Scaling law of COVID-19 cases and city size and its evolution over time

Urban scaling law quantifies the disproportional growth of urban indicators with urban population size, which is one of the simple rules behind the complex urban system. Infectious diseases are closely related to social interactions that intensify in large cities, resulting in a faster speed of transmission in large cities. However, how this scaling relationship varies in an evolving pandemic is rarely investigated and remains unclear. Here, taking the COVID- 19 epidemic in the United States as an example, we collected daily added cases and deaths from January 2020 to June 2022 in more than three thousand counties to explore the scaling law of COVID- 19 cases and city size and its evolution over time. Results show that COVID- 19 cases super- linearly scaled with population size, which means cases increased faster than population size from a small city to a large city, resulting in a higher morbidity rate of COVID- 19 in large cities. Temporally, the scaling exponent that reflects the scaling relationship stabilized at around 1.25 after a fast increase from less than one. The scaling exponent gradually decreased until it was close to one. In comparison, deaths caused by the epidemic did not show a super-linear scaling relationship with population size, which revealed that the fatality rate of COVID-19 in large cities was not higher than that in small or medium-sized cities. The scaling exponent of COVID- 19 deaths shared a similar trend with that of COVID- 19 cases but with a lag in time. We further estimated scaling exponents in each wave of the epidemic, respectively, which experienced the common evolution process of first rising, then stabilizing, and then decreasing. We also analyzed the evolution of scaling exponents over time from regional and provincial perspectives. The northeast, where New York State is located, had the highest scaling exponent, and the scaling exponent of COVID- 19 deaths was higher than that of COVID-19 cases, which indicates that large cities in this region were more prominently affected by the epidemic. This study reveals the size effect of infectious diseases based on the urban scaling law, and the evolution process of scaling exponents over time also promotes the understanding of the urban scaling law. The mechanism behind temporal variations of scaling exponents is worthy of further exploration. © 2023 Science Press. All rights reserved.

Upscaling vaccine manufacturing capacity - key bottlenecks and lessons learned.

The COVID-19 pandemic put enormous pressure on the vaccine production chain as billions of vaccines had to be produced in the shortest timeframe possible. Vaccine production chains struggled to keep up with demand, resulting in disruptions and production delays. This study aimed to make an inventory of challenges and opportunities that occurred in the production chain of the COVID-19 vaccine. Insights derived through approximately 80 interviews and roundtable discussions were combined with findings from a scoping literature review. Data were analysed through an inductive process where barriers and opportunities were linked to specific facets of the production chain. Key bottlenecks identified include a lack of manufacturing facilities, a lack of tech-transfer personnel, inefficient arrangement of production stakeholders, critical shortages in raw materials, and restricting protectionist measures. A need for a central governing body to map out shortages and to coordinate allocation of available resource became evident. Other suggested solutions were to repurpose existing facilities and to build in more flexibility in the production process by making materials interchangeable. Also, simplification of the production chain could be achieved through geographical reengagement of processes. Three overarching themes were identified, impacting overall functioning of the vaccine production chain: regulatory and visibility, collaboration and communication, and funding and policy. The results in this study showed a multitude of interdependent processes underlying the vaccine production chain, executed by diverse stakeholders with differing objectives. It characterizes the global complexity of the pharmaceutical production chain and highlights its extreme vulnerability to disruptions. More resilience and robustness must be integrated into the vaccine production chain, and low-middle income countries should be empowered to manufacture vaccines themselves. In conclusion, there's a need to rethink the production system for vaccines and other essential medicines in order to become better prepared for future health crises.

COVID-19 Impact on the Italian Community-based System of Mental Health Care: Reflections and Lessons Learned for the Future

Surface longwave downward radiation (LWDR) is a key factor affecting the surface energy balance. The daily LWDR and the diurnal variations of LWDR are of great significance for studies of climate change and surface processes. How to obtain LWDR at an averaged temporal scale from instantaneous LWDR is one of the longstanding problems in the field of radiation budget from remote sensing. In this paper, two temporal upscaling methods are introduced, namely, a method based on the diurnal variations of LWDR (diurnal variation based, DVB) and a method based on random forest regression (RFR). The results reveal that: (1) The DVB method has a global hourly and daily LWDR root-mean-square error (RMSE) of less than 21 W/m2 and 15 W/m2, respectively, and the RMSE of the daily LWDR based on RFR is less than 7 W/m2;(2) When compared with four existing statistical interpolation methods, the DVB method can not only ensure the accuracy, but also can overcome the problem of missing samples and/or an abnormal samples during upscaling;(3) Except for directly predict daily LWDR, the DVB methods can also obtain more accurate LWDR diurnal variations such as hourly, half-hourly etc. The RFR method enables high-efficiency and accurate estimation of daily averaged LWDR from instantaneous measurements. Compared with existing methods and products, the proposed methods are not only efficient, but also have a superior applicability and reliable accuracy. The proposed strategies provide new ideas for the community in estimating LWDR at continuous temporal scales from remotely sensed measurements.

LAB-ON-PCB TECHNOLOGY FOR HANDHELD, SAMPLE-IN-ANSWER-OUT SARS-CoV-2 DIAGNOSTIC

Since the early reports of SARS-CoV-2 in Wuhan, China in the winter of 2019, the virus spread has resulted in the most socially-crippling pandemic of the last century. Here, we report the development of a rapid, molecular COVID-19 test utilizing for the first time a loop-mediated isothermal amplification (LAMP) assay on Lab-on-Printed Circuit Board (Lab-on-PCB) to exploit the established integration and up-scaling advantages the latter offers. © 2021 MicroTAS 2021 - 25th International Conference on Miniaturized Systems for Chemistry and Life Sciences. All rights reserved.