Blockchain is a viable solution to provide data integrity for the enormous volume of 5G IoT social data, while we need to break through the throughput bottleneck of blockchain. Sharding is a promising technology to so...Blockchain is a viable solution to provide data integrity for the enormous volume of 5G IoT social data, while we need to break through the throughput bottleneck of blockchain. Sharding is a promising technology to solve the problem of low throughput in blockchains. However, cross-shard communication hinders the effective improvement of blockchain throughput. Therefore, it is critical to reasonably allocate transactions to different shards to improve blockchain throughput. Existing research on blockchain sharding mainly focuses on shards formation, configuration, and consensus, while ignoring the negative impact of cross-shard communication on blockchain throughput. Aiming to maximize the throughput of transaction processing, we study how to allocate blockchain transactions to shards in this paper. We propose an Associated Transaction assignment algorithm based on Closest Fit (ATCF). ATCF classifies associated transactions into transaction groups which are then assigned to different shards in the non-ascending order of transaction group sizes periodically. Within each epoch, ATCF tries to select a shard that can handle all the transactions for each transaction group. If there are multiple such shards, ATCF selects the shard with the remaining processing capacity closest to the number of transactions in the transaction group. When no such shard exists, ATCF chooses the shard with the largest remaining processing capacity for the transaction group. The transaction groups that cannot be completely processed within the current epoch will be allocated in the subsequent epochs. We prove that ATCF is a 2-approximation algorithm for the associated transaction assignment problem. Simulation results show that ATCF can effectively improve the blockchain throughput and reduce the number of cross-shard transactions.展开更多
A series of treaties between Lebanon and Syria on the use of the Orontes (‘Assi) River’s flows emerged in the mid-1990s, being reformed twice to result in a finalized 2002 agreement allocating Lebanon 96 million cub...A series of treaties between Lebanon and Syria on the use of the Orontes (‘Assi) River’s flows emerged in the mid-1990s, being reformed twice to result in a finalized 2002 agreement allocating Lebanon 96 million cubic meters (MCM) out of 403 MCM as measured at the Hermel Bridge gauge. Focusing on the area south of Ar-Rastan, Syria, this article seeks to explore these treaties’ treatment of groundwater, ultimately demonstrating that it is not sufficiently accounted for. This allows for intensive groundwater abstractions—which may be beyond the aquifer’s recharge rate—to be undertaken in Syria. The paper concludes with recommendations to better manage the basin’s groundwater resources, which include improving groundwater data, using these data to calibrate improved hydrologic models, and a renegotiation of the treaty to better account for groundwater use.展开更多
The 1997 United Nations Convention on the Law of the Non-navigational Uses of International Watercourses (UNWC) contains a negotiation framework for transboundary water rights. However, it is a subjective document ope...The 1997 United Nations Convention on the Law of the Non-navigational Uses of International Watercourses (UNWC) contains a negotiation framework for transboundary water rights. However, it is a subjective document open to a wide range of possibilities and interpretations. Water Rights Allocations (WRAs) as described by Dinar and Nigatu (2013) and Dinar and Tsur (2017) provide a limited number of quantifiable allocation possibilities based on the UNWC. It is suggested that this methodology streamlines the negotiation process and reduces the effects of hydro hegemony. These methodologies are explored and applied through a case study on the Orontes River Basin.展开更多
Objective To study the biochemecal and immunological characterization of the 200 kD schistosomulum surface antigen Method and results A very high molecular weight schistosomulum surface antigen of Mr】200kD was identi...Objective To study the biochemecal and immunological characterization of the 200 kD schistosomulum surface antigen Method and results A very high molecular weight schistosomulum surface antigen of Mr】200kD was identified and characterized using monoclonal antibodies. Carbohydrate modification experiments followed by radioimmunobinding assays demonstrated that the epitope recognised by the mAbs on this antigen was carbohydrate in nature, while protein digestion experiments followed by SDS-PAGE indicated that this antigen also contained protein. Immunoprecipitation of <sup>125</sup>I-labelled cercarial, schistosomulum, adult worm and miracidial surface antigens followed by gel analysis showed the carbohydrate epitope to be present on 5 cercarial, 2 schistosomulum and 5 miracidial surface molecules, and suggested a possible ecological function involved in adapting the parasite to the aquatic free-living stages of its life cycle and possibly also in protecting the early schistosomula from host immune damage. The 5 cercarial surfacs antigens proved to be associated with the CHR, since all the mAbs which recognised those antigens could induce a strong CHR. A kinetic investigation of the carbohydrate epitope on schistosomula of different ages demonstrated a gradual and possibly irreversible loss during the culture period. The epitope completely disappeared from the surface of adult worms. Conclusion To demonstrate an epitope common to a number of surface molecules of various developmental stages of schistosome and therefore explains the immunological cross-reactivity among different stages at the molecular level.展开更多
基金supported by Anhui Provincial Key R&D Program of China(202004a05020040),the open project of State Key Laboratory of Complex Electromagnetic Environment Effects on Electronics and Information System in China(CEMEE2018Z0102B)the open fund of Intelligent Interconnected Systems Laboratory of Anhui Province(PA2021AKSK0114),Hefei University of Technology.
