This paper describes the geographical distribution, utilization, cultural value and ex-situ conservation of bamboo resources in Xishuangbanna, Yunan Province, China. Sixty species of bamboo in 19 genera are recorded i...This paper describes the geographical distribution, utilization, cultural value and ex-situ conservation of bamboo resources in Xishuangbanna, Yunan Province, China. Sixty species of bamboo in 19 genera are recorded in Xishuangbanna. The area of natural bamboo forest is 14319 ha, accounting for 5.92% of whole area of Xishuangbanna. The abundant resource of bamboo plays an important role in the economics and culture of national minorities in Xishuangbanna. Xishuangbanna Tropic Botanic Garden, Chinese Academy of Sciences (CAS), started to introduce bamboo species in 1961 and established the ex-situ conservation reserve (8 ha) of bamboo in 1981. Up to now, 211 species in 27 genera collected from tropic and sub-tropic of China and South-east Asia have been planted in the bamboo reserve, of which 11 species have bloomed and seeded, and their seeds were cultivated in Xishuangbanna Tropical Botanic Gardens, CAS, China.展开更多
Guangdong has become a major"window" for invasive plants, and the largest zone, where cross-border and intercontinental migration frequencies reach the peak. The invasive plants in Guangdong are dominated by Mikania...Guangdong has become a major"window" for invasive plants, and the largest zone, where cross-border and intercontinental migration frequencies reach the peak. The invasive plants in Guangdong are dominated by Mikania micrantha, Eichhornia crassipes, Alternanthera philoxeroides, Eupatorium odoratum, and Wedelia trilobata. It is an important way for treating the invasive plants by exploring the prevention methods and making ful use of the characteristics of the invasive plants, and it is of great significance to prevent and utilize alien species in a scientific and effective way in order to control the invasive plants with minimal cost.展开更多
Agroforestry is a ubiquitous landscape on the slopes in Loess Plateau, where soil moisture is a limiting factor for plant growth and development. The spatial and temporal characteristics of soil moisture were studied ...Agroforestry is a ubiquitous landscape on the slopes in Loess Plateau, where soil moisture is a limiting factor for plant growth and development. The spatial and temporal characteristics of soil moisture were studied in three types of agroforestry boundaries: forest-grassland, forest-cropland and shelterbelt-cropland. The result shows that soil moisture content decreased with soil depth increasing from the surface to 110 cm. Soil moisture content differed significantly among the three boundaries all in the rainy season (July-September), dry season (May-June) and spring (March-April). The horizontal distribution of soil moisture in different soil layers in the three types of boundaries showed different patterns with line form, wave form, scoop form or "W" form. The distance of edge influence (DEI) of soil moisture in different types of landscape boundaries was estimated by variance analysis and multiple comparisons. In dry season the DEI in 0-10 cm soil layer was 0.4 H (H, average height of trees), which ranged from 0.2 H in grassland or in cropland to 0.2 H in forest field for both forest-grassland and forest-cropland boundaries, and 0.7 H (ranged from 0.2 H in cropland to 0.5 H in forest field) for shelterbelt-cropland boundary. In rainy season the DEI at soil depth of 0-110 cm was 0.7 H for the three boundaries. The results indicated that agroforestry type should be carefully selected to maintain soil moisture in land management, especially in restoring degraded land in Loess Plateau.展开更多
A laboratory simulated freeze-thaw was conducted to determine the effects of freeze-thaw on soil nutrient availability in temperate semi-arid regions. Soil samples were collected from sandy soils (0-20 cm) of three ...A laboratory simulated freeze-thaw was conducted to determine the effects of freeze-thaw on soil nutrient availability in temperate semi-arid regions. Soil samples were collected from sandy soils (0-20 cm) of three typical ecosystems (grassland, Mongolian pine plantation and poplar plantation) in southeastern Keerqin Sandy Lands of China and subjected to freeze-thaw treatment (-12℃ for 10 days, then r 20℃ for 10 days) or incubated at constant temperature (20℃ for 20 days). Concentrations of the soil NO3^--N, NH4^+-N, NaHCO3 extractable inorganic P (LPi) and microbial biomass P (MBP) were determined on three occasions: at the start of the incubation, immediate post-thawing and at the 10th day post-thawing. The results showed that soil net nitrification and N mineralization rates at three sites were negatively affected by freeze-thaw treatment, and decreased by 50%-85% as compared to the control, of which the greatest decline occurred in the soil collected from poplar plantation. In contrast, the concentration of soil NH4^+-N, NaHCO3 extractable inorganic P (LPi) and microbial biomass P were insignificantly influenced by freeze-thaw except that LPi and NH4^+-N showed a slight increase immediate post-thawing. The effects of freeze-thaw on soil N transformation were related to soil biological processes and the relatively constant available P was ascribed to severe soil aridity.展开更多
