The Weakest Failure Detector to Solve Mutual Exclusion

Mutual exclusion is not solvable in an asynchronous message-passing system where processes are subject to crash failures. Delporte-Gallet et. al. determined the weakest failure detector to solve this problem when a majority of processes are correct. Here we identify the weakest failure detector to solve mutual exclusion in any environment, i.e., regardless of the number of faulty processes. We also show a relation between mutual exclusion and consensus, arguably the two most fundamental problems in distributed computing. Specifically, we show that a failure detector that solves mutual exclusion is sufficient to solve non-uniform consensus but not necessarily uniform consensus

Spontaneous resolution of urinary calculi in a congenital solitary kidney: A case report

Spontaneous resolution of a large renal stone burden in adults is a rare occurrence with few reports in the last 50 years. Improved imaging techniques and understanding of the pharmacology of dissolution therapy have led to a better understanding of which stones have the potential for spontaneous passage or targeted dissolution via medical treatment. Less is known regarding stone outcomes in children, and anecdotes of pediatric patients spontaneously passing large stones has been widely propagated. Here we report a case of spontaneous resolution of a large renal stone burden in a child with a congenital solitary kidney

Web Archiving Democracy

Mary Haberle is a Web Archivist at Archive-It, which is the Internet Archive’s subscription web archiving service. She's part of a support team that provides training and direct support services to our partners, including the archivists on this panel who are all using Archive-It at their institutions. Dory Bower has been an Archives Specialist at the U.S. Government Publishing Office since 2010, where she has worked on a number of projects to increase access to electronic U.S. government resources. Dory began working with web archiving in 2011 and has played a key role in all aspects of the Federal Depository Library Program Web Archive. Megan Craynon has worked at the Maryland State Archives since 2011, and has spent the majority of that time as a team member on the web archiving project. She currently serves as the Deputy Director of Special Collections. Ben Goldman is the Kalin Librarian for Technological Innovations at Penn State University Libraries, where he has overseen web archiving efforts since 2012. Roger Christman is the Governors’ Records Archivist at the Library of Virginia. In his spare time, he also manages the Library’s web archiving program. Nicholas Worby is the Government Information and Statistics Librarian as well as the Web Archives Program Coordinator at the University of Toronto. Ian Milligan is an associate professor of digital and Canadian history at the University of Waterloo. He’s leading a Mellon-funded project to develop a cloud-based infrastructure for the analysis of web archives.As repositories of primary source materials, archives play a central role in supporting the democratic principles of transparency and accountability. Political discourse and many official records of government have shifted from analog to web-based delivery. Web archiving programs that collect content created by elected officials and governments are vital to a robust civil society, which is central to a healthy democracy. This panel brings together information professionals and a digital historian engaged with related content. Professionals actively acquiring websites of elected officials and online government publications will discuss why and how their institutions are building web archives in these areas and what gaps, if any, exist. Panelists will offer their perspectives on the current state of researcher access and how archives can better support researcher engagement with web archives. Questions of professional and institutional responsibility as citizens and as employees of democratic institutions will be explored

Revenue Maximization in Online Dial-a-ride

We study a variation of the Online-Dial-a-Ride Problem where each request comes with not only a source, destination and release time, but also has an associated revenue. The server’s goal is to maximize its total revenue within a given time limit, T. We show that the competitive ratio is unbounded for any deterministic online algorithm for the problem. We then provide a 3-competitive algorithm for the problem in a uniform metric space and a 6-competitive algorithm for the general case of weighted graphs (under reasonable assumptions about the input instance). We conclude with an experimental evaluation of our algorithm in simulated settings inspired by real-world Dial-a-Ride data. Experimental results show that our algorithm performs well when compared to an offline version of the algorithm and a greedy algorithm

Modelling dry season deciduousness in Mexican Yucatán forest using MODIS EVI data (2000-2011)

This study maps interannual variation in the spatial extent of deciduousness in the dry tropical forests of the southern Yucatán (Mexico) from 2000 to 2011 using seasonal variability thresholds based on Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) data and relates deciduousness to precipitation-and temperature-derived climate variables using linear regressions. The annual occurrence of deciduousness is most frequently observed in forests located in a regional rain shadow at moderate elevations. Regression results suggest that deciduousness is more strongly associated with atypically hot conditions (-2°C; R 2 = 0.44) than with atypically dry conditions (R 2 = 0.19), in contrast to other phenological processes (e.g. leaf growth, peak productivity) driven primarily by precipitation. © 2013 Taylor and Francis Group, LLC

Recent HbA1c values and mortality risk in type 2 diabetes. population-based case-control study.

This study aimed to evaluate mortality within 365 days of HbA1c values of 9.0% in participants with clinical type 2 diabetes mellitus. A matched nested case-control study was implemented, within a cohort of participants with type 2 diabetes from 2000 to 2008. Conditional logistic regression was used to model the odds ratio for mortality adjusting for comorbidity and drug utilisation. There were 97,450 participants with type 2 diabetes; 16,585 cases that died during follow up were matched to 16,585 controls. The most recent HbA1c value was 9.0% for 9.0% of cases and 7.7% of controls. In a complete case analysis, the adjusted odds ratio (AOR) for mortality associated with most recent HbA1c 9.0% of 1.51 (CI: 1.33, 1.70), in the multiple imputation analysis this was 1.29 (1.17,1.41). The risk associated with HbA1c 9.0% may be associated with increased mortality within one year in clinical type 2 diabetes. Relative risks may be higher at younger ages