Effects of Ecological Restoration and Climate Change on Herbaceous and Arboreal Phenology.

With global climate change, changes in vegetation phenology have become increasingly evident. Horqin Sandy Land is located near the eastern part of the West Liaohe River. It is the largest sandy land in China and its ecological environment is fragile. Investigating the changes in vegetation phenology in these sandy areas and determining the relationship between vegetation phenology and meteorological factors are of great importance for predicting the impacts of future climate change and understanding the response mechanisms of ecosystems. In this study, we used the time series of the Normalized Difference Vegetation Index (NDVI) from 2000 to 2021 and extracted the vegetation phenology in the Horqin Sandy Land using high-order curve fitting methods, including the start date of the growing season (SOS), the end date of the growing season (EOS), and the length of the growing season (LOS). We analyzed their temporal variation and used partial correlation analysis to determine their relationship with meteorological factors (temperature and precipitation). In addition, we compared the phenology and microclimate of forest and grassland within the study area. In the Horqin Sandy Land, the vegetation SOS was concentrated between the 115th and 150th day, the EOS was concentrated between the 260th and 305th day, and the LOS ranged from 125 to 190 days. Over the past 22 years, the SOS, EOS, and LOS of vegetation in the Horqin Sandy Land showed trends of delay, shift, and extension, with rates of change of 0.82 d/10a, 5.82 d/10a, and 5.00 d/10a, respectively. The start date of the growing season in the Horqin Sandy Land was mainly influenced by precipitation in April of the current year, while the end date was mainly influenced by precipitation in August of the current year. Overall, the SOS in the forested areas of the Horqin Sandy Land was slightly later than in the grasslands, but the EOS in the forested areas was significantly later than in the grasslands, resulting in a longer LOS in the forests. In addition, annual precipitation and the rate of precipitation increase were higher in the forested areas than in the grasslands, but soil temperature was higher in the grasslands than in the forests. Vegetation phenology in the Horqin Sandy Land has undergone significant changes, mainly manifested in the delayed end date of the growing season, the extended length of the growing season, and the differences between forest and grassland. This indicates that climate change has indeed affected phenological changes and provides a theoretical basis for subsequent ecological restoration and desertification prevention efforts in the region.

Melatonin Regulates Cisplatin Resistance and Glucose Metabolism Through Hippo Signaling in Hepatocellular Carcinoma Cells.

INTRODUCTION AND AIM: Hepatocellular carcinoma (HCC) is a primary malignancy that occurs in the liver. Clinical cases have been recorded worldwide, particularly in the Saharan area and Asia. In the present work, we aimed to probe the characteristics of melatonin involved in human HCC development, especially in cisplatin resistance and glucose metabolism. METHODS: Two HCC cells, HepG2 and Hep3B cells, were treated with melatonin. Cell cycle test was then used to define the role of melatonin in cell progression while Western blotting and qPCR assay were applied to determine the associated proteins in the treatment. Annexin V/PI staining and MTT assay was used to probe the involvement of melatonin in cisplatin-induced cell apoptosis process. Successively, we assessed glucose consumption in melatonin treated cells along with Western blotting for detection of GLUT-3 expression level. Yes-associated protein (YAP), a key regulator of Hippo signaling pathway, was further examined to characterize the function of melatonin on adjusting GLUT3 and Bcl-2 expression. RESULTS: Melatonin enabled inhibition of HepG2 and Hep3B proliferation and cell cycle progression via affecting the cell cycle-associated proteins. Annexin V/PI staining and MTT assay results demonstrated that melatonin assisted cisplatin-induced apoptosis accompanied with upregulated caspase-3 and poly ADP-ribose polymerase (PARP) cleavage, as well as Bcl-2 expression. It revealed that melatonin inhibits glucose uptake and ATP production via downregulation of Glucose transporter 3 (GLUT3). In addition, YAP was downregulated by melatonin treatment. The YAP depletion in HepG2 and Hep3B cells suppressed mRNA and protein expression of Bcl-2 and GLUT3, whereas overexpression of YAP in melatonin treated cells partly reversed the melatonin-induced inhibition on proliferation, cisplatin-induced apoptosis, and GLUT3 and Bcl-2 expression. CONCLUSION: Melatonin hindered HCC proliferation and aided cisplatin resistance via regulating the Hippo signaling pathway.

