Body Size of the Endosymbiotic Pea Crab Tumidotheres maculatus: Larger Hosts Hold Larger Crabs

The endosymbiotic pea crab, Tumidotheres maculatus, uses a broad range of host taxa, including several bivalve species, in the northern Gulf of Mexico. Because shelter size affects the size of other, free-living crab species, we hypothesized that pea crabs living in larger bivalve hosts should attain larger sizes. Crabs and hosts collected from 3 field sites in northern Florida show this trend. We examined crabs living in a large host, the pen shell Atrina rigida, and found them to be larger than pea crabs living in a small host, the bay scallop Argopecten irradians. Moreover, this trend was only apparent among female pea crabs, which are lifelong endosymbionts, but not among males, which are free-ranging and move among hosts. Our data support the broader conclusion that shelter size influences adult crab size in brachyuran crabs

Authentic assessment of reflection in an ePortfolio: How to make reflection more 'real' for students

In a doctoral study that focused on the enhancement of reflection through an ePortfolio-based learning environment, students' indicated that they felt reflection was not real when it was used for assessment. This led to an examination of assessment practices linked to reflection and ways to make it authentic. The literature revealed that reflection is often a component of authentic assessment rather than being a focus of it. The practices associated with the assessment of reflection are examined in order to formulate 4 guiding principles. These principles aim to make the process of reflection more 'real' to students in higher education settings, particularly when using an ePortfolio platform

Tools of the trade: 'Breaking the ice' with virtual tools in online learning

The reality is that online learning can be a daunting and lonely experience. This is why icebreakers can be a rewarding practice for both students and educators. The use of icebreakers allows students studying online to introduce themselves and become familiar with other members of the group and/or community. Not only are these icebreakers used as a starter within the first weeks of study, but they are also used to help motivate students throughout the course. Highlighted in this paper are particular online (virtual) tools that can be used as icebreakers within an online learning environment and help shift the view of isolation associated with learning online and create a more engaged community of practice with effective learning

Virtual worlds for learning: Done and dusted?

When Second Life first came to the attention of the mainstream media in 2007, educators recognised the potential of virtual worlds for teaching and learning. They seemed to be the ideal environments to facilitate authentic learning, alleviate the tyranny of distance for students not on campus, and provide an inexpensive and safe environment to teach skills that were too dangerous or expensive to teach in the real world. In spite of all this fanfare, virtual worlds have failed to gain significant traction in higher education. This paper outlines a preliminary investigation into the reasons why virtual worlds have not been adopted for learning and teaching. The reflections of the six authors on this topic were subjected to a thematic analysis with themes arranged under four broad topics. This information informed the development of a survey to be distributed more widely to further explore this phenomenon

Coming of the third wave: A move toward best practice, user defined tools and mainstream integration for virtual worlds in education

The Gartner Hype Cycle has placed virtual worlds on the climb up the Slope of Enlightenment. While some authors in the past have made much of the educational use of virtual worlds languishing in the Trough of Disillusionment, there has been a community of authors, designers and educators working to further understanding of the limitations and affordances of such technologies. It is time to pool this knowledge, experience, tools and practice to solidify best practice, focus research on development of specific elements and forge ahead to shape the third wave of educational virtual worlds. This paper attempts to outline this information and practice while offering solutions for further development

An informal community of practice: The case of the DEHub Virtual Worlds Working Group

The DEHub Virtual Worlds Working Group has an informal membership of nearly 200 members with an interest in education and virtual worlds within the Australian and New Zealand context. Members come from a variety of academic disciplines and may be teaching or research academics, Research Higher Degree candidates, project managers, virtual world builders and developers. The group acts as an informal Community of Practice, facilitating learning and the transfer of skills through social contact, opportunities to collaborate on projects and publications, and through the sharing of knowledge and experience. This poster provides a snapshot of the activity of this highly active group

Homeosis in a scorpion supports a telopodal origin of pectines and components of the book lungs

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

Teaching and learning in virtual worlds: Is it worth the effort?

Educators have been quick to spot the enormous potential afforded by virtual worlds for situated and authentic learning, practising tasks with potentially serious consequences in the real world and for bringing geographically dispersed faculty and students together in the same space (Gee, 2007; Johnson and Levine, 2008). Though this potential has largely been realised, it generally isn't without cost in terms of lack of institutional buy-in, steep learning curves for all participants, and lack of a sound theoretical framework to support learning activities (Campbell, 2009; Cheal, 2007; Kluge & Riley, 2008). This symposium will explore the affordances and issues associated with teaching and learning in virtual worlds, all the time considering the question: is it worth the effort?. © 2010 Helen Farley, Sue Gregory, Allan Ellis, Geoffrey Crisp, Jenny Grenfell, Angela Thomas & Mathew Campbell

PLP and GABA Trigger GabR-mediated Transcription Regulation in Bacillus Subtilis via External Aldimine Formation

The Bacillus subtilis protein regulator of the gabTD operon and its own gene (GabR) is a transcriptional activator that regulates transcription of γ-aminobutyric acid aminotransferase (GABA-AT; GabT) upon interactions with pyridoxal-5′-phosphate (PLP) and GABA, and thereby promotes the biosynthesis of glutamate from GABA. We show here that the external aldimine formed between PLP and GABA is apparently responsible for triggering the GabR-mediated transcription activation. Details of the “active site” in the structure of the GabR effector-binding/oligomerization (Eb/O) domain suggest that binding a monocarboxylic γ-amino acid such as GABA should be preferred over dicarboxylic acid ligands. A reactive GABA analog, (S)-4-amino-5-fluoropentanoic acid (AFPA), was used as a molecular probe to examine the reactivity of PLP in both GabR and a homologous aspartate aminotransferase (Asp-AT) from Escherichia coli as a control. A comparison between the structures of the Eb/O–PLP–AFPA complex and Asp-AT–PLP–AFPA complex revealed that GabR is incapable of facilitating further steps of the transamination reaction after the formation of the external aldimine. Results of in vitro and in vivo assays using full-length GabR support the conclusion that AFPA is an agonistic ligand capable of triggering GabR-mediated transcription activation via formation of an external aldimine with PLP