5,401 research outputs found

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 129, June 1974

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    This special bibliography lists 280 reports, articles, and other documents introduced into the NASA scientific and technical information system in May 1974

    Challenges and opportunities for quantifying roots and rhizosphere interactions through imaging and image analysis

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    The morphology of roots and root systems influences the efficiency by which plants acquire nutrients and water, anchor themselves and provide stability to the surrounding soil. Plant genotype and the biotic and abiotic environment significantly influence root morphology, growth and ultimately crop yield. The challenge for researchers interested in phenotyping root systems is, therefore, not just to measure roots and link their phenotype to the plant genotype, but also to understand how the growth of roots is influenced by their environment. This review discusses progress in quantifying root system parameters (e.g. in terms of size, shape and dynamics) using imaging and image analysis technologies and also discusses their potential for providing a better understanding of root:soil interactions. Significant progress has been made in image acquisition techniques, however trade-offs exist between sample throughput, sample size, image resolution and information gained. All of these factors impact on downstream image analysis processes. While there have been significant advances in computation power, limitations still exist in statistical processes involved in image analysis. Utilizing and combining different imaging systems, integrating measurements and image analysis where possible, and amalgamating data will allow researchers to gain a better understanding of root:soil interactions

    Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 187

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    This supplement to Aerospace Medicine and Biology lists 247 reports, articles and other documents announced during November 1978 in Scientific and Technical Aerospace Reports (STAR) or in International Aerospace Abstracts (IAA). In its subject coverage, Aerospace Medicine and Biology concentrates on the biological, physiological, psychological, and environmental effects to which man is subjected during and following simulated or actual flight in the earth's atmosphere or in interplanetary space. References describing similar effects of biological organisms of lower order are also included. Emphasis is placed on applied research, but reference to fundamental studies and theoretical principles related to experimental development also qualify for inclusion. Each entry in the bibliography consists of a bibliographic citation accompanied in most cases by an abstract

    Aerospace medicine and biology: A continuing bibliography with indexes, supplement 183

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    This bibliography lists 273 reports, articles, and other documents introduced into the NASA scientific and technical information system in July 1978

    Rafigh: A Living Media System for Motivating Target Application Use for Children

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    Digital living media systems combine living media such as plants, animals and fungi with computational components. In this dissertation, I respond to the question of how can digital living media systems better motivate children to use target applications (i.e., learning and/or therapeutic applications)? To address this question, I employed a participatory design approach where I incorporated input from children, parents, speech language pathologists and teachers into the design of a new system. Rafigh is a digital embedded system that uses the growth of a living mushrooms colony to provide positive reinforcements to children when they conduct target activities. The growth of the mushrooms is affected by the amount of water administered to them, which in turn corresponds to the time children spend on target applications. I used an iterative design process to develop and evaluate three Rafigh prototypes. The evaluations showed that the system must be robust, customizable, and should include compelling engagement mechanisms to keep the children interested. I evaluated Rafigh using two case studies conducted in participants homes. In each case study, two siblings and their parent interacted with Rafigh over two weeks and the parents identified a series of target applications that Rafigh should motivate the children to use. The study showed that Rafigh motivated the children to spend significantly more time on target applications during the intervention phase and that it successfully engaged one out of two child participants in each case study who showed signs of responsibility, empathy and curiosity towards the living media. The study showed that the majority of participants described the relationship between using target applications and mushrooms growth correctly. Further, Rafigh encouraged more communication and collaboration between the participants. Rafighs slow responsivity did not impact the engagement of one out of two child participants in each case study and might even have contributed to their investment in the project. Finally, Rafighs presence as an ambient physical object allowed users to interact with it freely and as part of their home environment

    Phototactic and Chemotactic Signal Transduction by Transmembrane Receptors and Transducers in Microorganisms

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    Microorganisms show attractant and repellent responses to survive in the various environments in which they live. Those phototaxic (to light) and chemotaxic (to chemicals) responses are regulated by membrane-embedded receptors and transducers. This article reviews the following: (1) the signal relay mechanisms by two photoreceptors, Sensory Rhodopsin I (SRI) and Sensory Rhodopsin II (SRII) and their transducers (HtrI and HtrII) responsible for phototaxis in microorganisms; and (2) the signal relay mechanism of a chemoreceptor/transducer protein, Tar, responsible for chemotaxis in E. coli. Based on results mainly obtained by our group together with other findings, the possible molecular mechanisms for phototaxis and chemotaxis are discussed

    A practical review on the measurement tools for cellular adhesion force

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    Cell cell and cell matrix adhesions are fundamental in all multicellular organisms. They play a key role in cellular growth, differentiation, pattern formation and migration. Cell-cell adhesion is substantial in the immune response, pathogen host interactions, and tumor development. The success of tissue engineering and stem cell implantations strongly depends on the fine control of live cell adhesion on the surface of natural or biomimetic scaffolds. Therefore, the quantitative and precise measurement of the adhesion strength of living cells is critical, not only in basic research but in modern technologies, too. Several techniques have been developed or are under development to quantify cell adhesion. All of them have their pros and cons, which has to be carefully considered before the experiments and interpretation of the recorded data. Current review provides a guide to choose the appropriate technique to answer a specific biological question or to complete a biomedical test by measuring cell adhesion
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