249 research outputs found

    Vehicle Scheduling Optimization considering the Passenger Waiting Cost

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    In the operational planning process of public transport, the time a passenger spends on waiting is a very critical element for judging passenger service. Schedule synchronization is a useful strategy for reducing bus waiting time and improving service connectivity. This paper develops an extended vehicle scheduling model, taking into account the interests of passengers and operators in attaining optimization of timetable synchronization integrated with vehicle scheduling and considering the passenger waiting cost. Deficit functions at terminals are formulated. Deadheading (DH), shifting departure time (SDT), and network flow technique are used for vehicle scheduling with the consideration of passenger waiting times. An experimental study in Beijing is conducted and three important bus lines are selected as a regional bus network to demonstrate the methodology developed. Results show that both the fleet size of bus operators and the waiting cost of passengers are minimized. For example, the minimum fleet size can be reduced from 28 vehicles to 24 ones while the passenger times are less than 20 minutes in this multidepot network. Document type: Articl

    2,2′,6,6′-Tetra­ethyl-4,4′-methyl­enedibenzonitrile

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    The asymmetric unit of the title compound, C23H26N2, contains one half-mol­ecule, which is completed by the operation of a crystallographic twofold axis. In the mol­ecule, the two benzene rings form a dihedral angle of 77.09 (7)°

    Demethylation of the miR-146a promoter by 5-Aza-2’-deoxycytidine correlates with delayed progression of castration-resistant prostate cancer

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    BACKGROUND: Androgen deprivation therapy is the primary strategy for the treatment of advanced prostate cancer; however, after an initial regression, most patients will inevitably develop a fatal androgen-independent tumor. Therefore, understanding the mechanisms of the transition to androgen independence prostate cancer is critical to identify new ways to treat older patients who are ineligible for conventional chemotherapy. METHODS: The effects of 5-Aza-2’-deoxycytidine (5-Aza-CdR) on the viability and the apoptosis of the androgen-dependent (LNCaP) and androgen-independent (PC3) cell lines were examined by MTS assay and western blot analysis for the activation of caspase-3. The subcutaneous LNCaP xenografts were established in a nude mice model. MiR-146a and DNMTs expressions were analyzed by qRT-PCR and DNA methylation rates of LINE-1 were measured by COBRA-IRS to determine the global DNA methylation levels. The methylation levels of miR-146a promoter region in the different groups were quantified by the bisulfite sequencing PCR (BSP) assay. RESULTS: We validated that 5-Aza-CdR induced cell death and increased miR-146a expression in both LNCaP and PC3 cells. Notably, the expression of miR-146a in LNCaP cells was much higher than in PC3 cells. MiR-146a inhibitor was shown to suppress apoptosis in 5-Aza-CdR-treated cells. In a castrate mouse LNCaP xenograft model, 5-Aza-CdR significantly suppressed the tumors growth and also inhibited prostate cancer progression. Meanwhile, miR-146a expression was significantly enhanced in the tumor xenografts of 5-Aza-CdR-treated mice and the androgen-dependent but not the androgen-independent stage of castrated mice. In particular, the expression of miR-146a was significantly augmented in both stages of the combined treatment (castration and 5-Aza-CdR). Additionally, the methylation percentage of the two CpG sites (−444 bp and −433 bp), which were around the NF-κB binding site at miR-146a promoter, showed the lowest methylation levels among all CpG sites in the combined treatment tumors of both stages. CONCLUSION: Up-regulating miR-146a expression via the hypomethylation of the miR-146a promoter by 5-Aza-CdR was correlated with delayed progression of castration-resistant prostate cancers. Moreover, site-specific DNA methylation may play an important role in miR-146a expression in androgen-dependent prostate cancer progression to androgen-independent prostate cancer and therefore provides a potentially useful biomarker for assessing drug efficacy in prostate cancer

