The big five personality traits and individual job performance growth trajectories in maintenance and transitional job stages.

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Thoresen, Carl J; Bradley, Jill C; Bliese, Paul D; Thoresen, Joseph D

2004-10-01

This study extends the literature on personality and job performance through the use of random coefficient modeling to test the validity of the Big Five personality traits in predicting overall sales performance and sales performance trajectories--or systematic patterns of performance growth--in 2 samples of pharmaceutical sales representatives at maintenance and transitional job stages (K. R. Murphy, 1989). In the maintenance sample, conscientiousness and extraversion were positively associated with between-person differences in total sales, whereas only conscientiousness predicted performance growth. In the transitional sample, agreeableness and openness to experience predicted overall performance differences and performance trends. All effects remained significant with job tenure statistically controlled. Possible explanations for these findings are offered, and theoretical and practical implications of findings are discussed. (c) 2004 APA, all rights reserved

Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood

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Nora Wiium

2015-10-01

Full Text Available Based on nine waves of data collected during a period of 17 years (1990–2007, the present study explored different developmental trajectories of the following unhealthy behaviors: regular smoking, lack of regular exercise, lack of daily fruit intake, and drunkenness. A baseline sample of 1195 13-year-old pupils was from 22 randomly selected schools in the Hordaland County in western Norway. Latent class growth analysis revealed three developmental trajectories. The first trajectory was a conventional trajectory, comprising 36.3% of participants, who showed changes in smoking, physical exercise, fruit intake, and drunkenness consistent with the prevailing age specific norms of these behaviors in the Norwegian society at the time. The second trajectory was a passive trajectory, comprising 25.5% of participants, who reported low levels of both healthy and unhealthy behaviors during the 17-year period. The third trajectory was an unhealthy trajectory, comprising 38.2% of participants, who had high levels of unhealthy behaviors over time. Several covariates were examined, but only sex and mother’s and father’s educational levels were found to be significantly associated with the identified trajectories. While these findings need to be replicated in future studies, the identification of the different trajectories suggests the need to tailor intervention according to specific needs.

Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood

Science.gov (United States)

Wiium, Nora; Breivik, Kyrre; Wold, Bente

2015-01-01

Based on nine waves of data collected during a period of 17 years (1990–2007), the present study explored different developmental trajectories of the following unhealthy behaviors: regular smoking, lack of regular exercise, lack of daily fruit intake, and drunkenness. A baseline sample of 1195 13-year-old pupils was from 22 randomly selected schools in the Hordaland County in western Norway. Latent class growth analysis revealed three developmental trajectories. The first trajectory was a conventional trajectory, comprising 36.3% of participants, who showed changes in smoking, physical exercise, fruit intake, and drunkenness consistent with the prevailing age specific norms of these behaviors in the Norwegian society at the time. The second trajectory was a passive trajectory, comprising 25.5% of participants, who reported low levels of both healthy and unhealthy behaviors during the 17-year period. The third trajectory was an unhealthy trajectory, comprising 38.2% of participants, who had high levels of unhealthy behaviors over time. Several covariates were examined, but only sex and mother’s and father’s educational levels were found to be significantly associated with the identified trajectories. While these findings need to be replicated in future studies, the identification of the different trajectories suggests the need to tailor intervention according to specific needs. PMID:26516889

Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood.

Science.gov (United States)

Wiium, Nora; Breivik, Kyrre; Wold, Bente

2015-10-28

Based on nine waves of data collected during a period of 17 years (1990-2007), the present study explored different developmental trajectories of the following unhealthy behaviors: regular smoking, lack of regular exercise, lack of daily fruit intake, and drunkenness. A baseline sample of 1195 13-year-old pupils was from 22 randomly selected schools in the Hordaland County in western Norway. Latent class growth analysis revealed three developmental trajectories. The first trajectory was a conventional trajectory, comprising 36.3% of participants, who showed changes in smoking, physical exercise, fruit intake, and drunkenness consistent with the prevailing age specific norms of these behaviors in the Norwegian society at the time. The second trajectory was a passive trajectory, comprising 25.5% of participants, who reported low levels of both healthy and unhealthy behaviors during the 17-year period. The third trajectory was an unhealthy trajectory, comprising 38.2% of participants, who had high levels of unhealthy behaviors over time. Several covariates were examined, but only sex and mother's and father's educational levels were found to be significantly associated with the identified trajectories. While these findings need to be replicated in future studies, the identification of the different trajectories suggests the need to tailor intervention according to specific needs.

Individual- and community-level correlates of cigarette-smoking trajectories from age 13 to 32 in a U.S. population-based sample.

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Fuemmeler, Bernard; Lee, Chien-Ti; Ranby, Krista W; Clark, Trenette; McClernon, F Joseph; Yang, Chongming; Kollins, Scott H

2013-09-01

Characterizing smoking behavior is important for informing etiologic models and targeting prevention efforts. This study explored the effects of both individual- and community-level variables in predicting cigarette use vs. non-use and level of use among adolescents as they transition into adulthood. Data on 14,779 youths (53% female) were drawn from the National Longitudinal Study of Adolescent Health (Add Health); a nationally representative longitudinal cohort. A cohort sequential design allowed for examining trajectories of smoking typologies from age 13 to 32 years. Smoking trajectories were evaluated by using a zero-inflated Poisson (ZIP) latent growth analysis and latent class growth analysis modeling approach. Significant relationships emerged between both individual- and community-level variables and smoking outcomes. Maternal and peer smoking predicted increases in smoking over development and were associated with a greater likelihood of belonging to any of the four identified smoking groups versus Non-Users. Conduct problems and depressive symptoms during adolescence were related to cigarette use versus non-use. State-level prevalence of adolescent smoking was related to greater cigarette use during adolescence. Individual- and community-level variables that distinguish smoking patterns within the population aid in understanding cigarette use versus non-use and the quantity of cigarette use into adulthood. Our findings suggest that efforts to prevent cigarette use would benefit from attention to both parental and peer smoking and individual well-being. Future work is needed to better understand the role of variables in the context of multiple levels (individual and community-level) on smoking trajectories. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

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Simone Vincenzi

2014-09-01

Full Text Available The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth and L∞ (asymptotic size. Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC, the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

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Vincenzi, Simone; Mangel, Marc; Crivelli, Alain J; Munch, Stephan; Skaug, Hans J

2014-09-01

The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups) determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth) and L∞ (asymptotic size). Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC), the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

Modeling Math Growth Trajectory--An Application of Conventional Growth Curve Model and Growth Mixture Model to ECLS K-5 Data

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Lu, Yi

2016-01-01

To model students' math growth trajectory, three conventional growth curve models and three growth mixture models are applied to the Early Childhood Longitudinal Study Kindergarten-Fifth grade (ECLS K-5) dataset in this study. The results of conventional growth curve model show gender differences on math IRT scores. When holding socio-economic…

Impact of childhood asthma on growth trajectories in early adolescence: Findings from the Childhood Asthma Prevention Study (CAPS).

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Movin, Maria; Garden, Frances L; Protudjer, Jennifer L P; Ullemar, Vilhelmina; Svensdotter, Frida; Andersson, David; Kruse, Andreas; Cowell, Chris T; Toelle, Brett G; Marks, Guy B; Almqvist, Catarina

2017-04-01

Understanding the associations between childhood asthma and growth in early adolescence by accounting for the heterogeneity of growth during puberty has been largely unexplored. The objective was to identify sex-specific classes of growth trajectories during early adolescence, using a method which takes the heterogeneity of growth into account and to evaluate the association between childhood asthma and different classes of growth trajectories in adolescence. Our longitudinal study included participants with a family history of asthma born during 1997-1999 in Sydney, Australia. Hence, all participants were at high risk for asthma. Asthma status was ascertained at 8 years of age using data from questionnaires and lung function tests. Growth trajectories between 11 and 14 years of age were classified using a latent basis growth mixture model. Multinomial regression analyses were used to evaluate the association between asthma and the categorized classes of growth trajectories. In total, 316 participants (51.6% boys), representing 51.3% of the entire cohort, were included. Sex-specific classes of growth trajectories were defined. Among boys, asthma was not associated with the classes of growth trajectories. Girls with asthma were more likely than girls without asthma to belong to a class with later growth (OR: 3.79, 95% CI: 1.33, 10.84). Excluding participants using inhaled corticosteroids or adjusting for confounders did not significantly change the results for either sex. We identified sex-specific heterogeneous classes of growth using growth mixture modelling. Associations between childhood asthma and different classes of growth trajectories were found for girls only. © 2016 Asian Pacific Society of Respirology.

Trajectories of Marijuana Use from Adolescence into Adulthood: Environmental and Individual Correlates

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Epstein, Marina; Hill, Karl G.; Nevell, Alyssa M.; Guttmannova, Katarina; Bailey, Jennifer A.; Abbott, Robert D.; Kosterman, Rick; Hawkins, J. David

2015-01-01

This study sought to identify trajectories of marijuana use in the Seattle Social Development Project (n = 808) sample from age 14 through 30, and to examine the extent to which individuals in these trajectories differed in their substance use problems, mental health, problem behavior, economic outcomes, and positive functioning at age 33. In…

Forecasting craniofacial growth in individuals with class III malocclusion by computational modelling.

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Auconi, Pietro; Scazzocchio, Marco; Defraia, Efisio; McNamara, James A; Franchi, Lorenzo

2014-04-01

To develop a mathematical model that adequately represented the pattern of craniofacial growth in class III subject consistently, with the goal of using this information to make growth predictions that could be amenable to longitudinal verification and clinical use. A combination of computational techniques (i.e. Fuzzy clustering and Network analysis) was applied to cephalometric data derived from 429 untreated growing female patients with class III malocclusion to visualize craniofacial growth dynamics and correlations. Four age groups of subjects were examined individually: from 7 to 9 years of age, from 10 to 12 years, from 13 to 14 years, and from 15 to 17 years. The connections between pathway components of class III craniofacial growth can be visualized from Network profiles. Fuzzy clustering analysis was able to define further growth patterns and coherences of the traditionally reported dentoskeletal characteristics of this structural imbalance. Craniofacial growth can be visualized as a biological, space-constraint-based optimization process; the prediction of individual growth trajectories depends on the rate of membership to a specific 'winner' cluster, i.e. on a specific individual growth strategy. The reliability of the information thus gained was tested to forecast craniofacial growth of 28 untreated female class III subjects followed longitudinally. The combination of Fuzzy clustering and Network algorithms allowed the development of principles for combining multiple auxological cephalometric features into a joint global model and to predict the individual risk of the facial pattern imbalance during growth.

Identification of individual coherent sets associated with flow trajectories using Coherent Structure Coloring

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Schlueter-Kuck, Kristy; Dabiri, John

2017-11-01

In recent years, there has been a proliferation of techniques that aim to characterize fluid flow kinematics on the basis of Lagrangian trajectories of collections of tracer particles. Most of these techniques depend on presence of tracer particles that are initially closely-spaced, in order to compute local gradients of their trajectories. In many applications, the requirement of close tracer spacing cannot be satisfied, especially when the tracers are naturally occurring and their distribution is dictated by the underlying flow. Moreover, current methods often focus on determination of the boundaries of coherent sets, whereas in practice it is often valuable to identify the complete set of trajectories that are coherent with an individual trajectory of interest. We extend the concept of Coherent Structure Coloring to achieve identification of the coherent set associated with individual Lagrangian trajectories. This algorithm is proven successful in identifying coherent structures of varying complexities in canonical unsteady flows. Importantly, although the method is demonstrated here in the context of fluid flow kinematics, the generality of the approach allows for its potential application to other unsupervised clustering problems in dynamical systems. This work was supported by the Department of Defense (DoD) through the National Defense Science & Engineering Graduate Fellowship (NDSEG) Program.

Effect of Helicobacter pylori infection on growth trajectories in young Ethiopian children: a longitudinal study

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Bineyam Taye

2016-09-01

Conclusions: These findings add to the growing body of evidence supporting that H. pylori infection is inversely associated with childhood growth trajectory, after controlling for a range of factors associated with reduced growth and H. pylori status. Further follow-up will be important to confirm possible catch-up in height trajectory among H. pylori-infected children as they grow older.

A millennium of north-east Atlantic cod juvenile growth trajectories inferred from archaeological otoliths.

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Guðbjörg Ásta Ólafsdóttir

Full Text Available Archaeological excavations of historical fishing sites across the North Atlantic have recovered high quantities of Atlantic cod (Gadus morhua bones. In the current study we use Atlantic cod otoliths from archaeological excavations of a historical fishing sites in north-west Iceland, dated to AD 970 -AD 1910 to examine historical growth trajectories of cod. No large scale growth variations or shifts in growth patterns were observed in the current chronologies, supporting the stability of historical Atlantic cod growth trajectories. The most significant variation in growth patterns was consistent with those that have been observed in recent times, for example, reduced early juvenile growth during periods of colder ocean temperature. The current results represent a high resolution chronological record of north-east Atlantic cod growth, greatly increasing the prior temporal range of such data, thereby providing a valuable baseline for a broad range of studies on Atlantic cod growth.

Developmental Growth Trajectories in Understanding of Fraction Magnitude from Fourth through Sixth Grade

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Resnick, Ilyse; Jordan, Nancy C.; Hansen, Nicole; Rajan, Vinaya; Rodrigues, Jessica; Siegler, Robert S.; Fuchs, Lynn S.

2016-01-01

Development of fraction number line estimation was assessed longitudinally over 5 time points between 4th and 6th grades. Although students showed positive linear growth overall, latent class growth analyses revealed 3 distinct growth trajectory classes: Students who were highly accurate from the start and became even more accurate (n = 154);…

On the proposed new funding framework - a trajectory for growth or ...

African Journals Online (AJOL)

In essence, the funding framework although advocating a new trajectory towards sustainable growth, paradoxically appears to lead historically disadvantaged technikons towards negative entropy. This article explores the implications of the proposed funding mechanism on technikon research outputs and highlights the ...

Linear spline multilevel models for summarising childhood growth trajectories: A guide to their application using examples from five birth cohorts.

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Howe, Laura D; Tilling, Kate; Matijasevich, Alicia; Petherick, Emily S; Santos, Ana Cristina; Fairley, Lesley; Wright, John; Santos, Iná S; Barros, Aluísio Jd; Martin, Richard M; Kramer, Michael S; Bogdanovich, Natalia; Matush, Lidia; Barros, Henrique; Lawlor, Debbie A

2016-10-01

Childhood growth is of interest in medical research concerned with determinants and consequences of variation from healthy growth and development. Linear spline multilevel modelling is a useful approach for deriving individual summary measures of growth, which overcomes several data issues (co-linearity of repeat measures, the requirement for all individuals to be measured at the same ages and bias due to missing data). Here, we outline the application of this methodology to model individual trajectories of length/height and weight, drawing on examples from five cohorts from different generations and different geographical regions with varying levels of economic development. We describe the unique features of the data within each cohort that have implications for the application of linear spline multilevel models, for example, differences in the density and inter-individual variation in measurement occasions, and multiple sources of measurement with varying measurement error. After providing example Stata syntax and a suggested workflow for the implementation of linear spline multilevel models, we conclude with a discussion of the advantages and disadvantages of the linear spline approach compared with other growth modelling methods such as fractional polynomials, more complex spline functions and other non-linear models. © The Author(s) 2013.

Adolescent Trajectories of Aerobic Fitness and Adiposity as Markers of Cardiometabolic Risk in Adulthood.

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Jackowski, S A; Eisenmann, J C; Sherar, L B; Bailey, D A; Baxter-Jones, A D G

2017-01-01

The aim of this study was to investigate whether adolescent growth trajectories of aerobic fitness and adiposity were associated with mid-adulthood cardiometabolic risk (CMR). Participants were drawn from the Saskatchewan Growth and Development Study (1963-1973). Adolescent growth trajectories for maximal aerobic capacity (absolute VO 2 (AbsVO 2 )), skinfolds (SF), representing total body (Sum6SF) and central adiposity (TrunkSF), and body mass index (BMI) were determined from 7 to 17 years of age. In mid-adulthood (40 to 50 years of age), 61 individuals (23 females) returned for follow-ups. A CMR score was calculated to group participants as displaying either high or a low CMR. Multilevel hierarchical models were constructed, comparing the adolescent growth trajectories of AbsVO 2, Sum6SF, TrunkSF, and BMI between CMR groupings. There were no significant differences in the adolescent development of AbsVO 2, Sum6SF, TrunkSF, and BMI between adult CMR groupings ( p > 0.05). Individuals with high CMR accrued 62% greater adjusted total body fat percentage from adolescence to adulthood ( p =0.03). Growth trajectories of adolescent aerobic fitness and adiposity do not appear to be associated with mid-adulthood CMR. Individuals should be encouraged to participate in behaviours that promote healthy aerobic fitness and adiposity levels throughout life to reduce lifelong CMR.

Adolescent Trajectories of Aerobic Fitness and Adiposity as Markers of Cardiometabolic Risk in Adulthood

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S. A. Jackowski

2017-01-01

Full Text Available Purpose. The aim of this study was to investigate whether adolescent growth trajectories of aerobic fitness and adiposity were associated with mid-adulthood cardiometabolic risk (CMR. Methods. Participants were drawn from the Saskatchewan Growth and Development Study (1963–1973. Adolescent growth trajectories for maximal aerobic capacity (absolute VO2 (AbsVO2, skinfolds (SF, representing total body (Sum6SF and central adiposity (TrunkSF, and body mass index (BMI were determined from 7 to 17 years of age. In mid-adulthood (40 to 50 years of age, 61 individuals (23 females returned for follow-ups. A CMR score was calculated to group participants as displaying either high or a low CMR. Multilevel hierarchical models were constructed, comparing the adolescent growth trajectories of AbsVO2, Sum6SF, TrunkSF, and BMI between CMR groupings. Results. There were no significant differences in the adolescent development of AbsVO2, Sum6SF, TrunkSF, and BMI between adult CMR groupings (p>0.05. Individuals with high CMR accrued 62% greater adjusted total body fat percentage from adolescence to adulthood (p=0.03. Conclusions. Growth trajectories of adolescent aerobic fitness and adiposity do not appear to be associated with mid-adulthood CMR. Individuals should be encouraged to participate in behaviours that promote healthy aerobic fitness and adiposity levels throughout life to reduce lifelong CMR.

Growth trajectories of the human embryonic head and periconceptional maternal conditions.

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Koning, I V; Baken, L; Groenenberg, I A L; Husen, S C; Dudink, J; Willemsen, S P; Gijtenbeek, M; Koning, A H J; Reiss, I K M; Steegers, E A P; Steegers-Theunissen, R P M

2016-05-01

Can growth trajectories of the human embryonic head be created using 3D ultrasound (3D-US) and virtual reality (VR) technology, and be associated with second trimester fetal head size and periconceptional maternal conditions? Serial first trimester head circumference (HC) and head volume (HV) measurements were used to create reliable growth trajectories of the embryonic head, which were significantly associated with fetal head size and periconceptional maternal smoking, age and ITALIC! in vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) treatment. Fetal growth is influenced by periconceptional maternal conditions. We selected 149 singleton pregnancies with a live born non-malformed fetus from the Rotterdam periconception cohort. Bi-parietal diameter and occipital frontal diameter to calculate HC, HV and crown-rump length (CRL) were measured weekly between 9 + 0 and 12 + 6 weeks gestational age (GA) using 3D-US and VR. Fetal HC was obtained from second trimester structural anomaly scans. Growth trajectories of the embryonic head were created with general additive models and linear mixed models were used to estimate associations with maternal periconceptional conditions as a function of GA and CRL, respectively. A total of 303 3D-US images of 149 pregnancies were eligible for embryonic head measurements (intra-class correlation coefficients >0.99). Associations were found between embryonic HC and fetal HC ( ITALIC! ρ = 0.617, ITALIC! P head measured by HC and HV (All ITALIC! P head may be of benefit in future early antenatal care. This study was funded by the Department of Obstetrics and Gynaecology, Erasmus MC University Medical Centre and Sophia Foundation for Medical Research, Rotterdam, The Netherlands (SSWO grant number 644). No competing interests are declared. © The Author 2016. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email

Growth Trajectories of Exercise Self-Efficacy in Older Adults: Influence of Measures and Initial Status

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McAuley, Edward; Mailey, Emily L.; Mullen, Sean P.; Szabo, Amanda N.; Wójcicki, Thomas R.; White, Siobhan M.; Gothe, Neha; Olson, Erin A.; Kramer, Arthur F.

2012-01-01

Objective This study examines differential trajectories of exercise-related self-efficacy beliefs across a 12-month randomized controlled exercise trial. Methods Previously inactive older adults (N = 144; M age = 66.5) were randomly assigned to one of two exercise conditions (walking, flexibility-toning-balance) and completed measures of barriers self-efficacy (BARSE), exercise self-efficacy (EXSE), and self-efficacy for walking (SEW) across a 12-month period. Changes in efficacy were examined according to efficacy type and inter-individual differences. Latent growth curve modeling was employed to (a) examine average levels and change in each type of efficacy for the collapsed sample and by intervention condition, and (b) explore subpopulations (i.e., latent classes) within the sample that differ in their baseline efficacy and trajectory. Results Analyses revealed two negative trends in BARSE and EXSE at predicted transition points, in addition to a positive linear trend in SEW. Two subgroups with unique baseline efficacy and trajectory profiles were also identified. Conclusions These results shed new light on the relationship between exercise and self-efficacy in older adults, and highlight the need for strategies for increasing and maintaining efficacy within interventions, namely targeting participants who start with a disadvantage (lower efficacy) and integrating efficacy-boosting strategies for all participants prior to program end. PMID:21038962

Perinatal programming of childhood asthma: early fetal size, growth trajectory during infancy, and childhood asthma outcomes.

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Turner, Steve

2012-01-01

The "fetal origins hypothesis" or concept of "developmental programming" suggests that faltering fetal growth and subsequent catch-up growth are implicated in the aetiology of cardiovascular disease. Associations between reduced birth weight, rapid postnatal weight gain, and asthma suggest that there are fetal origins to respiratory disease. The present paper first summarises the literature relating birth weight and post natal growth trajectories to asthma outcomes. Second, issues regarding the interpretation of antenatal fetal ultrasound measurements are discussed. Finally, recent reports linking antenatal measurement and growth trajectory to early childhood asthma outcomes are discussed. Understanding the nature and timing of factors which influence antenatal growth may give important insight into the antecedents of early-onset asthma with implications for interventions.

The Impact of Race and Socioeconomic Status on the Reading Comprehension Growth Trajectories of Adolescents

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Pickens, Tyra W.

2016-01-01

The purpose of the current study was to examine features of adolescent reading comprehension trajectories and make within-person and between-person analyses of growth that occurs during the high school grades. Racial and socioeconomic group differences of the adolescent reading trajectories were also investigated and compared. This examination…

NAVIGATION AIDS AS TOOLS TO SUPPORT THE DEVELOPMENT OF COMPETENCES IN THE CONDITIONS OF REALIZATION OF INDIVIDUAL EDUCATIONAL TRAJECTORY

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E. F. Zeer

2017-01-01

Full Text Available Introduction. Continuing education or «education through all life» is required of the person by modern realities of the information, quickly changing society; thus, continuing education is carried out on a development trajectory, individual for each person. Maintenance of such educational process needs effective tools. The relevance of its development caused the research presented in the publication.The aim is to show the possibilities of navigation aids during realization of individual routes of the training conforming to federal state educational standards and considering the purposes and interests of each separately taken personality.Methodology and research methods. The leading methodological basis is personality-oriented approach in the implementation of individual educational trajectory. Logical-pedagogical analysis of students’ individual educational trajectory progress is used.Results and scientific novelty. The interrelation of the concepts «individual educational trajectory» and «individual educational route» is revealed. The conceptual model of maintenance of an individual educational trajectory as a set of reference points of mastering of competences necessary for the expert is offered. Navigators of educational process and cases of individual educational achievements assessment act as didactic means in model. It is shown whence application of components of models allows to: organize the professional orientation actions more effectively; exercise entrance control of knowledge prior to training; control actions during vocational training; correlate an individual trajectory of training to the standard; have a guide when studying disciplines of various cycles, when passing educational and production training, protection of final qualification work; finally, it is possible for a pupil to carry out self-estimation of the acquired competences.Practical significance. The materials of the present publication will be useful to

Perinatal Programming of Childhood Asthma: Early Fetal Size, Growth Trajectory during Infancy, and Childhood Asthma Outcomes

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Steve Turner

2012-01-01

Full Text Available The “fetal origins hypothesis” or concept of “developmental programming” suggests that faltering fetal growth and subsequent catch-up growth are implicated in the aetiology of cardiovascular disease. Associations between reduced birth weight, rapid postnatal weight gain, and asthma suggest that there are fetal origins to respiratory disease. The present paper first summarises the literature relating birth weight and post natal growth trajectories to asthma outcomes. Second, issues regarding the interpretation of antenatal fetal ultrasound measurements are discussed. Finally, recent reports linking antenatal measurement and growth trajectory to early childhood asthma outcomes are discussed. Understanding the nature and timing of factors which influence antenatal growth may give important insight into the antecedents of early-onset asthma with implications for interventions.

Identification of individual coherent sets associated with flow trajectories using coherent structure coloring

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Schlueter-Kuck, Kristy L.; Dabiri, John O.

2017-09-01

We present a method for identifying the coherent structures associated with individual Lagrangian flow trajectories even where only sparse particle trajectory data are available. The method, based on techniques in spectral graph theory, uses the Coherent Structure Coloring vector and associated eigenvectors to analyze the distance in higher-dimensional eigenspace between a selected reference trajectory and other tracer trajectories in the flow. By analyzing this distance metric in a hierarchical clustering, the coherent structure of which the reference particle is a member can be identified. This algorithm is proven successful in identifying coherent structures of varying complexities in canonical unsteady flows. Additionally, the method is able to assess the relative coherence of the associated structure in comparison to the surrounding flow. Although the method is demonstrated here in the context of fluid flow kinematics, the generality of the approach allows for its potential application to other unsupervised clustering problems in dynamical systems such as neuronal activity, gene expression, or social networks.

Early Childhood Memory and Attention as Predictors of Academic Growth Trajectories

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Stipek, Deborah; Valentino, Rachel A.

2015-01-01

Longitudinal data from the children of the National Longitudinal Survey of Youth (NLSY) were used to assess how well measures of short-term and working memory and attention in early childhood predicted longitudinal growth trajectories in mathematics and reading comprehension. Analyses also examined whether changes in memory and attention were more…

Helical growth trajectories in plant roots interacting with stiff barriers

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Gerbode, Sharon; Noar, Roslyn; Harrison, Maria

2009-03-01

Plant roots successfully navigate heterogeneous soil environments with varying nutrient and water concentrations, as well as a variety of stiff obstacles. While it is thought that the ability of roots to penetrate into a stiff lower soil layer is important for soil erosion, little is known about how a root actually responds to a rigid interface. We have developed a laser sheet imaging technique for recording the 3D growth dynamics of plant roots interacting with stiff barriers. We find that a root encountering an angled interface does not grow in a straight line along the surface, but instead follows a helical trajectory. These experiments build on the pioneering studies of roots grown on a tilted 2D surface, which reported ``root waving,'' a similar curved pattern thought to be caused by the root's sensitivity to both gravity and the rigid surface on which it is grown. Our measurements extend these results to the more physiologically relevant case of 3D growth, where the spiral trajectory can be altered by tuning the relative strengths of the gravity and touch stimuli, providing some intuition for the physical mechanism driving it.

Histories of poverty and self-rated health trajectories.

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McDonough, Peggy; Berglund, Pat

2003-06-01

This paper investigates the dynamic relationship between poverty histories and self-rated health trajectories. We are interested in patterns of change in individuals' health over time and the ways in which such patterns are structured by continuity and change in poverty experiences. Data, collected for adults aged 25 and older in 1984 (N = 7,258), are from the 1968-1996 annual waves of Panel Study of Income Dynamics (PSID). Individual growth curves allow us to investigate health trajectories as continuous processes, as well as individual and group heterogeneity in these trajectories. We find that, on average, health deteriorates slowly over time, but there is significant variation in health in 1984 and the rate at which health declines. Histories of poverty partly accounted for the sources of individual differences in self-rated health in 1984, but they were not related to health change over time. Although increasing incomes were better for self-rated health than falling incomes, current economic circumstances did not erase the health effects of earlier poverty experiences.

Levers for Language Growth: Characteristics and Predictors of Language Trajectories between 4 and 7 Years.

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Cristina McKean

Full Text Available Evidence is required as to when and where to focus resources to achieve the greatest gains for children's language development. Key to these decisions is the understanding of individual differences in children's language trajectories and the predictors of those differences. To determine optimal timing we must understand if and when children's relative language abilities become fixed. To determine where to focus effort we must identify mutable factors, that is those with the potential to be changed through interventions, which are associated with significant differences in children's language scores and rate of progress.Uniquely this study examined individual differences in language growth trajectories in a population sample of children between 4 and 7 years using the multilevel model for change. The influence of predictors, grouped with respect to their mutability and their proximity to the child (least-mutable, mutable-distal, mutable-proximal, were estimated.A significant degree of variability in rate of progress between 4 and 7 years was evident, much of which was systematically associated with mutable-proximal factors, that is, those factors with evidence that they are modifiable through interventions with the child or family, such as shared book reading, TV viewing and number of books in the home. Mutable-distal factors, such as family income, family literacy and neighbourhood disadvantage, hypothesised to be modifiable through social policy, were important predictors of language abilities at 4 years.Potential levers for language interventions lie in the child's home learning environment from birth to age 4. However, the role of a family's material and cultural capital must not be ignored, nor should the potential for growth into the school years. Early Years services should acknowledge the effects of multiple, cascading and cumulative risks and seek to promote child language development through the aggregation of marginal gains in the pre

A MapReduce-Based Parallel Frequent Pattern Growth Algorithm for Spatiotemporal Association Analysis of Mobile Trajectory Big Data

Directory of Open Access Journals (Sweden)

Dawen Xia

2018-01-01

Full Text Available Frequent pattern mining is an effective approach for spatiotemporal association analysis of mobile trajectory big data in data-driven intelligent transportation systems. While existing parallel algorithms have been successfully applied to frequent pattern mining of large-scale trajectory data, two major challenges are how to overcome the inherent defects of Hadoop to cope with taxi trajectory big data including massive small files and how to discover the implicitly spatiotemporal frequent patterns with MapReduce. To conquer these challenges, this paper presents a MapReduce-based Parallel Frequent Pattern growth (MR-PFP algorithm to analyze the spatiotemporal characteristics of taxi operating using large-scale taxi trajectories with massive small file processing strategies on a Hadoop platform. More specifically, we first implement three methods, that is, Hadoop Archives (HAR, CombineFileInputFormat (CFIF, and Sequence Files (SF, to overcome the existing defects of Hadoop and then propose two strategies based on their performance evaluations. Next, we incorporate SF into Frequent Pattern growth (FP-growth algorithm and then implement the optimized FP-growth algorithm on a MapReduce framework. Finally, we analyze the characteristics of taxi operating in both spatial and temporal dimensions by MR-PFP in parallel. The results demonstrate that MR-PFP is superior to existing Parallel FP-growth (PFP algorithm in efficiency and scalability.

Understanding adolescent personality pathology from growth trajectories of childhood oddity.

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De Clercq, Barbara; Verbeke, Lize; De Caluwé, Elien; Vercruysse, Tom; Hofmans, Joeri

2017-10-01

Research on developmental trajectories of early maladaptive features for understanding later personality disorders (PDs) is increasingly recognized as an important study area. The course of early odd features is highly relevant in this regard, as only a few researchers have addressed childhood oddity in the context of emerging PDs. Using latent growth modeling, the current study explores growth parameters of odd features in a mixed sample of Flemish community and referred children (N = 485) across three measurement waves with 1-year time intervals. Personality pathology was assessed at a fourth assessment point in adolescence. Beyond a general declining trend in oddity characteristics, the results demonstrated that both an early onset and an increasing trend of oddity-related characteristics over time are independent predictors of adolescent PDs. Childhood oddity tends to be the most manifest precursor for PDs with a core oddity feature (i.e., the schizotypal and borderline PD), but also appears to predict most of the other DSM-5 PDs. Results are discussed from an overarching developmental framework on PDs (Cicchetti, 2014), specifically focusing on the principle of multifinality. From a clinical perspective, the significance of increasing or steady-high childhood oddity trajectories for adolescent PDs highlights the relevance of systematic screening processes across time.

Sex is associated with differences in individual trajectories of change in social health after implantable cardioverter-defibrillator.

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Lauck, Sandra B; Sawatzky, Richard; Johnson, Joy L; Humphries, Karin; Bennett, Matthew T; Chakrabarti, Santabhanu; Kerr, Charles R; Tung, Stanley; Yeung-Lai-Wah, John A; Ratner, Pamela A

2015-03-01

Social health is a dimension of quality of life, and refers to people's involvement in, and satisfaction with social roles, responsibilities, and activities. The implantable cardioverter-defibrillator is associated with changes in overall quality of life, but little is known about sex differences in individual trajectories of change in social health. We prospectively measured changes in 3 subscales of the SF-36v2 generic health questionnaire (role physical, role emotional, and social functioning), 2 Patient-Reported Outcomes Measurement Information System short forms (satisfaction with participation in social roles and satisfaction with participation in discretionary social activities), and the Florida Patient Acceptance Survey before and at 1, 2, and 6 months after implantation. Individual growth models of temporal change were estimated. The scores of the 6 indicators improved with time. The unconditional model demonstrated significant (fixed effects: Pchange in the scores of 3 of the 6 measures. Although men's mean scores exceeded women's mean scores on all indicators at baseline (range of relative mean difference: 11.0% to 17.8%), the rate of women's change resulted in a reversal in relative standing at 6 months after implantation, with the mean scores of women exceeding the men's by 4.5% to 5.6%. Men and women differed in their trajectories of change in social health, both in terms of their starting points (ie, baseline scores) and their rates of change. © 2015 American Heart Association, Inc.

Structural growth trajectories and rates of change in the first 3 months of infant brain development.

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Holland, Dominic; Chang, Linda; Ernst, Thomas M; Curran, Megan; Buchthal, Steven D; Alicata, Daniel; Skranes, Jon; Johansen, Heather; Hernandez, Antonette; Yamakawa, Robyn; Kuperman, Joshua M; Dale, Anders M

2014-10-01

The very early postnatal period witnesses extraordinary rates of growth, but structural brain development in this period has largely not been explored longitudinally. Such assessment may be key in detecting and treating the earliest signs of neurodevelopmental disorders. To assess structural growth trajectories and rates of change in the whole brain and regions of interest in infants during the first 3 months after birth. Serial structural T1-weighted and/or T2-weighted magnetic resonance images were obtained for 211 time points from 87 healthy term-born or term-equivalent preterm-born infants, aged 2 to 90 days, between October 5, 2007, and June 12, 2013. We segmented whole-brain and multiple subcortical regions of interest using a novel application of Bayesian-based methods. We modeled growth and rate of growth trajectories nonparametrically and assessed left-right asymmetries and sexual dimorphisms. Whole-brain volume at birth was approximately one-third of healthy elderly brain volume, and did not differ significantly between male and female infants (347 388 mm3 and 335 509 mm3, respectively, P = .12). The growth rate was approximately 1%/d, slowing to 0.4%/d by the end of the first 3 months, when the brain reached just more than half of elderly adult brain volume. Overall growth in the first 90 days was 64%. There was a significant age-by-sex effect leading to widening separation in brain sizes with age between male and female infants (with male infants growing faster than females by 200.4 mm3/d, SE = 67.2, P = .003). Longer gestation was associated with larger brain size (2215 mm3/d, SE = 284, P = 4×10-13). The expected brain size of an infant born one week earlier than average was 5% smaller than average; at 90 days it will not have caught up, being 2% smaller than average. The cerebellum grew at the highest rate, more than doubling in 90 days, and the hippocampus grew at the slowest rate, increasing by 47% in 90 days. There was left

Kindergarten Children’s Growth Trajectories in Reading and Mathematics: Who Falls Increasingly Behind?

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Morgan, Paul L.; Farkas, George; Wu, Qiong

2015-01-01

We used a large sample of children (N ≈ 7,400) participating in the Early Childhood Longitudinal Study – Kindergarten Cohort to estimate kindergarten children’s academic achievement growth trajectories in reading and mathematics. We were particularly interested in whether the growth trajectories of children with learning disabilities (LD) or speech language impairments (SLI)—as well as those of other groups of children—were consistent with a cumulative or compensatory developmental cycle. Both LD and SLI children displayed significantly lower levels of kindergarten reading achievement than non-disabled children. However, and over the subsequent five years of elementary school, only children with SLI lagged increasingly behind non-disabled peers in their reading skills growth. We observed a different pattern for mathematics achievement. Children with LD, but not SLI, lagged increasingly behind non-disabled children in their mathematics skills growth. We also observed some consistency in “poor-get-poorer” effects across reading and mathematic achievement for additional population subgroups. Those kindergarten children who were from lower socio-economic status (SES) families, who were African-American, and who more frequently displayed learning-related behaviors problems initially had lower levels of reading and mathematics achievement and also lagged increasingly behind in their acquisition of these skills over time. Some groups of children, including those with SLI, experience a cumulative rather than compensatory cycle of achievement growth. PMID:21856991

Growth trajectories from conception through middle childhood and cognitive achievement at age 8 years: Evidence from four low- and middle-income countries.

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Georgiadis, Andreas; Benny, Liza; Crookston, Benjamin T; Duc, Le Thuc; Hermida, Priscila; Mani, Subha; Woldehanna, Tassew; Stein, Aryeh D; Behrman, Jere R

2016-12-01

Child chronic malnutrition is endemic in low- and middle-income countries and deleterious for child development. Studies investigating the relationship between nutrition at different periods of childhood, as measured by growth in these periods (growth trajectories), and cognitive development have produced mixed evidence. Although an explanation of this has been that different studies use different approaches to model growth trajectories, the differences across approaches are not well understood. Furthermore, little is known about the pathways linking growth trajectories and cognitive achievement. In this paper, we develop and estimate a general path model of the relationship between growth trajectories and cognitive achievement using data on four cohorts from Ethiopia, India, Peru, and Vietnam. The model is used to: a) compare two of the most common approaches of modelling growth trajectories in the literature, namely the lifecourse plot and the conditional body size model, and b) investigate the potential channels via which the association between growth in each period and cognitive achievement manifests. We show that the two approaches are expected to produce systematically different results that have distinct interpretations. Results suggest that growth from conception through age 1 year, between age 1 and 5 years, and between 5 and 8 years are each positively and significantly associated with cognitive achievement at age 8 years and that this may be partly explained by the fact that faster-growing children start school earlier. We also find that a significant share of the association between early growth and later cognitive achievement is mediated through growth in interim periods.

Deep Processing Strategies and Critical Thinking: Developmental Trajectories Using Latent Growth Analyses

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Phan, Huy P.

2011-01-01

The author explored the developmental courses of deep learning approach and critical thinking over a 2-year period. Latent growth curve modeling (LGM) procedures were used to test and trace the trajectories of both theoretical frameworks over time. Participants were 264 (119 women, 145 men) university undergraduates. The Deep Learning subscale of…

Developmental trajectories of the fronto-temporal lobes from infancy to early adulthood in healthy individuals.

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Tanaka, Chiaki; Matsui, Mie; Uematsu, Akiko; Noguchi, Kyo; Miyawaki, Toshio

2012-01-01

Brain development during early life in healthy individuals is rapid and dynamic, indicating that this period plays a very important role in neural and functional development. The frontal and temporal lobes are known to play a particularly important role in cognition. The study of healthy frontal and temporal lobe development in children is therefore of considerable importance. A better understanding of how these brain regions develop could also aid in the diagnosis and treatment of neurodevelopmental disorders. Some developmental studies have used magnetic resonance imaging (MRI) to examine infant brains, but it remains the case that relatively little is known about cortical brain development in the first few years of life. In the present study we examined whole brain, temporal lobe and frontal lobe developmental trajectories from infancy to early adulthood in healthy individuals, considering gender and brain hemisphere differences. We performed a cross-sectional, longitudinal morphometric MRI study of 114 healthy individuals (54 females and 60 males) aged 1 month to 25 years old (mean age ± SD 8.8 ± 6.9). We measured whole brain, temporal and frontal lobe gray matter (GM)/white matter (WM) volumes, following previously used protocols. There were significant non-linear age-related volume changes in all regions. Peak ages of whole brain, temporal lobe and frontal lobe development occurred around pre-adolescence (9-12 years old). GM volumes for all regions increased significantly as a function of age. Peak age was nevertheless lobe specific, with a pattern of earlier peak ages for females in both temporal and frontal lobes. Growth change in whole brain GM volume was larger in males than in females. However, GM volume growth changes for the temporal and frontal lobes showed a somewhat different pattern. GM volume for both temporal and frontal lobes showed a greater increase in females until around 5-6 years old, at which point this tendency reversed (GM volume

Trajectories of growth in body mass index across childhood: Associations with maternal and paternal employment.

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Morrissey, Taryn W

2013-10-01

Research links mothers' employment to higher body mass index (BMI), a measure of weight-for-height, among their children. However, how maternal employment patterns relate to their children's BMI trajectories, and the role that fathers' employment plays in when and at what rate children grow, remain unclear. With data on children from 2 to 15 years of age living in two-parent families from the U.S. NICHD's Study of Early Child Care and Youth Development (N = 1107), individual growth models are used to describe American children's BMI trajectories as predicted by maternal and paternal employment characteristics. Results indicate that, by age 15, children's BMIs are, on average, nearly one-half of a standard deviation above recommended levels, and the majority of growth occurs during the preschool period. The duration of maternal employment, and combined measures of maternal and paternal employment duration, are both associated with higher child BMI across childhood. Associations are small but cumulative. Notably, the association between the duration of time children lived in dual-earner families and child BMI is larger than that between maternal employment duration alone and children's BMI, which is strongest during the preschool period. Combined measures of maternal and paternal employment intensity, defined as the number of periods both parents worked 35 or more hours per week, are associated with higher child BMI during the preschool period only. Findings highlight the importance of taking into account both parents' employment characteristics in investigating children's physical development. Copyright © 2012 Elsevier Ltd. All rights reserved.

Growth trajectories from conception through middle childhood and cognitive achievement at age 8 years: Evidence from four low- and middle-income countries

Directory of Open Access Journals (Sweden)

Andreas Georgiadis

2016-12-01

Full Text Available Child chronic malnutrition is endemic in low- and middle-income countries and deleterious for child development. Studies investigating the relationship between nutrition at different periods of childhood, as measured by growth in these periods (growth trajectories, and cognitive development have produced mixed evidence. Although an explanation of this has been that different studies use different approaches to model growth trajectories, the differences across approaches are not well understood. Furthermore, little is known about the pathways linking growth trajectories and cognitive achievement. In this paper, we develop and estimate a general path model of the relationship between growth trajectories and cognitive achievement using data on four cohorts from Ethiopia, India, Peru, and Vietnam. The model is used to: (a compare two of the most common approaches to modelling growth trajectories in the literature, namely the lifecourse plot and the conditional body size model, and (b investigate the potential channels via which the association between growth in each period and cognitive achievement manifests. We show that the two approaches are expected to produce systematically different results that have distinct interpretations. Results suggest that growth from conception through age 1 year, between age 1 and 5 years, and between 5 and 8 years, are each positively and significantly associated with cognitive achievement at age 8 years and that this may be partly explained by the fact that faster-growing children start school earlier. We also find that a significant share of the association between early growth and later cognitive achievement is mediated through growth in interim periods. Keywords: Nutrition, Cognitive achievement, Path analysis, Cohort study, Ethiopia, India, Peru, Vietnam

STATISTICAL GROWTH MODELING OF LONGITUDINAL DT-MRI FOR REGIONAL CHARACTERIZATION OF EARLY BRAIN DEVELOPMENT.

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Sadeghi, Neda; Prastawa, Marcel; Fletcher, P Thomas; Gilmore, John H; Lin, Weili; Gerig, Guido

2012-01-01

A population growth model that represents the growth trajectories of individual subjects is critical to study and understand neurodevelopment. This paper presents a framework for jointly estimating and modeling individual and population growth trajectories, and determining significant regional differences in growth pattern characteristics applied to longitudinal neuroimaging data. We use non-linear mixed effect modeling where temporal change is modeled by the Gompertz function. The Gompertz function uses intuitive parameters related to delay, rate of change, and expected asymptotic value; all descriptive measures which can answer clinical questions related to growth. Our proposed framework combines nonlinear modeling of individual trajectories, population analysis, and testing for regional differences. We apply this framework to the study of early maturation in white matter regions as measured with diffusion tensor imaging (DTI). Regional differences between anatomical regions of interest that are known to mature differently are analyzed and quantified. Experiments with image data from a large ongoing clinical study show that our framework provides descriptive, quantitative information on growth trajectories that can be directly interpreted by clinicians. To our knowledge, this is the first longitudinal analysis of growth functions to explain the trajectory of early brain maturation as it is represented in DTI.

An imputation/copula-based stochastic individual tree growth model for mixed species Acadian forests: a case study using the Nova Scotia permanent sample plot network

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John A. KershawJr

2017-09-01

Full Text Available Background A novel approach to modelling individual tree growth dynamics is proposed. The approach combines multiple imputation and copula sampling to produce a stochastic individual tree growth and yield projection system. Methods The Nova Scotia, Canada permanent sample plot network is used as a case study to develop and test the modelling approach. Predictions from this model are compared to predictions from the Acadian variant of the Forest Vegetation Simulator, a widely used statistical individual tree growth and yield model. Results Diameter and height growth rates were predicted with error rates consistent with those produced using statistical models. Mortality and ingrowth error rates were higher than those observed for diameter and height, but also were within the bounds produced by traditional approaches for predicting these rates. Ingrowth species composition was very poorly predicted. The model was capable of reproducing a wide range of stand dynamic trajectories and in some cases reproduced trajectories that the statistical model was incapable of reproducing. Conclusions The model has potential to be used as a benchmarking tool for evaluating statistical and process models and may provide a mechanism to separate signal from noise and improve our ability to analyze and learn from large regional datasets that often have underlying flaws in sample design.

Periconception Maternal Folate Status and Human Embryonic Cerebellum Growth Trajectories : The Rotterdam Predict Study

NARCIS (Netherlands)

Koning, Irene V; Groenenberg, Irene A L; Gotink, Anniek W; Willemsen, Sten P; Gijtenbeek, Manon; Dudink, Jeroen; Go, Attie T J I; Reiss, Irwin K M; Steegers, Eric A P; Steegers-Theunissen, Régine P M

2015-01-01

We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks

Trajectories of Social Withdrawal from Middle Childhood to Early Adolescence

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Oh, Wonjung; Rubin, Kenneth H.; Bowker, Julie C.; Booth-LaForce, Cathryn; Rose-Krasnor, Linda; Laursen, Brett

2008-01-01

Heterogeneity and individual differences in the developmental course of social withdrawal were examined longitudinally in a community sample (N = 392). General Growth Mixture Modeling (GGMM) was used to identify distinct pathways of social withdrawal, differentiate valid subgroup trajectories, and examine factors that predicted change in…

Self-esteem growth trajectory from adolescence to mid-adulthood and its predictors in adolescence.

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Kiviruusu, Olli; Huurre, Taina; Aro, Hillevi; Marttunen, Mauri; Haukkala, Ari

2015-03-01

The present study examined the trajectory of self-esteem from adolescence to mid-adulthood and its predictors in adolescence in a prospective cohort sample with a 26-year follow-up. Participants of a Finnish cohort study in 1983 at 16 years (N = 2194) were followed up at ages 22 (N = 1656), 32 (N = 1471) and 42 (N = 1334) years. Self-esteem development was analyzed using latent growth curve models with parental socioeconomic status (SES), parental divorce, school achievement, daily smoking, and heavy drinking as time invariant covariates. Self-esteem grew linearly from 16 to 32 years, but stabilized after that with no growth between 32 and 42 years. Males had significantly higher self-esteem throughout the follow-up, although females had a faster growth rate. Better school performance and higher parental SES were associated with a higher initial level of self-esteem among both genders, while parental divorce among females and daily smoking among males were associated with a lower initial level of self-esteem. Among females the growth rate of self-esteem was practically unaffected by the studied covariates. Among males, however, the initial differences in self-esteem favouring those from a higher SES background were indicated to diminish, while the differences between non-smokers and smokers were indicated to increase. The studied adolescent covariates combined had only limited predictive value for the later self-esteem development. However, the effects of any covariate on the level and slope of the self-esteem trajectory, even if small, should be assessed in combination in order to identify whether they lead to converging, diverging or constantly equidistant self-esteem trajectories. The findings highlight the variety of roles that adolescent behaviours and social environments may have in the developmental process of self-esteem from adolescence into mid-adulthood. Copyright © 2014 Elsevier Ltd. All rights reserved.

Year of the Woman, Decade of the Man: trajectories of growth in women's state legislative representation.

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Paxton, Pamela; Painter, Matthew A; Hughes, Melanie M

2009-03-01

The expansion of women's political representation ranks among the most significant trends in American politics of the last 100 years. In this paper, we develop two longitudinal theories to explain patterns of growth and change in women's state legislative representation over time. Gender salience suggests that years in which women's absence from politics is problematized (e.g., 1992-the Year of the Woman) will demonstrate higher levels of growth. Political climate suggests that periods in which domestic issues are stressed (e.g., the 1990s) will produce higher levels of growth than periods in which international issues are stressed (e.g., post 9/11). Combinations of these two theories create four possible trajectories of growth in women's representation that may be observed over time. We use latent growth curve models to assess the four theoretical trajectories, using data on women's state legislative representation from 1982 to 2006. We find that while women achieved fleeting success in the Year of the Woman, further gains were limited in the remainder of the 1990s and average growth stalled completely after 2001. Our results show futher that gender salience and, to a lesser extent political, climate matter to growth and change in women's political power over time.

Individual variation in growth in sea cucumber Apostichopus japonicus (Selenck) housed individually

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Liang, Miao; Dong, Shuanglin; Gao, Qinfeng; Wang, Fang; Tian, Xiangli

2010-09-01

The exceptionally large individual growth variation has been previously recognized in several sea cucumber cohorts. However, there is a lack of information regarding the mechanism of such individual differences. In this study, the sea cucumber Apostichopus japonicus (Selenka) was reared individually in order to eliminate possible effects of social interaction, stocking density, etc. The results showed that there were substantial differences in growth among the sea cucumber individuals during the 100-day experiment. The special growth rate of the sea cucumber individuals differed by up to three folds (from 0.40% to 1.01%), and the coefficient of variation in body weight increased from 12.04% to 40.51%. The final wet body weight, food intake and food conversion efficiency for each sea cucumber were generally positively correlated with their initial wet body weight ( Psea cucumber individuals, largely accounting for the individual growth variation of the cohort sea cucumber. These results will provide some basic data for promoting selective breeding and farming of the sea cucumber.

Identifying Latent Trajectories of Personality Disorder Symptom Change: Growth Mixture Modeling in the Longitudinal Study of Personality Disorders

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Hallquist, Michael N.; Lenzenweger, Mark F.

2013-01-01

Although previous reports have documented mean-level declines in personality disorder (PD) symptoms over time, little is known about whether personality pathology sometimes emerges among nonsymptomatic adults, or whether rates of change differ qualitatively among symptomatic persons. Our study sought to characterize heterogeneity in the longitudinal course of PD symptoms with the goal of testing for and describing latent trajectories. Participants were 250 young adults selected into two groups using a PD screening measure: those who met diagnostic criteria for a DSM-III-R PD (PPD, n = 129), and those with few PD symptoms (NoPD, n = 121). PD symptoms were assessed three times over a four-year study using semistructured interviews. Total PD symptom counts and symptoms of each DSM-III-R PD were analyzed using growth mixture modeling. In the NoPD group, latent trajectories were characterized by stable, minor symptoms; the rapid or gradual remission of subclinical symptoms; or the emergence of symptoms of Avoidant, Obsessive-Compulsive, or Paranoid PD. In the PPD group, three latent trajectories were evident: rapid symptom remission, slow symptom decline, or a relative absence of symptoms. Rapid remission of PD symptoms was associated with fewer comorbid disorders, lower negative emotionality, and greater positive emotionality and constraint, whereas emergent personality dysfunction was associated with comorbid PD symptoms and lower positive emotionality. In most cases, symptom change for one PD was associated with concomitant changes in other PDs, depressive symptoms, and anxiety. These results indicate that the longitudinal course of PD symptoms is heterogeneous, with distinct trajectories evident for both symptomatic and nonsymptomatic individuals. The prognosis of PD symptoms may be informed by an assessment of personality and comorbid psychopathology. PMID:23231459

Family income trajectory during childhood is associated with adiposity in adolescence: a latent class growth analysis.

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Kendzor, Darla E; Caughy, Margaret O; Owen, Margaret Tresch

2012-08-05

Childhood socioeconomic disadvantage has been linked with obesity in cross-sectional research, although less is known about how changes in socioeconomic status influence the development of obesity. Researchers have hypothesized that upward socioeconomic mobility may attenuate the health effects of earlier socioeconomic disadvantage; while downward socioeconomic mobility might have a negative influence on health despite relative socioeconomic advantages at earlier stages. The purpose of the current study was to characterize trajectories of family income during childhood, and to evaluate the influence of these trajectories on adiposity at age 15. Data were collected as part of the Study of Early Child Care and Youth Development (SECCYD) between 1991 and 2007 at 10 sites across the United States. A latent class growth analysis (LCGA) was conducted to identify trajectories of family income from birth to 15 years of age. Analyses of covariance (ANCOVAs) were conducted to determine whether measures of adiposity differed by trajectory, while controlling for relevant covariates. The LCGA supported a 5-class trajectory model, which included two stable, one downward, and two upward trajectories. ANCOVAs indicated that BMI percentile, waist circumference, and skinfold thicknesses at age 15 differed significantly by trajectory, such that those who experienced downward mobility or stable low income had greater adiposity relative to the more advantaged trajectories. Conversely, upwardly mobile children and those with consistently adequate incomes had similar and more positive outcomes relative to the most disadvantaged trajectories. Findings suggest that promoting upward socioeconomic mobility among disadvantaged families may have a positive impact on obesity-related outcomes in adolescence.

Construction of an individual trajectory of learning computer science using an electronic database of educational material

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Алексей Андреевич Заславский

2010-09-01

Full Text Available In this paper the approach for the use of automated information system directly in the classroom to form a personal set of tasks for a particular student and build individual trajectory of its development.

Trajectories of suicidal ideation over 6 months among 482 outpatients with bipolar disorder

DEFF Research Database (Denmark)

Köhler-Forsberg, Ole; Madsen, Trine; Behrendt-Møller, Ida

2017-01-01

INTRODUCTION: Suicidal ideation occurs frequently among individuals with bipolar disorder; however, its course and persistence over time remains unclear. We aimed to investigate 6-months trajectories of suicidal ideation among adults with bipolar disorder. METHODS: The Bipolar CHOICE study...... randomized 482 outpatients with bipolar disorder to 6 months of lithium- or quetiapine-based treatment including other psychotropic medications as clinically indicated. Participants were asked at 9 visits about suicidal ideation using the Concise Health Risk Tracking scale. We performed latent Growth Mixture...... Modelling analysis to empirically identify trajectories of suicidal ideation. Multinomial logistic regression analyses were applied to estimate associations between trajectories and potential predictors. RESULTS: We identified four distinct trajectories. The Moderate-Stable group represented 11...

Family income trajectory during childhood is associated with adiposity in adolescence: a latent class growth analysis

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Kendzor Darla E

2012-08-01

Full Text Available Abstract Background Childhood socioeconomic disadvantage has been linked with obesity in cross-sectional research, although less is known about how changes in socioeconomic status influence the development of obesity. Researchers have hypothesized that upward socioeconomic mobility may attenuate the health effects of earlier socioeconomic disadvantage; while downward socioeconomic mobility might have a negative influence on health despite relative socioeconomic advantages at earlier stages. The purpose of the current study was to characterize trajectories of family income during childhood, and to evaluate the influence of these trajectories on adiposity at age 15. Methods Data were collected as part of the Study of Early Child Care and Youth Development (SECCYD between 1991 and 2007 at 10 sites across the United States. A latent class growth analysis (LCGA was conducted to identify trajectories of family income from birth to 15 years of age. Analyses of covariance (ANCOVAs were conducted to determine whether measures of adiposity differed by trajectory, while controlling for relevant covariates. Results The LCGA supported a 5-class trajectory model, which included two stable, one downward, and two upward trajectories. ANCOVAs indicated that BMI percentile, waist circumference, and skinfold thicknesses at age 15 differed significantly by trajectory, such that those who experienced downward mobility or stable low income had greater adiposity relative to the more advantaged trajectories. Conversely, upwardly mobile children and those with consistently adequate incomes had similar and more positive outcomes relative to the most disadvantaged trajectories. Conclusions Findings suggest that promoting upward socioeconomic mobility among disadvantaged families may have a positive impact on obesity-related outcomes in adolescence.

