Measuring the impacts of Bus Rapid Transit on residential property values : The Beijing case

The authors acknowledge the financial support provided by the National Natural Science Foundation of China (Grant No. 41201102).Peer reviewedPostprin

Causal conditional hidden Markov model for multimodal traffic prediction

Multimodal traffic flow can reflect the health of the transportation system, and its prediction is crucial to urban traffic management. Recent works overemphasize spatio-temporal correlations of traffic flow, ignoring the physical concepts that lead to the generation of observations and their causal relationship. Spatio-temporal correlations are considered unstable under the influence of different conditions, and spurious correlations may exist in observations. In this paper, we analyze the physical concepts affecting the generation of multimode traffic flow from the perspective of the observation generation principle and propose a Causal Conditional Hidden Markov Model (CCHMM) to predict multimodal traffic flow. In the latent variables inference stage, a posterior network disentangles the causal representations of the concepts of interest from conditional information and observations, and a causal propagation module mines their causal relationship. In the data generation stage, a prior network samples the causal latent variables from the prior distribution and feeds them into the generator to generate multimodal traffic flow. We use a mutually supervised training method for the prior and posterior to enhance the identifiability of the model. Experiments on real-world datasets show that CCHMM can effectively disentangle causal representations of concepts of interest and identify causality, and accurately predict multimodal traffic flow.Comment: 8 pages, 5 figure

Construction of a Food-grade Expression Vector Based on pyrF Gene in Lactococcus lactis

In this study, the pyrF screening marker and the genomic DNA fragments were used to construct the expression vectors in food-grade Lactococcus lactis (L. lactis). Such expression system could potentially be used to express and produce food-grade and medicinal polypeptides. Firstly, the NZ3900 ΔpyrF auxotrophic strain was created from the homologous recombination mutant cassette. Secondly, the repA and repC genes were used as the replication elements, the pyrF gene as the screening marker, the P32 and P8 elements from L. lactis as the promoters, and the Tusp45 and TpepN from L. lactis as the terminators, all of which were constructed in the expression plasmid pLD. Finally, the reporter gene ZsGreen (a fluorescent protein) was used to verify the expression of recombinant protein in the NZ3900 ΔpyrF mutant strain and the genetic stability of pLD-ZsG plasmid. The result showed that the prototrophic ZsGreen positive transformants could grow normally in common Elliker culture medium, and the green fluorescent signal was observed under a fluorescence microscope. In addition, ZsGreen protein could be highly expressed in NZ3900 ΔpyrF and the expression plasmid could be stably transmitted through at least 30 generations, according to the results of the PCR and Western blotting, indicating that the recombinant protein was expressed in L. lactis in a stable manner. Based on the above results, the approach for creating an L. lactis expression vector (without antibiotic resistance gene) based on the pyrF auxotrophic marker is feasible and offers a basis for further investigation into the use of L. lactis to manufacture food- and pharmaceutical-grade polypeptides

Evaluation of Bus Rapid Transit Implementation in China: Current Performance and Progress

This paper evaluates the physical characteristics, technical performance, and operational issues associated with bus rapid transit (BRT) systems implemented in 13 Chinese cities. BRT systems in China have shown medium performance; the peak ridership averaged 5,874  passengers/h/direction, and the peak hour speed averaged 20.2   km/h. Compared with Latin American BRT systems, Chinese BRT systems operate at a comparable speed but carry much fewer passengers. The empirical analysis of Chinese BRT systems implies that the technical performance of BRT is not significantly related with urban size. This paper gives some evidence that overtaking lanes and shared lanes have significant impacts on peak ridership and frequency, and long station-spacing has a positive impact on peak hour speed. Although BRT has become a viable option of transportation improvement, some notable disadvantages identified in Chinese BRT design and operation should be taken into consideration for improving BRT implementation. Read More: http://ascelibrary.org/doi/abs/10.1061/(ASCE)UP.1943-5444.000015

Spatio-Temporal Neural Structural Causal Models for Bike Flow Prediction

As a representative of public transportation, the fundamental issue of managing bike-sharing systems is bike flow prediction. Recent methods overemphasize the spatio-temporal correlations in the data, ignoring the effects of contextual conditions on the transportation system and the inter-regional time-varying causality. In addition, due to the disturbance of incomplete observations in the data, random contextual conditions lead to spurious correlations between data and features, making the prediction of the model ineffective in special scenarios. To overcome this issue, we propose a Spatio-temporal Neural Structure Causal Model(STNSCM) from the perspective of causality. First, we build a causal graph to describe the traffic prediction, and further analyze the causal relationship between the input data, contextual conditions, spatio-temporal states, and prediction results. Second, we propose to apply the frontdoor criterion to eliminate confounding biases in the feature extraction process. Finally, we propose a counterfactual representation reasoning module to extrapolate the spatio-temporal state under the factual scenario to future counterfactual scenarios to improve the prediction performance. Experiments on real-world datasets demonstrate the superior performance of our model, especially its resistance to fluctuations caused by the external environment. The source code and data will be released

Efficient Tissue Culture Protocol for Magnolia lucida (Magnoliaceae) and Confirmation of Genetic Stability of the Regenerated Plants