    Modeling and Analysis of Truck Mounted Concrete Pump Boom by Virtual Prototyping

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    By far there is lack of research on different working conditions between rigid and flexible dynamics of truck mounted concrete pump booms. First a 3D model has been established by using virtual prototyping technology of a 37 m long boom in Pro/Engineering software. Then the rigid body simulation model has been built. Next modal superimposition method is adopted to change the 4 rigid body booms into flexible ones. Kinematics law and dynamic characteristics of 4 common working conditions had been studied then. Next tip displacement and the first boom hydraulic cylinder force of the 4 working conditions between rigid and flexible models have been researched. Furthermore the first natural frequencies of the structure have been calculated. The results show that the frequency of the horizontal condition has the lowest of all and the roof condition has the largest of all. Besides the cylinder forces of the flexible model are larger than the corresponding rigid ones because of the flexible boom vibration. Finally an experiment has been done on a boom test rig which proved that the established simulation model is reasonable and the frequency results are correct. All of these provide design reference to mechanical manipulator as well as reducing product development cost of such mechanism

    FLATTEN: optical FLow-guided ATTENtion for consistent text-to-video editing

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    Text-to-video editing aims to edit the visual appearance of a source video conditional on textual prompts. A major challenge in this task is to ensure that all frames in the edited video are visually consistent. Most recent works apply advanced text-to-image diffusion models to this task by inflating 2D spatial attention in the U-Net into spatio-temporal attention. Although temporal context can be added through spatio-temporal attention, it may introduce some irrelevant information for each patch and therefore cause inconsistency in the edited video. In this paper, for the first time, we introduce optical flow into the attention module in the diffusion model's U-Net to address the inconsistency issue for text-to-video editing. Our method, FLATTEN, enforces the patches on the same flow path across different frames to attend to each other in the attention module, thus improving the visual consistency in the edited videos. Additionally, our method is training-free and can be seamlessly integrated into any diffusion-based text-to-video editing methods and improve their visual consistency. Experiment results on existing text-to-video editing benchmarks show that our proposed method achieves the new state-of-the-art performance. In particular, our method excels in maintaining the visual consistency in the edited videos.Comment: Project page: https://flatten-video-editing.github.io

    Hydrogeochemical processes of groundwater system and its mining-motivated effect in mining areas of Western China

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    The exploitation of coal resources will destroy the aquifer structure, disturb the groundwater system and produce a new water cycle model. As the focus of coal supply and production, the western mining area is short of water resources and fragile in ecology. High-intensity and large-scale mining aggravates this disturbance and makes the hydrochemical process such as water-rock interaction more intense. The coal mining-motivated effect of groundwater system hydrochemistry behind it is a key scientific problem related to the prediction accuracy of coal mine safety mining and the protection of groundwater environment in green mining. In view of this, taking the Caojiatan coal mine in western Yushen mining area as an example, using the principles and methods of hydrogeochemistry, from the perspective of ‘what it is’, ‘why it is’ and ‘how it changes’, the results of mining-motivated effect, the process of mining-motivated effect, and the evolution trend of hydrochemistry are systematically studied. The results show that the groundwater in the study area can be divided into five clusters. Cluster Ⅰ represents the shallow groundwater dominated by Quaternary and weathered bedrock aquifers in the west wing of the mine field after coal mining. Cluster Ⅱ represents the mixing of groundwater before and after mining. Cluster Ⅲ represents the groundwater before mining. Cluster Ⅳ and Cluster Ⅴ mainly represent the groundwater of Yan’an Formation after mining. After coal mining, the proportion of HCO3–Ca and HCO3–Mg in the groundwater samples of the fourth and fifth sections of Zhiluo Formation and Yan’an Formation increased, the shallow groundwater quality after mining in the west wing of the mine field was the best as a whole, and the water quality of each aquifer has a tendency to evolve well and is not sensitive to the response of coal mining. The groundwater in the study area is controlled by the ion exchange, and the groundwater in the fourth and above aquifers of Yan’an Formation before coal mining is controlled by the dissolution of carbonate and silicate rocks. The shallow groundwater in the west wing of the mine field after coal mining is controlled by the dissolution of carbonate rocks. The groundwater in the aquifers of the Zhiluo Formation and the fourth and fifth sections of the Yan’an Formation is mainly controlled by the dissolution of silicate rocks and the oxidation of FeS2. The groundwater in the aquifers of the third and lower sections of the Yan’an Formation is mainly controlled by the dissolution of evaporated salt. Coal mining accelerates the circulation speed of groundwater and the hydraulic connection between aquifers. The resulting dilution effect and the discharge measures after mine water treatment are the reasons for the hydrochemical characteristics and water quality evolution of the aquifers in the fourth section of Yan'an Formation and above. In the future, we should continue to do a good job in the discharge of mine water after treatment, and pay attention to the trend of groundwater characteristics in the fifth section of Zhiluo Formation and Yan’an Formation evolving to shallow groundwater, so as to avoid misjudgment of the results of water inrush sources

