64 research outputs found
Using immersive audio and vibration to enhance remote diagnosis of mechanical failure in uncrewed vessels.
There is increasing interest in the maritime industry in the potential use of uncrewed vessels to improve the efficiency and safety of maritime operations. This leads to a number of questions relating to the maintenance and repair of mechanical systems, in particular, critical propulsion systems which if a failure occurs could endanger the vessel. While control data is commonly monitored remotely, engineers on board ship also employ a wide variety of sensory feedback such as sound and vibration to diagnose the condition of systems, and these are often not replicated in remote monitoring. In order to assess the potential for enhancement of remote monitoring and diagnosis, this project simulated an engine room (ER) based on a real vessel in Unreal Engine 4 for the HTC ViveTM VR headset. Audio was recorded from the vessel, with mechanical faults synthesized to create a range of simulated failures. In order to simulate operational requirements, the system was remotely fed data from an external server. The system allowed users to view normal control room data, listen to the overall sound of the space presented spatially over loudspeakers, isolate the sound of particular machinery components, and feel the vibration of machinery through a body worn vibration transducer. Users could scroll through a 10-hour time history of system performance, including audio, vibration and data for snapshots at hourly intervals. Seven experienced marine engineers were asked to assess several scenarios for potential faults in different elements of the ER. They were assessed both quantitatively regarding correct fault identification, and qualitatively in order to assess their perception of usability of the system. Users were able to diagnose simulated mechanical failures with a high degree of accuracy, mainly utilising audio and vibration stimuli, and reported specifically that the immersive audio and vibration improved realism and increased their ability to diagnose system failures from a remote location
Enhance Engine Room Diagnostics Through Audio-Focused VR Simulation
A marine engineer’s task is to maintain all systems in an operational state, to diagnose and rectify problems arising, and to understand what maintenance will be required to keep the vessel appropriately operational and safe. This capability is built upon the training and experience of the engineering crew, the information that can be gained by reading and interpreting engine room instrumentation, and the familiarity with the vessel and an in-situ intuitive feel for normal operation. In this paper, we examine how audio can enhance remote interaction and feedback information. We gathered real-world data from an engine room that allow us to create a realistic virtual engine room for testing. We carried out usability test on simulated failure scenarios where we look at how VR technology might enable engineers to experience immersive information from a remote location and allow them to diagnose and give feedback on the system. Our findings suggest that sound plays a vital role in identifying failures and could potentially be used in the operation of unmanned and autonomous vessels
Shape memory alloy honeycombs: experiments & simulation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76238/1/AIAA-2007-1739-156.pd
Early events of Bacillus anthracis germination identified by time-course quantitative proteomics
Germination of Bacillus anthracis spores involves rehydration of the spore interior and rapid degradation of several of the protective layers, including the spore coat. Here, we examine the temporal changes that occur during B. anthracis spore germination using an isobaric tagging system. Over the course of 17 min from the onset of germination, the levels of at least 19 spore proteins significantly decrease. Included are acid-soluble proteins, several known and predicted coat proteins, and proteins of unknown function. Over half of these proteins are small (less than 100 amino acids) and would have been undetectable by conventional gel-based analysis. We also identified 20 proteins, whose levels modestly increased at the later time points when metabolism has likely resumed. Taken together, our data show that isobaric labeling of complex mixtures is particularly effective for temporal studies. Furthermore, we describe a rigorous statistical approach to define relevant changes that takes into account the nature of data obtained from multidimensional protein identification technology coupled with the use of isobaric tags. This study provides an expanded list of the proteins that may be involved in germination of the B. anthracis spore and their relative levels during germination.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55849/1/5199_ftp.pd
