[Objective] The aim was to study the effect of RPlys on digestive metabolism of nitrogen in sheep.[Method] The contribution of RPlys for nitrogen residual in sheep was researched by digestive metabolism test.[Result] ...[Objective] The aim was to study the effect of RPlys on digestive metabolism of nitrogen in sheep.[Method] The contribution of RPlys for nitrogen residual in sheep was researched by digestive metabolism test.[Result] The results showed that adding RPlys decreased excretion of urine nitrogen (P0.05) and had no significant effect on excretion of fecal nitrogen (P0.05),and precipitation coefficient of nitrogen was increased (P0.05).[Conclusion] RPlys is propitious to the aggradations of nitrogen in sheep.展开更多
Twenty-nine surface samples (mosses) from five vertical distribution vegetation zones in Changbai Mountain, Northeast China have been palynologically analyzed and the results were tested by correspondence analysis. Th...Twenty-nine surface samples (mosses) from five vertical distribution vegetation zones in Changbai Mountain, Northeast China have been palynologically analyzed and the results were tested by correspondence analysis. The results show that, except a few samples, arboreal pollen is predominant in almost all pollen assemblages; Pinus and Betula are the main pollen types in quantities and they are found in all vegetation zones of Changbai Mountain. The highest pollen proportion of Pinus occurs in the mixed conifer and broadleaved forest where Pinus koraiensis is the main component; Betula pollen is found in high percentage in both subalpine B. ermanii forest and broadleaved deciduous forest predominated by Betula and Quercus; in the former Betula pollen is accompanied by cold-tolerant shrub such as Rhododendron; whereas in the latter it appears a large amount of fern spores. Pollen assemblage of broadleaved deciduous forests is marked by high diversity and proportions of deciduous trees and a large number of fern spores. Subalpine conifer forest is distinguished by high percentage of Picea pollen. Although tree pollen is slightly dominated, very few or absent of fern spores and increasing of herb and small shrub pollen proportions, particularly predominance of Rhododendron in herbaceous pollen and occurrence of tundra indicator type-Dryas pollen distinguish pollen assemblages of alpine tundra.展开更多
[ Objective] The study was to investigate the volatile components of secondary metabolites from M. alpine producing arachidonic acid and explore the changes in its metabolic pathway. [ Method] The air above M. alpine ...[ Objective] The study was to investigate the volatile components of secondary metabolites from M. alpine producing arachidonic acid and explore the changes in its metabolic pathway. [ Method] The air above M. alpine broth was extracted by solid-phase microextraction(SPME) during the post-exponential phase of growth and analyzed by GC-MS. [Result] 13 compounds were identified, 12 of which were sesquiterpenes with C15H24 formula and accounting for 99.62% of the complete compounds. Thujopsene-( 12), α-Guaiene and Aristolene were three most sesquiterpenes accounting for 10.66%, 33.69% and 34.85% of total content respectively. It can be sufficiently certified that sesquiterpene metabolic pathway existing in M. alpine. [ Coclusion] Metabolic flux of sesquiterpene pathway increased to improve its mass accumulation, because one or several key enzyme genes mutation in isoprene or sesquiterpene pathway enhanced their activities during induction of mutation from initial strain.展开更多
Arachidonic acid (ARA or AA), one of the most important polyunsaturated fatty acids (PUFAs), has various physiological activities and positive effects on human health. ARA production by Mortierella alpina has beco...Arachidonic acid (ARA or AA), one of the most important polyunsaturated fatty acids (PUFAs), has various physiological activities and positive effects on human health. ARA production by Mortierella alpina has become a hot topic in recent years, owing to that it is effective, safe and easy to control. How to improve ARA yield and purification efficiency is important to ARA production in M. alpina. Therefore, in this review, we summarized some methods to improve ARA yield: optimization of culture conditions, mycelium aging technologies and metabolic regulation, and the commonly used methods for ARA isolation and purification, to provide a theoretical basis for ARA production by M. alpina fermentation.展开更多
