Dissertations / Theses on the topic 'Design of observational studies'
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Grünewald, Maria. "Design and analysis of response selective samples in observational studies." Doctoral thesis, Stockholms universitet, Matematiska institutionen, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-49328.
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Outcome dependent sampling may increase efficiency in observational studies. It is however not always obvious how to sample efficiently, and how to analyze the resulting data without introducing bias. This thesis describes a general framework for efficiency calculations in multistage sampling, with focus on what is sometimes referred to as ascertainment sampling. A method for correcting for the sampling scheme in analysis of ascertainment samples is also presented. Simulation based methods are used to overcome computational issues in both efficiency calculations and analysis of data.At the time of doctoral defense, the following paper was unpublished and had a status as follows: Paper 1: Submitted.
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Nattino, Giovanni. "Causal Inference in Observational Studies with Complex Design: Multiple Arms, Complex Sampling and Intervention Effects." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562582646286934.
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Baker, Jeremy Charles. "Observational Animation: An Exploration of Improvisation, Interactivity and Spontaneity in Animated Filmmaking." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1357315576.
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Cash, Philip. "Characterising the relationship between practice and laboratory-based studies of designers for critical design situations." Thesis, University of Bath, 2012. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557814.
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Experimental study of the designer plays a critical role in design research. However laboratory based study is often poorly compared and contrasted to practice, leading to a lack of uptake and subsequent research impact. The importance of addressing this issue is highlighted by its significant influence on design research and many related fields. As such the main aim of this work is to improve empirical design research by characterising the relationship between practice and laboratory-based studies for critical design situations. A review of the state of the art methods in design research and key related fields is reported. This highlights the importance and commonality of a set or core issues connected to the failure to effectively link study of practice and study in the laboratory. Further to this a technical review and scoping was carried out to establish the most efective capture strategy to be used when studying the designer empirically. Subsequently three studies are reported, forming a three point comparison between practice the laboratory (with student practitioners) and an intermediary case (a laboratory with practitioners) . Results from these studies contextualise the critical situations in practice and develop a detailed multi-level comparison between practice and the laboratory which was then validated with respect to a number of existing studies. The primary contribution of this thesis is the development of a detailed multi-level relationship between practice and the laboratory for critical design situations: information seeking, ideation and design review. The second key contribution is the development of a generic method for the empirical study of designers in varying contexts - allowing researchers to build on this work and more effectively link diverse studies together. The final key contribution of this work is the identification of a number of core methodological issues and mitigating techniques affecting both design research and its related fields.
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Bornsäter, Jonas, and Sara Hoffsten. "Att synliggöra det omedvetna : En komparativ studie mellan marknadsförares och industridesigners arbetsmetodik vid produktutveckling." Thesis, Södertörn University College, School of Business Studies, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:sh:diva-3714.
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När företag ska utveckla produkter och tjänster behöver de informationsunderlag om kunder och användare. Traditionella marknadsundersökningar kräver ett rationellt förhållningssätt och avslöjar åsikter och attityder, men uppvisar brister när det kommer till att upptäcka omedvetna behov hos användare. Lösningen på denna problematik är att observera användare i deras egen kontext, ett tillvägagångssätt som är vanligt bland industridesigners.
Syftet med studien var att jämföra hur industridesigners och marknadsförare arbetar för att samla in information om användare i samband med produkt- och tjänsteutveckling. Därefter syftade studien till att ställa dessa likheter och skillnader i kontrast till tre teorier: Marketing Research Process, Design Thinking samt Empathic Design. Tre intervjuer genomfördes med tre olika företag: ett industridesignföretag, ett marknadsundersökningsföretag samt ett tjänstedesignföretag.
Studien resulterade i ett antal slutsatser. Den första är att ett rationellt förhållningssätt inte nödvändigtvis är någonting negativt utan snarare något positivt och elementärt. Tillämpningen måste dock ske på rätt sätt parallellt under produktutvecklingsprocessen, för att verifiera att den framtagna produkten eller tjänsten faktiskt fyller ett konsumentbehov på marknaden. Ytterligare en slutsats är att metoder och tekniker som ses som typiska för designers även tillämpas och nyttjas av ett traditionellt marknadsundersökningsföretag. Saknas dessa typer av kompetenser inom företaget hyrs designers in som experter.
Alla de undersökta företagen, inklusive det renodlade marknadsundersökningsföretaget, använde sig av observationsmetoder där de observerade användare i deras egen kontext, samtidigt som de interagerade med produkten eller tjänsten. De hade således lyckats ta sig runt problematiken med att upptäcka de dolda omedvetna behoven.
Likheterna mellan de två olika professionerna har varit mer utmärkande än skillnaderna, och den övergripande slutsatsen blir således att verkligheten har kommit ifatt den teoretiska diskussionen. Marknadsförare och industridesigners arbetar mer lika än olika.
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Lam, Tsz-yan, and 林梓仁. "Observational studies of supernova 1998S." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B30244900.
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Xie, Siqi, and 谢思琪. "Observational studies of pedestrian flows." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B49617990.
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Walking is an environmentally friendly mode of transportation. A better understanding of pedestrian activities and effective planning of walking facilities are particularly important for densely populated Asian cities like Hong Kong. Empirical studies on pedestrian flows can be classified as controlled experiments and observational surveys. Controlled experiments are flexible and can be designed to fulfill the requirements of specific studies and eliminate influence from unrelated factors. Observational surveys provide data for pedestrian movements in different types of walking facilities. This thesis aims to develop a mathematical model for multidirectional pedestrian flows based on knowledge obtained from both a controlled experiment and observational surveys on three different walking facilities. Bayesian inference is adopted for model calibration, as it can combine the prior information from the controlled experiment and the observed data from the observational surveys.
The proposed model is based on Drake’s (1967) model of traffic flow. However, multidirectional pedestrian flows are much more complicated than the unidirectional and bidirectional flows. Therefore, instead of relating the speed of a pedestrian stream solely to pedestrian density, the flow ratio and intersecting angles between streams are introduced as factors that may influence stream speed. The proposed model takes the form of a set of structural equations rather than a single deterministic function.
