Several animal models of migraine have been established, and those based on trigeminovascular system activation are widely accepted. How- ever, most of these models have been established on lower animals, such as rode...Several animal models of migraine have been established, and those based on trigeminovascular system activation are widely accepted. How- ever, most of these models have been established on lower animals, such as rodents, and involve only a single administration of a noxious stimulus. In this study, an inflammatory soup （10 μL）, consisting of prostaglandin E2 （0.2 mM）, serotonin （2 mM）, bradykinin （2 raM） and histamine （2 raM）, was injected into the dura mater of conscious rhesus monkeys through an indwelling catheter. The infusion started on day 8 and was repeated every 3 days, for a total of six administrations, to induce neurogenic inflammation. We performed behavioral assessments and measured the expression of the oncogene c-fos, neuronal nitric oxide synthase （nNOS） and calcitonin gene related peptide （CGRP） ill the trigeminal system and in multiple brain regions involved in pain processing by immunohistochemical staining. Compared with monkeys in the control group, three of the four animals in the inflammatory soup group displayed decreased motor behaviors, and two showed increased ipsilateral nose and mouth secretions during the stimulus period. Higher expression levels of c-fos, nNOS and CGRP were found in various brain areas of experimental animals compared with controls, including the trigeminal nucleus caudalis, thalamus, hypothalamus, midbrain, pons and other areas involved in pain perception. These results suggest that repeated inflammatory soup stimulation of the dura activates the trigeminovascular system and produces migraine-like pathological changes and abnormal behaviors in conscious rhesus monkeys.展开更多
The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau fiver ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and fiver ecolo...The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau fiver ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and fiver ecology. In this study, the composition, abundance, and diversity of periphytic protozoa were investigated across four seasons from 2008 to 2009 to better understand their spatio-temporal patterns and relationship to the environment. Our investigation shows that periphytic protozoa in the Niyang River contained 15 genera, belonged to Tubulinea, Alveolata, Discosea and Rhizaria, Alveolata possessed most genera, up to nine, with highest share in abundance, exceeding 50%, Difflugia and Glaucoma were dominant genera. Moreover, four diversity indices of periphytic protozoa, including species richness, total abundance, Shannon-Wiener diversity index and Pielou＇s evenness index, displayed a significant descending trend as the seasons continued, in the order of winter, spring, summer and autumn; with a significant difference existing between winter and summer （or autumn） for Shannon-Wiener diversity index and species richness （P〈0.05）. Four of these diversity indices also presented a V-shaped pattern between the upper middle course of the Niyang River and the confluence of the Niyang River and Yarlung Zangbo River, with the lowest value occurred in the middle course of the Niyang River. However, no significant variation was found through the Niyang River （P〉0.05）. In addition, canonical correlation analysis （CCA） shows that the densities of Difflugia, Glaucomais, Enchelydium, Cyphoderia, and Enchelys correlate with water temperature, alkalinity, hardness, pH, and dissolved oxygen, respectively. Lastly, the relationship between periphytic protozoa diversity and the environmental factors of the Niyang River can be predicted using classification and regression trees （CART） annalysis, which suggests that the total abundance and Shannon-Wiener diversity index would be higher when the elevation is above 3 308 m. On the other hand, the Shannon-Wiener diversity index and Pielou＇s evenness index would be lower when pH and ammoniacal nitrogen have lower or higher values. Finally yet importantly, close attention should be paid to periphytic protozoa and its environment to ensure sustainable development of the Niyang River ecosystem.展开更多
Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetr...Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetry Seismic Network in the Capital Circle Region of China and its surrounding areas from January 2002 to June 2006 by the Brune model.Relevant formulas that were used for the calculation of dynamic source parameters include rupture radius,seismic moment,seismic energy,stress drop,and apparent stress.Scaling relations and characteristics of temporal-spatial variations of these dynamic parameters before the MS5.1 Wenan earthquake in Hebei Province that occurred on July 20,2006 were analyzed.Results show that apparent stress,stress drop,and the ratio of seismic energy to the rupture radius had relatively high values in some areas before the Wenan earthquake.These high-value concentration areas were mainly distributed in the North China Plain seismic zone.As is seen from the time curves,parameters,such as apparent stress,stress drop,and ratio of seismic energy to rupture radius underwent significant ascending processes before the Wenan earthquake,but the variation in the corner frequency showed a descending trend.This result might be related to the enhancement of stress in the North China Plain seismic zone before the earthquake.展开更多
The incision of the Sanmen Gorge marks the birth of the modern Yellow River,but its timing varies from the late Miocene-early Pliocene to the late Pleistocene(~0.15 Ma),and the suggested forcing mechanisms vary from t...The incision of the Sanmen Gorge marks the birth of the modern Yellow River,but its timing varies from the late Miocene-early Pliocene to the late Pleistocene(~0.15 Ma),and the suggested forcing mechanisms vary from the uplift of the Tibetan Plateau to global climate change.Here,we report sedimentologic,geochronologic,and provenance data from a drill core near the Sanmen Gorge,the last gorge along the main course of the Yellow River.Our results indicate that typical river channel deposits,with detritus from the Ordos Block in the upstream regions,started to accumulate in the Sanmen Gorge at~1.25 Ma.When integrated with river terrace evidence from the upstream and downstream regions,the results provide robust evidence that the final integration of the modern Yellow River occurred at~1.25 Ma,consistent with the beginning of the Mid-Pleistocene transition(MPT).We propose that the accelerated lowering of eustatic sea level during the MPT may play as important a role as tectonism in driving the birth and evolution of the modern Yellow River.展开更多
The wetted perimeter method(WPM) is used in hydrology and hydraulics to calculate instream flows.The WPM requires few data.It requires only the values of the wetted perimeter,flow and water level,which can be obtained...The wetted perimeter method(WPM) is used in hydrology and hydraulics to calculate instream flows.The WPM requires few data.It requires only the values of the wetted perimeter,flow and water level,which can be obtained from the hydrologic stations of the river in question.In addition,the WPM is not limited by the impacts of human activities on the river runoff.Therefore,this method is generally suitable for the current conditions in China.However,the process of applying the WPM involves two key aspects:how to plot the curve describing the relationship between the wetted perimeter and the discharge and how to confirm the breakpoint of the wetted perimeter-discharge curve.The traditional method is to calculate the curvature or the slope of the wetted perimeter-discharge curve to obtain the minimum flow.According to this method,the minimum flow corresponds to the point of maximum curvature or to the point at which the slope of the curve is equal to 1.The wetted perimeter-discharge curve of a natural river is only part of the complete curve.Thus,the instream flow calculated by the traditional method is the minimum or maximum discharge.The new criterion for defining the breakpoint of the wetted perimeter-discharge curve is that the slope at the breakpoint is a relative maximum,the second-largest slope.The discharges at the breakpoints corresponded to the minimum flow levels required to maintain the ecological function of the river.The minimum instream flow requirements(MIFRs) of four typical reaches,Zhuba,Daofu,Ganzi and Zumuzu hydrological stations on the West Course of the First Stage Project of the South-North Water Transfer Project(WCFSPSNWTP),are calculated using an improved wetted perimeter method(IWPM).The results show that the MIFRs of Zhuba,Daofu,Ganzi and Zumuzu are approximately 9.06-14.5 m 3 s-1,20.7-43.5 m3 s-1,38.8-77.2 m 3 s-1 and 40.4-59.5 m 3 s-1,corresponding to 11.7%-33.9%,14.2%-37.6%,12.4%-28.4% and 17.5%-30.2%,respectively of the annual average flow(AAF).These MIFRs can maintain good ecological function in a river according to the criterion furnished by the Tennant method.展开更多
China and neighboring countries start new cooperation pattern in the Lancang-Mekong River regionThe strongest El Ni？o weather cycle on record has exacerbated drought in the Mekong River area since the end of last year.
