881 resultados para multiple discriminant analysis
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Thesis (Master's)--University of Washington, 2016-06
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Minimum/maximum autocorrelation factor (MAF) is a suitable algorithm for orthogonalization of a vector random field. Orthogonalization avoids the use of multivariate geostatistics during joint stochastic modeling of geological attributes. This manuscript demonstrates in a practical way that computation of MAF is the same as discriminant analysis of the nested structures. Mathematica software is used to illustrate MAF calculations from a linear model of coregionalization (LMC) model. The limitation of two nested structures in the LMC for MAF is also discussed and linked to the effects of anisotropy and support. The analysis elucidates the matrix properties behind the approach and clarifies relationships that may be useful for model-based approaches. (C) 2003 Elsevier Science Ltd. All rights reserved.
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Aims: To investigate the prevalence of vitamin A deficiency among lactating women in a poor urban population of Bangladesh, and to examine the relationship between various factors and vitamin A status. Design: Cross-sectional study. Setting: Maternal and child health clinic in Dhaka City, Bangladesh. Subjects and methods: A total of 120 lactating women aged 17-37 years were randomly selected from women who attended a local maternal and child health clinic in Dhaka City for immunisation of their children. Various socio-economic, personal characteristics, dietary intakes of vitamin A and anthropometric data were collected. Serum retinol (vitamin A) concentration was determined as a measure of vitamin A status. Results: Of the subjects, 37% had low serum vitamin A levels (<30 μg dl(-1)), with 13.3% having sub-clinical vitamin A deficiency (<20 mug dl(-1)). Eighty-seven per cent had vitamin A intakes below the recommended dietary allowance. The lactating women who were either illiterate or received only informal education had significantly (P=0.002) lower serum vitamin A levels compared with those who received formal education. The women whose husbands received formal education had significantly (P=0.05) higher serum vitamin A levels than those whose husbands were either illiterate or received only informal education. The serum vitamin A levels of women in households with poor sanitation/latrine practice were significantly (P=0.03) lower than those of women in households with good sanitation/latrine practice. The women with one child had significantly (P=0.015) lower serum vitamin A levels than those with two or more children. Women with a lactation period of 6 months or more had significantly (P=0.034) lower serum vitamin A levels than women with a lactation period of less than 6 months. The women who consumed less than the median vitamin A intake (274.8 mug day(-1)) had significantly (P=0.01) lower serum vitamin A levels than those who consumed more than the median vitamin A intake. By multiple regression analysis, education level of the women, number of living children, duration of lactation and dietary intake of vitamin A were found to have significant independent relationships with serum vitamin A. The overall F-ratio (6.8) was highly significant (P=0.000), the adjusted R-2 was 0.16 (multiple R=0.44). Conclusion: A significant proportion of poor, urban, lactating women in Bangladesh have vitamin A deficiency. Among the various factors, education level of the women, number of living children, duration of lactation and dietary intake of vitamin A appear to be important in influencing the vitamin A status of these women.
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This cross-sectional study investigated the prevalence of anaemia and vitamin A deficiency (VAD) among pregnant women in a poor urban population of Bangladesh. It also examined the association of various socio-economic and dietary factors with anaemia and vitamin A status. A maternal and child health clinic in Dhaka city, Bangladesh was used to obtain the sample. Three hundred and eighty three pregnant women, aged 20-30 years, of 20-30 weeks gestation were randomly selected from women on their first presentation for antenatal care. Socio-economic, pregnancy related information, usual dietary pattern, and anthropometric data were collected. Blood haemoglobin and serum retinol (vitamin A) concentrations were determined. About 40% of the pregnant women were anaemic (haemoglobin <11.0 g/dl) and 45% had low serum vitamin A levels (<30 mug/dl); with 8.6% having sub-clinical VAD (serum retinol <20 μg/dl). The women with low serum vitamin A levels had 1.8 times greater risk of being anaemic than did the women with normal vitamin A status. Food frequency data revealed that a large proportion of these women did not consume egg (49%), milk (25%), meat (31%), liver (83%), large fish (32%), small fish (39%) and sweet pumpkin (52%) at all; while about 25% of the women reported consuming dark green leafy vegetables (DGLV) and 64% reported an intake of fruit at least four servings a week. The pregnant women who were either illiterate or received only informal education (up to grade ten) had significantly lower haemoglobin and serum vitamin A levels compared to those who completed at least a secondary school certificate. The women whose husbands were illiterate or received only informal education had significantly (P=0.01) lower serum vitamin A levels than those whose husbands had received at least a secondary school certificate. The women who came from families with a per-capita income below the poverty line had significantly lower haemoglobin and serum vitamin A levels compared to those who came from families with a per-capita income