Motivation: the inside story

AbstractIn this article, we will look at the difference between extrinsic and intrinsic motivation, and why extrinsic motivation alone is not satisfactory for learning in the long run. It is suggested that although students may embark on learning for extrinsic reasons, a more intrinsic motivation can be developed in the classroom. A taxonomy of intrinsically motivating materials and tasks is proposed, based on the four categories interest, personalization, entertainment and challenge

A spectroscopic study of the star -forming properties of the center of Ngc 4194

We have obtained STIS longslit spectra of the central region of the advanced merger NGC 4194. The spectra cover the wavelength ranges 1150--1750A in the UV and 2900--10270A in the visible. Results from the study of the properties of 14 star forming regions (knots) are presented. We determine the average E(B-V) = 1.1 mag using the combined Halpha+[N II] flux. If the [N II] contribution is 40% then the average E(B-V) = 0.7 mag. The metal abundances are found to be approximately solar. The average abundances calculated range from 8.1 +/- 0.5 to 8.9 +/- 0.1. The Halpha luminosities of the 14 observed knots yield a total SFR of ∼46 M⊙ yr-1. The sizes of the H II regions in the knots were determined from L(Hbeta) and range from ∼28 pc to ∼119 pc when a filling factor of 0.1 is assumed. The sizes are a factor of ∼2.15 smaller when a filling factor of 1 is assumed. Using Starburst99, and the EW(Halpha+[N II]) and EW(Hbeta), we estimate the ages of the star forming regions to be 5.5--10.5 Myr. From ground based spectra, the effective temperatures of the H II regions were found to be ∼11,000 K and the electron densities were determined to be ∼530 cm-3. We find that 8 of the knots likely formed with a Salpeter Initial Mass Function truncated at an upper mass of 30 M⊙ and that one of the knots likely formed with a standard Salpeter Initial Mass Function. We find that the knots formed with a median SFE ≈ 18%. The knots in our sample have stellar masses in the range ∼0.6 x 106 M⊙ up to ∼27 x 106 M⊙ . We suggest that the knots in our sample are likely the precursors of globular clusters

Starbursts in the UV bright interacting galaxies NGC 3395 and NGC 3396

We have obtained ultraviolet and visible wavelength images for the interacting galaxies, NGC 3395/6, using the Space Telescope Imaging Spectrograph (STIS) on Hubble Space Telescope (HST). The images show many isolated sources of ultraviolet emission which are young star forming regions with ages ≤8 x 107 years. Reddening of the star forming knots ranges from E(B--V) = 0.0 to E(B--V) = 0.3, indicating variable amounts of dust surrounding these regions. The full width at half maximum of most of the knots in both galaxies are ≤20 pc. The distribution of far ultraviolet (FUV) fluxes in the knots corresponds to ∼3 to ∼150 O5V stars. These knots were found to have masses less than 106 M ⊙ . There are no significant differences in the luminosities, sizes, masses and ages of the knots in the two galaxies. The knots in NGC 3395 are scattered throughout. There seems to be no correlation between age and position. The knots in NGC 3396 tend to be younger toward the center and older toward the edges, except at the outer edges where the knots tend to be Youn

Integrating 2D Mouse Emulation with 3D Manipulation for Visualizations on a Multi-Touch Table

We present the Rizzo, a multi-touch virtual mouse that has been designed to provide the fine grained interaction for information visualization on a multi-touch table. Our solution enables touch interaction for existing mouse-based visualizations. Previously, this transition to a multi-touch environment was difficult because the mouse emulation of touch surfaces is often insufficient to provide full information visualization functionality. We present a unified design, combining many Rizzos that have been designed not only to provide mouse capabilities but also to act as zoomable lenses that make precise information access feasible. The Rizzos and the information visualizations all exist within a touch-enabled 3D window management system. Our approach permits touch interaction with both the 3D windowing environment as well as with the contents of the individual windows contained therein. We describe an implementation of our technique that augments the VisLink 3D visualization environment to demonstrate how to enable multi-touch capabilities on all visualizations written with the popular prefuse visualization toolkit.

The Origin of the 4.5 micron Excess from Dwarf Galaxies

Dwarf galaxies tend to have redder [3.6 micron] - [4.5 micron] Spitzer broadband colors than spirals. To investigate this effect, for a large sample of dwarf galaxies we combine Spitzer fluxes with data at other wavelengths and compare to population synthesis models. Lower metallicity systems are found to have redder [3.6] - [4.5] colors on average, but with considerable scatter. The observed range in [3.6] - [4.5] color is too large to be accounted for solely by variations in stellar colors due to age or metallicity differences; interstellar effects must contribute as well. For the reddest systems, the 4.5 micron luminosity may not be a good tracer of stellar mass. We identify three factors that redden this color in dwarfs. First, in some systems, strong Br-alpha emission contributes significantly to the 4.5 micron emission. Second, in some cases high optical depths lead to strong reddening of the starlight in the Spitzer bands. Third, in some galaxies, the nebular continuum dominates the 4.5 micron flux, and in extreme cases, the 3.6 micron flux as well. The harder UV radiation fields in lower metallicity systems produce both more gaseous continuum in the infrared and more Br-alpha per star formation rate. The combination of these three factors can account for the 4.5 micron excess in our sample galaxies, thus it is not necessary to invoke a major contribution from hot dust to the 4.5 micron band. However, given the uncertainties, we are not able to completely rule out hot dust emission at 4.5 micron. More spectroscopic observations in the 3 - 5 micron range are needed to disentangle these effects.Comment: Accepted by Astronomical Journa

