Identifying longitudinal trajectories of emotional distress symptoms 5 years after traumatic brain injury.

PubMed

Sigurdardottir, S; Andelic, N; Roe, C; Schanke, A K

2014-01-01

To evaluate longitudinal trajectories of emotional distress symptoms after traumatic brain injury (TBI). Longitudinal study. Patients with mild-to-severe TBI, 118 patients participated at 3 months, 109 attended at 1-year and 89 attended the 5-year follow-up. Emotional distress was measured with the Impact of Event Scale-Revised. Patients were also assessed for coping style, anxiety, depression, substance abuse and trauma severity. Based on growth mixture modelling, four trajectories of emotional distress symptoms were identified: 73.5% of patients were characterized by a pattern of resilience, 6.8% by a pattern of delayed distress, 14.6% by recovery and 5.1% by chronic distress. Relative to the resilience trajectory, avoidant-coping style and psychiatric problems were related to recovery and chronic trajectories. The delayed trajectory was similar to the resilience trajectory, except for elevated depressive and anxiety symptoms at 1- and 5-years. Demographics and injury-related variables were not significantly associated with emotional distress trajectories. Resilience was the most common trajectory following TBI. Patients characterized by recovery and chronic trajectories required attention and long-term clinical monitoring of their symptoms. Future research would benefit from longitudinal studies to analyse emotional distress symptoms and the strength of resilience over time.

Predictors and Trajectories of Morning Fatigue Are Distinct from Evening Fatigue

PubMed Central

Wright, Fay; Melkus, Gail D’Eramo; Hammer, Marilyn; Schmidt, Brian L.; Knobf, M. Tish; Paul, Steven M.; Cartwright, Frances; Mastick, Judy; Cooper, Bruce A.; Chen, Lee-May; Melisko, Michelle; Levine, Jon D.; Kober, Kord; Aouizerat, Bradley E.; Miaskowski, Christine

2015-01-01

Context Fatigue is the most common symptom in oncology patients during chemotherapy (CTX). Little is known about the predictors of interindividual variability in initial levels and trajectories of morning fatigue severity in these patients. Objectives An evaluation was done to determine which demographic, clinical, and symptom characteristics were associated with initial levels as well as the trajectories of morning fatigue and to compare findings with our companion paper on evening fatigue. Methods A sample of outpatients with breast, gastrointestinal, gynecological, and lung cancer (N=586) completed demographic and symptom questionnaires a total of six times over two cycles of CTX. Fatigue severity was evaluated using the Lee Fatigue Scale. Hierarchical linear modeling (HLM) was used to answer the study objectives. Results A large amount of interindividual variability was found in the morning fatigue trajectories. A piecewise model fit the data best. Patients with higher body mass index (BMI), who did not exercise regularly, with a lower functional status, and who had higher levels of state anxiety, sleep disturbance and depressive symptoms, reported higher levels of morning fatigue at enrollment. Variations in the trajectories of morning fatigue were predicted by the patients’ ethnicity and younger age. Conclusion The modifiable risk factors that were associated with only morning fatigue were BMI, exercise, and state anxiety. Modifiable risk factors that were associated with both morning and evening fatigue included functional status, depressive symptoms, and sleep disturbance. Using this information, clinicians can identify patients at higher risk for more severe morning fatigue and evening fatigue, provide individualized patient education, and tailor interventions to address the modifiable risk factors. PMID:25828559

Distinct Trajectories of Cortisol Response to Prolonged Acute Stress Are Linked to Affective Responses and Hippocampal Gray Matter Volume in Healthy Females

PubMed Central

Treadway, Michael T.; Valeri, Linda; Douglas, Samuel

2017-01-01

The development of robust laboratory procedures for acute stress induction over the last decades has greatly advanced our understanding of stress responses in humans and their underlying neurobiological mechanisms. Nevertheless, attempts to uncover linear relationships among endocrine, neural, and affective responses to stress have generally yielded inconsistent results. Here, 79 healthy females completed a well established laboratory procedure of acute stress induction that was modified to prolong its effect. Endocrinological and subjective affect assessments revealed stress-induced increases in cortisol release and negative affect that persisted 65 and 100 min after stress onset, respectively, confirming a relatively prolonged acute stress induction. Applying latent class linear mixed modeling on individuals' patterns of cortisol responses identified three distinct trajectories of cortisol response: the hyper-response (n = 10), moderate-response (n = 21), and mild-response (n = 48) groups. Notably, whereas all three groups exhibited a significant stress-induced increase in cortisol release and negative affect, the hyper-response and mild-response groups both reported more negative affect relative to the moderate-response group. Structural MRI revealed no group differences in hippocampal and amygdala volumes, yet a continuous measure of cortisol response (area under the curve) showed that high and low levels of stress-induced cortisol release were associated with less hippocampal gray matter volume compared with moderate cortisol release. Together, these results suggest that distinct trajectories of cortisol response to prolonged acute stress among healthy females may not be captured by conventional linear analyses; instead, quadratic relations may better describe links between cortisol response to stress and affective responses, as well as hippocampal structural variability. SIGNIFICANCE STATEMENT Despite substantial research, it is unclear whether and how

Distinct Trajectories of Cortisol Response to Prolonged Acute Stress Are Linked to Affective Responses and Hippocampal Gray Matter Volume in Healthy Females.

PubMed

Admon, Roee; Treadway, Michael T; Valeri, Linda; Mehta, Malavika; Douglas, Samuel; Pizzagalli, Diego A

2017-08-16

The development of robust laboratory procedures for acute stress induction over the last decades has greatly advanced our understanding of stress responses in humans and their underlying neurobiological mechanisms. Nevertheless, attempts to uncover linear relationships among endocrine, neural, and affective responses to stress have generally yielded inconsistent results. Here, 79 healthy females completed a well established laboratory procedure of acute stress induction that was modified to prolong its effect. Endocrinological and subjective affect assessments revealed stress-induced increases in cortisol release and negative affect that persisted 65 and 100 min after stress onset, respectively, confirming a relatively prolonged acute stress induction. Applying latent class linear mixed modeling on individuals' patterns of cortisol responses identified three distinct trajectories of cortisol response: the hyper-response ( n = 10), moderate-response ( n = 21), and mild-response ( n = 48) groups. Notably, whereas all three groups exhibited a significant stress-induced increase in cortisol release and negative affect, the hyper-response and mild-response groups both reported more negative affect relative to the moderate-response group. Structural MRI revealed no group differences in hippocampal and amygdala volumes, yet a continuous measure of cortisol response (area under the curve) showed that high and low levels of stress-induced cortisol release were associated with less hippocampal gray matter volume compared with moderate cortisol release. Together, these results suggest that distinct trajectories of cortisol response to prolonged acute stress among healthy females may not be captured by conventional linear analyses; instead, quadratic relations may better describe links between cortisol response to stress and affective responses, as well as hippocampal structural variability. SIGNIFICANCE STATEMENT Despite substantial research, it is unclear whether and how

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

PubMed

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.

Trajectories of functional limitation in early rheumatoid arthritis and their association with mortality.

PubMed

Norton, Sam; Sacker, Amanda; Dixey, Josh; Done, John; Williams, Peter; Young, Adam

2013-11-01

This study aimed to identify subgroups with distinct trajectories of functional (HAQ) progression over 10 years following diagnosis of RA and identify baseline characteristics associated with the trajectories and their prognostic value for mortality. Between 1986 and 1998, 1460 patients with RA symptoms <2 years and prior to disease-modifying treatment (DMARDs) were recruited to an inception cohort (Early RA Study). Standard clinical, functional and laboratory assessments were performed at presentation and annually. Deaths were tracked by the National Health Service Central Register. Growth mixture modelling was used to identify distinct trajectories of HAQ score progression and survival analysis employed to compare all-cause mortality across the trajectory classes. Four HAQ score progression classes were identified: moderate increasing (46%), low stable (6%), moderate stable (28%) and high stable (20%). Only the moderate-increasing class exhibited an accelerated decline in function over normal ageing. Compared with the moderate-increasing class, individuals with high-stable HAQ scores were more likely to be female, have more severe disease and other coexistent conditions. Low-stable class patients were more likely to be male and report less pain. The high-stable class had increased risk of mortality compared with the moderate-increasing class after adjusting for potential confounding factors, whereas low-stable and moderate-stable classes were at reduced mortality risk. The effect of RA on function is set within the first few years and is affected by comorbidity. Identifying distinct groups of patients may help to target those at greater risk of poor functional outcome and mortality.

Benefit finding trajectories in cancer patients receiving psychological care: Predictors and relations to depressive and anxiety symptoms.

PubMed

Zhu, Lei; Ranchor, Adelita V; Helgeson, Vicki S; van der Lee, Marije; Garssen, Bert; Stewart, Roy E; Sanderman, Robbert; Schroevers, Maya J

2018-05-01

This study aimed to (1) identify benefit finding trajectories in cancer patients receiving psychological care; (2) examine associations of benefit finding trajectories with levels of and changes in psychological symptoms; and (3) examine whether socio-demographic and medical characteristics distinguished trajectories. Naturalistic longitudinal study design. Participants were 241 cancer patients receiving psychological care at specialized psycho-oncological institutions in the Netherlands. Data were collected before starting psychological care, and three and 9 months thereafter. Latent class growth analysis was performed to identify benefit finding trajectories. Five benefit finding trajectories were identified: 'high level-stable' (8%), 'very low level-small increase' (16%), 'low level-small increase' (39%), 'low level-large increase' (9%), and 'moderate level-stable' (28%). People in distinct benefit finding trajectories reported significant differential courses of depression but not of anxiety symptoms. Compared with the other four trajectories, people in the 'low level-large increase' trajectory reported the largest decreases in depression over time. Perceptions of cancer prognosis distinguished these trajectories, such that people with a favourable prognosis were more likely to belong to the 'high level-stable' trajectory, while people perceiving an uncertain prognosis were more likely to belong to the 'low level-large increase' trajectory of benefit finding. Cancer patients showed distinct benefit finding trajectories during psychological care. A small proportion reporting a large increase in benefit finding were also most likely to show decreases in depressive symptoms over time. These findings suggest a relation between perceiving benefits from cancer experience and improved psychological functioning in cancer patients receiving psychological care. Statement of contribution What is already known on this subject? People vary in course of benefit finding

Lifetime Segmented Assimilation Trajectories and Health Outcomes in Latino and Other Community Residents

PubMed Central

Marsiglia, Flavio F.; Kulis, Stephen; Kellison, Joshua G.

2010-01-01

Objectives. Under an ecodevelopmental framework, we examined lifetime segmented assimilation trajectories (diverging assimilation pathways influenced by prior life conditions) and related them to quality-of-life indicators in a diverse sample of 258 men in the Pheonix, AZ, metropolitan area. Methods. We used a growth mixture model analysis of lifetime changes in socioeconomic status, and used acculturation to identify distinct lifetime segmented assimilation trajectory groups, which we compared on life satisfaction, exercise, and dietary behaviors. We hypothesized that lifetime assimilation change toward mainstream American culture (upward assimilation) would be associated with favorable health outcomes, and downward assimilation change with unfavorable health outcomes. Results. A growth mixture model latent class analysis identified 4 distinct assimilation trajectory groups. In partial support of the study hypotheses, the extreme upward assimilation trajectory group (the most successful of the assimilation pathways) exhibited the highest life satisfaction and the lowest frequency of unhealthy food consumption. Conclusions. Upward segmented assimilation is associated in adulthood with certain positive health outcomes. This may be the first study to model upward and downward lifetime segmented assimilation trajectories, and to associate these with life satisfaction, exercise, and dietary behaviors. PMID:20167890

Trajectory Classes of Body Mass Index in a Representative Elderly Community Sample

PubMed Central

2013-01-01

Background. It is unclear whether distinct weight-related trajectory classes, differing in course, demographics, and health characteristics, exist in the elderly population. Methods. Data came from the 10-year (1986–1996) Duke Established Populations for Epidemiologic Studies of the Elderly study of 3,861 black (54%) and white (46%) participants aged 65–105 years. Latent-class trajectories of body mass index (BMI: kg/m2) based on self-reported weight and height at baseline, 3, 6, and 10 years later were determined using generalized mixture models. Polytomous logistic regression was used to identify baseline demographic and health characteristics that distinguished the trajectories, and 10-year postbaseline data to confirm the findings. Results. We identified three trajectories: normal weight (BMI ~24, 27.6% of the sample), overweight (BMI ~26, 65.1%), and obese (BMI ~31, 7.3%). Demographic characteristics distinguished the three trajectories: highest odds of blacks, women, and less education in the obese trajectory, lowest in the normal-weight trajectory. Obese and overweight differed adversely from normal-weight trajectories, but not significantly from each other on cognitive impairment, hypertension, and diabetes. Depressive symptomatology was more prevalent in the obese; they were also younger. There was no association with cancer or heart disease. Conclusion. Distinct trajectories and course of BMI were present in this older population. Weight loss increased with increase in BMI class. Although demographic characteristics distinguished all trajectory classes, adverse health characteristics distinguished the overweight and obese classes from the normal-weight class, but not from each other. Problems associated with education and health are present at study entry and should be addressed earlier in life. PMID:23089335

Trajectories of Developmental Functioning among Children of Adolescent Mothers: Factors Associated with Risk for Delay

ERIC Educational Resources Information Center

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

2016-01-01

Children of adolescent mothers are at risk for developmental delays. Less is known about the heterogeneity in these children's developmental trajectories, and factors associated with different patterns of development. This longitudinal study used latent class growth analysis (LCGA) to identify distinct trajectories in children of Mexican-origin…

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

PubMed

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

Employment Trajectories: Exploring Gender Differences and Impacts of Drug Use

ERIC Educational Resources Information Center

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…

Development of Distinct Body Mass Index Trajectories Among Children Before Age 5 Years: A Population-Based Study.

PubMed

Lynch, Brian A; Rutten, Lila J Finney; Ebbert, Jon O; Kumar, Seema; Yawn, Barbara P; Jacobson, Debra; Sauver, Jennifer St

2017-10-01

The prevalence of childhood obesity has increased over the past 3 decades. This study was designed to understand how childhood body mass index (BMI) influences later risk of obesity. We calculated BMIs for children residing in Olmsted County, Minnesota, between January 1, 2005 and December 31, 2012 using medical records data. We defined homogenous BMI trajectory clusters using a nonparametric hill-climbing algorithm. Overall, 16,538 (47%) children had >3 weight assessments at least 1 year apart and were included in the analyses. Within the 8-year follow-up period, children who were younger than 2 years and overweight had a 3- fold increase of obesity (adjusted hazard ratio [HR] = 3.24; 95% confidence interval [CI] = 2.69-3.89) and those aged 5 years and overweight had a 10-fold increased risk of obesity (adjusted HR = 9.97, 95% CI = 8.55-11.62). Three distinct BMI trajectories could be distinguished prior to 5 years of age. The risk of developing obesity in those who are overweight increased dramatically with increasing age. Interventions to prevent obesity need to occur prior to school age to prevent children from entering unhealthy BMI trajectories.

Developmental trajectories of cigarette use and associations with multilayered risk factors among Chinese adolescents.

PubMed

Xie, Bin; Palmer, Paula; Li, Yan; Lin, Cindy; Johnson, C Anderson

2013-10-01

We aimed to identify developmental trajectories of cigarette use and risk factors associated with the distinct developmental courses of smoking in Chinese early adolescents from age 12 to 16 years. Analysis was conducted with secondary data from a longitudinal, prospective cohort of 3,521 Chinese adolescents randomly selected from 4 rural and 7 urban middle schools in Wuhan, China. A group-based growth mixture modeling approach was adopted to identify developmental trajectories of cigarette use. Multilayered intrapersonal (e.g., attitudes toward smoking) and interpersonal (e.g., parental smoking and perceived parental disapproval of smoking) risk factors selected from an ecological perspective were prospectively linked to the identified patterns of smoking trajectory. Three trajectory patterns were identified from the whole cohort: nonsmokers (48.7%), stable light/occasional smokers (48.6%), and accelerating smokers (2.7%). After adjustments for gender, urban residence, and family socioeconomic status, adolescents with higher levels of problems in parent-child relationships and family disharmony, higher perceived norms of peer smoking, higher proportion of good friend smoking, having more troubles with teachers, poorer academic performance, and reporting more frequent depressive symptoms were significantly more likely to be in the trajectory group of either stable light/occasional smokers or accelerating smokers than in the group of nonsmokers. The probability of being in the accelerating smoking trajectory group was positively and significantly related to parental smoking and lack of school bonding. Study findings help to advance knowledge of the distinct developmental courses of smoking behavior and their associations with multilayered risk factors among Chinese early adolescents.

Trajectories of fathers' psychological distress across the early parenting period: Implications for parenting.

PubMed

Giallo, Rebecca; Cooklin, Amanda; Brown, Stephanie; Christensen, Daniel; Kingston, Dawn; Liu, Cindy H; Wade, Catherine; Nicholson, Jan M

2015-10-01

Fathers' parenting behavior is a likely key mechanism underlying the consistent associations between paternal mental health difficulties and poor emotional-behavioral outcomes for children. This study investigates the association between fathers' mental health trajectories and key parenting behaviors (warmth, hostility, consistency) spanning the first 8-9 years postpartum. Secondary analyses of 5 waves of data from 2,662 fathers participating in the Longitudinal Study of Australian Children were conducted. Latent growth class analysis was used to identify distinct trajectories of fathers' distress (Kessler-6; Kessler et al., 2003), and latent growth models estimated parenting warmth, hostility, and consistency. Multiple group analyses were conducted to describe and compare the course of parenting behaviors for fathers assigned to the distress trajectories identified. Two distinct classes of fathers were identified based on the trajectories of distress: minimal distress (92%) and persistent and increasing distress (8%). The latter group reported significantly lower parenting warmth when their children were 8-9 years and lower consistency and higher hostility across all study intervals. The postnatal and early parenting period is a critical time for the development of parenting behaviors that are important for children's development. Engagement and support for fathers around well-being and parenting is vital for promoting optimal family and child developmental outcomes. (c) 2015 APA, all rights reserved).

Sleep Trajectories of Women Undergoing Elective Cesarean Section: Effects on Body Weight and Psychological Well-Being.

PubMed

Tzeng, Ya-Ling; Chen, Shu-Ling; Chen, Chuen-Fei; Wang, Fong-Chen; Kuo, Shu-Yu

2015-01-01

After cesarean section (CS), women may be at great risk for sleep disturbance, but little is known about temporal changes in their sleep patterns and characteristics. We had two aims: 1) to identify distinct classes of sleep-disturbance trajectories in women considering elective CS from third-trimester pregnancy to 6 months post-CS and 2) to examine associations of sleep trajectories with body mass index (BMI), depressive symptoms, and fatigue scores. We analyzed data from a prospective cohort study of 139 Taiwanese pregnant women who elected CS. Sleep components were assessed using the Pittsburgh Sleep Quality Index in third-trimester pregnancy, 1 day, 1 week, 1 month, and 6 months post-CS. Data were collected on depressive symptoms, fatigue symptoms, and BMI. Sleep-quality trajectories were identified by group-based trajectory modeling. We identified three distinct trajectories: stable poor sleep (50 women, 36.0%), progressively worse sleep (67 women, 48.2%), and persistently poor sleep (22 women, 15.8%). Poor sleep was significantly associated with pre-pregnancy BMI and more baseline (third-trimester pregnancy) depressive and fatigue symptoms. At 6 months post-CS, women classified as progressively worse or persistently poor sleepers showed a trend toward higher BMI (p<0.03), more depressive symptoms (p<0.001), and higher fatigue scores (p<0.001) than those with stable poor sleep. Women had three distinct sleep-disturbance trajectories before and after elective CS. These poor-sleep courses were associated with BMI and psychological well-being. Our findings suggest a need to continuously assess sleep quality among women considering elective CS and up to 6 months post-CS.

Trajectories of Youthful Antisocial Behavior: Categories or Continua?

ERIC Educational Resources Information Center

Walters, Glenn D.; Ruscio, John

2013-01-01

The purpose of this study was to determine whether qualitatively distinct trajectories of antisocial behavior could be identified in 1,708 children (843 boys, 865 girls) from the 1979 National Longitudinal Survey of Youth-Child Data (NLSY-C). Repeated ratings were made on the Behavior Problems Index (BPI: Peterson and Zill "Journal of Marriage and…

Trajectories of Social Withdrawal from Middle Childhood to Early Adolescence

ERIC Educational Resources Information Center

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…

Residential treatment for combat-related posttraumatic stress disorder: identifying trajectories of change and predictors of treatment response.

PubMed

Currier, Joseph M; Holland, Jason M; Drescher, Kent D

2014-01-01

Combat-related posttraumatic stress disorder (PTSD) can be a difficult condition to treat and has been associated with serious medical and economic issues among U.S. military veterans. Distinguishing between treatment responders vs. non-responders in this population has become an important public health priority. This study was conducted to identify pre-treatment characteristics of U.S. veterans with combat-related PTSD that might contribute to favorable and unfavorable responses to high value treatments for this condition. This study focused on 805 patients who completed a VHA PTSD residential program between 2000 and 2007. These patients completed the PTSD Clinical Checklist at pre-treatment, post-treatment, and a four-month follow-up assessment. Latent growth curve analysis (LCGA) was incorporated to determine trajectories of changes in PTSD across these assessments and whether several key clinical concerns for this population were associated with their treatment responses. LCGA indicated three distinct trajectories in PTSD outcomes and identified several clinical factors that were prospectively linked with changes in veterans' posttraumatic symptomatology. When compared to a group with high PTSD symptom severity that decreased over the program but relapsed at follow-up (41%), the near half (48.8%) of the sample with an improving trajectory had less combat exposure and superior physical/mental health. However, when compared to a minority (10.2%) with relatively low symptomatology that also remained somewhat stable, patients in the improving group were younger and also reported greater combat exposure, poorer physical/mental health status, and more problems with substance abuse before the start of treatment. Findings suggest that veterans are most likely to benefit from residential treatment in an intermediate range of symptoms and risk factors, including PTSD symptom severity, history of combat exposure, and comorbid issues with physical/mental health

General versus Specific Predictors of Male Arrest Trajectories: A Test of the Moffitt and Patterson Theories

ERIC Educational Resources Information Center

Wiesner, Margit; Capaldi, Deborah M.; Kim, Hyoun K.

2012-01-01

Developmental taxonomies of crime disagree on whether distinctive offender trajectories are related to common or unique risks. This study examined childhood risks of differing arrest trajectories across childhood through early adulthood (from ages 10-11 to 26-27 years) that were identified in prior work for 203 at-risk, predominantly Caucasian…

Dysfunctional Autism Risk Genes Cause Circuit-Specific Connectivity Deficits With Distinct Developmental Trajectories.

PubMed

Zerbi, Valerio; Ielacqua, Giovanna D; Markicevic, Marija; Haberl, Matthias Georg; Ellisman, Mark H; A-Bhaskaran, Arjun; Frick, Andreas; Rudin, Markus; Wenderoth, Nicole

2018-07-01

Autism spectrum disorders (ASD) are a set of complex neurodevelopmental disorders for which there is currently no targeted therapeutic approach. It is thought that alterations of genes regulating migration and synapse formation during development affect neural circuit formation and result in aberrant connectivity within distinct circuits that underlie abnormal behaviors. However, it is unknown whether deviant developmental trajectories are circuit-specific for a given autism risk-gene. We used MRI to probe changes in functional and structural connectivity from childhood to adulthood in Fragile-X (Fmr1-/y) and contactin-associated (CNTNAP2-/-) knockout mice. Young Fmr1-/y mice (30 days postnatal) presented with a robust hypoconnectivity phenotype in corticocortico and corticostriatal circuits in areas associated with sensory information processing, which was maintained until adulthood. Conversely, only small differences in hippocampal and striatal areas were present during early postnatal development in CNTNAP2-/- mice, while major connectivity deficits in prefrontal and limbic pathways developed between adolescence and adulthood. These findings are supported by viral tracing and electron micrograph approaches and define 2 clearly distinct connectivity endophenotypes within the autism spectrum. We conclude that the genetic background of ASD strongly influences which circuits are most affected, the nature of the phenotype, and the developmental time course of the associated changes.

Trajectories of Physical Dating Violence from Middle to High School: Association with Relationship Quality and Acceptability of Aggression

ERIC Educational Resources Information Center

Orpinas, Pamela; Hsieh, Hsien-Lin; Song, Xiao; Holland, Kristin; Nahapetyan, Lusine

2013-01-01

Although research on dating violence is growing, little is known about the distinct developmental trajectories of dating violence during adolescence. The current study identifies trajectories of physical dating violence victimization and perpetration that boys and girls follow from sixth to twelfth grade, examines the overlap of these…

Identifying Trajectories of Adolescents' Depressive Phenomena: An Examination of Early Risk Factors

ERIC Educational Resources Information Center

Mazza, James J.; Fleming, Charles B.; Abbott, Robert D.; Haggerty, Kevin P.; Catalano, Richard F.

2010-01-01

Few studies have examined risk factors of childhood and early adolescent depressive symptomatology trajectories. This study examined self-report depressive symptomatology across a 6-year time period from 2nd to 8th grade to identify latent groups of individuals with similar patterns of depressive phenomena in a sample of 951 children (440 girls,…

Heterogeneity of Depressive Symptom Trajectories through Adolescence: Predicting Outcomes in Young Adulthood.

PubMed

Chaiton, Michael; Contreras, Gisèle; Brunet, Jennifer; Sabiston, Catherine M; O'Loughlin, Erin; Low, Nancy C P; Karp, Igor; Barnett, Tracie A; O'Loughlin, Jennifer

2013-05-01

This study describes developmental trajectories of depressive symptoms in adolescents and examines the association between trajectory group and mental health outcomes in young adulthood. Depressive symptoms were self-reported every three months from grade seven through grade 11 by 1293 adolescents in the Nicotine Dependence in Teens (NDIT) study and followed in young adulthood (average age 20.4, SD=0.7, n=865). Semi-parametric growth modeling was used to identify sex-specific trajectories of depressive symptoms. THREE DISTINCT TRAJECTORY GROUPS WERE IDENTIFIED: 50% of boys and 29% of girls exhibited low, decreasing levels of depressive symptoms; 14% of boys and 28% of girls exhibited high and increasing levels; and 36% of boys and 43% of girls exhibited moderate levels with linear increase. Trajectory group was a statistically significant independent predictor of depression, stress, and self-rated mental health in young adulthood in boys and girls. Boys, but not girls, in the high trajectory group had a statistically significant increase in the likelihood of seeking psychiatric care. Substantial heterogeneity in changes in depressive symptoms over time was found. Because early depressive symptoms predict mental health problems in young adulthood, monitoring adolescents for depressive symptoms may help identify those most at risk and in need of intervention.