Evolution of Groundwater in Yinchuan Oasis at the Upper Reaches of the Yellow River after Water-Saving Transformation and Its Driving Factors.

In recent years, the amount of water diverted from the Yellow River has been decreasing year by year, which is the biggest problem for the development and utilization of water resources in Yinchuan Oasis (YCO). Through the implementation of the Agricultural Water-saving Transformation Project (AWSTP), water resource shortage in the YCO has been alleviated greatly, and ecological degradation problems, such as soil salinization, have also been effectively addressed. However, how the shallow groundwater in YCO has changed after the AWSTP remains unclear. This paper, based on a lot of statistical data and measured data, and by using statistical and geostatistical methods, reveals the evolution of shallow groundwater in YCO in the past 18 years (2000-2017), since the implementation of the AWSTP and its driving factors, from two aspects: groundwater dynamics and groundwater quality. The results show that compared with the initial stage of AWSTP, the amount of water diverted from the Yellow River for the YCO reduced by 36%, and accordingly, the average groundwater depth in the irrigation period increased from 0.98 m to 2.01 m, representing an increase of 1.03 m, and an average annual increase of 6cm. Moreover, the depth increase in the irrigation period is higher than that in the non-irrigation period, and that in the Northern Irrigation Area (NIA) is higher than that in the Southern Irrigation Area (SIA). Furthermore, the groundwater storage is decreasing at a rate of 855.6 × 104 m3·a-1, and the cumulative storage has reduced by nearly 1.54 × 108 m3, indicating that it is in a long-term negative equilibrium. In terms of temporal and spatial distribution of total dissolved solids (TDS) in groundwater, the TDS in SIA and NIA decreased from 1.41 g·L-1 and 1.84 g·L-1 to 1.15 g·L-1 and 1.77 g·L-1, respectively. The saline water area with a TDS above 5 g·L-1 and the freshwater area with a TDS below 1 g·L-1 decreased by 16.6 km2 and 334.4 km2, respectively, while the brackish water area with a TDS of 1~3 g·L-1 increased by 492 km2. The spatial and temporal distribution heterogeneity of TDS in groundwater is reduced and is in a slight desalinized trend overall. However, the groundwater in some areas, such as the Xingqing District, Jinfeng District, Xixia District, Yongning County, Helan County and Huinong District of Yinchuan Oasis, is at risk of further salinization. Due to the agricultural water-saving caused by the reduction of water amount diverted from the Yellow River, the groundwater recharge in YCO was reduced by 36.3%, which, together with measures such as drainage, groundwater exploitation, and industrial restructuring, drives the groundwater circulation in the YCO to a new equilibrium. This study can help us to understand the influencing process and mechanism of agricultural water-saving on groundwater systems in YCO and provide reference for efficient use and optimal allocation and management of agricultural water resources.

Phosphine-induced physiological and biochemical responses in rice seedlings.

Paddy fields have been demonstrated to be one of the major resources of atmospheric phosphine and may have both positive and negative effects on rice plants. To elucidate the physiological and biochemical responses of rice plants to phosphine, rice seedlings (30 d old) were selected as a model plant and were treated with different concentrations of phosphine (0, 1.4, 4.2, and 7.0 mg m(-3)). Antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and lipid peroxidation measured via malondialdehyde (MDA) were determined as indicators of the physiological and biochemical responses of the rice seedlings to phosphine exposure. Increasing concentrations of phosphine treatment enhanced the activity of SOD, POD, and CAT. In addition, the MDA content increased with increasing concentrations of phosphine. These results suggested that antioxidant enzymes played important roles in protecting rice seedlings from ROS damage. Moreover, rice seedlings were able to cope with the oxidative stress induced by low concentrations of phosphine via an increase in antioxidant enzymatic activities. However, oxidative stress may not fully be prevented when the plants were exposed to higher concentrations of phosphine.

Physiological and biochemical responses of rice seeds to phosphine exposure during germination.

