Search Research Outputs
Recent Additions
- PublicationCharged-particle production as a function of the relative transverse activity classifier in pp, p–Pb, and Pb–Pb collisions at the LHC(2024-01-01)Measurements of charged-particle production in pp, p–Pb, and Pb–Pb collisions in the toward, away, and transverse regions with the ALICE detector are discussed. These regions are defined event-by-event relative to the azimuthal direction of the charged trigger particle, which is the reconstructed particle with the largest transverse momentum pTtrig in the range 8
- PublicationMicrowave-assisted Transfer Hydrogenation of Carbonyl and Nitro Compounds by Bimetallic Ru(II) cymene Complexes(2024-01-01)Herein we report on the investigation of microwave-assisted catalytic transfer hydrogenation (TH) of carbonyl and nitro compounds by employing Ru(II) complexes bimetallic [(p-cymene)2(RuCl)2L1]2X (X = BF4(Cat2); X = PF6(Cat3)) and mononuclear [(p-cymene)(RuCl)L2]BF4(Cat4) (where L1= N,N'-(3,3',5,5'-tetraisopropyl-[1,1'-biphenyl]-4,4'-diyl)bis(1-(pyridin-2-yl)methanimine); L2 = N-(2,6-diisopropyl-phenyl)-1-(pyridin-2-yl)-methanimine). At a low catalyst loading of 0.01 mol% (Cat2/Cat3), a broad substrate scope has been achieved for aromatic as well as aliphatic ketones and aldehydes, with a short reaction time of just 10 minutes. Additionally, chemoselective hydrogenation of nitroaromatic compounds has been achieved under microwave irradiation by Cat2 within 5 minutes. Control experiments demonstrate that microwave heating conditions outperform conventional heating method in terms of improved catalytic activity and reaction efficiency. The bimetallic Cat2 catalyst can be used at a very low loading of 0.001 mol% to achieve the high TONs and TOFs of 7.7 × 104and 2.3 × 105h-1, respectively, for TH reaction. Spectrometry experiments for intermediate trapping have been used to propose a probable mechanism for TH of carbonyl compounds.
- PublicationNumerical study of nonlinear interaction of the guided wave due to breathing type debonding in stiffened panel(2024-03-01)The common tool for assessment of breathing-type debonding in metallic or composite structures is nonlinear guided wave-based technique. The past studies show that with debonding size, the strength of the nonlinearity does not exhibit strictly increasing or decreasing trends, or that the monocity is valid up to a certain size limit of debonding. This paper presents the study of non-linear interaction of guided waves in the debonding interface of a metallic stiffened panel. The study attempts to establish a relationship between the contact energy generated by the contact acoustic nonlinearity (CAN) at the debonding interface and the associated nonlinearity strength for various debonding sizes at various excitation frequencies. A numerical model of the stiffened panels is developed in three-dimensional finite element (FE) and validated with experiments for the study of interaction of nonlinear guided waves. The validated FE model is used to conduct studies on nonlinear interactions in debonding. The outcome of this study contributes to a better understanding of how guided waves can be used to effectively assess the debonding in metallic stiffened panels by considering non-linear interactions at the debonding interface. The study also provides insights into a more accurate and consistent quantification of the debonding using higher harmonic signals and contact energy produced by non-linear interactions.
- PublicationTransforming Simulated Data into Experimental Data Using Deep Learning for Vibration-Based Structural Health Monitoring(2024-03-01)While machine learning (ML) has been quite successful in the field of structural health monitoring (SHM), its practical implementation has been limited. This is because ML model training requires data containing a variety of distinct instances of damage captured from a real structure and the experimental generation of such data is challenging. One way to tackle this issue is by generating training data through numerical simulations. However, simulated data cannot capture the bias and variance of experimental uncertainty. To overcome this problem, this work proposes a deep-learning-based domain transformation method for transforming simulated data to the experimental domain. Use of this technique has been demonstrated for debonding location and size predictions of stiffened panels using a vibration-based method. The results are satisfactory for both debonding location and size prediction. This domain transformation method can be used in any field in which experimental data for training machine-learning models is scarce.
