The study investigated the streamflow response to the shrinking cryosphere under changing climate in the Lidder valley, Upper Indus Basin(UIB), Kashmir Himalayas. We used a combination of multitemporal satellite data ...The study investigated the streamflow response to the shrinking cryosphere under changing climate in the Lidder valley, Upper Indus Basin(UIB), Kashmir Himalayas. We used a combination of multitemporal satellite data and topographic maps to evaluate the changes in area, length and volume of the glaciers from 1962 to 2013. A total of 37 glaciers from the Lidder valley, with an area of 39.76 km^2 in 1962 were selected for research in this study. It was observed that the glaciers in the valley have lost ~28.89 ±0.1% of the area and ~19.65 ±0.069% of the volume during the last 51 years, with variable interdecadal recession rates. Geomorphic and climatic influences on the shrinking glacier resources were studied. 30-years temperature records(1980-2010) in the study area showed a significant increasing trend in all the seasons. However, the total annual precipitation during the same period showed a nonsignificant decreasing trend except during the late summer months(July, August and September), when the increasing trend is significant. The depletion of glaciers has led to the significant depletion of the streamflows under the changing climate in the valley. Summer streamflows(1971-2012) have increased significantly till mid-nineties but decreased significantly thereafter, suggesting that the tipping point of streamflow peak, due to the enhanced glacier-melt contribution under increasing global temperatures, may have been already reached in the basin. The observed glacier recession and climate change patterns, if continued in future, would further deplete the streamflows with serious implications on water supplies for different uses in the region.展开更多
Hepatic angiosarcoma is a mesenchymal tumor originating from liver sinusoidal endothelial cells. It is an extremely rare malignant neoplasm accounting for less than 1% of primary malignant liver tumors. The deregulate...Hepatic angiosarcoma is a mesenchymal tumor originating from liver sinusoidal endothelial cells. It is an extremely rare malignant neoplasm accounting for less than 1% of primary malignant liver tumors. The deregulated coagulopathy that can be seen in hepatic angiosarcoma fulfills the clinical diagnostic criteria of disseminated intravascular coagulation. However, the mechanism that governs this coagulopathy has been poorly understood. This case report provides histological evidence of the consumption of coagulation factors along with trapped platelets occurring within the tumor, which is the foundation for the concept of Kasabach-Merritt syndrome(KMS). KMS is characterized by thrombocytopenia and hyperconsumption of coagulation factors within a vascular tumor. However, KMS associated with angiosarcoma has not been well recognized. This case report describes, for the first time, the histological evidence of KMS that occurred in an extremely rare mesenchymal malignant tumor of the liver.展开更多
The aim of this study was to better understand the mechanisms of regional climate variation in mountain ranges with contrasting aspects as mediated by changes in global climate. It may help predict trends of vegetatio...The aim of this study was to better understand the mechanisms of regional climate variation in mountain ranges with contrasting aspects as mediated by changes in global climate. It may help predict trends of vegetation variations in native ecosystems in natural reserves. As measures of climate response, temperature and precipitation data from the north, east, and south-facing mountain ranges of Shennongjia Massif in the coldest and hottest months(January and July), different seasons(spring, summer, autumn, and winter) and each year were analyzed from a long-term dataset(1960 to 2003) to tested variations characteristics, temporal and spatial quantitative relationships of climates. The results showed that the average seasonal temperatures and precipitation in the north, east, and south aspects of the mountain ranges changed at different rates. The average seasonal temperatures change rate ranges in the north, east, and south-facing mountain ranges were from –0.0210℃/yr to 0.0143℃/yr, –0.0166℃/yr to 0.0311℃/yr, and –0.0290 ℃/yr to 0.0084℃/yr, respectively, and seasonal precipitation variation magnitude were from –1.4940 mm/yr to 0.6217 mm/yr, –1.6833 mm/yr to 2.6182 mm/yr, and –0.8567 mm/yr to 1.4077 mm/yr, respectively. The climates variation trend among the three mountain ranges were different in magnitude and direction, showing a complicated change of the climates in mountain ranges and some inconsistency with general trends in global climate change. The climate variations were significantly different and positively correlated cross mountain ranges, revealing that aspects significantly affected on climate variations and these variations resulted from a larger air circulation system, which were sensitive to global climate change. We conclude that location and terrain of aspect are the main factors affecting differences in climate variation among the mountain ranges with contrasting aspects.展开更多