By applying Bayesian inference, the proposed model is calibrated with the three sets of observed data respectively, based on the prior distribution specified by the controlled experiment results. Finally, pedestrian movements in three different walking facilities are analyzed based on the properties of the calibrated model.published_or_final_version
Civil Engineering
Master
Master of Philosophy
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Deuss, A. F. "Theoretical and observational studies in global seismology." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270362.
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Nose, Masahito. "Observational studies on long-period geomagnetic pulsations." 京都大学 (Kyoto University), 1997. http://hdl.handle.net/2433/86495.
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Uthas, Helena. "Observational studies of highly evolved cataclysmic variables." Thesis, University of Southampton, 2011. https://eprints.soton.ac.uk/202889/.
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Cataclysmic Variables (CV) are binary systems where a main-sequence star transfers mass onto a white dwarf (WD). According to standard evolutionary theory, angular momentum loss drives CVs to initially evolve from longer to shorter orbital periods until a minimum period is reached (≈ 80 minutes). At roughly this stage, the donors becomes degenerate, expand in size, and the systems move towards longer orbital periods. Theory predicts that 70% of all CVs should have passed their minimum period and have sub-stellar donors, but until recently, no such systems were known. I present one CV showing evidence of harbouring a sub-dwarf donor, SDSS J1507+52. Due to the system’s unusually short orbital period of ≈ 65 minutes, and very high space velocity, two origins for SDSS J1507+52 have been proposed; either the system was formed from a young WD/brown-dwarf binary, or the system is a halo CV. In order to distinguish between these two theories, I present UV spectroscopy and find a metallicity consistent with halo origin. Systems close to the minimum period are expected to be faint and have low accretion rates. Some of these CVs show absorption in their spectra, implying that the underlying WD is exposed. This yields a rare opportunity to study the WD in a CV. I introduce two new systems showing WD signatures in their light curves and spectra, SDSS J1457+51 and BW Sculptoris. Despite the fact that CVs close to the minimum period should be faint, we find systems that aremuch too bright for their orbital periods. Such a system is T Pyxidis – a recurrent nova with an unusually high accretion rate and a photometrically determined period < 2 hours. The systemis ∼ 2 times brighter than any other CV at its period. However, to confirm the status of this unusual star, a more reliable period determination is needed. Here, I present a spectroscopic study of T Pyxidis confirming its evolutionary status as a short-period CV. In this thesis, I discuss what implications these systems may have on the current understanding of CV evolution, and the importance of studying individual systems in general
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Hutchinson, Mark Gerard. "Observational studies of pre-main sequence stars." Thesis, Keele University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.716860.
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Notsu, Yuta. "Observational studies on solar-type superflare stars." Kyoto University, 2019. http://hdl.handle.net/2433/242613.
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Hsu, Danny Chung. "Mechanistic Studies on Memory of Chirality Alkylations of 1,4-Benzodiazepin-2-ones & Structure-based Design of Insecticidal AChE Inhibitors for Malaria Mosquito, Anopheles gambiae." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29192.
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Memory of chirality (MOC) is an emerging strategy for asymmetric synthesis which relies upon the intermediacy of transiently non-racemic reactive species. In these reactions the configuration of the sole stereogenic center of the enantiopure starting material is "memorized" by a chiral non-racemic conformation in the intermediate; trapping then captures the stereochemical information, and generates a new stereogenic center with high fidelity. We experimentally and computationally studied the highly retentive deprotonation/alkylations of 1,4-benzodiazepin-2-ones (BZDs) that rely upon this strategy. We captured a transiently non-racemic BZD enolate intermediate in enantiopure form, then released the enolate and observed its subsequent reaction. This approach allowed the first ever step-wise observation of the stereochemical course of such a MOC process.
Approximately 2 million deaths are caused by malaria every year in the world. In total roughly 3.2 billion people are living under the risk of malaria transmission. Current use of anticholinesterase insecticides has been limited by their toxicity to human beings. A major African malaria insect vector, Anopheles gambiae (Ag), was targeted. Based on sequence alignment and homology models of AgAChE, a strategy of dual-site binding was adopted that targets Trp84 in the active site and Cys286 at the peripheral site. Selective AChE inhibitors have been designed and synthesized.Ph. D.
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Worters, Hannah Leigh. "Observational studies of key stages in stellar evolution." Thesis, University of Central Lancashire, 2009. http://clok.uclan.ac.uk/20096/.
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This thesis presents observational investigations into three poorly-understood, but key stages in stellar evolution. Stars undergoing the post T Tauri phase - which lies between the well-studied T Tauri stage of disc accretion and the arrival onto the Main Sequence - are difficult to identify and thus little-investigated. Knowledge of the processes occurring in this stage is clearly essential to understanding the events that lead a star to the Main Sequence. Optical photometric observations of flaring on post T Tauri stars, obtained with the Southern African Large Telescope and smaller SAAO telescopes, are presented here. The energies and magnitudes of flares on a sample of targets have been derived and compared with more famous flare stars, and a new flare star has been discovered. A preliminary search for oscillations in flare loops has been undertaken. At the other end of a star's lifetime, the very late thermal pulse (VLTP) is an extremely brief stage that occurs in ' S-' 15% of intermediate-mass stars. Observable examples are thus very rare. Sakurai's Object underwent a VLTP in 1995, evolving from a white dwarf back to a red giant in only two years. This is described as "born-again" evolution. Sakurai's Object is the first star since 1917 in which the born-again stage has been observed, and therefore the first example to be studied using modern instrumental techniques and at the wide range of wavelengths now accessible. Observational data are essential to constraining models of the VLTP phase, which as yet cannot explain the extremely rapid evolution of Sakurai's Object. Near-infrared spectra of Sakurai's Object are analysed in this work, finding that 2.5 x 10-6 M® of CO, with an isotopic ratio of 12C/ 13C 3, was ejected in a fast wind (500 + 80 km r') during the VLTP. The cooling CO is modelled as a shell, mixed with graphitic dust, at a distance of 1011 km from the central star. The evolution of stars in a symbiotic binary system is profoundly effected by mass-transfer from the red giant component. itS Ophiuchi is such a system, containing a white dwarf that accretes matter from its red giant companion. The accumulation of accreted matter on the white dwarf has resulted in observed eruptions every 10-20 years in the past century, making RS Oph the most active of the recurrent novae. The mechanisms of mass-transfer (Roche lobe overflow or direct wind accretion) and eruption (thermonuclear runaway or accretion models) are the subjects of considerable controversy. Observations of optical flickering are presented here, plaing limits on the time at which accretion resumed following the most recent outburst of RS Oph in 2006. This is the first time the re-establishment of accretion has been observed in a recurrent nova. It is demonstrated that the accretion rate at this time spans the range for Roche lobe overflow and direct accretion mechanisins, and is insufficient to result in eruptions by thermonuclear runaway with such a short outburst interval as is observed. A variable accretion rate is proposed, perhaps increasing with time as accretion is re-established following the disruption of an outburst.