Transitional labour markets : a social investment and risk mitigation strategy for social policy

Drawing on transitional labor market (TLM) theory, this introductory chapter highlights major themes, overviews the contributions to this volume and suggests a future agenda for policy makers. The focus of applied research projects has been the impact of post-modem social transformations on systems of social protection, looking through the lens of the labor market and shifts in household and family structure. The Transitional Labor Market project uses the TLM model as a means of developing new thinking on how flexibility and innovation might be paired with social investment and new forms of social protection. TLM theory emphasizes the importance of institutions and of the links between different institutions which frequently operate as policy silos, rather than integrated systems to buffer risks and support capability and enhance employability. The great advantage of the TLM model is that it draws attention to the right places for strategic reform. It does not offer a standard set of institutions to facilitate transitions however.<br /

Advancing imaging technologies for patients with spinal pain : with a focus on whiplash injury

Background: Radiological observations of soft-tissue changes that may relate to clinical symptoms in patients with traumatic and non-traumatic spinal disorders are highly controversial. Studies are often of poor quality and findings are inconsistent. A plethora of evidence suggests some pathoanatomical findings from traditional imaging applications are common in asymptomatic participants across the life span, which further questions the diagnostic, prognostic, and theranostic value of traditional imaging. Although we do not dispute the limited evidence for the clinical importance of most imaging findings, we contend that the disparate findings across studies may in part be due to limitations in the approaches used in assessment and analysis of imaging findings. Purpose: This clinical commentary aimed to (1) briefly detail available imaging guidelines, (2) detail research-based evidence around the clinical use of findings from advanced, but available, imaging applications (eg, fat and water magnetic resonance imaging and magnetization transfer imaging), and (3) introduce how evolving imaging technologies may improve our mechanistic understanding of pain and disability, leading to improved treatments and outcomes. Study Design/Setting: A non-systematic review of the literature is carried out. Methods: A narrative summary (including studies from the authors' own work in whiplash injuries) of the available literature is provided. Results: An emerging body of evidence suggests that the combination of existing imaging sequences or the use of developing imaging technologies in tandem with a good clinical assessment of modifiable risk factors may provide important diagnostic information toward the exploration and development of more informed and effective treatment options for some patients with traumatic neck pain. Conclusions: Advancing imaging technologies may help to explain the seemingly disconnected spectrum of biopsychosocial signs and symptoms of traumatic neck pain

Event Representations for Automated Story Generation with Deep Neural Nets

Automated story generation is the problem of automatically selecting a sequence of events, actions, or words that can be told as a story. We seek to develop a system that can generate stories by learning everything it needs to know from textual story corpora. To date, recurrent neural networks that learn language models at character, word, or sentence levels have had little success generating coherent stories. We explore the question of event representations that provide a mid-level of abstraction between words and sentences in order to retain the semantic information of the original data while minimizing event sparsity. We present a technique for preprocessing textual story data into event sequences. We then present a technique for automated story generation whereby we decompose the problem into the generation of successive events (event2event) and the generation of natural language sentences from events (event2sentence). We give empirical results comparing different event representations and their effects on event successor generation and the translation of events to natural language.Comment: Submitted to AAAI'1

Stochastic `Beads on a String' in the Accretion Tail of Arp 285

We present Spitzer infrared, GALEX UV, and SDSS and SARA optical images of the peculiar interacting galaxy pair Arp 285 (NGC 2856/4), and compare with a new numerical model of the interaction. We estimate the ages of clumps of star formation in these galaxies using population synthesis models, carefully considering the uncertainties on these ages. This system contains a striking example of `beads on a string': a series of star formation complexes ~1 kpc apart. These `beads' are found in a tail-like feature that is perpendicular to the disk of NGC 2856, which implies that it was formed from material accreted from the companion NGC 2854. The extreme blueness of the optical/UV colors and redness of the mid-infrared colors implies very young stellar ages (~4 - 20 Myrs) for these star forming regions. Spectral decomposition of these `beads' shows excess emission above the modeled stellar continuum in the 3.6 micron and 4.5 micron bands, indicating either contributions from interstellar matter to these fluxes or a second older stellar population. These clumps have -12.0 < M(B) < -10.6, thus they are less luminous than most dwarf galaxies. Our model suggests that bridge material falling into the potential of the companion overshoots the companion. The gas then piles up at apo-galacticon before falling back onto the companion, and star formation occurs in the pile-up. A luminous (M(B) ~ -13.6) extended (FWHM ~ 1.3 kpc) `bright spot' is visible at the northwestern edge of the NGC 2856 disk, with an intermediate stellar population (400 - 1500 Myrs). Our model suggests that this feature is part of a expanding ripple-like `arc' created by an off-center ring-galaxy-like collision between the two disks.Comment: Accepted by the Astronomical Journal. For color figures and appendix material, go tohttp://www.etsu.edu/physics/bsmith/research/sg/arp285/arp285.htm