Trajectories of adolescent substance use development and the influence of healthy leisure: A growth mixture modeling approach.

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Weybright, Elizabeth H; Caldwell, Linda L; Ram, Nilam; Smith, Edward A; Wegner, Lisa

2016-06-01

Considerable heterogeneity exists in adolescent substance use development. To most effectively prevent use, distinct trajectories of use must be identified as well as differential associations with predictors of use, such as leisure experience. The current study used a person-centered approach to identify distinct substance use trajectories and how leisure is associated with trajectory classes. Data came from a larger efficacy trial of 2.249 South African high school students who reported substance use at any time across 8 waves. Growth mixture modeling was used to identify developmental trajectories of substance use and the influence of healthy leisure. Results identified three increasing and one stable substance use trajectory and subjective healthy leisure served to protect against use. This study is the first of its kind to focus on a sample of South African adolescents and serves to develop a richer understanding of substance use development and the role of healthy leisure. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Developmental trajectories in primary schoolchildren using n-back task

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Mónica eLópez-Vicente

2016-05-01

Full Text Available Background: Neuropsychological instruments to assess cognitive trajectories during childhood in epidemiological studies are needed. This would improve neurodevelopment characterization in order to identify its potential determinants. We aimed to study whether repeated measures of n-back, a working memory task, detect developmental trajectories in schoolchildren during a one-year follow-up.Methods: We administered the n-back task to 2,897 healthy children aged 7-11 years old from 39 schools in Barcelona (Spain. The task consisted of 2 levels of complexity or loads (2- and 3-back and 2 different stimuli (numbers and words. Participants performed the task four times from January 2012 to March 2013. To study the trajectories during the follow-up, we performed linear mixed-effects models including school, individual and age as random effects.Results: We observed improvements related to age in n-back outcomes d’, HRT and accuracy, as well as reduced cognitive growth at older ages in d’ and HRT. Greater improvements in performance were observed at younger ages, in 2-back, in verbal rather than numerical stimuli and in girls compared to boys. Boys responded faster at baseline, while girls showed increased growth in 2-back numbers. Children with ADHD (Attention Deficit and Hyperactivity Disorder symptoms (15% of boys and 6% of girls had a lower working memory at baseline, but they showed similar cognitive growth trajectories in numbers variants of the task, as compared to children without ADHD symptoms. However, the age-related improvement in response speed was not observed in children with ADHD symptoms. Conclusions: Changes in n-back outcomes reflected developmental trajectories in one-year follow-up. The present results suggest that the repeated administration of this task can be used to study the factors that may alter the cognitive development during childhood.

The Role of PS Ability and RC Skill in Predicting Growth Trajectories of Mathematics Achievement

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Vista, Alvin

2016-01-01

There are relatively few studies in Australia and South-East Asian region that combine investigating models of math growth trajectories with predictors such as reasoning ability and reading comprehension skills. Math achievement is one of the major components of overall academic achievement and it is important to determine what factors (especially…

The utility of estimating population-level trajectories of terminal wellbeing decline within a growth mixture modelling framework.

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Burns, R A; Byles, J; Magliano, D J; Mitchell, P; Anstey, K J

2015-03-01

Mortality-related decline has been identified across multiple domains of human functioning, including mental health and wellbeing. The current study utilised a growth mixture modelling framework to establish whether a single population-level trajectory best describes mortality-related changes in both wellbeing and mental health, or whether subpopulations report quite different mortality-related changes. Participants were older-aged (M = 69.59 years; SD = 8.08 years) deceased females (N = 1,862) from the dynamic analyses to optimise ageing (DYNOPTA) project. Growth mixture models analysed participants' responses on measures of mental health and wellbeing for up to 16 years from death. Multi-level models confirmed overall terminal decline and terminal drop in both mental health and wellbeing. However, modelling data from the same participants within a latent class growth mixture framework indicated that most participants reported stability in mental health (90.3 %) and wellbeing (89.0 %) in the years preceding death. Whilst confirming other population-level analyses which support terminal decline and drop hypotheses in both mental health and wellbeing, we subsequently identified that most of this effect is driven by a small, but significant minority of the population. Instead, most individuals report stable levels of mental health and wellbeing in the years preceding death.

Exploring Service-led Growth Trajectories for Analytical Equipment Providers

DEFF Research Database (Denmark)

Raja, Jawwad; Frandsen, Thomas; Mouritsen, Jan

2016-01-01

This paper examines the dilemmas encountered by advanced analytical equipment providers in developing service-led growth strategies to expand their business in pursuit of more attractive revenue models. It does so by adopting a case based research approach. The findings detail the capabilities...... and solutions-in different contexts, with a view to expanding markets and developing solution based business models, are discussed. It is argued that analytical equipment providers encounter dilemmas as managing these different trajectories implies different needs in terms of the technological sophistication...... of equipment required. This does not necessarily imply that one context is less complex than the other, but rather suggests that the role of integration is qualitatively different and that the relationship between product and service varies when developing solutions in these different arenas....

Personality development from adolescence to emerging adulthood: linking trajectories of ego development to the family context and identity formation.

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Syed, Moin; Seiffge-Krenke, Inge

2013-02-01

This longitudinal study analyzed personality development using an individual approach by examining changes in ego development across the transition from adolescence to emerging adulthood. Specifically, the study mapped the heterogeniety in ego development growth trajectories and linked the different trajectories to the family context in adolescence and identity development in emerging adulthood. Participants were 98 families with a child who were followed from age 14 to age 24. Latent class growth analysis identified 4 distinct trajectories of growth in ego development of the children over the 10-year period. The results indicated that growth was more rapid during adolescence and tended to taper off in emerging adulthood. In addition, promotion of personal growth within the family and parents' ego development were particulary instrumental in children's ego developmental gains in adolescence. Finally, youth who demonstrated continued ego development into emerging adulthood also demonstrated heightened levels of identity exploration. (c) 2013 APA, all rights reserved.

The influence of work-family conflict trajectories on self-rated health trajectories in Switzerland: a life course approach.

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Cullati, Stéphane

2014-07-01

Self-rated health (SRH) trajectories tend to decline over a lifetime. Moreover, the Cumulative Advantage and Disadvantage (CAD) model indicates that SRH trajectories are known to consistently diverge along socioeconomic positions (SEP) over the life course. However, studies of working adults to consider the influence of work and family conflict (WFC) on SRH trajectories are scarce. We test the CAD model and hypothesise that SRH trajectories diverge over time according to socioeconomic positions and WFC trajectories accentuate this divergence. Using longitudinal data from the Swiss Household Panel (N = 2327 working respondents surveyed from 2004 to 2010), we first examine trajectories of SRH and potential divergence over time across age, gender, SEP and family status using latent growth curve analysis. Second, we assess changes in SRH trajectories in relation to changes in WFC trajectories and divergence in SRH trajectories according to gender, SEP and family status using parallel latent growth curve analysis. Three measures of WFC are used: exhaustion after work, difficulty disconnecting from work, and work interference in private family obligations. The results show that SRH trajectories slowly decline over time and that the rate of change is not influenced by age, gender or SEP, a result which does not support the CAD model. SRH trajectories are significantly correlated with exhaustion after work trajectories but not the other two WFC measures. When exhaustion after work trajectories are taken into account, SRH trajectories of higher educated people decline slower compared to less educated people, supporting the CAD hypothesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trajectories of autonomy development across the adolescent transition in children with spina bifida.

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Friedman, Deborah; Holmbeck, Grayson N; DeLucia, Christian; Jandasek, Barbara; Zebracki, Kathy

2009-02-01

The current study investigated individual growth in autonomy development across the adolescent transition, comparing the trajectories of children with and without spina bifida. Individual growth curve modeling procedures were utilized to describe the developmental course of autonomy across four waves of data collection, from ages 9 to 15, and to test whether illness status [spina bifida vs. matched comparison group (N = 68 for both groups at Time 1)] would significantly predict individual variability in autonomy development. Potential moderators [child gender, SES, and Peabody Picture Vocabulary Test (PPVT) score] of the association between illness status and autonomy development were also examined. Children with spina bifida demonstrated distinct developmental trajectories, though the nature of the group differences varied by type of autonomy development (emotional vs. behavioral), context (i.e. school vs. family), and reporter. Significant interactions with PPVT score and child gender were found. Overall, children with spina bifida show considerable developmental resiliency, but may lag behind their peers in specific areas of autonomy. Boys with spina bifida, and children with spina bifida who have lower than average levels of verbal intelligence, appear to be at greater risk for exhibiting delays in autonomy development.

The Gavialis-Tomistoma debate: the contribution of skull ontogenetic allometry and growth trajectories to the study of crocodylian relationships.

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Piras, Paolo; Colangelo, Paolo; Adams, Dean C; Buscalioni, Angela; Cubo, Jorge; Kotsakis, Tassos; Meloro, Carlo; Raia, Pasquale

2010-01-01

The phylogenetic placement of Tomistoma and Gavialis crocodiles depends largely upon whether molecular or morphological data are utilized. Molecular analyses consider them as sister taxa, whereas morphological/paleontological analyses set Gavialis apart from Tomistoma and other crocodylian species. Here skull allometric trajectories of Tomistoma and Gavialis were contrasted with those of two longirostral crocodylian taxa, Crocodylus acutus and Mecistops cataphractus, to examine similarities in growth trajectories in light of this phylogenetic controversy. Entire skull shape and its two main modules, rostrum and postrostrum, were analyzed separately. We tested differences for both multivariate angles between trajectories and for shape differences at early and late stages of development. Based on a multivariate regression of shape data and size, Tomistoma seems to possess a peculiar rate of growth in comparison to the remaining taxa. However, its morphology at both juvenile and adult sizes is always closer to those of Brevirostres crocodylians, for the entire head shape, as well as the shape of the postrostrum and rostrum. By contrast, the allometric trajectory of Gavialis always begins and ends in a unique region of the multidimensional morphospace. These findings concur with a morphological hypothesis that places Gavialis separate from Brevirostres, and Tomistoma closer to other crocodylids, and provides an additional, and independent, data set to inform on this ongoing phylogenetic discussion. © 2010 Wiley Periodicals, Inc.

Periconception Maternal Folate Status and Human Embryonic Cerebellum Growth Trajectories: The Rotterdam Predict Study.

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Irene V Koning

Full Text Available We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks gestational age (GA. Viable non-malformed singleton pregnancies were selected for cerebellar measurements; transcerebellar diameter, (TCD, left and right cerebellar diameters (LCD, RCD. Linear mixed models were performed to estimate associations between questionnaire data on the timing of maternal folic acid supplement initiation and longitudinal cerebellar measurements as a function of crown-rump length (CRL and GA. Maternal red blood cell folate concentrations were analysed before 8 weeks GA to validate the associations. A total of 263 serial high quality three-dimensional ultrasound scans of 135 pregnancies were studied. Preconceptional compared to postconceptional initiation of folic acid use was associated with slightly larger cerebellar diameters per millimetre increase of CRL (TCD: β = 0.260mm, 95%CI = 0.023-0.491, p<0.05; LCD: β = 0.171mm, 95%CI = 0.038-0.305, p<0.05; RCD: β = 0.156mm, 95%CI = 0.032-0.280, p<0.05 and with proportional cerebellar growth (TCD/CRL:β = 0.015mm/mm, 95%CI = 0.005-0.024, p<0.01; LCD/CRL:β = 0.012mm/mm, 95%CI = 0.005-0.018, p<0.01; RCD/CRL:β = 0.011mm/mm, 95%CI = 0.005-0.017, p<0.01. Cerebellar growth was significantly highest in the third quartile of maternal red blood cell folate levels (1538-1813 nmol/L. These first findings show that periconceptional maternal folate status is associated with human embryonic cerebellar development. Implications of these small but significant variations for fetal cerebellar growth trajectories and the child's neurodevelopmental outcome are yet unknown and warrant further investigation.

Trajectories of Heroin Addiction: Growth Mixture Modeling Results Based on a 33-Year Follow-Up Study

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Hser, Yih-Ing; Huang, David; Chou, Chih-Ping; Anglin, M. Douglas

2007-01-01

This study investigates trajectories of heroin use and subsequent consequences in a sample of 471 male heroin addicts who were admitted to the California Civil Addict Program in 1964-1965 and followed over 33 years. Applying a two-part growth mixture modeling strategy to heroin use level during the first 16 years of the addiction careers since…

An Innovative Context-Based Crystal-Growth Activity Space Method for Environmental Exposure Assessment: A Study Using GIS and GPS Trajectory Data Collected in Chicago.

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Wang, Jue; Kwan, Mei-Po; Chai, Yanwei

2018-04-09

Scholars in the fields of health geography, urban planning, and transportation studies have long attempted to understand the relationships among human movement, environmental context, and accessibility. One fundamental question for this research area is how to measure individual activity space, which is an indicator of where and how people have contact with their social and physical environments. Conventionally, standard deviational ellipses, road network buffers, minimum convex polygons, and kernel density surfaces have been used to represent people's activity space, but they all have shortcomings. Inconsistent findings of the effects of environmental exposures on health behaviors/outcomes suggest that the reliability of existing studies may be affected by the uncertain geographic context problem (UGCoP). This paper proposes the context-based crystal-growth activity space as an innovative method for generating individual activity space based on both GPS trajectories and the environmental context. This method not only considers people's actual daily activity patterns based on GPS tracks but also takes into account the environmental context which either constrains or encourages people's daily activity. Using GPS trajectory data collected in Chicago, the results indicate that the proposed new method generates more reasonable activity space when compared to other existing methods. This can help mitigate the UGCoP in environmental health studies.

Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions.

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Brienen, Roel J W; Zuidema, Pieter A; Martínez-Ramos, Miguel

2010-06-01

Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees--those that have not attained the canopy--are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests.

Academic trajectories of newcomer immigrant youth.

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Suárez-Orozco, Carola; Gaytán, Francisco X; Bang, Hee Jin; Pakes, Juliana; O'Connor, Erin; Rhodes, Jean

2010-05-01

Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some newcomer students performed at high or improving levels over time, others showed diminishing performance. Multinomial logistic regressions identified significant group differences in academic trajectories, particularly between the high-achieving youth and the other groups. In keeping with ecological-developmental and stage-environment fit theories, School Characteristics (school segregation rate, school poverty rate, and student perceptions of school violence), Family Characteristics (maternal education, parental employment, and household structure), and Individual Characteristics (academic English proficiency, academic engagement, psychological symptoms, gender, and 2 age-related risk factors, number of school transitions and being overaged for grade placement) were associated with different trajectories of academic performance. A series of case studies triangulate many of the quantitative findings as well as illuminate patterns that were not detected in the quantitative data. Thus, the mixed-methods approach sheds light on the cumulative developmental challenges that immigrant students face as they adjust to their new educational settings. 2010 APA, all rights reserved

Webinar Presentation: Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes

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This presentation, Exposures to Polycyclic Aromatic Hydrocarbons and Childhood Growth Trajectories and Body Composition: Linkages to Disrupted Self-Regulatory Processes, was given at the NIEHS/EPA Children's Centers 2016 Webinar Series: Childhood Obesity

Friendship networks and trajectories of adolescent tobacco use.

Science.gov (United States)

Pollard, Michael S; Tucker, Joan S; Green, Harold D; Kennedy, David; Go, Myong-Hyun

2010-07-01

This article examines how friendship networks in adolescence are linked to tobacco use trajectories through a combination of analytic techniques that traditionally are located in separate literatures: social network analysis and developmental trajectory analysis. Using six years of longitudinal data from the National Longitudinal Study of Adolescent Health, we identify a set of six unique developmental trajectories of smoking (never smokers, steady lows, delayed increasers, early increasers, decreasers, and steady highs). Individuals' locations in their friendship networks were then linked to their trajectory group membership. Adolescents with a greater number of smoking friends were more likely to belong to the higher use trajectories. Beyond this exposure to smoking peers, individuals who at baseline were either members of a smoking group or liaisons to a smoking group were more likely than members of a nonsmoking group to belong to the higher use trajectories. Liaisons to a smoking group were particularly likely to belong to the delayed increaser trajectory group. Trajectory group membership for adolescents who belonged to a nonsmoking group did not significantly differ from those who were isolates or liaisons to a nonsmoking group. The study suggests features of an individual's social network have long-lasting associations with smoking behaviors. 2010 Elsevier Ltd. All rights reserved.

Two-year trajectory of fall risk in people with Parkinson’s disease: a latent class analysis

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Paul, Serene S; Thackeray, Anne; Duncan, Ryan P; Cavanaugh, James T; Ellis, Theresa D; Earhart, Gammon M; Ford, Matthew P; Foreman, K Bo; Dibble, Leland E

2015-01-01

Objective To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson’s disease (PD). Design Latent class analysis, specifically growth mixture modeling (GMM) of longitudinal fall risk trajectories. Setting Not applicable. Participants 230 community-dwelling PD participants of a longitudinal cohort study who attended at least two of five assessments over a two year period. Interventions Not applicable. Main Outcome Measures Fall risk trajectory (low, medium or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6-monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. Results The GMM optimally grouped participants into three fall risk trajectories that closely mirrored baseline fall risk status (p=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium risk trajectories (pfall risk (posterior probability fall risk trajectories over two years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD. PMID:26606871

Two-Year Trajectory of Fall Risk in People With Parkinson Disease: A Latent Class Analysis.

Science.gov (United States)

Paul, Serene S; Thackeray, Anne; Duncan, Ryan P; Cavanaugh, James T; Ellis, Theresa D; Earhart, Gammon M; Ford, Matthew P; Foreman, K Bo; Dibble, Leland E

2016-03-01

To examine fall risk trajectories occurring naturally in a sample of individuals with early to middle stage Parkinson disease (PD). Latent class analysis, specifically growth mixture modeling (GMM), of longitudinal fall risk trajectories. Assessments were conducted at 1 of 4 universities. Community-dwelling participants with PD of a longitudinal cohort study who attended at least 2 of 5 assessments over a 2-year follow-up period (N=230). Not applicable. Fall risk trajectory (low, medium, or high risk) and stability of fall risk trajectory (stable or fluctuating). Fall risk was determined at 6 monthly intervals using a simple clinical tool based on fall history, freezing of gait, and gait speed. The GMM optimally grouped participants into 3 fall risk trajectories that closely mirrored baseline fall risk status (P=.001). The high fall risk trajectory was most common (42.6%) and included participants with longer and more severe disease and with higher postural instability and gait disability (PIGD) scores than the low and medium fall risk trajectories (Pfall risk (posterior probability fall risk trajectories over 2 years. Further investigation is required to determine whether interventions to improve gait and balance may improve fall risk trajectories in people with PD. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size

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King, Richard B.

2016-01-01

Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females) and annual growth increments of individuals of unknown age (1,152 males, 730 females). We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631–820 mm snout-vent length in males and from 835–1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further investigation. PMID

Size Matters: Individual Variation in Ectotherm Growth and Asymptotic Size.

Directory of Open Access Journals (Sweden)

Richard B King

Full Text Available Body size, and, by extension, growth has impacts on physiology, survival, attainment of sexual maturity, fecundity, generation time, and population dynamics, especially in ectotherm animals that often exhibit extensive growth following attainment of sexual maturity. Frequently, growth is analyzed at the population level, providing useful population mean growth parameters but ignoring individual variation that is also of ecological and evolutionary significance. Our long-term study of Lake Erie Watersnakes, Nerodia sipedon insularum, provides data sufficient for a detailed analysis of population and individual growth. We describe population mean growth separately for males and females based on size of known age individuals (847 captures of 769 males, 748 captures of 684 females and annual growth increments of individuals of unknown age (1,152 males, 730 females. We characterize individual variation in asymptotic size based on repeated measurements of 69 males and 71 females that were each captured in five to nine different years. The most striking result of our analyses is that asymptotic size varies dramatically among individuals, ranging from 631-820 mm snout-vent length in males and from 835-1125 mm in females. Because female fecundity increases with increasing body size, we explore the impact of individual variation in asymptotic size on lifetime reproductive success using a range of realistic estimates of annual survival. When all females commence reproduction at the same age, lifetime reproductive success is greatest for females with greater asymptotic size regardless of annual survival. But when reproduction is delayed in females with greater asymptotic size, lifetime reproductive success is greatest for females with lower asymptotic size when annual survival is low. Possible causes of individual variation in asymptotic size, including individual- and cohort-specific variation in size at birth and early growth, warrant further

The Developmental Trajectory of Self-Injurious Behaviours in Individuals with Prader Willi Syndrome, Autism Spectrum Disorder and Intellectual Disability

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Lauren J. Rice

2016-02-01

Full Text Available In the present study we examined the nature and developmental trajectory of self-injurious behaviour in Prader Willi syndrome (PWS and autism spectrum disorder (ASD. The development of interventions is greatly aided by understanding gene to behaviour pathways, and this requires an accurate description of the behaviour phenotype, that is, which types and natural history of self-injurious behaviour are more common in PWS and ASD and which are shared with other forms of developmental disability. Self-injury displayed by individuals with PWS and individuals with ASD was compared with that reported in a group of individuals with intellectual disability due to mixed aetiology (ID group. Three self-injurious behaviours (head banging, skin-picking and hitting and/or biting self were measured on five occasions over 18 years using the Developmental Behaviour Checklist (DBC a well-validated caregiver report measure. Rates of skin picking were higher in individuals with PWS and hitting and/or biting self was higher in individuals with ASD compared to the ID group. Rates of head banging were similar across the three groups. Over time, skin-picking and head banging increased with age for individuals with ASD and hitting and/or biting self increased for the PWS group. In the PWS and mixed ID groups head banging decreased with age. These findings suggest that the typology and developmental trajectories of self-injurious behaviours differ between those with PWS and ASD.

Beyond experimentation: Five trajectories of cigarette smoking in a longitudinal sample of youth.

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Lauren M Dutra

Full Text Available The first goal of this study was to identify the most appropriate measure of cigarette smoking for identifying unique smoking trajectories among adolescents; the second goal was to describe the resulting trajectories and their characteristics. Using 15 annual waves of smoking data in the National Longitudinal Survey of Youth 1997 (NLSY97, we conducted an exploratory latent class growth analysis to determine the best of four outcome variables for yearly smoking (cigarettes per day on days smoked, days smoked per month, mean cigarettes per day, and total cigarettes per month among individuals aged 12 to 30 (n = 8,791. Days smoked per month was the best outcome variable for identifying unique longitudinal trajectories of smoking and characteristics of these trajectories that could be used to target different types of smokers for prevention and cessation. Objective statistics were used to identify four trajectories in addition to never smokers (34.1%: experimenters (13.6%, quitters (8.1%, early established smokers (39.0%, and late escalators (5.2%. We identified a quitter and late escalator class not identified in the only other comparable latent class growth analysis. Logistic regressions were used to identify the characteristics of individuals in each trajectory. Compared with never smokers, all trajectories except late escalators were less likely to be black; experimenters were more likely to be out of school and unemployed and drink alcohol in adolescence; quitters were more likely to have a mother with a high school degree/GED or higher (versus none and to use substances in adolescence and less likely to have ever married as a young adult; early established smokers were more likely to have a mother with a high school diploma or GED, be out of school and unemployed, not live with both parents, have used substances, be depressed, and have peers who smoked in adolescence and to have children as young adults and less likely to be Hispanic and to

Individual trajectories in stress covary with immunity during recovery from cancer diagnosis and treatments.

Science.gov (United States)

Thornton, Lisa M; Andersen, Barbara L; Crespin, Timothy R; Carson, William E

2007-02-01

Research connects stressful events with altered immune regulation, but the role of subjective stress is uncertain. Using a longitudinal design, we provide a statistically powerful test of the relationship between subjective stress (perceived stress, emotional distress) and immunity (T cell blastogenesis, natural killer cell cytotoxicity, [NKCC]) as individuals adjust to a severe stressor, a cancer diagnosis and its treatments. Women with regional breast cancer (N=113) were assessed at diagnosis/surgery and reassessed 4, 8, 12, and 18 months later. Latent growth curve analysis tested two hypotheses: (1) initial levels of subjective stress will correlate inversely with initial levels of immunity, and (2) rate of change in subjective stress will correlate inversely with rate of change in immunity. As predicted by Hypothesis 1, participants with high initial subjective stress showed poor initial blastogenesis. As predicted by Hypothesis 2, participants exhibiting an early, rapid decline in subjective stress also showed rapid improvement in NKCC. Follow-up analyses revealed perceived stress to be strongly related to immune function, while emotional distress was not. This is the first study to investigate trajectories in stress and immunity during recovery from a major stressor. Results imply that NK and T cells are sensitive to different aspects of the stress response. While T cell blastogenesis correlated with initial (peak) subjective stress, NKCC correlated with change (improvement) in subjective stress. These data highlight the importance of subjective stress, particularly stress appraisals, in the immune response to a major stressor.

Developmental Growth Trajectories of Self-Esteem in Adolescence: Associations with Child Neglect and Drug Use and Abuse in Young Adulthood.

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Oshri, Assaf; Carlson, Matthew W; Kwon, Josephine A; Zeichner, Amos; Wickrama, Kandauda K A S

2017-01-01

Neglectful rearing is linked with young adults' substance use and abuse, though the developmental mechanisms that underlie this association are unclear. The present study examines links between self-esteem growth during adolescence, childhood supervisory versus physical neglect severity, and substance use and abuse in young adulthood. A sample of youth was obtained from the Add Health study (N = 8738; 55.4 %-Female; 20 %-African American, 14.7 %-Hispanic). Growth mixture modeling analyses supported declining, ascending, and stable high self-esteem trajectories. The declining and ascending trajectories reported greater neglect and alcohol abuse (but not use) as well as cannabis use and abuse. The findings suggest that compromised development of self-esteem underlies associations between neglect and substance use and abuse. Preventive interventions may benefit from targeting self-esteem among neglected youth.

Atomic Scale Imaging of Nucleation and Growth Trajectories of an Interfacial Bismuth Nanodroplet.

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Li, Yingxuan; Bunes, Benjamin R; Zang, Ling; Zhao, Jie; Li, Yan; Zhu, Yunqing; Wang, Chuanyi

2016-02-23

Because of the lack of experimental evidence, much confusion still exists on the nucleation and growth dynamics of a nanostructure, particularly of metal. The situation is even worse for nanodroplets because it is more difficult to induce the formation of a nanodroplet while imaging the dynamic process with atomic resolution. Here, taking advantage of an electron beam to induce the growth of Bi nanodroplets on a SrBi2Ta2O9 platelet under a high resolution transmission electron microscope (HRTEM), we directly observed the detailed growth pathways of Bi nanodroplets from the earliest stage of nucleation that were previously inaccessible. Atomic scale imaging reveals that the dynamics of nucleation involves a much more complex trajectory than previously predicted based on classical nucleation theory (CNT). The monatomic Bi layer was first formed in the nucleation process, which induced the formation of the prenucleated clusters. Following that, critical nuclei for the nanodroplets formed both directly from the addition of atoms to the prenucleated clusters by the classical growth process and indirectly through transformation of an intermediate liquid film based on the Stranski-Krastanov growth mode, in which the liquid film was induced by the self-assembly of the prenucleated clusters. Finally, the growth of the Bi nanodroplets advanced through the classical pathway and sudden droplet coalescence. This study allows us to visualize the critical steps in the nucleation process of an interfacial nanodroplet, which suggests a revision of the perspective of CNT.

Trajectories of acute low back pain: a latent class growth analysis.

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Downie, Aron S; Hancock, Mark J; Rzewuska, Magdalena; Williams, Christopher M; Lin, Chung-Wei Christine; Maher, Christopher G

2016-01-01

Characterising the clinical course of back pain by mean pain scores over time may not adequately reflect the complexity of the clinical course of acute low back pain. We analysed pain scores over 12 weeks for 1585 patients with acute low back pain presenting to primary care to identify distinct pain trajectory groups and baseline patient characteristics associated with membership of each cluster. This was a secondary analysis of the PACE trial that evaluated paracetamol for acute low back pain. Latent class growth analysis determined a 5 cluster model, which comprised 567 (35.8%) patients who recovered by week 2 (cluster 1, rapid pain recovery); 543 (34.3%) patients who recovered by week 12 (cluster 2, pain recovery by week 12); 222 (14.0%) patients whose pain reduced but did not recover (cluster 3, incomplete pain recovery); 167 (10.5%) patients whose pain initially decreased but then increased by week 12 (cluster 4, fluctuating pain); and 86 (5.4%) patients who experienced high-level pain for the whole 12 weeks (cluster 5, persistent high pain). Patients with longer pain duration were more likely to experience delayed recovery or nonrecovery. Belief in greater risk of persistence was associated with nonrecovery, but not delayed recovery. Higher pain intensity, longer duration, and workers' compensation were associated with persistent high pain, whereas older age and increased number of episodes were associated with fluctuating pain. Identification of discrete pain trajectory groups offers the potential to better manage acute low back pain.

Complexity Science Applications to Dynamic Trajectory Management: Research Strategies

Science.gov (United States)

Sawhill, Bruce; Herriot, James; Holmes, Bruce J.; Alexandrov, Natalia

2009-01-01

The promise of the Next Generation Air Transportation System (NextGen) is strongly tied to the concept of trajectory-based operations in the national airspace system. Existing efforts to develop trajectory management concepts are largely focused on individual trajectories, optimized independently, then de-conflicted among each other, and individually re-optimized, as possible. The benefits in capacity, fuel, and time are valuable, though perhaps could be greater through alternative strategies. The concept of agent-based trajectories offers a strategy for automation of simultaneous multiple trajectory management. The anticipated result of the strategy would be dynamic management of multiple trajectories with interacting and interdependent outcomes that satisfy multiple, conflicting constraints. These constraints would include the business case for operators, the capacity case for the Air Navigation Service Provider (ANSP), and the environmental case for noise and emissions. The benefits in capacity, fuel, and time might be improved over those possible under individual trajectory management approaches. The proposed approach relies on computational agent-based modeling (ABM), combinatorial mathematics, as well as application of "traffic physics" concepts to the challenge, and modeling and simulation capabilities. The proposed strategy could support transforming air traffic control from managing individual aircraft behaviors to managing systemic behavior of air traffic in the NAS. A system built on the approach could provide the ability to know when regions of airspace approach being "full," that is, having non-viable local solution space for optimizing trajectories in advance.

Trajectories of health-related quality of life among family caregivers of individuals with dementia: A home-based caregiver-training program matters.

Science.gov (United States)

Kuo, Li-Min; Huang, Huei-Ling; Liang, Jersey; Kwok, Yam-Ting; Hsu, Wen-Chuin; Liu, Chin-Yi; Shyu, Yea-Ing L

To determine distinct courses of change in health-related quality of life (HRQoL) among family caregivers of individuals with dementia and how participating in a home-based caregiver-training program affects the probability of belonging to each course. Sixty three caregivers were in the intervention group, and 66 caregivers were in the control group of a single-blinded randomized clinical trial. Two distinct trajectories of HRQoL were identified: a well-functioning trajectory and a poor-functioning trajectory. Caregivers who received the training program were more likely than those who did not have a well-functioning trajectory of HRQoL over 18 months. This trajectory included bodily pain (b = 1.02, odds ratio [OR] = 2.76), general health perception (b = 1.28, OR = 3.60), social functioning (b = 1.12, OR = 3.05), vitality (b = 1.51, OR = 4.49), general mental health (b = 1.08, OR = 2.94), and mental component summary (b = 1.27, OR = 3.55). Home-based caregiver training can be considered as part of the protocol for managing patients with dementia and their caregivers. NCT02667951. Copyright © 2016 Elsevier Inc. All rights reserved.

Using personality traits to construct linear growth models of mental health in family members of individuals with severe brain injury.

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Trujillo, Michael; Perrin, Paul B; Doser, Karoline; Norup, Anne

2016-11-01

No studies have examined the impact of personality traits on mental health among caregivers of individuals with severe brain injury. Therefore, the purpose of the current study was to construct linear growth models to examine whether the personality traits of family members of individuals with severe brain injury could predict the trajectories of their own mental health-related quality of life (HRQoL), anxiety, and depression beginning in a neurointensive care unit through 1 year after injury. Danish family members of individuals with severe brain injury (n = 52) completed the Short Form-36 assessing mental HRQoL (vitality, social functioning, role limitations-emotional, mental health), anxiety, and depression across 5 time points during the 1st year after injury. The measure of personality was administered 3 months after the patients' discharge. All mental HRQoL, anxiety, and depression variables improved significantly over time. Caregivers who were less neurotic and less conscientious had higher vitality, social functioning, and mental health over time, whereas caregivers who were more agreeable had higher social functioning over time. Caregivers with lower neuroticism had lower anxiety and depression over time, as well as a more accelerated decrease in anxiety and depression. Caregivers' personality traits were strongly associated over time with mental HRQoL, anxiety, and depression, with neuroticism being especially important for trajectories of anxiety and depression. These results suggest that personality assessments for caregivers of individuals with severe brain injury could help identify those most at risk for poor mental health over the course of rehabilitation. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Growth trajectory and pubertal tempo from birth till final height in a girl with Wolf-Hirschhorn syndrome.

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Siew, Jia Xuan; Yap, Fabian

2018-01-01

Growth anomaly is a prominent feature in Wolf-Hirschhorn syndrome (WHS), a rare congenital disorder caused by variable deletion of chromosome 4p. While growth charts have been developed for WHS patients 0-4 years of age and growth data available for Japanese WHS patients 0-17 years, information on pubertal growth and final height among WHS children remain lacking. Growth hormone (GH) therapy has been reported in two GH-sufficient children with WHS, allowing for pre-puberty catch up growth; however, pubertal growth and final height information was also unavailable. We describe the complete growth journey of a GH-sufficient girl with WHS from birth until final height (FH), in relation to her mid parental height (MPH) and target range (TR). Her growth trajectory and pubertal changes during childhood, when she was treated with growth hormone (GH) from 3 years 8 months old till 6 months post-menarche at age 11 years was fully detailed. Pubertal growth characteristics and FH information in WHS is lacking.While pre-pubertal growth may be improved by GH, GH therapy may not translate to improvement in FH in WHS patients.Longitudinal growth, puberty and FH data of more WHS patients may improve the understanding of growth in its various phases (infancy/childhood/puberty).

Growth assessment in diagnosis of Fetal Growth Restriction. Review.

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Albu, A R; Horhoianu, I A; Dumitrascu, M C; Horhoianu, V

2014-06-15

The assessment of fetal growth represents a fundamental step towards the identification of the true growth restricted fetus that is associated to important perinatal morbidity and mortality. The possible ways of detecting abnormal fetal growth are taken into consideration in this review and their strong and weak points are discussed. An important debate still remains about how to discriminate between the physiologically small fetus that does not require special surveillance and the truly growth restricted fetus who is predisposed to perinatal complications, even if its parameters are above the cut-off limits established. In this article, we present the clinical tools of fetal growth assessment: Symphyseal-Fundal Height (SFH) measurement, the fetal ultrasound parameters widely taken into consideration when discussing fetal growth: Abdominal Circumference (AC) and Estimated Fetal Weight (EFW); several types of growth charts and their characteristics: populational growth charts, standard growth charts, individualized growth charts, customized growth charts and growth trajectories.

Fluctuation theorems and atypical trajectories

International Nuclear Information System (INIS)

Sahoo, M; Lahiri, S; Jayannavar, A M

2011-01-01

In this work, we have studied simple models that can be solved analytically to illustrate various fluctuation theorems. These fluctuation theorems provide symmetries individually to the distributions of physical quantities such as the classical work (W c ), thermodynamic work (W), total entropy (Δs tot ) and dissipated heat (Q), when the system is driven arbitrarily out of equilibrium. All these quantities can be defined for individual trajectories. We have studied the number of trajectories which exhibit behaviour unexpected at the macroscopic level. As the time of observation increases, the fraction of such atypical trajectories decreases, as expected at the macroscale. The distributions for the thermodynamic work and entropy production in nonlinear models may exhibit a peak (most probable value) in the atypical regime without violating the expected average behaviour. However, dissipated heat and classical work exhibit a peak in the regime of typical behaviour only.

Trajectories of suicidal ideation in patients with first-episode psychosis

DEFF Research Database (Denmark)

Madsen, Trine; Karstoft, Karen-Inge; Secher, Rikke Gry

2016-01-01

BACKGROUND: Heterogeneity in suicidal ideation over time in patients with first-episode psychosis is expected, but prototypical trajectories of this have not yet been established. We aimed to identify trajectories of suicidal ideation over a 3-year period and to examine how these trajectories...... assessments in a latent growth mixture modelling analysis to empirically identify trajectories of suicidal ideation. Multivariable logistic regression analyses were applied to estimate associations between trajectories and subsequent suicidality. This trial is registered with ClinicalTrials.gov, number NCT...

Childhood adiposity trajectories are associated with late adolescent blood pressure: birth to twenty cohort

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Richard J. Munthali

2016-07-01

Full Text Available Abstract Background Elevated blood pressure in childhood is a risk factor for adult hypertension which is a global health problem. Excess adiposity in childhood creates a predisposition to develop adult hypertension. Our aim was to explore distinct sex-specific adiposity trajectories from childhood to late adolescence and examined their association with blood pressure. Methods Latent Class Growth Mixture Modeling (LCGMM on longitudinal data was used to derive sex-specific and distinct body mass index (BMI: kg/m2 trajectories. We studied 1824 black children (boys = 877, girls = 947 from the Birth to Twenty (Bt20 cohort from Soweto, South Africa, and obtained BMI measures at ages 5 through 18 years. Participants with at least two age-point BMI measures, were included in the analysis. Analysis of variance (ANOVA, chi-square test, multivariate linear and standard logistic regressions were used to test study characteristics and different associations. Results We identified three (3 and four (4 distinct BMI trajectories in boys and girls, respectively. The overall prevalence of elevated blood pressure (BP was 34.9 % (39.4 % in boys and 30.38 % in girls. Boys and girls in the early onset obesity or overweight BMI trajectories were more likely to have higher BP values in late adolescence. Compared to those in the normal weight BMI trajectory, girls in early onset obesity trajectories had an increased risk of elevated BP with odds ratio (OR of 2.18 (95 % confidence interval 1.31 to 4.20 and 1.95 (1.01 to 3.77. We also observed the weak association for boys in early onset overweight trajectory, (p-value = 0.18 and odds ratio of 2.39 (0.67 to 8.57 Conclusions Distinct weight trajectories are observed in black South African children from as early as 5 years. Early onset adiposity trajectories are associated with elevated BP in both boys and girls. It is important to consider individual patterns of early-life BMI development, so that

Fetal growth trajectory and risk for eczema in a Saudi population.

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AlMakoshi, Amel; Ellahi, Awaiss; Sallout, Bala; Devereux, Graham; Turner, Steve

2015-12-01

Recent studies in Western cohorts have identified associations between increasing fetal abdominal circumference (AC) during mid-pregnancy and increased risk for eczema and atopy. We sought to replicate these findings in a Saudi population where antenatal environmental exposures are different compared with Western countries. A Saudi birth cohort was recruited to relate maternal dietary intake and fetal growth to wheeze, eczema, and rhinitis in the first 2 yrs. Fetal size was determined from routine ultrasound scan measurements in the second and third trimesters and birthweight was noted. Parent-reported outcomes during the first 2 yrs were acquired by telephone-administered questionnaire. There were 1076 mothers recruited. AC was determined in 562 for the second, in 632 for the third, and in 281 for both second and third trimesters. A history of eczema was determined in 814 children at 2 yrs of age. There was an inverse relationship between change in abdominal circumference between the second and third trimesters for eczema (OR 0.66 per z score increase in AC [95% CI 0.49, 0.89]), and the quartile with the greatest faltering growth were at increased risk compared with other groups (p ≤ 0.045). Change in fetal size between the third trimester and birth was not associated with altered eczema risk. There were no associations between fetal growth and wheeze at the age of 2 yrs. Our findings contrast observations made in Western populations but nonetheless suggest that factors associated with changing fetal growth trajectory in the second half of pregnancy are also relevant to atopy development on the global setting. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Math Growth Trajectories of Students with Disabilities: Disability Category, Gender, Racial, and Socioeconomic Status Differences from Ages 7 to 17

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Wei, Xin; Lenz, Keith B.; Blackorby, Jose

2013-01-01

This study examined math growth trajectories by disability category, gender, race, and socioeconomic status using a nationally representative sample of students ages 7 to 17. The students represented 11 federal disability categories. Compared with the national norming sample, students in all 11 disability categories had lower math achievement…

The Impact of Salient Role Stress on Trajectories of Health in Late Life among Survivors of a Seven-Year Panel Study: Analyses of Individual Growth Curves

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Shaw, Benjamin A.; Krause, Neal

2002-01-01

The purpose of this study is twofold: 1) to model changes in health over time among older adults; and 2) to assess the degree to which stress arising in salient social roles accounts for individual variation in these changes. Individual growth curve analyses using Hierarchical Linear Modeling (HLM) software were employed with longitudinal data…

Trajectories of mothers' emotional availability: relations with infant temperament in predicting attachment security.

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Kim, Bo-Ram; Chow, Sy-Miin; Bray, Bethany; Teti, Douglas M

2017-02-01

The present study examined observations of parenting quality (mothers' emotional availability - EA) during infant bedtimes at 4 points across the infants' first year, assessing relations between levels and trajectories of EA and infant attachment at 12 months and the role of infant temperament in moderating these associations. The sample (N = 128) was predominantly Euro-American (82.5%) and at low socioeconomic risk. Latent growth curve modeling with latent basis coefficients indicated substantial individual differences in initial levels and slopes in EA trajectories across the first year. Both levels of maternal EA and EA trajectories across the first year predicted 12-month infant attachment security. Although maternal EA tended to decrease across the first year in the full sample, EA trajectories that showed a "bounce-back" between 6 and 12 months, suggesting more successful maternal adaptation to an expanding infant developmental repertoire, predicted greater infant security at 12 months. In addition, linkages between latent EA trajectories and 12-month attachment were moderated by 3-month infant temperamental reactivity and regulation. These findings indicate that infant attachment security is sensitive to both static and dynamic aspects of parenting quality across the first year, and that infant temperament can interact with both in predicting infant attachment.

Body Mass Index Trajectories among Middle-Aged and Elderly Canadians and Associated Health Outcomes

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Meng Wang

2016-01-01

Full Text Available Background. Whether there is heterogeneity in the development of BMI from middle-age onward is still unknown. The primary aim of this study is to analyze long-term obesity and how BMI trajectories are associated with health outcomes in midlife. Methods. Latent Class Growth Modelling was used to capture the changes in BMI over time. In this study, 3070 individuals from the National Population Health Survey (NPHS, aged 40–55 years at baseline, were included. Results. Four BMI trajectory groups, “Normal-Stable” (N-S, “Overweight-Stable” (OV-S, “Obese I-Stable” (OB I-S, and “Obese II-Stable” (OB II-S, were identified. Men, persons of White ancestry, and individuals who had no postsecondary education had higher odds of being in the latter three groups. Moreover, members of the OV-S, OB I-S, and OB II-S groups experienced more asthma, arthritis, hypertension, diabetes, heart disease, cognitive impairment, and reduced self-rated overall health. Individuals in the OB II-S group were at greater risk for back problems, chronic bronchitis or emphysema, and emotional issues when compared to the N-S group. Conclusion. Understanding different BMI trajectories is important in order to identify people who are at the highest risk of developing comorbidities due to obesity and to establish programs to intervene appropriately.

Stunted at 10 Years. Linear Growth Trajectories and Stunting from Birth to Pre-Adolescence in a Rural Bangladeshi Cohort.

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Pernilla Svefors

Full Text Available Few studies in low-income settings analyse linear growth trajectories from foetal life to pre-adolescence. The aim of this study is to describe linear growth and stunting from birth to 10 years in rural Bangladesh and to analyse whether maternal and environmental determinants at conception are associated with linear growth throughout childhood and stunting at 10 years.Pregnant women participating in the MINIMat trial were identified in early pregnancy and a birth cohort (n = 1054 was followed with 19 growth measurements from birth to 10 years. Analyses of baseline predictors and mean height-for-age Z-scores (HAZ over time were modelled using GLMM. Logistic regression analysis was used to investigate the associations between baseline predictors and stunting (HAZ<-2 at 10 years. HAZ decreased to 2 years, followed by an increase up to 10 years, while the average height-for-age difference in cm (HAD to the WHO reference median continued to increase up to 10 years. Prevalence of stunting was highest at 2 years (50% decreasing to 29% at 10 years. Maternal height, maternal educational level and season of conception were all independent predictors of HAZ from birth to pre-adolescence (p<0.001 and stunting at 10 years. The highest probability to be stunted at 10 years was for children born by short mothers (<147.5 cm (ORadj 2.93, 95% CI: 2.06-4.20, mothers with no education (ORadj 1.74, 95% CI 1.17-2.81 or those conceived in the pre-monsoon season (ORadj 1.94, 95% CI 1.37-2.77.Height growth trajectories and prevalence of stunting in pre-adolescence showed strong intergenerational associations, social differentials, and environmental influence from foetal life. Targeting women before and during pregnancy is needed for the prevention of impaired child growth.

Social Dimensions of Personal Growth following Widowhood: A Three-Wave Study.

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Recksiedler, Claudia; Loter, Katharina; Klaas, Hannah S; Hollstein, Betina; Perrig-Chiello, Pasqualina

2018-01-01

Losing one's spouse is one of the most stressful life events in old age, yet research on positive consequences of overcoming critical life events describes experiences of personal growth for survivors. Because prior studies conceptualized personal growth as a stable accomplishment of an individual, our study challenges this assumption by examining trajectories of personal growth and its links to two aspects of social support. We assume that personal growth is boosted by heightened levels of loss-related social support seeking during early years of widowhood. However, toward the later stages in the bereavement process, we expect personal growth to be fostered by perceived social embeddedness. Data stem from a survey on relationships in later life conducted in 2012, 2014, and 2016 in Switzerland. The final analytical sample consisted of 508 individuals aged 50+ years, who were on average 73 years old and widowed for about 3 years at baseline. Longitudinal explorative factor analyses yielded a 3-factorial solution for personal growth. Random-effects group-specific growth curves were used to examine the trajectories of personal growth and its subdimensions, by different levels of loss-related social support seeking and embeddedness in a supportive network, over the first 8 years of widowhood. Our analyses included time-invariant and time-varying covariates. On average, our findings point to a stable trajectory of personal growth after having become widowed in later life. Group-specific analyses, however, showed different courses in the trajectories for specific subdimensions of personal growth - particularly for spiritual change and appreciation of life. Average marginal effects also yielded group differences by loss-related support seeking in the level of personal growth over time, which highlight the importance of social support seeking, rather than social embeddedness, at all stages of the bereavement process. Findings underline the importance of a longitudinal and

Long-term trajectories of posttraumatic stress disorder in veterans

DEFF Research Database (Denmark)

Karstoft, Karen-Inge; Armour, Cherie; Elklit, Ask

2013-01-01

OBJECTIVE: To (1) identify long-term trajectories of combat-induced posttraumatic stress disorder (PTSD) symptoms over a 20-year period from 1983 to 2002 in veterans with and without combat stress reaction (CSR) and (2) identify social predictors of these trajectories. METHOD: A latent growth...

Trajectories of health-related quality of life during the natural history of dementia: a six-wave longitudinal study.

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Yu, Hongmei; Gao, Caihong; Zhang, Yanbo; He, Runlian; Zhou, Liye; Liang, Ruifeng

2017-09-01

The objective of this study was to explore profiles of quality of life (QoL) trajectories during the natural history of dementia and individual variations contributing to QoL trajectories. We conducted a longitudinal community-based study of 520 elderly people with mild cognitive impairment and 100 healthy people aged 60 years or over. We conducted six waves of assessment between October 2010 and May 2013 in Taiyuan, mainland China. Cognitively normal, mild cognitive impairment, global impairment, and Alzheimer's disease (AD) were defined as state 1, 2, 3, and 4, respectively. We assessed health-related QoL (HRQoL) via the Quality of Life-Alzheimer's Disease (QoL-AD) Chinese version. We used the latent growth curve model (LGCM) to investigate change in HRQoL over time. Latent growth curve model analysis revealed a mean initial QoL level of 29.865 with substantial variation and a significant mean slope for the whole sample. Multigroup LGCM showed substantial variations across individuals in initial QoL levels for each cognitive state transition group. For the slope factor, we found significant changes and variations for the transition from state 2 to 3 and from state 3 to 4. We estimated mean QoL levels over six assessments based on intercept, slope, and factor loadings for the whole sample and the three cognitive state transition groups. A decline in subjective QoL is not inevitable during the natural history of dementia in community settings, and there is a degree of individual variation in QoL. Future studies should investigate the factors associated with individual variations in QoL trajectories in AD. Copyright © 2016 John Wiley & Sons, Ltd.

Trajectories of Depressive Symptoms in Older Adults and Risk of Dementia.

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Kaup, Allison R; Byers, Amy L; Falvey, Cherie; Simonsick, Eleanor M; Satterfield, Suzanne; Ayonayon, Hilsa N; Smagula, Stephen F; Rubin, Susan M; Yaffe, Kristine

2016-05-01

Depression has been identified as a risk factor for dementia. However, most studies have measured depressive symptoms at only one time point, and older adults may show different patterns of depressive symptoms over time. To investigate the association between trajectories of depressive symptoms and risk of dementia in older adults. This was a prospective cohort investigation of black and white community-dwelling older adults in the Health, Aging, and Body Composition study. Participants were enrolled between May 1997 and June 1998 and followed up through 2001-2002. The dates of this analysis were September 2014 to December 2015. The setting was community research centers in Memphis, Tennessee, and Pittsburgh, Pennsylvania. Trajectories of depressive symptoms were assessed from baseline to year 5. Symptoms were measured with the Center for Epidemiologic Studies Depression Scale Short Form, and trajectories were calculated using latent class growth curve analysis. Incident dementia through year 11, determined by dementia medication use, hospital records, or significant cognitive decline (≥1.5 SD race-specific decline on the Modified Mini-Mental State Examination). We examined the association between depressive symptom trajectories and dementia incidence using Cox proportional hazards regression models adjusted for demographics, health factors that differed between groups, and cognition during the depressive symptom assessment period (baseline to year 5). The analytic cohort included 2488 black and white older adults with repeated depressive symptom assessments from baseline to year 5 who were free of dementia throughout that period. Their mean (SD) age at baseline was 74.0 (2.8) years, and 53.1% (n = 1322) were female. The following 3 depressive symptom trajectories were identified: consistently minimal symptoms (62.0% [n = 1542] of participants), moderate and increasing symptoms (32.2% [n = 801] of participants), and high and increasing symptoms (5

Trajectories of Intimate Partner Violence Victimization

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Kevin M. Swartout

2012-08-01

Full Text Available Introduction: The purposes of this study were to assess the extent to which latent trajectories of female intimate partner violence (IPV victimization exist; and, if so, use negative childhood experiences to predict trajectory membership.Methods: We collected data from 1,575 women at 5 time-points regarding experiences during adolescence and their 4 years of college. We used latent class growth analysis to fit a series of personcentered, longitudinal models ranging from 1 to 5 trajectories. Once the best-fitting model was selected, we used negative childhood experience variables—sexual abuse, physical abuse, and witnessing domestic violence—to predict most-likely trajectory membership via multinomial logistic regression.Results: A 5-trajectory model best fit the data both statistically and in terms of interpretability. The trajectories across time were interpreted as low or no IPV, low to moderate IPV, moderate to low IPV, high to moderate IPV, and high and increasing IPV, respectively. Negative childhood experiences differentiated trajectory membership, somewhat, with childhood sexual abuse as a consistent predictor of membership in elevated IPV trajectories.Conclusion: Our analyses show how IPV risk changes over time and in different ways. These differential patterns of IPV suggest the need for prevention strategies tailored for women that consider victimization experiences in childhood and early adulthood. [West J Emerg Med. 2012;13(3:272–277.

Developmental trajectories of bullying and associated factors.

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Pepler, Debra; Jiang, Depeng; Craig, Wendy; Connolly, Jennifer

2008-01-01

Trajectories in bullying through adolescence were studied along with individual, family, and peer relationship factors. At the outset, participants' ages ranged from 10 to 14; 74% identified as European Canadian with the remainder from diverse backgrounds. With 8 waves of data over 7 years, 871 students (466 girls and 405 boys) were studied to reveal 4 trajectories: 9.9% reported consistently high levels of bullying, 13.4% reported early moderate levels desisting to almost no bullying at the end of high school, 35.1% reported consistently moderate levels, and 41.6% almost never reported bullying. Students who bullied had elevated risks in individual, parent, and peer relationship domains. Risk profiles and trajectories provide direction for interventions to curtail the development of power and aggression in relationships.

Simulation of Growth Trajectories of Childhood Obesity into Adulthood.

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Ward, Zachary J; Long, Michael W; Resch, Stephen C; Giles, Catherine M; Cradock, Angie L; Gortmaker, Steven L

2017-11-30

Although the current obesity epidemic has been well documented in children and adults, less is known about long-term risks of adult obesity for a given child at his or her present age and weight. We developed a simulation model to estimate the risk of adult obesity at the age of 35 years for the current population of children in the United States. We pooled height and weight data from five nationally representative longitudinal studies totaling 176,720 observations from 41,567 children and adults. We simulated growth trajectories across the life course and adjusted for secular trends. We created 1000 virtual populations of 1 million children through the age of 19 years that were representative of the 2016 population of the United States and projected their trajectories in height and weight up to the age of 35 years. Severe obesity was defined as a body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) of 35 or higher in adults and 120% or more of the 95th percentile in children. Given the current level of childhood obesity, the models predicted that a majority of today's children (57.3%; 95% uncertainly interval [UI], 55.2 to 60.0) will be obese at the age of 35 years, and roughly half of the projected prevalence will occur during childhood. Our simulations indicated that the relative risk of adult obesity increased with age and BMI, from 1.17 (95% UI, 1.09 to 1.29) for overweight 2-year-olds to 3.10 (95% UI, 2.43 to 3.65) for 19-year-olds with severe obesity. For children with severe obesity, the chance they will no longer be obese at the age of 35 years fell from 21.0% (95% UI, 7.3 to 47.3) at the age of 2 years to 6.1% (95% UI, 2.1 to 9.9) at the age of 19 years. On the basis of our simulation models, childhood obesity and overweight will continue to be a major health problem in the United States. Early development of obesity predicted obesity in adulthood, especially for children who were severely obese. (Funded by the JPB

A Latent Growth Mixture Modeling Approach to PTSD Symptoms in Rape Victims.

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Armour, Cherie; Shevlin, Mark; Elklit, Ask; Mroczek, Dan

2012-03-01

The research literature has suggested that longitudinal changes in posttraumatic stress disorder (PTSD) could be adequately described in terms of one universal trajectory, with individual differences in baseline levels (intercept) and rate of change (slope) being negligible. However, not everyone who has experienced a trauma is diagnosed with PTSD, and symptom severity levels differ between individuals exposed to similar traumas. The current study employed the latent growth mixture modeling technique to test for multiple trajectories using data from a sample of Danish rape victims (N = 255). In addition, the analysis aimed to determine whether a number of explanatory variables could differentiate between the trajectories (age, acute stress disorder [ASD], and perceived social support). Results concluded the existence of two PTSD trajectories. ASD was found to be the only significant predictor of one trajectory characterized by high initial levels of PTSD symptomatology. The present findings confirmed the existence of multiple trajectories with regard to PTSD symptomatology in a way that may be useful to clinicians working with this population.