- PublicationExperimental and Computational Analyses of Sustainable Approaches in Railways(2024-03-01)Railway transportation is widely recognized as an environment-friendly and sustainable means for conveying freight and passengers over long distances. This article investigates the effectiveness of utilizing scrap tire rubber granules and geosynthetics to enhance track performance in response to the growing demands for railway transport and the consequent escalation of train-induced loading. A multi-faceted methodology, incorporating experimental, numerical, and analytical techniques, is employed to examine the efficacy of these sustainable approaches. Results from three-dimensional (3D) finite element (FE) analyses conducted on slab tracks for high-speed railways reveal that the addition of a resilient layer, comprising scrap tire rubber granules, reduces vertical stress within the track substructure. Laboratory investigations on an innovative composite material consisting of soil, scrap rubber granules, and polyurethane demonstrate its potential to enhance track performance. Findings from two-dimensional (2D) FE analyses conducted on pile-supported railway embankments highlight an enhanced transfer of load to the pile head following the installation of a geogrid layer at the embankment base. Finally, the results from the analytical approach indicate a reduction in track settlement and a decrease in the track geometry degradation rate on reinforcing the ballast layer with 3D cellular geoinclusion. The novelty of this study lies in the comprehensive assessment of the innovative composite material under drained and cyclic loading conditions, the investigation of the influence of train loading on geosynthetic tension and the load transfer mechanism in railway embankments, and the development of an innovative computational methodology capable of assessing the effectiveness of 3D cellular inclusions in improving the ballasted railway track performance. The findings from this article underscore the effectiveness of these sustainable approaches in mitigating the challenges posed by increased loads on railway tracks, providing valuable insights for the ongoing efforts to optimize railway transportation infrastructure.
Most viewed
- PublicationPTEN Regulates Glucose Transporter Recycling by Impairing SNX27 Retromer Assembly(2017-11-07)The tumor suppressor PTEN executes cellular functions predominantly through its phosphatase activity. Here we identified a phosphatase-independent role for PTEN during vesicular trafficking of the glucose transporter GLUT1. PTEN physically interacts with SNX27, a component of the retromer complex that recycles transmembrane receptors such as GLUT1 from endosomes to the plasma membrane. PTEN binding with SNX27 prevents GLUT1 accumulation at the plasma membrane because of defective recycling and thus reduces cellular glucose uptake. Mechanistically, PTEN blocks the association of SNX27 with VPS26 and thereby hinders assembly of a functional retromer complex during the receptor recycling process. Importantly, we found a PTEN somatic mutation (T401I) that is defective in disrupting the association between SNX27 and VPS26, suggesting a critical role for PTEN in controlling optimal GLUT1 levels at the membrane to prevent tumor progression. Together, our results reveal a fundamental role of PTEN in the regulation of the SNX27 retromer pathway, which governs glucose transport and might contribute to PTEN tumor suppressor function. Shinde et al. identify a critical role for the tumor suppressor PTEN in the regulation of glucose uptake by cells. PTEN binds SNX27 and hinders its access to the VPS26 retromer complex, preventing recycling of the glucose transporter GLUT1 to the plasma membrane, which leads to impaired cellular glucose uptake.
- PublicationIdentifying and Mitigating Algorithmic Bias in Student Emotional Analysis(2024-01-01)Algorithmic bias in educational environments has garnered increasing scrutiny, with numerous studies highlighting its significant impacts. This research contributes to the field by investigating algorithmic biases, i.e., selection, label, and data biases in the assessment of students’ affective states through video analysis in two educational settings: (1) an open-ended science learning environment and (2) an embodied learning context, involving 41 and 12 students, respectively. Utilizing the advanced High-speed emotion recognition library (HSEmotion) and Multi-task Cascaded Convolutional Networks (MTCNN), and contrasting these with the commercially available iMotions platform, our study delves into biases in these systems. We incorporate real student data to better represent classroom demographics. Our findings not only corroborate the existence of algorithmic bias in detecting student emotions but also highlight successful bias mitigation strategies. The research advances the development of equitable educational technologies and supports the emotional well-being of students by demonstrating that targeted interventions can effectively diminish biases.
