Turbopump thermodynamic cooling

System for cooling turbopumps used in cryogenic fluid storage facilities is described. Technique uses thermodynamic propellant vent to intercept pump heat at desired conditions. Cooling system uses hydrogen from outside source or residual hydrogen from cryogenic storage tank

Government financial support for civil aircraft research, technology and development in four European countries and the United States

Data on the levels of government financial support for civil aircraft airframe and engine (CAAE) research and technology (R&T) in the United States and Europe (United Kingdom, West Germany, France and The Netherlands) and means of comparing these levels are provided. Data are presented for the years 1974-1977. European R&T expenditure data were obtained through visits to each of the four European countries, to the Washington office of the European Communities, and by a search of applicable literature. CAAE R&T expenditure data for the United States were obtained from NASA and Federal Aviation Administration (FAA)

A major depression prognosis calculator based on episode duration

BACKGROUND: Epidemiological data have shown that the probability of recovery from an episode declines with increasing episode duration, such that the duration of an episode may be an important factor in determining whether treatment is required. The objective of this study is to incorporate episode duration data into a calculator predicting the probability of recovery during a specified interval of time. METHODS: Data from two Canadian epidemiological studies were used, both studies were components of a program undertaken by the Canadian national statistical agency. One component was a cross-sectional psychiatric epidemiological survey (n = 36,984) and the other was a longitudinal study (n = 17,262). RESULTS: A Weibull distribution provided a good description of episode durations reported by subjects with major depression in the cross-sectional survey. This distribution was used to develop a discrete event simulation model for episode duration calibrated using the longitudinal data. The resulting estimates were then incorporated into a predictive calculator. During the early weeks of an episode, recovery probabilities are high. The model predicts that approximately 20% will recover in the first week after diagnostic criteria for major depression are met. However, after six months of illness, recovery during a subsequent week is less than 1%. CONCLUSION: The duration of an episode is relevant to the probability of recovery. This epidemiological feature of depressive disorders can inform prognostic judgments. Watchful waiting may be an appropriate strategy for mild episodes of recent onset, but the risks and benefits of this strategy must be assessed in relation to time since onset of the episode

Markov models of major depression for linking psychiatric epidemiology to clinical practice

BACKGROUND: Most epidemiological studies of major depression report estimates of period prevalence. Such estimates are useful for public health applications, but are not very helpful for informing clinical practice. Period prevalence is determined predominantly by incidence and episode duration, but it is difficult to connect these epidemiological concepts to clinical issues such as risk and prognosis. Incidence is important for primary and secondary prevention, and prognostic information is useful for clinical decision-making. The objective of this study was to decompose period prevalence data for major depression into its constituent elements, thereby enhancing the value of these estimates for clinical practice. Data from a series of population-based Canadian studies were used in the analysis. Markov models depicting incidence, prevalence and recovery from major depressive episodes were developed. Monte Carlo simulation was used to constrain model parameters to the epidemiological data. RESULTS: The association of sex with major depression was found to be due to a higher incidence in women. In distinction, the higher prevalence in unmarried subjects was mostly due to a different prognosis. Age-related changes in prevalence were influenced by both factors. Education, which was not found to be associated with major depression in the survey data, had no impact either on risk or prognosis. CONCLUSION: The period prevalence of major depression is influenced both by incidence (risk) and episode duration (prognosis). Mathematical modeling of the underlying epidemiological relationships can make such data more readily interpretable in relation to clinical practice

The impact of antidepressant treatment on population health: synthesis of data from two national data sources in Canada

BACKGROUND: In randomized, controlled trials, antidepressant medications have been shown to reduce the duration of major depressive episodes and to reduce the frequency of relapse during long-term treatment. The epidemiological impact of antidepressant use on episode duration and relapse frequency, however, has not been described. METHODS: Data from two Canadian general health surveys were used in this analysis: the National Population Health Survey (NPHS) and the Canadian Community Health Survey (CCHS). The NPHS is a longitudinal study that collected data between 1994 and 2000. These longitudinal data allowed an approximation of episode incidence to be calculated. The cross-sectional CCHS allowed estimation of episode duration. The surveys used the same sampling frame and both incorporated a Short Form version of the Composite International Diagnostic Interview. RESULTS: Episodes occurring in antidepressant users lasted longer than those in non-users. The apparent incidence of major depressive episodes among those taking antidepressants was higher than that among respondents not taking antidepressants. Changes in duration and incidence over the data collection interval were not observed. CONCLUSIONS: The most probable explanation for these results is confounding by indication and/or severity: members of the general population who are taking antidepressants probably have more highly recurrent and more severe mood disorders. In part, this may have been due to the use of a brief predictive diagnostic interview, which may be prone to detection of sub-clinical cases. Whereas antidepressant use increased considerably over the data-collection period, differences in episode incidence and duration over time were not observed. This suggests that the impact of antidepressant medications on population health may have been less than expected