The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenya...The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenyang Experimental Station of Ecology, Chinese Academy of Sciences in November of 2003. The results showed that different land uses had different profile distributions of soil total nitrogen (STN), alkali N, ammonium (NH4+-N) and nitrate (NO3--N). The sequence of STN storage was woodland >maize field > fallow field > paddy field, while that of NO3--N content was maize field > paddy field > woodland > fallow field, suggesting the different root biomass and biological N cycling under various land uses. The STN storage in the depth of 0-100 cm of woodland averaged to 11.41 thm-1, being 1.65 and 1.25 times as much as that in paddy and maize fields, respec-tively, while there was no significant difference between maize and fallow fields. The comparatively higher amount of NO3--N in maize and paddy fields may be due to nitrogen fertilization and anthropogenic disturbance. Soil alkali N was significantly related with STN, and the correlation could be expressed by a linear regression model under each land use (R20.929, p<0.001). Such a correlation was slightly closer in nature (woodland and fallow field) than in agro ecosystems (paddy and maize fields). Heavy N fertilization induced an excess of crop need, and led to a comparatively higher amount of soil NO3--N in cultivated fields than in fallow field and woodland. It is suggested that agroforestry practices have the potential to make a significant contribution to both crop production and environment protection.展开更多
Habitat use by Galliformes in an ornithologically unexplored region,a forest area in southeastern Tibet,was investigated during the summer and autumn periods of 1995.A total of seven species were recorded,most of whic...Habitat use by Galliformes in an ornithologically unexplored region,a forest area in southeastern Tibet,was investigated during the summer and autumn periods of 1995.A total of seven species were recorded,most of which preferred habitats on south-facing slopes and avoided those on north-facing slopes where conditions were relatively humid.A hybrid population of White (Crossoptilon crossoptilon) versus Tibetan Eared-pheasants (C.harmani) was predominant among the Galliforme community,followed by Blood Pheasants (Ithaginis cruentus) and Chinese Grouse (Bonasa sewerzowi).A further investigation in 2001 showed that on account of little human activity in the distant primary forests,the birds suffered less of a threat from hunting and habitat disturbance.展开更多
Presently, more and more attention is paid to cultural landscapes by peo-ple at travel ing, especial y for folk culture in ethnic minority regions where rich hu-man landscapes could be ful y made use of to improve lan...Presently, more and more attention is paid to cultural landscapes by peo-ple at travel ing, especial y for folk culture in ethnic minority regions where rich hu-man landscapes could be ful y made use of to improve landscape quality. In the research, cultural landscapes in Zhangjiajie National Forest Park were surveyed and evaluated to analyze characters of cultural utilization, as wel as problems existing in the Park. In addition, highlights were given to protection on cultural landscapes in a forest park construction, presentation of ethnic minority culture, and ful development of tourism products.展开更多
The impact of land-use on distributed groundwater recharge and discharge in the western Jilin (WJ) was analyzed in this study. WJ is a transitional, semi-arid zone with a fragile, hydrological closed ecosystem in the ...The impact of land-use on distributed groundwater recharge and discharge in the western Jilin (WJ) was analyzed in this study. WJ is a transitional, semi-arid zone with a fragile, hydrological closed ecosystem in the Songhua River Basin (SRB). The research tool includes a seamlessly linked MODFLOW, WetSpass, the Seepage packages, and ArcGIS. The model calibration showed good agreement between simulated water table elevation and measured water table depths, while predicted groundwater discharge zones showed strong correlations with field occurrences of drainage