3,133 research outputs found
Bid-Ask Spread Modelling in the South African Bond Market
Pitsillis and Taylor (2014) calculate bid-ask spread estimates of South African government bonds over a single year, using the models of De Jong and Rindi (2009) and Huang and Stoll (1997). This dissertation tests the effectiveness of both models by comparing the modelled equity spread estimates against the actual equity spread estimates. Furthermore, this dissertation investigates the stability of the De Jong and Rindi (2009) and Huang and Stoll (1997) models in the bond market by extending the spread estimate dataset to run annually over 5 years. The final section of this dissertation proposes a new method of estimating the bond spread through the use of a Kalman filter, as it can be used to leverage information from an onscreen market (albeit a different market) to imply bid-ask spread estimates in an off-screen market. The results indicate that the Huang and Stoll (1997) model consistently outperforms the De Jong and Rindi (2009) model. Furthermore, the yield estimate results of Pitsillis and Taylor (2014) align with the results obtained in this dissertation. The spread estimate results are stable over the 5-year period, indicating a strong provision of liquidity by the Primary Dealers
From Sites to Systems: Scales of Behaviour from the Spatial Distribution of Lithics at Open-Air Sites in the Doring Catchment, South Africa
The vast bulk of the evidence we have for the human past derives from open-air settings. This is true of both the archaeological record, which in landscapes like those of southern Africa often occurs as a continuous distribution of varying density, and of the hunter-gatherer ethnographic record, which generally comprises observations of activities undertaken in the open. And yet when reconstructing human behaviours in Palaeolithic we rely on data taken disproportionately from rock shelters. This incongruity reflects a long-standing distrust of data from open-air sites, and particularly those open-air sites composed of surface-exposed artefacts that are subject to cycles of erosion, redistribution, and redeposition. It is the contention of this thesis that that distrust stems from two sources: a failure to engage in depth with the patterns that are preserved in such open-air sites, and a failure to generate scale-appropriate questions when interpreting those patterns.
The focus of the thesis is on the open-air archaeological record of the Doring River catchment in the south west of South Africa, a region which includes innumerable open-air sites along with well-resolved rock shelter sequences extending beyond 100 000 years. The thesis poses three central questions: What is the archaeological composition of open-air localities along the Doring River? Are there differences in technological compositions and/or organisational strategies between these open-air sites and rock shelters within the catchment? Is the spatial distribution of lithic material at these open-air localities governed solely by taphonomic processes, or can we observe behavioural patterning â and if so at what scales
Contextualizing GayâStraight Alliances: Student, Advisor and Structural Factors Related to Positive Youth Development among Members
Gay-straight alliances (GSAs) may promote resilience. Yet, what GSA components predict well-being? Among 146 youth and advisors in 13 GSAs (58% lesbian, gay, bisexual, or questioning; 64% White; 38% received free/reduced-cost lunch), student (demographics, victimization, attendance frequency, leadership, support, control), advisor (years served, training, control), and contextual factors (overall support or advocacy, outside support for the GSA) that predicted purpose, mastery, and self-esteem were tested. In multilevel models, GSA support predicted all outcomes. Racial/ethnic minority youth reported greater well-being, yet lower support. Youth in GSAs whose advisors served longer and perceived more control and were in more supportive school contexts reported healthier outcomes. GSA advocacy also predicted purpose. Ethnographic notes elucidated complex associations and variability as to how GSAs operated
Identifying the Plessy Remainder: State Exploitation of Private Discriminatory-Impact Actions
Public education in the U.S. is arguably more racially segregated now than it was in 1954, when the U.S. Supreme Court declared in Brown v. Board of Education that in the field of public education the doctrine of separate but equal\u27 has no place. Although scholars may differ in the extent they believe that racial integration might be necessary for educational equality, most agree that educational segregation, whether imposed by law, socioeconomics, or happenstance, is not likely to reverse in any meaningful way in the near future.
In the absence of a recognized federal right to education, federal-court- supervised school desegregation has been, perhaps, the most viable vehicle for students of color to access educational opportunities enjoyed by white students. This phenomenon remains salient, almost to the point of truism, but not because of any inherent or behavioral differences among students by race or because of any benefits proximity to whiteness affords students of color. Rather, the desegregation remedy is primarily a function of intractable political and socioeconomic realities that enable educational opportunity hoarding by wealthier and whiter stakeholders at the expense of poorer Black stakeholders and stakeholders of color
The Public Right to Education
Public education is the most important function of state and local government and yet not a fundamental right or liberty. This Article engages one of constitutional law\u27s most intractable problems by introducing the public right to education as a doctrinal pathway to a constitutional right to education process in three steps. First, it identifies that the otherwise right-to-education foreclosing case, San Antonio Independent School District v. Rodriguez, only contemplated education as a fundamental right or liberty interest. Second, by identifying public education as a due process protected property interest, this Article presents a viable pathway for circumventing Rodriguez. Third, mindful of myriad judicial competency concerns and consistent with the Court\u27s recent call to reimagine a twenty-first century due process, it reintroduces the public right to understand how school children might appeal to substantive due process to protect their rights to state-created interests. This ambitious yet modest approach covers securing schoolchildren\u27s rights to both discrete education tangibles and the integral educational opportunity that the states have assumed the affirmative duty to provide. This approach also has promise for improving individual rights to quality public schooling
Creating the Urban Educational Desert through School Closures and Dignity Taking
Closures of urban open-enrollment neighborhood schools that primarily serve students of color are intensely controversial. Districts seeking to economize often justify closures by pointing to population shifts in historically densely populated urban areas. They argue that net reductions in a neighborhoodâs school-aged population result in underutilized schools, which do a disservice to students at higher cost to districts. Students and their families and communities counter, pointing to histories of district neglect of their schools and recent school expansions in more affluent neighborhoods of similar population density as belying district claims of utility-based downsizing. In this article, I use a critical discourse analysis (CDA) of Chicago Public Schoolsâ (CPS) school closure hearings process for William H. King Elementary School to show how affected communities experience formal process-driven school closure as an âabnormal justiceâ moment, characterized by âmisrecognizingâ community-based notions of property, âmisrepresentingâ these interests in how they characterize the schoolâs value, and âmaldistributingâ the physical school property through closure. I argue that closing schools in this manner compounds the physical property loss with a âdignity takingâ that leaves an âeducational desertâ in its aftermath, with implications for laws on educational property interests
THE FABRICATION AND STUDY OF METAL CHELATING STATIONARY PHASES FOR THE HIGH PERFORMANCE SEPARATION OF METAL IONS
The preparation and characterisation of chelating sorbents suitable for the high efficiency
separation of trace metals in complex samples, using a single column and isocratic elution,
is described.
