Chinese Assam tea(Camellia sinensis var.assamica)is an important tea crop with a long history of cultivation in Yunnan,China.Despite its potential value as a genetic resource,its genetic diversity and domestication/br...Chinese Assam tea(Camellia sinensis var.assamica)is an important tea crop with a long history of cultivation in Yunnan,China.Despite its potential value as a genetic resource,its genetic diversity and domestication/breeding history remain unclear.To address this issue,we genotyped 469 ancient tea plant trees representing 26 C.sinensis var.assamica populations,plus two of its wild relatives(six and three populations of C.taliensis and C.crassicolumna,respectively)using 16 nuclear microsatellite loci.Results showed that Chinese Assam tea has a relatively high,but comparatively lower gene diversity(H_(S)=0.638)than the wild relative C.crassicolumna(H_S=0.658).Clustering in STRUCTURE indicated that Chinese Assam tea and its two wild relatives formed distinct genetic groups,with considerable interspecific introgression.The Chinese Assam tea accessions clustered into three gene pools,corresponding well with their geographic distribution.However,New Hybrids analysis indicated that 68.48%of ancient Chinese Assam tea plants from Xishuangbanna were genetic intermediates between the Puer and Lincang gene pools.In addition,10%of the ancient Chinese Assam tea individuals were found to be hybrids between Chinese Assam tea and C.taliensis.Our results suggest that Chinese Assam tea was domesticated separately in three gene pools(Puer,Lincang and Xishuangbanna)in the Mekong River valley and that the hybrids were subsequently selected during the domestication process.Although the domestication history of Chinese Assam tea in southwestern Yunnan remains complex,our results will help to identify valuable genetic resources that may be useful in future tea breeding programs.展开更多
In this study, we investigated the origin of the overland flow roughness problem and divided the current overland flow roughness research into three types, as follows: the first type of research takes into account the...In this study, we investigated the origin of the overland flow roughness problem and divided the current overland flow roughness research into three types, as follows: the first type of research takes into account the effects of roughness on the volume and velocity of surface runoff, flood peaks, and the scouring capability of flows, but has not addressed the spatial variability of roughness in detail; the second type of research considers that surface roughness varies spatially with different land usage types, land-cover conditions, and different tillage forms, but lacks a quantitative study of the spatial variability; and the third type of research simply deals with the spatial variability of roughness in each grid cell or land type. We present three shortcomings of the current overland flow roughness research, including(1) the neglect of roughness in distributed hydrological models when simulating the overland flow direction and distribution,(2) the lack of consideration of spatial variability of roughness in hydrological models, and(3) the failure to distinguish the roughness formulas in different overland flow regimes. To solve these problems,distributed hydrological model research should focus on four aspects in regard to overland flow: velocity field observations, flow regime mechanisms, a basic roughness theory, and scale problems.展开更多
The influence of intracortical inhibition on the response adaptation of visual cortical neurons remains in debate. To clarify this issue, in the present study the influence of surround suppression evoked through the l...The influence of intracortical inhibition on the response adaptation of visual cortical neurons remains in debate. To clarify this issue, in the present study the influence of surround suppression evoked through the local inhibitory interneurons on the adaptation effects of neurons in the primary visual cortex （V1） were observed. Moreover, the adaptations of V1 neurons to both the high-contrast visual stimuli presented in the classical receptive field （CRF） and to the costimulation presented in the CRF and the surrounding nonclassical receptive field （nCRF） were compared. The intensities of surround suppression were modulated with different sized grating stimuli. The results showed that the response adaptation of V1 neurons decreased significantly with the increase of surround suppression and this adaptation decrease was due to the reduction of the initial response of V1 neurons to visual stimuli. However, the plateau response during adaptation showed no significant changes. These findings indicate that the adaptation effects of V1 neurons may not be directly affected by surround suppression, but may be dynamically regulated by a negative feedback network and be finely adjusted by its initial spiking response to stimulus. This adaptive regulation is not only energy efficient for the central nervous system, but also beneficially acts to maintain the homeostasis of neuronal response to long-presenting visual signals.展开更多
The development of efficient strategies for constructing oxo-heterocyclic architectures is a highly significant topic in modern synthetic chemistry,due to their wide existence in plenty of natural products,medical and...The development of efficient strategies for constructing oxo-heterocyclic architectures is a highly significant topic in modern synthetic chemistry,due to their wide existence in plenty of natural products,medical and agricultural chemicals[1-4].It is well-known that selectivity,especially stereoselectivity,still lags largely behind many precedent endeavors,which stimulates the synthetic community to search for more efficient and selective methods for oxo-heterocycle synthesis.展开更多
A taxonomic revision of the genus Phryganogryllacris Karny, 1937 is provided. Twelve species of the genus from China are recorded, including 5 species described as new to science, namely P. sichuanensis Li, Liu ＆ Li,...A taxonomic revision of the genus Phryganogryllacris Karny, 1937 is provided. Twelve species of the genus from China are recorded, including 5 species described as new to science, namely P. sichuanensis Li, Liu ＆ Li, sp. nov., P. parva Li, Liu ＆ Li, sp. nov., P. truncata Li, Liu ＆ Li, sp. nov., P. interrupta Li, Liu ＆ Li, sp. nov. and P. longicerca Li, Liu ＆ Li, sp. nov. Two new combinations are also reported here, P. gialai（Gorochov, 2004）（Vietnam） comb. nov. and P. alia（Gorochov, 2004）（Vietnam） comb. nov. A key to Chinese species of the genus was provided.展开更多
基金supported by funds from the National Natural Science Foundation of China(31970363,31161140350)the Key Basic Research Program of Yunnan Province,China(202101BC070003)supported by the Scottish Government’s Rural and Environment Science and Analytical Services division。
文摘Chinese Assam tea(Camellia sinensis var.assamica)is an important tea crop with a long history of cultivation in Yunnan,China.Despite its potential value as a genetic resource,its genetic diversity and domestication/breeding history remain unclear.To address this issue,we genotyped 469 ancient tea plant trees representing 26 C.sinensis var.assamica populations,plus two of its wild relatives(six and three populations of C.taliensis and C.crassicolumna,respectively)using 16 nuclear microsatellite loci.Results showed that Chinese Assam tea has a relatively high,but comparatively lower gene diversity(H_(S)=0.638)than the wild relative C.crassicolumna(H_S=0.658).Clustering in STRUCTURE indicated that Chinese Assam tea and its two wild relatives formed distinct genetic groups,with considerable interspecific introgression.The Chinese Assam tea accessions clustered into three gene pools,corresponding well with their geographic distribution.However,New Hybrids analysis indicated that 68.48%of ancient Chinese Assam tea plants from Xishuangbanna were genetic intermediates between the Puer and Lincang gene pools.In addition,10%of the ancient Chinese Assam tea individuals were found to be hybrids between Chinese Assam tea and C.taliensis.Our results suggest that Chinese Assam tea was domesticated separately in three gene pools(Puer,Lincang and Xishuangbanna)in the Mekong River valley and that the hybrids were subsequently selected during the domestication process.Although the domestication history of Chinese Assam tea in southwestern Yunnan remains complex,our results will help to identify valuable genetic resources that may be useful in future tea breeding programs.
