ExPERT: An online database of University Examination Papers

In this presentation, we discuss: . the development and operation of ExPERT . how previous systems influenced the design of ExPERT . the System Analysis and Design . the selection of generic descriptor sets for describing examination papers . an overview of the system (web- based) architecture; the user- interface; and a walkthrough of system operation . user take- up, operational issues and system maintenance . a brief plan for future work on the syste

Who is buying urban condominiums? : a tale of four cities

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Architecture, 2005.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references.This thesis is an analysis of the current trend in urban condominium and loft sales in the United States. It focuses specifically on the question of whom, demographically speaking, is buying the incredible influx of new urban residential products that has come onto the market since 2000. There is only anecdotal evidence gathered to date, where some claim that it is the empty-nesters abandoning the suburbs for the convenience of city life. However, there has not been the corresponding drop in suburban population levels or house sale levels to corroborate that hypothesis. Other market participants claim that the sales are primarily to investors, who are either renting or riding appreciation expectations to resell. If that is true, then there are considerable market implications for the future. Others project that it is an urban pied-a-terre trend; however the 2000 census only identifies 3% of the whole housing stock as seasonal, recreational, or second homes. This thesis pools and analyzes recent historical data in four urban downtowns: Atlanta, Boston, Chicago, and San Diego to determine what is happening in each city and to try to discover a national trend. It utilizes raw mortgage origination data, assessor's data, and surveys and interviews with developers and brokers in each of the four designated cities.(cont.) In addition to demographic profiles of buyers, this study determines whether these are second homes, speculative purchases, or complete relocations from outside the city. Ultimately, what can be concluded from this analysis is that a much larger segment of demand for urban condos in Atlanta, Boston, Chicago and San Diego consists of second home purchasers and investors than are counted in the 2000 Census. Surveys of 7849 units indicate 66% owner occupancy, 22% second home purchase plus investors with no plan to rent and finally another 12% investors who rent out their units. Trends are similar across markets, although the Atlanta market is driven by younger buyers and San Diego has the lowest percentage of owner occupants, indicating the most speculative buying.by Robert M. DeLaney and Linda K. Pizzuti.S.M

Public Perception of Pesticide Exposure in Vermont

Introduction: A pesticide is any substance intended for preventing, destroying, repelling, or mitigating any pest.1 The public generally believes that insects, diseases, and other pests need to be controlled but is also becoming concerned about the impact of pesticides on their health and the local ecosystem. Pesticide exposure occurs with public and private use. Studies indicate consumers have diverse levels of awareness, knowledge, and attitudes regarding pesticide use and health risks.2 The goal of this project is to identify levels of awareness, knowledge, and attitudes toward pesticide usage in Vermont to help State agencies focus public awareness and education.https://scholarworks.uvm.edu/comphp_gallery/1217/thumbnail.jp

Parents' Psychological and Decision-Making Outcomes following Prenatal Diagnosis with Complex Congenital Heart Defect: An Exploratory Study