We use 15 seismic stations, crossing the Qinling orogen （QO）, Weihe graben （WG） and Ordos block （OB）, to study the crustal structures by receiver functions （RFs） methods. The results show quite a difference in...We use 15 seismic stations, crossing the Qinling orogen （QO）, Weihe graben （WG） and Ordos block （OB）, to study the crustal structures by receiver functions （RFs） methods. The results show quite a difference in crustal structures and materials of three tectonic units （orogenic belt, extentional basin and stable craton）. The average crustal thickness in the northern QO is 37.8 km, and Poisson ratio is 0.247, which indicates the increase of felsic materials in QO. In the southern OB, the average crustal thickness is 39.2 km and Poisson ratio is 0.265. Comparatively high value of Poisson ratio is related with old crystallized base in the lower crust and shallow sediments. The artificial RFs reveal that low-velocity and thick sediments have a significant ef fect on phases of the MohoroviEi6 discontinuity （Moho）. As a result, the Moho phases in WG are tangled. S-wave velocity （Vs） inversion shows that there are shallow sediment layers with 4-8 km＇s thickness and high velocity zones in the middle-lower crust in WG. Complex Moho structure and high velocity zone may have been induced by the activities of the Weihe faults series.展开更多
The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyze...The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyzed the drilling,well logging,core data,and seismic profiles of basin level,and by using the sequence stratigraphy,identified one secondary sequence boundary,two third-order sequence boundaries,and eight fourth-order sequence boundaries in the Nenjiang Formation.These eleven sequence boundaries can be divided into structural unconformity,depositional unconformity,flooding surface,and forced regression surface.Therefore the Nenjiang Formation can be subdivided into one secondary sequence,three third-order sequences,and ten fourth-order sequences.We have restored the sedimentary filling evolution within the stratigraphic framework of fourth-order sequences in the Nenjiang Formation.The sedimentary period of the first member of the Nenjiang Formation was corresponded to the global transgression period,which is also the development period of transgression cycle(T cycle),when the lake basin had the largest scope and deepest sedimentary water,the SB07(the maximum flooding surface)was formed on the top of strata during this period;covering above the SB07,there developed a set of condensation layer-oil shale,which is distributed in the whole basin and is the important source bed and regional cover.Therefore,a retrogradation sequence was formed in the T cycle of the first member of the Nenjiang Formation,characterized by the retrograding delta at a low angle.The delta has a giant front,a small plain,and many underwater distributary channels.Meanwhile,large gravity flow channels and sublacustrine fans are developed in the front of the delta.During the depositional period of the second member of the Nenjiang Formation,the R cycle began to develop due to the compression of the pacific tectonic domain;the source direction rotated 90°along with the eastern uplifting of the basin,and formed a series of east-west prograded and forced retrogradations.The prograding delta at high angel was developed in the interior of the sequence;the delta had a small front,a giant plain,and fewer underwater distributary channels,with the collapse at the foreslope,forming a series of slump fans.The slump fans can be divided into three types:discrete type,superimposed type,and fluid type.We built a whole"triad model"of the slump fan.Pointed out that the sequence of forced retrogradation formed by R cycle is a good structural mark of basin optimization,and rejected the viewpoint of"transgression"in the Nenjiang Formation of the Songliao Basin.展开更多
基金supported by the National Natural Science Foundation of China,No.81500959(to NC)
文摘Several animal models of migraine have been established, and those based on trigeminovascular system activation are widely accepted. How- ever, most of these models have been established on lower animals, such as rodents, and involve only a single administration of a noxious stimulus. In this study, an inflammatory soup （10 μL）, consisting of prostaglandin E2 （0.2 mM）, serotonin （2 mM）, bradykinin （2 raM） and histamine （2 raM）, was injected into the dura mater of conscious rhesus monkeys through an indwelling catheter. The infusion started on day 8 and was repeated every 3 days, for a total of six administrations, to induce neurogenic inflammation. We performed behavioral assessments and measured the expression of the oncogene c-fos, neuronal nitric oxide synthase （nNOS） and calcitonin gene related peptide （CGRP） ill the trigeminal system and in multiple brain regions involved in pain processing by immunohistochemical staining. Compared with monkeys in the control group, three of the four animals in the inflammatory soup group displayed decreased motor behaviors, and two showed increased ipsilateral nose and mouth secretions during the stimulus period. Higher expression levels of c-fos, nNOS and CGRP were found in various brain areas of experimental animals compared with controls, including the trigeminal nucleus caudalis, thalamus, hypothalamus, midbrain, pons and other areas involved in pain perception. These results suggest that repeated inflammatory soup stimulation of the dura activates the trigeminovascular system and produces migraine-like pathological changes and abnormal behaviors in conscious rhesus monkeys.