Dysfunctional Autism Risk Genes Cause Circuit-Specific Connectivity Deficits With Distinct Developmental Trajectories

PubMed Central

Ielacqua, Giovanna D; Markicevic, Marija; Haberl, Matthias Georg; Ellisman, Mark H; A-Bhaskaran, Arjun; Frick, Andreas; Rudin, Markus; Wenderoth, Nicole

2018-01-01

Abstract Autism spectrum disorders (ASD) are a set of complex neurodevelopmental disorders for which there is currently no targeted therapeutic approach. It is thought that alterations of genes regulating migration and synapse formation during development affect neural circuit formation and result in aberrant connectivity within distinct circuits that underlie abnormal behaviors. However, it is unknown whether deviant developmental trajectories are circuit-specific for a given autism risk-gene. We used MRI to probe changes in functional and structural connectivity from childhood to adulthood in Fragile-X (Fmr1−/y) and contactin-associated (CNTNAP2−/−) knockout mice. Young Fmr1−/y mice (30 days postnatal) presented with a robust hypoconnectivity phenotype in corticocortico and corticostriatal circuits in areas associated with sensory information processing, which was maintained until adulthood. Conversely, only small differences in hippocampal and striatal areas were present during early postnatal development in CNTNAP2−/− mice, while major connectivity deficits in prefrontal and limbic pathways developed between adolescence and adulthood. These findings are supported by viral tracing and electron micrograph approaches and define 2 clearly distinct connectivity endophenotypes within the autism spectrum. We conclude that the genetic background of ASD strongly influences which circuits are most affected, the nature of the phenotype, and the developmental time course of the associated changes. PMID:29901787

Antecedents and Outcomes of Joint Trajectories of Mother-Son Conflict and Warmth during Middle Childhood and Adolescence

PubMed Central

Trentacosta, Christopher J.; Criss, Michael M.; Shaw, Daniel S.; Lacourse, Eric; Hyde, Luke W.; Dishion, Thomas J.

2011-01-01

This study investigated the development of mother-son relationship quality from ages 5 to 15 in a sample of 265 low-income families. Non-parametric random effects modeling was utilized to uncover distinct and homogeneous developmental trajectories of conflict and warmth; antecedents and outcomes of the trajectory groups also were examined. Four conflict trajectory groups and three warmth trajectory groups were identified. Difficult temperament in early childhood discriminated both conflict and warmth trajectory group membership (TGM), and adult relationship quality in early childhood was related to warmth trajectories. In addition, conflict TGM differentiated youth antisocial behavior during adolescence, and warmth trajectories predicted adolescent peer relationship quality and youth moral disengagement. Implications for socialization processes are discussed. PMID:21883153

Weight Change Trajectories After Incident Lower-Limb Amputation.

PubMed

Bouldin, Erin D; Thompson, Mary Lou; Boyko, Edward J; Morgenroth, David C; Littman, Alyson J

2016-01-01

To characterize weight change after amputation by identifying typical weight trajectories in men with incident lower-limb amputation (LLA) and describing characteristics associated with each trajectory. Retrospective cohort study and analyzed using group-based trajectory modeling. Administrative data. Veterans who were men (N=759), living in the Northwest United States, and who had an incident toe, foot, or leg amputation between 1997 and 2008 and at least 18 months of amputation-free survival thereafter. Not applicable. Postamputation weight and body mass index change. The mean weight at baseline was 91.6±24 kg (202±53 lb), and average follow-up was 2.4 years. We identified 4 trajectory groups for weight change: weight loss (13%), stable weight (47%), slow weight gain (33%), and rapid weight gain (7%). Men with a toe or foot amputation most frequently were assigned to the stable weight group (58%), whereas men with transtibial or transfemoral amputations were most commonly assigned to the slow weight gain group (42% each). Men who died during follow-up were more likely to be assigned to the weight loss group (24%) than men who did not die (11%). We identified distinct weight change trajectories that represent heterogeneity in weight change after LLA. An improved understanding of factors predictive of weight gain or loss in people with LLA may help better target rehabilitation and prosthetic prescription. Additional research is needed to fully understand the relation between weight change and health status after amputation. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Application of latent growth modeling to identify different working life trajectories: the case of the Spanish WORKss cohort.

PubMed

Serra, Laura; López Gómez, María Andrée; Sanchez-Niubo, Albert; Delclos, George L; Benavides, Fernando G

2017-01-01

Objective The aim of this study was to describe the application of latent class growth analysis (LCGA) to identify different working life trajectories (WLT) using employed working time by year as a repeated measure. Methods Trajectories are estimated using LCGA, which considers all individuals within a trajectory to be homogeneous. The methodology was applied to a subsample of the Spanish WORKing life Social Security (WORKss) cohort, limited to persons born 1956-1965 (N=247 475). The number of days worked per year is used as a repeated measure across 32 time points (1981-2013). Results According to the model-fit results and further guided by expert knowledge, a four WTL model was selected as the optimal approach: WLT1 or "high labor force participation" (N=99 591; 40.2%); WLT2 or "decreased labor force participation" (N= 22 846; 9.2%); WLT3 or "increased labor force participation" (N=59 213; 23.9%); and WLT4 or "low labor force participation" (N=65 827; 26.6%). WLT1 consisted mainly of men with more years of work experience (>19 years) while WLT4 was mainly composed by women with <9 years. The other two trajectories had opposite trends and no sex differences. The occupational category variable had little influence in the trajectories. Conclusions Longitudinal data that are regularly collected by administrative systems can benefit from LCGA approaches to identify different trajectory patterns that may be associated with an outcome of interest. In occupational epidemiology, this study represents a step forward by using this modeling approach to identify different WLT.

Links between Friendship Relations and Early Adolescents' Trajectories of Depressed Mood

ERIC Educational Resources Information Center

Brendgen, Mara; Lamarche, Veronique; Wanner, Brigitte; Vitaro, Frank

2010-01-01

The present study examined to what extent different types of friendship experiences (i.e., friendlessness, having depressed friends, and having nondepressed friends) are associated with early adolescents' longitudinal trajectories of depressed mood. On the basis of a sample of 201 youths (108 girls, 93 boys), we identified 3 distinct longitudinal…

Latent trajectories of internalizing symptoms from preschool to school age: A multi-informant study in a high-risk sample.

PubMed

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.

Clustering of self-organizing map identifies five distinct medulloblastoma subgroups.

PubMed

Cao, Changjun; Wang, Wei; Jiang, Pucha

2016-01-01

Medulloblastoma is one the most malignant paediatric brain tumours. Molecular subgrouping these medulloblastomas will not only help identify specific cohorts for certain treatment but also improve confidence in prognostic prediction. Currently, there is a consensus of the existences of four distinct subtypes of medulloblastoma. We proposed a novel bioinformatics method, clustering of self-organizing map, to determine the subgroups and their molecular diversity. Microarray expression profiles of 46 medulloblastoma samples were analysed and five clusters with distinct demographics, clinical outcome and transcriptional profiles were identified. The previously reported Wnt subgroup was identified as expected. Three other novel subgroups were proposed for later investigation. Our findings underscore the value of SOM clustering for discovering the medulloblastoma subgroups. When the suggested subdivision has been confirmed in large cohorts, this method should serve as a part of routine classification of clinical samples.

Early Risk Factors of Overweight Developmental Trajectories during Middle Childhood

PubMed Central

Pryor, Laura E.; Brendgen, Mara; Tremblay, Richard E.; Pingault, Jean-Baptiste; Liu, Xuecheng; Dubois, Lise; Touchette, Evelyne; Falissard, Bruno; Boivin, Michel; Côté, Sylvana M.

2015-01-01

Background Research is needed to identify early life risk factors associated with different developmental paths leading to overweight by adolescence. Objectives To model heterogeneity in overweight development during middle childhood and identify factors associated with differing overweight trajectories. Methods Data was drawn from the Quebec Longitudinal Study of Child Development (QLSCD; 1998-2010). Trained research assistants measured height and weight according to a standardized protocol and conducted yearly home interviews with the child’s caregiver (mother in 98% of cases). Information on several putative early life risk factors for the development of overweight were obtained, including factors related to the child’s perinatal, early behavioral family and social environment. Group-based trajectories of the probability of overweight (6-12 years) were identified with a semiparametric method (n=1678). Logistic regression analyses were used to identify early risk factors (5 months- 5 years) associated with each trajectory. Results Three trajectories of overweight were identified: “early-onset overweight” (11.0 %), “late-onset overweight” (16.6%) and “never overweight” (72.5%). Multinomial analyses indicated that children in the early and late-onset group, compared to the never overweight group, had 3 common types of risk factors: parental overweight, preschool overweight history, and large size for gestational age. Maternal overprotection (OR= 1.12, CI: 1.01-1.25), short nighttime sleep duration (OR=1.66, CI: 1.07-2.57), and immigrant status (OR=2.01, CI: 1.05-3.84) were factors specific to the early-onset group. Finally, family food insufficiency (OR=1.81, CI: 1.00-3.28) was weakly associated with membership in the late-onset trajectory group. Conclusions The development of overweight in childhood follows two different trajectories, which have common and distinct risk factors that could be the target of early preventive interventions. PMID

Identifying sources of fugitive emissions in industrial facilities using trajectory statistical methods

NASA Astrophysics Data System (ADS)

Brereton, Carol A.; Johnson, Matthew R.

2012-05-01

Fugitive pollutant sources from the oil and gas industry are typically quite difficult to find within industrial plants and refineries, yet they are a significant contributor of global greenhouse gas emissions. A novel approach for locating fugitive emission sources using computationally efficient trajectory statistical methods (TSM) has been investigated in detailed proof-of-concept simulations. Four TSMs were examined in a variety of source emissions scenarios developed using transient CFD simulations on the simplified geometry of an actual gas plant: potential source contribution function (PSCF), concentration weighted trajectory (CWT), residence time weighted concentration (RTWC), and quantitative transport bias analysis (QTBA). Quantitative comparisons were made using a correlation measure based on search area from the source(s). PSCF, CWT and RTWC could all distinguish areas near major sources from the surroundings. QTBA successfully located sources in only some cases, even when provided with a large data set. RTWC, given sufficient domain trajectory coverage, distinguished source areas best, but otherwise could produce false source predictions. Using RTWC in conjunction with CWT could overcome this issue as well as reduce sensitivity to noise in the data. The results demonstrate that TSMs are a promising approach for identifying fugitive emissions sources within complex facility geometries.

Four-body trajectory optimization

NASA Technical Reports Server (NTRS)

Pu, C. L.; Edelbaum, T. N.

1973-01-01

A collection of typical three-body trajectories from the L1 libration point on the sun-earth line to the earth is presented. These trajectories in the sun-earth system are grouped into four distinct families which differ in transfer time and delta V requirements. Curves showing the variations of delta V with respect to transfer time, and typical two and three-impulse primer vector histories, are included. The development of a four-body trajectory optimization program to compute fuel optimal trajectories between the earth and a point in the sun-earth-moon system are also discussed. Methods for generating fuel optimal two-impulse trajectories which originate at the earth or a point in space, and fuel optimal three-impulse trajectories between two points in space, are presented. A brief qualitative comparison of these methods is given. An example of a four-body two-impulse transfer from the Li libration point to the earth is included.

Mixed membership trajectory models of cognitive impairment in the multicenter AIDS cohort study.

PubMed

Molsberry, Samantha A; Lecci, Fabrizio; Kingsley, Lawrence; Junker, Brian; Reynolds, Sandra; Goodkin, Karl; Levine, Andrew J; Martin, Eileen; Miller, Eric N; Munro, Cynthia A; Ragin, Ann; Sacktor, Ned; Becker, James T

2015-03-27

The longitudinal trajectories that individuals may take from a state of normal cognition to HIV-associated dementia are unknown. We applied a novel statistical methodology to identify trajectories to cognitive impairment, and factors that affected the 'closeness' of an individual to one of the canonical trajectories. The Multicenter AIDS Cohort Study (MACS) is a four-site longitudinal study of the natural and treated history of HIV disease among gay and bisexual men. Using data from 3892 men (both HIV-infected and HIV-uninfected) enrolled in the neuropsychology substudy of the MACS, a Mixed Membership Trajectory Model (MMTM) was applied to capture the pathways from normal cognitive function to mild impairment to severe impairment. MMTMs allow the data to identify canonical pathways and to model the effects of risk factors on an individual's 'closeness' to these trajectories. First, we identified three distinct trajectories to cognitive impairment: 'normal aging' (low probability of mild impairment until age 60); 'premature aging' (mild impairment starting at age 45-50); and 'unhealthy' (mild impairment in 20s and 30s) profiles. Second, clinically defined AIDS, and not simply HIV disease, was associated with closeness to the premature aging trajectory, and, third, hepatitis-C infection, depression, race, recruitment cohort and confounding conditions all affected individual's closeness to these trajectories. These results provide new insight into the natural history of cognitive dysfunction in HIV disease and provide evidence for a potential difference in the pathophysiology of the development of cognitive impairment based on trajectories to impairment.

Trajectories of depression in adults with newly diagnosed type 1 diabetes: results from the German Multicenter Diabetes Cohort Study.

PubMed

Kampling, Hanna; Petrak, Frank; Farin, Erik; Kulzer, Bernd; Herpertz, Stephan; Mittag, Oskar

2017-01-01

There is a paucity of longitudinal data on type 1 diabetes and depression, especially in adults. The present study prospectively analysed trajectories of depressive symptoms in adults during the first 5 years of living with type 1 diabetes. We aimed to identify distinct trajectories of depressive symptoms and to examine how they affect diabetes outcome. We reanalysed data from a prospective multicentre observational cohort study including 313 adults with newly diagnosed type 1 diabetes. At baseline and in annual postal surveys over 5 consecutive years, we gathered patient characteristics and behavioural and psychosocial data (e.g. Symptom Checklist-90-R [SCL-90-R]). Medical data (e.g. HbA 1c levels) was obtained from the treating physicians. We applied growth mixture modelling (GMM) to identify distinct trajectories of depression over time. Five years after diagnosis, 7.8% (n = 20) of patients were moderately depressed and 10.2% (n = 26) were severely depressed. GMM statistics identified three possible models of trajectories (class 1, 'no depressive symptoms'; class 2, 'worsening depressive symptoms that improve after 2 years'; class 3, 'worsening depressive symptoms'). Severity of depression symptoms at baseline (subscale of the SCL-90-R questionnaire) significantly predicted membership of classes 2 and 3 vs class 1. After 5 years, higher HbA 1c values were detected in class 3 patients (mean = 8.2%, 66 mmol/mol) compared with class 1 and class 2 (both: mean = 7.2%, 55 mmol/mol). We identified distinct trajectories of depressive symptoms that are also relevant for diabetes outcome. Patients with worsening depressive symptoms over time exhibited poor glycaemic control after the first 5 years of living with diabetes. They also exhibited a reduced quality of life and increased diabetes-related distress.

Trajectories of Diurnal Cortisol in Mothers of Children with Autism and Other Developmental Disabilities: Relations to Health and Mental Health

ERIC Educational Resources Information Center

Dykens, Elisabeth M.; Lambert, Warren

2013-01-01

This study used a stress biomarker, diurnal cortisol, to identify how elevated stress in mothers of children and adults with autism and other disabilities relates to their health and mental health. Based on semi-parametric, group-based trajectory analysis of 91 mothers, two distinctive cortisol trajectories emerged: blunted (63%) or steep (37%).…

Developmental Trajectories of Cigarette Smoking from Adolescence to the Early Thirties: Personality and Behavioral Risk Factors

PubMed Central

Brook, David W.; Brook, Judith S.; Zhang, Chenshu; Whiteman, Martin; Cohen, Patricia; Finch, Stephen J.

2013-01-01

The purpose of this study was to identify distinct trajectories of cigarette smoking from ages 14 to 32, and to examine adolescent personality factors that distinguish trajectories of smoking behavior. Participants (N=975) were randomly selected and followed prospectively since 1975. Follow-up data on cigarette use and personality and behavioral attributes were collected at five points in time, using structured interviews given in private by trained interviewers. Of these subjects, 746 comprised the cohort used in this study. Growth mixture modeling identified five smoking trajectory groups: nonsmokers, occasional smokers, late starters, quitters, and heavy/continuous smokers. Adolescent personality and behavioral risk factors such as lower ego integration, more externalizing behavior, and lower educational aspirations distinguished the trajectory groups. No gender differences were noted. The findings supported the hypotheses indicating multiple distinct trajectory groups of smoking behavior. Smoking behavior appeared in early adolescence and most often continued into adulthood. Emotional difficulties (i.e., lower ego integration), externalizing behavior, and lower educational aspirations in early adolescence were associated both with smoking at an early age and with continuing to smoke into the thirties. To be more effective, smoking prevention programs should target personality and behavioral variations, before smoking becomes habitual, particularly focused on characteristics reflecting behavioral problems as manifested in emotional difficulties, externalizing behavior, and low educational aspirations in early adolescence. The implications for research, prevention, and treatment are discussed. PMID:18686175

Identifying mechanisms for superdiffusive dynamics in cell trajectories

NASA Astrophysics Data System (ADS)

Passucci, Giuseppe; Brasch, Megan; Henderson, James; Manning, M. Lisa

Self-propelled particle (SPP) models have been used to explore features of active matter such as motility-induced phase separation, jamming, and flocking, and are often used to model biological cells. However, many cells exhibit super-diffusive trajectories, where displacements scale faster than t 1 / 2 in all directions, and these are not captured by traditional SPP models. We extract cell trajectories from image stacks of mouse fibroblast cells moving on 2D substrates and find super-diffusive mean-squared displacements in all directions across varying densities. Two SPP model modifications have been proposed to capture super-diffusive dynamics: Levy walks and heterogeneous motility parameters. In mouse fibroblast cells displacement probability distributions collapse when time is rescaled by a power greater than 1/2, which is consistent with Levy walks. We show that a simple SPP model with heterogeneous rotational noise can also generate a similar collapse. Furthermore, a close examination of statistics extracted directly from cell trajectories is consistent with a heterogeneous mobility SPP model and inconsistent with a Levy walk model. Our work demonstrates that a simple set of analyses can distinguish between mechanisms for anomalous diffusion in active matter.

Longitudinal investigation of anxiety sensitivity growth trajectories and relations with anxiety and depression symptoms in adolescence.

PubMed

Allan, Nicholas P; Felton, Julia W; Lejuez, Carl W; MacPherson, Laura; Schmidt, Norman B

2016-05-01

Anxiety sensitivity (AS), the belief that anxious arousal is harmful, is a malleable risk factor that has been implicated in anxiety and depression symptoms in adolescents. Although there is some evidence that adolescents possess distinct developmental trajectories, few studies have explored this topic. This study examined the developmental trajectory of AS in 248 adolescents (M age = 11.0 years, SD = 0.82; 56% male) across 6 years, beginning when children were age 11. This study also examined the influence of AS trajectories on anxiety and depression at age 16. Finally, this study examined the utility of AS classes in identifying anxiety and depression growth. Three AS classes were found, described by normative-stable, high-stable, and high-unstable trajectories. Adolescents in the high-stable and the high-unstable AS classes had higher levels of anxiety and depression at age 16 than did adolescents in the normative-stable AS class. In addition, the anxiety and depression trajectories fit by AS class mirrored the AS class trajectories. These findings suggest three AS trajectories can be identified in adolescents. These trajectories are discussed in relation to a developmental perspective of AS.

Posttraumatic stress disorder symptom trajectories in Hurricane Katrina affected youth.

PubMed

Self-Brown, Shannon; Lai, Betty S; Thompson, Julia E; McGill, Tia; Kelley, Mary Lou

2013-05-01

This study examined trajectories of posttraumatic stress disorder symptoms in Hurricane Katrina affected youth. A total of 426 youth (51% female; 8-16 years old; mean age=11 years; 75% minorities) completed assessments at 4 time points post-disaster. Measures included Hurricane impact variables (initial loss/disruption and perceived life threat); history of family and community violence exposure, parent and peer social support, and post-disaster posttraumatic stress symptoms. Latent class growth analysis demonstrated that there were three distinct trajectories of posttraumatic stress disorder symptoms identified for this sample of youth (resilient, recovering, and chronic, respectively). Youth trajectories were associated with Hurricane-related initial loss/disruption, community violence, and peer social support. The results suggest that youth exposed to Hurricane Katrina have variable posttraumatic stress disorder symptom trajectories. Significant risk and protective factors were identified. Specifically, youth Hurricane and community violence exposure increased risk for a more problematic posttraumatic stress disorder symptom trajectory, while peer social support served as a protective factor for these youth. Identification of these factors suggests directions for future research as well as potential target areas for screening and intervention with disaster exposed youth. The convenience sample limits the external validity of the findings to other disaster exposed youth, and the self-report data is susceptible to response bias. Copyright © 2012 Elsevier B.V. All rights reserved.

Genetically distinct genogroup IV norovirus strains identified in wastewater.

PubMed

Kitajima, Masaaki; Rachmadi, Andri T; Iker, Brandon C; Haramoto, Eiji; Gerba, Charles P

2016-12-01

We investigated the prevalence and genetic diversity of genogroup IV norovirus (GIV NoV) strains in wastewater in Arizona, United States, over a 13-month period. Among 50 wastewater samples tested, GIV NoVs were identified in 13 (26 %) of the samples. A total of 47 different GIV NoV strains were identified, which were classified into two genetically distinct clusters: the GIV.1 human cluster and a unique genetic cluster closely related to strains previously identified in Japanese wastewater. The results provide additional evidence of the considerable genetic diversity among GIV NoV strains through the analysis of wastewater containing virus strains shed from all populations.

Identifying Gender-Specific Developmental Trajectories of Nonviolent and Violent Delinquency from Adolescence to Young Adulthood

PubMed Central

Zheng, Yao; Cleveland, H. Harrington

2013-01-01

Most research examining gender differences in developmental trajectories of antisocial behavior does not consider subtypes of antisocial behavior and is difficult to generalize due to small nonrepresentative samples. The current study investigated gender difference in developmental trajectories from adolescence to young adulthood while addressing those limitations. Analyses were limited to respondents ages 15 and 16 in wave 1 (16–17 in wave 2, and 21–22 in wave 3) of the National Longitudinal Study of Adolescent Health (n = 6244, 49.5% males). Self-report nonviolent and violent delinquencies were simultaneously entered into latent class analysis. Four latent classes were identified: low, desister, decliner, and chronic (male-only). In addition to finding a male-specific chronic class, gender differences included differences in levels of nonviolent and violent delinquency between synonymous classes of males and females, and differences in prevalence of classes across genders. Neighborhood disadvantage and family support predicted trajectories. PMID:23375843

The enduring effect of education-socioeconomic differences in disability trajectories from age 85 years in the Newcastle 85+ Study.

PubMed

Kingston, Andrew; Davies, Karen; Collerton, Joanna; Robinson, Louise; Duncan, Rachel; Kirkwood, Thomas B L; Jagger, Carol

2015-01-01

Little is known about disability progression in very old age despite this being vital for care planning. We investigate whether distinct trajectories of disability are evident from age 85 to 90 and their association with socio-economic status (SES). The Newcastle 85+ Study recruited people born in 1921 through participating general practices in Newcastle and North Tyneside. Participants underwent a health assessment (HA) at baseline, 18, 36 and 60 months and a GP record review (GPRR) at baseline, 36 and 60 months. Disability was measured via difficulty in 17 Activities of Daily Living. Trajectory identification was assessed by gender stratified, mortality adjusted, group-based trajectory modelling (GBTM) and the impact of life-course SES (level of education; occupational class; deprivation) on trajectory membership evaluated (adjusting for confounding variables). 851 participants agreed to HA and GPRR, 840 (98.7%) with complete disability data. Four distinct trajectories were evident for both sexes. A disability-free trajectory between age 85 and 90 was identified in men only (9% of the sample). The most disabled trajectories had severe disability at age 85 progressing to profound disability by age 90. After adjusting for confounders education remained significant; men and women with most education being less likely to be in the most disabled trajectory (Men: OR=0.80, 95% CI 0.65-0.98; women: OR=0.59, 95% CI 0.42-0.83). Distinct disability trajectories are evident in the very old and these are influenced by education, suggesting SES disadvantages cumulate throughout the life-course to create health and mortality inequalities later. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

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

PubMed

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.

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

PubMed Central

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 – 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 under-control or dramatic changes from high ego under-control to high ego over-control exhibited poor adjustment. Experiencing multiple maltreatment subtypes and physical/sexual abuse were related to higher levels of ego under-control 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. PMID:19583889

Association Between Early Life Growth and Blood Pressure Trajectories in Black South African Children.

PubMed

Kagura, Juliana; Adair, Linda S; Munthali, Richard J; Pettifor, John M; Norris, Shane A

2016-11-01

Early growth is associated with blood pressure measured on one occasion, but whether early life growth patterns are associated with longitudinal blood pressure trajectories is under-researched. Therefore, we sought to examine the association between early growth and blood pressure trajectories from childhood to adulthood. Blood pressure was measured on 7 occasions between ages 5 and 18 years in the Birth to Twenty cohort study, and conditional variables for growth in infancy and mid-childhood were computed from anthropometric measures (n=1937, 52% girls). We used a group-based trajectory modeling approach to identify distinct height-adjusted blood pressure trajectories and then tested their association with growth between birth and mid-childhood adjusting for several covariates. Three trajectory groups were identified for systolic and diastolic blood pressure: lower, middle, and upper in boys and girls, separately. In boys, predictors of the middle or upper systolic blood pressure trajectories versus the lower trajectory were in birth weight (odds ratio 0.75 [95% confidence interval 0.58-0.96] per SD) and relative weight gain in infancy (4.11 [1.25-13.51] per SD). In girls, greater relative weight gain and linear growth in both infancy and mid-childhood were consistently associated with an almost 2-fold higher likelihood of being in the upper versus lower systolic blood pressure trajectory. The associations for the diastolic blood pressure trajectories were inconsistent. These findings emphasize the importance of identifying children at risk of progression to high blood pressure. Accelerated growth in infancy and mid-childhood may be a key target for early life intervention in prevention of elevated blood pressure progression. © 2016 American Heart Association, Inc.

Same Program, Distinctive Development: Exploring the Biliteracy Trajectories of Two Dual Language Schools

ERIC Educational Resources Information Center

Babino, Alexandra

2017-01-01

Using a mixed methods comparative case study, the researcher explored the dual language contexts at each school before examining the second- through fifth-grade Spanish and English reading biliteracy trajectories. While both campuses' students experienced positive trajectories toward biliteracy by the end of fifth grade, each campus was…

Obesity status trajectory groups among elementary school children

USDA-ARS?s Scientific Manuscript database

Little is known about patterns in the transition from healthy weight to overweight or obesity during the elementary school years. This study examined whether there were distinct body mass index (BMI) trajectory groups among elementary school children, and predictors of trajectory group membership. T...

Personal and Familial Predictors of Peer Victimization Trajectories from Primary to Secondary School

ERIC Educational Resources Information Center

Brendgen, Mara; Girard, Alain; Vitaro, Frank; Dionne, Ginette; Boivin, Michel

2016-01-01

Using a sample of 767 children (403 girls, 364 boys), this study aimed to (a) identify groups with distinct trajectories of peer victimization over a 6-year period from primary school through the transition to secondary school, and (b) examine the associated personal (i.e., aggression or internalizing problems) and familial (family status,…

Cigarette Smoking Trajectories From Sixth to Twelfth Grade: Associated Substance Use and High School Dropout.

PubMed

Orpinas, Pamela; Lacy, Beth; Nahapetyan, Lusine; Dube, Shanta R; Song, Xiao

2016-02-01

The purpose of this longitudinal study was to identify distinct trajectories of cigarette smoking from sixth to twelfth grade and to characterize these trajectories by use of other drugs and high school dropout. The diverse sample for this analysis consisted of a cohort of 611 students from Northeast Georgia who participated in the Healthy Teens Longitudinal Study (2003-2009). Students completed seven yearly assessments from sixth through twelfth grade. We used semi-parametric, group-based modeling to identify groups of students whose smoking behavior followed a similar progression over time. Current smoking (past 30 day) increased from 6.9% among sixth graders to 28.8% among twelfth graders. Four developmental trajectories of cigarette smoking were identified: Abstainers/Sporadic Users (71.5% of the sample), Late Starters (11.3%), Experimenters (9.0%), and Continuous Users (8.2%). The Abstainer/Sporadic User trajectory was composed of two distinct groups: those who never reported any tobacco use (True Abstainers) and those who reported sporadic, low-level use (Sporadic Users). The True Abstainers reported significantly less use of alcohol and other drugs and lower dropout rates than students in all other trajectories, and Sporadic Users had worse outcomes than True Abstainers. Experimenters and Continuous Users reported the highest drug use. Over one-third of Late Starters (35.8%) and almost half of Continuous Users (44.4%) dropped out of high school. Cigarette smoking was associated with behavioral and academic problems. Results support early and continuous interventions to reduce use of tobacco and other drugs and prevent high school dropout. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Night-waking trajectories and associated factors in French preschoolers from the EDEN birth-cohort.