UNLABELLED: Background. Parents with a fetus diagnosed with a complex congenital heart defect (CHD) are at high risk of negative psychological outcomes. Purpose. To explore whether parents' psychological and decision-making outcomes differed based on their treatment decision and fetus/neonate survival status. Methods. We prospectively enrolled parents with a fetus diagnosed with a complex, life-threatening CHD from September 2018 to December 2020. We tested whether parents' psychological and decision-making outcomes 3 months posttreatment differed by treatment choice and survival status. Results. Our sample included 23 parents (average Age[years]: 27 ± 4, range = 21-37). Most were women (n = 18), non-Hispanic White (n = 20), and married (n = 21). Most parents chose surgery (n = 16), with 11 children surviving to the time of the survey; remaining parents (n = 7) chose comfort-directed care. Parents who chose comfort-directed care reported higher distress (x¯ = 1.51, s = 0.75 v. x¯ = 0.74, s = 0.55; Mdifference = 0.77, 95% confidence interval [CI], 0.05-1.48) and perinatal grief (x¯ = 91.86, s = 22.96 v. x¯ = 63.38, s = 20.15; Mdifference = 27.18, 95% CI, 6.20-48.16) than parents who chose surgery, regardless of survival status. Parents who chose comfort-directed care reported higher depression (x¯ = 1.64, s = 0.95 v. x¯ = 0.65, s = 0.49; Mdifference = 0.99, 95% CI, 0.10-1.88) than parents whose child survived following surgery. Parents choosing comfort-directed care reported higher regret (x¯ = 26.43, s = 8.02 v. x¯ = 5.00, s = 7.07; Mdifference = 21.43, 95% CI, 11.59-31.27) and decisional conflict (x¯ = 20.98, s = 10.00 v. x¯ = 3.44, s = 4.74; Mdifference = 17.54, 95% CI; 7.75-27.34) than parents whose child had not survived following surgery. Parents whose child survived following surgery reported lower grief (Mdifference = -19.71; 95% CI, -39.41 to -0.01) than parents whose child had not. Conclusions. The results highlight the potential for interventions and care tailored to parents' treatment decisions and outcomes to support parental coping and well-being. HIGHLIGHTS: Question: Do the psychological and decision-making outcomes of parents differ based on their treatment decision and survival outcome following prenatal diagnosis with complex CHD?Findings: In this exploratory study, parents who decided to pursue comfort-directed care after a prenatal diagnosis reported higher levels of psychological distress and grief as well as higher decisional conflict and regret than parents who decided to pursue surgery.Meaning: The findings from this exploratory study highlight potential differences in parents' psychological and decision-making outcomes following a diagnosis of complex CHD for their fetus, which appear to relate to the treatment approach and the treatment outcome and may require tailoring of psychological and decision support

Sulfide geochronology along the Endeavour Segment of the Juan de Fuca Ridge

Forty-nine hydrothermal sulfide-sulfate rock samples from the Endeavour Segment of the Juan de Fuca Ridge, northeastern Pacific Ocean, were dated by measuring the decay of 226Ra (half-life of 1600 years) in hydrothermal barite to provide a history of hydrothermal venting at the site over the past 6000 years. This dating method is effective for samples ranging in age from ∼200 to 20,000 years old and effectively bridges an age gap between shorter- and longer-lived U-series dating techniques for hydrothermal deposits. Results show that hydrothermal venting at the active High Rise, Sasquatch, and Main Endeavour fields began at least 850, 1450, and 2300 years ago, respectively. Barite ages of other inactive deposits on the axial valley floor are between ∼1200 and ∼2200 years old, indicating past widespread hydrothermal venting outside of the currently active vent fields. Samples from the half-graben on the eastern slope of the axial valley range in age from ∼1700 to ∼2925 years, and a single sample from outside the axial valley, near the westernmost valley fault scarp is ∼5850 ± 205 years old. The spatial relationship between hydrothermal venting and normal faulting suggests a temporal relationship, with progressive younging of sulfide deposits from the edges of the axial valley toward the center of the rift. These relationships are consistent with the inward migration of normal faulting toward the center of the valley over time and a minimum age of onset of hydrothermal activity in this region of 5850 years

Assessment of learning curves in complex surgical interventions: a consecutive case-series study

Background: Surgical interventions are complex, which complicates their rigorous assessment through randomised clinical trials. An important component of complexity relates to surgeon experience and the rate at which the required level of skill is achieved, known as the learning curve. There is considerable evidence that operator performance for surgical innovations will change with increasing experience. Such learning effects complicate evaluations; the start of the trial might be delayed, resulting in loss of surgeon equipoise or, if an assessment is undertaken before performance has stabilised, the true impact of the intervention may be distorted. Methods: Formal estimation of learning parameters is necessary to characterise the learning curve, model its evolution and adjust for its presence during assessment. Current methods are either descriptive or model the learning curve through three main features: the initial skill level, the learning rate and the final skill level achieved. We introduce a fourth characterising feature, the duration of the learning period, which provides an estimate of the point at which learning has stabilised. We propose a two-phase model to estimate formally all four learning curve features. Results: We demonstrate that the two-phase model can be used to estimate the end of the learning period by incorporating a parameter for estimating the duration of learning. This is achieved by breaking down the model into a phase describing the learning period and one describing cases after the final skill level is reached, with the break point representing the length of learning. We illustrate the method using cardiac surgery data. Conclusions: This modelling extension is useful as it provides a measure of the potential cost of learning an intervention and enables statisticians to accommodate cases undertaken during the learning phase and assess the intervention after the optimal skill level is reached. The limitations of the method and implications for the optimal timing of a definitive randomised controlled trial are also discussed

