123 resultados para Panel data analysis


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This paper proposes to apply multiagent based data mining technologies to biological data analysis. The rationale is justified from multiple perspectives with an emphasis on biological context. Followed by that, an initial multiagent based bio-data mining framework is presented. Based on the framework, we developed a prototype system to demonstrate how it helps the biologists to perform a comprehensive mining task for answering biological questions. The system offers a new way to reuse biological datasets and available data mining algorithms with ease.

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This paper investigates undergraduate programs in electrical and electronics engineering offered by twelve universities in Australia, Asia, Europe, and America. The investigation focuses on the structure and content of the programs, and the contact hour and assessment of the subjects involved in the programs. The investigation is carried out in four stages: selection of universities, collection of data, analysis of data, and formulation of outcomes. A list of subjects is created based on the content of the programs. The average percentage coverage of each subject in the twelve programs is calculated. The subjects are then grouped into nine program components. The average percentage coverage of each component per university is calculated. For each component, the total number of contact hours for lecture, tutorial, and practical is calculated. Also, the average percentage of four assessment methods for each component is found. Discussions on the outcome of the investigation are presented.

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Objective: The pharmacokinetic profile of a drug often gives little indication of its potential therapeutic application, with many therapeutic uses of drugs being discovered serendipitously while being studied for different indications. As hypothesis-driven, quantitative research methodology is exclusively used in early-phase trials, unexpected but important phenomena may escape detection. In this context, this study aimed to examine the potential for integrating qualitative research methods with quantitative methods in early-phase drug trials. To our knowledge, this mixed methodology has not previously been applied to blinded psychopharmacologic trials.

Method: We undertook qualitative data analysis of clinical observations on the dataset of a randomized, double-blind, placebo-controlled trial of N-acetylcysteine (NAC) in patients with DSM-IV-TR–diagnosed schizophrenia (N = 140). Textual data on all participants, deliberately collected for this purpose, were coded using NVivo 2, and emergent themes were analyzed in a blinded manner in the NAC and placebo groups. The trial was conducted from November 2002 to July 2005.

Results: The principal findings of the published trial could be replicated using a qualitative methodology. In addition, significant differences between NAC- and placebo-treated participants emerged for positive and affective symptoms, which had not been captured by the rating scales utilized in the quantitative trial. Qualitative data in this study subsequently led to a positive trial of NAC in bipolar disorder.

Conclusions: The use of qualitative methods may yield broader data and has the potential to complement traditional quantitative methods and detect unexpected efficacy and safety signals, thereby maximizing the findings of early-phase clinical trial research.

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This paper is concerned with explaining the levels of innovative activity in New Zealand's SMEs. It is arguable that New Zealand provides a special case where innovation and R&D levels are comparatively low in SMEs, yet, paradoxically, it is also a nation of high rates of entrepreneurial activity. This paper seeks to examine the factors that affect innovation levels in New Zealand SMEs from an analysis of panel data set of 1500 SMEs. We test research propositions based on existing theory and literature on innovation levels in SMEs and discuss our findings. Firm size is found to be significant; we argue that New Zealand has too few growth firms rather than too many small firms and we suggest that barriers to innovation, such as access to finance, remain an issue which should be a focus for government support.

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From data generated using 1H NMR titrations, different methodologies to calculate binding constants are compared. The ‘local’ analysis method that uses only a single isotherm (only one H-bond donor) is compared against the ‘global’ method (that includes many or all H-bond donors). The results indicate that for simple systems both methods are suitable, however, the global approach consistently provides a K a value with uncertainties up to 30% smaller. For more complex binding, the global analysis method gives much more robust results than the local methods. This study also highlights the need to explore several different modes when data do not fit well to a simple 1:1 complexation model and illustrates the need for better methods to estimate uncertainties in supramolecular binding experiments.

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The dramatic rise in childhood obesity prevalence in the last two decades has prompted concern about the risk factors that may precipitate or maintain weight gain, or both, in early childhood. Media use has long been implicated in policy debates in Australia, particularly around limits to advertising. However the Australian research funding ecology and dominant paradigms in Australian communication and media studies have resulted in a lack of independent, nationally representative studies upon which to base advice. Australian researchers often can’t afford to collect the kind of data they would like in order to intervene productively as policy actors. As a test case for innovative ways round this dilemma, this paper mobilises secondary data analysis methodologies to explore potential influences of parenting on children’s media use and their weight status.

