946 research outputs found

    On the molecular biology and evolution of plant parasitism by nematodes

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    Plant-parasitic nematodes (PPN) are among the most devastating plant pathogens. However, our understanding of how nematodes adapted to plant parasitism, and the molecular mechanisms that PPN use during infection is limited. Among the most important genomic changes that occurred in the free-living nematode ancestors of PPN were multiple horizontal gene transfer (HGT) events from bacteria. Though it is clear that HGT helped shape the genomes of many PPN, how this process occurred is unknown. Also, it is evident that successful parasitism occurs from the delivery of proteinaceous effectors into plant roots to hijack and modify host cellular processes. The research included in this dissertation aims at addressing several important questions regarding HGT in PPN, and investigates important molecular, cellular and developmental processes that are determined critical for successful parasitism. Of particular emphasis throughout this dissertation is the soybean cyst nematode, Heterodera glycines, due to a highly specialized and agronomically important interaction with its soybean host. Major findings for HGT in PPN include the identification of eighteen new H. glycines effectors, three of which are determined to have been part of more ancient HGT events from rhizosphere bacteria. Additionally, homologs of two of the three HGT genes are shown to have been transferred numerous different times from bacteria to diverse eukaryotes and archaea. The latter findings indicate the likely evolutionary advantages that these genes provided not just to PPN, but many different taxa. Intriguingly, we reveal that a group of retroviruses specific to distal nematode clades is genomically associated with HGT genes in PPN genomes. These retroviruses potentially have all of the elements that would be necessary for HGT to occur in PPN. Thus, we propose the tempting hypothesis that this specific group of retroviruses might have contributed to HGT in these nematodes. We also reveal several novelties for plant-nematode interactions. Major findings include the discovery of a strongly expressed H. glycines effector that is essential for virulence and efficiently targets plant cell nucleoli for suppression of innate immune responses. Also, this H. glycines effector contains marginal, but significant sequence similarity with an immunosuppressive effector found only in Plasmodium spp., the malaria parasites. Extensive database searches, phylogenetic analyses, and functional complementation experiments conclude that the similarities are best explained by sequence convergence due to similar immunosuppressive functions. Furthermore, we determine that a specific microRNA network in soybean that is essential for plant development delineates the formation of the H. glycines feeding site, and interfering with this network renders soybean roots much less susceptible to infection. In conclusion, the major findings included in this dissertation reveal novel insights into how nematodes adapted to plant parasitism, and for how PPN manipulate their host plants during infection to establish compatible interactions. Moreover, these findings will undoubtedly provide foundations for developing novel control measures against these important plant pathogens

    The effects of eccentric training on strength and muscle development in pre-pubertal and pubertal boys

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    It is now generally accepted that strength training in pubertal children will increase strength, but it is unlikely to induce morphological changes. However research in this area is limited as most studies fail to control for the confounding effects of normal growth, or employ appropriate training programs. To overcome these limitations it is suggested that researchers should use a within-subject design employing an exercise regime of sufficient intensity. In adults, eccentric training has been shown to have the greatest effect on hypertrophy and strength. The purpose of the study was to examine the effects of eccentric training on muscle strength and development in children, using a one arm training model. Seventeen boys in grades 6, 7, and 8 participated in an eight week eccentric elbow flexion training program; three training sessions per week. The program consisted of 2 – 5 sets of 6 – 10 reps using progressive resistance. Pre and post test strength (Eccentric and concentric elbow flexion maximal strength by a Biodex System 3 Dynamometer and 1 RM with dumbbells) and bicep thickness measurements were performed. The change in biceps thickness was significantly greater in the training arm versus the non-training arm (7.3 +/- 8.3% vs. 0.7 +/- 7.5%) (p0.05), but isokinetic eccentric strength gain in the training arm was significantly greater than the non-training arm (25.4 +/- 16.6% vs. 2.4% +/- 15.6%) (

