As técnicas de lente térmica (LT) e \"Z-scan\" foram usadas para estudar as propriedades termo-óticas (difusividade térmica, condutividade térmica, taxa de variação do caminho ótico em função da temperatura e eficiência quântica de fluorescência) e não-lineares (partes real e imaginária do índice de refração não-linear, diferença de polarizabilidade e da seção de choque de absorção entre os estados excitado e fundamental, respectivamente) de sólidos dopados com Neodímio e Cromo. Uma nova extensão da técnica de LT foi proposta para determinar a eficiência quântica de fluorescência sem necessitar de amostra referência, como é feito na maioria dos métodos fototérmicos. Além disso, ambas técnicas foram usadas como espectroscopia, ou seja, a LT foi usada para estudar a forma de linha do calor gerado no material quando a excitação é feita próximo da banda de absorção do material, possibilitando assim a determinação da eficiência de transferência entre a matriz e o íon dopante, e a técnica \"Z-scan\" foi adaptada para medir a forma de linha do índice de refração não-linear próximo das linhas de emissão laser nos cristais dopados com Cromo. / The Thermal Lens (TL) and Z-scan technique were used to study the thermo-optical (thermal diffusivity, thermal conductivity, temperature coefficient of the optical path length change and fluorescence quantum efficiency) and nonlinear optical (parts real and imaginary of the refractive index, polarizability difference and absorption cross section between the excited and ground states, respectively) properties of Neodymium and Chromium doped solids. A new extension of the TL technique was proposed to determine the fluorescence quantum efficiency without measuring a reference sample, as done by any photothermal method Moreover, both techniques were used as an spectroscopy one, i. e., the TL was used to study the line shape of the heat created in material when the excitation is done near at the host absorption band, allowing the determination of the energy transfer efficiency between the host and the dopant ion, and the 2-scan technique was adapted to measure the line shape of the nonlinear refractive index near the laser lines in Chromium doped crystals.

This thesis investigates the feasibility of loading silicone hydrogel (SiHy) contact lenses with two different hydrophobic therapeutics, latanoprost and DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine), for treatment of glaucoma and hyperemia respectively. The two methods of loading were 1) thermal loading in an aqueous medium and 2) convective loading in a solution of n-propanol. Dailies Total1® lenses prepared in this manner were tested for their loading and their release into artificial tears. Continuous release over 1-4 days at therapeutic levels is achievable from thermal loading of DMPC, convective loading of DMPC, and convective loading of latanoprost. The DMPC loading processes can be naturally integrated into standard manufacturing lines for Dailies Total1®. Both DMPC and latanoprost release at rates proportional to the amount loaded into a contact lens. Latanoprost loads into a contact lens strictly proportionally to the loading concentration and the time of loading. The convective loading step represents a significant improvement on both the time of loading (reduced from days to minutes) and the loading capacity of silicone hydrogel contact lenses. This thesis also compares the loading and release of latanoprost in the convective loading procedure using the SiHy contact lenses of Acuvue Advance® (Johnson & Johnson Vision Care, Jacksonville, FL) , Air Optix® (Alcon, Copenhagen, Denmark), Biofinity® (CooperVision), PureVision® (Bausch & Lomb), and Dailies Total1® (Alcon), and the polyHEMA lens, SofLens 38® (Bausch & Lomb), finding that silicone hydrogels load an order of magnitude more drug than the polyHEMA lens and release into artificial tears for an order of magnitude longer. Overall, these experiments provide a quantitative understanding of the dynamics of loading and release for both DMPC and latanoprost.