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Cooper, Heather Danielle Blythe. "Observational studies of regions of massive star formation." Thesis, University of Leeds, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.634202.
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Massive stars have a profound influence on their surroundings. However, relatively little is known about their formation. The study of massive star formation is hindered by a lack of observational evidence, primarily due to difficulties observing massive stars at early stages in their development.
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Seigar, Marcus S. "Observational studies of the structure of spiral galaxies." Thesis, Liverpool John Moores University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.242314.
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Hurst, Mark Edward. "Observational studies of stellar, circumstellar and interstellar matter." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312198.
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Fang, Xiao Ph D. Massachusetts Institute of Technology. "Uplift modeling for randomized experiments and observational studies." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/115770.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 101-107).
Uplift modeling refers to the problem where we need to identify from a set of treatments the candidate that leads to the most desirable outcome based on subject characteristics. Most work in the last century focus on the average effect of a treatment across a population of interest, but ignores subject heterogeneity which is very common in real world. Recently there has been explosion of empirical settings which makes it possible to infer individualized treatment responses. We first consider the problem with data from randomized experiments. We put forward an unbiased estimate of the expected response, which makes it possible to evaluate an uplift model with multiple treatments. This is the first evaluation metric of uplift models aligning with the problem objective in the literature. Based on this evaluation metric, we design an ensemble tree-based algorithm (CTS) for uplift modeling. The splitting criterion and termination conditions are derived with the consideration of the special structure of uplift modeling problem. Experimental results on synthetic data and industry data show the advantage of our specialized uplift modeling algorithm over separate model approach and other existing uplift modeling algorithms. We next prove the asymptotic properties of a simplified CTS algorithm. The exhaustive search for locally optimal splitting points makes it difficult to theoretically analyze tree-based algorithms. Thus we adopt dyadic splits to CTS algorithm and obtain the bound of regret-expectation of performance difference between oracle and our algorithm. The convergence rate of the regret depends on the feature dimension, which emphasizes the importance of feature selection. While model performance usually improves with the number of features, it requires exponentially more data to approximate the optimal treatment rule. Choosing the appropriate complexity of the model and selecting the most powerful features are critical to achieving desirable performance. Finally we study the uplift modeling problem in the context of observational studies. In observational studies. treatment selection is influenced by subject characteristics. As a result. baseline characteristics often differ systematically between different treatments. Thus confounding factors need to be untangled before valid predictions are made. We combine a modification of the standard feed-forward architecture with our CTS algorithm to optimize predictive accuracy and minimize feature distribution distance between treatment. Experimental results on synthetic data show that the combination of neural network feature representation and ensemble tree-based model is promising to handle real-world problems.
by Xiao Fang.
Ph. D.
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Kimura, Mariko. "Observational and theoretical studies on dwarf-nova outbursts." Kyoto University, 2020. http://hdl.handle.net/2433/253084.
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Lu, Danni. "Representation Learning Based Causal Inference in Observational Studies." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/102426.
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This dissertation investigates novel statistical approaches for causal effect estimation in observational settings, where controlled experimentation is infeasible and confounding is the main hurdle in estimating causal effect. As such, deconfounding constructs the main subject of this dissertation, that is (i) to restore the covariate balance between treatment groups and (ii) to attenuate spurious correlations in training data to derive valid causal conclusions that generalize. By incorporating ideas from representation learning, adversarial matching, generative causal estimation, and invariant risk modeling, this dissertation establishes a causal framework that balances the covariate distribution in latent representation space to yield individualized estimations, and further contributes novel perspectives on causal effect estimation based on invariance principles.
The dissertation begins with a systematic review and examination of classical propensity score based balancing schemes for population-level causal effect estimation, presented in Chapter 2. Three causal estimands that target different foci in the population are considered: average treatment effect on the whole population (ATE), average treatment effect on the treated population (ATT), and average treatment effect on the overlap population (ATO). The procedure is demonstrated in a naturalistic driving study (NDS) to evaluate the causal effect of cellphone distraction on crash risk. While highlighting the importance of adopting causal perspectives in analyzing risk factors, discussions on the limitations in balance efficiency, robustness against high-dimensional data and complex interactions, and the need for individualization are provided to motivate subsequent developments.
Chapter 3 presents a novel generative Bayesian causal estimation framework named Balancing Variational Neural Inference of Causal Effects (BV-NICE). Via appealing to the Robinson factorization and a latent Bayesian model, a novel variational bound on likelihood is derived, explicitly characterized by the causal effect and propensity score. Notably, by treating observed variables as noisy proxies of unmeasurable latent confounders, the variational posterior approximation is re-purposed as a stochastic feature encoder that fully acknowledges representation uncertainties. To resolve the imbalance in representations, BV-NICE enforces KL-regularization on the respective representation marginals using Fenchel mini-max learning, justified by a new generalization bound on the counterfactual prediction accuracy. The robustness and effectiveness of this framework are demonstrated through an extensive set of tests against competing solutions on semi-synthetic and real-world datasets.