Synedra ulna var, repanda Q. X. Wang & Q. M. You, a new variety of Synedra (Bacillariophyta) from Xinjiang, China, is described and illustrated, and the characteristic of the variety: includes undulate-linear valv...Synedra ulna var, repanda Q. X. Wang & Q. M. You, a new variety of Synedra (Bacillariophyta) from Xinjiang, China, is described and illustrated, and the characteristic of the variety: includes undulate-linear valves and straight pseudoraphe, differs from other species of Synedra.展开更多
Recent reports from pulmonary arterial hypertension (PAH) registries suggest that the mean age at diagnosis is increasing in a growing proportion of elderly patients. The combination of several reasons such as aging...Recent reports from pulmonary arterial hypertension (PAH) registries suggest that the mean age at diagnosis is increasing in a growing proportion of elderly patients. The combination of several reasons such as aging popula- tion, increase in life expectancy, growing PAH awareness of physicians and patients, and availability of more treatment options could explain the changing picture of PAH. PAH should be considered as an emerging entity in the elderly.展开更多
The Gongga Mountain of eastern Tibet Plateau is a representative of the alpine regions with high peaks and deep valleys. Climate change over the last thousand years has controlled the dynamics of glacier and debris fl...The Gongga Mountain of eastern Tibet Plateau is a representative of the alpine regions with high peaks and deep valleys. Climate change over the last thousand years has controlled the dynamics of glacier and debris flow occurrence, which resulted in substantial changes in the mountainous environment. The authors surveyed the community structure of primary forests in Gongga Mountain and forest succession processes in woodland plots. The changing features in the subalpine environment are discussed in this paper. Tree species and sizes between the glacier shrinking areas and debris flow fans in Hailuogou Valley are compared. The pioneer species that settle in debris flow fans and the glacier shrinking areas are Salix spp. and Populus purdomii. Abies fabri and Picea brachytyla are the climax tree species. The succession process of primary vegetation in Hailuogou (2700 ~ 3200 m) can be divided into four stages: Slash surface (20~ 200 yr) Salix-Populus seeding community (10 ~ 30 yr) Populus-Salix sapling community (30 ~ 100 yr) Populus-Abies mixed community (50 ~ 100 yr) Abies-Picea climax In a natural and undisturbed environment, trees compete for light, water and nutrients. Disaster disturbance in mountains is a very important driving factor for regeneration of woody plants. Repeated destruction of forests by glacier movement or debris flows generated additional forest gaps that allow young plants to grow. In this study the Gongga Forest Succession Model (GFSM) was developed for simulation of forest community succession processes on different scales in Gongga Mountain. A soil succession module was added to the GFSM model to simulate soil formation and chemical element change of woodland. In order to represent major features of forests in Southwestern China, many field works has been done to identify ecological parameters of various trees in the subalpine region. On the basis of simulation of tree life history, the GFSM combines forest succession with soil change in both material components and nutrition content. The Monte-Carlo method was applied to simulate random weather fluctuation and the uncertainty of tree death. These modeled processes agreed with the field investigation results in this region. The elevation distribution of different tree species was also simulated; and the results are consistent with field observations of ecological features of tree species. The modeling approach reflects well the succession dynamics of primary forests in Southwestern China. These results are very useful for improving the management policies and prediction technology for restoration and conservation of primary forests in Southwestern China.展开更多
Diabetes mellitus is an important risk factor for coronary atherosclerosis and many patients present extensive coronary stenosis at coronarography. However, in patients with diabetes, endothelial and microvascular dys...Diabetes mellitus is an important risk factor for coronary atherosclerosis and many patients present extensive coronary stenosis at coronarography. However, in patients with diabetes, endothelial and microvascular dysfunction also participate in chronic and acute myocardial ischemia. Although the majority of diabetic patients with myocardial infarction have angiographic evidence of significant coronary artery disease.展开更多
