Data arising from Cluster Randomized Trials (CRTs) and longitudinal studies are correlated and generalized estimating equations (GEE) are a popular analysis method for correlated data. Previous research has shown that analyses using GEE could result in liberal inference due to the use of the empirical sandwich covariance matrix estimator, which can yield negatively biased standard error estimates when the number of clusters or subjects is not large. Many techniques have been presented to correct this negative bias; However, use of these corrections can still result in biased standard error estimates and thus test sizes that are not consistently at their nominal level. Therefore, there is a need for an improved correction such that nominal type I error rates will consistently result. First, GEEs are becoming a popular choice for the analysis of data arising from CRTs. We study the use of recently developed corrections for empirical standard error estimation and the use of a combination of two popular corrections. In an extensive simulation study, we find that nominal type I error rates can be consistently attained when using an average of two popular corrections developed by Mancl and DeRouen (2001, Biometrics 57, 126-134) and Kauermann and Carroll (2001, Journal of the American Statistical Association 96, 1387-1396) (AVG MD KC). Use of this new correction was found to notably outperform the use of previously recommended corrections. Second, data arising from longitudinal studies are also commonly analyzed with GEE. We conduct a simulation study, finding two methods to attain nominal type I error rates more consistently than other methods in a variety of settings: First, a recently proposed method by Westgate and Burchett (2016, Statistics in Medicine 35, 3733-3744) that specifies both a covariance estimator and degrees of freedom, and second, AVG MD KC with degrees of freedom equaling the number of subjects minus the number of parameters in the marginal model. Finally, stepped wedge trials are an increasingly popular alternative to traditional parallel cluster randomized trials. Such trials often utilize a small number of clusters and numerous time intervals, and these components must be considered when choosing an analysis method. A generalized linear mixed model containing a random intercept and fixed time and intervention covariates is the most common analysis approach. However, the sole use of a random intercept applies assumptions that will be violated in practice. We show, using an extensive simulation study based on a motivating example and a more general design, alternative analysis methods are preferable for maintaining the validity of inference in small-sample stepped wedge trials with binary outcomes. First, we show the use of generalized estimating equations, with an appropriate bias correction and a degrees of freedom adjustment dependent on the study setting type, will result in nominal type I error rates. Second, we show the use of a cluster-level summary linear mixed model can also achieve nominal type I error rates for equal cluster size settings.

All of New Zealand's five endemic species of mudfish (Neochanna) are threatened, and translocation has been recommended as an option for conservation. This research undertakes a translocation of black mudfish (Neochanna diversus) into wetland margins of Lake Kaituna, in the Waikato region, and addresses research questions applicable to improving translocation success. Results from this research are intended to aid possible future translocations of the more threatened Northland mudfish (Neochanna heleios) and other genetically distinct populations of black mudfish. Captive rearing of juveniles collected from the wild is currently the most feasible option for sourcing translocation stock. Mudfish juveniles (greater than 25 mm T.L.) had greater survival rates, compared to mudfish fry less than 25 mm T.L. Mudfish growth was far greater when fed on a combined diet of brine shrimp (Artemia salina) and white worms (Enchytraeus albidus) than when fed exclusively on brine shrimp. Temperature was found to have a small effect on mudfish growth, with a slightly greater growth in fish at 15 C than those at 10 C. The introduced species Gambusia affinis has been the subject of concern for mudfish conservation and commonly found at wetland sites suitable for mudfish translocation. Found to prey on mudfish fry and eggs in aquaria, it was important to determine the effects of Gambusia density prior to undertaking a translocation to a location where Gambusia were present. Investigations were made into the effect of Gambusia density on black mudfish juveniles in 9 outdoor mesocosms. Increasing Gambusia density was found to have an inhibitory effect on black mudfish growth. This may be due to increased competition for food, a theory supported by analysis of zooplankton communities, where, in the presence of Gambusia, large zooplankton had been removed and smaller rotifers flourished. Monitoring programmes are required to assess any impacts or improvements of mudfish populations, including those created by translocation. A Gee minnow trapping programme in outdoor mesocosms was conducted to test the reliability of traps, finding that water depth, mudfish density, mudfish memory and trap shyness had no effect on the trapability of mudfish. Trap position was found to have the most significant effect, with a greater number of mudfish caught when traps were set overnight at the surface than when set on the bottom of mesocosms. Black mudfish adults and juveniles were translocated into 18 pools (~1 m diameter) on the wetland margins of Lake Kaituna in September 2006, followed by monthly monitoring. Water quality monitoring and an assessment of hydrology and vegetation was undertaken. Habitat characterisation was found to be a key factor, with correlations between water quality data and trapping results finding fewer fish remaining in pools with less suitable characteristics for mudfish (e.g. high turbidity and conductivity). Other species were found to have a large impact, with predation by shortfinned eels (Anguilla australis) thought to have eliminated mudfish from some pools. In addition fewer mudfish were caught in pools with Gambusia, possibly due to increased competition.

