618 research outputs found

    CONIKS: Bringing Key Transparency to End Users

    Get PDF
    We present CONIKS, an end-user key verification service capable of integration in end-to-end encrypted communication systems. CONIKS builds on transparency log proposals for web server certificates but solves several new challenges specific to key verification for end users. CONIKS obviates the need for global third-party monitors and enables users to efficiently monitor their own key bindings for consistency, downloading less than 20 kB per day to do so even for a provider with billions of users. CONIKS users and providers can collectively audit providers for non-equivocation, and this requires downloading a constant 2.5 kB per provider per day. Additionally, CONIKS preserves the level of privacy offered by today’s major communication services, hiding the list of usernames present and even allowing providers to conceal the total number of users in the system

    Development of the (d,n) proton-transfer reaction in inverse kinematics for structure studies

    Get PDF
    Transfer reactions have provided exciting opportunities to study the structure of exotic nuclei and are often used to inform studies relating to nucleosynthesis and applications. In order to benefit from these reactions and their application to rare ion beams (RIBs) it is necessary to develop the tools and techniques to perform and analyze the data from reactions performed in inverse kinematics, that is with targets of light nuclei and heavier beams. We are continuing to expand the transfer reaction toolbox in preparation for the next generation of facilities, such as the Facility for Rare Ion Beams (FRIB), which is scheduled for completion in 2022. An important step in this process is to perform the (d,n) reaction in inverse kinematics, with analyses that include Q-value spectra and differential cross sections. In this way, proton-transfer reactions can be placed on the same level as the more commonly used neutron-transfer reactions, such as (d,p), (9Be,8Be), and (13C,12C). Here we present an overview of the techniques used in (d,p) and (d,n), and some recent data from (d,n) reactions in inverse kinematics using stable beams of 12C and 16O.Comment: 9 pages, 4 figures, presented at the XXXV Mazurian Lakes Conference on Physics, Piaski, Polan

    Variation and disparities in awareness of myocardial infarction symptoms among adults in the United States

    Get PDF
    Importance: Prompt recognition of myocardial infarction symptoms is critical for timely access to lifesaving emergency cardiac care. However, patients with myocardial infarction continue to have a delayed presentation to the hospital.Objective: To understand the variation and disparities in awareness of myocardial infarction symptoms among adults in the United States.Design, setting, and participants: This cross-sectional study used data from the 2017 National Health Interview Survey among adult residents of the United States, assessing awareness of the 5 following common myocardial infarction symptoms among different sociodemographic subgroups: (1) chest pain or discomfort, (2) shortness of breath, (3) pain or discomfort in arms or shoulders, (4) feeling weak, lightheaded, or faint, and (5) jaw, neck, or back pain. The response to a perceived myocardial infarction (ie, calling emergency medical services vs other) was also assessed.Main outcomes and measures: Prevalence and characteristics of individuals who were unaware of myocardial infarction symptoms and/or chose not to call emergency medical services in response to these symptoms.Results: Among 25 271 individuals (13 820 women [51.6%; 95% CI, 50.8%-52.4%]; 17 910 non-Hispanic white individuals [69.9%; 95% CI, 68.2%-71.6%]; and 21 826 individuals [82.7%; 95% CI, 81.5%-83.8%] born in the United States), 23 383 (91.8%; 95% CI, 91.0%-92.6%) considered chest pain or discomfort a symptom of myocardial infarction; 22 158 (87.0%; 95% CI, 86.1%-87.8%) considered shortness of breath a symptom; 22 064 (85.7%; 95% CI, 84.8%-86.5%) considered pain or discomfort in arm a symptom; 19 760 (77.0%; 95% CI, 76.1%-77.9%) considered feeling weak, lightheaded, or faint a symptom; and 16 567 (62.6%; 95% CI, 61.6%-63.7%) considered jaw, neck, or back pain a symptom. Overall, 14 075 adults (53.0%; 95% CI, 51.9%-54.1%) were aware of all 5 symptoms, whereas 4698 (20.3%; 95% CI, 19.4%-21.3%) were not aware of the 3 most common symptoms and 1295 (5.8%; 95% CI, 5.2%-6.4%) were not aware of any symptoms. Not being aware of any symptoms was associated with male sex (odds ratio [OR], 1.23; 95% CI, 1.05-1.44; P = .01), Hispanic ethnicity (OR, 1.89; 95% CI, 1.47-2.43; P \u3c .001), not having been born in the United States (OR, 1.85; 95% CI, 1.47-2.33; P \u3c .001), and having a lower education level (OR, 1.31; 95% CI, 1.09-1.58; P = .004). Among 294 non-Hispanic black or Hispanic individuals who were not born in the United States, belonged to the low-income or lowest-income subgroup, were uninsured, and had a lower education level, 61 (17.9%; 95% CI, 13.3%-23.6%) were not aware of any symptoms. This group had 6-fold higher odds of not being aware of any symptoms (OR, 6.34; 95% CI, 3.92-10.26; P \u3c .001) compared with individuals without these characteristics. Overall, 1130 individuals (4.5%; 95% CI, 4.0%-5.0%) chose a different response than calling emergency medical services in response to a myocardial infarction.Conclusions and relevance: Many adults in the United States remain unaware of the symptoms of and appropriate response to a myocardial infarction. In this study, several sociodemographic subgroups were associated with a higher risk of not being aware. They may benefit the most from targeted public health initiatives

