Aerospace medicine and biology: A cumulative index to a continuing bibliography (supplement 345)

This publication is a cumulative index to the abstracts contained in Supplements 333 through 344 of Aerospace Medicine and Biology: A Continuing Bibliography. Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number, and accession number

A Mechanism for Spatial Orientation Based on Sensory Adaptation in Caenorhabditis Elegans

During chemotaxis, animals compute spatial information about odor gradients to make navigational choices for finding or avoiding an odor source. The challenge to the neural circuitry is to interpret and respond to odor concentrations that change over time as animals traverse a gradient. In this thesis, I ask how a nervous system regulates spatial navigation by studying the chemotaxis response of Caenorhabditis elegans to diacetyl. A behavioral analysis demonstrated that AWA sensory neurons drive chemotaxis over several orders of magnitude in odor concentration, providing an entry point for dissecting the mechanistic basis of chemotaxis at the level of neural activity. Precise microfluidic stimulation enabled me to dissociate space from time in the olfactory input to characterize how odor sensing relates to behavior. I systematically measured neuronal responses to odor in the diacetyl chemotaxis circuit, aided by a newly developed imaging system with flexible stimulus delivery and elevated throughput. I found reliable sensory responses to the behaviorally relevant range of odor concentrations. I then followed odor-evoked activity to downstream interneurons that integrate sensory input. Adaptation of neuronal responses to odor yielded a highly sensitive response to small increases in odor concentration at the interneuron level, providing a mechanism for efficient gradient sensing during klinokinesis. Adaptation dynamics at the sensory level were stimulus-dependent and cell-autonomously altered in several classes of mutant animals. Behavioral responses to different concentrations of diacetyl resulted from overlapping contributions from multiple sensory neurons. AWA was specifically required for orientation behavior in response to small increases in odor concentration that are encountered in shallow gradients, demonstrating functional specialization amongst sensory neurons for stimulus characteristics. This work sheds light on an algorithm underlying acute behavioral computation and its biological implementation. The experimental results are presented in two parts: Chapter 2 describes the development of a microscope for high-throughput imaging of neuronal activity in Caenorhabditis elegans. I present a characterization of chemosensory responses to odor and its correlation with behavior. This work has been published (Larsch et al., 2013). Chapter 3 describes the functional architecture of the AWA chemosensory circuit and the role of adaptation in maintaining sensitivity over a wide range of stimulus intensities. This work is currently being prepared for publication

Microdevices and Microsystems for Cell Manipulation

Microfabricated devices and systems capable of micromanipulation are well-suited for the manipulation of cells. These technologies are capable of a variety of functions, including cell trapping, cell sorting, cell culturing, and cell surgery, often at single-cell or sub-cellular resolution. These functionalities are achieved through a variety of mechanisms, including mechanical, electrical, magnetic, optical, and thermal forces. The operations that these microdevices and microsystems enable are relevant to many areas of biomedical research, including tissue engineering, cellular therapeutics, drug discovery, and diagnostics. This Special Issue will highlight recent advances in the field of cellular manipulation. Technologies capable of parallel single-cell manipulation are of special interest

Design and Development of an Automated Mobile Manipulator for Industrial Applications