Glacial cirques are typical landscape features of mid-latitude mountain environments like the Central Pyrenees. Their morphology as well as their spatial distribution provides insights about past glaciers and climates...Glacial cirques are typical landscape features of mid-latitude mountain environments like the Central Pyrenees. Their morphology as well as their spatial distribution provides insights about past glaciers and climates. In this study, we examine the distribution, morphometrical and topographical characteristics of glacial cirques in two U-shaped glacial valleys located in the Central Pyrenees – the Aran and the Boí valleys. They are located in different aspects of this mountain range(north vs south) under different climatic influences that promoted distinct glaciation patterns during the late Pleistocene. The spatial mapping of these landforms was carried out using high-resolution imagery and field observations. We analysed the data of the morphometrical and topographical variables of the glacial cirques by using different statistical and geospatial methods in order tounveil the factors controlling their formation and development. A total of 186 glacial cirques were mapped in the study area, including 119 in the Aran and 67 in the Boí valleys. The local topography and microclimate conditions lead to substantial differences in both areas in terms of the morphology and dimensions of the cirques. Glacial cirques in Boí are distributed at slightly higher elevations than in Aran and they are also larger, though their dimensions decrease with elevation in both valleys. Aran cirques are mostly oriented NE, while Boí landforms do not show any prevailing aspect. Even though lithology does not control the distribution of the glacial cirques, some specific lithological settings may favour the development of larger cirques. In general, glacial cirques in the Aran and the Boí valleys show morphometrical properties similar to those reported in other mid-latitude mountain ranges.展开更多
Objective To investigate the impact of meteorological conditions and PM2.5 on the onset of acute aortic dissection in monsoonal climate. Methods A linear regression analysis was performed in monsoonal climate epidemio...Objective To investigate the impact of meteorological conditions and PM2.5 on the onset of acute aortic dissection in monsoonal climate. Methods A linear regression analysis was performed in monsoonal climate epidemiological survey for a period of four years on the impact of meteorological factors (minimal temperature, mean temperature, maximal temperature, average daily surface temperature, day temperature range, relative humidity, mean wind speed, and atmospheric pressure) and PM2.5 concentration on the daily incidences of acute aortic dissections. Meteorological variables and PM2.5 concentration were retrieved on a daily basis from Beijing Regional Climate Center and the Ministry of Environmental Protection of the People’s Republic of China’s website, and the daily incidences of acute aortic dissections were retrieved from the Clinical Data Analysis and Reporting System in the Emergency and Critical Care Center of Beijing Anzhen Hospital. Results During the study period (from January 2011 to December 2014), 1164 patients were identified as having acute aortic dissections. The corresponding incidences in spring and autumn were 0.96 and 1.00, respectively, which significantly higher than that in summer and winter. The incidences of acute aortic dissection in a day could be predicted by diurnal temperature range (DTR) using the following linear multiple regression models: incidences of acute aortic dissection = 0.543 + 0.025 × DTR. Conclusion This is the first study to show an attributable effect of DTR on acute aortic events in monsoonal climate. Our study confirms that meteorological variables were important factors influencing the incidence of acute aortic dissection.展开更多
Variations and trends in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, twelve indices of temperature extremes and 11 indices of p...Variations and trends in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, twelve indices of temperature extremes and 11 indices of precipita- tion extremes at 32 meteorological stations in Hengduan Mountains were examined for the period 1961-2008. The re- suits reveal statistically significant increases in the temperature of the warmest and coldest nights and in the frequen- cies of extreme warm days and nights. Decreases of the diurnal temperature range and the numbers of frost days and ice days are statistically significant. Regional averages of growing season length also display the trends consistent and significant with warming. At a large proportion of the stations, patterns of temperature extremes are consistent with warming since 1961: warming trends in minimum temperature indices are greater than those relating to maximum temperature. As the center of the Shaluli Mountain, the warming magnitudes decrease from inner to outer. Changes in precipitation extremes is low: trends are difficult to detect against the larger inter-annual and decadal-scale variability of precipitation, and only the wet day precipitation and the regional trend in consecutive dry days are significant at the 0.05 level. It can be concluded that the variation of extreme precipitation events is not obvious in the Hengduan Mountains, however, the regional trends generally decrease from the south to the north. Overall, the spatial distribution of temporal changes of all extreme climate indices in the Hengduan Mountains illustrated here reflects the climatic complexity in mountainous regions.展开更多
