31 research outputs found
Online detection and quantification of epidemics
<p>Abstract</p> <p>Background</p> <p>Time series data are increasingly available in health care, especially for the purpose of disease surveillance. The analysis of such data has long used periodic regression models to detect outbreaks and estimate epidemic burdens. However, implementation of the method may be difficult due to lack of statistical expertise. No dedicated tool is available to perform and guide analyses.</p> <p>Results</p> <p>We developed an online computer application allowing analysis of epidemiologic time series. The system is available online at <url>http://www.u707.jussieu.fr/periodic_regression/</url>. The data is assumed to consist of a periodic baseline level and irregularly occurring epidemics. The program allows estimating the periodic baseline level and associated upper forecast limit. The latter defines a threshold for epidemic detection. The burden of an epidemic is defined as the cumulated signal in excess of the baseline estimate. The user is guided through the necessary choices for analysis. We illustrate the usage of the online epidemic analysis tool with two examples: the retrospective detection and quantification of excess pneumonia and influenza (P&I) mortality, and the prospective surveillance of gastrointestinal disease (diarrhoea).</p> <p>Conclusion</p> <p>The online application allows easy detection of special events in an epidemiologic time series and quantification of excess mortality/morbidity as a change from baseline. It should be a valuable tool for field and public health practitioners.</p
Competition for co-operation: Roles and Realities in Russian Foreign Policy
The discursive reconstruction of Eurasia has brought about structural changes, which have strengthened Russia’s position internationally, and fortified its soft power. As such, the Eurasian project reflects Russia’s broader approach to parties including BRICS and the EU. Russia’s political elite routinely promotes specific conceptions of Russia’s international identity and role with different partners as a means to facilitate cooperation. This creates significant geographical and policy overlaps and breeds inconsistency and competition, but nonetheless contributes to Russia’s preferred low-cost, low-commitment version of co-operation. The Eurasian project therefore represents just one (albeit important) example of the Russian leadership’s conversion of ideas about the international arena into political realities. By balancing competing roles and relationships, Russia maintains a ‘multi-vector’ foreign policy that is flexible, unencumbered by restrictive alliances, and oriented towards sovereignty, great power and strength
A coiled-coil domain acts as a molecular ruler to regulate O-antigen chain length in lipopolysaccharide
Long-chain bacterial polysaccharides have important roles in pathogenicity. In Escherichia coli O9a, a model for ABC transporter–dependent polysaccharide assembly, a large extracellular carbohydrate with a narrow size distribution is polymerized from monosaccharides by a complex of two proteins, WbdA (polymerase) and WbdD (terminating protein). Combining crystallography and small-angle X-ray scattering, we found that the C-terminal domain of WbdD contains an extended coiled-coil that physically separates WbdA from the catalytic domain of WbdD. The effects of insertions and deletions in the coiled-coil region were analyzed in vivo, revealing that polymer size is controlled by varying the length of the coiled-coil domain. Thus, the coiled-coil domain of WbdD functions as a molecular ruler that, along with WbdA:WbdD stoichiometry, controls the chain length of a model bacterial polysaccharide