Amine-Promoted Alkene Aziridination

Aziridines, the smallest saturated aza-heterocycle, are not only prevalent in several natural products, but also represent a versatile synthetic tool for the chemist via exploitation of the strained ring system. Research described in this thesis concerns the chemistry of N-N ylides (aminimines), which were utilised in a novel tertiary amine-promoted organocatalytic approach to the aziridination of α,β-unsaturated carbonyl compounds. Through the use of modified conditions two important classes of substrates, dienones and alpha-enolizable enones, both of which had previously shown poor reactivity with the system, can now be aziridinated in good yields. Studies have also focused on the development of an asymmetric variant of the methodology using chiral tertiary amine promoters. A variety of novel chiral six-membered 1,4-heterocycles and cinchona alkaloid derivatives have been synthesised and their utility towards asymmetric alkene aziridination has been assessed, aiding the understanding of the proposed transition state model for the reaction

The effect of common groundwater anions on the aqueous corrosion of zero-valent iron nanoparticles and associated removal of aqueous copper and zinc

This work has investigated the influence of common groundwater anions (Cl-, NO3-, SO42- and HCO3-) on the corrosion behaviour and associated removal of copper (Cu) and zinc (Zn) ions onto nanoscale zero-valent iron particles (nZVI). After 16 week exposure to solutions containing each anion at 10 mM concentrations, nZVI was observed to corrode into different iron (hydr)oxide phases (determined using XRD), depending upon the anion present: HNO3- produced goethite particles; NO3- produced predominantly magnetite/maghemite particles; both SO42- and Cl- produced a mixture of phases, including magnetite/maghemite, lepidocrocite and goethite. For solutions containing the different anions and 0.3 mM concentrations of Cu or Zn, near-total metal removal onto nZVI was recorded in the initial stages of the reaction (e.g. <24 hrs) for all systems tested. However, when Cl- and SO42- were also present significant subsequent desorption was recorded and attributed to the influence of anionic pitting corrosion. In contrast, no Cu or Zn desorption was recorded for batch systems containing NO3-, which was attributed to the enmeshment of Cu or Zn in a mixed-valent iron oxide shell. Results herein therefore demonstrate that NO3- could be utilised alongside nZVI to improve its long-term performance for in situ water treatment applications

Mathematical analysis of vortex sheets

We consider the motion of the interface separating two domains of the same fluid that moves with different velocities along the tangential direction of the interface. The evolution of the interface (the vortex sheet) is governed by the Birkhoff-Rott (BR) equations. We consider the question of the weakest possible assumptions such that the Birkhoff-Rott equation makes sense. This leads us to introduce chord-arc curves to this problem. We present three results. The first can be stated as the following: Assume that the Birkhoff-Rott equation has a solution in a weak sense and that the vortex strength is bounded away from 0 and ∞. Moreover, assume that the solution gives rise to a vortex sheet curve that is chord-arc. Then the curve is automatically smooth, in fact analytic, for fixed time. The second and third results demonstrate that the Birkhoff-Rott equation can be solved if and only if only half the initial data is given. © 2005 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/34394/1/20110_fta.pd

Immunohistochemical Analysis of Scarring Trachoma Indicates Infiltration by Natural Killer and Undefined CD45 Negative Cells.

INTRODUCTION: The phenotype and function of immune cells infiltrating the conjunctiva in scarring trachoma have yet to be fully characterized. We assessed tissue morphology and immunophenotype of cellular infiltrates found in trachomatous scarring compared to control participants. METHODOLOGY: Clinical assessments and conjunctival biopsy samples were obtained from 34 individuals with trachomatous scarring undergoing trichiasis surgery and 33 control subjects undergoing cataract or retinal detachment surgery. Biopsy samples were fixed in buffered formalin and embedded in paraffin wax. Hematoxylin and eosin (H&E) staining was performed for assessment of the inflammatory cell infiltrate. Immunohistochemical staining of single markers on individual sections was performed to identify cells expressing CD3 (T-cells), CD4 (helper T-cells), CD8 (suppressor/cytotoxic T-cells and Natural Killer, NK, cells), NCR1 (NK cells), CD20 (B-cells), CD45 (nucleated hematopoietic cells), CD56 (NK and T-cells), CD68 (macrophages/monocytes) and CD83 (mature dendritic cells). The degree of scarring was assessed histologically using cross-polarized light to visualize collagen fibres. PRINCIPLE FINDINGS: Scarring, regardless of clinical inflammation, was associated with increased inflammatory cell infiltrates on H&E and CD45 staining. Scarring was also associated with increased CD8+ and CD56+ cells, but not CD3+ cells, suggestive of a NK cell infiltrate. This was supported by the presence of NCR1+ cells. There was some increase in CD20+ cells, but no evidence for increased CD4+, CD68+ or CD83+ cells. Numerous CD45 negative cells were also seen in the population of infiltrating inflammatory cells in scarred conjunctiva. Disorganization of the normal collagen architecture was strongly associated with clinical scarring. CONCLUSIONS/SIGNIFICANCE: These data point to the infiltration of immune cells with a phenotype suggestive of NK cells in conjunctival trachomatous scarring. A large proportion of CD45 negative inflammatory cells were also present. Future work should seek to understand the stimuli leading to the recruitment of these cells and their role in progressive scarring

Strengthen causal models for better conservation outcomes for human well-being.

