The effect of interurban movements on the spatial distribution of population

Understanding how interurban movements can modify the spatial distribution of the population is important for transport planning but is also a fundamental ingredient for epidemic modeling. We illustrate this on vacation trips for all transportation modes in China during the Lunar New Year and compare the results for 2019 with the ones for 2020 where travel bans were applied for mitigating the spread of a novel coronavirus (COVID-19). We first show that inter-urban travel flows are broadly distributed and display both large temporal and spatial fluctuations, making their modeling very difficult. When flows are larger, they appear to be more dispersed over a larger number of origins and destinations, creating de facto hubs that can spread an epidemic at a large scale. These movements quickly induce (in about a week for this case) a very strong population concentration in a small set of cities. We characterize quantitatively the return to the initial distribution by defining a pendular ratio which allows us to show that this dynamics is in general very slow and even stopped for the 2020 Lunar New Year due to travel restrictions. Travel restrictions obviously limit the spread of the diseases between different cities, but have thus the counter-effect of keeping high concentration in a small set of cities, a priori favoring intra-city spread, unless individual contacts are strongly limited. These results shed some light on the statistics of interurban movements and how they modify the national distribution of populations, a crucial ingredient for devising effective control strategies at a national level. Copyright © 2022 Ye, Hu, Ji and Barthelemy.

[Evaluation of efficiency of different anti-cysticercus antibody test kits for serodiagnosis of cysticercosis].

OBJECTIVE: To evaluate the diagnostic efficiency of four anti-cysticercus IgG, IgG4 or IgM antibody test kits (enzyme-linked immunosorbent assay, ELISA) by different manufacturers, so as to provide insights into the epidemiological investigation and clinical detection of cysticercosis. METHODS: Forty serum samples from cerebral cysticercosis patients, 100 serum samples from healthy volunteers, 30 serum samples from paragonimiasis skrjabini patients, 17 serum samples from cystic echinococcosis and 19 serum samples from subcutaneous or cerebral sparganosis patients were collected and detected using anti-cysticercus IgG, IgG4 or IgM antibody test kits (brand A) and the anti-cysticercus IgG antibody test kit (brand B). The sensitivity, specificity and false negative rate of the four kits for detection of cysticercosis were estimated. RESULTS: The anti-cysticercus IgG, IgG4 or IgM antibody test kits (brand A) showed 95.00% (38/40), 87.50% (35/40), 7.50% (3/40) sensitivities and 98.00% (98/100), 100.00% (100/100) and 100.00% (100/100) for detection of cysticercosis, while the anti-cysticercus IgG antibody test kit (brand B) presented a 75.00% (30/40) sensitivity and 100.00% (100/100) specificity for detection of cysticercosis. The sensitivity for detection of cysticercosis was significantly higher by the anti-cysticercus IgG antibody test kit (brand A) than by the anti-cysticercus IgG antibody test kit (brand B) (χ2 = 6.28, P < 0.05); however, no significant difference was seen in the specificity by two kits (χ2 = 2.01, P > 0.05). The four ELISA kits showed overall false positive rates of 37.88% (25/66), 22.73% (15/66), 62.12% (41/66) and 15.15% (10/66) for detection of paragonimiasis, echinococcosis and sparganosis (χ2 = 37.61, P < 0.05), and the anti-cysticercus IgG antibody test kit (brand A) presented the highest overall false positive rate for detection of paragonimiasis, echinococcosis and sparganosis (χ2 = 7.56, P' < 0.008), while a higher overall false positive rate was seen for detection of paragonimiasis, echinococcosis and sparganosis by the anti-cysticercus IgG antibody test kit (brand A) than by the anti-cysticercus IgG antibody test kit (brand B) (χ2 = 8.75, P' < 0.008). The four ELISA kits showed false positive rates of 40.00% (12/30), 16.67% (5/30), 76.67% (23/30) and 13.33% (4/30) for detection of paragonimiasis (χ2 = 32.88, P < 0.05) and 21.05% (4/19), 26.32% (5/19), 73.68% (14/19) and 15.79% (3/19) for detection of sparganosis (χ2 = 19.97, P < 0.05), and the highest false positive rates were found by the anti-cysticercus IgM antibody test kit (brand A) for detection of paragonimiasis and sparganosis (all P' < 0.008). However, the four ELISA kits showed comparable false positive rates of 52.94% (9/17), 29.41% (5/17), 23.53% (4/17) and 17.65% (3/17) for detection of echinococcosis (χ2 = 8.24, P > 0.05). In addition, the anti-cysticercus IgM anti-body test kit (brand A) showed false positive rates of 76.67% (23/30), 23.53% (4/17) and 73.68% (14/19) for detection of paragonimiasis, echinococcosis and sparganosis (χ2 = 14.537, P < 0.05), with the lowest false positive rate seen for detection of echinococcosis (χ2 = 14.537, P' < 0.014), while no significant differences were seen in the false positive rate for detection of paragonimiasis, echinococcosis and sparganosis by other three ELISA kits (all P > 0.05). CONCLUSIONS: The four anti-cysticercus IgG, IgG4 or IgM antibody test kits exhibit various efficiencies for serodiagnosis of cysticercosis. The anti-cysticercus IgG antibody test kit (brand A) has a high sensitivity for serodiagnosis of cysticercosis; however, it still needs to solve the problems of cross-reaction with other parasitic diseases and stability.