As the popularity of open source projects,the volume of incoming pull requests is too large,which puts heavy burden on integrators who are responsible for accepting or rejecting pull requests.An accepted pull request ...As the popularity of open source projects,the volume of incoming pull requests is too large,which puts heavy burden on integrators who are responsible for accepting or rejecting pull requests.An accepted pull request prediction approach can help integrators by allowing them either to enforce an immediate rejection of code changes or allocate more resources to overcome the deficiency.In this paper,an approach CTCPPre is proposed to predict the accepted pull requests in GitHub.CTCPPre mainly considers code features of modified changes,text features of pull requests’description,contributor features of developers’previous behaviors,and project features of development environment.The effectiveness of CTCPPre on 28 projects containing 221096 pull requests is evaluated.Experimental results show that CTCPPre has good performances by achieving accuracy of 0.82,AUC of 0.76 and F1-score of 0.88 on average.It is compared with the state of art accepted pull request prediction approach RFPredict.On average across 28 projects,CTCPPre outperforms RFPredict by 6.64%,16.06%and 4.79%in terms of accuracy,AUC and F1-score,respectively.展开更多
A passive optical network (PON) scheme based on optical code division multiplexing (OCDM) for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM...A passive optical network (PON) scheme based on optical code division multiplexing (OCDM) for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM technology to guarantee the security, while the upstream traffics pass through the same optical fiber by the common time division multiple access (TDMA) technology to decrease the cost. This schemes are denoted as OCDM/TDMA-PON, which can be applied to an optical access network (OAN) with full services on demand, such as Internet protocol, video on demand, tele-presence and high quality audio. The proposed OCDM/TDMA-PON scheme combines advantages of PON, TDMA, and OCDM technology. Simulation results indicate that the designed scheme improves the OAN performance, and enhances flexibility and scalability of the system.展开更多
Although the forest floor plays important roles in water-holding and nutrient cycling, there is not enough knowledge of the functional changes of the forest floor resulting from changes in vegetation. To evaluate the ...Although the forest floor plays important roles in water-holding and nutrient cycling, there is not enough knowledge of the functional changes of the forest floor resulting from changes in vegetation. To evaluate the effect on the hydrological properties of forest floor by the substitution of plantation species for native coppice, we selected four species substituting plantations and one native coppice (secondary native broad-leaved forest, dominated by Quercus liaotungensis and Corylus heterophylla var. sutchuenensis) (QC) as a comparison forest. The substituting plantations were Cercidiphyllum japonicum (Cj), Pinus tabulaeformis (Pt), Pinus armandi (Pa), Larix kaempferi (Lk). These were established in 1987 with a stocking density of approximately 2500 stem ha -1 . Thickness and the amount of floor in coniferous plantations were significantly higher compared to secondary native broad-leaved forest and pure broad- leaved plantation. The maximal water-holding capacity of the floor showed the same trend as thickness and amount of litter. Main contributors to the difference in hydrological characteristics in the plantations were the quantity of forest floor and the maximal water holding capacity per unit weight of the floor. The relationships between water absorption processes, water absorption rate and the immersion time for litter, fitted to logarithmic and exponential regressions, respectively. Water absorption processes differed significantly between the various plantations and different decomposition floor horizons. Water absorption characteristics were influenced by leaf structure in various tree species and the degree of decomposed litter. Our results showed that litter amount in coniferous plantations were significantly higher than in deciduous broad-leaved plantation. This suggests that a large amount of nutrients are held in the litter horizon, delaying return to the soil and utilization by plants. At the same time, maximal water-holding capacity of the forest floor in F [fermentation] and H [hummus] horizons was significantly higher than that in L [fresh litter] horizon. Therefore, improving litter transformation from L horizon to F and H horizons by promoting forest floor environment would be one of the best methods for plantation management.展开更多
