The medial prefrontal cortex (mPFC) plays a critical role in the organization of goal directed behavior. This role is suggested by the anatomy of mPFC as the region rests at the top of a complex cortical and sub-cortical hierarchy, receives convergent sensory and motor information from multiple modalities, and is the target of modulatory brainstem nuclei that respond to prediction and reward. Given these observations, it was hypothesized that mPFC neurons store associations between stimuli when the stimuli contribute to the prediction of reward. To test this hypothesis, neural ensemble spiking activity was recorded in the mPFC as rats performed a paired-associate discrimination task. In one condition, both elements of the paired-associate stimulus-sequence provided information about reward delivery. In another condition, only the first stimulus contributed to the prediction. As hypothesized, stimulus-selective, prospective delay activity was observed during sequences in which both elements contributed to reward-prediction. Unexpectedly, however, selective delay responses were associated with slight variations in head position and thus were not necessarily generated by intrinsic mnemonic processes. Interestingly, the sensitivity of neurons to head position was greatest during intervals when reward delivery was certain. These result suggest that a major portion of delay activity in the rat mPFC reflects task-relevant sensory-motor activity, possibly related to behavioral strategies rather than to the local storage of stimulus-stimulus associations. These observations agree with evidence suggesting that mPFC neurons are particularly responsive during the performance of actions related to the acquisition of reward. These results also indicate that considerable attention must be given to the monitoring of sensory-motor variables during delay tasks as slight changes in position can produce activity that appears to be driven by intrinsic mechanisms. It is further suggested that such activity may perform an important role in memory guided behavior, although this role may contrast sharply with standard theories of delay activity and short term memory storage. In particular, it is suggested that delay activity observed in the prefrontal cortex may correspond to the maintenance of memories that are 'stored' in the body or in the environment in the forms of embodied or situated behaviors.

Problem: There is a lack of knowledge about women who are screened for breast cancer, have an abnormal finding on mammogram, and then do not return in a timely manner for diagnostics and treatment. Lack of follow- up likely constitutes delayed treatment and poorer outcomes. Delays may result in later entry into the health system with advanced disease, more extensive and expensive care, burdening resources. Late stage breast cancer likely results in poorer health outcomes or early death.Purpose and Aims: The purpose of this research is to describe contextual characteristics at the health delivery level as well as individual characteristics of women with abnormal mammography, and their association with use of follow- up health services. Particularly, this research examines the differences between women who are early and late responders after an abnormal mammogram.Population: The participants were a convenience sample of 380 women who participated in mobile breast cancer screening. A subset of women with inconclusive or abnormal mammogram findings was the focus of analysis.Methods: This research utilized a descriptive design with quantitative data collection through participant survey at mobile mammogram screening events in multiple urban and rural Arizona sites. Participants requiring further health care were followed by chart review. Analysis of correlations with the outcome variable: time to first follow- up appointment for recommended health care in women with abnormal mammograms was conducted.Findings: Data indicated the time to the first follow- up appointment ranged from 1- 110 days with follow- up for 77.4% of participants within 60 days, 6.5% within 60-90 days, and 16.1% without follow- up after 90 days. Significant relationships between contextual and individual characteristics and follow- up were found. Categories included organizational health system characteristics of geographic location, clinical breast exam and shared case management; individual characteristics of beliefs including value of health care; finance including out of pocket costs and perceptions of financial assistance; perceived needs including breast symptoms; and satisfaction with the last health visit and mammograms in general.Implications: Recognition of barriers to follow- up after breast cancer screening is important for development of interventions to improve outcomes and has implications for screening and treatment management programs, community health centers and private practice. Health disparity related to screening without adequate options for access to health care is ethically untenable. Nurses are well positioned to reduce barriers to health care.