above the poverty line. The women who consumed three servings or less of DGLV and fruit per week had significantly lower haemoglobin and serum vitamin A levels than those who consumed four or more servings a week. The women who never consumed large fish had significantly lower haemoglobin compared to those who reported at least one serving a week. Furthermore, the women who never consumed sweet pumpkin had significantly lower serum vitamin A than the women who ate at least one serving a week. By multiple regression analysis, intake of meat, DGLV and fruit, and serum vitamin A levels were found to have a significant independent relationship with haemoglobin. The overall F-ratio (9.9) was highly significant (P=0.000), the adjusted R-square was 0.086 (multiple R=0.309). Multiple regression analysis for serum vitamin A also revealed a significant independent relationship with per capita income, haemoglobin levels, intakes of DGLV and sweet pumpkin. The overall F-ratio (10.2) was highly significant (P=0.000), the adjusted R-square was 0.10 (multiple R=0.312). In conclusion, anaemia and vitamin A deficiency were highly prevalent among poor urban pregnant women in Bangladesh. Various socio-economic and dietary factors may influence the anaemia and vitamin A status of these women. The present study emphasizes the need for a comprehensive intervention strategy, which include both nutritional and environmental factors, to improve the nutritional status of this population.
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The present study investigated neuropsychological and psychological factors associated with successful treatment outcome following a group intervention for individuals with acquired brain injury (ABI). Participants were classified into two groups (Clinically Improved and Not Improved) based upon the findings of a previous study (Ownsworth, McFarland, & Young, 2000a). A discriminant analysis was used to predict group membership on three outcome measures (Awareness and Strategy Behaviour indices of the Self-Regulation Skills Interview and the Psychosocial Dimension of the Sickness Impact Profile) between pre-assessment and post-assessment, and between pre-assessment and 6 months follow-up. Neuropsychological factors involved measures of executive functioning and psychological factors were assessed using measures of personality-related denial and coping-related denial. Overall, the results indicated that individuals with impaired executive functioning were most likely to be classified as Clinically Improved on measures of awareness, strategy behaviour and psychosocial functioning. Individuals who deny or minimise their ABI symptoms were less likely to improve their psychosocial functioning following the group intervention. Future research needs to evaluate interventions for enhancing self-regulation skills and improving psychosocial functioning for individuals who employ denial as a main strategy for coping following ABI.
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This study presents the first analysis of the impact of NASCAR sponsorship announcements on the stock prices of sponsoring firms. The primary finding of the study-that NASCAR sponsorship announcements were accompanied by the largest increases in shareholder wealth ever recorded in the marketing literature in response to a voluntary marketing program-represents a striking and unambiguous stock market endorsement of the sponsorships. Indeed, the 24 sponsors analyzed in this study experienced mean increases in shareholder wealth of over $300 million dollars, net of all of the costs associated with the sponsorships. A multiple regression analysis of firm-specific stock price changes and select corporate and sponsorship attributes indicates that NASCAR sponsorships with more successful racing teams, corporate (as opposed to product or divisional) sponsorships, and sponsorships with direct ties to the consumer automotive industry are all positively correlated with perceived sponsorship success, while corporate cash flow per share (a well-known proxy for agency conflicts within the firm) is negatively related with shareholder approval.
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This paper investigates how demographic (socioeconomic) and land-use (physical and environmental) data can be integrated within a decision support framework to formulate and evaluate land-use planning scenarios. A case-study approach is undertaken with land-use planning scenarios for a rapidly growing coastal area in Australia, the Shire of Hervey Bay. The town and surrounding area require careful planning of the future urban growth between competing land uses. Three potential urban growth scenarios are put forth to address this issue. Scenario A ('continued growth') is based on existing socioeconomic trends. Scenario B ('maximising rates base') is derived using optimisation modelling of land-valuation data. Scenario C ('sustainable development') is derived using a number of social, economic, and environmental factors and assigning weightings of importance to each factor using a multiple criteria analysis approach. The land-use planning scenarios are presented through the use of maps and tables within a geographical information system, which delineate future possible land-use allocations up until 2021. The planning scenarios are evaluated by using a goal-achievement matrix approach. The matrix is constructed with a number of criteria derived from key policy objectives outlined in the regional growth management framework and town planning schemes. The authors of this paper examine the final efficiency scores calculated for each of the three planning scenarios and discuss the advantages and disadvantages of the three land-use modelling approaches used to formulate the final scenarios.
