Motivated by traffic congestion and air pollution, Beijing is one of several major cities to restrict vehicle ownership by requiring residents to win a lottery for the right to obtain an additional car. We examine the welfare cost of preventing people from owning cars because of misallocation: under a lottery, some individuals with low willingness to pay (WTP) for cars can obtain cars, while other individuals with high WTP cannot. We estimate welfare costs using a new contingent valuation method survey of Beijing lottery participants which we designed and conducted explicitly for this purpose. We find that restricting vehicle ownership reduced private welfare by 26 billion yuan. Back-of-the-envelope calculations suggest that the benefits of lower congestion and pollution roughly equal the costs. Our WTP estimates indicate a net welfare gain of approximately 32 billion yuan if Beijing’s lottery were replaced with an auction, which is similar to previous estimates.

Hand, foot and mouth disease (HFMD) is a common infection in the world, and its epidemics result in heavy disease burdens. Over the past decade, HFMD has been widespread among children in China, with Shanxi Province being a severely affected northern province. Located in the temperate monsoon climate, Shanxi has a GDP of over 2.5 trillion yuan. It is important to have a comprehensive understanding of the basic features of HFMD in those areas that have similar meteorological and economic backgrounds to northern China. We aimed to investigate epidemiological characteristics, identify spatial clusters and predict monthly incidence of HFMD. All reported HFMD cases were obtained from the Shanxi Center for Disease Control and Prevention. Overall HFMD incidence showed a significant downward trend from 2017 to 2020, increasing again in 2021. Children aged < 5 years were primarily affected, with a high incidence of HFMD in male patients (relative risk: 1.316). The distribution showed a seasonal trend, with major peaks in June and July and secondary peaks in October and November with the exception of 2020. Other enteroviruses were the predominant causative agents of HFMD in most years. Areas with large numbers of HFMD cases were primarily in central Shanxi, and spatial clusters in 2017 and 2018 showed a positive global spatial correlation. Local spatial autocorrelation analysis showed that hot spots and secondary hot spots were concentrated in Jinzhong and Yangquan in 2018. Based on monthly incidence from September 2021 to August 2022, the mean absolute error (MAE), mean absolute percentage error (MAPE), and root mean square error (RMSE) of the long short-term memory (LSTM) and seasonal autoregressive integrated moving average (SARIMA) models were 386.58 vs. 838.25, 2.25 vs. 3.08, and 461.96 vs. 963.13, respectively, indicating that the predictive accuracy of LSTM was better than that of SARIMA. The LSTM model may be useful in predicting monthly incidences of HFMD, which may provide early warnings of HFMD epidemics.

The study was to evaluate the reproducibility and validity of the FFQ for residents of northeast China. A total of 131 participants completed two FFQ (FFQ1 and FFQ2) within a 3-month period, 125 participants completed 8-d weighed diet records (WDR) and 112 participants completed blood biomarker testing. Reproducibility was measured by comparing nutrient and food intake between FFQ1 and FFQ2. The validity of the FFQ was assessed by WDR and the triad method. The Spearman correlation coefficients (SCC) and intraclass correlation coefficients (ICC) for reproducibility ranged from 0·41 to 0·69 (median = 0·53) and from 0·18 to 0·68 (median = 0·53) for energy and nutrients and from 0·37 to 0·73 (median = 0·59) and from 0·33 to 0·86 (median = 0·60) for food groups, respectively. The classifications of same or adjacent quartiles ranged from 73·64 to 93·80 % for both FFQ. The crude SCC between the FFQ and WDR ranged from 0·27 to 0·55 (median = 0·46) for the energy and nutrients and from 0·26 to 0·70 (median = 0·52) for food groups, and classifications of the same or adjacent quartiles ranged from 65·32 to 86·29 %. The triad method indicated that validation coefficients for the FFQ were above 0·3 for most nutrients, which indicated a moderate or high level of validity. The FFQ that was developed for residents of northeast China for the Northeast Cohort Study of China is reliable and valid for assessing the intake of most foods and nutrients.

To investigate the association between the Metabolic Score for Visceral Fat (METS-VF) and risk of type 2 diabetes mellitus (T2DM) and compare the predictive value of the METS-VF for T2DM incidence with other obesity indices in Chinese people. A total of 12 237 non-T2DM participants aged over 18 years from the Rural Chinese Cohort Study of 2007–2008 were included at baseline and followed up during 2013–2014. The cox proportional hazards regression was used to calculate hazard ratios (HR) and 95 % CI for the association between baseline METS-VF and T2DM risk. Restricted cubic splines were used to model the association between METS-VF and T2DM risk. Area under the receiver operating characteristic curve (AUC) analysis was used to evaluate the ability of METS-VF to predict T2DM incidence. During a median follow-up of 6·01 (95 % CI 5·09, 6·06) years, 837 cases developed T2DM. After adjusting for potential confounding factors, the adjusted HR for the highest v. lowest METS-VF quartile was 5·97 (95 % CI 4·28, 8·32), with a per 1-sd increase in METS-VF positively associated with T2DM risk. Positive associations were also found in the sensitivity and subgroup analyses, respectively. A significant nonlinear dose–response association was observed between METS-VF and T2DM risk for all participants (Pnonlinearity = 0·0347). Finally, the AUC value of METS-VF for predicting T2DM was largest among six indices. The METS-VF may be a reliable and applicable predictor of T2DM incidence in Chinese people regardless of sex, age or BMI.

