• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 524
  • 90
  • 57
  • 55
  • 20
  • 8
  • 8
  • 7
  • 6
  • 6
  • 5
  • 4
  • 3
  • 3
  • 1
  • Tagged with
  • 1048
  • 270
  • 162
  • 140
  • 140
  • 114
  • 105
  • 104
  • 98
  • 87
  • 80
  • 74
  • 74
  • 68
  • 63
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
301

Performance, performance persistence and fund flows : UK equity unit trusts/open-ended investment companies vs. UK equity unit-linked personal pension funds

Clark, James Peter January 2013 (has links)
This thesis analyses and compares the performance, performance persistence and fund flows for UK equity unit trusts/OEICs and UK equity unit-linked personal pensions over the sample period January 1980 to December 2007. Unit-linked personal pension funds are an illiquid investment from the investor’s perspective since any invested capital is inaccessible until retirement whereas for unit trusts/OEICs capital invested can be withdrawn at any time. Since decreasing returns to scale from fund flows are the equilibrating mechanism in Berk and Green (2004) that results in no persistence in performance the illiquid nature of unit-linked personal pension funds should ensure more evidence of performance persistence in comparison to unit trusts/OEICs. I find significant evidence using performance ranked portfolio strategies that underlying portfolios that are only composed of unit-linked personal pension funds have greater performance persistence than unit-linked personal pension funds that have underlying portfolios that also include at least a unit trust/OEIC. This evidence is consistent with Berk and Green (2004) since the illiquid nature of personal pension funds results in an attenuated performance fund flow relationship restricting the equilibrating mechanism. However, there are anomalies in the performance persistence results in relation to Berk and Green (2004) but it could be due to the differential between the number of non-surviving unit trusts/OEICs and non-surviving unit-linked personal pension funds. I also find that the performance fund flow relationship based on abnormal returns from a Carhart four factor model for both UK equity unit trusts/OEICs and UK unit-linked personal pensions is convex but the performance fund flow relationship is more attenuated for the unit-linked personal pension funds. For the worst performing unit trusts/OEICs there are outflows on average whereas for unit-linked personal pensions there are fund inflows on average. For performance persistence tests conditional on underlying portfolio fund flows unit trusts/OEICs that have the worst performance but the lowest net fund flows in the ranking period have significantly greater subsequent performance in comparison to the unit trusts/OEICs that have the worst performance but the highest net fund flows in the ranking period. This empirical evidence provides support for Berk and Green (2004) but for the unit-linked personal pension funds the evidence is less convincing. There is very little evidence that UK equity unit-trusts/OEICs or UK equity unit-linked personal pensions produce abnormal returns. These results are robust across the single index (CAPM) model, the Fama and French three factor model and the Carhart four factor model for both conditional and unconditional models. There is also no evidence that unit trusts/OEICs or unit-linked personal pension funds can time the market. There is a significantly negative timing effect across unconditional factor models which becomes insignificant for the conditional models. There is also no evidence that unit trusts/OEICs have significantly different performance than unit-linked personal pension funds.
302

A Contribution to the Empirics of Labour and Development Economics / Regional and Individual Unemployment Persistence, Cash Transfer Program and International Poverty Line

