34 research outputs found

    Designing and Building a Crew-Centric Mobile Scheduling and Planning Tool for Exploring Crew Autonomy Concepts Onboard the International Space Station

    Get PDF
    During 2015, as part of our ongoing research on crew autonomy, our team adapted and extended the plan viewing tool, Playbook, into a mobile tool for exploring crew autonomy onboard the International Space Station (ISS). This work enables crewmembers to intuitively re-plan and schedule on their own with limited input from mission control. Designed for ease of use, re-planning is composed of simple drag and drop interactions and learning the tool requires little to no training. Playbook was successfully uplinked onto ISS as a technology demonstration and completed its onboard ground and crew checkouts in August and September 2015, respectively. We will discuss and describe how Playbook was able to integrate with actual ISS operational plans and operational procedures without disrupting real mission operations. This work will also outline the design and technical constraints required to build a collaborative tool that allows multiple users to simultaneously self-schedule and synchronize during communication dropouts in the restricted networking and computing environment onboard ISS. Finally, we will explore the aspects of crew autonomy that this technology enables as well as discuss our next steps and possible extensions

    Chameleon radiation by oceanic dispersal

    Full text link
    Historical biogeography is dominated by vicariance methods that search for a congruent pattern of fragmentation of ancestral distributions produced by shared Earth history(1-3). A focus of vicariant studies has been austral area relationships and the break-up of the supercontinent Gondwana(3-5). Chameleons are one of the few extant terrestrial vertebrates thought to have biogeographic patterns that are congruent with the Gondwanan break-up of Madagascar and Africa(6,7). Here we show, using molecular and morphological evidence for 52 chameleon taxa, support for a phylogeny and area cladogram that does not fit a simple vicariant history. Oceanic dispersal-not Gondwanan breakup-facilitated species radiation, and the most parsimonious biogeographic hypothesis supports a Madagascan origin for chameleons, with multiple 'out-of-Madagascar' dispersal events to Africa, the Seychelles, the Comoros archipelago, and possibly Reunion Island. Although dispersal is evident in other Indian Ocean terrestrial animal groups(8-16), our study finds substantial out-of-Madagascar species radiation, and further highlights the importance of oceanic dispersal as a potential precursor for speciation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62614/1/415784a.pd

    Shaping Skeletal Growth by Modular Regulatory Elements in the Bmp5 Gene

    Get PDF
    Cartilage and bone are formed into a remarkable range of shapes and sizes that underlie many anatomical adaptations to different lifestyles in vertebrates. Although the morphological blueprints for individual cartilage and bony structures must somehow be encoded in the genome, we currently know little about the detailed genomic mechanisms that direct precise growth patterns for particular bones. We have carried out large-scale enhancer surveys to identify the regulatory architecture controlling developmental expression of the mouse Bmp5 gene, which encodes a secreted signaling molecule required for normal morphology of specific skeletal features. Although Bmp5 is expressed in many skeletal precursors, different enhancers control expression in individual bones. Remarkably, we show here that different enhancers also exist for highly restricted spatial subdomains along the surface of individual skeletal structures, including ribs and nasal cartilages. Transgenic, null, and regulatory mutations confirm that these anatomy-specific sequences are sufficient to trigger local changes in skeletal morphology and are required for establishing normal growth rates on separate bone surfaces. Our findings suggest that individual bones are composite structures whose detailed growth patterns are built from many smaller lineage and gene expression domains. Individual enhancers in BMP genes provide a genomic mechanism for controlling precise growth domains in particular cartilages and bones, making it possible to separately regulate skeletal anatomy at highly specific locations in the body

    Notes on Chameleons I. Comparative cytology: aid and new complications in Chameleon-taxonomy

    No full text
    1. Comparison is made between the subdivision of the genus Chamaeleo in groups of species based on cytological considerations (MATTHEY & VAN BRINK) and the subdivision of this genus in groups based on taxonomical considerations (HILLENIUS). Both subdivisions were developed independently from each other and show relatively few discordances (see Table 2). 2. Detailed discussion is given of the case of two specimens (Ch. voeltzkowi and Ch. monoceras), taxonomically to be regarded as belonging to Ch. rhinoceratus. Their chromosome-patterns, however, differ so greatly as most probably not to be able to yield fertile offspring. They should then be regarded as belonging to different species. As the chromosomepatterns of the types of Ch. rhinoceratus c.s. are unknown (only accessible in fresh specimens), it is advised for the moment to let the taxonomic considerations prevail. 3. In the Conclusion an attempt is made to explain the discordances between the subdivision of MATTHEY & VAN BRINK and of HILLENIUS

    Pair-bonding in Chameleons

    No full text
    corecore