HIV Risk and Associations of HIV Infection among men who have sex with men in Peri-Urban Cape Town, South Africa

<p>Abstract</p> <p>Background</p> <p>The HIV epidemic in Sub Saharan Africa has been traditionally assumed to be driven by high risk heterosexual and vertical transmission. However, there is an increasing body of data highlighting the disproportionate burden of HIV infection among MSM in the generalized HIV epidemics across of Southern Africa. In South Africa specifically, there has been an increase in attention focused on the risk status and preventive needs of MSM both in urban centers and peri-urban townships. The study presented here represents the first evaluation of HIV prevalence and associations of HIV infection among MSM in the peri-urban townships of Cape Town.</p> <p>Methods</p> <p>The study consisted of an anonymous probe of 200 men, reporting ever having had sex with another man, recruited through venue-base sampling from January to February, 2009.</p> <p>Results</p> <p>Overall, HIV prevalence was 25.5% (n = 51/200). Of these prevalent HIV infections, only 6% of HIV-1 infected MSM were aware of their HIV status (3/50). 0% of men reported always having safe sex as defined by always wearing condoms during sex and using water-based lubricants. Independent associations with HIV infection included inconsistent condom use with male partners (aOR 2.3, 95% CI 1.0-5.4), having been blackmailed (aOR 4.4, 95% CI 1.6-20.2), age over 26 years (aOR 4.2, 95% CI 1.6-10.6), being unemployed (aOR 3.7, 95% CI 1.5-9.3), and rural origin (aOR 6.0, 95% CI 2.2-16.7). Bisexual activity was reported by 17.1% (34/199), and a total of 8% (16/200) reported having a regular female partner. Human rights violations were common with 10.5% (n = 21/200) reporting having been blackmailed and 21.0% (n = 42/200) reporting being afraid to seek health care.</p> <p>Conclusions</p> <p>The conclusions from this study include that a there is a high risk and underserved population of MSM in the townships surrounding Cape Town. The high HIV prevalence and high risk sexual practices suggest that prevalence will continue to increase among these men in the context of an otherwise slowing epidemic. These data further highlight the need to better characterize risk factors for HIV prevention and appropriate targeted combination packages of HIV interventions including biomedical, behavioural, and structural approaches to mitigate HIV risk among these men.</p

The Human Mitochondrial tRNAMet: Structure/Function Relationship of a Unique Modification in the Decoding of Unconventional Codons

Human mitochondrial mRNAs utilize the universal AUG and the unconventional isoleucine AUA codons for methionine. In contrast to translation in the cytoplasm, human mitochondria use one tRNA, hmtRNAMetCAU, to read AUG and AUA codons at both the peptidyl- (P-), and aminoacyl-(A-) sites of the ribosome. The hmtRNAMetCAU has a unique post-transcriptional modification, 5-formylcytidine, at the wobble position 34 (f5C34), and a cytidine substituting for the invariant uridine at position 33 of the canonical “U-turn” in tRNAs. The structure of the tRNA's anticodon stem and loop domain (hmtASLMetCAU), determined by NMR restrained molecular modeling, revealed how the f5C34 modification facilitates the decoding of AUA at the P- and A-sites. The f5C34 defined a reduced conformational space for the nucleoside, in what appears to have restricted the conformational dynamics of the anticodon bases of the modified hmtASLMetCAU. The hmtASLMetCAU exhibited a “C-turn” conformation that has some characteristics of the U-turn motif. Codon binding studies with both E. coli and bovine mitochondrial ribosomes revealed that the f5C34 facilitates AUA binding in the A-site and suggested that the modification favorably alters the ASL's binding kinetics. Mitochondrial translation by many organisms including humans sometimes initiates with the universal isoleucine codons AUU and AUC. The f5C34 enabled P-site codon binding to these normally isoleucine codons. Thus, the physicochemical properties of this one modification, f5C34, expand codon recognition from the traditional AUG to the non-traditional, synonymous codons AUU and AUC as well as AUA, in the reassignment of universal codons in the mitochondria