基金Supported by Regional Fund Key Projects from Technology Gallery in Tibet,Agro-Technical Popularization from Finance Department in Tibet,the National Special Research Fund for Non-Profit Sector(Agriculture)(No.201403012)the National Natural Science Foundation of China(No.31560144)the State Key Laboratory of Freshwater Ecology and Biotechnology(No.2011FBZ28)
文摘The Niyang River, a main tributary of the Yarlung Zangbo River, is an important and typical plateau fiver ecosystem in Tibet, China. At present, few studies have focused on its aquatic living resources and fiver ecology. In this study, the composition, abundance, and diversity of periphytic protozoa were investigated across four seasons from 2008 to 2009 to better understand their spatio-temporal patterns and relationship to the environment. Our investigation shows that periphytic protozoa in the Niyang River contained 15 genera, belonged to Tubulinea, Alveolata, Discosea and Rhizaria, Alveolata possessed most genera, up to nine, with highest share in abundance, exceeding 50%, Difflugia and Glaucoma were dominant genera. Moreover, four diversity indices of periphytic protozoa, including species richness, total abundance, Shannon-Wiener diversity index and Pielou＇s evenness index, displayed a significant descending trend as the seasons continued, in the order of winter, spring, summer and autumn; with a significant difference existing between winter and summer （or autumn） for Shannon-Wiener diversity index and species richness （P〈0.05）. Four of these diversity indices also presented a V-shaped pattern between the upper middle course of the Niyang River and the confluence of the Niyang River and Yarlung Zangbo River, with the lowest value occurred in the middle course of the Niyang River. However, no significant variation was found through the Niyang River （P〉0.05）. In addition, canonical correlation analysis （CCA） shows that the densities of Difflugia, Glaucomais, Enchelydium, Cyphoderia, and Enchelys correlate with water temperature, alkalinity, hardness, pH, and dissolved oxygen, respectively. Lastly, the relationship between periphytic protozoa diversity and the environmental factors of the Niyang River can be predicted using classification and regression trees （CART） annalysis, which suggests that the total abundance and Shannon-Wiener diversity index would be higher when the elevation is above 3 308 m. On the other hand, the Shannon-Wiener diversity index and Pielou＇s evenness index would be lower when pH and ammoniacal nitrogen have lower or higher values. Finally yet importantly, close attention should be paid to periphytic protozoa and its environment to ensure sustainable development of the Niyang River ecosystem.
基金the Special Research Fund for Earthquake Science,China (200708023)
文摘Source spectra,corner frequency and zero frequency amplitudes in near-source conditions were measured using waveform data from 989 earthquakes with magnitudes larger than ML2.0 observed by the Beijing Digital Telemetry Seismic Network in the Capital Circle Region of China and its surrounding areas from January 2002 to June 2006 by the Brune model.Relevant formulas that were used for the calculation of dynamic source parameters include rupture radius,seismic moment,seismic energy,stress drop,and apparent stress.Scaling relations and characteristics of temporal-spatial variations of these dynamic parameters before the MS5.1 Wenan earthquake in Hebei Province that occurred on July 20,2006 were analyzed.Results show that apparent stress,stress drop,and the ratio of seismic energy to the rupture radius had relatively high values in some areas before the Wenan earthquake.These high-value concentration areas were mainly distributed in the North China Plain seismic zone.As is seen from the time curves,parameters,such as apparent stress,stress drop,and ratio of seismic energy to rupture radius underwent significant ascending processes before the Wenan earthquake,but the variation in the corner frequency showed a descending trend.This result might be related to the enhancement of stress in the North China Plain seismic zone before the earthquake.