systems and wetlands. Simulated averages for distributed recharge, water table elevation and groundwater drawdown were 377.42mm/yr, 194.43m, and 0.18m respectively. Forest vegetation showed the highest recharge, followed by ag- ricultural farmlands, while open-water and other drainage systems constituted groundwater exit zones. When present land-use conditions were compared with the hypothetical natural pre-development scenario, an overall loss of ground- water recharge (24.09mm/yr) was observed, which for the project area is 18.05×108m3. Groundwater abstraction seemed to be the cause of water table drawdown, especially in the immediate vicinities of the supply wells. An important issue of the findings was the ability of the hypothetical forest vegetation to protect, and hence sustain aquifer reserves and dependent ecosystems. The profound data capture capability of ArcGIS makes it particularly useful in spa- tio-temporal hydroecological modeling.展开更多
The phenomenon of tree waves (hedges and ribbons) formation within the alpine ecotone in Altai Mountains and its response to observed air temperature increase was considered. At the upper limit of tree growth Siberi...The phenomenon of tree waves (hedges and ribbons) formation within the alpine ecotone in Altai Mountains and its response to observed air temperature increase was considered. At the upper limit of tree growth Siberian pine (Pinus sibirica) forms hedges on windward slopes and ribbons on the leeward ones. Hedges were formed by prevailing winds and oriented along winds direction. Ribbons were formed by snow blowing and accumulating on the leeward slope and perpendicular to the prevailing winds, as well as to the elevation gradient. Hedges were always linked with microtopography features, whereas ribbons were not. Trees are migrating upward by waves and new ribbons and hedges are forming at or near tree line, whereas at lower elevations ribbons and hedges are being transformed into dosed forests. Time series of high-resolution satellite scenes (from 1968 to 2OLO) indicated an upslope shift in the position ribbons averaged 155+26 m (or 3-7 m yr^-1) and crown closure increased (about 35%-90%). The hedges advance was limited by poor regeneration establishment and was negligible. Regeneration within the ribbon zone was approximately 2.5 times (5060 vs 2120 ha^-1) higher then within the hedges zone. During the last four decades, Siberian pine in both hedges and ribbons strongly increased its growth increment, and recent tree growth rate for 50 year-old trees was about twice higher than those recorded for similarly-aged trees at the beginning of the 20^th century. Hedges and ribbons are phenomena that are widespread within the southern and northern Siberian Mountains.展开更多
Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalp...Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5) tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P < 0.05) in the soils, which was in contrast to the significant increases (P <0.05) of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification.展开更多
Ischemic colitis is a rare complication of interferon administration.Only 9 cases in 6 reports have been described to-date.This report describes a case of ischemic colitis during pegylated interferon and ribavirin tre...Ischemic colitis is a rare complication of interferon administration.Only 9 cases in 6 reports have been described to-date.This report describes a case of ischemic colitis during pegylated interferon and ribavirin treatment for chronic hepatitis C,and includes a review of the relevant literature.A 48-year-old woman was treated with pegylated interferon-2a and ribavirin for chronic hepatitis C,genotype Ib.After 19 wk of treatment,the patient complained of severe afebrile abdominal pain with hematochezia.Vital signs were stable and serum white blood cell count was within the normal range.Abdominal computed tomography showed diffuse colonic wall thickening from the splenic flexure to the proximal sigmoid colon,which is the most vulnerable area for the development of ischemic colitis.Colonoscopy revealed an acute mucosal hyperemic change,with edema and ulcerations extending from the proximal descending colon to the sigmoid colon.Colonic mucosal biopsy revealed acute exudative colitis.Polymerase chain reaction and culture for Mycobacterium tuberculosis were negative and the cultures for cytomegalovirus,Salmonella and Shigella species were negative.After discontinuation of interferon and ribavirin therapy,abdominal pain and hematochezia subsided and,following colonoscopy showed improvement of the mucosal ulcerations.Ischemic colitis cases during interferon therapy in patients with chronic hepatitis C reported so far have all involved the descending colon.Ischemic colitis is a rarely encountered complication of interferon administration in patients with chronic hepatitis C and should be considered when a patient complains of abdominal pain and hematochezia.展开更多
AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Althou...AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.展开更多
The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimizat...The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program.展开更多
AIM: To assess the clinical, biochemical and virological long-term outcome in chronic hepatitis C (CHC) patients with a sustained virological response (SVR) after peginterferon (PEG-IFN) plus ribavirin combination the...AIM: To assess the clinical, biochemical and virological long-term outcome in chronic hepatitis C (CHC) patients with a sustained virological response (SVR) after peginterferon (PEG-IFN) plus ribavirin combination therapy. METHODS: One hundred and fifty three patients with a SVR after treatment with PEG-IFN plus ribavirin were included in a 5-year follow-up study in a single Spanish center, based on standard clinical practice. Clinical anamnesis, biochemical analysis, hepatitis C virus RNA and alpha-fetoprotein measurement, ultrasonography and transient elastography were performed annually. RESULTS: The mean follow-up period of the 153 patients was 76 ± 13 mo after they obtained a SVR. Five patients (3.26%) presented with cirrhosis before treatment and 116 (75.8%) had genotype 1. No patient showed evidence of hepatic decompensation. One patient (0.65%) developed a hepatocellular carcinoma at month 30 after achieving SVR. There were no virological relapses during this follow-up period. Persistently elevated alanine aminotransferase was found in only one patient (0.65%). At the end of the 5-year follow-up, the mean value of transient elastography was 7 ± 4.3 kPa (F1). There were no deaths and no other tumors. CONCLUSION: The long-term outcome of 153 CHC patients with SVR to PEG-IFN plus ribavirin was good. No evidence of a virological relapse was seen. One patient (0.65%) developed a hepatocellular carcinoma.展开更多
AIM: To study the efficacy and factors associated with a sustained virological response (SVR) in chronic hepatitis C (CHC) relapsing patients. METHODS: Out of 1228 CHC patients treated with pegylated interferon (PEG-I...AIM: To study the efficacy and factors associated with a sustained virological response (SVR) in chronic hepatitis C (CHC) relapsing patients. METHODS: Out of 1228 CHC patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV), 165 (13%) had a relapse. Among these, 62 patients were retreated with PEG-IFN-2a or-2b and RBV. Clinical, biological, virological and histological data were collected. Initial doses and treatment modifications were recorded. The efficacy of retreatment and predictive factors for SVR were analyzed. RESULTS: An SVR was achieved in 42% of patients. SVR was higher in young (< 50 years) (61%) than old patients (27%) (P = 0.007), and in genotype 2 or 3 (57%) than in genotype 1 or 4 (28%) patients (P = 0.023). Prolonging therapy for at least 24 wk more than the previous course was associated with higher SVR rates (53% vs 28%, P = 0.04). Also, a better SVR rate was observed with RBV dose/body weight > 15.2 mg/kg per day (70% vs 35%, P = 0.04). In logistic regression, predictors of a response were age (P = 0.018), genotype (P = 0.048) and initial RBV dose/body weight (P = 0.022). None of the patients without a complete early virological response achieved an SVR (negative predictive value = 100%). CONCLUSION: Retreatment with PEG-IFN/RBV is effective in genotype 2 or 3 relapsers, especially in young patients. A high dose of RBV seems to be important for the retreatment response.展开更多
基金The Ministry of Science and Technology of the People’s Republic of China (2004DKA30400-05-01-02)
文摘This paper describes the geographical distribution, utilization, cultural value and ex-situ conservation of bamboo resources in Xishuangbanna, Yunan Province, China. Sixty species of bamboo in 19 genera are recorded in Xishuangbanna. The area of natural bamboo forest is 14319 ha, accounting for 5.92% of whole area of Xishuangbanna. The abundant resource of bamboo plays an important role in the economics and culture of national minorities in Xishuangbanna. Xishuangbanna Tropic Botanic Garden, Chinese Academy of Sciences (CAS), started to introduce bamboo species in 1961 and established the ex-situ conservation reserve (8 ha) of bamboo in 1981. Up to now, 211 species in 27 genera collected from tropic and sub-tropic of China and South-east Asia have been planted in the bamboo reserve, of which 11 species have bloomed and seeded, and their seeds were cultivated in Xishuangbanna Tropical Botanic Gardens, CAS, China.
