On the evolution of probability-weighting function and its impact on gambling

It is well known that individuals treat losses and gains differently and there exists non-linearity in probability. The asymmetry between gains and losses is highlighted by the reflection effect. The non-linearity in probability is described by the curvature of the probability-weighting function. This paper studies the evolution of the probability-weighting function. It is assumed that the probability weighting for an individual follows a mean-reverting stochastic process. The Monte Carlo simulation technique is employed to study the evolution of the weighting function. The evolution of the probability- weighting function implies that an individual does not treat gains or losses consistently over time, this may be due to the change of the individual’s psychological status

Evaluation of a Novel Glycoprotein on Commercial Contact Lenses

PURPOSE The purpose of this thesis was to evaluate the interaction of a novel glycoprotein, known as proteoglycan 4 (PRG4), with various commercial contact lenses. METHODS PRG4 was investigated for its effects on commercial contact lenses. Both bovine PRG4 and recombinant human PRG4 (rhPRG4) were examined on six silicone hydrogels (balafilcon A, senofilcon A, lotrafilcon B, comfilcon A, delefilcon A, narafilcon A) and one conventional hydrogel (etafilcon A). Lens parameters, such as material wettability, bacterial adhesion and viability, and location of sorbed PRG4, were investigated in the following: • The effect of PRG4 on the wettability of both commercially available silicone and conventional hydrogel lens materials was investigated in vitro. Additionally, the substantivity of PRG4 onto the lens surface was also examined (Chapter 3) • Using a novel labeling technique, rhPRG4 was fluorescently tagged and visualized, using confocal microscopy, to elucidate the sorption profile within various commercial lens materials (Chapter 4) • The antibacterial effect of bovine PRG4- and rhPRG4-treated lenses was investigated. Staphylococcus aureus was radiolabeled with 3H-uridine and the bacterial suspension was exposed to various lenses. The total bacterial adhesion was measured by using a Beta counter to detect the 3H isotope, and viability was determined using an agar plate counting method for each lens type (Chapter 5) RESULTS The lens material largely influences how PRG4 interacts with the contact lens. The presence of a surface treatment and/or ionically charged monomers has a significant impact on the wettability and sorption of PRG4. Generally, the incorporation of PRG4 onto relatively hydrophobic surfaces appears to enhance the surface wettability, though PRG4 exhibited greater substantivity on relatively hydrophilic surfaces. PRG4 did not demonstrate significant antibacterial properties against S. aureus. However, PRG4 did not significantly increase bacterial adhesion, even though proteins on lens surfaces are known to attract more bacteria. In addition, it is possible that PRG4 is denatured to a certain extent within the lens, which may ultimately serve as a source of nutrients for the bacteria to thrive on. Future work is required to investigate this supposition. CONCLUSIONS The results from this thesis have demonstrated that PRG4 can have a significant positive impact on lens material wettability and perhaps other metrics as well, which can possibly translate to enhanced lens wear comfort and lower drop-out rates. Since the lens composition is the major contributing factor in how PRG4 interacts with the material, lens manufacturers can potentially use this information to develop lenses to better incorporate PRG4 for various wear modalities. The unique combination of contact lens and PRG4 is a fairly novel area of research and has the potential for future additional studies

Vascular Response to Sildenafil Citrate in Aging and Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) - the leading cause of vision loss in the elderly - share many risks factors as atherosclerosis, which exhibits loss of vascular compliance resulting from aging and oxidative stress. Here, we attempt to explore choroidal and retinal vascular compliance in patients with AMD by evaluating dynamic vascular changes using live ocular imaging following treatment with oral sildenafil citrate, a phosphodiesterase type 5 (PDE5) inhibitor and potent vasodilator. Enhanced-depth imaging optical coherence tomography (EDI-OCT) and OCT angiography (OCT-A) were performed on 46 eyes of 23 subjects, including 15 patients with non-exudative AMD in one eye and exudative AMD in the fellow eye, and 8 age-matched control subjects. Choroidal thickness, choroidal vascularity, and retinal vessel density were measured across the central macula at 1 and 3 hours after a 100 mg oral dose of sildenafil citrate. Baseline choroidal thickness was 172.1 ± 60.0 μm in non-exudative AMD eyes, 196.4 ± 89.8 μm in exudative AMD eyes, and 207.4 ± 77.7 μm in control eyes, with no difference between the 3 groups (P = 0.116). After sildenafil, choroidal thickness increased by 6.0% to 9.0% at 1 and 3 hours in all groups (P = 0.001-0.014). Eyes from older subjects were associated with choroidal thinning at baseline (P = 0.005) and showed less choroidal expansion at 1 hour and 3 hours after sildenafil (P = 0.001) regardless of AMD status (P = 0.666). The choroidal thickening appeared to be primarily attributed to expansion of the stroma rather than luminal component. Retinal vascular density remained unchanged after sildenafil in all 3 groups (P = 0.281-0.587). Together, our studies suggest that vascular response of the choroid to sildenafil decreases with age, but is not affected by the presence of non-exudative or exudative AMD, providing insight into changes in vessel compliance in aging and AMD

Superfaults and Pseudotachylytes: Evidence of Catastrophic Earth Movements

Superfaults often exhibit an unusual rock called pseudotachylyte, and together these two features are critical to our understanding of catastrophic tectonics. Superfaults are rapid-moving, single-slip displacement surfaces involving very large offsets with the moving-block side of the fault being unconfined or unpinned during rapid gravity offset. Pseudotachylyte is the dark-colored, metamorphic silicate glass formed by frictional melting upon the superfault surface at temperature exceeding 1000 oC, and often displaying distinctive isotropic or cryptocrystalline optical properties. Pseudotachylyte is understood to be evidence of high-speed rock movement during superquakes, where displacements occurred much faster than during modern magnitude 9 earthquakes. Superfaults, pseudotachylyte and superquakes are interpreted as support for global catastrophic tectonic activity. Hand specimens and field data were collected from Homestake Shear Zone in central Colorado, and from the Pasagshak Thrust, Kodiak Island, Alaska. Thin-section analysis shows the presence of glass melt and/or aphanitic black rocks containing pseudotachylyte, and the development of numerous pressure solution surfaces within cataclasite rocks. Cross-cutting relationships support repeated episodes of fault movement and subsequent melt development at both sites. Data gathered from the Homestake Shear Zone supports rapid catastrophic Earth movements during the formation of the North American continent on Day 3 of the Creation Week. Evidence from the Pasagshak Thrust supports the subduction model of catastrophic plate tectonics, with the fault being active during and after Noah’s Flood