Hydrophobic, neutral polystyrene divinylbenzene resins were either impregnated with
chelating dyes or dynamically modified with heterocyclic organic acids, using physical
adsorption and chemisorption processes respectively. A hydrophilic silica substrate was
covalently bonded with a chelating aminomethylphosphonic acid group, to assess the
chelating potential of this molecule.
These substrates were characterised in terms of metal retention capability (selectivity
coefficients and capacity factors), separation performance, column efficiency and
suitability for analytical applications. Chelating molecules with different ligand groups
were found to have unique selectivity patterns dependant upon the conditional stability
constants of the chelate.
Other factors, including mobile phase constituents - complexing agents, ionic strength and
pH, column length and column capacity were additionally investigated to examine their
effect upon the separation profiles achieved.
The promising metal separation abilities illustrated by a number of these chelating columns
were exploited for the determination of trace toxic metals in complex sample matrices
using High Performance Chelation Ion Chromatography (HPCIC). This included the
determination of beryllium in a certified stream sediment, uranium in seawater and a
certified stream sediment, and cadmium, lead and copper in a certified rice flour. The
results for each analysis fell within the certified limits, and reproducibility was good. The
optimisation of post column detection systems using chromogenic ligands additionally
gave good detection limits for the metals in each separation system
The Perils of Asian-American Erasure
Affirmative action, particularly its most well-known variant, race-conscious college admissions practices, has long occupied a precarious position in constitutional jurisprudence of equal protection and statutory antidiscrimination law. As a policy matter, affirmative action practices are necessary to reduce the impact of durable structural barriers to opportunity that have been imposed on members of identifiable racial groups because of their race. Legally, theyâre on far less secure footing.
As a constitutional matter, these measures have been summarily divorced from any reparative purpose since the âdiversity rationaleâ emerged from Regents of the University of California v. Bakke as the only compelling interest a public college or university may have in race-consciousness enrollment management. Without âa [predicate] judicial determination of constitutional violation,â a public college or university simply cannot appeal to remedy to justify its use of race classifications. The question currently before the Court in Students for Fair Admissions, Inc. v. University of North Carolina is whether the diversity rationale alone is constitutionally sufficient. In the companion case, Students for Fair Admissions, Inc. v. President & Fellows of Harvard College, the question is whether a federal-funds-receiving educational institutionâs consideration of race can be compatible with the Title VI statutory requirement that such institutions not discriminate on racial grounds. Unlike in the University of North Carolina case, the certified question in the President & Fellows of Harvard College case specifically asks if institutional consideration of race âpenalize[es] Asian-American applicants.â
This is the first time that the Court has explicitly asked for consideration of the effects race-conscious admissions policies might have on Asian Americans. Though this motivating premise is left unstated, in Professor Vinay Harpalaniâs article, Asian Americans, Racial Stereotypes, and Elite Admissions, itâs long overdue
Development and Pilot of a Patient Reported Outcome Measure for Proximal Thoracic Aortic Aneurysms
Background: Disease specific questionnaires are increasingly being used to evaluate treatment outcomes from the perspective of patients. There are currently no validated questionnaires that measure patient reported outcomes after proximal thoracic aortic aneurysm surgery. Objectives: To develop and pilot a newly formulated patient focussed questionnaire that measures the patientâs health status and health related quality of life before and after proximal thoracic aortic aneurysm surgery. Methods: Based on a literature review, a thematic analysis of audio recorded patient interviews and expert clinical testimony, a pool of items was generated to form a new questionnaire instrument. Suitable patients who were scheduled for elective aortic surgery at Liverpool Heart and Chest Hospital were identified and invited to participate in the pilot study. Patients were asked to complete the questionnaire prior to surgery and then at 6 weeks and 3 months after their operation. The newly developed instrument underwent preliminary testing for its appropriateness, acceptability, feasibility, interpretability, precision, reliability and responsiveness. Results: Several items from the CROQ (Coronary Revascularisation Outcomes Questionnaire) formed the basis of the instrument, with the addition of 10 items derived from a newly formulated conceptual model of proximal thoracic aortic disease. The items were arranged into four domains (symptoms, physical, psychosocial and cognitive). Initial testing showed that the newly developed instrument performed to acceptable standards. It showed good internal consistency (Cronbachâs alpha results for all domains >0.85), and test retest reliability (intraclass correlation coefficient for all domains >0.85). In paired sample tests, the values in each domain led to statistically significant differences from baseline at either 6 weeks or 3 months (p<0.05), supporting the construct validity and responsiveness of the instrument. Conclusions: The new instrument demonstrated satisfactory validity as well as good internal reliability and test retest reliability for each item across all four domains. The initial findings suggest that the measure is sensitive and responsive to the effects of surgical treatment for proximal thoracic aortic aneurysms
- âŚ