Exploration of remote scientific research training for medical students during the COVID-19 pandemic

BACKGROUND AND AIMS: We aimed to investigate a new team-based remote teaching model (TRTM) among M.D and Ph.D. candidates major in nephrology to improve their scientific research training and reduce stresses during the COVID-19 pandemic. METHOD: From February 1 to April 30 in 2020, we set up TRTM (Fig 1) via online conferencing systems as: (i) Plan-Do-Check-Action cycle every two to three days to promote project progress, (ii) weekly lab meetings for sharing experiences and ideas;and (iii) weekly journal clubs for literature reading and knowledge expansion. We recruited nine students in TRTM training, and another 25 students as control group, who arranged their schedule by themselves during the quarantine. RESULTS: 1. A survey about the remote teaching: 25 mentors and 34 students had received a survey and all believed that teamwork, lab meeting, and short-term academic goals were essential in remote training. Non-scheduled discussion (72.0%,18/ 25) and regular online lab meetings (60.0%,15/25) were the most common traditional methods. About 85.3% of students and 28.0% of the mentors agreed that 'poor selfcontrol' was the main cause of remote-teaching difficulty. 2. The effectiveness of TRTM training: Compared to the control group, students in TRTM had more self-reported benefits from 'mentors' feedback', 'team support', and 'team communication' (All P<0.05), despite no significant differences in learning productivity or daily work progress. Meanwhile, the TRTM group presented with lower 'anxiety related to the COVID-19 pandemic' and lower 'stress-related to scientific research' (Both P<0.05). For TRTM students, the academic ability was also evaluated at the baseline and after three months of practice, by team members (7 teachers and 9 students). They made progress in varied aspects during the pandemic, such as executing planned tasks, self-improvement based on feedback, and teamwork ability (All P<0.001). CONCLUSION: Our team-based remote teaching model helped students gain more supports and growth in academics and reduce psychological pressures caused by isolation.

The price-rent dynamics and linkage of urban housing: evidence from Singapore

Purpose: The aim of this paper is to examine dynamic linkages between price and rent and between property types. Intuition suggests that housing market segments experience different market cycles in response to macroeconomic shocks. However, they may be dynamically interlinked in urban areas because of substitutability. The linkage may even change, if preference weakens for multiple occupancies. A sudden reduction in apartment demand may create repercussions to other housing segments. Past analyses, despite their contributions, are static and do not consider possible linkages between property types. To fill this void, this paper investigates the price-rent dynamics for urban homes by adopting the case of Singapore. Design/methodology/approach: This paper applies a methodology from Phillips et al. (2015) to Singaporean housing (price and rent) data. Phillips et al. (2015) recently proposed a test for an explosive root in time series data and has spurred several empirical applications in the bubble literature. Findings: This paper finds for Singapore that the markets were subjected to explosive growth (where rents grew at a higher rate than prices did) during the Global Financial Crisis. Also, the results suggest that rent drives price and that non-landed housing (offices in central areas) leads to other residential housing (non-residential housing) in both price and rent. Practical implications: Overall, the present findings suggest that rent drives price, while property types are interlinked. Non-landed homes and offices in central areas are the sources of repercussions. Under normal circumstances, rental shocks may be propagated positively from nonlanded housing (central offices) to the other residential (non-residential) property types as the present findings suggest, which enables us to infer that a decrease in non-landed housing (central offices) rent may lead to an increase in rent on other property types because pandemic shocks only shift demand fromone property type to another, unlike typical macroeconomic shocks. Originality/value: Urban homes are faced with uncertainty arising from the COVID-19 outbreak for which city residents have a stronger incentive to exile to suburbs. Urban life may no longer be attractive because of social distancing and work from home policy. This has implications for urban home demands that are closely linked to urban house price and rent. In the present study, the paper set out to investigate the price-rent and property-type dynamics for urban homes in Singapore. © 2021, Emerald Publishing Limited.

Bridging office-based care with the virtual practice care model: Evolving care for CKD patients in the COVID-19 pandemic-and beyond

Background: Since the outbreak of the coronavirus epidemic, the 'virtual' telemedicine has become a critical substitute for patient-provider interactions. However, virtual encounters often face challenges in care for high-risk patients such as chronic kidney disease (CKD) patients. In this study, we explore the patient's satisfaction and practical effects of a newly established telemedicine program in CKD patients' care during the pandemic. Methods: We established an online CKD patient care program, including triage strategy, medical care delivery, and psychological support, based on a smartphone application. A total of 278 CKD patients were invited, at least 3 months before the pandemic or during the pandemic. A pilot survey interrogating medical and psychologicalconditions was conducted. The feedback to the program and the psychological assessment repeated after one month. Results: Totally, 181 patients showed active responses to the program, with 289 person-time medical consultations occurred during the study. The virtual care program provided a rapid triage, with 17% patients provided a timely referral to in-patient medical encounters. Nearly all patients (97.4%) believed the program was helpful. The number of symptoms (OR 1.309, 95%CI 1.113-1.541;P=0.001) and being enrolled during pandemic (OR 3.939, 95% CI 1.174-13.221;P=0.026) were associated with high stress. After the follow-up, the high-stress CKD group at baseline showed a significant decrease in avoidance score (6.9±4.7 vs. 9.8±1.9, P=0.015). Conclusions: During the pandemic, we established an online telemedicine care program for CKD patients that provides a rapid triage function, effective CKD disease management, and essential psychological support.