PubMed

Reynaud, Eve; Forhan, Anne; Heude, Barbara; de Lauzon-Guillain, Blandine; Charles, Marie-Aline; Plancoulaine, Sabine

Night waking in preschoolers has been associated with adverse health outcomes in cross-sectional studies, but has rarely been analyzed in a longitudinal setting. Therefore, little is known about the evolution of night waking in early childhood. The objectives of the present study were: to identify night-waking trajectories in preschoolers, and to examine the risk factors associated with those trajectories. Analyses were based on the French birth-cohort study EDEN, which recruited 2002 pregnant women between 2003 and 2006. Data on a child's night waking at the ages of two, three, and five, six years, and potential confounders, were collected through parental self-reported questionnaires. Night-waking trajectories were computerized using group-based trajectory modeling on 1346 children. Two distinct developmental patterns were identified: the "2-5 rare night-waking" (77% of the children) and the "2-5 common night-waking" pattern. Logistic regressions were performed to identify the factors associated with the trajectories. Risk factors for belonging to the "2-5 common night-waking" trajectory were: exposure to passive smoking at home, daycare in a collective setting, watching television for extended periods, bottle feeding at night, high emotionality, and low shyness. This approach allowed identification of risk factors associated with night waking during a critical age window, and laid the groundwork for identifying children at higher risk of deleterious sleep patterns. Those risk factors were mainly living habits, which indicated that prevention and intervention programs could be highly beneficial in this population. Copyright © 2016 Elsevier B.V. All rights reserved.

Trajectories of Mexican American and Mainstream Cultural Values Among Mexican American Adolescents

PubMed Central

Knight, George P.; Basilio, Camille D.; Cham, Heining; Gonzales, Nancy A.; Liu, Yu; Umaña-Taylor, Adriana J.

2013-01-01

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. PMID:23877194

Trajectories of Mexican American and mainstream cultural values among Mexican American adolescents.

PubMed

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.

Kinematic Optimization of Robot Trajectories for Thermal Spray Coating Application

NASA Astrophysics Data System (ADS)

Deng, Sihao; Liang, Hong; Cai, Zhenhua; Liao, Hanlin; Montavon, Ghislain

2014-12-01

Industrial robots are widely used in the field of thermal spray nowadays. Due to their characteristics of high-accuracy and programmable flexibility, spraying on complex geometrical workpieces can be realized in the equipped spray room. However, in some cases, the robots cannot guarantee the process parameters defined by the robot movement, such as the scanning trajectory, spray angle, relative speed between the torch and the substrate, etc., which have distinct influences on heat and mass transfer during the generation of any thermally sprayed coatings. In this study, an investigation on the robot kinematics was proposed to find the rules of motion in a common case. The results showed that the motion behavior of each axis of robot permits to identify the motion problems in the trajectory. This approach allows to optimize the robot trajectory generation in a limited working envelop. It also minimizes the influence of robot performance to achieve a more constant relative scanning speed which is represented as a key parameter in thermal spraying.

Trajectories of depressive and anxiety symptoms in older adults: a 6-year prospective cohort study.

PubMed

Holmes, Sophie E; Esterlis, Irina; Mazure, Carolyn M; Lim, Yen Ying; Ames, David; Rainey-Smith, Stephanie; Fowler, Chris; Ellis, Kathryn; Martins, Ralph N; Salvado, Olivier; Doré, Vincent; Villemagne, Victor L; Rowe, Christopher C; Laws, Simon M; Masters, Colin L; Pietrzak, Robert H; Maruff, Paul

2018-02-01

Depressive and anxiety symptoms are common in older adults, significantly affect quality of life, and are risk factors for Alzheimer's disease. We sought to identify the determinants of predominant trajectories of depressive and anxiety symptoms in cognitively normal older adults. Four hundred twenty-three older adults recruited from the general community underwent Aβ positron emission tomography imaging, apolipoprotein and brain-derived neurotrophic factor genotyping, and cognitive testing at baseline and had follow-up assessments. All participants were cognitively normal and free of clinical depression at baseline. Latent growth mixture modeling was used to identify predominant trajectories of subthreshold depressive and anxiety symptoms over 6 years. Binary logistic regression analysis was used to identify baseline predictors of symptomatic depressive and anxiety trajectories. Latent growth mixture modeling revealed two predominant trajectories of depressive and anxiety symptoms: a chronically elevated trajectory and a low, stable symptom trajectory, with almost one in five participants falling into the elevated trajectory groups. Male sex (relative risk ratio (RRR) = 3.23), lower attentional function (RRR = 1.90), and carriage of the brain-derived neurotrophic factor Val66Met allele in women (RRR = 2.70) were associated with increased risk for chronically elevated depressive symptom trajectory. Carriage of the apolipoprotein epsilon 4 allele (RRR = 1.92) and lower executive function in women (RRR = 1.74) were associated with chronically elevated anxiety symptom trajectory. Our results indicate distinct and sex-specific risk factors linked to depressive and anxiety trajectories, which may help inform risk stratification and management of these symptoms in older adults at risk for Alzheimer's disease. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

At-risk depressive symptoms and alcohol use trajectories in adolescence: a person-centred analysis of co-occurrence.

PubMed

Willoughby, Teena; Fortner, Adrian

2015-04-01

Long-term longitudinal studies that examine whether there are distinct trajectories of at-risk depressive symptoms and alcohol use across the high school years (e.g., high co-occurrence) are rare in normative samples of adolescent boys and girls; yet, this assessment is of critical importance for developing effective prevention and intervention strategies. Moreover, the role of self-regulation and novelty-seeking behavior in differentiating among distinct subgroups of adolescents is not clear. To address these gaps, the present study sought to identify subgroups of adolescent boys and girls that indicated at-risk trajectories across the high school years for both depressive symptoms and alcohol use, and examined the role of delay of gratification and novelty seeking at baseline in differentiating among the subgroups. Canadian adolescents (N = 4,412; 49 % female) were surveyed at four time points (grades 9, 10, 11, and 12). Parallel process latent class growth analyses revealed four distinct subgroups for both boys and girls, encompassing high co-occurrence, depressive symptoms only, alcohol use only, and low co-occurrence. Across gender, delay of gratification at baseline differentiated among the four subgroups, with the High Co-Occurrence Group group scoring the lowest and the Low Co-Occurrence Group the highest. Lower novelty-seeking scores at baseline were associated more with being in the Depressive Symptoms Only Group relative to the other groups, particularly the Alcohol Use Only Group for boys. Thus, delay of gratification and novelty seeking may be useful in identifying youth at risk for co-occurring depressive symptoms and alcohol use trajectories, as well as at-risk trajectories for only one of these behaviors.

Identifying Finnish Children's Impulsivity Trajectories from Kindergarten to Grade 4: Associations with Academic and Socioemotional Development

ERIC Educational Resources Information Center

Hirvonen, Riikka; Poikkeus, Anna-Maija; Pakarinen, Eija; Lerkkanen, Marja-Kristiina; Nurmi, Jari-Erik

2015-01-01

Research Findings: The purpose of this study was to identify the developmental trajectories of impulsive behavior among 378 Finnish children who were followed from kindergarten to 4th grade. In addition to ratings of children's impulsivity, the analyses included measures of motivation, cognitive skills, socioemotional adjustment, and…

Distinct Trajectories of Massive Recent Gene Gains and Losses in Populations of a Microbial Eukaryotic Pathogen

PubMed Central

Hartmann, Fanny E.; Croll, Daniel

2017-01-01

Abstract Differences in gene content are a significant source of variability within species and have an impact on phenotypic traits. However, little is known about the mechanisms responsible for the most recent gene gains and losses. We screened the genomes of 123 worldwide isolates of the major pathogen of wheat Zymoseptoria tritici for robust evidence of gene copy number variation. Based on orthology relationships in three closely related fungi, we identified 599 gene gains and 1,024 gene losses that have not yet reached fixation within the focal species. Our analyses of gene gains and losses segregating in populations showed that gene copy number variation arose preferentially in subtelomeres and in proximity to transposable elements. Recently lost genes were enriched in virulence factors and secondary metabolite gene clusters. In contrast, recently gained genes encoded mostly secreted protein lacking a conserved domain. We analyzed the frequency spectrum at loci segregating a gene presence–absence polymorphism in four worldwide populations. Recent gene losses showed a significant excess in low-frequency variants compared with genome-wide single nucleotide polymorphism, which is indicative of strong negative selection against gene losses. Recent gene gains were either under weak negative selection or neutral. We found evidence for strong divergent selection among populations at individual loci segregating a gene presence–absence polymorphism. Hence, gene gains and losses likely contributed to local adaptation. Our study shows that microbial eukaryotes harbor extensive copy number variation within populations and that functional differences among recently gained and lost genes led to distinct evolutionary trajectories. PMID:28981698

Identifying drugs that cause acute thrombocytopenia: an analysis using 3 distinct methods

PubMed Central

Reese, Jessica A.; Li, Xiaoning; Hauben, Manfred; Aster, Richard H.; Bougie, Daniel W.; Curtis, Brian R.; George, James N.

2010-01-01

Drug-induced immune thrombocytopenia (DITP) is often suspected in patients with acute thrombocytopenia unexplained by other causes, but documenting that a drug is the cause of thrombocytopenia can be challenging. To provide a resource for diagnosis of DITP and for drug safety surveillance, we analyzed 3 distinct methods for identifying drugs that may cause thrombocytopenia. (1) Published case reports of DITP have described 253 drugs suspected of causing thrombocytopenia; using defined clinical criteria, 87 (34%) were identified with evidence that the drug caused thrombocytopenia. (2) Serum samples from patients with suspected DITP were tested for 202 drugs; drug-dependent, platelet-reactive antibodies were identified for 67 drugs (33%). (3) The Food and Drug Administration's Adverse Event Reporting System database was searched for drugs associated with thrombocytopenia by use of data mining algorithms; 1444 drugs had at least 1 report associated with thrombocytopenia, and 573 (40%) drugs demonstrated a statistically distinctive reporting association with thrombocytopenia. Among 1468 drugs suspected of causing thrombocytopenia, 102 were evaluated by all 3 methods, and 23 of these 102 drugs had evidence for an association with thrombocytopenia by all 3 methods. Multiple methods, each with a distinct perspective, can contribute to the identification of drugs that can cause thrombocytopenia. PMID:20530792

Employment Trajectories: Exploring Gender Differences and Impacts of Drug Use

PubMed Central

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

2010-01-01

This study investigated the impact of drug use on employment over 20 years among men and women, utilizing data on 7,661 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 for men and women except that a U-shape employment trajectory was uniquely identified for women. Early-initiation drug users, users of “hard” drugs, and frequent drug users were more likely to demonstrate consistently low levels of employment, and the negative relationship between drug use and employment was more apparent among men than women. Also, positive associations between employment and marriage became more salient for men over time, as did negative associations between employment and childrearing among women. Processes are dynamic and complex, suggesting that throughout the life course, protective factors that reduce the risk of employment problems emerge and change, as do critical periods for maximizing the impact of drug prevention and intervention efforts. PMID:21765533

Parental Child-Rearing Conflicts Through Adolescence: Trajectories and Associations With Child Characteristics and Externalizing Patterns.

PubMed

Helland, Maren S; Kjeldsen, Anne; von Soest, Tilmann; Røysamb, Espen; Gustavson, Kristin; Nilsen, Wendy

2017-06-01

Research on longitudinal interparental conflict patterns and offspring development is scarce. The population-based TOPP study (N = 459) was used to investigate (1) child-rearing conflict trajectories through four time points during childhood and adolescence (ages 8-16), and (2) associations between conflict trajectories and child characteristics (i.e., birth order, gender, externalizing patterns from early childhood). Latent profile analysis identified six distinct trajectories. Conflict levels decreased for most respondents over the adolescent offspring period, but offspring's birth order and externalizing problems were related to less typical trajectories and higher levels of conflict. Onset of externalizing problems was of additional importance for the course of parental child-rearing conflicts. The results highlight the perception of the whole family as an interwoven system. © 2017 The Authors. Journal of Research on Adolescence © 2017 Society for Research on Adolescence.

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

PubMed Central

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

Age-Related Differences in Profiles of Mood-Change Trajectories

PubMed Central

Stanley, Jennifer Tehan; Isaacowitz, Derek M.

2010-01-01

As a group, older adults report positive affective lives. The extent to which there are subgroups of older adults whose moods are less positive, however, is unclear. The aim of the present study was to identify and characterize different subgroups of adults who exhibit distinct trajectories of mood-change across a relatively short time period. Seventy-nine young and 103 older adults continuously reported their moods while viewing emotional and neutral faces. Cluster analysis revealed four subgroups of mood-change trajectories. Both the most positive and the most negative subgroups included more older than younger adults (ps < .05), suggesting that not all older adults exhibit higher positive affect than young adults. Analyses of variance revealed that the most negative group exhibited slower processing speed, more state anxiety and neuroticism, and looked less at happy faces, than the other groups (ps < .05). The results are discussed from an adult developmental perspective, focusing on the increased variability of mood trajectories in the older adults and whether this is a reflection of adaptive functioning, or a potential harbinger of dysfunction. PMID:21171749

Trajectories of body mass index among Canadian seniors and associated mortality risk.

PubMed

Wang, Meng; Yi, Yanqing; Roebothan, Barbara; Colbourne, Jennifer; Maddalena, Victor; Sun, Guang; Wang, Peizhong Peter

2017-12-04

This study aims to characterize the heterogeneity in BMI trajectories and evaluate how different BMI trajectories predict mortality risk in Canadian seniors. Data came from the Canadian National Population Health Survey (NPHS, 1994-2011) and 1480 individuals aged 65-79 years with at least four BMI records were included in this study. Group-based trajectory model was used to identify distinct subgroups of longitudinal trajectories of BMI measured over 19 years for men and women. Cox proportional hazards models were used to examine the association between BMI trajectories and mortality risks. Distinct trajectory patterns were found for men and women: 'Normal Weight-Down'(N-D), 'Overweight-Normal weight' (OV-N), 'Obese I-Down' (OB I-D), and 'Obese II- Down' (OB II-D) for women; and 'Normal Weight-Down' (N-D), 'Overweight-Normal weight' (OV-N), 'Overweight-Stable' (OV-S), and 'Obese-Stable' (OB-S) for men. Comparing with OV-N, men in the OV-S group had the lowest mortality risk followed by the N-D (HR = 1.66) and OB-S (HR = 1.98) groups, after adjusting for covariates. Compared with OV-N, women in the OB II-D group with three or more chronic health conditions had higher mortality risk (HR = 1.61); however, women in OB II-D had lower risk (HR = 0.56) if they had less than three conditions. The course of BMI over time in Canadian seniors appears to follow one of four different patterns depending on gender. The findings suggest that men who were overweight at age 65 and lost weight over time had the lowest mortality risk. Interestingly, obese women with decreasing BMI have different mortality risks, depending on their chronic health conditions. The findings provide new insights concerning the associations between BMI and mortality risk.

Association between income trajectories in childhood and psychiatric disorder: a Swedish population-based study.

PubMed

Björkenstam, Emma; Cheng, Siwei; Burström, Bo; Pebley, Anne R; Björkenstam, Charlotte; Kosidou, Kyriaki

2017-07-01

Childhood family income variation is an understudied aspect of households' economic context that may have distinct consequences for children. We identified trajectories of childhood family income over a 12-year period, and examined associations between these trajectories and later psychiatric disorders, among individuals born in Sweden between 1987 and 1991 (n=534 294). We used annual income data between the ages of 3-14 years and identified 5 trajectories (2 high-income upward, 1 downward and 2 low-income upward trajectories). Psychiatric disorders in the follow-up period after age 15 were defined from International Classification of Disease (ICD)-codes in a nationwide patient register. Multiadjusted risks for all psychiatric disorders, as well as for specific psychiatric diagnoses, were calculated as HRs with 95% CIs. Of the 5 identified income trajectories, the constant low and the downward trajectories were particularly associated with later psychiatric disorder. Children with these trajectories had increased risks for psychiatric disorder, including mood, anxiety, psychotic disorders and attention deficit/hyperactivity disorder. The association remained, even after adjusting for important variables including parental psychiatric disorder. In contrast, the relationship was reversed for eating disorders, for which children in higher income trajectories had elevated risks. Findings show that children growing up in a household characterised by low or decreasing family income have an increased risk for psychiatric disorder. Continued work is needed to reduce socioeconomic inequalities in psychiatric disorders. Policies and interventions for psychiatric disorders should consider the socioeconomic background of the family as an important risk or protective factor. 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/.

Multivariate trajectories across multiple domains of health-related quality of life in children with new-onset epilepsy.

PubMed

Sajobi, Tolulope T; Wang, Meng; Ferro, Mark A; Brobbey, Anita; Goodwin, Shane; Speechley, Kathy N; Wiebe, Samuel

2017-10-01

The diagnosis of epilepsy in children is known to impact the trajectory of their health-related quality of life (HRQOL) over time. However, there is limited knowledge about variations in longitudinal trajectories across multiple domains of HRQOL. This study aims to characterize the heterogeneity in HRQOL trajectories across multiple HRQOL domains and to evaluate predictors of differences among the identified trajectory groups in children with new-onset epilepsy. Data were obtained from the Health Related Quality of Life in Children with Epilepsy Study (HERQULES), a prospective multi-center study of 373 children newly diagnosed with new-onset epilepsy who were followed up over 2years. Child HRQOL and family factors were reported by parents, and clinical characteristics were reported by neurologists. Group-based multi-trajectory modeling was adopted to characterize longitudinal trajectories of HRQOL as measured by the individual domains of cognitive, emotional, physical, and social functioning in the 55-item Quality of Life in Childhood Epilepsy Questionnaire (QOLCE-55). Multinomial logistic regression was used to assess potential factors that explain differences among the identified latent trajectory groups. Three distinct HRQOL trajectory subgroups were identified in children with new-onset epilepsy based on HRQOL scores: "High" (44.7%), "Intermediate" (37.0%), and "Low" (18.3%). While most trajectory groups exhibited increasing scores over time on physical and social domains, both flat and declining trajectories were noted on emotional and cognitive domains. Less severe epilepsy, an absence of cognitive and behavioral problems, lower parental depression scores, better family functioning, and fewer family demands were associated with a "Higher" or "Intermediate" HRQOL trajectory. The course of HRQOL over time in children with new-onset epilepsy appears to follow one of three different trajectories. Addressing the clinical and psychosocial determinants identified

Trajectories of Perinatal Depressive and Anxiety Symptoms in a Community Cohort.

PubMed

Bayrampour, Hamideh; Tomfohr, Lianne; Tough, Suzanne

2016-11-01

The evidence on trajectories of perinatal depression is mostly based on studies composed of women at high risk for poor mental health. Research on maternal anxiety trajectories is also scarce. Using a large community cohort, the All Our Babies study, in Alberta, Canada, we examined trajectories of perinatal depressive and anxiety symptoms and compared characteristics of women across trajectories. Anxiety and depressive symptoms were measured at the second and third trimesters and at 4 and 12 months postpartum among 1,445 women recruited between May 2008 and December 2010. The state subscale of the Spielberger State-Trait Anxiety Inventory was used to measure anxiety symptoms, and depressive symptoms were measured with the Edinburgh Postnatal Depression Scale. Semiparametric group-based mixed modeling was performed to identify the optimal trajectory shape, number of groups, and proportion of the sample belonging to each trajectory. Model fit was evaluated using the Bayesian information criterion. Multinomial logistic regression analysis was conducted to compare characteristics across the trajectories. Five distinct trajectory groups with constant and variable patterns were identified for both depressive and anxiety symptoms: minimal, mild, antepartum, postpartum, and chronic. Common risk factors of depression and anxiety across groups with elevated symptoms were history of mental health issues (odds ratios [ORs] varied from 1.83 to 7.64), history of abuse/neglect (ORs varied from 1.67 to 8.97), and low social support (ORs varied from 1.64 to 11.37). The magnitude of the influence of the psychosocial risk factors was greater in the chronic group compared to others, suggesting a dose-related relationship. Heterogeneity of anxiety and depressive symptoms highlights the importance of multiple mental health assessments during the perinatal period. The patterns and intensity of postpartum depression differed between community and high-risk samples, underlining the

Trajectories of affective states in adolescent hockey players: turning point and motivational antecedents.

PubMed

Gaudreau, Patrick; Amiot, Catherine E; Vallerand, Robert J

2009-03-01

This study examined longitudinal trajectories of positive and negative affective states with a sample of 265 adolescent elite hockey players followed across 3 measurement points during the 1st 11 weeks of a season. Latent class growth modeling, incorporating a time-varying covariate and a series of predictors assessed at the onset of the season, was used to chart out distinct longitudinal trajectories of affective states. Results provided evidence for 3 trajectories of positive affect and 3 trajectories of negative affect. Two of these trajectories were deflected by team selection, a seasonal turning point occurring after the 1st measurement point. Furthermore, the trajectories of positive and negative affective states were predicted by theoretically driven predictors assessed at the start of the season (i.e., self-determination, need satisfaction, athletic identity, and school identity). These results contribute to a better understanding of the motivational, social, and identity-related processes associated with the distinct affective trajectories of athletes participating in elite sport during adolescence.

Change Trajectories for the Youth Outcome Questionnaire Self-Report: Identifying Youth at Risk for Treatment Failure

ERIC Educational Resources Information Center

Cannon, Jennifer A. N.; Warren, Jared S.; Nelson, Philip L.; Burlingame, Gary M.

2010-01-01

This study used longitudinal youth outcome data in routine mental health services to test a system for identifying cases at risk for treatment failure. Participants were 2,715 youth (M age = 14) served in outpatient managed care and community mental health settings. Change trajectories were developed using multilevel modeling of archival data.…

Family Antecedents and Consequences of Trajectories of Depressive Symptoms from Adolescence to Young Adulthood: A Life Course Investigation

ERIC Educational Resources Information Center

Wickrama, K. A. S.; Conger, Rand D.; Lorenz, Frederick O.; Jung, Tony

2008-01-01

Using prospective data from 485 adolescents over a 10-year period, the present study identifies distinct segments of depressive symptom trajectories--a nonsignificant slope during adolescence and a significant negative slope during the transition to adulthood. The study hypothesized that different age-graded life experiences would differentially…

Identifying latent trajectories of personality disorder symptom change: growth mixture modeling in the longitudinal study of personality disorders.

PubMed

Hallquist, Michael N; Lenzenweger, Mark F

2013-02-01

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 4-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. 2013 APA, all rights reserved

Trajectory of body shape across the lifespan and cancer risk

PubMed Central

Song, Mingyang; Willett, Walter C.; Hu, Frank B.; Spiegelman, Donna; Must, Aviva; Wu, Kana; Chan, Andrew T.; Giovannucci, Edward L.

2016-01-01

The influence of adiposity over life course on cancer risk remains poorly understood. We assessed trajectories of body shape from age 5 up to 60 using a group-based modeling approach among 73,581 women from the Nurses’ Health Study and 32,632 men from the Health Professionals Follow-up Study. After a median of approximately 10 years of follow-up, we compared incidence of total and obesity-related cancers (cancers of the esophagus [adenocarcinoma only], colorectum, pancreas, breast [after menopause], endometrium, ovaries, prostate [advanced only], kidney, liver and gallbladder) between these trajectories. We identified 5 distinct trajectories of body shape: lean-stable, lean-moderate increase, lean-marked increase, medium-stable, and heavy-stable/increase. Compared with women in the lean-stable trajectory, those in the lean-marked increase and heavy-stable/increase trajectories had a higher cancer risk in the colorectum, esophagus, pancreas, kidney, and endometrium (relative risk [RR] ranged from 1.22 to 2.56). Early life adiposity was inversely while late life adiposity was positively associated with postmenopausal breast cancer risk. In men, increased body fatness at any life period was associated with a higher risk of esophageal adenocarcinoma and colorectal cancer (RR ranged from 1.23 to 3.01), and the heavy-stable/increase trajectory was associated with a higher risk of pancreatic cancer, but lower risk of advanced prostate cancer. The trajectory-cancer associations were generally stronger for non-smokers and women who did not use menopausal hormone therapy. In conclusion, trajectories of body shape throughout life were related to cancer risk with varied patterns by sex and organ, indicating a role for lifetime adiposity in carcinogenesis. PMID:26704725

Trajectories of martian habitability.

PubMed

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.

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

PubMed

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.

Distinct Trajectories of Massive Recent Gene Gains and Losses in Populations of a Microbial Eukaryotic Pathogen.

PubMed

Hartmann, Fanny E; Croll, Daniel

2017-11-01

Differences in gene content are a significant source of variability within species and have an impact on phenotypic traits. However, little is known about the mechanisms responsible for the most recent gene gains and losses. We screened the genomes of 123 worldwide isolates of the major pathogen of wheat Zymoseptoria tritici for robust evidence of gene copy number variation. Based on orthology relationships in three closely related fungi, we identified 599 gene gains and 1,024 gene losses that have not yet reached fixation within the focal species. Our analyses of gene gains and losses segregating in populations showed that gene copy number variation arose preferentially in subtelomeres and in proximity to transposable elements. Recently lost genes were enriched in virulence factors and secondary metabolite gene clusters. In contrast, recently gained genes encoded mostly secreted protein lacking a conserved domain. We analyzed the frequency spectrum at loci segregating a gene presence-absence polymorphism in four worldwide populations. Recent gene losses showed a significant excess in low-frequency variants compared with genome-wide single nucleotide polymorphism, which is indicative of strong negative selection against gene losses. Recent gene gains were either under weak negative selection or neutral. We found evidence for strong divergent selection among populations at individual loci segregating a gene presence-absence polymorphism. Hence, gene gains and losses likely contributed to local adaptation. Our study shows that microbial eukaryotes harbor extensive copy number variation within populations and that functional differences among recently gained and lost genes led to distinct evolutionary trajectories. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

College students' drinking patterns: trajectories of AUDIT scores during the first four years at university.

