Local anesthesia is critical for performing corneal procedures in horses. Studying non- ophthalmic local anesthetics for corneal use is necessary because the efficacy and availability of ophthalmic preparations may be limited. This study aimed to evaluate the effects and potential adverse consequences of ropivacaine hydrochloride 0.5% and lidocaine hydrochloride 2% when applied topically to the corneas of eight healthy equids compared to an eyewash control. Data collection occurred over one week. Corneal touch threshold (CTT) was assessed via Cochet-Bonnet esthesiometry before and at pre-determined times after medication application. Ocular toxicity was assessed immediately following each trial and prior to the second trial using the semiquantitative preclinical ocular toxicity system (SPOTS). Ropivacaine and lidocaine significantly reduced CTT from baseline values. However, mean CTT and time to maximum anesthesia were not significantly different between drugs. No local side effects were seen. Ropivacaine and lidocaine could be used topically to reduce corneal sensitivity.

No / The spatial and temporal properties of human colour vision are examined using isoluminant, red¿green and blue¿yellow tritanopic gratings. Chromatic sensitivity is found to be low-pass as a function of both spatial and temporal frequency along all the chromatic axes investigated, including the tritanopic confusion lines employed to examine the properties of the S-cone driven mechanism. Comparison of sensitivity to on-off and contrast reversing stimuli indicates that transient mechanisms contribute to the detection of red¿green patterns but that the detection of S-cone specific patterns is governed by sustained mechanisms. By compensating for transient contributions to red¿green sensitivity, it is shown that sensitivity of chromatic mechanisms dominated by L- and M-cone input are closely matched to those with S-cone input.

Yes / Purpose: Even during steady fixation, people make small eye movements such as microsaccades, whose rate is altered by presentation of salient stimuli. Our goal was to develop a practical method for objectively and robustly estimating contrast sensitivity from microsaccade rates in a diverse population. Methods: Participants, recruited to cover a range of contrast sensitivities, were visually normal (n = 19), amblyopic (n = 10), or had cataract (n = 9). Monocular contrast sensitivity was estimated behaviorally while binocular eye movements were recorded during interleaved passive trials. A probabilistic inference approach was used to establish the likelihood of observed microsaccade rates given the presence or absence of a salient stimulus. Contrast sensitivity was estimated from a function fitted to the scaled log-likelihood ratio of the observed microsaccades in the presence or absence of a salient stimulus across a range of contrasts. Results: Microsaccade rate signature shapes were heterogeneous; nevertheless, estimates of contrast sensitivity could be obtained in all participants. Microsaccade-estimated contrast sensitivity was unbiased compared to behavioral estimates (1.2% mean), with which they were strongly correlated (Spearman's ρ 0.74, P < 0.001, median absolute difference 7.6%). Measurement precision of microsaccade-based contrast sensitivity estimates was worse than that of behavioral estimates, requiring more than 20 times as many presentations to equate precision. Conclusions: Microsaccade rate signatures are heterogeneous in shape when measured across populations with a broad range of contrast sensitivities. Contrast sensitivity can be robustly estimated from rate signatures by probabilistic inference, but more stimulus presentations are currently required to achieve similarly precise estimates to behavioral techniques. / Supported by a Confidence in Concept grant from the Medical Research Council, a Fight for Sight Project Grant (5059/5060) and a Wellcome Trust Research Fellowship to NWR (WT097387).

The problem of this study is an attempt to construct a dependable instrument of measurement in the field of social sensitivity. An endeavor will be made to make this instrument sensitive enough to give some degree of precision and reliability to its results. Other attempted methods of measurement applied to this quantity have given results only in scattered generalities.

This paper tests Reiss' (1991) expectancy theory of fearfulness. Reiss' moderation model of fears speculates that individual differences in fearfulness and phobic avoidance is a function of the interaction between trait vulnerabilities (i.e., sensitivities) and beliefs about potential outcomes during exposure to phobic stimuli (i.e., expectancies). Four hundred and forty-five undergraduates completed questionnaires related to Reiss' fundamental sensitivities (e.g., "anxiety sensitivity"), expectancies (e.g., "expectancy of physical injury or harm") and the intensity of common fears. Informed by findings concerning fear-related outcome expectancies, a system for measuring expectancies was developed for this study called the Focus of Apprehension Survey Schedule (FASS). Additionally, "disgust sensitivity" and "expectancy of contamination or illness" were included to examine whether they account for fearfulness beyond that predicted by Reiss' sensitivities and expectancies alone. In Experiment 1, hierarchical multivariate regression was employed to test Reiss' moderation model of expectancy theory for four fear subtypes (animal, blood/injection/injury (BII), claustrophobic, social). For each of these fear types, results did not support Reiss' moderation model. However, disgust sensitivity improved the prediction of animal fears and contamination expectancies improved the prediction of BII fears beyond Reiss' fundamental sensitivities and expectancies alone. In Experiment 2, a competing mediation model of expectancy theory was tested in which sensitivities were expected to indirectly influence individual differences in fearfulness through outcome expectancies. Results of path analysis using LISREL 8.54 did not support a mediation model per se. However, expectancies were found to mediate relationships between sensitivities and fears in several predicted instances (e.g., contamination expectancies mediated the disgust-BII fears relationship). The results provide some encouraging replications of prior studies and are discussed in the context of implications for theories of fear as well as for future directions in research.

