Jane Claire Dirks\u27s Correspondence with Stanley G. Jewett

This exchange between Jane Claire Dirks (later Jane Claire Dirks-Edmunds) and Stanley G. Jewett, a biologist with Region 1 of the Fish and Wildlife Service (serving Oregon and five other states), is an example of the type of correspondence Dirks had with various experts on the Pacific forest region while she was completing her doctoral thesis. Dirks-Edmunds began to study Zoology in Illinois immediately after earning her Bachelor\u27s degree in Biology from Linfield College in 1937. She returned to teach in the Biology department at Linfield from 1941-1974

Photophysical evaluation of substituted zinc phthalocyanines as sensitisers for photodynamic therapy

Zinc phthalocyanines (ZnPc) are currently being investigated in relation to their use as sensitisers for Photodynamic Therapy (PDT). In particular, the photophysical properties of these dyes are of interest since then- ability to generate the cytotoxic species, singlet oxygen ((^1)O(_2)), is believed to be central to their role in causing tumour necrosis. In this study, a detailed investigation of the photophysical properties of substituted zinc phthalocyanines under various conditions is described. Two novel β-tetra substituted zinc phthalocyanines have been synthesised, ZnPc(CMe(C0(_2)Me)(_2))(_4) and ZnPc(CHMeCO(_2)H)(_4). The nature of peripheral substituents has little effect on triplet state or singlet oxygen production by ZnPc, however, ZnPc(CHMeCO(_2)H)(_4) displays a remarkable sensitivity to the ionic strength of non aqueous solutions. Ion concentrations below 10(^-4) mol dm(^-3) induce dimerisation whilst concentrations greater than this promote monomerisation. This behaviour is attributed to ion pairing effects. Photophysical properties of substituted zinc phthalocyanines in heterogenous media and on solid substrates are also described. The temperature and pH of solvent media greatly influence the photophysical properties of phtiialocyanines. Octadecyl zinc phthalocyanine (C10) aggregates upon cooling to 77 K in ether-pentane-alcohol (5:5:2) solution. Additional structure in the absorption spectrum is observed, accompanied by the appearance of a fluorescence emission band at 760 nm. Aluminium phthalocyanine chloride in methanol dimerises upon addition of 2.5 x 10(^-5) mol dm(^-3) fluoride ions. Dimer species are characterised by a blue shifted peak in the absorption spectrum and are non-fluorescent. These results are ascribed to different aggregate geometries and discussed in terms of exciton theory. Low pH induces stepwise protonation of the azomethine bridges of the phthalocyanme ring, Pc + nH(^+) PcH(_n)(^n+)+, where n = 0 to 4. Protonation results in significant changes in absorption, fluorescence and triplet state properties of the phthalocyanine. A dramatic decrease in singlet oxygen generation by the phthalocyanine (ɸ∆ (n = 0) = 0.54, ɸ∆ (n = 1) = 0.075) is reported, and occurs under surprisingly mild conditions (pK(_a) of ZnPcS(_2) in 1% Triton X-100/H(_2)O = 4.4). The propensity of ZnPc's to bind to serum protein and to participate in electron transfer reactions with potential electron donors is discussed

Teacher Supervision and Reflectivity: A Relational and Interactional Process

This dissertation examines teacher supervision and reflectivit

Development of high-throughput technologies for the study of drug-membrane interactions

Understanding how drug molecules interact with our body and what effects they may induce as a result is of fundamental concern to the pharmaceutical industry. Crucially we want to use this knowledge to our advantage during the drug discovery process in order to manipulate a drug’s efficacy in vivo - therefore the development of new technologies, able to effectively screen numerous desirable drug-membrane interactions, is of key importance. The first half of this thesis details the development of a vesicle leakage assay, as a means to assess the effect of cationic amphiphilic drugs (CADs) on model lipid membranes. Having demonstrated the reproducibility of the assay, the assay was transferred into a microfluidic format where water-in-oil droplet systems act as individual experimental vessels. As such, it has been demonstrated that the use of fluorescence lifetime techniques can provide a way in which to translate this assay into a high-throughput format. The second part of the thesis is concerned with using droplet interface bilayers (DIBs) as a means to probe the effect of exogenous species upon a single lipid bilayer, as opposed to bulk vesicle populations. Several advantages exist for using such a system, including for example the ease with which one is able to control the composition of the aqueous compartments on either side of the bilayer and to form asymmetric bilayers. An assay, involving the use of pH gradients, is detailed, where proof-of-concept experiments illustrate that pH sensitive dyes could be used to report the extent to which lipid bilayers are perturbed by drug molecules for example. Furthermore, a novel automated approach has been developed, offering advantages over the manual manipulation of lipid-containing droplets for DIB formation, where a microfluidic approach is used for their generation in high-throughput. Consequently, this approach enables the formation of multiple DIBs, where the composition may be differed and the droplet dimensions controlled, enabling the formation of DIB networks that can be arranged in either two- or three-dimensions

