Evaluating the Performance of Low-cost PM Sensors over Multiple COALESCE Network Sites

Air quality is a global concern, with particulate matter receiving considerable attention due to its impact on human health and climate change. Recent advances in low-cost sensors allow their deployment in large number to measure spatio-temporal and real-time air quality data. Low-cost sensors need careful evaluation with both regulatory approved methods and other data sets to understand their efficacy. In this work, PM concentrations measured by deploying low-cost sensors at four regional sites are evaluated through comparison with satellite-based model MERRA-2 and the SASS reference instrument. Daily PM2.5 mass concentration variation was analyzed at four regional sites of India from January 2020 to July 2020, including pre-lockdown and six different lockdown periods. Higher PM2.5 concentration was observed at Rohtak (119 mu g m-3) compared to Mahabaleshwar (33 mu g m-3), Bhopal (45 mu g m-3) and Kashmir sites during the pre-lock down period. During the lockdown period, the PM2.5 mass concentration was reduced significantly compared to the pre-lockdown period at every location, although the PM2.5 concentration was different at each location. The air quality trend was quite similar in both the measurements, however, MERRA-2 reconstructed PM2.5 was significantly lower in the pre-lockdown period compared to the lockdown periods. Significant differences were observed between low-cost sensor measurements and MERRA-2 reanalysis data. These are attributed to the MERRA-2 modelling analysis that measures less PM2.5 concentration as compared to ground-based measurements, whereas low-cost sensor are and biases.

Lost in Transmission: Investigating Filtering of COVID-19 Websites

After the unprecedented arrival of the COVID-19 pandemic, the Internet has become a crucial source of essential information on the virus. To prevent the spread of misinformation and panic, many authorities have resorted to exercising higher control over Internet resources. Although there is anecdotal evidence that websites containing information about the pandemic are blocked in specific countries, the global extent of these censorship efforts is unknown. In this work, we perform the first global censorship measurement study of websites obtained from search engine queries on COVID-19 information in more than 180 countries. Using two remote censorship measurement techniques, Satellite and Quack, we collect more than 67 million measurements on the DNS and Application layer blocking of 1,291 domains containing COVID-19 information from 49,245 vantage points in 5,081 ASes. Analyzing global patterns, we find that blocking of these COVID-19 websites is relatively low on average, 0.20%-0.34% of websites containing information about the pandemic experience interference. As expected, we see higher blocking in countries known for censorship such as Iran, China, and Kazakhstan. Surprisingly, however, we also find significant blocking of websites containing information about the pandemic in countries generally considered as "free" in the Internet space, such as Switzerland (DNS), Croatia (DNS), and Canada (Application layer). We discover that network filters in these countries flag many websites related to COVID-19 as phishing or malicious and hence restrict access to them. However, our investigation suggests that this categorization may be incorrect most websites do not contain serious security threats causing unnecessary blocking. We advocate for stricter auditing of filtering policies worldwide to help prevent the loss of access to relevant information.

A Phase II Safety and Efficacy Study on Prognosis of Moderate Pneumonia in Coronavirus Disease 2019 Patients With Regular Intravenous Immunoglobulin Therapy.

BACKGROUND: Currently, there is no specific drug for the treatment of coronavirus disease 2019 (COVID-19). Therapeutic benefits of intravenous immunoglobulin (IVIG) have been demonstrated in wide range of diseases. The present study is conducted to evaluate the safety and efficacy of IVIG in the treatment of COVID-19 patients with moderate pneumonia. METHODS: An open-label, multicenter, comparative, randomized study was conducted on COVID-19 patients with moderate pneumonia. One hundred eligible patients were randomized in 1:1 ratio either to receive IVIG + standard of care (SOC) or SOC. RESULTS: Duration of hospital stay was significantly shorter in the IVIG group compared with that of SOC alone (7.7 vs 17.5 days). Duration for normalization of body temperature, oxygen saturation, and mechanical ventilation were significantly shorter in IVIG compared with SOC. Percentages of patients on mechanical ventilation in 2 groups were not significantly different (24% vs 38%). Median time to reverse-transcription polymerase chain reaction negativity was significantly shorter with IVIG than SOC (7 vs 18 days). There were only mild to moderate adverse events in both groups except for 1 patient (2%), who died in SOC. CONCLUSIONS: Intravenous immunoglobulin was safe and efficacious as an adjuvant with other antiviral drugs in the treatment of COVID-19.