Characterizing and Improving the Reliability of Broadband Internet Access

In this paper, we empirically demonstrate the growing importance of reliability by measuring its effect on user behavior. We present an approach for broadband reliability characterization using data collected by many emerging national initiatives to study broadband and apply it to the data gathered by the Federal Communications Commission's Measuring Broadband America project. Motivated by our findings, we present the design, implementation, and evaluation of a practical approach for improving the reliability of broadband Internet access with multihoming.Comment: 15 pages, 14 figures, 6 table

Inflammasome Sensor Nlrp1b-Dependent Resistance to Anthrax Is Mediated by Caspase-1, IL-1 Signaling and Neutrophil Recruitment

Bacillus anthracis infects hosts as a spore, germinates, and disseminates in its vegetative form. Production of anthrax lethal and edema toxins following bacterial outgrowth results in host death. Macrophages of inbred mouse strains are either sensitive or resistant to lethal toxin depending on whether they express the lethal toxin responsive or non-responsive alleles of the inflammasome sensor Nlrp1b (Nlrp1bS/S or Nlrp1bR/R, respectively). In this study, Nlrp1b was shown to affect mouse susceptibility to infection. Inbred and congenic mice harboring macrophage-sensitizing Nlrp1bS/S alleles (which allow activation of caspase-1 and IL-1β release in response to anthrax lethal toxin challenge) effectively controlled bacterial growth and dissemination when compared to mice having Nlrp1bR/R alleles (which cannot activate caspase-1 in response to toxin). Nlrp1bS-mediated resistance to infection was not dependent on the route of infection and was observed when bacteria were introduced by either subcutaneous or intravenous routes. Resistance did not occur through alterations in spore germination, as vegetative bacteria were also killed in Nlrp1bS/S mice. Resistance to infection required the actions of both caspase-1 and IL-1β as Nlrp1bS/S mice deleted of caspase-1 or the IL-1 receptor, or treated with the Il-1 receptor antagonist anakinra, were sensitized to infection. Comparison of circulating neutrophil levels and IL-1β responses in Nlrp1bS/S,Nlrp1bR/R and IL-1 receptor knockout mice implicated Nlrp1b and IL-1 signaling in control of neutrophil responses to anthrax infection. Neutrophil depletion experiments verified the importance of this cell type in resistance to B. anthracis infection. These data confirm an inverse relationship between murine macrophage sensitivity to lethal toxin and mouse susceptibility to spore infection, and establish roles for Nlrp1bS, caspase-1, and IL-1β in countering anthrax infection

Trying Broadband Characterization at Home

Abstract. In recent years the quantity and diversity of Internet-enabled consumer devices in the home have increased significantly. These trends complicate device usability and home resource management and have implications for crowdsourced approaches to broadband characterization. The UPnP protocol has emerged as an open standard for device and service discovery to simplify device usability and resource management in home networks. In this work, we leverage UPnP to understand the dynamics of home device usage, both at a macro and micro level, and to sketch an effective approach to broadband characterization that runs behind the last meter. Using UPnP measurements collected from over 13K end users, we show that while home networks can be quite complex, the number of devices that actively and regularly connect to the Internet is limited. Furthermore, we find a high correlation between the number of UPnP-enabled devices in home networks and the presence of UPnP-enabled gateways, and show how this can be leveraged for effective broadband characterization.

Crowdsourcing ISP characterization to the network edge

Evaluating and characterizing Internet Service Providers (ISPs) is critical to subscribers shopping for alternative ISPs, companies providing reliable Internet services, and governments surveying the coverage of broadband services to its citizens. Ideally, ISP characterization should be done at scale, continuously, and from end users. While there has been significant progress toward this end, current approaches exhibit apparently unavoidable tradeoffs between coverage, continuous monitoring and capturing userperceived performance. In this paper, we argue that network-intensive applications running on end systems avoid these tradeoffs, thereby offering an ideal platform for ISP characterization. Based on data collected from 500,000 peer-to-peer BitTorrent users across 3,150 networks, togetherwiththereportedresultsfromtheU.K.Ofcom/SamKnows studies, we show the feasibility of this approach to characterize the service that subscribers can expect from a particular ISP. We discussremainingresearchchallengesanddesignrequirementsfor a solution that enables efficient and accurate ISP characterization at an Internet scale

Association Between Surgeon and Anesthesiologist Sex Discordance and Postoperative Outcomes: A Population-based Cohort Study

OBJECTIVE: The aim of this study was to examine the effect of surgeon-anesthesiologist sex discordance on postoperative outcomes. SUMMARY BACKGROUND DATA: Optimal surgical outcomes depend on teamwork, with surgeons and anesthesiologists forming two key components. There are sex and sex-based differences in interpersonal communication and medical practice which may contribute to patients\u27 perioperative outcomes. METHODS: We performed a population-based, retrospective cohort study among adult patients undergoing 1 of 25 common elective or emergent surgical procedures from 2007 to 2019 in Ontario, Canada. We assessed the association between differences in sex between surgeon and anesthesiologists (sex discordance) on the primary endpoint of adverse postoperative outcome, defined as death, readmission, or complication within 30 days following surgery using generalized estimating equations. RESULTS: Among 1,165,711 patients treated by 3006 surgeons and 1477 anesthesiologists, 791,819 patients were treated by sex concordant teams (male surgeon/male anesthesiologist: 747,327 and female surgeon/female anesthesiologist: 44,492), whereas 373,892 were sex discordant (male surgeon/female anesthesiologist: 267,330 and female surgeon/male anesthesiologist: 106,562). Overall, 12.3% of patients experienced \u3e1 adverse postoperative outcomes of whom 1.3% died. Sex discordance between surgeon and anesthesiologist was not associated with a significant increased likelihood of composite adverse postoperative outcomes (adjusted odds ratio 1.00, 95% confidence interval 0.97-1.03). CONCLUSIONS: We did not demonstrate an association between intraoperative surgeon and anesthesiologist sex discordance on adverse postoperative outcomes in a large patient cohort. Patients, clinicians, and administrators may be reassured that physician sex discordance in operating room teams is unlikely to clinically meaningfully affect patient outcomes after surgery