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  • 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.
231

Assessing Alternate Approaches for Conveying Automated Vehicle Intentions

Basantis, Alexis Rae 30 October 2019 (has links)
Objectives: Research suggests the general public has a lack of faith in highly automated vehicles (HAV) stems from a lack of system transparency while in motion (e.g., the user not being informed on roadway perception or anticipated responses of the car in certain situations). This problem is particularly prevalent in public transit or ridesharing applications, where HAVs are expected to debut, and when the user has minimal training on, and control over, the vehicle. To improve user trust and their perception of comfort and safety, this study aimed to develop more detailed and tailored human-machine interfaces (HMI) aimed at relying automated vehicle intended actions (i.e., "intentions") and perceptions of the driving environment to the user. Methods: This project developed HMI systems, with a focus on visual and auditory displays, and implemented them into a HAV developed at the Virginia Tech Transportation Institute (VTTI). Volunteer participants were invited to the Smart Roads at VTTI to experience these systems in real-world driving scenarios, especially ones typically found in rideshare or public transit operations. Participant responses and opinions about the HMIs and their perceived levels of comfort, safety, trust, and situational awareness were captured via paper-based surveys administered during experimentation. Results: There was a considerable link found between HMI modality and users' reported levels of comfort, safety, trust, and situational awareness during experimentation. In addition, there were several key behavioral factors that made users more or less likely to feel comfortable in the HAV. Conclusions: Moving forward, it will be necessary for HAVs to provide ample feedback to users in an effort to increase system transparency and understanding. Feedback should consistently and accurately represent the driving landscape and clearly communicate vehicle states to users. / Master of Science / One of the greatest barriers to the entry of highly automated vehicles (HAV) into the market is the lack of user trust in the vehicle. Research has shown that this lack of faith in the system primarily stems from a lack of system transparency while in motion (e.g., the user not being told how the car will react in a certain situation) and not having an effective way to control the vehicle in the event of a system failure. This problem is particularly prevalent in public transit or ridesharing applications, where HAVs are expected to first appear and where the user has less training and control over the vehicle. To improve user trust and perceptions of comfort and safety, this study developed human-machine interface (HMI) systems, focusing on visual and auditory displays, to better relay automated vehicle "intentions" and the perceived driving environment to the user. These HMI systems were then implemented into a HAV developed at the Virginia Tech Transportation Institute (VTTI) and tested with volunteer participants on the Smart Roads.
232

APOE genotype, eicosapentaenoic acid (EPA) supplementation and n-3 highly unsaturated fatty acid (HUFA) levels in patients with multiple colorectal polyps: A secondary analysis of the seAFOod polyp prevention trial

Sun, G., Davies, J.R., Mell, T., Harland, M., Saleh, R.M.H., Race, Amanda D., Loadman, Paul, Williams, E.A., Minihane, A.M., Hull, M.A. 29 August 2024 (has links)
Yes / Introduction: We examined the relationship between Apolipoprotein E (APOE) genotype and n-3 highly unsaturated fatty acid (HUFA) levels in participants of the seAFOod trial, who were undergoing colonoscopy surveillance after removal of colorectal polyps. Methods: Baseline and on-treatment (eicosapentaenoic acid [EPA] 2 g daily or placebo for 6 months) levels of n-3 HUFAs, and plasma 18-hydroxyeicosapentaenoic acid (HEPE), were analysed according to APOE genotype (based on polymorphisms rs429358 and rs7412) in 584 participants. Results: Before treatment, APOE2/2 individuals had lower levels, and APOE4/4 participants had higher levels, of n-3 HUFAs, including EPA, than APOE3/3 counterparts (P < 0.01 for the APOE2/2 versus APOE4/4 comparison). After EPA supplementation, n-3 HUFA levels were not significantly different when stratified by APOE genotype, although APOE4 carriers displayed lower plasma 18-HEPE levels than individuals without an APOE4 allele (P = 0.002). Conclusions: APOE genotype is associated with differential n-3 HUFA and 18-HEPE levels in individuals with multiple colorectal polyps. / This project (NIHR128210) was funded by the Efficacy and Mechanism Evaluation (EME) Programme, an MRC and NIHR partnership. The views expressed in this publication are those of the authors and not necessarily those of the MRC, NIHR or the Department of Health and Social Care. MAH is a NIHR Senior Investigator. MAH is supported by Cancer Research UK grant C23434/A24939.
233

Highly-branched poly(N-isopropyl acrylamide)s with core-shell morphology below the lower critical solution temperature