In recognition of the reliability issue when extending causal conclusions beyond training distributions, Chapter 4 argues ascertaining causal stability is the key and introduces a novel procedure called Risk Invariant Causal Estimation (RICE). By carefully re-examining the relationship between statistical invariance and causality, RICE cleverly leverages the observed data disparities to enable the identification of stable causal effects. Concretely, the causal inference objective is reformulated under the framework of invariant risk modeling (IRM), where a population-optimality penalty is enforced to filter out un-generalizable effects across heterogeneous populations. Importantly, RICE allows settings where counterfactual reasoning with unobserved confounding or biased sampling designs become feasible. The effectiveness of this new proposal is verified with respect to a variety of study designs on real and synthetic data.
In summary, this dissertation presents a flexible causal inference framework that acknowledges the representation uncertainties and data heterogeneities. It enjoys three merits: improved balance to complex covariate interactions, enhanced robustness to unobservable latent confounders, and better generalizability to novel populations.Doctor of Philosophy
Reasoning cause and effect is the innate ability of a human. While the drive to understand cause and effect is instinct, the rigorous reasoning process is usually trained through the observation of countless trials and failures. In this dissertation, we embark on a journey to explore various principles and novel statistical approaches for causal inference in observational studies. Throughout the dissertation, we focus on the causal effect estimation which answers questions like ``what if" and ``what could have happened". The causal effect of a treatment is measured by comparing the outcomes corresponding to different treatment levels of the same unit, e.g. ``what if the unit is treated instead of not treated?". The challenge lies in the fact that i) a unit only receives one treatment at a time and therefore it is impossible to directly compare outcomes of different treatment levels; ii) comparing the outcomes across different units may involve bias due to confounding as the treatment assignment potentially follows a systematic mechanism. Therefore, deconfounding constructs the main hurdle in estimating causal effects. This dissertation presents two parallel principles of deconfounding: i) balancing, i.e., comparing difference under similar conditions; ii) contrasting, i.e., extracting invariance under heterogeneous conditions. Chapter 2 and Chapter 3 explore causal effect through balancing, with the former systematically reviews a classical propensity score weighting approach in a conventional data setting and the latter presents a novel generative Bayesian framework named Balancing Variational Neural Inference of Causal Effects(BV-NICE) for high-dimensional, complex, and noisy observational data. It incorporates the advance deep learning techniques of representation learning, adversarial learning, and variational inference. The robustness and effectiveness of the proposed framework are demonstrated through an extensive set of experiments. Chapter 4 extracts causal effect through contrasting, emphasizing that ascertaining stability is the key of causality. A novel causal effect estimating procedure called Risk Invariant Causal Estimation(RICE) is proposed that leverages the observed data disparities to enable the identification of stable causal effects. The improved generalizability of RICE is demonstrated through synthetic data with different structures, compared with state-of-art models. In summary, this dissertation presents a flexible causal inference framework that acknowledges the data uncertainties and heterogeneities. By promoting two different aspects of causal principles and integrating advance deep learning techniques, the proposed framework shows improved balance for complex covariate interactions, enhanced robustness for unobservable latent confounders, and better generalizability for novel populations.
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Fowler, Philip. "Methods for improving covariate balance in observational studies." Doctoral thesis, Umeå universitet, Statistik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-139523.
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This thesis contributes to the field of causal inference, where the main interest is to estimate the effect of a treatment on some outcome. At its core, causal inference is an exercise in controlling for imbalance (differences) in covariate distributions between the treated and the controls, as such imbalances otherwise can bias estimates of causal effects. Imbalance on observed covariates can be handled through matching, where treated and controls with similar covariate distributions are extracted from a data set and then used to estimate the effect of a treatment. The first paper of this thesis describes and investigates a matching design, where a data-driven algorithm is used to discretise a covariate before matching. The paper also gives sufficient conditions for if, and how, a covariate can be discretised without introducing bias. Balance is needed for unobserved covariates too, but is more difficult to achieve and verify. Unobserved covariates are sometimes replaced with correlated counterparts, usually referred to as proxy variables. However, just replacing an unobserved covariate with a correlated one does not guarantee an elimination of, or even reduction of, bias. In the second paper we formalise proxy variables in a causal inference framework and give sufficient conditions for when they lead to nonparametric identification of causal effects. The third and fourth papers both concern estimating the effect an enhanced cooperation between the Swedish Social Insurance Agency and the Public Employment Service has on reducing sick leave. The third paper is a study protocol, where the matching design used to estimate this effect is described. The matching was then also carried out in the study protocol, before the outcome for the treated was available, ensuring that the matching design was not influenced by any estimated causal effects. The third paper also presents a potential proxy variable for unobserved covariates, that is used as part of the matching. The fourth paper then carries out the analysis described in the third paper, and uses an instrumental variable approach to test for unobserved confounding not captured by the supposed proxy variable.
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Bjermo, Helena. "Dietary Fatty Acids and Inflammation : Observational and Interventional Studies." Doctoral thesis, Uppsala universitet, Klinisk nutrition och metabolism, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-156074.
