An Optimal Self-Stabilizing Firing Squad

Consider a fully connected network where up to $t$ processes may crash, and all processes start in an arbitrary memory state. The self-stabilizing firing squad problem consists of eventually guaranteeing simultaneous response to an external input. This is modeled by requiring that the non-crashed processes "fire" simultaneously if some correct process received an external "GO" input, and that they only fire as a response to some process receiving such an input. This paper presents FireAlg, the first self-stabilizing firing squad algorithm. The FireAlg algorithm is optimal in two respects: (a) Once the algorithm is in a safe state, it fires in response to a GO input as fast as any other algorithm does, and (b) Starting from an arbitrary state, it converges to a safe state as fast as any other algorithm does.Comment: Shorter version to appear in SSS0

Adoption and use of social media among public health departments

<p>Abstract</p> <p>Background</p> <p>Effective communication is a critical function within any public health system. Social media has enhanced communication between individuals and organizations and has the potential to augment public health communication. However, there is a lack of reported data on social media adoption within public health settings. The purposes of this study were to assess: 1) the extent to which state public health departments (SHDs) are using social media; 2) which social media applications are used most often; and 3) how often social media is used interactively to engage audiences.</p> <p>Methods</p> <p>This was a non-experimental, cross sectional study of SHD social media sites. Screen capture software Snag-It^®was used to obtain screenshots of SHD social media sites across five applications. These sites were coded for social media presence, interactivity, reach, and topic.</p> <p>Results</p> <p>Sixty percent of SHDs reported using at least one social media application. Of these, 86.7% had a Twitter account, 56% a Facebook account, and 43% a YouTube channel. There was a statistically significant difference between average population density and use of social media (p = .01). On average, SHDs made one post per day on social media sites, and this was primarily to distribute information; there was very little interaction with audiences. SHDs have few followers or friends on their social media sites. The most common topics for posts and tweets related to staying healthy and diseases and conditions. Limitations include the absence of a standard by which social media metrics measure presence, reach, or interactivity; SHDs were only included if they had an institutionally maintained account; and the study was cross sectional.</p> <p>Conclusions</p> <p>Social media use by public health agencies is in the early adoption stage. However, the reach of social media is limited. SHDs are using social media as a channel to distribute information rather than capitalizing on the interactivity available to create conversations and engage with the audience. If public health agencies are to effectively use social media then they must develop a strategic communication plan that incorporates best practices for expanding reach and fostering interactivity and engagement.</p

Prevalence of non Helicobacter pylori species in patients presenting with dyspepsia