Plenderleith, R.A., Swift, Thomas, Rimmer, Stephen 10 March 2014 (has links)
Yes / Highly-branched poly(N-isopropyl acrylamide)s in water pass through coil-to-globule transitions. Using calorimetry and the colour change of a solvatochromic dye within the polymer, we show that some compositions have biphasic core–shell morphologies, with globular cores and open coil shells. The two-phase structure is favoured by increased branching and arises because the chain ends penetrate only to a limited degree into the polymer coil.
234

Observation of highly decoupled conductivity in protic ionic conductors

Wojnarowska, Z., Wang, Y., Paluch, Krzysztof J., Sokolov, A.P., Paluch, M. 27 March 2014 (has links)
Yes / Ionic liquids (ILs) are key materials for the development of a wide range of emerging technologies. Protic ionic liquids, an important class of ILs, have long been envisioned as promising anhydrous electrolytes for fuel cells. It is well known that in comparison to all other cations, protons exhibit abnormally high conductivity in water. Such superprotonic dynamics was expected in protic ionic conductors as well. However, many years of extensive studies led to the disappointing conclusion that this is not the case and most protic ionic liquids display subionic behavior. Therefore, the relatively low conductivity seems to be the main obstacle for the application of protic ionic liquids in fuel cells. Using dielectric spectroscopy, herein we report the observation of highly decoupled conductivity in a newly synthesized protic ionic conductor. We show that its proton transport is strongly decoupled from the structural relaxation, in terms of both temperature dependence and characteristic rates. This finding offers a fresh look on the charge transport mechanism in PILs and also provides new ideas for design of anhydrous materials with exceptionally high proton conductivity. / National Science Centre within the framework of the Opus project (Grant No. DEC 2011/03/B/ST3/02072). Financial assistance from FNP START. The LDRD Program of ORNL, managed by UT-Battelle, LLC, for the U.S. DOE. Support from the NSF under grant CHE-1213444.
235

Label-Free Electrochemical Sensor for Rapid Bacterial Pathogen Detection Using Vancomycin-Modified Highly Branched Polymers

Schulze, H., Wilson, H., Cara, I., Carter, Steven, Dyson, Edward, Elangovan, R., Rimmer, Stephen, Bachmann, T.T. 12 May 2021 (has links)
Yes / Rapid point of care tests for bacterial infection diagnosis are of great importance to reduce the misuse of antibiotics and burden of antimicrobial resistance. Here, we have successfully combined a new class of non-biological binder molecules with electrochemical impedance spectroscopy (EIS)-based sensor detection for direct, label-free detection of Gram-positive bacteria making use of the specific coil-to-globule conformation change of the vancomycin-modified highly branched polymers immobilized on the surface of gold screen-printed electrodes upon binding to Gram-positive bacteria. Staphylococcus carnosus was detected after just 20 min incubation of the sample solution with the polymer-functionalized electrodes. The polymer conformation change was quantified with two simple 1 min EIS tests before and after incubation with the sample. Tests revealed a concentration dependent signal change within an OD600 range of Staphylococcus carnosus from 0.002 to 0.1 and a clear discrimination between Gram-positive Staphylococcus carnosus and Gram-negative Escherichia coli bacteria. This exhibits a clear advancement in terms of simplified test complexity compared to existing bacteria detection tests. In addition, the polymer-functionalized electrodes showed good storage and operational stability.
236

A comparison of the effectiveness of protease inhibitor-based highly active anti-retroviral treatment regiments in Trinidad and Tobago

Ziregbe, Elohor 21 October 2014 (has links)
Few studies have assessed the optimum second line highly active anti-retroviral therapy (HAART) regimen in patients who had failed on the first-line HAART in resource-limited settings. This study aimed to compare the Protease inhibitor (PI)-based second line HAART regimens used in one clinic in Trinidad by comparing immunological, virological and clinical outcomes of patients on the different second line HAART regimens. The records of 35 treatment-experienced patients, over 21years of age and on PI-based regimens for at least six months, were analysed using SPSS version 20. The regimen containing TDF/FTC/AZT/LPV/r proved to produce superior outcomes compared to the other second line regimens. Due the small number of usable patients’ records, the findings cannot be generalised but indicate directions for future studies attempting to compare the treatment outcomes of different second line HAART regimens / Health Studies / M. A. (Public Health)
237

Prevalence and predictors of immunologic failure among HIV patients on HAART in southern Ethiopia