PubMed

Johnsson, Kent O; Leifman, Anders; Berglund, Mats

2008-01-01

Changes in AUDIT score trajectories were examined in a student population during their first 4 years at a university, including high-risk consumers and a subsample of low-risk consumers. 359 students were selected for the present study, comprising all high-risk consumers (the 27% with highest scores, i.e. 11 for males and 7 for females) and a randomized sample of low-risk consumers (n = 177 and 182, respectively). The Alcohol Use Disorder Identification Test (AUDIT) was used as screening instrument. Trajectory analyses were made using a semiparametric group-based model. In the low-AUDIT group, five distinct trajectories were identified: three stable non-risky consumption groups (83%) and two increasing groups (17%; from non-risky to risky). In the high-AUDIT group, three groups were identified: two stable high groups (58%) and one decreasing group (from risky to non-risky consumption; 41%). In the integrated model, stable risky consumption comprised 16% of the total sample, decreasing consumption 11%, increasing consumption comprised 13% and stable non-risky consumption 60% of the sample. Gender influenced the trajectories. The pattern of changes in risk consumption is similar to that found in corresponding US studies. (c) 2008 S. Karger AG, Basel

Youth Aggressive/Disruptive Behavior Trajectories and subsequent Gambling among Urban Male Youth

PubMed Central

Martins, Silvia S.; Liu, Weiwei; Hedden, Sarra L.; Goldweber, Asha; Storr, Carla L.; Derevensky, Jeffrey L.; Stinchfield, Randy; Ialongo, Nicholas S.; Petras, Hanno

2013-01-01

Objective This study examines the association between aggressive/disruptive behavior development in two distinct developmental periods, childhood (i.e., grades 1–3) and early adolescence (i.e., grades 6–10) and subsequent gambling behavior in late adolescence up to age 20. Method The sample consists of 310 urban males of predominately minority and low socioeconomic status followed from first grade to late adolescence. Separate general growth mixture models (GGMM) were estimated to explore the heterogeneity in aggressive/disruptive behavior development in the above-mentioned two time periods. Results Three distinct behavior trajectories were identified for each time period: a chronic high, a moderate increasing and a low increasing class for childhood, and a chronic high, a moderate increasing followed by decreasing and a low stable class for early adolescence. There was no association between childhood behavior trajectories and gambling involvement. Males with a moderate behavior trajectory in adolescence where two times more likely to gamble compared to those in the low stable class (OR=1.89, 95% CI=1.11, 3.24). Those with chronic high trajectories during either childhood or early adolescence (OR=2.60, 95% CI=1.06, 6.38; OR=3.19, 95% CI=1.18, 8.64, respectively) were more likely to be at-risk/problem gamblers than those in the low class. Conclusions Aggressive/disruptive behavior development in childhood and early adolescence is associated with gambling and gambling problems in late adolescence among urban male youth. Preventing childhood and youth aggressive/disruptive behavior may be effective to prevent youth problem gambling. PMID:23410188

Peer Victimization Trajectories and Their Association with Children's Affect in Late Elementary School

ERIC Educational Resources Information Center

Biggs, Bridget K.; Vernberg, Eric; Little, Todd D.; Dill, Edward J.; Fonagy, Peter; Twemlow, Stuart W.

2010-01-01

The current study examined peer victimization trajectories for 1528 children from third to fifth grade and the association of those trajectories to children's positive and negative affect. On average, victimization was low to moderate and remained stable (self-report) or increased (peer-reports). In addition, five distinct trajectories were…

Trajectories of diurnal cortisol in mothers of children with autism and other developmental disabilities: Relations to health and mental health

PubMed Central

Dykens, Elisabeth M.; Lambert, Warren

2014-01-01

This study used a stress biomarker, diurnal cortisol, to identify how elevated stress in mothers of children and adults with autism and other disabilities relates to their health and mental health. Based on semi-parametric, group-based trajectory analysis of 91 mothers, two distinctive cortisol trajectories emerged: blunted (63%) or steep (37%). Mothers in the blunted (versus steep) trajectory had higher stress levels, lower health ratings, and 89% of mothers of children with autism, and 53% with other disabilities, belonged to this trajectory. Atypical cortisol awakening responses and evening rises were differentially associated with anxiety, depression, health problems and employment status. Stress-reducing interventions are needed for parents of children with autism and other disabilities that include biomarkers as indices of risk or treatment outcome. PMID:23468069

Positive and negative mood trajectories and their relationship with work ability, self-rated health, and life satisfaction: a 13-year follow-up study.

PubMed

Airila, Auli; Hakanen, Jari J; Luukkonen, Ritva; Lusa, Sirpa; Punakallio, Anne

2013-07-01

To investigate the change trajectories of positive and negative moods and their relationship to work ability, self-rated health, and life satisfaction in a three-wave 13-year follow-up study. The data, consisting of Finnish firefighters (n = 360), were collected via questionnaires in 1996, 1999, and 2009. Four distinct mood trajectories were identified by latent class growth modeling: (1) high positive, (2) high positive but decreasing, (3) moderately positive, and (4) high negative. The trajectory groups were differentially related to well-being. Members of the high positive trajectory had better well-being than members of other latent mood trajectories. Different trajectories exist in positive and negative moods, and these trajectories are differentially related to well-being. Developing work environments in which a positive mood can flourish is beneficial in terms of better well-being among employees.

Developmental Trajectories of Physical Activity, Sports, and Television Viewing During Childhood to Young Adulthood: Iowa Bone Development Study.

PubMed

Kwon, Soyang; Janz, Kathleen F; Letuchy, Elena M; Burns, Trudy L; Levy, Steven M

2015-07-01

The diverse developmental patterns of obesogenic behaviors during childhood and adolescence can be better understood by using new analytic approaches to assess the heterogeneity in variation during growth and development and to map the clustering of behavior patterns. To identify distinct trajectories of daily time spent in moderate- to vigorous-intensity physical activity (MVPA) from ages 5 to 19 years and to examine the associations of MVPA trajectories with sports participation and television viewing trajectories. Cohort members in the prospective population-based Iowa Bone Development Study participated in MVPA assessments via accelerometry from September 16, 1998, to December 9, 2013, at ages 5, 8, 11, 13, 15, 17, and 19 years and completed a questionnaire every 6 months on sports participation and daily time spent in television viewing. Trajectories of MVPA (minutes per day), participation in organized sports (yes or no), and television viewing time (hours per day). Based on the data from 537 participants (50.1% females; 94.6% white), we identified 4 MVPA trajectories: consistently inactive (14.9%), consistently active (18.1%), decreasing moderate physical activity (52.9%), and substantially decreasing high physical activity (14.1%). All participants in the consistently inactive trajectory also followed a trajectory of no participation in sports. The consistently active trajectory was associated with decreasing an already low television viewing trajectory (P < .001). This study provided a nuanced look at the known decrease in MVPA during childhood and adolescence. Sports participation could be a critical way to avoid the consistently inactive pattern. Most important, we identified a subset of participants who maintained a seemingly healthy level of MVPA from childhood to young adulthood. The developmental pathways of physical activity and television viewing behaviors could be related. Additional studies should examine the determinants and health

Longitudinal trajectories of peer relations in children with specific language impairment.

PubMed

Mok, Pearl L H; Pickles, Andrew; Durkin, Kevin; Conti-Ramsden, Gina

2014-05-01

Peer relations is a vulnerable area of functioning in children with specific language impairment (SLI), but little is known about the developmental trajectories of individuals. Peer problems were investigated over a 9-year period (from 7 to 16 years of age) in 171 children with a history of SLI. Discrete factor growth modelling was used to chart developmental trajectories. Multinomial logistic regression analysis was conducted to investigate factors associated with group membership. Four distinct developmental trajectories were identified: low-level/no problems in peer relations (22.2% of participants), childhood-limited problems (12.3%), childhood-onset persistent problems (39.2%) and adolescent-onset problems (26.3%). Risk of poor trajectories of peer relations was greater for those children with pragmatic language difficulties. Prosocial behaviour was the factor most strongly associated with trajectory group membership. Overall, the more prosocial children with better pragmatic language skills and lower levels of emotional problems had less difficulty in developing peer relations. Analysis of developmental trajectories enriches our understanding of social development. A sizeable minority in the present sample sustained positive relations through childhood and adolescence, and others overcame early difficulties to achieve low levels of problems by their early teens; the majority, however, showed childhood-onset persistent or adolescent-onset problems. © 2014 The Authors Journal of Child Psychology and Psychiatry published by John Wiley © Sons Ltd on behalf of Association for Child and Adolescent Mental Health.

Symptom Cluster Trajectories During Chemotherapy in Breast Cancer Outpatients.

PubMed

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.

Trajectories of Martian Habitability

PubMed Central

2014-01-01

Abstract 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. Key Words: Mars—Habitability—Liquid water—Planetary science. Astrobiology 14, 182–203. PMID:24506485

The role of parental alcohol use, parental discipline and antisocial behaviour on adolescent drinking trajectories.

PubMed

Alati, R; Baker, P; Betts, K S; Connor, J P; Little, K; Sanson, A; Olsson, C A

2014-01-01

Parental drinking, harsh parental discipline and adolescent antisocial behaviour have been independently implicated in adolescent alcohol use. Robust prospective studies are required to examine developmental relationships between these factors and their effect on trajectories of alcohol use across adolescence. Data were ascertained at three consecutive adolescent waves (13.5, 15.5 and 17.5 years) from the Australian Temperament Project, a 15-wave (30 year) general population birth cohort in Victoria, Australia. Adolescent alcohol trajectories, adjusted for time-varying measures of parenting and antisocial behaviour, were regressed on time-stable measures of parental alcohol use. The full case analysis comprised 751 individuals with complete data. Two distinct alcohol trajectories were identified across the three adolescent waves after adjusting for time-varying factors: a higher and lower drinking group. Both trajectories increased linearly over the study period. Antisocial behaviour was positively associated with both trajectories while harsh parental discipline was positively associated with alcohol use in the lower-use group only. Increased maternal and paternal drinking at 13.5 years placed teenagers at a greater risk of being included in the high-risk trajectory. Parental drinking was the strongest predictor of different drinking trajectories in adolescence. This finding underscores the importance of comprehensive public heath approaches that target both parental and adolescent drinking attitudes and behaviour.

Adaptation of Drosophila to a novel laboratory environment reveals temporally heterogeneous trajectories of selected alleles.

PubMed

Orozco-terWengel, Pablo; Kapun, Martin; Nolte, Viola; Kofler, Robert; Flatt, Thomas; Schlötterer, Christian

2012-10-01

The genomic basis of adaptation to novel environments is a fundamental problem in evolutionary biology that has gained additional importance in the light of the recent global change discussion. Here, we combined laboratory natural selection (experimental evolution) in Drosophila melanogaster with genome-wide next generation sequencing of DNA pools (Pool-Seq) to identify alleles that are favourable in a novel laboratory environment and traced their trajectories during the adaptive process. Already after 15 generations, we identified a pronounced genomic response to selection, with almost 5000 single nucleotide polymorphisms (SNP; genome-wide false discovery rates < 0.005%) deviating from neutral expectation. Importantly, the evolutionary trajectories of the selected alleles were heterogeneous, with the alleles falling into two distinct classes: (i) alleles that continuously rise in frequency; and (ii) alleles that at first increase rapidly but whose frequencies then reach a plateau. Our data thus suggest that the genomic response to selection can involve a large number of selected SNPs that show unexpectedly complex evolutionary trajectories, possibly due to nonadditive effects. © 2012 Blackwell Publishing Ltd.

Group-based developmental BMI trajectories, polycystic ovary syndrome, and gestational diabetes: a community-based longitudinal study.

PubMed

Kakoly, Nadira Sultana; Earnest, Arul; Moran, Lisa J; Teede, Helena J; Joham, Anju E

2017-11-06

Obesity is common in young women, increasing insulin resistance (IR) and worsening pregnancy complications, including gestational diabetes (GDM). Women with polycystic ovary syndrome (PCOS) are commonly obese, which aggravates the severity of PCOS clinical expression. Relationships between these common insulin-resistant conditions, however, remain unclear. We conducted a secondary analysis of the Australian Longitudinal Study on Women's Health (ALSWH) database, including data from 8009 women aged 18-36 years across six surveys. We used latent-curve growth modelling to identify distinct body mass index (BMI) trajectories and multinomial logistic regression to explore sociodemographic and health variables characterizing BMI group membership. Logistic regression was used to assess independent risk of GDM. A total of 662 women (8.29%, 95% CI 7.68-8.89) reported PCOS. Three distinct BMI trajectories emerged, namely low stable (LSG) (63.8%), defined as an average trajectory remaining at ~25 kg/m 2 ; moderately rising (MRG) (28.8%), a curvilinear trajectory commencing in a healthy BMI and terminating in the overweight range; and high-rising (HRG) (7.4%), a curvilinear trajectory starting and terminating in the obese range. A high BMI in early reproductive life predicted membership in higher trajectories. The HRG BMI trajectory was independently associated with GDM (OR 2.50, 95% CI 1.80-3.48) and was a stronger correlate than PCOS (OR 1.89, 95% CI 1.41-2.54), maternal age, socioeconomic status, or parity. Our results suggest heterogeneity in BMI change among Australian women of reproductive age, with and without PCOS. Reducing early adult life weight represents an ideal opportunity to intervene at an early stage of reproductive life and decreases the risk of long-term metabolic complications such as GDM.

Developmental trajectories of marital happiness in continuously married individuals: a group-based modeling approach.

PubMed

Anderson, Jared R; Van Ryzin, Mark J; Doherty, William J

2010-10-01

Most contemporary studies of change in marital quality over time have used growth curve modeling to describe continuously declining mean curves. However, there is some evidence that different trajectories of marital quality exist for different subpopulations. Group-based trajectory modeling provides the opportunity to conduct an empirical investigation of the variance in marital quality trajectories. We applied this method to analyze data from continuously married individuals from the Marital Instability over the Life Course Study (N = 706). Instead of a single continuously declining trajectory of marital happiness, we found 5 distinct trajectories. Nearly two thirds of participants reported high and stable levels of happiness over time, and the other one third showed either a pattern of continuous low happiness, low happiness that subsequently declined, or a curvilinear pattern of high happiness, decline, and recovery. Marital problems, time spent in shared activities, and (to a lesser degree) economic hardship were able to distinguish trajectory group membership. Our results suggest that marital happiness may have multiple distinct trajectories across reasonably diverse populations. Implications for theory, research, and practice are discussed.

Developmental trajectories of self-injurious behavior, suicidal behavior and substance misuse and their association with adolescent borderline personality pathology.

PubMed

Nakar, Orit; Brunner, Romuald; Schilling, Oliver; Chanen, Andrew; Fischer, Gloria; Parzer, Peter; Carli, Vladimir; Wasserman, Danuta; Sarchiapone, Marco; Wasserman, Camilla; Hoven, Christina W; Resch, Franz; Kaess, Michael

2016-06-01

Adolescent risk-taking and self-harm behaviors are associated with affect dysregulation and impulsivity, both core features of borderline personality disorder (BPD). We hypothesized that the developmental courses of these behaviors i) tend to cluster rather than appear individually, and ii) might indicate adolescent BPD pathology. Therefore, we explored the developmental trajectories of self-injurious behavior (SIB), suicidal behavior (SB) and substance misuse (SM) in a community sample of adolescents; and we investigated the trajectories' overlap and its associations with BPD traits. 513 adolescents, aged 15-17 years, were followed for two years as part of the Saving and Empowering Young Lives in Europe study and its subsequent follow-up. Distinct developmental trajectories were explored using general growth mixture modeling. Three distinct classes were identified within each of the harmful behaviors SIB, SB and SM. Both the high-risk SIB trajectory and the high-risk SB trajectory demonstrated elevated initial degree of engagement, followed by a gradual decrease. The SM high-risk trajectory had a medium initial degree of engagement, which increased over time. There was a high degree of overlap (80-90%) among the high-risk trajectories for the three behaviors (SIB, SB and SM), and this overlap was significantly associated with elevated levels of BPD pathology. The data collection was based on participants' self-report. The findings indicate a similar pattern of reduction over time between SIB and SB for the high-risk trajectories, whereas the high-risk trajectories for SM show a pattern of increase over time. The observed symptom shift is associated with borderline personality pathology in adolescents. Therefore these behaviors might represent early indicators of risk supporting potential early detection. Copyright © 2016 Elsevier B.V. All rights reserved.

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

PubMed

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.

Longitudinal trajectory patterns of social support: correlates and associated mental health in an Australian national cohort of young women.

PubMed

Holden, Libby; Dobson, Annette J; Ware, Robert S; Hockey, Richard; Lee, Christina

2015-09-01

Although social support is a significant contributor to health and well-being, little is known about patterns of perceived social support over time in young adulthood. It is also unclear which personal characteristics are associated with different patterns, and whether there is an association between social support and mental health over time. We explore these issues in a large national cohort of young women. We used six waves of longitudinal data spanning 16 years, from 10,369 women from the Australian Longitudinal Study on Women's Health, initially aged 18-23. We used group-based trajectory modelling to identify patterns of social support across Surveys 2-6; multinomial logistic regression to identify socio-demographic and health-behaviour predictors at Survey 1 and correlates at Survey 6 for each trajectory group; and generalised linear mixed modelling to estimate mean levels of mental health over the trajectory period for each group, adjusted for confounders. Four distinct trajectory groups of social support were identified: 'High' (58.5 %), 'Decreasing' (20.6 %), 'Low' (9.3 %), and 'Increasing' (11.6 %). Poor health and living outside metropolitan areas at both Surveys 1 and 6 were characteristics of women in all trajectory groups other than the 'High' group, as were early motherhood and being un-partnered at age 34-39. Other characteristics were specific to one or two trajectory groups. Patterns of mental health over time were consistent with patterns of social support. Longitudinal trajectory patterns of social support are associated with mental health, health behaviours, and demographic factors even in early adulthood.

PANTHER. Trajectory Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rintoul, Mark Daniel; Wilson, Andrew T.; Valicka, Christopher G.

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 generallymore » 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.« less

Children's Postdisaster Trajectories of PTS Symptoms: Predicting Chronic Distress

ERIC Educational Resources Information Center

La Greca, Annette M.; Lai, Betty S.; Llabre, Maria M.; Silverman, Wendy K.; Vernberg, Eric M.; Prinstein, Mitchell J.

2013-01-01

Background: There are no studies of the distinct trajectories of children's psychological distress over the first year after a destructive natural disaster and the determinants of these trajectories. Objective: We examined these issues using an existing dataset of children exposed to Hurricane Andrew, one of the most devastating natural…

Identification of posttraumatic growth trajectories in the first year after breast cancer surgery.

PubMed

Wang, Ashley Wei-Ting; Chang, Cheng-Shyong; Chen, Shou-Tung; Chen, Dar-Ren; Hsu, Wen-Yau

2014-12-01

Empirical studies of the relationship between posttraumatic growth (PTG) and adjustment outcomes reveal a fairly inconclusive picture. We argue that the inconsistent findings are likely due to the heterogeneity of the PTG experience over time. In this regard, we predicted that individuals with different PTG trajectories vary in the level of adjustment and the correlational patterns between PTG and adjustment. Participants were 124 Taiwanese women who underwent surgery for breast cancer. Measures of PTG and adjustment variables, including positive affect, negative affect, mental and physical quality of life, anxiety, and depression, were assessed at 1 day and 3, 6, and 12 months after surgery. A group-based trajectory model was used to identify subpopulations of individuals who shared homogenous growth patterns. Then, we determined whether the trajectory predicted adjustment at 12 months after surgery. The correlations between PTG and adjustment outcomes were computed in each subpopulation across every time point. The patients were categorized into the following four groups, which showed very different patterns of PTG change over the first year after breast cancer surgery: stable high (27.4%), high decreasing (39.4%), low increasing (16.9%), and low decreasing (16.9%). Differences in the level of adjustment at 12 months and the patterns of the correlations across time were found among these latent subgroups This study was the first longitudinal examination of PTG trajectories and their different levels of adjustment. The findings support our argument that identifying distinct PTG trajectories can better determine the nature of the relationship between PTG and adjustment. Copyright © 2014 John Wiley & Sons, Ltd.

Predictors of PTSD Treatment Response Trajectories in a Sample of Childhood Sexual Abuse Survivors: The Roles of Social Support, Coping, and PTSD Symptom Clusters.

PubMed

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.

The impact of youth, family, peer and neighborhood risk factors on developmental trajectories of risk involvement from early through middle adolescence.

PubMed

Wang, Bo; Deveaux, Lynette; Li, Xiaoming; Marshall, Sharon; Chen, Xinguang; Stanton, Bonita

2014-04-01

Few studies have analyzed the development course beginning in pre-/early adolescence of overall engagement in health-risk behaviors and associated social risk factors that place individuals in different health-risk trajectories through mid-adolescence. The current longitudinal study identified 1276 adolescents in grade six and followed them for three years to investigate their developmental trajectories of risk behaviors and to examine the association of personal and social risk factors with each trajectory. Group-based trajectory modeling was applied to identify distinctive trajectory patterns of risk behaviors. Multivariate multinomial logistic regression analyses were performed to examine the effects of the personal and social risk factors on adolescents' trajectories. Three gender-specific behavioral trajectories were identified for males (55.3% low-risk, 37.6% moderate-risk, increasing, and 7.1% high-risk, increasing) and females (41.4% no-risk, 53.4% low-risk, increasing and 5.2% moderate to high-risk, increasing). Sensation-seeking, family, peer, and neighborhood factors at baseline predicted following the moderate-risk, increasing trajectory and the high-risk, increasing trajectory in males; these risk factors predicted following the moderate to high-risk, increasing trajectory in females. The presence of all three social risk factors (high-risk neighborhood, high-risk peers and low parental monitoring) had a dramatic impact on increased probability of being in a high-risk trajectory group. These findings highlight the developmental significance of early personal and social risk factors on subsequent risk behaviors in early to middle adolescence. Future adolescent health behavior promotion interventions might consider offering additional prevention resources to pre- and early adolescent youth who are exposed to multiple contextual risk factors (even in the absence of risk behaviors) or youth who are early-starters of delinquency and substance use behaviors

Exploring 2.5-Year Trajectories of Functional Decline in Older Adults by Applying a Growth Mixture Model and Frequency of Outings as a Predictor: A 2010-2013 JAGES Longitudinal Study.

PubMed

Saito, Junko; Kondo, Naoki; Saito, Masashige; Takagi, Daisuke; Tani, Yukako; Haseda, Maho; Tabuchi, Takahiro; Kondo, Katsunori

2018-06-23

We explored the distinct trajectories of functional decline among older adults in Japan, and evaluated whether the frequency of outings, an important indicator of social activity, predicts the identified trajectories. We analyzed data on 2,364 adults aged 65 years or older from the Japan Aichi Gerontological Evaluation Study. Participants were initially independent and later developed functional disability during a 31-month follow-up period. We used the level of long-term care needs certified in the public health insurance system as a proxy of functional ability and linked the fully tracked data of changes in the care levels to the baseline data. A low frequency of outings was defined as leaving one's home less than once per week at baseline. We applied a growth mixture model to identify trajectories in functional decline by sex and then examined the association between the frequency of outings and the identified trajectories using multinomial logistic regression analysis. Three distinct trajectories were identified: "slowly declining" (64.3% of men and 79.7% of women), "persistently disabled" (4.5% and 3.7%, respectively), and "rapidly declining" (31.3% and 16.6%, respectively). Men with fewer outings had 2.14 times greater odds (95% confidence interval, 1.03-4.41) of being persistently disabled. The association between outing frequency and functional decline trajectory was less clear statistically among women. While the majority of older adults showed a slow functional decline, some showed persistent moderate disability. Providing more opportunities to go out or assistance in that regard may be important for preventing persistent disability, and such needs might be greater among men.

Trajectories of perceived emotional and physical distress in patients with an implantable cardioverter defibrillator.

PubMed

van den Broek, Krista C; Kupper, Nina; van der Voort, Pepijn H; Alings, Marco; Denollet, Johan; Nyklíček, Ivan

2014-02-01

Little is known about the course of emotional and physical distress in patients with an implantable cardioverter defibrillator (ICD). We examined (1) trajectories of emotional and physical distress in the first 18 months postimplantation and (2) predictors of these trajectories, including demographical, clinical, and personality factors. Dutch patients with an ICD (N = 645) completed measures on anxiety, depression, somatic symptoms, and perceived disability at the time of implantation, and 2, 12, and 18 months postimplantation. Measures on Type D personality (tendency to inhibit the expression of negative emotions) and anxiety sensitivity (tendency to fear anxiety-related sensations) were also completed at baseline. Latent class analysis (LatentGOLD) identified six to seven distinct trajectories, varying largely in overall levels of distress, and remaining relatively stable after a small initial decline. Multinomial regression showed that Type D personality and anxiety sensitivity were the most prominent predictors, particularly of trajectories that reflected higher distress levels. Cardiac resynchronization therapy and coronary artery disease also increased the risk for distress, whereas ICD indication and shocks did not. The course of emotional and physical distress may be relatively stable after ICD implantation. In clinical practice, identification of patients with high risk of higher levels of emotional and physical distress may be warranted; as such, patients with high levels of anxiety sensitivity or a Type D personality should be identified and offered behavioral support.

Trajectory Design Tools for Libration and Cis-Lunar Environments

NASA Technical Reports Server (NTRS)

Folta, David C.; Webster, Cassandra M.; Bosanac, Natasha; Cox, Andrew; Guzzetti, Davide; Howell, Kathleen C.

2016-01-01

Innovative trajectory design tools are required to support challenging multi-body regimes with complex dynamics, uncertain perturbations, and the integration of propulsion influences. Two distinctive tools, Adaptive Trajectory Design and the General Mission Analysis Tool have been developed and certified to provide the astrodynamics community with the ability to design multi-body trajectories. In this paper we discuss the multi-body design process and the capabilities of both tools. Demonstrable applications to confirmed missions, the Lunar IceCube Cubesat lunar mission and the Wide-Field Infrared Survey Telescope (WFIRST) Sun-Earth L2 mission, are presented.

Distinct Host Tropism Protein Signatures to Identify Possible Zoonotic Influenza A Viruses.

PubMed

Eng, Christine L P; Tong, Joo Chuan; Tan, Tin Wee

2016-01-01

Zoonotic influenza A viruses constantly pose a health threat to humans as novel strains occasionally emerge from the avian population to cause human infections. Many past epidemic as well as pandemic strains have originated from avian species. While most viruses are restricted to their primary hosts, zoonotic strains can sometimes arise from mutations or reassortment, leading them to acquire the capability to escape host species barrier and successfully infect a new host. Phylogenetic analyses and genetic markers are useful in tracing the origins of zoonotic infections, but there are still no effective means to identify high risk strains prior to an outbreak. Here we show that distinct host tropism protein signatures can be used to identify possible zoonotic strains in avian species which have the potential to cause human infections. We have discovered that influenza A viruses can now be classified into avian, human, or zoonotic strains based on their host tropism protein signatures. Analysis of all influenza A viruses with complete proteome using the host tropism prediction system, based on machine learning classifications of avian and human viral proteins has uncovered distinct signatures of zoonotic strains as mosaics of avian and human viral proteins. This is in contrast with typical avian or human strains where they show mostly avian or human viral proteins in their signatures respectively. Moreover, we have found that zoonotic strains from the same influenza outbreaks carry similar host tropism protein signatures characteristic of a common ancestry. Our results demonstrate that the distinct host tropism protein signature in zoonotic strains may prove useful in influenza surveillance to rapidly identify potential high risk strains circulating in avian species, which may grant us the foresight in anticipating an impending influenza outbreak.

Longitudinal Trajectories of Cigarette Smoking Following Rape

PubMed Central

Amstadter, Ananda B.; Resnick, Heidi S.; Nugent, Nicole R.; Acierno, Ron; Rheingold, Alyssa A.; Minhinnett, Robin; Kilpatrick, Dean G.

2009-01-01

Although prior research has identified increases in cigarette smoking following trauma exposure, no studies have examined longitudinal trajectories of smoking following rape. The present investigation identifies and characterizes longitudinal (< 3 months, 3-6 months, and > 6 months post-assault) trajectories of smoking (N = 152) following a rape in a sample of 268 sexual assault victims participating in a forensic medical exam. Further, we examine acute predictors of subsequent smoking trajectories. Of participants endorsing smoking post-rape, a two-class solution was identified, with the majority of participants (74.6%) evidencing moderate smoking with a slight decrease over time and remaining participants showing heavy smoking with a slight increase over time. Having sustained an injury, minority status, and post-exam distress all predicted subsequent smoking trajectory. PMID:19370699

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.

