79 research outputs found

    Limits To Certainty in QoS Pricing and Bandwidth

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    Advanced services require more reliable bandwidth than currently provided by the Internet Protocol, even with the reliability enhancements provided by TCP. More reliable bandwidth will be provided through QoS (quality of service), as currently discussed widely. Yet QoS has some implications beyond providing ubiquitous access to advance Internet service, which are of interest from a policy perspective. In particular, what are the implications for price of Internet services? Further, how will these changes impact demand and universal service for the Internet. This paper explores the relationship between certainty of bandwidth and certainty of price for Internet services over a statistically shared network and finds that these are mutually exclusive goals.Comment: 29th TPRC Conference, 200

    Retail Prices and Facility-Based Entry into the Telecommunications Market

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    There is growing sentiment that rate rebalancing to eliminate cross subsidies between local business and local residential telephone markets is necessary to induce efficient entry in the residential market. If the elasticity of supply with respect to the relative prices for business and residential local service is high in both the local business and local residential markets, then the efficiency gains from rebalancing may be large. Alternatively, other factors related to differences in characteristics between business and residential local telephone markets, such as lower costs, lower elasticity of demand, and greater willingness-to-pay for quality or redundancy in the business segment of local telephone may be more important determinants of entry. In this paper we simultaneously measure the elasticity of supply in the business market with regards to the price of business services relative to the price of residential service, using entry, economic and demographic data a the wire center level. We find that business entry is driven by market demand and cost characteristics, and that the effect of cross subsidies in prices on entry is less clear

    Circulating Unmetabolized Folic Acid: Relationship to Folate Status and Effect of Supplementation

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    There are increasing concerns that exposure to unmetabolized folic acid, which results from folic acid intakes that overwhelm the liver's metabolic capacity, may be associated with adverse effects. In this paper, we examined the folic acid status of women of reproductive age in relation to dietary intake and the effect of folic acid supplementation (1.1 mg or 5 mg). Plasma unmetabolized folic acid was not significantly correlated with folate intake estimated by food frequency questionnaire or biomarkers. The proportion of women with detectable levels of unmetabolized folic acid increased from 65% to 100% after twelve weeks of supplementation (P<0.05); however, the increase in concentrations did not reach statistical significance and the effect was not sustained. Moreover, there were no significant differences between the two doses. This suggests that there are mechanisms by which the body adapts to high folic acid intakes to limit exposure to unmetabolized folic acid

    The effect of distant reiki on pain in women after elective Caesarean section: a double-blinded randomised controlled trial

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    Introduction: Approximately 25% of all babies in North America are delivered via Caesarean section (C-section). Though a common surgical procedure, C-section recovery can be painful. Opioids, specifically codeine, are commonly used to ease pain; however, its active metabolite, morphine, passes into breast milk, and may produce unwanted side effects in neonates; therefore, alternatives to opioids are being sought. Reiki is an ancient Japanese form of healing where practitioners transfer healing energy through light touch and positive healing intention. Although 1.2 million Americans use reiki to reduce pain or depression, there is a lack of strong evidence supporting its effectiveness. A recent systematic review showed existing studies to be of poor methodological quality, with the common limitation of lack of blinding. To overcome this issue, the authors used distant reiki to assess its effectiveness in reducing pain following an elective C-section. Methods: In this randomised, double-blinded study, women who underwent an elective C-section were allocated to either usual care (control, n=40) or three distant reiki sessions in addition to usual care (n=40). Pain was assessed using a visual analogue scale (VAS). The primary endpoint was the Area Under the VAS-Time Curve (AUC) for days 1-3. Secondary measures included: The proportion of women who required opioid medications and dose consumed, rate of healing and vital signs. Results: AUC for pain was not significantly different in the distant reiki and control groups (mean±SD; 212.16104.7 vs 223.16117.8; p=0.96). There were no significant differences in opioid consumption or rate of healing; however, the distant reiki group had a significantly lower heart rate (74.368.1 bpm vs 79.867.9 bpm, p=0.003) an

    A Tale Of 160 Scientists, Three Applications, a Workshop, and a Cloud

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    The NASA Exoplanet Science Institute (NExScI) hosts the annual Sagan Workshops, thematic meetings aimed at introducing researchers to the latest tools and methodologies in exoplanet research. The theme of the Summer 2012 workshop, held from July 23 to July 27 at Caltech, was to explore the use of exoplanet light curves to study planetary system architectures and atmospheres. A major part of the workshop was to use hands-on sessions to instruct attendees in the use of three open source tools for the analysis of light curves, especially from the Kepler mission. Each hands-on session involved the 160 attendees using their laptops to follow step-by-step tutorials given by experts. One of the applications, PyKE, is a suite of Python tools designed to reduce and analyze Kepler light curves; these tools can be invoked from the Unix command line or a GUI in PyRAF. The Transit Analysis Package (TAP) uses Markov Chain Monte Carlo (MCMC) techniques to fit light curves under the Interactive Data Language (IDL) environment, and Transit Timing Variations (TTV) uses IDL tools and Java-based GUIs to confirm and detect exoplanets from timing variations in light curve fitting. Rather than attempt to run these diverse applications on the inevitable wide range of environments on attendees laptops, they were run instead on the Amazon Elastic Cloud 2 (EC2). The cloud offers features ideal for this type of short term need: computing and storage services are made available on demand for as long as needed, and a processing environment can be customized and replicated as needed. The cloud environment included an NFS file server virtual machine (VM), 20 client VMs for use by attendees, and a VM to enable ftp downloads of the attendees' results. The file server was configured with a 1 TB Elastic Block Storage (EBS) volume (network-attached storage mounted as a device) containing the application software and attendees home directories. The clients were configured to mount the applications and home directories from the server via NFS. All VMs were built with CentOS version 5.8. Attendees connected their laptops to one of the client VMs using the Virtual Network Computing (VNC) protocol, which enabled them to interact with a remote desktop GUI during the hands-on sessions. We will describe the mechanisms for handling security, failovers, and licensing of commercial software. In particular, IDL licenses were managed through a server at Caltech, connected to the IDL instances running on Amazon EC2 via a Secure Shell (ssh) tunnel. The system operated flawlessly during the workshop

    Leveraging International Influenza Surveillance Systems and Programs during the COVID-19 Pandemic.

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    A network of global respiratory disease surveillance systems and partnerships has been built over decades as a direct response to the persistent threat of seasonal, zoonotic, and pandemic influenza. These efforts have been spearheaded by the World Health Organization, country ministries of health, the US Centers for Disease Control and Prevention, nongovernmental organizations, academic groups, and others. During the COVID-19 pandemic, the US Centers for Disease Control and Prevention worked closely with ministries of health in partner countries and the World Health Organization to leverage influenza surveillance systems and programs to respond to SARS-CoV-2 transmission. Countries used existing surveillance systems for severe acute respiratory infection and influenza-like illness, respiratory virus laboratory resources, pandemic influenza preparedness plans, and ongoing population-based influenza studies to track, study, and respond to SARS-CoV-2 infections. The incorporation of COVID-19 surveillance into existing influenza sentinel surveillance systems can support continued global surveillance for respiratory viruses with pandemic potential
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