A theorem on maximal monotonic sets in Hilbert space

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32073/1/0000117.pd

An exploration of the relationship of chemical and physical parameters in the micromechanical characterisation of the apparent interfacial strength in glass fibre epoxy systems

This paper focuses on the cure shrinkage and the thermomechanical properties of an amine cured epoxy resin system and its adhesion to glass fibre. The fibre-matrix interfacial shear strength (IFSS) was characterized using the microbond test over a range of test temperatures and a range of amine:epoxy ratios. The apparent IFSS in this glass-epoxy system was shown to be strongly dependent on the testing temperature and the matrix stoichiometry. High levels of cure shrinkage were measured in the IFSS microdroplets which resulted in internal stresses causing significant levels of droplet deformation. The results presented here can be interpreted as providing further support for the hypothesis that a significant fraction of the interfacial stress transfer capability in epoxy composites can be attributed to a combination of residual radial compressive stress and static friction at the fibre-matrix interface

Can mixed reality technologies teach surgical skills better than traditional methods? A prospective randomised feasibility study

Background Basic surgical skills teaching is often delivered with didactic audio-visual content, and new digital technologies may allow more engaging and effective ways of teaching to be developed. The Microsoft HoloLens 2 (HL2) is a multi-functional mixed reality headset. This prospective feasibility study sought to assess the device as a tool for enhancing technical surgical skills training. Methods A prospective randomised feasibility study was conducted. 36 novice medical students were trained to perform a basic arteriotomy and closure using a synthetic model. Participants were randomised to receive a structured surgical skills tutorial via a bespoke mixed reality HL2 tutorial (n = 18), or via a standard video-based tutorial (n = 18). Proficiency scores were assessed by blinded examiners using a validated objective scoring system and participant feedback collected. Results The HL2 group showed significantly greater improvement in overall technical proficiency compared to the video group (10.1 vs. 6.89, p = 0.0076), and a greater consistency in skill progression with a significantly narrower range of scores (SD 2.48 vs. 4.03, p = 0.026). Participant feedback showed the HL2 technology to be more interactive and engaging with minimal device related problems experienced. Conclusions This study has demonstrated that mixed reality technology may provide a higher quality educational experience, improved skill progression and greater consistency in learning when compared to traditional teaching methodologies for basic surgical skills. Further work is required to refine, translate, and evaluate the scalability and applicability of the technology across a broad range of skills-based disciplines

Microbial Production of Cellulosic Isobutanol: Integrating Ecology and Evolutionary Approaches with Engineering.

Biofuels derived from lignocellulosic feedstocks are widely considered to be among the most promising renewable fuels that can be produced at a large scale and in a sustainable manner. However, many challenges exist. In this work, we aim to address two of them, which are interconnected under an overall goal of achieving efficient microbial conversion of lignocellulosic feedstocks to isobutanol, an advanced biofuel: i) enabling consolidated bioprocessing of lignocellulosic feedstocks to biofuels, through engineering synthetic microbial consortia; and ii) improving microbial stress tolerance, through genome evolution and engineering. Inspired by the versatility and robustness of ubiquitous natural microbial ecosystems, the first part of our work explores engineering synthetic multispecies microbial communities for cellulosic biofuel production. The required biochemical functions are divided between two specialist organisms: the fungus Trichoderma reesei, which secretes cellulases to hydrolyze lignocellulose into soluble saccharides, and the bacterium Escherichia coli, which metabolizes soluble saccharides into isobutanol. We developed and experimentally validated a comprehensive modeling framework, allowing us to elucidate key ecological interactions and develop mechanisms for stabilizing and tuning population composition. To illustrate bioprocessing applications, we demonstrate direct conversion of cellulosic feedstocks to isobutanol, achieving titers up to 1.86 g/L and 62% of theoretical yield. In the second part, we leverage recent advances in DNA sequencing and genome engineering technologies to decode and refactor microbial tolerance to isobutanol, a complex phenotype with a poorly understood genetic basis. We experimentally evolved isobutanol tolerant E. coli strains, and then used genome re-sequencing and functional dissection studies to reverse engineer mechanisms and genetic bases of tolerance. Next, we exploited our initial results to select genetic loci for targeted mutagenesis using Multiplex Automated Genome Engineering (MAGE), allowing us to refactor isobutanol tolerance and explore large genotype spaces for hyper-tolerant variants. In summary, we have integrated ecology and evolutionary approaches with engineering to develop novel microbial systems for biofuel production. Our synthetic microbial consortium approach provides key advantages over the conventional paradigm of engineering a single microbe (“super-bug”); in parallel, our genome evolution and engineering work has generated new insights into genetic and biochemical mechanisms underlying microbial tolerance to toxic chemicals.PHDChemical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99954/1/jminty_1.pd

The Double Quasar Q2138-431: Lensing by a Dark Galaxy?

