A method of spectrum estimation based on the genetic simulated annealing(GSA)algorithm is proposed,which is applied to retrieve the three-dimensional wind field of typhoon Nangka observed by our research group.Compare...A method of spectrum estimation based on the genetic simulated annealing(GSA)algorithm is proposed,which is applied to retrieve the three-dimensional wind field of typhoon Nangka observed by our research group.Compared to the genetic algorithm(GA),the GSA algorithm not only extends the detection range and guarantees the accuracy of retrieval results but also demonstrates a faster retrieval speed.Experimental results indicate that both the GA and GSA algorithms can enhance the detection range by 35%more than the least squares method.However,the convergence speed of the GSA algorithm is 17 times faster than that of the GA,which is more beneficial for real-time data processing.展开更多
In this paper,we generalize the direct method of lines for linear elasticity problems of composite materials in star-shaped domains and consider its application to inverse elasticity problems.We assume that the bounda...In this paper,we generalize the direct method of lines for linear elasticity problems of composite materials in star-shaped domains and consider its application to inverse elasticity problems.We assume that the boundary of the star-shaped domain can be described by an explicit C 1 parametric curve in the polar coordinate.We introduce the curvilinear coordinate,in which the irregular star-shaped domain is converted to a regular semi-infinite strip.The equations of linear elasticity are discretized with respect to the angular variable and we solve the resulting semidiscrete approximation analytically using a direct method.The eigenvalues of the semi-discrete approximation converge quickly to the true eigenvalues of the elliptic operator,which helps capture the singularities naturally.Moreover,an optimal error estimate of our method is given.For the inverse elasticity problems,we determine the Lam´e coefficients from measurement data by minimizing a regularized energy functional.We apply the direct method of lines as the forward solver in order to cope with the irregularity of the domain and possible singularities in the forward solutions.Several numerical examples are presented to show the effectiveness and accuracy of our method for both forward and inverse elasticity problems of composite materials.展开更多
The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty ...The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty Simmental crossbred male calves(body weight=86.47±4.41 kg and 70±4 d of age)were randomly divided into 2 groups:control(CON)(fed basal ration)and ADY(fed basal ration and 5 g/d ADY per calf).The dietary concentrate-to-roughage ratio was 35:65.All the calves were regularly provided rations 3 times a day at 07:00,13:00,and 19:00 and had free access to wate r.The experiment lasted for 60 d.The average daily gain of ADY group was higher(P=0.007)than that of the CON group,and the ratio of feed intake to average daily gain in the ADY group was reduced(P=0.022)as compared to the CON group.The concentration of ruminal ammonia-N was higher(P=0.023)in the CON group than that in the ADY group,but an opposite trend of microbial protein was found between the 2 groups.Also,the ruminal concentrations of propionate and butyrate were higher(P<0.05)in the ADY group than those in the CON group.Calves fed ADY exhibited higher(P<0.05)crude protein and neutral detergent fiber digestibility.Supplementation of ADY increased(P<0.05)the contents of glucose,glutathione peroxidase,superoxide dismutase,immunoglobulin A,immunoglobulin M,and interleukin 10 in the serum of calves,but an opposite trend was observed in malondialdehyde,interleukin 1 beta,and tumor necrosis factor alpha contents between the 2 groups.In conclusion,dietary supplementation with ADY could improve the growth performance,rumen fermentation,nutrient digestibility,antioxidant ability,and immune response of weaned beef calves.展开更多
The a3* nAChRs, which are considered to be promising drug targets for problems such as pain, addiction, cardiovascular function, cognitive disorders etc., are found throughout the central and peripheral nervous syste...The a3* nAChRs, which are considered to be promising drug targets for problems such as pain, addiction, cardiovascular function, cognitive disorders etc., are found throughout the central and peripheral nervous system. The α-conotoxin (α-CTx) LvlA has been identified as the most selective inhibitor of α3β2 nAChRs known to date, and it can distinguish the α3132 nAChR subtype from the α6/α3β2β3 and α3β4 nAChR subtypes. However, the mechanism of its selectivity towards α3132, α6/α3β2β3, and α3β4 nAChRs remains elusive. Here we report the co-crystal structure of LvlA in complex with Aplysia californica acetylcholine binding protein (Ac-AChBP) at a resolution of 3.4 A. Based on the structure of this complex, together with homology modeling based on other nAChR subtypes and binding affinity assays, we conclude that Asp-11 of LvlA plays an important role in the selectivity of LvlA towards α3132 and α31o6132133 nAChRs by making a salt bridge with Lys-155 of the rat α3 subunit. Asn-9 lies within a hydrophobic pocket that is formed by Met-36, Thr-59, and Phe-119 of the rat β2 subunit in the α3β2 nAChR model, revealing the reason for its more potent selectivity towards the a3β2 nAChR subtype. These results provide molecular insights that can be used to design ligands that selectively target α3β2 nAChRs, with significant implications for the design of new therapeutic a-CTxs.展开更多
