Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
-
Partial differential equations (PDEs) have become an essential tool for modeling complex physical systems. Such equations are typically solved numerically via mesh-based methods, such as finite element methods, with solutions over the spatial domain. However, obtaining these solutions are often prohibitively costly, limiting the feasibility of exploring parameters in PDEs. In this article, we propose an efficient emulator that simultaneously predicts the solutions over the spatial domain, with theoretical justification of its uncertainty quantification. The novelty of the proposed method lies in the incorporation of the mesh node coordinates into the statistical model. In particular, the proposed method segments the mesh nodes into multiple clusters via a Dirichlet process prior and fits Gaussian process models with the same hyperparameters in each of them. Most importantly, by revealing the underlying clustering structures, the proposed method can provide valuable insights into qualitative features of the resulting dynamics that can be used to guide further investigations. Real examples are demonstrated to show that our proposed method has smaller prediction errors than its main competitors, with competitive computation time, and identifies interesting clusters of mesh nodes that possess physical significance, such as satisfying boundary conditions. An R package for the proposed methodology is provided in an open repository.more » « lessFree, publicly-accessible full text available July 2, 2025
-
Free, publicly-accessible full text available March 31, 2025
-
SUMMARY Cell differentiation and morphogenesis are crucial for the establishment of diverse cell types and organs in multicellular organisms. Trichome cells offer an excellent paradigm for dissecting the regulatory mechanisms of plant cell differentiation and morphogenesis due to their unique growth characteristics. Here, we report the isolation of an Arabidopsis mutant,
(a berrantlyb ranchedt richome 3–1abt3‐1 ), with a reduced trichome branching phenotype. Positional cloning and molecular complementation experiments confirmed thatabt3‐1 is a new mutant allele ofAuxin resistant 1 (AXR1 ), which encodes the N‐terminal half of ubiquitin‐activating enzyme E1 and functions in auxin signaling pathway. Meanwhile, we found that transgenic plants expressing constitutively active version ofROP2 (CA‐ROP2 ) caused a reduction of trichome branches, resembling that ofabt3‐1 . ROP2 is a member of Rho GTPase of plants (ROP) family, serving as versatile signaling switches involved in a range of cellular and developmental processes. Our genetic and biochemical analyses showedAXR1 genetically interacted withROP2 and mediated ROP2 protein stability. The loss ofAXR1 aggravated the trichome defects ofCA‐ROP2 and induced the accumulation of steady‐state ROP2. Consistently, elevatedAXR1 expression levels suppressedROP2 expression and partially rescued trichome branching defects inCA‐ROP2 plants. Together, our results presented a new mutant allele ofAXR1 , uncovered the effects ofAXR1 andROP2 during trichome development, and revealed a pathway ofROP2 ‐mediated regulation of plant cell morphogenesis in Arabidopsis. -
Abstract The Arabidopsis (Arabidopsis thaliana) TRANSPARENT TESTA GLABRA2 (TTG2) gene encodes a WRKY transcription factor that regulates a range of development events like trichome, seed coat, and atrichoblast formation. Loss-of-function of TTG2 was previously shown to reduce or eliminate trichome specification and branching. Here, we report the identification of an allele of TTG2, ttg2-6. In contrast to the ttg2 mutants described before, ttg2-6 displayed unique trichome phenotypes. Some ttg2-6 mutant trichomes were hyper-branched, whereas others were hypo-branched, distorted, or clustered. Further, we found that in addition to specifically activating R3 MYB transcription factor TRIPTYCHON (TRY) to modulate trichome specification, TTG2 also integrated cytoskeletal signaling to regulate trichome morphogenesis. The ttg2-6 trichomes displayed aberrant cortical microtubules (cMTs) and actin filaments (F-actin) configurations. Moreover, genetic and biochemical analyses showed that TTG2 could directly bind to the promoter and regulate the expression of BRICK1 (BRK1), which encodes a subunit of the actin nucleation promoting complex suppressor of cyclic AMP repressor (SCAR)/Wiskott–Aldrich syndrome protein family verprolin homologous protein (WAVE). Collectively, taking advantage of ttg2-6, we uncovered a function for TTG2 in facilitating cMTs and F-actin cytoskeleton-dependent trichome development, providing insight into cellular signaling events downstream of the core transcriptional regulation during trichome development in Arabidopsis.
-
Distributed denial-of-service (DDoS) attack is a malicious cybersecurity attack that has become a global threat. Machine learning (ML) as an advanced technology has been proven to be an effective way against DDoS attacks. Feature selection is a crucial step in ML, and researchers have put endless efforts to mitigate the “Curse of Dimensionality”. Feature selection is also causing problems to ML models, such as a decrease in prediction accuracy. Four supervised classification techniques, namely, Decision Tree (DT), k-Nearest Neighbors (KNN), Logistic Regression (LR), and Random Forest (RF), are tested using mutual information score ranking to study the necessity of feature selection in DDoS detection.more » « less
-
SUMMARY Trichome development is a fascinating model to elaborate the plant cell differentiation and growth processes. A wealth of information has pointed to the contributions of the components associated with cell cycle control and ubiquitin/26S proteasome system (UPS) to trichome morphogenesis, but how these two pathways are connected remains obscure. Here, we report that HECT‐type ubiquitin ligase KAKTUS (KAK) targets the cyclin‐dependent kinase (CDK) inhibitor KRP2 (for kip‐related protein 2) for proteasome‐dependent degradation during trichome branching in Arabidopsis. We show that over‐expression of
KRP2 promotes trichome branching and endoreduplication which is similar tokak loss of function mutants. KAK directly interacts with KRP2 and mediates KRP2 degradation. Mutation ofKAK results in the accumulation of steady‐state KRP2. Consistently, inkak pKRP2:KRP2‐GFP plants, the trichome branching is further induced compared with the single mutant. Taken together, our studies bridge the cell cycle control and UPS pathways during trichome development and underscore the importance of post‐translational control in epidermal differentiation.