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Recent molecular analyses indicate that many reef coral species belong to hybridizing species complexes or "syngameons." Such complexes consist of numerous genetically distinct-species or lineages, which periodically split and/or fuse as they extend through time. During splitting and fusion, morphologic intermediates form and species overlap. Here we focus on processes associated with lineage fusion, specifically introgressive hybridization, and the recognition of such hybridization in the fossil record. Our approach involves comparing patterns of ecologic and morphologic overlap in genetically characterized modern species with fossil representatives of the same or closely related species. We similarly consider the long-term consequences of past hybridization on the structure of modern-day species boundaries. Our study involves the species complex Montastraea annularis s.l. and is based in the Bahamas, where, unlike other Caribbean locations, two of the three members of the complex today are not genetically distinct. We measured and collected colonies along linear transects across Pleistocene reef terraces of last interglacial age (approximately 125 Ka) on the islands of San Salvador, Andros, and Great Inagua. We performed quantitative ecologic and morphologic analyses of the fossil data, and compared patterns of overlap among species with data from modern localities where species are and are not genetically distinct. Ecologic and morphologic analyses reveal "moderate" overlap (>10%, but statistically significant differences) and sometimes "high" overlap (no statistically significant differences) among Pleistocene growth forms (= "species"). Ecologic analyses show that three species (massive, column, organ-pipe) co-occurred. Although organ-pipes had higher abundances in patch reef environments, columnar and massive species exhibited broad, completely overlapping distributions and had abundances that were not related to reef environment. For morphometric analyses, we used multivariate discriminant analysis on landmark data and linear measurements. The results show that columnar species overlap "moderately" with organ-pipe and massive species. Comparisons with genetically characterized colonies from Panama show that the Pleistocene Bahamas species have intermediate morphologies, and that the observed "moderate" overlap differs from the morphologic separation among the three modern species. In contrast, massive and columnar species from the Pleistocene of the Dominican Republic comprise distinct morphologic clusters, similar to the modern species; organ-pipe species exhibit "low" overlap (
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In recognition of a central role of the kidney in long-term blood pressure control, we undertook an in-depth analysis of the relationship between blood pressure and kidney damage caused by environmental exposure to the common pollutants cadmium and lead. The subjects were 200 healthy Thais, 16 and 60 years of age (100 female non-smokers, 53 male non-smokers, and 47 male smokers). None of these subjects had been exposed to Cd or Pb in the workplace and their urinary Cd concentrations ranged from 0.4 to 37 nM, whereas their urinary Pb concentrations ranged from 0.1 to 30 nM. The prevalence of high blood pressure was 2%, 8% and 19%, respectively in subjects with low, average and high Cd-burden (linear trend chi(2) = 6.4, P = 0.01). Multiple regression analysis revealed a significant positive association between Cd-burden and blood pressure in male nonsmokers (adjusted beta = 0.31, P = 0.02) and an inverse association between blood pressure and urinary Pb excretion rate in male smokers (adjusted beta = -0.38, P = 0.005). Associations between Cd-burden and nephropathies were evidenced by increases in urinary excretion of beta 2-microglobutin (P = 0.02) and N-acetyl-beta-D-glucosaminidase (P = 0.005) in subjects with high Cd-burden, compared with the subjects with average Cd-burden. In addition, an association between Cd-related nephropathy and high blood pressure was evidenced by a 20% increase in the prevalence of high blood pressure in people with NAG-uria (linear trend chi(2) = 4.3, P = 0.04). Our present study provides first evidence for a possible link between renal tubular damage and dysfunction caused by environmental Cd exposure and increased risk of high blood pressure. (c) 2005 Elsevier Ireland Ltd. All rights reserved.
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Background: The objective was to determine whether the pattern of environmental and genetic influences on deviant personality scores differs from that observed for the normative range of personality, comparing results in adolescent and adult female twins. Methods: A sample of 2,796 female adolescent twins ascertained from birth records provided Junior Eysenck Personality Questionnaire data. The average age of the sample was 17.0 years ( S. D. 2.3). Genetic analyses of continuous and extreme personality scores were conducted. Results were compared for 3,178 adult female twins. Results: Genetic analysis of continuous traits in adolescent female twins were similar to findings in adult female twins, with genetic influences accounting for between 37% and 44% of the variance in Extraversion (Ex), Neuroticism (N), and Social Non-Conformity (SNC), with significant evidence of shared environmental influences (19%) found only for SNC in the adult female twins. Analyses of extreme personality characteristics, defined categorically, in the adolescent data and replicated in the adult female data, yielded estimates for high N and high SNC that deviated substantially (p < .05) from those obtained in the continuous trait analyses, and provided suggestive evidence that shared family environment may play a more important role in determining personality deviance than has been previously found when personality is viewed continuously. However, multiple-threshold models that assumed the same genetic and environmental determinants of both normative range variation and extreme scores gave acceptable fits for each personality dimension. Conclusions: The hypothesis of differences in genetic or environmental factors responsible for N and SNC among female twins with scores in the extreme versus normative ranges was partially supported, but not for Ex.