PubMed

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 < 0.05). Overall, the combined trajectories indicated three major distinct patterns: (1) dramatic and sustained early improvement in both negative and positive symptoms (n = 70, 18%), (2) mild and sustained improvement in negative and positive symptoms (n = 237, 59%), and (3) no improvement

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

PubMed Central

2013-01-01

Background 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. Methods 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. Results 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 < 0.05). Overall, the combined trajectories indicated three major distinct patterns: 1) dramatic and sustained early improvement in both negative and positive symptoms (n = 70, 18%), 2) mild and sustained improvement in negative and positive symptoms (n = 237, 59

Postnatal Developmental Trajectories of Neural Circuits in the Primate Prefrontal Cortex: Identifying Sensitive Periods for Vulnerability to Schizophrenia

PubMed Central

Hoftman, Gil D.; Lewis, David A.

2011-01-01

Schizophrenia is a disorder of cognitive neurodevelopment with characteristic abnormalities in working memory attributed, at least in part, to alterations in the circuitry of the dorsolateral prefrontal cortex. Various environmental exposures from conception through adolescence increase risk for the illness, possibly by altering the developmental trajectories of prefrontal cortical circuits. Macaque monkeys provide an excellent model system for studying the maturation of prefrontal cortical circuits. Here, we review the development of glutamatergic and γ-aminobutyric acid (GABA)-ergic circuits in macaque monkey prefrontal cortex and discuss how these trajectories may help to identify sensitive periods during which environmental exposures, such as those associated with increased risk for schizophrenia, might lead to the types of abnormalities in prefrontal cortical function present in schizophrenia. PMID:21505116

Distinct meteoroid families identified on the lunar seismograms

NASA Technical Reports Server (NTRS)

Oberst, Jurgen; Nakamura, Yosio

1987-01-01

The meteoroid impact-seismic activity data recorded by the Apollo lunar seismic network is examined. The study investigates the difference in temporal distribution between large and small impacts, clustering of impacts in a two-dimensional space of the time of the year and the time of the month, and the relationship of these observations with terrestrial observations. Several distinct families of meteoroids impacting the moon are identified. Most meteoroids producing small impact-seismic events, including ones associated with cometary showers, appear to approach from retrograde heliocentric orbits. In contrast, most meteoroids associated with large impact-seismic events appear to approach from prograde orbits; the observation is consistent with a hypothesis that many of them represent stony asteroidal material. It is suggested that the previously reported discrepancy between lunar and terrestrial meteoroid-flux estimates may be due to the differences in lunar and terrestrial detection efficiency among various families of meteoroids.

Trajectory Recognition as the Basis for Object Individuation: A Functional Model of Object File Instantiation and Object-Token Encoding

PubMed Central

Fields, Chris

2011-01-01

The perception of persisting visual objects is mediated by transient intermediate representations, object files, that are instantiated in response to some, but not all, visual trajectories. The standard object file concept does not, however, provide a mechanism sufficient to account for all experimental data on visual object persistence, object tracking, and the ability to perceive spatially disconnected stimuli as continuously existing objects. Based on relevant anatomical, functional, and developmental data, a functional model is constructed that bases visual object individuation on the recognition of temporal sequences of apparent center-of-mass positions that are specifically identified as trajectories by dedicated “trajectory recognition networks” downstream of the medial–temporal motion-detection area. This model is shown to account for a wide range of data, and to generate a variety of testable predictions. Individual differences in the recognition, abstraction, and encoding of trajectory information are expected to generate distinct object persistence judgments and object recognition abilities. Dominance of trajectory information over feature information in stored object tokens during early infancy, in particular, is expected to disrupt the ability to re-identify human and other individuals across perceptual episodes, and lead to developmental outcomes with characteristics of autism spectrum disorders. PMID:21716599

Illness trajectories in patients with amyotrophic lateral sclerosis: How illness progression is related to life narratives and interpersonal relationships.

PubMed

Cipolletta, Sabrina; Gammino, Giorgia Rosamaria; Palmieri, Arianna

2017-12-01

To identify illness trajectories in amyotrophic lateral sclerosis by analysing personal, social and functional dimensions related to amyotrophic lateral sclerosis progression. Previous studies have considered some psychological distinct variables that may moderate illness progression, but no research has combined an extensive qualitative understanding of amyotrophic lateral sclerosis patients' psychological characteristics and illness progression. A mixed-methods approach was used to combine quantitative and qualitative measures. Illness progression was assessed through a longitudinal design. Eighteen patients with amyotrophic lateral sclerosis attending a Neurology Department in northern Italy participated in the study. Semi-structured interviews to explore personal experience, and dependency grids to assess the distribution of dependency; ALSFRS-R and neuropsychological screening were, respectively, used to measure physical and cognitive impairment. To assess the progression of the disease, ALSFRS-R was re-administered after 8 months and mortality rate was considered. Data were analysed using the grounded theory approach. Illness progression changed according to the perception of the disease, the trust placed in medical care, self-construction and the distribution of dependency. Based on these categories, cases that had similar experiences were grouped, and four illness trajectories were identified: aggressiveness, threat, constriction and guilt. The findings suggest that it is possible to identify different illness trajectories in amyotrophic lateral sclerosis. Personalised intervention strategies may be construed based on the different trajectories identified. © 2017 John Wiley & Sons Ltd.

Symptom Trajectories in Children Receiving Treatment for Leukemia: A Latent Class Growth Analysis With Multitrajectory Modeling.

PubMed

Hockenberry, Marilyn J; Hooke, Mary C; Rodgers, Cheryl; Taylor, Olga; Koerner, Kari M; Mitby, Pauline; Moore, Ida; Scheurer, Michael E; Pan, Wei

2017-07-01

Cancer treatment symptoms play a major role in determining the health of children with cancer. Symptom toxicity often results in complications, treatment delays, and therapy dose reductions that can compromise leukemia therapy and jeopardize chances for long-term survival. Critical to understanding symptom experiences during treatment is the need for exploration of "why" inter-individual symptom differences occur; this will determine who may be most susceptible to treatment toxicities. This study examined specific symptom trajectories during the first 18 months of childhood leukemia treatment. Symptom measures included fatigue, sleep disturbances, pain, nausea, and depression. Symptom trajectories of 236 children with leukemia three to 18 years old were explored prospectively over four periods: initiation of post-induction therapy, four and eight post-induction therapy, and the last time point was at the beginning of maintenance/continuation therapy. Latent class growth analysis was used to classify patients into distinctive groups with similar symptom trajectories based on patients' response patterns on the symptom measures over time. Three latent classes of symptom trajectories were identified and classified into mild, moderate, and severe symptom trajectories. The only demographic characteristic with a significant relationship to membership in the latent class symptom trajectories was race/ethnicity. All other demographic characteristics including leukemia risk levels showed no significant relationships. This study is unique in that groups of patients with similar symptoms were identified rather than groups of symptoms. Further research using latent class growth analysis is needed. Copyright © 2017 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.

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

PubMed

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.

Mothers’ Trajectories of Depressive Symptoms Across Mexican-Origin Adolescent Daughters’ Transition to Parenthood

PubMed Central

Updegraff, Kimberly A.; Perez-Brena, Norma J.; Umaña-Taylor, Adriana J.; Jahromi, Laudan B.; Harvey-Mendoza, Elizabeth C.

2013-01-01

This study draws from a life-course perspective in examining trajectories of mothers’ depressive symptoms across their adolescent daughters’ adjustment to parenthood in 204 Mexican-origin families using latent class growth analysis. Four distinct trajectories were identified based on mothers’ depressive symptoms prior to the birth and 10 and 24 months postpartum. Two trajectories were characterized by stable levels of depressive symptoms but were differentiated in their levels of symptoms (i.e., High/Stable and Low/Stable). The remaining two trajectories were characterized by changes from pre- to post-birth, with one group exhibiting increases in depressive symptoms (i.e., Low/Post-Birth Increase) and the other group characterized by decreases in depressive symptoms (i.e., Low/Post-Birth Decrease). Consistent with a risk and resilience perspective, mothers with more disadvantaged socioeconomic circumstances and fewer intrapersonal resources (i.e., self-esteem, ethnic identity affirmation) were more likely to be members of the High/Stable group. In addition, daughters of mothers in the High/Stable group were more likely to have lower self-esteem as compared to daughters in the other three groups. Collectively, these findings suggested that the High/Stable group was at risk for adjustment difficulties from the third trimester to two years postpartum. In contrast, membership in the Low/Post-Birth Decrease trajectory group was associated with lower depressive symptoms and higher self-esteem for mothers and daughters. Findings point to the need to identify mothers who are at risk for depressive symptoms during their adolescent daughters’ pregnancy and offer prevention and intervention programs that reduce risks and enhance protective factors. PMID:23750520

Developmental Trajectories of Anxiety Symptoms in Early Adolescence: The Influence of Anxiety Sensitivity

PubMed Central

Allan, Nicholas P.; Capron, Daniel W.; Lejuez, Carl W.; Reynolds, Elizabeth K.; MacPherson, Laura; Schmidt, Norman B.

2014-01-01

Children and adolescents seem to suffer from anxiety disorders at rates similar to adults. Interestingly, anxiety symptoms appear to generally decline over time within children as evidenced by lower rates in early and middle adolescence. There is some evidence that there may be heterogeneous subpopulations of adolescent children with different trajectories of anxiety symptoms, including a class of adolescents with elevated levels of anxiety that do not dissipate over time. Anxiety sensitivity has been identified as an important risk factor in the development of anxiety psychopathology. This study prospectively examined the development of anxiety symptoms in a sample of 277 adolescents (Mage=11.52; 44 % female, 56 % male) over a 3 year period including the influence of anxiety sensitivity on this development. Further, this study investigated whether there were distinct classes of adolescents based on their anxiety symptom trajectories and including anxiety sensitivity as a predictor. Consistent with other reports, findings indicated an overall decline in anxiety symptoms over time in the sample. However, three classes of adolescents were found with distinct anxiety symptom trajectories and anxiety sensitivity was an important predictor of class membership. Adolescents with elevated anxiety sensitivity scores were more likely to be classified as having high and increasing anxiety symptoms over time versus having moderate to low and decreasing anxiety symptoms over time. There are important implications for identification of adolescents and children who are at risk for the development of an anxiety disorder. PMID:24062146

Developmental trajectories of anxiety symptoms in early adolescence: the influence of anxiety sensitivity.

PubMed

Allan, Nicholas P; Capron, Daniel W; Lejuez, Carl W; Reynolds, Elizabeth K; MacPherson, Laura; Schmidt, Norman B

2014-05-01

Children and adolescents seem to suffer from anxiety disorders at rates similar to adults. Interestingly, anxiety symptoms appear to generally decline over time within children as evidenced by lower rates in early and middle adolescence. There is some evidence that there may be heterogeneous subpopulations of adolescent children with different trajectories of anxiety symptoms, including a class of adolescents with elevated levels of anxiety that do not dissipate over time. Anxiety sensitivity has been identified as an important risk factor in the development of anxiety psychopathology. This study prospectively examined the development of anxiety symptoms in a sample of 277 adolescents (M age = 11.52; 44 % female, 56 % male) over a 3 year period including the influence of anxiety sensitivity on this development. Further, this study investigated whether there were distinct classes of adolescents based on their anxiety symptom trajectories and including anxiety sensitivity as a predictor. Consistent with other reports, findings indicated an overall decline in anxiety symptoms over time in the sample. However, three classes of adolescents were found with distinct anxiety symptom trajectories and anxiety sensitivity was an important predictor of class membership. Adolescents with elevated anxiety sensitivity scores were more likely to be classified as having high and increasing anxiety symptoms over time versus having moderate to low and decreasing anxiety symptoms over time. There are important implications for identification of adolescents and children who are at risk for the development of an anxiety disorder.

Developmental Trajectories of Social Skills during Early Childhood and Links to Parenting Practices in a Japanese Sample.

PubMed

Takahashi, Yusuke; Okada, Kensuke; Hoshino, Takahiro; Anme, Tokie

2015-01-01

This study used data from a nationwide survey in Japan to model the developmental course of social skills during early childhood. The goals of this study were to identify longitudinal profiles of social skills between 2 and 5 years of age using a group-based trajectory approach, and to investigate whether and to what extent parenting practices at 2 years of age predicted developmental trajectories of social skills during the preschool period. A relatively large sample of boys and girls (N > 1,000) was assessed on three social skill dimensions (Cooperation, Self-control, and Assertion) at four time points (ages 2, 3, 4, and 5), and on four parenting practices (cognitive and emotional involvement, avoidance of restriction and punishment, social stimulation, and social support for parenting) at age 2. The results indicated that for each social skill dimension, group-based trajectory models identified three distinct trajectories: low, moderate, and high. Multinomial regression analysis revealed that parenting practice variables showed differential contributions to development of child social skills. Specifically, Cooperation and Assertion were promoted by cognitive and emotional involvement, Self-control by social stimulation, and Assertion by avoidance of restriction and punishment. Abundant social support for parenting was not associated with higher child social skills trajectories. We found heterogeneity in developmental profiles of social skills during the preschool ages, and we identified parenting practices that contributed to different patterns of social skills development. We discussed the implications of higher-quality parenting practices on the improvement of child social skills across early childhood.

Developmental Trajectories of Social Skills during Early Childhood and Links to Parenting Practices in a Japanese Sample

PubMed Central

Takahashi, Yusuke; Okada, Kensuke; Hoshino, Takahiro; Anme, Tokie

2015-01-01

This study used data from a nationwide survey in Japan to model the developmental course of social skills during early childhood. The goals of this study were to identify longitudinal profiles of social skills between 2 and 5 years of age using a group-based trajectory approach, and to investigate whether and to what extent parenting practices at 2 years of age predicted developmental trajectories of social skills during the preschool period. A relatively large sample of boys and girls (N > 1,000) was assessed on three social skill dimensions (Cooperation, Self-control, and Assertion) at four time points (ages 2, 3, 4, and 5), and on four parenting practices (cognitive and emotional involvement, avoidance of restriction and punishment, social stimulation, and social support for parenting) at age 2. The results indicated that for each social skill dimension, group-based trajectory models identified three distinct trajectories: low, moderate, and high. Multinomial regression analysis revealed that parenting practice variables showed differential contributions to development of child social skills. Specifically, Cooperation and Assertion were promoted by cognitive and emotional involvement, Self-control by social stimulation, and Assertion by avoidance of restriction and punishment. Abundant social support for parenting was not associated with higher child social skills trajectories. We found heterogeneity in developmental profiles of social skills during the preschool ages, and we identified parenting practices that contributed to different patterns of social skills development. We discussed the implications of higher-quality parenting practices on the improvement of child social skills across early childhood. PMID:26267439

Romantic attraction and adolescent smoking trajectories.

PubMed

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.

Trajectories of maternal depressive symptoms during pregnancy and the first 12 months postpartum and child externalizing and internalizing behavior at three years

PubMed Central

Kehler, Heather; Austin, Marie-Paule; Mughal, Muhammad Kashif; Wajid, Abdul; Vermeyden, Lydia; Benzies, Karen; Brown, Stephanie; Stuart, Scott; Giallo, Rebecca

2018-01-01

Background Most evidence of the association between maternal depression and children’s development is limited by being cross-sectional. To date, few studies have modelled trajectories of maternal depressive symptoms from pregnancy through the early postpartum years and examined their association with social emotional and behavior functioning in preschool children. The objectives of this study were to: 1) identify distinct groups of women defined by their trajectories of depressive symptoms across four time points from mid-pregnancy to one year postpartum; and 2) examine the associations between these trajectories and child internalizing and externalizing behaviors. Methods We analyzed data from the All Our Families (AOF) study, a large, population based pregnancy cohort of mother-child dyads in Alberta, Canada. The AOF study is an ongoing pregnancy cohort study designed to investigate relationships between the prenatal and early life period and outcomes for children and mothers. Maternal depressive symptoms were assessed using the Edinburgh Postnatal Depression Scale. Children’s behavioral functioning at age 3 was assessed using the Behavior Scales developed for the Canadian National Longitudinal Survey of Children and Youth. Longitudinal latent class analysis was conducted to identify trajectories of women’s depressive symptoms across four time points from pregnancy to 1 year postpartum. We used multivariable logistic regression to assess the relationship between trajectories of maternal depressive symptoms and children’s behavior, while adjusting for other significant maternal, child and psychosocial factors. Results 1983 participants met eligibility criteria. We identified four distinct trajectories of maternal depressive symptoms: low level (64.7%); early postpartum (10.9%); subclinical (18.8%); and persistent high (5.6%). In multivariable models, the proportion of children with elevated behavior symptoms was highest for children whose mothers had

Automated Cooperative Trajectories

NASA Technical Reports Server (NTRS)

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.

Management by Trajectory

NASA Image and Video Library

2018-05-05

This video provides an overview of the Management by Trajectory (MBT) concept of operations developed as part on a NASA Research Announcement (NRA) sponsored by NASA’s Aviation Operations and Safety Program (AOSP). Possible changes in roles and responsibilities among various agents in the air traffic system are identified, and the concept’s potential impact on system safety in a way that brings the National Airspace System (NAS) closer to a full Trajectory-Based Operations (TBO) environment is described.

The impact of covariance misspecification in group-based trajectory models for longitudinal data with non-stationary covariance structure.

PubMed

Davies, Christopher E; Glonek, Gary Fv; Giles, Lynne C

2017-08-01

One purpose of a longitudinal study is to gain a better understanding of how an outcome of interest changes among a given population over time. In what follows, a trajectory will be taken to mean the series of measurements of the outcome variable for an individual. Group-based trajectory modelling methods seek to identify subgroups of trajectories within a population, such that trajectories that are grouped together are more similar to each other than to trajectories in distinct groups. Group-based trajectory models generally assume a certain structure in the covariances between measurements, for example conditional independence, homogeneous variance between groups or stationary variance over time. Violations of these assumptions could be expected to result in poor model performance. We used simulation to investigate the effect of covariance misspecification on misclassification of trajectories in commonly used models under a range of scenarios. To do this we defined a measure of performance relative to the ideal Bayesian correct classification rate. We found that the more complex models generally performed better over a range of scenarios. In particular, incorrectly specified covariance matrices could significantly bias the results but using models with a correct but more complicated than necessary covariance matrix incurred little cost.

Who Were the Early Adopters of Dabigatran? An Application of Group-Based Trajectory Models

PubMed Central

Lo-Ciganic, Wei-Hsuan; Gellad, Walid F.; Huskamp, Haiden A.; Choudhry, Niteesh K.; Chang, Chung-Chou H.; Zhang, Ruoxin; Jones, Bobby L.; Guclu, Hasan; Richards-Shubik, Seth; Donohue, Julie M.

2016-01-01

BACKGROUND Variation in physician adoption of new medications is poorly understood. Traditional approaches (e.g., measuring time to first prescription) may mask substantial heterogeneity in technology adoption. OBJECTIVE Apply group-based trajectory models to examine the physician adoption of dabigratran, a novel anticoagulant. METHODS A retrospective cohort study using prescribing data from IMS Xponent™ on all Pennsylvania physicians regularly prescribing anticoagulants (n=3,911) and data on their characteristics from the American Medical Association Masterfile. We examined time to first dabigatran prescription as well as group-based trajectory models to identify adoption trajectories in the first 15 months. Factors associated with rapid adoption were examined using multivariate logistic regressions. OUTCOMES Trajectories of monthly share of oral anticoagulant prescriptions for dabigatran RESULTS We identified five distinct adoption trajectories: 3.7% rapidly and extensively adopted dabigatran (adopting in ≤3 months with 45% of prescriptions) and 13.4% were rapid and moderate adopters (≤3 months with 20% share). Two groups accounting for 21.6% and 16.1% of physicians, respectively, were slower to adopt (6 to 10 months post-introduction) and dabigatran accounted for <10% share. Nearly half (45.2%) of anticoagulant prescribers did not adopt dabigatran. Cardiologists were much more likely than primary care physicians to rapidly adopt (odds ratio [OR] 12.2, 95%CI: 9.27–16.1) as were younger prescribers (age 36–45 years: OR 1.49, 95%CI: 1.13–1.95, age 46–55: OR 1.34, 95%CI 1.07–1.69 vs. >55 years). CONCLUSIONS Trajectories of physician adoption of dabigatran were highly variable with significant differences across specialties. Heterogeneity in physician adoption has potential implications for the cost and effectiveness of treatment. PMID:27116109

Organized Sport Trajectories from Childhood to Adolescence and Health Associations.

PubMed

Howie, Erin K; McVeigh, Joanne A; Smith, Anne J; Straker, Leon M

2016-07-01

The purpose of this study was to identify unique organized sport trajectories from early childhood to late adolescence in an Australian pregnancy cohort, the Raine Study. Participation in organized sport was assessed at ages 5, 8, 10, 14, and 17 yr. Physical activity, body composition, and self-rated physical and mental health were assessed at the age of 20 yr. Latent class analysis was used to identify patterns of sport participation. To assess the internal validity of the trajectory classes, differences in health characteristics between trajectories were analyzed using generalized linear models. For girls, three trajectory classes were identified: consistent sport participators (47.5%), sport dropouts (34.3%), and sport nonparticipators (18.1%). For boys, three trajectory classes were identified: consistent sport participators (55.2%), sport dropouts (36.9%), and sport joiners (8.1%). For girls, there were overall differences across trajectory classes in lean body mass (P = 0.003), lean mass index (P = 0.06), and physical health (P = 0.004). For boys, there were differences across classes in physical activity (P = 0.018), percent body fat (P = 0.002), lean body mass (P < 0.001), lean mass index (P < 0.001), physical health (P = 0.06), and depression scores (P = 0.27). This study identified unique, sex-specific trajectories of organized sport participation. The differences in health outcomes between trajectory classes, such as participants with consistent sport participation having more preferable health outcomes at the age of 20 yr, support the internal validity of the trajectories. Strategies are needed to identify and encourage those in the dropout trajectory to maintain their participation and those in the nonparticipator or joiner trajectories to join sport earlier. Specifically, interventions to encourage early sport participation in girls and help nonparticipating boys to join sport during adolescence may help more children receive the benefits of sport

Trajectories of Physical Discipline: Early Childhood Antecedents and Developmental Outcomes

PubMed Central

Lansford, Jennifer E.; Criss, Michael M.; Dodge, Kenneth A.; Shaw, Daniel S.; Pettit, Gregory S.; Bates, John E.

2009-01-01

This study examined childhood antecedents and developmental outcomes associated with trajectories of mild and harsh parental physical discipline. Interview, questionnaire, and observational data were available from 499 children followed from age 5 to 16 and from 258 children in an independent sample followed from age 5 to 15. Analyses indicated distinct physical discipline trajectory groups that varied in frequency of physical discipline and rate of change. In both samples, family ecological disadvantage differentiated the trajectory groups; in the first sample, early child externalizing also differentiated the groups. Controlling for early childhood externalizing, the minimal/ceasing trajectory groups were associated with the lowest levels of subsequent adolescent antisocial behavior in both samples and with parent-adolescent positive relationship quality in the second sample. PMID:19765007

Trajectories of physical discipline: early childhood antecedents and developmental outcomes.

PubMed

Lansford, Jennifer E; Criss, Michael M; Dodge, Kenneth A; Shaw, Daniel S; Pettit, Gregory S; Bates, John E

2009-01-01

This study examined childhood antecedents and developmental outcomes associated with trajectories of mild and harsh parental physical discipline. Interview, questionnaire, and observational data were available from 499 children followed from ages 5 to 16 and from 258 children in an independent sample followed from ages 5 to 15. Analyses indicated distinct physical discipline trajectory groups that varied in frequency of physical discipline and rate of change. In both samples, family ecological disadvantage differentiated the trajectory groups; in the first sample, early child externalizing also differentiated the groups. Controlling for early childhood externalizing, the minimal/ceasing trajectory groups were associated with the lowest levels of subsequent adolescent antisocial behavior in both samples and with parent-adolescent positive relationship quality in the second sample.

Trajectories of social withdrawal and cognitive decline in the schizophrenia prodrome.

PubMed

Cullen, Kathryn; Guimaraes, Angela; Wozniak, Jeffrey; Anjum, Afshan; Schulz, S Charles; White, Tonya

2011-01-01

Schizophrenia is a heterogeneous neurodevelopmental disorder. Patients with high levels of negative symptoms have been identified as a specific subtype, but little is known about how the neurodevelopmental course may differ in this group. This study aimed to characterize developmental trajectories of premorbid social withdrawal and cognitive decline between patients with high versus low levels of negative symptoms in youth with schizophrenia-spectrum disorders. A standardized timeline was used to delineate the emergence of psychosis, social withdrawal, and cognitive decline in 52 subjects aged 8 to 19 with schizophrenia (n=36), schizophreniform (n=6), or schizoaffective disorder (n=10). The sample was divided into subgroups of high- (n=26) versus low- (n=26) negative symptoms, and developmental trajectories of premorbid symptoms were compared between groups. Mean ages for emergence of social withdrawal, cognitive decline, and psychosis were 11.1 years (SD=2.5), 11.9 (SD=4.4) and 13.2 years (SD=1.2), respectively. In the high-negative symptom group, the premorbid developmental trajectory for social withdrawal was more protracted. This group also had more severe cognitive decline at the onset of psychosis, but the premorbid trajectories for cognitive decline did not differ significantly between groups. This work documents a more severe and protracted trajectory of premorbid social withdrawal in patients with high levels of negative symptoms in comparison to those with low-negative symptoms. The findings reported here are supportive of the hypothesis that patients with illness characterized by high levels of negative symptoms may represent a subgroup with distinct neurodevelopmental abnormalities.

Early Life Growth Predictors of Childhood Adiposity Trajectories and Future Risk for Obesity: Birth to Twenty Cohort.

PubMed

Munthali, Richard J; Kagura, Juliana; Lombard, Zané; Norris, Shane A

2017-10-01

There is growing evidence of variations in adiposity trajectories among individuals, but the influence of early life growth patterns on these trajectories is underresearched in low- and middle-income countries. Therefore, our aim was to examine the association between early life conditional weight gain and childhood adiposity trajectories. We previously identified distinct adiposity trajectories (four for girls and three for boys) in black South African children (boys = 877; girls = 947). The association between the trajectories and early life growth patterns, and future obesity risk was assessed by multivariate linear and multinomial logistic and logistic regressions. Conditional weight gain independent of height was computed for infancy (0-2 years) and early childhood (2-4 years). Conditional weight gain before 5 years of age was significantly associated with early onset of obesity or overweight (excess weight) BMI trajectories in both boys and girls. In girls, greater conditional weight gain in infancy was associated with increased relative risk of being in the early-onset obese to morbid obese trajectory, with relative risk ratios of 2.03 (95% confidence interval: 1.17-3.52) compared to belonging to a BMI trajectory in the normal range. Boys and girls in the early-onset obesity or overweight BMI trajectories were more likely to be overweight or obese in early adulthood. Excessive weight gain in infancy and early childhood, independent of linear growth, predicts childhood and adolescent BMI trajectories toward obesity. These results underscore the importance of early life factors in the development of obesity and other NCDs in later life.

Risk and Protective Factors Associated with Trajectories of Depressed Mood from Adolescence to Early Adulthood

PubMed Central

Costello, Darcé M.; Swendsen, Joel; Rose, Jennifer S.; Dierker, Lisa C.

2009-01-01

This study used semi-parametric group-based modeling to explore unconditional and conditional trajectories of self-reported depressed mood from age 12 to 25. Drawing on data from the National Longitudinal Study of Adolescent Health (N=11,559), four distinct trajectories were identified: no depressed mood, stable low depressed mood, early high declining depressed mood, and late escalating depressed mood. Baseline risk factors associated with greater likelihood of membership in depressed mood trajectory groups compared to the no depressed mood group included being female, Black/African American, Hispanic/Latino American, or Asian American, lower SES, using alcohol, tobacco, or other drugs on a weekly basis, and delinquent behavior. Baseline protective factors associated with greater likelihood of membership in the no depressed mood group compared to the depressed mood trajectory groups included two-parent family structure, feeling connected to parents, peers, or school, and self esteem. With the exception of delinquent behavior, risk and protective factors also distinguished the likelihood of membership among several of the three depressed mood groups. The results add to basic etiologic research regarding developmental pathways of depressed mood in adolescence and young adulthood. PMID:18377115

Factors related to criminal justice expenditure trajectories for adults with serious mental illness.