基金Guangdong Boluo Agro-technique Extension Center-South China Agricultural Univeristy Cooperation Project(7700-H13510)~~
文摘Guangdong has become a major"window" for invasive plants, and the largest zone, where cross-border and intercontinental migration frequencies reach the peak. The invasive plants in Guangdong are dominated by Mikania micrantha, Eichhornia crassipes, Alternanthera philoxeroides, Eupatorium odoratum, and Wedelia trilobata. It is an important way for treating the invasive plants by exploring the prevention methods and making ful use of the characteristics of the invasive plants, and it is of great significance to prevent and utilize alien species in a scientific and effective way in order to control the invasive plants with minimal cost.
基金supported by the National Key Tech-nologies R&D Program of China (No. 2006BAD03A0502)the Major State Basic Research Development Program of China (No. 2002CB111506)
文摘Agroforestry is a ubiquitous landscape on the slopes in Loess Plateau, where soil moisture is a limiting factor for plant growth and development. The spatial and temporal characteristics of soil moisture were studied in three types of agroforestry boundaries: forest-grassland, forest-cropland and shelterbelt-cropland. The result shows that soil moisture content decreased with soil depth increasing from the surface to 110 cm. Soil moisture content differed significantly among the three boundaries all in the rainy season (July-September), dry season (May-June) and spring (March-April). The horizontal distribution of soil moisture in different soil layers in the three types of boundaries showed different patterns with line form, wave form, scoop form or "W" form. The distance of edge influence (DEI) of soil moisture in different types of landscape boundaries was estimated by variance analysis and multiple comparisons. In dry season the DEI in 0-10 cm soil layer was 0.4 H (H, average height of trees), which ranged from 0.2 H in grassland or in cropland to 0.2 H in forest field for both forest-grassland and forest-cropland boundaries, and 0.7 H (ranged from 0.2 H in cropland to 0.5 H in forest field) for shelterbelt-cropland boundary. In rainy season the DEI at soil depth of 0-110 cm was 0.7 H for the three boundaries. The results indicated that agroforestry type should be carefully selected to maintain soil moisture in land management, especially in restoring degraded land in Loess Plateau.
基金the grants from the National Natural Science Foundation of China (No. 30471377)the National Key Basic Research Program of China (No. 2007CB106803)the National Key Technologies R & D Program of China (No. 2006BAD26B0201-1)
文摘A laboratory simulated freeze-thaw was conducted to determine the effects of freeze-thaw on soil nutrient availability in temperate semi-arid regions. Soil samples were collected from sandy soils (0-20 cm) of three typical ecosystems (grassland, Mongolian pine plantation and poplar plantation) in southeastern Keerqin Sandy Lands of China and subjected to freeze-thaw treatment (-12℃ for 10 days, then r 20℃ for 10 days) or incubated at constant temperature (20℃ for 20 days). Concentrations of the soil NO3^--N, NH4^+-N, NaHCO3 extractable inorganic P (LPi) and microbial biomass P (MBP) were determined on three occasions: at the start of the incubation, immediate post-thawing and at the 10th day post-thawing. The results showed that soil net nitrification and N mineralization rates at three sites were negatively affected by freeze-thaw treatment, and decreased by 50%-85% as compared to the control, of which the greatest decline occurred in the soil collected from poplar plantation. In contrast, the concentration of soil NH4^+-N, NaHCO3 extractable inorganic P (LPi) and microbial biomass P were insignificantly influenced by freeze-thaw except that LPi and NH4^+-N showed a slight increase immediate post-thawing. The effects of freeze-thaw on soil N transformation were related to soil biological processes and the relatively constant available P was ascribed to severe soil aridity.
