soil OM content is built with DCLRR at 1 260 nm as independent varialble and OM as dependent variable, and the coefficients of determination R2 of the model is 0.71, RMSE is 0.42, so the model is quite good in stability and predictability, and can be used in fast testing of organic matter in black soil.