Designing an online support community for novice computer users

This project seeks to identify characteristics of successful online communities and apply them to designing and prototyping an online discussion forum where novice computer users can share computer questions and answers. Usability and sociability are identified as essential goals in the development of online communities. Appropriate and effective Computer Mediated Communication (CMC) software is evaluated and selected to run the discussion forum

Teaching Software Engineering with Free Open Source Software Development: An Experience Report

We report on the design and delivery of a senior Software Engineering course within the limits of a Computer Science program. The course is structured around a collaboration with a large, active Free Open Source Software project. We show how this structure allows us to (a) incorporate principles of Project Based Learning and of Service Learning, reaping the benefits of these pedagogies, (b) effectively, using a hands-on approach, teach a number of essential topics in Software Engineering, (c) provide the students with a capstone project experience, given the lack of one in our curriculum, and (d) use the project as a powerful motivating factor for the students. We outline the experiences of the course instructor, of the teaching assistants team, and of the students of the course. We also describe the experience of the lead developers of this open source project, and report on the benefits and costs (time commitment) to the project

The abrupt development of adult-like grid cell firing in the medial entorhinal cortex

Understanding the development of the neural circuits subserving specific cognitive functions such as navigation remains a central problem in neuroscience. Here, we characterize the development of grid cells in the medial entorhinal cortex, which, by nature of their regularly spaced firing fields, are thought to provide a distance metric to the hippocampal neural representation of space. Grid cells emerge at the time of weaning in the rat, at around 3 weeks of age. We investigated whether grid cells in young rats are functionally equivalent to those observed in the adult as soon as they appear, or if instead they follow a gradual developmental trajectory. We find that, from the very youngest ages at which reproducible grid firing is observed (postnatal day 19): grid cells display adult-like firing fields that tessellate to form a coherent map of the local environment; that this map is universal, maintaining its internal structure across different environments; and that grid cells in young rats, as in adults, also encode a representation of direction and speed. To further investigate the developmental processes leading up to the appearance of grid cells, we present data from individual medial entorhinal cortex cells recorded across more than 1 day, spanning the period before and after the grid firing pattern emerged. We find that increasing spatial stability of firing was correlated with increasing gridness

Photocatalytic nitrate reduction under solar-simulated light using modified TiO2

The purpose of this project is to enhance the photocatalytic activity of TiO2 for the photocatalytic reduction of aqueous nitrates for application as a solar-catalytic treatment of polluted water. The aim is also to establish a better understanding of the mechanisms by which noble metals enhance the activity of TiO2. Mono-metallic and bi-metallic Au, Ag and other M-TiO2 catalysts were prepared with the aim of improving charge-carrier separation,these catalysts were then characterised by XRD, BET and TEM. Preparation method variables such as calcination temperature and metal loading were investigated and found to have a large effect on catalytic activity. Metal loadings of between 0.3 and 0.4% were found to give the highest activity and this was concluded to be due to an optimum amount of surface coverage by small metal nanoparticles. The catalysts were found to be very selective towards nitrogen with Au catalysts tending to form ammonia at high conversions and Ag catalysts forming nitrite at low conversions. Bimetallic AuAg catalysts were prepared that had higher activities than their mono-metallic equivalents with 100% selectivity to N2. These catalysts were found to be highly reusable. None of the prepared M-TiO2 catalysts were found to have any visible-only activity for nitrate photo-reduction and the enhancement of photo-activity with the deposition of metals was concluded to be due to increased charge-carrier separation effects. Attempts were made at visibly-active TiO2 by N-doping but although UV-visible DRS analysis showed a redshift in the adsorption band of these catalysts and XRD found the anatase to rutile ratio to be near ideal no reproducible visible-light activity was achieved

VLBI study of maser kinematics in high-mass SFRs. I. G16.59-0.05

The present paper focuses on the high-mass star-forming region G16.59-0.05. Methods: Using the VLBA and the EVN arrays, we conducted phase-referenced observations of the three most powerful maser species in G16.59-0.05: H2O at 22.2 GHz (4 epochs), CH3OH at 6.7 GHz (3 epochs), and OH at 1.665 GHz (1 epoch). In addition, we performed high-resolution (> 0".1), high-sensitivity (< 0.1 mJy) VLA observations of the radio continuum emission from the star-forming region at 1.3 and 3.6 cm. Results: This is the first work to report accurate measurements of the "relative" proper motions of the 6.7 GHz CH3OH masers. The different spatial and 3-D velocity distribution clearly indicate that the 22 GHz water and 6.7 GHz methanol masers are tracing different kinematic environments. The bipolar distribution of 6.7 GHz maser l.o.s. velocities and the regular pattern of observed proper motions suggest that these masers are tracing rotation around a central mass of about 35 solar masses. The flattened spatial distribution of the 6.7 GHz masers, oriented NW-SE, suggests that they can originate in a disk/toroid rotating around the massive YSO which drives the 12CO(2-1) outflow, oriented NE-SW, observed on arcsec scale. The extended, radio continuum source observed close to the 6.7 GHz masers could be excited by a wide-angle wind emitted from the YSO associated with the methanol masers, and such a wind is proven to be sufficiently energetic to drive the NE-SW 12CO(2-1) outflow. The H2O masers distribute across a region offset about 0".5 to the NW of the CH3OH masers, in the same area where emission of high-density molecular tracers, typical of HMCs, was detected. We postulate that a distinct YSO, possibly in an earlier evolutionary phase than that exciting the methanol masers, is responsible for the excitation of the water masers and the HMC molecular lines. (Abridged)Comment: 20 pages, 8 figures, 3 tables, accepted by Astronomy and Astrophysic