Pasaribu, Syamsul Hidayat 16 December 2014 (has links)
Die vorliegende Dissertation umfasst vier Aufsätze, von denen die ersten beiden die regionale und individuelle Persistenz von Arbeitslosigkeit analysieren. Der dritte Aufsatz erforscht das passende Design für die Höhe von finanziellen Leistungen im Rahmen von Cash-Transfer-Programmen und der vierte Aufsatz präsentiert eine alternative internationale Armutsgrenze verglichen mit der aktuellen offiziellen Armutsgrenze der Weltbank. Während die ersten drei Essays sich auf die Situation Indonesiens beziehen, geht der vierte Aufsatz auf die Situation aller Entwicklungsländer ein. Der erste Essay testet die Hysterese-Hypothese gegen verschiedene Hypothesen zur Persistenz von Arbeitslosigkeitsraten in den Provinzen Indonesiens und verwendet dabei Zeitreihen- und Panel-Unit-Root-Analysen mit Daten aus den Jahren 1990 bis 2012. Die Ergebnisse zeigen einerseits, dass die meisten individuellen Tests auf Provinzebene, die sich auf lineare Trends und CBS-Definitionen stützen, die Hysterese-Hypothese nicht verwerfen können. Andererseits wird die Hysterese-Vermutung vermehrt verworfen, wenn die Tests quadratische Trends und die alte Definition (U1) nutzen. Die wichtigsten Ergebnisse der Tests, die die Hysterese-Hypothese anhand verschiedener Sample-Kategorien, wie beispielsweise Geschlecht, analysieren, legen das Verwerfen der Hypothese ebenfalls nahe. Wenn die Ergebnisse mittels Panel-Daten untersucht werden, verwirft die Mehrheit der Tests Hysterese, ganz gleich ob lineare oder quadratische Trends benutzt werden. Schließlich stellt der Artikel fest, dass lokale Wirtschaftsmaßnahmen zur Investitionsförderung und Politiken, die auf das Wachstum der realen regionalen Mindestlöhne ausgerichtet sind, sich besser als die Erhöhung lokaler staatlicher Ausgaben dazu eignen, die Arbeitslosenquote zu senken und sie an normale Levels auf den lokalen Arbeitsmärkten anzupassen. Der zweite Essay führt eine dynamische Probit-Analyse bezüglich dem Auftreten individueller Arbeitslosigkeit durch und benutzt dabei Paneldaten des National Socio-Economic Surveys (Susenas) von 2008-2010. Der Aufsatz vergleicht mehrere dynamische Random-Effects-Schätzer miteinander, wobei er besonders auf die Ansätze von Heckman (1981) und Wooldridge (2005) eingeht. Die Ergebnisse finden starke Belege für die Persistenz bzw. die zeitliche Abhängigkeit individueller Arbeitslosigkeit in Indonesien. Dieses Resultat fügt sich in die Theorie des "Scar-Unemployment" ein. Der dritte Essay untersucht die derzeitige Empfängergruppe von Cash-Transfer-Programmen (mit Fokus auf BLT und PKH Programmen) in Indonesien. Als Alternative zu bestehenden, fixen, staatlichen Leistungen der indonesischen Regierung im Rahmen der Cash-Transfer-Programme, schlägt der Aufsatz bessere Methoden für das Design und die Berechnung der Höhe der finanziellen Unterstützung vor. Die Ergebnisse zeigen, dass eine signifikante Anzahl von nicht-armen oder nicht-berechtigten Haushalten staatliche Leistungen erhalten. Auf der Grundlage von Simulationen ergeben sich deshalb folgende alternative Optionen für die Höhe der Auszahlungen: (1) die Transferzahlungen so anpassen, dass sie dem Einkommensdefizit des armen Haushalts zzgl. der erwarteten Inflation entsprechen, oder (2) die Leistungen so auszahlen, dass sie dem 75%-Perzentil des Einkommensdefizits der Haushalte zzgl. der erwarteten Inflation in den entsprechenden Provinzen entsprechen. Diese zwei alternativen Optionen reduzieren die regionalen Armutsraten signifikant verglichen mit der derzeitigen fixen und generellen staatlichen Transferleistung. Schließlich zeigen wir mit dem letzten Aufsatz, dass die von Ravallion, Chen, und Sangraula (2009) geschätzte Beziehung zwischen durchschnittlichem Konsum und nationalen Armutsgrenzen für die Herleitung der absoluten internationalen Armutsgrenze in Höhe von $1.25 pro Tag statistisch problematisch ist. Unsere alternative statistische Schätzung erzeugt einen Punktschätzer einer absoluten internationalen Armutsgrenze, der substanziell höher liegt als $1.25 pro Tag; allerdings verfügen die Schätzer über sehr hohe Standardfehler.
303

