Massive MIMO systems have got extraordinary spectral efficiency using a large number of base station antennas,but it is in the challenge of pilot contamination using the aligned pilots.To address this issue,a selectiv...Massive MIMO systems have got extraordinary spectral efficiency using a large number of base station antennas,but it is in the challenge of pilot contamination using the aligned pilots.To address this issue,a selective transmission is proposed using time-shifted pilots with cell grouping,where the strong interfering users in downlink transmission cells are temporally stopped during the pilots transmission in uplink cells.Based on the spatial characteristics of physical channel models,the strong interfering users are selected to minimize the inter-cell interference and the cell grouping is designed to have less temporally stopped users within a smaller area.Furthermore,a Kalman estimator is proposed to reduce the unexpected effect of residual interferences in channel estimation,which exploits both the spatial-time correlation of channels and the share of the interference information.The numerical results show that our scheme significantly improves the channel estimation accuracy and the data rates.展开更多
Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in...Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China.In order to clarify the interrelation among key ecological zone plans,this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas(key ecological function areas,key regions of ecological service function,national nature reserves)and the research on ecological conditions,based on multi-scale ecological spatial theme information,which incorporates elements like ecological quality and type,and by the aid of spatial information analysis and GIS modeling.The results showed a contrastively fine spatial consistency with 68.8%of priority areas of biodiversity conservation overlapping with three key ecological areas.Although the environment in priority areas of biodiversity conservation were in good conditions,protection pressure is also increasing,powerful supervision and protection should not be ignored.The environmental conditions in the overlapping areas,as a whole,were superior to those in the non-overlapping areas.Since two areas have different characteristics,targeted protection measures should be formulated based on this difference,which will be very important for biodiversity conservation in priority areas of biodiversity conservation.展开更多
The tumor necrosis factor （TNF）-α/NF-kB-signaling pathway plays a pivotal role in various processes including apoptosis, cellular differentiation, host defense, inflammation, autoimmunity and organogenesis. The com...The tumor necrosis factor （TNF）-α/NF-kB-signaling pathway plays a pivotal role in various processes including apoptosis, cellular differentiation, host defense, inflammation, autoimmunity and organogenesis. The complexity of the TNF-α/NF-kB signaling is in part due to the dynamic protein behaviors of key players in this pathway. In this present work, a dynamic and global view of the signaling components in the nucleus at the early stages of TNF-a/ NF-KB signaling was obtained in HEK293 cells, by a combination of subcellular fractionation and stable isotope la- beling by amino acids in cell culture （SILAC）. The dynamic profile patterns of 547 TNF-α-induced nuclei-associated proteins were quantified in our studies. The functional characters of all the profiles were further analyzed using that Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway annotation. Additionally, many previously unknown effectors of TNF-α/NF-kB signaling were identified, quantified and clustered into differential activation profiles. In- terestingly, levels of Fanconi anemia group D2 protein （FANCD2）, one of the Fanconi anemia family proteins, was found to be increased in the nucleus by SILAC quantitation upon TNF-α stimulation, which was further verified by western blotting and immunofluorescence analysis. This indicates that FANCD2 might be involved in TNF-α/NF-kB signaling through its accumulation in the nucleus. In summary, the combination of subcellular proteomics with quan- titative analysis not only allowed for a dissection of the nuclear TNF-α/NF-kB-signaling pathway, but also provided a systematic strategy for monitoring temporal and spatial changes in cell signaling.展开更多
Using the normally ordered Gaussian form of the Wigner operator we recapitulate the quantum phase space representation, we derive a new formula for searching for the classical correspondence of quantum mechanical oper...Using the normally ordered Gaussian form of the Wigner operator we recapitulate the quantum phase space representation, we derive a new formula for searching for the classical correspondence of quantum mechanical operators; we also show that if there exists the eigenvector ｜q〉λ,v of linear combination of the coordinate and momentum operator, （λQ ＋ vP）, where λ,v are real numbers, and ｜q〉λv is complete, then the projector ｜q〉λ,vλ,v〈q｜ must be the Radon transform of Wigner operator. This approach seems concise and physical appealing.展开更多
基金Supported by the Program for Excellent Talents in Beijing(No.2014000020124G040)National Natural Science Foundation of China(No.61372089,61571021)National Natural Science Foundation of Beijing(No.4132007,4132015,4132019)
文摘Massive MIMO systems have got extraordinary spectral efficiency using a large number of base station antennas,but it is in the challenge of pilot contamination using the aligned pilots.To address this issue,a selective transmission is proposed using time-shifted pilots with cell grouping,where the strong interfering users in downlink transmission cells are temporally stopped during the pilots transmission in uplink cells.Based on the spatial characteristics of physical channel models,the strong interfering users are selected to minimize the inter-cell interference and the cell grouping is designed to have less temporally stopped users within a smaller area.Furthermore,a Kalman estimator is proposed to reduce the unexpected effect of residual interferences in channel estimation,which exploits both the spatial-time correlation of channels and the share of the interference information.The numerical results show that our scheme significantly improves the channel estimation accuracy and the data rates.
