Faithful tissue-specific expression of the human chromosome 21-linked COL6A1 gene in BAC-transgenic mice

We created transgenic mice with a bacterial artificial chromosome (BAC) containing the human COL6A1 gene. In high-copy and low-copy transgenic lines, we found correct temporal and spatial expression of COL6A1 mRNA, paralleling the expression of the murine Col6a1 gene in a panel of nine adult and four fetal organs. The only exception was the fetal lung, in which the transgene was expressed poorly com- pared with the endogenous gene. Expression of COL6A1 mRNA from the transgene was copy number-dependent, and the increased gene dosage correlated with increased production of collagen VI alpha 1 in skin and heart, as indicated by Western blotting and immunohistochemistry. COL6A1 maps to Chromosome 21 and this gene has been a candi- date for contributing to cardiac defects and skin abnormalities in Down syndrome. The low-copy and high-copy COL6A1 transgenics were born and sur- vived in normal Mendelian proportions, without cardiac malformations or altered skin histology. These data indicate that the major promoter and enhancer sequences regulating COL6A1 expression are present in this 167-kb BAC clone. The lack of a strong cardiac or skin phenotype in the COL6A1 BAC-transgenic mice suggests that the increased expression of this gene does not, by itself, account for these phenotypes in Down syndrome

Creation and characterization of BAC-transgenic mice with physiological over-expression of epitope-tagged RCAN1 (DSCR1)

The chromosome 21 gene RCAN1, encoding a modulator of the calcineurin (CaN) phosphatase, is a candidate gene for contributing to cognitive disability in people with Down syndrome (DS; trisomy 21). To develop a physiologically relevant model for studying the biochemistry of RCAN1 and its contribution to DS, we generated bacterial artificial chromosome-transgenic (BAC-Tg) mouse lines containing the human RCAN1 gene with a C-terminal HA-FLAG epitope tag incorporated by recombineering. The BAC-Tg was expressed at levels only moderately higher than the native Rcan1 gene; approximately 1.5-fold in RCAN1BAC-Tg1 and 2-fold in RCAN1BAC-Tg2. Affinity purification of the RCAN1 protein complex from brains of these mice revealed a core complex of RCAN1 with calcineurin (CaN), glycogen synthase kinase 3-beta (Gsk3b), and calmodulin, with sub-stoichiometric components including LOC73419. The BAC- Tg mice are fully viable, but long-term synaptic potentiation (LTP) is impaired in proportion to BAC-Tg dosage in hippocampal brain slices from these mice. RCAN1 can act as a tumor suppressor in some systems, but we found that the RCAN1 BAC-Tg did not reduce mammary cancer growth when present at a low copy number in Tp53;WAP-Cre mice. This work establishes a useful mouse model for investigating the biochemistry and dose-dependent functions of the RCAN1 protein in vivo

Modeling and Parameter Optimization of Flexible NC Polishing Vibration of Abrasive Cloth Wheel Based on Sensitivity Analysis

The blisk is a typical cantilever beam structure, which is prone to vibration during the polishing process. This vibration will cause the polishing tool to wear seriously and reduce the surface quality of the blade.In order to control the vibration of polishing process, a method of predicting the RMS (root mean square) value of polishing vibration signal was proposed. Firstly, an empirical model of process parameters for polishing vibration was established by an orthogonal experiment. Then, based on the response surface and sensitivity analysis method, the stability range of the process parameters and the influence on the polishing vibration are obtained. Finally, through the polishing experiment, it is determined that the stable range of each process parameter is reliable. There is no significant vibration during the polishing process. By analyzing the surface texture and surface topography of the blade, the surface quality of the blade meets the requirements. The results showed that the optimal stability ranges of significant parameters through sensitivity analysis are compression depth within [0.6 mm, 0.9 mm], spindle speed within [6000 r/min, 7500 r/min], feed rate within [0.4 mm/min, 0.6 mm/min], and granularity within [400#, 600#]. This study provides a basis for the theoretical research of polishing vibration in the flexible polishing process and the relationship between process parameters and polishing vibration

Passenger Flow Scale Prediction of Urban Rail Transit Stations Based on Multilayer Perceptron (MLP)

Accurately predicting passenger flow at rail stations is an effective way to reduce operation and maintenance costs, improve the quality of passenger travel while meeting future passenger travel demand. The improvement of data acquisition capability allows fine-grained and large-scale built environment data to be extracted. Therefore, this paper focuses on investigating the relationship between the built environment around the station and the station passenger flow and discusses whether the built environment data can be applied to the station passenger flow prediction. Firstly, the evaluation system of station passenger flow influencing factors is built based on multisource data. The inner relationship between built environment factors and station passenger flow is investigated using the Pearson correlation analysis. Based on this, a multilayer perceptron (MLP)-based passenger flow prediction model was developed to predict the passenger flow at key stations. The study results show that the built environment factors impact station passenger flow, and the MLP prediction model has better prediction accuracy and applicability. The results of the study can be applied to predict the passenger flow scale of rail stations without historical passenger flow data and thus are also applicable to new rail stations

Evolutionary Game Analysis on Sharing Bicycles and Metro Strategies: Impact of Phasing out Subsidies for Bicycle–Metro Integration Model

The rapid development of sharing bicycles has facilitated the last mile of travel and provided new opportunities for the sustainable development of metro transportation. However, there is still insufficient literature on how to promote the bicycle–metro integration mode. This paper designs a bicycle–metro integrated model based on evolutionary game theory and explores the evolutionary mechanism of the sharing of bicycles connection system and metro system under the subsidy phasing out. The conditions for achieving different equilibrium states were discussed based on the replication dynamics equation. In order to prove the evolutionary game analysis, the system dynamics simulation model was used to reveal the effects of the cost factor, subsidy factor, reward, and penalty factors on the equilibrium of the integrated model. Moreover, the values of the influence factors that make the system reach the optimal equilibrium were obtained through sensitivity analysis. The results show that by reasonably adjusting the values of the parameters, sharing bicycles connection systems, metro systems and connection travelers can reach an equilibrium state where they are willing to cooperate. Subsidy phasing-out policies for travelers were key to promoting the equilibrium of the model. The unit price of shared bicycles has a greater impact on users, and the irregular parking ratio changes have a greater impact on the benefits of travelers compared to the benefits of the metro system. In order to promote bicycle–metro integration and enhance the attractiveness of metro transportation, policies designed for participants should be integrated with dynamic evolution