The present study aimed to investigate the association of the Chinese visceral adiposity index (CVAI) and its 6-year change with hypertension risk and compare the ability of CVAI and other obesity indices to predict hypertension based on the Rural Chinese Cohort Study. Study participants were randomly recruited by a cluster sampling procedure, and 10 304 participants ≥18 years were included. Modified Poisson regression was used to derive adjusted relative risks (RR) and 95 % CI. We identified 2072 hypertension cases during a median of 6·03 years of follow-up. The RR for the highest v. lowest CVAI quartile were 1·29 (95 % CI 1·05, 1·59) for men and 1·53 (95 % CI 1·22, 1·91) for women. Per-sd increase in CVAI was associated with hypertension for both men (RR 1·09, 95 % CI 1·02, 1·16) and women (RR 1·14, 95 % CI 1·06, 1·22). Also, the area under the receiver operating characteristic curve value for hypertension was higher for CVAI than the four other obesity indices for both sexes (all P < 0·05). Finally, per-sd increase in CVAI change was associated with hypertension for both men (RR 1·26, 95 % CI 1·16, 1·36) and women (RR 1·23, 95 % CI 1·15, 1·30). Similar results were observed in sensitivity analyses. CVAI and its 6-year change are positively associated with hypertension risk. CVAI has better performance in predicting hypertension than other visceral obesity indices for both sexes. The current findings suggest CVAI as a reliable and applicable predictor of hypertension in rural Chinese adults.

The frequency division multiple access (FDMA) strategy used in GLONASS causes inter-frequency phase bias (IFPB) and inter-frequency code bias (IFCB) between receivers from different manufacturers. The existence of IFPB and IFCB significantly increases the difficulties of fixing GLONASS ambiguity and limits the accuracy and reliability of GLONASS positioning. Moreover, the initial value of IFPB and IFCB may be unavailable or unreliable with the increasing number of receivers from different manufacturers in recent years. In this study, a real-time and reliable calibration algorithm of IFPB and IFCB based on multi-GNSS assistance is proposed by providing a fixed solution. Real-time IFPB rate and IFCB can be obtained using this algorithm without the initial IFPB and IFCB. The IFPB rate for all GLONASS satellites and IFCB for each GLONASS satellite are estimated due to different characteristics of IFPB and IFCB. IFPB calibration can be divided into constant and real-time IFPB calibrations to meet the different positioning requirements. Results show that constant IFPB rate has only 2 mm difference from the mean value of real-time IFPB rate. The IFPB rate and IFCB estimated by this algorithm have excellent stability, and the change in reference satellite cannot affect the results of IFPB rate and the stability of IFCB. The centimetre-level positioning results can be obtained using two calibration methods, and the positioning results with real-time calibration method are 10%–20% better than those with the constant calibration method. Under satellite-deprived environments, the improvements of multi-GNSS positioning accuracy with constant inter-frequency bias calibration gradually increase as the satellite cut-off elevation angle increases compared with GPS/BDS, which can reach up to 0·9 cm in the vertical direction.

The present study was designed to investigate the in vivo biological processes of multivesicular bodies (MVBs) and exosomes in mitochondria-rich cells (MRCs), goblet cells (GCs), and absorptive cells (ACs) in turtle intestines during hibernation. The exosome markers, cluster of differentiation 63 (CD63) and tumor susceptibility gene 101 (TSG101), were positively expressed in intestinal villi during turtle hibernation. The distribution and formation processes of MVBs and exosomes in turtle MRCs, GCs, and ACs were further confirmed by transmission electron microscopy. During hibernation, abundantly secreted early endosomes (ees) were localized in the luminal and basal cytoplasm of the MRCs and ACs, and late endosomes (les) were dispersed with the supranuclear parts of the MRCs and ACs. Many “heterogeneous” MVBs were identified throughout the cytoplasm of the MRCs and ACs. Interestingly, the ees, les, and MVBs were detected in the cytoplasm of the GCs during hibernation; however, they were absent during nonhibernation. Furthermore, the exocytosis pathways of exosomes and autophagic vacuoles were observed in the MRCs, GCs, and ACs during hibernation. In addition, the number of different MVBs with intraluminal vesicles (ILVs) and heterogeneous endosome–MVB–exosome complexes was significantly increased in the MRCs, GCs, and ACs during hibernation. All these findings indicate that intestinal epithelial cells potentially perform a role in the secretion of MVBs and exosomes, which are essential for mucosal immunity, during hibernation.