Examination of the toxicity and inflammatory potential of multi-walled carbon nanotubes in vitro and in vivo

Sternad, Karl Alexander January 2010 (has links)
The rise of nanotechnology industries has led to the design and production of new nano-scaled materials such as quantum dots, nano-metals, carbon nanotubes, fullerenes and a myriad of functionalised derivatives. Extensive work concerning well characterised pathogenic fibres has led to the development of a fibre paradigm that suggests respirable fibres vary in their ability to cause disease based on length and pulmonary bio-persistence. Induction of oxidative stress is also a central plank of the mechanism used to explain inflammatory, fibrotic and carcinogenic effects of fibres. The toxicity of different particle types has consistently been shown to depend upon particle size and surface area, reactive surface molecular groups, metal content, organic content and the presence of endotoxins. A growing body of work has begun to examine the potential pathogenicity of carbon nanotubes to the pulmonary system as a consequence of superficial similarities to known pathogenic particle and fibres. The aim of this thesis was to investigate the potential toxicity of two commercially manufactured multi-walled carbon nanotubes (MWCNT) compared to a panel of low and high toxicity particles and fibres. The pro-inflammatory nature of MWCNT was examined in vitro and in vivo to determine the effects they may exert in the pulmonary system. In aqueous solutions of phosphate buffered saline, saline and cell culture medium (with or without foetal calf serum supplementation) MWCNT were found to exist as tight aggregates even after sonication. Analysis of metal content of MWCNT by ICP-AES revealed the presence of a low percentage of non extractable residual iron. From analysis of MWCNT by electron spin resonance (ESR) the CNT were found to be ready producers of a free radical species, despite this MWCNT were not able to cleave plasmid DNA. Upon incubation with the alveolar epithelial cell line A549 MWCNTs did not cause noticeable toxicity but did dose dependently deplete total glutathione levels. No increase in production of the pro-inflammatory cytokine IL-8 could be detected at the level of protein or at the level of mRNA. Analysis of the levels (protein and mRNA) of the pro-fibrotic mediator TGF-β did not indicate induction of a fibrotic response to MWCNT. Neither were MWCNTs found to consistently activate the pro-inflammatory associated transcription factor nuclear factor kappa B (NF-κB). Upon instillation into the peritoneal cavity of mice MWCNT failed to induce a pro-inflammatory response in contrast to long amosite asbestos that induced an extensive inflammatory reaction. Analysis of the diaphragms of exposed animals revealed the induction by MWCNT of an apparent foreign body type reaction. Overall with limited processing and dispersion MWCNT were morphologically more akin to particles than fibres. Although apparently able to spontaneously generate ROS in aqueous solution this did not translate into a capacity to cause toxicity or a capacity to induce inflammation either in vitro or in vivo.
304

EXPLORING SENSE OF COMMUNITY IN A FIRST-YEAR EXPERIENCE COURSE AND HOW SENSE OF COMMUNITY IMPACTS STUDENTS’ PERCEPTIONS OF TRANSITION AND PERSISTENCE IN COLLEGE

Mayo, Karen L. 01 January 2015 (has links)
This study examines how community was created in a community college FYE 105 Achieving Academic Success course and the impact of classroom community on students’ perceptions of transition and persistence. Community colleges increasingly are focusing on student success as measured by persistence and goal completion such as transfer or attainment of credentials. The classroom learning environment is critical to student success but is a neglected area in retention research. Therefore, it is important to expand the research on initiatives that support students in their quest for success and educational goal completion. This research focused on one course section of FYE 105 taught at a community college; the students and the professor of the class are the participants for the study. New insight and understanding into classroom sense of community was gained through classroom participant-observations throughout the duration of a semester (16 weeks), faculty and student interviews, and review of materials related to the course. The data generated from the study were analyzed using thematic analysis. In order to explore how community is constructed and the role it plays for students, McMillan and Chavis’s sense of community theory and the academic communities component of Braxton, Hirschy, and McClendon’s conceptual model of student departure in commuter colleges and universities were used as the theoretical and conceptual frameworks for the study. Study results reveal that the professor concentrated efforts during the first class sessions on communicating the classroom rules, engaging in active learning, establishing emotional safety and belonging, and facilitating student interdependence, which were critical elements in establishing a sense of community in the classroom. Additionally, the findings show that students perceive the professor, classmates, classroom environment, active learning, and course content as components that contribute to a sense of community that impact their transition. Students were less clear of the role that sense of community played in their college persistence. Findings suggest that faculty would benefit from professional development to enhance their pedagogical skills. Suggestions for future research include a focus on students’ external and campus support systems,electronic technology, classroom diversity, and longitudinal and departure data collection.
305

