Synthesis and Characterisation of Poly(vinyl alcohol) based materials for use within Personal Products

Cationic polymers based upon poly(vinyl alcohol) (PVA) are synthesised with various levels of charge densities, molecular architectures and hydrophobicities. Furthermore, macroinitiators incorporating PVA segments are synthesized and subsequently used for single electron transfer - living radical polymerisation (SET-LRP) for the synthesis of a range of graft copolymers. Chapter 1 is a general introduction on cationic polymers, their use within conditioning shampoo formulations and the chemical properties required for this application. The polymerisation techniques: ring-opening polymerisation and reversible deactivation radical polymerisation (RDRP); as well as the polymeric materials: PVA and polyglycerol are also discussed. Chapter 2 involves the synthesis of cationic PVA through either etherification or esterification reactions. The etherification of PVA using either glycidyltrimethylammonium chloride (GTMAC) or 1,2-chlorohydroxypropyltrimethyammonium chloride (CHPTMAC) to synthesise poly[(vinyl alcohol)-ran-(vinyl, 2-hydroxypropyl ether trimethylammonium chloride)] (P[VA)-r-(VETMAC)]) is investigated. The charge densities of the polymers synthesised by slowing the rate of reaction with GTMAC were determined to be greater than the charge densities claimed in the literature. The synthesis of poly(vinyl betaine) (PVB) via the synthesis of poly(vinyl chloroacetate) as an intermediate is discussed, as well as attempts to control the charge density of the resulting PVB. The charge density of the synthesised polymers were determined using UV-Vis spectroscopy and by nuclear magnetic resonance (NMR) spectroscopy. Chapter 3 discusses the synthesis of a novel hyperbranched graft copolymer, poly[(vinyl alcohol)-graft-(hyperbranched glycerol)] (P[(VA)-g-(hPG)]). The effects of the reaction conditions on the mole fraction of hyperbranched polyglycerol (x(hPG)), the degree of branching (%DB) and the degree of substitution (%DS) were all monitored for the water solvated reactions. The synthesis of P[(VA)-g-(hPG)] in organic solvents is also discussed. Furthermore, comparisons between P[(VA)-g-(hPG)] and physical blends of PVA and hyperbranched polyglycerol are also made. Chapter 4 entails the synthesis of cationic polymers based upon P[(VA)-g-(hPG)] synthesised in Chapter 3. Poly[(vinyl alcohol)-ran-(vinyl,2-hydroxypropyl ether trimethylammonium chloride)-graft-(hyperbranched polyglycerol-2-hydroxypropyl ether trimethylammonium chloride)] (P[(VA)-r-(VETMAC)-g-(hPG-PETMAC)]) was synthesized from the reaction between P[(VA)-g-(hPG)] as the macroinitiator and GTMAC. The charge density of the resulting polymer was found to increase with increasing x(hPG) in themacroinitiator; charge densities up to 5.4 meq g-1 were determined. Furthermore, the synthesis of poly[(vinyl betaine)-graft-(hyperbranched polyglycerol betaine)] is also discussed. Chapter 5 describes the synthesis of hydrophobic derivatives of the polymers synthesized in the previous chapters using epoxyoctane to synthesise poly[(vinyl alcohol)-ran-(vinyl, 2- hydroxy octyl ether)], poly[(vinyl alcohol)-ran-(vinyl, 2-hydroxy octyl ether)-ran-(vinyl, 2- hydroxypropyl ether trimethylammonium chloride)], poly[(vinyl alcohol)-ran-(vinyl, 2- hydroxy octyl ether)-graft-(hyperbranched polyglycerol-2-hydroxyoctyl ether)] and poly[(vinyl, 2-hydroxy octyl ether)-ran-(vinyl, 2-hydroxypropyl ether trimethylammonium chloride)-ran-(vinyl alcohol)-graft-(hyperbranched polyglycerol)-(2-hydroxypropyl ether trimethylammonium chloride)/(2-hydroxy octyl ether)]). The hydrophobicity of the synthesised polymers is measured based upon their contact angle and aqueous solubility. Chapter 6 focuses on the synthesis of macroinitiators for RDRP containing PVA and poly(vinyl, 2-bromopropionate) (PVBrP) repeat units. 2-bromopropionic anhydride was synthesised for the reaction with PVA. Poly[(vinyl, 2-bromopropionate)-ran-(vinyl2- butyral)] was synthesised when the reaction was carried out in butanone. However when 1,4-dioxane was used as the reaction solvent poly[(vinyl alcohol)-ran-(vinyl, 2- bromopropionate)] (P[(VA)-r-(VBrP)]) was successfully synthesised, with 62% or 79% initiating groups (PVBrP groups). Chapter 7 details the synthesis of graft copolymers by SET-LRP, using P[(VA)-r-(VBrP)] macroinitiators which were synthesised in Chapter 6. Methyl acrylate was polymerised with P[(VA)-r-(VBrP)] macroinitiators containing 62% or 79% initiating sites (PVBrP), with a molecular weight of 2.31 x 106 gmol-1 determined by atomic force microscopy. Hydroxyethyl acrylate was polymerised with P[(VA)-r-(VBrP)] macroinitiator containing 62% initiating sites to synthesise poly[(vinyl alcohol)-ran-(vinyl 2-bromopropionate)-graft- (hydroxyethyl acrylate)] (P[(VA)-r-(VBrP)-g-(HEA)]), a water soluble polymer. When unpurified HEA monomer was polymerised, a cross-linked material was recovered with a 50% swelling ratio. N-isopropylacrylamide was also polymerised using P[(VA)-r-(VBrP)] macroinitiator containing 62% initiating sites, to synthesise a thermoresponsive polymer with a lower critical saturation temperature of 36 oC. Chapter 8 surmises and concludes the work covered in Chapters 2 - 7, and further work is also suggested

