The cosmopolitan Pteridium aquilinum (L.) Kuhn is widespread throughout eastern North American, where it is represented primarily by Tryon's (1941) var. latiusculum (Desv.) Underw. and var. pseudocaudatum (Clute) Heller. The taxonomy of Pteridium is controversial. Fourteen isozyme loci and 12 morphological characters were used to assess the taxonomic relationship of these two varieties. Isozyme data indicated a high mean genetic identity (I = 0.976) between eleven bracken populations. Strong patterns of geographic variation for isozyme allele frequencies were also observed. The isozyme results did not separate the two taxa. Numerical analysis of the morphology distinguished the two taxa when the qualitative characters were used alone or in conjunction with some of the quantitative traits. All qualitative characters differed significantly between the two taxa. No perceptible geographic pattern of variation was observed. Morphological distinctiveness was maintained even in those localities where both taxa were present, with few or no intermediates being found. Isozyme evidence suggestive of gene flow between the two varieties was found at Greensboro, NC, where the two morphotypes were easily recognizable. The isozyme evidence strongly indicates conspecificity, while the morphological evidence supports their status at the varietal level. / Master of Science

Many of the skills that are considered noteworthy in our societies are either acquired through training and dedication or granted to those lucky enough to have the right genetics and environment. But one skill that is often overlooked is the ability to keep rhythm. This skill is both remarkable in temporal accuracy and common. And although rhythm-keeping is a common cognitive skill, not much is known about the neural correlates of rhythm-keeping. The aim of the current exploratory study was to investigate the electrophysiological correlates of rhythm-keeping. In this study, participants were asked to perform a task where they were introduced to a rhythm with both auditory and visual cues to correct themselves after. They were then supposed to keep the rhythm for approximately thirty seconds, even though all stimuli indicating the rhythm were removed after six seconds of performing the task. During the task, electrophysiological data were collected using electroencephalography (EEG). The electrophysiological data and task performance were then analysed using mass univariate analysis, but no significant relationship was found between the electrophysiological data and rhythm-keeping performance. Potential issues underlying these non-significant findings, as well as solutions to address these, will be addressed.

One of the most important threats for many firms today, despite their nature of the operation, size and longevity, is insolvency. Existing empirical evidence has shown that in the past two decades, business failures have occurred at a higher rate than any time since the 1930s. Many business failure studies have been conducted over time using financial ratios as inputs and traditional statistical techniques. Some of these studies examined whether cash flow information improves the prediction of business failure. Most recently, researchers have employed discriminant analysis to perform business failure prediction. The recent changes in the world caused by unstable environments where many firms fail more than ever, there is increasing need to predict business failure. To this date, there have been limited previous studies conducted on failure prediction for UK firms. Even in other countries, there has been a small amount of research done in the field of firm failures. Therefore, this study investigates the extension of Altman’s (1968) original model in predicting the health of UK firms using discriminant analysis and performance ratios to test which ratios are statistically significant in predicting the health of the UK firms .a selected sample containing 90 failed and 1000 non failed on UK industrial firms from 2000 – 2013. The main purpose of this study is to contribute towards Altman’s (1968) original Z-score model by adding new variables (Cash flow ratio). The study found that cash flow, when combined with Altman’s original variables is highly significant in predicting the health of UK general firms. A J-UK model was developed to test the health of UK firms. When compared with the re-estimated the Altman’s original model in the UK context, the predictive power of the model was 82.9%, which is consistent with Taffler’s (1982) UK model. Furthermore, to test the predictive power of the model before, during and after the financial crisis periods; results show that J-UK model had a higher accuracy to predict the health of UK firms than the re-estimated Altman’s original model. Finally, the study proves that liquidity, profitability, leverage and capital turnover ratios are significant ratios in predicting failure. Liquidity and profitability have the highest contribution to the results of both re-estimated Altman’s original model and J-UK model. This study has implications for decision makers. Regulatory bodies and practitioners have to take into account the ratios, which contributed highest to the model in order to serve as early warning signals for corrective action.