Objective To study the relationship between syndrome elements and anterior communicating artery(ACoA)opening in patients with symptomatic severe carotid artery stenosis/occlusion.Methods Thirty-six patients with sympt...Objective To study the relationship between syndrome elements and anterior communicating artery(ACoA)opening in patients with symptomatic severe carotid artery stenosis/occlusion.Methods Thirty-six patients with symptomatic severe carotid stenosis/occlusion were collected,including 26 patients with cerebral infarction and 10 patients with transient ischemic attack(TIA).Syndrome elements at five time points were collected.Computer tomography angiography(CTA)combined with magenic resonance angiograp(MRA)was used to evaluate the primary collateral circulation,and the prognosis and syndrome elements were statistically analyzed according to whether the ACoA was open or not.Results The ACoA was open more in the primary collateral circulation among patients with symptomatic severe carotid stenosis/occlusion.There was a statistically significant difference in national institute of health stroke scale(NIHSS)score improvement and good prognosis[the modified rankin scale(mRS)≤2]between the ACoA open group and the ACoA nonopen group on the 90th day(P<0.05).The proportion of patients with internal wind syndrome,blood stasis syndrome,Qi deficiency syndrome,and Yin deficiency syndrome in the ACoA non-open group was higher than that in the open group.Conclusion In the patients with severe carotid artery stenosis/occlusion,the group with presence of anterior communicating artery had better prognosis.The syndrome elements are more complex in the group without the presence of anterior communicating artery.The proportion of Qi deficiency syndrome was positively correlated with the non-opening of anterior communicating artery.The imaging evaluation of collateral circulation can provide guidance for syndrome differentiation and treatment.展开更多
Projections of climate change are essential to guide sustainable development plans in the tropical Andean countries such as Peru. This study assessed the projections of precipitation and potential evaporation, rain er...Projections of climate change are essential to guide sustainable development plans in the tropical Andean countries such as Peru. This study assessed the projections of precipitation and potential evaporation, rain erosive potential, and precipitation concentration in the Mantaro River Basin, in the Peruvian Andes, which is important for agriculture and energy production in Peru. We assumed the Intergovernmental Panel on Climate Change (IPCC) AIB greenhouse gas emission scenario and simulated the global climate change by the HadCM3 global climate model. Due to the steepness of the mountain slopes and the narrowness of the river valley, this study uses the downscaling of the global model simulations by the regional Eta model down to 2o-km resolution. The downscaling projections show decrease in the monthly precipitation with respect to the baseline period, especially during the rainy season, between February and April, until the end of the 21st century. Meanwhile, a progressive increase in the monthly evaporation from the baseline period is projected. The Modified Fournier Index (MFI) shows a statistically significant downward trend in the Mantaro River Basin, whieh suggests a possible reduction in the rain erosive potential. The Precipitation Concentration Index (PCI) shows a statistically significant increasing trend, which indicates increasingly more irregular temporal distribution of precipitation towards the end of the century. The results of this study allow us to conclude that there should be a gradual increase in water deficit and precipitation concentration. Both changes can be negative for agriculture, power generation, and water supply in the Mantaro River Basin in Peru.展开更多
In the summer of 2010/2011 Chile suffered the third most severe energy and water supply crisis in only one decade. This may be surprising as the Andes which accompany the country along 4,200 km are a water tower and c...In the summer of 2010/2011 Chile suffered the third most severe energy and water supply crisis in only one decade. This may be surprising as the Andes which accompany the country along 4,200 km are a water tower and could provide more electricity and water than needed. On top of that, it has to be mentioned that Chile also counts with sunny and windy climates and with excellent geothermal energy resources and thus has a huge potential as far as renewable energies are concerned. After analyzing the existing natural conditions, the infrastructure and the present challenges of climate change, it has to be asked in which way Chile can make use of this potential in the near future, considering the legal and political situation and the technological opportunities. It seems that the resources are still hidden in the Andes, and only the key is missing to realize the country's natural potential. This research has been based on the analysis of existing literature, media, quantitative data from government institutions and other antecedents obtained by the authors in field work done in the South of Chile in 2OLO. The added value of this compilation lies in the comprehensive perspective, linking the knowledge of climatologists, hydrologists, mountain researchers and energy experts in order to support a sustainable energy and water supply for the future in Chile. From this present research, it can be concluded that Chile necessarilyhas to adopt new energy-related strategies, particularly those aimed at diminishing the strong dependence on traditional sources of energy and establishing new techniques and technologies for generating electrieity and utilizing the vast potential that the country is ready to offer, such as that provided by the Andes along 4,200 kilometers.展开更多