PubMed

Robst, John; Constantine, Robert; Andel, Ross; Boaz, Timothy; Howe, Andrew

2011-12-01

Criminal careers have been extensively studied in general population sample, but less is known about such patterns among people with major mental illness, and where so, criminal justice expenditure has not been taken into account. Our aim was to examine criminal justice system expenditure over time in one Florida county. Our main research question was whether treatment for mental disorders was related to a change in criminal offending and expenditure trajectory. We used the Pinellas County (Florida) Criminal Justice Information System to identify individuals under age 65 arrested between July 2003 and June 2004. Archival medical service, social and homeless services data were used to identify individuals with a serious mental illness. A two-step analysis was used to examine the data: first, we identified groups of people with similar patterns of criminal justice expenditures over 4 years (July 2002 to June 2006); second, we evaluated their demographic characteristics, diagnosis and treatment as potential predictors of group membership. Three thousand seven hundred sixty-nine people with serious mental illness were identified in the Pinellas County jail population. Their average length of stay in jail was 151 days and in prison was 48 days. The trajectory analysis identified three groups of individuals with distinct trajectories of criminal justice expenditures: those with low stable, those with initially high but decreasing and those with initially high and sustained or increasing. Mental health treatment, whether acute or sustained, voluntary or mandatory, was associated with membership of the low stable group. Review of criminal justice expenditure over time on individuals with major mental disorder may provide important indicators of unmet need for mental health services. Furthermore, it seems probable that improved provision of such services for them could reduce recidivism as well as improving health. Interventions may also be better focused if criminal

Identification and prediction of drinking trajectories in early and mid-adolescence.

PubMed

Van Der Vorst, Haske; Vermulst, Ad A; Meeus, Wim H J; Deković, Maja; Engels, Rutger C M E

2009-05-01

The aim of this study was to identify subgroups of early and mid-adolescents with different drinking trajectories. In addition, we examined whether gender, parental, and peer factors predicted adolescents' membership of these drinking trajectories. We used longitudinal data of 428 families (fathers, mothers, mid-adolescents, and their younger siblings). Latent Class Growth Analyses were performed to identify drinking trajectories. Four drinking trajectories emerged for early adolescents: abstainers, light drinkers, increasers, and heavy drinkers. For mid-adolescents, we identified a fifth group (stable drinkers) in addition to the four trajectories identified for early adolescents. Our results showed that being a boy, having a best friend or father who drinks heavily, and having parents who are permissive toward adolescents' alcohol creates increased risk for both siblings to attend the more heavy drinking trajectories.

Trajectory analysis via a geometric feature space approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rintoul, Mark D.; Wilson, Andrew T.

This study aimed to organize a body of trajectories in order to identify, search for and classify both common and uncommon behaviors among objects such as aircraft and ships. Existing comparison functions such as the Fréchet 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 the total distance traveled and the distance between start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally,more » these features can generally be mapped easily to behaviors of interest to humans who are searching large databases. Most of these geometric features are invariant under rigid transformation. Furthermore, we demonstrate the use of different subsets of these features to identify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories and identify outliers.« less

Trajectory analysis via a geometric feature space approach

DOE PAGES

Rintoul, Mark D.; Wilson, Andrew T.

2015-10-05

This study aimed to organize a body of trajectories in order to identify, search for and classify both common and uncommon behaviors among objects such as aircraft and ships. Existing comparison functions such as the Fréchet 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 the total distance traveled and the distance between start/stop points as well as geometric features related to the properties of the convex hull, trajectory curvature and general distance geometry. Additionally,more » these features can generally be mapped easily to behaviors of interest to humans who are searching large databases. Most of these geometric features are invariant under rigid transformation. Furthermore, we demonstrate the use of different subsets of these features to identify trajectories similar to an exemplar, cluster a database of several hundred thousand trajectories and identify outliers.« less

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

PubMed

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.

Genetic divergence between two phenotypically distinct bottlenose dolphin ecotypes suggests separate evolutionary trajectories.

PubMed

Fruet, Pedro F; Secchi, Eduardo R; Di Tullio, Juliana C; Simões-Lopes, Paulo César; Daura-Jorge, Fábio; Costa, Ana P B; Vermeulen, Els; Flores, Paulo A C; Genoves, Rodrigo Cezar; Laporta, Paula; Beheregaray, Luciano B; Möller, Luciana M

2017-11-01

Due to their worldwide distribution and occupancy of different types of environments, bottlenose dolphins display considerable morphological variation. Despite limited understanding about the taxonomic identity of such forms and connectivity among them at global scale, coastal (or inshore) and offshore (or oceanic) ecotypes have been widely recognized in several ocean regions. In the Southwest Atlantic Ocean (SWA), however, there are scarce records of bottlenose dolphins differing in external morphology according to habitat preferences that resemble the coastal-offshore pattern observed elsewhere. The main aim of this study was to analyze the genetic variability, and test for population structure between coastal ( n  = 127) and offshore ( n  = 45) bottlenose dolphins sampled in the SWA to assess whether their external morphological distinction is consistent with genetic differentiation. We used a combination of mtDNA control region sequences and microsatellite genotypes to infer population structure and levels of genetic diversity. Our results from both molecular marker types were congruent and revealed strong levels of structuring (microsatellites F ST  = 0.385, p  < .001; mtDNA F ST  =  0.183, p  < .001; Φ ST  = 0.385, p  < .001) and much lower genetic diversity in the coastal than the offshore ecotype, supporting patterns found in previous studies elsewhere. Despite the opportunity for gene flow in potential "contact zones", we found minimal current and historical connectivity between ecotypes, suggesting they are following discrete evolutionary trajectories. Based on our molecular findings, which seem to be consistent with morphological differentiations recently described for bottlenose dolphins in our study area, we recommend recognizing the offshore bottlenose dolphin ecotype as an additional Evolutionarily Significant Unit (ESU) in the SWA. Implications of these results for the conservation of bottlenose dolphins in SWA are also discussed.

Profiling of ARDS pulmonary edema fluid identifies a metabolically distinct subset

PubMed Central

Contrepois, Kévin; Wu, Manhong; Zheng, Ming; Peltz, Gary; Ware, Lorraine B.; Matthay, Michael A.

2017-01-01

There is considerable biological and physiological heterogeneity among patients who meet standard clinical criteria for acute respiratory distress syndrome (ARDS). In this study, we tested the hypothesis that there exists a subgroup of ARDS patients who exhibit a metabolically distinct profile. We examined undiluted pulmonary edema fluid obtained at the time of endotracheal intubation from 16 clinically phenotyped ARDS patients and 13 control patients with hydrostatic pulmonary edema. Nontargeted metabolic profiling was carried out on the undiluted edema fluid. Univariate and multivariate statistical analyses including principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were conducted to find discriminant metabolites. Seven-hundred and sixty unique metabolites were identified in the pulmonary edema fluid of these 29 patients. We found that a subset of ARDS patients (6/16, 38%) presented a distinct metabolic profile with the overrepresentation of 235 metabolites compared with edema fluid from the other 10 ARDS patients, whose edema fluid metabolic profile was indistinguishable from those of the 13 control patients with hydrostatic edema. This “high metabolite” endotype was characterized by higher concentrations of metabolites belonging to all of the main metabolic classes including lipids, amino acids, and carbohydrates. This distinct group with high metabolite levels in the edema fluid was also associated with a higher mortality rate. Thus metabolic profiling of the edema fluid of ARDS patients supports the hypothesis that there is considerable biological heterogeneity among ARDS patients who meet standard clinical and physiological criteria for ARDS. PMID:28258106

Distinct longitudinal patterns of absenteeism and their antecedents in full-time Australian employees.

PubMed

Magee, Christopher A; Caputi, Peter; Lee, Jeong Kyu

2016-01-01

This paper investigated distinct longitudinal trajectories of absenteeism over time, and underlying demographic, work, and health antecedents. Data from the Household, Income, and Labor Dynamics in Australia Survey were used; this is a panel study of a representative sample of Australian households. This paper focused on 2,481 full-time employees across a 5-year period. Information on annual sick leave and relevant sociodemographic, work, and health-related factors was collected through interviews and self-completed surveys. Growth mixture modeling indicated 4 distinct longitudinal patterns of absenteeism over time. The moderate absenteeism trajectory (34.8%) of the sample had 4-5 days of sick leave per year and was used as the reference group. The low absenteeism trajectory (33.5%) had 1-2 days of absenteeism per year, while the no absenteeism trajectory (23.6%) had very low rates of absenteeism (<1 day per year). Finally, a smaller trajectory accounting for 8.1% of the sample had high levels of absenteeism (>11 days per year). Compared with the moderate absenteeism trajectory, the high absenteeism trajectory was characterized by poor health; the no absenteeism and low absenteeism trajectories had better health but may also reflect processes relating to presenteeism. These results provide important insights into the nature of absenteeism in Australian employees, and suggest that different patterns of absenteeism over time could reflect a range of demographic, work, and health related factors. (c) 2016 APA, all rights reserved).

Identifying Gender-Specific Developmental Trajectories of Nonviolent and Violent Delinquency from Adolescence to Young Adulthood

ERIC Educational Resources Information Center

Zheng, Yao; Cleveland, H. Harrington

2013-01-01

Most research examining gender differences in developmental trajectories of antisocial behavior does not consider subtypes of antisocial behavior and is difficult to generalize due to small non-representative samples. The current study investigated gender difference in developmental trajectories from adolescence to young adulthood while addressing…

The effect of spatial orientation on detecting motion trajectories in noise.

PubMed

Pavan, Andrea; Casco, Clara; Mather, George; Bellacosa, Rosilari M; Cuturi, Luigi F; Campana, Gianluca

2011-09-15

A series of experiments investigated the extent to which the spatial orientation of a signal line affects discrimination of its trajectory from the random trajectories of background noise lines. The orientation of the signal line was either parallel (iso-) or orthogonal (ortho-) to its motion direction and it was identical in all respects to the noise (orientation, length and speed) except for its motion direction, rendering the signal line indistinguishable from the noise on a frame-to-frame basis. We found that discrimination of ortho-trajectories was generally better than iso-trajectories. Discrimination of ortho-trajectories was largely immune to the effects of spatial jitter in the trajectory, and to variations in step size and line-length. Discrimination of iso-trajectories was reliable provided that step-size was not too short and did not exceed line length, and that the trajectory was straight. The new result that trajectory discrimination in moving line elements is modulated by line orientation suggests that ortho- and iso-trajectory discrimination rely upon two distinct mechanisms: iso-motion discrimination involves a 'motion-streak' process that combines motion information with information about orientation parallel to the motion trajectory, while ortho-motion discrimination involves extended trajectory facilitation in a network of receptive fields with orthogonal orientation tuning. Copyright © 2011 Elsevier Ltd. All rights reserved.

Developmental Trajectories of Anxiety Symptoms Among Boys Across Early and Middle Childhood

PubMed Central

Feng, Xin; Shaw, Daniel S.; Silk, Jennifer S.

2009-01-01

This study examined the developmental trajectory of anxiety symptoms among 290 boys and evaluated the association of trajectory groups with child and family risk factors and children’s internalizing disorders. Anxiety symptoms were measured using maternal reports from the Child Behavior Checklist (T. M. Achenbach, 1991, 1992) for boys between the ages of 2 and 10. A group-based trajectory analysis revealed 4 distinct trajectories in the development of anxiety symptoms: low, low increasing, high declining, and high-increasing trajectories. Child shy temperament tended to differentiate between initial high and low groups, whereas maternal negative control and maternal depression were associated with increasing trajectories and elevated anxiety symptoms in middle childhood. Follow-up analyses to diagnoses of preadolescent depression and/or anxiety disorders revealed different patterns on the basis of trajectory group membership. The results are discussed in terms of the mechanisms of risk factors and implications for early identification and prevention. PMID:18266484

Trajectories of Global Self-Worth in Adolescents with ADHD: Associations with Academic, Emotional, and Social Outcomes.

PubMed

Dvorsky, Melissa R; Langberg, Joshua M; Becker, Stephen P; Evans, Steven W

2018-05-01

Resilience models suggest that there are likely to be multiple trajectories of self-worth and that despite experiencing impairment, some youth with attention deficit/hyperactivity disorder (ADHD) may maintain a positive self-worth, which could buffer them against negative outcomes. The present study used a cohort-sequential longitudinal design to evaluate developmental trajectories of global self-worth in a sample of 324 middle-school-age adolescents (71% male) diagnosed with ADHD between ages 11 and 14 in predicting outcomes at age 15. Sex, medication status, and ADHD/oppositional defiant disorder symptom severity were included as covariates in the models. Using growth mixture modeling, 3 distinct self-worth trajectory groups were identified: (a) high and increasing (44.4% of participants), (b) moderate and decreasing (48.8%), and (c) low and decreasing (6.8%). Participants with high and increasing global self-worth were less likely to exhibit co-occurring depressive symptoms and had better social functioning and higher grades at age 15 relative to those in either decreasing trajectory. Implications of these findings for monitoring and supporting positive global self-worth for adolescents with ADHD are discussed.

Trajectories of Delinquency and Parenting Styles

ERIC Educational Resources Information Center

Hoeve, Machteld; Blokland, Arjan; Dubas, Judith Semon; Loeber, Rolf; Gerris, Jan R. M.; van der Laan, Peter H.

2008-01-01

We investigated trajectories of adolescent delinquent development using data from the Pittsburgh Youth Study and examined the extent to which these different trajectories are differentially predicted by childhood parenting styles. Based on self-reported and official delinquency seriousness, covering ages 10-19, we identified five distinct…

Six-Degree-of-Freedom Trajectory Optimization Utilizing a Two-Timescale Collocation Architecture

NASA Technical Reports Server (NTRS)

Desai, Prasun N.; Conway, Bruce A.

2005-01-01

Six-degree-of-freedom (6DOF) trajectory optimization of a reentry vehicle is solved using a two-timescale collocation methodology. This class of 6DOF trajectory problems are characterized by two distinct timescales in their governing equations, where a subset of the states have high-frequency dynamics (the rotational equations of motion) while the remaining states (the translational equations of motion) vary comparatively slowly. With conventional collocation methods, the 6DOF problem size becomes extraordinarily large and difficult to solve. Utilizing the two-timescale collocation architecture, the problem size is reduced significantly. The converged solution shows a realistic landing profile and captures the appropriate high-frequency rotational dynamics. A large reduction in the overall problem size (by 55%) is attained with the two-timescale architecture as compared to the conventional single-timescale collocation method. Consequently, optimum 6DOF trajectory problems can now be solved efficiently using collocation, which was not previously possible for a system with two distinct timescales in the governing states.

Developmental Trajectories of Adaptive Behaviors from Early Childhood to Adolescence in a Cohort of 152 Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Baghdadli, Amaria; Assouline, Brigitte; Sonie, Sandrine; Pernon, Eric; Darrou, Celine; Michelon, Cecile; Picot, Marie-Christine; Aussilloux, Charles; Pry, Rene

2012-01-01

This study examines change in 152 children over an almost 10-year period (T1: 4.9 (plus or minus 1.3) years; T2: 8.1 (plus or minus 1.3) years; T3: 15(plus or minus 1.6) years) using a group-based, semi-parametric method in order to identify distinct developmental trajectories. Important deficits remain at adolescence in the adaptive abilities of…

Profiling of ARDS pulmonary edema fluid identifies a metabolically distinct subset.

PubMed

Rogers, Angela J; Contrepois, Kévin; Wu, Manhong; Zheng, Ming; Peltz, Gary; Ware, Lorraine B; Matthay, Michael A

2017-05-01

There is considerable biological and physiological heterogeneity among patients who meet standard clinical criteria for acute respiratory distress syndrome (ARDS). In this study, we tested the hypothesis that there exists a subgroup of ARDS patients who exhibit a metabolically distinct profile. We examined undiluted pulmonary edema fluid obtained at the time of endotracheal intubation from 16 clinically phenotyped ARDS patients and 13 control patients with hydrostatic pulmonary edema. Nontargeted metabolic profiling was carried out on the undiluted edema fluid. Univariate and multivariate statistical analyses including principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were conducted to find discriminant metabolites. Seven-hundred and sixty unique metabolites were identified in the pulmonary edema fluid of these 29 patients. We found that a subset of ARDS patients (6/16, 38%) presented a distinct metabolic profile with the overrepresentation of 235 metabolites compared with edema fluid from the other 10 ARDS patients, whose edema fluid metabolic profile was indistinguishable from those of the 13 control patients with hydrostatic edema. This "high metabolite" endotype was characterized by higher concentrations of metabolites belonging to all of the main metabolic classes including lipids, amino acids, and carbohydrates. This distinct group with high metabolite levels in the edema fluid was also associated with a higher mortality rate. Thus metabolic profiling of the edema fluid of ARDS patients supports the hypothesis that there is considerable biological heterogeneity among ARDS patients who meet standard clinical and physiological criteria for ARDS. Copyright © 2017 the American Physiological Society.

Transitional Life Events and Trajectories of Cigarette and Alcohol Use During Emerging Adulthood: Latent Class Analysis and Growth Mixture Modeling

PubMed Central

Huh, Jimi; Huang, Zhaoqing; Liao, Yue; Pentz, Maryann; Chou, Chih-Ping

2013-01-01

Objective: Emerging adulthood (ages 18–25 years) has been associated with elevated substance use. Transitional life events (TLEs) during emerging adulthood in relation to substance use are usually examined separately, rather than as a constellation. The purposes of this study were (a) to explore distinct subgroups experiencing various TLEs during emerging adulthood, (b) to identify heterogeneous trajectories of cigarette and alcohol use during emerging adulthood, and (c) to examine the association of TLEs with cigarette and alcohol use trajectories. Method: Five waves of longitudinal data (mean age range: 19.5–26.0 years) were used from a community-based drug prevention program (n = 946, 49.9% female). Distinct subgroups of emerging adults who experienced various TLEs were identified using latent class analysis. Cigarette and alcohol use were examined using a latent growth mixture model. Results: A three-class model fit the data best in identifying TLE subgroups (new family, college attenders [NFCA]; uncommitted relationships, college attenders [URCA]; hibernators [HBN]). Three-trajectory models fit the data best for cigarette and alcohol use during emerging adulthood. The TLE categories were significantly associated with the cigarette (p < .05) and alcohol use groups (p < .001); specifically, the URCA and HBN groups were significantly more likely to be classified as accelerating cigarette users, relative to NFCA (ps < .05). The NFCA and HBN groups were significantly more likely to be classified as accelerating alcohol users, relative to URCA (ps < .01). Conclusions: To characterize an “at-risk” emerging adult group for cigarette and alcohol use over time, a range of life events during emerging adulthood should be considered. Interventions tailored to young adulthood may benefit from targeting the absence of these life events typifying “independence” as a potential marker for underlying substance use problems and provide supplemental screening methods

KymoKnot: A web server and software package to identify and locate knots in trajectories of linear or circular polymers.

PubMed

Tubiana, Luca; Polles, Guido; Orlandini, Enzo; Micheletti, Cristian

2018-06-07

The KymoKnot software package and web server identifies and locates physical knots or proper knots in a series of polymer conformations. It is mainly intended as an analysis tool for trajectories of linear or circular polymers, but it can be used on single instances too, e.g. protein structures in PDB format. A key element of the software package is the so-called minimally interfering chain closure algorithm that is used to detect physical knots in open chains and to locate the knotted region in both open and closed chains. The web server offers a user-friendly graphical interface that identifies the knot type and highlights the knotted region on each frame of the trajectory, which the user can visualize interactively from various viewpoints. The dynamical evolution of the knotted region along the chain contour is presented as a kymograph. All data can be downloaded in text format. The KymoKnot package is licensed under the BSD 3-Clause licence. The server is publicly available at http://kymoknot.sissa.it/kymoknot/interactive.php .

Toddler hand preference trajectories predict 3-year language outcome.

PubMed

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 bullying and social dominance in youth.

PubMed

Reijntjes, Albert; Vermande, Marjolijn; Goossens, Frits A; Olthof, Tjeert; van de Schoot, Rens; Aleva, Liesbeth; van der Meulen, Matty

2013-04-01

Bullying is increasingly conceptualized as strategic behavior motivated by a desire to gain social dominance in the peer group. Cross-sectional research has shown that relative to their peers bullies are higher in social dominance as indexed by resource control, and are often perceived as powerful and "cool." However, research examining the developmental relationship between bullying and resource control is lacking. The present longitudinal study fills this gap in the literature. Using a three wave design, participants (N=394) were followed from late childhood into early adolescence. Joint trajectory analyses were used to test whether groups with distinct developmental trajectories of bullying and resource control can be identified, and how these trajectories are related. For both bullying and resource control three groups emerged (high, medium, and low), indicating that bullies and social dominants do not constitute one homogeneous group. More intense bullying is associated with higher levels of social dominance. Being consistently high in bullying is almost synonymous with being consistently high in resource control, whereas the reverse is not the case. Findings suggest that high bullying leads to the attainment of high social dominance, and do not support the view that children high in social dominance engage in bullying to maintain their dominant position. This study further underscores the need for interventions targeting mechanisms by which the peer group assigns social dominance to bullies. Copyright © 2012 Elsevier Ltd. All rights reserved.

Growth trajectories in early childhood, their relationship with antenatal and postnatal factors, and development of obesity by age 9 years: results from an Australian birth cohort study.

PubMed

Giles, L C; Whitrow, M J; Davies, M J; Davies, C E; Rumbold, A R; Moore, V M

2015-07-01

In an era where around one in four children in the United Kingdom, the United States, and Australia are overweight or obese, the development of obesity in early life needs to be better understood. We aimed to identify groups of children with distinct trajectories of growth in infancy and early childhood, to examine any association between these trajectories and body size at age 9, and to assess the relative influence of antenatal and postnatal exposures on growth trajectories. Prospective Australian birth cohort study. In total, 557 children with serial height and weight measurements from birth to 9 years were included in the study. Latent class growth models were used to derive distinct groups of growth trajectories from birth to age 3½ years. Multivariable logistic regression models were used to explore antenatal and postnatal predictors of growth trajectory groups, and multivariable linear and logistic regression models were used to examine the relationships between growth trajectory groups and body size at age 9 years. We identified four discrete growth trajectories from birth to age 3½ years, characterised as low, intermediate, high, or accelerating growth. Relative to the intermediate growth group, the low group had reduced z-body mass index (BMI) (-0.75 s.d.; 95% confidence interval (CI) -1.02, -0.47), and the high and accelerating groups were associated with increased body size at age 9 years (high: z-BMI 0.70 s.d.; 95% CI 0.49, 0.62; accelerating: z-BMI 1.64 s.d.; 95% CI 1.16, 2.11). Of the antenatal and postnatal exposures considered, the most important differentiating factor was maternal obesity in early pregnancy, associated with a near quadrupling of risk of membership of the accelerating growth trajectory group compared with the intermediate growth group (odds ratio (OR) 3.72; 95% CI 1.15, 12.05). Efforts to prevent childhood obesity may need to be embedded within population-wide strategies that also pay attention to healthy weight for women in

Trajectories of Depressive Symptoms Throughout the Peri- and Postpartum Period: Results from the First Baby Study.

PubMed

McCall-Hosenfeld, Jennifer S; Phiri, Kristen; Schaefer, Eric; Zhu, Junjia; Kjerulff, Kristen

2016-11-01

Postpartum depression (PPD) is a common complication of childbearing, but the course of PPD is not well understood. We analyze trajectories of depression and key risk factors associated with these trajectories in the peripartum and postpartum period. Women in The First Baby Study, a cohort of 3006 women pregnant with their first baby, completed telephone surveys measuring depression during the mother's third trimester, and at 1, 6, and 12 months postpartum. Depression was assessed using the Edinburgh Postnatal Depression Scale. A semiparametric mixture model was used to estimate distinct group-based developmental trajectories of depression and determine whether trajectory group membership varied according to maternal characteristics. A total of 2802 (93%) of mothers completed interviews through 12 months. The mixture model indicated six distinct depression trajectories. A history of anxiety or depression, unattached marital status, and inadequate social support were significantly associated with higher odds of belonging to trajectory groups with greater depression. Most of the depression trajectories were stable or slightly decreased over time, but one depression trajectory, encompassing 1.7% of the mothers, showed women who were nondepressed at the third trimester, but became depressed at 6 months postpartum and were increasingly depressed at 12 months after birth. This trajectory study indicates that women who are depressed during pregnancy tend to remain depressed during the first year postpartum or improve slightly, but an important minority of women become newly and increasingly depressed over the course of the first year after first childbirth.

Patterns of Crime and Drug Use Trajectories in Relation to Treatment Initiation and 5-Year Outcomes: An Application of Growth Mixture Modeling across Three Data Sets

ERIC Educational Resources Information Center

Prendergast, Michael; Huang, David; Hser, Yih-Ing

2008-01-01

Drug abusers vary considerably in their drug use and criminal behavior over time, and these trajectories are likely to influence drug treatment participation and treatment outcomes. Drawing on longitudinal natural history data from three samples of adult male drug users, we identify four groups with distinctive drug use and crime trajectories…

Quantifying ataxia: ideal trajectory analysis--a technical note

NASA Technical Reports Server (NTRS)

McPartland, M. D.; Krebs, D. E.; Wall, C. 3rd

2000-01-01

We describe a quantitative method to assess repeated stair stepping stability. In both the mediolateral (ML) and anterioposterior (AP) directions, the trajectory of the subject's center of mass (COM) was compared to an ideal sinusoid. The two identified sinusoids were unique in each direction but coupled. Two dimensionless numbers-the mediolateral instability index (IML) and AP instability index (IAP)-were calculated using the COM trajectory and ideal sinusoids for each subject with larger index values resulting from less stable performance. The COM trajectories of nine nonimpaired controls and six patients diagnosed with unilateral or bilateral vestibular labyrinth hypofunction were analyzed. The average IML and IAP values of labyrinth disorder patients were respectively 127% and 119% greater than those of controls (p<0.014 and 0.006, respectively), indicating that the ideal trajectory analysis distinguishes persons with labyrinth disorder from those without. The COM trajectories also identify movement inefficiencies attributable to vestibulopathy.

Trajectories of the relationships of physical activity with body composition changes in older men: the MrOS study.

PubMed

Laddu, Deepika R; Cawthon, Peggy M; Parimi, Neeta; Hoffman, Andrew R; Orwoll, Eric; Miljkovic, Iva; Stefanick, Marcia L

2017-06-05

Excess adiposity gains and significant lean mass loss may be risk factors for chronic disease in old age. Long-term patterns of change in physical activity (PA) and their influence on body composition decline during aging has not been characterized. We evaluated the interrelationships of PA and body composition at the outset and over longitudinal follow-up to changes in older men. Self-reported PA by the Physical Activity Scale for the Elderly (PASE), clinic body weight, and whole-body lean mass (LM) and fat mass, by dual-energy x-ray absorptiometry (DXA), were assessed in 5964 community-dwelling men aged ≥65 years at baseline (2000-2002) and at two subsequent clinic visits up until March 2009 (an average 4.6 and 6.9 years later). Group-based trajectory modeling (GBTM) identified patterns of change in PA and body composition variables. Relationships of PA and body composition changes were then assessed. GBTM identified three discrete trajectory patterns, all with declining PA, associated primarily with initial PA levelshigh-activity (7.2% of men), moderate-activity (50.0%), and low-activity (42.8%). In separate models, GBTM identified eight discrete total weight change groups, five fat mass change groups, and six LM change groups. Joint trajectory modeling by PA and body composition group illustrated significant declines in total weight and LM, whereas fat mass levels were relatively unchanged among high-activity and low-activity-declining groups, and significantly increased in the moderate-activity-declining group. Although patterns of change in PA and body composition were identified, groups were primarily differentiated by initial PA or body composition rather than by distinct trajectories of change in these variables.

