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| 2. |
- Zhang, Yanqing, et al.
(författare)
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HflX is a ribosome-splitting factor rescuing stalled ribosomes under stress conditions
- 2015
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Ingår i: Nature Structural & Molecular Biology. - : Springer Science and Business Media LLC. - 1545-9993 .- 1545-9985. ; 22:11, s. 906-913
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Tidskriftsartikel (refereegranskat)abstract
- Adverse cellular conditions often lead to nonproductive translational stalling and arrest of ribosomes on mRNAs. Here, we used fast kinetics and cryo-EM to characterize Escherichia coil HflX, a GTPase with unknown function. Our data reveal that HflX is a heat shock-induced ribosome-splitting factor capable of dissociating vacant as well as mRNA-associated ribosomes with deacylated tRNA in the peptidyl site. Structural data demonstrate that the N-terminal effector domain of HflX binds to the peptidyl transferase center in a strikingly similar manner as that of the class I release factors and induces dramatic conformational changes in central intersubunit bridges, thus promoting subunit dissociation. Accordingly, loss of HflX results in an increase in stalled ribosomes upon heat shock, These results suggest a primary role of HflX in rescuing translationally arrested ribosomes under stress conditions.
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| 3. |
- Feng, Boya, et al.
(författare)
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Structural and Functional Insights into the Mode of Action of a Universally Conserved Obg GTPase
- 2014
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 12:5, s. e1001866-
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Tidskriftsartikel (refereegranskat)abstract
- Obg proteins are a family of P-loop GTPases, conserved from bacteria to human. The Obg protein in Escherichia coli (ObgE) has been implicated in many diverse cellular functions, with proposed molecular roles in two global processes, ribosome assembly and stringent response. Here, using pre-steady state fast kinetics we demonstrate that ObgE is an anti-association factor, which prevents ribosomal subunit association and downstream steps in translation by binding to the 50S subunit. ObgE is a ribosome dependent GTPase; however, upon binding to guanosine tetraphosphate (ppGpp), the global regulator of stringent response, ObgE exhibits an enhanced interaction with the 50S subunit, resulting in increased equilibrium dissociation of the 70S ribosome into subunits. Furthermore, our cryo-electron microscopy (cryo-EM) structure of the 50S? ObgE? GMPPNP complex indicates that the evolutionarily conserved N-terminal domain (NTD) of ObgE is a tRNA structural mimic, with specific interactions with peptidyl-transferase center, displaying a marked resemblance to Class I release factors. These structural data might define ObgE as a specialized translation factor related to stress responses, and provide a framework towards future elucidation of functional interplay between ObgE and ribosome-associated (p) ppGpp regulators. Together with published data, our results suggest that ObgE might act as a checkpoint in final stages of the 50S subunit assembly under normal growth conditions. And more importantly, ObgE, as a (p) ppGpp effector, might also have a regulatory role in the production of the 50S subunit and its participation in translation under certain stressed conditions. Thus, our findings might have uncovered an under-recognized mechanism of translation control by environmental cues.
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| 4. |
- Fagerlönn, Johan, et al.
(författare)
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Collaboration with Highly Automated Vehicles via Voice Interaction and Augmented Reality
- 2023
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Ingår i: Prooc. of HRI '23. - New York, NY, USA : ACM. - 9781450399708 ; , s. 540-544
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Konferensbidrag (refereegranskat)abstract
- In future confined industrial contexts (hubs), highly automated vehicles and human operators may work in shared spaces and collaborate on joint tasks. This will probably generate a demand for new user interfaces between humans and machines that need to be designed to facilitate high levels of safety and efficiency as well as a positive user experience (UX). The present work investigates the potential of using a combination of voice interaction (VI) and visual augmented reality (AR) to support collaboration between automated vehicles and humans manually operating a machine. A concept using VI and AR for a loading scenario in a logistic center was created and evaluated using a VR headset to provide an immersive experience. A user study with 18 forklift drivers was conducted. Our study shows that the concept generated high scores in terms of usability and UX, which indicates a promising potential to use VI and AR to facilitate interaction between human machine operators and unmanned highly automated vehicles when performing collaborative tasks. Our study also implies a need to explore the design and implementation of more complex and social VI for users in logistic centers.
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| 5. |
- Fagerlönn, Johan, 1980-, et al.