    Beyond BMI: The “Metabolically healthy obese” phenotype & its association with clinical/subclinical cardiovascular disease and all-cause mortality -- a systematic review

    Get PDF
    Background: A subgroup has emerged within the obese that do not display the typical metabolic disorders associated with obesity and are hypothesized to have lower risk of complications. The purpose of this review was to analyze the literature which has examined the burden of cardiovascular disease (CVD) and all-cause mortality in the metabolically healthy obese (MHO) population. Methods: Pubmed, Cochrane Library, and Web of Science were searched from their inception until December 2012. Studies were included which clearly defined the MHO group (using either insulin sensitivity and/or components of metabolic syndrome AND obesity) and its association with either all cause mortality, CVD mortality, incident CVD, and/or subclinical CVD. Results: A total of 20 studies were identified; 15 cohort and 5 cross-sectional. Eight studies used the NCEP Adult Treatment Panel III definition of metabolic syndrome to define “metabolically healthy”, while another nine used insulin resistance. Seven studies assessed all-cause mortality, seven assessed CVD mortality, and nine assessed incident CVD. MHO was found to be significantly associated with all-cause mortality in two studies (30%), CVD mortality in one study (14%), and incident CVD in three studies (33%). Of the six studies which examined subclinical disease, four (67%) showed significantly higher mean common carotid artery intima media thickness (CCA-IMT), coronary artery calcium (CAC), or other subclinical CVD markers in the MHO as compared to their MHNW counterparts. Conclusions: MHO is an important, emerging phenotype with a CVD risk between healthy, normal weight and unhealthy, obese individuals. Successful work towards a universally accepted definition of MHO would improve (and simplify) future studies and aid inter-study comparisons. Usefulness of a definition inclusive of insulin sensitivity and stricter criteria for metabolic syndrome components as well as the potential addition of markers of fatty liver and inflammation should be explored. Clinicians should be hesitant to reassure patients that the metabolically benign phenotype is safe, as increased risk cardiovascular disease and death have been shown

    Obtaining high resolution excitation functions with an active thick-target approach and validating them with mirror nuclei

    Full text link
    Measurement of fusion excitation functions for stable nuclei has largely been restricted to nuclei with significant natural abundance. Typically, to investigate neighboring nuclei with low natural abundance has required obtaining isotopically enriched material. This restriction often limits the ability to perform such measurements. We report the measurement of a high quality fusion excitation function for a 17^{17}O beam produced from unenriched material with 0.038\% natural abundance. The measurement is enabled by using an active thick-target approach and the accuracy of the result is validated using its mirror nucleus 17^{17}F and resonances. The result provides important information about the average fusion cross-section for the oxygen isotopic chain as a function of neutron excess.Comment: 4 pages, 4 figure
    corecore