Aims: Many men endure immunosuppressive or anticancer treatments that contain alkylating agents before the age of sexual maturity, especially the increasing number of preadolescent males who undergo busulfan treatment for myeloablative conditioning before hematopoietic stem cell transplantation. Before sperm production, there are no sperm available for cryopreservation. Thus, it is necessary to identify a solution to ameliorate the busulfan-induced damage of spermatogonial stem cells (SSCs). Results: In this study, we demonstrated that melatonin relieved the previously described SSC loss and apoptosis in mouse testes. Melatonin increased the expression of manganese superoxide dismutase (MnSOD), which regulated the production of busulfan-induced reactive oxygen species (ROS). Moreover, melatonin promoted sirtuin type 1 (SIRT1) expression. SIRT1 participated in the deacetylation of p53, which promotes p53 ubiquitin degradation. Decreased concentrations of deacetylated p53 resulted in spermatogonial cell resistance to apoptosis. Acute T cell leukemia cell assay demonstrated that melatonin does not affect busulfan-induced cancer cell apoptosis and ROS. Innovation: The current evidence suggests that melatonin may alleviate the side effects of alkylating drugs, such as busulfan. Conclusion: Melatonin promoted MnSOD and SIRT1 expression, which successfully ameliorated busulfan-induced SSC apoptosis caused by high concentrations of ROS and p53.
Both temperature and precipitation are predicted to increase in the region of the Stipa steppe of Inner Mongolia. We conducted an experiment to simulate both the individual and combined effects of warming and increased precipitation on community structure (biomass and diversity) and ecological processes (soil respiration and ecosystem carbon exchange). Open-topped chambers were used to simulate climatic warming, and irrigation was applied to simulate a 20% increase in precipitation. Open-topped chambers were effective in producing significant increases in mean air temperature in each year of the experiment (2011-2015), with the average increase ranging from 2.5 degrees C to 3 degrees C in the final 3 years of the study. Mean soil temperature was significantly increased in 2 of the 5 years of observation. Irrigation significantly increased soil moisture. The experimental treatments thus produced environmental changes consistent with those expected in the region by mid-century and provide a basis for examining the likely effects of climate change on the grassland ecosystem as reported in companion papers.
A randomised block experiment was conducted to study the response of plant community characteristics (biomass, density and diversity) and ecosystem carbon exchange processes to warming, increased precipitation and their combination on Stipa steppe in Inner Mongolia. Increased precipitation enhanced the effect that warming had in promoting community diversity and biomass. Increased precipitation directly increased net ecosystem exchange and gross ecosystem productivity, although ecosystem respiration and soil respiration also increased. However, warming did not have a significant effect on net ecosystem exchange and gross ecosystem productivity, whereas ecosystem respiration and soil respiration were significantly decreased by warming. All carbon flux processes had a significantly positive correlation with soil moisture. However, the carbon sequestration processes, gross ecosystem productivity and net ecosystem exchange, were significantly negatively correlated with temperature, contrary to carbon emission processes, soil respiration and ecosystem respiration. Results suggest that Stipa steppe may be benefited by future climate change, as the predicted precipitation is increasing with warming in Inner Mongolia. However, it is hard to predict the feedback of Stipa steppe to climate, because of the uncertainty in magnitude and temporal dynamics of climate change. To reveal the mechanism of the observed responses, further studies are suggested in this region on the effects of altered climate variables on plant species interactions, soil organic carbon composition, soil extracellular enzyme activity, microbial biomass and microbial respiration.
Today, fractal image encoding method becomes an effective loss compression method in multimedia without resolution, and its negativeness is that its high computational complexity. So many approximate methods are given to decrease the computation time. So the distribution of error points is valued to research. In this paper, by extracted primary additional error values, we first present a novel fast fractal encoding method. Then, with the extracted primary additional error values,we abstract the distribution of these values.We find that the different distribution of values denotes the different parts in images. Finally, we analyze the experimental results and find some properties of these values.The experimental results also show the effectiveness of the method.