From Safe Harbor to Choppy Waters: YouTube, the Digital Millennium Copyright Act,and a Much Needed Change of Course

YouTube.com, named Time magazine\u27s Invention of the Year for 2006 and widely recognized as the most-visited video site on the Internet, has changed the face of online entertainment. With the site\u27s acquisition by Google in October 2006, the possibilities for YouTube\u27s growth became truly endless. However, there is a darker side to the story of the Internet sensation, one that is grounded in its potential liability for copyright infringement. The issue is that many of the most-viewed and most-popular videos on the site are copyrighted. The copyright owners of those popular clips want their works back and are suing YouTube and Google for infringing their copyrights. In 1998, Congress passed the Digital Millennium Copyright Act (DMCA), specifically addressing the potential copyright liability of Internet service providers. The DMCA provides a series of safe harbors for certain activities of Internet service providers, ensuring limited liability so long as providers comply with the notice and take-down provision of the statute. To date, YouTube has been capitalizing on the safe harbors provided by the DMCA and has avoided liability for infringement. Although the DMCA protects Internet service providers like YouTube, it leaves copyright holders out in the cold. This Note first traces the development of copyright law and the liability of Internet service providers from the Copyright Act of 1976 to the DMCA. The Author then evaluates potential copyright claims against YouTube and Google under both statutes, with special emphasis on the applicability of the safe harbor provisions of the DMCA. The Author then discusses the current legal status of YouTube, how the site has avoided copyright liability in the past, and how it fares under the more traditional fair use analysis. The Author concludes that YouTube should not be eligible for a fair use defense and argues that the site, with all of its far-reaching capabilities, should be held responsible for its infringing actions

An animated depiction of major depression epidemiology

<p>Abstract</p> <p>Background</p> <p>Epidemiologic estimates are now available for a variety of parameters related to major depression epidemiology (incidence, prevalence, etc.). These estimates are potentially useful for policy and planning purposes, but it is first necessary that they be synthesized into a coherent picture of the epidemiology of the condition. Several attempts to do so have been made using mathematical modeling procedures. However, this information is not easy to communicate to users of epidemiological data (clinicians, administrators, policy makers).</p> <p>Methods</p> <p>In this study, up-to-date data on major depression epidemiology were integrated using a discrete event simulation model. The mathematical model was animated in Virtual Reality Modeling Language (VRML) to create a visual, rather than mathematical, depiction of the epidemiology.</p> <p>Results</p> <p>Consistent with existing literature, the model highlights potential advantages of population health strategies that emphasize access to effective long-term treatment. The paper contains a web-link to the animation.</p> <p>Conclusion</p> <p>Visual animation of epidemiological results may be an effective knowledge translation tool. In clinical practice, such animations could potentially assist with patient education and enhanced long-term compliance.</p

Enhancing the Utility of the Dexamethasone Suppression Test: A Chart Review and Application of Bayes\u27 Theorem

The dexamethasone suppression test (DST) is the most extensively studied biological test in psychiatry. Despite this, its role in the diagnostic assessment of psychiatric patients remains controversial. Shortcomings of the test include limited sensitivity (45%) and limited specificity (75-80%) (1). The DST has many proposed uses, including the differentiation of endogenous from non-endogenous depressions, helping to decide when maintenance medications may be withdrawn, and as a diagnostic test for major depression. This paper is concerned with the latter use only, that is, the ability of the DST to function as a useful diagnostic test for major depression. The significance of the low sensitivity and specificity of the DST have been discussed extensively in the psychiatric lite rature (2,3). When the DST is used as a diagnostic test for major depression its sensitivity represents the likelihood of a positive test given that the tested patient has a major depression. Specificity represents the likelihood of a negative test given that the tested patient does not have a major depression. Notably, both sensitivity and specificity represent probabilities conditional on the presence or absence of disease. However, in the usual clinical situation, the diagnosis is unknown at the time the diagnostic test is ordered. Indeed, if the diagnosis is known then the test should not be performed. Thus neither sensitivity nor specificity is directly relevant to the interpretation of the results of diagnostic tests in a clinical setting. Another parameter, the positive predictive value (+ PV), is of more clinical relevance

Preliminary testing of a prototype portable X-ray fluorescence spectrometer

A portable X-ray fluorescence spectrometer for use as an analyzer in mineral resource investigative work was built and tested. The prototype battery powered spectrometer, measuring 11 by 12 by 5 inches and weighing only about 15 pounds, was designed specifically for field use. The spectrometer has two gas proportional counters and two radioactive sources, Cd (10a) and Fe (55). Preliminary field and laboratory tests on rock specimens and rock pulps have demonstrated the capability of the spectrometer to detect 33 elements to date. Characteristics of the system present some limitations, however, and further improvements are recommended