作者机构：
[Su, Tao; Wu, Beibei; He, Rongqiao; Qiang, Min; Liu, Ying; Tong, Zhiqian; Han, Chanshuai] Chinese Acad Sci, Inst Biophys, State Key Lab Brain & Cognit Sci, Beijing 100101, Peoples R China.;[Luo, Hongjun; Li, Hui; Luo, Wenhong] Shantou Univ, Coll Med, Cent Lab, Shantou 515041, Guangdong, Peoples R China.;[Yang, Xu] Huazhong Normal Univ, Lab Environm Sci, Wuhan 430079, Peoples R China.;[Su, Tao; Wu, Beibei; Qiang, Min; Han, Chanshuai] Grad Univ, Chinese Acad Sci, Beijing 100049, Peoples R China.;[Wan, You; Tong, Zhiqian; Cui, Dehua] Peking Univ, Neurosci Res Inst, Beijing 100191, Peoples R China.
通讯机构：
[Cui, Dehua] P;Peking Univ, Neurosci Res Inst, Beijing 100191, Peoples R China.
摘要：
Recent studies show that formaldehyde participates in DNA demethylation/methylation cycle. Emerging evidence identifies that neuronal activity induces global DNA demethylation and re-methylation; and DNA methylation is a critical step for memory formation. These data suggest that endogenous formaldehyde may intrinsically link learning-responsive DNA methylation status and memory formation. Here, we report that during spatial memory formation process, spatial training induces an initial global DNA demethylation and subsequent re-methylation associated with hippocampal formaldehyde elevation then decline to baseline level in Sprague Dawley rats. Scavenging this elevated formaldehyde by formaldehyde-degrading enzyme (FDH), or enhancing DNA demethylation by a DNA demethylating agent, both led to spatial memory deficits by blocking DNA re-methylation in rats. Furthermore, we found that the normal adult rats intrahippocampally injected with excess formaldehyde can imitate the aged-related spatial memory deficits and global DNA methylation decline. These findings indicate that aging-associated excess formaldheyde contributes to cognitive decline during aging.
关键词：
Land degradation;agriculture;environment pollution;heavy metal;risk model
摘要：
This paper aimed to use ecological risk analysis method to assess ecological degradation risk of cultivated land in Houhu Farm of Jianghan Plain in China. The results indicated that the pollution degrees of single factor followed the order of Cd>As>Cu>Zn>Dichlorodiphenyl-trichloroethane (DDT)>Hg>Cr>Pb>Hexachlorocyclohexane (HCH). Eight plots were slightly polluted by these pollutants, especially Cd was the primary heavy metal pollutant and DDT was the primary organic pesticide in this area. Of cultivated land 3.81% was slightly polluted and 15.59% was at the warning level. Based on the degradation risk evaluation models, the degree of degradation risk for cultivated land was classified into 4 levels, where small risk and average risk were predominant portions with their areas accounting for 83.1% of the total. Three evaluation plots of study area with high risk accounted for 5.01% of the total. The available phosphorus, accessibility of road and composite pollution index were the primary degradation risk factors and important issues of risk management for agriculture. The results can be used as a quantitative basis in evaluation of cultivated land quality and resolution of the soil degradation risk in this region.
期刊：
Journal of Food, Agriculture and Environment,2011年9(3-4):963-966 ISSN：1459-0255
通讯作者：
Cai, Chongfa
作者机构：
[Liu, Wei; Cai, Chongfa] Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China.;[Zhao, Yijun; Liu, Wei; Cheng, Kai] Cent China Normal Univ, Hubei Key Lab Urban Water Environm Ecol, Wuhan 430079, Peoples R China.;[Lu Shaoyong; Jin Xiangcan] Chinese Res Inst Environm Sci, State Environm Protect Key Lab Lake Pollut Contro, Res Ctr Lake Environm, Beijing 100012, Peoples R China.
摘要：
The decay of virioplankton is one of the most important process of virioplankton population dynamics. Besides the solar-ultraviolet radiation b, other factors can also lead to the decay of virioplankton. Experiment was carried out to study the decay rate of cyanophage PP caused by some environmental factors: non-UVB radiation in sunlight, particle materials, heat-sensitive substances and water temperature. The results indicated that the decay rate of cyanophage PP by the non-UVB radiation part of sunlight at noon was 3.8%.h(-1), however, the decay rate was swiftly attenuated to less than 1.0%-h(-1) with the attenuation of sunlight intensity; in dark condition, the decay rate of cyanophage PP in field sample was steadily 2.5%-h(-1), among which 2.01%-h(-1) contributed to particle materials (in more turbid waters, the number would be as high as 15.0%-h(-1)), and 2.1 %-h(-1) contributed to heat-sensitive substances. The dark decay rate in field sample varied at different temperatures, it was 8.75%-h(-1) at 35 degrees C which was 2.5 times greater than the decay rate at 28 degrees C. Our results suggest that heat-sensitive particle substances are the most important contributing factor to viral dark decay in high eutrophic freshwater and also point to the significance of water temperature in influencing the dark decay rate.