Role of angiopoietin-like protein 3 in sugar-induced dyslipidemia in rhesus macaques: suppression by fish oil or RNAi.

Angiopoietin-like protein 3 (ANGPTL3) inhibits lipid clearance and is a promising target for managing cardiovascular disease. Here we investigated the effects of a high-sugar (high-fructose) diet on circulating ANGPTL3 concentrations in rhesus macaques. Plasma ANGPTL3 concentrations increased ∼30% to 40% after 1 and 3 months of a high-fructose diet (both P < 0.001 vs. baseline). During fructose-induced metabolic dysregulation, plasma ANGPTL3 concentrations were positively correlated with circulating indices of insulin resistance [assessed with fasting insulin and the homeostatic model assessment of insulin resistance (HOMA-IR)], hypertriglyceridemia, adiposity (assessed as leptin), and systemic inflammation [C-reactive peptide (CRP)] and negatively correlated with plasma levels of the insulin-sensitizing hormone adropin. Multiple regression analyses identified a strong association between circulating APOC3 and ANGPTL3 concentrations. Higher baseline plasma levels of both ANGPTL3 and APOC3 were associated with an increased risk for fructose-induced insulin resistance. Fish oil previously shown to prevent insulin resistance and hypertriglyceridemia in this model prevented increases of ANGPTL3 without affecting systemic inflammation (increased plasma CRP and interleukin-6 concentrations). ANGPTL3 RNAi lowered plasma concentrations of ANGPTL3, triglycerides (TGs), VLDL-C, APOC3, and APOE. These decreases were consistent with a reduced risk of atherosclerosis. In summary, dietary sugar-induced increases of circulating ANGPTL3 concentrations after metabolic dysregulation correlated positively with leptin levels, HOMA-IR, and dyslipidemia. Targeting ANGPTL3 expression with RNAi inhibited dyslipidemia by lowering plasma TGs, VLDL-C, APOC3, and APOE levels in rhesus macaques

Expressed in the yeast Saccharomyces cerevisiae, human ERK5 is a client of the Hsp90 chaperone that complements loss of the Slt2p (Mpk1p) cell integrity stress-activated protein kinase