BACKGROUND: Understanding how the conservation of nature can lead to improvement in human conditions is a research area with significant growth and attention. Progress towards effective conservation requires understanding mechanisms for achieving impact within complex social-ecological systems. Causal models are useful tools for defining plausible pathways from conservation actions to impacts on nature and people. Evaluating the potential of different strategies for delivering co-benefits for nature and people will require the use and testing of clear causal models that explicitly define the logic and assumptions behind cause and effect relationships. OBJECTIVES AND METHODS: In this study, we outline criteria for credible causal models and systematically evaluated their use in a broad base of literature (~1,000 peer-reviewed and grey literature articles from a published systematic evidence map) on links between nature-based conservation actions and human well-being impacts. RESULTS: Out of 1,027 publications identified, only ~20% of articles used any type of causal models to guide their work, and only 14 total articles fulfilled all criteria for credibility. Articles rarely tested the validity of models with empirical data. IMPLICATIONS: Not using causal models risks poorly defined strategies, misunderstanding of potential mechanisms for affecting change, inefficient use of resources, and focusing on implausible efforts for achieving sustainability

Don’t Say Yes, Say Yes: Interacting with Synthetic Speech Using Tonetable

This demo is not about what you say but how you say it. Using a tangible system, Tonetable, we explore the shades of meaning carried by the same word said in many different ways. The same word or phrase is synthesised using the Intel Edison with different expressive techniques. Tonetable allows participants to play these different tokens and select the manner they should be synthesised for different contexts. Adopting the visual language of mid-century modernism, the system provokes participants to think deeply about how they might want to say yes, oh really, or I see. Designed with the very serious objective of supporting expressive personalisation of AAC devices, but with the ability to produce a playful and amusing experience, Tonetable will change the way you think about speech synthesis and what yes really means

Development of a low-power wireless acoustic emission sensor node for aerospace applications

Acoustic emission (AE) is the spontaneous release of energy caused by the growth of damage, the monitoring of which gives an indication of the presence of damage within a structure. The current standard for AE localisation is difficult to apply in a low‐power system as sensors must either be wired together or Node's time synchronised, which is power intensive. This paper proposes the use of a method of bonding three piezoelectric sensors in a small triangular array, which has previously been shown by Aljets et al. to be capable of locating sources in simple structures. In this prior work the wave's A0 mode was used to predict the angle of arrival and the distance the wave has travelled through single sensor modal analysis. This paper presents the development of hardware to apply this technique and testing that showed artificial sources could be located in simple plates to a good level of accuracy. The addition of complexity to structures significantly reduced accuracy. This prompted hardware modifications to use the S0 mode for angle prediction. Testing showed that this significantly improved performance in a complex composite structure. The power consumption of the device is very low, consuming 0.33 mW in sleep mode, 17.44 mW whilst waiting for an event and 38 mW to record, process and transmit an event. This level of consumption has the potential to be self‐powered via energy harvesting

Evidence Synthesis International (ESI): Position Statement

This paper is the initial Position Statement of Evidence Synthesis International, a new partnership of organizations that produce, support and use evidence synthesis around the world. The paper (i) argues for the importance of synthesis as a research exercise to clarify what is known from research evidence to inform policy, practice and personal decision making; (ii) discusses core issues for research synthesis such as the role of research evidence in decision making, the role of perspectives, participation and democracy in research and synthesis as a core component of evidence ecosystems; (iii) argues for 9 core principles for ESI on the nature and role of research synthesis; and (iv) lists the 5 main goals of ESI as a coordinating partnership for promoting and enabling the production and use of research synthesis

Grazing Collisions of Black Holes via the Excision of Singularities

We present the first simulations of non-headon (grazing) collisions of binary black holes in which the black hole singularities have been excised from the computational domain. Initially two equal mass black holes $m$ are separated a distance $\approx10m$ and with impact parameter $\approx2m$. Initial data are based on superposed, boosted (velocity $\approx0.5c$) solutions of single black holes in Kerr-Schild coordinates. Both rotating and non-rotating black holes are considered. The excised regions containing the singularities are specified by following the dynamics of apparent horizons. Evolutions of up to $t \approx 35m$ are obtained in which two initially separate apparent horizons are present for $t\approx3.8m$. At that time a single enveloping apparent horizon forms, indicating that the holes have merged. Apparent horizon area estimates suggest gravitational radiation of about 2.6% of the total mass. The evolutions end after a moderate amount of time because of instabilities.Comment: 2 References corrected, reference to figure update

In vivo confocal microscopy and histopathology of the conjunctiva in trachomatous scarring and normal tissue: a systematic comparison.

AIM: To compare in vivo confocal microscopy (IVCM) with the histopathological examination of tissue and cellular changes in normal and diseased conjunctiva. METHODS: Participants underwent clinical examination and IVCM of the tarsal conjunctiva. A biopsy of the upper tarsal conjunctiva was collected and stained with tinctorial stains and by immunohistochemical staining for CD45 and CD83. Connective tissue scarring, inflammatory cell density and the presence of dendritiform cells were quantitatively assessed in a masked manner by both IVCM and histological assessments for comparative analysis. RESULTS: Thirty-four participants with severe trachomatous conjunctival scarring and 33 participants with healthy conjunctiva were recruited. The IVCM connective tissue scarring score was strongly associated with the histological grading of scarring (p<0.001). There was limited evidence of an association between the IVCM inflammatory cell infiltrate and the histological inflammatory cell grade (p=0.05). We did not find any evidence to support the hypothesis that dendritiform cells seen with IVCM are mature, conventional dendritic cells. CONCLUSIONS: The results show that IVCM can be used to robustly quantitate connective tissue scarring and also has a role in measuring the inflammatory cell infiltrate. The discordance between IVCM dendritiform cells and immunohistochemical dendritic cells may be a result of study limitations or may be because these dendritiform structures represent another cell type, such as fibroblasts, rather than dendritic cells