Photophysical Characterization of Luminophores for Use in Sensing Applications

Traditionally, in luminescence-based sensing, a sensor molecule is designed for one specific analyte. A new method of sensing was proposed which combines a non-luminescent sensing matrix and a luminescent reporter molecule that reacts to the change in its environment upon the interaction of the matrix with an analyte. In previous attempts at this method of sensing an environmentally-sensitive fluorophore was embedded into a hydrogel. However, leaching of the reporter molecule occurred with repeated use in aqueous phase sensing. In response to this limitation, two specific reporter molecules are explored: a nitrile derivative of dapoxyl sulfonic acid (compound 1), which can be covalently bonded to the polymer support matrix and [Os(CO)2(sulf-dpp)Cl2], which can be incorporated into a luminescent metal organic framework. The solvent sensitivity of 1 was measured, and it was found that the derivative exhibits solvent-sensitivity, albeit complicated by the presence of two accessible excited states. The fluorophore was polymerized into an analyte-responsive hydrogel, and the sensitivity of the derivative to change in relative humidity was measured. It was found that the derivative lost some sensitivity when incorporated into the gel, though modified analyses of resultant data may allow for the emission responses to changes in polarity to be calibrated. The viability of [Os(CO)2(sulf-dpp)Cl2] as a reporter complex was determined. The quantum yield was found to be 0.00092 ± 0.00006 and the molar extinction coefficient was 410 ± 10 L·mol-1cm-1 indicating that a fair amount of complex may be ii necessary to provide reasonable sensor signal. However, if incorporated into a luminescent metal organic framework, the response might improve due to the increased rigidity of the environment of the complex

Stigma and Discrimination Based on Mental Health Status: The Impact of Familiarity, Attitudes, and Social Norms/Influence

Individuals with psychological disorders must work to make a living just like everyone else. However, despite potential advantages of self-disclosure, the threat of public stigma may impact the decision to reveal their disability status to their co-workers, with many opting for concealment. Research suggests that this concern may be justified; stigma and discrimination based on mental health status have been noted to occur in the workplace, particularly when co-workers have less direct experience with mental health diagnoses. The purpose of the present literature review is to identify factors that may contribute to the likelihood of individuals with psychological disorders experiencing discrimination in the workplace based on their disclosure. Specifically, we explore the relative impacts of familiarity, attitudes, and social norms/influence on stigma against individuals with psychological disorders. Further, we propose a theoretical framework which suggests a cyclical relationship between familiarity, attitudes, and social norms/influence in creating, perpetuating, and reducing public stigma towards individuals with psychological disorders. This framework is applied to the workplace environment to identify the pathways through which stigma may be perpetuated as well as reduced. Additionally, we outline the methodology for a preliminary study which may be conducted in the future to test the factors posited by the present theoretical framework and assess their influence in the workplace environment. Finally, we suggest strategies for the reduction of mental health stigma in the workplace

SYNTHESIS OF POLYMERIC MATERIALS FOR DRUG DELIVERY AND INDUSTRIAL APPLICATIONS

This dissertation reports the synthesis of polymeric materials for industrial and medicinal applications. Depending on their chemical structure, polymers have different properties and applications. Polyolefins, used in packaging and films, are one of the most highly produced polymeric materials in industry, whereas only a handful of polymeric materials are in the market for drug delivery. The first part of this thesis presents a method to deoxygenate linear polyols producing branched polyolefins. In Chapter 2, linear polyols, such as poly(vinyl alcohol) (PVA), are hydrosilylatively deoxygenated using catalytic amounts of B(C6F5)3 and a reducing hydrosilane. Following reduction, a highly branched, predominantly saturated structure is obtained. Depending on the alcohol-protecting group and the hydrosilane used, the branch numbers can exceed 200 branches per 1000 carbons. The branching microstructure is also dependent on the protecting group and silane. For instance, the deoxygenation of TMS-protected PVA with diethylsilane produced a polymer with different branch types when compared to the polymer that results from the deoxygenation of TES-protected PVA. The B(C6F5)3-catalyzed deoxygenation was applied to a triblock system wherein the central block was a 1,5-polyol structure to produce otherwise inaccessible triblock polymers with an amorphously branched interior block (Chapter 3). The starting polymer was obtained by sequential hydroboration/oxidation of poly(styrene-b-butadiene-b-styrene) (SBS), which converts the polybutadiene block into a 1,5-polyol block. The hydroxylated SBS polymer was then completely deoxygenated to yield a novel triblock polymer with a highly branched interior, with the branching being predominantly butyl or longer chains as established by 13C-NMR spectroscopy. The structure-property relationships of this new triblock system still need to be investigated and compared to SBS. The second section of this thesis discusses an alternative drug delivery approach utilizing nanoscale coordination polymers (NCPs). Chapter 4 presents the synthesis of Ca(II) and Mn(II)-based NCP formulations containing a cisplatin prodrug. Coating the NCPs with a lipid bilayer stabilized both of these formulations. Drug release profiles demonstrated sustained cisplatin release from the NCPs. Drug loadings of 20% for Ca-based NCP and 25% for Mn-NCP were determined. Due to the exceptionally high drug loadings and nanoscale size, these cisplatin NCPs are promising drug delivery candidates.Doctor of Philosoph