基金supported by the Item of Yongding River ecological architecturethe restoration of technology research and demonstration,Open Research Fund Program of State Key Laboratory of Water Resources and Hydropower Engineering Science(No.2009B050)the National Natural Science Foundation of China(No.50809027)
基金supported by the Fundamental Research Funds for the Central Universities,China(lzujbky-2021-ey12)the National Natural Science Foundation of China(42072211)+1 种基金the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0602)the National Non-Profit Fundamental Research Grant of China(IGCEA 2008)。
文摘The incision of the Sanmen Gorge marks the birth of the modern Yellow River,but its timing varies from the late Miocene-early Pliocene to the late Pleistocene(~0.15 Ma),and the suggested forcing mechanisms vary from the uplift of the Tibetan Plateau to global climate change.Here,we report sedimentologic,geochronologic,and provenance data from a drill core near the Sanmen Gorge,the last gorge along the main course of the Yellow River.Our results indicate that typical river channel deposits,with detritus from the Ordos Block in the upstream regions,started to accumulate in the Sanmen Gorge at~1.25 Ma.When integrated with river terrace evidence from the upstream and downstream regions,the results provide robust evidence that the final integration of the modern Yellow River occurred at~1.25 Ma,consistent with the beginning of the Mid-Pleistocene transition(MPT).We propose that the accelerated lowering of eustatic sea level during the MPT may play as important a role as tectonism in driving the birth and evolution of the modern Yellow River.
基金supported by the National Natural Science Foundation of China (Grant No. 50809027)the Fundamental Research Funds for the Central Universities (Grant No. 11MG15)the Open Research Fund Program of State Key Laboratory of Water Resources and Hydropower Engineering Science (Grant No. 2009B050)
文摘The wetted perimeter method(WPM) is used in hydrology and hydraulics to calculate instream flows.The WPM requires few data.It requires only the values of the wetted perimeter,flow and water level,which can be obtained from the hydrologic stations of the river in question.In addition,the WPM is not limited by the impacts of human activities on the river runoff.Therefore,this method is generally suitable for the current conditions in China.However,the process of applying the WPM involves two key aspects:how to plot the curve describing the relationship between the wetted perimeter and the discharge and how to confirm the breakpoint of the wetted perimeter-discharge curve.The traditional method is to calculate the curvature or the slope of the wetted perimeter-discharge curve to obtain the minimum flow.According to this method,the minimum flow corresponds to the point of maximum curvature or to the point at which the slope of the curve is equal to 1.The wetted perimeter-discharge curve of a natural river is only part of the complete curve.Thus,the instream flow calculated by the traditional method is the minimum or maximum discharge.The new criterion for defining the breakpoint of the wetted perimeter-discharge curve is that the slope at the breakpoint is a relative maximum,the second-largest slope.The discharges at the breakpoints corresponded to the minimum flow levels required to maintain the ecological function of the river.The minimum instream flow requirements(MIFRs) of four typical reaches,Zhuba,Daofu,Ganzi and Zumuzu hydrological stations on the West Course of the First Stage Project of the South-North Water Transfer Project(WCFSPSNWTP),are calculated using an improved wetted perimeter method(IWPM).The results show that the MIFRs of Zhuba,Daofu,Ganzi and Zumuzu are approximately 9.06-14.5 m 3 s-1,20.7-43.5 m3 s-1,38.8-77.2 m 3 s-1 and 40.4-59.5 m 3 s-1,corresponding to 11.7%-33.9%,14.2%-37.6%,12.4%-28.4% and 17.5%-30.2%,respectively of the annual average flow(AAF).These MIFRs can maintain good ecological function in a river according to the criterion furnished by the Tennant method.