A Latent Growth Mixture Modeling Approach to PTSD Symptoms in Rape Victims

Science.gov (United States)

Armour, Cherie; Shevlin, Mark; Elklit, Ask; Mroczek, Dan

2012-01-01

The research literature has suggested that longitudinal changes in posttraumatic stress disorder (PTSD) could be adequately described in terms of one universal trajectory, with individual differences in baseline levels (intercept) and rate of change (slope) being negligible. However, not everyone who has experienced a trauma is diagnosed with PTSD, and symptom severity levels differ between individuals exposed to similar traumas. The current study employed the latent growth mixture modeling technique to test for multiple trajectories using data from a sample of Danish rape victims (N = 255). In addition, the analysis aimed to determine whether a number of explanatory variables could differentiate between the trajectories (age, acute stress disorder [ASD], and perceived social support). Results concluded the existence of two PTSD trajectories. ASD was found to be the only significant predictor of one trajectory characterized by high initial levels of PTSD symptomatology. The present findings confirmed the existence of multiple trajectories with regard to PTSD symptomatology in a way that may be useful to clinicians working with this population. PMID:22661909

Using Bayesian statistics for modeling PTSD through Latent Growth Mixture Modeling: implementation and discussion

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Sarah Depaoli

2015-03-01

Full Text Available Background: After traumatic events, such as disaster, war trauma, and injuries including burns (which is the focus here, the risk to develop posttraumatic stress disorder (PTSD is approximately 10% (Breslau & Davis, 1992. Latent Growth Mixture Modeling can be used to classify individuals into distinct groups exhibiting different patterns of PTSD (Galatzer-Levy, 2015. Currently, empirical evidence points to four distinct trajectories of PTSD patterns in those who have experienced burn trauma. These trajectories are labeled as: resilient, recovery, chronic, and delayed onset trajectories (e.g., Bonanno, 2004; Bonanno, Brewin, Kaniasty, & Greca, 2010; Maercker, Gäbler, O'Neil, Schützwohl, & Müller, 2013; Pietrzak et al., 2013. The delayed onset trajectory affects only a small group of individuals, that is, about 4–5% (O'Donnell, Elliott, Lau, & Creamer, 2007. In addition to its low frequency, the later onset of this trajectory may contribute to the fact that these individuals can be easily overlooked by professionals. In this special symposium on Estimating PTSD trajectories (Van de Schoot, 2015a, we illustrate how to properly identify this small group of individuals through the Bayesian estimation framework using previous knowledge through priors (see, e.g., Depaoli & Boyajian, 2014; Van de Schoot, Broere, Perryck, Zondervan-Zwijnenburg, & Van Loey, 2015. Method: We used latent growth mixture modeling (LGMM (Van de Schoot, 2015b to estimate PTSD trajectories across 4 years that followed a traumatic burn. We demonstrate and compare results from traditional (maximum likelihood and Bayesian estimation using priors (see, Depaoli, 2012, 2013. Further, we discuss where priors come from and how to define them in the estimation process. Results: We demonstrate that only the Bayesian approach results in the desired theory-driven solution of PTSD trajectories. Since the priors are chosen subjectively, we also present a sensitivity analysis of the

Analyzing growth trajectories

Czech Academy of Sciences Publication Activity Database

McKeague, I. W.; López-Pintado, S.; Hallin, M.; Šiman, Miroslav

2011-01-01

Roč. 2, č. 6 (2011), s. 322-329 ISSN 2040-1744 R&D Projects: GA MŠk(CZ) 1M06047 Institutional research plan: CEZ:AV0Z10750506 Keywords : data depth contours * growth curves * nonparametric Bayes Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 1.556, year: 2011 http://library.utia.cas.cz/separaty/2011/SI/siman-0376411.pdf

The mean and the individual: Integrating variable-centered and person-centered analyses of cognitive recovery in patients with substance use disorders

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Marsha E. Bates

2013-12-01

Full Text Available Neuropsychological and cognitive deficits are observed in the majority of persons with alcohol and drug use disorders and may interfere with treatment processes and outcomes. Although, on average, the brain and cognition improve with abstinence or markedly reduced substance use, better understanding of the heterogeneity in the time-course and extent of cognitive recovery at the individual level is useful to promote bench-to-bedside translation and inform clinical decision making. This study integrated a variable-centered and a person-centered approach to characterize diversity in cognitive recovery in 197 patients in treatment for a substance use disorder. We assessed executive function, verbal ability, memory, and complex information processing speed at treatment entry, and then 6, 26, and 52 weeks later. Structural equation modeling was used to define underlying ability constructs and determine the mean level of cognitive changes in the sample while minimizing measurement error and practice effects on specific tests. Individual-level empirical growth plots of latent factor scores were used to explore prototypical trajectories of cognitive change. At the level of the mean, small to medium effect size gains in cognitive abilities were observed over one year. At the level of the individual, the mean trajectory of change was also the modal individual recovery trajectory shown by about half the sample. Other prototypical cognitive change trajectories observed in all four cognitive domains included Delayed Gain, Loss of Gain, and Continuous Gain. Together these trajectories encompassed between 86% and 94% of individual growth plots across the four latent abilities. Further research is needed to replicate and predict trajectory membership. Replication of the present findings would have useful implications for targeted treatment planning and the new cognitive interventions being developed to enhance treatment outcomes.

Estimation of Foot Plantar Center of Pressure Trajectories with Low-Cost Instrumented Insoles Using an Individual-Specific Nonlinear Model

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Xinyao Hu

2018-02-01

Full Text Available Postural control is a complex skill based on the interaction of dynamic sensorimotor processes, and can be challenging for people with deficits in sensory functions. The foot plantar center of pressure (COP has often been used for quantitative assessment of postural control. Previously, the foot plantar COP was mainly measured by force plates or complicated and expensive insole-based measurement systems. Although some low-cost instrumented insoles have been developed, their ability to accurately estimate the foot plantar COP trajectory was not robust. In this study, a novel individual-specific nonlinear model was proposed to estimate the foot plantar COP trajectories with an instrumented insole based on low-cost force sensitive resistors (FSRs. The model coefficients were determined by a least square error approximation algorithm. Model validation was carried out by comparing the estimated COP data with the reference data in a variety of postural control assessment tasks. We also compared our data with the COP trajectories estimated by the previously well accepted weighted mean approach. Comparing with the reference measurements, the average root mean square errors of the COP trajectories of both feet were 2.23 mm (±0.64 (left foot and 2.72 mm (±0.83 (right foot along the medial–lateral direction, and 9.17 mm (±1.98 (left foot and 11.19 mm (±2.98 (right foot along the anterior–posterior direction. The results are superior to those reported in previous relevant studies, and demonstrate that our proposed approach can be used for accurate foot plantar COP trajectory estimation. This study could provide an inexpensive solution to fall risk assessment in home settings or community healthcare center for the elderly. It has the potential to help prevent future falls in the elderly.

Estimation of Foot Plantar Center of Pressure Trajectories with Low-Cost Instrumented Insoles Using an Individual-Specific Nonlinear Model.

Science.gov (United States)

Hu, Xinyao; Zhao, Jun; Peng, Dongsheng; Sun, Zhenglong; Qu, Xingda

2018-02-01

Postural control is a complex skill based on the interaction of dynamic sensorimotor processes, and can be challenging for people with deficits in sensory functions. The foot plantar center of pressure (COP) has often been used for quantitative assessment of postural control. Previously, the foot plantar COP was mainly measured by force plates or complicated and expensive insole-based measurement systems. Although some low-cost instrumented insoles have been developed, their ability to accurately estimate the foot plantar COP trajectory was not robust. In this study, a novel individual-specific nonlinear model was proposed to estimate the foot plantar COP trajectories with an instrumented insole based on low-cost force sensitive resistors (FSRs). The model coefficients were determined by a least square error approximation algorithm. Model validation was carried out by comparing the estimated COP data with the reference data in a variety of postural control assessment tasks. We also compared our data with the COP trajectories estimated by the previously well accepted weighted mean approach. Comparing with the reference measurements, the average root mean square errors of the COP trajectories of both feet were 2.23 mm (±0.64) (left foot) and 2.72 mm (±0.83) (right foot) along the medial-lateral direction, and 9.17 mm (±1.98) (left foot) and 11.19 mm (±2.98) (right foot) along the anterior-posterior direction. The results are superior to those reported in previous relevant studies, and demonstrate that our proposed approach can be used for accurate foot plantar COP trajectory estimation. This study could provide an inexpensive solution to fall risk assessment in home settings or community healthcare center for the elderly. It has the potential to help prevent future falls in the elderly.

Individual heterogeneity and offspring sex affect the growth-reproduction trade-off in a mammal with indeterminate growth.

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Gélin, Uriel; Wilson, Michelle E; Cripps, Jemma; Coulson, Graeme; Festa-Bianchet, Marco

2016-04-01

Reproduction can lead to a trade-off with growth, particularly when individuals reproduce before completing body growth. Kangaroos have indeterminate growth and may always face this trade-off. We combined an experimental manipulation of reproductive effort and multi-year monitoring of a large sample size of marked individuals in two populations of eastern grey kangaroos to test the predictions (1) that reproduction decreases skeletal growth and mass gain and (2) that mass loss leads to reproductive failure. We also tested if sex-allocation strategies influenced these trade-offs. Experimental reproductive suppression revealed negative effects of reproduction on mass gain and leg growth from 1 year to the next. Unmanipulated females, however, showed a positive correlation between number of days lactating and leg growth over periods of 2 years and longer, suggesting that over the long term, reproductive costs were masked by individual heterogeneity in resource acquisition. Mass gain was necessary for reproductive success the subsequent year. Although mothers of daughters generally lost more mass than females nursing sons, mothers in poor condition experienced greater mass gain and arm growth if they had daughters than if they had sons. The strong links between individual mass changes and reproduction suggest that reproductive tactics are strongly resource-dependent.

Trajectories of body mass index amongst children who develop type 2 diabetes as adults.

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Eriksson, J G; Kajantie, E; Lampl, M; Osmond, C

2015-08-01

Type 2 diabetes (T2D) is a heterogeneous disorder. The aim of this study was to examine the trajectories of childhood growth associated with T2D. A total of 13 345 individuals born in Helsinki, Finland between 1934 and 1944 were included in the study. The participants' growth had been recorded in detail during childhood, and 11.7% (n = 1558) had been diagnosed with T2D. We divided the cohort around the median body mass index (BMI) at 11 years. Body composition and glucose tolerance were assessed in a clinical subsample (n = 2003) in adulthood. Two pathways of growth were associated with T2D. Both began with low weight and BMI at birth. In one, persistent low BMI through infancy was followed by a rapid increase in BMI in childhood. Amongst individuals with a BMI at 11 years above the median value, the odds ratio for T2D associated with a one z-score increase in BMI between 2 and 11 years was 1.31 (95% confidence interval 1.21-1.42, P developed diabetes followed this trajectory; they developed T2D at a lower BMI and lower fat percentage than women with a BMI above the median at 11 years of age. Two pathways of early growth trigger T2D. Low fat deposition leading to thinness at birth and during infancy results in fat acquisition during childhood. Reduced linear growth leading to short length at birth is associated with lower body fat percentage in adulthood but increased risk of developing diabetes. © 2015 The Association for the Publication of the Journal of Internal Medicine.

Differences in growth trajectory and strategy of two sympatric congeneric species in an Indonesian floodplain forest.

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Yamada, Toshihiro; Ngakan, Oka Putu; Suzuki, Eizi

2005-01-01

Whole-plant development trajectories and sapling leaf displays were compared for two sympatric congeneric species, Pterospermum diversifolium and P. javanicum, in a tropical floodplain forest in East Kalimantan, Indonesia. We assessed their growth strategies and developed hypotheses for their coexistence within the community. Pterospermum diversifolium retains a monoaxial growth habit that promotes quick stem elongation; thus, it is taller when branches are initiated than is P. javanicum. The species differed significantly in height growth and total crown expansion per unit increment of biomass: monoaxial P. diversifolium saplings devote more effort to stem elongation, whereas branched P. javanicum saplings devote more effort to branch expansion. Monoaxial P. diversifolium sustained more severe self-shading than P. javanicum. The sapling growth strategy of P. diversifolium appears to be dynamic, emphasizing the opportunistic use of light following a disturbance, whereas that of P. javanicum appears to be static, optimizing leaf display for current light conditions. The advantages of these strategies depend on context, and the two species may coexist within a community by adopting different regeneration niches based on differing understory light conditions: P. diversifolium is favored over P. javanicum at high light levels, but the opposite is true at low light levels.

Multiple growth-correlated life history traits estimated simultaneously in indivuals

NARCIS (Netherlands)

Mollet, F.M.; Ernande, B.; Brunel, T.P.A.; Rijnsdorp, A.D.

2010-01-01

We present a new methodology to estimate rates of energy acquisition, maintenance, reproductive investment and the onset of maturation (four-trait estimation) by fitting an energy allocation model to individual growth trajectories. The accuracy and precision of the method is evaluated on simulated

Trajectories of women's abortion-related care: A conceptual framework.

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Coast, Ernestina; Norris, Alison H; Moore, Ann M; Freeman, Emily

2018-03-01

We present a new conceptual framework for studying trajectories to obtaining abortion-related care. It assembles for the first time all of the known factors influencing a trajectory and encourages readers to consider the ways these macro- and micro-level factors operate in multiple and sometimes conflicting ways. Based on presentation to and feedback from abortion experts (researchers, providers, funders, policymakers and advisors, advocates) (n = 325) between 03/06/2014 and 22/08/2015, and a systematic mapping of peer-reviewed literature (n = 424) published between 01/01/2011 and 30/10/2017, our framework synthesises the factors shaping abortion trajectories, grouped into three domains: abortion-specific experiences, individual contexts, and (inter)national and sub-national contexts. Our framework includes time-dependent processes involved in an individual trajectory, starting with timing of pregnancy awareness. This framework can be used to guide testable hypotheses about enabling and inhibiting influences on care-seeking behaviour and consideration about how abortion trajectories might be influenced by policy or practice. Research based on understanding of trajectories has the potential to improve women's experiences and outcomes of abortion-related care. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Modeling the Nature of Grammar and Vocabulary Trajectories From Prekindergarten to Third Grade.

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Jiang, Hui; Logan, Jessica A; Jia, Rongfang

2018-04-17

This study investigated the longitudinal development of 2 important contributors to reading comprehension, grammar, and vocabulary skills. The primary interest was to examine the trajectories of the 2 skill areas from preschool to 3rd grade. The study involved a longitudinal sample of 420 children from 4 sites. Language skills, including grammar and vocabulary, were assessed annually with multiple measures. Multivariate latent growth curve modeling was used to examine the developmental trajectories of grammar and vocabulary, to test the correlation between the 2 domains, and to investigate the effects of demographic predictors on language growth. Results showed that both grammar and vocabulary exhibited decelerating growth from preschool to Grade 2. In Grade 3, grammar growth further flattened, whereas vocabulary continued to grow stably. Growth of vocabulary and grammar were positively correlated. Demographic characteristics, such as child gender and family socioeconomic status, were found to predict the intercept but not the slope of the growth trajectories. Children's growth in grammar skills is differentiated in a number of important ways from their growth in vocabulary skills. Results of this study suggest the need to differentiate these dimensions of language when seeking to closely examine growth from preschool to primary grades.

Identifying Trajectories of Borderline Personality Features in Adolescence: Antecedent and Interactive Risk Factors.

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Haltigan, John D; Vaillancourt, Tracy

2016-03-01

To examine trajectories of adolescent borderline personality (BP) features in a normative-risk cohort (n = 566) of Canadian children assessed at ages 13, 14, 15, and 16 and childhood predictors of trajectory group membership assessed at ages 8, 10, 11, and 12. Data were drawn from the McMaster Teen Study, an on-going study examining relations among bullying, mental health, and academic achievement. Participants and their parents completed a battery of mental health and peer relations questionnaires at each wave of the study. Academic competence was assessed at age 8 (Grade 3). Latent class growth analysis, analysis of variance, and logistic regression were used to analyze the data. Three distinct BP features trajectory groups were identified: elevated or rising, intermediate or stable, and low or stable. Parent- and child-reported mental health symptoms, peer relations risk factors, and intra-individual risk factors were significant predictors of elevated or rising and intermediate or stable trajectory groups. Child-reported attention-deficit hyperactivity disorder (ADHD) and somatization symptoms uniquely predicted elevated or rising trajectory group membership, whereas parent-reported anxiety and child-reported ADHD symptoms uniquely predicted intermediate or stable trajectory group membership. Child-reported somatization symptoms was the only predictor to differentiate the intermediate or stable and elevated or rising trajectory groups (OR 1.15, 95% CI 1.04 to 1.28). Associations between child-reported reactive temperament and elevated BP features trajectory group membership were 10.23 times higher among children who were bullied, supporting a diathesis-stress pathway in the development of BP features for these youth. Findings demonstrate the heterogeneous course of BP features in early adolescence and shed light on the potential prodromal course of later borderline personality disorder. © The Author(s) 2015.

Exploring Categorical Body Mass Index Trajectories in Elementary School Children

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Moreno-Black, Geraldine; Boles, Shawn; Johnson-Shelton, Deb; Evers, Cody

2016-01-01

Background: Studies of body mass index (BMI) change have focused on understanding growth trajectories from childhood to adolescence and adolescence to adulthood, but few have explored BMI trajectories solely in elementary (grades K-5) school children. This report complements these studies by exploring changes in obesity status using analytic…

Advancing nursing science through health trajectory research: an introduction.

Science.gov (United States)

Wyman, Jean F; Henly, Susan J

2011-01-01

The Minnesota Center for Health Trajectory Research has focused on developing ways to better understand how interventions influence health trajectories during transitional, acute, or chronic health challenges across the life span. The health trajectory perspective advances nursing science by providing a person-centered point of view that emphasizes change in health over time within individuals, families, groups, or communities. Theoretical considerations and statistical modeling approaches used in studying health trajectories, along with exemplars from nursing research studies from this special issue of Nursing Research, are highlighted.

Trajectories of schizotypy and their emotional and social functioning: An 18-month follow-up study.

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Wang, Yi; Shi, Hai-Song; Liu, Wen-Hua; Xie, Dong-Jie; Geng, Fu-Lei; Yan, Chao; Wang, Ya; Xiao, Ya-Hui; So, Suzanne H W; Chiu, Chui-De; Leung, Patrick W L; Cheung, Eric F C; Gooding, Diane C; Chan, Raymond C K

2018-03-01

Schizotypy is a set of personality traits that convey liability to develop schizophrenia. Studying schizotypy in healthy individuals may facilitate the understanding of the psychopathological processes underlying schizophrenia. The present study aimed to examine the developmental trajectories of schizotypy over time using a longitudinal study design. The Chapman Scales for Psychosis Proneness were administered to 1541 college students at baseline, and subsequently at six-monthly intervals up to 18months. Latent class growth analysis was conducted to track the different trajectories. In addition, self-reported scales were used to measure idea of reference, emotional experiences and expression, stress and coping, as well as social functioning. We identified four latent classes with distinct trajectories: "nonschizotypy" group (LC1), "stable high schizotypy" group (LC3), "high reactive schizotypy" group (LC2) and "low reactive schizotypy" group (LC4). These findings suggest that there may be distinct developmental trajectories for schizotypy. Two groups may be of particular interest: the "stable high schizotypy" group that displayed the worst clinical and functioning outcomes on almost all measures and the "high reactive schizotypy" group characterized by a relatively rapid decline in functioning. Copyright © 2017 Elsevier B.V. All rights reserved.

The Language Growth of Spanish-Speaking English Language Learners

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Rojas, Raul; Iglesias, Aquiles

2013-01-01

Although the research literature regarding language growth trajectories is burgeoning, the shape and direction of English Language Learners' (ELLs) language growth trajectories are largely not known. This study used growth curve modeling to determine the shape of ELLs' language growth trajectories across 12,248 oral narrative language samples…

Stochastic Individual-Based Modeling of Bacterial Growth and Division Using Flow Cytometry

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Míriam R. García

2018-01-01

Full Text Available A realistic description of the variability in bacterial growth and division is critical to produce reliable predictions of safety risks along the food chain. Individual-based modeling of bacteria provides the theoretical framework to deal with this variability, but it requires information about the individual behavior of bacteria inside populations. In this work, we overcome this problem by estimating the individual behavior of bacteria from population statistics obtained with flow cytometry. For this objective, a stochastic individual-based modeling framework is defined based on standard assumptions during division and exponential growth. The unknown single-cell parameters required for running the individual-based modeling simulations, such as cell size growth rate, are estimated from the flow cytometry data. Instead of using directly the individual-based model, we make use of a modified Fokker-Plank equation. This only equation simulates the population statistics in function of the unknown single-cell parameters. We test the validity of the approach by modeling the growth and division of Pediococcus acidilactici within the exponential phase. Estimations reveal the statistics of cell growth and division using only data from flow cytometry at a given time. From the relationship between the mother and daughter volumes, we also predict that P. acidilactici divide into two successive parallel planes.

The periconception maternal cardiovascular risk profile influences human embryonic growth trajectories in IVF/ICSI pregnancies.

Science.gov (United States)

Wijnands, K P J; van Uitert, E M; Roeters van Lennep, J E; Koning, A H J; Mulders, A G M G J; Laven, J S E; Steegers, E A P; Steegers-Theunissen, R P M

2016-06-01

Is the maternal cardiovascular (CV) risk profile associated with human embryonic growth trajectories and does the mode of conception affect this association? This small study suggests that the maternal CV risk profile is inversely associated with first trimester embryonic growth trajectories in in vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) pregnancies, but not in spontaneously conceived pregnancies. Maternal high-blood pressure and smoking affect placental function, accompanied by increased risk of fetal growth restriction and low-birthweight. Mothers who experience pregnancies complicated by fetal growth restriction are at increased risk of CV disease in later life. In a prospective periconception birth cohort conducted in a tertiary hospital, 111 singleton ongoing pregnancies with reliable pregnancy dating, no pre-existing maternal disease and no malformed live borns were investigated. Spontaneously conceived pregnancies with a reliable first day of the last menstrual period and a regular menstrual cycle of 25-31 days only (n = 66) and IVF/ICSI pregnancies (n = 45) were included. Women underwent weekly three-dimensional ultrasound scans (3D US) from 6- to 13-week gestational age. To estimate embryonic growth, serial crown-rump length (CRL) measurements were performed using the V-Scope software in a BARCO I-Space. Maternal characteristics and CV risk factors were collected by self-administered questionnaires. The CV risk profile was created based on a score of risk factors, including maternal age, body-mass index, CV disease in the family, diet and smoking. Quartiles of the CV risk score were calculated. Associations between the CV risk score and embryonic growth were assessed using square root transformed CRL in multivariable linear mixed model analyses. From the 111 included pregnancies, 696 3D US data sets were obtained of which 637 (91.5%) CRLs could be measured. In the total group, The CV risk score was inversely, but not significantly

Mean motion and trajectories of heavy particles falling through a boundary layer

Energy Technology Data Exchange (ETDEWEB)

Stout, J.E.; Arya, S.P. [North Carolina State Univ., Raleigh, NC (United States)

1994-12-31

As particles fall through a turbulent boundary layer they experience a rather complex and unique time series of aerodynamic forces and, thus, each individual particle follows a rather complex and unique trajectory to the surface. For sufficiently large and heavy particles, the turbulence induced particle motion can be thought of as a small perturbation superimposed on the mean trajectory. By ignoring the turbulent contribution to particle motion it is possible to calculate the trajectory of a particle due to the mean flow alone. The mean trajectory provides an estimate of the ensemble-averaged path of a set of particles released from a given point in the atmosphere. The effect of turbulence on individual particle trajectories, the distribution of particle displacements from the mean trajectory, and their deposition patterns on the surface will be investigated in a separate study, using a random walk model.

Positive Youth Development and Resilience: Growth Patterns of Social Skills Among Youth Investigated for Maltreatment.

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Oshri, Assaf; Topple, Trasie A; Carlson, Matthew W

2017-07-01

Maltreated children are a vulnerable population, yet many of these youth follow positive developmental pathways. The primary aim was to identify social skills growth trajectories among at-risk youth to understand processes underlying resilience. Nationally representative, longitudinal data from 1,179 families investigated for child maltreatment (M age  = 12.75) were obtained from the National Survey of Child and Adolescent Well-Being. Four trajectories were identified-stress-resistant, emergent resilience, breakdown, and unresponsive-maladaptive. Protective resources from multiple levels of the youth ecology (individual, family, school, and social service) predicted positive growth social skills trajectories. Resilience process and attendant positive outcomes in multiple domains of functioning were evident among the stress-resistant and emergent resilience trajectories. Results underscore the saliency of social skills development for resilient outcomes in youth. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

Parenting styles and body mass index trajectories from adolescence to adulthood.

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Fuemmeler, Bernard F; Yang, Chongming; Costanzo, Phil; Hoyle, Rick H; Siegler, Ilene C; Williams, Redford B; Ostbye, Truls

2012-07-01

Parenting styles such as authoritarian, disengaged, or permissive are thought to be associated with greater adolescent obesity risk than an authoritative style. This study assessed the relationship between parenting styles and changes in body mass index (BMI) from adolescence to young adulthood. The study included self-reported data from adolescents in the National Longitudinal Study of Adolescent Health. Factor mixture modeling, a data-driven approach, was used to classify participants into parenting style groups based on measures of acceptance and control. Latent growth modeling (LGM) identified patterns of developmental changes in BMI. After a number of potential confounders were controlled for, parenting style variables were entered as predictors of BMI trajectories. Analyses were also conducted for male and female individuals of 3 racial-ethnic groups (Hispanic, black, white) to assess whether parenting styles were differentially associated with BMI trajectories in these 6 groups. Parenting styles were classified into 4 groups: authoritarian, disengaged, permissive, and balanced. Compared with the balanced parenting style, authoritarian and disengaged parenting styles were associated with a less steep average BMI increase (linear slope) over time, but also less leveling off (quadratic) of BMI over time. Differences in BMI trajectories were observed for various genders and races, but the differences did not reach statistical significance. Adolescents who reported having parents with authoritarian or disengaged parenting styles had greater increases in BMI as they transitioned to young adulthood despite having a lower BMI trajectory through adolescence.

Predictors of Latent Trajectory Classes of Physical Dating Violence Victimization

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Brooks-Russell, Ashley; Foshee, Vangie A.; Ennett, Susan T.

2013-01-01

This study identified classes of developmental trajectories of physical dating violence victimization from grades 8 to 12 and examined theoretically-based risk factors that distinguished among trajectory classes. Data were from a multi-wave longitudinal study spanning 8th through 12th grade (n = 2,566; 51.9 % female). Growth mixture models were…

Predicting Change in Postpartum Depression: An Individual Growth Curve Approach.

Science.gov (United States)

Buchanan, Trey

Recently, methodologists interested in examining problems associated with measuring change have suggested that developmental researchers should focus upon assessing change at both intra-individual and inter-individual levels. This study used an application of individual growth curve analysis to the problem of maternal postpartum depression.…

Using Personality Traits to Construct Linear Growth Models of Mental Health in Family Members of Individuals With Severe Brain Injury

DEFF Research Database (Denmark)

Trujillo, Michael; Perrin, Paul B; Doser, Karoline

2016-01-01

Objective: No studies have examined the impact of personality traits on mental health among caregivers of individuals with severe brain injury. Therefore, the purpose of the current study was to construct linear growth models to examine whether the personality traits of family members...... neuroticism had lower anxiety and depression over time, as well as a more accelerated decrease in anxiety and depression. Conclusions: Caregivers' personality traits were strongly associated over time with mental HRQoL, anxiety, and depression, with neuroticism being especially important for trajectories...... the Short Form-36 assessing mental HRQoL (vitality, social functioning, role limitations-emotional, mental health), anxiety, and depression across 5 time points during the 1st year after injury. The measure of personality was administered 3 months after the patients' discharge. Results: All mental HRQo...

Trajectories of posttraumatic stress symptoms (PTSS) after major war among Palestinian children: Trauma, family- and child-related predictors.

Science.gov (United States)

Punamäki, Raija-Leena; Palosaari, Esa; Diab, Marwan; Peltonen, Kirsi; Qouta, Samir R

2015-02-01

Research shows great individual variation in changes in posttraumatic stress symptoms (PTSSs) after major traumas of terrorist attacks, military combat, and natural disasters. Earlier studies have identified specific mental health trajectories both in children and adults. This study aimed, first, to identify potential PTSS-related trajectories by using latent class growth analyses among children in a three-wave assessment after the 2008/2009 War on Gaza, Palestine. Second, it analyzed how family- and child related factors (e.g., attachment relations, posttraumatic cognitions (PTCs), guilt, and emotion regulation) associate with the trajectory class membership. The sample consisted of 240 Palestinian children (49.4% girls and 50.6% boys) of 10-13 years of age (M=11.29, SD=0.68), who completed PTSS (CRIES) assessments at 3 (T1), 5 (T2), and 11 (T3) months after the war. Children reported their personal exposure to war trauma, attachment style, cognitive trauma processing, and emotion regulation, and their parents reported family war trauma exposure and attachment style. Results revealed a three-trajectory solution, a majority of children belonging to the Recovery trajectory (n=183), and a minority belonged either to Resistant trajectory (n=29) or to Increasing symptoms trajectory (n=28). Low levels of negative posttraumatic cognitive appraisals, feelings of guilt and emotion regulation were characteristic of children in the Resistant trajectory as compared to Increasing symptoms trajectory. Father׳s attachment security was further associated with the Resistant trajectory membership. Children׳s attachment avoidance and high parental trauma were typical to children in Recovery trajectory (as compared to the Increasing symptoms trajectory). Copyright © 2014 Elsevier B.V. All rights reserved.

Trajectories of suicidal ideation in depressed older adults undergoing antidepressant treatment.

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Kasckow, John; Youk, Ada; Anderson, Stewart J; Dew, Mary Amanda; Butters, Meryl A; Marron, Megan M; Begley, Amy E; Szanto, Katalin; Dombrovski, Alexander Y; Mulsant, Benoit H; Lenze, Eric J; Reynolds, Charles F

2016-02-01

Suicide is a public health concern in older adults. Recent cross sectional studies suggest that impairments in executive functioning, memory and attention are associated with suicidal ideation in older adults. It is unknown whether these neuropsychological features predict persistent suicidal ideation. We analyzed data from 468 individuals ≥ age 60 with major depression who received venlafaxine XR monotherapy for up to 16 weeks. We used latent class growth modeling to classify groups of individuals based on trajectories of suicidal ideation. We also examined whether cognitive dysfunction predicted suicidal ideation while controlling for time-dependent variables including depression severity, and age and education. The optimal model using a zero inflated Poisson link classified individuals into four groups, each with a distinct temporal trajectory of suicidal ideation: those with 'minimal suicidal ideation' across time points; those with 'low suicidal ideation'; those with 'rapidly decreasing suicidal ideation'; and those with 'high and persistent suicidal ideation'. Participants in the 'high and persistent suicidal ideation' group had worse scores relative to those in the "rapidly decreasing suicidal ideation" group on the Color-Word 'inhibition/switching' subtest from the Delis-Kaplan Executive Function Scale, worse attention index scores on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and worse total RBANS index scores. These findings suggest that individuals with poorer ability to switch between inhibitory and non-inhibitory responses as well as worse attention and worse overall cognitive status are more likely to have persistently higher levels of suicidal ideation. CLINICALTRIAL. NCT00892047. Published by Elsevier Ltd.

Individualism in plant populations: using stochastic differential equations to model individual neighbourhood-dependent plant growth.

Science.gov (United States)

Lv, Qiming; Schneider, Manuel K; Pitchford, Jonathan W

2008-08-01

We study individual plant growth and size hierarchy formation in an experimental population of Arabidopsis thaliana, within an integrated analysis that explicitly accounts for size-dependent growth, size- and space-dependent competition, and environmental stochasticity. It is shown that a Gompertz-type stochastic differential equation (SDE) model, involving asymmetric competition kernels and a stochastic term which decreases with the logarithm of plant weight, efficiently describes individual plant growth, competition, and variability in the studied population. The model is evaluated within a Bayesian framework and compared to its deterministic counterpart, and to several simplified stochastic models, using distributional validation. We show that stochasticity is an important determinant of size hierarchy and that SDE models outperform the deterministic model if and only if structural components of competition (asymmetry; size- and space-dependence) are accounted for. Implications of these results are discussed in the context of plant ecology and in more general modelling situations.

Entropic Movement Complexity Reflects Subjective Creativity Rankings of Visualized Hand Motion Trajectories

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Peng, Zhen; Braun, Daniel A.

2015-01-01

In a previous study we have shown that human motion trajectories can be characterized by translating continuous trajectories into symbol sequences with well-defined complexity measures. Here we test the hypothesis that the motion complexity individuals generate in their movements might be correlated to the degree of creativity assigned by a human observer to the visualized motion trajectories. We asked participants to generate 55 novel hand movement patterns in virtual reality, where each pattern had to be repeated 10 times in a row to ensure reproducibility. This allowed us to estimate a probability distribution over trajectories for each pattern. We assessed motion complexity not only by the previously proposed complexity measures on symbolic sequences, but we also propose two novel complexity measures that can be directly applied to the distributions over trajectories based on the frameworks of Gaussian Processes and Probabilistic Movement Primitives. In contrast to previous studies, these new methods allow computing complexities of individual motion patterns from very few sample trajectories. We compared the different complexity measures to how a group of independent jurors rank ordered the recorded motion trajectories according to their personal creativity judgment. We found three entropic complexity measures that correlate significantly with human creativity judgment and discuss differences between the measures. We also test whether these complexity measures correlate with individual creativity in divergent thinking tasks, but do not find any consistent correlation. Our results suggest that entropic complexity measures of hand motion may reveal domain-specific individual differences in kinesthetic creativity. PMID:26733896

Heterogeneity in Trajectories of Child Maltreatment Severity: A Two-Part Growth Mixture Model

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Yampolskaya, Svetlana; Greenbaum, Paul E.; Brown, C. Hendricks; Armstrong, Mary I.

2016-01-01

This study examined the trajectories of maltreatment severity and substantiation over a 24-month period among children (N = 82,396) with repeated maltreatment reports. Findings revealed two different longitudinal patterns. The first pattern, Elevated Severity, showed a higher level of maltreatment during the initial incident and increased maltreatment severity during subsequent incidents but the substantiation rates for this class decreased over time. The second pattern, Lowered Severity, showed a much lower level of severity, but the likelihood of substantiation increased over time. The Elevated Severity class was comprised of children with an elevated risk profile due to both individual and contextual risk factors including older age, female gender, caregivers’ substance use problems, and a higher number of previous maltreatment reports. Implications of the findings are discussed. PMID:26300381

Academic Trajectories of Newcomer Immigrant Youth

Science.gov (United States)

Suarez-Orozco, Carola; Gaytan, Francisco X.; Bang, Hee Jin; Pakes, Juliana; O'Connor, Erin; Rhodes, Jean

2010-01-01

Immigration to the United States presents both challenges and opportunities that affect students' academic achievement. Using a 5-year longitudinal, mixed-methods approach, we identified varying academic trajectories of newcomer immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve…

Measuring the Distance of Moving Objects from Big Trajectory Data

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Khaing Phyo Wai

2017-03-01

Full Text Available Location-based services have become important in social networking, mobile applications, advertising, traffic monitoring, and many other domains. The growth of location sensing devices has led to the vast generation of dynamic spatial-temporal data in the form of moving object trajectories which can be characterized as big trajectory data. Big trajectory data enables the opportunities such as analyzing the groups of moving objects. To obtain such facilities, the issue of this work is to find a distance measurement method that respects the geographic distance and the semantic similarity for each trajectory. Measurement of similarity between moving objects is a difficult task because not only their position changes but also their semantic features vary. In this research, a method to measure trajectory similarity based on both geographical features and semantic features of motion is proposed. Finally, the proposed methods are practically evaluated by using real trajectory dataset.

The development of loneliness from mid- to late adolescence: trajectory classes, personality traits, and psychosocial functioning.

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Vanhalst, Janne; Goossens, Luc; Luyckx, Koen; Scholte, Ron H J; Engels, Rutger C M E

2013-12-01

Although loneliness is a common problem across late adolescence, its developmental course has not been investigated in depth in this period of life. The present study aims to fill this gap by means of a five-wave cohort-sequential longitudinal study spanning ages 15 to 20 (N = 389). Both variable-centered (i.e., latent growth curve modeling) and person-centered (i.e., latent class growth analysis) approaches were used. Variable-centered analyses showed that loneliness generally decreased over time. Person-centered analyses pointed to considerable inter-individual differences in the development of loneliness, and identified five trajectory classes (i.e., stable low, low increasing, moderate decreasing, high increasing, and chronically high). These five trajectory classes were differentially related to personality traits at age 15 (i.e., extraversion, agreeableness, and emotional stability) and psychosocial functioning at age 20 (i.e., depressive symptoms, self-esteem, anxiety, and perceived stress). These findings underscore the additional value of studying subgroups regarding the development of loneliness. Copyright © 2012 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

The individual life-cycle, annuity market imperfections and economic growth

NARCIS (Netherlands)

Heijdra, Ben J.; Mierau, Jochen O.

We study the effects of an annuity market imperfection on individual agents' life-cycle decisions and on the macroeconomic growth rate in an overlapping generations model with single-sector endogenous growth. Our model features both age-dependent mortality and labour productivity. We model imperfect

A Measure of Similarity Between Trajectories of Vessels

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Le QI

2016-03-01

Full Text Available The measurement of similarity between trajectories of vessels is one of the kernel problems that must be addressed to promote the development of maritime intelligent traffic system (ITS. In this study, a new model of trajectory similarity measurement was established to improve the data processing efficiency in dynamic application and to reflect actual sailing behaviors of vessels. In this model, a feature point detection algorithm was proposed to extract feature points, reduce data storage space and save computational resources. A new synthesized distance algorithm was also created to measure the similarity between trajectories by using the extracted feature points. An experiment was conducted to measure the similarity between the real trajectories of vessels. The growth of these trajectories required measurements to be conducted under different voyages. The results show that the similarity measurement between the vessel trajectories is efficient and correct. Comparison of the synthesized distance with the sailing behaviors of vessels proves that results are consistent with actual situations. The experiment results demonstrate the promising application of the proposed model in studying vessel traffic and in supplying reliable data for the development of maritime ITS.

An individual-based growth and competition model for coastal redwood forest restoration

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van Mantgem, Phillip J.; Das, Adrian J.

2014-01-01

Thinning treatments to accelerate coastal redwood forest stand development are in wide application, but managers have yet to identify prescriptions that might best promote Sequoia sempervirens (Lamb. ex D. Don) Endl. (redwood) growth. The creation of successful thinning prescriptions would be aided by identifying the underlying mechanisms governing how individual tree growth responds to competitive environments in coastal redwood forests. We created a spatially explicit individual-based model of tree competition and growth parameterized using surveys of upland redwood forests at Redwood National Park, California. We modeled competition for overstory trees (stems ≥ 20 cm stem diameter at breast height, 1.37 m (dbh)) as growth reductions arising from sizes, distances, and species identity of competitor trees. Our model explained up to half of the variation in individual tree growth, suggesting that neighborhood crowding is an important determinant of growth in this forest type. We used our model to simulate the effects of novel thinning prescriptions (e.g., 40% stand basal area removal) for redwood forest restoration, concluding that these treatments could lead to substantial growth releases, particularly for S. sempervirens. The results of this study, along with continued improvements to our model, will help to determine spacing and species composition that best encourage growth.

Trajectories of Ethnic-Racial Identity and Autonomy among Mexican-origin Adolescent Mothers in the U.S

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Umaña-Taylor, Adriana J.; Updegraff, Kimberly A.; Jahromi, Laudan B.; Zeiders, Katharine H.

2015-01-01

This study examined trajectories of ethnic-racial identity (ERI) and autonomy development among Mexican-origin adolescent females in the U.S. (N = 181; Mage at Wave 1 = 16.80 years, SD = 1.00) as they transitioned through the first five years of parenthood. Trajectories of ERI and autonomy also were examined in relation to psychosocial functioning. Unconditional latent growth models indicated significant growth in autonomy, ERI resolution, and ERI affirmation from middle to late adolescence. Conditional latent growth models indicated that autonomy and ERI exploration growth trajectories were positively associated with psychosocial adjustment. Although adolescent mothers are experiencing transitions that are not normative during adolescence, they also engage in normative developmental processes, and their engagement in such processes is linked with better adjustment. PMID:26450526

Cannabis use and psychotic-like experiences trajectories during early adolescence: the coevolution and potential mediators.

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Bourque, Josiane; Afzali, Mohammad H; O'Leary-Barrett, Maeve; Conrod, Patricia

2017-12-01

The authors sought to model the different trajectories of psychotic-like experiences (PLE) during adolescence and to examine whether the longitudinal relationship between cannabis use and PLE is mediated by changes in cognitive development and/or change in anxiety or depression symptoms. A total of 2,566 youths were assessed every year for 4-years (from 13- to 16-years of age) on clinical, substance use and cognitive development outcomes. Latent class growth models identified three trajectories of PLE: low decreasing (83.9%), high decreasing (7.9%), and moderate increasing class (8.2%). We conducted logistic regressions to investigate whether baseline levels and growth in cannabis use were associated with PLE trajectory membership. Then, we examined the effects of potential mediators (growth in cognition and anxiety/depression) on the relationship between growth in cannabis use and PLE trajectory. A steeper growth in cannabis use from 13- to 16-years was associated with a higher likelihood of being assigned to the moderate increasing trajectory of PLE [odds ratio, 2.59; 95% confidence interval (CI), 1.11-6.03], when controlling for cumulative cigarette use. Growth in depression symptoms, not anxiety or change in cognitive functioning, mediated the relationship between growth in cannabis use and the PLE moderate increasing group (indirect effect: 0.07; 95% CI, 0.03-0.11). Depression symptoms partially mediated the longitudinal link between cannabis use and PLE in adolescents, suggesting that there may be a preventative effect to be gained from targeting depression symptoms, in addition to attempting to prevent cannabis use in youth presenting increasing psychotic experiences. © 2017 Association for Child and Adolescent Mental Health.

Diabetic Nephropathy and CKD?Analysis of Individual Patient Serum Creatinine Trajectories: A Forgotten Diagnostic Methodology for Diabetic CKD Prognostication and Prediction

OpenAIRE

Onuigbo, Macaulay Amechi Chukwukadibia; Agbasi, Nneoma

2015-01-01

Creatinine is produced in muscle metabolism as the end-product of creatine phosphate and is subsequently excreted principally by way of the kidneys, predominantly by glomerular filtration. Blood creatinine assays constitute the most common clinically relevant measure of renal function. The use of individual patient-level real-time serum creatinine trajectories provides a very attractive and tantalizing methodology in nephrology practice. Topics covered in this review include acute kidney inju...

Trajectories of depressive symptoms over two years postpartum among overweight or obese women

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Lee, Chien-Ti; Stroo, Marissa; Fuemmeler, Bernard; Malhotra, Rahul; Østbye, Truls

2014-01-01

Background Although depressive symptoms are common postpartum, few studies have followed women beyond 12 months postpartum to investigate changes in the number and severity of these symptoms over time, especially in overweight and obese women. Using two complementary analytical methods, this study aims to identify trajectories of depressive symptoms over two years postpartum among overweight or obese mothers, and assess the demographic, socio-economic , and health covariates for these trajectories. Methods Using longitudinal data from two behavioral intervention studies (KAN-DO and AMP; N = 844), we used latent growth modeling to identify the overall trajectory of depressive symptoms and how it was related to key covariates. Next, we used latent class growth analysis to assess the heterogeneity in the depressive symptom trajectories over time, and thereby, identify subgroups of women with distinct trajectories. Findings The overall trajectory of depressive symptoms over two years postpartum was relatively stable in our sample. However, the presence of three distinct latent class trajectories [stable-low (82.5%), decreasing symptoms (7.3%) and increasing symptoms (10.2%)], identified based on trajectory shape and mean depressive symptom score, supported heterogeneity in depressive symptom trajectories over time. Lower maternal education was related to a higher symptom score, and poorer subjective health status at baseline predicted inclusion in the increasing symptoms trajectory. Conclusions In some overweight or obese mothers postpartum depressive symptoms do not resolve quickly. Practitioners should be aware of this phenomenon and continue to screen for depression for longer periods of time postpartum. PMID:25213748

Trajectory modeling of gestational weight: A functional principal component analysis approach.

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Menglu Che

Full Text Available Suboptimal gestational weight gain (GWG, which is linked to increased risk of adverse outcomes for a pregnant woman and her infant, is prevalent. In the study of a large cohort of Canadian pregnant women, our goals are to estimate the individual weight growth trajectory using sparsely collected bodyweight data, and to identify the factors affecting the weight change during pregnancy, such as prepregnancy body mass index (BMI, dietary intakes and physical activity. The first goal was achieved through functional principal component analysis (FPCA by conditional expectation. For the second goal, we used linear regression with the total weight gain as the response variable. The trajectory modeling through FPCA had a significantly smaller root mean square error (RMSE and improved adaptability than the classic nonlinear mixed-effect models, demonstrating a novel tool that can be used to facilitate real time monitoring and interventions of GWG. Our regression analysis showed that prepregnancy BMI had a high predictive value for the weight changes during pregnancy, which agrees with the published weight gain guideline.

Evaluation of Adherence to Nutritional Intervention Through Trajectory Analysis.

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Sevilla-Villanueva, B; Gibert, K; Sanchez-Marre, M; Fito, M; Covas, M I

2017-05-01

Classical pre-post intervention studies are often analyzed using traditional statistics. Nevertheless, the nutritional interventions have small effects on the metabolism and traditional statistics are not enough to detect these subtle nutrient effects. Generally, this kind of studies assumes that the participants are adhered to the assigned dietary intervention and directly analyzes its effects over the target parameters. Thus, the evaluation of adherence is generally omitted. Although, sometimes, participants do not effectively adhere to the assigned dietary guidelines. For this reason, the trajectory map is proposed as a visual tool where dietary patterns of individuals can be followed during the intervention and can also be related with nutritional prescriptions. The trajectory analysis is also proposed allowing both analysis: 1) adherence to the intervention and 2) intervention effects. The analysis is made by projecting the differences of the target parameters over the resulting trajectories between states of different time-stamps which might be considered either individually or by groups. The proposal has been applied over a real nutritional study showing that some individuals adhere better than others and some individuals of the control group modify their habits during the intervention. In addition, the intervention effects are different depending on the type of individuals, even some subgroups have opposite response to the same intervention.

Redefining Individual Growth and Development Indicators: Oral Language

Science.gov (United States)

Bradfield, Tracy A.; Besner, Amanda C.; Wackerle-Hollman, Alisha K.; Albano, Anthony D.; Rodriguez, Michael C.; McConnell, Scott R.

2014-01-01

Language skills developed during preschool contribute strongly to later reading and academic achievement. Effective preschool assessment and intervention should focus on core components of language development, specifically oral language skills. The Early Language and Literacy Individual Growth and Development Indicators (IGDIs) are a set of…

Understanding adolescent personality pathology from growth trajectories of childhood oddity

NARCIS (Netherlands)

De Clercq, Barbara; Verbeke, Lize; De Caluwe, E.A.L.; Vercruysse, Tom; Hofmans, Joeri

2017-01-01

Research on developmental trajectories of early maladaptive features for understanding later personality disorders (PDs) is increasingly recognized as an important study area. The course of early odd features is highly relevant in this regard, as only a few researchers have addressed childhood

Associations between trajectories of perceived racial discrimination and psychological symptoms among African American adolescents.

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Smith-Bynum, Mia A; Lambert, Sharon F; English, Devin; Ialongo, Nicholas S

2014-11-01

Many African American adolescents experience racial discrimination, with adverse consequences; however, stability and change in these experiences over time have not been examined. We examined longitudinal patterns of perceived racial discrimination assessed in Grades 7-10 and how these discrimination trajectories related to patterns of change in depressive and anxious symptoms and aggressive behaviors assessed over the same 4-year period. Growth mixture modeling performed on a community epidemiologically defined sample of urban African American adolescents (n = 504) revealed three trajectories of discrimination: increasing, decreasing, and stable low. As predicted, African American boys were more frequent targets for racial discrimination as they aged, and they were more likely to be in the increasing group. The results of parallel process growth mixture modeling revealed that youth in the increasing racial discrimination group were four times more likely to be in an increasing depression trajectory than were youth in the low stable discrimination trajectory. Though youth in the increasing racial discrimination group were nearly twice as likely to be in the high aggression trajectory, results were not statistically significant. These results indicate an association between variation in the growth of perceived racial discrimination and youth behavior and psychological well-being over the adolescent years.

General and disease-specific pain trajectories as predictors of social and political outcomes in arthritis and cancer.

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James, Richard J E; Walsh, David A; Ferguson, Eamonn

2018-04-09

While the heterogeniety of pain progression has been studied in chronic diseases, the extent to which patterns of pain progression among people in general as well as across different diseases affect social, civic and political engagement is unclear. We explore these issues for the first time. Using data from the English Longitudinal Study of Ageing, latent class growth models were used to estimate trajectories of self-reported pain in the entire cohort, and within subsamples reporting diagnoses of arthritis and cancer. These were compared at baseline on physical health (e.g. body mass index, smoking) and over time on social, civic and political engagement. Very similar four-trajectory models fit the whole sample and arthritis subsamples, whereas a three-trajectory model fit the cancer subsample. All samples had a modal group experiencing minimal chronic pain and a group with high chronic pain that showed slight regression (more pronounced in cancer). Biometric indices were more predictive of the most painful trajectory in arthritis than cancer. In both samples the group experiencing the most pain at baseline reported impairments in social, civic and political engagement. The impact of pain differs between individuals and between diseases. Indicators of physical and psychological health differently predicted membership of the trajectories most affected by pain. These trajectories were associated with differences in engagement with social and civic life, which in turn were associated with poorer health and well-being.

Characterizing Resilience and Growth Among Soldiers: A Trajectory Study

Science.gov (United States)

2014-04-01

studies that showed the possible link between positive psychological assets and health outcomes is The Nun Study .38 A group of American nuns who were...38. Danner DD, Snowdon DA, Friesen VW. Positive emotions in early life and longevity: findings from the nun study . J Pers Soc Psychol. 2000; 80...Trajectory Study PRINCIPAL INVESTIGATOR: Nansook Park CONTRACTING ORGANIZATION: University of Michigan, Ann Arbor, MI 48109

Scaling of cluster growth for coagulating active particles

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Cremer, Peet; Löwen, Hartmut

2014-02-01

Cluster growth in a coagulating system of active particles (such as microswimmers in a solvent) is studied by theory and simulation. In contrast to passive systems, the net velocity of a cluster can have various scalings dependent on the propulsion mechanism and alignment of individual particles. Additionally, the persistence length of the cluster trajectory typically increases with size. As a consequence, a growing cluster collects neighboring particles in a very efficient way and thus amplifies its growth further. This results in unusual large growth exponents for the scaling of the cluster size with time and, for certain conditions, even leads to "explosive" cluster growth where the cluster becomes macroscopic in a finite amount of time.

Trajectories of positive, negative and general psychopathology symptoms in first episode psychosis and their relationship with functioning over a 2-year follow-up period.

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Abdin, Edimansyah; Chong, Siow Ann; Vaingankar, Janhavi Ajit; Peh, Chao Xu; Poon, Lye Yin; Rao, Sujatha; Verma, Swapna; Subramaniam, Mythily

2017-01-01

Few studies have examined the trajectories of symptom severity in first episode psychosis (FEP) and their impact on functioning. This study aimed to identify discrete trajectories of positive, negative and general psychopathological symptoms and functioning, determine predictors of the identified symptom trajectories and subsequently investigate the relationship between symptom and functioning trajectories over the 2-year follow-up period. Data were extracted from the Singapore Early Psychosis Intervention Programme clinical database. Trajectories of the Positive and Negative Syndrome Scale and Global Assessment of Functioning (GAF) scale over the two-year follow up were modelled using latent class growth curve modelling. Two distinct trajectories (early response and stable trajectory and delayed response trajectory) for positive symptoms, four distinct trajectories (early response and stable trajectory, early response and relapse trajectory, slower response and no response trajectory and delayed response trajectory) for negative and general psychopathology symptoms and three distinct trajectories for functioning (high functioning trajectory, moderately stable functioning trajectory and deterioration in functioning trajectory) were identified in our sample. Compared to individuals in the early response and stable trajectory, those in the delayed response trajectory for positive and negative symptoms, early response and relapse for negative and general psychopathology symptoms and slower response and no response trajectories for general psychopathology symptoms were significantly associated with higher odds of having deterioration in functioning over time. Poor symptom trajectories were also significantly predicted by younger age, male gender, unemployed and economically inactive status, lower education, longer duration of untreated psychosis and diagnosis of schizophrenia spectrum and delusional disorders. The results confirm that the symptoms trajectories among

Trajectories of positive, negative and general psychopathology symptoms in first episode psychosis and their relationship with functioning over a 2-year follow-up period.

Directory of Open Access Journals (Sweden)

Edimansyah Abdin

Full Text Available Few studies have examined the trajectories of symptom severity in first episode psychosis (FEP and their impact on functioning. This study aimed to identify discrete trajectories of positive, negative and general psychopathological symptoms and functioning, determine predictors of the identified symptom trajectories and subsequently investigate the relationship between symptom and functioning trajectories over the 2-year follow-up period.Data were extracted from the Singapore Early Psychosis Intervention Programme clinical database. Trajectories of the Positive and Negative Syndrome Scale and Global Assessment of Functioning (GAF scale over the two-year follow up were modelled using latent class growth curve modelling.Two distinct trajectories (early response and stable trajectory and delayed response trajectory for positive symptoms, four distinct trajectories (early response and stable trajectory, early response and relapse trajectory, slower response and no response trajectory and delayed response trajectory for negative and general psychopathology symptoms and three distinct trajectories for functioning (high functioning trajectory, moderately stable functioning trajectory and deterioration in functioning trajectory were identified in our sample. Compared to individuals in the early response and stable trajectory, those in the delayed response trajectory for positive and negative symptoms, early response and relapse for negative and general psychopathology symptoms and slower response and no response trajectories for general psychopathology symptoms were significantly associated with higher odds of having deterioration in functioning over time. Poor symptom trajectories were also significantly predicted by younger age, male gender, unemployed and economically inactive status, lower education, longer duration of untreated psychosis and diagnosis of schizophrenia spectrum and delusional disorders.The results confirm that the symptoms

Indexing the Trajectories of Moving Objects in Symbolic Indoor Space

DEFF Research Database (Denmark)

Jensen, Christian Søndergaard; Lu, Hua; Yang, Bin

2009-01-01

. This scenario calls for the indexing of indoor trajectories. Based on an appropriate notion of indoor trajectory and definitions of pertinent types of queries, the paper proposes two R-tree based structures for indexing object trajectories in symbolic indoor space. The RTR-tree represents a trajectory as a set......Indoor spaces accommodate large populations of individuals. With appropriate indoor positioning, e.g., Bluetooth and RFID, in place, large amounts of trajectory data result that may serve as a foundation for a wide variety of applications, e.g., space planning, way finding, and security...... for each index. An empirical performance study suggests that the two indexes are effective, efficient, and robust. The study also elicits the circumstances under which our proposals perform the best....

Trajectories of BMI change impact glucose and insulin metabolism.

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Walsh, E I; Shaw, J; Cherbuin, N

2018-03-01

The aim of this study was to examine, in a community setting, whether trajectory of weight change over twelve years is associated with glucose and insulin metabolism at twelve years. Participants were 532 community-living middle-aged and elderly adults from the Personality and Total Health (PATH) Through Life study. They spanned the full weight range (underweight/normal/overweight/obese). Latent class analysis and multivariate generalised linear models were used to investigate the association of Body Mass Index (BMI, kg/m 2 ) trajectory over twelve years with plasma insulin (μlU/ml), plasma glucose (mmol/L), and HOMA2 insulin resistance and beta cell function at follow-up. All models were adjusted for age, gender, hypertension, pre-clinical diabetes status (normal fasting glucose or impaired fasting glucose) and physical activity. Four weight trajectories were extracted; constant normal (mean baseline BMI = 25; follow-up BMI = 25), constant high (mean baseline BMI = 36; follow-up BMI = 37), increase (mean baseline BMI = 26; follow-up BMI = 32) and decrease (mean baseline BMI = 34; follow-up BMI = 28). At any given current BMI, individuals in the constant high and increase trajectories had significantly higher plasma insulin, greater insulin resistance, and higher beta cell function than those in the constant normal trajectory. Individuals in the decrease trajectory did not differ from the constant normal trajectory. Current BMI significantly interacted with preceding BMI trajectory in its association with plasma insulin, insulin resistance, and beta cell function. The trajectory of preceding weight has an independent effect on blood glucose metabolism beyond body weight measured at any given point in time. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier

Predicting Longitudinal Change in Language Production and Comprehension in Individuals with Down Syndrome: Hierarchical Linear Modeling.

Science.gov (United States)

Chapman, Robin S.; Hesketh, Linda J.; Kistler, Doris J.

2002-01-01

Longitudinal change in syntax comprehension and production skill, measured over six years, was modeled in 31 individuals (ages 5-20) with Down syndrome. The best fitting Hierarchical Linear Modeling model of comprehension uses age and visual and auditory short-term memory as predictors of initial status, and age for growth trajectory. (Contains…

Standard metabolic rate predicts growth trajectory of juvenile Chinese crucian carp (Carassius auratus under changing food availability

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Ling-Qing Zeng

2017-09-01

Full Text Available Phenotypic traits vary greatly within populations and can have a significant influence on aspects of performance. The present study aimed to investigate the effects of individual variation in standard metabolic rate (SMR on growth rate and tolerance to food deprivation in juvenile Chinese crucian carp (Carassius auratus under varying levels of food availability. To address this issue, 19 high and 16 low SMR individuals were randomly assigned to a satiation diet for 3 weeks, whereas another 20 high and 16 low SMR individuals were assigned to a restricted diet (approximately 50% of satiation for the same period. Then, all fish were completely food-deprived for another 3 weeks. High SMR individuals showed a higher growth rate when fed to satiation, but this advantage of SMR did not exist in food-restricted fish. This result was related to improved feeding efficiency with decreased food intake in low SMR individuals, due to their low food processing capacity and maintenance costs. High SMR individuals experienced more mass loss during food deprivation as compared to low SMR individuals. Our results here illustrate context-dependent costs and benefits of intraspecific variation in SMR whereby high SMR individuals show increased growth performance under high food availability but had a cost under stressful environments (i.e. food shortage.