- PublicationUbiquitin chains earmark GPCRs for BBSome-mediated removal from cilia(2020-12-07)Regulated trafficking of G protein–coupled receptors (GPCRs) controls cilium-based signaling pathways. β-Arrestin, a molecular sensor of activated GPCRs, and the BBSome, a complex of Bardet–Biedl syndrome (BBS) proteins, are required for the signal-dependent exit of ciliary GPCRs, but the functional interplay between β-arrestin and the BBSome remains elusive. Here we find that, upon activation, ciliary GPCRs become tagged with ubiquitin chains comprising K63 linkages (UbK63) in a β-arrestin–dependent manner before BBSome-mediated exit. Removal of ubiquitin acceptor residues from the somatostatin receptor 3 (SSTR3) and from the orphan GPCR GPR161 demonstrates that ubiquitination of ciliary GPCRs is required for their regulated exit from cilia. Furthermore, targeting a UbK63-specific deubiquitinase to cilia blocks the exit of GPR161, SSTR3, and Smoothened (SMO) from cilia. Finally, ubiquitinated proteins accumulate in cilia of mammalian photoreceptors and Chlamydomonas cells when BBSome function is compromised. We conclude that Ub chains mark GPCRs and other unwanted ciliary proteins for recognition by the ciliary exit machinery.
- PublicationThe ancestral ESCRT protein TOM1L2 selects ubiquitinated cargoes for retrieval from cilia(2023-04-24)Many G protein-coupled receptors (GPCRs) reside within cilia of mammalian cells and must undergo regulated exit from cilia for the appropriate transduction of signals such as hedgehog morphogens. Lysine 63-linked ubiquitin (UbK63) chains mark GPCRs for regulated removal from cilia, but the molecular basis of UbK63 recognition inside cilia remains elusive. Here, we show that the BBSome—the trafficking complex in charge of retrieving GPCRs from cilia—engages the ancestral endosomal sorting factor target of Myb1-like 2 (TOM1L2) to recognize UbK63 chains within cilia of human and mouse cells. TOM1L2 directly binds to UbK63 chains and the BBSome, and targeted disruption of the TOM1L2/BBSome interaction results in the accumulation of TOM1L2, ubiquitin, and the GPCRs SSTR3, Smoothened, and GPR161 inside cilia. Furthermore, the single-cell alga Chlamydomonas also requires its TOM1L2 ortholog in order to clear ubiquitinated proteins from cilia. We conclude that TOM1L2 broadly enables the retrieval of UbK63-tagged proteins by the ciliary trafficking machinery.
- PublicationA Human Tyrosine Phosphatase Interactome Mapped by Proteomic Profiling(2017-08-04)Tyrosine phosphatases play a critical role in many cellular processes and pathogenesis, yet comprehensive analysis of their functional interacting proteins in the cell is limited. By utilizing a proteomic approach, here we present an interaction network of 81 human tyrosine phosphatases built on 1884 high-confidence interactions of which 85% are unreported. Our analysis has linked several phosphatases with new cellular processes and unveiled protein interactions genetically linked to various human diseases including cancer. We validated the functional importance of an identified interaction network by characterizing a distinct novel interaction between PTPN5 and Mob1a. PTPN5 dephosphorylates Mob1a at Y26 residue. Further, we identify that PTPN5 is required for proper midbody abscission during cytokinesis through regulation of Mob1a dephosphorylation. In conclusion, our study provides a valuable resource of tyrosine phosphatase interactions, which can be further utilized to dissect novel cellular functions of these enzymes.