基金supported by the National Natural Science Foundation of China(Grants No.41471025 and 40971021)the Natural Science Foundation of Shandong Province(Grant No.ZR2014DM004)
文摘In this study, we investigated the origin of the overland flow roughness problem and divided the current overland flow roughness research into three types, as follows: the first type of research takes into account the effects of roughness on the volume and velocity of surface runoff, flood peaks, and the scouring capability of flows, but has not addressed the spatial variability of roughness in detail; the second type of research considers that surface roughness varies spatially with different land usage types, land-cover conditions, and different tillage forms, but lacks a quantitative study of the spatial variability; and the third type of research simply deals with the spatial variability of roughness in each grid cell or land type. We present three shortcomings of the current overland flow roughness research, including(1) the neglect of roughness in distributed hydrological models when simulating the overland flow direction and distribution,(2) the lack of consideration of spatial variability of roughness in hydrological models, and(3) the failure to distinguish the roughness formulas in different overland flow regimes. To solve these problems,distributed hydrological model research should focus on four aspects in regard to overland flow: velocity field observations, flow regime mechanisms, a basic roughness theory, and scale problems.
基金supported by the National Natural Science Foundation of China(31171082)the Natural Science Foundation of Anhui Province(070413138)+1 种基金the Key Research Foundation of the Anhui Provincial Education Department(KJ2009A167)the Foundation of Key Laboratories of Anhui Province and the Anhui Provincial Education Department
文摘The influence of intracortical inhibition on the response adaptation of visual cortical neurons remains in debate. To clarify this issue, in the present study the influence of surround suppression evoked through the local inhibitory interneurons on the adaptation effects of neurons in the primary visual cortex （V1） were observed. Moreover, the adaptations of V1 neurons to both the high-contrast visual stimuli presented in the classical receptive field （CRF） and to the costimulation presented in the CRF and the surrounding nonclassical receptive field （nCRF） were compared. The intensities of surround suppression were modulated with different sized grating stimuli. The results showed that the response adaptation of V1 neurons decreased significantly with the increase of surround suppression and this adaptation decrease was due to the reduction of the initial response of V1 neurons to visual stimuli. However, the plateau response during adaptation showed no significant changes. These findings indicate that the adaptation effects of V1 neurons may not be directly affected by surround suppression, but may be dynamically regulated by a negative feedback network and be finely adjusted by its initial spiking response to stimulus. This adaptive regulation is not only energy efficient for the central nervous system, but also beneficially acts to maintain the homeostasis of neuronal response to long-presenting visual signals.
基金This work was supported by the National Natural Science Foundation of China(21822103,21820102003,21772052,21772053,and 91956201)the Program of Introducing Talents of Discipline to Universities of China(111 Program,B17019).
文摘The development of efficient strategies for constructing oxo-heterocyclic architectures is a highly significant topic in modern synthetic chemistry,due to their wide existence in plenty of natural products,medical and agricultural chemicals[1-4].It is well-known that selectivity,especially stereoselectivity,still lags largely behind many precedent endeavors,which stimulates the synthetic community to search for more efficient and selective methods for oxo-heterocycle synthesis.
基金supported by the Natural Science Foundation of Shanghai,China(14ZR1413000)the Scientific Research Innovation Foundation of East China Normal University(78210268)+1 种基金the Science-technology Basic Condition Platform from the Ministry of Science and Technology of the People’s Republic of China(2005DKA21402)Informationization Project of CAS-Integration of Scientific Databases in Zoological Science(XXH12504-1-03)
文摘A taxonomic revision of the genus Phryganogryllacris Karny, 1937 is provided. Twelve species of the genus from China are recorded, including 5 species described as new to science, namely P. sichuanensis Li, Liu ＆ Li, sp. nov., P. parva Li, Liu ＆ Li, sp. nov., P. truncata Li, Liu ＆ Li, sp. nov., P. interrupta Li, Liu ＆ Li, sp. nov. and P. longicerca Li, Liu ＆ Li, sp. nov. Two new combinations are also reported here, P. gialai（Gorochov, 2004）（Vietnam） comb. nov. and P. alia（Gorochov, 2004）（Vietnam） comb. nov. A key to Chinese species of the genus was provided.