Evaluation of a pharmacist-led medication management program in high-risk diabetic patients: impact on clinical outcomes, medication adherence, and pharmacy costs

Hanson, Kristin Anne 07 September 2010 (has links)
Diabetes mellitus is a group of metabolic disorders caused by a relative or absolute lack of insulin. Currently, 23.6 million Americans have diabetes. Diabetes can lead to serious microvascular and macrovascular complications, such as cardiovascular disease, blindness, kidney disease, lower-limb amputations, and premature death. Due to the potential cardiovascular complications and the high prevalence of co-morbid hypertension and/or hyperlipidemia in patients with diabetes, diabetes management should include close monitoring of blood glucose, blood pressure, and cholesterol levels. Medical management of diabetic patients is costly; approximately 1 in every 10 health care dollars is currently spent treating diabetes. Studies have shown that in chronic conditions such as diabetes, increased medication use results in demonstrable improvements in health outcomes, reduced hospitalization rates, and decreased direct health care costs. To date no studies have evaluated the impact of a pharmacist-led intervention on diabetic medication adherence. The purpose of this investigation was to analyze the impact of a pharmacist-led medication management program on medication adherence and pharmacy costs and to evaluate clinical measures of diabetes, hypertension, and hyperlipidemia. This study was a quasi-experimental, longitudinal, pre-post study, with a control group. Scott & White Health Plan (SWHP) patients with diabetes (type 1 or type 2), poor glycemic control (most recent A1C >7.5%), and living within 30 miles of participating pharmacies were invited to participate in the intervention which consisted of monthly appointments with a clinical pharmacist and a co-payment waiver for all diabetes medications and testing supplies. A total of 118 patients met study inclusion criteria and were enrolled in the intervention between August 2006 and July 2008. Intervention patients were matched on sex and age to SWHP patients with poor diabetes control living more than 30 miles from a participating pharmacy. To measure the impact of the intervention, medical and pharmacy data were evaluated for one year before and after the study enrollment date. A significant difference was seen in the percentage of patients with type 1 diabetes in the intervention group (14) and the control group (3). The medication management program significantly improved A1C levels in intervention patients relative to controls (-1.1% vs. 0.6%) and was more effective in lowering A1Cs in type 2 diabetics than type 1 patients. Although the generalized linear model did not show that the intervention significantly improved the percentage of patients achieving the ADA goal A1C of <7% compared to controls, the multivariate logistic regression, which controlled for factors such as diabetes type, showed that patients participating in the intervention were 8.7 times more likely to achieve the A1C goal. Persistence with diabetic medications and the number of medications taken significantly increased in the intervention group; however, adherence rates, as measured by medication possession ratio (MPR), did not significantly improve relative to controls. The expenditure on diabetic medications and testing supplies increased substantially more in the intervention group than in the control group. The percentage of patients adherent with antihypertensive medications (MPR ≥80%) increased from 76% to 91% in the intervention group and decreased from 68% to 63% in the control group (P<0.05); no significant difference in blood pressure control was observed. For hyperlipidemia medications, adherence and persistence increased and pharmacy costs decreased in both groups, likely due to the introduction of the first generic HMG-CoA reductase inhibitor into the market during the study period. Future research is needed on the impact of the intervention on medical resource utilization and costs. / text
306

Integrating programming languages and databases via program analysis and language design

