Measurement of carotenoid levels in human serum and a catalog of the lutein conformation populations from semi-empirical calculations

Lutein is a principal constituent of the human macular pigment. This study is composed of two projects. The first studies the conformational geometries of lutein and its potential adaptability in biological systems. The second is a study of the response of human subjects to lutein supplements. Using semi-empirical parametric method 3 (PM3) and density functional theory with the B3LYP/6-31G* basis set, the relative energies of s- cis conformers of lutein were determined. All 512 s-cis conformers were calculated with PM3. A smaller, representative group was also studied using density functional theory. PM3 results were correlated systematically to B3LYP values and this enables the results to be calibrated. The relative energies of the conformers range from 1-30 kcal/mole, and many are dynamically accessible at normal temperatures. Four commercial formulations containing lutein were studied. The serum and macular pigment (MP) responses of human subjects to these lutein supplements with doses of 9 or 20 mg/day were measured, relative to a placebo, over a six month period. In each instance, lutein levels in serum increased and correlated with MP increases. The results demonstrate that responses are significantly dependent upon formulation and that components other than lutein have an important influence serum response.

A method for enhancing digital information displayed to computer users with visual refractive errors via spatial and spectral processing

This research pursued the conceptualization, implementation, and verification of a system that enhances digital information displayed on an LCD panel to users with visual refractive errors. The target user groups for this system are individuals who have moderate to severe visual aberrations for which conventional means of compensation, such as glasses or contact lenses, does not improve their vision. This research is based on a priori knowledge of the user's visual aberration, as measured by a wavefront analyzer. With this information it is possible to generate images that, when displayed to this user, will counteract his/her visual aberration. The method described in this dissertation advances the development of techniques for providing such compensation by integrating spatial information in the image as a means to eliminate some of the shortcomings inherent in using display devices such as monitors or LCD panels. Additionally, physiological considerations are discussed and integrated into the method for providing said compensation. In order to provide a realistic sense of the performance of the methods described, they were tested by mathematical simulation in software, as well as by using a single-lens high resolution CCD camera that models an aberrated eye, and finally with human subjects having various forms of visual aberrations. Experiments were conducted on these systems and the data collected from these experiments was evaluated using statistical analysis. The experimental results revealed that the pre-compensation method resulted in a statistically significant improvement in vision for all of the systems. Although significant, the improvement was not as large as expected for the human subject tests. Further analysis suggest that even under the controlled conditions employed for testing with human subjects, the characterization of the eye may be changing. This would require real-time monitoring of relevant variables (e.g. pupil diameter) and continuous adjustment in the pre-compensation process to yield maximum viewing enhancement.

3D navigation with six degrees-of-freedom using a multi-touch display

With the introduction of new input devices, such as multi-touch surface displays, the Nintendo WiiMote, the Microsoft Kinect, and the Leap Motion sensor, among others, the field of Human-Computer Interaction (HCI) finds itself at an important crossroads that requires solving new challenges. Given the amount of three-dimensional (3D) data available today, 3D navigation plays an important role in 3D User Interfaces (3DUI). This dissertation deals with multi-touch, 3D navigation, and how users can explore 3D virtual worlds using a multi-touch, non-stereo, desktop display. ^ The contributions of this dissertation include a feature-extraction algorithm for multi-touch displays (FETOUCH), a multi-touch and gyroscope interaction technique (GyroTouch), a theoretical model for multi-touch interaction using high-level Petri Nets (PeNTa), an algorithm to resolve ambiguities in the multi-touch gesture classification process (Yield), a proposed technique for navigational experiments (FaNS), a proposed gesture (Hold-and-Roll), and an experiment prototype for 3D navigation (3DNav). The verification experiment for 3DNav was conducted with 30 human-subjects of both genders. The experiment used the 3DNav prototype to present a pseudo-universe, where each user was required to find five objects using the multi-touch display and five objects using a game controller (GamePad). For the multi-touch display, 3DNav used a commercial library called GestureWorks in conjunction with Yield to resolve the ambiguity posed by the multiplicity of gestures reported by the initial classification. The experiment compared both devices. The task completion time with multi-touch was slightly shorter, but the difference was not statistically significant. The design of experiment also included an equation that determined the level of video game console expertise of the subjects, which was used to break down users into two groups: casual users and experienced users. The study found that experienced gamers performed significantly faster with the GamePad than casual users. When looking at the groups separately, casual gamers performed significantly better using the multi-touch display, compared to the GamePad. Additional results are found in this dissertation.^

