888 resultados para latent growth curve modeling


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This study further explored the impact of sectarian violence and children's emotional insecurity about community on child maladjustment using a 4-wave longitudinal design. The study included 999 mother-child dyads in Belfast, Northern Ireland (482 boys, 517 girls). Across the 4 waves, child mean age was 12.19 (SD = 1.82), 13.24 (SD = 1.83), 13.61 (SD = 1.99), and 14.66 years (SD = 1.96), respectively. Building on previous studies of the role of emotional insecurity in child adjustment, the current study examines within-person change in emotional insecurity using latent growth curve analyses. The results showed that children's trajectories of emotional insecurity about community were related to risk for developing conduct and emotion problems. These findings controlled for earlier adjustment problems, age, and gender, and took into account the time-varying nature of experience with sectarian violence. Discussion considers the implications for children's emotional insecurity about community for relations between political violence and children's adjustment, including the significance of trajectories of emotional insecurity over time.

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Forgiveness is often assumed to be adaptive for psychological adjustment following interpersonal transgressions. Three hundred and forty seven individuals who had experienced a recent interpersonal transgression were surveyed on four occasions over the course of six weeks. Forgiveness was assessed with scales measuring interpersonal avoidance and revenge motivation and psychological adjustment was assessed with scales measuring depression and rumination. Latent growth curve analyses showed that intraindividual changes in forgiveness were positively correlated with changes in adjustment. Latent difference score analyses indicated that adjustment predicted subsequent change in forgiveness, but that forgiveness did not predict subsequent change in adjustment. The results suggest that adjustment facilitates forgiveness, but not that forgiveness facilitates adjustment.

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Can one observe an increasing level of individual lack of orientation because of rapid social change in modern societies? This question is examined using data from a representative longitudinal survey in Germany conducted in 2002–04. The study examines the role of education, age, sex, region (east/west), and political orientation for the explanation of anomia and its development. First we present the different sources of anomie in modern societies, based on the theoretical foundations of Durkheim and Merton, and introduce the different definitions of anomia, including our own cognitive version. Then we deduce several hypotheses from the theory, which we test by means of longitudinal data for the period 2002–04 in Germany using the latent growth curve model as our statistical method. The empirical findings show that all the sociodemographic variables, including political orientation, are strong predictors of the initial level of anomia. Regarding the development of anomia over time (2002–04), only the region (west) has a significant impact. In particular, the results of a multi-group analysis show that western German people with a right-wing political orientation become more anomic over this period. The article concludes with some theoretical implications.

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Objective: There is an ongoing debate concerning how outcome variables change during the course of psychotherapy. We compared the dose–effect model, which posits diminishing effects of additional sessions in later treatment phases, against a model that assumes a linear and steady treatment progress through termination. Method: Session-by-session outcome data of 6,375 outpatients were analyzed, and participants were categorized according to treatment length. Linear and log-linear (i.e., negatively accelerating) latent growth curve models (LGCMs) were estimated and compared for different treatment length categories. Results: When comparing the fit of the various models, the log-linear LGCMs assuming negatively accelerating treatment progress consistently outperformed the linear models irre- spective of treatment duration. The rate of change was found to be inversely related to the length of treatment. Conclusion: As proposed by the dose–effect model, the expected course of improvement in psychotherapy appears to follow a negatively accelerated pattern of change, irrespective of the duration of the treatment. However, our results also suggest that the rate of change is not constant across various treatment lengths. As proposed by the “good enough level” model, longer treatments are associated with less rapid rates of change.

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The present research is concerned with the direction of influence between objective and subjective career success. We conducted a prospective longitudinal study with five waves of measurement that covered a time span of 10 years. Participants were professionals working in different occupational fields (N=1,336). We modelled the changes in objective success (income, hierarchical position), in other-referent subjective success (subjective success as compared to a reference group), and in self-referent subjective success (job satisfaction) by means of latent growth curve analysis. Objective success influenced both the initial level and the growth of other-referent subjective success, but it had no influence on job satisfaction. Most importantly, both measures of subjective success and both their initial levels and their changes had strong influences on the growth of objective success. We conclude that the ‘objective success influences subjective success’ relationship is smaller than might be expected, whereas the ‘subjective success influences objective success’ relationship is larger than might be expected.