Objective: In recent years there has been an increasing interest within the clinical (medical) science in measuring people’s health. When estimating quality of life, present practise is to use the EQ-5D questionnaire and an index which weighs the different questions. The question is what happens if the individuals estimate there own health, would it differ from the public preferences? The aim is to make a new prediction model based on the opinion of patients and compare it to the present model based on public preferences. Method: A sample of 362 patients with unstable coronary artery disease from the Frisc II trial, valued their quality of life in the acute phase and after 3, 6 and 12 months. The EQ-5D question form and also the Time Trade-off method (TTO), a direct method of valuing health was used. A regression technique managing panel data had to be used in estimating TTO by the EQ-5D and other variables like gender and age. Result: Different regression techniques vary in estimating parameters and standard errors. A Generalized Estimating Equation approach with empirical correlation structure is the most suitable regression technique for the data material. A model based on the EQ-5D question form and a continuous age variable proves to be the best model for an index derived by individuals. The difference between heart patients own opinion of health and the public preferences differs a great amount in the severe health conditions, but are rather small for healthy patients. Of the total 243 health conditions, only eight of the conditions were estimated higher by the public index. Conclusions: As the differences between the approaches are significantly large the choice of index could affect the decision making in a health economic study.

This essay researches video games and learning. The academic interest in video games is steadily growing and this teacher‟s degree unifies interactive game play with the learning possibilities of the media. The study compares the Swedish upper secondary school curriculum Lpf94 with Gee‟s educational theory. The correlations are analyzed for compatibility, and Bioware‟s 2007 video game Mass Effect is applied to see what elements are capable to teach playing students English. A qualitative methodology is used according to Malterud‟s template analysis style and follows a top-down fashion. The material is analyzed through a triangulation system where each piece is read as a text and is compared and interpreted. The results show that Lpf94 and Gee‟s theory has a generally high compatibility. English learning is viable since Mass Effect provides the player with a language simulator that puts the language in a logical environment. Although the game script is static, the study shows that Mass Effect includes vocabulary training, a pragmatic understanding of language, and a tool for class room teaching.