The research reported here uses data from the first three waves of the Longitudinal Study of Australian Children. Results from a path model suggest that children of mothers who were less consistent in the way in which they enforce their rules were more likely to adopt unhealthy lifestyle behaviours, such as sedentary behaviour and consuming unhealthy snacks. Of the lifestyle behaviours considered, time spent watching television or DVDs was the only predictor of child weight status in late childhood. These results suggest a clear pathway linking consistent parenting and other parental practices, children’s lifestyle behaviours and weight status.

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This paper describes the application of existing and novel adaptations of visualisation techniques to routinely collected health data. The aim of this case study is to examine the capacity for visualisation approaches to quickly and e ectively inform clinical, policy, and scal decision making to improve healthcare provision. We demonstrate the use of interactive graphics, fluctuation plots, mosaic plots, time plots, heatmaps, and disease maps to visualise patient admission, transfer, in-hospital mortality, morbidity coding, execution of diagnosis and treatment guidelines, and the temporal and spatial variations of diseases. The relative e ectiveness of these techniques and associated challenges are discussed.

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This small-scale study carried out in a Melbourne metropolitan hospital explored patients’ and their carers’ perceptions of information, adequacy of information, and their utilization of information concerning post-discharge care received from health professionals during their stay in hospital. The research design consisted of two stages. Stage one involved a qualitative approach using focused interviews of five pairs of patients and their carers, 2 weeks after discharge from hospital. Five main themes emerged from the content analysis of the interview transcripts: information given by health professionals to patients and carers, patients’ and carers’ psychological well-being, activities of daily living, caring tasks of the patients, and community linkages. A quantitative approach was used for stage two involving two sets of questionnaires, one for the patient and one for the carer, developed from the themes identified in stage one. A pilot study was conducted on three pairs of patients and their carers, 2 weeks after discharge from hospital. The main study consisted of a convenience sample of 40 pairs of patients and their carers who completed the questionnaires 2 weeks post-discharge. Data analysis of stage two of the study consisted of descriptive statistics and cross-tabulations. The main findings suggested that carers received very little information from health professionals concerning their patients’ health problems and care at home. The carers’ health and employment states were often not considered in their patients’ discharge plan. Carers who were present with their patients when they received information concerning post-discharge care experienced a decrease in anxiety during their patients’ convalescence at home, greater satisfaction with the information they received, and their patients experienced fewer medical problems post-discharge. The implications for nursing practice and research include recommendations for a more effective system of discharge planning, and further research to include a larger population with a more varied group of participants.

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This thesis explores some of the associations between income inequality, education and economic growth. In addition, the thesis also explores the effects of democracy and regime duration on growth. The analysis is conducted at three levels: for Malaysia as a nation using time series data, for a panel of Malaysian states and for a panel of Southeast Asian countries. The main empirical tools applied are metaregression analysis and panel data econometrics. Specifically, the thesis explores the following associations: (i) the effect of education on inequality; (ii) the effect of economic development and economic growth on inequality; (iii) the effect of education on growth; (iv) the effect of inequality on growth; (v) the effect of democracy on growth; and (vi) the effect of regime duration on growth.

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In a recent study, Westerlund (Empir Econ 37:517–531, 2009) shows that the performance of the popular LLC (Levin et al., J Econ 108:1–24, 2002) panel unit root test depends critically on the choice of lag truncation used when correcting for serial correlation, and that it is only when this parameter is set as a function of time that the power raises above size. The purpose of the current paper is to propose a modified test that does not suffer from this drawback. The new test is not only simpler to compute but also superior in terms of small-sample performance, which is illustrated using an example purchasing power parity for less developed countries.

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This paper points to some of the facts that have emerged from 20 years of research into the analysis of unit roots in panel data, an area that has been heavily influenced by two studies, IPS (Im, Pesaran, and Shin, 2003) and LLC (Levin et al., 2002). Some of these facts are known, others are not. But they all have in common that, if ignored, the effects can be very serious. This is demonstrated using both simulations and theoretical arguments.