Liposomes are used as carriers for targeted drug delivery by the intravenous route. The aim of our study was to prepare lomustine loaded liposomes (CCNU-Lips) and evaluate its physicochemical properties and the tiss...Liposomes are used as carriers for targeted drug delivery by the intravenous route. The aim of our study was to prepare lomustine loaded liposomes (CCNU-Lips) and evaluate its physicochemical properties and the tissue targeting after intravenous (i.v.) injection. CCNU-Lips were prepared by film dispersion method. In vitro drug release was investigated in phosphate-buffered saline (pH 6.8) at 37℃. The concentrations of CCNU in selected organs were determined using reversed-phase high-performance liquid chromatography (HPLC) following i.v. administration of CCNU-Lips and inclusion complex solution of CCNU with hydroxypropyl-β-cyclodextrin (CCNU-Sol). CCNU-Lips had an average diameter of (189.8±28.5) nm with a zeta potential of (-19.13±0.12) mV and the in vitro drug release was monitored for up to 3 d, and the release behavior was in accordance with Weibull-equation. The CCNU-Lips exhibited a longer elimination half life (t1/2β) in vivo compared with CCNU-Sol after i.v. injection to New Zealand rabbits. The encapsulation of lomustine in liposomes also changed its biodistribution in mice. CCNU-Lips showed significant brain targeting with AUC, Te and Re of the brain all showing obvious elevation. These results indicated that CCNU-Lips were promising passive targeting formulation to the brain.展开更多
This paper studies the tracking control of general linear multi-agent systems with out time delays. The observer-based event-triggered control schemes will be considered or with- For the conventional distributed track...This paper studies the tracking control of general linear multi-agent systems with out time delays. The observer-based event-triggered control schemes will be considered or with- For the conventional distributed tracking protocol, the authors will not update the relative state in continuous time, i.e., the relative state will be updated by some events which happened in discrete time. A completely decentralized event-trigger will be designed for leader-follower systems. It is shown that all followers can track the leader asymptotically by the proposed protocol, if the feedback gain matrices are designed appropriately. Numerical simulations are also provided and the results show highly consistent with the theoretical results.展开更多
基金Supported by Special Fund for Basic Scientific Research Expensesin Non-profit Research Institutions at the Central level "Study onProtective Lysine Feed Additive of Rumen in Sheep"(BRF070104)~~
文摘[Objective] The aim was to study the effect of RPlys on digestive metabolism of nitrogen in sheep.[Method] The contribution of RPlys for nitrogen residual in sheep was researched by digestive metabolism test.[Result] The results showed that adding RPlys decreased excretion of urine nitrogen (P0.05) and had no significant effect on excretion of fecal nitrogen (P0.05),and precipitation coefficient of nitrogen was increased (P0.05).[Conclusion] RPlys is propitious to the aggradations of nitrogen in sheep.
文摘Twenty-nine surface samples (mosses) from five vertical distribution vegetation zones in Changbai Mountain, Northeast China have been palynologically analyzed and the results were tested by correspondence analysis. The results show that, except a few samples, arboreal pollen is predominant in almost all pollen assemblages; Pinus and Betula are the main pollen types in quantities and they are found in all vegetation zones of Changbai Mountain. The highest pollen proportion of Pinus occurs in the mixed conifer and broadleaved forest where Pinus koraiensis is the main component; Betula pollen is found in high percentage in both subalpine B. ermanii forest and broadleaved deciduous forest predominated by Betula and Quercus; in the former Betula pollen is accompanied by cold-tolerant shrub such as Rhododendron; whereas in the latter it appears a large amount of fern spores. Pollen assemblage of broadleaved deciduous forests is marked by high diversity and proportions of deciduous trees and a large number of fern spores. Subalpine conifer forest is distinguished by high percentage of Picea pollen. Although tree pollen is slightly dominated, very few or absent of fern spores and increasing of herb and small shrub pollen proportions, particularly predominance of Rhododendron in herbaceous pollen and occurrence of tundra indicator type-Dryas pollen distinguish pollen assemblages of alpine tundra.