This thesis presents the modeling, control and coordination of an automated mobile manipulator. A mobile manipulator in this investigation consists of a robotic manipulator and a mobile platform resulting in a hybrid mechanism that includes a mobile platform for locomotion and a manipulator arm for manipulation. The structural complexity of a mobile manipulator is the main challenging issue because it includes several problems like adapting a manipulator and a redundancy mobile platform at non-holonomic constraints. The objective of the thesis is to fabricate an automated mobile manipulator and develop control algorithms that effectively coordinate the arm manipulation and mobility of mobile platform. The research work starts with deriving the motion equations of mobile manipulators. The derivation introduced here makes use of motion equations of robot manipulators and mobile platforms separately, and then integrated them as one entity. The kinematic analysis is performed in two ways namely forward & inverse kinematics. The motion analysis is performed for various WMPs such as, Omnidirectional WMP, Differential three WMP, Three wheeled omni-steer WMP, Tricycle WMP and Two steer WMP. From the obtained motion analysis results, Differential three WMP is chosen as the mobile platform for the developed mobile manipulator. Later motion analysis is carried out for 4-axis articulated arm. Danvit-Hartenberg representation is implemented to perform forward kinematic analysis. Because of this representation, one can easily understand the kinematic equation for a robotic arm. From the obtained arm equation, Inverse kinematic model for the 4-axis robotic manipulator is developed. Motion planning of an intelligent mobile robot is one of the most vital issues in the field of robotics, which includes the generation of optimal collision free trajectories within its work space and finally reaches its target position. For solving this problem, two evolutionary algorithms namely Particle Swarm Optimization (PSO) and Artificial Immune System (AIS) are introduced to move the mobile platform in intelligent manner. The developed algorithms are effective in avoiding obstacles, trap situations and generating optimal paths within its unknown environments. Once the robot reaches its goal (within the work space of the manipulator), the manipulator will generate its trajectories according to task assigned by the user. Simulation analyses are performed using MATLAB-2010 in order to validate the feasibility of the developed methodologies in various unknown environments. Additionally, experiments are carried out on an automated mobile manipulator. ATmega16 Microcontrollers are used to enable the entire robot system movement in desired trajectories by means of robot interface application program. The control program is developed in robot software (Keil) to control the mobile manipulator servomotors via a serial connection through a personal computer. To support the proposed control algorithms both simulation and experimental results are presented. Moreover, validation of the developed methodologies has been made with the ER-400 mobile platform

Linking neural circuits to the mechanics of animal behavior in Drosophila larval locomotion

The motions that make up animal behavior arise from the interplay between neural circuits and the mechanical parts of the body. Therefore, in order to comprehend the operational mechanisms governing behavior, it is essential to examine not only the underlying neural network but also the mechanical characteristics of the animal’s body. The locomotor system of fly larvae serves as an ideal model for pursuing this integrative approach. By virtue of diverse investigation methods encompassing connectomics analysis and quantification of locomotion kinematics, research on larval locomotion has shed light on the underlying mechanisms of animal behavior. These studies have elucidated the roles of interneurons in coordinating muscle activities within and between segments, as well as the neural circuits responsible for exploration. This review aims to provide an overview of recent research on the neuromechanics of animal locomotion in fly larvae. We also briefly review interspecific diversity in fly larval locomotion and explore the latest advancements in soft robots inspired by larval locomotion. The integrative analysis of animal behavior using fly larvae could establish a practical framework for scrutinizing the behavior of other animal species