文摘The vertical variation and storage of nitrogen in the depth of 0-150 cm of an aquic brown soil were studied under 14 years of four land use patterns, i.e., paddy field, maize field, fallow field and woodland in Shenyang Experimental Station of Ecology, Chinese Academy of Sciences in November of 2003. The results showed that different land uses had different profile distributions of soil total nitrogen (STN), alkali N, ammonium (NH4+-N) and nitrate (NO3--N). The sequence of STN storage was woodland >maize field > fallow field > paddy field, while that of NO3--N content was maize field > paddy field > woodland > fallow field, suggesting the different root biomass and biological N cycling under various land uses. The STN storage in the depth of 0-100 cm of woodland averaged to 11.41 thm-1, being 1.65 and 1.25 times as much as that in paddy and maize fields, respec-tively, while there was no significant difference between maize and fallow fields. The comparatively higher amount of NO3--N in maize and paddy fields may be due to nitrogen fertilization and anthropogenic disturbance. Soil alkali N was significantly related with STN, and the correlation could be expressed by a linear regression model under each land use (R20.929, p<0.001). Such a correlation was slightly closer in nature (woodland and fallow field) than in agro ecosystems (paddy and maize fields). Heavy N fertilization induced an excess of crop need, and led to a comparatively higher amount of soil NO3--N in cultivated fields than in fallow field and woodland. It is suggested that agroforestry practices have the potential to make a significant contribution to both crop production and environment protection.
基金supported by the Tibetan Bureau of Science and Technologythe National Natural Science Foundation of China (Grant No. 39800016)the Tibet Important Bird Area Survey Programme organized by BirdLife International
文摘Habitat use by Galliformes in an ornithologically unexplored region,a forest area in southeastern Tibet,was investigated during the summer and autumn periods of 1995.A total of seven species were recorded,most of which preferred habitats on south-facing slopes and avoided those on north-facing slopes where conditions were relatively humid.A hybrid population of White (Crossoptilon crossoptilon) versus Tibetan Eared-pheasants (C.harmani) was predominant among the Galliforme community,followed by Blood Pheasants (Ithaginis cruentus) and Chinese Grouse (Bonasa sewerzowi).A further investigation in 2001 showed that on account of little human activity in the distant primary forests,the birds suffered less of a threat from hunting and habitat disturbance.
基金Supported by Research Foundation of Education Bureau of Hunan Province(09AC073)~~
文摘Presently, more and more attention is paid to cultural landscapes by peo-ple at travel ing, especial y for folk culture in ethnic minority regions where rich hu-man landscapes could be ful y made use of to improve landscape quality. In the research, cultural landscapes in Zhangjiajie National Forest Park were surveyed and evaluated to analyze characters of cultural utilization, as wel as problems existing in the Park. In addition, highlights were given to protection on cultural landscapes in a forest park construction, presentation of ethnic minority culture, and ful development of tourism products.
文摘The impact of land-use on distributed groundwater recharge and discharge in the western Jilin (WJ) was analyzed in this study. WJ is a transitional, semi-arid zone with a fragile, hydrological closed ecosystem in the Songhua River Basin (SRB). The research tool includes a seamlessly linked MODFLOW, WetSpass, the Seepage packages, and ArcGIS. The model calibration showed good agreement between simulated water table elevation and measured water table depths, while predicted groundwater discharge zones showed strong correlations with field occurrences of drainage systems and wetlands. Simulated averages for distributed recharge, water table elevation and groundwater drawdown were 377.42mm/yr, 194.43m, and 0.18m respectively. Forest vegetation showed the highest recharge, followed by ag- ricultural farmlands, while open-water and other drainage systems constituted groundwater exit zones. When present land-use conditions were compared with the hypothetical natural pre-development scenario, an overall loss of ground- water recharge (24.09mm/yr) was observed, which for the project area is 18.05×108m3. Groundwater abstraction seemed to be the cause of water table drawdown, especially in the immediate vicinities of the supply wells. An important issue of the findings was the ability of the hypothetical forest vegetation to protect, and hence sustain aquifer reserves and dependent ecosystems. The profound data capture capability of ArcGIS makes it particularly useful in spa- tio-temporal hydroecological modeling.