Quantum trajectories for time-dependent adiabatic master equations

Science.gov (United States)

Yip, Ka Wa; Albash, Tameem; Lidar, Daniel A.

2018-02-01

We describe a quantum trajectories technique for the unraveling of the quantum adiabatic master equation in Lindblad form. By evolving a complex state vector of dimension N instead of a complex density matrix of dimension N2, simulations of larger system sizes become feasible. The cost of running many trajectories, which is required to recover the master equation evolution, can be minimized by running the trajectories in parallel, making this method suitable for high performance computing clusters. In general, the trajectories method can provide up to a factor N advantage over directly solving the master equation. In special cases where only the expectation values of certain observables are desired, an advantage of up to a factor N2 is possible. We test the method by demonstrating agreement with direct solution of the quantum adiabatic master equation for 8-qubit quantum annealing examples. We also apply the quantum trajectories method to a 16-qubit example originally introduced to demonstrate the role of tunneling in quantum annealing, which is significantly more time consuming to solve directly using the master equation. The quantum trajectories method provides insight into individual quantum jump trajectories and their statistics, thus shedding light on open system quantum adiabatic evolution beyond the master equation.

Does social status within a dominance hierarchy mediate individual growth, residency and relocation?

Science.gov (United States)

Akbaripasand, Abbas; Ramezani, J; Krkosek, Martin; Lokman, P Mark; Closs, Gerard P

2014-11-01

The availability of food, and hence energy, is known to influence the abundance, habitat choice and growth of individuals. In contrast, there is a paucity of knowledge on how the interaction of energy supply and social status determines patterns of residency and movement. This study tests whether the presence of conspecifics and an individual's social status in relation to food supply influence the fitness and movement of a drift-feeding fish (Galaxias fasciatus). Using an information-theoretic approach (AIC), our analysis indicated that the most parsimonious model of fish movement among pools was one that included food supply, social rank and fish relative growth rate. Our results indicated that subordinate fish relocated more frequently compared to dominant fish, most likely as a consequence of intra-specific competition that limited the access of these smaller fish to resources and constrained their growth. Our results suggest that energy constraints may force individuals to explore new habitats in an effort to find more energetically profitable patches. We conclude that intra-specific competition mediated through the social hierarchy amongst closely interacting individuals plays a key role in determining individual growth, residency and relocation.

Tracing developmental trajectories of oppositional defiant behaviors in preschool children.

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Lourdes Ezpeleta

Full Text Available Previous studies on developmental trajectories have used ad hoc definitions of oppositional defiant behaviors (ODB, which makes it difficult to compare results. This article defines developmental trajectories of ODB from ages 3-5 based on five different standard measurements derived from three separate instruments.A sample of 622 three-year-old preschoolers, followed up at ages 4, 5, and 6, was assessed with the five measures of oppositionality answered by parents and teachers. Growth-Mixture-Modeling (GMM estimated separate developmental trajectories for each ODB measure for ages 3 to 5.The number of classes-trajectories obtained in each GMM depended on the ODB measure, but two clear patterns emerged: four trajectories (persistent low, decreasers, increasers/high increasers, persistent moderate/persistent high or three trajectories (persistent low, decreasers, increasers/high increasers. Persistent high trajectories accounted for 4.4%-9.5% of the children. The trajectories emerging from the different ODB measures at ages 3 to 5 discriminated disruptive disorders, comorbidity, use of services, and impairment at age 6, and globally showed a similar pattern, summarizing longitudinal information on oppositionality in preschool children in a similar way.Trajectories resulting from standard scales of the questionnaires have predictive validity for identifying relevant clinical outcomes, but are measure-specific. The results contribute to knowledge about the development of ODB in preschool children.

Predicting Comorbid Conditions and Trajectories using Social Health Records.

Science.gov (United States)

Ji, Xiang; Ae Chun, Soon; Geller, James

2016-05-05

Many patients suffer from comorbidity conditions, for example, obese patients often develop type-2 diabetes and hypertension. In the US, 80% of Medicare spending is for managing patients with these multiple coexisting conditions. Predicting potential comorbidity conditions for an individual patient can promote preventive care and reduce costs. Predicting possible comorbidity progression paths can provide important insights into population heath and aid with decisions in public health policies. Discovering the comorbidity relationships is complex and difficult, due to limited access to Electronic Health Records by privacy laws. In this paper, we present a collaborative comorbidity prediction method to predict likely comorbid conditions for individual patients, and a trajectory prediction graph model to reveal progression paths of comorbid conditions. Our prediction approaches utilize patient generated health reports on online social media, called Social Health Records (SHR). The experimental results based on one SHR source show that our method is able to predict future comorbid conditions for a patient with coverage values of 48% and 75% for a top-20 and a top-100 ranked list, respectively. For risk trajectory prediction, our approach is able to reveal each potential progression trajectory between any two conditions and infer the confidence of the future trajectory, given any observed condition. The predicted trajectories are validated with existing comorbidity relations from the medical literature.

Trajectories of Identity Formation Modes and Their Personality Context in Adolescence.

Science.gov (United States)

Topolewska-Siedzik, Ewa; Cieciuch, Jan

2018-04-01

Identity formation is a dynamic process during adolescence. Trajectories of identity formation were assessed longitudinally in early and middle adolescents, taking into account the personality underpinnings of this process. Identity formation was conceptualized according to the circumplex of identity formation modes. The model distinguishes basic modes rooted in Marcia's categories of exploration and commitment. Plasticity and stability, the two higher order Big Five meta-traits, were used to assess personality underpinnings. This study includes five measurement waves over 1.5 years and involves 1,839 Polish participants; 914 early adolescents (53.9% girls) and 925 middle adolescents (63.8% girls). The results suggest that (1) the four identity formation modes change dynamically, showing linear and curvilinear growth and that (2) identity formation mode trajectories are more dynamic in middle adolescence than in early adolescence. The results also showed that, in the conditional model, (3) the higher-order personality factors and gender affect the growth factors of identity formation modes. Overall, trajectories of identity formation modes are more linear during early adolescence and more curvilinear during middle adolescence. The initial levels in identity trajectories are influenced by the personality metatraits but only plasticity is related to change among early adolescents.

Transcriptome analysis of the sea cucumber (Apostichopus japonicus) with variation in individual growth.

Science.gov (United States)

Gao, Lei; He, Chongbo; Bao, Xiangbo; Tian, Meilin; Ma, Zhen

2017-01-01

The sea cucumber (Apostichopus japonicus) is an economically important aquaculture species in China. However, the serious individual growth variation often caused financial losses to farmers and the genetic mechanisms are poorly understood. In the present study, the extensively analysis at the transcriptome level for individual growth variation in sea cucumber was carried out. A total of 118946 unigenes were assembled from 255861 transcripts, with N50 of 1700. Of all unigenes, about 23% were identified with at least one significant match to known databases. In all four pair of comparison, 1840 genes were found to be expressed differently. Global hypometabolism was found to be occurred in the slow growing population, based on which the hypothesis was raised that growth retardation in individual growth variation of sea cucumber is one type of dormancy which is used to be against to adverse circumstances. Besides, the pathways such as ECM-receptor interaction and focal adhesion were enriched in the maintenance of cell and tissue structure and communication. Further, 76645 SSRs, 765242 SNPs and 146886 ins-dels were detected in the current study providing an extensive set of data for future studies of genetic mapping and selective breeding. In summary, these results will provides deep insight into the molecular basis of individual growth variation in marine invertebrates, and be valuable for understanding the physiological differences of growth process.

Transcriptome analysis of the sea cucumber (Apostichopus japonicus with variation in individual growth.

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Lei Gao

Full Text Available The sea cucumber (Apostichopus japonicus is an economically important aquaculture species in China. However, the serious individual growth variation often caused financial losses to farmers and the genetic mechanisms are poorly understood. In the present study, the extensively analysis at the transcriptome level for individual growth variation in sea cucumber was carried out. A total of 118946 unigenes were assembled from 255861 transcripts, with N50 of 1700. Of all unigenes, about 23% were identified with at least one significant match to known databases. In all four pair of comparison, 1840 genes were found to be expressed differently. Global hypometabolism was found to be occurred in the slow growing population, based on which the hypothesis was raised that growth retardation in individual growth variation of sea cucumber is one type of dormancy which is used to be against to adverse circumstances. Besides, the pathways such as ECM-receptor interaction and focal adhesion were enriched in the maintenance of cell and tissue structure and communication. Further, 76645 SSRs, 765242 SNPs and 146886 ins-dels were detected in the current study providing an extensive set of data for future studies of genetic mapping and selective breeding. In summary, these results will provides deep insight into the molecular basis of individual growth variation in marine invertebrates, and be valuable for understanding the physiological differences of growth process.

Optimal Acceleration-Velocity-Bounded Trajectory Planning in Dynamic Crowd Simulation

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Fu Yue-wen

2014-01-01

Full Text Available Creating complex and realistic crowd behaviors, such as pedestrian navigation behavior with dynamic obstacles, is a difficult and time consuming task. In this paper, we study one special type of crowd which is composed of urgent individuals, normal individuals, and normal groups. We use three steps to construct the crowd simulation in dynamic environment. The first one is that the urgent individuals move forward along a given path around dynamic obstacles and other crowd members. An optimal acceleration-velocity-bounded trajectory planning method is utilized to model their behaviors, which ensures that the durations of the generated trajectories are minimal and the urgent individuals are collision-free with dynamic obstacles (e.g., dynamic vehicles. In the second step, a pushing model is adopted to simulate the interactions between urgent members and normal ones, which ensures that the computational cost of the optimal trajectory planning is acceptable. The third step is obligated to imitate the interactions among normal members using collision avoidance behavior and flocking behavior. Various simulation results demonstrate that these three steps give realistic crowd phenomenon just like the real world.

A prospective study of fetal head growth, autistic traits and autism spectrum disorder

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Blanken, Laura M. E.; Dass, Alena; Alvares, Gail; van der Ende, Jan; Schoemaker, Nikita K.; El Marroun, Hanan; Hickey, Martha; Pennell, Craig; White, Scott; Maybery, Murray T.; Dissanayake, Cheryl; Jaddoe, Vincent W. V.; Verhulst, Frank C.; Tiemeier, Henning; McIntosh, Will; Whitehouse, Andrew

2018-01-01

Altered trajectories of brain growth are often reported in Autism Spectrum Disorder (ASD), particularly during the first year of life. However, less is known about prenatal head growth trajectories, and no study has examined the relation with postnatal autistic symptom severity. The current study prospectively examined the association between fetal head growth and the spectrum of autistic symptom severity in two large population‐based cohorts, including a sample of individuals with clinically diagnosed ASD. This study included 3,820 children from two longitudinal prenatal cohorts in The Netherlands and Australia, comprising 60 individuals with a confirmed diagnosis of ASD. Latent growth curve models were used to examine the relationship between fetal head circumference measured at three different time points and autistic traits measured in postnatal life using either the Social Responsiveness Scale or the Autism‐Spectrum Quotient. While lower initial prenatal HC was weakly associated with increasing autistic traits in the Dutch cohort, this relationship was not observed in the Australian cohort, nor when the two cohorts were analysed together. No differences in prenatal head growth were found between individuals with ASD and controls. This large population‐based study identified no consistent association across two cohorts between prenatal head growth and postnatal autistic traits. Our mixed findings suggest that further research in this area is needed. Autism Res 2018, 11: 602–612. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc. Lay Summary It is not known whether different patterns of postnatal brain growth in Autism Spectrum Disorder (ASD) also occurs prenatally. We examined fetal head growth and autistic symptoms in two large groups from The Netherlands and Australia. Lower initial prenatal head circumference was associated with autistic traits in the Dutch, but not the Australian

A prospective study of fetal head growth, autistic traits and autism spectrum disorder.

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Blanken, Laura M E; Dass, Alena; Alvares, Gail; van der Ende, Jan; Schoemaker, Nikita K; El Marroun, Hanan; Hickey, Martha; Pennell, Craig; White, Scott; Maybery, Murray T; Dissanayake, Cheryl; Jaddoe, Vincent W V; Verhulst, Frank C; Tiemeier, Henning; McIntosh, Will; White, Tonya; Whitehouse, Andrew

2018-04-01

Altered trajectories of brain growth are often reported in Autism Spectrum Disorder (ASD), particularly during the first year of life. However, less is known about prenatal head growth trajectories, and no study has examined the relation with postnatal autistic symptom severity. The current study prospectively examined the association between fetal head growth and the spectrum of autistic symptom severity in two large population-based cohorts, including a sample of individuals with clinically diagnosed ASD. This study included 3,820 children from two longitudinal prenatal cohorts in The Netherlands and Australia, comprising 60 individuals with a confirmed diagnosis of ASD. Latent growth curve models were used to examine the relationship between fetal head circumference measured at three different time points and autistic traits measured in postnatal life using either the Social Responsiveness Scale or the Autism-Spectrum Quotient. While lower initial prenatal HC was weakly associated with increasing autistic traits in the Dutch cohort, this relationship was not observed in the Australian cohort, nor when the two cohorts were analysed together. No differences in prenatal head growth were found between individuals with ASD and controls. This large population-based study identified no consistent association across two cohorts between prenatal head growth and postnatal autistic traits. Our mixed findings suggest that further research in this area is needed. Autism Res 2018, 11: 602-612. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc. It is not known whether different patterns of postnatal brain growth in Autism Spectrum Disorder (ASD) also occurs prenatally. We examined fetal head growth and autistic symptoms in two large groups from The Netherlands and Australia. Lower initial prenatal head circumference was associated with autistic traits in the Dutch, but not the Australian, group. No differences

An Approach of Estimating Individual Growth Curves for Young Thoroughbred Horses Based on Their Birthdays

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ONODA, Tomoaki; YAMAMOTO, Ryuta; SAWAMURA, Kyohei; MURASE, Harutaka; NAMBO, Yasuo; INOUE, Yoshinobu; MATSUI, Akira; MIYAKE, Takeshi; HIRAI, Nobuhiro

2014-01-01

ABSTRACT We propose an approach of estimating individual growth curves based on the birthday information of Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. The compensatory growth patterns appear during only the winter and spring seasons in the life of growing horses, and the meeting point between winter and spring depends on the birthday of each horse. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Based on the equations, a parameter denoting the birthday information was added for the modeling of the individual growth curves for each horse by shifting the meeting points in the compensatory growth periods. A total of 5,594 and 5,680 body weight and age measurements of Thoroughbred colts and fillies, respectively, and 3,770 withers height and age measurements of both sexes were used in the analyses. The results of predicted error difference and Akaike Information Criterion showed that the individual growth curves using birthday information better fit to the body weight and withers height data than not using them. The individual growth curve for each horse would be a useful tool for the feeding managements of young Japanese Thoroughbreds in compensatory growth periods. PMID:25013356

Economic Motivations for Master’s Students’ Choice of Educational, Scientific and Professional Trajectories

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Daniil Gennadyevich Sandler

2016-06-01

Full Text Available The article examines the motivations for Master’s students’ choice of individual trajectories. In the course of their studies, the students’ trajectories have educational, scientific and professional aspects. Educational, scientific and professional students’ trajectories determine a system of interaction between master’s students and other people in the context of educational process (teachers, other students and beyond it (employers, research workers from Russian and foreign universities. The authors emphasize the importance of studying the master’s students’ individual trajectories from both scientific (identifying the peculiarities of students’ trajectories formation and development and practical points of view (investments to master’s students to enhance the professional competence in the regional labour market. The authors have analysed the master’s students’ individual trajectories on the basis of monitoring data obtained from the survey carried out in February and December 2014. The master’s students’ assessments allowed to identify what educational experience they were able to get during the education and whether their experience met their expectations. The master’s students’ economic expectations are examined during the implementation of educational and professional trajectories. The analysis of the results has shown that the biggest gap between the expectations and the experience of the master’s students was found according to the criteria related to the student’s scientific trajectory and opportunities to participate in the internationalisation processes. The results of the research may be used to improve the master’s programmes taking into account the revealed master’s students’ expectations, as well as to ensure highly qualified professionals in the labour market and for the effective investments to the human capital by the government authorities

Romantic attraction and adolescent smoking trajectories.

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Pollard, Michael S; Tucker, Joan S; Green, Harold D; Kennedy, David P; Go, Myong-Hyun

2011-12-01

Research on sexual orientation and substance use has established that lesbian, gay, and bisexual (LGB) individuals are more likely to smoke than heterosexuals. This analysis furthers the examination of smoking behaviors across sexual orientation groups by describing how same- and opposite-sex romantic attraction, and changes in romantic attraction, are associated with distinct six-year developmental trajectories of smoking. The National Longitudinal Study of Adolescent Health dataset is used to test our hypotheses. Multinomial logistic regressions predicting smoking trajectory membership as a function of romantic attraction were separately estimated for men and women. Romantic attraction effects were found only for women. The change from self-reported heterosexual attraction to lesbian or bisexual attraction was more predictive of higher smoking trajectories than was a consistent lesbian or bisexual attraction, with potentially important differences between the smoking patterns of these two groups. Copyright © 2011 Elsevier Ltd. All rights reserved.

Markers of Oxidative Stress in Human Milk do not Differ by Maternal BMI But are Related to Infant Growth Trajectories.

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Young, Bridget E; Patinkin, Zachary W; Pyle, Laura; de la Houssaye, Becky; Davidson, Barbara S; Geraghty, Sheela; Morrow, Ardythe L; Krebs, Nancy

2017-06-01

Objective Obesity in adults is associated with inflammation and oxidative stress. Whether or not this phenotype is reflected in human milk (HM) composition, or may impact infant growth remains unknown. We investigated whether HM from overweight/obese (OW/Ob) mothers exhibited higher concentrations of inflammatory cytokines and markers of oxidative stress. We also correlated these bioactive components with infant growth patterns. Methods This was an observational cohort of 56 breastfeeding mothers and their infants [33 normal weight (NW) and 23 OW/Ob]. Infants were followed until 6 months of age and HM collected at 2-weeks and 4-months. Results Markers of oxidative stress, 8-hydroxy-deoxyguanosine (8OHdG) and 4-hydroxynonenol (HNE), decreased in HM over time (p < 0.001) and did not differ between NW and OW/Ob women. Concentrations of inflammatory cytokines, IL-6, IL-8, and TNF-α, were all inter-correlated (p < 0.001) but did not differ between NW and OW/Ob women. HM fat, protein, lactose, and total calories did not differ between NW and OW/Ob women. Infant growth patterns did not differ by group. In a model of infant weight-for-length-Z score trajectory, there was a significant interaction between both lactose and 8OHdG with maternal group: HM lactose and 8OHdG concentrations were both positively associated with increases in WLZ trajectory only among infants breastfed by OW/Ob mothers. Conclusions for Practice HM composition was relatively stable between NW and OW/Ob women. In exclusively breastfed infants, HM concentrations of lactose and 8OHdG, a marker of oxidative stress, may contribute to regulation of infant weight gain, especially among infants of OW/Ob women.

Identifying developmental trajectories of body mass index in childhood using latent class growth (mixture modelling: associations with dietary, sedentary and physical activity behaviors: a longitudinal study

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Maaike Koning

2016-10-01

Full Text Available Abstract Background To date, many epidemiologic studies examining associations between obesity and dietary and sedentary/physical activity behaviors have focused on assessing Body Mass Index (BMI at one point in time. Recent developments in statistical techniques make it possible to study the potential heterogeneity in the development of BMI during childhood by identifying distinct subpopulations characterized by distinct developmental trajectories. Using Latent Class Growth (Mixture Modelling (LCGMM techniques we aimed to identify BMI trajectories in childhood and to examine associations between these distinct trajectories and dietary, sedentary and physical activity behaviors. Methods This longitudinal study explored BMI standard deviation score (SDS trajectories in a sample of 613 children from 4 to 12 years of age. In 2006, 2009 and 2012 information on children’s health related behaviors was obtained by parental questionnaires, and children’s height and weight were measured. Associations with behaviors were investigated with logistic regression models. Results We identified two BMI SDS trajectories; a decreasing BMI SDS trajectory (n = 416; 68 % and an increasing BMI SDS trajectory (n = 197; 32 %. The increasing BMI SDS trajectory consisted of more participants of lower socio-economic status (SES and of non-western ethnicity. Maternal overweight status was associated with being in the increasing BMI SDS trajectory at both baseline and follow-up six years later (2006: Odds Ratio (OR, 2.9; 95 % confidence interval (CI 1.9 to 4.3; 2012 OR, 1.8; 95 % CI 1.2 to 2.6. The increasing BMI SDS trajectory was associated with the following behaviors; drinking sugared drinks > 3 glasses per day, participation in organized sports  2 h per day, though participation in organized sports at follow-up was the only significant result. Conclusions Our results indicate the importance of healthy lifestyle behaviors at a young age, and

Influence of Asthma on the Longitudinal Trajectories of Cigarette Use Behaviors From Adolescence to Adulthood Using Latent Growth Curve Models

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Jisuk Bae

2015-03-01

Full Text Available Objectives: While epidemiologic research indicates that the prevalence of risk-taking behaviors including cigarette smoking among young people with asthma is substantial, the longitudinal patterns of cigarette smoking in this vulnerable population have received little attention. The aim of this study was to evaluate differences in the longitudinal trajectories of cigarette use behaviors from adolescence to adulthood between young people with and without asthma. Methods: Data from the National Longitudinal Study of Adolescent to Adult Health (Add Health during the years 1994 to 1995 (Wave I, adolescence, 2001 to 2002 (Wave III, young adulthood, and 2007 to 2008 (Wave IV, adulthood were analyzed (n=12 244. Latent growth curve models were used to examine the longitudinal trajectories of cigarette use behaviors during the transition to adulthood according to asthma status. Results: Regardless of asthma status, the trajectory means of cigarette use behaviors were found to increase, and then slightly decrease from adolescence to adulthood. In total participants, there were no statistically significant differences in initial levels and changes in cigarette use behaviors according to asthma status. However, in select sex and race subgroups (i.e., females and non-whites, former asthmatics showed greater escalation in cigarette use behaviors than did non-asthmatics or current asthmatics. Conclusions: This study indicated that the changing patterns of cigarette use behaviors during the transition to adulthood among young people with asthma are comparable to or even more drastic than those among young people without asthma.

White matter developmental trajectories associated with persistence and recovery of childhood stuttering.

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Chow, Ho Ming; Chang, Soo-Eun

2017-04-08

Stuttering affects the fundamental human ability of fluent speech production, and can have a significant negative impact on an individual's psychosocial development. While the disorder affects about 5% of all preschool children, approximately 80% of them recover naturally within a few years of stuttering onset. The pathophysiology and neuroanatomical development trajectories associated with persistence and recovery of stuttering are still largely unknown. Here, the first mixed longitudinal diffusion tensor imaging (DTI) study of childhood stuttering has been reported. A total of 195 high quality DTI scans from 35 children who stutter (CWS) and 43 controls between 3 and 12 years of age were acquired, with an average of three scans per child, each collected approximately a year apart. Fractional anisotropy (FA), a measure reflecting white matter structural coherence, was analyzed voxel-wise to examine group and age-related differences using a linear mixed-effects (LME) model. Results showed that CWS exhibited decreased FA relative to controls in the left arcuate fasciculus, underlying the inferior parietal and posterior temporal areas, and the mid body of corpus callosum. Further, white matter developmental trajectories reflecting growth rate of these tract regions differentiated children with persistent stuttering from those who recovered from stuttering. Specifically, a reduction in FA growth rate (i.e., slower FA growth with age) in persistent children relative to fluent controls in the left arcuate fasciculus and corpus callosum was found, which was not evident in recovered children. These findings provide first glimpses into the possible neural mechanisms of onset, persistence, and recovery of childhood stuttering. Hum Brain Mapp, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Trajectories of childhood weight gain: the relative importance of local environment versus individual social and early life factors.

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Megan A Carter

Full Text Available To determine the association between local environmental factors with child weight status in a longitudinal study, using a semi-parametric, group-based method, while also considering social and early life factors.Standardized, directly measured BMI from 4-10 y of age, and group-based trajectory modeling (PROC TRAJ were used to estimate developmental trajectories of weight change in a Québec birth cohort (n = 1,566. Associations between the weight trajectories and living location, social cohesion, disorder, and material and social deprivation were estimated after controlling for social and early life factors.FOUR WEIGHT TRAJECTORY GROUPS WERE ESTIMATED: low-increasing (9.7%; low-medium, accelerating (36.2%; medium-high, increasing (43.0%; and high-stable (11.1%. In the low-increasing and medium-high trajectory groups, living in a semi-urban area was inversely related to weight, while living in a rural area was positively related to weight in the high-stable group. Disorder was inversely related to weight in the low-increasing group only. Other important risk factors for high-stable weight included obesity status of the mother, smoking during pregnancy, and overeating behaviors.In this study, associations between local environment factors and weight differed by trajectory group. Early life factors appear to play a more consistent role in weight status. Further work is needed to determine the influence of place on child weight.

Trajectories of glycaemia, insulin sensitivity and insulin secretion in South Asian and white individuals before diagnosis of type 2 diabetes

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Hulman, Adam; Simmons, Rebecca K; Brunner, Eric J

2017-01-01

AIMS/HYPOTHESIS: South Asian individuals have reduced insulin sensitivity and increased risk of type 2 diabetes compared with white individuals. Temporal changes in glycaemic traits during middle age suggest that impaired insulin secretion is a particular feature of diabetes development among South...... Asians. We therefore aimed to examine ethnic differences in early changes in glucose metabolism prior to incident type 2 diabetes. METHODS: In a prospective British occupational cohort, subject to 5 yearly clinical examinations, we examined ethnic differences in trajectories of fasting plasma glucose...... (FPG), 2 h post-load plasma glucose (2hPG), fasting serum insulin (FSI), 2 h post-load serum insulin (2hSI), HOMA of insulin sensitivity (HOMA2-S) and secretion (HOMA2-B), and the Gutt insulin sensitivity index (ISI0,120) among 120 South Asian and 867 white participants who developed diabetes during...

Trajectories of Return to Work Among People on Sick Leave with Mood or Anxiety Disorders

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Hellström, Lone; Madsen, Trine; Nordentoft, Merete

2017-01-01

Purpose The return to work (RTW) of people with mood and anxiety disorders is a heterogeneous process. We aimed to identify prototypical trajectories of RTW over a two-year period in people on sick leave with mood and anxiety disorders, and investigate if socio-demographic or clinical factors...... years, using data from a nationwide Danish register (DREAM). Latent growth mixture modelling analysis was carried out to identify trajectories of RTW and logistic regression analyses were used to estimate predictors for trajectory membership. Results Four trajectory classes of RTW were identified; non...

Employment Trajectories After Spinal Cord Injury : Results From a 5-Year Prospective Cohort Study

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Ferdiana, Astri; Post, Marcel W.; Hoekstra, Trynke; van der Woude, Luccas H.; van der Klink, Jac J.; Bultmann, Ute

Objectives: To identify different employment trajectories in individuals with spinal cord injury (SCI) after discharge from initial rehabilitation and to determine predictors of different trajectories from demographic, injury, functional, and psychological characteristics. Design: Prospective cohort

Dynamics of individual growth in a recovering population of lake trout (Salvelinus namaycush)

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Fabrizio, Mary C.; Dorazio, Robert M.; Schram, Stephen T.

2001-01-01

In 1976, the Wisconsin Department of Natural Resources established a refuge for a nearly depleted population of lake trout (Salvelinus namaycush) at Gull Island Shoal, Lake Superior. The refuge was intended to reduce fishing mortality by protecting adult lake trout. We examined the growth dynamics of these lake trout during the period of recovery by comparing estimates of ndividual growth before and after the refuge was established. Our estimates are based on an annual mark-recapture survey conducted at the spawning area since 1969. We developed a model that allowed mean growth rates to differ among individuals of different sizes and that accommodated variation in growth rates of individuals of the same size. Likelihood ratio tests were used to determine if the mean growth increments of lake trout changed ater the refuge was established. Our results suggest that growth of mature lake trout (particularly wild fish) decreased significantly in the postrefuge period. This decreased growth may have been associated with a reduction in food availability. We also observed reductions in growth as wild fish grew older and larger, which suggests that the growth of these fish may be adequately approximated by a von Bertalanffy growth model if it becomes possible to obtain accurate ages.

Longitudinal Study of Headache Trajectories in the Year After Mild Traumatic Brain Injury: Relation to Posttraumatic Stress Disorder Symptoms.

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Sawyer, Kathryn; Bell, Kathleen R; Ehde, Dawn M; Temkin, Nancy; Dikmen, Sureyya; Williams, Rhonda M; Dillworth, Tiara; Hoffman, Jeanne M

2015-11-01

To examine headache trajectories among persons with mild traumatic brain injury (MTBI) in the year after injury and the relation of headache trajectory to posttraumatic stress disorder (PTSD) at 1 year postinjury. Prospective, longitudinal study. Participants were recruited through a university medical center and participated in follow-up assessments by telephone. Prospectively enrolled individuals (N=212) within 1 week of MTBI who were hospitalized for observation or other system injuries. Participants were assessed at baseline and 3, 6, and 12 months postinjury. Not applicable. Participants rated average headache pain intensity using the 0 to 10 numerical rating scale at each assessment period. The PTSD Checklist-Civilian Version was completed at 12 months postinjury. Latent class growth analysis produced a 4-trajectory group model, with groups labeled resolved, worsening, improving, and chronic. Multivariate regression modeling revealed that younger age and premorbid headache correlated with membership in the worse trajectory groups (worsening and chronic; PHeadache is common in the year after MTBI, with younger people, persons who previously had headaches, and persons with PTSD more likely to report chronic or worsening headache. Further research is needed to examine whether PTSD symptoms exacerbate headaches or whether problematic headache symptoms exacerbate PTSD. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Drug use trajectory patterns among older drug users

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Tyndall B

2011-05-01

Full Text Available Miriam Boeri, Thor Whalen, Benjamin Tyndall, Ellen BallardKennesaw State University, Department of Sociology and Criminal Justice, Kennesaw GA, USAAbstract: To better understand patterns of drug use trajectories over time, it is essential to have standard measures of change. Our goal here is to introduce measures we developed to quantify change in drug use behaviors. A secondary goal is to provide effective visualizations of these trajectories for applied use. We analyzed data from a sample of 92 older drug users (ages 45 to 65 to identify transition patterns in drug use trajectories across the life course. Data were collected for every year since birth using a mixed methods design. The community-drawn sample of active and former users were 40% female, 50% African American, and 60% reporting some college or greater. Their life histories provided retrospective longitudinal data on the diversity of paths taken throughout the life course and changes in drug use patterns that occurred over time. Bayesian analysis was used to model drug trajectories displayed by innovative computer graphics. The mathematical techniques and visualizations presented here provide the foundation for future models using Bayesian analysis. In this paper we introduce the concepts of transition counts, transition rates and relapse/remission rates, and we describe how these measures can help us better understand drug use trajectories. Depicted through these visual tools, measurements of discontinuous patterns provide a succinct view of individual drug use trajectories. The measures we use on drug use data will be further developed to incorporate contextual influences on the drug trajectory and build predictive models that inform rehabilitation efforts for drug users. Although the measures developed here were conceived to better examine drug use trajectories, the applications of these measures can be used with other longitudinal datasets.Keywords: drug use, trajectory patterns

Automatic trajectory measurement of large numbers of crowded objects

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Li, Hui; Liu, Ye; Chen, Yan Qiu

2013-06-01

Complex motion patterns of natural systems, such as fish schools, bird flocks, and cell groups, have attracted great attention from scientists for years. Trajectory measurement of individuals is vital for quantitative and high-throughput study of their collective behaviors. However, such data are rare mainly due to the challenges of detection and tracking of large numbers of objects with similar visual features and frequent occlusions. We present an automatic and effective framework to measure trajectories of large numbers of crowded oval-shaped objects, such as fish and cells. We first use a novel dual ellipse locator to detect the coarse position of each individual and then propose a variance minimization active contour method to obtain the optimal segmentation results. For tracking, cost matrix of assignment between consecutive frames is trainable via a random forest classifier with many spatial, texture, and shape features. The optimal trajectories are found for the whole image sequence by solving two linear assignment problems. We evaluate the proposed method on many challenging data sets.

Capturing the Diversity of Successful Aging: An Operational Definition Based on 16-Year Trajectories of Functioning.

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Kok, Almar A L; Aartsen, Marja J; Deeg, Dorly J H; Huisman, Martijn

2017-04-01

To determine the prevalence and extent of successful aging (SA) when various suggestions proposed in the previous literature for improving models of SA are incorporated into one holistic operational definition. These suggestions include defining and measuring SA as a developmental process, including subjective indicators alongside more objective ones, and expressing SA on a continuum. Data were used from 2,241 respondents in the Longitudinal Aging Study Amsterdam, a multidisciplinary study in a nationally representative sample of older adults in the Netherlands. Latent class growth analysis was used to identify successful 16-year trajectories within nine indicators of physical, cognitive, emotional, and social functioning. SA was quantified as the number of indicators in which individual respondents showed successful trajectories (range 0-9). Successful trajectories were characterized by stability, limited decline, or even improvement of functioning over time. Of the respondents, 39.6% of men and 29.3% of women were successful in at least seven indicators; 7% of men and 11% of women were successful in less than three indicators. Proportions of successful respondents were largest in life satisfaction (>85%) and smallest in social activity (<25%). Correlations of success between separate indicators were low to moderate (range r = .02-.37). Many older adults age relatively successfully, but the character of successful functioning over time varies between indicators, and the combinations of successful indicators vary between individuals. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Trajectories of Leisure Activity and Disability in Older Adults Over 11 Years in Taiwan.

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Yu, Hsiao-Wei; Chiang, Tung-Liang; Chen, Duan-Rung; Tu, Yu-Kang; Chen, Ya-Mei

2018-06-01

We aimed to identify leisure activity (LA) trajectories and examined the association among baseline characteristics, LA trajectories, and the later disability among older Taiwanese adults. Data were from the Taiwan Longitudinal Study on Aging Survey for the years 1996-2007 ( N = 3,186). LA trajectories were identified by using latent class growth curve modeling. Regression analyses were applied to predict the relationships among baseline characteristics, LA trajectories, and disability. Four LA trajectories-consistent high, consistent low, increasing, and decreasing-were identified. Lower depressive symptom was related to consistently active in LAs. Younger age and fewer comorbidities were related to develop an increasing LA trajectory. Participants in the consistent-high or increasing LA trajectories were more likely to be functionally independent, but those in the decreasing LA subgroup were more at risk of developing disability. The findings suggested that long-term changes in LA over time have benefits on physical health in older population.

Trajectories of suicidal ideation over 6 months among 482 outpatients with bipolar disorder.

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Köhler-Forsberg, Ole; Madsen, Trine; Behrendt-Møller, Ida; Sylvia, Louisa; Bowden, Charles L; Gao, Keming; Bobo, William V; Trivedi, Madhukar H; Calabrese, Joseph R; Thase, Michael; Shelton, Richard C; McInnis, Melvin; Tohen, Mauricio; Ketter, Terence A; Friedman, Edward S; Deckersbach, Thilo; McElroy, Susan L; Reilly-Harrington, Noreen A; Nierenberg, Andrew A

2017-12-01

Suicidal ideation occurs frequently among individuals with bipolar disorder; however, its course and persistence over time remains unclear. We aimed to investigate 6-months trajectories of suicidal ideation among adults with bipolar disorder. The Bipolar CHOICE study randomized 482 outpatients with bipolar disorder to 6 months of lithium- or quetiapine-based treatment including other psychotropic medications as clinically indicated. Participants were asked at 9 visits about suicidal ideation using the Concise Health Risk Tracking scale. We performed latent Growth Mixture Modelling analysis to empirically identify trajectories of suicidal ideation. Multinomial logistic regression analyses were applied to estimate associations between trajectories and potential predictors. We identified four distinct trajectories. The Moderate-Stable group represented 11.1% and was characterized by constant suicidal ideation. The Moderate-Unstable group included 2.9% with persistent thoughts about suicide with a more fluctuating course. The third (Persistent-low, 20.8%) and fourth group (Persistent-very-low, 65.1%) were characterized by low levels of suicidal ideation. Higher depression scores and previous suicide attempts (non-significant trend) predicted membership of the Moderate-Stable group, whereas randomized treatment did not. No specific treatments against suicidal ideation were included and suicidal thoughts may persist for several years. More than one in ten adult outpatients with bipolar disorder had moderately increased suicidal ideation throughout 6 months of pharmacotherapy. The identified predictors may help clinicians to identify those with additional need for treatment against suicidal thoughts and future studies need to investigate whether targeted treatment (pharmacological and non-pharmacological) may improve the course of persistent suicidal ideation. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting the peak growth velocity in the individual child: validation of a new growth model.

NARCIS (Netherlands)

Busscher, I.; Kingma, I.; de Bruin, R.; Wapstra, F.H.; Verkerke, G.J.; Veldhuizen, A.G.

2012-01-01

Predicting the peak growth velocity in an individual patient with adolescent idiopathic scoliosis is essential or determining the prognosis of the disorder and timing of the (surgical) treatment. Until the present time, no accurate method has been found to predict the timing and magnitude of the

Predicting the peak growth velocity in the individual child : validation of a new growth model

NARCIS (Netherlands)

Busscher, Iris; Kingma, Idsart; de Bruin, Rob; Wapstra, Frits Hein; Verkerke, Gijsvertus J.; Veldhuizen, Albert G.

Predicting the peak growth velocity in an individual patient with adolescent idiopathic scoliosis is essential or determining the prognosis of the disorder and timing of the (surgical) treatment. Until the present time, no accurate method has been found to predict the timing and magnitude of the

Predicting the peak growth velocity in the individual child: validation of a new growth model

NARCIS (Netherlands)

Busscher, I.; Kingma, I.; Bruin, R.; Wapstra, F.H.; Verkerke, Gijsbertus Jacob; Veldhuizen, A.G.

2012-01-01

Predicting the peak growth velocity in an individual patient with adolescent idiopathic scoliosis is essential or determining the prognosis of the disorder and timing of the (surgical) treatment. Until the present time, no accurate method has been found to predict the timing and magnitude of the

Functional Trajectories, Cognition, and Subclinical Cerebrovascular Disease.

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Dhamoon, Mandip S; Cheung, Ying-Kuen; Gutierrez, Jose; Moon, Yeseon P; Sacco, Ralph L; Elkind, Mitchell S V; Wright, Clinton B

2018-03-01

Cognition and education influence functional trajectories, but whether associations differ with subclinical brain infarcts (SBI) or white matter hyperintensity volume (WMHV) is unknown. We hypothesized that SBI and WMHV moderated relationships between cognitive performance and education and functional trajectories. A total of 1290 stroke-free individuals underwent brain magnetic resonance imaging and were followed for 7.3 years (mean) with annual functional assessments with the Barthel index (range, 0-100). Magnetic resonance imaging measurements included pathology-informed SBI (PI-SBI) and WMHV (% total cranial volume). Generalized estimating equation models tested associations between magnetic resonance imaging variables and baseline Barthel index and change in Barthel index, adjusting for demographic, vascular, cognitive, and social risk factors, and stroke and myocardial infarction during follow-up. We tested interactions among education level, baseline cognitive performance (Mini-Mental State score), and functional trajectories and ran models stratified by levels of magnetic resonance imaging variables. Mean age was 70.6 (SD, 9.0) years; 19% had PI-SBI, and mean WMHV was 0.68%. Education did not modify associations between cognition and functional trajectories. PI-SBI modified associations between cognition and functional trajectories ( P =0.04) with a significant protective effect of better cognition on functional decline seen only in those without PI-SBI. There was no significant interaction for WMHV ( P =0.8). PI-SBI, and greater WMHV, were associated with 2- to 3-fold steeper functional decline, holding cognition constant. PI-SBI moderated the association between cognition and functional trajectories, with 3-fold greater decline among those with PI-SBI (compared with no PI-SBI) and normal baseline cognition. This highlights the strong and independent association between subclinical markers and patient-centered trajectories over time. © 2018 American Heart

Control of individual daily growth in group-housed pigs using feeding stations

NARCIS (Netherlands)

Ramaekers, P.J.L.

1996-01-01

In this thesis, it was examined whether it is possible to control individual daily growth and carcass composition in group-housed pigs using feeding stations. A forelegs weighing system to estimate the daily individual body weight (BW) of group-housed pigs was developed and validated. In two

Trajectories and associated factors of quality of life, global outcome, and post-concussion symptoms in the first year following mild traumatic brain injury.

Science.gov (United States)

Chiang, Chia-Chen; Guo, Su-Er; Huang, Kuo-Chang; Lee, Bih-O; Fan, Jun-Yu

2016-08-01

To investigate the associated factors and change trajectories of quality of life (QoL), global outcome, and post-concussion symptoms (PCS) over the first year following mild traumatic brain injury (mTBI). This was a prospective longitudinal study of 100 participants with mTBI from neurosurgical outpatient departments in Chiayi County District Hospitals in Taiwan. The checklist of post-concussion syndromes (CPCS) was used to assess PCS at enrollment and at 1, 3, and 12 months after mTBI; the glasgow outcome scale extended (GOSE), the quality of life after brain injured (QOLIBRI), Chinese version, and the Short Form 36 Health Survey (SF-36), Taiwan version, were used to assess mTBI global outcome and QoL at 1, 3, and 12 months after mTBI. Latent class growth models (LCGMs) indicated the change trajectories of QOLIBRI, PCS SF-36, MCS SF-36, GOSE, and PCS. Classes of trajectory were associated with age ≥40 years, unemployment at 1 month after injury, and educational level ≤12 years. Univariate analysis revealed that employment status at 1 month post-injury was correlated with the trajectories of QOLIBRI, PCS SF-36, MCS SF-36, and GOSE, but not PCS. Employment status was the most crucial associated factor for QoL in individuals with mTBI at the 1-year follow-up. Future studies should explore the benefits of employment on QoL of individuals with mTBI.

Effect of culture methods on individual variation in the growth of sea cucumber Apostichopus japonicus within a cohort and family

Science.gov (United States)

Qiu, Tianlong; Zhang, Libin; Zhang, Tao; Bai, Yucen; Yang, Hongsheng

2014-07-01

There is substantial individual variation in the growth rates of sea cucumber Apostichopus japonicus individuals. This necessitates additional work to grade the seed stock and lengthens the production period. We evaluated the influence of three culture methods (free-mixed, isolated-mixed, isolated-alone) on individual variation in growth and assessed the relationship between feeding, energy conversion efficiency, and individual growth variation in individually cultured sea cucumbers. Of the different culture methods, animals grew best when reared in the isolated-mixed treatment (i.e., size classes were held separately), though there was no difference in individual variation in growth between rearing treatment groups. The individual variation in growth was primarily attributed to genetic factors. The difference in food conversion efficiency caused by genetic differences among individuals was thought to be the origin of the variance. The level of individual growth variation may be altered by interactions among individuals and environmental heterogeneity. Our results suggest that, in addition to traditional seed grading, design of a new kind of substrate that changes the spatial distribution of sea cucumbers would effectively enhance growth and reduce individual variation in growth of sea cucumbers in culture.

Trajectories of low back pain

DEFF Research Database (Denmark)

Axén, Iben; Leboeuf-Yde, Charlotte

2013-01-01

Low back pain is not a self-limiting problem, but rather a recurrent and sometimes persistent disorder. To understand the course over time, detailed investigation, preferably using repeated measurements over extended periods of time, is needed. New knowledge concerning short-term trajectories...... indicates that the low back pain 'episode' is short lived, at least in the primary care setting, with most patients improving. Nevertheless, in the long term, low back pain often runs a persistent course with around two-thirds of patients estimated to be in pain after 12 months. Some individuals never have...... low back pain, but most have it on and off or persistently. Thus, the low back pain 'condition' is usually a lifelong experience. However, subgroups of patients with different back pain trajectories have been identified and linked to clinical parameters. Further investigation is warranted...

Mexican-Origin Youth Participation in Extracurricular Activities: Predicting Trajectories of Involvement from 7th to 12th Grade.

Science.gov (United States)

Dawes, Nickki Pearce; Modecki, Kathryn L; Gonzales, Nancy; Dumka, Larry; Millsap, Roger

2015-11-01

The potential benefits of participation in extracurricular activities may be especially important for youth who are at risk for academic underachievement, such as low income Mexican-origin youth in the U.S. To advance understanding of factors that drive participation for this population, this study examined Mexican-origin youth's trajectories of participation in extracurricular activities across Grades 7-12 and tested theoretically-derived predictors of these trajectories. Participants were 178 adolescents (53.9 % Female, Mage = 12.28) and their mothers who separately completed in-home interviews. Youth reported the frequency of their participation across a range of extracurricular activities. Latent growth curve models of overall extracurricular activities participation, sports participation, and fine arts participation were individually estimated via structural equation modeling. The findings demonstrated developmental declines in overall participation and in sports participation. For fine arts, declines in participation in middle school were followed by subsequent increases during high school (a curvilinear pattern). Motivationally-salient predictors of participation trajectories included youth's traditional cultural values orientation (sports), the mothers' educational aspirations for the youth (sports, fine arts, overall activity), and youth gender (sports, fine arts). Overall, the results suggest variability in participation trajectories based on program type, and highlight the need for additional research to enhance our understanding of the impact of culturally-relevant predictors on participation over time.

Growth modes of individual ferrite grains in the austenite to ferrite transformation of low carbon steels

International Nuclear Information System (INIS)

Li, D.Z.; Xiao, N.M.; Lan, Y.J.; Zheng, C.W.; Li, Y.Y.

2007-01-01

The mesoscale deterministic cellular automaton (CA) method and probabilistic Q-state Potts-based Monte Carlo (MC) model have been adopted to investigate independently the individual growth behavior of ferrite grain during the austenite (γ)-ferrite (α) transformation. In these models, the γ-α phase transformation and ferrite grain coarsening induced by α/α grain boundary migration could be simulated simultaneously. The simulations demonstrated that both the hard impingement (ferrite grain coarsening) and the soft impingement (overlapping carbon concentration field) have a great influence on the individual ferrite growth behavior. Generally, ferrite grains displayed six modes of growth behavior: parabolic growth, delayed nucleation and growth, temporary shrinkage, partial shrinkage, complete shrinkage and accelerated growth in the transformation. Some modes have been observed before by the synchrotron X-ray diffraction experiment. The mesoscopic simulation provides an alternative tool for investigating both the individual grain growth behavior and the overall transformation behavior simultaneously during transformation

Trajectories of quality of life among Chinese patients diagnosed with nasopharynegeal cancer.

Directory of Open Access Journals (Sweden)

Wendy W T Lam

Full Text Available OBJECTIVE: This secondary longitudinal analysis describes distinct quality of life trajectories during eight months of radiation therapy (RT among patients with nasopharyngeal cancer (NPC and examines factors differentiating these trajectories. METHODS: 253 Chinese patients with NPC scheduled for RT were assessed at pre-treatment, and 4 months and 8 months later on QoL (Chinese version of the FACT-G, optimism, pain, eating function, and patient satisfaction. Latent growth mixture modelling identified different trajectories within each of four QoL domains: Physical, Emotional, Social/family, and Functional well-being. Multinomial logistic regression compared optimism, pain, eating function, and patient satisfaction by trajectories adjusted for demographic and medical characteristics. RESULTS: We identified three distinct trajectories for physical and emotional QoL domains, four trajectories for social/family, and two trajectories for functional domains. Within each domain most patients (physical (77%, emotional (85%, social/family (55% and functional (63% experienced relatively stable high levels of well-being over the 8-month period. Different Physical trajectory patterns were predicted by pain and optimism, whereas for Emotion-domain trajectories pain, optimism, eating enjoyment, patient satisfaction with information, and gender were predictive. Age, appetite, optimism, martial status, and household income predicted Social/family trajectories; household income, eating enjoyment, optimism, and patient satisfaction with information predicted Functional trajectories. CONCLUSION: Most patients with NPC showed high stable QoL during radiotherapy. Optimism predicted good QoL. Symptom impacts varied by QoL domain. Information satisfaction was protective in emotional and functional well-being, reflecting the importance in helping patients to establish a realistic expectation of treatment impacts.

Trajectories of Life Satisfaction Over the First 10 Years After Traumatic Brain Injury: Race, Gender, and Functional Ability.

Science.gov (United States)

Williamson, Meredith L C; Elliott, Timothy R; Bogner, Jennifer; Dreer, Laura E; Arango-Lasprilla, Juan Carlos; Kolakowsky-Hayner, Stephanie A; Pretz, Christopher R; Lequerica, Anthony; Perrin, Paul B

2016-01-01

This study investigated the influence of race, gender, functional ability, and an array of preinjury, injury-related, and sociodemographic variables on life satisfaction trajectories over 10 years following moderate to severe traumatic brain injury (TBI). A sample of 3157 individuals with TBI from the TBI Model Systems database was included in this study. Hierarchical linear modeling (HLM) analyses were conducted to examine the trajectories of life satisfaction. The Functional Independence Measure, Glasgow Coma Scale, and the Satisfaction With Life Scale were utilized. Initial models suggested that life satisfaction trajectories increased over the 10-year period and Asian/Pacific Islander participants experienced an increase in life satisfaction over time. In a comprehensive model, time was no longer a significant predictor of increased life satisfaction. Black race, however, was associated with lower life satisfaction, and significant interactions revealed that black participants' life satisfaction trajectory decreased over time while white participants' trajectory increased over the same time period. Life satisfaction trajectories did not significantly differ by gender, and greater motor and cognitive functioning were associated with increasingly positive life satisfaction trajectories over the 10 years. Individuals with more functional impairments are at risk for decreases in life satisfaction over time. Further research is needed to identify the mechanisms and factors that contribute to the lower levels of life satisfaction observed among black individuals post-TBI. This work is needed to determine strategic ways to promote optimal adjustment for these individuals.

Assessing the Relationship Between Chronic Health Conditions and Productivity Loss Trajectories

Science.gov (United States)

Pranksy, Glenn

2014-01-01

Objective: To examine the relationship between health conditions and the risk for membership in longitudinal trajectories of productivity loss. Methods: Trajectories of productivity loss from the ages of 25 to 44 years, previously identified in the National Longitudinal Survey of Youth (NLSY79), were combined with information on health conditions from the age 40 years health module in the NLSY79. Multinomial logistic regression was used to examine the relative risk of being in the low-risk, early-onset increasing risk, late-onset increasing risk, or high-risk trajectories compared with the no-risk trajectory for having various health conditions. Results: The trajectories with the greatest probability of productivity loss longitudinally had a greater prevalence of the individual health conditions and a greater total number of health conditions experienced. Conclusions: Health conditions are associated with specific longitudinal patterns of experiencing productivity loss. PMID:25479294

Validation of Multibody Program to Optimize Simulated Trajectories II Parachute Simulation with Interacting Forces

Science.gov (United States)

Raiszadeh, Behzad; Queen, Eric M.; Hotchko, Nathaniel J.

2009-01-01

A capability to simulate trajectories of multiple interacting rigid bodies has been developed, tested and validated. This capability uses the Program to Optimize Simulated Trajectories II (POST 2). The standard version of POST 2 allows trajectory simulation of multiple bodies without force interaction. In the current implementation, the force interaction between the parachute and the suspended bodies has been modeled using flexible lines, allowing accurate trajectory simulation of the individual bodies in flight. The POST 2 multibody capability is intended to be general purpose and applicable to any parachute entry trajectory simulation. This research paper explains the motivation for multibody parachute simulation, discusses implementation methods, and presents validation of this capability.

Development of a shortleaf pine individual-tree growth equation using non-linear mixed modeling techniques

Science.gov (United States)

Chakra B. Budhathoki; Thomas B. Lynch; James M. Guldin

2010-01-01

Nonlinear mixed-modeling methods were used to estimate parameters in an individual-tree basal area growth model for shortleaf pine (Pinus echinata Mill.). Shortleaf pine individual-tree growth data were available from over 200 permanently established 0.2-acre fixed-radius plots located in naturally-occurring even-aged shortleaf pine forests on the...

Development of sustainable precision farming systems for swine: estimating real-time individual amino acid requirements in growing-finishing pigs.

Science.gov (United States)

Hauschild, L; Lovatto, P A; Pomar, J; Pomar, C

2012-07-01

The objective of this study was to develop and evaluate a mathematical model used to estimate the daily amino acid requirements of individual growing-finishing pigs. The model includes empirical and mechanistic model components. The empirical component estimates daily feed intake (DFI), BW, and daily gain (DG) based on individual pig information collected in real time. Based on DFI, BW, and DG estimates, the mechanistic component uses classic factorial equations to estimate the optimal concentration of amino acids that must be offered to each pig to meet its requirements. The model was evaluated with data from a study that investigated the effect of feeding pigs with a 3-phase or daily multiphase system. The DFI and BW values measured in this study were compared with those estimated by the empirical component of the model. The coherence of the values estimated by the mechanistic component was evaluated by analyzing if it followed a normal pattern of requirements. Lastly, the proposed model was evaluated by comparing its estimates with those generated by the existing growth model (InraPorc). The precision of the proposed model and InraPorc in estimating DFI and BW was evaluated through the mean absolute error. The empirical component results indicated that the DFI and BW trajectories of individual pigs fed ad libitum could be predicted 1 d (DFI) or 7 d (BW) ahead with the average mean absolute error of 12.45 and 1.85%, respectively. The average mean absolute error obtained with the InraPorc for the average individual of the population was 14.72% for DFI and 5.38% for BW. Major differences were observed when estimates from InraPorc were compared with individual observations. The proposed model, however, was effective in tracking the change in DFI and BW for each individual pig. The mechanistic model component estimated the optimal standardized ileal digestible Lys to NE ratio with reasonable between animal (average CV = 7%) and overtime (average CV = 14%) variation

In situ data analytics and indexing of protein trajectories.

Science.gov (United States)

Johnston, Travis; Zhang, Boyu; Liwo, Adam; Crivelli, Silvia; Taufer, Michela

2017-06-15

The transition toward exascale computing will be accompanied by a performance dichotomy. Computational peak performance will rapidly increase; I/O performance will either grow slowly or be completely stagnant. Essentially, the rate at which data are generated will grow much faster than the rate at which data can be read from and written to the disk. MD simulations will soon face the I/O problem of efficiently writing to and reading from disk on the next generation of supercomputers. This article targets MD simulations at the exascale and proposes a novel technique for in situ data analysis and indexing of MD trajectories. Our technique maps individual trajectories' substructures (i.e., α-helices, β-strands) to metadata frame by frame. The metadata captures the conformational properties of the substructures. The ensemble of metadata can be used for automatic, strategic analysis within a trajectory or across trajectories, without manually identify those portions of trajectories in which critical changes take place. We demonstrate our technique's effectiveness by applying it to 26.3k helices and 31.2k strands from 9917 PDB proteins and by providing three empirical case studies. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Long range trajectories

Energy Technology Data Exchange (ETDEWEB)

Allen, P. W.; Jessup, E. A.; White, R. E. [Air Resources Field Research Office, Las Vegas, Nevada (United States)

1967-07-01

A single air molecule can have a trajectory that can be described with a line, but most meteorologists use single lines to represent the trajectories of air parcels. A single line trajectory has the disadvantage that it is a categorical description of position. Like categorized forecasts it provides no qualification, and no provision for dispersion in case the parcel contains two or more molecules which may take vastly different paths. Diffusion technology has amply demonstrated that an initial aerosol cloud or volume of gas in the atmosphere not only grows larger, but sometimes divides into puffs, each having a different path or swath. Yet, the average meteorologist, faced with the problem of predicting the future motion of a cloud, usually falls back on the line trajectory approach with the explanation that he had no better tool for long range application. In his more rational moments, he may use some arbitrary device to spread his cloud with distance. One such technique has been to separate the trajectory into two or more trajectories, spaced about the endpoint of the original trajectory after a short period of travel, repeating this every so often like a chain reaction. This has the obvious disadvantage of involving a large amount of labor without much assurance of improved accuracy. Another approach is to draw a circle about the trajectory endpoint, to represent either diffusion or error. The problem then is to know what radius to give the circle and also whether to call it diffusion or error. Meteorologists at the Nevada Test Site (NTS) are asked frequently to provide advice which involves trajectory technology, such as prediction of an aerosol cloud path, reconstruction of the motion of a volume of air, indication of the dilution, and the possible trajectory prediction error over great distances. Therefore, we set out, nearly three years ago, to provide some statistical knowledge about the status of our trajectory technology. This report contains some of the

Young adults' trajectories of Ecstasy use: a population based study.