Magnolia lucida (Magnoliaceae) is classified as an endangered species by the International Union for Conservation of Nature. It has high commercial value owing to its attractive tree shape and flowers. We adopted an excellent genotype of M. lucida as the parent material and established a mini-cut orchard through grafting to provide trunk shoots explants over the long-term. Optimal sterilization was achieved using a combination of 75% ethanol for 30 s, one percent benzalkonium bromide for five minutes, and 0.1% mercuric chloride for five minutes. Modified Murashige and Skoog medium (ML) was the optimal medium for the growth of M. lucida. Addition of one mg/L of 6-benzyl adenine (BA) and 0.05 mg/L of α-naphthaleneacetic acid (NAA) to the medium increased the shoot induction rate to 95.56%, and the ML medium containing 0.4 mg/L BA and 0.04 mg/L NAA achieved the maximum multiplication rate (284.56%). Dark treatment for seven days, followed by continuous light treatment could better resolve the challenge of difficult rooting in M. lucida plants. Using random amplified polymorphic DNA and inter simple sequence repeat markers, we confirmed the genetic uniformity and stability of the regenerated plants. Our protocol should be helpful for the propagation and conservation of this endangered plant

Adverse trends of cardiovascular risk factors among low risk populations (1983-1994) - a cohort study of workers and farmers in Guangzhou, China

Abstract Background The levels and trends of cardiovascular risk factors vary greatly throughout China. We examine 10-year trends of cardiovascular risk factors (1983-1994) and the factors related to these trends among low-risk cohorts of workers and farmers in Guangzhou, China. Methods This is a cohort study of 3,131 workers and 3,493 farmers aged 25-64 years at baseline with 10 years of follow-up. We performed a longitudinal analysis to account for the aging of the cohorts and the repeated measures of the same individual. Results At baseline the prevalence of overweight (including obese) ranged from 1.0% to 11.8%, hypertension ranged from 3.8% to 10.5%, and mean serum total cholesterol (TC) ranged from 155.4 mg/dl to 187.2 mg/dl. Although prevalence of smoking declined, blood pressure levels and body mass index (BMI) increased significantly, and lipid profiles changed unfavorably during the 10-year follow-ups. The prevalence of hypertension increased from 5.0 percentage points (female farmers) to 12.3 percentage points (male farmers). Mean TC increased significantly (e.g., +22.8 mg/dl and +17.0 mg/dl in male and female farmers, respectively). In the longitudinal data analyses, increase in BMI was associated with increase in blood pressure levels and TC. Significant adverse trends of risk factors persisted after adjustment for aging, education, BMI, smoking, and alcohol intake. Conclusion Urgent action is needed to prevent and reverse the unhealthy trends occurring among these low risk Chinese workers and farmers.</p

Systematic gene therapy derived from an investigative study of AAV2/8 vector gene therapy for Fabry disease

Abstract Background Fabry disease (FD) is a progressive multisystemic disease characterized by a lysosomal enzyme deficiency. A lack of α-galactosidase A (α-Gal A) activity results in the progressive systemic accumulation of its substrates, including globotriaosylceramide (Gb3) and globotriaosylsphingosine (Lyso-Gb3), which results in renal, cardiac, and/or cerebrovascular disease and early death. Enzyme replacement therapy (ERT) is the current standard of care for FD; however, it has important limitations, including a low half-life, limited distribution, and requirement of lifelong biweekly infusions of recombinant enzymes. Methods Herein, we evaluated a gene therapy approach using an episomal adeno-associated viral 2/8 (AAV2/8) vector that encodes the human GLA cDNA driven by a liver-specific expression cassette in a mouse model of FD that lacks α-Gal A activity and progressively accumulates Gb3 and Lyso-Gb3 in plasma and tissues. Results A pharmacology and toxicology study showed that administration of AAV2/8-hGLA vectors (AAV2/8-hGLA) in FD mice without immunosuppression resulted in significantly increased plasma and tissue α-Gal A activity and substantially normalized Gb3 and Lyso-Gb3 content. Conclusions Moreover, the plasma enzymatic activity of α-Gal A continued to be stably expressed for up to 38 weeks and sometimes even longer, indicating that AAV2/8-hGLA is effective in treating FD mice, and that α-Gal A is continuously and highly expressed in the liver, secreted into plasma, and absorbed by various tissues. These findings provide a basis for the clinical development of AAV2/8-hGLA

Development of Lanzyme as the Potential Enzyme Replacement Therapy Drug for Fabry Disease

Fabry disease (FD) is a progressive multisystemic disease characterized by lysosomal enzyme deficiency. Enzyme replacement therapy (ERT) is one of the most significant advancements and breakthroughs in treating FD. However, limited resources and the high cost of ERT might prevent patients from receiving prompt and effective therapy, thereby resulting in severe complications. Future progress in ERT can uncover promising treatment options. In this study, we developed and validated a recombinant enzyme (Lanzyme) based on a CHO-S cell system to provide a new potential option for FD therapy. Our results indicated that Lanzyme was heavily glycosylated, and its highest activity was similar to a commercial enzyme (Fabrazyme®). Our pharmacokinetic assessment revealed that the half-life of Lanzyme was up to 11 min, which is nearly twice that of the commercial enzyme. In vivo experiments revealed that Lanzyme treatment sharply decreased the accumulation levels of Gb3 and lyso-Gb3 in various tissues of FD model mice, with superior or comparable therapeutic effects to Fabrazyme®. Based on these data, Lanzyme may represent a new and promising treatment approach for FD. Building this enzyme production system for ERT can offer additional choice, potentially with enhanced efficacy, for the benefit of patients with FD