Phosphorus pools and internal loading in a eutrophic lake with gradients in sediment geochemistry created by land use in the watershed

Spatial variations in phosphorus (P) fractionation, sediment geochemistry, and sorptive properties for P are assessed to test the hypothesis that these sediment properties vary within the lake and are governed by different land uses in the watershed. The dynamic equilibrium between P in sediment and water is investigated using sorption–desorption isotherms. Sediments in the littoral zone were rich in iron (Fe), aluminium (Al), and clay material in comparison to sediments from the lake proper and thus had better abilities to sorb and retain P. In the limnetic zone, there was an increasing abundance of primary minerals, and the fraction of apatite-P was high, while the level of total P was low. The amount of labile adsorbed P (LAP) in the littoral sediments varied because of contrasting land use in the sub-catchments draining into different parts of the lake. Sediments in areas where forest streams enter the lake contained significantly more LAP than sediments in areas impacted by agricultural influenced streams. Internal P loading from sediments predominantly originating from forest streams is mainly governed by sediment resuspension. The dominant P pool in sediments near the inlets of agriculturally influenced streams was non-apatite inorganic P, of which the Fe-bound is a potentially important source of P under anoxic conditions. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited

Air pollution reduction during China's 11th Five-Year Plan period—local implementation and achievements in Shanxi province

Facing the increasing environmental degradation locally and globally, the Chinese government set mandatory goals of 10% reduction of SO2 emission in its 11th Five-Year Plan period (FYP, 2006–2010). In this paper we use Shanxi province to illustrate how policies and measures are implemented in practice at a provincial level as a response to the National FYP issued by the central government. Local policies are described and their effects are analyzed. We find that the 11th FYP goal for SO2 pollution reduction in Shanxi has been surpassed. SO2 reduction from estimated baseline level was calculated for the FYP period in order to identify which sectors have had the largest reductions. Regarding SO2, we find that Flue-gas desulfurization (FGD) in power plants has been the most important, while either the FGD operation rate or the efficiency, or both, are much lower in practice than officially required. SO2 emission reduction from closing down outdated production capacity is small according to our estimates. This is due to the comparatively small use of coal in the units being closed down in Shanxi. Necessary steps to achieve the targets in the 12th FYP are briefly discusse

Prognostic value of normal levels of preoperative tumor markers in colorectal cancer

Abstract Carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and alpha-fetoprotein (AFP) are widely used tumor markers for colorectal cancer (CRC), but their clinical significance is unknown when the levels of these tumor markers were within the normal range. This retrospective study included 2145 CRC patients. The entire cohort was randomly divided into training and validation datasets. The optimal cut-off values of tumor markers were calculated using X-tile software, and univariate and multivariate analyses were performed to assess its association with overall survival (OS). The nomogram model was constructed and validated. The entire cohort was randomly divided into a training dataset (1502 cases, 70%) and a validation dataset (643 cases,30%). Calculated from the training dataset, the optimal cut-off value was 2.9 ng/mL for CEA, 10.1 ng/mL for CA19-9, 13.4 U/mL for CA125, and 1.8 ng/mL for AFP, respectively. Multivariate analysis revealed that age, tumor location, T stage, N stage, preoperative CA19-9, and CA125 levels were independent prognostic predictors. Even within the normal range, CRC patients with relatively high levels of CA19-9 or CA125 worse OS compared to those with relatively low levels. Then, based on the independent prognostic predictors from multivariate analysis, two models with/without (model I/II) CA19-9 and CA125 were built, model I showed better prediction and reliability than model II. Within the normal range, relatively high levels of preoperative CA19-9 and CA125 were significantly associated with poor OS in CRC patients. The nomogram based on CA19-9 and CA125 levels showed improved predictive accuracy ability for CRC