46,986 research outputs found
Combining Theory and Practice in the Teaching of Science Institutions: A Collaborative Program between the City University of New York and the American Museum of Natural History
The National Science Education Standards contain several mandates that share the use of alternative and creative experiences in the teaching of science at all levels. An important feature of these standards is the call for learning settings and environments different from the traditional classroom in order to enhance student interest and participation in the learning process. New York City is rich in institutions that are ideal for the implementation of effective science teaching through the use of informal resources. This article uses the American Museum of Natural History as a prime example of this
LGBTQ Grantmakers 2008 Report Card on Racial Equity
A research study examining how a subset of lesbian, gay, bisexual, transgender and queer (LGBTQ) grantmakers addresses racial equity in grantmaking, governing documents, policies and practices, demographics and leadership, and strategic communications
Efficient Joint Sampling of Impact Parameters and Transit Depths in Transiting Exoplanet Light Curves
When fitting transiting exoplanet lightcurves, it is usually desirable to
have ranges and/or priors for the parameters which are to be retrieved that
include our degree of knowledge (or ignorance) in the routines which are being
used. In Markov Chain Monte Carlo (MCMC) routines, for example, these enter as
prior distributions. These can either represent our current knowledge of the
distribution of such parameters (e.g., based on their observed values) or
physically plausible parameters ranges to be sampled. Among the parameters that
are constrained by transiting exoplanet lightcurves, there are two which are of
much physical significance: the impact parameter of the orbit, , and the planet-to-star radius ratio, (which defines the
transit depth, ). These two are natural parameters to extract and
constrain as they usually have well defined limits. A common set of
"uninformative" priors used for those two parameters are uniform priors.
However, this poses a sampling problem especially important for grazing orbits:
given that we sample a value from the prior on , the only physically
plausible values for to be sampled given are those that satisfy . If we simply reject the sample if the sampled value of b is greater
than , then we will reject points from a significant portion of the
prior area depending on its size. It is desirable, thus, to have an algorithm
that efficiently samples values from the physically plausible zone in the
plane. Here we present such an algorithm.Comment: 3 pages, 1 figur
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