Evaluating Digital Libraries: A Longitudinal and Multifaceted View

published or submitted for publicatio

Conceptual design study for an advanced cab and visual system, volume 2

The performance, design, construction and testing requirements are defined for developing an advanced cab and visual system. The rotorcraft system integration simulator is composed of the advanced cab and visual system and the rotorcraft system motion generator, and is part of an existing simulation facility. User's applications for the simulator include rotorcraft design development, product improvement, threat assessment, and accident investigation

Enhancing the Impact of Cross-Sector Partnerships. Four Impact Loops for Channeling Partnership Studies

This paper addresses the topic of this special symposium issue: how to enhance the impact of cross-sector partnerships. The paper takes stock of two related discussions: the discourse in cross-sector partnership research on how to assess impact and the discourse in impact assessment research on how to deal with more complex organizations and projects. We argue that there is growing need and recognition for cross-fertilization between the two areas. Cross-sector partnerships are reaching a paradigmatic status in society, but both research and practice need more thorough evidence of their impacts and of the conditions under which these impacts can be enhanced. This paper develops a framework that should enable a constructive interchange between the two research areas, while also framing existing research into more precise categories that can lead to knowledge accumulation. We address the preconditions for such a framework and discuss how the constituent parts of this framework interact. We distinguish four different pathways or impact loops that refer to four distinct orders of impact. The paper concludes by applying these insights to the four papers included in this special issue

The SIMPSONS project: An integrated Mars transportation system

In response to the Request for Proposal (RFP) for an integrated transportation system network for an advanced Martian base, Frontier Transportation Systems (FTS) presents the results of the SIMPSONS project (Systems Integration for Mars Planetary Surface Operations Networks). The following topics are included: the project background, vehicle design, future work, conclusions, management status, and cost breakdown. The project focuses solely on the surface-to-surface transportation at an advanced Martian base

Comparative Genomics of Microbial Chemoreceptor Sequence, Structure, and Function

Microbial chemotaxis receptors (chemoreceptors) are complex proteins that sense the external environment and signal for flagella-mediated motility, serving as the GPS of the cell. In order to sense a myriad of physicochemical signals and adapt to diverse environmental niches, sensory regions of chemoreceptors are frenetically duplicated, mutated, or lost. Conversely, the chemoreceptor signaling region is a highly conserved protein domain. Extreme conservation of this domain is necessary because it determines very specific helical secondary, tertiary, and quaternary structures of the protein while simultaneously choreographing a network of interactions with the adaptor protein CheW and the histidine kinase CheA. This dichotomous nature has split the chemoreceptor community into two major camps, studying either an organism’s sensory capabilities and physiology or the molecular signal transduction mechanism. Fortunately, the current vast wealth of sequencing data has enabled comparative study of chemoreceptors. Comparative genomics can serve as a bridge between these communities, connecting sequence, structure, and function through comprehensive studies on scales ranging from minute and molecular to global and ecological. Herein are four works in which comparative genomics illuminates unanswered questions across the broad chemoreceptor landscape. First, we used evolutionary histories to refine chemoreceptor interactions in Thermotoga maritima, pairing phylogenetics with x-ray crystallography. Next, we uncovered the origin of a unique chemoreceptor, isolated only from hypervirulent strains of Campylobacter jejuni, by comparing chemoreceptor signaling and sensory regions from Campylobacter and Helicobacter. We then selected the opportunistic human pathogen Pseudomonas aeruginosa to address the question of assigning multiple chemoreceptors to multiple chemotaxis pathways within the same organism. We assigned all P. aeruginosa receptors to pathways using a novel in silico approach by incorporating sequence information spanning the entire taxonomic order Pseudomonadales and beyond. Finally, we surveyed the chemotaxis systems of all environmental, commensal, laboratory, and pathogenic strains of the ubiquitous Escherichia coli, where we discovered an ancestral chemoreceptor gene loss event that may have predisposed a well-studied subpopulation to adopt extra-intestinal pathogenic lifestyles. Overall, comparative genomics is a cutting edge method for comprehensive chemoreceptor study that is poised to promote synergy within and expand the significance of the chemoreceptor field

RoboCrane: a system for providing a power and a communication link between lunar surface and lunar caves for exploring robots

Lava caves are the result of a geological process related to the cooling of basaltic lava flows. On the Moon, this process may lead to caves several kilometers long and diameters of hundreds of meters. Access to lava tubes can be granted through skylights, a vertical pit between the lava tube and the lunar surface. This represents an outstanding opportunity for long-term missions, for future permanent human settlements, and for accessing pristine samples of lava, secondary minerals and volatiles. Given this, the ESA launched a campaign through the Open Space Innovation Platform calling for ideas that would tackle the many challenges of exploring lava pits. Five projects, including Robocrane, were selected. Solar light and direct line of sight (for communications) with the lunar surface are not available inside lava tubes. This is a problem for any robot (or swarm of robots) exploring the lava tubes. Robocrane tackles both problems by deploying an element (called the Charging head, or CH) at the bottom of the skylight by means of a crane. This CH behaves as a battery charger and a communication relay for the exploring robots. The required energy is extracted from the crane’s solar panel (on the surface) and driven to the bottom of the skylight through an electrical wire running in parallel to the crane hoisting wire. Using a crane allows the system to deal with unstable terrain around the skylight rim and protect the wires from abrasion from the rocky surface and the pit rim. The charger in the CH is wireless so that the charging process can begin as soon as any of the robots get close enough to the CH. This avoids complex and time-consuming docking operations, aggravated by the skylight floor orography. The crane infrastructure can also be used to deploy the exploring robots inside the pit, reducing their design constraints and mass budget, as the robots do not need to implement their own self-deployment system. Finally, RoboCrane includes all the sensors and actuators for remote operation from a ground station. RoboCrane has been designed in a parametric tool so it can be dynamically and rapidly adjusted to input-variable changes, such as the number of exploring robots, their electrical characteristics, and crane reach, etc.Agencia Estatal de Investigación | Ref. RTI2018-099682-A-I0