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The authors examined the development of self-esteem across the life span. Data came from a German longitudinal study with 3 assessments across 4 years of a sample of 2,509 individuals ages 14 to 89 years. The self-esteem measure used showed strong measurement invariance across assessments and birth cohorts. Latent growth curve analyses indicated that self-esteem follows a quadratic trajectory across the life span, increasing during adolescence, young adulthood, and middle adulthood, reaching a peak at age 60 years, and then declining in old age. No cohort effects on average levels of self-esteem or on the shape of the trajectory were found. Moreover, the trajectory did not differ across gender, level of education, or for individuals who had lived continuously in West versus East Germany (i.e., the 2 parts of Germany that had been separate states from 1949 to 1990). However, the results suggested that employment status, household income, and satisfaction in the domains of work, relationships, and health contribute to a more positive life span trajectory of self-esteem. The findings have significant implications, because they call attention to developmental stages in which individuals may be vulnerable because of low self-esteem (such as adolescence and old age) and to factors that predict successful versus problematic developmental trajectories.

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We examined the development of self-esteem in adolescence and young adulthood. Data came from the Young Adults section of the National Longitudinal Survey of Youth, which includes 8 assessments across a 14-year period of a national probability sample of 7,100 individuals age 14 to 30 years. Latent growth curve analyses indicated that self-esteem increases during adolescence and continues to increase more slowly in young adulthood. Women and men did not differ in their self-esteem trajectories. In adolescence, Hispanics had lower self-esteem than Blacks and Whites, but the self-esteem of Hispanics subsequently increased more strongly, so that at age 30 Blacks and Hispanics had higher self-esteem than Whites. At each age, emotionally stable, extraverted, and conscientious individuals experienced higher self-esteem than emotionally unstable, introverted, and less conscientious individuals. Moreover, at each age, high sense of mastery, low risk taking, and better health predicted higher self-esteem. Finally, the results suggest that normative increase in sense of mastery accounts for a large proportion of the normative increase in self-esteem.

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The authors examined the development of self-esteem from young adulthood to old age. Data came from the Americans’ Changing Lives study, which includes 4 assessments across a 16-year period of a nationally representative sample of 3,617 individuals aged 25 years to 104 years. Latent growth curve analyses indicated that self-esteem follows a quadratic trajectory across the adult life span, increasing during young and middle adulthood, reaching a peak at about age 60 years, and then declining in old age. No cohort differences in the self-esteem trajectory were found. Women had lower self-esteem than did men in young adulthood, but their trajectories converged in old age. Whites and Blacks had similar trajectories in young and middle adulthood, but the self-esteem of Blacks declined more sharply in old age than did the self-esteem of Whites. More educated individuals had higher self-esteem than did less educated individuals, but their trajectories were similar. Moreover, the results suggested that changes in socioeconomic status and physical health account for the decline in self-esteem that occurs in old age.

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We investigated whether a physiological marker of cardiovascular health, pulse pressure (PP), and age magnified the effect of the functional COMT Val158Met (rs4680) polymorphism on 15-years cognitive trajectories [episodic memory (EM), visuospatial ability, and semantic memory] using data from 1585 non-demented adults from the Betula study. A multiple-group latent growth curve model was specified to gauge individual differences in change, and average trends therein. The allelic variants showed negligible differences across the cognitive markers in average trends. The older portion of the sample selectively age-magnified the effects of Val158Met on EM changes, resulting in greater decline in Val compared to homozygote Met carriers. This effect was attenuated by statistical control for PP. Further, PP moderated the effects of COMT on 15-years EM trajectories, resulting in greater decline in Val carriers, even after accounting for the confounding effects of sex, education, cardiovascular diseases (diabetes, stroke, and hypertension), and chronological age, controlled for practice gains. The effect was still present after excluding individuals with a history of cardiovascular diseases. The effects of cognitive change were not moderated by any other covariates. This report underscores the importance of addressing synergistic effects in normal cognitive aging, as the addition thereof may place healthy individuals at greater risk for memory decline.

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Very few studies have defined trajectories of smoking. In the present study, we modeled growth in adolescent smoking and empirically identified prototypical trajectories. We conceptualized escalation of smoking as a growth process and modeled rates of change and heterogeneity of these patterns using latent growth mixture modeling. The analysis identified six trajectories with low ambiguity about group membership (early rapid escalators, late rapid escalators, late moderate escalators, late slow escalators-smokers, stable puffers, and late slow escalators-puffers). A trajectory of quitters was not identified. We also examined predictors of the smoking trajectories. The predictors were assessed across the adolescent years and included variables related to smoking and other substance use, as well as a range of variables related to sociodemographic factors and mental health. Observed change in the pattern of predictors across age has implications for the mechanism of effect of these variables in relation to smoking trajectories, including predictors that differentiated among daily smokers, variables that may determine the trajectory (e.g., friends smoking), and variables that may result from the trajectory (e.g., marijuana use, less attachment to friends).