文摘China and neighboring countries start new cooperation pattern in the Lancang-Mekong River regionThe strongest El Ni？o weather cycle on record has exacerbated drought in the Mekong River area since the end of last year.
基金supported by National Natural Science Foundation of China(Grant Nos.41174038 and 40474017)
文摘We use 15 seismic stations, crossing the Qinling orogen （QO）, Weihe graben （WG） and Ordos block （OB）, to study the crustal structures by receiver functions （RFs） methods. The results show quite a difference in crustal structures and materials of three tectonic units （orogenic belt, extentional basin and stable craton）. The average crustal thickness in the northern QO is 37.8 km, and Poisson ratio is 0.247, which indicates the increase of felsic materials in QO. In the southern OB, the average crustal thickness is 39.2 km and Poisson ratio is 0.265. Comparatively high value of Poisson ratio is related with old crystallized base in the lower crust and shallow sediments. The artificial RFs reveal that low-velocity and thick sediments have a significant ef fect on phases of the MohoroviEi6 discontinuity （Moho）. As a result, the Moho phases in WG are tangled. S-wave velocity （Vs） inversion shows that there are shallow sediment layers with 4-8 km＇s thickness and high velocity zones in the middle-lower crust in WG. Complex Moho structure and high velocity zone may have been induced by the activities of the Weihe faults series.
基金supported by National Basic Research Program of China(Grant Nos.2006CB701404,2009CB219308)
文摘The Nenjiang Formation in the Songliao Basin is a symmetrical sequence of progradation-retrogradation,and is formed in the transgression cycle and regression cycle(T-R cycles)of the base level of deposition.We analyzed the drilling,well logging,core data,and seismic profiles of basin level,and by using the sequence stratigraphy,identified one secondary sequence boundary,two third-order sequence boundaries,and eight fourth-order sequence boundaries in the Nenjiang Formation.These eleven sequence boundaries can be divided into structural unconformity,depositional unconformity,flooding surface,and forced regression surface.Therefore the Nenjiang Formation can be subdivided into one secondary sequence,three third-order sequences,and ten fourth-order sequences.We have restored the sedimentary filling evolution within the stratigraphic framework of fourth-order sequences in the Nenjiang Formation.The sedimentary period of the first member of the Nenjiang Formation was corresponded to the global transgression period,which is also the development period of transgression cycle(T cycle),when the lake basin had the largest scope and deepest sedimentary water,the SB07(the maximum flooding surface)was formed on the top of strata during this period;covering above the SB07,there developed a set of condensation layer-oil shale,which is distributed in the whole basin and is the important source bed and regional cover.Therefore,a retrogradation sequence was formed in the T cycle of the first member of the Nenjiang Formation,characterized by the retrograding delta at a low angle.The delta has a giant front,a small plain,and many underwater distributary channels.Meanwhile,large gravity flow channels and sublacustrine fans are developed in the front of the delta.During the depositional period of the second member of the Nenjiang Formation,the R cycle began to develop due to the compression of the pacific tectonic domain;the source direction rotated 90°along with the eastern uplifting of the basin,and formed a series of east-west prograded and forced retrogradations.The prograding delta at high angel was developed in the interior of the sequence;the delta had a small front,a giant plain,and fewer underwater distributary channels,with the collapse at the foreslope,forming a series of slump fans.The slump fans can be divided into three types:discrete type,superimposed type,and fluid type.We built a whole"triad model"of the slump fan.Pointed out that the sequence of forced retrogradation formed by R cycle is a good structural mark of basin optimization,and rejected the viewpoint of"transgression"in the Nenjiang Formation of the Songliao Basin.