The Black-Scholes model and corresponding option pricing formula has led to a wide and extensive industry, used by financial institutions and investors to speculate on market trends or to control their level of risk from other investments. From the formation of the Chicago Board Options Exchange in 1973, the nature of options contracts available today has grown dramatically from the single-date contracts considered by Black and Scholes (1973) to a wider and more exotic range of derivatives. These include American options, which can be exercised at any time up to maturity, as well as options based on the weighted sums of assets, such as the Asian and basket options which we consider. Moreover, the underlying models considered have also grown in number and in this work we are primarily motivated by the increasing interest in past-dependent asset pricing models, shown in recent years by market practitioners and prominent authors. These models provide a natural framework that considers past history and behaviour, as well as present information, in the determination of the future evolution of an underlying process. In our studies, we explore option pricing techniques for arithmetic Asian and basket options under a Stochastic Delay Differential Equation (SDDE) approach. We obtain explicit closed-form expressions for a number of lower and upper bounds before giving a practical, numerical analysis of our result. In addition, we also consider the properties of the approximate numerical integration methods used and state the conditions for which numerical stability and convergence can be achieved.

This article reports the findings of a grounded theory study of the processes involved in adherence and treatment seeking delay for febrile neutropenia in chemotherapy patients. Interviews were conducted with 12 patients. Six theoretical constructs were generated, namely ‘Recall of Treatment Advice’, ‘Impact of Emotions’, ‘Influence of Social Networks’, ‘Symptom Monitoring Behaviour’, ‘Symptom Interpretation’, and ‘Preparation and Journey Time’. A model was developed to reflect the complex interplay between these theoretical constructs. Data extracts are presented to illustrate the grounding of the model in patients’ accounts, and the model is discussed with reference to previous theory and research.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / This paper analyzes the probability of bit error for PCM-FM over a standard IRIG channel subject to multipath interference modeled by the aeronautical fading channel. The aeronautical channel model assumes a mobile transmitter and a stationary receiver and specifies the correlation of the fading component. This model describes fading which is typical of that encountered at military test ranges. An expression for the bit error rate on the fading channel with a delay line demodulator is derived and compared with the error rate for the Gaussian channel. The increase in bit error rate over that of the Gaussian channel is determined along with the power penalty caused by the fading. In addition, the effects of several channel parameters on the probability of bit error are determined.

Doctor of Philosophy / Department of Physics / Chii-Dong Lin / Isolated attosecond pulse (IAP) is a tool of probing electronic dynamics occurring in atoms, molecules, clusters and solids, since the time scale of electronic motion is on the order of attoseconds. The generation, characterization and applications of IAPs has become one of the fast frontiers of laser experiments. This dissertation focuses on several aspects of attosecond physics. First, we study the driving wavelength scaling of the yield of high-order harmonic generation (HHG) by applying the quantum orbit theory. The unfavorable scaling law especially for the short quantum orbit is of great importance to attoseond pulse generation toward hundreds of eVs or keV photon energy region by mid-infrared (mid-IR) lasers. Second, we investigate the accuracy of the current frequency-resolved optical gating for complete reconstruction of attosecond bursts (FROG-CRAB) and phase retrieval by omega oscillation filtering (PROOF) methods for IAP characterization by simulating the experimental data by theoretical calculation. This calibration is critical but has not been carefully carried out before. We also present an improved method, namely the swPROOF which is more universal and robust than the original PROOF method. Third, we investigate the controversial topic of photoionization time delay. We find the limitation of the FROG-CRAB method which has been used to extract the photoionization time delay between the 2s and 2p channels in neon. The time delay retrieval is sensitive to the attochirp of the XUV pulse, which may lead to discrepancies between experiment and theory. A new fitting method is proposed in order to overcome the limitations of FROG-CRAB. Finally, IAPs are used to probe the dynamic of electron correlation in helium atom by means of attosecond transient absorption spectroscopy. The agreement between the measurement and our analytical model verifies the observation of time-dependent build up of the 2s2p Fano resonance.