Wiedermann, Benjamin Alan 23 August 2010 (has links)
Researchers and practitioners alike have long sought to integrate programming languages and databases. Today's integration solutions focus on the data-types of the two domains, but today's programs lack transparency. A transparently persistent program operates over all objects in a uniform manner, regardless of whether those objects reside in memory or in a database. Transparency increases modularity and lowers the barrier of adoption in industry. Unfortunately, fully transparent programs perform so poorly that no one writes them. The goal of this dissertation is to increase the performance of these programs to make transparent persistence a viable programming paradigm. This dissertation contributes two novel techniques that integrate programming languages and databases. Our first contribution--called query extraction--is based purely on program analysis. Query extraction analyzes a transparent, object-oriented program that retrieves and filters collections of objects. Some of these objects may be persistent, in which case the program contains implicit queries of persistent data. Our interprocedural program analysis extracts these queries from the program, translates them to explicit queries, and transforms the transparent program into an equivalent one that contains the explicit queries. Query extraction enables programmers to write programs in a familiar, modular style and to rely on the compiler to transform their program into one that performs well. Our second contribution--called RBI-DB+--is an extension of a new programming language construct called a batch block. A batch block provides a syntactic barrier around transparent code. It also provides a latency guarantee: If the batch block compiles, then the code that appears in it requires only one client-server communication trip. Researchers previously have proposed batch blocks for databases. However, batch blocks cannot be modularized or composed, and database batch blocks do not permit programmers to modify persistent data. We extend database batch blocks to address these concerns and formalize the results. Today's technologies integrate the data-types of programming languages and databases, but they discourage programmers from using procedural abstraction. Our contributions restore procedural abstraction's use in enterprise applications, without sacrificing performance. We argue that industry should combine our contributions with data-type integration. The result would be a robust, practical integration of programming languages and databases. / text
307

Factors associated with the initiation of biologic disease modifying antirheumatic drugs in Texas Medicaid patients with rheumatoid arthritis

Kim, Gilwan 10 October 2014 (has links)
Rheumatoid arthritis (RA) is a progressive autoimmune disorder of joints that is associated with high health care costs and yet lacks guidance on how early to initiate biologic disease-modifying antirheumatic drugs (DMARDs), a class of medications that is the major cost driver in RA management. The main purpose of this study was to examine patient socio-demographics, medication use patterns, and clinical characteristics associated with initiation of biologic DMARDs. This was a retrospective study using Texas Medicaid prescription and medical claims database during the study period of July 1, 2003 – December 31, 2010. Patients (18 – 63 years) with an RA diagnosis (ICD-9-CM code 714.xx), no non-biologic DMARD or biologic DMARD use during the pre-index period, and a minimum of 2 prescription claims for the same non-biologic DMARD during the post-index period were included in the study. The primary study outcomes were time to initiation of biologic DMARDs and likelihood of initiating biologic DMARDs. There was a total of 2,714 subjects included in the study. The majority had claims for pain medications (92.4%), glucocorticoids (64.9%), and non-biologic DMARD monotherapy (86.4%); while 24.3% initiated on biologic DMARDs and 58.9% had a Charlson Comorbidity Index (CCI) score=1. Compared to time to initiation (days) of biologic DMARDs for methotrexate (539.7±276.9) users, it was longer for sulfasalazine (670.2±167.8) and hydroxychloroquine (680.2±158.7) users and similar to leflunomide users (541.6±286.5; p<0.0001). There were no significant differences in time to initiation between non-biologic DMARD mono vs. dual therapy. Younger age, glucocorticoid use, methotrexate user (vs. sulfasalazine, hydroxychloroquine users), and non-biologic DMARD monotherapy user (vs. dual therapy user) were significantly associated with higher likelihood to initiate biologic DMARDs. In conclusion, age, glucocorticoid use, non-biologic DMARD type and therapy were significant factors associated with initiation of biologic DMARDs. Healthcare providers and Texas Medicaid should recognize these potential driving factors and take efforts to achieve optimal therapy for RA patients through thorough RA medication evaluation, well-structured RA monitoring programs, and patient education. / text
308