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Dietary fat quality influences the risk of type 2 diabetes and cardiovascular disease. A low-grade inflammation is suggested to contribute to the disease development, often accompanied by obesity. Whereas n-3 polyunsaturated fatty acids (PUFA) have been considered anti-inflammatory, n-6 PUFA have been proposed to act pro-inflammatory. Saturated fatty acids (SFA) act pro-inflammatory in vitro. This thesis aimed to investigate effects of different fatty acids on low-grade inflammation in observational and interventional studies. In Paper I and II, fatty acid composition in serum cholesterol esters was used as objective marker of dietary fat quality and related to serum C-reactive protein (CRP) and other circulating inflammatory markers in two population-based cohorts, conducted in middle-aged men and elderly men and women, respectively. In Paper III and IV, the impact of diets differing in fat quality on inflammation and oxidative stress was investigated in randomised controlled studies, in subjects with metabolic syndrome and abdominal obesity. In Paper I and II, a low proportion of linoleic acid (18:2 n-6) in serum was associated with higher CRP concentrations, indicating that a low intake of vegetable fats may be related to low-grade inflammation. High CRP concentrations were also associated with high proportions of palmitoleic (16:1) and oleic (18:1) acids and high stearoyl coenzymeA desaturase index, possibly reflecting altered fat metabolism and/or high SFA intake in this population. When comparing two high-fat diets rich in either saturated or monounsaturated fat, and two low-fat diets with or without long-chain n-3 PUFA supplementation during 12 weeks (Paper III), no differences in inflammation or oxidative stress markers were observed. Moreover, a 10-week intervention (Paper IV) with high linoleic acid intake showed no adverse effects on inflammation or oxidative stress. Instead, interleukin-1 receptor antagonist and tumor necrosis factor receptor-2 decreased after linoleic acid intake compared with a diet high in SFA. The results in this thesis indicate that dietary n-6 PUFA found in vegetable fats is associated with lower inflammation marker levels, and to some extent reduces systemic inflammation when compared with SFA. Supplementation of n-3 PUFA did not exert any systemic anti-inflammatory effects, maybe due to a relatively low dose.
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So, Chu-wing, and 蘇柱榮. "Observational studies of the night sky in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B43758150.
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Hägg, David. "Psoriasis in Sweden : observational studies from an epidemiological perspective." Doctoral thesis, Umeå universitet, Dermatologi och venereologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-113894.
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Background: Psoriasis is a heterogeneous disease with several clinical manifestations; the symptoms are characterized by redness, scaliness and thickness of the skin. There are several treatment options available for psoriasis and patients with moderate to severe psoriasis generally need systemic agents. In 2004 biologics were introduced for patients with moderate to severe psoriasis in Sweden. Methods: The Swedish Health Care Registers and the Swedish registry for systemic treatment of psoriasis PsoReg, were used to; estimate the incidence of psoriasis cases in the Swedish specialist care, to examine the treatment allocation and important factors related to the initiation of especially biologic treatment. Results: On average 9000 new psoriasis patients entered specialist care in Sweden each year under study, corresponding to an incidence of 98 patients per 100,000 person-years. In the treatment allocation analysis of the incident psoriasis cases in the Swedish specialist care Patients living in a Metropolitan Area and with a University degree were more likely to initiate a biologic treatment. By analysing biologic-naïve patients enrolled in PsoReg, PASI (the physician’s assessment of the psoriasis severity) and Psoriasis Arthropathy were shown to be two important factors associated with the initiation of biologic treatment while sex was not. Furthermore, it was also shown that the decision to initiate biological treatment was more strongly associated with PASI than with DLQI (the patients’ assessment of the disease impact Quality of Life). Conclusion: These studies indicate that there are inequalities in the assignments of systemic psoriasis treatments (especially in biologic treatment). Since the allocation of treatments should not depend on sex, education or residency in a Metropolitan Area but rather the need of care, it is important that future studies continue analysing possible factors that could influence the initiation of treatment in clinical practice.
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Asai, Ayumi. "Observational studies on energy release mechanism in solar flares." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/59308.
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Nakakushi, Takashi. "Observational studies of the Martian low-latitude cloud belt." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/64949.
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Lu, Rong. "Statistical Methods for Functional Genomics Studies Using Observational Data." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1467830759.
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So, Chu-wing. "Observational studies of the night sky in Hong Kong." Click to view the E-thesis via HKUTO, 2010. http://sunzi.lib.hku.hk/hkuto/record/B43758150.
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Savage, Chandra Shannon. "Ions, isotopes, and metal cyanides: Observational and laboratory studies." Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/290082.
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Chemistry in the interstellar medium is very different from the processes which take place in terrestrial settings. Environments such as circumstellar envelopes, molecular clouds, and comets contain diverse and complex chemical networks. The low temperatures (10-50 K) and densities (1-10⁶ cm⁻³) allow normally unstable molecules to exist in significant quantities. At these temperatures, the rotational energy levels of molecules are populated, and thus these species can be detected by millimeter-wave radio astronomy. The detection and quantification of interstellar molecules, including metal cyanides and molecular ions, is the basis of this dissertation work. While conducting observations of CN and ¹³CN to determine the ¹²C/¹³C ratio throughout the Galaxy, it was found that the ratios in photon-dominated regions (PDRs) were much higher than those in nearby molecular clouds. This can be explained by isotope-selective photodissociation, in which the ¹²CN molecules are self-shielded. However, the chemistry in these regions is poorly understood, and other processes may be occurring. In order to understand one of the chemical networks present in PDRs, observations of HCO⁺, HOC⁺, and CO⁺ were made toward several of these sources. Previous studies indicated that the HCO⁺/HOC⁺ ratio was much lower in PDRs, due to the presence of CO⁺. The new observations indicate that there is a strong correlation between CO⁺ and HOC⁺ abundances, which suggests that other molecular ions which have not been detected in molecular clouds may be present in PDRs. There is a significant obstacle to the detection of new interstellar molecular ions, however. The laboratory spectra are virtually unknown for many of these species, due to their inherent instability. Thus, techniques which can selectively detect ionic spectra must be utilized. One such method is velocity modulation, which incorporates an AC electrical discharge to produce and detect ions. Previously, velocity modulation spectroscopy was employed only at infrared wavelengths. The final phase of this dissertation work was to design, build and test a velocity modulation spectrometer which functions at millimeter/sub-mm wavelengths. This system was then used to measure the previously unknown pure rotational spectrum of SH⁺ (X3Σ⁻).
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Kozu, Hiromichi. "Observational studies of convective structure in emerging flux regions." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144186.
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Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第12103号
理博第2997号
新制||理||1446(附属図書館)
23939
UT51-2006-J98
京都大学大学院理学研究科物理学・宇宙物理学専攻
(主査)助教授 北井 礼三郎, 教授 黒河 宏企, 教授 長田 哲也
学位規則第4条第1項該当
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Narukage, Noriyuki. "Observational studies of flare-associated waves and reconnection inflows." 京都大学 (Kyoto University), 2006. http://hdl.handle.net/2433/144188.