关键词：
environmental tropism;nature conservation;natural tourist destination;tourism-nature relationship;Jiuz- haigou National Park
摘要：
People′s environmental tropism has an effect on their understanding of tourism-nature relationship,and also influences their attitudes to natural resources utilization and environmental protection.Taking Jiuzhaigou National Park of China as a study case,the authors conducted some quantitative analyses with the tools of SPSS 16.0 and LISREL 8.7,to explore the influence of tourists′ environmental tropism on their attitudes to tourism and nature conservation in the natural tourist destination.Three hypotheses and the theoretic model of influences of tourists′ environmental tropism on their attitudes to tourism and nature conservation have been tested and accepted based on the Structural Equation Model analysis on survey data collected in Jiuzhaigou National Park of China.Some conclusions were drawn as follows: 1) tourists′ human-prioritized concept influences their cognition to tourism-nature relationship.This concept has a positive influence on their supportive attitudes to tourism,but a negative influence on their attitudes to nature conservation;2) tourists′ human-nature coordination concept has a positive influence on their supportive attitudes to both tourism and nature conservation,especially to the latter.This paper generally proves that human′s environmental tropism does have an influence on their attitudes to tourism and nature conservation in natural tourist destinations.
作者机构：
[Xu, Kai] Beijing Normal Univ, State Key Lab Remote Sensing Sci, Sch Geog, Res Ctr Remote Sensing, Beijing 100875, Peoples R China.;[Xu, Kai] Beijing Normal Univ, State Key Lab Remote Sensing Sci, Sch Geog, GIS, Beijing 100875, Peoples R China.;[Xu, Kai] Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA.;[Deng, Hongbin] China Univ Geosci, Fac Humanity & Econ, Wuhan 430074, Peoples R China.;[Zhang, Yi] Cent China Normal Univ, Coll Urban & Environm Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Xu, Kai] B;Beijing Normal Univ, State Key Lab Remote Sensing Sci, Sch Geog, Res Ctr Remote Sensing, Beijing 100875, Peoples R China.
关键词：
fractal dimension;Geographic Information System (GIS);landscape ecology;shape index;stability index;sustainable development
摘要：
Tangxunhu wetland is one of China’s largest freshwater lakes and plays a significant role in the sustainable development of the city of Wuhan. Based on terrain maps, TM images, and statistical data from 1953 to 2005, the spatial characters and changing features of Tangxunhu wetland were quantitatively assessed by calculating the landscape metrics of shape index (SI), fractal dimension (D), and stability index (S). The results showed that Tangxunhu wetland had meandrous development over the past 53 years, withSI, D, and S decreasing from 1953 to 1967, increasing from 1967 to 2000, and then decreasing again from 2000 to 2005.SI, D, andS were lowest in 1967, indicating maximuminstability, but highest in 2000, indicating maximum stability. These changes in Tangxunhu wetland were associated with various natural, social, and economic factors. Key Wordsfractal dimension-Geographic Information System (GIS)-landscape ecology-shape index-stability index-sustainable development
期刊：
Journal of Hydrology,2007年333(2-4):265-274 ISSN：0022-1694
通讯作者：
Zhang, Qiang
作者机构：
Chinese Acad Sci, Nanjing Inst Geog & Limnol, Nanjing 210008, Peoples R China.;Univ Giessen, Inst Geog, D-35390 Giessen, Germany.;Huazhong Normal Univ, Sch Urban & Environm Sci, Wuhan 430079, Peoples R China.;[Zhang, Qiang] Chinese Acad Sci, Nanjing Inst Geog & Limnol, 73 E Beijing Rd, Nanjing 210008, Peoples R China.
通讯机构：
[Zhang, Qiang] C;Chinese Acad Sci, Nanjing Inst Geog & Limnol, 73 E Beijing Rd, Nanjing 210008, Peoples R China.