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An increasingly older population will most likely lead to greater demands on the health care system, as older age is associated with an increased risk of having acute and chronic conditions. The number of diseases or disabilities is not the only marker of the amount of health care utilized, as persons may seek hospitalization without a disease and/or illness that requires hospital healthcare. Hospitalization may pose a severe risk to older persons, as exposure to the hospital environment may lead to increased risks of iatrogenic disorders, confusion, falls and nosocomial infections, i.e., disorders that may involve unnecessary suffering and lead to serious consequences. Aims: The overall aim of this thesis was to describe and explore individual trajectories of cognitive development in relation to hospitalization and risk factors for hospitalization among older persons living in different accommodations in Sweden and to explore older persons' reasons for being transferred to a hospital. Methods: The study designs were longitudinal, prospective and descriptive, and both quantitative and qualitative methods were used. Specifically, latent growth curve modelling was used to assess the association of cognitive development with hospitalization. The Cox proportional hazards regression model was used to analyse factors associated with hospitalization risk overtime. In addition, an explorative descriptive design was used to explore how home health care patients experienced and perceived their decision to seek hospital care. Results: The most common reasons for hospitalization were cardiovascular diseases, which caused more than one-quarter of first hospitalizations among the persons living in ordinary housing and nursing home residents (NHRs). The persons who had been hospitalized had a lower mean level of cognitive performance in general cognition, verbal, spatial/fluid, memory and processing speed abilities compared to those who had not been hospitalized. Significantly steeper declines in general cognition, spatial/fluid and processing speed abilities were observed among the persons who had been hospitalized. Cox proportional hazards regression analysis showed that the number of diseases, number of drugs used, having experienced a fall and being assessed as malnourished according to the Mini Nutritional Assessment scale were related to an increased hospitalization risk among the NHRs. Among the older persons living in ordinary housing, the risk factors for hospitalization were related to marital status, i.e., unmarried persons and widows/widowers had a decreased hospitalization risk. In addition, among social factors, receipt of support from relatives was related to an increased hospitalization risk, while receipt of support from friends was related to a decreased risk. The number of illnesses was not associated with the hospitalization risk for older persons in any age group or for those of either sex, when controlling for other variables. The older persons who received home health care described different reasons for their decisions to seek hospital care. The underlying theme of the home health care patients’ perceptions of their transfer to a hospital involved trust in hospitals. This trust was shared by the home health care patients, their relatives and the home health care staff, according to the patients. Conclusions: This thesis revealed that middle-aged and older persons who had been hospitalized exhibited a steeper decline in cognition. Specifically, spatial/fluid, processing speed, and general cognitive abilities were affected. The steeper decline in cognition among those who had been hospitalized remained even after controlling for comorbidities. The most common causes of hospitalization among the older persons living in ordinary housing and in nursing homes were cardiovascular diseases, tumours and falls. Not only health-related factors, such as the number of diseases, number of drugs used, and being assessed as malnourished, but also social factors and marital status were related to the hospitalization risk among the older persons living in ordinary housing and in nursing homes. Some risk factors associated with hospitalization differed not only between the men and women but also among the different age groups. The information provided in this thesis could be applied in care settings by professionals who interact with older persons before they decide to seek hospital care. To meet the needs of an older population, health care systems need to offer the proper health care at the most appropriate level, and they need to increase integration and coordination among health care delivered by different care services.

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In this study, relations among students’ perceptions of instrumental help/support from their teachers and their reading and math ability beliefs, subjective task values, and academic grades, were explored from elementary through high school. These relations were examined in an overall sample of 1,062 students from the Childhood and Beyond (CAB) study dataset, a cohort-sequential study that followed students from elementary to high school and beyond. Multi-group structural equation model (SEM) analyses were used to explore these relations in adjacent grade pairs (e.g., second grade to third grade) in elementary school and from middle school through high school separately for males and females. In addition, multi-group latent growth curve (LGC) analyses were used to explore the associations among change in the variables of interest from middle school through high school separately for males and females. The results showed that students’ perceptions of instrumental help from teachers significantly positively predicted: (a) students’ math ability beliefs and reading and math task values in elementary school within the same grade for both girls and boys, and (b) students’ reading and math ability beliefs, reading and math task values, and GPA in middle and high school within the same grade for both girls and boys. Overall, students’ perceptions of instrumental help from teachers more consistently predicted ability beliefs and task values in the academic domain of math than in the academic domain of reading. Although there were some statistically significant differences in the models for girls and boys, the direction and strength of the relations in the models were generally similar for both girls and boys. The implications for these findings and suggestions for future research are discussed.