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Kyoto University (京都大学)0048
新制・課程博士
博士(理学)
甲第12105号
理博第2999号
新制||理||1447(附属図書館)
23941
UT51-2006-J100
京都大学大学院理学研究科物理学・宇宙物理学専攻
(主査)教授 柴田 一成, 助教授 北井 礼三郎, 教授 長田 哲也
学位規則第4条第1項該当
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Hosokawa, Keisuke. "Observational Studies on the High-Latitude Ionospheric Plasma Irregularities." 京都大学 (Kyoto University), 2003. http://hdl.handle.net/2433/149076.
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Li, Chih-Lin. "Propensity Score Matching in Observational Studies with Multiple Time Points." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1313420291.
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Blais, Lucie. "Observational studies of drug effectiveness in asthma : time-related issues." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ36957.pdf.
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Knott, Fiona. "The sibling relationships of children with autism : two observational studies." Thesis, University of Reading, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332960.
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Shahbaz, Tariq. "Observational studies of Galactic neutron star and black-hole binaries." Thesis, Keele University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.261527.
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Lin, Jinrong Ph D. Massachusetts Institute of Technology. "Observational and evolutionary studies of neutron star X-ray binaries." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/77487.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2011.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 117-125).
In this thesis, we present our observational and evolutionary studies of neutron stars in X-ray binary systems. A variety of topics are discussed, which are all related by a single scientific theme, namely, helping to set constraints on the mass-radius relation of neutron stars, and hence on their equations of state (EOS). In Chapter 1 we review the current neutron star masses M and radii R measurement techniques utilizing the X-ray observation of neutron stars in binaries. These techniques fall into two categories: timing and spectral analysis. In Chapter 2 we present our spectral and timing analysis of 4U 2129+47. We show that 4U 2129+47 might be in a hierarchical triple system. The source has been dropping into deeper quiescence during the last decade. The absence of the power-law hard tail in its X-ray spectrum make it a good candidate for measuring neutron star radius. In Chapter 3 we present our analysis of EXO 0748-676. We show that the previously reported narrow absorption lines are inconsistent with the detected high amplitude of the 552 Hz burst oscillations. In Chapter 4 we present our semi-numerical method of evaluating the significance of burst oscillations. With this method, we searched 1187 archived RXTE Type-I X-ray bursts for high frequency oscillation modes. In Chapter 5, we present our evolutionary study of the most massive neutron star that has been recently found: PSR J1614-2230. The study has been carried out with the recently developed star evolution code "MESA". We We have computed an extensive grid of binary evolution tracks to represent low- and intermediate-mass X-ray binaries (LMXBs and IMXBs). The general results will be presented in Chapter 6.
by Jinrong Lin.
Ph.D.
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Delorey, Daniel Pierce. "Observational Studies of Software Engineering Using Data from Software Repositories." Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1716.pdf.
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Small, Jennifer D. "Observational studies of the microphysics and dynamics of warm cumulus clouds /." Diss., Digital Dissertations Database. Restricted to UC campuses, 2009. http://uclibs.org/PID/11984.
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Snellman, Greta. "Boning up on Vitamin D : Observational Studies on Bone and Health." Doctoral thesis, Uppsala universitet, Ortopedi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-159873.
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The primary function of vitamin D in humans is to maintain sufficient circulating calcium concentrations. Low vitamin D levels could result in excessive calcium resorption from bone. Vitamin deficiency may therefore decrease bone mineral density (BMD), resulting in an increased risk of fracture. This thesis sought to determine the association between vitamin D intake and bone health and to estimate circulating levels of vitamin D optimal for bone health without increasing the risk for non-bone disease. Furthermore, the thesis assessed the difference in performance between common serum vitamin D assays and the genetic influence of vitamin D status. In prospective population-based cohorts, blood concentrations <40 nmol/L (lowest 5%) increased the risk of fracture in elderly men. Low levels were further associated with a slight decrease in lumbar spine BMD. Both high (>98 nmol/L) and low (<46 nmol/L) vitamin D levels were associated with higher cancer and overall mortality. In another cohort, also of older men and women, no association was found between vitamin D levels and fracture. Low vitamin D levels were weakly associated with decreased total body BMD in men but not in women. Dietary intake of vitamin D over a 20-year period in more than 60,000 Swedish women was not associated with osteoporosis or fracture, regardless of calcium intake. During summer, dietary vitamin D intake and other life style habits are of minor importance for the variation in vitamin D levels relative to sun exposure and genes. In summer time, genes explain about half of the variation in vitamin D levels, but none of the variance in winter time. The variability between vitamin D assays was substantial. Three assays classified 8, 22 and 43% of the same study population as vitamin D insufficient if <50 nmol/L was set as the insufficiency level. Based on the results in this thesis, low 25(OH)D levels and low dietary vitamin D intake are not a major cause of fractures in community-dwelling elderly Swedish women and men. Differences in assay performance and potential negative health outcomes of high 25(OH)D levels need to be considered.
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Shidatsu, Megumi. "Observational Studies of Accretion Disks in Black Hole X-ray Binaries." 京都大学 (Kyoto University), 2015. http://hdl.handle.net/2433/199106.
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Wang, Q. (Qin). "Epidemiological applications of quantitative serum NMR metabolomics:causal inference from observational studies." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526215082.
