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Sundar G.S.,University of Maryland University College | Islam E.,University of Maryland University College | Gera K.,University of Maryland University College | Gera K.,Open Mountain | And 2 more authors.
Molecular Microbiology | Year: 2017

The Group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram-positive human pathogen that must adapt to unique host environments in order to survive. Links between sugar metabolism and virulence have been demonstrated in GAS, where mutants in the phosphoenolpyruvate-dependent phosphotransferase system (PTS) exhibited Streptolysin S (SLS)-mediated hemolysis during exponential growth. This early onset hemolysis correlated with an increased lesion size and severity in a murine soft tissue infection model when compared with parental M1T1 MGAS5005. To identify the PTS components responsible for this phenotype, we insertionally inactivated the 14 annotated PTS EIIC-encoding genes in the GAS MGAS5005 genome and subjected this library to metabolic and hemolysis assays to functionally characterize each EIIC. It was found that a few EIIs had a very limited influence on PTS sugar metabolism, whereas others were fairly promiscuous. The mannose-specific EII locus, encoded by manLMN, was expressed as a mannose-inducible operon that exhibited the most influence on PTS sugar metabolism, including mannose. Importantly, components of the mannose-specific EII also acted to prevent the early onset of SLS-mediated hemolysis. Interestingly, these roles were not identical in two different M1T1 GAS strains, highlighting the possible versatility of the PTS to adapt to strain-specific needs. © 2016 John Wiley & Sons Ltd


Taylor J.R.,George Washington University | Drumwright E.M.,Toyota Research Institute | Hsu J.,Open Mountain
2016 IEEE International Conference on Simulation, Modeling, and Programming for Autonomous Robots, SIMPAR 2016 | Year: 2016

Rigid body simulation libraries are sophisticated software systems that include multiple, tricky to implement numerical algorithms: solving initial value problems, root finding, geometric intersection (collision detection) and contact determination, and solving mathematical programming and optimization problems. How and why such systems fail to produce expected behavior is not readily known and not easy to discern; few of the components described above use reference implementations or are modular, for example, which makes attempting to identify points of failure challenging. Additionally, most libraries present an extraordinary number of parameters to be tuned, which complicates assessment. For the field of robotics, such failures are frustrating. One of the most seminal tasks in the domain, grasping of rigid objects, can require considerable parameter tuning. This paper uses a recent development, the support of four open-source physics engines in the GAZEBO simulator, to assess the ability of simulated robots to maintain grasps of rigid objects. We develop a metric that captures grasping performance and run a multitude of experiments to ascertain causes of failure. We have made all of our experimental code and data freely available, which allows others to reproduce our results and the authors of the corresponding physics engines to compete toward maximizing performance on the grasping task. © 2016 IEEE.


Biggs G.,Japan National Institute of Advanced Industrial Science and Technology | Rusu R.B.,Open Perception | Gerkey B.,Open Mountain | Vaughan R.,Simon Fraser University
IEEE Robotics and Automation Magazine | Year: 2013

When robot researchers talk about robot middle ware, inevitably Player will enter the discussion. This piece of software and its related tools have become one of the most popular software tools in robotics research. Its range of hardware support and the flexibility it offers users, as well as its ease of use and shallow learning curve, have ensured its success. © 2013 IEEE.


Quigley M.,Open Mountain | Salisbury C.,SRI International | Ng A.Y.,Stanford University | Salisbury J.K.,Stanford University
International Journal of Robotics Research | Year: 2014

Historically, robotic hand research has tended to focus on two areas: severely underactuated hands, and high-degree-of-freedom fully actuated hands. Comparatively little research has been done in between those spaces. Furthermore, despite the large number of robotic hand designs that have been proposed in the past few decades, very few robot hands are available for purchase on the commercial market. In this paper, we present a hand designed for minimalistic dexterous manipulation, in which every stage of the design process also considered its manufacturing cost. We discuss the various trade-offs made in the design. Finally, we present the results of experiments in which the robotic hand was affixed to a manipulator arm and teleoperated to grasp and manipulate a variety of objects. © The Author(s) 2014.


Koenig N.,Open Mountain | Mataric M.J.,University of Southern California
Autonomous Robots | Year: 2016

Programming a robot to act intelligently is a challenging endeavor beyond the skill level of most people. Trained roboticists generally program robots for a single purpose. Enabling robots to be programmed by non-experts and to perform multiple tasks are both open challenges in robotics. This paper presents a framework that allows life-long robot task learning from demonstrations. To make that possible, the paper introduces a task representation based on influence diagrams, and a method to transfer knowledge between similar tasks. A novel approach to influence diagram learning is presented along with a demonstration method that allows non-experts to teach tasks to the robot in an intuitive manner. The results from three user studies validate that the approach enables both a simulated and a physical robot to learn complex tasks from a variety of teachers, refining those tasks during on-line performance, successfully completing the tasks in different environments, and transferring knowledge from one task to another. © 2016 Springer Science+Business Media New York


Foote T.,Open Mountain
IEEE Conference on Technologies for Practical Robot Applications, TePRA | Year: 2013