基金Supported by the National Natural Science Foundation of China(20606018)the National Basic Research Program (also called 973Program)(2007CB707805)the Six Projects Sponsoring Talent Summits of Jiangsu Province~~
文摘[ Objective] The study was to investigate the volatile components of secondary metabolites from M. alpine producing arachidonic acid and explore the changes in its metabolic pathway. [ Method] The air above M. alpine broth was extracted by solid-phase microextraction(SPME) during the post-exponential phase of growth and analyzed by GC-MS. [Result] 13 compounds were identified, 12 of which were sesquiterpenes with C15H24 formula and accounting for 99.62% of the complete compounds. Thujopsene-( 12), α-Guaiene and Aristolene were three most sesquiterpenes accounting for 10.66%, 33.69% and 34.85% of total content respectively. It can be sufficiently certified that sesquiterpene metabolic pathway existing in M. alpine. [ Coclusion] Metabolic flux of sesquiterpene pathway increased to improve its mass accumulation, because one or several key enzyme genes mutation in isoprene or sesquiterpene pathway enhanced their activities during induction of mutation from initial strain.
基金Supported by Natural Science Foundation of Yunnan Province(2016FB030)Young Academic and Technical Talent Program of Yunnan Province(2011CI027)~~
文摘Arachidonic acid (ARA or AA), one of the most important polyunsaturated fatty acids (PUFAs), has various physiological activities and positive effects on human health. ARA production by Mortierella alpina has become a hot topic in recent years, owing to that it is effective, safe and easy to control. How to improve ARA yield and purification efficiency is important to ARA production in M. alpina. Therefore, in this review, we summarized some methods to improve ARA yield: optimization of culture conditions, mycelium aging technologies and metabolic regulation, and the commonly used methods for ARA isolation and purification, to provide a theoretical basis for ARA production by M. alpina fermentation.
基金Project(2018YFB1004202)supported by the National Key Research and Development Program of ChinaProject(61732019)supported by the National Natural Science Foundation of ChinaProject(SKLSDE-2018ZX-06)supported by the State Key Laboratory of Software Development Environment,China
文摘As the popularity of open source projects,the volume of incoming pull requests is too large,which puts heavy burden on integrators who are responsible for accepting or rejecting pull requests.An accepted pull request prediction approach can help integrators by allowing them either to enforce an immediate rejection of code changes or allocate more resources to overcome the deficiency.In this paper,an approach CTCPPre is proposed to predict the accepted pull requests in GitHub.CTCPPre mainly considers code features of modified changes,text features of pull requests’description,contributor features of developers’previous behaviors,and project features of development environment.The effectiveness of CTCPPre on 28 projects containing 221096 pull requests is evaluated.Experimental results show that CTCPPre has good performances by achieving accuracy of 0.82,AUC of 0.76 and F1-score of 0.88 on average.It is compared with the state of art accepted pull request prediction approach RFPredict.On average across 28 projects,CTCPPre outperforms RFPredict by 6.64%,16.06%and 4.79%in terms of accuracy,AUC and F1-score,respectively.
文摘A passive optical network (PON) scheme based on optical code division multiplexing (OCDM) for the downstream traffics is proposed and analyzed in detail. In the PON, the downstream traffics are broadcasted by OCDM technology to guarantee the security, while the upstream traffics pass through the same optical fiber by the common time division multiple access (TDMA) technology to decrease the cost. This schemes are denoted as OCDM/TDMA-PON, which can be applied to an optical access network (OAN) with full services on demand, such as Internet protocol, video on demand, tele-presence and high quality audio. The proposed OCDM/TDMA-PON scheme combines advantages of PON, TDMA, and OCDM technology. Simulation results indicate that the designed scheme improves the OAN performance, and enhances flexibility and scalability of the system.