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Abstract Cardiovascular diseases are the leading cause of death worldwide and type 2 diabetes is reaching a global epidemic. Epidemiological studies have identified numerous risk factors and pharmacotherapies in relation to these cardiometabolic diseases. However, the detailed molecular mechanisms of these risk factors and drug therapies generally remain incompletely understood. Elucidating the underlying molecular effects would be essential for better understanding of the disease pathogenesis and also for discovering new therapeutic targets. Quantitative serum metabolomics, which allows for simultaneous quantification of multiple circulating metabolic measures, provides a hypothesis-free approach to systematically inspect the metabolic changes in response to endogenous and exogenous stimuli. Metabolomics thus presents a valuable tool to study the detailed molecular effects of disease risk factors and drug therapies. However, current metabolomics studies are mostly conducted in small cross-sectional studies and the causal relations of the risk factors on the metabolic measures are generally unclear, providing limited public health impact. The present thesis serves as a proof-of-concept to illustrate that well-designed observational studies can be used to infer causality. With the exemplars of assessing molecular effects of two risk factors (body mass index and sex hormone-binding globulin) and two drug therapies (statins and oral contraceptives), the thesis demonstrates that an improved causal inference can be achieved in observational studies via the combination of multiple study designs, including cross-sectional, longitudinal and Mendelian randomization analysis. This robust study design approach together with metabolomics data can be also extended to study the molecular effects of other risk factors and drug therapies. With an improved molecular understanding of a wide range of risk factors and therapies, better understanding of disease pathogenesis is ensuredTiivistelmä Sydän- ja verisuonitaudit ovat johtava kuolinsyy maailmassa ja tyypin 2 diabetes on saavuttamassa globaalin epidemian mittasuhteet. Epidemiologiset tutkimukset ovat löytäneet useita riskitekijöitä ja lääkehoitoja edellä mainituille yleisille taudeille. Tyypin 2 diabetekseen ja sydän- ja verisuonitauteihin liittyvät yksityiskohtaiset molekylaariset mekanismit ymmärretään kuitenkin puutteellisesti. Molekylaaristen yksityiskohtien tarkempi ymmärtäminen olisi siten erittäin merkittävää sekä tautiprosessien ymmärtämiseksi että lääkehoitojen kehittämiseksi. Seerumin kvantitatiivinen metabolomiikka mahdollistaa useiden metabolisten suureiden samanaikaisen määrittämisen verenkierrosta ja tarjoaa siten hypoteesittoman lähestymistavan sekä sisäisten että ulkoisten ärsykkeiden aiheuttamien metabolisten muutosten systemaattiseen tutkimukseen. Metabolomiikka on siten arvokas työkalu yksityiskohtaisten molekylaaristen mekanismien tutkimuksessa, olipa kyseessä taudin riskitekijät tai lääkehoito. Metabolomiikkatutkimuksia on kuitenkin pääasiassa tehty pienissä poikittaistutkimuksissa ja riskitekijöihin liittyvien metabolisten suureiden syy- ja seuraussuhteet ovat yleisesti epäselviä, josta johtuen metabolisten suureiden kansanterveydellinen sovellettavuus on ollut heikkoa. Tämä väitöskirja esittelee tutkimuskonseptin hyvin suunniteltujen havaintotutkimuksien soveltamiseksi syy- ja seuraussuhteiden arvioinnissa. Työ sisältää esimerkit kahden riskitekijän (painoindeksi ja sukupuolihormoneja sitova globuliini) ja kahden lääkehoidon (statiinit ja ehkäisypillerit) molekylaaristen vaikutusten kausaalisista tutkimuksista. Tulokset havainnollistavat, että kausaalisten johtopäätösten luotettavuutta voidaan parantaa yhdistämällä useita tutkimusasetelmia, kuten poikittais- ja pitkittäistutkimuksia sekä Mendelististä satunnaistamista. Esitettyjä luotettavia tutkimusasetelmia, yhdessä metabolomiikkadatan kanssa, voidaan laajentaa muiden riskitekijöiden ja lääkehoitojen molekylaaristen vaikutusten tutkimuksiin. Parantunut molekyylitason ymmärrys useista riskitekijöistä ja lääkehoidoista johtaa myös parempaan tautiprosessien ymmärtämiseen
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Meredith, Christina. "Auditory alarms in the intensive care unit : experimental and observational studies." Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/2264.
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There are many problems associated with the number of auditory warnings in hospital environments such as the Intensive Care Unit. As the amount of medical technology used to monitor a patient's condition increases, there is a concomitant increase in the number of auditory warnings. Each piece of equipment has its own alarm and often the sounds used are inappropriate. For example, the sounds are often too loud, too insistent and are irritating to staff, distracting them from other tasks. A further feature of sounds used for auditory alarms is that there is, at present, no agreement between manufacturers on the types of sounds used. This means that the same item of equipment can have different alarms if produced by different manufacturers. Subsequently there is the potential for confusion between alarms to occur if sounds are similar. The research presented in this thesis aims to investigate the psychological dimension of confusion between alarm sounds and the correct identification of a set of twelve auditory warnings currently in use in the I.C.U. Derriford Hospital, Plymouth. Hence, the first set of experiments examines the learning and retention of the set of auditory warnings in a laboratory setting. However, the many problems regarding auditory warnings should not be considered in isolation and in order to determine the types of activities undertaken by staff in the I.C.U. environment when alarms are activated, two observational studies were undertaken. The first study used a video camera and the second study involved direct observation using two observers. A series of tasks were developed that used the multiple resources literature as a framework and also represented tasks undertaken in the environment of the I.C.U. In the second experiment, participants were again required to learn and retain the set of auditory warnings. The tasks were introduced during the return stage of the experiment in order to examine first, whether there was an effect on the primary task of correctly identifying the sounds and whether the confusions between sounds increased or changed, and second to examine performance on the secondary tasks. The results showed that for all experiments in general participants required few trials to learn the sounds and the information was retained for a period of over one week. The results also showed that features of some sounds were easier to learn than other sounds and that certain sounds were consistently confused during each experiment. When the tasks were introduced performance on the primary task remained fairly constant, with no overall change or increase in the number of confusions between sounds. However, there was a decrement in the performance of the secondary tasks, as predicted by the dual-task literature. In conclusion, the results suggest that identification of sounds may depend on a global, overall label for a sound, such as a 'melodic' sound or a 'continuous' sound, with the more intricate details undetected by participants. The results also suggest that participants in the laboratory may alter their strategies to maintain performance on the primary task, by either responding more rapidly to task demands or by consciously deciding not to respond to one of the secondary tasks.
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Helbert, Justin (Justin C. ). "Methods for observational studies using data from massive open online courses." Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/106126.