Kesetebirhan Delele Yirdaw 20 August 2015 (has links)
Immunologic monitoring is part of the standard care for patients on antiretroviral treatment. Yet, little is known about the routine implementation of immunologic monitoring in Ethiopia. This study assessed the pattern of immunologic monitoring, immunologic response, level of immunologic treatment failure and factors related to it among patients on antiretroviral therapy in selected hospitals in southern Ethiopia. A retrospective longitudinal analytic study was conducted using documents of patients started on antiretroviral therapy. A total of 1,321 documents of patients reviewed revealed timely immunologic monitoring were inadequate. Despite overall adequate immunologic response, the prevalence of immunologic failure was 11.5% (n=147). Having WHO Stage III/IV of the disease and a higher CD4 (cluster differentiation 4) cell count at baseline were identified as risks for immunologic failure. These findings highlight the magnitude of the problem of immunologic failure. Prioritizing monitoring for high risk patients may help in effective utilisation of meager resources / Health Studies / M.A. (Public Health)
238

Prevalence and predictors of immunologic failure among HIV patients on HAART in southern Ethiopia

Kesetebirhan Delele Yirdaw 20 August 2015 (has links)
Immunologic monitoring is part of the standard care for patients on antiretroviral treatment. Yet, little is known about the routine implementation of immunologic monitoring in Ethiopia. This study assessed the pattern of immunologic monitoring, immunologic response, level of immunologic treatment failure and factors related to it among patients on antiretroviral therapy in selected hospitals in southern Ethiopia. A retrospective longitudinal analytic study was conducted using documents of patients started on antiretroviral therapy. A total of 1,321 documents of patients reviewed revealed timely immunologic monitoring were inadequate. Despite overall adequate immunologic response, the prevalence of immunologic failure was 11.5% (n=147). Having WHO Stage III/IV of the disease and a higher CD4 (cluster differentiation 4) cell count at baseline were identified as risks for immunologic failure. These findings highlight the magnitude of the problem of immunologic failure. Prioritizing monitoring for high risk patients may help in effective utilisation of meager resources / Health Studies / M. A. (Public Health)
239

Capacity of Communications Channels with 1-Bit Quantization and Oversampling at the Receiver

Krone, Stefan, Fettweis, Gerhard 25 January 2013 (has links) (PDF)
Communications receivers that rely on 1-bit analogto-digital conversion are advantageous in terms of hardware complexity and power dissipation. Performance limitations due to the 1-bit quantization can be tackled with oversampling. This paper considers the oversampling gain from an information-theoretic perspective by analyzing the channel capacity with 1-bit quantization and oversampling at the receiver for the particular case of AWGN channels. This includes a numerical computation of the capacity and optimal transmit symbol constellations, as well as the derivation of closed-form expressions for large oversampling ratios and for high signal-to-noise ratios of the channel.
240

Resultados de um protocolo de atenção a gestantes portadoras do vírus da imunodeficiência humana em um serviço do nordeste do Brasil = Assessed results for a treatment protocol for HIV-positive pregnant women in northeastern Brazilian healt service / Assessed results for a treatment protocol for HIV-positive pregnant women in northeastern Brazilian healt service