(författare)
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Designing Collaboration between Human Beings and Self-driving Heavy Vehicles with Emerging Interaction Technologies
- 2021
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Ingår i: AutomotiveUI '21 Adjunct. - New York, NY, USA : ACM. ; , s. 123-127
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Konferensbidrag (refereegranskat)abstract
- The present work-in-progress paper describes the development ofnovel user interface concepts that allow human operators to collaborate with self-driving heavy vehicles in a mining context. Conceptdevelopment was performed within a user-centered design processcontaining three main steps. First, a study was performed to identifyinteraction points between heavy vehicle drivers and other humanoperators in mines. Second, potential interaction technologies wereinvestigated. Finally, suggestions for interaction models were designed and implemented in 3D animated movies. The concepts weredesigned to support human operators performing loading tasks together with self-driving vehicles and utilize voice interaction and anaugmented reality head-up-display to facilitate the interaction. Inaddition to the mining context, similar concepts were developed tosupport forklift drivers performing loading tasks in logistic centers.In the next step of this project, the suggested interaction modelswill be evaluated with mine workers and forklift drivers.
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| 6. |
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| 7. |
- Fagerlönn, Johan, et al.
(författare)
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Interaction with Automated Heavy Vehicles Using Gestures and External Interfaces in Underground Mines
- 2023
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Ingår i: Proceedings of HCII 2023 (Part of Lecture Notes in Computer Science; 14048). ; , s. 255-267
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Konferensbidrag (refereegranskat)abstract
- The present study investigated the potential of using gestures to guide and control unmanned automated heavy vehicles in underground mine contexts, as well as the effects of adding external human-machine interfaces (eHMIs) to provide feedback during the gesture interaction. A study with 12 professional operators was conducted in a simulated mine environment, utilizing a Wizard of Oz methodology. The subjects used gestures to guide and control a heavy vehicle in three different scenarios in the mine, and different aspects of the user experience (UX) were assessed. The results support the notion that there is high potential in using gestures when operators stand in close proximity to the vehicles. Moreover, the results suggest that eHMI solutions can enhance the operator’s acceptance and feelings of safety. The selected gestures seemed appropriate for the investigated scenarios, which should be valuable insights for practitioners intending to develop and implement gesture interaction for similar applications.
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| 9. |
- Guo, Xuewen, et al.
(författare)
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Novel small-molecule zwitterionic electrolyte with ultralow work function as cathode modifier for inverted polymer solar cells
- 2018
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Ingår i: Organic electronics. - : ELSEVIER SCIENCE BV. - 1566-1199 .- 1878-5530. ; 59, s. 15-20
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Tidskriftsartikel (refereegranskat)abstract
- Interfacial compatibility between the electrode and organic semiconductor plays a critical role in controlling the charge transport and hence efficiency of organic solar cell. Here, we introduce a novel small-molecule zwitterionic electrolyte (S1) combined with ZnO as electron transporting interlayer employed for the inverted PTB7:PC71BM bulk heterojunction solar cell. The resulting device with the S1/ZnO stacked interlayer achieves a high PCE of 8.59%, obtaining a 16.2% improvement over the control device performance of 7.4% without the S1 attributed to the significant increased short-circuit current density and fill factor. The interfacial properties are investigated. It is found that the S1/ZnO interlayer possess an ultralow work function of 3.6 eV, which originates from the interfacial double dipole step induced by the zwitterionic side chain electrostatic realignment at interface. The S1/ZnO interlayer exhibits the excellent charge extraction ability, suppresses the charge recombination loss and decreases the series resistance at the active layer/electrode contact.
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| 10. |
- Guo, Xuewen, et al.
(författare)
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Understanding the effect of N2200 on performance of J71 : ITIC bulk heterojunction in ternary non-fullerene solar cells
- 2019
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Ingår i: Organic electronics. - : Elsevier. - 1566-1199 .- 1878-5530. ; 71, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- None-fullerene solar cells with ternary architecture have attracted much attention because it is an effective approach for boosting the device power conversion efficiency. Here, the crystalline polymer N2200 as the third component is integrated into J71: ITIC bulk heterojunction. A series of characterizations indicate that N2200 could increase photo-harvesting, balanced hole and electron mobilities, enhanced exciton dissociation, and suppressed charge recombination, which result in the comprehensive improvement of open circuit voltage, short circuit current and fill factor in the device. Moreover, after introduction of N2200, the morphology of the ternary active layer is optimized, and the film crystallinity is improved. This work demonstrates that adding a small quantity of high crystallization acceptor into non-fullerene donor: acceptor mixture is a promising strategy toward developing high-performance organic solar cells.
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