Self-assembly enables nature to build complex forms, from multicellular organisms to complex animal structures such as flocks of birds, through the interaction of vast numbers of limited and unreliable individuals. Creating this ability in engineered systems poses challenges in the design of both algorithms and physical systems that can operate at such scales. We report a system that demonstrates programmable self-assembly of complex two-dimensional shapes with a thousand-robot swarm. This was enabled by creating autonomous robots designed to operate in large groups and to cooperate through local interactions and by developing a collective algorithm for shape formation that is highly robust to the variability and error characteristic of large-scale decentralized systems. This work advances the aim of creating artificial swarms with the capabilities of natural ones.

In current robotics research there is a vast body of work on algorithms and control methods for groups of decentralized cooperating robots, called a swarm or collective. These algorithms are generally meant to control collectives of hundreds or even thousands of robots; however, for reasons of cost, time, or complexity, they are generally validated in simulation only, or on a group of a few tens of robots. To address this issue, this paper presents Kilobot, a low-cost robot designed to make testing collective algorithms on hundreds or thousands of robots accessible to robotics researchers. To enable the possibility of large Kilobot collectives where the number of robots is an order of magnitude larger than the largest that exist today, each robot is made with only $14 worth of parts and takes 5 minutes to assemble. Furthermore, the robot design allows a single user to easily operate a large Kilobot collective, such as programming, powering on, and charging all robots, which would be difficult or impossible to do with many existing robotic systems.

No abstract

One of the most challenging issues for a selfsustaining robotic system is how to use its limited resources to accomplish a large variety of tasks. The scope of such tasks could include transportation, exploration, construction, inspection, maintenance, in-situ resource utilization, and support for astronauts. This paper proposes a modular and reconfigurable solution for this challenge by allowing a robot to support multiple modes of locomotion and select the appropriate mode for the task at hand. This solution relies on robots that are made of reconfigurable modules. Each locomotion mode consists of a set of characteristics for the environment type, speed, turning-ability, energy-efficiency, and recoverability from failures. This paper demonstrates a solution using the SuperBot robot that combines advantages from M-TRAN, CONRO, ATRON, and other chain-based and lattice-based robots. At the present, a single real SuperBot module can move, turn, sidewind, maneuver, and travel on batteries up to 500 m on carpet in an office environment. In physics-based simulation, SuperBot modules can perform multimodal locomotions such as snake, caterpillar, insect, spider, rolling track, H-walker, etc. It can move at speeds of up to 1.0 m/s on flat terrain using less than 6 W per module, and climb slopes of no less 40 degrees.

Abslrad-Docking between independent groups of selfreconfigurnble robotic modules enables the merger of two or more independent self-reconfigurable robots. This ability allows independent reconfigurable robots in the same environment to join together to complete a task that could otherwise not be possible with the individual robots prior to mergins The challenges for this task include (1) coordinate and align two independent self-reconfigurable robots using the docking guidance system available only at the connectors of the docking modules; (2) overcome the ineritable errors in the alignment by a novel and coordinated movements from both docking ends, (3) ensum the secore conneetion at the end of docking; (4) switch configuration and let modules to discover the changes and new connections so that the two docked robots will move as a single coherent robot. We have developed methods for overcome these challenging problems and accomplished for the fmt time an actual docking between two independent CONRO robots each with multiple modules. Kqnvords-se~-reconfigigurabIe robots,LTuIDnomous docking, remote sensor dignemenf, complian: docking. I. IATRODUCTIONDocking between multiple components is a basic problem that occurs in almost all engineering systems that must dynamically change their structures for various purposes. Generally speaking, docking behavior can be either human-operated or autonomous.Human-operated docking is widely seen in daily life, and can be as simple as changiog a blade in a razor 01 as complex as docking one spacecraft to another. One example of humanoperated docking is docking the space shuttle to an orbiting crafl. Here docking has to be very precise and the procedure can be lengthy. It can take hours to accomplish space docking under human master-slave control. The position and attihrde requirements are very severe since the opening is large and the joint has to be good enough to support an airlack. Thus, not only is it necessary to control the position and orientation, but the farce needed to compress the w i n g seal must be controlled correctly also, thus adding complexity to the task In comparison with human-operated docking, autonomous docking is a more difficult problem. For example, two satellites docking in space may take many hours to align, approach, dock and secure. In many engineaing domains, conditions are preset in order to make the process feasible and reliable. For example, docking among lwmotives and railroad cars is an example worth looking at in detail. The cars are on rails; all rads in one country have the same width (to quite high tolerances); all cars have the same height (again to quite high tolerances); the coupling hooks are genderless (hermaphroditic) and held loosely enough so that the hook on one cax will slide over the hook on the second car in spite of the build-up of tolerances and then lock. Under these conditions, docking can happen automatically when two railroad cars are approaching each other on the same track with a certain speed A f l~ docking is establish...

No abstract

Telomerase consists of at least two essential elements, an RNA component hTR or TERC that contains the template for telomere DNA addition and a catalytic reverse transcriptase (TERT). While expression of TERT has been considered the key rate-limiting component for telomerase activity, increasing evidence suggests an important role for the regulation of TERC in telomere maintenance and perhaps other functions in human cancer. By using three orthogonal methods including RNAseq, RT-qPCR, and an analytically validated chromogenic RNA in situ hybridization assay, we report consistent overexpression of TERC in prostate cancer. This overexpression occurs at the precursor stage (e.g. high-grade prostatic intraepithelial neoplasia or PIN) and persists throughout all stages of disease progression. Levels of TERC correlate with levels of MYC (a known driver of prostate cancer) in clinical samples and we also show the following: forced reductions of MYC result in decreased TERC levels in eight cancer cell lines (prostate, lung, breast, and colorectal); forced overexpression of MYC in PCa cell lines, and in the mouse prostate, results in increased TERC levels; human TERC promoter activity is decreased after MYC silencing; and MYC occupies the TERC locus as assessed by chromatin immunoprecipitation (ChIP). Finally, we show that knockdown of TERC by siRNA results in reduced proliferation of prostate cancer cell lines. These studies indicate that TERC is consistently overexpressed in all stages of prostatic adenocarcinoma and that its expression is regulated by MYC. These findings nominate TERC as a novel prostate cancer biomarker and therapeutic target.

No abstract