<p> Polycystic Ovarian Syndrome (PCOS) is a metabolic and endocrine disorder that is the most common cause of infertility. PCOS can manifest itself as a long and short term disability and is characterized by insulin resistance (IR), hyperandrogenism, anovulation, hyperinsulinaemia and polycystic ovaries. Our lack of understanding of this disorder and its long term effects has complicated the treatment of the disorder; yet, it is clear that PCOS involves the intricate interaction between genetics, environments and behaviors. To study this disease, scientists have used various animal models. Since the <i> Drosophila</i> model for PCOS has only been postulated,in this work, we determined whether starvation along with the addition of steroid hormones would induce a PCOS-like disorder in <i>D. melanogaster</i> after 24 hour exposure. </p><p> In women with PCOS, testosterone levels and the expression of the androgen receptor are elevated. In fruit flies, ecdysone (E) and its &ldquo;active&rdquo; form, 20-hydroxyecdysone (20E), are homologous to the human testosterone and 20-hydroxytestosterone, respectively. This hormone is required for circadian cycles, molting, and maturation in insects. More specifically, this hormone is also located in ovarian tissue and aids in follicular development. The receptor for ecdysone is the ecdysone receptor (EcR). In this work, we examined the expression of the ecdysone receptor (EcR) upon starvation for up to 24 hours by immunofluorescence microcopy. Using qRT-PCR, we determined the levels of expression of genes usually associated with inflammation. Ovarian dysfunction was examined by measuring the fecundity of the females. Starvation increases the expression of the EcR and pro-inflammatory gene expression and decreases fecundity, suggesting that <i>Drosophila melanogaster</i> is a potentially useful model organism in the study of PCOS.</p>

The purpose of this project was to investigate 8-month-old infants' representation and tracking of objects in occlusion events. Recent research has shown that young infants are able to reason about various aspects of physical objects' behavior. This project further explores this ability and delineates some limits to it. Specifically, the first set of studies (1A-1F) investigated whether infants' apply spatiotemporal continuity to collections of objects as they do to single objects. Because to adults a collection can be viewed as multiple objects as well as a non-object individual, infants' tracking of a collection may thus inform us not only about their representation of objects but also about their representation of non-object entities. The second set of studies (2A and 2B) focused on infants' detection of spatiotemporal discontinuity in object behavior in different situations: The disappearance versus appearance situation. These two sets of studies revealed two limitations in infants' application of spatiotemporal continuity: While 8-month-old infants are able to detect the discontinuous disappearance of single objects, they (a) do not readily detect the discontinuous disappearance of a collection but succeed only in certain circumstances, and (b) do not detect the discontinuous appearance of single objects. These limitations have important implications for infants' knowledge of and tracking systems for objects. Finally, some general issues arising from the current project are discussed.

The spliceosome is a dynamic macromolecular machine composed of five different small nuclear ribonucleoproteins (snRNPs), the Nineteen Complex (NTC), RNA helicases, and other proteins that catalyze the removal of introns from pre-mRNA. Although the spliceosome has been extensively studied, there are still many unanswered questions regarding the molecular mechanisms of pre-mRNA splicing. In this work we used the Schizosaccharomyces pombe model system to characterize the structure and function of the spliceosome. By examining the in vitro RNA ability of S. pombe Cdc5, a core component of the NTC, we were able to propose a mechanism where protein components of the NTC can bind and stabilize RNA within the active site of the spliceosome. We also used an RNA helicase mutant, S. pombe prp16-1, to isolate a second step splicing complex. This work has provided insight into the general mechanisms on how the spliceosome functions to process pre-mRNA.

This study explored infants’ sensitivity to speaker reliability in verb labeling. Past research has focused primarily on nouns (Koenig & Echols, 2003). The participants in this study were 32 24-month-old infants. Visual stimuli included a group of intransitive verbs that should be familiar to 24-month-olds such as jumping, turning, and waving. These stimuli were shown on a television display. Half of the participants were in a True Labeling Condition, in which they heard labels that correctly matched the familiar actions. The other half of the participants were in a False Labeling Condition, in which they heard familiar labels that did not correspond with the familiar actions they saw. The amounts of time that infants looked at action, labeler, and parent were compared across true and false conditions using t-tests. I expected to find that infants have similar expectations about how labels map to referents for verbs and for nouns, such that they expect speakers to apply consistent labels to both. As a result, infants were expected to look longer to the “false” than “true” labeler. Contrary to predictions, infants failed to look longer at the action in the true condition than the false, or to the speaker in the false condition as compared to the true. The comprehensive results for the studies did not indicate that infants expect accurate labels for actions from humans who are intending to refer, as did previous research with objects. / text