Heterosis,or hybrid vigor,is the phenomenon whereby progeny of two inbred lines exhibit superior agronomic performance compared with either parent.We analyzed the expression of miRNAs and highly expressed small RNAs ...Heterosis,or hybrid vigor,is the phenomenon whereby progeny of two inbred lines exhibit superior agronomic performance compared with either parent.We analyzed the expression of miRNAs and highly expressed small RNAs (defined according to Solexa sequencing results) in two rice (Oryza sativa) subspecies (japonica cv.Nipponbare and indica cv.93-11) and their reciprocal hybrids using microarrays.We found that of all the 1141 small RNAs tested,140 (12%,140 of 1141) and 157 (13%,157 of 1141) were identified being significantly differentially expressed in two reciprocal hybrids,respectively.All possible modes of action,including additive,high-and low-parent,above high-and below low-parent modes were exhibited.Both F1 hybrids showed non-additive expression patterns,with downregulation predominating.Interestingly,15 miRNAs displayed stark opposite expression trends relative to midparent in reciprocal hybrids.Computational prediction of targets of differentially expressed miRNAs showed that they participated in multifaceted developmental pathways,and were not distinguishable from the targets of non-differentially expressed miRNAs.Together,our findings reveal that small RNAs play roles in heterosis and add a new layer in the understanding and exploitation of molecular mechanisms of heterosis.展开更多
One fast simulation method using Markov chains was introduced to simulate angular,energy,and temporal characteristics of pulsed laser beam propagation underwater.Angular dispersion of photons with a different number o...One fast simulation method using Markov chains was introduced to simulate angular,energy,and temporal characteristics of pulsed laser beam propagation underwater.Angular dispersion of photons with a different number of collisions was calculated based on scattering function and the state transition matrix of Markov chains.Temporal distribution and energy on the receiving plane were obtained,respectively,by use of a novel successive layering model and receiving ratio.The validity of this method was verified by comparing it with the Monte Carlo ray tracing(MCRT)method.The simulation results were close to those obtained by MCRT but were less time consuming and had smoother curves.展开更多
基金supported by the Pre-research Project of Civilian Space(No.D040103)the Joint Project of National Natural Science Foundation of China(No.U23A20379)。
文摘A method of spectrum estimation based on the genetic simulated annealing(GSA)algorithm is proposed,which is applied to retrieve the three-dimensional wind field of typhoon Nangka observed by our research group.Compared to the genetic algorithm(GA),the GSA algorithm not only extends the detection range and guarantees the accuracy of retrieval results but also demonstrates a faster retrieval speed.Experimental results indicate that both the GA and GSA algorithms can enhance the detection range by 35%more than the least squares method.However,the convergence speed of the GSA algorithm is 17 times faster than that of the GA,which is more beneficial for real-time data processing.
基金This work was partially supported by the NSFC Projects No.12025104,11871298,81930119.
文摘In this paper,we generalize the direct method of lines for linear elasticity problems of composite materials in star-shaped domains and consider its application to inverse elasticity problems.We assume that the boundary of the star-shaped domain can be described by an explicit C 1 parametric curve in the polar coordinate.We introduce the curvilinear coordinate,in which the irregular star-shaped domain is converted to a regular semi-infinite strip.The equations of linear elasticity are discretized with respect to the angular variable and we solve the resulting semidiscrete approximation analytically using a direct method.The eigenvalues of the semi-discrete approximation converge quickly to the true eigenvalues of the elliptic operator,which helps capture the singularities naturally.Moreover,an optimal error estimate of our method is given.For the inverse elasticity problems,we determine the Lam´e coefficients from measurement data by minimizing a regularized energy functional.We apply the direct method of lines as the forward solver in order to cope with the irregularity of the domain and possible singularities in the forward solutions.Several numerical examples are presented to show the effectiveness and accuracy of our method for both forward and inverse elasticity problems of composite materials.
基金supported by the National Key Research and Development Program(2017YFD0502005)Sichuan Science and Technology Program(2018NZ0002)China Agriculture(Beef Cattle/Yak)Research System of MOF and MARA(CARS-37)。
文摘The objective of this experiment was to investigate the potential benefits of active dry yeast(ADY)on the growth performance,rumen fermentation,nutrient digestibility,and serum parameters of weaned beef calves.Thirty Simmental crossbred male calves(body weight=86.47±4.41 kg and 70±4 d of age)were randomly divided into 2 groups:control(CON)(fed basal ration)and ADY(fed basal ration and 5 g/d ADY per calf).The dietary concentrate-to-roughage ratio was 35:65.All the calves were regularly provided rations 3 times a day at 07:00,13:00,and 19:00 and had free access to wate r.The experiment lasted for 60 d.The average daily gain of ADY group was higher(P=0.007)than that of the CON group,and the ratio of feed intake to average daily gain in the ADY group was reduced(P=0.022)as compared to the CON group.The concentration of ruminal ammonia-N was higher(P=0.023)in the CON group than that in the ADY group,but an opposite trend of microbial protein was found between the 2 groups.Also,the ruminal concentrations of propionate and butyrate were higher(P<0.05)in the ADY group than those in the CON group.Calves fed ADY exhibited higher(P<0.05)crude protein and neutral detergent fiber digestibility.Supplementation of ADY increased(P<0.05)the contents of glucose,glutathione peroxidase,superoxide dismutase,immunoglobulin A,immunoglobulin M,and interleukin 10 in the serum of calves,but an opposite trend was observed in malondialdehyde,interleukin 1 beta,and tumor necrosis factor alpha contents between the 2 groups.In conclusion,dietary supplementation with ADY could improve the growth performance,rumen fermentation,nutrient digestibility,antioxidant ability,and immune response of weaned beef calves.
