A leader election algorithm for dynamic networks with causal clocks

An algorithm for electing a leader in an asynchronous network with dynamically changing communication topology is presented. The algorithm ensures that, no matter what pattern of topology changes occurs, if topology changes cease, then eventually every connected component contains a unique leader. The algorithm combines ideas from the Temporally Ordered Routing Algorithm for mobile ad hoc networks (Park and Corson in Proceedings of the 16th IEEE Conference on Computer Communications (INFOCOM), pp. 1405–1413 (1997) with a wave algorithm (Tel in Introduction to distributed algorithms, 2nd edn. Cambridge University Press, Cambridge, MA, 2000), all within the framework of a height-based mechanism for reversing the logical direction of communication topology links (Gafni and Bertsekas in IEEE Trans Commun C–29(1), 11–18 1981). Moreover, a generic representation of time is used, which can be implemented using totally-ordered values that preserve the causality of events, such as logical clocks and perfect clocks. A correctness proof for the algorithm is provided, and it is ensured that in certain well-behaved situations, a new leader is not elected unnecessarily, that is, the algorithm satisfies a stability condition.National Science Foundation (U.S.) (0500265)Texas Higher Education Coordinating Board (ARP-00512-0007-2006)Texas Higher Education Coordinating Board (ARP 000512-0130-2007)National Science Foundation (U.S.) (IIS-0712911)National Science Foundation (U.S.) (CNS-0540631)National Science Foundation (U.S.) (Research Experience for Undergraduates (Program) (0649233)

2015 Building a Grad Nation Report: Progress and Challenge in Ending the High School Dropout Epidemic

This sixth annual report to the nation highlights the significant progress that has been made, but also the serious challenges that remain – closing gaping graduation gaps between various student populations; tackling the challenge in key states and school districts; and keeping the nation's focus on ensuring that all students – whom Robert Putnam calls "our kids" – have an equal chance at the American Drea

Evaluation of a large-scale health department naloxone distribution program: Per capita naloxone distribution and overdose morality

OBJECTIVES: To report per-capita distribution of take-home naloxone to lay bystanders and evaluate changes in opioid overdose mortality in the county over time. METHODS: Hamilton County Public Health in southwestern Ohio led the program from Oct 2017-Dec 2019. Analyses included all cartons distributed within Hamilton County or in surrounding counties to people who reported a home address within Hamilton County. Per capita distribution was estimated using publicly available census data. Opioid overdose mortality was compared between the period before (Oct 2015-Sep 2017) and during (Oct 2017-Sep 2019) the program. RESULTS: A total of 10,416 cartons were included for analyses, with a total per capita distribution of 1,275 cartons per 100,000 county residents (average annual rate of 588/100,000). Median monthly opioid overdose mortality in the two years before (28 persons, 95% CI 25-31) and during (26, 95% CI 23-28) the program did not differ significantly. CONCLUSIONS: Massive and rapid naloxone distribution to lay bystanders is feasible. Even large-scale take-home naloxone distribution may not substantially reduce opioid overdose mortality rates

Orally active antischistosomal early leads identified from the open access malaria box.

BACKGROUND: Worldwide hundreds of millions of schistosomiasis patients rely on treatment with a single drug, praziquantel. Therapeutic limitations and the threat of praziquantel resistance underline the need to discover and develop next generation drugs. METHODOLOGY: We studied the antischistosomal properties of the Medicines for Malaria Venture (MMV) malaria box containing 200 diverse drug-like and 200 probe-like compounds with confirmed in vitro activity against Plasmodium falciparum. Compounds were tested against schistosomula and adult Schistosoma mansoni in vitro. Based on in vitro performance, available pharmacokinetic profiles and toxicity data, selected compounds were investigated in vivo. PRINCIPAL FINDINGS: Promising antischistosomal activity (IC50: 1.4-9.5 µM) was observed for 34 compounds against schistosomula. Three compounds presented IC50 values between 0.8 and 1.3 µM against adult S. mansoni. Two promising early leads were identified, namely a N,N'-diarylurea and a 2,3-dianilinoquinoxaline. Treatment of S. mansoni infected mice with a single oral 400 mg/kg dose of these drugs resulted in significant worm burden reductions of 52.5% and 40.8%, respectively. CONCLUSIONS/SIGNIFICANCE: The two candidates identified by investigating the MMV malaria box are characterized by good pharmacokinetic profiles, low cytotoxic potential and easy chemistry and therefore offer an excellent starting point for antischistosomal drug discovery and development

Blood donation screening for hepatitis B virus core antibodies: The importance of confirmatory testing and initial implication for rare blood donor groups

Background and Objectives: Exclusion of blood donors with hepatitis B virus (HBV) core antibodies (anti‐HBc) prevents transfusion‐transmitted HBV infection but can lead to significant donor loss. As isolated anti‐HBc positivity does not always indicate true past HBV infection, we have investigated the effectiveness of confirmatory anti‐HBc testing and the representation of rare blood groups in anti‐HBc‐positive donors. Materials and Methods: Three hundred ninety‐seven HBV surface antigen‐negative and anti‐HBc initially reactive blood donor samples were tested by five different anti‐HBc assays. Results: Eighty percentage of samples reactive in Architect anti‐HBc assay were positive by the Murex assay and anti‐HBc neutralization. Eleven out of 397 samples showed discordant results in supplementary testing from the Murex confirmatory test result, and five remained undetermined following extensive serological testing. Thirty‐eight percentage of anti‐HBc‐positive donors identified as minority ethnic groups compared with 11% representation in anti‐HBc‐negative donors (p < 0.0001); the frequency of the Ro blood group in anti‐HBc‐positive donors was 18 times higher in non‐white ethnic groups. Conclusion: Using two anti‐HBc assays effectively enabled the identification of HBV‐exposed and potentially infectious donors, their deferral and potential clinical follow‐up. However, the exclusion of confirmed anti‐HBc‐positive donors will still impact the supply of rare blood such as Ro