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The purpose of this project was to investigate four markers of early cognitive development in preterm and fullterm infants with uncomplicated pre- and peri-natal medical histories. These included object memory, location memory, memory and manual search, and inhibitory control of reaching. In addition, the relation between behavioral organization at term and the development of these abilities was investigated. For all test sessions, the PT infants were tested at corrected age (age since expected due date) rather than chronological age (age since birth). The Assessment of Preterm Infant Behavior (APIB) was used to measure regulation of attention, orientation to visual stimuli, motor functioning, and modulatory abilities at 2 weeks corrected age. At 2.5, 4.5, and 6.5 months corrected age, each infant was tested on Visual Paired Comparison and Visual Search. At 8.5, 10.5, and 12.5 months of corrected age each infant was tested on A-not-B and Object Retrieval. Successful performance on VPC and VS is thought to depend on the functional development of the object vision and spatial vision systems, respectively. Successful performance on A-not-B and OR depends on the functional integrity of the dorsolateral prefrontal cortex. FT infants evidenced better performance on all domains of functioning measured by the APIB. While the infants did not evidence object memory at any age tested, which was attributed to difficulty of task demands, they did evidence location memory at all ages tested. There was not a direct effect of PT birth on VPC or VS performance. However, there was an indirect effect of PT birth, mediated by APIB performance, on attention behaviors during both tasks. There was not a direct effect of PT birth on A-not-B or OR performance. However, there was an indirect effect of PT birth, mediated by APIB performance, on the development of OR abilities. These findings indicate that group differences in behavioral organization at 2 weeks of age differentially predict rates of development on some cognitive tasks. Finally, the overall pattern of results indicates that uncomplicated PT birth does not alter the functional development of the neural systems studied.

Two hierarchical regressions were posed to examine the relative contribution of several predictor variables on retention test performance. The retention test encompassed content from a beginning graduate level statistics class. Cross-sectional methodology was employed to include students who had taken the course sometime during a twenty-two year interval. This study had a unique opportunity to examine long term remembering in an ecological setting where the content area and the teaching had been stable. Grade, from the original course, was the strongest predictor in both hierarchical models. Other independent variables which had significant impact on retention test performance were number of continuing classes in statistics and number of classes in research design and methodology. Rehearsal frequency as well as rehearsal recency were significant predictors. The level of original learning and what one does during the retention interval are more important than the length of the interval itself. The effect of spaced vs. mass practice, as defined by the length of the acquisition interval, was examined. Subjects who took the course over a 15 week semester session outperformed subjects who had the 5 week summer session. In this study, the rate of decline was affected by the subject's age at the time of the retention test. This indicates increasingly rapid forgetting during adult development and has implications for the maintenance of marginal knowledge.

This study addressed the free recall and recognition memory processes of elementary school children. It has been discovered that when children recall items from episodically related collections, a non-monotonic relationship is found between the memory strengths of those items and the order in which they are recalled. This relationship is known as cognitive triage, and it is not understood if the same phenomena would occur with recall involving semantic memory. Regarding recognition memory, experiments have tapped children's tendency to falsely remember words whose gist is the same as the gist of newly learned items. These past studies have focused primarily on a reversal of the standard false-recognition effect, where related distractors were easier to reject than unrelated distractors under some conditions. No research to date has ignored reversals and clearly examined the false-recognition effect itself. This study examined kindergarten, third, and sixth grade children's free recall organization and false-recognition of related distractors. The cognitive triage experiment examined semantic memory through having children recall exemplars from categories in Battig and Montague's (1969) lists. The recognition experiment examined developmentally the differential rate of false-recognition for related and unrelated distractors. Fuzzy Trace Theory (FTT) contends that the ability to inhibit interference increases with age. Hence, younger children were hypothesized to show a weaker cognitive triage effect and more false-recognition than older children. The latter result was found, whereas the former result was not. False-recognition did decrease with age but although a triage effect was observed for category exemplar production, the effect did not vary developmentally. The principle difference between this triage study and previous research is that lists offering preexperimental measures of memory strength were employed. These lists were normed on adults and therefore cognitive triage may have been different for children. Thus, this study indicates that developmental effects are found for false-recognition of related distractors but not for category exemplar production when using Battig and Montague's (1969) lists.

This study investigated the presence of the framing bias in children's probabilistic decision-making. Under investigation was whether children would frame when presented with problems analogous to those known to elicit framing in adults. Prospect theory (Tversky & Kahneman, 1979) was pitted against fuzzy-trace theory (Brainerd & Reyna, 1990) to determine which provided a better explanation of children's decision-making. Preschoolers, second-, and fifth-graders were asked to make choices in a probabilistic situation across various levels of probability and expected values of outcome. It was expected that the amount of framing would increase with age.