    Haploinsufficiency of SIRT1 Enhances Glutamine Metabolism and Promotes Cancer Development

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    SIRT1, the most conserved mammalian NAD+-dependent protein deacetylase, plays a vital role in the regulation of metabolism, stress responses, and genome stability. However, the role of SIRT1 in the multi-step process leading to transformation and/or tumorigenesis, as either a tumor suppressor or tumor promoter, is complex and maybe dependent upon the context in which SIRT1 activity is altered, and the role of SIRT1 in tumor metabolism is unknown. Here we demonstrate that SIRT1 dose-dependently regulates cellular glutamine metabolism and apoptosis, which in turn differentially impact cell proliferation and cancer development. Heterozygous deletion of Sirt1 induces c-Myc expression, enhancing glutamine metabolism and subsequent proliferation, autophagy, stress resistance and cancer formation. In contrast, homozygous deletion of Sirt1 triggers cellular apoptotic pathways, increases cell death, diminishes autophagy, and reduces cancer formation. Consistent with the observed dose-dependence in cells, intestine-specific Sirt1 heterozygous mice have enhanced intestinal tumor formation, whereas intestine-specific Sirt1 homozygous knockout mice have reduced development of colon cancer. Furthermore, SIRT1 reduction but not deletion is associated with human colorectal tumors, and colorectal cancer patients with low protein expression of SIRT1 have a poor prognosis. Taken together, our findings indicate that the dose-dependent regulation of tumor metabolism and possibly apoptosis by SIRT1 mechanistically contributes to the observed dual roles of SIRT1 in tumorigenesis. Our study highlights the importance of maintenance of a suitable SIRT1 dosage for metabolic and tissue homeostasis, which will have important implications in SIRT1 small molecule activators/inhibitors based therapeutic strategies for cancers

    Identification and transcriptome analysis of the R2R3-MYB gene family in Haloxylon ammodendron

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    The MYB transcription factor family is widespread in plants and plays an important role in plant growth and development as well as in plant responses to stress. The MYB transcription factor family has been identified in a variety of organisms; however, it has not been identified and analysed in the desert plant Haloxylon ammodendron. In this study, R2R3-MYB genes were identified and analysed using a bioinformatic approach. A total of 78 R2R3-MYB genes were identified and named according to their position on the chromosome. The R2R3-MYB genes were unevenly distributed on nine chromosomes. Phylogenetic analysis showed that the HaMYB genes were all divided into 31 subfamilies. Covariance analysis revealed the presence of three pairs of fragmentary duplicated genes in H. ammodendron (HaMYB54 and HaMYB17, HaMYB44 and HaMYB36, HaMYB42 and HaMYB27). Gene structure and conserved structural domain analysis revealed different subgroups with different orders of magnitude of variation in gene structures and conserved structural domains. Analysis of cis-elements showed that the cis-acting elements of HaMYBs were mainly associated with hormone and abiotic stress responses. Real-time quantitative PCR was used to detect the expression levels of HaR2R3-MYB genes, and six HaR2R3-MYB genes were found to respond to salt stress and six HaR2R3-MYB genes to drought stress, with HaMYB22 and HaMYB27 showing upregulated expression under both stresses. Transcriptome analysis showed that HaMYB63 was significantly differentially expressed in the assimilated branches of H. ammodendron, and the subcellular localization of this protein showed that it was located in the nucleus and had transcriptional self-activating activity. These results provide a theoretical basis for further studies on the functions of the R2R3-MYB gene family and the molecular mechanisms of resistance in H. ammodendron
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