Abbott & Costello Meet Frankenstein

In lieu of an abstract, here is the article\u27s first paragraph: Years after writing Frankenstein, Mary Shelley published her Rambles in Germany and Italy in 1840, 1842, and 1843. Early on in it she states her therapeutic intent: “Travelling will cure all: my busy, brooding thoughts will be scattered abroad; and, to use a figure of speech, my mind will, amidst novel and various scenes, renew the outworn and tattered garments in which it has long been clothed, and array itself in a vesture all gay in fresh and glossy hues, when we are beyond the Alps.” (Part I, Letter I, p.2) Even if the classic 1948 comedy Abbott and Costello Meet Frankenstein deviates from Mary Shelley’s novel too much, it is spot-on regarding her larger project of how best to navigate in the pilgrimage of life. By pilgrimage here I mean not a predetermined track, but rather just the opposite, since what is most abhorrent is to let someone else determine your proper path, instead of having a keyed-up watchfulness for the full range of possible futures

Towards a semantic modeling of learners for social networks

The Friend of a Friend (FOAF) ontology is a vocabulary for mapping social networks. In this paper we propose an extension to FOAF in order to allow it to model learners and their social networks. We analyse FOAF alongside different learner modeling standards and specifications, and based on this analysis we introduce a taxonomy of the different features found in those models. We then compare the learner models and FOAF against the taxonomy to see how their characteristics have been shaped by their purpose. Based on this we propose extensions to FOAF in order to produce a learner model that is capable of forming the basis of a semantic social network.<br/

Why They Come, Why They Go, and Why They Stay: Factors Affecting Volunteerism in 4-H Programs

The 4-H program depends on the work of thousands of adult volunteers. It seems prudent to understand more about the factors involved in an adult becoming a leader, factors contributing to the leader having a positive experience, and, in particular, the factors causing the leader to end his or her role. In order to better understand the experience of 4-H leaders and the factors contributing to their success, an exit survey was conducted with individuals who had terminated their leadership role. Key reasons for volunteering and leaving are identified

X-Ray Emission from M32: X-Ray Binaries or a micro-AGN?

We have analysed archival {\it ROSAT} PSPC data for M32 in order to study the x-ray emission from this nearest elliptical galaxy. We fit spectra from three long exposures with Raymond-Smith, thermal bremsstrahlung, and power-law models. All models give excellent fits. The thermal fits have kT$\approx$4 keV, the Raymond-Smith iron abundance is $0.4^{+0.7}_{-0.3}$ Solar, the power-law fit has $\alpha$=1.6$\pm$0.1, and all fits have $N_H$ consistent with the Galactic column. The source is centered on M32 to an accuracy of 9$''$, and unresolved at 27$''$ FWHM ($\sim$90 pc). M32 is x-ray variable by a factor of 3--5 on timescales of a decade down to minutes, with evidence for a possible period of $\sim$1.3 days. There are two plausible interpretations for these results: 1) Emission due to low-mass x-ray binaries; 2) Emission due to accretion onto a massive central black hole. Both of these possibilities are supported by arguments based on previous studies of M32 and other old stellar systems; the {\it ROSAT} PSPC data do not allow us to unambiguously choose between them. Observations with the {\it ROSAT} HRI and with {\it ASCA} are required to determine which of these two very different physical models is correct.Comment: 9 pages, 5 PostScript figures, uses AASTeX style files, Accepted for publication in Astrophysical Journal Letter

Limits from BBN on Light Electromagnetic Decays

Injection of electromagnetic energy - photons, electrons, or positrons - into the plasma of the early universe can destroy light elements created by primordial Big Bang Nucleosynthesis (BBN). The success of BBN at predicting primordial abundances has thus been used to impose stringent constraints on decay or annihilation processes with primary energies near or above the electroweak scale. In this work we investigate the constraints from BBN on electromagnetic decays that inject lower energies, between 1-100 MeV. We compute the electromagnetic cascade from such injections and we show that it can deviate significantly from the universal spectrum commonly used in BBN calculations. For electron injection below 100 MeV, we find that the final state radiation of photons can have a significant impact on the resulting spectrum relevant for BBN. We also apply our results on electromagnetic cascades to investigate the limits from BBN on light electromagnetic decays prior to recombination, and we compare them to other bounds on such decays.Comment: 31 pages, 9 figures, corrected note added, updated references, minor code and plot fixes but nearly identical result