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Gold mine tailing is an important source of arsenic pollution. There are great differences in the arsenic forms of mine tailings formed by different smelting processes. Different arsenic form directly affects its migration and transformation in the environment. Confirming the existing form of arsenic is an important method in the study of repairing arsenic contamination sites. Based on mine tailings generated by two different leaching methods (flotation process and biological oxidation process) for gold, pH meter and Eh meter was used to measure the physical properties of mine tailings (pH, Eh), X-ray Diffraction and X-ray Fluorescent to analyze the mineral phases and main compositions of the mine tailings and Electro-probe Microanalysis to analyze the arsenic existing form. The characterization result shows that the physical properties of flotation mine tailing and biological oxidation mine tailing change with the stacking environment. pH, Eh and pHpzc are almost equal, ie pH≈8.5 and pHpzc≈8.5. The choice of repair method is also restricted because both min tailings belong to the alkaline condition. For example, the electric repair method is only suitable for the acid condition but not for the two main mine tailings. Meanwhile the choice of repair reagent must be alkaline substance and iron oxide (hydroxide). The main mineral compositions of flotation mine tailing are quartz, dolomite and clay minerals and their chemical components are mainly Si and Al. The color of mine tailing is off-white. The arsenic content of this mine tailing is about 754 μg/g, mainly existing in the form of arsenopyrite (FeAsS). However, the main mineral type of biological oxidation mine tailing is gypsum. The main chemical components are Fe, Ca and S with a reddish-brown colour. The arsenic content is about 26350 μg/g. The existing forms of arsenic of this mine tailing are mainly arsenopyrite (FeAsS) and arsenic pentoxide (As2O5). There are many differences in mineral phase, main chemical components and arsenic forms of two kinds of mine tailings because every procedure step of the two-gold leaching processes is different. Therefore, in the in-situ repair work of mine tailings, it should be considered that different methods of gold leaching will influence the piled-up environment of mine tailings and arsenic forms and should be taken into consideration in order to choose a more appropriate, cheap and efficient repair method and choice of reagents.

Long-term intensive use of mineral fertilizers in double rice-cropping systems has led to soil acidification and soil degradation. Manure fertilization was suggested as an alternative strategy to mitigate soil degradation. However, the effects of long-term mineral and manure fertilization on rice grain yield, yield stability, soil organic carbon (SOC) content, soil total nitrogen (TN) content, and the underlying mechanisms are unclear. Based on a long-term experiment established in 1981 in southern China, we compared four treatments: no fertilizer application (Control); application of nitrogen–phosphorus–potassium (NPK); NPK plus green manure in early rice (M1); and M1 plus farmyard manure in late rice and rice straw return in winter (M2). Our results showed that 37 years of NPK, M1, and M2 significantly increased rice grain yield by 54%, 46%, and 72%, and yield stability by 22%, 17%, and 9%, respectively. M1 and M2 significantly increased SOC content by 39% and 23% compared to Control, respectively, whereas there was no difference between Control and NPK. Regarding soil TN content, it was significantly increased by 8%, 46%, and 20% by NPK, M1, and M2, respectively. In addition, M2 significantly increased bacterial OTU richness by 68%, Chao1 index by 79%, and altered the bacterial community composition. Changes in soil nutrient availability and bacterial Simpson index were positively correlated with the changes in grain yield, while shifts in bacterial community were closely related to yield stability. This study provides pioneer comprehensive assessments of the simultaneous responses of grain yield, yield stability, SOC and TN content, nutrient availability, and bacterial community composition to long-term mineral and manure fertilization in a double rice-cropping system. Altogether, this study spanning nearly four decades provides new perspectives for developing sustainable yet intensive rice cultivation to meet growing global demands. [ABSTRACT FROM AUTHOR]