Hybrid bio-robotics: from the nanoscale to the macroscale

[eng] Hybrid bio-robotics is a discipline that aims at integrating biological entities with synthetic materials to incorporate features from biological systems that have been optimized through millions of years of evolution and are difficult to replicate in current robotic systems. We can find examples of this integration at the nanoscale, in the field of catalytic nano- and micromotors, which are particles able to self-propel due to catalytic reactions happening in their surface. By using enzymes, these nanomotors can achieve motion in a biocompatible manner, finding their main applications in active drug delivery. At the microscale, we can find single-cell bio-swimmers that use the motion capabilities of organisms like bacteria or spermatozoa to transport microparticles or microtubes for targeted therapeutics or bio-film removal. At the macroscale, cardiac or skeletal muscle tissue are used to power small robotic devices that can perform simple actions like crawling, swimming, or gripping, due to the contractions of the muscle cells. This dissertation covers several aspects of these kinds of devices from the nanoscale to the macro-scale, focusing on enzymatically propelled nano- and micromotors and skeletal muscle tissue bio-actuators and bio-robots. On the field of enzymatic nanomotors, there is a need for a better description of their dynamics that, consequently, might help understand their motion mechanisms. Here, we focus on several examples of nano- and micromotors that show complex dynamics and we propose different strategies to analyze their motion. We develop a theoretical framework for the particular case of enzymatic motors with exponentially decreasing speed, which break the assumptions of constant speed of current methods of analysis and need different strategies to characterize their motion. Finally, we consider the case of enzymatic nanomotors moving in complex biological matrices, such as hyaluronic acid, and we study their interactions and the effects of the catalytic reaction using dynamic light scattering, showing that nanomotors with negative surface charge and urease-powered motion present enhanced parameters of diffusion in hyaluronic acid. Moving towards muscle-based robotics, we investigate the application of 3D bioprinting for the bioengineering of skeletal muscle tissue. We demonstrate that this technique can yield well-aligned and functional muscle fibers that can be stimulated with electric pulses. Moreover, we develop and apply a novel co-axial approach to obtain thin and individual muscle fibers that resemble the bundle-like organization of native skeletal muscle tissue. We further exploit the versatility of this technique to print several types of materials in the same process and we fabricate bio-actuators based on skeletal muscle tissue with two soft posts. Due to the deflection of these cantilevers when the tissue contracts upon stimulation, we can measure the generated forces, therefore obtaining a force measurement platform that could be useful for muscle development studies or drug testing. With these applications in mind, we study the adaptability of muscle tissue after applying various exercise protocols based on different stimulation frequencies and different post stiffness, finding an increase of the force generation, especially at medium frequencies, that resembles the response of native tissue. Moreover, we adapt the force measurement platform to be used with human-derived myoblasts and we bioengineer two models of young and aged muscle tissue that could be used for drug testing purposes. As a proof of concept, we analyze the effects of a cosmetic peptide ingredient under development, focusing on the kinematics of high stimulation contractions. Finally, we present the fabrication of a muscle-based bio-robot able to swim by inertial strokes in a liquid interface and a nanocomposite-laden bio-robot that can crawl on a surface. The first bio-robot is thoroughly characterized through mechanical simulations, allowing us to optimize the skeleton, based on a serpentine or spring-like structure. Moreover, we compare the motion of symmetric and asymmetric designs, demonstrating that, although symmetric bio-robots can achieve some motion due to spontaneous symmetry breaking during its self-assembly, asymmetric bio-robots are faster and more consistent in their directionality. The nanocomposite-laden crawling bio-robot consisted of embedded piezoelectric boron nitride nanotubes that improved the differentiation of the muscle tissue due to a feedback loop of piezoelectric effect activated by the same spontaneous contractions of the tissue. We find that bio-robots with those nanocomposites achieve faster motion and stronger force outputs, demonstrating the beneficial effects in their differentiation. This research presented in this thesis contributes to the development of the field of bio-hybrid robotic devices. On enzymatically propelled nano- and micromotors, the novel theoretical framework and the results regarding the interaction of nanomotors with complex media might offer useful fundamental knowledge for future biomedical applications of these systems. The bioengineering approaches developed to fabricate murine- or human-based bio-actuators might find applications in drug screening or to model heterogeneous muscle diseases in biomedicine using the patient’s own cells. Finally, the fabrication of bio-hybrid swimmers and nanocomposite crawlers will help understand and improve the swimming motion of these devices, as well as pave the way towards the use of nanocomposite to enhance the performance of future actuators.[spa] La bio-robótica híbrida es una disciplina cuyo objetivo es la integración de entidades biológicas con materiales sintéticos para superar los desafíos existentes en el campo de la robótica blanda, incorporando características de los sistemas biológicos que han sido optimizadas durante millones de años de evolución natural y no son fáciles de reproducir artificialmente. Esta tesis cubre varios aspectos de este tipo de dispositivos desde la nanoescala a la macroescala, enfocándose en nano- y micromotores propulsados enzimáticamente y bio-actuadores y bio-robots basados en tejido muscular esquelético. En el campo de nanomotores enzimáticos, existe la necesidad de encontrar mejores modelos que puedan describir la dinámica de su movimiento para llegar a entender sus mecanismos de propulsión subyacentes. Aquí, nos enfocamos en diversos ejemplos de nano- y micromotores que muestran dinámicas de movimiento complejas y proponemos diferentes estrategias que se pueden utilizar para analizar y caracterizar este movimiento. Moviéndonos hacia robots basados en células musculares, investigamos la aplicación de la técnica de bioimpresión en 3D para la biofabricación de músculo esquelético. Demostramos que esta técnica puede producir fibras musculares funcionales y bien alineadas que puede ser estimuladas y contraerse con pulsos eléctricos. Investigamos la versatilidad de esta técnica para imprimir varios tipos de materiales en el mismo proceso y fabricamos bio-actuadores basados en músculo esquelético. Debido a los movimientos de unos postes gracias a las contracciones musculares, podemos obtener medidas de la fuerza ejercida, obteniendo una plataforma de medición de fuerzas que podría ser de utilidad para estudios sobre el desarrollo del músculo o para testeo de fármacos. Finalmente, presentamos la fabricación de un bio-robot basado en músculo esquelético capaz de nadar en la superficie de un líquido y un bio-robot con nanocompuestos incrustados que puede arrastrarse por una superficie sólida. El primer de ellos es minuciosamente caracterizado a través de simulaciones mecánicas, permitiéndonos optimizar su esqueleto, basado en una estructura tipo serpentina o muelle. El segundo bio-robot contiene nanotubos piezoeléctricos incrustados en su tejido, los cuales ayudan en la diferenciación del músculo debido a una retroalimentación basada en su efecto piezoeléctrico y activada por las contracciones espontáneas del tejido. Mostramos que estos bio-robots pueden generar un movimiento más rápido y una mayor generación de fuerza, demostrando los efectos beneficiales en la diferenciación del tejido