Zugl.: Witten, Herdecke, Univ., Diss., 2008

Submitted by JOCY ANA PAIXÃO DE SOUSA null (jocy_belem@hotmail.com) on 2018-02-06T16:26:54Z No. of bitstreams: 1 SOUSA, JOCY ANA PAIXÃO DE-DISSERTAÇÃO.pdf: 4608931 bytes, checksum: 2e5913d39dda79bea7ac97e19d2f5d15 (MD5) / Approved for entry into archive by Lucimara Kurokawa Shinoda null (lucimaraks@sorocaba.unesp.br) on 2018-02-07T11:59:59Z (GMT) No. of bitstreams: 1 sousa_jap_me_soro.pdf: 4608931 bytes, checksum: 2e5913d39dda79bea7ac97e19d2f5d15 (MD5) / Made available in DSpace on 2018-02-07T11:59:59Z (GMT). No. of bitstreams: 1 sousa_jap_me_soro.pdf: 4608931 bytes, checksum: 2e5913d39dda79bea7ac97e19d2f5d15 (MD5) Previous issue date: 2018-01-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As interferências antrópicas sobre natureza sempre provocaram impactos ambientais. Porém, entre os mais significativos encontram-se as mudanças de uso da terra, nos quais contribuem com as emissões dos gases do efeito estufa. Entre esses principais gases destacam-se o dióxido de carbono, CO2. O estudo apresentou como objetivo estimar as emissões do dióxido de carbono devido as mudanças de uso da terra para a análise do fluxo de carbono em bacia hidrográfica. A área de estudo localiza-se na Bacia Hidrográfica do Rio Una, Ibiúna, São Paulo. Para atingir os objetivos foram realizados o mapeamento de uso do solo e cobertura vegetal, mapeamento pedológico, análise da textura do solo, mapeamento da vegetação pretérita, estoque de carbono sob associação solo-vegetação, matriz de transição e os cálculos das emissões líquidas de CO2. Constatou-se que em relação ao mapeamento do uso do solo e cobertura vegetal, o maior quantitativo foi de floresta e estas predominam no sul da bacia. Ao longo de nove anos houve uma redução de florestas, campo e área alagada e um aumento da área de agricultura, área urbana, pastagem e reflorestamento. Foram encontrados solos do tipo Argissolos e Latossolos, além das texturas argilosa, franco-argilo-arenosa, argilo-arenosa e franco-argilosa. Para a vegetação pretérita constatou-se floresta ombrófila densa montana, floresta estacional decidual e semidecidual. Em relação ao conteúdo de carbono no solo sob a associação solo-vegetação foram definidos valores que variam de 2,59 a 6,33 Kgc/m2. Nas matrizes de transições para os períodos de 2007-2010, 2010-2013 e 2013-2016, observou-se que a floresta convertida para as demais categorias apresentou posição de destaque. As emissões líquidas para todos os períodos mostraram que há mais emissões do que remoções na bacia, com um destaque para o período de 2013 a 2016, em que houve uma maior estimativa de emissões CO2, porém a menor remoção ocorreu no último período. A pesquisa mostrou que a maioria das transições que ocorreram foram em função da mudança de floresta para outras categorias, fator que mais contribuiu para emissões líquidas de CO2, resultante do intenso processo de antropização da bacia. / Anthropogenic interference with nature has always had environmental impacts. However, among the most significant are land use changes, in which they contribute to the emissions of effect gases, especially carbon dioxide, CO2. The objective of the study was to estimate carbon dioxide emissions due to the change in land use for an analysis of the carbon flux in the watershed. The study area is located in the Una Watershed, Ibiúna, São Paulo. To achieve the objectives, the mapping of land use and vegetation cover, pedological mapping, soil texture analysis, mapping of past vegetation, carbon stock under soil-vegetation association, transition matrix, and calculations of net CO2 emissions. It was verified that in relation to the mapping of the land use and vegetal cover, the biggest quantitative one was of forest and these predominate in the south of the basin. During nine years there was a reduction of forests, field and flooded area and an increase of the area of agriculture, urban área, pasture and reforestation. Soils of the type Argisols and Latosols were found, in addition to clay, clay-loam-sandy, clay-sandy and loam-loamy textures. For the past vegetation it was verified dense montane forest, deciduous and semidecidual forest. Regarding the non-singlet carbon content in a soil-vegetation association to define values ranging from 2.59 to 6.33 Kgc / m2. In the transitional matrices for the periods 2007-2010, 2010-2013 and 2013-2016, it was observed that the forest converted to the other categories presented a prominent position. Net emissions for all periods showed that there are more emissions than removals in the basin, with a highlight for the period from 2013 to 2016, where there was a higher estimate of CO2 emissions, but the lowest removal occurred in the last period. The research showed that most of the transitions that occurred were due to the change of forest to other categories, which contributed most to net CO2 emissions, resulting from the intense process of anthropization of the basin.