Transport infrastructure shapes foraging habitat in a raptor community

Transport infrastructure elements are widespread and increasing in size and length in many countries, with the subsequent alteration of landscapes and wildlife communities. Nonetheless, their effects on habitat selection by raptors are still poorly understood. In this paper, we analyzed raptors ' foraging habitat selection in response to conventional roads and high capacity motorways at the landscape scale, and compared their effects with those of other variables, such as habitat structure, food availability, and presence of potential interspecific competitors. We also analyzed whether the raptors' response towards infrastructure depends on the spatial scale of observation, comparing the attraction or avoidance behavior of the species at the landscape scale with the response of individuals observed in the proximity of the infrastructure. Based on ecological hypotheses for foraging habitat selection, we built generalized linear mixed models, selected the best models according to Akaike Information Criterion and assessed variable importance by Akaike weights. At the community level, the traffic volume was the most relevant variable in the landscape for foraging habitat selection. Abundance, richness, and diversity values reached their maximum at medium traffic volumes and decreased at highest traffic volumes. Individual species showed different degrees of tolerance toward traffic, from higher abundance in areas with high traffic values to avoidance of it. Medium-sized opportunistic raptors increased their abundance near the traffic infrastructures, large scavenger raptors avoided areas with higher traffic values, and other species showed no direct response to traffic but to the presence of prey. Finally, our cross-scale analysis revealed that the effect of transport infrastructures on the behavior of some species might be detectable only at a broad scale. Also, food availability may attract raptor species to risky areas such as motorwaysAP was supported by a PhD grant of the Basque Government. This study forms part of the CENIT-OASIS Project funded by a consortium of companies supported by the Centro para el Desarrollo Tecnológico e Industrial of the Spanish Ministry of Science and Innovation (CENIT-2008 1016). The Comunidad de Madrid, together with the European Social Fund, supports the TEG research group through the REMEDINAL Research Network (S-2009/AMB/1783). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscri

Efficiency of spatio-temporal vaccination regimes in wildlife populations under different viral constraints

Classical Swine Fever (CSF) is considered an endemic disease in European wild boar populations. In view of the high economic impact of the introduction of the virus into domestic pig units, huge efforts are invested in the preventive control of CSF in wild boar populations. Recent European Community guidelines favour oral mass vaccination against CSF in wild boar populations. The guidelines are explicit on the temporal structure of the vaccination protocol, but little is known about the efficacy of different spatial application schemes, or how they relate to outbreak dynamics

What you see is where you go? Modeling dispersal in mountainous landscapes

Inter-patch connectivity can be strongly influenced by topography and matrix heterogeneity, particularly when dealing with species with high cognitive abilities. To estimate dispersal in such systems, simulation models need to incorporate a behavioral component of matrix effects to result in more realistic connectivity measures. Inter-patch dispersal is important for the persistence of capercaillie (Tetrao urogallus) in central Europe, where this endangered grouse species lives in patchy populations embedded in a mountainous landscape. We simulated capercaillie movements with an individual-based, spatially explicit dispersal model (IBM) and compared the resulting connectivity measure with distance and an expert estimation. We used a landscape comprising discrete habitat patches, temporary habitat, non-habitat forests, and non-habitat open land. First, we assumed that dispersing individuals have perfect knowledge of habitat cells within the perceptual range (null model). Then, we included constraints to perception and accessibility, i.e., mountain chains, open area and valleys (three sub-models). In a full model, all sub-models were included at once. Correlations between the different connectivity measures were high (Spearman's ρ>0.7) and connectivity based on the full IBM was closer to expert estimation than distance. For selected cases, simple distance differed strongly from the full IBM measure and the expert estimation. Connectivity based on the IBM was strongly sensitive to the size of perceptual range with higher sensitivity for the null model compared to the full model that included context dependent perceptual ranges. Our heuristic approach is adequate for simulating movements of species with high cognitive abilities in strongly structured landscapes that influence perception and permeabilit

Developmental biology and prey preference of Diomus notescens Blackburn (Coleoptera: Coccinellidae): A predator of Aphis gossypii Glover (Hemiptera: Aphididae)

The minute two-spotted ladybeetle, Diomus notescens Blackburn is a common predator of aphids and other pests in Australian agricultural crops, however little is known about the biology of D. notescens. The aim of this study was to provide information on the life cycle of this predator and improve our understanding of its biological control potential, particularly against one of the major pests of cotton, Aphis gossypii Glover. In laboratory experiments, juvenile development, prey consumption, as well as adult lifespan and fecundity were studied. Results from this study revealed that D. notescens could successfully complete development on A. gossypii, which at 25 °C required 21 days and during this period they each consume 129 ± 5.2 aphids. At 25 °C adult lifespan was 77 ± 9.6 days, with a mean daily prey consumption of 28 ± 1.8 aphids and a mean daily fecundity of 8 ± 0.5 eggs. Net reproductive rate was estimated as 187 ± 25.1 females and the intrinsic rate of increase was estimated as 0.14. Juvenile development was recorded at four constant temperatures (15, 21, 26 and 27 °C) and using a linear model, the lower threshold for D. notescens development was estimated to be 10 ± 0.6 °C with 285 ± 4.7 degree days required to complete development. A prey choice experiment studying predation rates revealed a strong preference for A. gossypii nymphs compared to Bemisia tabaci Gennadius eggs