271 research outputs found
Voice onset time variation in stop consonant to vowel transitions
Reduced duration, increased consistency, and improved intelligibility are goals of reducing the motor complexity of speech for individuals with cerebral palsy having dysarthria. In this study, measurement and analysis were made to compare an individual with spastic Cerebral Palsy (CP) having dysarthria to an individual with athetoid CP having dysarthria as well as to a non-dysarthric individual. Each participant\u27s normal speech, whispering, and speech using an artificial larynx was evaluated, utilizing the source-filter theory methodology. The plausibility of dysarthric speech duration reduction by minimizing vocalization is tested by stop consonant P,, to vowel transitions. The data suggest that speech duration is dependent on voice onset time (VOT) variation among the participants. This study could serve as a basis to encourage further research analyzing neuromotor and physiological articulatory control, which could lead to interventional treatment for individuals having dysarthria
Characterization of Illegal Wildlife Trade Networks
The legal and illegal trade in wild animals and their products is a multi-billion dollar industry that threatens the health and well-being of humans and animals alike. The management of the wildlife trade is a crisis-driven area, where decisions are made quickly, and, often, inefficiently. In particular, the regulation and control of the illegal wildlife trade is hampered by a dearth of formal quantitative analysis of the nature of the trade. This thesis represents a preliminary attempt to rectify that knowledge gap. It describes an investigation into the factors that support and promote the trade and is based upon information in two databases: CITES (the legal trade) and HealthMap (the illegal trade). The study 1) quantified the relationship between the illegal wildlife trade and several key factors thought to contribute to the illegal wildlife trade, namely road development, unemployment, and Corruption Perception Index (a score related to the perceived level of corruption); 2) measured the extent to which the product types, origins, destinations, and trade routes in the legal and the illegal wildlife trade are alike; and 3) identified locations to place resources to (a) restrict trade by causing the greatest network destabilization and (b) disseminate an educational message that would cause the greatest impact to the network. Several key factors and the legal trade were associated with the magnitude of various indices of the illegal trade at a country-level, but no generalizable findings can be asserted at this time. With regard to the best placement of regulatory resources, China was key with respect to network disruption and information dissemination targets. This thesis has begun the urgently needed analysis of the complex relationships of the illegal wildlife trade and identified specific ways to bring about change using network science. These findings offer hope for regulatory and enforcement agencies, NGOs, and governments that it will be possible to find more effective ways of combating the illegal wildlife trade and problems it brings with it
Glare and Ocular Diseases
Glare is the result of veiling luminance from the different light sources we are exposed to in our everyday lives. The luminance from glare can cause problems ranging from the discomfort of our eyes to vision loss. All individuals are affected by glare issues but those problems are intensified in patients living with ocular diseases. Therefore, understanding the effects of glare is applicable to elucidating visual function and pathology. This makes glare testing highly necessary in both clinic and research. However, there are many components involved in glare testing that makes attaining valid results difficult. This is evident in the flaws of current glare devices and the lack of a standardization of measuring glare. Despite the insufficiency of most glare devices, evaluating those weaknesses can potentially lead to a better understanding of glare and glare testing
Erythema nodosum and reactive arthritis accompanying tuberculosis: A case report
Erythema nodosum (EN) is the most common panniculitis, appearing as crops of erythematous nodules located symmetrically on the anterior aspect of lower extremities. It is precipitated by several infectious and non-infectious causes with primary tuberculosis (TB) being its most common cause in developing countries. Reactive arthritis associated with TB is known a
Predicting individual contrast sensitivity functions from acuity and letter contrast sensitivity measurements.
Contrast sensitivity (CS) is widely used as a measure of visual function in both basic research and clinical evaluation. There is conflicting evidence on the extent to which measuring the full contrast sensitivity function (CSF) offers more functionally relevant information than a single measurement from an optotype CS test, such as the Pelli-Robson chart. Here we examine the relationship between functional CSF parameters and other measures of visual function, and establish a framework for predicting individual CSFs with effectively a zero-parameter model that shifts a standard-shaped template CSF horizontally and vertically according to independent measurements of high contrast acuity and letter CS, respectively. This method was evaluated for three different CSF tests: a chart test (CSV-1000), a computerized sine-wave test (M&S Sine Test), and a recently developed adaptive test (quick CSF). Subjects were 43 individuals with healthy vision or impairment too mild to be considered low vision (acuity range of -0.3 to 0.34 logMAR). While each test demands a slightly different normative template, results show that individual subject CSFs can be predicted with roughly the same precision as test-retest repeatability, confirming that individuals predominantly differ in terms of peak CS and peak spatial frequency. In fact, these parameters were sufficiently related to empirical measurements of acuity and letter CS to permit accurate estimation of the entire CSF of any individual with a deterministic model (zero free parameters). These results demonstrate that in many cases, measuring the full CSF may provide little additional information beyond letter acuity and contrast sensitivity
Predicting the necessity of LASIK enhancement after cataract surgery in patients with multifocal IOL implantation
Pinakin Gunvant1,2, Anna Ablamowicz2, Subba Gollamudi31Western University of Health Sciences, College of Optometry, Pomona, CA, 2Southern College of Optometry, Memphis, TN, 3Eye Specialty Group, Memphis, TN, USAPurpose: To investigate if the parameters measured routinely prior to cataract surgery with multifocal intraocular lens (IOL) implantation can predict the necessity of additional laser in situ keratomileusis (LASIK) to improve visual outcome.Methods: Records of patients undergoing cataract surgery between January 2008 and December 2009 were reviewed. Individuals satisfied with visual outcome of cataract surgery and not satisfied were grouped (group 1 and 2, respectively). Preoperative data of refractive error, axial length, corneal astigmatism, intraocular pressure, and postoperative uncorrected visual acuity were recorded. Data was available for 62 patients (104 eyes), of which LASIK enhancement was deemed necessary in 21 eyes (20%; group 2). The receiver operator characteristic curves were used to discriminate between the groups and linear regression analysis was performed to predict the postoperative visual outcome.Results: The astigmatism measured preoperatively using manifest refraction had an accuracy of 64% in discriminating between the groups. Age, spherical component of refraction, axial length, corneal astigmatism, and intraocular pressure were very close to chance prediction 59%, 57%, 56%, 51%, and 51%, respectively. The postoperative uncorrected visual acuity had an accuracy of 79% in discriminating the groups. Individuals with uncorrected visual acuity worse than 20/40 after cataract surgery were most likely to undergo LASIK enhancement; however, approximately 20% of group 2 underwent LASIK enhancement despite having visual acuity of 20/30 or better. When combined, preoperative visual acuity accounted for just 7% of variance in postoperative uncorrected visual acuity.Conclusion: Requirement of LASIK enhancement after cataract surgery with multifocal IOL implant is complex in nature, and parameters routinely measured before surgery cannot successfully identify the group requiring LASIK enhancement or predict postoperative uncorrected visual acuity.Keywords: refractive error, axial length, corneal astigmatism, intraocular pressure, uncorrected visual acuity, visual outcome, multivariate analysis, LASIK enhancemen
Finite Difference Schemes for Variable Order Time-Fractional First Initial Boundary Value Problems
The aim of the study is to obtain the numerical solution of first initial boundary value problem (IBVP) for semi-linear variable order fractional diffusion equation by using different finite difference schemes. We developed the three finite difference schemes namely explicit difference scheme, implicit difference scheme and Crank-Nicolson difference scheme, respectively for variable order type semi-linear diffusion equation. For this scheme the stability as well as convergence are studied via Fourier method. At the end, solution of some numerical examples are discussed and represented graphically using Matlab
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