Science.gov (United States)

Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

2013-11-01

Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns. © 2013 Elsevier Ltd. All rights reserved.

Phenomenology of stochastic exponential growth

Science.gov (United States)

Pirjol, Dan; Jafarpour, Farshid; Iyer-Biswas, Srividya

2017-06-01

Stochastic exponential growth is observed in a variety of contexts, including molecular autocatalysis, nuclear fission, population growth, inflation of the universe, viral social media posts, and financial markets. Yet literature on modeling the phenomenology of these stochastic dynamics has predominantly focused on one model, geometric Brownian motion (GBM), which can be described as the solution of a Langevin equation with linear drift and linear multiplicative noise. Using recent experimental results on stochastic exponential growth of individual bacterial cell sizes, we motivate the need for a more general class of phenomenological models of stochastic exponential growth, which are consistent with the observation that the mean-rescaled distributions are approximately stationary at long times. We show that this behavior is not consistent with GBM, instead it is consistent with power-law multiplicative noise with positive fractional powers. Therefore, we consider this general class of phenomenological models for stochastic exponential growth, provide analytical solutions, and identify the important dimensionless combination of model parameters, which determines the shape of the mean-rescaled distribution. We also provide a prescription for robustly inferring model parameters from experimentally observed stochastic growth trajectories.

A Decade of War: Prospective Trajectories of Posttraumatic Stress Disorder Symptoms Among Deployed US Military Personnel and the Influence of Combat Exposure.

Science.gov (United States)

Donoho, Carrie J; Bonanno, George A; Porter, Ben; Kearney, Lauren; Powell, Teresa M

2017-12-15

Posttraumatic stress disorder (PTSD) is a common psychiatric disorder among service members and veterans. The clinical course of PTSD varies between individuals, and patterns of symptom development have yet to be clearly delineated. Previous studies have been limited by convenience sampling, short follow-up periods, and the inability to account for combat-related trauma. To determine the trajectories of PTSD symptoms among deployed military personnel with and without combat exposure, we used data from a population-based representative sample of 8,178 US service members who participated in the Millennium Cohort Study from 2001 to 2011. Using latent growth mixture modeling, trajectories of PTSD symptoms were determined in the total sample, as well as in individuals with and without combat exposure, respectively. Overall, 4 trajectories of PTSD were characterized: resilient, pre-existing, new-onset, and moderate stable. Across all trajectories, combat-deployed service members diverged from non-combat-deployed service members, even after a single deployment. The former also generally had higher PTSD symptoms. Based on the models, nearly 90% of those without combat exposure remained resilient over the 10-year period, compared with 80% of those with combat exposure. Findings demonstrate that although the clinical course of PTSD symptoms shows heterogeneous patterns of development, combat exposure is uniformly associated with poor mental health. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Trajectory Browser Website

Science.gov (United States)

Foster, Cyrus; Jaroux, Belgacem A.

2012-01-01

The Trajectory Browser is a web-based tool developed at the NASA Ames Research Center to be used for the preliminary assessment of trajectories to small-bodies and planets and for providing relevant launch date, time-of-flight and V requirements. The site hosts a database of transfer trajectories from Earth to asteroids and planets for various types of missions such as rendezvous, sample return or flybys. A search engine allows the user to find trajectories meeting desired constraints on the launch window, mission duration and delta V capability, while a trajectory viewer tool allows the visualization of the heliocentric trajectory and the detailed mission itinerary. The anticipated user base of this tool consists primarily of scientists and engineers designing interplanetary missions in the context of pre-phase A studies, particularly for performing accessibility surveys to large populations of small-bodies. The educational potential of the website is also recognized for academia and the public with regards to trajectory design, a field that has generally been poorly understood by the public. The website is currently hosted on NASA-internal URL http://trajbrowser.arc.nasa.gov/ with plans for a public release as soon as development is complete.

Socioeconomic Disparity in Later-Year Group Trajectories of Depressive Symptoms: Role of Health and Social Engagement Change.

Science.gov (United States)

Lee, Hyunjoo; Park, Sojung; Kwon, Eunsun; Cho, Joonyoung

2017-06-01

This study explored heterogeneous change patterns of South Korean older adults' depressive symptoms by poverty status, focusing on health status and social engagement changes. We used data from four waves (2006-2012) of the Korean Longitudinal Study of Aging (KLoSA). Our sample contained 2461 poor and 1668 non-poor individuals. All were 65 years old or older at baseline. We used latent class growth analysis to identify trajectory groups' depressive symptoms. Multinomial logistic regression was used to examine how a range of changes in health conditions and social engagement was associated with trajectories among poor and non-poor participants. Among the poor, five heterogeneous trajectories with clear patterns were identified: high-to-moderate, stable-high, slightly-increasing, steeply-increasing, and stable-low. Among non-poor, high-to-moderate, steeply-increasing, and stable-low groups were found. A decrease in health conditions was the most vulnerable subgroup's (steeply-increasing) primary risk factor. Poor older adults who reduced participation in, or decreased contact with, social networks were likely to belong to the steeply-increasing group. Our study provides impetus for organizational and/or environmental support systems to facilitate social engagement among poor older adults. Future research should examine whether the significance of social engagement among poor elders applies in less-developed and developed countries.

Interference, reduced action, and trajectories

OpenAIRE

Floyd, Edward R.

2006-01-01

Instead of investigating the interference between two stationary, rectilinear wave functions in a trajectory representation by examining the two rectilinear wave functions individually, we examine a dichromatic wave function that is synthesized from the two interfering wave functions. The physics of interference is contained in the reduced action for the dichromatic wave function. As this reduced action is a generator of the motion for the dichromatic wave function, it determines the dichroma...

Growth trajectories in the cave bear and its extant relatives: an examination of ontogenetic patterns in phylogeny.

Science.gov (United States)

Fuchs, Manuela; Geiger, Madeleine; Stange, Madlen; Sánchez-Villagra, Marcelo R

2015-11-02

The study of postnatal ontogeny can provide insights into evolution by offering an understanding of how growth trajectories have evolved resulting in adult morphological disparity. The Ursus lineage is a good subject for studying cranial and mandibular shape and size variation in relation to postnatal ontogeny and phylogeny because it is at the same time not diverse but the species exhibit different feeding ecologies. Cranial and mandibular shapes of Ursus arctos (brown bear), U. maritimus (polar bear), U. americanus (American black bear), and the extinct U. spelaeus (cave bear) were examined, using a three-dimensional geometric morphometric approach. Additionally, ontogenetic series of crania and mandibles of U. arctos and U. spelaeus ranging from newborns to senile age were sampled. The distribution of specimens in morphospace allowed to distinguish species and age classes and the ontogenetic trajectories U. arctos and U. spelaeus were found to be more similar than expected by chance. Cranial shape changes during ontogeny are largely size related whereas the evolution of cranial shape disparity in this clade appears to be more influenced by dietary adaptation than by size and phylogeny. The different feeding ecologies are reflected in different cranial and mandibular shapes among species. The cranial and mandibular shape disparity in the Ursus lineage appears to be more influenced by adaptation to diet than by size or phylogeny. In contrast, the cranial and mandibular shape changes during postnatal ontogeny in U. arctos and U. spelaeus are probably largely size related. The patterns of morphospace occupation of the cranium and the mandible in adults and through ontogeny are different.

Parent-child relationships of boys in different offending trajectories. A developmental perspective

Science.gov (United States)

Keijsers, Loes; Loeber, Rolf; Branje, Susan; Meeus, Wim

2012-01-01

Background This study tested the theoretical assumption that transformations of parent-child relationships in late childhood and adolescence would differ for boys following different offending trajectories. Methods Using longitudinal multiinformant data of 503 boys (ages 7–19), we conducted Growth Mixture Modeling to extract offending trajectories. Developmental changes in child reports of parent-child joint activities and relationship quality were examined using Latent Growth Curves. Results Five offending trajectories were found: non-offenders, moderate childhood offenders, adolescent-limited offenders, serious childhood offenders, and serious persistent offenders. Non-offenders reported high and stable levels of relationship quality between age 10 and 16. Adolescent-limited offenders reported a similarly high relationship quality as non-offenders at ages 7 and 10, but a lower and decreasing relationship quality in adolescence. Compared with non-offenders, serious persistent offenders reported poorer parent-child relationship quality at all ages, and a decreasing relationship quality in adolescence. Serious persistent offenders and adolescent-limited offenders reported similar levels and changes in parent-child relationship quality in adolescence. Although serious persistent offenders reported fewer joint activities at age 10 and 13 than non-offenders, a similar linear decrease in joint activities in early to middle adolescence was found for boys in each trajectory. Conclusion Developmental changes in parent-child relationship quality differ for different types of offenders. This finding has scientific and practical implications. PMID:22816682

Trajectories of Sensation Seeking Among Puerto-Rican Children and Youth

Science.gov (United States)

Martins, Silvia S.; Wall, Melanie M.; Eisenberg, Ruth; Blanco, Carlos; Santaella, Julian; Ramos-Olazagasti, Maria; Canino, Glorisa; Bird, Hector R.; Brown, Qiana; Duarte, Cristiane S.

2015-01-01

Objective To document the natural course of sensation seeking from childhood to adolescence, characterize distinct sensation-seeking trajectories, and examine how these trajectories vary according to selected predictors. Method Data were obtained from the Boricua Youth Study, a longitudinal study of 2,491 children and adolescents of Puerto Rican background (three assessments from 2000 to 2004). First, age-specific sensation-seeking levels were characterized. Then, age-adjusted residuals were analyzed using growth mixture models (GMM). Results On average, sensation seeking was stable in childhood (ages 5–10) and increased during adolescence (ages 11–17). Mean scores of sensation seeking were higher in the South Bronx vs. Puerto Rico and among males vs. females. Four classes of sensation-seeking trajectories were observed: most study participants had age-expected sensation-seeking trajectories following the average for their age (“normative,” 43.8%); others (37.2%) remained consistently lower than the expected average for their age (“low” sensation seeking); some (12.0%) had an “accelerated” sensation-seeking trajectory, increasing at a faster rate than expected, while a minority (7.0%) had a decreasing sensation-seeking trajectory that started high but decreased, reaching scores slightly higher than the age-average sensation-seeking scores (“stabilizers”). Site (South Bronx vs. Puerto Rico) and gender were predictors of membership in a specific class of sensation-seeking trajectory. Conclusion It is important to take a developmental approach when examining sensation seeking and to consider gender and the social environment when trying to understand how sensation seeking evolves during childhood and adolescence. PMID:26598479

The shifting trajectory of growth in femur length during gestation.

Science.gov (United States)

Bjørnerem, Ashild; Johnsen, Synnøve L; Nguyen, Tuan V; Kiserud, Torvid; Seeman, Ego

2010-05-01

Bone size is a determinant of bone strength and tracks in its percentile of origin during childhood and adolescence. We hypothesized that the ranking of an individual's femur length (FL) is established in early gestation and tracks thereafter. Fetal FL was measured serially using 2D ultrasound in 625 Norwegian fetuses. Tracking was assessed using Pearson correlation, a generalized estimating equation model, and by calculating the proportion of fetuses whose FL remained within the same quartile. Baseline FL Z-score (weeks 10 to 19) and later measurements correlated, but more weakly as gestation advanced: r = 0.59 (weeks 20 to 26); r = 0.45 (weeks 27 to 33); and r = 0.32 (weeks 34 to 39) (p baseline FL Z-score, placental weight (150 g), maternal height (5 cm), and weight (10 kg), was associated with a 0.25, 0.15, 0.10, and 0.05 SD higher FL Z-score at the end of gestation, respectively (p ranging from <0.001 to 0.02). Tracking within the same percentile throughout the whole of gestation, as suggest by growth charts, is uncommon. Deviation from tracking is more common and is the result of changes in growth velocity within and between fetuses and is partly influenced by maternal, fetal, and placental factors. (c) 2010 American Society for Bone and Mineral Research.

Management by Trajectory: Trajectory Management Study Report

Science.gov (United States)

Leiden, Kenneth; Atkins, Stephen; Fernandes, Alicia D.; Kaler, Curt; Bell, Alan; Kilbourne, Todd; Evans, Mark

2017-01-01

In order to realize the full potential of the Next Generation Air Transportation System (NextGen), improved management along planned trajectories between air navigation service providers (ANSPs) and system users (e.g., pilots and airline dispatchers) is needed. Future automation improvements and increased data communications between aircraft and ground automation would make the concept of Management by Trajectory (MBT) possible.

Predicting longitudinal trajectories of health probabilities with random-effects multinomial logit regression.

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Liu, Xian; Engel, Charles C

2012-12-20

Researchers often encounter longitudinal health data characterized with three or more ordinal or nominal categories. Random-effects multinomial logit models are generally applied to account for potential lack of independence inherent in such clustered data. When parameter estimates are used to describe longitudinal processes, however, random effects, both between and within individuals, need to be retransformed for correctly predicting outcome probabilities. This study attempts to go beyond existing work by developing a retransformation method that derives longitudinal growth trajectories of unbiased health probabilities. We estimated variances of the predicted probabilities by using the delta method. Additionally, we transformed the covariates' regression coefficients on the multinomial logit function, not substantively meaningful, to the conditional effects on the predicted probabilities. The empirical illustration uses the longitudinal data from the Asset and Health Dynamics among the Oldest Old. Our analysis compared three sets of the predicted probabilities of three health states at six time points, obtained from, respectively, the retransformation method, the best linear unbiased prediction, and the fixed-effects approach. The results demonstrate that neglect of retransforming random errors in the random-effects multinomial logit model results in severely biased longitudinal trajectories of health probabilities as well as overestimated effects of covariates on the probabilities. Copyright © 2012 John Wiley & Sons, Ltd.

Assisted Reproduction Causes Reduced Fetal Growth Associated with Downregulation of Paternally Expressed Imprinted Genes That Enhance Fetal Growth in Mice.

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Li, Bo; Chen, Shuqiang; Tang, Na; Xiao, Xifeng; Huang, Jianlei; Jiang, Feng; Huang, Xiuying; Sun, Fangzhen; Wang, Xiaohong

2016-02-01

Alteration of intrauterine growth trajectory is linked to metabolic diseases in adulthood. In mammalian and, specifically, human species, pregnancies through assisted reproductive technology (ART) are associated with changes in intrauterine growth trajectory. However, it is still unclear how ART alters intrauterine growth trajectory, especially reduced fetal growth in early to midgestation. In this study, using a mouse model, it was found that ART procedures reduce fetal and placental growth at Embryonic Day 10.5. Furthermore, ART leads to decreased methylation levels at H19, KvDMR1, and Snrpn imprinting control regions in the placentae, instead of fetuses. Furthermore, in the placenta, ART downregulated a majority of parentally expressed imprinted genes, which enhance fetal growth, whereas it upregulated a majority of maternally expressed genes which repress fetal growth. Additionally, the expression of genes that regulate placental development was also affected by ART. ART also downregulated a majority of placental nutrient transporters. Disruption of genomic imprinting and abnormal expression of developmentally and functionally relevant genes in placenta may influence the placental development and function, which affect fetal growth and reprogramming. © 2016 by the Society for the Study of Reproduction, Inc.

Developmental Trajectories for Children With Dyslexia and Low IQ Poor Readers

Science.gov (United States)

2016-01-01

Reading difficulties are found in children with both high and low IQ and it is now clear that both groups exhibit difficulties in phonological processing. Here, we apply the developmental trajectories approach, a new methodology developed for studying language and cognitive impairments in developmental disorders, to both poor reader groups. The trajectory methodology enables identification of atypical versus delayed development in datasets gathered using group matching designs. Regarding the cognitive predictors of reading, which here are phonological awareness, phonological short-term memory (PSTM) and rapid automatized naming (RAN), the method showed that trajectories for the two groups diverged markedly. Children with dyslexia showed atypical development in phonological awareness, while low IQ poor readers showed developmental delay. Low IQ poor readers showed atypical PSTM and RAN development, but children with dyslexia showed developmental delay. These divergent trajectories may have important ramifications for supporting each type of poor reader, although all poor readers showed weakness in all areas. Regarding auditory processing, the developmental trajectories were very similar for the two poor reader groups. However, children with dyslexia demonstrated developmental delay for auditory discrimination of Duration, while the low IQ children showed atypical development on this measure. The data show that, regardless of IQ, poor readers have developmental trajectories that differ from typically developing children. The trajectories approach enables differences in trajectory classification to be identified across poor reader group, as well as specifying the individual nature of these trajectories. PMID:27110928

Three-year latent class trajectories of attention-deficit/hyperactivity disorder (ADHD) symptoms in a clinical sample not selected for ADHD.

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Arnold, L Eugene; Ganocy, Stephen J; Mount, Katherine; Youngstrom, Eric A; Frazier, Thomas; Fristad, Mary; Horwitz, Sarah M; Birmaher, Boris; Findling, Robert; Kowatch, Robert A; Demeter, Christine; Axelson, David; Gill, Mary Kay; Marsh, Linda

2014-07-01

This study aims to examine trajectories of attention-deficit/hyperactivity disorder (ADHD) symptoms in the Longitudinal Assessment of Manic Symptoms (LAMS) sample. The LAMS study assessed 684 children aged 6 to 12 years with the Kiddie-Schedule for Affective Disorders and Schizophrenia (K-SADS) and rating scales semi-annually for 3 years. Although they were selected for elevated manic symptoms, 526 children had baseline ADHD diagnoses. With growth mixture modeling (GMM), we separately analyzed inattentive and hyperactive/impulsive symptoms, covarying baseline age. Multiple standard methods determined optimal fit. The χ(2) and Kruskal-Wallis analysis of variance compared resulting latent classes/trajectories on clinical characteristics and medication. Three latent class trajectories best described inattentive symptoms, and 4 classes best described hyperactive/impulsive symptoms. Inattentive trajectories maintained their relative position over time. Hyperactive/impulsive symptoms had 2 consistent trajectories (least and most severe). A third trajectory (4.5%) started mild, then escalated; and a fourth (14%) started severe but improved dramatically. The improving trajectory was associated with the highest rate of ADHD and lowest rate of bipolar diagnoses. Three-fourths of the mildest inattention class were also in the mildest hyperactive/impulsive class; 72% of the severest inattentive class were in the severest hyperactive/impulsive class, but the severest inattention class also included 62% of the improving hyperactive-impulsive class. An ADHD rather than bipolar diagnosis prognosticates a better course of hyperactive/impulsive, but not inattentive, symptoms. High overlap of relative severity between inattention and hyperactivity/impulsivity confirms the link between these symptom clusters. Hyperactive/impulsive symptoms wane more over time. Group means are insufficient to understand individual ADHD prognosis. A small subgroup deteriorates over time in

Cosmic ray particle dosimetry and trajectory tracing

International Nuclear Information System (INIS)

Cruty, M.R.; Benton, E.V.; Turnbill, C.E.; Philpott, D.E.

1975-01-01

Five pocket mice (Perognathus longimembris) were flown on Apollo XVII, each with a solid-state (plastic) nuclear track detector implanted beneath its scalp. The subscalp detectors were sensitive to HZE cosmic ray particles with a LET greater than or approximately equal to 0.15 million electron volts per micrometer (MeV/micron). A critical aspect of the dosimetry of the experiment involved tracing individual particle trajectories through each mouse head from particle tracks registered in the individual subscalp detectors, thereby establishing a one-to-one correspondence between a trajectory location in the tissue and the presence or absence of a lesion. The other major aspect was the identification of each registered particle. An average of 16 particles with Z greater than or equal to 6 and 2.2 particles with Z greater than or equal to 20 were found per detector. The track density, 29 tracks/sq cm, when adjusted for detection volume, was in agreement with the photographic emulsion data from an area dosimeter located next to the flight package

Contributions to Variations in Academic Trajectories amongst Recent Immigrant Youth

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Suarez-Orozco, Carola; Bang, Hee Jin; Onaga, Marie

2010-01-01

Immigration presents both challenges and opportunities that affect students' academic achievement. Over the course of five years, varying academic trajectories were identified for recent immigrant students from Central America, China, the Dominican Republic, Haiti, and Mexico. Latent class growth curve analysis revealed that although some students…

Influence of weather and climate variables on the basal area growth of individual shortleaf pine trees

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Pradip Saud; Thomas B. Lynch; Duncan S. Wilson; John Stewart; James M. Guldin; Bob Heinemann; Randy Holeman; Dennis Wilson; Keith Anderson

2015-01-01

An individual-tree basal area growth model previously developed for even-aged naturally occurring shortleaf pine trees (Pinus echinata Mill.) in western Arkansas and southeastern Oklahoma did not include weather variables. Individual-tree growth and yield modeling of shortleaf pine has been carried out using the remeasurements of over 200 plots...

Trajectories of martian habitability.

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Cockell, Charles S

2014-02-01

Beginning from two plausible starting points-an uninhabited or inhabited Mars-this paper discusses the possible trajectories of martian habitability over time. On an uninhabited Mars, the trajectories follow paths determined by the abundance of uninhabitable environments and uninhabited habitats. On an inhabited Mars, the addition of a third environment type, inhabited habitats, results in other trajectories, including ones where the planet remains inhabited today or others where planetary-scale life extinction occurs. By identifying different trajectories of habitability, corresponding hypotheses can be described that allow for the various trajectories to be disentangled and ultimately a determination of which trajectory Mars has taken and the changing relative abundance of its constituent environments.

Early Life Factors and Inter-Country Heterogeneity in BMI Growth Trajectories of European Children: The IDEFICS Study.

Directory of Open Access Journals (Sweden)

Claudia Börnhorst

Full Text Available Starting from birth, this explorative study aimed to investigate between-country differences in body mass index (BMI trajectories and whether early life factors explain these differences.The sample included 7,644 children from seven European countries (Belgium, Cyprus, Germany, Hungary, Italy, Spain, Sweden participating in the multi-centre IDEFICS study. Information on early life factors and in total 53,409 repeated measurements of height and weight from 0 to <12 years of age were collected during the baseline (2007/2008 and follow-up examination (2009/2010 supplemented by records of routine child health visits. Country-specific BMI growth curves were estimated using fractional polynomial mixed effects models. Several covariates focussing on early life factors were added to the models to investigate their role in the between-countries differences.Large between-country differences were observed with Italian children showing significantly higher mean BMI values at all ages ≥ 3 years compared to the other countries. For instance, at age 11 years mean BMI values in Italian boys and girls were 22.3 [21.9;22.8; 99% confidence interval] and 22.0 [21.5;22.4], respectively, compared to a range of 18.4 [18.1;18.8] to 20.3 [19.8;20.7] in boys and 18.2 [17.8;18.6] to 20.3 [19.8;20.7] in girls in the other countries. After adjustment for early life factors, differences between country-specific BMI curves became smaller. Maternal BMI was the factor being most strongly associated with BMI growth (p<0.01 in all countries with associations increasing during childhood. Gestational weight gain (GWG was weakly associated with BMI at birth in all countries. In some countries, positive associations between BMI growth and children not being breastfed, mothers' smoking during pregnancy and low educational level of parents were found.Early life factors seem to explain only some of the inter-country variation in growth. Maternal BMI showed the strongest association

Trajectory approach to dissipative quantum phase space dynamics: Application to barrier scattering

International Nuclear Information System (INIS)

Hughes, Keith H.; Wyatt, Robert E.

2004-01-01

The Caldeira-Leggett master equation, expressed in Lindblad form, has been used in the numerical study of the effect of a thermal environment on the dynamics of the scattering of a wave packet from a repulsive Eckart barrier. The dynamics are studied in terms of phase space trajectories associated with the distribution function, W(q,p,t). The equations of motion for the trajectories include quantum terms that introduce nonlocality into the motion, which imply that an ensemble of correlated trajectories needs to be propagated. However, use of the derivative propagation method (DPM) allows each trajectory to be propagated individually. This is achieved by deriving equations of motion for the partial derivatives of W(q,p,t) that appear in the master equation. The effects of dissipation on the trajectories are studied and results are shown for the transmission probability. On short time scales, decoherence is demonstrated by a swelling of trajectories into momentum space. For a nondissipative system, a comparison is made of the DPM with the 'exact' transmission probability calculated from a fixed grid calculation

Parental nonstandard work schedules during infancy and children's BMI trajectories

Directory of Open Access Journals (Sweden)

Afshin Zilanawala

2017-09-01

Full Text Available Background: Empirical evidence has demonstrated adverse associations between parental nonstandard work schedules (i.e., evenings, nights, or weekends and child developmental outcomes. However, there are mixed findings concerning the relationship between parental nonstandard employment and children's body mass index (BMI, and few studies have incorporated information on paternal work schedules. Objective: This paper investigated BMI trajectories from early to middle childhood (ages 3-11 by parental work schedules at 9 months of age, using nationally representative cohort data from the United Kingdom. This study is the first to examine the link between nonstandard work schedules and children's BMI in the United Kingdom. Methods: We used data from the Millennium Cohort Study (2001‒2013, n = 13,021 to estimate trajectories in BMI, using data from ages 3, 5, 7, and 11 years. Joint parental work schedules and a range of biological, socioeconomic, and psychosocial covariates were assessed in the initial interviews at 9 months. Results: Compared to children in two-parent families where parents worked standard shifts, we found steeper BMI growth trajectories for children in two-parent families where both parents worked nonstandard shifts and children in single-parent families whose mothers worked a standard shift. Fathers' shift work, compared to standard shifts, was independently associated with significant increases in BMI. Conclusions: Future public health initiatives focused on reducing the risk of rapid BMI gain in childhood can potentially consider the disruptions to family processes resulting from working nonstandard hours. Contribution: Children in families in which both parents work nonstandard schedules had steeper BMI growth trajectories across the first decade of life. Fathers' nonstandard shifts were independently associated with increases in BMI.

Maternal Metabolic Health Parameters During Pregnancy in Relation to Early Childhood BMI Trajectories.

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Montazeri, Parisa; Vrijheid, Martine; Martinez, David; Basterrechea, Mikel; Fernandez-Somoano, Ana; Guxens, Monica; Iñiguez, Carmen; Lertxundi, Aitana; Murcia, Mario; Tardon, Adonina; Sunyer, Jordi; Valvi, Damaskini

2018-03-01

The objective of this study was to evaluate the associations between maternal metabolic parameters and early childhood BMI trajectories. Two thousand two hundred fifty-one children born in Spain between 2004 and 2008 were analyzed. Five BMI z score trajectories from birth to age 4 years were identified by using latent class growth analysis. Multinomial regression assessed the associations between maternal metabolic parameters and offspring's BMI trajectories. Children in the reference BMI trajectory had average size at birth followed by a slower BMI gain. Maternal prepregnancy obesity was associated with trajectories of accelerated BMI gain departing from either higher (relative risk ratio [RRR] = 1.77; 95% CI: 1.07-2.91) or lower size at birth (RRR = 1.91; 95% CI: 1.17-3.12). Gestational weight gain (GWG) above clinical guidelines was associated with a trajectory of higher birth size followed by accelerated BMI gain (RRR = 2.14; 95% CI: 1.53-2.97). Maternal serum triglycerides were negatively associated with BMI trajectories departing from lower birth sizes. Gestational diabetes, maternal serum cholesterol, and C-reactive protein were unrelated to children's BMI trajectories. Maternal prepregnancy obesity, GWG, and serum triglycerides are associated with longitudinal BMI trajectories in early childhood that may increase disease risk in later life. Health initiatives should promote healthy weight status before and during pregnancy to improve maternal and child health. © 2018 The Obesity Society.

Trajectories of Sensation Seeking Among Puerto Rican Children and Youth.

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Martins, Silvia S; Wall, Melanie M; Eisenberg, Ruth; Blanco, Carlos; Santaella, Julian; Ramos-Olazagasti, Maria; Canino, Glorisa; Bird, Hector R; Brown, Qiana; Duarte, Cristiane S

2015-12-01

To document the natural course of sensation seeking from childhood to adolescence, characterize distinct sensation seeking trajectories, and examine how these trajectories vary according to selected predictors. Data were obtained from the Boricua Youth Study, a longitudinal study of 2,491 children and adolescents of Puerto Rican background (3 assessments from 2000 to 2004). First, age-specific sensation seeking levels were characterized, and then age-adjusted residuals were analyzed using growth mixture models. On average, sensation seeking was stable in childhood (ages 5-10 years) and increased during adolescence (ages 11-17 years). Mean scores of sensation seeking were higher in the South Bronx versus Puerto Rico and among males versus females. Four classes of sensation seeking trajectories were observed: most study participants had age-expected sensation seeking trajectories following the average for their age ("normative," 43.8%); others (37.2%) remained consistently lower than the expected average for their age ("low" sensation seeking); some (12.0%) had an "accelerated" sensation seeking trajectory, increasing at a faster rate than expected; and a minority (7.0%) had a decreasing sensation seeking trajectory that started high but decreased, reaching scores slightly higher than the age-average sensation seeking scores ("stabilizers"). Site (South Bronx versus Puerto Rico) and gender were predictors of membership in a specific class of sensation seeking trajectory. It is important to take a developmental approach when examining sensation seeking and to consider gender and the social environment when trying to understand how sensation seeking evolves during childhood and adolescence. Copyright © 2015 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

Symptom Cluster Trajectories During Chemotherapy in Breast Cancer Outpatients.

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Hsu, Hsin-Tien; Lin, Kuan-Chia; Wu, Li-Min; Juan, Chiung-Hui; Hou, Ming-Feng; Hwang, Shiow-Li; Liu, Yi; Dodd, Marylin J

2017-06-01

Breast cancer patients often experience multiple symptoms and substantial discomfort. Some symptoms may occur simultaneously and throughout the duration of chemotherapy treatment. The aim of this study was to investigate symptom severity and symptom cluster trajectories during chemotherapy in outpatients with breast cancer in Taiwan. This prospective, longitudinal, repeated measures study administered a standardized questionnaire (M. D. Anderson Symptom Inventory Taiwan version) to 103 breast cancer patients during each day of the third 21-day cycle of chemotherapy. Latent class growth analysis was performed to examine symptom cluster trajectories. Three symptom clusters were identified within the first 14 days of the 21-day chemotherapy cycle: the neurocognition cluster (pain, shortness of breath, vomiting, memory problems, and numbness/tingling) with a trajectory of Y = 2.09 - 0.11 (days), the emotion-nausea cluster (nausea, disturbed sleep, distress/upset, drowsiness, and sadness) with a trajectory ofY = 3.57 - 0.20 (days), and the fatigue-anorexia cluster (fatigue, lack of appetite, and dry mouth) with a trajectory of Y = 4.22 - 0.21 (days). The "fatigue-anorexia cluster" and "emotion-nausea cluster" peaked at moderate levels on chemotherapy days 3-5, and then gradually decreased to mild levels within the first 14 days of the 21-day chemotherapy cycle. Distinct symptom clusters were observed during the third cycle of chemotherapy. Systematic and ongoing evaluation of symptom cluster trajectories during cancer treatment is essential. Healthcare providers can use these findings to enhance communication with their breast cancer patients and to prioritize symptoms that require attention and intervention. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

Trajectory data analyses for pedestrian space-time activity study.

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Qi, Feng; Du, Fei

2013-02-25

It is well recognized that human movement in the spatial and temporal dimensions has direct influence on disease transmission(1-3). An infectious disease typically spreads via contact between infected and susceptible individuals in their overlapped activity spaces. Therefore, daily mobility-activity information can be used as an indicator to measure exposures to risk factors of infection. However, a major difficulty and thus the reason for paucity of studies of infectious disease transmission at the micro scale arise from the lack of detailed individual mobility data. Previously in transportation and tourism research detailed space-time activity data often relied on the time-space diary technique, which requires subjects to actively record their activities in time and space. This is highly demanding for the participants and collaboration from the participants greatly affects the quality of data(4). Modern technologies such as GPS and mobile communications have made possible the automatic collection of trajectory data. The data collected, however, is not ideal for modeling human space-time activities, limited by the accuracies of existing devices. There is also no readily available tool for efficient processing of the data for human behavior study. We present here a suite of methods and an integrated ArcGIS desktop-based visual interface for the pre-processing and spatiotemporal analyses of trajectory data. We provide examples of how such processing may be used to model human space-time activities, especially with error-rich pedestrian trajectory data, that could be useful in public health studies such as infectious disease transmission modeling. The procedure presented includes pre-processing, trajectory segmentation, activity space characterization, density estimation and visualization, and a few other exploratory analysis methods. Pre-processing is the cleaning of noisy raw trajectory data. We introduce an interactive visual pre-processing interface as well as an

Language growth in children with heterogeneous language disorders: a population study.

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Norbury, Courtenay Frazier; Vamvakas, George; Gooch, Debbie; Baird, Gillian; Charman, Tony; Simonoff, Emily; Pickles, Andrew

2017-10-01

Language development has been characterised by significant individual stability from school entry. However, the extent to which trajectories of language growth vary in children with language disorder as a function of co-occurring developmental challenges is a question of theoretical import, with implications for service provision. SCALES employed a population-based survey design with sample weighting procedures to estimate growth in core language skills over the first three years of school. A stratified sample (n = 529) received comprehensive assessment of language, nonverbal IQ, and social, emotional and behavioural difficulties at 5-6 years of age and 95% of the sample (n = 499) were assessed again at ages 7-8. Language growth was measured using both raw and standard scores in children with typical development, children with language disorder of unknown origin, and children with language disorders associated with a known clinical condition and/or intellectual disability. Overall, language was stable at the individual level (estimated ICC = 0.95) over the first three years of school. Linear mixed effects models highlighted steady growth in language raw scores across all three groups, including those with multiple developmental challenges. There was little evidence, however, that children with language disorders were narrowing the gap with peers (z-scores). Adjusted models indicated that while nonverbal ability, socioeconomic status and social, emotional and behavioural deficits predicted initial language score (intercept), none predicted language growth (slope). These findings corroborate previous studies suggesting stable language trajectories after ages 5-6 years, but add considerably to previous work by demonstrating similar developmental patterns in children with additional nonverbal cognitive deficits, social, emotional, and behavioural challenges, social disadvantage or clinical diagnoses. © 2017 The Authors. Journal of Child Psychology and

"Mental retirement?" Trajectories of work engagement preceding retirement among older workers.

Science.gov (United States)

de Wind, Astrid; Leijten, Fenna Rm; Hoekstra, Trynke; Geuskens, Goedele A; Burdorf, Alex; van der Beek, Allard J

2017-01-01

Objectives Before actual retirement, employees may already distance themselves from work, which could be referred to as "mental retirement". However, trajectories of work motivation, ie, work engagement, have not been studied yet. The present study aimed to (i) identify different trajectories of work engagement among older workers approaching the retirement age, and (ii) examine their associations with actual retirement. Methods In total 3171 employees aged 55-62 years, who participated in the Dutch Study on Transitions in Employment, Ability and Motivation were included in this study. Participants completed questionnaires in 2010, 2011, 2012, and 2013. Latent class growth mixture modeling was performed to identify groups of employees with similar three-year trajectories in work engagement. Logistic regression analyses were performed to study whether trajectory membership was associated with retirement. Results Of the 3171 employees, 16.2% made a transition from work to (early) retirement (N=513). Four trajectories of work engagement were identified: steady high (76.3%), steady low (12.7%), decreasing (6.2%), and increasing (4.8%). A steady low work engagement trajectory was associated with retirement [odds ratio (OR) 1.46], compared to a steady high work engagement trajectory. Although not statistically significant, an increasing work engagement trajectory seemed to be associated with retirement as well (OR 1.60). Conclusions This study did not support the concept of mental retirement before actual retirement, ie, a decrease in work engagement among those facing retirement. However, as one in eight employees did experience steady low work engagement in the years before retirement, interventions promoting work motivation are recommended to support the employability of these employees.

The national trajectory project of individuals found not criminally responsible on account of mental disorder in Canada. Part 3: trajectories and outcomes through the forensic system.

Science.gov (United States)

Crocker, Anne G; Charette, Yanick; Seto, Michael C; Nicholls, Tonia L; Côté, Gilles; Caulet, Malijai

2015-03-01

To examine the processing and Review Board (RB) disposition outcomes of people found not criminally responsible on account of mental disorder (NCRMD) across the 3 most populous provinces in Canada. Although the Criminal Code is federally legislated, criminal justice is administered by provinces and territories. It follows that a person with mental illness who comes into conflict with the law and subsequently comes under the management of a legally mandated RB may experience different trajectories across jurisdictions. The National Trajectory Project examined 1800 men and women found NCRMD in British Columbia (n = 222), Quebec (n = 1094), and Ontario (n = 484) between May 2000 and April 2005, followed until December 2008. We found significant interprovincial differences in the trajectories of people found NCRMD, including time detained in hospital and time under the supervision of an RB. The odds of being conditionally or absolutely discharged by the RB varied across provinces, even after number of past offences, diagnosis at verdict, and most severe index offence (all covariates decreased likelihood of discharge) were considered. Considerable discrepancies in the application of NCRMD legislation and the processing of NCRMD cases through the forensic system across the provinces suggests that fair and equitable treatment under the law could be enhanced by increased national integration and collaboration.

Eight-Year Latent Class Trajectories of Academic and Social Functioning in Children with Attention-Deficit/Hyperactivity Disorder.

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DuPaul, George J; Morgan, Paul L; Farkas, George; Hillemeier, Marianne M; Maczuga, Steve

2017-09-15

We examined trajectories of academic and social functioning in children with attention-deficit/hyperactivity disorder (ADHD) to identify those who might be at risk for especially severe levels of academic and social impairment over time. We estimated a series of growth mixture models using data from two subsamples of children participating in the NIMH Collaborative Multisite Multimodal Treatment Study of Children with ADHD (MTA) including those with at least baseline and 96-month data for reading and mathematics achievement (n = 392; 77.3% male; M age = 7.7; SD = 0.8) or social skills ratings from teachers (n = 259; 74.9% male; M age = 7.6; SD = 0.8). We compared latent trajectories for children with ADHD to mean observed trajectories obtained from a local normative (i.e., non-ADHD) comparison group (n = 289; 80.6% male; M age = 9.9; SD = 1.1). Results indicated six latent trajectory classes for reading and mathematics and four classes for teacher social skills ratings. There was not only a relationship between trajectories of inattention symptoms and academic impairment, but also a similarly strong association between trajectory classes of hyperactive-impulsive symptoms and achievement. Trajectory class membership correlated with socio-demographic and diagnostic characteristics, inattention and hyperactive-impulsive symptom trajectories, externalizing behavior in school, and treatment receipt and dosage. Although children with ADHD display substantial heterogeneity in their reading, math, and social skills growth trajectories, those with behavioral and socio-demographic disadvantages are especially likely to display severe levels of academic and social impairment over time. Evidence-based early screening and intervention that directly address academic and social impairments in elementary school-aged children with ADHD are warranted. The ClinicalTrials.gov identifier is NCT00000388.

Parent-child acculturation profiles as predictors of Chinese American adolescents' academic trajectories.

Science.gov (United States)

Kim, Su Yeong; Wang, Yijie; Chen, Qi; Shen, Yishan; Hou, Yang

2015-06-01

Acculturation plays a critical role in the adjustment of Asian Americans, as a large proportion of them are immigrants in the US. However, little is known about how acculturation influences Asian American adolescents' academic trajectories over time. Using a longitudinal sample of 444 Chinese American families (54% female children), the current study explored the effect of mothers', fathers', and adolescents' individual acculturation profiles and parent-child acculturation dissonance on adolescents' academic trajectories from 8th to 12th grade. Academic performance was measured by grade point average (GPA), and by standardized test scores in English language arts (ELA) and Math every year. Latent growth modeling analyses showed that adolescents with a Chinese-oriented father showed faster decline in GPA, and Chinese-oriented adolescents had lower initial ELA scores. Adolescents whose parents had American-oriented acculturation profiles tended to have lower initial Math scores. These results suggest that Chinese and American profiles may be disadvantageous for certain aspects of academic performance, and bicultural adolescents and/or adolescents with bicultural parents are best positioned to achieve across multiple domains. In terms of the role of parent-child acculturation dissonance on academic trajectories, the current study highlighted the importance of distinguishing among different types of dissonance. Adolescents who were more Chinese-oriented than their parents tended to have the lowest initial ELA scores, and adolescents experiencing more normative acculturation dissonance (i.e., who were more American-oriented than their parents) had the highest initial ELA scores. No effects of parent-child acculturation dissonance were observed for GPAs or standardized Math scores. Altogether, the current findings add nuances to the current understanding of acculturation and adolescent adjustment.

Parent-Child Acculturation Profiles as Predictors of Chinese American Adolescents’ Academic Trajectories

Science.gov (United States)

Kim, Su Yeong; Wang, Yijie; Chen, Qi; Shen, Yishan; Hou, Yang

2014-01-01

Acculturation plays a critical role in the adjustment of Asian Americans, as a large proportion of them are immigrants in the U.S. However, little is known about how acculturation influences Asian American adolescents’ academic trajectories over time. Using a longitudinal sample of 444 Chinese American families (54% female children), the current study explored the effect of mothers’, fathers’, and adolescents’ individual acculturation profiles and parent-child acculturation dissonance on adolescents’ academic trajectories from 8th to 12th grade. Academic performance was measured by Grade Point Average (GPA), and by standardized test scores in English Language Arts (ELA) and Math every year. Latent growth modeling analyses showed that adolescents with a Chinese-oriented father showed faster decline in GPA, and Chinese-oriented adolescents had lower initial ELA scores. Adolescents whose parents had American-oriented acculturation profiles tended to have lower initial Math scores. These results suggest that Chinese and American profiles may be disadvantageous for certain aspects of academic performance, and bicultural adolescents and/or adolescents with bicultural parents are best positioned to achieve across multiple domains. In terms of the role of parent-child acculturation dissonance on academic trajectories, the current study highlighted the importance of distinguishing among different types of dissonance. Adolescents who were more Chinese-oriented than their parents tended to have the lowest initial ELA scores, and adolescents experiencing more normative acculturation dissonance (i.e., who were more American-oriented than their parents) had the highest initial ELA scores. No effects of parent-child acculturation dissonance were observed for GPAs or standardized Math scores. Altogether, the current findings add nuances to the current understanding of acculturation and adolescent adjustment. PMID:24820295

A hybrid spatio-temporal data indexing method for trajectory databases.

Science.gov (United States)

Ke, Shengnan; Gong, Jun; Li, Songnian; Zhu, Qing; Liu, Xintao; Zhang, Yeting

2014-07-21

In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type.

A Hybrid Spatio-Temporal Data Indexing Method for Trajectory Databases

Directory of Open Access Journals (Sweden)

Shengnan Ke

2014-07-01

Full Text Available In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type.

A Hybrid Spatio-Temporal Data Indexing Method for Trajectory Databases

Science.gov (United States)

Ke, Shengnan; Gong, Jun; Li, Songnian; Zhu, Qing; Liu, Xintao; Zhang, Yeting

2014-01-01

In recent years, there has been tremendous growth in the field of indoor and outdoor positioning sensors continuously producing huge volumes of trajectory data that has been used in many fields such as location-based services or location intelligence. Trajectory data is massively increased and semantically complicated, which poses a great challenge on spatio-temporal data indexing. This paper proposes a spatio-temporal data indexing method, named HBSTR-tree, which is a hybrid index structure comprising spatio-temporal R-tree, B*-tree and Hash table. To improve the index generation efficiency, rather than directly inserting trajectory points, we group consecutive trajectory points as nodes according to their spatio-temporal semantics and then insert them into spatio-temporal R-tree as leaf nodes. Hash table is used to manage the latest leaf nodes to reduce the frequency of insertion. A new spatio-temporal interval criterion and a new node-choosing sub-algorithm are also proposed to optimize spatio-temporal R-tree structures. In addition, a B*-tree sub-index of leaf nodes is built to query the trajectories of targeted objects efficiently. Furthermore, a database storage scheme based on a NoSQL-type DBMS is also proposed for the purpose of cloud storage. Experimental results prove that HBSTR-tree outperforms TB*-tree in some aspects such as generation efficiency, query performance and query type. PMID:25051028

Longitudinal Trajectories and Inter-parental Dynamics of Prairie Vole Biparental Care

Directory of Open Access Journals (Sweden)

Forrest D. Rogers

2018-06-01

Full Text Available For altricial mammalian species, early life social bonds are constructed principally between offspring and their mothers, and the mother-offspring relationship sets the trajectory for offspring bio-behavioral development. In the rare subset of monogamous and biparental species, offspring experience an expanded social network which includes a father. Accordingly, in biparental species fathers also have the potential to influence trajectories of offspring development. Previous semi-natural and laboratory study of one monogamous and biparental species, the prairie vole (Microtus ochrogaster, has given insight into the role that mothers and fathers play in shaping behavioral phenotypes of offspring. Of particular interest is the influence of biparental care in the development of monogamous behavior in offspring. Here, we first briefly review that influence. We then present novel research which describes how parental investment in prairie voles changes across sequential litters of pups, and the extent to which it is coordinated between mothers and fathers. We use approximately 6 years of archival data on prairie vole parenting to investigate trajectories and inter-parent dynamics in prairie vole parenting. We use a series of latent growth models to assess the stability of parental investment across the first 4 l. Our findings suggest that prairie voles display sexually dimorphic patterns of change in parental behavior: mothers' investment declines linearly whereas fathers' pattern of change is characterized by initial decline between litters 1 and 2 with subsequent increase from litters 2 to 4. Our findings also support a conclusion that prairie vole paternal care may be better characterized as compensatory—that is, fathers may compensate for decline in maternal investment. Opposing trends in investment between mothers and fathers ultimately imply stability in offspring investment across sequential litters. These findings, combined with previous

Mothers' Depression and Educational Attainment and Their Children's Academic Trajectories

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Augustine, Jennifer March; Crosnoe, Robert

2010-01-01

In this study, we take a dynamic approach to studying the connections among mothers' education, their depression, and their children's academic trajectories during elementary school. Applying latent growth curve modeling to longitudinal data from the National Institute of Child Health and Human Development's Study of Early Child Care and Youth…

When Natural Disaster Follows Economic Downturn: The Incremental Impact of Multiple Stressor Events on Trajectories of Depression and Posttraumatic Stress Disorder.

Science.gov (United States)

Mandavia, Amar D; Bonanno, George A

2018-04-29

To determine whether there were incremental mental health impacts, specifically on depression trajectories, as a result of the 2008 economic crisis (the Great Recession) and subsequent Hurricane Sandy. Using latent growth mixture modeling and the ORANJ BOWL dataset, we examined prospective trajectories of depression among older adults (mean age, 60.67; SD, 6.86) who were exposed to the 2 events. We also collected community economic and criminal justice data to examine their impact upon depression trajectories. Participants (N=1172) were assessed at 3 times for affect, successful aging, and symptoms of depression. We additionally assessed posttraumatic stress disorder (PTSD) symptomology after Hurricane Sandy. We identified 3 prospective trajectories of depression. The majority (83.6%) had no significant change in depression from before to after these events (resilience), while 7.2% of the sample increased in depression incrementally after each event (incremental depression). A third group (9.2%) went from high to low depression symptomology following the 2 events (depressive-improving). Only those in the incremental depression group had significant PTSD symptoms following Hurricane Sandy. We identified a small group of individuals for whom the experience of multiple stressful events had an incremental negative effect on mental health outcomes. These results highlight the importance of understanding the perseveration of depression symptomology from one event to another. (Disaster Med Public Health Preparedness. 2018;page 1 of 10).

Developmental Trajectories of Male Physical Violence and Theft

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Barker, Edward D.; Séguin, Jean R.; White, Helene Raskin; Bates, Marsha E.; Lacourse, Éric; Carbonneau, René; Tremblay, Richard E.

2012-01-01

Context Neurocognitive mechanisms have long been hypothesized to influence developmental trajectories of antisocial behavior. However, studies examining this association tend to aggregate a variety of problem behaviors that may be differently affected by neurocognitive deficits. Objective To describe the developmental trajectories of physical violence and theft from adolescence to adulthood, their associations, and the neurocognitive characteristics of individuals following different patterns of trajectory association. Design Accelerated cohort-sequential, longitudinal design. Setting Rutgers Health and Human Development Project. Participants Six hundred ninety-eight men. Main Outcome Measures Self-reports of physical violence (ages 12–24 years) and theft (ages 12–31 years) were collected across 5 waves. Neurocognitive performance was assessed with executive function and verbal IQ tests between late adolescence and early adulthood. Results The majority (55%) of subjects showed an increased frequency of theft during the study period, while only a minority (13%) evinced an increasing frequency of physical violence. Executive function and verbal IQ performance were negatively related to high frequency of physical violence but positively related to high frequency of theft. Conclusions Developmental trajectories of physical violence and theft during adolescence and early adulthood are different and differently related to neurocognitive functioning. Global indexes of antisocial behavior mask the development of antisocial behavior subtypes and putative causal mechanisms. PMID:17485611

PANTHER. Trajectory Analysis

Energy Technology Data Exchange (ETDEWEB)

Rintoul, Mark Daniel [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Wilson, Andrew T. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Valicka, Christopher G. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Kegelmeyer, W. Philip [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Shead, Timothy M. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Newton, Benjamin D. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Czuchlewski, Kristina Rodriguez [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

2015-09-01

We want to organize a body of trajectories in order to identify, search for, classify and predict behavior among objects such as aircraft and ships. Existing compari- son functions such as the Fr'echet distance are computationally expensive and yield counterintuitive results in some cases. We propose an approach using feature vectors whose components represent succinctly the salient information in trajectories. These features incorporate basic information such as total distance traveled and distance be- tween start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally, these features can generally be mapped easily to behaviors of interest to humans that are searching large databases. Most of these geometric features are invariant under rigid transformation. We demonstrate the use of different subsets of these features to iden- tify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories, predict destination and apply unsupervised machine learning algorithms.

Individual-Tree Diameter Growth Models for Mixed Nothofagus Second Growth Forests in Southern Chile

Directory of Open Access Journals (Sweden)

Paulo C. Moreno

2017-12-01

Full Text Available Second growth forests of Nothofagus obliqua (roble, N. alpina (raulí, and N. dombeyi (coihue, known locally as RORACO, are among the most important native mixed forests in Chile. To improve the sustainable management of these forests, managers need adequate information and models regarding not only existing forest conditions, but their future states with varying alternative silvicultural activities. In this study, an individual-tree diameter growth model was developed for the full geographical distribution of the RORACO forest type. This was achieved by fitting a complete model by comparing two variable selection procedures: cross-validation (CV, and least absolute shrinkage and selection operator (LASSO regression. A small set of predictors successfully explained a large portion of the annual increment in diameter at breast height (DBH growth, particularly variables associated with competition at both the tree- and stand-level. Goodness-of-fit statistics for this final model showed an empirical coefficient of correlation (R2emp of 0.56, relative root mean square error of 44.49% and relative bias of −1.96% for annual DBH growth predictions, and R2emp of 0.98 and 0.97 for DBH projection at 6 and 12 years, respectively. This model constitutes a simple and useful tool to support management plans for these forest ecosystems.

Individualized assessment of post-arthroplasty recovery by actigraphy

DEFF Research Database (Denmark)

Engelund Luna, Iben; Peterson, Barry; Kehlet, Henrik

2017-01-01

time. The aim of this study was to describe a novel methodology using actigraphy data to describe specific activity-intensities potentially affected by surgery and patients with poor rehabilitation trajectories. Actigraphy data from 10 patients scheduled for primary unilateral TKA were recorded...... recovery trajectories were described by the gradient of the regression line of post- versus pre-operative physical activity over the study period. TKA had a negative impact on all activity intensities with gradual improvement towards preoperative values during the study period. The inter......-individual variation increased with intensified activity. Identification of individual patients with positive, neutral or negative activity trajectories was possible. The methodology should be considered in future interventional studies to improve rehabilitation strategies....

Individuality and universality in the growth-division laws of single E. coli cells

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Kennard, Andrew S.; Osella, Matteo; Javer, Avelino; Grilli, Jacopo; Nghe, Philippe; Tans, Sander J.; Cicuta, Pietro; Cosentino Lagomarsino, Marco

2016-01-01

The mean size of exponentially dividing Escherichia coli cells in different nutrient conditions is known to depend on the mean growth rate only. However, the joint fluctuations relating cell size, doubling time, and individual growth rate are only starting to be characterized. Recent studies in bacteria reported a universal trend where the spread in both size and doubling times is a linear function of the population means of these variables. Here we combine experiments and theory and use scaling concepts to elucidate the constraints posed by the second observation on the division control mechanism and on the joint fluctuations of sizes and doubling times. We found that scaling relations based on the means collapse both size and doubling-time distributions across different conditions and explain how the shape of their joint fluctuations deviates from the means. Our data on these joint fluctuations highlight the importance of cell individuality: Single cells do not follow the dependence observed for the means between size and either growth rate or inverse doubling time. Our calculations show that these results emerge from a broad class of division control mechanisms requiring a certain scaling form of the "division hazard rate function," which defines the probability rate of dividing as a function of measurable parameters. This "model free" approach gives a rationale for the universal body-size distributions observed in microbial ecosystems across many microbial species, presumably dividing with multiple mechanisms. Additionally, our experiments show a crossover between fast and slow growth in the relation between individual-cell growth rate and division time, which can be understood in terms of different regimes of genome replication control.

Mapping concentrations of posttraumatic stress and depression trajectories following Hurricane Ike.

Science.gov (United States)

Gruebner, Oliver; Lowe, Sarah R; Tracy, Melissa; Joshi, Spruha; Cerdá, Magdalena; Norris, Fran H; Subramanian, S V; Galea, Sandro

2016-08-25

We investigated geographic concentration in elevated risk for a range of postdisaster trajectories of chronic posttraumatic stress symptom (PTSS) and depression symptoms in a longitudinal study (N = 561) of a Hurricane Ike affected population in Galveston and Chambers counties, TX. Using an unadjusted spatial scan statistic, we detected clusters of elevated risk of PTSS trajectories, but not depression trajectories, on Galveston Island. We then tested for predictors of membership in each trajectory of PTSS and depression (e.g., demographic variables, trauma exposure, social support), not taking the geographic nature of the data into account. After adjusting for significant predictors in the spatial scan statistic, we noted that spatial clusters of PTSS persisted and additional clusters of depression trajectories emerged. This is the first study to show that longitudinal trajectories of postdisaster mental health problems may vary depending on the geographic location and the individual- and community-level factors present at these locations. Such knowledge is crucial to identifying vulnerable regions and populations within them, to provide guidance for early responders, and to mitigate mental health consequences through early detection of mental health needs in the population. As human-made disasters increase, our approach may be useful also in other regions in comparable settings worldwide.

Employment Trajectories: Exploring Gender Differences and Impacts of Drug Use

Science.gov (United States)

Huang, David Y. C.; Evans, Elizabeth; Hara, Motoaki; Weiss, Robert E.; Hser, Yih-Ing

2011-01-01

This study investigated the impact of drug use on employment over 20 years among men and women, utilizing data on 7661 participants in the National Longitudinal Survey of Youth. Growth mixture modeling was applied, and five distinct employment trajectory groups were identified for both men and women. The identified patterns were largely similar…

Aging Trajectories in Different Body Systems Share Common Environmental Etiology: The Healthy Aging Twin Study (HATS).

Science.gov (United States)

Moayyeri, Alireza; Hart, Deborah J; Snieder, Harold; Hammond, Christopher J; Spector, Timothy D; Steves, Claire J

2016-02-01

Little is known about the extent to which aging trajectories of different body systems share common sources of variance. We here present a large twin study investigating the trajectories of change in five systems: cardiovascular, respiratory, skeletal, morphometric, and metabolic. Longitudinal clinical data were collected on 3,508 female twins in the TwinsUK registry (complete pairs:740 monozygotic (MZ), 986 dizygotic (DZ), mean age at entry 48.9 ± 10.4, range 18-75 years; mean follow-up 10.2 ± 2.8 years, range 4-17.8 years). Panel data on multiple age-related variables were used to estimate biological ages for each individual at each time point, in linear mixed effects models. A weighted average approach was used to combine variables within predefined body system groups. Aging trajectories for each system in each individual were then constructed using linear modeling. Multivariate structural equation modeling of these aging trajectories showed low genetic effects (heritability), ranging from 2% in metabolic aging to 22% in cardiovascular aging. However, we found a significant effect of shared environmental factors on the variations in aging trajectories in cardiovascular (54%), skeletal (34%), morphometric (53%), and metabolic systems (53%). The remainder was due to environmental factors unique to each individual plus error. Multivariate Cholesky decomposition showed that among aging trajectories for various body systems there were significant and substantial correlations between the unique environmental latent factors as well as shared environmental factors. However, there was no evidence for a single common factor for aging. This study, the first of its kind in aging, suggests that diverse organ systems share non-genetic sources of variance for aging trajectories. Confirmatory studies are needed using population-based twin cohorts and alternative methods of handling missing data.

Childhood predictors of lung function trajectories and future COPD risk: a prospective cohort study from the first to the sixth decade of life.

