98 research outputs found

    MaxEnt power spectrum estimation using the Fourier transform for irregularly sampled data applied to a record of stellar luminosity

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    The principle of maximum entropy is applied to the spectral analysis of a data signal with general variance matrix and containing gaps in the record. The role of the entropic regularizer is to prevent one from overestimating structure in the spectrum when faced with imperfect data. Several arguments are presented suggesting that the arbitrary prefactor should not be introduced to the entropy term. The introduction of that factor is not required when a continuous Poisson distribution is used for the amplitude coefficients. We compare the formalism for when the variance of the data is known explicitly to that for when the variance is known only to lie in some finite range. The result of including the entropic measure factor is to suggest a spectrum consistent with the variance of the data which has less structure than that given by the forward transform. An application of the methodology to example data is demonstrated.Comment: 15 pages, 13 figures, 1 table, major revision, final version, Accepted for publication in Astrophysics & Space Scienc

    Systematics of proton emission

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    A very simple formula is presented that relates the logarithm of the half-life, corrected by the centrifugal barrier, with the Coulomb parameter in proton decay processes. The corresponding experimental data lie on two straight lines which appear as a result of a sudden change in the nuclear shape marking two regions of deformation independently of the angular momentum of the outgoing proton. This feature provides a powerful tool to assign experimentally quantum numbers in proton emitters.Comment: 4 pages, 3 figure

    Amyloid and tau pathology associations with personality traits, neuropsychiatric symptoms, and cognitive lifestyle in the preclinical phases of sporadic and autosomal dominant Alzheimer’s disease

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    Background Major prevention trials for Alzheimer’s disease (AD) are now focusing on multidomain lifestyle interventions. However, the exact combination of behavioral factors related to AD pathology remains unclear. In 2 cohorts of cognitively unimpaired individuals at risk of AD, we examined which combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle (years of education or lifetime cognitive activity) related to the pathological hallmarks of AD, amyloid-ÎČ, and tau deposits. Methods A total of 115 older adults with a parental or multiple-sibling family history of sporadic AD (PREVENT-AD [PRe-symptomatic EValuation of Experimental or Novel Treatments for AD] cohort) underwent amyloid and tau positron emission tomography and answered several questionnaires related to behavioral attributes. Separately, we studied 117 mutation carriers from the DIAN (Dominant Inherited Alzheimer Network) study group cohort with amyloid positron emission tomography and behavioral data. Using partial least squares analysis, we identified latent variables relating amyloid or tau pathology with combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle. Results In PREVENT-AD, lower neuroticism, neuropsychiatric burden, and higher education were associated with less amyloid deposition (p = .014). Lower neuroticism and neuropsychiatric features, along with higher measures of openness and extraversion, were related to less tau deposition (p = .006). In DIAN, lower neuropsychiatric burden and higher education were also associated with less amyloid (p = .005). The combination of these factors accounted for up to 14% of AD pathology. Conclusions In the preclinical phase of both sporadic and autosomal dominant AD, multiple behavioral features were associated with AD pathology. These results may suggest potential pathways by which multidomain interventions might help delay AD onset or progression

    Observations of wake characteristics at the Goodnoe Hills MOD-2 array

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    The array of three MOD-2 wind turbines and two meteorological towers at Goodnoe Hills, Washington, provides an opportunity to evaluate turbine and wake interactions in a real environment. The triangular arrangement of the three turbines provides opportunities to study the effect of wakes on the performance of a downwind turbine at three different distances: 5, 7, and 10 rotor diameters (D), where 1 D is 300 ft. The information obtained from this test configuration is critical to future wind farm activities and is a key objective of the MOD-2 test program. This report describes the analysis of data measured at the turbines and towers from August 29 to November 12, 1982. The data are 2-min averages of 1-s values. Background flow characteristics were also examined to determine if flow variations across the site could mask wake measurements. For this analysis, one year's data gathered at the meteorological towers were analyzed. The results show some differences between characteristics measured at the towers, but these differences were not great enough to consider in evaluating wakes at the towers

    Candidate wind turbine generator site: annual data summary, January 1981-December 1981

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    Summarized hourly meteorological data for 34 candidate and wind turbine generator sites for calendar year 1981 are presented. These data are collected for the purpose of evaluating the wind energy potential at these sites and are used to assist in selection of potential sites for installation and testing of large wind turbines in electric utility systems. For each site, wind speed, direction, and distribution data are given in eight tables. Use of information from these tables, with information about specific wind turbines, should allow the user to estimate the potential for wind energy production at each site

    Community-engaged healthcare model for currently under-served individuals involved in the healthcare system

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    In the US, many people are excluded from healthcare structures and systems, due to multiple macro and micro factors. Poverty, health ecosystems, mental health, and community amenities are some of the issues confronting those who are not able to access appropriate support. This population is often referred to as ‘high needs, high cost’ (HNHC), a term that has been applied to refer to people who repeatedly utilize services without significant benefit (we have replaced this term with ‘currently under-served’; C-US). For many traditional health solutions may not address the fundamental issues confronting their health. Community-Engaged Healthcare (CEH) is an approach that equips members of the community to levy power to advocate for their own health or social solutions, designing their own interventions to address needs with support from health providers. A realist review was conducted to identify the existing literature around CEH. This yielded ten papers that were reviewed by at least two authors and rated in terms of quality. A model describing the processes underpinning CEH was then iteratively generated, resulting in additional terms that were used in a second review of the literature. A further 16 peer-reviewed articles were identified and were independently reviewed and quality rated. These articles were used to refine further iterations of the model and included in the review where appropriate. The resulting model schematically posits a set of relational factors identified to be important in the establishment of CEH. Notably, the transfer of autonomy and power over health decision-making processes is emphasized, which will require revolutionary thinking about how healthcare is delivered for patients

    Candidate wind-turbine generator site cumulative meteorological data summary and data for January 1982 through September 1982

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    Summarized cumulative hourly meteorological data for 20 new sites selected in early 1980 as part of the expanded candidate site program are presented. The reporting period is July 1980 through September 1982. The data collection program at some individual sites may not span this entire period, but will be contained within the reporting period. The purpose of providing the summarized data is to document the data collection program and to provide data that could be considered representative of longer-term meteorological conditions at each site. For each site, data are given in eight tables and in a topographic map showing the approximated location of the meteorological tower and turbine, if applicable. Use of the information from these tables, along with information about specific wind turbines, should allow the user to estimate the potential for longer-term average wind energy production at each site. Two appendices of other data are provided. Appendix A contains summarized data collected at new and original sites during the period January 1982 through September 1982. Appendix B contains cumulative summarized data for those original sites selected in 1976 with data collection programs continuing into 1982
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