基金the National Natural Science Foundation of China(No.40701181)the Strategic Leader in Science and Technology Projects(No.XDA05070306)+1 种基金the National Science & Technology Pillar Program in12th Five-year Plan of China(No.2011BAC09B04-02)Main Direction Program of Knowledge Innovation of CAS(No.KSCX2-EW-J-22)
文摘Although the forest floor plays important roles in water-holding and nutrient cycling, there is not enough knowledge of the functional changes of the forest floor resulting from changes in vegetation. To evaluate the effect on the hydrological properties of forest floor by the substitution of plantation species for native coppice, we selected four species substituting plantations and one native coppice (secondary native broad-leaved forest, dominated by Quercus liaotungensis and Corylus heterophylla var. sutchuenensis) (QC) as a comparison forest. The substituting plantations were Cercidiphyllum japonicum (Cj), Pinus tabulaeformis (Pt), Pinus armandi (Pa), Larix kaempferi (Lk). These were established in 1987 with a stocking density of approximately 2500 stem ha -1 . Thickness and the amount of floor in coniferous plantations were significantly higher compared to secondary native broad-leaved forest and pure broad- leaved plantation. The maximal water-holding capacity of the floor showed the same trend as thickness and amount of litter. Main contributors to the difference in hydrological characteristics in the plantations were the quantity of forest floor and the maximal water holding capacity per unit weight of the floor. The relationships between water absorption processes, water absorption rate and the immersion time for litter, fitted to logarithmic and exponential regressions, respectively. Water absorption processes differed significantly between the various plantations and different decomposition floor horizons. Water absorption characteristics were influenced by leaf structure in various tree species and the degree of decomposed litter. Our results showed that litter amount in coniferous plantations were significantly higher than in deciduous broad-leaved plantation. This suggests that a large amount of nutrients are held in the litter horizon, delaying return to the soil and utilization by plants. At the same time, maximal water-holding capacity of the forest floor in F [fermentation] and H [hummus] horizons was significantly higher than that in L [fresh litter] horizon. Therefore, improving litter transformation from L horizon to F and H horizons by promoting forest floor environment would be one of the best methods for plantation management.
文摘Liposomes are used as carriers for targeted drug delivery by the intravenous route. The aim of our study was to prepare lomustine loaded liposomes (CCNU-Lips) and evaluate its physicochemical properties and the tissue targeting after intravenous (i.v.) injection. CCNU-Lips were prepared by film dispersion method. In vitro drug release was investigated in phosphate-buffered saline (pH 6.8) at 37℃. The concentrations of CCNU in selected organs were determined using reversed-phase high-performance liquid chromatography (HPLC) following i.v. administration of CCNU-Lips and inclusion complex solution of CCNU with hydroxypropyl-β-cyclodextrin (CCNU-Sol). CCNU-Lips had an average diameter of (189.8±28.5) nm with a zeta potential of (-19.13±0.12) mV and the in vitro drug release was monitored for up to 3 d, and the release behavior was in accordance with Weibull-equation. The CCNU-Lips exhibited a longer elimination half life (t1/2β) in vivo compared with CCNU-Sol after i.v. injection to New Zealand rabbits. The encapsulation of lomustine in liposomes also changed its biodistribution in mice. CCNU-Lips showed significant brain targeting with AUC, Te and Re of the brain all showing obvious elevation. These results indicated that CCNU-Lips were promising passive targeting formulation to the brain.
基金supported by the 863 Program under Grant No.2012AA041709the National Natural Science Foundation of China under Grant No.61333007
文摘This paper studies the tracking control of general linear multi-agent systems with out time delays. The observer-based event-triggered control schemes will be considered or with- For the conventional distributed tracking protocol, the authors will not update the relative state in continuous time, i.e., the relative state will be updated by some events which happened in discrete time. A completely decentralized event-trigger will be designed for leader-follower systems. It is shown that all followers can track the leader asymptotically by the proposed protocol, if the feedback gain matrices are designed appropriately. Numerical simulations are also provided and the results show highly consistent with the theoretical results.