Functional brain images are extraordinarily rich data sets that reveal distributed brain networks engaged in a wide variety of cognitive operations. It is a substantial challenge both to create models of cognition that mimic behavior and underlying cognitive processes and to choose a suitable analytic method to identify underlying brain networks. Most of the contemporary techniques used in analyses of functional neuroimaging data are based on univariate approaches in which single image elements (i.e. voxels) are considered to be computationally independent measures. Beyond univariate methods (e.g. statistical parametric mapping), multivariate approaches, which identify a network across all regions of the brain rather than a tessellation of regions, are potentially well suited for analyses of brain imaging data. A multivariate method (e.g. partial least squares) is a computational strategy that determines time-varying distributed patterns of the brain (as a function of a cognitive task). Compared to its univariate counterparts, a multivariate approach provides greater levels of sensitivity and reflects cooperative interactions among brain regions. Thus, by considering information across more than one measuring point, additional information on brain function can be revealed. Similarly, by considering information across more than one measuring technique, the nature of underlying cognitive processes become well-understood. Cognitive processes have been investigated in conjunction with multiple neuroimaging modalities (e.g. fMRI, sMRI, EEG, DTI), whereas the typical method has been to analyze each modality separately. Accordingly, little work has been carried out to examine the relation between different modalities. Indeed, due to the interconnected nature of brain processing, it is plausible that changes in one modality locally or distally modulate changes in another modality. This thesis focuses on multivariate and multimodal methods of image analysis applied to various cognitive questions. These methods are used in order to extract features that are inaccessible using univariate / unimodal analytic approaches. To this end, I implemented multivariate partial least squares analysis in study I and II in order to identify neural commonalities and differences between the available and accessible information in memory (study I), and also between episodic encoding and episodic retrieval (study II). Study I provided evidence of a qualitative differences between availability and accessibility signals in memory by linking memory access to modality-independent brain regions, and availability in memory to elevated activity in modality-specific brain regions. Study II provided evidence in support of general and specific memory operations during encoding and retrieval by linking general processes to the joint demands on attentional, executive, and strategic processing, and a process-specific network to core episodic memory function. In study II, III, and IV, I explored whether the age-related changes/differences in one modality were driven by age-related changes/differences in another modality. To this end, study II investigated whether age-related functional differences in hippocampus during an episodic memory task could be accounted for by age-related structural differences. I found that age-related local structural deterioration could partially but not entirely account for age-related diminished hippocampal activation. In study III, I sought to explore whether age-related changes in the prefrontal and occipital cortex during a semantic memory task were driven by local and/or distal gray matter loss. I found that age-related diminished prefrontal activation was driven, at least in part, by local gray matter atrophy, whereas the age-related decline in occipital cortex was accounted for by distal gray matter atrophy. Finally, in study IV, I investigated whether white matter (WM) microstructural differences mediated age-related decline in different cognitive domains. The findings implicated WM as one source of age-related decline on tasks measuring processing speed, but they did not support the view that age-related differences in episodic memory, visuospatial ability, or fluency were strongly driven by age-related differences in white-matter pathways. Taken together, the architecture of different aspects of episodic memory (e.g. encoding vs. retrieval; availability vs. accessibility) was characterized using a multivariate partial least squares. This finding highlights usefulness of multivariate techniques in guiding cognitive theories of episodic memory. Additionally, competing theories of cognitive aging were investigated by multimodal integration of age-related changes in brain structure, function, and behavior. The structure-function relationships were specific to brain regions and cognitive domains. Finally, we urged that contemporary theories on cognitive aging need to be extended to longitudinal measures to be further validated.

Submitted by (ana.araujo@ufrpe.br) on 2016-05-18T16:23:27Z No. of bitstreams: 1 Adalberto Gomes de Araujo.pdf: 1912427 bytes, checksum: f5afb060ed8c40727f32cece528acc33 (MD5) / Made available in DSpace on 2016-05-18T16:23:27Z (GMT). No. of bitstreams: 1 Adalberto Gomes de Araujo.pdf: 1912427 bytes, checksum: f5afb060ed8c40727f32cece528acc33 (MD5) Previous issue date: 2005-06-15 / The objective of this work was to use multivariate and univariate statistical methods, in the selection of independent variables, in mathematical models, in the construction of volume tables for Leucaena leucocephala, looking for reduction in time and costs, without loss of precision. The data came from an experiment carried out at the Experimental Station of the Institute of Agriculture Research (IPA), Caruaru-PE. It was used 201 trees of leucena that had their volumes (dependent variable) measured by the method of Smalian, and 20 variables independent measured in the same trees. For the selection of the independent variables the following methods were used: Principal Components, Cluster Analysis, Maximum and Minimum R2, Stepwise, Forward, Backward and Criterion of Akaike. In the general, the univariate and multivariate methods used in the selection of independent variables for volume models, showed similar responses, even though they had different structures in relation to the independent variables, since the number of those variables is high. Besides the applied statistical tests, the researcher'sjudgment about the relevance of the selected independent variables in the final equations has a great importance, mainly, in the reduction of costs and sampling errors. / O objetivo deste trabalho foi utilizar métodos estatísticos univariados e multivariados na seleção de variáveis independentes, em modelos matemáticos, para a construção de tabelas de volumes para Leucaena leucocephala, visando reduzir tempo e custos sem perda de precisão. Os dados foram provenientes de um experimento conduzido na Estação Experimental da Empresa Pernambucana de Pesquisa Agropecuária (IPA), Caruaru-PE. Foram utilizadas 201 árvores de leucena, que tiveram seus volumes cubados pelo método de Smalian, e 20 variáveis independentes medidas nas mesmas árvores. Para a seleção das variáveis independentes foram utilizados os seguintes métodos: Componentes Principais, Análise de Agrupamento, R2 Máximo e Mínimo, Stepwise, Forward, Backward e Critério de Akaike. No geral, os métodos univariados e multivariados empregados no descarte de variáveis independentes para modelos volumétricos, conduzem a respostas semelhantes, mesmo que possuam estruturas diferentes em relação às variáveis independentes, desde que o número dessas variáveis seja elevado. Além dos testes estatísticos aplicados, o julgamento do pesquisador sobre a relevância das variáveis selecionadas nas equações resultantes, é de grande importância, principalmente, na redução de custos e do erro de amostragem