基金part of the Department of Science and Technology(DST),Government of India sponsored national research project titled“Himalayan Cryosphere:Science and Society”
文摘The study investigated the streamflow response to the shrinking cryosphere under changing climate in the Lidder valley, Upper Indus Basin(UIB), Kashmir Himalayas. We used a combination of multitemporal satellite data and topographic maps to evaluate the changes in area, length and volume of the glaciers from 1962 to 2013. A total of 37 glaciers from the Lidder valley, with an area of 39.76 km^2 in 1962 were selected for research in this study. It was observed that the glaciers in the valley have lost ~28.89 ±0.1% of the area and ~19.65 ±0.069% of the volume during the last 51 years, with variable interdecadal recession rates. Geomorphic and climatic influences on the shrinking glacier resources were studied. 30-years temperature records(1980-2010) in the study area showed a significant increasing trend in all the seasons. However, the total annual precipitation during the same period showed a nonsignificant decreasing trend except during the late summer months(July, August and September), when the increasing trend is significant. The depletion of glaciers has led to the significant depletion of the streamflows under the changing climate in the valley. Summer streamflows(1971-2012) have increased significantly till mid-nineties but decreased significantly thereafter, suggesting that the tipping point of streamflow peak, due to the enhanced glacier-melt contribution under increasing global temperatures, may have been already reached in the basin. The observed glacier recession and climate change patterns, if continued in future, would further deplete the streamflows with serious implications on water supplies for different uses in the region.
文摘Hepatic angiosarcoma is a mesenchymal tumor originating from liver sinusoidal endothelial cells. It is an extremely rare malignant neoplasm accounting for less than 1% of primary malignant liver tumors. The deregulated coagulopathy that can be seen in hepatic angiosarcoma fulfills the clinical diagnostic criteria of disseminated intravascular coagulation. However, the mechanism that governs this coagulopathy has been poorly understood. This case report provides histological evidence of the consumption of coagulation factors along with trapped platelets occurring within the tumor, which is the foundation for the concept of Kasabach-Merritt syndrome(KMS). KMS is characterized by thrombocytopenia and hyperconsumption of coagulation factors within a vascular tumor. However, KMS associated with angiosarcoma has not been well recognized. This case report describes, for the first time, the histological evidence of KMS that occurred in an extremely rare mesenchymal malignant tumor of the liver.
基金Under the auspices of National Natural Science Foundation of China(No.41371216)Natural Science Foundation of Hubei Province(No.2014CFB376)
文摘The aim of this study was to better understand the mechanisms of regional climate variation in mountain ranges with contrasting aspects as mediated by changes in global climate. It may help predict trends of vegetation variations in native ecosystems in natural reserves. As measures of climate response, temperature and precipitation data from the north, east, and south-facing mountain ranges of Shennongjia Massif in the coldest and hottest months(January and July), different seasons(spring, summer, autumn, and winter) and each year were analyzed from a long-term dataset(1960 to 2003) to tested variations characteristics, temporal and spatial quantitative relationships of climates. The results showed that the average seasonal temperatures and precipitation in the north, east, and south aspects of the mountain ranges changed at different rates. The average seasonal temperatures change rate ranges in the north, east, and south-facing mountain ranges were from –0.0210℃/yr to 0.0143℃/yr, –0.0166℃/yr to 0.0311℃/yr, and –0.0290 ℃/yr to 0.0084℃/yr, respectively, and seasonal precipitation variation magnitude were from –1.4940 mm/yr to 0.6217 mm/yr, –1.6833 mm/yr to 2.6182 mm/yr, and –0.8567 mm/yr to 1.4077 mm/yr, respectively. The climates variation trend among the three mountain ranges were different in magnitude and direction, showing a complicated change of the climates in mountain ranges and some inconsistency with general trends in global climate change. The climate variations were significantly different and positively correlated cross mountain ranges, revealing that aspects significantly affected on climate variations and these variations resulted from a larger air circulation system, which were sensitive to global climate change. We conclude that location and terrain of aspect are the main factors affecting differences in climate variation among the mountain ranges with contrasting aspects.