<p>Abstract</p> <p>Background</p> <p>Helicobacter species associated with human infection include <it>Helicobacter pylori, Helicobacter heilmannii </it>and <it>Helicobacter felis </it>among others. In this study we determined the prevalence of <it>H. pylori </it>and non-<it>Helicobacter pylori </it>organisms <it>H. felis and H. heilmannii </it>and analyzed the association between coinfection with these organisms and gastric pathology in patients presenting with dyspepsia. Biopsy specimens were obtained from patients with dyspepsia on esophagogastroduodenoscopy (EGD) for rapid urease test, histology and PCR examination for Helicobacter genus specific 16S rDNA, <it>H. pylori </it>phosphoglucosamine mutase (<it>glmM</it>) and urease B (<it>ureB</it>) gene of <it>H. heilmannii </it>and <it>H. felis</it>. Sequencing of PCR products of <it>H. heilmannii </it>and <it>H. felis </it>was done.</p> <p>Results</p> <p>Two hundred-fifty patients with dyspepsia were enrolled in the study. The mean age was 39 ± 12 years with males 162(65%). Twenty-six percent (66 out of 250) were exposed to cats or dogs. PCR for Helicobacter genus specific 16S rDNA was positive in 167/250 (67%), <it>H. pylori glmM </it>in 142/250 (57%), <it>H. heilmannii </it>in 17/250 (6%) and <it>H. felis </it>in 10/250 (4%), respectively. All the <it>H. heilmannii </it>and <it>H. felis </it>PCR positive patients were also positive for <it>H. pylori </it>PCR amplification. The occurrence of coinfection of <it>H. pylori </it>and <it>H. heilmannii </it>was 17(6%) and with <it>H. felis </it>was 10(4%), respectively. Only one out of 66 exposed to pets were positive for <it>H. heilmannii </it>and two for <it>H. felis</it>. Histopathology was carried out in 160(64%) of 250 cases. Chronic active inflammation was observed in 53(56%) (p = 0.001) of the patients with <it>H. pylori </it>infection alone as compared to 3(37%) (p = 0.73) coinfected with <it>H. heilmannii </it>and <it>H. pylori </it>and 3(60%) coinfected with <it>H. felis </it>and <it>H. pylori </it>(p = 0.66). Intestinal metaplasia was observed in 3(3%)(p = 1.0) of the patients with <it>H. pylori </it>infection alone as compared to 2(25%) (p = 0.02) coinfected with <it>H. heilmannii </it>and <it>H. pylori </it>and 1(20%) coinfected with <it>H. felis </it>and <it>H. pylori </it>(p = 0.15).</p> <p>Conclusion</p> <p>The prevalence of <it>H. heilmannii </it>and <it>H. felis </it>was low in our patients with dyspepsia. Exposure to pets did not increase the risk of <it>H. heilmannii </it>or <it>H. felis </it>infection. The coinfection of <it>H. pylori </it>with <it>H. heilmannii </it>was seen associated with intestinal metaplasia, however this need further confirmation.</p

Diagnosing gestational diabetes

The newly proposed criteria for diagnosing gestational diabetes will result in a gestational diabetes prevalence of 17.8%, doubling the numbers of pregnant women currently diagnosed. These new diagnostic criteria are based primarily on the levels of glucose associated with a 1.75-fold increased risk of giving birth to large-for-gestational age infants (LGA) in the Hyperglycemia Adverse Pregnancy Outcome (HAPO) study; they use a single OGTT. Thus, of 23,316 pregnancies, gestational diabetes would be diagnosed in 4,150 women rather than in 2,448 women if a twofold increased risk of LGA were used. It should be recognised that the majority of women with LGA have normal glucose levels during pregnancy by these proposed criteria and that maternal obesity is a stronger predictor of LGA. The expected benefit of a diagnosis of gestational diabetes in these 1,702 additional women would be the prevention of 140 cases of LGA, 21 cases of shoulder dystocia and 16 cases of birth injury. The reproducibility of an OGTT for diagnosing mild hyperglycaemia is poor. Given that (1) glucose is a weak predictor of LGA, (2) treating these extra numbers has a modest outcome benefit and (3) the diagnosis may be based on a single raised OGTT value, further debate should occur before resources are allocated to implementing this change