A method for enhancing digital information displayed to computer users with visual refractive errors via spatial and spectral processing

This research pursued the conceptualization, implementation, and verification of a system that enhances digital information displayed on an LCD panel to users with visual refractive errors. The target user groups for this system are individuals who have moderate to severe visual aberrations for which conventional means of compensation, such as glasses or contact lenses, does not improve their vision. This research is based on a priori knowledge of the user's visual aberration, as measured by a wavefront analyzer. With this information it is possible to generate images that, when displayed to this user, will counteract his/her visual aberration. The method described in this dissertation advances the development of techniques for providing such compensation by integrating spatial information in the image as a means to eliminate some of the shortcomings inherent in using display devices such as monitors or LCD panels. Additionally, physiological considerations are discussed and integrated into the method for providing said compensation. In order to provide a realistic sense of the performance of the methods described, they were tested by mathematical simulation in software, as well as by using a single-lens high resolution CCD camera that models an aberrated eye, and finally with human subjects having various forms of visual aberrations. Experiments were conducted on these systems and the data collected from these experiments was evaluated using statistical analysis. The experimental results revealed that the pre-compensation method resulted in a statistically significant improvement in vision for all of the systems. Although significant, the improvement was not as large as expected for the human subject tests. Further analysis suggest that even under the controlled conditions employed for testing with human subjects, the characterization of the eye may be changing. This would require real-time monitoring of relevant variables (e.g. pupil diameter) and continuous adjustment in the pre-compensation process to yield maximum viewing enhancement.

The effects of therapeutic ultrasound on open wounds

The purpose of this study was to evaluate the evidence for the effectiveness of therapeutic ultrasound (US) therapy in the treatment of open wounds as an adjunct to the usual and customary treatment provided by physical therapists. An exhaustive search of all published studies on the effects of therapeutic ultrasound on open wounds was performed. Every article, which met certain criteria, was reviewed in detail. Criteria included the use of human subjects, animal subjects, or human cells in vitro, publication in referred journals indexed by MEDLINE, CINAHL and availability of full text in the English language. Fourteen studies met the selection criteria. A total of 31 possible outcomes were available from these studies. Outcomes were categorized as positive, negative or non-significant. The results indicated a total of seventeen positives, eight negatives and six non-significant outcomes. The results of the analysis indicate that there is evidence in the literature to suggest that therapeutic US is beneficial in the treatment of open wounds.

3D Navigation with Six Degrees-of-Freedom using a Multi-Touch Display

With the introduction of new input devices, such as multi-touch surface displays, the Nintendo WiiMote, the Microsoft Kinect, and the Leap Motion sensor, among others, the field of Human-Computer Interaction (HCI) finds itself at an important crossroads that requires solving new challenges. Given the amount of three-dimensional (3D) data available today, 3D navigation plays an important role in 3D User Interfaces (3DUI). This dissertation deals with multi-touch, 3D navigation, and how users can explore 3D virtual worlds using a multi-touch, non-stereo, desktop display. The contributions of this dissertation include a feature-extraction algorithm for multi-touch displays (FETOUCH), a multi-touch and gyroscope interaction technique (GyroTouch), a theoretical model for multi-touch interaction using high-level Petri Nets (PeNTa), an algorithm to resolve ambiguities in the multi-touch gesture classification process (Yield), a proposed technique for navigational experiments (FaNS), a proposed gesture (Hold-and-Roll), and an experiment prototype for 3D navigation (3DNav). The verification experiment for 3DNav was conducted with 30 human-subjects of both genders. The experiment used the 3DNav prototype to present a pseudo-universe, where each user was required to find five objects using the multi-touch display and five objects using a game controller (GamePad). For the multi-touch display, 3DNav used a commercial library called GestureWorks in conjunction with Yield to resolve the ambiguity posed by the multiplicity of gestures reported by the initial classification. The experiment compared both devices. The task completion time with multi-touch was slightly shorter, but the difference was not statistically significant. The design of experiment also included an equation that determined the level of video game console expertise of the subjects, which was used to break down users into two groups: casual users and experienced users. The study found that experienced gamers performed significantly faster with the GamePad than casual users. When looking at the groups separately, casual gamers performed significantly better using the multi-touch display, compared to the GamePad. Additional results are found in this dissertation.