基金Under the auspices of Public Science and Technology Research Funds of Environment(No.201009021,2011467026,2012467044)National Key Technology R&D Program of China(No.2012BAH32B03)National Natural Science Foundation of China(No.41171318,41001160)
文摘Formulation of different ecological zone plans according to the corresponding protection targets and the necessity of proper conservation policy is one of the measures to achieve the goal of ecological conservation in China.In order to clarify the interrelation among key ecological zone plans,this paper carried out the research on spatial relation of priority areas of biodiversity conservation and three key ecological areas(key ecological function areas,key regions of ecological service function,national nature reserves)and the research on ecological conditions,based on multi-scale ecological spatial theme information,which incorporates elements like ecological quality and type,and by the aid of spatial information analysis and GIS modeling.The results showed a contrastively fine spatial consistency with 68.8%of priority areas of biodiversity conservation overlapping with three key ecological areas.Although the environment in priority areas of biodiversity conservation were in good conditions,protection pressure is also increasing,powerful supervision and protection should not be ignored.The environmental conditions in the overlapping areas,as a whole,were superior to those in the non-overlapping areas.Since two areas have different characteristics,targeted protection measures should be formulated based on this difference,which will be very important for biodiversity conservation in priority areas of biodiversity conservation.
基金Abbreviations： TNF （tumor necrosis factor） SILAC （stable isotope label- ing by amino acids in cell culture）+4 种基金 LC-MS/MS （liquid chromatography tandem mass spectrometry） LTQ-Orbitrap （linear ion trap/Orbitrap） HPRD （Human Protein Reference Database） SMARC （SWI/SNF-related matrix-associated actin-dependent regulator chromatin） KEGG （Kyoto Encyclopedia of Genes and Genomes）Acknowledgment We would like to thank Dr/an Scott （Department of Molecular Genetics, University of Toronto）, Dr Chengjian Tu （Vanderbilt Medical Center, Vanderbilt University） and Ya-Wen Tian （Key Laboratory of Systems Biology, Shanghai Institutes for Biologi- cal Sciences） for critical reading of the manuscript. This work was supported by the National Natural Science Foundation of China （30425021, 30521005）, Basic Research Foundation （2006CB910700）, CAS Project （KSCX2-YW-R-106, KSCX1- YW-02） and High-technology Project （2007AA02Z334）.
文摘The tumor necrosis factor （TNF）-α/NF-kB-signaling pathway plays a pivotal role in various processes including apoptosis, cellular differentiation, host defense, inflammation, autoimmunity and organogenesis. The complexity of the TNF-α/NF-kB signaling is in part due to the dynamic protein behaviors of key players in this pathway. In this present work, a dynamic and global view of the signaling components in the nucleus at the early stages of TNF-a/ NF-KB signaling was obtained in HEK293 cells, by a combination of subcellular fractionation and stable isotope la- beling by amino acids in cell culture （SILAC）. The dynamic profile patterns of 547 TNF-α-induced nuclei-associated proteins were quantified in our studies. The functional characters of all the profiles were further analyzed using that Kyoto Encyclopedia of Genes and Genomes （KEGG） pathway annotation. Additionally, many previously unknown effectors of TNF-α/NF-kB signaling were identified, quantified and clustered into differential activation profiles. In- terestingly, levels of Fanconi anemia group D2 protein （FANCD2）, one of the Fanconi anemia family proteins, was found to be increased in the nucleus by SILAC quantitation upon TNF-α stimulation, which was further verified by western blotting and immunofluorescence analysis. This indicates that FANCD2 might be involved in TNF-α/NF-kB signaling through its accumulation in the nucleus. In summary, the combination of subcellular proteomics with quan- titative analysis not only allowed for a dissection of the nuclear TNF-α/NF-kB-signaling pathway, but also provided a systematic strategy for monitoring temporal and spatial changes in cell signaling.
基金Supported by National Natural Science Foundation of China under Grant Nos. 10874174 and 10775097
文摘Using the normally ordered Gaussian form of the Wigner operator we recapitulate the quantum phase space representation, we derive a new formula for searching for the classical correspondence of quantum mechanical operators; we also show that if there exists the eigenvector ｜q〉λ,v of linear combination of the coordinate and momentum operator, （λQ ＋ vP）, where λ,v are real numbers, and ｜q〉λv is complete, then the projector ｜q〉λ,vλ,v〈q｜ must be the Radon transform of Wigner operator. This approach seems concise and physical appealing.