Rice seeds (Tianyou, 3618) were used to examine the physiological and biochemical responses to phosphine exposure during germination. A control (0 mg m(-3)) and four concentrations of phosphine (1.4 mg m(-3), 4.2 mg m(-3), 7.0 mg m(-3) and 13.9 mg m(-3)) were used to treat the rice seeds. Each treatment was applied for 90 min once per day for five days. The germination rate (GR); germination potential (GP); germination index (GI); antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT); and lipid peroxidation measured through via malondialdehyde (MDA) were determined as indicators of the physiological and biochemical responses of the rice seeds to phosphine exposure. These indicators were determined once per day for five days. The results indicated that the GR, GP and GI of the rice seeds markedly decreased after phosphine exposure. The changes in the activities of the antioxidant enzymes due to the phosphine exposure were also significant. The exposure lowered the CAT and SOD activities and increased POD activity in the treated rice seeds compared with controls. The MDA content exhibited a slow increase trend with the increase of phosphine concentration. These results suggest that phosphine has inhibitory effects on seed germination. In addition, phosphine exposure caused oxidative stress in the seeds. The antioxidant enzymes could play a pivotal role against oxidative injury. Overall, the effect of phosphine on rice seeds is different from what has been reported previously for insects and mammals.

Phosphine in paddy fields and the effects of environmental factors.

Ambient levels of phosphine (PH3) in the air, phosphine emission fluxes from paddy fields and rice plants, and the distribution of matrix-bound phosphine (MBP) in paddy soils were investigated throughout the growing stages of rice. The relationships between MBP and environmental factors were analyzed to identify the principal factors determining the distribution of MBP. The phosphine ambient levels ranged from 2.368±0.6060 ng m(-3) to 24.83±6.529 ng m(-3) and averaged 14.25±4.547 ng m(-3). The highest phosphine emission flux was 22.54±3.897 ng (m(2)h)(-1), the lowest flux was 7.64±4.83 ng (m(2)h)(-1), and the average flux was 14.17±4.977 ng (m(2)h)(-1). Rice plants transport a significant portion of the phosphine emitted from the paddy fields. The highest contribution rate of rice plants to the phosphine emission fluxes reached 73.73% and the average contribution was 43.00%. The average MBP content of 111.6 ng kg(-1)fluctuated significantly in different stages of rice growth and initially increased then decreased with increasing depth. The peak MBP content in each growth stage occurred approximately 10 cm under the surface of paddy soils. Pearson correlation analyses and stepwise multiple regression analysis showed that soil temperature (Ts), acid phosphatase (ACP) and total phosphorus (TP) were the principal environmental factors, with correlative rankings of Ts>ACP>TP.

Chicken skin mucosa surrounding adult colorectal adenomas is a risk factor for carcinogenesis.

OBJECTIVES: Transformation of normal mucosa to colorectal adenoma could occur over a span of 5 to 20 years, whereas transformation of colorectal adenoma to colorectal cancer could take an additional 5 to 15 years. This study aims to investigate whether chicken skin mucosa (CSM) surrounding adult colorectal adenomas may be a risk factor for carcinogenesis. METHODS: Patients with colorectal mucosa, colorectal adenomas without CSM, or colorectal adenomas with CSM were enrolled in this study. Immunohistochemistry and enzyme-linked immunosorbent assays were used to determine the expression levels of proliferation markers (ki-67 and COX-2) and apoptosis factors (survivin and caspase-3) in tissues. RESULTS: The expression of ki-67 was significantly higher in colorectal adenomas with CSM compared with colorectal adenoma tissues (P < 0.01). Colorectal adenocarcinoma showed significantly higher levels of COX-2 protein compared with normal colorectal mucosa and colorectal adenoma tissues (P < 0.001). COX-2 expression was significantly higher in adenomas with CSM compared with normal colorectal mucosa (P < 0.001). Adenomas with CSM and adenocarcinomas exhibited significantly higher levels of survivin when compared with colorectal adenoma without CSM and normal tissues (P < 0.001). Although we found no significant difference in caspase-3 levels between adenocarcinomas and adenomas with CSM, caspase-3 expression was significantly lower in these tissues when compared with colorectal adenomas without CSM and normal mucosa (P < 0.001). CONCLUSIONS: The biological characteristics of colorectal adenomas with CSM were different from those of colorectal adenomas without CSM. Colorectal adenomas with CSM exhibited active cell proliferation and inhibition of apoptotic pathways, suggesting an increased risk of carcinogenesis in these adenomas.