5 resultados para Age-related maculopathy

em Digital Commons at Florida International University


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Eighty-four young and 84 older men and women participants, read scenarios in which a male or female target uses either a self-enhancement or a self-deprecation tactic to present him/herself in front of either a close friend or a new acquaintance. Then participants i.e., perceivers) rated their impressions of the self-enhancing or self-deprecating target on six scales: likable, self-knowledgeable, honest, depressed, happy, and anxious. Overall, both young and old perceivers gave more favorable ratings to self-enhancing targets than to self-deprecating targets. Both young and old perceivers' impressions did not differ for a target who presented him/herself in front of a friend or in front of an acquaintance. Also, perceivers completed Singelis' (1994) Self-Construal Measurement, which measures both interdependent and independent self-construals. As predicted, older perceivers had a higher level of interdependent self-construal than did young perceivers. Unexpectedly, female perceivers had a higher level of independent self-construal than did male perceivers. Neither the age-related nor gender-related differences in self-construals were associated with any age-related or gender-related differences in perceivers' impressions of the self-enhancing and self-deprecating targets. That is, the moderator effects of self-construals on the relationships between self-presentation tactic conditions and ratings of targets were not-significant. ^

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Preimplantation genetic diagnosis (PGD) following in vitro fertilization (IVF) offers couples at risk for transmitting genetic disorders the opportunity to identify affected embryos prior to replacement. In particular, embryo gender determination permits screening for X-linked diseases of unknown etiology. Analysis of embryos can be performed by polymerase chain reaction (PCR) amplification of material obtained by micromanipulation. This approach provides an alternative to the termination of an established pregnancy following chorionic villi sampling or amniocentesis. ^ Lately, the focus of preimplantation diagnosis and intervention has been shifting toward an attempt to correct cytoplasmic deficiencies. Accordingly, it is the aim of this investigation to develop methods to permit the examination of single cells or components thereof for clinical evaluation. In an attempt to lay the groundwork for precise therapeutic intervention for age related aneuploidy, transcripts encoding proteins believed to be involved in the proper segregation of chromosomes during human oocyte maturation were examined and quantified. Following fluorescent rapid cycle RT-PCR analysis it was determined that the concentration of cell cycle checkpoint gene transcripts decreases significantly as maternal age increases. Given the well established link between increasing maternal age and the incidence of aneuploidy, these results suggest that the degradation of these messages in aging oocytes may be involved with inappropriate chromosome separation during meiosis. ^ In order to investigate the cause of embryonic rescue observed following clinical cytoplasmic transfer procedures and with the objective of developing a diagnostic tool, mtDNA concentrations in polar bodies and subcellular components were evaluated. First, the typical concentration of mtDNA in human and mouse oocytes was determined by fluorescent rapid cycle PCR. Some disparity was noted between the copy numbers of individual cytoplasmic samples which may limit the use of the current methodology for the clinical assessment of the corresponding oocyte. ^

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The purpose of this study was to investigate the effectiveness of an experimental teaching method, Sport Aerobics, on the basketball skill acquisition of fifth grade students. This study investigated the differences in the shooting, dribbling, and passing scores of students taught with Sport Aerobics instruction compared to those taught with a traditional method, Practice Style. Sport Aerobics is an instructional method based on a theoretical framework developed by the researcher to enhance skill acquisition. This framework leads to teaching strategies such as using immediate feedback and specific cueing; arranging for students to engage in object free movement; arranging lessons, according to the framework's concept of movement progression, into lessons staged according to skill and sub-skill complexity; and instructing based on whole group organization. Sport Aerobic instructional strategies were designed to facilitate process learning that is recognized as important in today's development learning approach for age related curriculums. In contrast, the traditional Practice Style uses product-oriented strategies. ^ Four classrooms, consisting of seventy-nine fifth grade students from two physical education programs, at different locations, were randomly assigned to two treatments; Sport Aerobics and Practice Style for instruction over a 15 period curriculum. Using the American Alliance Physical Education Recreation & Dance tests, both groups were pretested and posttested for skill achievement of shooting, dribbling, and passing. Pretest and posttest skill score samples were collected and evaluated. ANCOVAs were performed on the posttests adjusted for the pretests to determine whether or not there would be greater achievement of skills with the Sport Aerobics method. Results failed to establish significant scoring differences between the two methods. Based on the literature and study findings a recommendation is made that longer lesson units will assist in the investigation of the effectiveness of both the instructional model and the individual elements that facilitate skill acquisition. ^

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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.

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Heart valve disease occurs in adults as well as in pediatric population due to age-related changes, rheumatic fever, infection or congenital condition. Current treatment options are limited to mechanical heart valve (MHV) or bio-prosthetic heart valve (BHV) replacements. Lifelong anti-coagulant medication in case of MHV and calcification, durability in case of BHV are major setbacks for both treatments. Lack of somatic growth of these implants require multiple surgical interventions in case of pediatric patients. Advent of stem cell research and regenerative therapy propose an alternative and potential tissue engineered heart valves (TEHV) treatment approach to treat this life threatening condition. TEHV has the potential to promote tissue growth by replacing and regenerating a functional native valve. Hemodynamics play a crucial role in heart valve tissue formation and sustained performance. The focus of this study was to understand the role of physiological shear stress and flexure effects on de novo HV tissue formation as well as resulting gene and protein expression. A bioreactor system was used to generate physiological shear stress and cyclic flexure. Human bone marrow mesenchymal stem cell derived tissue constructs were exposed to native valve-like physiological condition. Responses of these tissue constructs to the valve-relevant stress states along with gene and protein expression were investigated after 22 days of tissue culture. We conclude that the combination of steady flow and cyclic flexure helps support engineered tissue formation by the co-existence of both OSS and appreciable shear stress magnitudes, and potentially augment valvular gene and protein expression when both parameters are in the physiological range.