This diploma aims to analyze the development of the European Union Member States for last thirty years in terms of demographic indicators. First chapter is focused on the historical development of the world's population, followed by the development of the European population and political history of the European Union. Next chapter is focused on the most commonly used demographic indicators for international comparisons divided into groups according to demographic processes, their interpretation and calculation. The main part of the work is analysis of selected indicators for the Member States of the EU with regard to the European average of 27 Member States in the period between 1981 and 2011. Another chapter is devoted to modify data for above mentioned simple analysis and cluster analysis, which is located in the last chapter. Cluster analysis was performed using Euclidean distance and using nearest and furthest neighbor and Ward's method. In 1981 the furthest neighbor method divided Member States into five clusters and in 2011 the Ward's method divided Member States again within five clusters, but with a different composition. Original data for Multidimensional description is added to annex with the results of calculations and graphs.

Metabolomics as a field has been used to track changes and perturbations in the human body by investigating metabolite profiles indicating the change of metabolite levels over time and in response to different challenges. In this thesis work, the main focus was on applying multiplatform-metabolomics to study the human metabolome following exposure to perturbations, such as diet (in the form of a challenge meal) and exhaust emissions (air pollution exposure in a controlled setting). The cutting-edge analytical platforms used for this purpose were nuclear magnetic resonance (NMR), as well as gas chromatography (GC) and liquid chromatography (LC) coupled to mass spectrometry (MS). Each platform offered unique characterization features, allowing detection and identification of a specific range of metabolites. The use of multiplatform-metabolomics was found to enhance the metabolome coverage and to provide complementary findings that enabled a better understanding of the biochemical processes reflected by the metabolite profiles. Using non-targeted analysis, a wide range of unknown metabolites in plasma were identified during the postprandial stage after a well-defined challenge meal (in Paper I). In addition, a considerable number of metabolites were detected and identified in lung lavage fluid after biodiesel exhaust exposure compared to filtered air exposure (in Paper II). In parallel, using targeted analysis, both lung lavage and plasma fatty acid metabolites were detected and quantified in response to filtered air and biodiesel exhaust exposure (in Paper III and IV). Data processing of raw data followed by data analysis, using both univariate and multivariate methods, enabled changes occurring in metabolites levels to be screened and investigated. For the initial pilot postprandial study, the aim was to investigate the plasma metabolome response after a well-defined meal during the postprandial stage for two types of diet. It was found that independent of the background diet type, levels of metabolites returned to their baseline levels after three hours. This finding was taken into consideration for the biodiesel exhaust exposures studies, designed to limit the impact of dietary effects. Both targeted and non-targeted approaches resulted in important findings. For instance, different metabolite profiles were detected in bronchial wash (BW) compared to bronchoalveolar lavage (BAL) fluid with mainly NMR and LC-MS. Furthermore, biodiesel exhaust exposure resulted in different metabolite profiles as observed by GC-MS, especially in BAL. In addition, fatty acid metabolites in BW, BAL, and plasma were shown to be responsive to biodiesel exhaust exposure, as measured by a targeted LC-MS/MS protocol. In summary, the new analytical methods developed to investigate the responsiveness of the human plasma and lung lavage metabolome proved to be useful in an analytical perspective, and provided important biological findings. However, further studies are needed to validate these results. / Metabolomik har använts för att spåra förändringar och störningar i kroppens funktioner genom undersökning av metabolit-profiler. I detta avhandlingasarbete har huvudfokus varit på tillämpning av flera olika analytiska plattformar för metabolomikstudier av det mänskliga metabolomet efter exponering för olika kost och avgasutsläpp från biodieselbränsle. De sofistikerade analytiska plattformarna som användes för detta ändamål var kärnmagnetisk resonans (NMR), samt gaskromatografi (GC) och vätskekromatografi (LC) kopplat till masspektrometri (MS). Varje plattform erbjöd unika karakteriseringsmöjligheter med detektion och identifiering av specifika grupper av metaboliter. Användningen av multipattformmetabolomik förbättrade täckningen av metabolomet och genererade kompletterande resultat som möjliggjorde en bättre förståelse av de biokemiska processer som reflekteras av metabolitprofilerna. Med hjälp av breda analyser har ett stort antal okända metaboliter i plasma identifierats under den postprandial fasen efter en väldefinerad måltid (i Paper I). Dessutom har ett stort antal metaboliter påvisats och identifierats i lungsköljvätska efter exponering av biodieselavgaser jämfört med kontollexponering med filtrerad luft (i Paper II). Parallellt med dessa breda analyser har också riktade analyser genomförts av både lungsköljvätska och plasma. Därigenom har bioaktiva lipider detekterats och kvantifieras efter avgasexponering och resultaten har jämförts med filtrerad luft som kontrollexponering (Paper III och IV). Processning av rådata följt av dataanalys, med både univariata och multivariata metoder möjliggjorde screening och fördjupad undersökning av förändringen i metabolitnivåer. I den första pilotstudien av postprandiala nivåer var syftet att undersöka responsen i plasmametabolomet efter en väldefinierad måltid under den postprandiala fasen vid två olika typer av kost. Resultaten visade att oberoende av kosten, så återvände metabolitnivåerna till sina baslinjenivåer tre timmar efter måltiden. Detta togs i beaktande vid exponeringsstudierna för biodieselavgaser, som designades så att dietens inverkan minimerades. Både breda och riktade analyser resulterade i viktiga resultat. Exempelvis så detekterades olika metabolitprofiler i bronkiell sköljvätska (BW) jämfört med bronkoalveolär sköljvätska (BAL), speciellt med NMR och LC-MS. Dessutom resulterade avgasexponering i förändrade metabolitprofiler, observerade med GC-MS, särskilt i BAL. Dessutom uppvisade fettsyrametaboliter i BW, BAL och plasma förändrade halter efter avgasexponering, uppmätt genom en riktad LC-MS/MS-analys. Sammanfattningsvis så visade sig de nya metoderna som utvecklats för att undersöka  förändringar i metabolithalterna i plasma och lungsköljvätska fungera väl ur ett analytiskt perspektiv och resulterade i viktiga biologiska fynd. Fördjupade studier behövs dock för att validera resultaten.