Cost-effectiveness of external cephalic version for term breech presentation

<p>Abstract</p> <p>Background</p> <p>External cephalic version (ECV) is recommended by the American College of Obstetricians and Gynecologists to convert a breech fetus to vertex position and reduce the need for cesarean delivery. The goal of this study was to determine the incremental cost-effectiveness ratio, from society's perspective, of ECV compared to scheduled cesarean for term breech presentation.</p> <p>Methods</p> <p>A computer-based decision model (TreeAge Pro 2008, Tree Age Software, Inc.) was developed for a hypothetical base case parturient presenting with a term singleton breech fetus with no contraindications for vaginal delivery. The model incorporated actual hospital costs (e.g., $8,023 for cesarean and$5,581 for vaginal delivery), utilities to quantify health-related quality of life, and probabilities based on analysis of published literature of successful ECV trial, spontaneous reversion, mode of delivery, and need for unanticipated emergency cesarean delivery. The primary endpoint was the incremental cost-effectiveness ratio in dollars per quality-adjusted year of life gained. A threshold of $50,000 per quality-adjusted life-years (QALY) was used to determine cost-effectiveness.</p> <p>Results</p> <p>The incremental cost-effectiveness of ECV, assuming a baseline 58$7,900/QALY. If the estimated probability of successful ECV is less than 32%, then ECV costs more to society and has poorer QALYs for the patient. However, as the probability of successful ECV was between 32% and 63%, ECV cost more than cesarean delivery but with greater associated QALY such that the cost-effectiveness ratio was less than $50,000/QALY. If the probability of successful ECV was greater than 63%, the computer modeling indicated that a trial of ECV is less costly and with better QALYs than a scheduled cesarean. The cost-effectiveness of a trial of ECV is most sensitive to its probability of success, and not to the probabilities of a cesarean after ECV, spontaneous reversion to breech, successful second ECV trial, or adverse outcome from emergency cesarean.</p> <p>Conclusions</p> <p>From society's perspective, ECV trial is cost-effective when compared to a scheduled cesarean for breech presentation provided the probability of successful ECV is > 32%. Improved algorithms are needed to more precisely estimate the likelihood that a patient will have a successful ECV.</p

Identifying and prioritizing strategies for comprehensive liver cancer control in Asia

<p>Abstract</p> <p>Background</p> <p>Liver cancer is both common and burdensome in Asia. Effective liver cancer control, however, is hindered by a complex etiology and a lack of coordination across clinical disciplines. We sought to identify strategies for inclusion in a comprehensive liver cancer control for Asia and to compare qualitative and quantitative methods for prioritization.</p> <p>Methods</p> <p>Qualitative interviews (N = 20) with international liver cancer experts were used to identify strategies using Interpretative Phenomenological Analysis and to formulate an initial prioritization through frequency analysis. Conjoint analysis, a quantitative stated-preference method, was then applied among Asian liver cancer experts (N = 20) who completed 12 choice tasks that divided these strategies into two mutually exclusive and exhaustive subsets. Respondents' preferred plan was the primary outcome in a choice model, estimated using ordinary least squares (OLS) and logistic regression. Priorities were then compared using Spearman's Rho.</p> <p>Results</p> <p>Eleven strategies were identified: <it>Access to treatments; Centers of excellence; Clinical education; Measuring social burden; Monitoring of at-risk populations; Multidisciplinary management; National guidelines; Public awareness; Research infrastructure; Risk-assessment and referral</it>; and <it>Transplantation infrastructure</it>. Qualitative frequency analysis indicated that <it>Risk-assessment and referral </it>(85%), <it>National guidelines </it>(80%) and <it>Monitoring of at-risk populations </it>(80%) received the highest priority, while conjoint analysis pointed to <it>Monitoring of at-risk populations </it>(p < 0.001), <it>Centers of excellence </it>(p = 0.002), and <it>Access to treatments </it>(p = 0.004) as priorities, while <it>Risk-assessment and referral </it>was the lowest priority (p = 0.645). We find moderate concordance between the qualitative and quantitative methods (rho = 0.20), albeit insignificant (p = 0.554), and a strong concordance between the OLS and logistic regressions (rho = 0.979; p < 0.0001).</p> <p>Conclusions</p> <p>Identified strategies can be conceptualized as the ABCs of comprehensive liver cancer control as they focus on <it>Antecedents</it>, <it>Better care </it>and <it>Connections </it>within a national strategy. Some concordance was found between the qualitative and quantitative methods (e.g. <it>Monitoring of at-risk populations</it>), but substantial differences were also identified (e.g. qualitative methods gave highest priority to risk-assessment and referral, but it was the lowest for the quantitative methods), which may be attributed to differences between the methods and study populations, and potential framing effects in choice tasks. Continued research will provide more generalizable estimates of priorities and account for variation across stakeholders and countries.</p