关键词：
Annual maximum streamflow;El Niño/Southern Oscillation (ENSO);Wavelet approach;Yangtze River basin
摘要：
Variability and possible teleconnections between annual maximum streamflow from the lower, the middle and the upper Yangtze River basin and El Niño/Southern Oscillation (ENSO) are detected by continuous wavelet transform (CWT), cross-wavelet and wavelet coherence methods. The results show that: (1) different phase relations are found between annual maximum streamflow of the Yangtze River and El Niño/Southern Oscillation (ENSO) in the lower, the middle and the upper Yangtze River basin. In-phase relations are detected between annual maximum streamflow of the lower Yangtze River and anti-phase relations are found in the upper Yangtze River. But ambiguous phase relations occur in the middle Yangtze River, showing that the middle Yangtze River basin is a transition zone. Different climatic systems control the upper and the lower Yangtze River. The upper Yangtze River is mainly influenced by the Indian summer monsoon and the lower Yangtze is mainly influenced by the East Asian summer monsoon; (2) as for the individual stations, different phase relations are found in the longer and the shorter periods, respectively. In the longer periods, the annual maximum streamflow is more influenced by climatic variabilities, while in the shorter periods, it is influenced by other factors, e.g. human activities. The results of the study provide valuable information for improving the long-term forecasting of the streamflow using its relationship with ENSO and the Indian Monsoon.
作者机构：
[Shi, Zhengli] Chinese Acad Sci, Wuhan Inst Virol, State Key Lab Virol, Wuhan 430071, Peoples R China.;Cent China Normal Univ, Hubei Key Lab Urban Water Environm Ecol, Wuhan 430079, Peoples R China.;Chinese Acad Sci, Grad Sch, Beijing 100039, Peoples R China.
通讯机构：
[Shi, Zhengli] C;Chinese Acad Sci, Wuhan Inst Virol, State Key Lab Virol, Wuhan 430071, Peoples R China.
摘要：
Climatic indicators based on proxy historical flood/drought index series (1470–2003) in the Yangtze river (China) and ENSO (El Niño/La Niña) index series (1868–2003) are statistically analyzed to detect a long-term variability of the floods/droughts and ENSO events and to identify the teleconnections between ENSO and flood/drought series in the upper, middle and lower Yangtze River valley. In the lower and middle Yangtze catchments, El Niño shows a close relation with flood events and La Niña correlates with drought events. However, the relationships are reversed for the upper Yangtze catchment. These relations are significant at >90% confidence level based on χ2 test. Spectral analysis shows that main flood/drought variation cycle is longer than that of ENSO events. The latter shows periods of 3–4 year, 5.67 years, ∼10–12 years while the flood/drought cycle has periods of 16.69, 5.09 and 10.47 years (confidence level of 99%). Cross-spectral analysis results indicate the ENSO changes and flood/drought variation are significantly correlated at 5.04 year and ∼10–12 years periods. Therefore, from the viewpoint of periodicity, ENSO episodes (El Niño and La Niña) are in good teleconnection with floods/droughts in the Yangtze catchment. Eastern Asian summer and winter monsoons are influenced by ENSO through the strength of the subtropical high in the western Pacific region, which can possibly serve as the physical mechanism of the phenomenon mentioned above. The results tentatively suggest that the Chinese climatic index based on documentary records can be helpful for investigating the reconstruction of long-term ENSO activities.
关键词：
ecological construction;agricultural systems function;comprehensive measurement;regional differentiation regularity;Hubei Province;SOUTH FLORIDA;MANAGEMENT;SUSTAINABILITY;MODELS
摘要：
Located in Central China and the middle reaches of Yangtze River, Hubei Province is distributed in a transitional belt where physical conditions and landscapes are on the transition from north to south and from east to west. It is one of the regions possessing most energetic and greatest potential in both today and future socio-economic development in Central China. Well known as "a land of rice and fish", the region enjoys some of the favorable physical conditions, with a diversity of in natural resources and the suitability for growing various crops. According to analytic hierarchy process (AHP) the indicators' weights of the agricultural systems function system in Hubei Province are worked out. According to Multiple Hierarchies, Targets Fuzzy Comprehensive Measurement Model, Triangle Evaluation Model, the economic function, eco-environmental function and the social function in Hubei Province are all calculated, then the whole agricultural systems function is worked out and the regional differentiation regularity of agricultural systems function is summed up. It is considered that the difference of the agricultural systems function in each county in Hubei Province is great while the regional differentiation of agricultural systems function is regular. According to the difference seven agricultural systems function regions in Hubei Province (Wuhan-Ezhou-Huanggang (1), Northeast of Hubei (11), Southeast of Hubei (111), Jianghan (IV), North of Hubei (V), Northwest of Hubei (VI), and Southwest of Hubei (VII)) are distinguished, their function are identified and studied. Based on the analysis the problems of each of the regions are found out, solutions that can maximize integrated benefits economically, socially and ecologically by enhancing the management of ecosystems and optimizing systematic capability are sought out. (c) 2005 Elsevier B.V. All rights reserved.