The purpose of this study was to examine the effects of parenting training on the acquisition of parenting skills and its impact on self-esteem of incarcerated mothers. The program under study is the "Mothers Inside Loving Kids" (M.I.L.K.) program, which is a holistic training/visitation program designed for incarcerated mothers.Study participants included 40 volunteer incarcerated mothers at the Virginia Correctional Center for women. The treatment group consisted of 20 participants who were already involved in the "M.I.L.K." program. The comparison group was made up of 20 mothers who were on the waiting list for the program due to the lack of space. All participants were administered a battery of pre-tests and post-tests. Instruments utilized for the study included the Adult-Adolescent Parenting Inventory (AAPI), the Nurturing Quiz, the Index of Self Esteem (ISE), and a participant satisfaction survey.Bivariate analyses were used to test the difference between pre-test and post-test mean scores. Both parametric and non-parametric tests were conducted to determine if change scores revealed significant differences. Using independent t-tests to determine if there were significant differences between treatment and comparison groups on change scores, no significant differences were noted. However, in reviewing the direction of change scores for the two groups, the treatment group did show changes in the desired direction in four areas. Specifically, positive directional change occurred on the "Lack of Empathy for the Child" sub-scale, the "Belief in Corporal Punishment" sub-scale, the "Reversing Family Roles" sub-scale, and on the "Nurturing Quiz."Using the Wilcoxon non-parametric test, one measure revealed statistically significant differences between pre-test and post-test scores. Specifically, participants in the treatment group revealed significantly higher scores on the "Nurturing Quiz" at post-testing from pre-testing (z = -2.81, p = .005). This indicates an overall increase in knowledge about positive child management techniques. No significant pre-test to post-test differences were noted in any of the remaining areas under study. However, positive directional change scores were noted in the three different areas of "Inappropriate Expectations of the Child", "Nurturing", and "Self-Esteem."Overall, the findings suggest that the M.I.L.K. Program training positively impacts parenting techniques. Self-esteem appears more difficult to impact.

The purpose of this study was to understand what perceptions the social workers in the social services perceives the clients have about the social services and how this can affect the social workers in their work and private life. The data in this study was collected through a survey, conducted by social workers in six different municipalities. The study has been carried out through a mixed method research. The data was thereafter analyzed through a univariate analysis and a content analysis. The findings in this study shows that a majority of the social workers feel that the clients have bad perceptions about the social services. These are based on several factors, such as own experiences and feelings of shame. Media and rumors also play a significant role. Furthermore, the study also shows that the social workers are most affected in their work than in their private life. Another finding the study showed is that support from the director and the colleagues is a way for social workers to manage the clients' perceptions about them. Explaining and clarifying to the client and the public what the social service means, is an another way of managing it.