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Persistent intermittent headache is a common disorder and is often accompanied by neck aching or stiffness, which could infer a cervical contribution to headache. However, the incidence of cervicogenic headache is estimated to be 14-18% of all chronic headaches, highlighting the need for clear criterion of cervical musculoskeletal impairment to identify cervicogenic headache sufferers who may benefit from treatments such as manual therapy. This study examined the presence of cervical musculoskeletal impairment in 77 subjects, 27 with cervicogenic headache, 25 with migraine with aura and 25 control subjects. Assessments included a photographic measure of posture, range of movement, cervical manual examination, pressure pain thresholds, muscle length, performance in the cranio-cervical flexion test and cervical kinaesthetic sense. The results indicated that when compared to the migraine with aura and control groups who scored similarly in the tests, the cervicogenic headache group had less range of cervical flexion/extension (P = 0.048) and significantly higher incidences of painful upper cervical joint dysfunction assessed by manual examination (all P < 0.05) and muscle tightness (P < 0.05). Sternocleidomastoid normalized EMG values were higher in the latter three stages of the cranio-cervical flexion test although they failed to reach significance. There were no between group differences for other measures. A discriminant analysis revealed that manual examination could discriminate the cervicogenic headache group from the other subjects (migraine with aura and control subjects combined) with an 80% sensitivity. (C) 2005 Elsevier Ltd. All rights reserved.
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This study assessed the theory of mind (ToM) and executive functioning (EF) abilities of 124 typically developing preschool children aged 3 to 5 years in relation to whether or not they had a child-aged sibling (i.e. a child aged 1 to 12 years) at home with whom to play and converse. On a ToM battery that included tests of false belief, appearance-reality (AR) and pretend representation, children who had at least 1 child-aged sibling scored significantly higher than both only children and those whose only siblings were infants or adults. The numbers of child-aged siblings in preschoolers' families positively predicted their scores on both a ToM battery (4 tasks) and an EF battery (2 tasks), and these associations remained significant with language ability partialled out. Results of a hierarchical multiple regression analysis revealed that independent contributions to individual differences in ToM were made by language ability, EF skill and having a child-aged sibling. However, even though some conditions for mediation were met, there was no statistically reliable evidence that EF skills mediated the advantage of presence of child-aged siblings for ToM performance. While consistent with the theory that distinctively childish interaction among siblings accelerates the growth of both TOM and EF capacities, alternative evidence and alternative theoretical interpretations for the findings were also considered.
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This trial of cognitive-behavioural therapy (CBT) based amphetamine abstinence program (n = 507) focused on refusal self-efficacy, improved coping, improved problem solving and planning for relapse prevention. Measures included the Severity of Dependence Scale (SDS), the General Health Questionnaire-28 (GHQ-28) and Amphetamine Refusal Self-Efficacy. Psychiatric case identification (caseness) across the four GHQ-28 sub-scales was compared with Australian normative data. Almost 90% were amphetamine-dependent (SDS 8.15 +/- 3.17). Pretreatment, all GHQ-28 sub-scale measures were below reported Australian population values. Caseness was substantially higher than Australian normative values {Somatic Symptoms (52.3%), Anxiety (68%), Social Dysfunction (46.5%) and Depression (33.7%). One hundred and sixty-eight subjects (33%) completed and reported program abstinence. Program completers reported improvement across all GHQ-28 sub-scales Somatic Symptoms (p < 0.001), Anxiety (p < 0.001), Social Dysfunction (p < 0.001) and Depression (p < 0.001)}. They also reported improvement in amphetamine refusal self-efficacy (p < 0.001). Improvement remained significant following intention-to-treat analyses, imputing baseline data for subjects that withdrew from the program. The GHQ-28 sub-scales, Amphetamine Refusal Self-Efficacy Questionnaire and the SDS successfully predicted treatment compliance through a discriminant analysis function (p