Abstract A revised Developmental Delay (DD) category became effective in Arizona on September 30, 2009 and allows children who demonstrate significant delays in at least two developmental areas to receive services in special education up to age 10. In order for the educational team to determine that a student meets the criteria for DD, an assessment in all five developmental areas, including cognitive, physical, communication, adaptive, and social/emotional must be completed. However, areas typically included in a neuropsychological assessment, like attention and executive functioning or memory and learning, are typically not part of an educational evaluation and have the potential to adversely affect learning when there are deficits in these areas. DD is a highly prevalent group that has a wide variety of genetic, environmental, and societal risk factors. The definition varies greatly in research, education, medical or health-related fields, as well as by culture. Since the DD category is viable until age 10, outcome studies have been conducted to find out if children with DD continue in special education and if so, under what categories. It has been found that children with DD generally stay in special education and continue receiving services, most often as students with specific learning disability, mild intellectual disability, and speech/language impairment, in addition to other categories. There is limited information in the available literature regarding the neuropsychological strengths and weaknesses for this prevalent group. Moreover, there is limited information available regarding the possible predictors of reading achievement for children with DD. The first aim of the study was to determine how much variability in performance there was for children who met the educational criteria for DD in Arizona as well as to assess strengths and weaknesses compared to normative means. The second aim of this study was to find out if two specific scores from a neuropsychological battery found to be significantly lower in children with a reading disorder were also significant predictors of reading performance in children with DD. A third aim involved an exploratory analysis to determine if there was evidence of a pattern of strengths and weaknesses by delay type. Thirty-three children with DD ages 5 to 9 years were recruited for this study from a single school district in Southern Arizona. Children were administered measures of cognition, attention and executive functioning, memory and learning, sensorimotor skills, and visuospatial processing, and reading. The parent/guardian of the child completed a structured developmental history. For the first aim, the total sample was split into two groups by presence of cognitive delay and analyzed separately. Qualitatively, the data in the form of box-plots was examined. Levene's and Nonparametric Levene's tests were used to quantitatively evaluate variance in score distributions. Single sample t-tests were used to compare group mean scale or subscale scores to the appropriate normative means. The second aim was analyzed using the total sample of children with DD. Stepwise linear regression models were used to determine if Speeded Naming and Inhibition Naming Total Completion Time scores significantly predicted reading performance as measured by the Reading Cluster score from the WJ IV ACH for all children with DD. Two other subtest scores, which were observed to be within normal limits in children with reading disorder on the NEPSY-II special group study, were also analyzed with stepwise linear regression to confirm that they did not predict reading in children with DD, namely Memory for Designs Total Score and Geometric Puzzles. Lastly, for the third aim, those with each delay type were analyzed separately from those without the delay type (e.g., no communication delay and communication delay). Like the first aim, box-plots were generated to visually represent the data. DD group mean scores of each scale or subscale were also compared to the appropriate normative means by single sample t-tests. Results from this study indicated that the variation in the scores was not significantly different between groups, except for a measure of graphomotor speed and precision. Children with DD with a cognitive delay were found to exhibit a wide range of deficits, including deficits in cognition, reading, attention and executive functioning, language, memory and learning, sensorimotor, and visuospatial processing. Children without cognitive impairment did not demonstrate impairments in cognition and reading and demonstrated specific skill deficits for sustained attention, speeded naming with accuracy, immediate and long-term visual memory, memory for organized verbal information, phonological short-term memory, and fine motor speed. When the total sample was analyzed together, three high reading scores were identified as outliers from group reading performance. Both predictor variables were found to be moderately related to reading whether the outliers were in or out. Only one of the two predictors were found to significantly contribute to the predictive model whether the outliers were in or out yet the strength of the prediction was weak, suggesting there are likely better predictors of reading for children with DD. In the analysis of the non-predictors, when the outlier scores were left in, Geometric Puzzles, a measure of visuospatial perception and mental rotation was indicated as a significant predictor of reading. When the outliers were removed, neither score was significantly related with reading. Lastly, meaningful group strengths and weaknesses were seen when the total sample of children with DD was broken into groups by delay, even when the majority performed below normative means. The results of this study indicate that children with DD are at increased risk for significant difficulties in many of the areas included in neuropsychological assessment. This points to the need for many of these areas, namely attention and executive functioning, memory and learning, and visuospatial processing to be included in a comprehensive evaluation in the school setting. Moreover, knowledge of group strengths and weaknesses can aid intervention selection and implementation in addition to appropriate accommodations to facilitate learning. This can inform intervention implementation and design. More research is needed in this area to have a better understanding of how neurocognitive skills relate to reading since the predictors selected for this study were not strong predictors of reading performance for children with DD. Visuospatial perception and mental rotation may be more highly related for children with DD that have higher reading skills.

