Low-angle dunes in the Changjiang (Yangtze) Estuary: Flow and sediment dynamics under tidal influence

It has long been highlighted that important feedbacks exist between river bed morphology, sediment transport and the turbulent flow field and that these feedbacks change in response to forcing mechanisms. However, our current understanding of bedform dynamics is largely based on studies of steady flow environments and cohesionless bed conditions. Few investigations have been made under rapidly changing flows. Here, we examine flow and sediment dynamics over low-angle dunes in unsteady flows in the Changjiang (Yangtze) Estuary, China. Topography, flow and sediment data were collected over a reach ca 1.8 km long through a semi-diurnal tidal cycle in a moderate tide of flood season. The results show that: (1) roughness length derived from the upper flow changes little with the flow reversing and displays the same value on both the ebb and flood tide. Moreover, the variability of individual bedform features plays an important role in roughness length variation. (2) Shear stress over the crest of low-angle dunes roughly represents the total spatially averaged stress over dunes in this study area, which has significant implications for advancing numerical models. (3) Changes in morphology, flow and sediment dynamics over dunes through time reveal how low-angle dunes evolve within a tidal cycle. (4) The clockwise hysteresis loops between flow dynamics and bedform features (height and aspect ratio) are also observed. The combination of suspended sediment transport and bedload transport on dune transformation and migration attributes to the clockwise hysteresis. The specific sediment composition of the riverbed, in some extent, affects the mechanism of sediment transport related to the exchange between suspended sediment and riverbed, but further investigation is needed to figure out the mechanism behind this for extended series of tides, such as spring/neap tide and tides in flooding and dry season

Measuring Retiming Responses of Passengers to a Prepeak Discount Fare by Tracing Smart Card Data: A Practical Experiment in the Beijing Subway

Understanding passengers’ responses to fare changes is the basis to design reasonable price policies. This work aims to explore retiming responses of travelers changing departure times due to a prepeak discount pricing strategy in the Beijing subway in China, using smart card records from an automatic fare collection (AFC) system. First, a new set of classification indicators is established to segment passengers through a two-step clustering approach. Then, the potentially influenced passengers for the fare policy are identified, and the shifted passengers who changed their departure time are detected by tracing changes in passengers’ expected departure times before and after the policy. Lastly, the fare elasticity of departure time is defined to measure the retiming responses of passengers. Two scenarios are studied of one month (short term) and six months (middle term) after the policy. The retiming elasticity of different passenger groups, retiming elasticity over time, and retiming elasticity functions of shifted time are measured. The results show that there are considerable differences in the retiming elasticities of different passenger groups; low-frequency passengers are more sensitive to discount fares than high-frequency passengers. The retiming elasticity decreases greatly with increasing shifted time, and 30 minutes is almost the maximum acceptable shifted time for passengers. Moreover, the retiming elasticity of passengers in the middle term is approximately twice that in the short term. Applications of fare optimization are also executed, and the results suggest that optimizing the valid time window of the discount fares is a feasible way to improve the congestion relief effect of the policy, while policy makers should be cautious to change fare structures and increase discounts. Document type: Articl

Multiobjective Optimization Model for Profile Design of Hump Distributing Zone

Railway freight trains consist of many cars heading to different destinations. Hump is the special equipment that distributes cars with different destinations to different tracks in a marshalling station. In recent years, with the development of Chinese freight car technology, the axle load has risen from 21 ton to 23 ton and will rise to 27 ton in the future. Many rolling problems appear in the hump distributing zone with the application of 23-ton axle load cars, which will be exacerbated by 27-ton axle load cars. This paper proposes a multiobjective optimization model based on the angle of the hump profile design with minimizing weighted accumulating rolling time (WART) and hump height as optimization goals and uses the improved genetic algorithm NSGA-II to determine a solution. In case study, Pareto solution set is obtained, and the contrast analysis with traditional method is made

Managing Recurrent Congestion of Subway Network in Peak Hours with Station Inflow Control

Station inflow control (SIC) is an important and effective method for reducing recurrent congestion during peak hours in the Beijing, Shanghai, and Guangzhou subway systems. This work proposes a practical and efficient method for establishing a static SIC scheme in normal weekdays for large-scale subway networks. First, a traffic assignment model without capacity constraint is utilized to determine passenger flow distributions on the network. An internal relationship between station inflows and section flows is then constructed. Second, capacity bottlenecks are identified by considering the transport capacity of each section. Then, a feedback-based bottleneck elimination strategy is established to search target control stations and determine their control time and control strength. To validate the effectiveness of the proposed approach, a decision support system coded in the C# programming language was developed, and the Beijing subway was used as a case study. The results indicate that the proposed method and tool are capable of practical applications, and the generated SIC plan has better performance over the existing SIC plan. This study provides a practical and useful method for operation agencies to construct SIC schemes in the subway system