The focus of this work was on the use of otolith microchemistry and fish eye lens chemical profiles to measure fish movement and provided indirect support for the use of otolith microchemistry to examine exposure to crude oil. Chapter 1 provides an introduction to the applications of otolith microchemistry and eye lens isotopic profiles. In the second chapter, which examined associations between metal exposure and lesion formation in fishes collected after the Deepwater Horizon (DWH) oil spill, I did not observe any change in oil-associated metal concentrations in otoliths coinciding with the timing of the DWH oil spill. This suggests that either the technique used is not sensitive enough to detect any transient changes that may have occurred because of exposure to the oil spill or that the fish examined were not exposed to the oil spill. However, I did find that lesioned fish may have been exposed to a persistent source of trace-metals in the GoM prior to, during, and after the oil spill, and metal-induced immunomodulation may have occurred in these fish. These interactions between the physiological and environmental modulation of otolith element incorporation were explored further in Chapter 3 in which multiple tests demonstrated that physiology explained more of the variation in otolith chemical tags than ambient water chemistry. These findings suggest that the use of otolith microchemistry alone to track fish movement and potential exposure to harmful metals may be complicated by physiological control of otolith microchemistry. Thus, in Chapter 4, I pursued a novel method to evaluate the movement of fish across isoscapes of varying δ15N. I validated the use of fish eye lenses as potential lifetime recorders of isotopic histories and in Chapter 5 compared the use of fish eye lens δ15N profiles to otolith microchemistry profiles to examine fish movement. Both techniques suggested similar patterns of movement in Red Snapper from the northern GoM to the West Florida Shelf. This is the first study to use these complimentary techniques to track fish movement.

The lens of the eye needs to be transparent with a high refractive index to focus images on the retina. In cataracts the lens becomes opaque, eventually leading to blindness. There are many possible causes of cataract but a lot of evidence implicates oxidative damage as contributing to opacification. This includes epidemiological studies showing that diets rich in antioxidants lowered the prevalence of cataract. This research tested the hypothesis that if cataracts were at least partially caused by oxidative damage then their progression would be slowed by application of antioxidants. The antioxidants used were two plant compounds found in the diet, resveratrol and quercetin. The system used was sheep lenses cultured in Eagles Minimal Essential Medium (EMEM). Lenses remained transparent for up to 7 days in EMEM but became opaque within 24 h when exposed to 1 mM hydrogen peroxide (H2O2). The lens is exposed to H2O2 in vivo as it is found in the aqueous humor. Prior Lenses pre-treated with quercetin reduced but did not prevent opacification. Lens cell death, as determined by measurement of leakage of lactate dehydrogenase, was found to increase with H2O2 and the increase was prevented by pre-treatment with antioxidants. The role of the endogenous antioxidant glutathione was also investigated. It was found that H2O2 decreased the amount of reduced glutathione in the lens cortex and increased the levels of oxidised glutathione but only at levels of 2 mM and above. Thus the results of this research indicate that H2O2 at low concentration (1 mM) is able to damage lens cells and cause opacification without affecting the reduced glutathione levels and that the exogenous antioxidants have some ability to protect the lens.

Salinity is the 2nd major limiting abiotic factor on plant growth. As a result of this, soil salinity greatly reduce the yield of the crop production by dual action on plants which are ionic toxicity and water deficit. Therefore, improvement of stress tolerance is greatly concerned. This study was performed to screen and select a salt-resistant and a salt-sensitive cultivar among 6 Turkish lentil cultivars (Lens culinaris M.) which are &Ccedil / agil, &Ccedil / ift&ccedil / i, Kafkas, Malazgirt, Seyran and &Ouml / zbek according to the physiological and biochemical properties. 12 days old lentil seedlings which were exposed to salt stress (100 mM NaCl and 150 mM NaCl) for 5 days as well as control groups analyzed physiologically by root-shoot fresh weights, and lengths / and biochemically by ion leakage, MDA, H

Clinical decision rules improve health care fidelity, benefit patients, physicians and healthcare systems, without reducing patient safety or satisfaction, while promoting cost-effective practice standards. It is critical to appropriately and consistently apply clinical decision rules to realize these benefits. The objective of this thesis was to understand how physicians use the Ottawa Ankle Rules to guide radiography decision-making. The study employed a clinical judgment survey targeting members of the Canadian Association of Emergency Physicians. Statistical analyses were informed by the Brunswik Lens Model and Social Judgment Analysis. Physicians’ overall agreement with the ankle rule was high, but can be improved. Physicians placed greatest value on rule-based cues, while considering non-rule-based cues as moderately important. There is room to improve physician agreement with the ankle rule and use of rule-based cues through knowledge translation interventions. Further development of this Lens Modeling technique could lend itself to a valuable cognitive behavioral intervention.