Book of Abstracts 15th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering and 3rd Conference on Imaging and Visualization

In this edition, the two events will run together as a single conference, highlighting the strong connection with the Taylor & Francis journals: Computer Methods in Biomechanics and Biomedical Engineering (John Middleton and Christopher Jacobs, Eds.) and Computer Methods in Biomechanics and Biomedical Engineering: Imaging and Visualization (JoãoManuel R.S. Tavares, Ed.). The conference has become a major international meeting on computational biomechanics, imaging andvisualization. In this edition, the main program includes 212 presentations. In addition, sixteen renowned researchers will give plenary keynotes, addressing current challenges in computational biomechanics and biomedical imaging. In Lisbon, for the first time, a session dedicated to award the winner of the Best Paper in CMBBE Journal will take place. We believe that CMBBE2018 will have a strong impact on the development of computational biomechanics and biomedical imaging and visualization, identifying emerging areas of research and promoting the collaboration and networking between participants. This impact is evidenced through the well-known research groups, commercial companies and scientific organizations, who continue to support and sponsor the CMBBE meeting series. In fact, the conference is enriched with five workshops on specific scientific topics and commercial software.info:eu-repo/semantics/draf

On the development of slime mould morphological, intracellular and heterotic computing devices

The use of live biological substrates in the fabrication of unconventional computing (UC) devices is steadily transcending the barriers between science fiction and reality, but efforts in this direction are impeded by ethical considerations, the field’s restrictively broad multidisciplinarity and our incomplete knowledge of fundamental biological processes. As such, very few functional prototypes of biological UC devices have been produced to date. This thesis aims to demonstrate the computational polymorphism and polyfunctionality of a chosen biological substrate — slime mould Physarum polycephalum, an arguably ‘simple’ single-celled organism — and how these properties can be harnessed to create laboratory experimental prototypes of functionally-useful biological UC prototypes. Computing devices utilising live slime mould as their key constituent element can be developed into a) heterotic, or hybrid devices, which are based on electrical recognition of slime mould behaviour via machine-organism interfaces, b) whole-organism-scale morphological processors, whose output is the organism’s morphological adaptation to environmental stimuli (input) and c) intracellular processors wherein data are represented by energetic signalling events mediated by the cytoskeleton, a nano-scale protein network. It is demonstrated that each category of device is capable of implementing logic and furthermore, specific applications for each class may be engineered, such as image processing applications for morphological processors and biosensors in the case of heterotic devices. The results presented are supported by a range of computer modelling experiments using cellular automata and multi-agent modelling. We conclude that P. polycephalum is a polymorphic UC substrate insofar as it can process multimodal sensory input and polyfunctional in its demonstrable ability to undertake a variety of computing problems. Furthermore, our results are highly applicable to the study of other living UC substrates and will inform future work in UC, biosensing, and biomedicine