MODEL-BASED UNBALANCE ESTIMATION FOR STEAM TURBINE-GENERATORS

ABSTRACT As demanded for parameter estimation based on the measured signals, a model-based method to estimate the unbalance distribution of steam turbine-generators due to unbalance response was proposed in this paper. The equivalent modal damping ratios for each mode estimated by GA from the measured Bode plots are incorporated into the modal models. A finite number of the modes are used to calculate the influence coefficient matrix. Finally, the equivalent unbalance distribution on the selected correction planes is estimated based on the measured responses. The merit of this approach is that no test run of trial mass is required. The feasibility of this method is demonstrated using a steam turbine-generator. The method presented not only provides a useful means for balancing work, but also can be further developed into an identification and diagnosis tool

Increased wheat price spikes and larger economic inequality with 2°C global warming

Climate change poses complex impacts on the global wheat supply and demand chain. The impacts of climate change on average wheat yields are reasonably well studied, but its effects on yield variability and the associated economic consequences are poorly understood. Here, we show that future global wheat prices will exhibit steeper spikes at 2°C global warming (6.2% increase in the 95th percentile of global consumer price anomalies) despite a 1.7% increase in production given that CO2 fertilization benefits crops. Such economic stresses could be abated by trade liberalization with lower prices. However, on the supply side, trade liberalization has contrasting effects: the profitability of farmers in advanced economies can be maintained or even raised, but this will inevitably cause economic losses and inequalities for farmers in less-developed, wheat-importing countries. Agricultural trade liberalization accompanied by protection policies in developing countries would be beneficial for global food security in the threat of climate change

Additional file 6 of LncRNA FAM83H-AS1 promotes the malignant progression of pancreatic ductal adenocarcinoma by stabilizing FAM83H mRNA to protect β-catenin from degradation

Additional file 6: Table S6. Correlation between FAM83H-AS1 expression and clinicopathological parameters

Additional file 7 of LncRNA FAM83H-AS1 promotes the malignant progression of pancreatic ductal adenocarcinoma by stabilizing FAM83H mRNA to protect β-catenin from degradation

Additional file 7: Supplementary Figure 1. Hierarchical cluster heat map of differentially expressed lncRNAs in PDAC and corresponding normal tissues generated from RNA sequencing data from the TCGA database. Red in the heat map represents upregulation; Green represents downregulation. 817 differentially expressed lncRNAs were screened out in the comparing mode between PDAC and pancreas. Supplementary Figure 2. Hierarchical cluster heat map of differentially expressed lncRNAs in T2N0M0 PDAC and T2N1M0/T2N0M1/T2N1M1 PDAC tissues generated from RNA sequencing data from the TCGA database. Red in the heat map represents upregulation; Green represents downregulation. 275 differentially expressed lncRNAs were screened out in the comparing mode between T2N0M0 and T2N1M0/T2N0M1/T2N1M1. Supplementary Figure 3. Hierarchical cluster heat map of differentially expressed lncRNAs in T3N0M0 PDAC and T3N1M0/T3N0M1/T3N1M1 PDAC tissues generated from RNA sequencing data from the TCGA database. Red in the heat map represents upregulation; Green represents downregulation. 169 differentially expressed lncRNAs were screened out in the comparing mode between T3N0M0 with T3N1M0/T3N0M1/T3N1M1. Supplementary Figure 4. Survival analysis was used to illustrate the relationship between the level of 6 lncRNAs (FAM83H-AS1, LINC00365, LINC00628, LINC00261, AFAP1-AS1, and HNF1A-AS1) and overall survival in TCGA cohort, respectively. Supplementary Figure 5. Migration capacities of 6 lncRNAs were estimated in vitro. (A) Transwell assays were used to determine the migration capabilities of 6 lncRNAs siRNA-transfected PDAC cells, respectively; Scale bar: 100 μm. (B) Wound healing assays were conducted to evaluate the migration abilities of 6 lncRNAs siRNA-transfected PDAC cells, respectively; Scale bar: 100 μm. *P < 0.05, **P < 0.01, ***P < 0.001. Supplementary Figure 6. Effect of knockdown of 6 candidate lncRNAs on the filamentous state of F-actin. SW 1990 cells were treated with lncRNAs siRNA or control siRNA respectively and analyzed by immunofluorescence, which were estimated the bundling and disassembling sates of F-actin. Supplementary Figure 7. Expression of FAM83H-AS1 in serums were tested in the patients with PDAC, benign non-pancreatic disease and benign pancreatic disease from Tongji hospital. Supplementary Figure 8. Survival analysis was used to illustrate the relationship between the level of FAM83H-AS1 and overall survival in high purity TCGA cohort, in which the samples below 60% neoplastic cellularity were excluded. Supplementary Figure 9. CCK-8 assays were used to compare the cell viability between LV-FAM83H-AS1 group and LV-Control group in PANC-1 and SW 1990 cells. ***P < 0.001. Supplementary Figure 10. FAM83H expression in stable FAM83H overexpressed and down-expressed PDAC cells, confirmed by RT-qPCR analysis. *P < 0.05, **P < 0.01, ***P < 0.001. Supplementary Figure 11. FAM83H-AS1 promotes β-catenin nuclear location via FAM83H. Western blot for FAM83H, β-catenin, GAPDH, and Histone-H3 with the protein lysates fractionated according to subcellular localization after overexpressing FAM83H-AS1 and knocking down FAM83H in PANC-1 and SW 1990 cells