Purpose: Contact lens (CL) materials, modalities of wear and replacement, and care systems have changed considerably since the early studies of CL compliance were first conducted. Silicone hydrogel (SiHy) and daily disposable (DD) lenses are now the most popular lenses worn worldwide and the care systems that are currently available for them have been designed to be straightforward to use. The purpose of this research was to investigate patient knowledge of and compliance with the use of these contemporary CLs and care products, to determine whether non-compliant CL wearers experience ocular complications relating to lens wear more frequently and are more likely to discontinue lens wear, and to try to determine the factors that may constrain or enable patients to follow recommendations for appropriate lens wear and care. Methods: There are many ways in which compliance can be assessed in health care. Several different methodologies were employed during this research: A questionnaire was administered to just over 100 current lens wearers to determine whether photographic aids would help them to recognize which products they were using. More than 500 contact lens (CL) wearers were recruited by their eye care practitioners (ECPs) and mailed a questionnaire designed to evaluate their compliance with contact lens wear and care and to determine whether they had experienced any contact lens related complications which may have occurred as a result of non-compliance. Close to 5000 Current and lapsed CL wearers in Canada were recruited using Facebook to take part in an on line survey investigating CL wearing experiences during 2008 – 2010 and to establish the percentage of participants who temporarily and permanently discontinued CL wear during the period surveyed, the reasons for discontinuation and whether compliance with lens wear and care may have played a role. ECPs and patients independently completed more than 2000 linked questionnaires evaluating their contact lens wear and care. In addition the frequency with which patients attended their ECP’s office for eye examinations was assessed to determine whether there was a relationship between this and their patients’ compliance. More than 800 daily disposable contact lens (DDCL) wearers in four countries completed an online questionnaire designed to investigate how frequently they reused their lenses, the reasons for reuse and how the lenses were stored between uses. Quantitative (online questionnaire) and qualitative (focus groups) research methods were used to explore in detail the lens wear and care habits of adapted contact lens wearers in an attempt to seek a better understanding of what enables and constrains patient compliance with appropriate lens wear and lens care. Results: The rates of non-compliance with the wear of contemporary CLs were found to be similar to those previously reported. Non-compliance with recommendations for CL replacement was shown to be associated with a higher rate of CL related problems. CL wearers continue to “drop-out” for reasons of discomfort and dryness with their lenses but the drop out rates were not found to be different between compliant and non-compliant CL wearers. Patients who were non-compliant with lens replacement were found to attend their ECP’s offices less frequently. Wearers of DDCLs were the most compliant with lens replacement; however, some did report reusing these lenses and sleeping overnight in them. Focus group participants were able to provide a greater insight into why non-compliant behaviour occurs in CL wearers with the most frequently occurring themes identified as the “consequences” that may occur if patients are non-compliant with one or more aspects of their contact lens wear and the importance of receiving “instructions” regarding the most appropriate way to wear and care for their lenses. Most of the themes that emerged from this qualitative research study were both constraints to, and enablers of, compliance. Conclusions: Compliance with contemporary CLs and care products remains poor. Non-compliant behaviour can result in serious complications and patients may not always be aware of this. Careful counseling and education on the risks associated with CL wear is required to provide patients with a better lens wearing experience and continued successful contact lens wear. ECPs and the contact lens industry can hopefully apply this greater understanding of why patients fail to wear and care for their lenses as they should and to help them develop strategies and tools to aid compliance and success in contact lens wear.