以XML資料庫為儲存體的Java永續物件之研究 / Persistent Java Data Objects on XML Databases

侯語政, Hou, Yu-Cheng Unknown Date (has links)
物件永續化是應用系統設計時經常會面臨的需求,傳統做法是由開發人員自行設法將物件轉為資料庫可接受的格式,再存入後端資料庫。但這往往使得開發人員必須同時處理兩種資料模型,除了應用系統所用的物件模型之外,開發人員還要處理後端資料庫所用的資料模型,譬如表格等,以及兩種模型間的轉換。這不僅增加系統開發的複雜度,維護系統亦不容易。新的資料永續性技術Java資料物件(JDO)提供一個標準的框架,能夠幫助開發人員代為處理物件永續化的問題。因此開發人員能夠以單純的物件模型發展應用系統。另一方面,XML技術的興起帶動XML文件在資料交換與儲存方面的加速發展,其中專門儲存XML文件的資料庫也日益普遍。我們的研究是在瞭解如何使用XML資料庫為後端的資料儲存庫,而對Java物件進行物件永續化。 / Object persistence often comes up at the development of the application systems. Traditionally, the developers should try to transfer the objects to forms that databases can accept, and then store them in databases. But this often makes developers deal with two kinds of data models at the same time: besides object model that the application usually uses, the developers should also deal with the data model used for the backend database, like the relation model, and the conversion between both models. This not only increases the complexity of the system, but also the difficulty to maintain the system. A new technology of object persistence is Java Data Objects (JDO), which offer a standard framework to help developers to deal with object persistence so that the developers can concern themselves with object model only. On the other hand, the rise of XML technologies makes it attractive in data exchange and storage. The use of XML databases as data repositories becomes more and more common. Our research in the thesis is to realize JDO by serializing Java objects as XML documents and use XML databases as persistent repositories to store the resulting documents.
309

The integration, involvement, and persistence of Chicano students.

von Destinon, Mark Alan. January 1989 (has links)
This study identified factors contributing to Mexican-American student persistence in higher education. Tinto's model of student withdrawal was blended with Astin's theory of involvement in a theoretical framework that also gave special focus to hispanic and Mexican-American student concerns. The data consisted of unstructured interviews with a small sample of Mexican-American students at the University of Arizona. Content analysis was used to categorize the data and symbolic interaction theory was used for its interpretation. Findings about personal and institutional factors, were combined to understand persistence in the context of person/environment interaction. The personal factors influencing student persistence were "self," human support, financial adversity, commitment, acculturation, and gender differences; none of these factors stood alone, and each was present to some degree in each of the successful students. Commitment was the most important overriding theme in these personal factors. The institutional factors influencing persistence were academic preparation, use of student services, student/instructor interaction, and academic experiences. Symbolic interaction theory was the analytic framework used to interpret these factors of student persistence in the light of the meanings students attached to events in their college experiences. Empowering students to succeed is proposed as the organizing model for institutions to influence persistence.
310

Identifying College Student Success: The Role of First Year Success Courses and Peer Mentoring

Corella, Arezu Kazemi January 2010 (has links)
Student Success continues to be a topic of great interest in the Higher Education Literature. Fifty percent of those students who enter a four-year institution actually graduate and 25 % of first year students do not persist into their second year in college. First-year success courses and peer mentoring along with other programming strategies have been developed to improve retention and success for college students during their first-year of college. This study explored how college students from nine different institutions defined college student success. In addition, students from these institutions were surveyed to find out how and if first-year success courses and/or peer mentoring contribute to college student success. Follow-up interviews allowed for a deeper understanding of how first-year success courses and peer mentoring contribute to college student success. The study found a new comprehensive definition for college student success. Also, first-year success courses and peer mentoring do have positive relationships with college student success however, they also have some shortcomings that were identified in this study.

Page generated in 0.0681 seconds