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Objective: To investigate whether the recently developed (statistically derived) "ASsessment in Ankylosing Spondylitis Working Group" improvement criteria (ASAS-IC) for ankylosing spondylitis (AS) reflect clinically relevant improvement according to the opinion of an expert panel. Methods: The ASAS-IC consist of four domains: physical function, spinal pain, patient global assessment, and inflammation. Scores on these four domains of 55 patients with AS, who had participated in a non-steroidal anti-inflammatory drug efficacy trial, were presented to an international expert panel (consisting of patients with AS and members of the ASAS Working Group) in a three round Delphi exercise. The number of (non-) responders according to the ASAS-IC was compared with the final-consensus of the experts. The most important domains in the opinion of the experts were identified, and also selected with discriminant analysis. A number of provisional criteria sets that best represented the consensus of the experts were defined. Using other datasets, these clinically derived criteria sets as well as the statistically derived ASAS-IC were then tested for discriminative properties and for agreement with the end of trial efficacy by patient and doctor. Results: Forty experts completed the three Delphi rounds. The experts considered twice as many patients to be responders than the ASAS-IC (42 v 21). Overall agreement between experts and ASAS-IC was 62%. Spinal pain was considered the most important domain by most experts and was also selected as such by discriminant analysis. Provisional criteria sets with an agreement of greater than or equal to 80% compared with the consensus of the experts showed high placebo response rates (27-42%), in contrast with the ASAS-IC with a predefined placebo response rate of 25%. All criteria sets and the ASAS-IC discriminated well between active and placebo treatment (chi(2) = 36-45; p < 0.001). Compared with the end of trial efficacy assessment, the provisional criteria sets showed an agreement of 71-82%, sensitivity of 67-83%, and specificity of 81-88%. The ASAS-IC showed an agreement of 70%, sensitivity of 62%, and specificity of 89%. Conclusion: The ASAS-IC are strict in defining response, are highly specific, and consequently show lower sensitivity than the clinically derived criteria sets. However, those patients who are considered as responders by applying the ASAS-IC are acknowledged as such by the expert panel as well as by. patients' and doctors' judgments, and are therefore likely to be true responders.
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Atualmente, características organizacionais vêm sendo estudadas sob um prisma diferenciado. Hoje, são pesquisados com maior ênfase os aspectos positivos que possam prover a possibilidade dos trabalhadores nutrirem sentimentos positivos para com suas organizações empregadoras e ao seu trabalho propriamente dito. Os desafios impostos atualmente giram em torno de se buscar identificar características organizacionais positivas que permitam o florescimento do trabalhador. Tais características são postuladas como benéficas tanto às organizações, por resultar em maior produtividade e lucratividade, assim como para promover o bem-estar dos trabalhadores. O objetivo deste estudo foi analisar os impactos que as dimensões da organização positiva exercem sobre o bem-estar dos trabalhadores. O bem-estar dos trabalhadores foi dividido em duas áreas, bem-estar subjetivo (composto por satisfação geral com a vida, afetos positivos e afetos negativos) e bem-estar no trabalho, composto por três dimensões: satisfação no trabalho, envolvimento com o trabalho e comprometimento organizacional afetivo. Organização positiva foi concebida como um construto composto por três dimensões: percepção de suporte organizacional, percepções de justiça organizacional (distributiva e de procedimentos) e confiança do empregado na organização. A amostra foi composta por 200 trabalhadores de diversas empresas do Estado de São Paulo, sendo 55 do sexo masculino e 145 do sexo feminino, solteiros e casados com escolaridade distribuída desde o ensino fundamental completo até pósgraduação completa. O instrumento de coleta de dados foi um questionário auto-aplicável composto por nove escalas que mediram as variáveis do estudo. Os resultados deste trabalho revelaram que bem-estar subjetivo e bem-estar no trabalho guardam relações entre si. Análises de regressão múltipla informaram que as dimensões da organização positiva tiveram impactos maiores sobre bem-estar no trabalho do que bem-estar subjetivo, destacando-se a capacidade de confiança do empregado na organização de prover explicações para o bem-estar de trabalhadores, seja nos domínios da vida pessoal ou no contexto de trabalho. Conforme tais resultados, confiança do empregado na organização, percepções de justiça e de suporte organizacional poderiam ser apontadas como importantes dimensões da organização positiva para promover e proteger o bem-estar dos trabalhadores. Futuros estudos deveriam incluir outras características organizacionais positivas para aumentar a explicação da variância do bem-estar dos trabalhadores