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The growth of red sea urchins (Strongylocentrotus franciscanus) was modeled by using tag-recapture data from northern California. Red sea urchins (n=211) ranging in test diameter from 7 to 131 mm were examined for changes in size over one year. We used the function Jt+1 = Jt + f(Jt) to model growth, in which Jt is the jaw size (mm) at tagging, and Jt+1 is the jaw size one year later. The function f(Jt), represents one of six deterministic models: logistic dose response, Gaussian, Tanaka, Ricker, Richards, and von Bertalanffy with 3, 3, 3, 2, 3, and 2 minimization parameters, respectively. We found that three measures of goodness of fi t ranked the models similarly, in the order given. The results from these six models indicate that red sea urchins are slow growing animals (mean of 7.2 ±1.3 years to enter the fishery). We show that poor model selection or data from a limited range of urchin sizes (or both) produces erroneous growth parameter estimates and years-to-fishery estimates. Individual variation in growth dominated spatial variation at shallow and deep sites (F=0.246, n=199, P=0.62). We summarize the six models using a composite growth curve of jaw size, J, as a function of time, t: J = A(B – e–Ct) + Dt, in which each model is distinguished by the constants A, B, C, and D. We suggest that this composite model has the flexibility of the other six models and could be broadly applied. Given the robustness of our results regarding the number of years to enter the fishery, this information could be incorporated into future fishery management plans for red sea urchins in northern California.

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Based on the literature data from HT-29 cell monolayers, we develop a model for its growth, analogous to an epidemic model, mixing local and global interactions. First, we propose and solve a deterministic equation for the progress of these colonies. Thus, we add a stochastic (local) interaction and simulate the evolution of an Eden-like aggregate by using dynamical Monte Carlo methods. The growth curves of both deterministic and stochastic models are in excellent agreement with the experimental observations. The waiting times distributions, generated via our stochastic model, allowed us to analyze the role of mesoscopic events. We obtain log-normal distributions in the initial stages of the growth and Gaussians at long times. We interpret these outcomes in the light of cellular division events: in the early stages, the phenomena are dependent each other in a multiplicative geometric-based process, and they are independent at long times. We conclude that the main ingredients for a good minimalist model of tumor growth, at mesoscopic level, are intrinsic cooperative mechanisms and competitive search for space. © 2013 Elsevier Ltd.

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OBJECTIVE: To examine the associations between attention-deficit/hyperactivity disorder (ADHD) symptoms, obesity and hypertension in young adults in a large population-based cohort. DESIGN, SETTING AND PARTICIPANTS: The study population consisted of 15,197 respondents from the National Longitudinal Study of Adolescent Health, a nationally representative sample of adolescents followed from 1995 to 2009 in the United States. Multinomial logistic and logistic models examined the odds of overweight, obesity and hypertension in adulthood in relation to retrospectively reported ADHD symptoms. Latent curve modeling was used to assess the association between symptoms and naturally occurring changes in body mass index (BMI) from adolescence to adulthood. RESULTS: Linear association was identified between the number of inattentive (IN) and hyperactive/impulsive (HI) symptoms and waist circumference, BMI, diastolic blood pressure and systolic blood pressure (all P-values for trend <0.05). Controlling for demographic variables, physical activity, alcohol use, smoking and depressive symptoms, those with three or more HI or IN symptoms had the highest odds of obesity (HI 3+, odds ratio (OR)=1.50, 95% confidence interval (CI) = 1.22-2.83; IN 3+, OR = 1.21, 95% CI = 1.02-1.44) compared with those with no HI or IN symptoms. HI symptoms at the 3+ level were significantly associated with a higher OR of hypertension (HI 3+, OR = 1.24, 95% CI = 1.01-1.51; HI continuous, OR = 1.04, 95% CI = 1.00-1.09), but associations were nonsignificant when models were adjusted for BMI. Latent growth modeling results indicated that compared with those reporting no HI or IN symptoms, those reporting 3 or more symptoms had higher initial levels of BMI during adolescence. Only HI symptoms were associated with change in BMI. CONCLUSION: Self-reported ADHD symptoms were associated with adult BMI and change in BMI from adolescence to adulthood, providing further evidence of a link between ADHD symptoms and obesity.