Science.gov (United States)

Bui, Dinh S; Lodge, Caroline J; Burgess, John A; Lowe, Adrian J; Perret, Jennifer; Bui, Minh Q; Bowatte, Gayan; Gurrin, Lyle; Johns, David P; Thompson, Bruce R; Hamilton, Garun S; Frith, Peter A; James, Alan L; Thomas, Paul S; Jarvis, Deborah; Svanes, Cecilie; Russell, Melissa; Morrison, Stephen C; Feather, Iain; Allen, Katrina J; Wood-Baker, Richard; Hopper, John; Giles, Graham G; Abramson, Michael J; Walters, Eugene H; Matheson, Melanie C; Dharmage, Shyamali C

2018-04-05

Lifetime lung function is related to quality of life and longevity. Over the lifespan, individuals follow different lung function trajectories. Identification of these trajectories, their determinants, and outcomes is important, but no study has done this beyond the fourth decade. We used six waves of the Tasmanian Longitudinal Health Study (TAHS) to model lung function trajectories measured at 7, 13, 18, 45, 50, and 53 years. We analysed pre-bronchodilator FEV 1 z-scores at the six timepoints using group-based trajectory modelling to identify distinct subgroups of individuals whose measurements followed a similar pattern over time. We related the trajectories identified to childhood factors and risk of chronic obstructive pulmonary disease (COPD) using logistic regression, and estimated population-attributable fractions of COPD. Of the 8583 participants in the original cohort, 2438 had at least two waves of lung function data at age 7 years and 53 years and comprised the study population. We identified six trajectories: early below average, accelerated decline (97 [4%] participants); persistently low (136 [6%] participants); early low, accelerated growth, normal decline (196 [8%] participants); persistently high (293 [12%] participants); below average (772 [32%] participants); and average (944 [39%] participants). The three trajectories early below average, accelerated decline; persistently low; and below average had increased risk of COPD at age 53 years compared with the average group (early below average, accelerated decline: odds ratio 35·0, 95% CI 19·5-64·0; persistently low: 9·5, 4·5-20·6; and below average: 3·7, 1·9-6·9). Early-life predictors of the three trajectories included childhood asthma, bronchitis, pneumonia, allergic rhinitis, eczema, parental asthma, and maternal smoking. Personal smoking and active adult asthma increased the impact of maternal smoking and childhood asthma, respectively, on the early below average, accelerated decline

Exposure to Violence during Adolescence as a Predictor of Perceived Stress Trajectories in Emerging Adulthood.

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Heinze, Justin E; Stoddard, Sarah A; Aiyer, Sophie M; Eisman, Andria B; Zimmerman, Marc A

2017-01-01

Early exposure to violence during adolescence is related to negative psycho-social outcomes later in life. In the present study, we examined the influence of cumulative exposure to violence during adolescence and trajectories of perceived stress in emerging adulthood in a sample of at-risk urban youth ( N = 850; 80.1% African American; 50% female). Growth curve modeling indicated an overall decrease in reported stress as individuals aged. Baseline levels of violence exposure ( M age = 14.9) were associated with higher perceived stress levels in emerging adulthood ( M age = 20.1), but also slightly more negative perceived stress slopes from adolescence into emerging adulthood ( M age = 15.9-22.1). Individuals reporting increased violence exposure over time during adolescence also reported higher perceived stress levels in emerging adulthood ( M age = 20.1). Associations held after controlling for demographics and baseline functioning variables. The results suggest that violence exposure may disrupt normative adaptation to daily stressors in emerging adulthood.

Poly-victimization and trajectories of binge drinking from adolescence to young adulthood among serious juvenile offenders.

Science.gov (United States)

Davis, Jordan P; Dumas, Tara M; Berey, Benjamin; Merrin, Gabriel J; Tan, Kevin; Madden, Danielle R

2018-05-01

Justice involved youth exposed to multiple forms of victimization (i.e., poly-victimization) may be at risk for long term substance use problems and difficulty in self-regulation, placing them at higher risk of long-term problematic behaviors. This study empirically identifies victimization classifications in a sample of justice involved youth and how long-term binge drinking is related to victimization experiences. We further sought to understand how self-regulatory abilities such as impulse control and emotion regulation effect emergent profiles and binge drinking trajectories. Based on a sample of 1354 justice involved youth from 15 to 25 years old, classes of victimization were extracted. Emergent classes were examined in relationship to their binge drinking trajectories using latent growth models. Finally, self-regulation was examined as a predictor of binge drinking trajectories across emergent classes. The analyses indicated three classes of victimization: poly-victimized, indirectly victimized, and lowly victimized. Latent growth models revealed that the poly-victimized class had significantly steeper growth in binge drinking as compared to the indirect and low victimized patterns. Impulse and emotional regulation both significantly decelerated binge drinking only for the indirect victimization group. Findings highlight the need to focus on poly-victimization in understanding binge drinking trajectories as well as the role impulse control and emotional regulation play among justice involved youth. Findings are discussed through the lens of adolescent development, coping strategies, and early traumatic experiences. Copyright © 2018 Elsevier B.V. All rights reserved.

Predictors of Latent Trajectory Classes of Dating Violence Victimization

Science.gov (United States)

Brooks-Russell, Ashley; Foshee, Vangie; Ennett, Susan

2014-01-01

This study identified classes of developmental trajectories of physical dating violence victimization from grades 8 to 12 and examined theoretically-based risk factors that distinguished among trajectory classes. Data were from a multi-wave longitudinal study spanning 8th through 12th grade (n = 2,566; 51.9% female). Growth mixture models were used to identify trajectory classes of physical dating violence victimization separately for girls and boys. Logistic and multinomial logistic regressions were used to identify situational and target vulnerability factors associated with the trajectory classes. For girls, three trajectory classes were identified: a low/non-involved class; a moderate class where victimization increased slightly until the 10th grade and then decreased through the 12th grade; and a high class where victimization started at a higher level in the 8th grade, increased substantially until the 10th grade, and then decreased until the 12th grade. For males, two classes were identified: a low/non-involved class, and a victimized class where victimization increased slightly until the 9th grade, decreased until the 11th grade, and then increased again through the 12th grade. In bivariate analyses, almost all of the situational and target vulnerability risk factors distinguished the victimization classes from the non-involved classes. However, when all risk factors and control variables were in the model, alcohol use (a situational vulnerability) was the only factor that distinguished membership in the moderate trajectory class from the non-involved class for girls; anxiety and being victimized by peers (target vulnerability factors) were the factors that distinguished the high from the non-involved classes for the girls; and victimization by peers was the only factor distinguishing the victimized from the non-involved class for boys. These findings contribute to our understanding of the heterogeneity in physical dating violence victimization during

Estimating trajectories of energy intake through childhood and adolescence using linear-spline multilevel models.

Science.gov (United States)

Anderson, Emma L; Tilling, Kate; Fraser, Abigail; Macdonald-Wallis, Corrie; Emmett, Pauline; Cribb, Victoria; Northstone, Kate; Lawlor, Debbie A; Howe, Laura D

2013-07-01

Methods for the assessment of changes in dietary intake across the life course are underdeveloped. We demonstrate the use of linear-spline multilevel models to summarize energy-intake trajectories through childhood and adolescence and their application as exposures, outcomes, or mediators. The Avon Longitudinal Study of Parents and Children assessed children's dietary intake several times between ages 3 and 13 years, using both food frequency questionnaires (FFQs) and 3-day food diaries. We estimated energy-intake trajectories for 12,032 children using linear-spline multilevel models. We then assessed the associations of these trajectories with maternal body mass index (BMI), and later offspring BMI, and also their role in mediating the relation between maternal and offspring BMIs. Models estimated average and individual energy intake at 3 years, and linear changes in energy intake from age 3 to 7 years and from age 7 to 13 years. By including the exposure (in this example, maternal BMI) in the multilevel model, we were able to estimate the average energy-intake trajectories across levels of the exposure. When energy-intake trajectories are the exposure for a later outcome (in this case offspring BMI) or a mediator (between maternal and offspring BMI), results were similar, whether using a two-step process (exporting individual-level intercepts and slopes from multilevel models and using these in linear regression/path analysis), or a single-step process (multivariate multilevel models). Trajectories were similar when FFQs and food diaries were assessed either separately, or when combined into one model. Linear-spline multilevel models provide useful summaries of trajectories of dietary intake that can be used as an exposure, outcome, or mediator.

Three-Year Trajectories of Parenting Behaviors among Physically Abusive Parents and Their Link to Child Adjustment

Science.gov (United States)

Okado, Yuko; Haskett, Mary E.

2015-01-01

Background: There is limited knowledge about how positive and negative parenting practices differ across individuals and change over time in parents with substantiated physical abuse history, and how trajectories of these parenting practices affect child adjustment. Objective: The present study examined latent trajectories of positive and negative…

Simulating the influence of life trajectory events on transport mode behavior in an agent-based system

NARCIS (Netherlands)

Verhoeven, M.; Arentze, T.A.; Timmermans, H.J.P.; Waerden, van der P.J.H.J.

2007-01-01

this paper describes the results of a study on the impact of lifecycle or life trajectory events on activity-travel decisions. This lifecycle trajectory of individual agents can be easily incorporated in an agent-based simulation system. This paper focuses on two lifecycle events, change in

Adaptive Trajectory Design

Data.gov (United States)

National Aeronautics and Space Administration — Adaptive Trajectory Design (ATD) is an original concept for quick and efficient end-to-end trajectory designs using proven piece-wise dynamical methods. With ongoing...

An investigation of the joint longitudinal trajectories of low body weight, binge eating, and purging in women with anorexia nervosa and bulimia nervosa

Science.gov (United States)

Lavender, Jason M.; De Young, Kyle P.; Franko, Debra L.; Eddy, Kamryn T.; Kass, Andrea E.; Sears, Meredith S.; Herzog, David B.

2015-01-01

Objectives To describe the longitudinal course of three core eating disorder symptoms – low body weight, binge eating, and purging – in women with anorexia nervosa (AN) and bulimia nervosa (BN) using a novel statistical approach. Method Treatment-seeking women with AN (n=136) or BN (n=110) completed the Eating Disorders Longitudinal Interval Follow-Up Evaluation interview every six months, yielding weekly eating disorder symptom data for a five-year period. Semi-parametric mixture modeling was used to identify longitudinal trajectories for the three core symptoms. Results Four individual trajectories were identified for each eating disorder symptom. The number and general shape of the individual trajectories was similar across symptoms, with each model including trajectories depicting stable absence and stable presence of symptoms as well as one or more trajectories depicting the declining presence of symptoms. Unique trajectories were found for low body weight (fluctuating presence) and purging (increasing presence). Conjunction analyses yielded the following joint trajectories: low body weight and binge eating, low body weight and purging, and binge eating and purging. Conclusions The course of individual eating disorder symptoms among patients with AN and BN is highly variable. Future research identifying clinical predictors of trajectory membership may inform treatment and nosological research. PMID:22072404

An investigation of the joint longitudinal trajectories of low body weight, binge eating, and purging in women with anorexia nervosa and bulimia nervosa.

Science.gov (United States)

Lavender, Jason M; De Young, Kyle P; Franko, Debra L; Eddy, Kamryn T; Kass, Andrea E; Sears, Meredith S; Herzog, David B

2011-12-01

To describe the longitudinal course of three core eating disorder symptoms-low body weight, binge eating, and purging-in women with anorexia nervosa (AN) and bulimia nervosa (BN) using a novel statistical approach. Treatment-seeking women with AN (n = 136) or BN (n = 110) completed the Eating Disorders Longitudinal Interval Follow-Up Evaluation interview every 6 months, yielding weekly eating disorder symptom data for a 5-year period. Semiparametric mixture modeling was used to identify longitudinal trajectories for the three core symptoms. Four individual trajectories were identified for each eating disorder symptom. The number and general shape of the individual trajectories was similar across symptoms, with each model including trajectories depicting stable absence and stable presence of symptoms as well as one or more trajectories depicting the declining presence of symptoms. Unique trajectories were found for low body weight (fluctuating presence) and purging (increasing presence). Conjunction analyses yielded the following joint trajectories: low body weight and binge eating, low body weight and purging, and binge eating and purging. The course of individual eating disorder symptoms among patients with AN and BN is highly variable. Future research identifying clinical predictors of trajectory membership may inform treatment and nosological research. Copyright © 2010 Wiley Periodicals, Inc.

Socio-economic status and family structure differences in early trajectories of child adjustment: Individual and neighbourhood effects.

Science.gov (United States)

Flouri, Eirini; Midouhas, Emily; Ruddy, Alexandra

2016-01-01

We examined the effects of single-parent family status and high parental socio-economic status (SES) on the trajectories of children's emotional/behavioural adjustment in early-to-middle childhood (ages 3-7 years). We also assessed whether these family characteristics interact with the equivalent neighbourhood characteristics of shares of single-parent families and high-SES adults in predicting these trajectories. Using data on 9850 children in England participating in the Millennium Cohort Study, we found that family status and parental SES predicted children's trajectories of adjustment. Even after controlling for these family factors and key child and parent characteristics, the neighbourhood shares of high-SES adults and single-parent families were related (negatively and positively, respectively) to child problem behaviour. Importantly, children of low-SES parents in neighbourhoods with a high concentration of high-SES adults had fewer emotional symptoms than their counterparts in areas with fewer high-SES adults. Surprisingly, the adverse effect of single-parent family status on child hyperactivity was attenuated in areas with a higher share of single-parent families. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Can Universal SEL Programs Benefit Universally? Effects of the Positive Action Program on Multiple Trajectories of Social-Emotional and Misconduct Behaviors.

Science.gov (United States)

Duncan, Robert; Washburn, Isaac J; Lewis, Kendra M; Bavarian, Niloofar; DuBois, David L; Acock, Alan C; Vuchinich, Samuel; Flay, Brian R

2017-02-01

Behavioral trajectories during middle childhood are predictive of consequential outcomes later in life (e.g., substance abuse, violence). Social and emotional learning (SEL) programs are designed to promote trajectories that reflect both growth in positive behaviors and inhibited development of negative behaviors. The current study used growth mixture models to examine effects of the Positive Action (PA) program on behavioral trajectories of social-emotional and character development (SECD) and misconduct using data from a cluster-randomized trial that involved 14 schools and a sample of predominately low-income, urban youth followed from 3rd through 8th grade. For SECD, findings indicated that PA was similarly effective at improving trajectories within latent classes characterized as "high/declining" and "low/stable". Favorable program effects were likewise evident to a comparable degree for misconduct across observed latent classes that reflected "low/rising" and "high/rising" trajectories. These findings suggest that PA and perhaps other school-based universal SEL programs have the potential to yield comparable benefits across subgroups of youth with differing trajectories of positive and negative behaviors, making them promising strategies for achieving the intended goal of school-wide improvements in student outcomes.

Strong persistent growth differences govern individual performance and population dynamics in a tropical forest understorey palm

NARCIS (Netherlands)

Jansen, M.; Zuidema, P.A.; Anten, N.P.R.; Martínez-Ramos, M.

2012-01-01

1. Persistent variation in growth rate between individual plants can have strong effects on population dynamics as fast growers reach the reproductive size at an earlier age and thus potentially contribute more to population growth than slow growers. In tropical forests, such persistent growth

Inattention/hyperactivity and aggression from early childhood to adolescence: heterogeneity of trajectories and differential influence of family environment characteristics.

Science.gov (United States)

Jester, Jennifer M; Nigg, Joel T; Adams, Kenneth; Fitzgerald, Hiram E; Puttler, Leon I; Wong, Maria M; Zucker, Robert A

2005-01-01

Inattention/hyperactivity and aggressive behavior problems were measured in 335 children from school entry throughout adolescence, at 3-year intervals. Children were participants in a high-risk prospective study of substance use disorders and comorbid problems. A parallel process latent growth model found aggressive behavior decreasing throughout childhood and adolescence, whereas inattentive/hyperactive behavior levels were constant. Growth mixture modeling, in which developmental trajectories are statistically classified, found two classes for inattention/hyperactivity and two for aggressive behavior, resulting in a total of four trajectory classes. Different influences of the family environment predicted development of the two types of behavior problems when the other behavior problem was held constant. Lower emotional support and lower intellectual stimulation by the parents in early childhood predicted membership in the high problem class of inattention/hyperactivity when the trajectory of aggression was held constant. Conversely, conflict and lack of cohesiveness in the family environment predicted membership in a worse developmental trajectory of aggressive behavior when the inattention/hyperactivity trajectories were held constant. The implications of these findings for the development of inattention/hyperactivity and for the development of risk for the emergence of substance use disorders are discussed.

Six years after the wave. Trajectories of posttraumatic stress following a natural disaster.

Science.gov (United States)

Johannesson, Kerstin Bergh; Arinell, Hans; Arnberg, Filip K

2015-12-01

The characteristics of long-term trajectories of distress after disasters are unclear, since few studies include a comparison group. This study examines trajectories of recovery among survivors in comparison to individuals with indirect exposure. Postal surveys were sent to Swedish tourists, repatriated from the 2004 Indian Ocean tsunami (n=2268), at 1, 3, and 6 years after the tsunami to assess posttraumatic stress (PTS) and poor mental health. Items were used to ascertain high and moderate disaster exposure groups and an indirect exposure comparison group. Long-term PTS trajectories were best characterized by a resilient (72.3%), a severe chronic (4.6%), a moderate chronic (11.2%) and a recovering (11.9%) trajectory. Trajectories reported higher levels of PTS than the comparison group. Exposure severity and bereavement were highly influential risk factors. These findings have implications regarding anticipation of long-term psychological adjustment after natural disasters and need for interventions after a single traumatic event with few secondary stressors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Parenting and Trajectories of Children’s Maladaptive Behaviors: A 12-year Prospective Community Study

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Luyckx, Koen; Tildesley, Elizabeth A.; Soenens, Bart; Andrews, Judy A.; Hampson, Sarah E.; Peterson, Missy; Duriez, Bart

2011-01-01

This study investigated how parenting accounted for inter-individual differences in developmental trajectories of different child behaviors across childhood and adolescence. In a cohort sequential community sample of 1,049 children, latent class growth analysis was applied to three parent-reported dimensions (monitoring, positive parenting, inconsistent discipline) across 12 annual assessments (ages 6–18). Four longitudinal parenting styles (authoritative, authoritarian, indulgent, uninvolved) were differentiated on the basis of levels and rates of change in the constituent parenting dimensions. Multi-group analyses demonstrated that these parenting styles were differentially related to changes in parent- and child-reported measures of children’s alcohol and cigarette use, antisocial behavior, and internalizing symptoms, with the authoritative parenting class being related to the most optimal long-term development. Practical implications and future research suggestions are discussed. PMID:21534057

Popularity Trajectories and Substance Use in early Adolescence.

Science.gov (United States)

Moody, James; Brynildsen, Wendy D; Osgood, D Wayne; Feinberg, Mark E; Gest, Scott

2011-05-01

This paper introduces new longitudinal network data from the "Promoting School-Community-University Partnerships to Enhance Resilience" or "PROSPER" peers project. In 28 communities, grade-level sociometric friendship nominations were collected from two cohorts of middle school students as they moved from 6(th), to 9(th) grade. As an illustration and description of these longitudinal network data, this paper describes the school popularity structure, changes in popularity position, and suggests linkages between popularity trajectory and substance use. In the cross-section, we find that the network is consistent with a hierarchical social organization, but exhibits considerable relational change in both particular friends and position at the individual level. We find that both the base level of popularity and the variability of popularity trajectories effect substance use.

Who Wants to Play? Sport Motivation Trajectories, Sport Participation, and the Development of Depressive Symptoms.

Science.gov (United States)

Wang, Ming-Te; Chow, Angela; Amemiya, Jamie

2017-09-01

Although sport involvement has the potential to enhance psychological wellbeing, studies have suggested that motivation to participate in sports activities declines across childhood and adolescence. This study incorporated expectancy-value theory to model children's sport ability self-concept and subjective task values trajectories from first to twelfth grade. Additionally, it examined if sport motivation trajectories predicted individual and team-based sport participation and whether sport participation in turn reduced the development of depressive symptoms. Data were drawn from the Childhood and Beyond Study, a cross-sequential longitudinal study comprised of three cohorts (N = 1065; 49% male; 92% European American; M ages for youngest, middle, and oldest cohorts at the first wave were 6.42, 7.39, and 9.36 years, respectively). Results revealed four trajectories of students' co-development of sport self-concept and task values: congruent stable high, incongruent stable high, middle school decreasing, and decreasing. Trajectory membership predicted individual and team-based sports participation, but only team-based sport participation predicted faster declines in depressive symptoms. The use of a person-centered approach enabled us to identify heterogeneity in trajectories of sport motivation that can aid in the development of nuanced strategies to increase students' motivation to participate in sports.

Informal work and formal plans: articulating the active role of patients in cancer trajectories

Directory of Open Access Journals (Sweden)

Rikke Juul Dalsted

2012-12-01

Full Text Available Introduction: Formal pathways models outline that patients should receive information in order to experience a coherent journey but do not describe an active role for patients or their relatives. The aim of this is paper is to articulate and discuss the active role of patients during their cancer trajectories.  Methods and theory: An in-depth case study of patient trajectories at a Danish hospital and surrounding municipality using individual interviews with patients. Theory about trajectory and work by Strauss was included.  Results: Patients continuously took initiatives to organize their treatment and care. They initiated processes in the trajectories, and acquired information, which they used to form their trajectories.  Patients presented problems to the healthcare professionals in order to get proper help when needed.  Discussion: Work done by patients was invisible and not perceived as work. The patients' requests were not sufficiently supported in the professional organisation of work or formal planning. Patients' insertion and use of information in their trajectories challenged professional views and working processes. And the design of the formal pathway models limits the patients´ active participation. When looking at integrated care from the perspective of patients, the development of a more holistic and personalized approach is needed. Introduction: Formal pathway models outline that patients should receive information in order to experience a coherent journey but do not describe an active role for patients or their relatives. The aim of this is paper is to articulate and discuss the active role of patients during their cancer trajectories. Methods and theory: An in-depth case study of patient trajectories at a Danish hospital and surrounding municipality using individual interviews with patients. Theory about trajectory and work by Strauss was included. Results: Patients continuously took initiatives to organize their

A prospective study of fetal head growth, autistic traits and autism spectrum disorder

NARCIS (Netherlands)

L.M.E. Blanken (Laura); Dass, A. (Alena); Alvares, G. (Gail); J. van der Ende (Jan); N.K. Schoemaker (Nikita); H. El Marroun (Hanan); Hickey, M. (Martha); C.E. Pennell (Craig); White, S. (Scott); Maybery, M.T. (Murray T.); Dissanayake, C. (Cheryl); V.W.V. Jaddoe (Vincent); F.C. Verhulst (Frank); H.W. Tiemeier (Henning); McIntosh, W. (Will); T.J.H. White (Tonya); A.J.O. Whitehouse (Andrew)

2018-01-01

textabstractAltered trajectories of brain growth are often reported in Autism Spectrum Disorder (ASD), particularly during the first year of life. However, less is known about prenatal head growth trajectories, and no study has examined the relation with postnatal autistic symptom severity. The

Trajectories for Novel and Detailed Traffic Information

DEFF Research Database (Denmark)

Krogh, Benjamin Bjerre; Andersen, Ove; Torp, Kristian

2012-01-01

the central metric free-flow speed from trajectories, instead of using point-based measurements such as induction-loops. This free-flow speed is widely used to compute and monitor the congestion level. The paper argues that the actual travel-time is a more accurate metric. The paper suggests a novel approach...... are correctly coordinated, and navigational device manufacturers to advice drivers in real-time on expected behavior of signalized intersections. The main conclusion is that trajectories can provide novel insight into the actual traffic situation that is not possible using existing approaches. Further...... to analyzing individual intersections that enables traffic analysts to compute queue lengths and estimated time to pass an intersection. Finally, the paper uses associative rule mining for evaluating green waves on road stretches. Such information can be used to verify that signalized intersections...

Parent-Child Relationships of Boys in Different Offending Trajectories: A Developmental Perspective

Science.gov (United States)

Keijsers, Loes; Loeber, Rolf; Branje, Susan; Meeus, Wim

2012-01-01

Background: This study tested the theoretical assumption that transformations of parent-child relationships in late childhood and adolescence would differ for boys following different offending trajectories. Methods: Using longitudinal multiinformant data of 503 boys (ages 7-19), we conducted Growth Mixture Modeling to extract offending…

Longitudinal Trajectories of Ethnic Identity during the College Years

Science.gov (United States)

Syed, Moin; Azmitia, Margarita

2009-01-01

The goals of this study were to examine trajectories of change in ethnic identity during the college years and to explore group-level and individual-level variations. Participants were 175 diverse college students who completed indices of ethnic identity exploration and commitment, self-esteem, and domain-general identity resolution. Multilevel…

The role of early life growth development, the FTO gene and exclusive breastfeeding on child BMI trajectories.

Science.gov (United States)

Wu, Yan Yan; Lye, Stephen; Briollais, Laurent

2017-10-01

Recent studies have implicated the FTO gene in child and adult obesity. A longer duration of exclusive breastfeeding (EXBF) has been shown to reduce body mass index (BMI) and the risk of being overweight in the general population and among FTO gene carriers. However, it remains unclear whether the preventive effect of EXBF could be explained by its impact on early life growth development, e.g. ages at adiposity peak (AP) and adiposity rebound (AR) and BMI velocities in the first years of life, which are major determinants of overweight and obesity later in life. We studied 5590 children from the British Avon Longitudinal Study of Parents and Children (ALSPAC) cohort and modelled their longitudinal BMI profiles with mixed effects models from birth to 16 years of age, as well as their ages at AP, AR and BMI velocities in relation to the FTO gene variant and EXBF. A longer duration of EXBF (i.e. at least 5 months) has substantial impact on BMI growth trajectories among children carrying the FTO adverse variant by modulating the age at AP, age at AR and BMI velocities. EXBF acts antagonistically to the FTO rs9939609 risk allele and by the age of 15, the predicted reduction in BMI after 5 months of EXBF is 0.56 kg/m2 [95% confidence interval (CI) 0.11-1.01; P = 0.003] and 1.14 kg/m2 (95% CI 0.67-1.62; P < 0.0001) in boys and girls, respectively. EXBF influences early life growth development and thus plays a critical role in preventing the risks of overweight and obesity even when those are exacerbated by genetic factors. © The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

Trajectories of dating violence: Differences by sexual minority status and gender.

Science.gov (United States)

Martin-Storey, Alexa; Fromme, Kim

2016-06-01

The purpose of this study was to examine how sexual minority status (as assessed using both identity and behavior) was associated with trajectories of dating violence. University students from a large Southwestern university completed questions on their sexual minority identity, the gender of their sexual partners, and about experiences of dating violence for six consecutive semesters (N = 1942). Latent growth curve modeling indicated that generally, trajectories of dating violence were stable across study participation. Sexual minority identity was associated with higher initial levels of dating violence at baseline, but also with greater decreases in dating violence across time. These differences were mediated by number of sexual partners. Having same and other-sex sexual partners was associated with higher levels of dating violence at baseline, and persisted in being associated with higher levels over time. No significant gender difference was observed regarding trajectories of dating violence. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Computing with spatial trajectories

CERN Document Server

2011-01-01

Covers the fundamentals and the state-of-the-art research inspired by the spatial trajectory data Readers are provided with tutorial-style chapters, case studies and references to other relevant research work This is the first book that presents the foundation dealing with spatial trajectories and state-of-the-art research and practices enabled by trajectories

Academic and Social Functioning Associated with Attention-Deficit/Hyperactivity Disorder: Latent Class Analyses of Trajectories from Kindergarten to Fifth Grade.

Science.gov (United States)

DuPaul, George J; Morgan, Paul L; Farkas, George; Hillemeier, Marianne M; Maczuga, Steve

2016-10-01

Children with attention-deficit/hyperactivity disorder (ADHD) are known to exhibit significantly lower academic and social functioning than other children. Yet the field currently lacks knowledge about specific impairment trajectories experienced by children with ADHD, which may constrain early screening and intervention effectiveness. Data were analyzed from a nationally representative U.S. cohort in the Early Childhood Longitudinal Study, Kindergarten Class of 1998-1999 (ECLS-K) for 590 children (72.7 % male) whose parents reported a formal diagnosis of ADHD. Children's math, reading, and interpersonal skills were assessed at 5 time points between kindergarten and fifth grade. Growth mixture model analyses indicated 4 latent trajectory classes for reading, 8 classes for math, and 4 classes for interpersonal skills. Membership in reading and math trajectory classes was strongly related; overlaps with interpersonal skills classes were weaker. Trajectory class membership was correlated with demographic characteristics and behavioral functioning. Children with ADHD display substantial heterogeneity in their reading, math, and interpersonal growth trajectories, with some groups of children especially likely to display relatively severe levels of academic and social impairment over time. Early screening and intervention to address impairment, particularly reading difficulties, among kindergarten students with ADHD is warranted.

Effect of Trajectories of Friends' and Parents' School Involvement on Adolescents' Engagement and Achievement.

Science.gov (United States)

Im, Myung Hee; Hughes, Jan N; West, Stephen G

2016-12-01

In a sample of 527 academically at-risk youth, we investigated trajectories of friends' and parents' school involvement across ages 12-14 and the joint contributions of these trajectories to adolescents' age 15 school engagement and academic achievement. Girls reported higher levels of friends' and parents' school involvement than boys. Both parents' and friends' school involvement declined across ages 12-14. Combined latent growth models and structural equation models showed effects of the trajectories of friends' and parents' school involvement on adolescents' age 15 school engagement and academic achievement, over and above adolescents' prior performance. These effects were additive rather than interactive. Strategies for enhancing parent involvement in school and students' affiliation with peers who are positively engaged in school are discussed.

Growth and Its Relationship to Individual Genetic Diversity of Mountain Hemlock (Tsuga mertensiana at Alpine Treeline in Alaska: Combining Dendrochronology and Genomics

Directory of Open Access Journals (Sweden)

Jeremy S. Johnson

2017-11-01

Full Text Available Globally, alpine treelines are characterized as temperature-limited environments with strong controls on tree growth. However, at local scales spatially heterogeneous environments generally have more variable impacts on individual patterns of tree growth. In addition to the landscape spatial heterogeneity there is local variability in individual tree genetic diversity (level of individual heterozygosity. It has been hypothesized that higher individual heterozygosity will result in more consistent patterns of growth. In this article, we combine genomics and dendrochronology to explore the relationship between individual genetic diversity and tree growth at a mountain hemlock (Tsuga mertensiana Bong. Carr alpine treeline on the Kenai Peninsula, Alaska, USA. We correlated average observed individual heterozygosity with average tree-ring width and variance in tree-ring width within individuals to test the hypothesis that trees with higher individual heterozygosity will also have more consistent growth patterns, suggesting that they may be more resilient to climate and environmental fluctuations at the alpine treeline. Our results showed that there was no significant relationship between tree growth and individual heterozygosity. However, there was a significant positive relationship between average tree-ring width and variance in tree-ring width implying that overall, fast growing trees in stressful environments, such as the alpine treeline, grow unstably regardless of the level of individual heterozygosity.

TRAJECTORY AND INCINERATION OF ROGUE DROPLETS IN A TURBULENT DIFFUSION FLAME

Science.gov (United States)

The trajectory and incineration efficiency of individual droplet streams of a fuel mixture injected into a swirling gas turbulent diffusion flame were measured as a function of droplet size, droplet velocity, interdroplet spacing, and droplet injection angle. Additional experimen...

Correlation between the trajectory of systolic blood pressure and new renal damage in a nonhypertensive population.

Science.gov (United States)

Wang, Zhi-Jun; Jia, Dao; Tian, Jun; Liu, Jie; Li, Li-Jie; Huang, Yu-Ling; Cao, Xin-Ying; Ning, Chun-Hong; Zhao, Quan-Hui; Yu, Jun-Xing; Zhang, Rui-Ying; Zhang, Ya-Jing; Gao, Jing-Sheng; Wu, Shou-Ling

2017-10-01

This study aims to investigate the correlation between the trajectory of systolic blood pressure (SBP) and new renal damage in a nonhypertensive population. This prospective cohort study included a total of 14 382 nonhypertensive individuals, employees of Kailuan Group of Companies, who took part in five healthy examinations in 2006-2007, 2008-2009, 2010-2011, 2012-2013, and 2014-2015, and had complete data. These individuals were divided into four groups according to the different trajectories of SBP: low-low, low-stable, middle-high, and high-high groups. The correlation between the trajectory of SBP and new renal damage in a nonhypertensive population was analyzed using a multivariate Cox's proportional hazard regression model. (a) A total of 14 382 individuals had complete data and the average age of these individuals was 44.6±10.8 years. Among these, 10 888 (75.7%) individuals were men and 3494 (24.3%) individuals were women. (b) These individuals were divided into four groups according to different trajectories of blood pressure: low-low group, accounting for 13.15% (blood pressure was group, accounting for 53.91% (blood pressure was between 115 and 116 mmHg); middle-high group, accounting for 28.77% (blood pressure was between 125 and 131 mmHg); and high-high group, accounting for 4.6% (blood pressure was between 126 and 151 mmHg). (c) With the increase in the trajectory of SBP, the detection rate of renal damage increased gradually. From the low-low group to the high-high group, the detection rates of estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m were 2.3, 2.4, 3.6, and 4.3%, respectively; the positive rates of urinary protein were 1.7, 2.9, 3.8, and 5.5%, respectively; and the detection rates of eGFR less than 60 ml/min/1.73 m or positive urinary protein were 4, 5.2, 7.3, and 9.3%, respectively (Pgroup, the risk of eGFR less than 60 ml/min/1.73 m increased by nearly 1.5 times in the high-high group and in

Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations.

Science.gov (United States)

Laver, Rebecca J; Purwandana, Deni; Ariefiandy, Achmad; Imansyah, Jeri; Forsyth, David; Ciofi, Claudio; Jessop, Tim S

2012-01-01

Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.

Life-history and spatial determinants of somatic growth dynamics in Komodo dragon populations.

Directory of Open Access Journals (Sweden)

Rebecca J Laver

Full Text Available Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world's largest lizard the Komodo dragon (Varanus komodoensis. The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species.

Life-History and Spatial Determinants of Somatic Growth Dynamics in Komodo Dragon Populations

Science.gov (United States)

Laver, Rebecca J.; Purwandana, Deni; Ariefiandy, Achmad; Imansyah, Jeri; Forsyth, David; Ciofi, Claudio; Jessop, Tim S.

2012-01-01

Somatic growth patterns represent a major component of organismal fitness and may vary among sexes and populations due to genetic and environmental processes leading to profound differences in life-history and demography. This study considered the ontogenic, sex-specific and spatial dynamics of somatic growth patterns in ten populations of the world’s largest lizard the Komodo dragon (Varanus komodoensis). The growth of 400 individual Komodo dragons was measured in a capture-mark-recapture study at ten sites on four islands in eastern Indonesia, from 2002 to 2010. Generalized Additive Mixed Models (GAMMs) and information-theoretic methods were used to examine how growth rates varied with size, age and sex, and across and within islands in relation to site-specific prey availability, lizard population density and inbreeding coefficients. Growth trajectories differed significantly with size and between sexes, indicating different energy allocation tactics and overall costs associated with reproduction. This leads to disparities in maximum body sizes and longevity. Spatial variation in growth was strongly supported by a curvilinear density-dependent growth model with highest growth rates occurring at intermediate population densities. Sex-specific trade-offs in growth underpin key differences in Komodo dragon life-history including evidence for high costs of reproduction in females. Further, inverse density-dependent growth may have profound effects on individual and population level processes that influence the demography of this species. PMID:23028983

Generic trajectory representation and trajectory following for wheeled robots

DEFF Research Database (Denmark)

Kjærgaard, Morten; Andersen, Nils Axel; Ravn, Ole

2014-01-01

will drive. Safe: Avoid fatal collisions. Based on a survey of existing methods and algorithms the article presents a generic way to represent constraints for different types of robots, a generic way to represent trajectories using Bëzier curves, a method to convert the trajectory so it can be driven...... in a smooth motion, a method to create a safe velocity profile for the robot, and a path following controller....

Etiology of Stability and Growth of Internalizing and Externalizing Behavior Problems Across Childhood and Adolescence.

Science.gov (United States)

Hatoum, Alexander S; Rhee, Soo Hyun; Corley, Robin P; Hewitt, John K; Friedman, Naomi P

2018-04-20

Internalizing and externalizing behaviors are heritable, and show genetic stability during childhood and adolescence. Less work has explored how genes influence individual differences in developmental trajectories. We estimated ACE biometrical latent growth curve models for the Teacher Report Form (TRF) and parent Child Behavior Checklist (CBCL) internalizing and externalizing scales from ages 7 to 16 years in 408 twin pairs from the Colorado Longitudinal Twin Study. We found that Intercept factors were highly heritable for both internalizing and externalizing behaviors (a2 = .61-.92), with small and nonsignificant environmental influences for teacher-rated data but significant nonshared environmental influences for parent-rated data. There was some evidence of heritability of decline in internalizing behavior (Slopes for teacher and parent ratings), but the Slope genetic variance was almost entirely shared with that for the Intercept when different than zero. These results suggest that genetic effects on these developmental trajectories operate primarily on initial levels and stability, with no significant unique genetic influences for change. Finally, cross-rater analyses of the growth factor scores revealed moderate to large genetic and environmental associations between growth factors derived from parents' and teachers' ratings, particularly the Intercepts.

Trajectories of Nutritional Status and Cognitive Impairment among Older Taiwanese with Hip Fracture.

Science.gov (United States)

Wang, H P; Liang, J; Kuo, L M; Chen, C Y; Shyu, Y I L

2017-01-01

This paper describes the trajectories of nutritional status and cognitive impairment and their correlation among older Taiwanese over 1 year after hip-fracture surgery. Secondary analysis of data from a clinical trial evaluating the effects of three types of post-discharge care for 292 older hip-fracture patients (age >60 years). Nutritional status was assessed by the Mini Nutritional Assessment before and 1, 3, 6, 12 months after hospital discharge. Cognitive function was measured by the Mini-Mental State Examination before surgery, at hospital discharge, 6 and 12 months after discharge. Trajectories of nutritional status and cognitive impairment were depicted by latent class growth modeling, whereas linkages between nutritional-status and cognitive-impairment trajectories were assessed by multinomial logistic regression. Nutritional status in general improved significantly, particularly during the first 3 months after discharge. We identified three trajectories of nutritional status: malnourished (15.4%), at risk for malnutrition (38.9%), and well-nourished (45.7%). In contrast, cognitive changes followed four largely linear but distinct trajectories: moderately impaired (12.2%), mildly impaired (27.8%), borderline impaired (21.8%), and cognitively intact (38.2%). Trajectories of nutritional status were significantly associated with cognitive-function trajectories. For instance, relative to malnourished patients, well-nourished patients were 95% less likely (OR=0.05, CI =0.01-0.24) to be moderately cognitively impaired. A good nutritional-status trajectory after hip fracture was associated with better cognitive function. To treat and care for elderly hip-fractured patients, specific interventions need to target those who are malnourished or at risk of malnutrition to decrease their risk for cognitive impairment.

Step-by-step variability of swing phase trajectory area during steady state walking at a range of speeds

Science.gov (United States)

Hurt, Christopher P.; Brown, David A.

2018-01-01

Background Step kinematic variability has been characterized during gait using spatial and temporal kinematic characteristics. However, people can adopt different trajectory paths both between individuals and even within individuals at different speeds. Single point measures such as minimum toe clearance (MTC) and step length (SL) do not necessarily account for the multiple paths that the foot may take during the swing phase to reach the same foot fall endpoint. The purpose of this study was to test a step-by-step foot trajectory area (SBS-FTA) variability measure that is able to characterize sagittal plane foot trajectories of varying areas, and compare this measure against MTC and SL variability at different speeds. We hypothesize that the SBS-FTA variability would demonstrate increased variability with speed. Second, we hypothesize that SBS-FTA would have a stronger curvilinear fit compared with the CV and SD of SL and MTC. Third, we hypothesize SBS-FTA would be more responsive to change in the foot trajectory at a given speed compared to SL and MTC. Fourth, SBS-FTA variability would not strongly co-vary with SL and MTC variability measures since it represents a different construct related to foot trajectory area variability. Methods We studied 15 nonimpaired individuals during walking at progressively faster speeds. We calculated SL, MTC, and SBS-FTA area. Results SBS-FTA variability increased with speed, had a stronger curvilinear fit compared with the CV and SD of SL and MTC, was more responsive at a given speed, and did not strongly co-vary with SL and MTC variability measures. Conclusion SBS foot trajectory area variability was sensitive to change with faster speeds, captured a relationship that the majority of the other measures did not demonstrate, and did not co-vary strongly with other measures that are also components of the trajectory. PMID:29370202

Relationship Factors and Trajectories of Intimate Partner Violence among South African Women during Pregnancy and the Postpartum Period

Science.gov (United States)

Groves, Allison K.; McNaughton-Reyes, H. Luz; Foshee, Vangie A.; Moodley, Dhayendre; Maman, Suzanne

2014-01-01

Intimate partner violence (IPV) is a significant public health problem in South Africa. However, there is limited research on whether and how IPV changes during pregnancy and the postpartum period and on the factors that might affect women's risk during this time. In this study, we describe the mean trajectories of physical and psychological IPV during pregnancy and the postpartum period and examine whether relationship power, partner social support, and relationship stress are associated with women's trajectories of IPV. Data come from a longitudinal study with 1,480 women recruited during pregnancy between May 2008 and June 2010 at a public clinic in Durban. Women completed behavioral assessments at their first antenatal visit, at fourteen weeks and at nine months postpartum. Women's experiences of IPV were measured at all three time points and relationship power, partner social support and relationship stress were each measured at the baseline assessment. We used multilevel random coefficients growth modeling to build our models. The mean trajectory for both types of IPV was flat which means that, on average, there was not significant change in levels of IPV over pregnancy and the postpartum period. However, there was significant individual variability in trajectories of IPV over the study period. Women who had higher relationship power had lower levels of physical and psychological IPV over time than women with lower relationship power. Additionally, women with higher relationship stress and lower partner support had higher levels of psychological IPV at pregnancy. Interventions that maximize women's relationship power and partner social support and minimize relationship stress during this transformative time are needed. PMID:25268363

Low Tree-Growth Elasticity of Forest Biomass Indicated by an Individual-Based Model

Directory of Open Access Journals (Sweden)

Robbie A. Hember

2018-01-01

Full Text Available Environmental conditions and silviculture fundamentally alter the metabolism of individual trees and, therefore, need to be studied at that scale. However, changes in forest biomass density (Mg C ha−1 may be decoupled from changes in growth (kg C year−1 when the latter also accelerates the life cycle of trees and strains access to light, nutrients, and water. In this study, we refer to an individual-based model of forest biomass dynamics to constrain the magnitude of system feedbacks associated with ontogeny and competition and estimate the scaling relationship between changes in tree growth and forest biomass density. The model was driven by fitted equations of annual aboveground biomass growth (Gag, probability of recruitment (Pr, and probability of mortality (Pm parameterized against field observations of black spruce (Picea mariana (Mill. BSP, interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn. Franco, and western hemlock (Tsuga heterophylla (Raf. Sarg.. A hypothetical positive step-change in mean tree growth was imposed half way through the simulations and landscape-scale responses were then evaluated by comparing pre- and post-stimulus periods. Imposing a 100% increase in tree growth above calibrated predictions (i.e., contemporary rates only translated into 36% to 41% increases in forest biomass density. This corresponded with a tree-growth elasticity of forest biomass (εG,SB ranging from 0.33 to 0.55. The inelastic nature of stand biomass density was attributed to the dependence of mortality on intensity of competition and tree size, which decreased stand density by 353 to 495 trees ha−1, and decreased biomass residence time by 10 to 23 years. Values of εG,SB depended on the magnitude of the stimulus. For example, a retrospective scenario in which tree growth increased from 50% below contemporary rates up to contemporary rates indicated values of εG,SB ranging from 0.66 to 0.75. We conclude that: (1 effects of

Associations between Race and Eating Disorder Symptom Trajectories in Black and White Girls.

Science.gov (United States)

Bodell, Lindsay P; Wildes, Jennifer E; Cheng, Yu; Goldschmidt, Andrea B; Keenan, Kate; Hipwell, Alison E; Stepp, Stephanie D

2018-04-01

Epidemiological research suggests racial differences in the presentation of eating disorder symptoms. However, no studies have examined associations between race and eating disorder symptom trajectories across youth and adolescence, which is necessary to inform culturally sensitive prevention programs. The purpose of the current study was to examine the trajectories of eating disorder symptoms from childhood to young adulthood and to examine whether race was associated with trajectory group membership. Data were drawn from 2,305 Black and White girls who participated in a community-based longitudinal cohort study (Pittsburgh Girls Study) examining the development of psychopathology. The child and adult versions of the Eating Attitudes Test assessed self-reported eating disorder symptoms at six time points between ages 9 and 21 years. Growth mixture modeling was used to examine developmental trajectories of dieting, bulimia/food preoccupation, and total eating disorder symptom scores. Given potential confounds with race and disordered eating, financial strain (i.e., receiving public assistance) and weight were included as covariates. Four to six distinct developmental patterns were found across eating disorder symptoms, including none, increasing, decreasing, or increasing-decreasing trajectories. Black girls had a greater likelihood of being in the decreasing trajectories for dieting, bulimia/food preoccupation, and total eating disorder symptom scores. White girls were more likely to follow increasing trajectories of dieting and total eating disorder symptom scores compared to Black girls. These results highlight the importance of examining the influence of racial background on eating disorder symptoms and the potential need for differences in the timing and focus of prevention interventions in these groups.

Neighborhood Walkability and Body Mass Index Trajectories: Longitudinal Study of Canadians.

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Wasfi, Rania A; Dasgupta, Kaberi; Orpana, Heather; Ross, Nancy A

2016-05-01

To assess the impact of neighborhood walkability on body mass index (BMI) trajectories of urban Canadians. Data are from Canada's National Population Health Survey (n = 2935; biannual assessments 1994-2006). We measured walkability with the Walk Score. We modeled body mass index (BMI, defined as weight in kilograms divided by the square of height in meters [kg/m(2)]) trajectories as a function of Walk Score and sociodemographic and behavioral covariates with growth curve models and fixed-effects regression models. In men, BMI increased annually by an average of 0.13 kg/m(2) (95% confidence interval [CI] = 0.11, 0.14) over the 12 years of follow-up. Moving to a high-walkable neighborhood (2 or more Walk Score quartiles higher) decreased BMI trajectories for men by approximately 1 kg/m(2) (95% CI = -1.16, -0.17). Moving to a low-walkable neighborhood increased BMI for men by approximately 0.45 kg/m(2) (95% CI = 0.01, 0.89). There was no detectable influence of neighborhood walkability on body weight for women. Our study of a large sample of urban Canadians followed for 12 years confirms that neighborhood walkability influences BMI trajectories for men, and may be influential in curtailing male age-related weight gain.

The growth benefits of aggressive behavior vary with individual metabolism and resource predictability

NARCIS (Netherlands)

Hoogenboom, Mia O.; Armstrong, John D.; Groothuis, Ton G. G.; Metcalfe, Neil B.

2013-01-01

Differences in behavioral responses to environmental conditions and biological interactions are a key determinant of individual performance. This study investigated how the availability and predictability of food resources modulates the growth of animals that adopt different behavioral strategies.

Parenting and Trajectories of Children's Maladaptive Behaviors: A 12-Year Prospective Community Study

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Luyckx, Koen; Tildesley, Elizabeth A.; Soenens, Bart; Andrews, Judy A.; Hampson, Sarah E.; Peterson, Missy; Duriez, Bart

2011-01-01

This study investigated how parenting accounted for interindividual differences in developmental trajectories of different child behaviors across childhood and adolescence. In a cohort sequential community sample of 1,049 children, latent class growth analysis was applied to three parent-reported dimensions (monitoring, positive parenting,…

Individual, spatial and inter-sex variation in somatic growth: a study of Piaractus mesopotamicus (Characiformes: Serrasalmidae, a long-distance freshwater Neotropical migratory fish

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Luzia da S. Lourenço

2017-06-01

Full Text Available ABSTRACT Growth is a fundamental biological process, driven by multiple endogenous (intra-individual and exogenous (environmental factors that maintain individual fitness and population stability. The current study aims to assess whether individual, spatial (headwaters and floodplains and inter-sex variation occurs in the growth of Piaractus mesopotamicus in the Cuiabá River basin. Samples were collected monthly from July 2006 to July 2007, at two areas in the Cuiabá River basin (headwaters and floodplain. Three growth models (individuals; individuals and sex factors; individuals and areas factors were developed and compared the fish growth parameters using Akaike information criterion (AIC. The best fit to the length-at-age data was obtained by a model that considered individual variation and sex. The theoretical maximum average length ( L∞ was 64.99 cm for females, and 63.23 cm for males. Females showed a growth rate (k of 0.230 yr-1and males of 0.196 yr-1. Thus, could be concluded that individual variability and sex were the main sources of variation in P. mesopotamicus somatic growth parameters.

Engagement with the auditory processing system during targeted auditory cognitive training mediates changes in cognitive outcomes in individuals with schizophrenia.

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Biagianti, Bruno; Fisher, Melissa; Neilands, Torsten B; Loewy, Rachel; Vinogradov, Sophia

2016-11-01

Individuals with schizophrenia who engage in targeted cognitive training (TCT) of the auditory system show generalized cognitive improvements. The high degree of variability in cognitive gains maybe due to individual differences in the level of engagement of the underlying neural system target. 131 individuals with schizophrenia underwent 40 hours of TCT. We identified target engagement of auditory system processing efficiency by modeling subject-specific trajectories of auditory processing speed (APS) over time. Lowess analysis, mixed models repeated measures analysis, and latent growth curve modeling were used to examine whether APS trajectories were moderated by age and illness duration, and mediated improvements in cognitive outcome measures. We observed significant improvements in APS from baseline to 20 hours of training (initial change), followed by a flat APS trajectory (plateau) at subsequent time-points. Participants showed interindividual variability in the steepness of the initial APS change and in the APS plateau achieved and sustained between 20 and 40 hours. We found that participants who achieved the fastest APS plateau, showed the greatest transfer effects to untrained cognitive domains. There is a significant association between an individual's ability to generate and sustain auditory processing efficiency and their degree of cognitive improvement after TCT, independent of baseline neurocognition. APS plateau may therefore represent a behavioral measure of target engagement mediating treatment response. Future studies should examine the optimal plateau of auditory processing efficiency required to induce significant cognitive improvements, in the context of interindividual differences in neural plasticity and sensory system efficiency that characterize schizophrenia. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Trajectories of premorbid childhood and adolescent functioning in schizophrenia-spectrum psychoses: A first-episode study.

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Horton, Leslie E; Tarbox, Sarah I; Olino, Thomas M; Haas, Gretchen L

2015-06-30

Evidence of social and behavioral problems preceding the onset of schizophrenia-spectrum psychoses is consistent with a neurodevelopmental model of these disorders. Here we predict that individuals with a first episode of schizophrenia-spectrum psychoses will evidence one of three patterns of premorbid adjustment: an early deficit, a deteriorating pattern, or adequate or good social adjustment. Participants were 164 (38% female; 31% black) individuals ages 15-50 with a first episode of schizophrenia-spectrum psychoses. Premorbid adjustment was assessed using the Cannon-Spoor Premorbid Adjustment Scale. We compared the fit of a series of growth mixture models to examine premorbid adjustment trajectories, and found the following 3-class model provided the best fit with: a "stable-poor" adjustment class (54%), a "stable-good" adjustment class (39%), and a "deteriorating" adjustment class (7%). Relative to the "stable-good" class, the "stable-poor" class experienced worse negative symptoms at 1-year follow-up, particularly in the social amotivation domain. This represents the first known growth mixture modeling study to examine premorbid functioning patterns in first-episode schizophrenia-spectrum psychoses. Given that the stable-poor adjustment pattern was most prevalent, detection of social and academic maladjustment as early as childhood may help identify people at increased risk for schizophrenia-spectrum psychoses, potentially increasing feasibility of early interventions. Published by Elsevier Ireland Ltd.

Long-term trajectories of patients with neck pain and low back pain presenting to chiropractic care: A latent class growth analysis.

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Ailliet, L; Rubinstein, S M; Hoekstra, T; van Tulder, M W; de Vet, H C W

2018-01-01

Information on the course of neck pain (NP) and low back pain (LBP) typically relies on data collected at few time intervals during a period of up to 1 year. In this prospective, multicentre practice-based cohort study, patients consulting a chiropractor responded weekly for 52 weeks to text messages on their cell phones. Data from 448 patients (153 NP, 295 LBP) who had returned at least one set of answers in the first 26 weeks were used. Outcome measures were pain intensity (VAS) and functional outcome, assessed using four different questions: pain intensity, limitation in activities of daily living (ADL), number of days with pain in the previous week and number of days limited in ADL. Distinct patterns of pain were analysed with quadratic latent class growth analysis. The final model was a 4-class model for NP and LBP. The 'recovering from mild baseline pain' is most common (76.3% of NP patients/58.3% of LBP patients) followed by the 'recovering from severe baseline pain' class (16.3% NP/29.8% LBP). They follow similar trajectories when considered over a period of 6 months. Pain at baseline, duration of complaints, functional status, limitations in ADL and the score on psychosocial scales were the variables that most contributed to distinguish between groups. Most patients with NP or LBP presenting in chiropractic care show a trajectory of symptoms characterized by persistent or fluctuating pain of low or medium intensity. Only a minority either experience a rapid complete recovery or develop chronic severe pain. Ninety percentage of patients with neck pain or low back pain presenting to chiropractors have a 30% improvement within 6 weeks and then show a trajectory of symptoms characterized by persistent or fluctuating pain of low or medium intensity. Only a minority either experience a rapid complete recovery or develop chronic severe pain. © 2017 European Pain Federation - EFIC®.

Lunar and interplanetary trajectories

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Biesbroek, Robin

2016-01-01

This book provides readers with a clear description of the types of lunar and interplanetary trajectories, and how they influence satellite-system design. The description follows an engineering rather than a mathematical approach and includes many examples of lunar trajectories, based on real missions. It helps readers gain an understanding of the driving subsystems of interplanetary and lunar satellites. The tables and graphs showing features of trajectories make the book easy to understand. .

Developmental trajectories of body mass index among Japanese children and impact of maternal factors during pregnancy.

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Chiyori Haga

Full Text Available BACKGROUND: The aims of this study were to 1 determine the distinct patterns of body mass index (BMI trajectories in Japanese children, and 2 elucidate the maternal factors during pregnancy, which contribute to the determination of those patterns. METHODOLOGY/PRINCIPAL FINDINGS: All of the children (1,644 individuals born in Koshu City, Japan, between 1991 and 1998 were followed in a longitudinal study exploring the subjects' BMI. The BMI was calculated 11 times for each child between birth and 12 years of age. Exploratory latent class growth analyses were conducted to identify trajectory patterns of the BMI z-scores. The distribution of BMI trajectories were best characterized by a five-group model for boys and a six-group model for girls. The groups were named "stable thin," "stable average," "stable high average," "progressive overweight," and "progressive obesity" in both sexes; girls were allocated to an additional group called "progressive average." Multinomial logistic regression found that maternal weight, smoking, and skipping breakfast during pregnancy were associated with children included in the progressive obesity pattern rather than the stable average pattern. These associations were stronger for boys than for girls. CONCLUSIONS/SIGNIFICANCE: Multiple developmental patterns in Japanese boys and girls were identified, some of which have not been identified in Western countries. Maternal BMI and some unfavorable behaviors during early pregnancy may impact a child's pattern of body mass development. Further studies to explain the gender and regional differences that were identified are warranted, as these may be important for early life prevention of weight-associated health problems.

Optimal trajectories of aircraft and spacecraft

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Miele, A.

1990-01-01

Work done on algorithms for the numerical solutions of optimal control problems and their application to the computation of optimal flight trajectories of aircraft and spacecraft is summarized. General considerations on calculus of variations, optimal control, numerical algorithms, and applications of these algorithms to real-world problems are presented. The sequential gradient-restoration algorithm (SGRA) is examined for the numerical solution of optimal control problems of the Bolza type. Both the primal formulation and the dual formulation are discussed. Aircraft trajectories, in particular, the application of the dual sequential gradient-restoration algorithm (DSGRA) to the determination of optimal flight trajectories in the presence of windshear are described. Both take-off trajectories and abort landing trajectories are discussed. Take-off trajectories are optimized by minimizing the peak deviation of the absolute path inclination from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. Abort landing trajectories are optimized by minimizing the peak drop of altitude from a reference value. The survival capability of an aircraft in a severe windshear is discussed, and the optimal trajectories are found to be superior to both constant pitch trajectories and maximum angle of attack trajectories. Spacecraft trajectories, in particular, the application of the primal sequential gradient-restoration algorithm (PSGRA) to the determination of optimal flight trajectories for aeroassisted orbital transfer are examined. Both the coplanar case and the noncoplanar case are discussed within the frame of three problems: minimization of the total characteristic velocity; minimization of the time integral of the square of the path inclination; and minimization of the peak heating rate. The solution of the second problem is called nearly-grazing solution, and its merits are pointed out as a useful

Longitudinal Trajectories of Suicidal Ideation and Subsequent Suicide Attempts among Adolescent Inpatients

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Czyz, E.K.; King, C.A.

