83 research outputs found
An Ant Colony-based Heuristic Algorithm for Joint Scheduling of Post-earthquake Road Repair and Relief Distribution
Emergency road repair and distribution of relief goods are crucial for post-earthquake response. However, interrelationships between those two tasks are not adequately considered in their work schedules, especially in cases with very limited repair resources, leading to unnecessary delay and expenditure. A time-space network model is constructed to better describe the constraints arising from the interrelationships in joint scheduling of road repair and relief distribution works. An ant colony-based heuristic algorithm is developed to solve the NP-hard model efficiently for practical use, followed by a case study of Wenchuan earthquake to validate the planning tool and to demonstrate its feasibility for resolving real world problem
Market reactions to changes in the Nasdaq-100 Index membership
We examine stock market reactions around the Nasdaq-100 Index reconstitutions. We find a symmetric and transitory price response accompanied by a significant increase in trading volume on the effective date. Firms added to the Nasdaq-100 Index experience significant increases in institutional ownership, the number of market makers, and the number of shareholders. In contrast, firms removed from the index show significant decreases in the number of institutional shareholders. Additions to the Nasdaq-100 Index also show significant increases in four liquidity measures, whereas deletions demonstrate significant decreases in two liquidity measures. These changes in liquidity are related to the abnormal return on the announcement day. Taken together, the results suggest support for the price pressure, liquidity, and investor awareness hypotheses
Observation of non-contact Casimir friction
Quantum mechanics predicts the occurrence of random electromagnetic field
fluctuations, or virtual photons, in vacuum. The exchange of virtual photons
between two bodies in relative motion could lead to non-contact quantum vacuum
friction or Casimir friction. Despite its theoretical significance, the
non-contact Casimir frictional force has not been observed and its theoretical
predictions have varied widely. In this work, we report the first measurement
of the non-contact Casimir frictional force between two moving bodies. By
employing two mechanical oscillators with resonant frequencies far lower than
those in Lorentz models of electrons in dielectric materials, we have amplified
the Casimir frictional force at low relative velocities by several orders of
magnitude. We directly measure the non-contact Casimir frictional force between
the two oscillators and show its linear dependence on velocity, proving the
dissipative nature of Casimir friction. This advancement marks a pivotal
contribution to the field of dissipative quantum electrodynamics and enhances
our understanding of friction at the nanoscale
Effects of Polymorphisms in the SjSP-13 Gene of Schistosoma japonicum on Its Diagnostic Efficacy and Immunogenicity
Schistosomiasis japonica is one of the most prevalent parasitic diseases in China. The scarcity of effective diagnostic tools is a major factor that contributes to the high prevalence of schistosomiasis japonica. SjSP-13 is a promising serological diagnostic biomarker of the disease. However, it is unclear whether polymorphisms in SjSP-13 affect its diagnostic efficacy and immunogenicity. Here, we found the SjSP-13 gene was highly polymorphic, and all the alleles of the gene were clustered into two clades, clade A and B. SjSP-13.6 and SjSP-13.25, the representative alleles of clade A and B, were produced in Escherichia coli. The diagnostic value of SjSP-13.6 (AUC = 0.983 ± 0.006), was found to be similar to the SjSP-13.25 (AUC = 0.973 ± 0.009) by receiver operating characteristic (ROC) analysis. SjSP-13.6 and SjSP-13.25 have the same specificity (96.7%), while the sensitivity of SjSP-13.6 (90.4%) is slightly but not significantly higher than SjSP-13.25 (85.2%). The combination use of the two alleles (SjSP-13.6/25) didn’t increase the diagnostic performance of SjSP-13 as the AUC value of SjSP-13.6/25 is 0.977 ± 0.009, lower than individual SjSP-13.6 (AUC = 0.983 ± 0.006). In addition, we found the immunogenicity of clade A alleles is significantly higher than clade B in Schistosoma japonicum naturally infected animals and patients, as the mean antibody levels of SjSP-13.6 was significantly higher than SjSP-13.25. We conclude that polymorphisms of the SjSP-13 gene should not affect its diagnostic efficacy, and it is not necessary to combine the alleles of the two clades for diagnosis of schistosomiasis
Self-crosslinkable chitosan-hyaluronic acid dialdehyde nanoparticles for CD44-targeted siRNA delivery to treat bladder cancer
Bladder cancer is one of the concerning malignancies worldwide, which is lacking effective targeted therapy. Gene therapy is a potential approach for bladder cancer treatment. While, a safe and effective targeted gene delivery system is urgently needed for prompting the bladder cancer treatment in vivo. In this study, we confirmed that the bladder cancer had CD44 overexpression and small interfering RNAs (siRNA) with high interfere to Bcl2 oncogene were designed and screened. Then hyaluronic acid dialdehyde (HAD) was prepared in an ethanol-water mixture and covalently conjugated to the chitosan nanoparticles (CS-HAD NPs) to achieve CD44 targeted siRNA delivery. The in vitro and in vivo evaluations indicated that the siRNA-loaded CS-HAD NPs (siRNA@CS-HAD NPs) were approximately 100 nm in size, with improved stability, high siRNA encapsulation efficiency and low cytotoxicity. CS-HAD NPs could target to CD44 receptor and deliver the therapeutic siRNA into T24 bladder cancer cells through a ligand-receptor-mediated targeting mechanism and had a specific accumulation capacity in vivo to interfere the targeted oncogene Bcl2 in bladder cancer. Overall, a CD44 targeted gene delivery system based on natural macromolecules was developed for effective bladder cancer treatment, which could be more conducive to clinical application due to its simple preparation and high biological safety
Rapid Scheduling of Efficient FPGA Architectures for Next-Generation HSDPA Wireless System Using Precision C Synthesizer
Conference PaperIn this paper, an efficient design flow integrating Mentor Graphics Precesion C and HDL designer is derived. In this hybrid prototyping environment, efficient FPGA architec-tures are scheduled rapidly with specific hardware re-source/timing/architecture constraints from C/C++ level modeling by allocating the usage of functional units and real-time requirements. Using this methodology, a system-on-chip architecture for the next-generation CDMA system, i.e., HSDPA system, is prototyped rapidly. Advanced algo-rithms including chip-level equalizer, turbo codec and clock tracking, frequency offset compensation, are scheduled with Precesion C. A relatively more area/timing efficient RTL architecture is generated automatically and integrated with other design blocks in HDL designer, then implemented efficiently in Xilinx FPGAs. This new design flow demon-strates productivity improvement of 2X for typical wireless communication algorithms and reduces the risk of product development dramatically.NokiaNational Science FoundationNational Science Foundatio
Rapid Scheduling of Efficient VLSI Architectures for Next-Generation HSDPA Wireless System Using Precision C Synthesizer
In this paper, an efficient design flow integrating Mentor Graphics Precesion C and HDL designer is derived. In this hybrid prototyping environment, efficient FPGA architectures are scheduled rapidly with specific hardware resource /timing/architecture constraints from C/C++ level modeling by allocating the usage of functional units and real-time requirements. Using this methodology, a systemon -chip architecture for the next-generation CDMA system, i.e., HSDPA system, is prototyped rapidly. Advanced algorithms including chip-level equalizer, turbo codec and clock tracking, frequency offset compensation, are scheduled with Precesion C. A relatively more area/timing efficient RTL architecture is generated automatically and integrated with other design blocks in HDL designer, then implemented efficiently in Xilinx FPGAs. This new design flow demonstrates productivity improvement of 2X for typical wireless communication algorithms and reduces the risk of product development dramatically
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