基金supported by the Russian Science Foundation(grant#14-24-00112)supported by NASA Terrestrial Ecology Program
文摘The phenomenon of tree waves (hedges and ribbons) formation within the alpine ecotone in Altai Mountains and its response to observed air temperature increase was considered. At the upper limit of tree growth Siberian pine (Pinus sibirica) forms hedges on windward slopes and ribbons on the leeward ones. Hedges were formed by prevailing winds and oriented along winds direction. Ribbons were formed by snow blowing and accumulating on the leeward slope and perpendicular to the prevailing winds, as well as to the elevation gradient. Hedges were always linked with microtopography features, whereas ribbons were not. Trees are migrating upward by waves and new ribbons and hedges are forming at or near tree line, whereas at lower elevations ribbons and hedges are being transformed into dosed forests. Time series of high-resolution satellite scenes (from 1968 to 2OLO) indicated an upslope shift in the position ribbons averaged 155+26 m (or 3-7 m yr^-1) and crown closure increased (about 35%-90%). The hedges advance was limited by poor regeneration establishment and was negligible. Regeneration within the ribbon zone was approximately 2.5 times (5060 vs 2120 ha^-1) higher then within the hedges zone. During the last four decades, Siberian pine in both hedges and ribbons strongly increased its growth increment, and recent tree growth rate for 50 year-old trees was about twice higher than those recorded for similarly-aged trees at the beginning of the 20^th century. Hedges and ribbons are phenomena that are widespread within the southern and northern Siberian Mountains.
文摘Soil nitrogen pools (NP), denitrification (DN), gross nitrification (GN), N2O and CO2 flux rates with their responses to temperature increases were determined under five different land uses and managements in a subalpine forest-grassland ecotone of the eastern Tibetan Plateau. Land uses consisted of 1) sparse woodland, 2) shrub-land, 3) natural pasture, 4)fenced pasture, and 5) tilled pasture mimicking a gradient degenerating ecosystem under grazing impacts. The NO3--N content was higher than the NH4+-N content. Comparing tilled pasture with fenced pasture showed that higher intensive management (tillage) led to a significant decrease of soil organic matter (SOM) (P < 0.05) in the soils, which was in contrast to the significant increases (P <0.05) of DN, GN, N2O and CO2 flux rates. GN (excluding tilled pasture) and CO2 flux rates increased with a temperature rise, but DN and N2O flux rates normally reached their maximum values at 12-14 ℃ with tilled pasture (the highest management intensity) being very sensitive to temperature increases. There was a difference between net nitrification and GN, with GN being a betterindicator of soil nitrification.
文摘Ischemic colitis is a rare complication of interferon administration.Only 9 cases in 6 reports have been described to-date.This report describes a case of ischemic colitis during pegylated interferon and ribavirin treatment for chronic hepatitis C,and includes a review of the relevant literature.A 48-year-old woman was treated with pegylated interferon-2a and ribavirin for chronic hepatitis C,genotype Ib.After 19 wk of treatment,the patient complained of severe afebrile abdominal pain with hematochezia.Vital signs were stable and serum white blood cell count was within the normal range.Abdominal computed tomography showed diffuse colonic wall thickening from the splenic flexure to the proximal sigmoid colon,which is the most vulnerable area for the development of ischemic colitis.Colonoscopy revealed an acute mucosal hyperemic change,with edema and ulcerations extending from the proximal descending colon to the sigmoid colon.Colonic mucosal biopsy revealed acute exudative colitis.Polymerase chain reaction and culture for Mycobacterium tuberculosis were negative and the cultures for cytomegalovirus,Salmonella and Shigella species were negative.After discontinuation of interferon and ribavirin therapy,abdominal pain and hematochezia subsided and,following colonoscopy showed improvement of the mucosal ulcerations.Ischemic colitis cases during interferon therapy in patients with chronic hepatitis C reported so far have all involved the descending colon.Ischemic colitis is a rarely encountered complication of interferon administration in patients with chronic hepatitis C and should be considered when a patient complains of abdominal pain and hematochezia.
