New Releases by Sean Chen

An investigation was performed to develop a process to design, fabricate, and integrate a large-scale stretchable sensor network to measure strain distribution over a surface area. Capable of measuring actual strains of a structure is critical not only at the structural design phase to validate the design, but also useful to assure quality of the fabrication in the manufacturing phase. Furthermore, if the true measurements could be provided during service, the data could assist evaluating the integrity and safety of operation of the structures. However, the application of distributed strain gauges in an in-situ health monitoring system for critical structural components is oftentimes limited by complicated cabling and performance penalty. In this thesis, a novel method is proposed to revolutionize the traditional way of multipoint load monitoring by designing and deploying a vast quantity of microfabricated metal-foil strain gauges in the form of a stretchable sensor network to collect the measurements at each desired location under deformations and environmental conditions. Specifically, this thesis seeks to examine and tackle two essential challenging problems in embedding large-scale strain sensor networks into structures: (1) the wire effect -- because not only strain sensors but also the entire wires are attached to structures, a model was developed to establish the optimized wiring and eliminate the wire-induced error; (2) the thermal effect -- because strain measurement is strongly temperature dependent, a collocated sensor node design must be devised for accurate thermal compensation. In order to prove and validate the model and design, by taking advantage of advanced micro-electro-mechanical system fabrication and vacuum bag molding techniques, a streamlined process was developed to produce stretchable sensor networks from standard 4-inch silicon wafers and integrate them to structures of various configurations. The concept of distributed strain sensing was demonstrated through a composite panel featuring hotspot detection, load monitoring, and shape estimation functions. To conclude, potential applications of the developed approach for aerospace structures (e.g., space satellite) are proposed.

Endogenous retroviruses (ERVs) constitute a significant fraction of mammalian genomes, but their impact on host biology remains poorly understood. One group of ERVs, murine ERV with leucine tRNA primer (MERVL), is highly expressed during the 2-cell (2C) stage of mouse preimplantation development but is silenced thereafter. While active, MERVL-derived cis-regulatory elements drive expression of hundreds of host genes, including “chimeric” isoforms with exonized MERVL sequences. Remarkably, loss of a single miRNA miR-34a in pluripotent stem cells is sufficient to derepress MERVL and imbue expanded fate potential reminiscent of totipotent 2C blastomeres. Using bioinformatic prediction and reporter assays, I identified gata2 as the primary target of miR-34a that mediates MERVL derepression in pluripotent stem cells. While miR-34a is required for MERVL silencing in pluripotent stem cells, it is dispensable for repressing MERVL during preimplantation development. To evaluate the role of MERVL in vivo, I applied a candidate approach to assess the role of one MERVL-driven chimeric gene tead4:MT2B1. Loss of tead4:MT2B1 results in compensatory upregulation of canonical tead4 transcripts, suggesting that the chimeric isoform functions redundantly in development. In order to facilitate efficient in vivo screening of additional candidates, I developed a high-throughput electroporation-based genome editing technique called CRISPR RNP Electroporation of Zygotes (CRISR-EZ). Compared to previous methodologies, CRISPR-EZ offers significant advantages in throughput, cost, and simplicity. Altogether, I have elucidated a molecular axis involved in the regulation of MERVL and fate potency, setting the stage for further in vivo characterization using improved genome editing tools.

Don''t miss this exciting sci-fi prequel graphic novel of the highly anticipated Warner Bros. & Legendary motion picture, Pacific Rim directed by Guillermo del Toro! Chronicling the very first time Earth is menaced by incredible monsters known as Kaiju, these inhuman beasts rise from the ocean depths and threaten to extinguish all mankind! Witness the race to develop massive robot fighting machines called Jaegers, each one controlled simultaneously by two pilots whose minds are locked in a neural bridge. This action-packed tale features many of the key characters from the film as we follow them in their early careers. Witten by Pacific Rim screenwriter himself, Travis Beacham, and with del Toro''s hands-on supervision, this volume is beautifully illustrated by Sean Chen, Yvel Guichet, and Pericles Junior; inks by Steve Bird and Mark McKenna; and fully painted cover by superstar artist Alex Ross. From the Hardcover edition.

Here''s a delightful collection of fairy-tale short stories written by children for children. A sheep with two heads. A fish who wants to be an adventurer. An inseparable sheep and a fish. A sad moon who learns to accept life. An ugly fish with three eyes. A baking sheep. From the depth of the imagination of young readers who take their turn at storytelling with wonderful hand-drawn illustrations by Alain Boulanger "Hilarious, engaging and imaginative "

When Wolverine rebuffs the reconstituted Weapon X program, management is forced to settle for second best -- but Deadpool''s first assignment may test the limits of his loyalty.