PTEN/MMAC1/TEP1 is a tumor suppressor that possesses intrinsic phosphatase activity. Deletions or mutations of its encoding gene are associated with a variety of human cancers. However, very little is known about the molecular mechanisms by which this important tumor suppressor regulates cell growth. Here, we show that PTEN expression potently suppressed the growth and tumorigenicity of human glioblastoma U87MG cells. The growth suppression activity of PTEN was mediated by its ability to block cell cycle progression in the [G.sub.1] phase. Such an arrest correlated with a significant increase of the cell cycle kinase inhibitor [p27.sup.KIP1] and a concomitant decrease in the activities of the [G.sub.1] cyclin-dependent kinases. PTEN expression also led to the inhibition of Akt/protein kinase B, a serine-threonine kinase activated by the phosphatidylinositol 3-kinase (PI 3-kinase) signaling pathway. In addition, the effect of PTEN on [p27.sup.KIP1] and the cell cycle can be mimicked by treatment of U87MG cells with LY294002, a selective inhibitor of PI 3-kinase. Taken together, our studies suggest that the PTEN tumor suppressor modulates [G.sub.1] cell cycle progression through negatively regulating the PI 3-kinase/Akt signaling pathway, and one critical target of this signaling process is the cyclin-dependent kinase inhibitor [p27.sup.KIP1].

We aimed to explore changes in basic soil productivity ( BSP) under different fertilization regimes in the Poyang Lake region, Jiangxi Province, China. Soil samples were collected from a long-term fertilization experiment (since 98) that included treatments of no fertilization (CK), chemical fertilization ( NPK), and combined chemical and organic fertilization ( NPKM) . Then, a three-year pot experiment (from 0 to 0) with double rice cropping was conducted with two different fertilization regimes (no fertilization, F0; fertilization, F1) using CK, NPK and NPKM soils. Grain yield and BSP were analyzed among soils with different fertilization regimes to identify the key factors driving changes in BSP. Results showed that grain yields in NPKM soil were higher than in NPK and CK soils regardless of fertilization in the pot experiment. Under the F0 condition, annual grain yields of NPKM soil were 7.7%-.9% and 0.8%-66.7% higher than CK and NPK soils, respectively. The BSP values of CK, NPK and NPKM soils in three years were .8%-5.%, 5.%-6.6% and 59.%-88.%, respectively. NPKM soil had significantly higher BSP than NPK and CK soils. Furthermore, there were significant positive correlations between soil organic matter and BSP as well as between organic carbon balance and BSP. These results suggested that long-term application of chemical and organic fertilizers could improve BSP in the double rice cropping system of the Poyang Lake region. In addition, soil organic matter and organic carbon balance are important factors for improving BSP in this region. [ABSTRACT FROM AUTHOR]

Colorectal cancer is one of the most serious illnesses among diagnosed cancer. As a new type of anti-cancer composition from tocotrienol-rich fraction of palm oil, γ-tocotrienol is widely used in anti-cancer research. The objectives of this study were to investigate the effects of γ-tocotrienol on human colon cancer SW620 and HCT-8 cells. We showed that treatment with different concentrations of γ-tocotrienol resulted in a dose dependent inhibition of cell growth. Cell death induced by γ-tocotrienol was mediated by a paraptosis-like cell death in SW620 and HCT-8 cells. Real-time RT-PCR and western blot analyses showed that γ-tocotrienol inhibited the expression level of β-catenin, cyclin D1 and c-jun. These data suggest that a paraptosis-like cell death induced by γ-tocotrienol in SW620 cells is associated with the suppression of the Wnt signaling pathway, which offers a novel tool for treating apoptosis-resistance colon cancer. [ABSTRACT FROM AUTHOR]

Abstract: A long-term field experiment (started at 2003) was conducted to determine the effects of different rice cultivation methods on growth characteristics and grain yield of late-season rice under double-rice cropping system in seasonal drought region of southeast China (Yujiang County, Jiangxi Province). The rice cultivation methods included no-tillage and flooded rice cultivation (N-F), no-tillage and non-flooded rice cultivation with straw mulching (N-SM), and no-tillage and non-flooded rice cultivation without straw mulching (N-ZM). There was no significant difference in rice grain yield between the N-SM and N-F treatments. However, the rice grain yields in the N-SM and N-F treatments were significantly higher than that in the N-ZM treatment. The late-season rice plants in the N-SM treatment had significantly higher numbers of effective panicles and total grains per hill compared with those in the N-ZM treatment. The above-ground dry matter of late-season rice was similar between the N-SM and N-F treatments. Compared with the N-F treatment, the N-ZM and N-SM treatments significantly decreased the leaf area at the heading stage. Moreover, the N-SM treatment could significantly increase total root length and root tip number at the grain-filling stage compared with the N-ZM treatment. [Copyright &y& Elsevier]