2013-01-01

Objective A period of particularly high risk for suicide attempts among adolescent inpatients is within 12 months after discharge. However, little is known about longitudinal trajectories of suicidal ideation in this high-risk group and how these relate to post-hospitalization suicide attempts and rehospitalizations. Our objectives were to identify these trajectories and examine their relationships with post-hospitalization psychiatric crises. We also examined predictors of trajectory group membership. Method Participants (N=376; ages 13-17; 72% females) were assessed at hospitalization and 3, 6, and 12 months later. Trajectory groups, and their predictors, were identified with latent class growth modeling. We used logistic regression to examine associations between trajectory groups and likelihood of suicide attempts and rehospitalization, controlling for attempt history. Results Three trajectory groups were identified: (1) subclinical ideators (31.6%); (2) elevated ideators with rapidly declining ideation (57.4%); and (3) chronically elevated ideators (10.9%). Adolescents in the chronically elevated ideation group had 2.29[(CI=1.08,4.85), p=0.03] and 4.15[(CI=1.65,10.44), psuicide and 3.23[(CI=1.37,7.69), p=0.01] and 11.20[(CI=4.33,29.01), psuicidal ideation. Conclusions Results suggest that suicidal ideation severity at hospitalization may not be an adequate marker for subsequent suicidal crises. It is important to identify adolescents vulnerable to persisting suicidal ideation, as they are at highest risk of psychiatric crises. Addressing hopelessness may facilitate faster declines in ideation after hospitalization. Results also highlight a need for consistent monitoring of these adolescents' suicidal ideation after discharge. PMID:24079705

Semantic Enrichment of GPS Trajectories

NARCIS (Netherlands)

de Graaff, V.; van Keulen, Maurice; de By, R.A.

2012-01-01

Semantic annotation of GPS trajectories helps us to recognize the interests of the creator of the GPS trajectories. Automating this trajectory annotation circumvents the requirement of additional user input. To annotate the GPS traces automatically, two types of automated input are required: 1) a

Trajectories of Work Disability and Economic Insecurity Approaching Retirement.

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Shuey, Kim M; Willson, Andrea E

2017-07-08

In this article, we examine the connection between trajectories of work disability and economic precarity in late midlife. We conceptualize work disability as a possible mechanism linking early and later life economic disadvantage. We model trajectories of work disability characterized by timing and stability for a cohort of Baby Boomers (22-32 in 1981) using 32 years of data from the Panel Study of Income Dynamics and latent class analysis. Measures of childhood disadvantage are included as predictors of work disability trajectories, which are subsequently included in logistic regression models predicting four economic outcomes (poverty, asset poverty, home ownership, and pension ownership) at ages 54-64. Childhood disadvantage selected individuals into five distinct classes of work disability that differed in timing and stability. All of the disability trajectories were associated with an increased risk of economic insecurity in late midlife compared to the never work disabled. This study contributes to the aging literature through its incorporation of the early life origins of pathways of disability and their links to economic outcomes approaching retirement. Findings suggest work disability is anchored in early life disadvantage and is associated with economic insecurity later in life. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Perceived Social Support Trajectories and the All-Cause Mortality Risk of Older Mexican American Women and Men

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Hill, Terrence D.; Uchino, Bert N.; Eckhardt, Jessica L.; Angel, Jacqueline L.

2016-01-01

Although numerous studies of non-Hispanic whites and blacks show that social integration and social support tend to favor longevity, it is unclear whether this general pattern extends to the Mexican American population. Building on previous research, we employed seven waves of data from the Hispanic Established Populations for the Epidemiologic Study of the Elderly to examine the association between perceived social support trajectories and the all-cause mortality risk of older Mexican Americans. Growth mixture estimates revealed three latent classes of support trajectories: high, moderate, and low. Cox regression estimates indicated that older Mexican American men in the low support trajectory tend to exhibit a higher mortality risk than their counterparts in the high support trajectory. Social support trajectories were unrelated to the mortality risk of older Mexican American women. A statistically significant interaction term confirmed that social support was more strongly associated with the mortality risk of men. PMID:26966256

Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells

International Nuclear Information System (INIS)

Umehara, Senkei; Hattori, Akihiro; Inoue, Ippei; Yasuda, Kenji

2007-01-01

Knowing how individual cells respond to environmental changes helps one understand phenotypic diversity in a bacterial cell population, so we simultaneously monitored the growth and motility of isolated motile Escherichia coli cells over several generations by using a method called on-chip single-cell cultivation. Starved cells quickly stopped growing but remained motile for several hours before gradually becoming immotile. When nutrients were restored the cells soon resumed their growth and proliferation but remained immotile for up to six generations. A flagella visualization assay suggested that deflagellation underlies the observed loss of motility. This set of results demonstrates that single-cell transgenerational study under well-characterized environmental conditions can provide information that will help us understand distinct functions within individual cells

Trajectories of Depressive Symptoms Among Web-Based Health Risk Assessment Participants.

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Bedrosian, Richard; Hawrilenko, Matt; Cole-Lewis, Heather

2017-03-31

Health risk assessments (HRAs), which often screen for depressive symptoms, are administered to millions of employees and health plan members each year. HRA data provide an opportunity to examine longitudinal trends in depressive symptomatology, as researchers have done previously with other populations. The primary research questions were: (1) Can we observe longitudinal trajectories in HRA populations like those observed in other study samples? (2) Do HRA variables, which primarily reflect modifiable health risks, help us to identify predictors associated with these trajectories? (3) Can we make meaningful recommendations for population health management, applicable to HRA participants, based on predictors we identify? This study used growth mixture modeling (GMM) to examine longitudinal trends in depressive symptomatology among 22,963 participants in a Web-based HRA used by US employers and health plans. The HRA assessed modifiable health risks and variables such as stress, sleep, and quality of life. Five classes were identified: A "minimal depression" class (63.91%, 14,676/22,963) whose scores were consistently low across time, a "low risk" class (19.89%, 4568/22,963) whose condition remained subthreshold, a "deteriorating" class (3.15%, 705/22,963) who began at subthreshold but approached severe depression by the end of the study, a "chronic" class (4.71%, 1081/22,963) who remained highly depressed over time, and a "remitting" class (8.42%, 1933/22,963) who had moderate depression to start, but crossed into minimal depression by the end. Among those with subthreshold symptoms, individuals who were male (PInternet Research (http://www.jmir.org), 31.03.2017.

Historical variation in young adult binge drinking trajectories and its link to historical variation in social roles and minimum legal drinking age

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Jager, Justin; Keyes, Katherine M.; Schulenberg, John E.

2015-01-01

This study examines historical variation in age 18–26 binge drinking trajectories, focusing on differences in both level of use and rates of change (growth) across cohorts of young adults over three decades. As part of the national Monitoring the Future Study, over 64,000 youths from the high school classes of 1976–2004 were surveyed at biennial intervals between ages 18 and 26. We found that, relative to past cohorts, recent cohorts both enter the age 18–26 age band engaging in lower levels and exit the age 18–26 age band engaging in higher levels of binge drinking. The reason for this reversal is that, relative to past cohorts, binge drinking among recent cohorts accelerates more quickly across ages 18–22 and decelerates more slowly across ages 22–26. Moreover, we found that historical increases in minimum legal drinking age account for a portion of the historical decline in age 18 level, while historical variation in social role acquisition (e.g., marriage, parenthood, and employment) accounts for a portion of the historical acceleration in age 18–22 growth. We also found that historical variation in the age 18–22 and age 22–26 growth rates was strongly and positively connected, suggesting common mechanism(s) underlie historical variation of both growth rates. Findings were generally consistent across gender and indicate that historical time is an important source of individual differences in young adult binge drinking trajectories. Beyond binge drinking, historical time may also inform the developmental course of other young adult risk behaviors, highlighting the interplay of epidemiology and etiology. PMID:26010381

Divergent Developmental Trajectories and Strategic Coupling in the Pearl River Delta: Where Is a Sustainable Way of Regional Economic Growth?

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Yi Liu

2017-10-01

Full Text Available This paper interprets regional economic sustainability in the context of the globalization of late-coming regions. Drawing upon the concept of strategic coupling from economic geography, this paper proposes two types of strategic coupling, captive and proactive coupling, for better understanding regional sustainability and resilience through the experiences of the Pearl River Delta in China. It finds that sub-regional economies under captive coupling become highly dependent on exogenous growth and are vulnerable to external shocks. This trajectory looks less sustainable according to the general understanding, but it interestingly shows better resilience during and after the 2008 global financial crisis. In contrast, the ones under proactive coupling are less volatile, but growing much slower and are less resilient. By reporting these regional economic dynamics, this paper argues that sustainability in late-coming regions cannot be explained by either intra-regional forces or the means of global integration alone. In contrast, it has to be explained by the combination of both; the alleged strategic coupling in which economic growth and learning happens. This paper thus calls for greater attention to strategic coupling, the trade-off of globalization and resilience for understanding regional sustainability, rather than purely focusing on resource utilization and ecological balance.

Impacts of parasites in early life: contrasting effects on juvenile growth for different family members.

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Thomas E Reed

Full Text Available Parasitism experienced early in ontogeny can have a major impact on host growth, development and future fitness, but whether siblings are affected equally by parasitism is poorly understood. In birds, hatching asynchrony induced by hormonal or behavioural mechanisms largely under parental control might predispose young to respond to infection in different ways. Here we show that parasites can have different consequences for offspring depending on their position in the family hierarchy. We experimentally treated European Shag (Phalacrocorax aristoteli nestlings with the broad-spectrum anti-parasite drug ivermectin and compared their growth rates with nestlings from control broods. Average growth rates measured over the period of linear growth (10 days to 30 days of age and survival did not differ for nestlings from treated and control broods. However, when considering individuals within broods, parasite treatment reversed the patterns of growth for individual family members: last-hatched nestlings grew significantly slower than their siblings in control nests but grew faster in treated nests. This was at the expense of their earlier-hatched brood-mates, who showed an overall growth rate reduction relative to last-hatched nestlings in treated nests. These results highlight the importance of exploring individual variation in the costs of infection and suggest that parasites could be a key factor modulating within-family dynamics, sibling competition and developmental trajectories from an early age.

Strength beyond structure : social and historical trajectories of agency in Africa

NARCIS (Netherlands)

Bruijn, de M.E.; Dijk, van R.A.; Gewald, J.B.

2007-01-01

This book explores the notion of agency in a range of empirical situations in Africa. It emphasizes the possibilities individuals and social groups perceive when faced with the constraints that tend to mark African social life. Contributions: Social and historical trajectories of agency in Africa:

Heterogeneity in 10-Year Course Trajectories of Moderate to Severe Major Depressive Disorder: A Danish National Register-Based Study.

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Musliner, Katherine L; Munk-Olsen, Trine; Laursen, Thomas M; Eaton, William W; Zandi, Peter P; Mortensen, Preben B

2016-04-01

Evidence suggests that long-term trajectories of major depressive disorder (MDD) are heterogeneous. The Danish Psychiatric Central Research Register (DPCRR) provides a rare opportunity to examine patterns and correlates of long-term trajectories in a large sample of patients with moderate to severe MDD. To characterize patterns and correlates of 10-year course trajectories of MDD in the DPCRR. A cohort containing 11 640 individuals born in Denmark in 1955 or later with their first recorded MDD diagnosis in the DPCRR between 1995 and 2002 was established. Patients were followed for 10 years from the date of their initial MDD diagnosis. Data were obtained from Danish civil and psychiatric national registers in June 2013 and were analyzed from April 4, 2014, to December 17, 2015. Correlates of trajectory class membership were sex, characteristics of the first recorded MDD episode (ie, age, severity, inpatient treatment, and record of suicide attempt or self-harm), and psychiatric diagnoses in parents (ie, depression, bipolar disorder, schizophrenia-spectrum disorders, substance abuse, and anxiety or somatoform disorders). The outcome variable was past-year contact at a psychiatric hospital with a main diagnosis of MDD during each of the 10 years following the initial MDD diagnosis. Trajectories were modeled using latent class growth analysis. The sample included 11 640 individuals (7493 [64.4%] women) aged 18 to 48 years (mean [SD], 31.4 [7.3]) at their first recorded MDD diagnosis. Four trajectory classes were identified: brief contact (77.0%) (characterized by low probability of contact after 2 years); prolonged initial contact (12.8%) (characterized by high decreasing probability of contact during the first 5 years); later reentry (7.1%) (characterized by moderate probability of contact during the second 5 years); and persistent contact (3.1%) (characterized by high or moderate probability of contact throughout). Female sex (odds ratio [OR] range, 1

Prospects of modern adolescents in the context of life trajectory

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Bochaver A.A.

2016-06-01

Full Text Available The article discusses the dynamics of theoretical and applied ideas of adolescence from the viewpoint of designing individual trajectory for this age. It also analyzes the blurring of lines of adolescence, delaying vital choices and hindered separation from parents as the trends of the modern existence of adolescence. The article examines the features of modern society (transitivity and its consequences, hindering the design of path of life and contributing to the shift of strategic thinking in this area to tactical. The article regards the role of the family, in particular, the cultureof discussing future, from the point of view of support to a teenager’s design of his/her life trajectory.

Trajectory grouping structure

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Maike Buchin

2015-03-01

Full Text Available The collective motion of a set of moving entities like people, birds, or other animals, is characterized by groups arising, merging, splitting, and ending. Given the trajectories of these entities, we define and model a structure that captures all of such changes using the Reeb graph, a concept from topology. The trajectory grouping structure has three natural parameters that allow more global views of the data in group size, group duration, and entity inter-distance. We prove complexity bounds on the maximum number of maximal groups that can be present, and give algorithms to compute the grouping structure efficiently. We also study how the trajectory grouping structure can be made robust, that is, how brief interruptions of groups can be disregarded in the global structure, adding a notion of persistence to the structure. Furthermore, we showcase the results of experiments using data generated by the NetLogo flocking model and from the Starkey project. The Starkey data describe the movement of elk, deer, and cattle. Although there is no ground truth for the grouping structure in this data, the experiments show that the trajectory grouping structure is plausible and has the desired effects when changing the essential parameters. Our research provides the first complete study of trajectory group evolvement, including combinatorial,algorithmic, and experimental results.

Impact of depressive symptoms, self-esteem and neuroticism on trajectories of overgeneral autobiographical memory over repeated trials.

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Kashdan, Todd B; Roberts, John E; Carlos, Erica L

2006-04-01

The present study examined trajectories of change in the frequency of overgeneral autobiographical memory (OGM) over the course of repeated trials, and tested whether particular dimensions of depressive symptomatology (somatic and cognitive-affective distress), self-esteem, and neuroticism account for individual differences in these trajectories. Given that depression is associated with impairments in effortful processing, we predicted that over repeated trials depression would be associated with increasingly OGM. Generalised Linear Mixed Models with Penalised Quasi-Likelihood demonstrated significant linear and quadratic trends in OGM over repeated trials, and somatic distress and self-esteem moderated these slopes. The form of these interactions suggested that somatic distress and low self-esteem primarily contribute to OGM during the second half of the trial sequence. The present findings demonstrate the value of a novel analytical approach to OGM that estimates individual trajectories of change over repeated trials.

Child personality facets and overreactive parenting as predictors of aggression and rule-breaking trajectories from childhood to adolescence.

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Becht, Andrik I; Prinzie, Peter; Deković, Maja; van den Akker, Alithe L; Shiner, Rebecca L

2016-05-01

This study examined trajectories of aggression and rule breaking during the transition from childhood to adolescence (ages 9-15), and determined whether these trajectories were predicted by lower order personality facets, overreactive parenting, and their interaction. At three time points separated by 2-year intervals, mothers and fathers reported on their children's aggression and rule breaking (N = 290, M age = 8.8 years at Time 1). At Time 1, parents reported on their children's personality traits and their own overreactivity. Growth mixture modeling identified three aggression trajectories (low decreasing, high decreasing, and high increasing) and two rule-breaking trajectories (low and high). Lower optimism and compliance and higher energy predicted trajectories for both aggression and rule breaking, whereas higher expressiveness and irritability and lower orderliness and perseverance were unique risk factors for increasing aggression into adolescence. Lower concentration was a unique risk factor for increasing rule breaking. Parental overreactivity predicted higher trajectories of aggression but not rule breaking. Only two Trait × Overreactivity interactions were found. Our results indicate that personality facets could differentiate children at risk for different developmental trajectories of aggression and rule breaking.

Factors that Influence Trajectories of Delinquency Throughout Adolescence.

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Evans, Sara Z; Simons, Leslie Gordon; Simons, Ronald L

2016-01-01

Given that one of the most powerful predictors of adult crime is the presence of behavior problems in childhood and adolescence, there is a need to further understand factors that determine behavior patterns during this developmental stage. This study focuses on stressful life experiences such as exposure to delinquent peers, racial discrimination, as well as family characteristics such as parenting style and family transitions. Data come from four waves of the Family and Community Health Survey, an African-American sample. The present study investigates 354 males from this dataset. We utilize a group-based trajectory model to estimate the number and type of trajectories of delinquency. We then estimate multinomial regression models to predict trajectory group membership. The results indicated that there were four distinct groups of offenders (negligible delinquents; early starter/declining; late starter; and early starter/chronic offenders). We predicted group membership using both early predictors and measures of change in these predictors across the study period. The results indicated that individuals who experience greater racial discrimination (both early in childhood and throughout adolescence) are more likely to be in trajectory groups that begin offending early and persist through adolescence. Additionally, those respondents who reported having friends with greater delinquent behavior were more likely to be in groups that began their offending early in life and persisted when compared to groups who started later or desisted as they entered adulthood. The results contribute to developmental research and provide information that may be helpful in preventing adolescents from persisting in antisocial behavior as they enter adulthood.

Unemployment in the teens and trajectories of alcohol consumption in adulthood.

Science.gov (United States)

Virtanen, Pekka; Lintonen, Tomi; Westerlund, Hugo; Nummi, Tapio; Janlert, Urban; Hammarström, Anne

2016-03-25

The unemployed are assumed to adopt unhealthy behaviours, including harmful use of alcohol. This study sought to elucidate the relations between unemployment before age 21 years and consumption of alcohol from 21 to 42 years. The design was based on the conception of youth as a sensitive period for obtaining 'drinking scars' that are visible up to middle age. The Northern Swedish Cohort Study has followed up a population sample from 1981 to 2007 with five surveys. All pupils (n=1083) attending the last year of compulsory school in Luleå participated in the baseline survey in classrooms, and 1010 of them (522 men and 488 women) participated in the last follow-up survey that was conducted at classmate reunions or by post or by phone. The trajectory of alcohol consumption from 21 to 43 years, obtained with latent class growth analyses, was scaled. Men were assigned to five and women to three consumption trajectories. The trajectory membership was regressed on accumulation of unemployment from 16 to 21 years, with multinomial logistic regression analyses. The trajectory of moderate consumption was preceded by lowest exposure to unemployment in men and in women. With reference to this, the relative risk ratios for high-level trajectory groups were 3.49 (1.25 to 9.79) in men and 1.41 (0.74 to 2.72) in women, but also the trajectories of low-level consumption were more probable (relative risk ratio 3.18 (1.12 to 9.02) in men and 2.41 (1.24 to 4.67) in women). High-level alcohol consumption throughout adulthood is, particularly among men, partly due to 'scars' from youth unemployment, particularly in men, but there are also groups of men and women where unemployment in the teens predicts a trajectory of low consumption. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Popularity Trajectories and Substance Use in early Adolescence1

Science.gov (United States)

Moody, James; Brynildsen, Wendy D.; Osgood, D. Wayne; Feinberg, Mark E.; Gest, Scott

2010-01-01

This paper introduces new longitudinal network data from the “Promoting School-Community-University Partnerships to Enhance Resilience” or “PROSPER” peers project. In 28 communities, grade-level sociometric friendship nominations were collected from two cohorts of middle school students as they moved from 6th, to 9th grade. As an illustration and description of these longitudinal network data, this paper describes the school popularity structure, changes in popularity position, and suggests linkages between popularity trajectory and substance use. In the cross-section, we find that the network is consistent with a hierarchical social organization, but exhibits considerable relational change in both particular friends and position at the individual level. We find that both the base level of popularity and the variability of popularity trajectories effect substance use. PMID:21765588

Interannual differences in growth and hatch-date distributions of early juvenile European anchovy in the Bay of Biscay: implications for recruitment

KAUST Repository

Aldanondo, Naroa

2016-01-22

© 2016 John Wiley & Sons Ltd. In order to understand better the recruitment variability in European anchovy in the Bay of Biscay, it is important to investigate the processes that affect survival during the early life stages. Anchovy juvenile growth trajectories and hatch-date distributions were inferred over a 3-year period based on otolith microstructure analysis. Otolith growth trajectories showed a characteristic shape depending on their hatch-date timing. Earlier-born juveniles had notably broader maximum increments than later born conspecifics, resulting in higher growth rates. This observation suggests that early hatching would be beneficial for larval and juvenile growth, and, therefore, survival. The estimated juvenile hatch-date distributions were relatively narrow compared with the extended anchovy spawning season (March-August) in the Bay of Biscay and indicated that only individuals originated mainly from the summer months (June-August) survived until autumn. Hatch-date distributions were markedly different among years and seemed to influence the interannual recruitment strength of anchovy. We conclude that years characterized by juvenile survivors originating from the peak spawning period (May and June) would lead to considerable recruitment success. Downwelling events during the peak spawning period seem to affect larval survival.

Emittance and trajectory control in the main linacs of the NLC

International Nuclear Information System (INIS)

Assmann, R.; Adolphsen, C.; Bane, K.; Raubenheimer, T.O.; Thompson, K.

1996-09-01

The main linacs of the next generation of linear colliders need to accelerate the particle beams to energies of up to 750 GeV while maintaining very small emittances. This paper describes the main mechanisms of static emittance growth in the main linacs of the Next Linear Collider (NLC). The authors present detailed simulations of the trajectory and emittance control algorithms that are foreseen for the NLC. They show that the emittance growth in the main linacs can be corrected down to about 110%. That number is significantly better than required for the NLC design luminosity

Interpersonal Callousness from Childhood to Adolescence: Developmental Trajectories and Early Risk Factors.

Science.gov (United States)

Byrd, Amy L; Hawes, Samuel W; Loeber, Rolf; Pardini, Dustin A

2018-01-01

Youth with a callous interpersonal style, consistent with features of adult psychopathy (e.g., lack of guilt, deceitful), are at risk for exhibiting severe and protracted antisocial behaviors. However, no studies have examined changes that occur in interpersonal callousness (IC) from childhood to adolescence, and little is known about the influence of early child, social, and contextual factors on trajectories of IC. The current study examined distinct patterns of IC across childhood and adolescence and associations with early risk factors. Participants were an at-risk sample of 503 boys (56% African American) assessed annually from around ages 7-15. Analyses examined child (anger dysregulation, fearfulness), social (peer, family, maltreatment), and contextual (psychosocial adversity) factors associated with teacher-reported IC trajectories across childhood and adolescence. Using latent class growth analysis, five trajectories of IC were identified (early-onset chronic, childhood-limited, adolescent-onset, moderate, low). Approximately 10% of boys followed an early-onset chronic trajectory, and a roughly equal percent of youth followed childhood-limited trajectory (10%) or an adolescent-onset trajectory (12%) of IC across development. Specifically, half of the boys with high IC in childhood did not continue to exhibit significant levels of these features into adolescence, whereas an equal proportion of youth with low IC in childhood demonstrated increasing levels during the transition to adolescence. Boys in the early-onset chronic group were characterized by the most risk factors and were differentiated from those with childhood-limited and adolescent-onset IC only by higher conduct problems, fearlessness, and emotional abuse/neglect. Findings are discussed in terms of developmental models of IC and several avenues for early targeted interventions.

Schoolchildren’s Career Trajectory Рlanning: Focus on “Want”, “Can” and “Need”

OpenAIRE

Valery A.; Evgenia A.

2018-01-01

Introduction: future youth career trajectory planning in Russian society is conditioned on by a strong gap in supply and demand in a labor market and educational services market in terms of its professional qualification structure. There are several reasons for such gap but one of them is that pupils’ vocational guidance is traditionally aimed at university or college choice for education rather than building conscious individual career trajectory taking into account occupations demand. The g...

Growth trajectories of mathematics achievement: Longitudinal tracking of student academic progress.

Science.gov (United States)

Mok, Magdalena M C; McInerney, Dennis M; Zhu, Jinxin; Or, Anthony

2015-06-01

A number of methods to investigate growth have been reported in the literature, including hierarchical linear modelling (HLM), latent growth modelling (LGM), and multidimensional scaling applied to longitudinal profile analysis (LPAMS). This study aimed at modelling the mathematics growth of students over a span of 6 years from Grade 3 to Grade 9. The sample comprised secondary longitudinal data collected in three waves from n = 866 Hong Kong students when they were in Grade 3, Grade 6, and Grade 9. Mathematics achievement was measured thrice on a vertical scale linked with anchor items. Linear and nonlinear latent growth models were used to assess students' growth. Gender differences were also examined. A nonlinear latent growth curve with a decelerated rate had a good fit to the data. Initial achievement and growth rate were negatively correlated. No gender difference was found. Mathematics growth from Grade 6 to Grade 9 was slower than that from Grade 3 to Grade 6. Students with lower initial achievement improved at a faster rate than those who started at a higher level. Gender did not affect growth rate. © 2014 The British Psychological Society.

Trajectory similarity join in spatial networks

KAUST Repository

Shang, Shuo

2017-09-07

The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider the case of trajectory similarity join (TS-Join), where the objects are trajectories of vehicles moving in road networks. Thus, given two sets of trajectories and a threshold θ, the TS-Join returns all pairs of trajectories from the two sets with similarity above θ. This join targets applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide a purposeful definition of similarity. To enable efficient TS-Join processing on large sets of trajectories, we develop search space pruning techniques and take into account the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer algorithm. For each trajectory, the algorithm first finds similar trajectories. Then it merges the results to achieve a final result. The algorithm exploits an upper bound on the spatiotemporal similarity and a heuristic scheduling strategy for search space pruning. The algorithm\\'s per-trajectory searches are independent of each other and can be performed in parallel, and the merging has constant cost. An empirical study with real data offers insight in the performance of the algorithm and demonstrates that is capable of outperforming a well-designed baseline algorithm by an order of magnitude.

Developing pongid dentition and its use for ageing individual crania in comparative cross-sectional growth studies.

Science.gov (United States)

Dean, M C; Wood, B A

1981-01-01

This study of the developing pongid dentition is based on cross-sectional radiographic data of juvenile Pan troglodytes, Gorilla gorilla, and Pongo pygmaeus skulls. Comparisons with developmental features of the human dentition are made, and possible explanations for the formation of larger teeth within the reduced pongid growth period are discussed. The data presented in this study provide an alternative method for ageing individual pongid crania in comparative cross-sectional growth studies. The advantages of this method are demonstrated by ageing individual Gorilla crania form radiographs and plotting relative dental age against length of the jaw.

Personalized trajectory matching in spatial networks

KAUST Repository

Shang, Shuo

2013-07-31

With the increasing availability of moving-object tracking data, trajectory search and matching is increasingly important. We propose and investigate a novel problem called personalized trajectory matching (PTM). In contrast to conventional trajectory similarity search by spatial distance only, PTM takes into account the significance of each sample point in a query trajectory. A PTM query takes a trajectory with user-specified weights for each sample point in the trajectory as its argument. It returns the trajectory in an argument data set with the highest similarity to the query trajectory. We believe that this type of query may bring significant benefits to users in many popular applications such as route planning, carpooling, friend recommendation, traffic analysis, urban computing, and location-based services in general. PTM query processing faces two challenges: how to prune the search space during the query processing and how to schedule multiple so-called expansion centers effectively. To address these challenges, a novel two-phase search algorithm is proposed that carefully selects a set of expansion centers from the query trajectory and exploits upper and lower bounds to prune the search space in the spatial and temporal domains. An efficiency study reveals that the algorithm explores the minimum search space in both domains. Second, a heuristic search strategy based on priority ranking is developed to schedule the multiple expansion centers, which can further prune the search space and enhance the query efficiency. The performance of the PTM query is studied in extensive experiments based on real and synthetic trajectory data sets. © 2013 Springer-Verlag Berlin Heidelberg.

Testing mechanistic models of growth in insects.

Science.gov (United States)

Maino, James L; Kearney, Michael R

2015-11-22

Insects are typified by their small size, large numbers, impressive reproductive output and rapid growth. However, insect growth is not simply rapid; rather, insects follow a qualitatively distinct trajectory to many other animals. Here we present a mechanistic growth model for insects and show that increasing specific assimilation during the growth phase can explain the near-exponential growth trajectory of insects. The presented model is tested against growth data on 50 insects, and compared against other mechanistic growth models. Unlike the other mechanistic models, our growth model predicts energy reserves per biomass to increase with age, which implies a higher production efficiency and energy density of biomass in later instars. These predictions are tested against data compiled from the literature whereby it is confirmed that insects increase their production efficiency (by 24 percentage points) and energy density (by 4 J mg(-1)) between hatching and the attainment of full size. The model suggests that insects achieve greater production efficiencies and enhanced growth rates by increasing specific assimilation and increasing energy reserves per biomass, which are less costly to maintain than structural biomass. Our findings illustrate how the explanatory and predictive power of mechanistic growth models comes from their grounding in underlying biological processes. © 2015 The Author(s).

The National Trajectory Project of Individuals Found Not Criminally Responsible on Account of Mental Disorder in Canada. Part 1: Context and Methods

Science.gov (United States)

Crocker, Anne G; Nicholls, Tonia L; Seto, Michael C; Côté, Gilles; Charette, Yanick; Caulet, Malijai

2015-01-01

The National Trajectory Project examined longitudinal data from a large sample of people found not criminally responsible on account of mental disorder (NCRMD) to assess the presence of provincial differences in the application of the law, to examine the characteristics of people with serious mental illness who come into conflict with the law and receive this verdict, and to investigate the trajectories of NCRMD–accused people as they traverse the mental health and criminal justice systems. Our paper describes the rationale for the National Trajectory Project and the methods used to collect data in Quebec, Ontario, and British Columbia, the 3 most populous provinces in Canada and the 3 provinces with the most people found NCRMD. PMID:25886685

Trajectory of physical activity after hip fracture: An analysis of community-dwelling individuals from the English Longitudinal Study of Ageing.

Science.gov (United States)

Aboelmagd, Tariq; Dainty, Jack R; MacGregor, Alex; Smith, Toby O

2018-03-01

To analyse physical activity participation in a community-dwelling people in England with hip fracture the interval prior to fracture, in the fracture recovery period, and a minimum of two years post-fracture. 215 individuals were identified from the English Longitudinal Study of Ageing cohort (2002-2014) who sustained a hip fracture following a fall and for whom data were available on physical activity participation relating to the period pre-fracture, within-fracture recovery phase and post-fracture (minimum of two years). Physical activity was assessed using the validated ELSA physical activity questionnaire. Prevalence of 'low' physical activity participation was calculated and multi-level modelling analyses were performed to explore physical activity trajectories over the follow-up phase, and whether age, depression, gender and frailty were associated with physical activity participation. Prevalence of low physical activity participation within two years prior to hip fracture was 16.7% (95% Confidence Intervals (CI): 11.6% to 21.8%). This increased at the final follow-up phase to 21.3% (95% CI: 15.1% to 27.6%). This was not a statistically significant change (P = 0.100). Age (P = 0.005) and frailty (P dwelling individuals. This contrasts with previous reports of reduced mobility post-hip fracture, suggesting that 'physical activity' and 'mobility' should be considered as separate outcomes in this population. Copyright © 2018 Elsevier Ltd. All rights reserved.

Trajectory planning and trajectory tracking for a small-scale helicopter in autorotation

NARCIS (Netherlands)

Taamallah, Skander; Bombois, Xavier; Van den Hof, Paul M.J.

2017-01-01

The design of a high-performance guidance and control system for a small-scale helicopterUnmanned Aerial Vehicle (UAV), with an engine OFF flight condition (i.e. autorotation), is known to be a challenging task. It is the purpose of this paper to present a Trajectory Planning (TP) and Trajectory

Mental health trajectories from childhood to young adulthood affect the educational and employment status of young adults: results from the TRAILS study.

Science.gov (United States)

Veldman, Karin; Reijneveld, Sijmen A; Ortiz, Josue Almansa; Verhulst, Frank C; Bültmann, Ute

2015-06-01

Young adults at work without basic educational level (BEL), and young adults in Neither Employment, Education nor Training (NEET) are at high risk of adverse employment outcomes. Evidence lacks on the impact of mental health problems during childhood, adolescence and young adulthood on employment outcomes of young adults. Therefore, the aims of this study were to (1) identify trajectories of mental health problems from childhood to young adulthood and (2) investigate the relation between these trajectories and the educational or employment status of young adults. Data were used from the Tracking Adolescents' Individual Lives Survey (TRAILS), a Dutch prospective cohort study with 9-year follow-up. Trajectories of mental health problems measured at ages 11, 13.5, 16 and 19 years were identified in 1711 young adults with latent class growth models. Young adults with high-stable trajectories of total problems, from childhood to young adulthood, were more likely to work without BEL or be in NEET at age 19, than to be at school or to work with BEL (28.0% vs 16.0%, p=0.01). The same was found for externalising problems (35.3% vs 23.2%, p=0.02). For internalising and attention problems, no statistically significant differences were found. Young adults with high-stable trajectories of mental health problems from age 11 to 19, were at risk of adverse employment outcomes. Interventions reducing mental health problems in childhood may improve the educational or employment status of young adults and their chances for successfully entering the labour market. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Maternal age and trajectories of cannabis use.

Science.gov (United States)

De Genna, Natacha M; Cornelius, Marie D; Goldschmidt, Lidush; Day, Nancy L

2015-11-01

Becoming a mother is a developmental transition that has been linked to desistance from substance use. However, timing of motherhood may be a key determinant of cannabis use in women, based on preliminary evidence from teenage mothers. The goal of this study was to identify trajectories of maternal cannabis use, and to determine if maternal age was associated with different trajectories of use. This prospective study examined 456 pregnant women recruited at a prenatal clinic, ranging in age from 13 to 42 years. The women were interviewed about their cannabis use 1 year prior to pregnancy and during each trimester of pregnancy, and at 6, 10, 14, and 16 years post-partum. A growth mixture model of cannabis use reported at each time point clearly delineated four groups: non/unlikely to use, decreasing likelihood of use, late desistance, and increasing likelihood/chronic use (Lo-Mendell-Rubin adjusted LRT test statistic=35.7, pdepressive symptoms were also associated with more frequent use. These findings have implications for both prevention and treatment of cannabis use in mothers. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Long-term trajectories of posttraumatic stress disorder in veterans: the role of social resources.

Science.gov (United States)

Karstoft, Karen-Inge; Armour, Cherie; Elklit, Ask; Solomon, Zahava

2013-12-01

To (1) identify long-term trajectories of combat-induced posttraumatic stress disorder (PTSD) symptoms over a 20-year period from 1983 to 2002 in veterans with and without combat stress reaction (CSR) and (2) identify social predictors of these trajectories. A latent growth mixture modeling analysis on PTSD symptoms was conducted to identify PTSD trajectories and predictors. PTSD was defined according to DSM-III and assessed through the PTSD Inventory. Israeli male veterans with (n = 369) and without (n = 306) CSR were queried at 1, 2, and 20 years after war about combat exposure, military unit support, family environment, and social reintegration. For both study groups, we identified 4 distinct trajectories with varying prevalence across groups: resilience (CSR = 34.4%, non-CSR = 76.5%), recovery (CSR = 36.3%, non-CSR = 10.5%), delayed onset (CSR = 8.4%, non-CSR = 6.9%), and chronicity (CSR = 20.9%, non-CSR = 6.2%). Predictors of trajectories in both groups included perception of war threat (ORs = 1.59-2.47, P values ≤ .30), and negative social reintegration (ORs = 0.24-0.51, P values ≤ .047). Social support was associated with symptomatology only in the CSR group (ORs = 0.40-0.61, P values ≤ .045), while family coherence was predictive of symptomatology in the non-CSR group (OR = 0.76, P = .015) but not in the CSR group. Findings confirmed heterogeneity of long-term sequelae of combat, revealing 4 trajectories of resilience, recovery, delay, and chronicity in veterans with and without CSR. Symptomatic trajectories were more prevalent for the CSR group, suggesting that acute functional impairment predicts pathological outcomes. Predictors of symptomatic trajectories included perceived threat and social resources at the family, network, and societal levels. © Copyright 2013 Physicians Postgraduate Press, Inc.

Peace and war: trajectories of posttraumatic stress disorder symptoms before, during, and after military deployment in Afghanistan.

Science.gov (United States)

Berntsen, Dorthe; Johannessen, Kim B; Thomsen, Yvonne D; Bertelsen, Mette; Hoyle, Rick H; Rubin, David C

2012-12-01

In the study reported here, we examined posttraumatic stress disorder (PTSD) symptoms in 746 Danish soldiers measured on five occasions before, during, and after deployment to Afghanistan. Using latent class growth analysis, we identified six trajectories of change in PTSD symptoms. Two resilient trajectories had low levels across all five times, and a new-onset trajectory started low and showed a marked increase of PTSD symptoms. Three temporary-benefit trajectories, not previously described in the literature, showed decreases in PTSD symptoms during (or immediately after) deployment, followed by increases after return from deployment. Predeployment emotional problems and predeployment traumas, especially childhood adversities, were predictors for inclusion in the nonresilient trajectories, whereas deployment-related stress was not. These findings challenge standard views of PTSD in two ways. First, they show that factors other than immediately preceding stressors are critical for PTSD development, with childhood adversities being central. Second, they demonstrate that the development of PTSD symptoms shows heterogeneity, which indicates the need for multiple measurements to understand PTSD and identify people in need of treatment.

Coparenting relationship trajectories: Marital violence linked to change and variability after separation.

Science.gov (United States)

Hardesty, Jennifer L; Ogolsky, Brian G; Raffaelli, Marcela; Whittaker, Angela; Crossman, Kimberly A; Haselschwerdt, Megan L; Mitchell, Elissa Thomann; Khaw, Lyndal

2017-10-01

Associations between marital intimate partner violence (IPV) and postseparation coparenting relationship trajectories were examined among 135 mothers who participated in 5 interviews at 3-month intervals in the year following their divorce filing. Growth curve analysis was conducted to assess change and variability in coparenting dimensions (i.e., conflict, support, communication about child rearing, and harassment) in the overall sample and by type of IPV. In the overall sample, coparenting conflict, communication about child rearing, and harassment decreased across the year following separation. However, coparenting relationships differed considerably based on marital IPV experiences. At Time 1, mothers in relationships with coercive controlling violence (CCV) reported higher levels of harassment and conflict, and lower levels of support and communication about coparenting, than mothers with situational couple violence (SCV) or no violence (NV). Furthermore, coparenting relationship trajectories differed significantly by IPV group, with mothers who experienced CCV showing more variability in conflict and harassment, and more marked changes in conflict, support, and harassment. Despite many similarities, mothers with SCV showed higher initial levels of harassment compared to mothers with NV. Findings can support family court and social service professionals' efforts to individualize interventions with divorcing parents based on IPV experiences. In cases of CCV, for example, attention to heightened control dynamics in the immediate separation period remain critical but the persistent volatility across the first year suggests the potential for chronic stress. With SCV, practitioners may be able to capitalize on parents' reasonable levels of communication and steady coparenting support. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Genetic and environmental influences on infant growth: prospective analysis of the Gemini twin birth cohort.

Directory of Open Access Journals (Sweden)

Laura Johnson

Full Text Available Infancy is a critical period during which rapid growth potentially programs future disease risk. Identifying the modifiable determinants of growth is therefore important. To capture the complexity of infant growth, we modeled growth trajectories from birth to six months in order to compare the genetic and environmental influences on growth trajectory parameters with single time-point measures at birth, three and six months of age.Data were from Gemini, a population sample of 2402 UK families with twins. An average 10 weight measurements per child made by health professionals were available over the first six months. Weights at birth, three and six months were identified. Longitudinal growth trajectories were modeled using SITAR utilizing all available weight measures for each child. SITAR generates three parameters: size (characterizing mean weight throughout infancy, tempo (indicating age at peak weight velocity (PWV, and velocity (reflecting the size of PWV. Genetic and environmental influences were estimated using quantitative genetic analysis.In line with previous studies, heritability of weight at birth and three months was low (38%, but it was higher at six months (62%. Heritability of the growth trajectory parameters was high for size (69% and velocity (57%, but low (35% for tempo. Common environmental influences predominated for tempo (42%.Modeled growth parameters using SITAR indicated that size and velocity were primarily under genetic influence but tempo was predominantly environmentally determined. These results emphasize the importance of identifying specific modifiable environmental determinants of the timing of peak infant growth.

Lunar Cube Transfer Trajectory Options

Science.gov (United States)

Folta, David; Dichmann, Donald James; Clark, Pamela E.; Haapala, Amanda; Howell, Kathleen

2015-01-01

Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can b e considered which have a wide range of transfer duration, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO) geostationary transfer orbits (GTO) and higher energy direct lunar transfer and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

INFORMATION MANAGEMENT SYSTEM FOR CREATION OF INDIVIDUAL STUDENTS’ EDUCATIONAL TRAJECTORY

Directory of Open Access Journals (Sweden)

Anatolii V. Bohdanov

2016-09-01

Full Text Available The article is devoted to development of information support for building an individual educational path of a student. European Tools for Mobility, Tools for Quality, Tools for Transparency as well as Portals and Databases are analyzed. These tools may be useful for the development and following of an individual educational path. Principles and structure of open module-based portal for information support for building individual educational tracks are presented. Its core modules are described. It is recommended to integrate modules using LEARNING TOOLS INTEROPERABILITY specification. It is demonstrated how to connect modules «Knowledge area» and «Abilities definer».

Trajectories of Italian Children's Peer Rejection: Associations with Aggression, Prosocial Behavior, Physical Attractiveness, and Adolescent Adjustment.

Science.gov (United States)

Di Giunta, Laura; Pastorelli, Concetta; Thartori, Eriona; Bombi, Anna Silvia; Baumgartner, Emma; Fabes, Richard A; Martin, Carol Lynn; Enders, Craig K

2017-12-08

In the present study, the predictors and outcomes associated with the trajectories of peer rejection were examined in a longitudinal sample of Italian children (338 boys, 269 girls) ages 10 to 14 years. Follow-up assessments included 60% of the original sample at age 16-17. Low, medium, and high rejection trajectory groups were identified using growth mixture models. Consistent with previous studies, we found that (a) being less prosocial and more physically aggressive at age 10 was characteristic of those children with the high rejection trajectory; (b) being less attractive was related to higher peer rejection from age 10 to 14; and (c) boys with a high rejection trajectory showed high levels of delinquency and anxiety-depression and low levels of academic aspiration at age 16-17, whereas girls with a high rejection trajectory showed low levels of academic aspiration and social competence at age 16-17. Our findings indicate the detrimental consequences of peer rejection on children's development and adjustment and shed light on the mechanisms that contribute to maintaining or worsening (e.g., being attractive, prosocial, and aggressive) a child's negative status (e.g., being rejected) within his or her peer group over time.

Child maltreatment and trajectories of personality and behavioral functioning: implications for the development of personality disorder.

Science.gov (United States)

Kim, Jungmeen; Cicchetti, Dante; Rogosch, Fred A; Manly, Jody Todd

2009-01-01

This study investigated the longitudinal impact of maltreatment parameters on personality processes and maladjustment and prospective relationships between personality trajectory classes and subsequent maladjustment outcomes. The sample involved maltreated (n = 249) and nonmaltreated (n = 200) children followed longitudinally between ages 6 and 10. Growth mixture modeling indicated multifinality in personality development depending on the risk status (i.e., maltreated vs. nonmaltreated). Two trajectory classes of ego resiliency were identified for maltreated children: those who showed a declining trajectory exhibited greater maladjustment. In contrast, three trajectory classes of ego control were identified for nonmaltreated children; the subgroups showing increases in ego undercontrol or dramatic changes from high ego undercontrol to high ego overcontrol exhibited poor adjustment. Experiencing multiple maltreatment subtypes and physical/sexual abuse were related to higher levels of ego undercontrol and externalizing symptomatology, whereas early onset of maltreatment was associated with the low and decreasing trajectory of ego resiliency and higher levels of internalizing symptomatology. The findings suggest that ego resiliency and ego control, personality processes related to self-regulation, may be important factors in identifying distinct pathways to later personality disorders as well as pathways to resilient functioning.

Towards Efficient Search for Activity Trajectories

DEFF Research Database (Denmark)

Zheng, Kai; Shang, Shuo; Yuan, Jing

2013-01-01

, recent proliferation in location-based web applications (e.g., Foursquare, Facebook) has given rise to large amounts of trajectories associated with activity information, called activity trajectory. In this paper, we study the problem of efficient similarity search on activity trajectory database. Given...

Mexican origin youths' trajectories of perceived peer discrimination from middle childhood to adolescence: variation by neighborhood ethnic concentration.

Science.gov (United States)

White, Rebecca M B; Zeiders, Katharine H; Knight, George P; Roosa, Mark W; Tein, Jenn-Yun

2014-10-01

Developmentally salient research on perceived peer discrimination among minority youths is limited. Little is known about trajectories of perceived peer discrimination across the developmental period ranging from middle childhood to adolescence. Ethically concentrated neighborhoods are hypothesized to protect minority youths from discrimination, but strong empirical tests are lacking. The first aim of the current study was to estimate trajectories of perceived peer discrimination from middle childhood to adolescence, as youths transitioned from elementary to middle and to high school. The second aim was to examine the relationship between neighborhood ethnic concentration and perceived peer discrimination over time. Using a diverse sample of 749 Mexican origin youths (48.9% female), a series of growth models revealed that youths born in Mexico, relative to those born in the U.S., perceived higher discrimination in the 5th grade and decreases across time. Youths who had higher averages on neighborhood ethnic concentration (across the developmental period) experienced decreases in perceived peer discrimination over time; those that had lower average neighborhood ethnic concentration levels showed evidence of increasing trajectories. Further, when individuals experienced increases in their own neighborhood ethnic concentration levels (relative to their own cross-time averages), they reported lower levels of perceived peer discrimination. Neighborhood ethnic concentration findings were not explained by the concurrent changes youths were experiencing in school ethnic concentrations. The results support a culturally-informed developmental view of perceived peer discrimination that recognizes variability in co-ethnic neighborhood contexts. The results advance a view of ethnic enclaves as protective from mainstream threats.

Efficient Trajectory Options Allocation for the Collaborative Trajectory Options Program

Science.gov (United States)

Rodionova, Olga; Arneson, Heather; Sridhar, Banavar; Evans, Antony

2017-01-01

The Collaborative Trajectory Options Program (CTOP) is a Traffic Management Initiative (TMI) intended to control the air traffic flow rates at multiple specified Flow Constrained Areas (FCAs), where demand exceeds capacity. CTOP allows flight operators to submit the desired Trajectory Options Set (TOS) for each affected flight with associated Relative Trajectory Cost (RTC) for each option. CTOP then creates a feasible schedule that complies with capacity constraints by assigning affected flights with routes and departure delays in such a way as to minimize the total cost while maintaining equity across flight operators. The current version of CTOP implements a Ration-by-Schedule (RBS) scheme, which assigns the best available options to flights based on a First-Scheduled-First-Served heuristic. In the present study, an alternative flight scheduling approach is developed based on linear optimization. Results suggest that such an approach can significantly reduce flight delays, in the deterministic case, while maintaining equity as defined using a Max-Min fairness scheme.

Flight test trajectory control analysis

Science.gov (United States)

Walker, R.; Gupta, N.

1983-01-01

Recent extensions to optimal control theory applied to meaningful linear models with sufficiently flexible software tools provide powerful techniques for designing flight test trajectory controllers (FTTCs). This report describes the principal steps for systematic development of flight trajectory controllers, which can be summarized as planning, modeling, designing, and validating a trajectory controller. The techniques have been kept as general as possible and should apply to a wide range of problems where quantities must be computed and displayed to a pilot to improve pilot effectiveness and to reduce workload and fatigue. To illustrate the approach, a detailed trajectory guidance law is developed and demonstrated for the F-15 aircraft flying the zoom-and-pushover maneuver.

Depression symptom trajectories and associated risk factors among adolescents in Chile.

Directory of Open Access Journals (Sweden)

Lexine A Stapinski

Full Text Available Adolescence is a key period for studying the development of depression, with studies in Europe and North America showing a pattern of elevated risk that begins in early adolescence and continues to increase as adolescents age. Few studies have examined the course of adolescent depression and associated risk factors in low and middle-income countries. This longitudinal cohort study examined depression symptom trajectories and risk factors in a sample of socio-economically disadvantaged adolescents in Chile (n = 2,508. Data were collected over an 18-month period as part of a clinical trial for secondary students aged 12 to 18 (median age 14. Clinical levels of depression were prevalent in this sample at baseline (35% for girls and 28% for boys; yet latent growth models of symptom trajectories revealed a pattern of decreasing symptoms over time. There was evidence of an anxiety-depression developmental pathway for girls, with elevated anxiety levels initially predicting poorer depression outcomes later on. Poor problem-solving skills were associated with initial depression levels but did not predict the course of depressive symptoms. Critically, the declining symptom trajectories raise important methodological issues regarding the effects of repeated assessment in longitudinal studies.

Depression symptom trajectories and associated risk factors among adolescents in Chile.

Science.gov (United States)

Stapinski, Lexine A; Montgomery, Alan A; Heron, Jon; Jerrim, John; Vignoles, Anna; Araya, Ricardo

2013-01-01

Adolescence is a key period for studying the development of depression, with studies in Europe and North America showing a pattern of elevated risk that begins in early adolescence and continues to increase as adolescents age. Few studies have examined the course of adolescent depression and associated risk factors in low and middle-income countries. This longitudinal cohort study examined depression symptom trajectories and risk factors in a sample of socio-economically disadvantaged adolescents in Chile (n = 2,508). Data were collected over an 18-month period as part of a clinical trial for secondary students aged 12 to 18 (median age 14). Clinical levels of depression were prevalent in this sample at baseline (35% for girls and 28% for boys); yet latent growth models of symptom trajectories revealed a pattern of decreasing symptoms over time. There was evidence of an anxiety-depression developmental pathway for girls, with elevated anxiety levels initially predicting poorer depression outcomes later on. Poor problem-solving skills were associated with initial depression levels but did not predict the course of depressive symptoms. Critically, the declining symptom trajectories raise important methodological issues regarding the effects of repeated assessment in longitudinal studies.

Adolescent inhalant abuse leads to other drug use and impaired growth; implications for diagnosis.

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Crossin, Rose; Cairney, Sheree; Lawrence, Andrew J; Duncan, Jhodie R

2017-02-01

Abuse of inhalants containing the volatile solvent toluene is a significant public health issue, especially for adolescent and Indigenous communities. Adolescent inhalant abuse can lead to chronic health issues and may initiate a trajectory towards further drug use. Identification of at-risk individuals is difficult and diagnostic tools are limited primarily to measurement of serum toluene. Our objective was to identify the effects of adolescent inhalant abuse on subsequent drug use and growth parameters, and to test the predictive power of growth parameters as a diagnostic measure for inhalant abuse. We retrospectively analysed drug use and growth data from 118 Indigenous males; 86 chronically sniffed petrol as adolescents. Petrol sniffing was the earliest drug used (mean 13 years) and increased the likelihood and earlier use of other drugs. Petrol sniffing significantly impaired height and weight and was associated with meeting 'failure to thrive' criteria; growth diagnostically out-performed serum toluene. Adolescent inhalant abuse increases the risk for subsequent and earlier drug use. It also impairs growth such that individuals meet 'failure to thrive' criteria, representing an improved diagnostic model for inhalant abuse. Implications for Public Health: Improved diagnosis of adolescent inhalant abuse may lead to earlier detection and enhanced health outcomes. © 2016 The Authors.

Unique Associations between Childhood Temperament Characteristics and Subsequent Psychopathology Symptom Trajectories from Childhood to Early Adolescence.

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Forbes, Miriam K; Rapee, Ronald M; Camberis, Anna-Lisa; McMahon, Catherine A

2017-08-01

Existing research suggests that temperamental traits that emerge early in childhood may have utility for early detection and intervention for common mental disorders. The present study examined the unique relationships between the temperament characteristics of reactivity, approach-sociability, and persistence in early childhood and subsequent symptom trajectories of psychopathology (depression, anxiety, conduct disorder, and attention-deficit hyperactivity disorder; ADHD) from childhood to early adolescence. Data were from the first five waves of the older cohort from the Longitudinal Study of Australian Children (n = 4983; 51.2% male), which spanned ages 4-5 to 12-13. Multivariate ordinal and logistic regressions examined whether parent-reported child temperament characteristics at age 4-5 predicted the study child's subsequent symptom trajectories for each domain of psychopathology (derived using latent class growth analyses), after controlling for other presenting symptoms. Temperament characteristics differentially predicted the symptom trajectories for depression, anxiety, conduct disorder, and ADHD: Higher levels of reactivity uniquely predicted higher symptom trajectories for all 4 domains; higher levels of approach-sociability predicted higher trajectories of conduct disorder and ADHD, but lower trajectories of anxiety; and higher levels of persistence were related to lower trajectories of conduct disorder and ADHD. These findings suggest that temperament is an early identifiable risk factor for the development of psychopathology, and that identification and timely interventions for children with highly reactive temperaments in particular could prevent later mental health problems.

Capitalist Diversity and De-growth Trajectories to Steady-state Economies

DEFF Research Database (Denmark)

Buch-Hansen, Hubert

2014-01-01

Growth-critical scholarship has done much to both expose the environmentally unsustainable nature of the capitalist growth-economies of the overdeveloped part of the world and to develop an alternative vision of a degrowth transition leading to a steady-state economy. However, this scholarship fa...

The longitudinal interplay between negative and positive symptom trajectories in patients under antipsychotic treatment: a post hoc analysis of data from a randomized, 1-year pragmatic trial.

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Chen, Lei; Johnston, Joseph A; Kinon, Bruce J; Stauffer, Virginia; Succop, Paul; Marques, Tiago R; Ascher-Svanum, Haya

2013-11-28

Schizophrenia is a highly heterogeneous disorder with positive and negative symptoms being characteristic manifestations of the disease. While these two symptom domains are usually construed as distinct and orthogonal, little is known about the longitudinal pattern of negative symptoms and their linkage with the positive symptoms. This study assessed the temporal interplay between these two symptom domains and evaluated whether the improvements in these symptoms were inversely correlated or independent with each other. This post hoc analysis used data from a multicenter, randomized, open-label, 1-year pragmatic trial of patients with schizophrenia spectrum disorder who were treated with first- and second-generation antipsychotics in the usual clinical settings. Data from all treatment groups were pooled resulting in 399 patients with complete data on both the negative and positive subscale scores from the Positive and Negative Syndrome Scale (PANSS). Individual-based growth mixture modeling combined with interplay matrix was used to identify the latent trajectory patterns in terms of both the negative and positive symptoms. Pearson correlation coefficients were calculated to examine the relationship between the changes of these two symptom domains within each combined trajectory pattern. We identified four distinct negative symptom trajectories and three positive symptom trajectories. The trajectory matrix formed 11 combined trajectory patterns, which evidenced that negative and positive symptom trajectories moved generally in parallel. Correlation coefficients for changes in negative and positive symptom subscale scores were positive and statistically significant (P negative and positive symptoms (n = 70, 18%), (2) mild and sustained improvement in negative and positive symptoms (n = 237, 59%), and (3) no improvement in either negative or positive symptoms (n = 82, 21%). This study of symptom trajectories over 1 year shows that changes in negative

Maternal caffeine intake during pregnancy and childhood growth and overweight: results from a large Norwegian prospective observational cohort study

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Botton, Jérémie; Brantsæter, Anne-Lise; Haugen, Margaretha; Alexander, Jan; Meltzer, Helle Margrete; Bacelis, Jonas; Elfvin, Anders; Jacobsson, Bo; Sengpiel, Verena

2018-01-01

Objectives To study the association between maternal caffeine intake during pregnancy and the child’s weight gain and overweight risk up to 8 years. Design Prospective nationwide pregnancy cohort. Setting The Norwegian Mother and Child Cohort Study. Participants A total of 50 943 mothers recruited from 2002 to 2008 and their children, after singleton pregnancies, with information about average caffeine intake assessed at mid-pregnancy. Outcome measure Child’s body size information at 11 age points from 6 weeks to 8 years. We defined excess growth in infancy as a WHO weight gain z-score of >0.67 from birth to age 1 year, and overweight according to the International Obesity Task Force. We used a growth model to assess individual growth trajectories. Results Compared with pregnant women with low caffeine intake (200 mg/day had consistently higher weight. Very high caffeine exposures were associated with higher weight gain velocity from infancy to age 8 years. Conclusion Any caffeine consumption during pregnancy is associated with a higher risk of excess infant growth and of childhood overweight, mainly at preschool ages. Maternal caffeine intake may modify the overall weight growth trajectory of the child from birth to 8 years. This study adds supporting evidence for the current advice to reduce caffeine intake during pregnancy. PMID:29685923

Stem analysis program (GOAP for evaluating of increment and growth data at individual tree

Directory of Open Access Journals (Sweden)

Gafura Aylak Özdemir

2016-07-01

Full Text Available Stem analysis is a method evaluating in a detailed way data of increment and growth of individual tree at the past periods and widely used in various forestry disciplines. Untreated data of stem analysis consist of annual ring count and measurement procedures performed on cross sections taken from individual tree by section method. The evaluation of obtained this untreated data takes quite some time. Thus, a computer software was developed in this study to quickly and efficiently perform stem analysis. This computer software developed to evaluate untreated data of stem analysis as numerical and graphical was programmed as macro by utilizing Visual Basic for Application feature of MS Excel 2013 program currently the most widely used. In developed this computer software, growth height model is formed from two different approaches, individual tree volume depending on section method, cross-sectional area, increments of diameter, height and volume, volume increment percent and stem form factor at breast height are calculated depending on desired period lengths. This calculated values are given as table. Development of diameter, height, volume, increments of these variables, volume increment percent and stem form factor at breast height according to periodic age are given as chart. Stem model showing development of diameter, height and shape of individual tree in the past periods also can be taken from computer software as chart.