基金Supported by the National Natural Science Foundation of China (No.30670154 & 30870162)the Leading Academic Discipline Project of Shanghai Municipal Education Commission (No.J50401)
文摘Synedra ulna var, repanda Q. X. Wang & Q. M. You, a new variety of Synedra (Bacillariophyta) from Xinjiang, China, is described and illustrated, and the characteristic of the variety: includes undulate-linear valves and straight pseudoraphe, differs from other species of Synedra.
文摘Recent reports from pulmonary arterial hypertension (PAH) registries suggest that the mean age at diagnosis is increasing in a growing proportion of elderly patients. The combination of several reasons such as aging popula- tion, increase in life expectancy, growing PAH awareness of physicians and patients, and availability of more treatment options could explain the changing picture of PAH. PAH should be considered as an emerging entity in the elderly.
文摘The Gongga Mountain of eastern Tibet Plateau is a representative of the alpine regions with high peaks and deep valleys. Climate change over the last thousand years has controlled the dynamics of glacier and debris flow occurrence, which resulted in substantial changes in the mountainous environment. The authors surveyed the community structure of primary forests in Gongga Mountain and forest succession processes in woodland plots. The changing features in the subalpine environment are discussed in this paper. Tree species and sizes between the glacier shrinking areas and debris flow fans in Hailuogou Valley are compared. The pioneer species that settle in debris flow fans and the glacier shrinking areas are Salix spp. and Populus purdomii. Abies fabri and Picea brachytyla are the climax tree species. The succession process of primary vegetation in Hailuogou (2700 ~ 3200 m) can be divided into four stages: Slash surface (20~ 200 yr) Salix-Populus seeding community (10 ~ 30 yr) Populus-Salix sapling community (30 ~ 100 yr) Populus-Abies mixed community (50 ~ 100 yr) Abies-Picea climax In a natural and undisturbed environment, trees compete for light, water and nutrients. Disaster disturbance in mountains is a very important driving factor for regeneration of woody plants. Repeated destruction of forests by glacier movement or debris flows generated additional forest gaps that allow young plants to grow. In this study the Gongga Forest Succession Model (GFSM) was developed for simulation of forest community succession processes on different scales in Gongga Mountain. A soil succession module was added to the GFSM model to simulate soil formation and chemical element change of woodland. In order to represent major features of forests in Southwestern China, many field works has been done to identify ecological parameters of various trees in the subalpine region. On the basis of simulation of tree life history, the GFSM combines forest succession with soil change in both material components and nutrition content. The Monte-Carlo method was applied to simulate random weather fluctuation and the uncertainty of tree death. These modeled processes agreed with the field investigation results in this region. The elevation distribution of different tree species was also simulated; and the results are consistent with field observations of ecological features of tree species. The modeling approach reflects well the succession dynamics of primary forests in Southwestern China. These results are very useful for improving the management policies and prediction technology for restoration and conservation of primary forests in Southwestern China.
文摘Diabetes mellitus is an important risk factor for coronary atherosclerosis and many patients present extensive coronary stenosis at coronarography. However, in patients with diabetes, endothelial and microvascular dysfunction also participate in chronic and acute myocardial ischemia. Although the majority of diabetic patients with myocardial infarction have angiographic evidence of significant coronary artery disease.
基金supported by the Research Group Climate Change and Environmental Systems(ZEPHYRUS)of the Institute of GeographySpatial Planning of the University of Lisbon+4 种基金a grant from the Erasmus+LLP Programme Grant funding the research stay of Luis Lopes at the University of Barcelonasupported by the Ramón y Cajal Program of the Spanish Ministry of Economy and Competitiveness(RYC-2015-17597)Financial support was also provided by the research group ANTALP(Antarctic,Arctic and Alpine environments,2017-SGR-1102)the PALEOGREEN(CTM2017-87976-P)CRONOANTAR(CTM2016-77878-P)projects of the Spanish Ministry of Economy and Competitiveness
文摘Glacial cirques are typical landscape features of mid-latitude mountain environments like the Central Pyrenees. Their morphology as well as their spatial distribution provides insights about past glaciers and climates. In this study, we examine the distribution, morphometrical and topographical characteristics of glacial cirques in two U-shaped glacial valleys located in the Central Pyrenees – the Aran and the Boí valleys. They are located in different aspects of this mountain range(north vs south) under different climatic influences that promoted distinct glaciation patterns during the late Pleistocene. The spatial mapping of these landforms was carried out using high-resolution imagery and field observations. We analysed the data of the morphometrical and topographical variables of the glacial cirques by using different statistical and geospatial methods in order tounveil the factors controlling their formation and development. A total of 186 glacial cirques were mapped in the study area, including 119 in the Aran and 67 in the Boí valleys. The local topography and microclimate conditions lead to substantial differences in both areas in terms of the morphology and dimensions of the cirques. Glacial cirques in Boí are distributed at slightly higher elevations than in Aran and they are also larger, though their dimensions decrease with elevation in both valleys. Aran cirques are mostly oriented NE, while Boí landforms do not show any prevailing aspect. Even though lithology does not control the distribution of the glacial cirques, some specific lithological settings may favour the development of larger cirques. In general, glacial cirques in the Aran and the Boí valleys show morphometrical properties similar to those reported in other mid-latitude mountain ranges.