基金ACKNOWLEDGEMENTS We thank scientists at SSRF BL17U beam line for assistance in diffraction data collection. This work was supported by the National Natural Science Foundation of China (Grant Nos. 31470751 and U1405228 to Xinquan Wang) and the Beijing Advanced Innovation Center for Structural Biology. This work was also supported, in part, by the Major Intemational Joint Research Project of National Natural Science Foundation of China (81420108028), and Changjiang Scholars and Innovative Research Teams in Universities Grant (IRT_I 5R15).
文摘The a3* nAChRs, which are considered to be promising drug targets for problems such as pain, addiction, cardiovascular function, cognitive disorders etc., are found throughout the central and peripheral nervous system. The α-conotoxin (α-CTx) LvlA has been identified as the most selective inhibitor of α3β2 nAChRs known to date, and it can distinguish the α3132 nAChR subtype from the α6/α3β2β3 and α3β4 nAChR subtypes. However, the mechanism of its selectivity towards α3132, α6/α3β2β3, and α3β4 nAChRs remains elusive. Here we report the co-crystal structure of LvlA in complex with Aplysia californica acetylcholine binding protein (Ac-AChBP) at a resolution of 3.4 A. Based on the structure of this complex, together with homology modeling based on other nAChR subtypes and binding affinity assays, we conclude that Asp-11 of LvlA plays an important role in the selectivity of LvlA towards α3132 and α31o6132133 nAChRs by making a salt bridge with Lys-155 of the rat α3 subunit. Asn-9 lies within a hydrophobic pocket that is formed by Met-36, Thr-59, and Phe-119 of the rat β2 subunit in the α3β2 nAChR model, revealing the reason for its more potent selectivity towards the a3β2 nAChR subtype. These results provide molecular insights that can be used to design ligands that selectively target α3β2 nAChRs, with significant implications for the design of new therapeutic a-CTxs.
基金supported by special funds from the Ministry of Science and Technology of China and Beijing Commission of Science and Technology
文摘Heterosis,or hybrid vigor,is the phenomenon whereby progeny of two inbred lines exhibit superior agronomic performance compared with either parent.We analyzed the expression of miRNAs and highly expressed small RNAs (defined according to Solexa sequencing results) in two rice (Oryza sativa) subspecies (japonica cv.Nipponbare and indica cv.93-11) and their reciprocal hybrids using microarrays.We found that of all the 1141 small RNAs tested,140 (12%,140 of 1141) and 157 (13%,157 of 1141) were identified being significantly differentially expressed in two reciprocal hybrids,respectively.All possible modes of action,including additive,high-and low-parent,above high-and below low-parent modes were exhibited.Both F1 hybrids showed non-additive expression patterns,with downregulation predominating.Interestingly,15 miRNAs displayed stark opposite expression trends relative to midparent in reciprocal hybrids.Computational prediction of targets of differentially expressed miRNAs showed that they participated in multifaceted developmental pathways,and were not distinguishable from the targets of non-differentially expressed miRNAs.Together,our findings reveal that small RNAs play roles in heterosis and add a new layer in the understanding and exploitation of molecular mechanisms of heterosis.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA22000000)the Ministry of Science and Technology of China (No. 2014AA093301)+1 种基金the Laboratory for Regional Oceanography and Numerical Modeling, Qingdao National Laboratory for Marine Science and Technology (No. 2017B04)the Natural Science Foundation of Shanghai (No. 19YF1453600)
文摘One fast simulation method using Markov chains was introduced to simulate angular,energy,and temporal characteristics of pulsed laser beam propagation underwater.Angular dispersion of photons with a different number of collisions was calculated based on scattering function and the state transition matrix of Markov chains.Temporal distribution and energy on the receiving plane were obtained,respectively,by use of a novel successive layering model and receiving ratio.The validity of this method was verified by comparing it with the Monte Carlo ray tracing(MCRT)method.The simulation results were close to those obtained by MCRT but were less time consuming and had smoother curves.