The global oscillation network group site survey. II. Results

The Global Oscillation Network Group (GONG) Project will place a network of instruments around the world to observe solar oscillations as continuously as possible for three years. The Project has now chosen the six network sites based on analysis of survey data from fifteen sites around the world. The chosen sites are: Big Bear Solar Observatory, California; Mauna Loa Solar Observatory, Hawaii; Learmonth Solar Observatory, Australia; Udaipur Solar Observatory, India; Observatorio del Teide, Tenerife; and Cerro Tololo Interamerican Observatory, Chile. Total solar intensity at each site yields information on local cloud cover, extinction coefficient, and transparency fluctuations. In addition, the performance of 192 reasonable components analysis. An accompanying paper describes the analysis methods in detail; here we present the results of both the network and individual site analyses. The selected network has a duty cycle of 93.3%, in good agreement with numerical simulations. The power spectrum of the network observing window shows a first diurnal sidelobe height of 3 × 10⁻⁴ with respect to the central component, an improvement of a factor of 1300 over a single site. The background level of the network spectrum is lower by a factor of 50 compared to a single-site spectrum

FLow and Benthic ECology 4D – FLOWBEC – an overview

This work is funded by NERC/DEFRA (grants NE/J004332/1, NE/J004308/1, NE/J004200/1, NE/J004359/1, NE/J004316/1, NE/J004219/1, NE/J00426X/1, NE/J004294/1). We also like to acknowledge OpenHydro Ltd and Atlantis Resources Ltd for allowing the placement of the FLOWBEC frame in close proximity to their installations at EMEC, and Marine Scotland Science for their support developing and deploying the FLOWBEC frame.Publisher PD

Blood donation screening for hepatitis B virus core antibodies: The importance of confirmatory testing and initial implication for rare blood donor groups

Background and ObjectivesExclusion of blood donors with hepatitis B virus (HBV) core antibodies (anti-HBc) prevents transfusion-transmitted HBV infection but can lead to significant donor loss. As isolated anti-HBc positivity does not always indicate true past HBV infection, we have investigated the effectiveness of confirmatory anti-HBc testing and the representation of rare blood groups in anti-HBc-positive donors.Materials and MethodsThree hundred ninety-seven HBV surface antigen-negative and anti-HBc initially reactive blood donor samples were tested by five different anti-HBc assays.ResultsEighty percentage of samples reactive in Architect anti-HBc assay were positive by the Murex assay and anti-HBc neutralization. Eleven out of 397 samples showed discordant results in supplementary testing from the Murex confirmatory test result, and five remained undetermined following extensive serological testing. Thirty-eight percentage of anti-HBc-positive donors identified as minority ethnic groups compared with 11% representation in anti-HBc-negative donors (p < 0.0001); the frequency of the Ro blood group in anti-HBc-positive donors was 18 times higher in non-white ethnic groups.ConclusionUsing two anti-HBc assays effectively enabled the identification of HBV-exposed and potentially infectious donors, their deferral and potential clinical follow-up. However, the exclusion of confirmed anti-HBc-positive donors will still impact the supply of rare blood such as Ro

Quantification of joint mobility limitation in adult type 1 diabetes

AimsDiabetic cheiroarthropathies limit hand mobility due to fibrosis and could be markers of a global profibrotic trajectory. Heterogeneity in definitions and lack of a method to measure it complicate studying associations with organ involvement and treatment outcomes. We measured metacarpophalangeal (MCP) joint extension as a metric and describe magnetic resonance (MR) imaging determinants of MCP restriction.MethodsAdults with type 1 diabetes were screened for hand manifestations using a symptom questionnaire, clinical examination, and function [Duruoz hand index (DHI) and grip strength]. Patients were segregated by mean MCP extension (&lt;20°, 20°–40°, 40°–60°, and &gt;60°) for MR imaging (MRI) scanning. Patients in the four groups were compared using ANOVA for clinical features and MRI tissue measurements (tenosynovial, skin, and fascia thickness). We performed multiple linear regression for determinants of MCP extension.ResultsOf the 237 patients (90 men), 79 (33.8%) with cheiroarthropathy had MCP extension limitation (39° versus 61°, p &lt; 0.01). Groups with limited MCP extension had higher DHI (1.9 vs. 0.2) but few (7%) had pain. Height, systolic blood pressure, and nephropathy were associated with mean MCP extension. Hand MRI (n = 61) showed flexor tenosynovitis in four patients and median neuritis in one patient. Groups with MCP mobility restriction had the thickest palmar skin; tendon thickness or median nerve area did not differ. Only mean palmar skin thickness was associated with MCP extension angle on multiple linear regression.ConclusionJoint mobility limitation was quantified by restricted mean MCP extension and had structural correlates on MRI. These can serve as quantitative measures for future associative and interventional studies