基金This study was supported by National Science Foundation Council of China (No.81700383), Jilin Provincial Industrial Innovation Special Fund Project (No.2016C041), Beijing Natural Science Foundation of China (8152019), Beijing Municipal Science and Technology of Chinese Medicine Development Funds Youth Research Project (No. QN2016-20), and Basic-Clinical Scientific Research Cooperation of Capital Medical University fund (No.17JL72). The authors declare no conflict of interest.
文摘Objective To investigate the impact of meteorological conditions and PM2.5 on the onset of acute aortic dissection in monsoonal climate. Methods A linear regression analysis was performed in monsoonal climate epidemiological survey for a period of four years on the impact of meteorological factors (minimal temperature, mean temperature, maximal temperature, average daily surface temperature, day temperature range, relative humidity, mean wind speed, and atmospheric pressure) and PM2.5 concentration on the daily incidences of acute aortic dissections. Meteorological variables and PM2.5 concentration were retrieved on a daily basis from Beijing Regional Climate Center and the Ministry of Environmental Protection of the People’s Republic of China’s website, and the daily incidences of acute aortic dissections were retrieved from the Clinical Data Analysis and Reporting System in the Emergency and Critical Care Center of Beijing Anzhen Hospital. Results During the study period (from January 2011 to December 2014), 1164 patients were identified as having acute aortic dissections. The corresponding incidences in spring and autumn were 0.96 and 1.00, respectively, which significantly higher than that in summer and winter. The incidences of acute aortic dissection in a day could be predicted by diurnal temperature range (DTR) using the following linear multiple regression models: incidences of acute aortic dissection = 0.543 + 0.025 × DTR. Conclusion This is the first study to show an attributable effect of DTR on acute aortic events in monsoonal climate. Our study confirms that meteorological variables were important factors influencing the incidence of acute aortic dissection.
基金Under the auspices of West Light Foundation of Chinese Academy of Sciences (No. Y000141001)Key Program ofNational Natural Science Foundation of China (No. 91025002)+1 种基金Program for Incubation of Specialists in Glaciology and Geocryology of National Natural Science Foundation of China (No. 11J0930003)National Natural Science Foundation of China (No. 40725001,30970492)
文摘Variations and trends in extreme climate events are more sensitive to climate change than the mean values, and so have received much attention. In this study, twelve indices of temperature extremes and 11 indices of precipita- tion extremes at 32 meteorological stations in Hengduan Mountains were examined for the period 1961-2008. The re- suits reveal statistically significant increases in the temperature of the warmest and coldest nights and in the frequen- cies of extreme warm days and nights. Decreases of the diurnal temperature range and the numbers of frost days and ice days are statistically significant. Regional averages of growing season length also display the trends consistent and significant with warming. At a large proportion of the stations, patterns of temperature extremes are consistent with warming since 1961: warming trends in minimum temperature indices are greater than those relating to maximum temperature. As the center of the Shaluli Mountain, the warming magnitudes decrease from inner to outer. Changes in precipitation extremes is low: trends are difficult to detect against the larger inter-annual and decadal-scale variability of precipitation, and only the wet day precipitation and the regional trend in consecutive dry days are significant at the 0.05 level. It can be concluded that the variation of extreme precipitation events is not obvious in the Hengduan Mountains, however, the regional trends generally decrease from the south to the north. Overall, the spatial distribution of temporal changes of all extreme climate indices in the Hengduan Mountains illustrated here reflects the climatic complexity in mountainous regions.