Class of 2013 Abstract / Specific Aims: To assess the association between marginal tax rates (MTR) and innovative output of biotechnology firms. The MTR plays an important role in firms’ financing choices. Assessment of a firm’s tax status may reveal how firms decide on investment policies that affect R&D. Methods: A retrospective database analysis was used. Subjects included were firms within the biotechnology sector with the Standard Industrial Classification code of 2836 from 1980 - 2011. MTR Data was obtained from the S&P Compustat database, and Patent data was obtained from the U.S. Patent and Trademark Office. Changes in MTR’s on outcomes of patents were analyzed by performing an inferential analysis. Generalized estimating equations (GEE) were used, specifically utilizing a GEE regression with a negative binomial distributional family with log link, independent correlation structure and robust standard error variance calculation. Patents were regressed by the lagged change in MTR, after interest deductions. Main Results: The lag years 2 and 5 of the MTR change were statistically significant, (p = 0.031) and (p = 0.026) for each model respectively. Every one unit increase in the change of the MTRs was associated with large and significant drops in patents 78.8% (IRR = 0.212), 90.7% (IRR = 0.093), 92.7% (IRR = 0.073) at year 2 lag and 84.8% (IRR = 0.152), 92.6% (IRR = 0.074) at year 5 lag. Conclusion: An increase in the change of the MTR results in significant drops in patenting activity.

No description available.

Monitoring carbon stock has emerged as a critical environmental problem among several worldwide organizations and collaborations in the context of global warming and climate change. This study seeks to provide a remote sensing solution based on three types of data, to explore the feasibility and reliability of estimating aboveground biomass (AGB) in order to improve the efficiency of monitoring carbon stock. The study attempted to investigate the potential of using Google Earth Engine (GEE), and the combinations of different datasets from Sentinel-1 (SAR), Sentinel-2 multispectral imagery, and LiDAR data to estimate AGB, by using the random forest algorithm (RF). Two models were proposed: the first one (Model 1) detected the AGB temporal changes from 2016 to 2021 in Southern Sweden; while the second one (Model 2) focused on Hultsfred municipality and studied the influence of different variables including the canopy height. Besides, six experimental groups of variables were tested to determine the performance of using different types of remote sensing data. We validated these two models with the observed AGB, and the findings showed that the combination of SAR polarization, multisprectral bands, vegetation indices able to estimate AGB for Model 1. In addition, Model 2 showed that further using the canopy height data can further improve the estimation.  We also found out that the spectral bands from Sentinel-2 contributed the most to AGB estimation for Model 1 in terms of: bands B3 (Green), B4 (Red), B5 (Red edge), B11 (SWIR), B12 (SWIR); and, vegetation indices of RVI, DVI, and EVI. On the other hand, for Model 2, B1(Ultra blue), B4 (Red), EVI, SAVI, and the canopy height are the most crucial variables for estimating AGB. Besides, the radar backscatter values using VV and VH modes from Sentienl-1 were both important for Models 1 and 2. For Model 1, the experimental group with the best accuracy was the group that used all variable combinations from Sentinel-1 and 2, and its   was 0.33~0.74. For Model 2, the group that used all the variables, in addition to the canopy height performed the best, where its   is 0.91. These therefore showed the benefit of integrating different remote sensing data sources.  In conclusion, this study showed the potential of using RF and GEE to estimate AGB in Southern Sweden. Furthermore, this study also shows the possibility of handling large dataset for a large scale area, at the resolution of 10 m, and producing time series AGB maps from 2016 to 2021. This can help enhance our understanding of AGB temporal changes and carbon stock detection in Southern Sweden, that can provide valuable insights for forest management and carbon monitoring.

No description available.