    FPGA-Based CNN Inference Accelerator Synthesized from Multi-Threaded C Software

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    A deep-learning inference accelerator is synthesized from a C-language software program parallelized with Pthreads. The software implementation uses the well-known producer/consumer model with parallel threads interconnected by FIFO queues. The LegUp high-level synthesis (HLS) tool synthesizes threads into parallel FPGA hardware, translating software parallelism into spatial parallelism. A complete system is generated where convolution, pooling and padding are realized in the synthesized accelerator, with remaining tasks executing on an embedded ARM processor. The accelerator incorporates reduced precision, and a novel approach for zero-weight-skipping in convolution. On a mid-sized Intel Arria 10 SoC FPGA, peak performance on VGG-16 is 138 effective GOPS

    Mindboggle: Automated brain labeling with multiple atlases

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    BACKGROUND: To make inferences about brain structures or activity across multiple individuals, one first needs to determine the structural correspondences across their image data. We have recently developed Mindboggle as a fully automated, feature-matching approach to assign anatomical labels to cortical structures and activity in human brain MRI data. Label assignment is based on structural correspondences between labeled atlases and unlabeled image data, where an atlas consists of a set of labels manually assigned to a single brain image. In the present work, we study the influence of using variable numbers of individual atlases to nonlinearly label human brain image data. METHODS: Each brain image voxel of each of 20 human subjects is assigned a label by each of the remaining 19 atlases using Mindboggle. The most common label is selected and is given a confidence rating based on the number of atlases that assigned that label. The automatically assigned labels for each subject brain are compared with the manual labels for that subject (its atlas). Unlike recent approaches that transform subject data to a labeled, probabilistic atlas space (constructed from a database of atlases), Mindboggle labels a subject by each atlas in a database independently. RESULTS: When Mindboggle labels a human subject's brain image with at least four atlases, the resulting label agreement with coregistered manual labels is significantly higher than when only a single atlas is used. Different numbers of atlases provide significantly higher label agreements for individual brain regions. CONCLUSION: Increasing the number of reference brains used to automatically label a human subject brain improves labeling accuracy with respect to manually assigned labels. Mindboggle software can provide confidence measures for labels based on probabilistic assignment of labels and could be applied to large databases of brain images

    Creation, God, and the Coronavirus

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    This short reflection argues that, in the face of natural crises that occur in the world, responsible Christian speech requires a much fuller and more thickly textured understanding of creation than is often presented. Reading the Bible leads us to avoid speculating on the origins or purposes of such crises. Rather, it bears witness to the divine promise of hope in the healing justice of God, and calls human persons and human communities to participate in that justice through responsible action

    The Westerville Naturals Baseball Team & Otterbein Health And Sport Sciences, Student Project

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    We had the privilege to give back to our community in the form of manual labor. The Westerville Naturals baseball team needed a hand moving gravel in order to store a shed behind their field. The team provided a gator to transport the gravel from the parking lot to the field. The objective was to scoop shovels full of gravel into the back of the gator. We took multiple trips to load the five tons of gravel and transport it to the new location. Once moved, the sheds needed a facelift so it was decided to paint the sheds. We were able to get in-touch with the coach and schedule a date and time that worked best with all of our schedules. We have also organized the opportunity for the Westerville Naturals’ players take the field with the Otterbein baseball players at a home game, while the national anthem was played. We are hoping this will be the start of a tradition/legacy that the kids look forward too for many years to come. The practice and game field conditions for the youth team will be much more efficient in setting up and tearing down each day. Now that equipment storage is in place, with a more sturdy foundation than before, the team has a tangible reminder about the work that are students were willing to do for them, in order to show support of their team. The entire project has proven to be successful, the only difficult thing being the scheduling. We had to make sure it worked with their team as well as our schedules before we could get started. In the future we would recommend having a few gators to transport the gravel, as it seemed we were standing around waiting for it to get back after being dumped. We would have also liked to have had a larger budget to provide the youth athletes with a piece of memorabilia to remind them of their experience with the Otterbein Baseball Team
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