Nowadays, many images of cropland are photographed and transferred by wireless sensors in agricultural automation. But one contradiction is that the recognition needs images with high quality and the transmission needs images with small sizes. So, in this paper, by extracted and analyzedthe loss in the fractal encoding,we use fractal image encoding into the compression because of its high compression ratio. To solve the most important problemin fractal image encoding method,which is its high computational complexityand long encoding time, we first use statisticalanalysis to the fractal encoding method. We create its box-plot to find the distributional of loss value. Then, we partition them to several parts and map them to the given model. After that, we present a novel method to save the loss and maintain the quality in image compression. Finally, agricultural experimental results show effectiveness of the novel method.
The chemistry of sedimentary organic phosphorus (OP) and its fraction distribution in sediments are greatly influenced by environmental conditions such as terrestrial inputs and runoffs. The linkage of OP with environmental conditions was analyzed on the basis of OP spatial and historical distributions in lake sediments. The redundancy analysis and OP spatial distribution results suggested that both NaOH-OP (OP extracted by NaOH) and Re-OP (residual OP) in surface sediments from the selected 13 lakes reflected the gradient effects of environmental conditions and the autochthonous and/or allochthonous inputs driven by latitude zonality in China. The lake level and salinity of Lake Hulun and the runoff and precipitation of its drainage basin were reconstructed on the basis of the geochemistry index. This work showed that a gradient in weather conditions presented by the latitude zonality in China impacts the OP accumulation through multiple drivers and in many ways. The drivers are mainly precipitation and temperature, governing organic matter (OM) production, degradation rate and transportation in the watershed. Over a long temporal dimension (4000 years), the vertical distributions of Re-OP and NaOH-OP based on a dated sediment profile from HLH were largely regulated by the autochthonous and/or allochthonous inputs, which depended on the environmental and climate conditions and anthropogenic activities in the drainage basin. This work provides useful environmental geochemistry information to understand the inherent linkage of OP fractionation with environmental conditions and lake evolution. (C) 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.
In wireless sensor networks, the problem of anchor (whose locations are a priori known) placement plays a vital role in improving the estimation accuracy of sensor (whose locations are unknown and need to be determined) locations. This paper deals with single-hop sensor localization from a novel perspective. On the one hand, unlike existing studies relying on ideal independent identically distributed (i.i.d.) noises in distance measurements, namely distance-independent noises, this paper defines a more realistic noise model in the sense that the noise variance is a function of sensor-to-anchor distances, namely distance-dependent noises. On the other hand, other than evaluating the localization performance for sensors at deterministic locations, a statistical approach is adopted by assuming a uniform and random distribution within a unit disk for the sensor location and evaluating the mean value of the associated Fisher information matrix determinant as the optimality metric for anchor placement. Through this metric, the optimal anchor placement is investigated from both theoretical and simulative perspectives. In the literature of optimal anchor placement with distance-independent noises, it has been addressed or conjectured to be true that it is optimal to have anchors equally spaced on the boundary. However, after a thorough analysis, it is shown that this conclusion is generally incorrect, but approaches to be true provided that the number of anchors goes to infinity. This study not only provides useful guidance for optimally deploying anchors in practice, but also yields valuable insights for future research on optimal anchor placement.
This paper studied the impact of a gully-type gangue dump in the Daliuta mine area, Shaanxi, China on the groundwater environment and its contamination control. Multiple methods including ecohydrogeological survey, soil column leaching test, field test and groundwater flow analysis were applied in the study. According to the field survey, the stack of gangue had changed the original feature of groundwater flow system, with the groundwater level of the gangue field raising about 1-3 m compared with the condition before the establishment of gangue dump. The long-term immersion of gangue had released various harmful substance into the groundwater and affected the downstream areas. The leaching test showed that the loess could significantly purify the mine wastewater by increasing pH value from 4.5 to 6.2-6.7 and absorbing heavy metals. Based on the loess column test, two loess permeable reactive barriers (LPRBs) were established in situ to improve the groundwater environment of gangue field. Besides, the vegetation restoration had been successfully carried out by covering a 30 cm thick loess layer on the coal gangues and planting Alfalfa and Artemisica ordosica to improve the ecological environment, and the vegetation coverage had increased from 10% in 2008 to about 65% in 2013. (C) 2017 Elsevier Ltd. All rights reserved.