12,254 research outputs found
Lifecourse social position and D-dimer; findings from the 1958 British birth cohort
The aim is to examine the association of lifecourse socioeconomic position (SEP) on circulating levels of D-dimer. Data from the 1958 British birth cohort were used, social class was determined at three stages of respondents' life: at birth, at 23 and at 42 years. A cumulative indicator score of SEP (CIS) was calculated ranging from 0 (always in the highest social class) to 9 (always in the lowest social class). In men and women, associations were observed between CIS and D-dimer (P<0.05). Thus, the respondents in more disadvantaged social classes had elevated levels of D-dimer compared to respondents in less disadvantaged social class. In multivariate analyses, the association of disadvantaged social position with D-dimer was largely explained by fibrinogen, C-reactive protein and von Willebrand Factor in women, and additionally by smoking, alcohol consumption and physical activity in men. Socioeconomic circumstances across the lifecourse at various stages also contribute independently to raised levels of D-dimer in middle age in women only. Risk exposure related to SEP accumulates across life and contributes to raised levels of D-dimer. The association of haemostatic markers and social differences in health may be mediated by inflammatory and other markers
Teaching About Magnetism
This web page, created by author David P. Stern, are the lecture notes for a presentation to middle and high school teachers to help teach magnetism. The lectures includes a brief history of the study of magnetism from its beginnings in ancient Greece and China to the present day, and three classroom demonstrations. This is part of a larger web site on "The Earth's Magnetosphere." Additionally, the author provides links to a glossary and expanded timeline to help better contextualize the theories addressed in these lecture notes
Newton's Laws
Authored and curated by David P. Stern, this series of web pages, part of "From Stargazers to Starships," describes Newton's three laws of motion and the two concepts on which they are based, force and inertia. The author breaks down the page in this fashion: the concept of force, motion against outside resistance, and motion with significant resistance. The author also provides additional links for further study on the life of Issac Newton. A lesson plan for instructors is also provided
Flight to Mars
Created by David P. Stern, this set of three web pages provides a calculation of paths, times, and distances for a flight to Mars and back. The author uses a Hohmann transfer ellipse between two circular orbits. This is an example and application of Kepler's Laws, which are explained in related web pages. Only algebra is used with Kepler's laws and the equation for the energy of Kepler motion. This is part of an extensive work, "From Stargazers to Stars that uses space science as an introduction to basic physics principles. Also available in French
Discovery of the Magnetic Compass
First of several linked files, telling the early history of the compass (discovered in China) and how Robert Norman in 1581 showed the magnetic force was not horizontal but slanted downwards, followed by William Gilbert's demonstration that the Earth behaved like a giant magnet; two reviews of Gilbert's 1600 book "De Magnete" follow, as well as a modern version of one of Gilbert's experiments. The web collection also includes several sections for science teachers. The page is a subset of a larger collection of articles of the history of magnetism created by author David P. Stern
E-book : Industrial Transformation In The Developing World (author: Michael T. Rock & David P. Angel)
Arsip Kuliah Online 2010: E-book : Industrial Transformation In The Developing World (author: Michael T. Rock & David P. Angel
E-book : "industrial Transformations In The Developing World (author: Michael T. Rock & David. P Angel)
Arsip Kuliah Online 2010: E-book : "industrial Transformations In The Developing World (author: Michael T. Rock & David. P Angel
Inference of disease associations with unmeasured genetic variants by combining results from genome-wide association studies with linkage disequilibrium patterns in a reference data set.
Results from whole-genome association studies of many common diseases are now available. Increasingly, these are being incorporated into meta-analyses to increase the power to detect weak associations with measured single-nucleotide polymorphisms (SNPs). Imputation of genotypes at unmeasured loci has been widely applied using patterns of linkage disequilibrium (LD) observed in the HapMap panels, but there is a need for alternative methods that can utilize the pooled effect estimates from meta-analyses and explore possible associations with SNPs and haplotypes that are not included in HapMap.By a weighted average technique, we show that association results for common SNPs in an observed data set can be scaled and combined to infer the effect of a genetic variant that has been measured only in an independent reference data set. We show that the ratio p(R-1)/[1 + p(R-1)], where R is the relative risk associated with a measured or unmeasured allele of frequency p, is appropriately scaled by 1/D' and weighted in proportion to r2, both common measures of LD being derived from the reference data set.We illustrate this computationally simple method by combining the results of a genome-wide association screen from the North American Rheumatoid Arthritis Consortium with LD measures from the British 1958 Birth Cohort, and explore the validity of underlying assumptions about the generalizability of LD from one population to another, and from healthy subjects to subjects with clinical disease
- …