ABSTRACT: The risk analysis of urban rainstorm water logging facing Tianjin city by using methods of probability, investigation and numerical simulation was carried out in this article. Firstly, a mathematical model for the urban rainstorm water logging was established on the basis of one- and two-dimensional unsteady flow theory and the technique of non-structural irregular grid division, Secondly, the precipitation over heavy rain was divided into seven grades, the experiential expression of frequency and rain grades was got according to the observed rainfall from May 1918 to October 1998. Thirdly, the mathematical model was used to simulate various rain process according to the features of the rainstorm and the draining rule, based on the simulated maximum water depths, 3 class of disaster extents were established, the disaster risks were mainly in Class I and Class II, The risk analysis of water logging on traffic were primarily evaluated, and finally, some management and mitigation measures of the urban rainstorm water logging disaster were discussed. [Copyright &y& Elsevier]

LATS (large tumour suppressor) is a family of conserved tumour suppressors identified in Drosophila and mammals. Here we show that human LATS1 binds to LIMK1 in vitro and in vivo and colocalizes with LIMK1 at the actomyosin contractile ring during cytokinesis. LATS1 inhibits both the phosphorylation of cofilin by LIMK1 and LIMK1-induced cytokinesis defects. Inactivation of LATS1 by antibody microinjection or RNA-mediated interference in cells, or gene knockout in mice, abrogates cytokinesis and increases the percentage of multinucleate cells. Our findings indicate that LATS1 is a novel cytoskeleton regulator that affects cytokinesis by regulating actin polymerization through negative modulation of LIMK1. [ABSTRACT FROM AUTHOR]

The lats gene encodes a family of proteins conserved from insects to humans. Drosophila carrying lats mutant cells or mice deficient for Lats1 develop tumors in various tissues. The mammalian LATS1 protein was previously shown to bind to CDC2, suggesting that LATS1 may modulate G2/M cell cycle progression by affecting CDC2 activity. In this study, we introduced human LATS1 into LATS-/- MEF cells by adenovirus-mediated gene transfer. Overexpression of LATS1 causes G2/M arrest through inhibition of CDC2 kinase activity. Furthermore, overexpression of LATS1 significantly suppressed the human tumor cell growth in vitro and tumorigenicity in vivo by inducing either cell cycle arrest in G2/M or apoptosis. These observations suggest that LATS1 is a potent growth suppressor and, like other tumor suppressors, it suppresses growth by inducing cell cycle arrest or apoptosis. Oncogene (2001) 20, 6516–6523. [ABSTRACT FROM AUTHOR]

Multiple signalling events interact in cancer cells. Oncogenic Ras cooperates with Egfr, which cannot be explained by the canonical signalling paradigm. In turn, Egfr cooperates with Hedgehog signalling. How oncogenic Ras elicits and integrates Egfr and Hedgehog signals to drive overgrowth remains unclear. Using a Drosophila tumour model, we show that Egfr cooperates with oncogenic Ras via Arf6, which functions as a novel regulator of Hh signalling. Oncogenic Ras induces the expression of Egfr ligands. Egfr then signals through Arf6, which regulates Hh transport to promote Hh signalling. Blocking any step of this signalling cascade inhibits Hh signalling and correspondingly suppresses the growth of both, fly and human cancer cells harbouring oncogenic Ras mutations. These findings highlight a non-canonical Egfr signalling mechanism, centered on Arf6 as a novel regulator of Hh signalling. This explains both, the puzzling requirement of Egfr in oncogenic Ras-mediated overgrowth and the cooperation between Egfr and Hedgehog. [ABSTRACT FROM AUTHOR]