Convergent Antibody Responses to SARS-CoV-2 Infection in Convalescent Individuals
During the COVID-19 pandemic, SARS-CoV-2 infected millions of people and claimed hundreds of thousands of lives. Virus entry into cells depends on the receptor binding domain (RBD) of the SARS-CoV-2 spike protein (S). Although there is no vaccine, it is likely that antibodies will be essential for protection. However, little is known about the human antibody response to SARS-CoV-2. Here we report on 149 COVID-19 convalescent individuals. Plasmas collected an average of 39 days after the onset of symptoms had variable half-maximal pseudovirus neutralizing titres: less than 1:50 in 33% and below 1:1,000 in 79%, while only 1% showed titres above 1:5,000. Antibody sequencing revealed expanded clones of RBD-specific memory B cells expressing closely related antibodies in different individuals. Despite low plasma titres, antibodies to three distinct epitopes on RBD neutralized at half-maximal inhibitory concentrations (ICâ‚…â‚€ values) as low as single digit nanograms per millitre. Thus, most convalescent plasmas obtained from individuals who recover from COVID-19 do not contain high levels of neutralizing activity. Nevertheless, rare but recurring RBD-specific antibodies with potent antiviral activity were found in all individuals tested, suggesting that a vaccine designed to elicit such antibodies could be broadly effective
The Hepatitis B Virus Ribonuclease H Is Sensitive to Inhibitors of the Human Immunodeficiency Virus Ribonuclease H and Integrase Enzymes
Nucleos(t)ide analog therapy blocks DNA synthesis by the hepatitis B virus (HBV) reverse transcriptase and can control the infection, but treatment is life-long and has high costs and unpredictable long-term side effects. The profound suppression of HBV by the nucleos(t)ide analogs and their ability to cure some patients indicates that they can push HBV to the brink of extinction. Consequently, more patients could be cured by suppressing HBV replication further using a new drug in combination with the nucleos(t)ide analogs. The HBV ribonuclease H (RNAseH) is a logical drug target because it is the second of only two viral enzymes that are essential for viral replication, but it has not been exploited, primarily because it is very difficult to produce active enzyme. To address this difficulty, we expressed HBV genotype D and H RNAseHs in E. coli and enriched the enzymes by nickel-affinity chromatography. HBV RNAseH activity in the enriched lysates was characterized in preparation for drug screening. Twenty-one candidate HBV RNAseH inhibitors were identified using chemical structure-activity analyses based on inhibitors of the HIV RNAseH and integrase. Twelve anti-RNAseH and anti-integrase compounds inhibited the HBV RNAseH at 10 μM, the best compounds had low micromolar IC50 values against the RNAseH, and one compound inhibited HBV replication in tissue culture at 10 μM. Recombinant HBV genotype D RNAseH was more sensitive to inhibition than genotype H. This study demonstrates that recombinant HBV RNAseH suitable for low-throughput antiviral drug screening has been produced. The high percentage of compounds developed against the HIV RNAseH and integrase that were active against the HBV RNAseH indicates that the extensive drug design efforts against these HIV enzymes can guide anti-HBV RNAseH drug discovery. Finally, differential inhibition of HBV genotype D and H RNAseHs indicates that viral genetic variability will be a factor during drug development. © 2013 Tavis et al
Selective Phosphorylation Modulates the PIP2 Sensitivity of the CaM-SK Channel Complex
Phosphatidylinositol bisphosphate (PIP2) regulates the activities of many membrane proteins including ion channels through direct interactions. However, the affinity of PIP2 is so high for some channel proteins that its physiological role as a modulator has been questioned. Here we show that PIP2 is an important cofactor for activation of small conductance Ca2+-activated potassium channels (SK) by Ca2+-bound calmodulin (CaM). Removal of the endogenous PIP2 inhibits SK channels. The PIP2-binding site resides at the interface of CaM and the SK C-terminus. We further demonstrate that the affinity of PIP2 for its target proteins can be regulated by cellular signaling. Phosphorylation of CaM T79, located adjacent to the PIP2-binding site, by Casein Kinase 2 reduces the affinity of PIP2 for the CaM-SK channel complex by altering the dynamic interactions among amino acid residues surrounding the PIP2-binding site. This effect of CaM phosphorylation promotes greater channel inhibition by G-protein-mediated hydrolysis of PIP2
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