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Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (page 51).
Measuring the effect of a course component in online classes present an opportunity to use propensity score methods. Propensity score methods aim to balance the effect of self-selecting biases and other confounding variables that arise in observational studies like this, as each student decides what components they engage in throughout the course. This method is applied to an edX course, 6.002x, to estimate the effect of attempting homework and other assessments on students' final exam performance.
by Justin Helbert.
M. Eng.
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De, Geer Lina. "Cardiac dysfunction in septic shock : Observational studies on characteristics and outcome." Doctoral thesis, Linköpings universitet, Institutionen för medicin och hälsa, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-122759.
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Background: Cardiac dysfunction is a well-known complication of sepsis, but its characteristics and consequences, especially on a longer term, remain unclear. The aim of this thesis was to study the characteristics and the implications of cardiac dysfunction for outcome in intensive care unit (ICU) patients with septic shock. Purpose: First, to assess the ability of a cardiac biomarker to predict outcome in ICU patients. Second, to characterise cardiac dysfunction in septic shock using speckle tracking echocardiography. Third, to investigate the reliability of echocardiographic methods used to describe cardiac dysfunction in septic shock. Fourth, to study long-term cardiac outcome in severe sepsis and septic shock patients. Materials and methods: The cardiac biomarker amino-terminal pro-brain natriuretic peptide (NTproBNP) was collected in 481 patients on ICU admission and its ability to predict death was assessed. In 50 patients with septic shock, echocardiography was performed on ICU admission and was repeated during and after ICU stay. Measurements of cardiac strain using speckle tracking echocardiography were assessed in relation to other echocardiographic function parameters, NT-proBNP and severity of illness scores, and their change over time was analysed. Echocardiograms from patients with septic shock were independently evaluated by two physicians and the results analysed regarding measurement variability. A nationwide-registry-based open cohort of 9,520 severe sepsis and septic shock ICU patients discharged alive from the ICU was analysed together with a non-septic control group matched for age, sex and severity of illness. In patients who died after ICU discharge, information on causes of death was collected. Results: A discriminatory level of significance of NT-proBNP on ICU admission was identified at ≥1,380 ng/L, above which NT-proBNP was an independent predictor of death. With increasing levels of NT-proBNP, patients were more severely ill, had a longer ICU stay and were more often admitted with septic shock. Cardiac strain was frequently impaired in septic shock patients but was not superior to other echocardiographic measurements in detecting cardiac dysfunction. Cardiac strain correlated with other echocardiographic function parameters and with NT-proBNP, and was the least user-dependent echocardiographic parameter in septic shock patients. Cardiac strain remained unchanged over time, did not differ between survivors and non-survivors and could not predict an increased risk of death. During a follow-up of up to nearly 6 years after ICU discharge, 3,954 (42%) of sepsis patients died, 654 (17%) with cardiac failure as the cause of death. With increasing severity of illness on admission, the risk of death with cardiac failure as the cause of death after ICU discharge increased. In comparison to other ICU patients with similar severity of illness, however, the risk of death due to cardiac was not increased in patients with severe sepsis or septic shock. Conclusions: Laboratory or echocardiographic signs of cardiac dysfunction are commonly seen in ICU patients in general and in septic shock patients in particular. The assessment of cardiac dysfunction in patients with septic shock is, however, complicated by pre-existing comorbidities, by treatment given in the ICU and by critical illness in itself. Signs of cardiac dysfunction, and the increasing risk of death related to cardiac failure seen after remission of sepsis, may therefore be reflections of critical illness per se, rather than of sepsis.
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Kalaycioglu, O. "Methods for handling missing data for observational studies with repeated measurements." Thesis, University College London (University of London), 2015. http://discovery.ucl.ac.uk/1463537/.
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Missing data is common in longitudinal observational studies where, data on both outcome and explanatory variables are collected repeatedly at several time points. The research in this thesis is motivated by the repeated measurements observational study with incomplete outcome and explanatory variables. When the missing values on the explanatory variables are related to the observed values of the outcome, it has been recommended to use multiple imputation (MI) techniques to alleviate the problems of both bias and the efficiency of the parameter estimates. In this thesis MI techniques were reviewed, extended where necessary and compared regarding the bias and efficiency of the regression coefficient estimates using simulation studies in order to suggest the choice of the most optimal MI method when MAR explanatory variables occur in repeated measurements studies. Multivariate normal imputation (MVNI) produced the least bias in most situations, is theoretically well justified and allows flexible correlation for the repeated measurements in the imputation model. Bayesian MI is efficient and maybe preferable for imputing categorical variables with extreme prevalences. Imputation by chained equations (ICE) approaches were sensitive to the correlation between the repeated measurements of the incomplete variables. A complete missing data analysis requires sensitivity analysis which investigates the departures from MAR mechanism. Models for handling MNAR in both outcome and explanatory variables are not well developed and can potentially be complicated, especially when there are several missingness patterns. In this thesis selection modelling and pattern mixture modelling frameworks are extended to accommodate MNAR mechanism on time-varying outcome and explanatory variables, with mixed type of missingness patterns using fully Bayesian estimation technique. The investigations suggested that, when the true form of missingness mechanism is specified and the variables that cause missingness are used in the missingness models, the parameter estimates will be less biased than using standard MAR methods. The bias can be reduced, if the true values of missingness parameters are incorporated into the missingness models using informative priors.
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Marcinko, Charlotte L. J. "Modelling and observational studies of dinoflagellate bioluminescence within the Northeast Atlantic." Thesis, University of Southampton, 2012. https://eprints.soton.ac.uk/384575/.
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Nicolet, Deedra Rae. "Enhancement of SAS and R for meta-analysis of observational studies." The Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=osu1407409901.
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ZHANG, YUYANG. "Heterogeneous Treatment Effect Estimation in Observational Studies using Tree-based methods." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587037857042995.
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Shiotani, Masato. "Observational studies on the atmospheric general circulation using global meteorological data." 京都大学 (Kyoto University), 1987. http://hdl.handle.net/2433/86380.
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