Background: Endometriosis is a common condition in women of reproductive age, causing pelvic pain and subfertility, but little is known about its impact on health-related quality of life (HRQoL) and work productivity worldwide. Methods: In 10 countries across five continents, this study recruited 1,418 women, aged 18-45, without a previous surgical diagnosis of endometriosis, scheduled to undergo a laparoscopy to investigate symptoms suggestive of endometriosis or to be sterilised. Pre-operatively, women completed a standardised questionnaire assessing symptoms, diagnostic delay, HRQoL and work productivity using validated instruments. Surgeons completed a standardised questionnaire incorporating findings at laparoscopy including endometriosis stage according to revised American Fertility Society criteria. Results: There was a mean delay of 9.2 years (SD 8.8), principally in primary care, between the onset of symptoms and diagnostic laparoscopy. This diagnostic delay was longer in centres where healthcare was predominantly state-funded (12.8 vs. 7.6 years; p<0.001). In multivariate analyses, the delay was positively associated with the number of pelvic symptoms (chronic pelvic pain, dysmenorrhoea, dyspareunia and heavy periods; p<0.001) and a higher body mass index (p<0.001). Physical HRQoL was significantly reduced in affected women compared to those with similar symptoms and no endometriosis (p=0.012). Not being in paid employment, severe pelvic pain and moderate-severe disease were associated with reduced physical HRQoL (all p<0.001). Each affected woman lost on average 10.0 hours (SD 10.6) of work weekly, due mainly to reduced effectiveness while working. The annual indirect cost of endometriosis associated with work productivity loss ranged from US$399 per woman in Ibadan (Nigeria) to US$18,586 per woman in Boston (USA). Conclusions: Endometriosis significantly impairs HRQoL and work productivity across countries and ethnicities, yet women continue to experience diagnostic delays in primary care. A higher index of suspicion is needed to expedite specialist assessment of symptomatic women. Future research should seek to clarify pain mechanisms in relation to endometriosis severity.

Humans and other animals discount the value of future rewards, a phenomenon known as delay discounting. Individuals vary widely in the extent to which they discount future rewards, and these tendencies have been associated with important life outcomes. Recent studies have demonstrated that imagining the future reduces subsequent discounting behavior, but no research to date has examined whether a similar principle applies at the trait level, and whether training visualization changes discounting. The current study examined if individual differences in visualization abilities are linked to individual differences in discounting and whether practicing visualization can change discounting behaviors in a lasting way. Participants (n = 48) completed the Vividness of Visual Imagery Questionnaire (VVIQ) and delay discounting task and then underwent a 4-week intervention consisting of visualization training (intervention) or relaxation training (control). Contrary to our hypotheses, participants who reported greater visualization abilities (lower scores) on the VVIQ were higher discounters. To further examine this relationship, an additional 106 participants completed the VVIQ and delay discounting task. In the total sample (n = 154), there was a significant negative correlation between VVIQ scores and discount rates, showing that individuals who are better visualizers are also higher discounters. Consistent with this relationship but again to our surprise, visualization training tended, albeit weakly, to increase discount rates, and those whose VVIQ decreased the most were those whose discount rates increased the most. These results suggest a novel association between visualization abilities and delay discounting.

Given the high rates of premature termination in training clinics, research aimed at understanding client attrition is urgently needed. Recent investigations in this area have implicated expectations of psychotherapy as a strong predictor of premature termination; however, this phenomenon has only been studied from the perspective of client expectations to date. There is reason to believe clinician expectations for the duration and effectiveness of psychotherapy may further impact the likelihood of their clients terminating prematurely. This study sought to address this gap in the literature by examining the association of clinicians' expectations to clients' psychotherapy outcomes and termination status in a training clinic setting. Clinicians were found to hold significantly higher expectations for client improvement than would be expected, and these high expectations were found to be positively correlated with clinically significant change in clients. Implications for improving client retention and treatment outcome in training clinics are discussed.