A qualitative analysis of the congruency of Jungian psychological preferences identified by the Myers-Briggs Type Indicator (MBTI) and the human resource development role of instructor/facilitator

The purpose of this ethnographic study was to describe and explain the congruency of psychological preferences identified by the Myers-Briggs Type Indicator (MBTI) and the human resource development (HRD) role of instructor/facilitator. This investigation was conducted with 23 HRD professionals who worked in the Miami, Florida area as instructors/facilitators with adult learners in job-related contexts.^ The study was conducted using qualitative strategies of data collection and analysis. The research participants were selected through a purposive sampling strategy. Data collection strategies included: (a) administration and scoring of the MBTI, Form G, (b) open-ended and semi-structured interviews, (c) participant observations of the research subjects at their respective work sites and while conducting training sessions, (d) field notes, and (e) contact summary sheets to record field research encounters. Data analysis was conducted with the use of a computer program for qualitative analysis called FolioViews 3.1 for Windows. This included: (a) coding of transcribed interviews and field notes, (b) theme analysis, (c) memoing, and (d) cross-case analysis.^ The three major themes that emerged in relation to the congruency of psychological preferences and the role of instructor/facilitator were: (1) designing and preparing instruction/facilitation, (2) conducting training and managing group process, and (3) interpersonal relations and perspectives among instructors/facilitators.^ The first two themes were analyzed through the combination of the four Jungian personality functions. These combinations are: sensing-thinking (ST), sensing-feeling (SF), intuition-thinking (NT), and intuition-feeling (NF). The third theme was analyzed through the combination of the attitudes or energy focus and the judgment function. These combinations are: extraversion-thinking (ET), extraversion-feeling (EF), introversion-thinking (IT), and introversion-feeling (IF).^ A last area uncovered by this ethnographic study was the influence exerted by a training and development culture on the instructor/facilitator role. This professional culture is described and explained in terms of the shared values and expectations reported by the study respondents. ^

Evaluation of contact and non-contact trapping efficiencies of human scent chemical profiles and their stabilities under different environmental conditions

Establishing an association between the scent a perpetrator left at a crime scene to the odor of the suspect of that crime is the basis for the use of human scent identification evidence in a court of law. Law enforcement agencies gather evidence through the collection of scent from the objects that a perpetrator may have handled during the execution of the criminal act. The collected scent evidence is consequently presented to the canines for identification line-up procedures with the apprehended suspects. Presently, canine scent identification is admitted as expert witness testimony, however, the accurate behavior of the dogs and the scent collection methods used are often challenged by the court system. The primary focus of this research project entailed an evaluation of contact and non-contact scent collection techniques with an emphasis on the optimization of collection materials of different fiber chemistries to evaluate the chemical odor profiles obtained using varying environment conditions to provide a better scientific understanding of human scent as a discriminative tool in the identification of suspects. The collection of hand odor from female and male subjects through both contact and non-contact sampling approaches yielded new insights into the types of VOCs collected when different materials are utilized, which had never been instrumentally performed. Furthermore, the collected scent mass was shown to be obtained in the highest amounts for both gender hand odor samples on cotton sorbent materials. Compared to non-contact sampling, the contact sampling methods yielded a higher number of volatiles, an enhancement of up to 3 times, as well as a higher scent mass than non-contact methods by more than an order of magnitude. The evaluation of the STU-100 as a non-contact methodology highlighted strong instrumental drawbacks that need to be targeted for enhanced scientific validation of current field practices. These results demonstrated that an individual's human scent components vary considerably depending on the method used to collect scent from the same body region. This study demonstrated the importance of collection medium selection as well as the collection method employed in providing a reproducible human scent sample that can be used to differentiate individuals.

Neanderthal admixture in current human populations

In the present body of work two primary subjects have been addressed, both individually and in their correspondence, namely (1) the potential for Neanderthals to have contributed to the Modern Human population, and (2) the genetic diversity of one of the most prehistorically impactful human popuations, the Armenians. The first subject is addressed by assessing 1000 mutations in 384 current humans, particularly for those mutations which appear to derive from the Neanderthal lineage. Additionally, the validity of the Neanderthal sequences themselves is evaluated through alignment analysis of fragementary DNA derived from the Vindija Cave sample. Armenian genetic diversity is analyzed through the autosomal short tandem repeats, y-chromsome single nucleotide polymorphisms, and y-chromosome short tandem repeats. The diversity found indicates that Armenians are a diverse group which has been genetically influenced by the various migrations and invasions which have entered their historic lands. Further, we find evidence that Armenians may be closely associated with the peopling of Europe.

