A Rate-based TCP Congestion Control Framework for Cellular Data Networks

Ph.DDOCTOR OF PHILOSOPH

Uncovering a Hidden wireless menace: Interference from 802.11x MAC acknowledgment frames

Abstract—Previous work on 802.11x (Wi-Fi) power control have focused almost exclusively on the mitigation of interference from data frames. Since Wi-Fi wireless access points are increas-ingly ubiquitous, it is now common for an 802.11x client to be able to receive signals from more than 10 APs simultaneously in a modern urban operating environment. At such high densities, we found that the interference from the MAC acknowledgment (ACK) frames can potentially reduce throughput by several fold. We show that by dynamically adjusting the transmission power of the ACK frames, a simple ACK power control algorithm, which we call MinPACK, can significantly mitigate interference and increase throughput by a median of 31%, while simultaneously improving fairness. MinPACK is complementary to existing data frames power control algorithms, and adapts rapidly to dynamic environments. I

Treatment received by cancer patients.

<p>Treatment received by cancer patients.</p

Kaplan-Meier estimate of percentage of cardiovascular mortality.

<p>Kaplan-Meier estimate of percentage of cardiovascular mortality.</p

Multi-variate Cox regression model of cardiovascular mortality in patients with and without cancer.

<p>Abbreviations: HR = hazards ratio; CI = confidence interval.</p

Multi-variate Cox regression model of recurrent stroke in patients with and without cancer.

<p>Abbreviations: HR = hazards ratio; CI = confidence interval.</p

Clinical characteristics of ischemic stroke patients with and without cancer.

<p>Clinical characteristics of ischemic stroke patients with and without cancer.</p

Corrigendum to ‘Neurology of COVID-19 in Singapore (vol 418, 117118, 2020)

10.1016/j.jns.2021.117406JOURNAL OF THE NEUROLOGICAL SCIENCES42

Association of Country Income Level With the Characteristics and Outcomes of Critically Ill Patients Hospitalized With Acute Kidney Injury and COVID-19

Introduction: Acute kidney injury (AKI) has been identified as one of the most common and significant problems in hospitalized patients with COVID-19. However, studies examining the relationship between COVID-19 and AKI in low- and low-middle income countries (LLMIC) are lacking. Given that AKI is known to carry a higher mortality rate in these countries, it is important to understand differences in this population. Methods: This prospective, observational study examines the AKI incidence and characteristics of 32,210 patients with COVID-19 from 49 countries across all income levels who were admitted to an intensive care unit during their hospital stay. Results: Among patients with COVID-19 admitted to the intensive care unit, AKI incidence was highest in patients in LLMIC, followed by patients in upper-middle income countries (UMIC) and high-income countries (HIC) (53%, 38%, and 30%, respectively), whereas dialysis rates were lowest among patients with AKI from LLMIC and highest among those from HIC (27% vs. 45%). Patients with AKI in LLMIC had the largest proportion of community-acquired AKI (CA-AKI) and highest rate of in-hospital death (79% vs. 54% in HIC and 66% in UMIC). The association between AKI, being from LLMIC and in-hospital death persisted even after adjusting for disease severity. Conclusions: AKI is a particularly devastating complication of COVID-19 among patients from poorer nations where the gaps in accessibility and quality of healthcare delivery have a major impact on patient outcomes