基金Supported by a grant from l’Agence National de la Recherche sur le Sida (ANRS grant 2001/011)
文摘AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.
文摘The paper took Wuhai District as an example, bases on the contrast be-tween the land use condition in 2005 and 2010, and applied the ecological green equivalence to establish a mathematic model of ecological optimization of land use structure, to establish the ecology green equivalent mathematical model and survey the value of region green equivalent, and then assess the ecological environment situation. The results show that the ecological environment has been deteriorated in Wuhai from 2005 to 2010, so the ecological environment was poor. In order to in-crease eco-efficiency of land use, garden, urban green space and woodland area should be raised in the optimization program.
基金Supported by Instituto de Investigacion La Princesa and CI-BERehd from Instituto de Salud Carlos Ⅲ, Madrid, Spain
文摘AIM: To assess the clinical, biochemical and virological long-term outcome in chronic hepatitis C (CHC) patients with a sustained virological response (SVR) after peginterferon (PEG-IFN) plus ribavirin combination therapy. METHODS: One hundred and fifty three patients with a SVR after treatment with PEG-IFN plus ribavirin were included in a 5-year follow-up study in a single Spanish center, based on standard clinical practice. Clinical anamnesis, biochemical analysis, hepatitis C virus RNA and alpha-fetoprotein measurement, ultrasonography and transient elastography were performed annually. RESULTS: The mean follow-up period of the 153 patients was 76 ± 13 mo after they obtained a SVR. Five patients (3.26%) presented with cirrhosis before treatment and 116 (75.8%) had genotype 1. No patient showed evidence of hepatic decompensation. One patient (0.65%) developed a hepatocellular carcinoma at month 30 after achieving SVR. There were no virological relapses during this follow-up period. Persistently elevated alanine aminotransferase was found in only one patient (0.65%). At the end of the 5-year follow-up, the mean value of transient elastography was 7 ± 4.3 kPa (F1). There were no deaths and no other tumors. CONCLUSION: The long-term outcome of 153 CHC patients with SVR to PEG-IFN plus ribavirin was good. No evidence of a virological relapse was seen. One patient (0.65%) developed a hepatocellular carcinoma.
基金Supported by Assistance publique-H pitaux de Paris, IN-SERM U773-CRB3 and University Paris-DiderotFees from Roche, Schering Plough, Novartis, Gilead Sciences, BMS,MSD, Vertex, Tibotec, Biolex, to Marcellin PZymmogenetics and grants from Gilead Sciences, Roche and Schering Plough
文摘AIM: To study the efficacy and factors associated with a sustained virological response (SVR) in chronic hepatitis C (CHC) relapsing patients. METHODS: Out of 1228 CHC patients treated with pegylated interferon (PEG-IFN) and ribavirin (RBV), 165 (13%) had a relapse. Among these, 62 patients were retreated with PEG-IFN-2a or-2b and RBV. Clinical, biological, virological and histological data were collected. Initial doses and treatment modifications were recorded. The efficacy of retreatment and predictive factors for SVR were analyzed. RESULTS: An SVR was achieved in 42% of patients. SVR was higher in young (< 50 years) (61%) than old patients (27%) (P = 0.007), and in genotype 2 or 3 (57%) than in genotype 1 or 4 (28%) patients (P = 0.023). Prolonging therapy for at least 24 wk more than the previous course was associated with higher SVR rates (53% vs 28%, P = 0.04). Also, a better SVR rate was observed with RBV dose/body weight > 15.2 mg/kg per day (70% vs 35%, P = 0.04). In logistic regression, predictors of a response were age (P = 0.018), genotype (P = 0.048) and initial RBV dose/body weight (P = 0.022). None of the patients without a complete early virological response achieved an SVR (negative predictive value = 100%). CONCLUSION: Retreatment with PEG-IFN/RBV is effective in genotype 2 or 3 relapsers, especially in young patients. A high dose of RBV seems to be important for the retreatment response.