Ten-Year Publication Trajectories of Health Services Research Career Development Award Recipients: Collaboration, Awardee Characteristics, and Productivity Correlates.

PubMed

Halvorson, Max A; Finlay, Andrea K; Cronkite, Ruth C; Bi, Xiaoyu; Hayashi, Ko; Maisel, Natalya C; Amundson, Erin O'Rourke; Weitlauf, Julie C; Litt, Iris F; Owens, Douglas K; Timko, Christine; Cucciare, Michael A; Finney, John W

2016-03-01

This study's purpose was to identify distinct publishing trajectories among 442 participants in three prominent mentored health services research career development programs (Veterans Affairs, National Institutes of Health, and Agency for Healthcare Research & Quality) in the 10 years after award receipt and to examine awardee characteristics associated with different trajectories. Curricula vitae (CVs) of researchers receiving awards between 1991 and 2010 were coded for publications, grants, and awardee characteristics. We found that awardees published at constant or increasing rates despite flat or decreasing rates of first-author publications. Senior-author publications rose concurrently with rates of overall publications. Higher overall publication trajectories were associated with receiving more grants, more citations as measured by the h-index, and more authors per article. Lower trajectory groups were older and had a greater proportion of female awardees. Career development awards supported researchers who generally published successfully, but trajectories varied across individual researchers. Researchers' collaborative efforts produced an increasing number of articles, whereas first author articles were written at a more consistent rate. Career development awards in health services research supported the careers of researchers who published at a high rate; future research should further examine reasons for variation in publishing among early career researchers. © The Author(s) 2014.

The Role of Family Income Dynamics in Predicting Trajectories of Internalizing and Externalizing Problems.

PubMed

Miller, Portia; Votruba-Drzal, Elizabeth

2017-04-01

Economic disparities in children's behavioral functioning have been observed in prior research. Yet, studies have ignored important perspectives from developmental psychopathology and have not delineated how aspects of income dynamics (i.e., cumulative family income versus income volatility) differentially relate to behavior problems. To address these limitations, the current study examined how both cumulative income and income volatility predict trajectories of children's internalizing and externalizing problems from kindergarten through fifth grade in a nationally representative sample of 10,900 children (51.4 % male). Results showed four distinct trajectories of internalizing problems and five distinct externalizing trajectories. Family income dynamics were related to trajectory group membership. Specifically, increased cumulative income decreased risk of membership in mid-increasing and mid-stable internalizing groups, and children whose families experienced multiple waves of income loss were 2.4 times as likely to be in the mid-increasing group instead of the low-stable group. With respect to externalizing, higher cumulative income increased the likelihood of belonging in the group exhibiting stably low externalizing problems. Experiencing income loss increased the risk of belonging in the trajectory group exhibiting chronically high externalizing behaviors. These results enhance our knowledge of the role of family income in the development of behavior problems.

The power of a single trajectory

NASA Astrophysics Data System (ADS)

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.

Longitudinal Trajectories of Metabolic Control From Childhood to Young Adulthood in Type 1 Diabetes From a Large German/Austrian Registry: A Group-Based Modeling Approach.

PubMed

Schwandt, Anke; Hermann, Julia M; Rosenbauer, Joachim; Boettcher, Claudia; Dunstheimer, Désirée; Grulich-Henn, Jürgen; Kuss, Oliver; Rami-Merhar, Birgit; Vogel, Christian; Holl, Reinhard W

2017-03-01

Worsening of glycemic control in type 1 diabetes during puberty is a common observation. However, HbA 1c remains stable or even improves for some youths. The aim is to identify distinct patterns of glycemic control in type 1 diabetes from childhood to young adulthood. A total of 6,433 patients with type 1 diabetes were selected from the prospective, multicenter diabetes patient registry Diabetes-Patienten-Verlaufsdokumentation (DPV) (follow-up from age 8 to 19 years, baseline diabetes duration ≥2 years, HbA 1c aggregated per year of life). We used latent class growth modeling as the trajectory approach to determine distinct subgroups following a similar trajectory for HbA 1c over time. Five distinct longitudinal trajectories of HbA 1c were determined, comprising group 1 = 40%, group 2 = 27%, group 3 = 15%, group 4 = 13%, and group 5 = 5% of patients. Groups 1-3 indicated stable glycemic control at different HbA 1c levels. At baseline, similar HbA 1c was observed in group 1 and group 4, but HbA 1c deteriorated in group 4 from age 8 to 19 years. Similar patterns were present in group 3 and group 5. We observed differences in self-monitoring of blood glucose, insulin therapy, daily insulin dose, physical activity, BMI SD score, body-height SD score, and migration background across all HbA 1c trajectories (all P ≤ 0.001). No sex differences were present. Comparing groups with similar initial HbA 1c but different patterns, groups with higher HbA 1c increase were characterized by lower frequency of self-monitoring of blood glucose and physical activity and reduced height (all P < 0.01). Using a trajectory approach, we determined five distinct longitudinal patterns of glycemic control from childhood to early adulthood. Diabetes self-care, treatment differences, and demographics were related to different HbA 1c courses. © 2017 by the American Diabetes Association.

Trajectories of Depressive Symptoms Throughout the Peri- and Postpartum Period: Results from the First Baby Study

PubMed Central

Phiri, Kristen; Schaefer, Eric; Zhu, Junjia; Kjerulff, Kristen

2016-01-01

Abstract Background: Postpartum depression (PPD) is a common complication of childbearing, but the course of PPD is not well understood. We analyze trajectories of depression and key risk factors associated with these trajectories in the peripartum and postpartum period. Methods: Women in The First Baby Study, a cohort of 3006 women pregnant with their first baby, completed telephone surveys measuring depression during the mother's third trimester, and at 1, 6, and 12 months postpartum. Depression was assessed using the Edinburgh Postnatal Depression Scale. A semiparametric mixture model was used to estimate distinct group-based developmental trajectories of depression and determine whether trajectory group membership varied according to maternal characteristics. Results: A total of 2802 (93%) of mothers completed interviews through 12 months. The mixture model indicated six distinct depression trajectories. A history of anxiety or depression, unattached marital status, and inadequate social support were significantly associated with higher odds of belonging to trajectory groups with greater depression. Most of the depression trajectories were stable or slightly decreased over time, but one depression trajectory, encompassing 1.7% of the mothers, showed women who were nondepressed at the third trimester, but became depressed at 6 months postpartum and were increasingly depressed at 12 months after birth. Conclusions: This trajectory study indicates that women who are depressed during pregnancy tend to remain depressed during the first year postpartum or improve slightly, but an important minority of women become newly and increasingly depressed over the course of the first year after first childbirth. PMID:27310295

Association of Trajectories of Higher-Level Functional Capacity with Mortality and Medical and Long-Term Care Costs Among Community-Dwelling Older Japanese.

PubMed

Taniguchi, Yu; Kitamura, Akihiko; Nofuji, Yu; Ishizaki, Tatsuro; Seino, Satoshi; Yokoyama, Yuri; Shinozaki, Tomohiro; Murayama, Hiroshi; Mitsutake, Seigo; Amano, Hidenori; Nishi, Mariko; Matsuyama, Yutaka; Fujiwara, Yoshinori; Shinkai, Shoji

2018-03-26

Higher-level functional capacity is crucial component for independent living in later life. We used repeated-measures analysis to identify aging trajectories in higher-level functional capacity. We then determined whether these trajectories were associated with all-cause mortality and examined differences in medical and long-term care costs between trajectories among community-dwelling older Japanese. 2,675 adults aged 65-90 years participated in annual geriatric health assessments and biennial health monitoring surveys during the period from October 2001 through August 2011. The average number of follow-up assessments was 4.0, and the total number of observations was 10,609. Higher-level functional capacity, which correspond to the fourth and fifth sublevels of Lawton's hierarchical model, was assessed with the Tokyo Metropolitan Institute of Gerontology-Index of Competence (TMIG-IC). We identified four distinct trajectory patterns (high-stable, late-onset decreasing, early-onset decreasing, and low-decreasing) on the TMIG-IC through age 65-90 years. As compared with the high-stable trajectory group, participants in the late-onset decreasing, early-onset decreasing, and low-decreasing TMIG-IC trajectory groups had adjusted hazard ratios for mortality of 1.22 (95% confidence interval: 1.01-1.47), 1.90 (1.53-2.36), and 2.87 (2.14-3.84), respectively. Participants with high-stable and late-onset decreasing higher-level functional capacity trajectories had lower mean monthly medical costs and long-term care costs. In contrast, mean total costs were higher for those with low-decreasing trajectories, after excluding the large increase in such costs at the end of life. People with a low-decreasing aging trajectory in higher-level functional capacity had higher risks of death and had high monthly total costs.

Trajectories of Delinquent Behaviour in Adolescence and Their Covariates: Relations with Initial and Time-Averaged Factors

ERIC Educational Resources Information Center

Wiesner, Margit; Silbereisen, Rainer K.

2003-01-01

This longitudinal study examined individual, family, and peer covariates of distinctive trajectories of juvenile delinquency, using data from a community sample of 318 German adolescents (mean age at the first wave was 11.45 years). Latent growth mixture modelling analysis revealed four trajectory groups: high-level offenders, medium-level…

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

PubMed

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.

Romantic Relationships Trajectories of African American Gay/Bisexual Adolescents

ERIC Educational Resources Information Center

Eyre, Stephen L.; Milbrath, Constance; Peacock, Ben

2007-01-01

The interview study reported here sought to identify the perceived trajectory of romantic relationships of a cohort of Oakland African American gay/bisexual adolescents. Biographical interviews were used to identify cultural models of romantic relationships in the study sample and discovered a trajectory of four phases. In the antecedent to the…

Trajectories of Delinquency from Age 14 to 23 in the National Longitudinal Survey of Youth Sample

PubMed Central

Murphy, Debra A.; Brecht, Mary-Lynn; Huang, David; Herbeck, Diane M.

2012-01-01

This study utilized data from the National Longitudinal Survey of Youth to investigate risk trajectories for delinquency and factors associated with different trajectories, particularly substance use. The sample (N = 8,984) was 49% female. A group-based trajectory model was applied, which identified four distinct trajectories for both males and females: (1) a High group with delinquency rates consistently higher than other groups, with some decrease across the age range; (2) a Decreased group, beginning at high levels with substantial decrease to near zero; (3) a Moderate group experiencing some decline but remaining at moderate rates of delinquency through most of the age range; and (4) a consistently Low group, having low rates of delinquency declining to near zero by mid- to late-teens. The Low group was distinguished by several protective factors, including higher rates of maternal authoritative parenting style, possible lower acculturation (higher rates of non-English spoken at home), higher rates of religious activity, later substance use initiation, lower rates of early delinquent activity, less early experience with neighborhood or personal violence, and higher rates of perceiving penalty for wrongdoing. Conversely, the High group was characterized by several vulnerability factors—essentially the converse of the protective factors above. PMID:23105164

Body Mass Trajectories and Mortality Among Older Adults: A Joint Growth Mixture–Discrete-Time Survival Analysis

PubMed Central

Zajacova, Anna

2014-01-01

Purpose of the Study: The aim of this study was to investigate heterogeneity in body weight trajectories among older adults and their association with mortality risks. Design and Methods: Information on body mass index (BMI) and survival come from nine waves of the Health and Retirement Study, a 16-year survey of adults aged 51–61 at baseline (N = 9,703). We used a sex-stratified joint growth mixture-discrete time survival model to characterize BMI trajectory groups and their associated mortality. Results: Three distinct classes of BMI trajectories were identified: “stable overweight,” “obese gaining,” and “obese losing.” Relative to the stable overweight class, which comprised about 90% of the sample, the obese gaining class had approximately 50% higher mortality risk; the highest mortality was found in the obese losing category (OR > 2.7, p < .001). The results were similar for men and women. Implications: The findings highlight substantial heterogeneity in weight trajectories of older Americans, as well as large survival differentials across the classes. The direction of weight changes appears inextricably linked to the overall BMI level in terms of predicting older adults’ longevity. Weight loss is associated with particularly high mortality risk even when the typical BMI change is from obesity to overweight. PMID:23355450

Functional Recovery of Older Hip-Fracture Patients after Interdisciplinary Intervention Follows Three Distinct Trajectories

ERIC Educational Resources Information Center

Tseng, Ming-Yueh; Shyu, Yea-Ing L.; Liang, Jersey

2012-01-01

Purpose To assess the effects of an interdisciplinary intervention on the trajectories of functional recovery among older patients with hip fracture during 2 years after hospitalization. Design and Methods In a randomized controlled trial with 24-month follow-up, 162 patients [greater than or equal to]60 years were enrolled after hip-fracture…

Designing train-speed trajectory with energy efficiency and service quality

NASA Astrophysics Data System (ADS)

Jia, Jiannan; Yang, Kai; Yang, Lixing; Gao, Yuan; Li, Shukai

2018-05-01

With the development of automatic train operations, optimal trajectory design is significant to the performance of train operations in railway transportation systems. Considering energy efficiency and service quality, this article formulates a bi-objective train-speed trajectory optimization model to minimize simultaneously the energy consumption and travel time in an inter-station section. This article is distinct from previous studies in that more sophisticated train driving strategies characterized by the acceleration/deceleration gear, the cruising speed, and the speed-shift site are specifically considered. For obtaining an optimal train-speed trajectory which has equal satisfactory degree on both objectives, a fuzzy linear programming approach is applied to reformulate the objectives. In addition, a genetic algorithm is developed to solve the proposed train-speed trajectory optimization problem. Finally, a series of numerical experiments based on a real-world instance of Beijing-Tianjin Intercity Railway are implemented to illustrate the practicability of the proposed model as well as the effectiveness of the solution methodology.

Perceived employability trajectories: A Swedish cohort study

PubMed Central

Törnroos (née Kirves), Kaisa; Bernhard-Oettel, Claudia; Leineweber, Constanze

2017-01-01

Objectives: This study identified perceived employability trajectories and their associations with sleeping difficulties and depressive symptoms over time. Methods: The sample was part of the Swedish Longitudinal Survey on Health from 2008 to 2014 (n=4,583). Results: Two stable trajectories (high and low perceived employability over time) and three trajectories with changes (increasing, decreasing, and V-shaped perceived employability over time) were identified. Workers with stable low perceived employability reported more sleeping difficulties and depressive symptoms than those who perceived high or increasing employability. Conclusion: Perceived employability is a rather stable personal resource, which is associated with well-being over time. However, changes in perceived employability do not seem to be echoed in well-being, at least not as immediately as theoretically expected. PMID:28539535

Response trajectories reveal conflict phase in image-word mismatch.

PubMed

van Vugt, Floris T; Cavanagh, Patrick

2012-02-01

In the present study, response trajectories were used in a picture–word conflict task to determine the timing of intermediate processing stages that are relatively inaccessible to response time measures. A marker was placed above or below the word ABOVE or BELOW so that its location was congruent or in conflict with the word's meaning. To report either word location(above or below the marker) or word meaning, participants moved a mouse upward toward the appropriate top left or right answer corner on the display screen.Their response trajectories showed a number of distinctive features: First, at about 200 ms after stimulus onset(the "decision moment"), the trajectory abruptly began to arc toward the appropriate answer corner; second,when the word's meaning and position were in conflict,the trajectory showed an interruption that continued until the conflict was resolved. By varying the SOA of the word and marker onsets, we found that the word meaning and word position became available at approximately 325 ms and 251 ms, respectively, after their onsets, and that the delay to resolve conflicts was about 138 ms. The timing of these response trajectory events was more stable than any extracted from the final response times, demonstrating the power of response trajectories to reveal processing stages that are only poorly resolved, if at all, by response time measures [added].

Trajectories of change in depression severity during treatment with antidepressants.

PubMed

Uher, R; Muthén, B; Souery, D; Mors, O; Jaracz, J; Placentino, A; Petrovic, A; Zobel, A; Henigsberg, N; Rietschel, M; Aitchison, K J; Farmer, A; McGuffin, P

2010-08-01

Response and remission defined by cut-off values on the last observed depression severity score are commonly used as outcome criteria in clinical trials, but ignore the time course of symptomatic change and may lead to inefficient analyses. We explore alternative categorization of outcome by naturally occurring trajectories of symptom change. Growth mixture models were applied to repeated measurements of depression severity in 807 participants with major depression treated for 12 weeks with escitalopram or nortriptyline in the part-randomized Genome-based Therapeutic Drugs for Depression study. Latent trajectory classes were validated as outcomes in drug efficacy comparison and pharmacogenetic analyses. The final two-piece growth mixture model categorized participants into a majority (75%) following a gradual improvement trajectory and the remainder following a trajectory with rapid initial improvement. The rapid improvement trajectory was over-represented among nortriptyline-treated participants and showed an antidepressant-specific pattern of pharmacogenetic associations. In contrast, conventional response and remission favoured escitalopram and produced chance results in pharmacogenetic analyses. Controlling for drop-out reduced drug differences on response and remission but did not affect latent trajectory results. Latent trajectory mixture models capture heterogeneity in the development of clinical response after the initiation of antidepressants and provide an outcome that is distinct from traditional endpoint measures. It differentiates between antidepressants with different modes of action and is robust against bias due to differential discontinuation.

Anatomy-driven multiple trajectory planning (ADMTP) of intracranial electrodes for epilepsy surgery.

PubMed

Sparks, Rachel; Vakharia, Vejay; Rodionov, Roman; Vos, Sjoerd B; Diehl, Beate; Wehner, Tim; Miserocchi, Anna; McEvoy, Andrew W; Duncan, John S; Ourselin, Sebastien

2017-08-01

Epilepsy is potentially curable with resective surgery if the epileptogenic zone (EZ) can be identified. If non-invasive imaging is unable to elucidate the EZ, intracranial electrodes may be implanted to identify the EZ as well as map cortical function. In current clinical practice, each electrode trajectory is determined by time-consuming manual inspection of preoperative imaging to find a path that avoids blood vessels while traversing appropriate deep and superficial regions of interest (ROIs). We present anatomy-driven multiple trajectory planning (ADMTP) to find safe trajectories from a list of user-defined ROIs within minutes rather than the hours required for manual planning. Electrode trajectories are automatically computed in three steps: (1) Target Point Selection to identify appropriate target points within each ROI; (2) Trajectory Risk Scoring to quantify the cumulative distance to critical structures (blood vessels) along each trajectory, defined as the skull entry point to target point. (3) Implantation Plan Computation: to determine a feasible combination of low-risk trajectories for all electrodes. ADMTP was evaluated on 20 patients (190 electrodes). ADMTP lowered the quantitative risk score in 83% of electrodes. Qualitative results show ADMTP found suitable trajectories for 70% of electrodes; a similar portion of manual trajectories were considered suitable. Trajectory suitability for ADMTP was 95% if traversing sulci was not included in the safety criteria. ADMTP is computationally efficient, computing between 7 and 12 trajectories in 54.5 (17.3-191.9) s. ADMTP efficiently compute safe and surgically feasible electrode trajectories.

Trajectories of perceived discrimination from adolescence to emerging adulthood and substance use among Hispanic youth in Los Angeles.

PubMed

Unger, Jennifer B; Soto, Daniel W; Baezconde-Garbanati, Lourdes

2016-02-01

Previous studies have documented associations between perceptions of racial/ethnic discrimination and adverse health outcomes among Hispanics and other minority groups. However, these studies have not examined change in perceived discrimination over the lifecourse and whether trajectories of perceived discrimination affect outcomes differently. This study of 2722 Hispanic students identified trajectories of perceived discrimination from 9th grade through emerging adulthood (approximately ages 14-23), and compared these trajectory groups on substance use outcomes. Four distinct trajectory groups were identified: (1) low and stable discrimination, (2) increasing discrimination, (3) initially high but decreasing discrimination, and (4) high and stable discrimination. Compared with the low and stable discrimination group, the groups that experienced higher levels of discrimination were at higher risk of cigarette, alcohol, marijuana, and hard drug use. Specifically, the group with increasing discrimination (group 2) had a higher risk of alcohol, marijuana, and hard drug use; the group with initially high but decreasing discrimination (group 3) had a higher risk of cigarette smoking and alcohol use; and the group with high and stable discrimination (group 4) had a higher risk of alcohol, marijuana, and hard drug use. Results indicate that experiencing discrimination during adolescence, emerging adulthood, or both, regardless of whether the discrimination increases or decreases, could place Hispanic youth at risk for substance use. Health education programs are needed to help Hispanic youth learn effective skills to cope with discrimination without resorting to substance use. Copyright © 2015 Elsevier Ltd. All rights reserved.

Convergent Metabolic Specialization through Distinct Evolutionary Paths in Pseudomonas aeruginosa

PubMed Central

Johansen, Helle Krogh; Molin, Søren

2018-01-01

ABSTRACT Evolution by natural selection under complex and dynamic environmental conditions occurs through intricate and often counterintuitive trajectories affecting many genes and metabolic solutions. To study short- and long-term evolution of bacteria in vivo, we used the natural model system of cystic fibrosis (CF) infection. In this work, we investigated how and through which trajectories evolution of Pseudomonas aeruginosa occurs when migrating from the environment to the airways of CF patients, and specifically, we determined reduction of growth rate and metabolic specialization as signatures of adaptive evolution. We show that central metabolic pathways of three distinct Pseudomonas aeruginosa lineages coevolving within the same environment become restructured at the cost of versatility during long-term colonization. Cell physiology changes from naive to adapted phenotypes resulted in (i) alteration of growth potential that particularly converged to a slow-growth phenotype, (ii) alteration of nutritional requirements due to auxotrophy, (iii) tailored preference for carbon source assimilation from CF sputum, (iv) reduced arginine and pyruvate fermentation processes, and (v) increased oxygen requirements. Interestingly, although convergence was evidenced at the phenotypic level of metabolic specialization, comparative genomics disclosed diverse mutational patterns underlying the different evolutionary trajectories. Therefore, distinct combinations of genetic and regulatory changes converge to common metabolic adaptive trajectories leading to within-host metabolic specialization. This study gives new insight into bacterial metabolic evolution during long-term colonization of a new environmental niche. PMID:29636437

Identifying transitions in terminal illness trajectories: a critical factor in hospital-based palliative care.

PubMed

Dalgaard, Karen Marie; Thorsell, Georg; Delmar, Charlotte

2010-02-01

This article describes the significance of the identification and explicit communication of the different clinical phases in incurable illness trajectories in a hospital setting. The article is part of a qualitative study carried out in a Danish haematology department. The data were obtained through a total of 157 hours of participant observation and informal interviews with patients, families, doctors and nurses and four focus group interviews with doctors and nursing staff. Grounded theory was applied for the data analysis. The findings outline how the unpredictability of certain haematological malignancies and barriers in professional practice tended to postpone identifications of transitions between clinical phases. The study has identified ten barriers including personal, professional, time-related, cultural and organizational-for an open dialogue between staff, patients and families about illness progression. The quality of palliative care was affected as different clinical phases require different treatment and care strategies. Complex intervention is called for.

Pre-Surgery Depression and Confidence to Manage Problems Predict Recovery Trajectories of Health and Wellbeing in the First Two Years following Colorectal Cancer: Results from the CREW Cohort Study

PubMed Central

Foster, Claire; Haviland, Joanne; Winter, Jane; Grimmett, Chloe; Chivers Seymour, Kim; Batehup, Lynn; Calman, Lynn; Corner, Jessica; Din, Amy; Fenlon, Deborah; May, Christine M.; Richardson, Alison; Smith, Peter W.

2016-01-01

Purpose This paper identifies predictors of recovery trajectories of quality of life (QoL), health status and personal wellbeing in the two years following colorectal cancer surgery. Methods 872 adults receiving curative intent surgery during November 2010 to March 2012. Questionnaires at baseline, 3, 9, 15, 24 months post-surgery assessed QoL, health status, wellbeing, confidence to manage illness-related problems (self-efficacy), social support, co-morbidities, socio-demographic, clinical and treatment characteristics. Group-based trajectory analyses identified distinct trajectories and predictors for QoL, health status and wellbeing. Results Four recovery trajectories were identified for each outcome. Groups 1 and 2 fared consistently well (scores above/within normal range); 70.5% of participants for QoL, 33.3% health status, 77.6% wellbeing. Group 3 had some problems (24.2% QoL, 59.3% health, 18.2% wellbeing); Group 4 fared consistently poorly (5.3% QoL, 7.4% health, 4.2% wellbeing). Higher pre-surgery depression and lower self-efficacy were significantly associated with poorer trajectories for all three outcomes after adjusting for other important predictors including disease characteristics, stoma, anxiety and social support. Conclusions Psychosocial factors including self-efficacy and depression before surgery predict recovery trajectories in QoL, health status and wellbeing following colorectal cancer treatment independent of treatment or disease characteristics. This has significant implications for colorectal cancer management as appropriate support may be improved by early intervention resulting in more positive recovery experiences. PMID:27171174

Joint trajectories of depression and perfectionism across adolescence and childhood risk factors.

PubMed

Vaillancourt, Tracy; Haltigan, John D

2018-05-01

The codevelopment of symptoms of depression and socially prescribed perfectionism across adolescence (age 12-17) and non-age-overlapping childhood predictors (age 10-11) of joint trajectory group membership were examined in a sample of 700 Canadian youth. Results indicated that most adolescents (75.8%) followed a trajectory of low depression symptoms (low stable), whereas 15.7% followed an increasing trajectory (increasing), and 8.5% followed a trajectory that began high and decreased over time (high decreasing). More girls than boys were found in the increasing and high decreasing depression trajectories. Adolescents followed three distinct trajectories of socially prescribed perfectionism: 41.6% were in a low stable group, 40.5% in a moderate increasing group, and 17.9% in a high increasing group. Eight percent followed a high-risk dual trajectory of increasing depression and high increasing socially prescribed perfectionism. This joint trajectory was predicted by being bullied, anxious, and relationally aggressive (compared to the low-risk trajectory of low stable depression and perfectionism) at ages 10 and 11. These same predictors, along with poorer family functioning and lower family income, differentiated the joint high decreasing depression/high increasing perfectionism group from the low/low joint group, which comprised of 3.8% of the sample. The developmental progression was best characterized as depression leading to socially prescribed perfectionism. Implications for clinical practice are discussed.

Predictors of Latent Trajectory Classes of Dating Violence Victimization

PubMed Central

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

Trajectories of Peer-Nominated Aggression: Risk Status, Predictors and Outcomes.

ERIC Educational Resources Information Center

van Lier, Pol A.C.; Crijnen, Alfons A.M.

2005-01-01

Developmental trajectories of peer-nominated aggression, risk factors at baseline, and outcomes were studied. Peer nominations of aggression were obtained annually from grades 1 to 3. Three developmental trajectories were identified: an early-onset/increasers trajectory with high levels of peer-nominated aggression at elementary school entry and…

Psychosocial Correlates of Smoking Trajectories Among Urban African American Adolescents

ERIC Educational Resources Information Center

Fergus, Stevenson; Zimmerman, Marc A.; Caldwell, Cleopatra H.