ERK5 is a mitogen-activated protein (MAP) kinase regulated in human cells by diverse mitogens and stresses but also suspected of mediating the effects of a number of oncogenes. Its expression in the slt2Delta Saccharomyces cerevisiae mutant rescued several of the phenotypes caused by the lack of Slt2p (Mpk1p) cell integrity MAP kinase. ERK5 is able to provide this cell integrity MAP kinase function in yeast, as it is activated by the cell integrity signaling cascade that normally activates Slt2p and, in its active form, able to stimulate at least one key Slt2p target (Rlm1p, the major transcriptional regulator of cell wall genes). In vitro ERK5 kinase activity was abolished by Hsp90 inhibition. ERK5 activity in vivo was also lost in a strain that expresses a mutant Hsp90 chaperone. Therefore, human ERK5 expressed in yeast is an Hsp90 client, despite the widely held belief that the protein kinases of the MAP kinase class are non-Hsp90-dependent activities. Two-hybrid and protein binding studies revealed that strong association of Hsp90 with ERK5 requires the dual phosphorylation of the TEY motif in the MAP kinase activation loop. These phosphorylations, at positions adjacent to the Hsp90-binding surface recently identified for a number of protein kinases, may cause a localized rearrangement of this MAP kinase region that leads to creation of the Hsp90-binding surface. Complementation of the slt2Delta yeast defect by ERK5 expression establishes a new tool with which to screen for novel agonists and antagonists of ERK5 signaling as well as for isolating mutant forms of ERK5

Greenland ice sheet motion coupled with daily melting in late summer

We use ground-based and satellite observations to detect large diurnal and longer-period variations in the flow of the Greenland Ice Sheet (GrIS) during late summer that are strongly coupled with changes in its surface hydrology. The diurnal signals are associated with periodic changes in surface melting, and the longer-period signals are associated with the episodic drainage of supra-glacial lakes. Ice velocity doubles around 2 hours after peak daily melting and returns approximately to wintertime levels around 12 hours afterwards, demonstrating an intimate link between the surface and basal hydrology. During late summer, the ice sheet accelerates by 35% per positive degree-day of melting. The observed link between surface melting and enhanced flow is typical of Alpine glaciers, which may provide an appropriate analogue for the evolution of the GrIS in a warming climate

Sonar Image Registration for Localization of an Underwater Vehicle

This paper presents a system to provide augmented localization to an AUV equipped with a side scan sonar. Upon revisiting an area, from which side scan data had previously been collected, the system generates an estimate to bound the error in the AUV’s estimate. Localization is accomplished through the comparison of sonar images. Image comparison is based on the extraction of features which characterize local gradient distributions, such as Lowe’s SIFT feature extractor. To resolve potential ambiguities and noise in the image comparison measurement, the localization system incorporates a Bayesian inference algorithm that considers both image based measurement and relative motion to refine the position estimate over time. We describe the particular methods, constraints and augmentations used to apply established image matching and alignment techniques to side scan sonar imagery. By applying consistent geographical corrections to the raw sonar data; using a flat-bottom assumption; and by adding the constraint that images are formed with north aligned up; the traditional problem of full pose estimation is reduced to the two-dimensional case of determining only the x,y translation independent of vehicle altitude. Due to the assumption of constant scale and orientation between images, sensitivity of image feature matching is shown to be controllable by filtering feature matches based on comparing their scale and orientation. This effect was quantified using binary classification analysis. The system’s performance was measured by performing tests on a large side scan survey which represents the familiar terrain that a returning AUV could use for localization

A modelling evaluation of electromagnetic fields emitted by buried subsea power cables and encountered by marine animals : considerations for marine renewable energy development