The tf library was designed to provide a standard way to keep track of coordinate frames and transform data within an entire system such that individual component users can be confident that the data is in the coordinate frame that they want without requiring knowledge of all the coordinate frames in the system. During early development of the Robot Operating System (ROS), keeping track of coordinate frames was identified as a common pain point for developers. The complexity of this task made it a common place for bugs when developers improperly applied transforms to data. The problem is also a challenge due to the often distributed sources of information about transformations between different sets of coordinate frames. This paper will explain the complexity of the problem and distill the requirements. Then it will discuss the design of the tf library in relation to the requirements. A few use cases will be presented to demonstrate successful deployment of the library. And powerful extensions to the core capabilities such as being able to transform data in time as well as in space. © 2013 IEEE.


Robinson N.,University of Colorado at Boulder | Armstead S.,University of Colorado at Boulder | Armstead S.,Open Mountain | Deane Bowers M.,University of Colorado at Boulder
Entomologia Experimentalis et Applicata | Year: 2012

We compared variation in butterfly communities across 3 years at six different habitats in a temperate ecosystem near Boulder, Colorado, USA. These habitats were classified by the local Open Space consortium as Grasslands, Tallgrass, Foothills Grasslands, Foothills Riparian, Plains Riparian, and Montane Woodland. Rainfall and temperature varied considerably during these years. We surveyed butterflies using the Pollard-Yates method of invertebrate sampling and compared abundance, species richness, and diversity across habitats and years. Communities were most influenced by habitat, with all three quantitative measures varying significantly across habitats but only two measures showing variation across years. Among habitats, butterfly abundance was higher in Plains Riparian sites than in Montane Woodland or Grassland sites, though diversity was lowest in Plains Riparian areas. Butterfly species richness was higher in Foothills Riparian sites than it was in all but one other habitat (Tallgrass). Among years, butterfly abundance and species richness were lower during the year of least rainfall and highest temperatures, suggesting a substantial impact of the hot, dry conditions. Across habitats and years, butterfly abundance was consistently high at Plains Riparian and Foothills Riparian sites, and richness and diversity were consistently high in Foothills Riparian areas. These two habitats may be highly suitable for butterflies in this ecosystem, regardless of weather conditions. Generally low abundance and species richness in Montane Woodlands sites, particularly in 2002, suggested low suitability of the habitat to butterflies in this ecosystem, and this may be especially important during drought-like conditions. Finally, to examine the effect that the presence of the very abundant non-native species Pieris rapae L. (Lepidoptera: Pieridae) has on these communities, we re-analyzed the data in the absence of this species. Excluding P. rapae dramatically reduced variation of both butterfly abundance and diversity across habitats, highlighting the importance of considering community membership in analyses like ours. © 2012 The Netherlands Entomological Society.


Trademark
Open Mountain | Date: 2012-10-03

Bicycles; sports bicycles; mountain bikes; bicycle parts, namely, forks, seat posts, cranks, handlebars, stems, wheels, saddles, derailleur gears, brakes, pedals, tires, gear controls, aerodynamic handlebars, frames, special baskets for bicycles, luggage racks, steering devices, wheel rims, spokes, inner tubes, valves, bands for wheel hubs, chains, nets, bells, stands, direction indicators, gears; structural parts for all the aforesaid. Clothing, namely, coats, jackets, sweaters, shirts, undershirts, sport shirts, t-shirts, pants, underpants, sport pants, trousers, suits, shorts, scarves, socks, swimming suits, bikinis, dresses, skirts, pullovers, blouses; sportswear, namely, jogging suits; footwear; headgear, namely, hats and caps. Bringing together for the benefit of others of various goods, excluding the transportation thereof, enabling the consumer to view and purchase them conveniently in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; online retail store services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; retail store services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; import-export agency services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; business consulting and commercial advice services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear.


Trademark
Open Mountain | Date: 2013-05-28

Bicycles; sports bicycles; mountain bikes; bicycle parts, namely, forks, seat posts, cranks, handlebars, stems, wheels, saddles, derailleur gears, brakes, pedals, tires, gear controls, aerodynamic handlebars, frames, special baskets for bicycles, luggage racks, steering devices, wheel rims, spokes, inner tubes, valves, bands for wheel hubs, chains, nets, bells, stands, direction indicators, gears; structural parts for all the aforesaid. Clothing, namely, coats, jackets, sweaters, shirts, undershirts, sport shirts, t-shirts, pants, underpants, sport pants, trousers, suits, shorts, scarves, socks, swimming suits, bikinis, dresses, skirts, pullovers, blouses; sportswear, namely, jogging suits; footwear; headgear, namely, hats and caps. Bringing together for the benefit of others of various goods, excluding the transportation thereof, enabling the consumer to view and purchase them conveniently in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; online retail store services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; retail store services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; import-export agency services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear; business consulting and commercial advice services in the field of bicycles as well as parts and accessories thereof, sports bicycles as well as parts and accessories thereof, mountain bikes as well as parts and accessories thereof, clothing, footwear and headgear.


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