This thesis reports a novel system capable of testing both the spectral responsivity and the spatial quantum efficiency uniformity of heterostructure photodiodes using optical fiber coupled radiation. Testing was performed to confirm device specifications. This study undertakes to quantify the spectral bandwidth of an AlGaAs I GaAs double heterostructure photodiode and two InGaAs I InP double heterostructure PIN photodiodes at D.C., through the use of spatial scanning. The spatial scanning was done using lasers at 670 nm, 780 nm, 848 nm, 1300 nm, and 1550 nm, coupled through singlemode optical fiber. The AlGaAs I GaAs material system covers the 600 - 870 nm wavelength region of research interest in the visible spectrum. The InGaAs I InP material system covers the 800 - 1650 nm region which contains the fiberoptic communications spectrum. The spatial measurement system incorporates a nearly diffraction limited spot of light that is scanned across the surf ace of nominally circular photodiodes using a piezoelectric driven stage. The devices tested range in size from 17 to 52 μin diameter. The smallest device scanned has a diameter approximately four times the diffraction limit of the radiation used for spatial scanning. This is the smallest diode yet reported as being spatially mapped. This is the first simultaneously reported spectral and spatial scans of the same heterostructure PIN photodiodes in the InGaAs I InP and AlGaAs I GaAs systems. The testing arrangement allows both spectral and spatial scans to be taken on the same stage. The diodes tested were taken from intermediate runs during their process development. All testing was performed at room temperature. This study describes the mechanical assembly, calibration and testing of a spatial quantum efficiency uniformity measurement system. The spectral quantum efficiency was measured with low power, incoherent broadband radiation coupled through multimode fiber from a tunable wavelength source to the device under test. The magnitude was corrected to the measured peak external quantum efficiency (Q.E.), determined during spatial scanning at a mid-spectral bandwidth wavelength using continuous wave (CW) higher power lasers. A procedure to improve the accuracy of the correction is recommended. This process has been automated through the use of National Instruments LabVIEW II software. The results from this procedure are plotted to show 2.5 D (pseudo 3D) and 2 D contour spatial quantum efficiency maps. These results give a quantified map of the relative homogeneity of the response. The non-homogeneity of the spatial scans on the smallest devices has not previously been reported. The Q.E. measurements made agree well with previously published results for similar device structures. The AlGaAs I GaAs device achieved a peak external Q.E. of 58.7% at 849 nm with -lOV bias. An InGaAs I InP device achieved 63.5% at 1300 nm with the same bias. The Q.E. results obtained are compared to theoretical calculations. The calculations were performed using the best optical constant data available in the literature at this time. The measured peak Q.E. was found to agree with the theoretical calculations to within 16% at longer wavelengths for both devices tested.

Sensory deficits represent a major global public health problem. According to the World Health Organization, vision impairment affects an estimated 300 million people worldwide, and hearing impairment affects an estimated 360 million people worldwide. Consistent clinical evaluations for all individuals with sensory deficits cannot be practically realized due to the rising costs of healthcare, capital and labor limitations, and inaccessibility to healthcare due to a multitude of factors including proximity. The high prevalence of visual and hearing deficits can be lessened through consistent, comprehensive, at-home testing which can allow a larger amount of the affected and at-risk populations to be screened for abnormal function earlier and prior to permanent loss, and provide a wealth of patient-specific data that can be used to understand the time-scale of diseases and monitor the effectiveness of clinical interventions in unprecedented detail. While health-oriented smartphone applications exhibit a strong presence on the app stores, these applications are seldom vetted by expert scientists, engineers, and clinicians, and there are considerable opportunities for methodological improvements. The present work discusses the creation, calibration, and proof-of-concept, preliminary validation of a suite of psychophysical tests implemented as smartphone applications that can be utilized to rapidly and objectively quantify several functional sensory behaviors including flicker sensitivity, contrast sensitivity, visual acuity, and hearing-in-noise. Rigorous steps were undertaken to perform the necessary calibrations (a feat not routinely achieved by the creators of existing medical smartphone applications), and ensure the technical validity of the varying stimuli presented. Preliminary tests in the clinic have documented the potential of these tests to objectively provide numerous quantifications of, but not limited to, individual visual and hearing function, and variation between normal and abnormal subjects and function. The foundation laid by this work allows novel psychophysical tests to rapidly be implemented, vetted, and added to this battery of publicly and universally accessible medical smartphone applications.

This study describes the strength, toughness and strain-rate sensitivity of fibre-reinforced cement-based foams subjected to variable loading rates. Drop-weight impact tests were conducted on beams with cast density between 475 - 1200 kg/cu.m. The study shows that under quasi-static loading, the compressive strength, elastic modulus and the modulus of rupture of plain mixes scale with the square of the relative density. On the other hand, the flexural toughness factor scaled linearly with it. Fibres were seen to increase the flexural strength at all rates of loading, regardless of cast density. Further, cement based foams were seen to be strain-rate sensitive. The resistance of cement-based foams to sulphate exposure was also investigated. Heavier cement-based foams are more susceptible to sulphate attack and perform poorly with an increase in the duration of exposure when compared to the lightest mix which showed improved responses up to 30 days of exposure due to self-healing. / Structural Engineering

The Rapid Thermal Chemical Vapor Deposition (RTCVD) system is an emerging and promising technology in semiconductor manufacturing which possess advantages of rapidly increasing wafer temperature and reducing the thermal budget over traditional batch processing. In recent years, the growth of thin films in the manufacture of semiconductor devices has been widely employed in the industry. Because the influences of processing variables on RTCVD systems may lead to spatial wafer temperature non-uniformity, the precise control of wafer temperature is an important issue up to the present. In this paper the complementary sensitivity function shaping based on H-infinite control theory is applied to design robust controllers for the single-input/single-output (SISO) model of the RTCVD system, the multi-input/multi-output (MIMO) model of the RTCVD system, and the MIMO model with multiplicative uncertainties. Through control the power of the tungsten-halogen lamps, it can achieve the temperature tracking with good uniformity. Finally, the computer simulation results are obviously that the performance of the proposed controllers is satisfactory.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xi, 101 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 95-99).