Applications of Mathematics To Climate Modeling: Analysis and Development of Ocean Parameterizations and Multivariate Localization Functions

This thesis discusses three different ways in which mathematics and statistics have led to improved understandings of our climate models. The first two chapters focus on different aspects of how ocean eddies are parameterized in ocean models, with particular attention to the use of high resolution ocean model output to inform coarser ocean models. The third chapter presents a method for dealing with the multiple length scales in coupled data assimilation. The Gent-McWilliams parameterization is commonly used in global ocean models to model the advective component of tracer transport effected by unresolved mesoscale eddies. In chapter 2 the vertical structure of the transfer coefficient in this parameterization is studied using data from a 0.1&deg;&nbsp;resolution global ocean-ice simulation.The vertical structure is found to be well approximated by a baroclinic mode structure with no flow at the bottom, though horizontal anisotropy is crucial for obtaining a good fit. This vertical structure is motivated by reference to the vertical structure of mesoscale eddy velocity and density anomalies, which are also diagnosed from the data. Unresolved temperature and salinity fluctuations interact with a nonlinear seawater equation of state to produce significant errors in the ocean model evaluation of the large scale density field. In chapter 3 it is shown that the impact of temperature fluctuations dominates the impact of salinity fluctuations and that the error in density is, to leading order, proportional to the product of a subgrid scale temperature variance and a second derivative of the equation of state. Two parameterizations are proposed to correct the large scale density field: one deterministic and one stochastic. Free parameters in both parameterizations are fit using fine-resolution model data. Both parameterizations are computationally efficient as they require only one additional evaluation of a nonlinear equation at each grid cell. A companion paper will discuss the climate impacts of the parameterizations proposed here.Localization is widely used in data assimilation schemes to mitigate the impact of sampling errors on ensemble-derived background error covariance matrices. Strongly coupled data assimilation allows observations in one component of a coupled model to directly impact another component through inclusion of cross-domain terms in the background error covariance matrix. When different components have disparate dominant spatial scales, localization between model domains must properly account for the multiple length scales at play. In chapter 4 we develop two new multivariate localization functions, one of which is a multivariate extension of the fifth-order piecewise rational Gaspari-Cohn localization function; the within-component localization functions are standard Gaspari-Cohn with different localization radii while the cross-localization function is newly constructed. The functions produce positive semidefinite localization matrices, which are suitable for use in both Kalman Filters and variational data assimilation schemes. We compare the performance of our two new multivariate localization functions to two other multivariate localization functions and to the univariate and weakly coupled analogs of all four functions in a simple experiment with the bivariate Lorenz '96 system. In our experiments the multivariate Gaspari-Cohn function leads to better performance than any of the other multivariate localization functions.</p

Use of the Complex Zeros of the Partition Function to Investigate the Critical Behavior of the Generalized Interacting Self-Avoiding Trail Model

The complex zeros of the canonical (fixed walk-length) partition function are calculated for both the self-avoiding trails model and the vertex-interacting self-avoiding walk model, both in bulk and in the presence of an attractive surface. The finite-size behavior of the zeros is used to estimate the location of phase transitions: the collapse transition in the bulk and the adsorption transition in the presence of a surface. The bulk and surface cross-over exponents, ϕ and ϕ S , are estimated from the scaling behavior of the leading partition function zeros

Continuous and Segmented Flow Microfluidics: Applications in High-throughput Chemistry and Biology

This account highlights some of our recent activities focused on developing microfluidic technologies for application in high-throughput and high-information content chemical and biological analysis. Specifically, we discuss the use of continuous and segmented flow microfluidics for artificial membrane formation, the analysis of single cells and organisms, nanomaterial synthesis and DNA amplification via the polymerase chain reaction. In addition, we report on recent developments in small-volume detection technology that allow access to the vast amounts of chemical and biological information afforded by microfluidic systems