Eddy-covariance (EC) CO₂ flux data were analysed and annual carbon (C) balances estimated for a four-year period (2004-2007) following clearcut harvesting of a boreal jack pine stand in northern Saskatchewan. The site was a source of C to the atmosphere for all years, with annual net ecosystem productivity (NEP) increasing from -153 g C m⁻² yr⁻¹ in 2004 to -63 g C m⁻² yr⁻¹ in 2007. This increase was mainly due to gross primary productivity (GPP) increasing significantly from 78 to 200 g C m⁻² yr⁻¹ , while ecosystem respiration (R) increased only slightly from 231 to 263 g C m⁻² yr⁻¹ over the same period. In the 2006 growing season (GS), a field campaign was conducted to investigate the relationships between monthly destructive measurements of leaf area index (LAI) and daily measurements of the normalized difference vegetation index (NDVI) and photosynthetic capacity (Amax). The latter was derived from 5-day, 16-day, 30-day and annual Michaelis-Menten light response analyses using daytime measurements of NEP and incident photosynthetically active radiation. Digital-camera data were used to evaluate the potential of using the rectilinear-lens vegetation index (RLVI) as a surrogate for NDVI of a young forest stand. Results showed that LAI was linearly related to NDVI and RLVI, which was largely the result of changes in the deciduous vegetation component across the GS. These results indicate that RLVI could be used as a surrogate for NDVI up to a GS maximum LAI of 0.91 m2 m⁻² observed in 2006. Measured mean (± 1 S.D.) GS LAI was 0.67 (± 0.24) m² m⁻² in 2006. LAI accounted for the majority of the variability in Amax at the 30-day time scale, while at shorter time scales air temperature was the dominant control. For 2004 to 2007, mean spring estimates of LAI were 0.25, 0.29, 0.38 (compared to 0.40 m² m⁻² from measurements) and 0.41 m² m⁻², respectively. Results suggest that a steady increase in the jack pine LAI component accounted for the annual increases in GPP and hence NEP over the four years.

Syfte: Studiens syfte var att jämföra två linsrengöringsmetoders påverkan på hornhinnan. Studien jämförde tillverkarens rekommenderade användningsinstruktioner för Opti-Free® Express®, med den alternativa rengöringsmetoden att gnugga linserna, något som ofta rekommenderas av optiker. Metod: Deltagarna sågs vid två tillfällen för utvärdering av eventuell påverkan på hornhinnan. Värdena som återfanns vid första tillfället fungerade som ett utgångsvärde. Samtliga fynd dokumenterades, graderades och poängräknades efter vilken typ av staining samt utbredning. Cornea delades in i fem regioner; centralt, superiort, inferiort, nasalt och temporalt. Typen staining som återfanns poängsattes enligt; mikropunktata (25), makropunktata (50), coalesced (75) och patch (100). Medelvärden för respektive deltagares ögon räknades ut genom att muliplicera poängen given för typen funnen staining med den procentuella utbredningen i varje region. Därefter dividera med fem för att få ett medelvärde utbrett över hela ögat. Deltagarna fick ett nytt par linser och blev därefter instruerade att under två veckors tid rengöra höger och vänster lins separat. Det ena sättet att rengöra var att följa tillverkarens rekommenderade instruktioner, något som innebär sköljning i fem sekunder per linssida. Det andra sättet var genom att gnugga linserna i en L-formad rörelse fem gånger per sida och därefter skölja linsen i fem sekunder. Efter två veckors tid undersöktes deltagarna på nytt. Funna värden sammanställdes och jämfördes sedan med varandra samt utgångsvärdena. Resultat: I de ögon vars linser gnuggades minskade medelvärdet av mängden staining från ursprungligen 140179 till 12185 (p = 0,68). Ursprungsvärdet för de ögon vars linser sköljdes var 125149, något som efter två veckor ökade till 214179 (p = 0,03). Medelvärdena efter två veckor för de båda rengöringsmetoderna uppkom till 12185 för gnugg respektive 214179 för skölj, jämförelser drogs emellan grupperna (p = 0,046). Slutsats: I de ögon vars linser rengjordes genom sköljning återfanns en högre grad av påverkan på hornhinnan. Mängd funnen staining var större i dessa ögon än i de ögon vars linser rengjordes genom gnuggning. Skillnaden var av statistisk signifikans. / The aim of this study was to compare the impact of contact lens cleaning on cornea using two different methods. The study compared the manufacturer’s recommended usage for Opti-Free® Express®, with the alternative cleaning method that involves rubbing the lens, a method often recommended by Optometrists. The participants were seen twice to evaluate the cornea. The values found on the first visit were used as baseline values. The participants were given a new pair of contact lenses and were told to clean them in two different ways for the upcoming two weeks. The first method was to follow the recommended instructions by the manufacturer. A method that involves rinsing the lens for five seconds per side. The alternative method was to rub both sides in shape of the letter L. This procedure was repeated five times per side followed by rinsing for five seconds. The participants were seen for a second visit after two weeks. Evaluations were once again made. The values found were compared with the baseline values as well with each other.  In those cases where the lenses had been cleaned by rubbing, the value of found staining decreased from 140179 at the baseline to 12185 after two weeks (p = 0,68). The baseline value for the eyes where the lenses were cleaned by rinsing was 125149. Those values increased to 214179 after two weeks (p = 0,03). A comparison between the two groups later values showed that there was a statistically significant difference between the two types of cleaning, where the eyes that were only rinsed contained a higher amount of staining (p = 0,046). In those eyes where lenses had been cleaned only by rinsing there were found a higher amount of staining compared to the ones cleaned by rubbing. The difference in found staining between the two cleaning methods were statistically significant.

