17,341 research outputs found

    Effect of fluoride on the calcification of allogenic bone implants in rats

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    Thesis (M.Sc.D.)--Boston University School of Graduate Dentistry, 1974. Periodontics.Bibliography included.In twenty-five (25) male adult rats which had decalcified allogenic bone implants placed in mid-fibular gaps and kept on a low-fluoride casein diet (1 ppm- fluoride), the addition of 25 p.p.m. fluoride to the drinking water did not show any direct detectable relationship to the mg % calcium in the ashed implants or in ashed adjacent tibial bone, nor in the percent ash content. Neither did the fluoride enhance or inhibit the success of the implants. For all implants did calcify and only one control mid-fibular gap closed on its own. It is our conclusion that fluoride at levels used in this experiment have no effect on calcification of allogenic bone implants

    The Impact of the Revenue Reconciliation Act of 1993 on the Pricing Structure of Equity REITs

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    Tax legislation included in the Revenue Reconciliation Act of 1993 made large-scale investments in equity real estate investment trusts (REITs) more desirable to institutional investors. Other studies have observed an increased level of institutional ownership in REITs during the timeframe following passage of the act. Based on an analysis of equity REITs before and after passage of the Act, the present study finds that its passage coincided with a significant change in the role of unsystematic risk in the pricing of equity REITs.

    A Review of the Open Educational Resources (OER) Movement: Achievements, Challenges, and New Opportunities

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    Examines the state of the foundation's efforts to improve educational opportunities worldwide through universal access to and use of high-quality academic content

    Chiral selection in the formation of borates from racemic binaphthols and related diols

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    A series of racemic or stereochemically labile chiral borate anions based on the 2,2′-biphenol motif was investigated. All borates were homochiral in the solid state, although in some cases the heterochiral diastereomers were computed to be thermodynamically preferred (DFT). The crystallographic preference for the homochiral diastereomer was attributed to its lower bulk, higher molecular symmetry, and the therewith associated better packing ability

    Alien Registration- Brown, John L. (Eastport, Washington County)

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    https://digitalmaine.com/alien_docs/1828/thumbnail.jp

    Evaluating the responsiveness of the Warwick Edinburgh Mental Well-Being Scale (WEMWBS) : group and individual level analysis

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    Background: Mental well-being now features prominently in UK and international health policy. However, progress has been hampered by lack of valid measures that are responsive to change. The objective of this study was to evaluate the responsiveness of the Warwick Edinburgh Mental Well-being Scale (WEMWBS) at both the individual and group level. Methods: Secondary analysis of twelve different interventional studies undertaken in different populations using WEMWBS as an outcome measure. Standardised response mean (SRM), probability of change statistic (P̂) and standard error of measurement (SEM) were used to evaluate whether WEMWBS detected statistically important changes at the group and individual level, respectively. Results: Mean change in WEMWBS score ranged from −0.6 to 10.6. SRM ranged from −0.10 (95% CI: -0.35, 0.15) to 1.35 (95% CI: 1.06, 1.64). In 9/12 studies the lower limit of the 95% CI for P̂ was greater than 0.5, denoting responsiveness. SEM ranged from 2.4 to 3.1 units, and at the threshold 2.77 SEM, WEMWBS detected important improvement in at least 12.8% to 45.7% of participants (lower limit of 95% CI>5.0%). Conclusions: WEMWBS is responsive to changes occurring in a wide range of mental health interventions undertaken in different populations. It offers a secure base for research and development in this rapidly evolving field. Further research using external criteria of change is warranted

    Interferometric data for a shock-wave/boundary-layer interaction

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    An experimental study of the axisymmetric shock-wave / boundary-layer strong interaction flow generated in the vicinity of a cylinder-cone intersection was conducted. The study data are useful in the documentation and understanding of compressible turbulent strong interaction flows, and are part of a more general effort to improve turbulence modeling for compressible two- and three-dimensional strong viscous/inviscid interactions. The nominal free stream Mach number was 2.85. Tunnel total pressures of 1.7 and 3.4 atm provided Reynolds number values of 18 x 10(6) and 36 x 10(6) based on model length. Three cone angles were studied giving negligible, incipient, and large scale flow separation. The initial cylinder boundary layer upstream of the interaction had a thickness of 1.0 cm. The subsonic layer of the cylinder boundary layer was quite thin, and in all cases, the shock wave penetrated a significant portion of the boundary layer. Owing to the thickness of the cylinder boundary layer, considerable structural detail was resolved for the three shock-wave / boundary-layer interaction cases considered. The primary emphasis was on the application of the holographic interferometry technique. The density field was deduced from an interferometric analysis based on the Able transform. Supporting data were obtained using a 2-D laser velocimeter, as well as mean wall pressure and oil flow measurements. The attached flow case was observed to be steady, while the separated cases exhibited shock unsteadiness. Comparisons with Navier-Stokes computations using a two-equation turbulence model are presented

    Measurement Error In Cross-Sectional and Longitudinal Labor Market Surveys: Results From Two Validation Studies

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    This paper reports evidence on the error properties of survey reports of labor market variables such as earnings and work hours. Our primary data source is the PSID Validation Study, a two-wave panel survey of a sample of workers employed by a large firm which also allowed us access to its very detailed records of its workers earnings. etc. The second data source uses individuals' 1977 and 1978 (March Current Population Survey) reports of earnings, matched to Social Security earnings records. In both data sets, individuals: reports of earnings are fairly accurately reported, and the errors are negatively related to true earnings. The latter property reduces the bias due to measurement error when earnings are used as an independent variable, but (unlike the classical-error case) leads to some bias when earnings are the dependent variable. Measurement-error-induced biases when change in earnings is the variable of interest are larger, but not dramatically so. Various measures of hourly earnings were much less reliable than annual earnings. Retrospective reports of unemployment showed considerable under-reporting, even of long spells.
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