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The calculation of the first few moments of elution peaks is necessary to determine: the amount of component in the sample (peak area or zeroth moment), the retention factor (first moment), and the column efficiency (second moment). It is a time consuming and tedious task for the analyst to perform these calculations, thus data analysis is generally completed by data stations associated to modern chromatographs. However, data acquisition software is a black box which provides no information to chromatographers on how their data are treated. These results are too important to be accepted on blind faith. The location of the peak integration boundaries is most important. In this manuscript, we explore the relationships between the size of the integration area, the relative position of the peak maximum within this area, and the accuracy of the calculated moments. We found that relationships between these parameters do exist and that computers can be programmed with relatively simple routines to automatize the extraction of key peak parameters and to select acceptable integration boundaries. It was also found that the most accurate results are obtained when the S/N exceeds 200.

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As part of a longitudinal study, infant/toddler pretend play development and maternal play modelling were investigated in dyadic context. A total of 21 children were videotaped in monthly play sessions with their mothers, from age 8 to 17 months. Child and mother pretend play frequencies and levels were measured using Brown’s Pretend Play Observation Scale. Child IQ assessments at 5 years (Stanford–Binet IV) indicated average to high ability levels (M = 122.62). Descriptive analyses showed that children’s levels of pretend development were markedly in advance of age-typical expectations. With a previous analysis showing no specific associations between play levels and IQ, intensive maternal scaffolding, data analysis approaches and use of abstract play materials are proposed as possible contributory factors to the children’s advanced pretend play development.

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Interpretative Phenomenological Analysis (IPA) has developed internationally into a growing qualitative approach to research in the areas of psychology, health sciences, social sciences, education and also specifically in music education. This chapter focuses on IPA as an experiential approach to research which explores the lived experience of the individual’s perception and how individuals make sense of it in their given context. As with other forms of phenomenological research, IPA takes account of the researcher’s own context and perceptions through a process of interpretation, while analyzing the phenomena under study. IPA offers a framework to undertake research based on the traditions of phenomenology, which uncover meanings and hermeneutics which interpret the meaning; it is idiographic in nature when undertaking data analysis. This chapter provides a narrative on IPA as an appropriate methodology that can be used when undertaking research in education and in particularly music education. As a tertiary researcher of music education I have employed IPA in my research. This chapter attempts to address broad questions in relation to: What is IPA? Where does it come from? How is it used? How does one analyze interview data and construct themes? A brief discussion of the strengths and limitations of the method is posed, giving examples where IPA has been successfully employed in music research. By balancing the tensions between phenomenology, hermeneutics and idiographic approaches, IPA situates music and music education research within the realm of qualitative experiential research. I argue that if more music educators apply IPA to their research, we can look forward to the emergence of new insights from research in music and music education that is rigorous and offers both convergent and divergent analysis, beyond description, using interpretation to explain insights.

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Background: Debate is ongoing about what role, if any, variation in the serotonin transporter linked polymorphic region (5-HTTLPR) plays in depression. Some studies report an interaction between 5-HTTLPR variation and stressful life events affecting the risk for depression, others report a main effect of 5-HTTLPR variation on depression, while others find no evidence for either a main or interaction effect. Meta-analyses of multiple studies have also reached differing conclusions.

Methods/Design:
To improve understanding of the combined roles of 5-HTTLPR variation and stress in the development of depression, we are conducting a meta-analysis of multiple independent datasets. This coordinated approach utilizes new analyses performed with centrally-developed, standardized scripts. This publication documents the protocol for this collaborative, consortium-based meta-analysis of 5-HTTLPR variation, stress, and depression.

Study eligibility criteria: Our goal is to invite all datasets, published or unpublished, with 5-HTTLPR genotype and assessments of stress and depression for at least 300 subjects. This inclusive approach is to minimize potential impact from publication bias.

Data sources: This project currently includes investigators from 35 independent groups, providing data on at least N = 33,761 participants.  The analytic plan was determined prior to starting data analysis. Analyses of individual study datasets will be performed by the investigators who collected the data using centrally-developed standardized analysis scripts to ensure a consistent analytical approach across sites. The consortium as a group will review and interpret the meta-analysis results.

Discussion:
Variation in 5-HTTLPR is hypothesized to moderate the response to stress on depression. To test specific hypotheses about the role of 5-HTTLPR variation on depression, we will perform coordinated meta-analyses of de novo results obtained from all available data, using variables and analyses determined a priori. Primary analyses, based on the original 2003 report by Caspi and colleagues of a GxE interaction will be supplemented by secondary analyses to help interpret and clarify issues ranging from the mechanism of effect to heterogeneity among the contributing studies. Publication of this protocol serves to protect this project from biased reporting and to improve the ability of readers to interpret the results of this specific meta-analysis upon its completion.