Cataract is one of the leading causes of vision loss worldwide. The rate of cataract surgery has been steadily increasing. Toxic Anterior Segment Syndrome (TASS) is a sterile inflammatory response in the anterior segment of the eye that may occur following cataract surgery. When left untreated, it can lead to permanent vision loss. Corneal endothelial cells are the cells most affected by TASS. These cells are unable to reproduce in vivo and consequently once the density of these cells drops below a certain level, vision is reduced and cannot be reversed. The damage is thought to be mediated by cytokines and endotoxins, primarily through the NF-κΒ pathway. It is hypothesized that anti-inflammatory drug delivery intraocular lenses may help reduce the occurrence of TASS and consequent vision loss. In this research thesis project, an in vitro model was developed as a tool to select drug and delivery material to be used in an anti-TASS ophthalmic biomaterial. In an attempt to find a novel and more effective approach to TASS prevention, dexamethasone, a potent anti-inflammatory steroid drug, was compared to triptolide, a cytokine inhibitor; aprotinin, a general protease inhibitor; and PPM-18, a NF-κΒ inhibitor. To assess the efficacy of these drugs, an in vitro assay using human umbilical vein endothelial cells (HUVEC) and lipopolysaccharide as a stimulant was developed. Cell response to dexamethasone (10 nM), triptolide (3 nM), aprotinin (20 μM) and PPM-18 (10 μM) with or without LPS was characterized by cell viability and flow cytometry analysis of cell activation. Activation was characterized using markers for cell adhesion and activation ICAM-1, PECAM-1, VCAM-1, β1-integrin, CD44 and E-selectin. Following preliminarily testing, the efficacy of dexamethasone (10 nM) and PPM-18 (10 μM) loaded polymer (PDMS) and copolymer (PDMS/pNIPAAm) interpenetrating polymer networks were evaluated over a 4 day release period. The results from soluble drug and LPS (100 ng/mL) testing indicated no decrease in cell viability after 24 h. Dexamethasone, triptolide, aprotinin, and PPM-18 did not reduce the significant ICAM-1 upregulation seen in HUVECs after exposure to LPS for 4 days. PPM-18 in combination with LPS significantly upregulated E-selectin iv and CD44 from unstimulated HUVEC cells. The polymer materials without drug loading did not influence the cell phenotype. However, PPM-18 delivering polymer and copolymer materials significantly upregulated VCAM-1, CD44 when compared to all other treatments. Propidium iodide uptake in HUVEC exposed to PPM-18 drug delivering polymer and copolymer treatments indicated that these treatments caused cell necrosis. None of the drugs, or the drug delivering materials were shown to counteract the upregulation seen from LPS stimulation of HUVEC cells. Future work should focus on validating the in vitro model to more closely replicate the in vivo environment of the anterior segment with the use of primary bovine corneal endothelial cells.