We report the discovery of a new gravitational lens candidate Q2138-431AB, comprising two quasar images at a redshift of 1.641 separated by 4.5 arcsecs. The spectra of the two images are very similar, and the redshifts agree to better than 115 km.sec$^{-1}$. The two images have magnitudes $B_J = 19.8$ and $B_J = 21.0$, and in spite of a deep search and image subtraction procedure, no lensing galaxy has been found with $R < 23.8$. Modelling of the system configuration implies that the mass-to-light ratio of any lensing galaxy is likely to be around $1000 M_{\odot}/L_{\odot}$, with an absolute lower limit of $200 M_{\odot}/L_{\odot}$ for an Einstein-de Sitter universe. We conclude that the most likely explanation of the observations is gravitational lensing by a dark galaxy, although it is possible we are seeing a binary quasar.Comment: 17 pages (Latex), 8 postscript figures included, accepted by MNRA

Asset integrity case development for normally unattended offshore installations: Bayesian network modelling

This research proposes the initial stages of the application of Bayesian Networks in conducting quantitative risk assessment of the integrity of an offshore system. The main focus is the construction of a Bayesian network model that demonstrates the interactions of multiple offshore safety critical elements to analyse asset integrity. A NUI (Normally Unattended Installation) - Integrity Case will enable the user to determine the impact of deficiencies in asset integrity and demonstrate that integrity is being managed to ensure safe operations in situations whereby physical human to machine interaction is not occurring. The Integrity Case can be said to be dynamic as it shall be continually updated for an installation as the Quantitative Risk Analysis (QRA) data is recorded. This allows for the integrity of the various systems and components of an offshore installation to be continually monitored. The Bayesian network allows cause-effect relationships to be modelled through clear graphical representation. The model accommodates for continual updating of failure data

The Analyzing Power for p-p Scattering at 180 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

The use of mixed reality technology for the objective assessment of clinical skills: a validation study

Background Mixed Reality technology may provide many advantages over traditional teaching methods. Despite its potential, the technology has yet to be used for the formal assessment of clinical competency. This study sought to collect validity evidence and assess the feasibility of using the HoloLens 2 mixed reality headset for the conduct and augmentation of Objective Structured Clinical Examinations (OSCEs). Methods A prospective cohort study was conducted to compare the assessment of undergraduate medical students undertaking OSCEs via HoloLens 2 live (HLL) and recorded (HLR), and gold-standard in-person (IP) methods. An augmented mixed reality scenario was also assessed. Results 13 undergraduate participants completed a total of 65 OSCE stations. Overall inter-modality correlation was 0.81 (p=0.01), 0.98 (p=0.01) and 0.82 (p=0.01) for IP vs. HLL, HLL vs. HLR and IP vs. HLR respectively. Skill based correlations for IP vs. HLR were assessed for history taking (0.82, p=0.01), clinical examination (0.81, p=0.01), procedural (0.88, p=0.01) and clinical skills (0.92, p=0.01), and assessment of a virtual mixed reality patient (0.74, p=0.01). The HoloLens device was deemed to be usable and practical (Standard Usability Scale (SUS) score = 51.5), and the technology was thought to deliver greater flexibility and convenience, and have the potential to expand and enhance assessment opportunities. Conclusions HoloLens 2 is comparable to traditional in-person examination of undergraduate medical students for both live and recorded assessments, and therefore is a valid and robust method for objectively assessing performance. The technology is in its infancy, and users need to develop confidence in its usability and reliability as an assessment tool. However, the potential to integrate additional functionality including holographic content, automated tracking and data analysis, and to facilitate remote assessment may allow the technology to enhance, expand and standardise examinations across a range of educational contexts