STEM, STEAM, and German Language Acquisition: Modified Project-Based Learning in a German Conversation Course

This project describes an investigation into the efficacy of employing a modified project-based learning model to enhance the presentation and conversation skills of students in German 235: Intermediate German Conversation. Unlike usual language conversation courses that rely on expensive textbooks and focus on reading selections followed by discussion questions, GER 235 sought to engage students in a journey of discovery as they explored topics typically more at home in science, technology, engineering, and mathematics courses (STEM) and that were supplemented by the arts: STEAM. The impetus for this course developed out of a teaching unit that I created on the concept of the “ecological backpack,” my final project for a professional development seminar at the University of Leipzig, Germany, in Summer 2015

Girls vs. boys in mathematics: Test scores provide one interpretation girls narratives suggest a different story

This study seeks to provide a data based critique of the claims of gender equity in mathematics. Specifically, this paper is an analysis of the personal well-remembered events (WREs) told and recorded by women who are in the first course of their preservice teaching professional sequence. Importantly, these are women who are on the professional track to teach mathematics. Using a narrative based methodology, the writings provide another angle of the intricate pieces of equity (i.e. test results say both genders are just as capable, stories of females say otherwise). The themes center around the safe zones, struggles, embarrassment, competition, and self-fulfilling prophecies. From these stories, we see subtle illustrations of existing gender inequities in mathematics

Calibration of conditional composite likelihood for Bayesian inference on Gibbs random fields

Gibbs random fields play an important role in statistics, however, the resulting likelihood is typically unavailable due to an intractable normalizing constant. Composite likelihoods offer a principled means to construct useful approximations. This paper provides a mean to calibrate the posterior distribution resulting from using a composite likelihood and illustrate its performance in several examples.Comment: JMLR Workshop and Conference Proceedings, 18th International Conference on Artificial Intelligence and Statistics (AISTATS), San Diego, California, USA, 9-12 May 2015 (Vol. 38, pp. 921-929). arXiv admin note: substantial text overlap with arXiv:1207.575

Noisy Hamiltonian Monte Carlo for doubly-intractable distributions

Hamiltonian Monte Carlo (HMC) has been progressively incorporated within the statistician's toolbox as an alternative sampling method in settings when standard Metropolis-Hastings is inefficient. HMC generates a Markov chain on an augmented state space with transitions based on a deterministic differential flow derived from Hamiltonian mechanics. In practice, the evolution of Hamiltonian systems cannot be solved analytically, requiring numerical integration schemes. Under numerical integration, the resulting approximate solution no longer preserves the measure of the target distribution, therefore an accept-reject step is used to correct the bias. For doubly-intractable distributions -- such as posterior distributions based on Gibbs random fields -- HMC suffers from some computational difficulties: computation of gradients in the differential flow and computation of the accept-reject proposals poses difficulty. In this paper, we study the behaviour of HMC when these quantities are replaced by Monte Carlo estimates

Do the low PN velocity dispersions around elliptical galaxies imply that these lack dark matter?

While kinematical modelling of the low PN velocity dispersions observed in the outer regions of elliptical galaxies suggest a lack of dark matter around these galaxies, we report on an analysis of a suite of $N$-body simulations (with gas) of major mergers of spiral galaxies embedded in dark matter halos, and find that the outer velocity dispersions are as low as observed for the PNe. The inconsistency between our dynamical modelling and previous kinematical modelling is caused by very radial stellar orbits and projection effects when viewing face-on oblate ellipticals. Our simulations (weakly) suggest the youth of PNe around ellipticals, and we propose that the universality of the PN luminosity function may be explained if the bright PNe in ellipticals are formed after the regular accretion of very low mass gas-rich galaxies.Comment: Contributed talk at meeting, "Planetary Nebulae as astronomical tools", Gdansk, Poland, June-July 2005, ed. R. Szczerba, G. Stasi\'nska, and S. K. G\'orny, AIP Conference Proceedings, Melville, New York, 2005. 4 or 5 pages, 6 figure

IPD - the Immuno Polymorphism Database

The Immuno Polymorphism Database (IPD) (http://www.ebi.ac.uk/ipd/) is a set of specialist databases related to the study of polymorphic genes in the immune system. IPD currently consists of four databases: IPD-KIR, contains the allelic sequences of Killer-cell Immunoglobulin-like Receptors; IPD-MHC, a database of sequences of the Major Histocompatibility Complex of different species; IPD-HPA, alloantigens expressed only on platelets; and IPD-ESTAB, which provides access to the European Searchable Tumour Cell-Line Database, a cell bank of immunologically characterized melanoma cell lines. The IPD project works with specialist groups or nomenclature committees who provide and curate individual sections before they are submitted to IPD for online publication. The IPD project stores all the data in a set of related databases. Those sections with similar data, such as IPD-KIR and IPD-MHC share the same database structure. The sharing of a common database structure makes it easier to implement common tools for data submission and retrieval. The data are currently available online from the website and ftp directory; files will also be made available in different formats to download from the website and ftp server. The data will also be included in SRS, BLAST and FASTA search engines at the European Bioinformatics Institute