文摘Blockchain is a viable solution to provide data integrity for the enormous volume of 5G IoT social data, while we need to break through the throughput bottleneck of blockchain. Sharding is a promising technology to solve the problem of low throughput in blockchains. However, cross-shard communication hinders the effective improvement of blockchain throughput. Therefore, it is critical to reasonably allocate transactions to different shards to improve blockchain throughput. Existing research on blockchain sharding mainly focuses on shards formation, configuration, and consensus, while ignoring the negative impact of cross-shard communication on blockchain throughput. Aiming to maximize the throughput of transaction processing, we study how to allocate blockchain transactions to shards in this paper. We propose an Associated Transaction assignment algorithm based on Closest Fit (ATCF). ATCF classifies associated transactions into transaction groups which are then assigned to different shards in the non-ascending order of transaction group sizes periodically. Within each epoch, ATCF tries to select a shard that can handle all the transactions for each transaction group. If there are multiple such shards, ATCF selects the shard with the remaining processing capacity closest to the number of transactions in the transaction group. When no such shard exists, ATCF chooses the shard with the largest remaining processing capacity for the transaction group. The transaction groups that cannot be completely processed within the current epoch will be allocated in the subsequent epochs. We prove that ATCF is a 2-approximation algorithm for the associated transaction assignment problem. Simulation results show that ATCF can effectively improve the blockchain throughput and reduce the number of cross-shard transactions.
文摘A series of treaties between Lebanon and Syria on the use of the Orontes (‘Assi) River’s flows emerged in the mid-1990s, being reformed twice to result in a finalized 2002 agreement allocating Lebanon 96 million cubic meters (MCM) out of 403 MCM as measured at the Hermel Bridge gauge. Focusing on the area south of Ar-Rastan, Syria, this article seeks to explore these treaties’ treatment of groundwater, ultimately demonstrating that it is not sufficiently accounted for. This allows for intensive groundwater abstractions—which may be beyond the aquifer’s recharge rate—to be undertaken in Syria. The paper concludes with recommendations to better manage the basin’s groundwater resources, which include improving groundwater data, using these data to calibrate improved hydrologic models, and a renegotiation of the treaty to better account for groundwater use.
文摘The 1997 United Nations Convention on the Law of the Non-navigational Uses of International Watercourses (UNWC) contains a negotiation framework for transboundary water rights. However, it is a subjective document open to a wide range of possibilities and interpretations. Water Rights Allocations (WRAs) as described by Dinar and Nigatu (2013) and Dinar and Tsur (2017) provide a limited number of quantifiable allocation possibilities based on the UNWC. It is suggested that this methodology streamlines the negotiation process and reduces the effects of hydro hegemony. These methodologies are explored and applied through a case study on the Orontes River Basin.
文摘Objective To study the biochemecal and immunological characterization of the 200 kD schistosomulum surface antigen Method and results A very high molecular weight schistosomulum surface antigen of Mr】200kD was identified and characterized using monoclonal antibodies. Carbohydrate modification experiments followed by radioimmunobinding assays demonstrated that the epitope recognised by the mAbs on this antigen was carbohydrate in nature, while protein digestion experiments followed by SDS-PAGE indicated that this antigen also contained protein. Immunoprecipitation of <sup>125</sup>I-labelled cercarial, schistosomulum, adult worm and miracidial surface antigens followed by gel analysis showed the carbohydrate epitope to be present on 5 cercarial, 2 schistosomulum and 5 miracidial surface molecules, and suggested a possible ecological function involved in adapting the parasite to the aquatic free-living stages of its life cycle and possibly also in protecting the early schistosomula from host immune damage. The 5 cercarial surfacs antigens proved to be associated with the CHR, since all the mAbs which recognised those antigens could induce a strong CHR. A kinetic investigation of the carbohydrate epitope on schistosomula of different ages demonstrated a gradual and possibly irreversible loss during the culture period. The epitope completely disappeared from the surface of adult worms. Conclusion To demonstrate an epitope common to a number of surface molecules of various developmental stages of schistosome and therefore explains the immunological cross-reactivity among different stages at the molecular level.