Modeling the growth of individuals in plant populations: local density variation in a strand population of Xanthium strumarium (Asteraceae).

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Weiner, J; Kinsman, S; Williams, S

1998-11-01

We studied the growth of individual Xanthium strumarium plants growing at four naturally occurring local densities on a beach in Maine: (1) isolated plants, (2) pairs of plants ≤1 cm apart, (3) four plants within 4 cm of each other, and (4) discrete dense clumps of 10-39 plants. A combination of nondestructive measurements every 2 wk and parallel calibration harvests provided very good estimates of the growth in aboveground biomass of over 400 individual plants over 8 wk and afforded the opportunity to fit explicit growth models to 293 of them. There was large individual variation in growth and resultant size within the population and within all densities. Local crowding played a role in determining plant size within the population: there were significant differences in final size between all densities except pairs and quadruples, which were almost identical. Overall, plants growing at higher densities were more variable in growth and final size than plants growing at lower densities, but this was due to increased variation among groups (greater variation in local density and/or greater environmental heterogeneity), not to increased variation within groups. Thus, there was no evidence of size asymmetric competition in this population. The growth of most plants was close to exponential over the study period, but half the plants were slightly better fit by a sigmoidal (logistic) model. The proportion of plants better fit by the logistic model increased with density and with initial plant size. The use of explicit growth models over several growth intervals to describe stand development can provide more biological content and more statistical power than "growth-size" methods that analyze growth intervals separately.

Longitudinal analysis of receptive vocabulary growth in young Spanish English-speaking children from migrant families.

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Jackson, Carla Wood; Schatschneider, Christopher; Leacox, Lindsey

2014-01-01

The authors of this study described developmental trajectories and predicted kindergarten performance of Spanish and English receptive vocabulary acquisition of young Latino/a English language learners (ELLs) from socioeconomically disadvantaged migrant families. In addition, the authors examined the extent to which gender and individual initial performance in Spanish predict receptive vocabulary performance and growth rate. The authors used hierarchical linear modeling of 64 children's receptive vocabulary performance to generate growth trajectories, predict performance at school entry, and examine potential predictors of rate of growth. The timing of testing varied across children. The ELLs (prekindergarten to 2nd grade) participated in 2-5 testing sessions, each 6-12 months apart. The ELLs' average predicted standard score on an English receptive vocabulary at kindergarten was nearly 2 SDs below the mean for monolingual peers. Significant growth in the ELLs' receptive vocabulary was observed between preschool and 2nd grade, indicating that the ELLs were slowly closing the receptive vocabulary gap, although their average score remained below the standard score mean for age-matched monolingual peers. The ELLs demonstrated a significant decrease in Spanish receptive vocabulary standard scores over time. Initial Spanish receptive vocabulary was a significant predictor of growth in English receptive vocabulary. High initial Spanish receptive vocabulary was associated with greater growth in English receptive vocabulary and decelerated growth in Spanish receptive vocabulary. Gender was not a significant predictor of growth in either English or Spanish receptive vocabulary. ELLs from low socioeconomic backgrounds may be expected to perform lower in English compared with their monolingual English peers in kindergarten. Performance in Spanish at school entry may be useful in identifying children who require more intensive instructional support for English vocabulary

IRVE-II Post-Flight Trajectory Reconstruction

Science.gov (United States)

O'Keefe, Stephen A.; Bose, David M.

2010-01-01

NASA s Inflatable Re-entry Vehicle Experiment (IRVE) II successfully demonstrated an inflatable aerodynamic decelerator after being launched aboard a sounding rocket from Wallops Flight Facility (WFF). Preliminary day of flight data compared well with pre-flight Monte Carlo analysis, and a more complete trajectory reconstruction performed with an Extended Kalman Filter (EKF) approach followed. The reconstructed trajectory and comparisons to an attitude solution provided by NASA Sounding Rocket Operations Contract (NSROC) personnel at WFF are presented. Additional comparisons are made between the reconstructed trajectory and pre and post-flight Monte Carlo trajectory predictions. Alternative observations of the trajectory are summarized which leverage flight accelerometer measurements, the pre-flight aerodynamic database, and on-board flight video. Finally, analysis of the payload separation and aeroshell deployment events are presented. The flight trajectory is reconstructed to fidelity sufficient to assess overall project objectives related to flight dynamics and overall, IRVE-II flight dynamics are in line with expectations

Parenting Styles and Body Mass Index Trajectories From Adolescence to Adulthood

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Fuemmeler, Bernard F.; Yang, Chongming; Costanzo, Phil; Hoyle, Rick H.; Ph.D.; Siegler, Ilene C.; Williams, Redford B.; Østbye, Truls

2013-01-01

Objective Parenting styles such as authoritarian, disengaged, or permissive are thought to be associated with greater adolescent obesity risk than an authoritative style. This study assessed the relationship between parenting styles and changes in body mass index (BMI) from adolescence to young adulthood. Methods The study included self-reported data from adolescents in the National Longitudinal Study of Adolescent Health. Factor mixture modeling, a data-driven approach, was used to classify participants into parenting style groups based on measures of acceptance and control. Latent growth modeling (LGM) identified patterns of developmental changes in BMI. After a number of potential cofounders were controlled for, parenting style variables were entered as predictors of BMI trajectories. Analyses were also conducted for males and females of three racial/ethnic groups (Hispanic, black, white) to assess whether parenting styles were differentially associated with BMI trajectories in these 6 groups. Results Parenting styles were classified into 4 groups: authoritarian, disengaged, permissive, and balanced. Compared with the balanced parenting style, authoritarian and disengaged parenting styles were associated with a less steep average BMI increase (linear slope) over time, but also less leveling off (quadratic) of BMI over time. Differences in BMI trajectories were observed for various genders and races, but the differences did not reach statistical significance. Conclusions Adolescents who reported having parents with authoritarian or disengaged parenting styles had greater increases in BMI as they transitioned to young adulthood despite having a lower BMI trajectory through adolescence. PMID:22545979

Automated Cooperative Trajectories

Science.gov (United States)

Hanson, Curt; Pahle, Joseph; Brown, Nelson

2015-01-01

This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

Heterogeneous body composition trajectories in infancy are associated with blood pressure in childhood: A latent class analysis

DEFF Research Database (Denmark)

Wibaek, Rasmus; Kæstel, Pernille; Girma, Tsinuel

to identify infants with distinct fat mass (FM) and fat-free mass (FFM) trajectories from 0-6 months of age and examined associations with BP at 4 years of age. Material and methods: Air displacement plethysmography was used to measure body composition monthly from birth to 6 months of age in 364 Ethiopian...... infants. BP was assessed at 4 years of age. Data driven latent class trajectory models were used to establish distinct FM and FFM trajectories, and multiple linear regression to examine their associations with BP at 4 years of age adjusted for sex, weight and length at birth, 3 and 6 months of age....... Results: We identified four distinct FM and two distinct FFM growth trajectories (figure 1). Overall mean (SD) systolic BP (SBP) was 87.4 (6.8) mmHg and diastolic BP (DBP) was 52.9 (8.3) mmHg at 4 years of age. Compared to the "High intermediate FM" reference group, infants in the "Accelerated FM" group...

Developmental trajectory of time perspective: From children to older adults.

Science.gov (United States)

Chen, Tao; Liu, Lu-Lu; Cui, Ji-Fang; Chen, Xing-Jie; Wang, Ya

2016-12-01

Time perspective is a fundamental dimension of the psychological time construct, with a pervasive and powerful influence on human behavior. However, the developmental trajectory of time perspective across a human lifespan remains unclear. The current study aimed to portray the developmental trajectory of all dimensions of time perspectives from children to older adults in a large sample. A total of 1,901 individuals (aged 9-84 years) completed measures of time perspective. They were then divided into five age groups: children, teenagers, young adults, middle-aged adults, and older adults. Results suggested that each time perspective showed a unique developmental pattern across the lifespan. Moreover, perceived economic situation and education were related to some dimensions of time perspective. © 2016 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Impact of social capital on depression trajectories of older women in Korea.

Science.gov (United States)

Park, Mi-Jin

2017-04-01

This study examines the impact of social capital on depressive symptoms trajectories among Korean women aged 65 years or older. It also examines the difference in depressive symptoms and social capital by economic status (poverty group, non-poverty group) among community-dwelling older women in Korea. This study used 2435 older women of the Korean Welfare Panel Study from 2006 (wave 1) to 2013 (wave 8) data using latent growth modeling. Social capital variables were cognitive (interpersonal trust, reciprocity) and structural (the size of family, the number of friends or neighbors, participation in leisure and volunteer activities). The results showed both intra- and inter-individual variability in depressive symptoms over time. Interpersonal trust and reciprocity as cognitive social capital had an effect on the change of depressive symptoms in intercept and slope. The size of family, participation in leisure activities among structural social capital were associated with lower levels of depressive symptoms in intercept and slope. The results of this study suggest some practical implications for depression intervention and prevention and further research on late-life depression.

Canonical transformations of Kepler trajectories

International Nuclear Information System (INIS)

Mostowski, Jan

2010-01-01

In this paper, canonical transformations generated by constants of motion in the case of the Kepler problem are discussed. It is shown that canonical transformations generated by angular momentum are rotations of the trajectory. Particular attention is paid to canonical transformations generated by the Runge-Lenz vector. It is shown that these transformations change the eccentricity of the orbit. A method of obtaining elliptic trajectories from the circular ones with the help of canonical trajectories is discussed.

The Chinese-born immigrant infant feeding and growth hypothesis

Directory of Open Access Journals (Sweden)

Kristy A. Bolton

2016-10-01

Full Text Available Abstract Background Rapid growth in the first six months of life is a well-established risk factor for childhood obesity, and child feeding practices (supplementation or substitution of breast milk with formula and early introduction of solids have been reported to predict this. The third largest immigrant group in Australia originate from China. Case-studies reported from Victorian Maternal and Child Health nurses suggest that rapid growth trajectories in the infants of Chinese parents is common place. Furthermore, these nurses report that high value is placed by this client group on rapid growth and a fatter child; that rates of breastfeeding are low and overfeeding of infant formula is high. There are currently no studies which describe infant growth or its correlates among this immigrant group. Presentation of hypothesis We postulate that in Australia, Chinese-born immigrant mothers will have different infant feeding practices compared to non-immigrant mothers and this will result in different growth trajectories and risk of overweight. We present the Chinese-born immigrant infant feeding and growth hypothesis - that less breastfeeding, high formula feeding and early introduction of solids in infants of Chinese-born immigrant mothers living in Australia will result in a high protein intake and subsequent rapid growth trajectory and increased risk of overweight and obesity. Testing the hypothesis Three related studies will be conducted to investigate the hypothesis. These will include two quantitative studies (one cross-sectional, one longitudinal and a qualitative study. The quantitative studies will investigate differences in feeding practices in Chinese-born immigrant compared to non-immigrant mothers and infants; and the growth trajectories over the first 3.5 years of life. The qualitative study will provide more in-depth understanding of the influencing factors on feeding practices in Chinese-born immigrant mothers. Implications of the

From the trajectory to the density memory

International Nuclear Information System (INIS)

Cakir, Rasit; Krokhin, Arkadii; Grigolini, Paolo

2007-01-01

In this paper we discuss the connection between trajectory and density memory. The first form of memory is a property of a stochastic trajectory, whose stationary correlation function shows that the fluctuation at a given time depends on the earlier fluctuations. The density memory is a property of a collection of trajectories, whose density time evolution is described by a time convoluted equation showing that the density time evolution depends on its past history. We show that the trajectory memory does not necessarily yields density memory, and that density memory might be compatible with the existence of abrupt jumps resetting to zero the system's memory. We focus our attention on a time-convoluted diffusion equation, when the memory kernel is an inverse power law with (i) negative and (ii) positive tail. In case (i) there exist both renewal trajectories and trajectories with memory, compatible with this equation. Case (ii), which has eluded so far a convincing interpretation in terms of trajectories, is shown to be compatible only with trajectory memory

Work functioning trajectories in cancer patients: Results from the longitudinal Work Life after Cancer (WOLICA) study.

Science.gov (United States)

Dorland, Heleen F; Abma, Femke I; Roelen, Corné A M; Stewart, Roy E; Amick, Benjamin C; Ranchor, Adelita V; Bültmann, Ute

2017-11-01

More than 60% of cancer patients are able to work after cancer diagnosis. However, little is known about their functioning at work. Therefore, the aims of this study were to (1) identify work functioning trajectories in the year following return to work (RTW) in cancer patients and (2) examine baseline sociodemographic, health-related and work-related variables associated with work functioning trajectories. This longitudinal cohort study included 384 cancer patients who have returned to work after cancer diagnosis. Work functioning was measured at baseline, 3, 6, 9 and 12 months follow-up. Latent class growth modeling (LCGM) was used to identify work functioning trajectories. Associations of baseline variables with work functioning trajectories were examined using univariate and multivariate analyses. LCGM analyses with cancer patients who completed on at least three time points the Work Role Functioning Questionnaire (n = 324) identified three work functioning trajectories: "persistently high" (16% of the sample), "moderate to high" (54%) and "persistently low" work functioning (32%). Cancer patients with persistently high work functioning had less time between diagnosis and RTW and had less often a changed meaning of work, while cancer patients with persistently low work functioning reported more baseline cognitive symptoms compared to cancer patients in the other trajectories. This knowledge has implications for cancer care and guidance of cancer patients at work. © 2017 UICC.

Growth Trajectories of Mathematics Achievement: Longitudinal Tracking of Student Academic Progress

Science.gov (United States)

Mok, Magdalena M. C.; McInerney, Dennis M.; Zhu, Jinxin; Or, Anthony

2015-01-01

Background: A number of methods to investigate growth have been reported in the literature, including hierarchical linear modelling (HLM), latent growth modelling (LGM), and multidimensional scaling applied to longitudinal profile analysis (LPAMS). Aims: This study aimed at modelling the mathematics growth of students over a span of 6 years from…

Individualism, innovation, and long-run growth.

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Gorodnichenko, Yuriy; Roland, Gerard

2011-12-27

Countries having a more individualist culture have enjoyed higher long-run growth than countries with a more collectivist culture. Individualist culture attaches social status rewards to personal achievements and thus, provides not only monetary incentives for innovation but also social status rewards, leading to higher rates of innovation and economic growth.

Pain trajectory and exercise-induced pain flares during 8 weeks of neuromuscular exercise in individuals with knee and hip pain.

Science.gov (United States)

Sandal, L F; Roos, E M; Bøgesvang, S J; Thorlund, J B

2016-04-01

Patients considering or engaged in exercise as treatment may expect or experience transient increases in joint pain, causing fear of exercise and influencing compliance. This study investigated the pain trajectory during an 8-week neuromuscular exercise (NEMEX) program together with acute exercise-induced pain flares in persons with knee or hip pain. Individuals above 35 years self-reporting persistent knee or hip pain for the past 3 months were offered 8 weeks of supervised NEMEX, performed in groups twice weekly. The program consisted of 11 exercises focusing on joint stability and neuromuscular control. Participants self-reported joint pain on a 0-10 numerical rating scale (NRS) at baseline and 8-weeks follow-up. NRS pain ratings were also collected before and immediately after every attended exercise session. Joint pain was reduced from baseline (NRS 3.6; 95% CI 3.2-4.1) to 8-weeks follow-up (2.6; 95% CI 2.1-3.1), (P neuromuscular exercise. Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Evaluating the Predictive Value of Growth Prediction Models

Science.gov (United States)

Murphy, Daniel L.; Gaertner, Matthew N.

2014-01-01

This study evaluates four growth prediction models--projection, student growth percentile, trajectory, and transition table--commonly used to forecast (and give schools credit for) middle school students' future proficiency. Analyses focused on vertically scaled summative mathematics assessments, and two performance standards conditions (high…

Childhood trajectories of anxiousness and disruptiveness as predictors of suicide attempts.

Science.gov (United States)

Brezo, Jelena; Barker, Edward D; Paris, Joel; Hébert, Martine; Vitaro, Frank; Tremblay, Richard E; Turecki, Gustavo

2008-11-01

To investigate the association of childhood trajectories of anxiousness and disruptiveness with suicide attempts in early adulthood. Prospective cohort study. Public francophone schools in Quebec, Canada, from the 1986 to 1988 school years. Of 4,488 French Canadian children attending kindergarten, a representative group of 1,001 boys and 999 girls was chosen for follow-up. Of these, 1,144 individuals participated in the study during early adulthood. Suicide attempt histories by early adulthood, adjusted odds ratios (ORs) associated with membership in high- vs low-risk trajectories of anxiousness and disruptiveness, moderation (by sex), and mediation (by adolescent Axis I disorders). We observed 4 distinct developmental profiles of anxiousness and disruptiveness and a frequent co-occurrence of similar levels of these traits. In contrast to anxiousness trajectories (OR = 1.60; 95% confidence interval, 1.00-2.65), disruptiveness (OR = 1.80; 95% confidence interval, 1.03-3.13) and joint (OR = 1.88; 95% confidence interval, 1.05-3.37) trajectories made statistically significant contributions to suicide attempts. We found no support for mediation by adolescent anxiety/mood or disruptive disorders. Sex, however, moderated the effect of joint trajectories, increasing the risk of suicide attempts in women (OR = 3.60; Wald chi(2) = 10.93; P anxious and disruptive traits as children. Anxious-disruptive girls and disruptive boys appear to be more likely than their peers to attempt suicide by early adulthood. Preventive efforts will require more research into the possible mechanisms behind this early sex difference, ie, gene-environment interplays and nonpsychiatric mediators.

Implicit Theories about Intelligence and Growth (Personal Best) Goals: Exploring Reciprocal Relationships

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Martin, Andrew J.

2015-01-01

Background: There has been increasing interest in growth approaches to students' academic development, including value-added models, modelling of academic trajectories, growth motivation orientations, growth mindsets, and growth goals. Aims: This study sought to investigate the relationships between implicit theories about intelligence…

Memory deficit associated with worse functional trajectories in older adults in low-vision rehabilitation for macular disease.

Science.gov (United States)

Whitson, Heather E; Whitaker, Diane; Sanders, Linda L; Potter, Guy G; Cousins, Scott W; Ansah, Deidra; McConnell, Eleanor; Pieper, Carl F; Landerman, Lawrence; Steffens, David C; Cohen, Harvey J

2012-11-01

To examine whether performance on a brief memory test is related to functional outcomes in older individuals undergoing low-vision rehabilitation (LVR) for macular disease. Observational cohort study of individuals receiving outpatient LVR. Academic center. Ninety-one individuals (average age 80.1) with macular disease. Memory was assessed at baseline using a 10-word list; memory deficit was defined as immediate recall of two or fewer words. Vision-related function was measured using the 25-item Visual Function Questionnaire (VFQ-25) administered at baseline and during subsequent interviews (mean follow-up, 115 days). Linear mixed models were constructed to compare average trajectories of four VFQ-25 subscales: near activities, distance activities, dependency, and role difficulty. The 29.7% of participants with memory deficits tended to decline in ability to accomplish activities that involved near vision. Controlling for age, sex, and education, the functional trajectory of participants with memory deficit differed significantly from that of those with better memory (P = .002), who tended to report improvements in ability to accomplish near activities. Of older adults receiving LVR for macular disease, those with memory deficits experienced worse functional trajectories in their ability to perform specific visually mediated tasks. A brief memory screen may help explain variability in rehabilitation outcomes and identify individuals who might require special accommodations. © 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.

Latent trajectories of internalizing symptoms from preschool to school age: A multi-informant study in a high-risk sample.

Science.gov (United States)

Klein, Annette M; Schlesier-Michel, Andrea; Otto, Yvonne; White, Lars O; Andreas, Anna; Sierau, Susan; Bergmann, Sarah; Perren, Sonja; von Klitzing, Kai

2018-04-29

Recent proposals suggest early adversity sets in motion particularly chronic and neurobiologically distinct trajectories of internalizing symptoms. However, few prospective studies in high-risk samples delineate distinct trajectories of internalizing symptoms from preschool age onward. We examined trajectories in a high-risk cohort, oversampled for internalizing symptoms, several preschool risk/maintenance factors, and school-age outcomes. Parents of 325 children completed the Strengths and Difficulties Questionnaire on up to four waves of data collection from preschool (3-5 years) to school age (8-9 years) and Preschool Age Psychiatric Assessment interviews at both ages. Multi-informant data were collected on risk factors and symptoms. Growth mixture modelling identified four trajectory classes of internalizing symptoms with stable low, rising low-to-moderate, stable moderate, and stable high symptoms. Children in the stable high symptom trajectory manifested clinically relevant internalizing symptoms, mainly diagnosed with anxiety disorders/depression at preschool and school age. Trajectories differed regarding loss/separation experience, maltreatment, maternal psychopathology, temperament, and stress-hormone regulation with loss/separation, temperament, maternal psychopathology, and stress-hormone regulation (trend) significantly contributing to explained variance. At school age, trajectories continued to differ on symptoms, disorders, and impairment. Our study is among the first to show that severe early adversity may trigger a chronic and neurobiologically distinct internalizing trajectory from preschool age onward.

Trajectories of higher- and lower-order dimensions of negative and positive affect relative to restrictive eating in anorexia nervosa.

Science.gov (United States)

Haynos, Ann F; Berg, Kelly C; Cao, Li; Crosby, Ross D; Lavender, Jason M; Utzinger, Linsey M; Wonderlich, Stephen A; Engel, Scott G; Mitchell, James E; Le Grange, Daniel; Peterson, Carol B; Crow, Scott J

2017-07-01

Despite robust support for the role of affect in the maintenance of binge eating and purging, the relationship between affect and restrictive eating remains poorly understood. To investigate the relationship between restrictive eating and affect, ecological momentary assessment data from 118 women with anorexia nervosa (AN) were used to examine trajectories of higher-order dimensions of negative affect (NA) and positive affect (PA), as well as lower-order dimensions of NA (Fear, Guilt) and PA (Joviality, Self-Assurance) relative to restrictive eating. Affect trajectories were modeled before and after restrictive eating episodes and AN subtype was examined as a moderator of these trajectories. Across the sample, Guilt significantly increased before and decreased after restrictive eating episodes. Global NA, Global PA, Fear, Joviality, and Self-Assurance did not vary relative to restrictive eating episodes across the sample. However, significant subtype by trajectory interactions were detected for PA indices. Among individuals with AN restricting subtype, Global PA, Joviality, and Self-Assurance decreased prior to and Self-Assurance increased following restrictive eating episodes. In contrast, Global PA and Self-Assurance increased prior to, but did not change following, restrictive eating episodes among individuals with AN binge eating/purging subtype. Results suggest that dietary restriction may function to mitigate guilt across AN subtypes and to enhance self-assurance among individuals with AN restricting subtype. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Predictors of PTSD Treatment Response Trajectories in a Sample of Childhood Sexual Abuse Survivors: The Roles of Social Support, Coping, and PTSD Symptom Clusters.

Science.gov (United States)

Fletcher, Shelley; Elklit, Ask; Shevlin, Mark; Armour, Cherie

2017-11-01

This study aimed to (a) identify posttraumatic stress disorder (PTSD) trajectories in a sample of Danish treatment-seeking childhood sexual abuse (CSA) survivors and (b) examine the roles of social support, coping style, and individual PTSD symptom clusters (avoidance, reexperiencing, and hyperarousal) as predictors of the identified trajectories. We utilized a convenience sample of 439 CSA survivors attending personalized psychotherapy treatment in Denmark. Four assessments were conducted on a six monthly basis over a period of 18 months. We used latent class growth analysis (LCGA) to test solutions with one to six classes. Following this, a logistic regression was conducted to examine predictors of the identified trajectories. Results revealed four distinct trajectories which were labeled high PTSD gradual response, high PTSD treatment resistant, moderate PTSD rapid response, and moderate PTSD gradual response. Emotional and detached coping and more severe pretreatment avoidance and reexperiencing symptoms were associated with more severe and treatment resistant PTSD. High social support and a longer length of time since the abuse were associated with less severe PTSD which improved over time. The findings suggested that treatment response of PTSD in CSA survivors is characterized by distinct patterns with varying levels and rates of PTSD symptom improvement. Results revealed that social support is protective and that emotional and detached coping and high pretreatment levels of avoidance and reexperiencing symptoms are risk factors in relation to PTSD severity and course. These factors could potentially identify patients who are at risk of not responding to treatment. Furthermore, these factors could be specifically addressed to increase positive outcomes for treatment-seeking CSA survivors.

Trajectories of Mexican American and mainstream cultural values among Mexican American adolescents.

Science.gov (United States)

Knight, George P; Basilio, Camille D; Cham, Heining; Gonzales, Nancy A; Liu, Yu; Umaña-Taylor, Adriana J

2014-12-01

Mexican Americans are one of the largest and fastest growing ethnic groups in the United States, yet we have limited knowledge regarding changes (i.e., developmental trajectories) in cultural orientation based upon their exposure to the Mexican American and mainstream cultures. We examined the parallel trajectories of Mexican American and mainstream cultural values in a sample of 749 Mexican American adolescents (49 % female) across assessments during the fifth grade (approximately 11 years of age), the seventh grade (approximately 13 years of age) and the tenth grade (approximately 16 years of age). We expected that these values would change over this developmental period and this longitudinal approach is more appropriate than the often used median split classification to identify distinct types of acculturation. We found four distinct acculturation trajectory groups: two trajectory groups that were increasing slightly with age in the endorsement of mainstream cultural values, one of which was relatively stable in Mexican American cultural values while the other was declining in their endorsement of these values; and two trajectory groups that were declining substantially with age in their endorsement of mainstream cultural values, one of which was also declining in Mexican American cultural values and the other which was stable in these values. These four trajectory groups differed in expected ways on a number of theoretically related cultural variables, but were not highly consistent with the median split classifications. The findings highlight the need to utilize longitudinal data to examine the developmental changes of Mexican American individual's adaptation to the ethnic and mainstream culture in order to understand more fully the processes of acculturation and enculturation.

Trajectories of cortical surface area and cortical volume maturation in normal brain development

Directory of Open Access Journals (Sweden)

Simon Ducharme

2015-12-01

Full Text Available This is a report of developmental trajectories of cortical surface area and cortical volume in the NIH MRI Study of Normal Brain Development. The quality-controlled sample included 384 individual typically-developing subjects with repeated scanning (1–3 per subject, total scans n=753 from 4.9 to 22.3 years of age. The best-fit model (cubic, quadratic, or first-order linear was identified at each vertex using mixed-effects models, with statistical correction for multiple comparisons using random field theory. Analyses were performed with and without controlling for total brain volume. These data are provided for reference and comparison with other databases. Further discussion and interpretation on cortical developmental trajectories can be found in the associated Ducharme et al.׳s article “Trajectories of cortical thickness maturation in normal brain development – the importance of quality control procedures” (Ducharme et al., 2015 [1].

Gyrotactic suppression and emergence of chaotic trajectories of swimming particles in three-dimensional flows

Science.gov (United States)

Richardson, S. I. Heath; Baggaley, A. W.; Hill, N. A.

2018-02-01

We study the effects of imposed three-dimensional flows on the trajectories and mixing of gyrotactic swimming microorganisms and identify phenomena not seen in flows restricted to two dimensions. Through numerical simulation of Taylor-Green and Arnold-Beltrami-Childress (ABC) flows, we explore the role that the flow and the cell shape play in determining the long-term configuration of the cells' trajectories, which often take the form of multiple sinuous and helical "plumelike" structures, even in the chaotic ABC flow. This gyrotactic suppression of Lagrangian chaos persists even in the presence of random noise. Analytical solutions for a number of cases reveal the how plumes form and the nature of the competition between torques acting on individual cells. Furthermore, studies of Lyapunov exponents reveal that, as the ratio of cell swimming speed relative to the flow speed increases from zero, the initial chaotic trajectories are first suppressed and then give way to a second unexpected window of chaotic trajectories at speeds greater than unity, before suppression of chaos at high relative swimming speeds.

Complex trajectories in a classical periodic potential

International Nuclear Information System (INIS)

Anderson, Alexander G; Bender, Carl M

2012-01-01

This paper examines the complex trajectories of a classical particle in the potential V(x) = −cos (x). Almost all the trajectories describe a particle that hops from one well to another in an erratic fashion. However, it is shown analytically that there are two special classes of trajectories x(t) determined only by the energy of the particle and not by the initial position of the particle. The first class consists of periodic trajectories; that is, trajectories that return to their initial position x(0) after some real time T. The second class consists of trajectories for which there exists a real time T such that x(t + T) = x(t) ± 2π. These two classes of classical trajectories are analogous to valence and conduction bands in quantum mechanics, where the quantum particle either remains localized or else tunnels resonantly (conducts) through a crystal lattice. These two special types of trajectories are associated with sets of energies of measure 0. For other energies, it is shown that for long times the average velocity of the particle becomes a fractal-like function of energy. (paper)

Complex trajectories in a classical periodic potential

Science.gov (United States)

Anderson, Alexander G.; Bender, Carl M.

2012-11-01

This paper examines the complex trajectories of a classical particle in the potential V(x) = -cos (x). Almost all the trajectories describe a particle that hops from one well to another in an erratic fashion. However, it is shown analytically that there are two special classes of trajectories x(t) determined only by the energy of the particle and not by the initial position of the particle. The first class consists of periodic trajectories; that is, trajectories that return to their initial position x(0) after some real time T. The second class consists of trajectories for which there exists a real time T such that x(t + T) = x(t) ± 2π. These two classes of classical trajectories are analogous to valence and conduction bands in quantum mechanics, where the quantum particle either remains localized or else tunnels resonantly (conducts) through a crystal lattice. These two special types of trajectories are associated with sets of energies of measure 0. For other energies, it is shown that for long times the average velocity of the particle becomes a fractal-like function of energy.

Kinematic evaluation of virtual walking trajectories.

Science.gov (United States)

Cirio, Gabriel; Olivier, Anne-Hélène; Marchal, Maud; Pettré, Julien

2013-04-01

Virtual walking, a fundamental task in Virtual Reality (VR), is greatly influenced by the locomotion interface being used, by the specificities of input and output devices, and by the way the virtual environment is represented. No matter how virtual walking is controlled, the generation of realistic virtual trajectories is absolutely required for some applications, especially those dedicated to the study of walking behaviors in VR, navigation through virtual places for architecture, rehabilitation and training. Previous studies focused on evaluating the realism of locomotion trajectories have mostly considered the result of the locomotion task (efficiency, accuracy) and its subjective perception (presence, cybersickness). Few focused on the locomotion trajectory itself, but in situation of geometrically constrained task. In this paper, we study the realism of unconstrained trajectories produced during virtual walking by addressing the following question: did the user reach his destination by virtually walking along a trajectory he would have followed in similar real conditions? To this end, we propose a comprehensive evaluation framework consisting on a set of trajectographical criteria and a locomotion model to generate reference trajectories. We consider a simple locomotion task where users walk between two oriented points in space. The travel path is analyzed both geometrically and temporally in comparison to simulated reference trajectories. In addition, we demonstrate the framework over a user study which considered an initial set of common and frequent virtual walking conditions, namely different input devices, output display devices, control laws, and visualization modalities. The study provides insight into the relative contributions of each condition to the overall realism of the resulting virtual trajectories.

A diffusion-based approach to stochastic individual growth and energy budget, with consequences to life-history optimization and population dynamics.

Science.gov (United States)

Filin, I

2009-06-01

Using diffusion processes, I model stochastic individual growth, given exogenous hazards and starvation risk. By maximizing survival to final size, optimal life histories (e.g. switching size for habitat/dietary shift) are determined by two ratios: mean growth rate over growth variance (diffusion coefficient) and mortality rate over mean growth rate; all are size dependent. For example, switching size decreases with either ratio, if both are positive. I provide examples and compare with previous work on risk-sensitive foraging and the energy-predation trade-off. I then decompose individual size into reversibly and irreversibly growing components, e.g. reserves and structure. I provide a general expression for optimal structural growth, when reserves grow stochastically. I conclude that increased growth variance of reserves delays structural growth (raises threshold size for its commencement) but may eventually lead to larger structures. The effect depends on whether the structural trait is related to foraging or defence. Implications for population dynamics are discussed.

Longitudinal Trajectory of Exposure to Psychological Interpersonal Violence.

Science.gov (United States)

Poehacker, Stefanie; Phillips, David; Riggs, Jessica; Lauterbach, Dean

2017-05-01

Psychological intimate partner violence (P-IPV) refers to verbal abuse from one partner to another and abuse of power or control from one partner to another. To date, no studies have examined the longitudinal course of P-IPV exposure among mothers or the effect that witnessing P-IPV can have on their children. Using latent class growth analysis, the current study identified five trajectory groups with the following intercept and growth characteristics: low stable, low-increasing, moderate-decreasing, high-decreasing, and consistently elevated. Membership in the four groups characterized by higher P-IPV exposure was predicted by maternal race and exposure to physical abuse. The children of mothers in the low-increasing and consistently elevated groups had elevated scores on the Internalizing and Externalizing scales of the Childhood Behavior Checklist. These findings remained after controlling for child sex, race, cumulative trauma exposure, and maternal depression.

Task Decomposition Module For Telerobot Trajectory Generation

Science.gov (United States)

Wavering, Albert J.; Lumia, Ron

1988-10-01

A major consideration in the design of trajectory generation software for a Flight Telerobotic Servicer (FTS) is that the FTS will be called upon to perform tasks which require a diverse range of manipulator behaviors and capabilities. In a hierarchical control system where tasks are decomposed into simpler and simpler subtasks, the task decomposition module which performs trajectory planning and execution should therefore be able to accommodate a wide range of algorithms. In some cases, it will be desirable to plan a trajectory for an entire motion before manipulator motion commences, as when optimizing over the entire trajectory. Many FTS motions, however, will be highly sensory-interactive, such as moving to attain a desired position relative to a non-stationary object whose position is periodically updated by a vision system. In this case, the time-varying nature of the trajectory may be handled either by frequent replanning using updated sensor information, or by using an algorithm which creates a less specific state-dependent plan that determines the manipulator path as the trajectory is executed (rather than a priori). This paper discusses a number of trajectory generation techniques from these categories and how they may be implemented in a task decompo-sition module of a hierarchical control system. The structure, function, and interfaces of the proposed trajectory gener-ation module are briefly described, followed by several examples of how different algorithms may be performed by the module. The proposed task decomposition module provides a logical structure for trajectory planning and execution, and supports a large number of published trajectory generation techniques.

Computer programmes for high current ion trajectories in a magnetic sector-type mass separator

International Nuclear Information System (INIS)

Nakai, Akira

1988-01-01

According to theoretical calculations previously proposed by the author, a new programme 'MALT' for electronic computers has been developed for numerical calculations of ion trajectories of a high current ion beam traversing a magnetic sector-type mass separator. In the programme, both effects of the fringing field and the space charge are taken into account in an analytical way, so that numerical calculations can be done straightforwardly. Furthermore, it becomes also possible to analyze and cotrol the trajectories of the high current ion beam. The programme MALT contains several subroutine programmes which are separated individually for the convenience of various calculations with respect to the high current ion beam. To demonstrate the calculations by the use of these subroutine programmes, a main programme for the calculation of the trajectories in the whole region of the separator is shown, which also makes it possible to draw the traces of the trajectories. The trajectories calculated by the proposed programme have been compared with the images of the ion beams recorded on novel dry plates developed by the author: the comparison enables us to evaluate the effective space charge and the effective space charge potential, and to analyze the behaviour of the beam of neutral particles accompanying the ion beam. (author)

Parallel trajectory similarity joins in spatial networks

KAUST Repository

Shang, Shuo

2018-04-04

The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider two cases of trajectory similarity joins (TS-Joins), including a threshold-based join (Tb-TS-Join) and a top-k TS-Join (k-TS-Join), where the objects are trajectories of vehicles moving in road networks. Given two sets of trajectories and a threshold θ, the Tb-TS-Join returns all pairs of trajectories from the two sets with similarity above θ. In contrast, the k-TS-Join does not take a threshold as a parameter, and it returns the top-k most similar trajectory pairs from the two sets. The TS-Joins target diverse applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide purposeful definitions of similarity. To enable efficient processing of the TS-Joins on large sets of trajectories, we develop search space pruning techniques and enable use of the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer search framework that lays the foundation for the algorithms for the Tb-TS-Join and the k-TS-Join that rely on different pruning techniques to achieve efficiency. For each trajectory, the algorithms first find similar trajectories. Then they merge the results to obtain the final result. The algorithms for the two joins exploit different upper and lower bounds on the spatiotemporal trajectory similarity and different heuristic scheduling strategies for search space pruning. Their per-trajectory searches are independent of each other and can be performed in parallel, and the mergings have constant cost. An empirical study with real data offers insight in the performance of the algorithms and demonstrates that they are capable of outperforming well-designed baseline algorithms by an order of magnitude.

Parallel trajectory similarity joins in spatial networks

KAUST Repository

Shang, Shuo; Chen, Lisi; Wei, Zhewei; Jensen, Christian S.; Zheng, Kai; Kalnis, Panos

2018-01-01

The matching of similar pairs of objects, called similarity join, is fundamental functionality in data management. We consider two cases of trajectory similarity joins (TS-Joins), including a threshold-based join (Tb-TS-Join) and a top-k TS-Join (k-TS-Join), where the objects are trajectories of vehicles moving in road networks. Given two sets of trajectories and a threshold θ, the Tb-TS-Join returns all pairs of trajectories from the two sets with similarity above θ. In contrast, the k-TS-Join does not take a threshold as a parameter, and it returns the top-k most similar trajectory pairs from the two sets. The TS-Joins target diverse applications such as trajectory near-duplicate detection, data cleaning, ridesharing recommendation, and traffic congestion prediction. With these applications in mind, we provide purposeful definitions of similarity. To enable efficient processing of the TS-Joins on large sets of trajectories, we develop search space pruning techniques and enable use of the parallel processing capabilities of modern processors. Specifically, we present a two-phase divide-and-conquer search framework that lays the foundation for the algorithms for the Tb-TS-Join and the k-TS-Join that rely on different pruning techniques to achieve efficiency. For each trajectory, the algorithms first find similar trajectories. Then they merge the results to obtain the final result. The algorithms for the two joins exploit different upper and lower bounds on the spatiotemporal trajectory similarity and different heuristic scheduling strategies for search space pruning. Their per-trajectory searches are independent of each other and can be performed in parallel, and the mergings have constant cost. An empirical study with real data offers insight in the performance of the algorithms and demonstrates that they are capable of outperforming well-designed baseline algorithms by an order of magnitude.

The power of a single trajectory

Science.gov (United States)

Schnellbächer, Nikolas D.; Schwarz, Ulrich S.

2018-03-01

Random walks are often evaluated in terms of their mean squared displacements, either for a large number of trajectories or for one very long trajectory. An alternative evaluation is based on the power spectral density, but here it is less clear which information can be extracted from a single trajectory. For continuous-time Brownian motion, Krapf et al now have mathematically proven that the one property that can be reliably extracted from a single trajectory is the frequency dependence of the ensemble-averaged power spectral density (Krapf et al 2018 New J. Phys. 20 023029). Their mathematical analysis also identifies the appropriate frequency window for this procedure and shows that the diffusion coefficient can be extracted by averaging over a small number of trajectories. The authors have verified their analytical results both by computer simulations and experiments.

Trajectories of maternal weight from before pregnancy through postpartum and associations with childhood obesity.

Science.gov (United States)

Leonard, Stephanie A; Rasmussen, Kathleen M; King, Janet C; Abrams, Barbara

2017-11-01

Background: Prepregnancy body mass index [BMI (in kg/m 2 )], gestational weight gain, and postpartum weight retention may have distinct effects on the development of child obesity, but their combined effect is currently unknown. Objective: We described longitudinal trajectories of maternal weight from before pregnancy through the postpartum period and assessed the relations between maternal weight trajectories and offspring obesity in childhood. Design: We analyzed data from 4436 pairs of mothers and their children in the National Longitudinal Survey of Youth 1979 (1981-2014). We used latent-class growth modeling in addition to national recommendations for prepregnancy BMI, gestational weight gain, and postpartum weight retention to create maternal weight trajectory groups. We used modified Poisson regression models to assess the associations between maternal weight trajectory group and offspring obesity at 3 age periods (2-5, 6-11, and 12-19 y). Results: Our analysis using maternal weight trajectories based on either latent-class results or recommendations showed that the risk of child obesity was lowest in the lowest maternal weight trajectory group. The differences in obesity risk were largest after 5 y of age and persisted into adolescence. In the latent-class analysis, the highest-order maternal weight trajectory group consisted almost entirely of women who were obese before pregnancy and was associated with a >2-fold increase in the risk of offspring obesity at ages 6-11 y (adjusted RR: 2.39; 95% CI: 1.97, 2.89) and 12-19 y (adjusted RR: 2.74; 95% CI: 2.13, 3.52). In the analysis with maternal weight trajectory groups based on recommendations, the risk of child obesity was consistently highest for women who were overweight or obese at the beginning of pregnancy. Conclusion: These findings suggest that high maternal weight across the childbearing period increases the risk of obesity in offspring during childhood, but high prepregnancy BMI has a stronger

Longitudinal Estimated GFR Trajectories in Patients With and Without Type 2 Diabetes and Nephropathy

DEFF Research Database (Denmark)

Weldegiorgis, Misghina; de Zeeuw, Dick; Li, Liang

2017-01-01

-renin-angiotensin-aldosterone-system antihypertensives were independently associated with a greater probability of a nonlinear eGFR trajectory. LIMITATIONS: Relatively short follow-up and no measured GFR. CONCLUSIONS: In both diabetes and nondiabetes trials, the majority of patients show a more or less linear eGFR decline. These data support...... with and without diabetes. STUDY DESIGN: Longitudinal observational study. SETTING & PARTICIPANTS: 6 clinical trials with repeated measurements of serum creatinine. PREDICTOR: Patient demographic and clinical parameters. OUTCOMES: Probability of nonlinear eGFR function trajectory calculated for each patient from...... a Bayesian model of individual eGFR trajectories. RESULTS: The median probability of a nonlinear eGFR decline in all trials was 0.26 (interquartile range, 0.13-0.48). The median probability was 0.28 in diabetes versus 0.09 in nondiabetes trials (P50% probability...

Toddler hand preference trajectories predict 3-year language outcome.

Science.gov (United States)

Nelson, Eliza L; Gonzalez, Sandy L; Coxe, Stefany; Campbell, Julie M; Marcinowski, Emily C; Michel, George F

2017-11-01

A growing body of work suggests that early motor experience affects development in unexpected domains. In the current study, children's hand preference for role-differentiated bimanual manipulation (RDBM) was measured at monthly intervals from 18 to 24 months of age (N = 90). At 3 years of age, children's language ability was assessed using the Preschool Language Scales 5th edition (PLS™-5). Three distinct RDBM hand preference trajectories were identified using latent class growth analysis: (1) children with a left hand preference but a moderate amount of right hand use; (2) children with a right hand preference but a moderate amount of left hand use; and (3) children with a right hand preference and only a mild amount of left hand use. Stability over time within all three trajectories indicated that children did not change hand use patterns from 18 to 24 months. Children with the greatest amount of preferred (i.e., right) hand use demonstrated higher expressive language scores compared to children in both trajectories with moderate levels of non-preferred hand use. Children with the greatest amount of right hand use also had higher scores for receptive language compared to children with a right hand preference but moderate left hand use. Results support that consistency in handedness as measured by the amount of preferred hand use is related to distal language outcomes in development. © 2017 Wiley Periodicals, Inc.

Developmental trajectories of anxious and depressive problems during the transition from childhood to adolescence: personality × parenting interactions.

Science.gov (United States)

Prinzie, Peter; van Harten, Leanthe V; Deković, Maja; van den Akker, Alithe L; Shiner, Rebecca L

2014-11-01

This study examined separate developmental trajectories of anxious and depressive symptoms from childhood to adolescence (9-15 years) in a community-based sample (N = 290). At three measurement points, mothers and fathers reported on their children's anxious and depressive symptoms, and at Time 1 they reported on lower order child personality facets and on their parenting. By means of growth mixture modeling, three developmental trajectories were identified for anxious symptoms: steady low (82%), moderate increasing-decreasing (5.9%), and high declining groups (12.1%). For depressive symptoms, two developmental trajectories were found: steady low (94.1%) and moderate increasing groups (5.9%). Higher shyness, irritability, and altruism predicted membership in more problematic anxious and depressive groups. The personality facets energy, optimism, compliance, and anxiety were unique predictors for class membership for anxious symptoms, and the effects of shyness, irritability, and compliance were moderated by overreactive parenting. Shyness and irritability increased the probability of following the moderate increasing-decreasing anxiety trajectory, but only in the context of high or average levels of overreactive parenting. Compliance increased the probability of following the moderate increasing-decreasing and high decreasing trajectories in the context of high overreactive parenting. Our results indicate that childhood personality facets differentiate trajectories of anxious and depressive symptoms in theoretically compelling ways.

Individual Differences in Trajectories of Emotion Regulation Processes: The Effects of Maternal Depressive Symptomatology and Children's Physiological Regulation

Science.gov (United States)

Blandon, Alysia Y.; Calkins, Susan D.; Keane, Susan P.; O'Brien, Marion

2008-01-01

Trajectories of emotion regulation processes were examined in a community sample of 269 children across the ages of 4 to 7 using hierarchical linear modeling. Maternal depressive symptomatology (Symptom Checklist-90) and children's physiological reactivity (respiratory sinus arrhythmia [RSA]) and vagal regulation ([delta]RSA) were explored as…

Identification of distinct fatigue trajectories in patients with breast cancer undergoing adjuvant chemotherapy.

Science.gov (United States)

Junghaenel, Doerte U; Cohen, Jules; Schneider, Stefan; Neerukonda, Anu R; Broderick, Joan E

2015-09-01

The goal of this study was to characterize changes in daily fatigue in women undergoing chemotherapy for breast cancer. We examined whether there are subgroups of patients with distinct fatigue trajectories and explored potential psychosocial and biomedical predictors of these subgroups. Participants were 77 women with breast cancer receiving adjuvant chemotherapy with AC-T (2-week cycle) and TC or TCH (3-week cycle) regimens. They completed 28 daily ratings online using an adapted version of the Patient-Reported Outcomes Measurement Information System (PROMIS®) fatigue instrument. Both regimens followed an "inverted-U-shaped" fatigue pattern over approximately 2 weeks. Growth mixture modeling identified three patient subgroups with distinct trajectories. Fatigue scores in the "low fatigue" group (23 %) increased following the infusion and quickly abated. The "transient fatigue" (27 %) group had a very pronounced increase. Patients in the "high fatigue" (50 %) group reported consistently elevated fatigue with a relatively small increase. Demographic and medical variables were not associated with fatigue trajectory. Patients in the "high fatigue" group reported significantly poorer physical, emotional, and social functioning, poorer general health, and more depressed mood than patients in the "low fatigue" group. The "transient fatigue" group reported significantly better physical and social functioning than the "high fatigue" group, but emotional distress and depression similar to the "high fatigue" group. The identification of patient subgroups with distinct fatigue trajectories during chemotherapy is an essential step for developing preventative strategies and tailored interventions. Our results suggest that different trajectories are associated with patients' psychosocial and general health.

Social adversity in pregnancy and trajectories of women's depressive symptoms: A longitudinal study.

Science.gov (United States)

Kingsbury, Ann M; Plotnikova, Maria; Clavarino, Alexandra; Mamun, Abullah; Najman, Jake M

2018-02-01

Sound evidence has linked the experience of adversity with depression. Less is known about this association over time. The aim of this study is to determine whether or not social adversity experienced by pregnant women is associated with their patterns of depressive symptoms over their reproductive life course. Data were obtained from a cohort of women collected at their first obstetrical clinic visit of an index pregnancy (time-point 1) and at a further six time-points to 27 years following the birth. Latent Class Growth Modelling was used to estimate trajectories of women's depressive symptoms over this time period. Logistic regression modelling determined the prospective association between measures of adversity in pregnancy and 27-year postpartum depression trajectories, controlling for potential confounders. Experiencing financial problems, housing problems, serious disagreements with partners and with others, and experiencing serious health problems in pregnancy were associated with membership of high and middle depression trajectories over the 27 years. Having someone close die or have a serious illness was associated with the high depression trajectory only. Younger maternal age and low family-income at first clinic visit were also associated with an increased risk of women's membership of both high and middle depression trajectories. Experiencing adversity during pregnancy predicts subsequent patterns of maternal depression over an extended period of women's reproductive life course. It is not clear whether women's experiences of adversity during pregnancy were causally associated with subsequent depression or whether there are other explanations of the observed association. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Aircraft 4D trajectories planning under uncertainties

OpenAIRE

Chaimatanan , Supatcha; Delahaye , Daniel; Mongeau , Marcel

2015-01-01

International audience; To sustain the rapidly increasing air traffic demand, the future air traffic management system will rely on a concept, called Trajectory-Based Operations (TBO), that will require aircraft to follow an assigned 4D trajectory (time-constrained trajectory) with high precision. TBO involves separating aircraft via strategic (long-term) trajectory deconfliction rather than the currently-practicing tactical (short-term) conflict resolution. In this context, this paper presen...

Association of 10-year C-reactive protein trajectories with markers of healthy aging: findings from the English Longitudinal Study of Ageing.

Science.gov (United States)

Lassale, Camille; Batty, G David; Steptoe, Andrew; Cadar, Dorina; Akbaraly, Tasnime N; Kivimäki, Mika; Zaninotto, Paola

2018-02-15

Elevated systematic inflammation is a hallmark of aging, but the association of long-term inflammation trajectories with subsequent aging phenotypes has been little examined. We assessed inflammatory marker C-reactive protein (CRP) repeatedly over time and examined whether long-term changes predicted aging outcomes. A total of 2,437 men and women aged 47-87 years at baseline (1998-2001) who were participants in the English Longitudinal Study of Ageing had CRP measured on two or three occasions between 1998 and 2009. Inflammation trajectories were computed using latent-class growth mixture modelling and were related to aging outcomes measured in 2012/2013: physical functioning, cardiometabolic, respiratory, mental health, and a composite "healthy aging" outcome. Four CRP trajectories were identified: 'stable-low' (71% of the sample) with baseline mean 1.33mg/L remaining <3mg/L; 'medium-to-high' (14%) with baseline 2.7mg/L rising to 5.3mg/L; 'high-to-medium' (10%) with baseline 6.6mg/L decreasing to 2.4mg/L; 'stable-high' (5%) with levels from 5.7 to 7.5mg/L. Relative to the stable-low trajectory, individuals in the medium-to-high had a higher risk of limitations in basic activities of daily living (ADL, Odds Ratio; 95% Confidence Interval: 2.09; 1.51,2.88), instrumental ADL (1.62; 1.15,2.30), impaired balance (1.59; 1.20,2.11) and walking speed (1.61; 1.15,2.24), arthritis (1.55; 1.16,2.06), hypertension (1.57; 1.21,2.04), obesity (1.95; 1.36,2.80), poor respiratory function (1.84; 1.36,2.50), and depression (1.55; 1.13,2.12). A lower odds of healthy aging was observed in people in the medium-to-high (0.57; 0.40,0.79) and stable-high (0.50; 0.27,0.91) trajectories. Older people who displayed an elevation in CRP levels over a decade experienced an increased risk of adverse aging outcomes.

Developmental trajectories of irritability and bidirectional associations with maternal depression.

Science.gov (United States)

Wiggins, Jillian Lee; Mitchell, Colter; Stringaris, Argyris; Leibenluft, Ellen

2014-11-01

Irritability is a dimensional trait in typical development and a common presenting symptom in many psychiatric disorders, including depression. However, little is known about the developmental trajectory of irritability or how child irritability interacts with maternal depression. The present study identifies classes of irritability trajectories from toddlerhood to middle childhood; characterizes maternal depression and other family, social environment, and child variables within each irritability trajectory class; and, as a more exploratory analysis, examines bidirectional associations between maternal depression and child irritability. A total of 4,898 families from the Fragile Families and Child Wellbeing Study reported on irritability symptoms at ages 3, 5, and 9 years, assessed with items from the Child Behavior Checklist. Parental major depressive episode was assessed using the Composite International Diagnostic Interview-Short Form at child ages 1, 3, 5, and 9 years. A latent class growth analysis identified 5 irritability classes: low decreasing; moderate decreasing; high steady; initially very high, then decreasing; and high increasing. Children with more severe irritability trajectories are more likely to have mothers with recurrent depression, and, with the exception of the most severe (high increasing irritability) class, were more likely to have mothers who were exposed to violence. Moreover, paternal depression and alcohol abuse, as well as maternal drug and alcohol abuse, were also risk factors for membership in the more severe irritability classes. A latent auto-regressive cross-lag model showed that child irritability at ages 3 and 5 years is associated with increased mother depression at ages 5 and 9, respectively. Conversely, mother depression at child ages 1 and 3 years is associated with increased child irritability at 3 and 5. Irritability development across toddlerhood and middle childhood has 5 main trajectory types, which differ on maternal

Dynamic trajectory-based couch motion for improvement of radiation therapy trajectories in cranial SRT

Energy Technology Data Exchange (ETDEWEB)

MacDonald, R. Lee [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Thomas, Christopher G., E-mail: Chris.Thomas@cdha.nshealth.ca [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Medical Physics, Nova Scotia Cancer Centre, Queen Elizabeth II Health Sciences Centre, Halifax, Nova Scotia B3H 1V7 (Canada); Department of Radiation Oncology, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Department of Radiology, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada)

2015-05-15

Purpose: To investigate potential improvement in external beam stereotactic radiation therapy plan quality for cranial cases using an optimized dynamic gantry and patient support couch motion trajectory, which could minimize exposure to sensitive healthy tissue. Methods: Anonymized patient anatomy and treatment plans of cranial cancer patients were used to quantify the geometric overlap between planning target volumes and organs-at-risk (OARs) based on their two-dimensional projection from source to a plane at isocenter as a function of gantry and couch angle. Published dose constraints were then used as weighting factors for the OARs to generate a map of couch-gantry coordinate space, indicating degree of overlap at each point in space. A couch-gantry collision space was generated by direct measurement on a linear accelerator and couch using an anthropomorphic solid-water phantom. A dynamic, fully customizable algorithm was written to generate a navigable ideal trajectory for the patient specific couch-gantry space. The advanced algorithm can be used to balance the implementation of absolute minimum values of overlap with the clinical practicality of large-scale couch motion and delivery time. Optimized cranial cancer treatment trajectories were compared to conventional treatment trajectories. Results: Comparison of optimized treatment trajectories with conventional treatment trajectories indicated an average decrease in mean dose to the OARs of 19% and an average decrease in maximum dose to the OARs of 12%. Degradation was seen for homogeneity index (6.14% ± 0.67%–5.48% ± 0.76%) and conformation number (0.82 ± 0.02–0.79 ± 0.02), but neither was statistically significant. Removal of OAR constraints from volumetric modulated arc therapy optimization reveals that reduction in dose to OARs is almost exclusively due to the optimized trajectory and not the OAR constraints. Conclusions: The authors’ study indicated that simultaneous couch and gantry motion