Part of this work was supported by the Bureau of Ocean Energy Management (contract number M14PC00009).The expanding marine renewable energy industry will increase the prevalence of electromagnetic fields (EMFs) from power cables in coastal waters. Assessments of environmental impacts are required within licensing/permitting processes and increased prevalence of cables will increase questions concerning EMF emissions and potential cumulative impacts. It is presumed that protecting a cable by burial, may also mitigate EMF emissions and potential impacts on species. Focussing on a bundled high voltage direct current (HVDC) transmission cable, we use computational and interpretive models to explore the influence of cable properties and burial depth on the DC magnetic field (DC-MF) potentially encountered by receptive species. Greater cable pair separation increased the deviations from the geomagnetic field and while deeper burial reduced the deviations, the DC-MF was present at intensities perceivable by receptive species. An animal moving along a cable route may be exposed to variable EMFs due to varied burial depth and that combined with an animal’s position in the water column determines the distance from source and EMF exposure. Modelling contextually realistic scenarios would improve assessments of potential effects. We suggest developers and cable industries make cable properties and energy transmission data available, enabling realistic modelling and environmental assessment supporting future developments.PostprintPeer reviewe

The future starts in the past:embedding learning for sustainability through culture and community in Scotland

Introduction: If sustainability is about imagining and pursuing desired futures, our past history, heritage, and culture will influence the kind of futures we seek and our chosen routes towards them. In Scotland, there is a strong connection between culture, land, and identity; a sense of community; and a perception of work ethic that derive from our biogeography and socio-political journey. Concepts and practises of education have been influenced by the ideas of key thinkers such as the Scot Sir Patrick Geddes, who introduced approaches to education and community through concepts such as “heart, hand, and head”, “think global, act local,” and “place, work, and folk”. This background influenced us in establishing Scotland's United Nations University-recognised Regional Centre of Expertise (RCE) in Education for Sustainable Development (ESD), known locally as “Learning for Sustainability Scotland”. Its initial development ten years ago and subsequent evolution have been built on engaging collaboratively across Scotland and linking formal, non-formal, and informal modes of learning for sustainability. In this paper, we explore how culture and context have influenced the emergence, governance, and activities of RCE Scotland over the past decade.Methods: We developed an analytical framework of possible cultural and contextual influences on Scottish education. We used a Delphi approach to develop a novel and locally relevant definition of ESD when the RCE was established.Results: Analysis of purposively selected RCE Scotland activities against our cultural framework illustrated how they had been influenced by culture or context. We propose that democratic intellect, local and global, and nature-culture connections have informed our initiative.Discussion: We conclude that connection to people, place, and nature influences engagement and action on sustainability, and we suggest that additional sustainability competencies should include physical, emotional, and spiritual aspects of nature connection

Atmospheric drivers of melt on Larsen C Ice Shelf: Surface energy budget regimes and the impact of foehn

Recent ice shelf retreat on the east coast of the Antarctic Peninsula has been principally attributed to atmospherically driven melt. However, previous studies on the largest of these ice shelves—Larsen C—have struggled to reconcile atmospheric forcing with observed melt. This study provides the first comprehensive quantification and explanation of the atmospheric drivers of melt across Larsen C, using 31-months' worth of observations from Cabinet Inlet, a 6-month, high-resolution atmospheric model simulation and a novel approach to ascertain the surface energy budget (SEB) regime. The dominant meteorological controls on melt are shown to be the occurrence, strength, and warmth of mountain winds called foehn. At Cabinet Inlet, foehn occurs 15% of the time and causes 45% of melt. The primary effect of foehn on the SEB is elevated turbulent heat fluxes. Under typical, warm foehn conditions, this means elevated surface heating and melting, the intensity of which increases as foehn wind speed increases. Less commonly—due to cooler-than-normal foehn winds and/or radiatively warmed ice—the relationship between wind speed and net surface heat flux reverses. This explains the seemingly contradictory results of previous studies. In the model, spatial variability in cumulative melt across Larsen C is largely explained by foehn, with melt maxima in inlets reflecting maxima in foehn wind strength. However, most accumulated melt (58%) occurs due to solar radiation in the absence of foehn. A broad north-south gradient in melt is explained by the combined influence of foehn and non-foehn conditions