基金We thank for the funding support from the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2017KJ150).
文摘Objective To study the relationship between syndrome elements and anterior communicating artery(ACoA)opening in patients with symptomatic severe carotid artery stenosis/occlusion.Methods Thirty-six patients with symptomatic severe carotid stenosis/occlusion were collected,including 26 patients with cerebral infarction and 10 patients with transient ischemic attack(TIA).Syndrome elements at five time points were collected.Computer tomography angiography(CTA)combined with magenic resonance angiograp(MRA)was used to evaluate the primary collateral circulation,and the prognosis and syndrome elements were statistically analyzed according to whether the ACoA was open or not.Results The ACoA was open more in the primary collateral circulation among patients with symptomatic severe carotid stenosis/occlusion.There was a statistically significant difference in national institute of health stroke scale(NIHSS)score improvement and good prognosis[the modified rankin scale(mRS)≤2]between the ACoA open group and the ACoA nonopen group on the 90th day(P<0.05).The proportion of patients with internal wind syndrome,blood stasis syndrome,Qi deficiency syndrome,and Yin deficiency syndrome in the ACoA non-open group was higher than that in the open group.Conclusion In the patients with severe carotid artery stenosis/occlusion,the group with presence of anterior communicating artery had better prognosis.The syndrome elements are more complex in the group without the presence of anterior communicating artery.The proportion of Qi deficiency syndrome was positively correlated with the non-opening of anterior communicating artery.The imaging evaluation of collateral circulation can provide guidance for syndrome differentiation and treatment.
基金FAPEMIG (PPM X 45-16)CNPqpartially funded by CNPq 308035/2013-5
文摘Projections of climate change are essential to guide sustainable development plans in the tropical Andean countries such as Peru. This study assessed the projections of precipitation and potential evaporation, rain erosive potential, and precipitation concentration in the Mantaro River Basin, in the Peruvian Andes, which is important for agriculture and energy production in Peru. We assumed the Intergovernmental Panel on Climate Change (IPCC) AIB greenhouse gas emission scenario and simulated the global climate change by the HadCM3 global climate model. Due to the steepness of the mountain slopes and the narrowness of the river valley, this study uses the downscaling of the global model simulations by the regional Eta model down to 2o-km resolution. The downscaling projections show decrease in the monthly precipitation with respect to the baseline period, especially during the rainy season, between February and April, until the end of the 21st century. Meanwhile, a progressive increase in the monthly evaporation from the baseline period is projected. The Modified Fournier Index (MFI) shows a statistically significant downward trend in the Mantaro River Basin, whieh suggests a possible reduction in the rain erosive potential. The Precipitation Concentration Index (PCI) shows a statistically significant increasing trend, which indicates increasingly more irregular temporal distribution of precipitation towards the end of the century. The results of this study allow us to conclude that there should be a gradual increase in water deficit and precipitation concentration. Both changes can be negative for agriculture, power generation, and water supply in the Mantaro River Basin in Peru.
文摘In the summer of 2010/2011 Chile suffered the third most severe energy and water supply crisis in only one decade. This may be surprising as the Andes which accompany the country along 4,200 km are a water tower and could provide more electricity and water than needed. On top of that, it has to be mentioned that Chile also counts with sunny and windy climates and with excellent geothermal energy resources and thus has a huge potential as far as renewable energies are concerned. After analyzing the existing natural conditions, the infrastructure and the present challenges of climate change, it has to be asked in which way Chile can make use of this potential in the near future, considering the legal and political situation and the technological opportunities. It seems that the resources are still hidden in the Andes, and only the key is missing to realize the country's natural potential. This research has been based on the analysis of existing literature, media, quantitative data from government institutions and other antecedents obtained by the authors in field work done in the South of Chile in 2OLO. The added value of this compilation lies in the comprehensive perspective, linking the knowledge of climatologists, hydrologists, mountain researchers and energy experts in order to support a sustainable energy and water supply for the future in Chile. From this present research, it can be concluded that Chile necessarilyhas to adopt new energy-related strategies, particularly those aimed at diminishing the strong dependence on traditional sources of energy and establishing new techniques and technologies for generating electrieity and utilizing the vast potential that the country is ready to offer, such as that provided by the Andes along 4,200 kilometers.