Cognitive performance and the thymus among HIV-infected subjects receiving HAART

Objective: To evaluate the impact of alcohol use, which is widespread in human immunodeficiency virus (HIV)+ individuals, on highly active antiretroviral therapy (HAART)-associated immune and cognitive improvements and the relationship between those two responses. Methods: In a case-control longitudinal study, thymic volume, cognition, and immune responses were evaluated at baseline and after 6 months therapy in HIV+ and HIV- controls. Cognitive performance was evaluated using the HIV Dementia Score (HDS) and the California Verbal Learning Test (CVLT). Results: Prior to HAART, thymic volume varied considerably from 2.7 to 29.3 cm3 (11 ± 7.2 cm3). Thymic volume at baseline showed a significantly inverse correlation with the patient’s number of years of drinking (r2 = 0.207; p < 0.01), as well as HDS and the CVLT scores in both HIV-infected (r2 = 0.37, p = 0.03) and noninfected (r2 = 0.8, p = 0.01). HIV-infected individuals with a small thymic volume scored in the demented range, as compared with those with a larger thymus (7 ± 2.7 vs. 12 ± 2.3, p = 0.005). After HAART, light/moderate drinkers exhibited thymus size twice that of heavy drinkers (14.8 ± 10.4 vs. 6.9 ± 3.3 cm3). Conclusions: HAART-associated increases of thymus volume appear to be negatively affected by alcohol consumption and significantly related to their cognitive status. This result could have important clinical implications.

Distribution of light in the human retina under natural viewing conditions

Age-related macular degeneration (AMD) is the leading cause of blindness inAmerica. The fact that AMD wreaks most of the damage in the center of the retina raises the question of whether light, integrated over long periods, is more concentrated in the macula. A method, based on eye-tracking, was developed to measure the distribution of light in the retina under natural viewing conditions. The hypothesis was that integrated over time, retinal illumination peaked in the macula. Additionally a possible relationship between age and retinal illumination was investigated. The eye tracker superimposed the subject's gaze position on a video recorded by a scene camera. Five informed subjects were employed in feasibility tests, and 58 naïve subjects participated in 5 phases. In phase 1 the subjects viewed a gray-scale image. In phase 2, they observed a sequence of photographic images. In phase 3 they viewed a video. In phase 4, they worked on a computer; in phase 5, the subjects walked around freely. The informed subjects were instructed to gaze at bright objects in the field of view and then at dark objects. Naïve subjects were allowed to gaze freely for all phases. Using the subject's gaze coordinates, and the video provided by the scene camera, the cumulative light distribution on the retina was calculated for ∼15° around the fovea. As expected for control subjects, cumulative retinal light distributions peaked and dipped in the fovea when they gazed at bright or dark objects respectively. The light distribution maps obtained from the naïve subjects presented a tendency to peak in the macula for phases 1, 2, and 3, a consistent tendency in phase 4 and a variable tendency in phase 5. The feasibility of using an eye-tracker system to measure the distribution of light in the retina was demonstrated, thus helping to understand the role played by light exposure in the etiology of AMD. Results showed that a tendency for light to peak in the macula is a characteristic of some individuals and of certain tasks. In these situations, risk of AMD could be increased. No significant difference was observed based on age.

The relationship between higher education curricular variables and human flight performance in a preliminary flying training program

The ability of the United States Air Force (USAF) to sustain a high level of operational ability and readiness is dependent on the proficiency and expertise of its pilots. Recruitment, education, training, and retention of its pilot force are crucial factors in the USAF's attainment of its operational mission: defense of this nation and its allies. Failure of a student pilot during a training program does not only represent a loss of costly training expenditures to the American public, but often consists of loss of human life, aircraft, and property. This research focused on the Air Force Reserve Officer Training Corps' (AFROTC) selection method for student pilots for the light aircraft training (LATR) program. The LATR program is an intense 16 day flight training program that precedes the Air Force's undergraduate pilot training (UPT) program. The study subjects were 265 AFROTC cadets in the LATR program. A variety of independent variables from each subject's higher education curricular background as well as results of preselection tests, participation in varsity athletics, prior flying experience and gender were evaluated against subsequent performance in LATR. Performance was measured by a quantitative performance score developed by this researcher based on 28 graded training factors as well as overall pass or fail of the LATR program. Study results showed participation in university varsity athletics was very significantly and positively related to performance in the LATR program, followed by prior flying experience and to a very slight degree portions of the Air Force Officers Qualifying Test. Not significantly related to success in the LATR program were independent variables such as grade point average, scholastic aptitude test scores, academic major, gender and the AFROTC selection and ranking system.

