20 research outputs found
ESR2–HDA6 complex negatively regulates auxin biosynthesis to delay callus initiation in Arabidopsis leaf explants during tissue culture
No full textPlants exhibit an astonishing ability to regulate organ regeneration upon wounding. Excision of leaf explants promotes the biosynthesis of indole-3-acetic acid (IAA), which is polar-transported to excised regions, where cell fate transition leads to root founder cell specification to induce de novo root regeneration. The regeneration capacity of plants has been utilized to develop in vitro tissue culture technologies. Here, we report that IAA accumulation near the wounded site of leaf explants is essential for callus formation on 2,4-dichlorophenoxyacetic acid (2,4-D)-rich callus-inducing medium (CIM). Notably, a high concentration of 2,4-D does not compensate for the action of IAA because of its limited efflux; rather, it lowers IAA biosynthesis via a negative feedback mechanism at an early stage of in vitro tissue culture, delaying callus initiation. The auxin negative feedback loop in CIM-cultured leaf explants is mediated by an auxin-inducible APETALA2 transcription factor, ENHANCER OF SHOOT REGENERATION 2 (ESR2), along with its interacting partner HISTONE DEACETYLASE 6 (HDA6). The ESR2-HDA6 complex binds directly to, and removes the H3ac mark from, the YUCCA1 ( YUC1 ), YUC7 , and YUC9 loci, consequently repressing auxin biosynthesis and inhibiting cell fate transition on 2,4-D-rich CIM. These findings indicate that negative feedback regulation of auxin biosynthesis by ESR2 and HDA6 interferes with proper cell fate transition and callus initiation.
The AGL6–ELF3–FT circuit controls flowering time in Arabidopsis
No full textAdjusting the timing of floral transition is essential for reproductive success in plants. A number of flowering regulators integrate internal and external signals to precisely determine the time to flower. We here report that the AGAMOUS-LIKE 6 (AGL6) – EARLY FLOWERING 3 (ELF3) module regulates flowering in the FLOWERING LOCUS T (FT)-dependent pathway in Arabidopsis. The AGL6 transcriptional repressor promotes floral transition by directly suppressing ELF3, which in turn directly represses FT expression that acts as a floral integrator. Indeed, ELF3 is epistatic to AGL6 in the control of floral transition. Overall, our findings propose that the AGL6–ELF3 module contributes to fine-tuning flowering time in plants
Editing reality made easy
No full textThesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2017.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Pages unnumbered. Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages [44]-[45]).The Reality Editor is a system based around the concept that physical objects may serve augmented reality web interfaces while communicating information about their state to the local environment. Its combination of an augmented reality web browser with an object messaging system leads to high usability and simplicity. In my contribution to the project, I reduce the difficulty of creating and controlling compelling augmented reality Internet of Things experiences using the Reality Editor. I simplify the creation process through three areas of work: creating reusable user interface components, designing an in-browser editor, and implementing a drag-and-drop in-app editor. My work on enhancing control takes two forms: developing an object memory system and integrating networked cameras. Finally, I improve the Reality Editor as a whole through a series of efforts targeting its documentation, performance, and reliability.by James Keat Hobin.M. Eng
Interactive Use of Cloud Services: Amazon SQS and S3
No full textAbstract-Interactive use of cloud services is of keen interest to science end users, including for storing and accessing shared data sets. This paper evaluates the viability of interactively using two important cloud services offered by Amazon: SQS (Simple Queue Service) and S3 (Simple Storage Service). Specifically, we first measure the send-to-receive message latencies of SQS and then determine and devise rate controls to obtain suitable latencies and latency variations. Second, for S3, when transferring data into the cloud, we determine that increased parallelism in TransferManager can significantly improve upload performance, achieving up to 4 times improvements with careful elimination of upload bottlenecks
From Back-of-the-Envelope to Informed Estimation of Edge Computing Benefits in Minutes Using Castnet
No full text
Instagram and Adoption Rates: The Impact of Proactive Social Media on Adoption Rates at the Arizona Animal Welfare League & SPCA
No full textabstract: This thesis explores how we can harness new technology to improve our relationship with companion animals and promote shelter animal welfare. The study looked into using the photo-sharing application Instagram to increase adoption rates at the Arizona Animal Welfare League & SPCA. An Instagram page was created and managed for the shelter, and data was collected regarding the impact the page had on adoption rates. The results were mixed, but overall it was determined that the Instagram page has unique value for the shelter
Addressing the Fragmentation Problem in Distributed and Decentralized Edge Computing: A Vision
No full textIdentification of chemical scaffolds for targeting ubiquitin-specific protease 11 (USP11) through high-throughput virtual screening
No full textUSP11 is a promising therapeutic target implicated in Alzheimer’s disease and various cancers; however, no specific inhibitors are currently available, with the only known inhibitor being mitoxantrone, which primarily targets topoisomerase II. To identify novel chemical starting points, we conducted high-throughput virtual screening using a USP11 homology model. Screening over 600,000 compounds yielded five structurally distinct hits with significant inhibitory activity. Biochemical validation highlighted two promising scaffolds: benzoxadiazole derivatives and pyrrolo-phenylamidine analogues, both demonstrating structure-dependent inhibition and tractable SAR profiles. Docking studies further characterised their binding modes, supporting their potential for optimisation. Hydroxyphenyl hydrazone analogues raised PAINS-related concerns, while compounds such as squalamine were deprioritized due to weak binding affinity and structural complexity. Overall, this study provides valuable scaffolds and mechanistic insights that can inform future development of potent, selective USP11 inhibitors