Pinho Neto, Otávio Soares, 1954- 12 February 2014 (has links)
Orientador: Helaine Maria Besteti Pires Mayer Milanez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T14:20:51Z (GMT). No. of bitstreams: 1 PinhoNeto_OtavioSoares_D.pdf: 1689484 bytes, checksum: 9ac072f9702d3565268cb5bc1930d222 (MD5) Previous issue date: 2014 / Resumo: OBJETIVO: Analisar os protocolos de Antirretrovirais em uma coorte de gestantes HIV positivas e recém-natos expostos em seguimento no Serviço de Assistência Especializada (SAE) Familiar/Hospital Universitário Lauro Wanderley (HULW)/Universidade Federal da Paraíba (UFPB) no período de 2005 a 2012. SUJEITOS E MÉTODOS: Estudo descritivo, do tipo coorte, retrospectivo, numa abordagem quantitativa, a partir de um grupo de gestantes HIV+ e seus recém-nascidos (RN) expostos, atendidas no SAE Familiar do HULW/UFPB. Os dados foram codificados, digitados e armazenados em um banco de dados criado com esse propósito. Cada par mãe-RN foi identificado com um número. Foi realizada uma análise descritiva das características sociodemográficas da gestante, do acompanhamento pré-natal, do uso de terapia antirretroviral (TARV), do parto e do recém-nascido, através de distribuição percentual ou média. Posteriormente, foi realizada a análise das classes dos antirretrovirais e seus desfechos para a mãe e recém-nascidos expostos. As possíveis associações entre as variáveis categóricas foram testadas através do teste t (dados paramétricos). Não foi possível a realização de análise multivariada devido ao pequeno número de crianças infectadas. RESULTADOS: A taxa de transmissão vertical (TV) no SAE Familiar HULW/UFPB entre 2005 e 2012 foi de 3,9% em uma coorte de 153 gestações analisadas. A média de idade das gestantes foi de 25 anos e a de escolaridade de 7 anos. A maioria era de mulheres negras (78,7%), com união estável (59%), e a principal categoria de exposição foi a sexual (96,5%). Mais de cinquenta por cento já apresentavam diagnóstico do HIV anterior à gravidez estando 41% em uso de TARV. A média de CD4 inicial foi de 440 células/ml e, após uso de TARV de 516,07 células/ml. A média de carga viral (CV) pré uso de TARV foi de 24.022. Mais de 70% apresentaram carga viral indetectável com 34 semanas de gestação. Usaram TARV com IP 92% e 8% um esquema com nevirapina. Não foi utilizada monoterapia com AZT nessa coorte. A média de idade gestacional no parto foi de 36 semanas e em 95% dos casos a via de parto foi cesárea. A grande maioria dos casos (98%) recebeu AZT endovenoso no parto. O peso médio dos recém-nascidos foi de 2,89 gramas e apenas 17,64% tiveram baixo peso. A presença de prematuridade, patologias neonatais e o não uso do AZT intraparto foram fatores que se associaram a um maior risco de transmissão vertical. Não foi possível a realização de análise multivariada devido ao pequeno número de crianças infectadas. Houve poucos efeitos colaterais associados ao uso da TARV na gestação, sendo o mais frequente a presença de anemia materna (58,4%) e de anemia neonatal (21,6%). Não se observaram efeitos adversos graves, tanto na mãe quanto no recém-nascido. CONCLUSÃO: A taxa de TV no serviço universitário de João Pessoa foi de 3,9%, principalmente associada à prematuridade, patologia neonatal e não uso do AZT venoso intraparto. Houve baixa ocorrência de efeitos adversos, sendo mais frequente a anemia, tanto na mãe quanto no recém-nascido / Abstract: OBJECTIVE: To analyze antiretroviral therapy protocols in a cohort of HIV-positive pregnant women and exposed newborns followed at Serviço de Assistência Especializada (SAE) Familiar / Hospital Universitário Lauro Wanderley (HULW), Universidade Federal da Paraíba (UFPB), from 2005 to 2012. SUBJECTS AND METHODS: Descriptive, retrospective cohort study, using a quantitative approach, conducted on a group of HIV-positive pregnant women and their exposed newborns followed at SAE/HULW. Data were codified, entered and stored in a database created specifically for this purpose. Each mother-child pair was identified by a number. A descriptive analysis of the sociodemographic characteristics of pregnant women, prenatal care, use of antiretroviral therapy (ART), and delivery and neonate parameters was conducted using percentages or means. An analysis of the classes of antiretroviral drugs and their associated outcomes for mothers and exposed newborns was then conducted. Potential associations between categorical variables were assessed with the t-test (parametric data). Multivariate analysis could not be performed due to the small number of children infected. RESULTS: The mother-to-child transmission rate at SAE/HULW-UFPB between 2005 and 2012 was 3.9%, in a cohort of 153 pregnancies. The mean patient age was 25 years and the mean educational attainment was 7 years of schooling. Most subjects were black women (78.7%), in a stable relationship (59%), and the main risk factor was sexual contact (96.5%). More than 50% already had a diagnosis of HIV infection prior to pregnancy, and 41% were on ART. The mean CD4 count was 440 cells/ml at baseline and 516.07 cells/ml after ART. The median viral load before ART was 24.022. Over 70% had an undetectable viral load at 34 weeks of gestation. Overall, 92% were on PI-containing ART regimens and 8% were on nevirapine-containing regimens. AZT monotherapy was not used in this cohort. The mean gestational age at delivery was 36 weeks, and in 95% of cases, the mode of delivery was cesarean. The vast majority of cases (98%) received intrapartum intravenous AZT. The average birth weight of newborns was 2,890 g, and only 17.6% were underweight. Presence of prematurity, neonatal morbidity, and failure to administer intrapartum AZT were factors associated with higher risk of vertical transmission. Multivariate analysis could not be performed due to the small number of infected children. There was a low incidence of side effects associated with ART during pregnancy, the most common being maternal anemia (58.4%) and neonatal anemia (21.6%). No serious adverse effects were observed in either mothers or newborns. CONCLUSION: The rate of mother-to-child transmission at this university-based facility in João Pessoa was 3.9%, and was mainly associated with prematurity, neonatal morbidity, and failure to administer intrapartum intravenous AZT. There was a low rate of adverse effects, the most common being anemia, in both mothers and newborns / Doutorado / Saúde Materna e Perinatal / Doutor em Ciências da Saúde

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