On-screen pre-deblurring of digital images using the wavefront aberration function of the human eye to improve computer access for the visually impaired

Traditional Optics has provided ways to compensate some common visual limitations (up to second order visual impairments) through spectacles or contact lenses. Recent developments in wavefront science make it possible to obtain an accurate model of the Point Spread Function (PSF) of the human eye. Through what is known as the "Wavefront Aberration Function" of the human eye, exact knowledge of the optical aberration of the human eye is possible, allowing a mathematical model of the PSF to be obtained. This model could be used to pre-compensate (inverse-filter) the images displayed on computer screens in order to counter the distortion in the user's eye. This project takes advantage of the fact that the wavefront aberration function, commonly expressed as a Zernike polynomial, can be generated from the ophthalmic prescription used to fit spectacles to a person. This allows the pre-compensation, or onscreen deblurring, to be done for various visual impairments, up to second order (commonly known as myopia, hyperopia, or astigmatism). The technique proposed towards that goal and results obtained using a lens, for which the PSF is known, that is introduced into the visual path of subjects without visual impairment will be presented. In addition to substituting the effect of spectacles or contact lenses in correcting the loworder visual limitations of the viewer, the significance of this approach is that it has the potential to address higher-order abnormalities in the eye, currently not correctable by simple means.

Genital human papillomavirus: Women's knowledge and attitudes of this sexually transmitted disease

The purpose of this study was to investigate women's knowledge and attitudes regarding genital human papillomavirus (n=100). Using a descriptive design, the Health Education Questionnaire was administered to 100 female patients (Mean Age = 33, SD = 7.17) at a physicians office in South Florida. The results indicated a lack of knowledge regarding genital human papillomavirus with 21 patients (21%) reported having knowledge and 79 (79%) having never heard of this disease. In addition, the group familiar with genital human papillomavirus also possessed a low level of knowledge with only 57% acknowledging an association of genital human papillomavirus and cervical cancer, 52% aware that a pap smear can detect the virus, 42% knowing that antibiotics can not treat the disease and 57% aware that it is not associated with a family history. An association was found between attitudes and health seeking behaviors. Subjects stating that they would take all measures to prevent genital human papillomavirus, were more likely to have a pap smear within the last year (Chi-square (1) = 4.33, p < .05). Higher levels of education and income were associated with increased knowledge regarding genital human papillomavirus when subjects were categorized according to sociodemographic characteristic (Chi-square (1) =9.45, p < .05; Chi-square (1) = 6.75, p < .05). There was no significant correlation between knowledge and ethnicity, marital status or age. Findings indicated the need for improved education and promotion of positive attitudes regarding human papillomaviurs in order to improve health seeking behaviors among women.

Distribution of Light in the Human Retina under Natural Viewing Conditions

Age-related macular degeneration (AMD) is the leading cause of blindness inAmerica. The fact that AMD wreaks most of the damage in the center of the retina raises the question of whether light, integrated over long periods, is more concentrated in the macula. A method, based on eye-tracking, was developed to measure the distribution of light in the retina under natural viewing conditions. The hypothesis was that integrated over time, retinal illumination peaked in the macula. Additionally a possible relationship between age and retinal illumination was investigated. The eye tracker superimposed the subject’s gaze position on a video recorded by a scene camera. Five informed subjects were employed in feasibility tests, and 58 naïve subjects participated in 5 phases. In phase 1 the subjects viewed a gray-scale image. In phase 2, they observed a sequence of photographic images. In phase 3 they viewed a video. In phase 4, they worked on a computer; in phase 5, the subjects walked around freely. The informed subjects were instructed to gaze at bright objects in the field of view and then at dark objects. Naïve subjects were allowed to gaze freely for all phases. Using the subject’s gaze coordinates, and the video provided by the scene camera, the cumulative light distribution on the retina was calculated for ~15° around the fovea. As expected for control subjects, cumulative retinal light distributions peaked and dipped in the fovea when they gazed at bright or dark objects respectively. The light distribution maps obtained from the naïve subjects presented a tendency to peak in the macula for phases 1, 2, and 3, a consistent tendency in phase 4 and a variable tendency in phase 5. The feasibility of using an eye-tracker system to measure the distribution of light in the retina was demonstrated, thus helping to understand the role played by light exposure in the etiology of AMD. Results showed that a tendency for light to peak in the macula is a characteristic of some individuals and of certain tasks. In these situations, risk of AMD could be increased. No significant difference was observed based on age.