2005-01-01

Little is known of smoking trajectories or of the correlates of smoking trajectories among African American youth. Ninth-grade African American adolescents (n = 566) were interviewed in Year 1 and then were subsequently interviewed annually for 3 additional years. Five trajectories of cigarette smokers were identified: abstainers,…

Developmental trajectories of DSM-IV symptoms of attention-deficit/hyperactivity disorder: genetic effects, family risk and associated psychopathology.

PubMed

Larsson, Henrik; Dilshad, Rezin; Lichtenstein, Paul; Barker, Edward D

2011-09-01

DSM-IV specifies three ADHD subtypes; the combined, the hyperactive-impulsive and the inattentive. Little is known about the developmental relationships underlying these subtypes. The objective of this study was to describe the development of parent-reported hyperactivity-impulsivity and inattention symptoms from childhood to adolescence and to study their associations with genetic factors, family risk, and later adjustment problems in early adulthood. Data in this study comes from 1,450 twin pairs participating in a population-based, longitudinal twin study. Developmental trajectories were defined using parent-ratings of hyperactivity-impulsivity and inattention symptoms at age 8-9, 13-14, and 16-17. Twin methods were used to explore genetic influences on trajectories. Family risk measures included low socioeconomic status, large family size and divorce. Self-ratings of externalizing and internalizing problems in early adulthood were used to examine adjustment problems related to the different trajectory combinations. We found two hyperactivity-impulsivity trajectories (low, high/decreasing) and two inattention trajectories (low, high/increasing). Twin modeling revealed a substantial genetic component underlying both the hyperactivity-impulsivity and the inattention trajectory. Joint trajectory analyses identified four groups of adolescents with distinct developmental patterns of hyperactivity-impulsivity and inattention: a low/low group, a primarily hyperactive, a primarily inattentive and a combined (high/high) trajectory type. These trajectory combinations showed discriminant relations to adjustment problems in early adulthood. The hyperactive, inattentive and combined trajectory subtypes were associated with higher rates of family risk environments compared to the low/low group. Study results showed that for those on a high trajectory, hyperactivity decreased whereas inattention increased. The combinations of these trajectories lend developmental insight into

Trajectories of distress, anxiety, and depression among women with breast cancer: Looking beyond the mean.

PubMed

Bidstrup, Pernille Envold; Christensen, Jane; Mertz, Birgitte Goldschmidt; Rottmann, Nina; Dalton, Susanne Oksbjerg; Johansen, Christoffer

2015-05-01

Little is known about the development of psychological wellbeing over time among women who have been treated for breast cancer. The aim of this study was to identify distinct patterns of distress, anxiety, and depression in such women. We invited 426 consecutive women with newly diagnosed primary breast cancer to participate in this study, and 323 (76%) provided information on distress ('distress thermometer') and on symptoms of anxiety and depression ('hospital anxiety and depression scale'). Semiparametric group-based mixture modeling was used to identify distinct trajectories of distress, anxiety, and depressive symptoms assessed the week before surgery and four and eight months later. Logistic regression analysis was used to evaluate the characteristics of women in the distinct groups. Although no sub-group of women with chronic severe anxiety or depressive symptoms was found, we did identify a sub-group of 8% of the women who experienced continuously severe distress. Young age, having a partner, shorter education, and receiving chemotherapy but not radiotherapy might characterize women whose psychological symptoms remain strong eight months after diagnosis. By looking beyond the mean, we found that 8% of the women experienced chronic severe distress; no sub-groups with chronic severe anxiety or depression were identified. Several socio-demographic and treatment factors characterized the women whose distress level remained severe eight months after diagnosis. The results suggest that support could be focused on relatively small groups of patients most in need.

Physical Aggression During Early Childhood: Trajectories and Predictors

PubMed Central

Tremblay, Richard E.; Nagin, Daniel S.; Séguin, Jean R.; Zoccolillo, Mark; Zelazo, Philip D.; Boivin, Michel; Pérusse, Daniel; Japel, Christa

2012-01-01

Objectives Physical aggression in children is a major public health problem. Not only is childhood physical aggression a precursor of the physical and mental health problems that will be visited on victims, but also aggressive children themselves are at higher risk of alcohol and drug abuse, accidents, violent crimes, depression, suicide attempts, spouse abuse, and neglectful and abusive parenting. Furthermore, violence commonly results in serious injuries to the perpetrators themselves. Although it is unusual for young children to harm seriously the targets of their physical aggression, studies of physical aggression during infancy indicate that by 17 months of age, the large majority of children are physically aggressive toward siblings, peers, and adults. This study aimed, first, to identify the trajectories of physical aggression during early childhood and, second, to identify antecedents of high levels of physical aggression early in life. Such antecedents could help to understand better the developmental origins of violence later in life and to identify targets for preventive interventions. Methods A random population sample of 572 families with a 5-month-old newborn was recruited. Assessments of physical aggression frequency were obtained from mothers at 17, 30, and 42 months after birth. Using a semiparametric, mixture model, distinct clusters of physical aggression trajectories were identified. Multivariate logit regression analysis was then used to identify which family and child characteristics, before 5 months of age, predict individuals on a high-level physical aggression trajectory from 17 to 42 months after birth. Results Three trajectories of physical aggression were identified. The first was composed of children who displayed little or no physical aggression. These individuals were estimated to account for ~28% of the sample. The largest group, estimated at ~58% of the sample, followed a rising trajectory of modest aggression. Finally, a group

Trajectories of Marijuana Use from Adolescence to Adulthood as Predictors of Unemployment Status in the Early Forties

PubMed Central

Zhang, Chenshu; Brook, Judith S.; Leukefeld, Carl G.; Brook, David W.

2016-01-01

Objectives To study the degree to which individuals in different trajectories of marijuana use are similar or different in terms of unemployment status at mean age 43. Methods We gathered longitudinal data on a prospective cohort taken from a community sample (N = 548). Forty nine percent of the original participants were females. Over 90% of the participants were white. The participants were followed from adolescence to early midlife. The mean ages of participants at the follow-up interviews were 14.1, 16.3, 22.3, 27.0, 31.9, 36.6, and 43.0, respectively. We used the growth mixture modeling (GMM) approach to identify the trajectories of marijuana use over a 29 year period. Results Five trajectories of marijuana use were identified: chronic users/decreasers (8.3%), quitters (18.6%), increasing users (7.3%), chronic occasional users (25.6%), and nonusers/experimenters (40.2%). Compared with nonusers/experimenters, chronic users/decreasers had a significantly higher likelihood of unemployment at mean age 43 (Adjusted Odds Ratio =3.51, 95% Confidence Interval = 1.13 – 10.91), even after controlling for the covariates. Conclusions and Scientific Significance The results of the associations between the distinct trajectories of marijuana use and unemployment in early midlife indicate that it is important to develop intervention programs targeting chronic marijuana use as well as unemployment in individuals at this stage of development. Results from this study should encourage clinicians, teachers, and parents to assess and treat chronic marijuana use in adolescents. PMID:26991779

Trajectories of depressive symptoms and their relationship to the progression of dementia.

PubMed

Barca, Maria Lage; Persson, Karin; Eldholm, Rannveig; Benth, Jūratė Šaltytė; Kersten, Hege; Knapskog, Anne-Brita; Saltvedt, Ingvild; Selbaek, Geir; Engedal, Knut

2017-11-01

The relationship between progression of Alzheimer's disease and depression and its underlying mechanisms has scarcely been studied. A sample of 282 outpatients with Alzheimer's disease (AD; 105 with amnestic AD and 177 with Alzheimer's dementia) from Norway were followed up for an average of two years. Assessment included Cornell Scale for Depression in Dementia and Clinical Dementia Rating Scale (CDR) at baseline and follow-up to examine the relationship between AD and depression. Additionally, MRI of the brain, CSF dementia biomarkers and APOE status were assessed at baseline. Progression of dementia was defined as the difference between CDR sum of boxes at follow-up and baseline (CDR-SB change). Trajectories of depressive symptoms on the Cornell Scale were identified using growth mixture modeling. Differences between the trajectories in regard to patients' characteristics were investigated. Three distinct trajectories of depressive symptoms were identified: 231 (82.8%) of the patients had stable low-average scores on the Cornell Scale (Class 1); 11 (3.9%) had high and decreasing scores (Class 2); and 37 (13.3%) had moderate and increasing scores (Class 3). All classes had average probabilities over 80%, and confidence intervals were non-overlapping. The only significant characteristic associated with membership in class 3 was CDR-SB change. Not all patients screened for participation were included in the study, but the included and non-included patients did not differ significantly. Some patients with amnestic MCI might have been misdiagnosed. A more rapid progression of dementia was found in a group of patients with increasing depressive symptoms. Copyright © 2017 Elsevier B.V. All rights reserved.

Developmental Trajectories of Body Mass Index Among Japanese Children and Impact of Maternal Factors during Pregnancy

PubMed Central

Haga, Chiyori; Kondo, Naoki; Suzuki, Kohta; Sato, Miri; Ando, Daisuke; Yokomichi, Hiroshi; Tanaka, Taichiro; Yamagata, Zentaro

2012-01-01

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. PMID:23272187

Uncertainty in predictions of oil spill trajectories in a coastal zone

NASA Astrophysics Data System (ADS)

Sebastião, P.; Guedes Soares, C.

2006-12-01

A method is introduced to determine the uncertainties in the predictions of oil spill trajectories using a classic oil spill model. The method considers the output of the oil spill model as a function of random variables, which are the input parameters, and calculates the standard deviation of the output results which provides a measure of the uncertainty of the model as a result of the uncertainties of the input parameters. In addition to a single trajectory that is calculated by the oil spill model using the mean values of the parameters, a band of trajectories can be defined when various simulations are done taking into account the uncertainties of the input parameters. This band of trajectories defines envelopes of the trajectories that are likely to be followed by the spill given the uncertainties of the input. The method was applied to an oil spill that occurred in 1989 near Sines in the southwestern coast of Portugal. This model represented well the distinction between a wind driven part that remained offshore, and a tide driven part that went ashore. For both parts, the method defined two trajectory envelopes, one calculated exclusively with the wind fields, and the other using wind and tidal currents. In both cases reasonable approximation to the observed results was obtained. The envelope of likely trajectories that is obtained with the uncertainty modelling proved to give a better interpretation of the trajectories that were simulated by the oil spill model.

Trajectories of self-evaluation bias in primary and secondary school: Parental antecedents and academic consequences.

PubMed

Bonneville-Roussy, Arielle; Bouffard, Thérèse; Vezeau, Carole

2017-08-01

Using a longitudinal approach spanning nine years of children's formal education, this study investigated the developmental trajectories of self-evaluation bias of academic competence. The study also examined how parenting styles were associated with the trajectories of bias in mid-primary school, and how those trajectories predicted academic outcomes at the end of secondary school and the beginning of college. A total of 711 children in 4th and 5th grades (mean age=10.71years old; 358 girls) participated in this study. Using a latent class growth modeling framework, results indicated that children can be classified in three latent growth trajectories of self-evaluation bias: the optimistic, realistic and pessimistic trajectories. These trajectories differed in their initial status of bias and also in their development over time. Children's adherence to a specific trajectory was associated with parenting variables in childhood. Finally, the optimistic, realistic, or pessimistic trajectories distinctively predicted achievement and persistence. Copyright © 2017 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Designing Asteroid Impact Scenario Trajectories

NASA Astrophysics Data System (ADS)

Chodas, Paul

2016-05-01

In order to study some of the technical and geopolitical issues of dealing with an asteroid on impact trajectory, a number of hypothetical impact scenarios have been presented over the last ten years or so. These have been used, for example, at several of the Planetary Defense Conferences (PDCs), as well as in tabletop exercises with the Federal Emergency Management Agency (FEMA), along with other government agencies. The exercise at the 2015 PDC involved most of the attendees, consisted of seven distinct steps (“injects”), and with all the presentations and discussions, took up nearly 10 hours of conference time. The trajectory for the PDC15 scenario was entirely realistic, and was posted ahead of the meeting. It was made available in the NEO Program’s Horizons ephemeris service so that users could , for example, design their own deflection missions. The simulated asteroid and trajectory had to meet numerous very exacting requirements: becoming observable on the very first day of the conference, yet remaining very difficult to observe for the following 7 years, and far enough away from Earth that it was out of reach of radar until just before impact. It had to be undetectable in the past, and yet provide multiple perihelion opportunities for deflection in the future. It had to impact in a very specific region of the Earth, a specific number of years after discovery. When observations of the asteroid are simulated to generate an uncertainty region, that entire region must impact the Earth along an axis that cuts across specific regions of the Earth, the “risk corridor”. This is important because asteroid deflections generally move an asteroid impact point along this corridor. One scenario had a requirement that the asteroid pass through a keyhole several years before impact. The PDC15 scenario had an additional constraint that multiple simulated kinetic impactor missions altered the trajectory at a deflection point midway between discovery and impact

Developmental Trajectories of Subjective Social Status.

PubMed

Goodman, Elizabeth; Maxwell, Sarah; Malspeis, Susan; Adler, Nancy

2015-09-01

Subjective social status (SSS), a person's sense of their (or for youth, abstract their family's) position in the socioeconomic hierarchy, is strongly related to health in adults but not health in adolescence. Understanding this developmental discrepancy requires first understanding the developmental trajectory of SSS. The objective of this study was to identify the number and shape of SSS trajectories as adolescents transition to adulthood and explore if trajectory membership affects health. Using data from 7436 assessments from the Princeton School District Study, a decade long cohort study of non-Hispanic black and white youth, latent class growth models with 3 to 7 SSS trajectories were developed. Model fit, trajectory structure, and shape were used to guide optimal model selection. Using this optimal model, the associations of trajectory membership with BMI and depressive symptoms in young adulthood were explored. The 5-class model was optimal. In this model, trajectories were persistent high (7.8%),mid–high (32.2%), middle (43.4%), low–lower (7.4%), and high–low (9.1%). Non-Hispanic black race/ethnicity, lower household income, and low parent education were associated with membership in this high–low trajectory. High–low trajectory membership was associated with higher BMI and depressive symptoms in non-Hispanic white subjects but was not associated with depressive symptoms. It was associated with lower BMI only after adjustment for BMI in adolescence in non-Hispanic black subjects. SSS is relatively stable in adolescence and the transition to adulthood, and it generally reflects objective markers of social advantage. However, socially disadvantaged youth with high SSS in early adolescence may be at increased health risk.

Developmental Trajectories of Subjective Social Status

PubMed Central

Maxwell, Sarah; Malspeis, Susan; Adler, Nancy

2015-01-01

BACKGROUND AND OBJECTIVE: Subjective social status (SSS), a person’s sense of their (or for youth, their family’s) position in the socioeconomic hierarchy, is strongly related to health in adults but not health in adolescence. Understanding this developmental discrepancy requires first understanding the developmental trajectory of SSS. The objective of this study was to identify the number and shape of SSS trajectories as adolescents transition to adulthood and explore if trajectory membership affects health. METHODS: Using data from 7436 assessments from the Princeton School District Study, a decade-long cohort study of non-Hispanic black and white youth, latent class growth models with 3 to 7 SSS trajectories were developed. Model fit, trajectory structure, and shape were used to guide optimal model selection. Using this optimal model, the associations of trajectory membership with BMI and depressive symptoms in young adulthood were explored. RESULTS: The 5-class model was optimal. In this model, trajectories were persistent high (7.8%), mid–high (32.2%), middle (43.4%), low–lower (7.4%), and high–low (9.1%). Non-Hispanic black race/ethnicity, lower household income, and low parent education were associated with membership in this high–low trajectory. High–low trajectory membership was associated with higher BMI and depressive symptoms in non-Hispanic white subjects but was not associated with depressive symptoms. It was associated with lower BMI only after adjustment for BMI in adolescence in non-Hispanic black subjects. CONCLUSIONS: SSS is relatively stable in adolescence and the transition to adulthood, and it generally reflects objective markers of social advantage. However, socially disadvantaged youth with high SSS in early adolescence may be at increased health risk. PMID:26324868

Trajectories of psychological distress among low-income, female survivors of Hurricane Katrina.

PubMed

Lowe, Sarah R; Rhodes, Jean E

2013-01-01

The purpose of this study was to investigate trajectories of psychological distress among low-income, primarily unmarried and African American women who survived Hurricane Katrina (N = 386). Data were collected in the year prior to the hurricane as well as approximately 1 and 3 years thereafter. Using Latent Class Growth Analysis (LCGA), we detected 6 distinct trajectory groups. Over half of the participants fit into a trajectory consistent with resilience; that is, they maintained low levels of psychological distress over the course of the study, but experienced an elevation in symptoms at the first predisaster time point followed by a return to predisaster levels. The other trajectories reflected a range of psychological responses to disasters and indicated that predisaster functioning had a major influence on postdisaster psychological outcomes. Degree of exposure to hurricane-related stressors, experiences of human and pet bereavement, perceived social support, and socioeconomic status were significant predictors of trajectory group membership. Implications for research and policy are discussed. © 2013 American Orthopsychiatric Association.

Associations of Family and Peer Experiences with Masculinity Attitude Trajectories at the Individual and Group Level in Adolescent and Young Adult Males

PubMed Central

Marcell, Arik V.; Eftim, Sorina E.; Sonenstein, Freya L.; Pleck, Joseph H.

2013-01-01

Data were drawn from 845 males in the National Survey of Adolescent Males who were initially aged 15–17, and followed-up 2.5 and 4.5 years later, to their early twenties. Mixed-effects regression models (MRM) and semiparametric trajectory analyses (STA) modeled patterns of change in masculinity attitudes at the individual and group levels, guided by gender intensification theory and cognitive-developmental theory. Overall, men’s masculinity attitudes became significantly less traditional between middle adolescence and early adulthood. In MRM analyses using time-varying covariates, maintaining paternal coresidence and continuing to have first sex in uncommitted heterosexual relationships were significantly associated with masculinity attitudes remaining relatively traditional. The STA modeling identified three distinct patterns of change in masculinity attitudes. A traditional-liberalizing trajectory of masculinity attitudes was most prevalent, followed by traditional-stable and nontraditional-stable trajectories. Implications for gender intensification and cognitive-developmental approaches to masculinity attitudes are discussed. PMID:24187483

Trajectories of childhood neighbourhood cohesion and adolescent mental health: evidence from a national Canadian cohort.

PubMed

Kingsbury, M; Kirkbride, J B; McMartin, S E; Wickham, M E; Weeks, M; Colman, I

2015-11-01

The objective of this study was to examine associations between trajectories of childhood neighbourhood social cohesion and adolescent mental health and behaviour. This study used data from the National Longitudinal Survey of Children and Youth, a nationally representative sample of Canadian children. The sample included 5577 children aged 0-3 years in 1994-1995, prospectively followed until age 12-15 years. Parental perceived neighbourhood cohesion was assessed every 2 years. Latent growth class modelling was used to identify trajectories of neighbourhood cohesion. Mental health and behavioural outcomes were self-reported at age 12-15 years. Logistic regression was used to examine associations between neighbourhood cohesion trajectories and outcomes, adjusting for potential confounders. Five distinct trajectories were identified: 'stable low' (4.2%); 'moderate increasing' (9.1%); 'stable moderate' (68.5%); 'high falling' (8.9%); and 'stable high' (9.3%). Relative to those living in stable moderately cohesive neighbourhoods, those in stable low cohesive neighbourhoods were more likely to experience symptoms of anxiety/depression [odds ratio (OR) = 1.73, 95% confidence interval (CI) 1.04-2.90] and engage in indirect aggression (OR = 1.62, 95% CI 1.07-2.45). Those with improvements in neighbourhood cohesion had significantly lower odds of hyperactivity (OR = 0.67, 95% CI 0.46-0.98) and indirect aggression (OR = 0.69, 95% CI 0.49-0.96). In contrast, those with a decline in neighbourhood cohesion had increased odds of hyperactivity (OR = 1.67, 95% CI 1.21-2.29). Those in highly cohesive neighbourhoods in early childhood were more likely to engage in prosocial behaviour ('high falling': OR = 1.93, 95% CI 1.38-2.69; 'stable high': OR = 1.89, 95% CI 1.35-2.63). These results suggest that neighbourhood cohesion in childhood may have time-sensitive effects on several domains of adolescent mental health and behaviour.

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

PubMed

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.

Low and Increasing Trajectories of Perpetration of Physical Dating Violence: 7-Year Associations with Suicidal Ideation, Weapons, and Substance Use.

PubMed

Orpinas, Pamela; Nahapetyan, Lusine; Truszczynski, Natalia

2017-05-01

Understanding the interrelation among problem behaviors and their change over time is fundamental for prevention research. The Healthy Teens Longitudinal Study followed a cohort of adolescents from Grades 6-12. Prior research identified two distinct trajectories of perpetration of physical dating violence: Low and Increasing. The purpose of this study was to examine whether adolescents in these two trajectories differed longitudinally on other problem behaviors: (1) suicidal ideation and attempts, (2) weapon-carrying and threats with a weapon, and (3) substance use, particularly alcohol and marijuana. The sample consisted of 588 randomly-selected students (52% males; 49% White, 36% Black, 12% Latino). Students completed a self-reported, computer-based survey each spring from Grades 6-12. To examine significant differences by perpetration of physical dating violence trajectory, we used Chi-square test and generalized estimating equations modeling. Across most grades, significantly more students in Increasing than in the Low trajectory reported suicidal ideation and attempts, carried a weapon, and threatened someone with a weapon. Adolescents in the Increasing trajectory also had higher trajectories of alcohol use, being drunk, and marijuana use than those in the Low trajectory. All differences were already significant in Grade 6. The difference in the rate of change between groups was not significant. This longitudinal study highlights that problem behaviors-physical dating violence, suicidal ideation and attempts, weapon carrying and threats, marijuana and alcohol use-cluster together as early as sixth grade and the clustering persists over time. The combination of these behaviors poses a great public health concern and highlight the need for early interventions.

Mission objectives and trajectories

NASA Technical Reports Server (NTRS)

1973-01-01

The present state of the knowledge of asteroids was assessed to identify mission and target priorities for planning asteroidal flights in the 1980's and beyond. Mission objectives, mission analysis, trajectory studies, and cost analysis are discussed. A bibliography of reports and technical memoranda is included.

A Repeated Trajectory Class Model for Intensive Longitudinal Categorical Outcome

PubMed Central

Lin, Haiqun; Han, Ling; Peduzzi, Peter N.; Murphy, Terrence E.; Gill, Thomas M.; Allore, Heather G.

2014-01-01

This paper presents a novel repeated latent class model for a longitudinal response that is frequently measured as in our prospective study of older adults with monthly data on activities of daily living (ADL) for more than ten years. The proposed method is especially useful when the longitudinal response is measured much more frequently than other relevant covariates. The repeated trajectory classes represent distinct temporal patterns of the longitudinal response wherein an individual’s membership in the trajectory classes may renew or change over time. Within a trajectory class, the longitudinal response is modeled by a class-specific generalized linear mixed model. Effectively, an individual may remain in a trajectory class or switch to another as the class membership predictors are updated periodically over time. The identification of a common set of trajectory classes allows changes among the temporal patterns to be distinguished from local fluctuations in the response. An informative event such as death is jointly modeled by class-specific probability of the event through shared random effects. We do not impose the conditional independence assumption given the classes. The method is illustrated by analyzing the change over time in ADL trajectory class among 754 older adults with 70500 person-months of follow-up in the Precipitating Events Project. We also investigate the impact of jointly modeling the class-specific probability of the event on the parameter estimates in a simulation study. The primary contribution of our paper is the periodic updating of trajectory classes for a longitudinal categorical response without assuming conditional independence. PMID:24519416

Early PTSD Symptom Trajectories: Persistence, Recovery, and Response to Treatment: Results from the Jerusalem Trauma Outreach and Prevention Study (J-TOPS)

PubMed Central

Galatzer-Levy, Isaac R.; Ankri, Yael; Freedman, Sara; Israeli-Shalev, Yossi; Roitman, Pablo; Gilad, Moran; Shalev, Arieh Y.

2013-01-01

Context Uncovering heterogeneities in the progression of early PTSD symptoms can improve our understanding of the disorder's pathogenesis and prophylaxis. Objectives To describe discrete symptom trajectories and examine their relevance for preventive interventions. Design Latent Growth Mixture Modeling (LGMM) of data from a randomized controlled study of early treatment. LGMM identifies latent longitudinal trajectories by exploring discrete mixture distributions underlying observable data. Setting Hadassah Hospital unselectively receives trauma survivors from Jerusalem and vicinity. Participants Adult survivors of potentially traumatic events consecutively admitted to the hospital's emergency department (ED) were assessed ten days and one-, five-, nine- and fifteen months after ED admission. Participants with data at ten days and at least two additional assessments (n = 957) were included; 125 received cognitive behavioral therapy (CBT) between one and nine months. Approach We used LGMM to identify latent parameters of symptom progression and tested the effect of CBT on these parameters. CBT consisted of 12 weekly sessions of either cognitive therapy (n = 41) or prolonged exposure (PE, n = 49), starting 29.8±5.7 days after ED admission, or delayed PE (n = 35) starting at 151.8±42.4 days. CBT effectively reduced PTSD symptoms in the entire sample. Main Outcome Measure Latent trajectories of PTSD symptoms; effects of CBT on these trajectories. Results Three trajectories were identified: Rapid Remitting (rapid decrease in symptoms from 1- to 5-months; 56% of the sample), Slow Remitting (progressive decrease in symptoms over 15 months; 27%) and Non-Remitting (persistently elevated symptoms; 17%). CBT accelerated the recovery of the Slow Remitting class but did not affect the other classes. Conclusions The early course of PTSD symptoms is characterized by distinct and diverging response patterns that are centrally relevant to understanding the disorder

Acute kidney injury subphenotypes based on creatinine trajectory identifies patients at increased risk of death.

PubMed

Bhatraju, Pavan K; Mukherjee, Paramita; Robinson-Cohen, Cassianne; O'Keefe, Grant E; Frank, Angela J; Christie, Jason D; Meyer, Nuala J; Liu, Kathleen D; Matthay, Michael A; Calfee, Carolyn S; Christiani, David C; Himmelfarb, Jonathan; Wurfel, Mark M

2016-11-17

Acute kidney injury (AKI) is common among intensive care unit (ICU) patients. AKI is highly heterogeneous, with variable links to poor outcomes. Current approaches to classify AKI severity and identify patients at highest risk for poor outcomes focus on the maximum change in serum creatinine (SCr) values. However, these scores are hampered by the need for a reliable baseline SCr value and the absence of a component differentiating transient from persistent rises in SCr. We hypothesized that identification of resolving or nonresolving AKI subphenotypes based on the early trajectory of SCr values in the ICU would better differentiate patients at risk of hospital mortality. We performed a secondary analysis of two prospective studies of ICU patients admitted to a trauma ICU (group 1; n = 1914) or general medical-surgical ICUs (group 2; n = 1867). In group 1, we tested definitions for resolving and nonresolving AKI subphenotypes and selected the definitions resulting in subphenotypes with the greatest separation in risk of death relative to non-AKI controls. We applied this definition to group 2 and tested whether the subphenotypes were independently associated with hospital mortality after adjustment for AKI severity. AKI occurred in 46% and 69% of patients in groups 1 and 2, respectively. In group 1, a resolving AKI subphenotype (defined as a decrease in SCr of 0.3 mg/dl or 25% from maximum in the first 72 h of study enrollment) was associated with a low risk of death. A nonresolving AKI subphenotype (defined as all AKI cases not meeting the "resolving" definition) was associated with a high risk of death. In group 2, the resolving AKI subphenotype was not associated with increased mortality (relative risk [RR] 0.86, 95% CI 0.63-1.17), whereas the nonresolving AKI subphenotype was associated with higher mortality (RR 1.68, 95% CI 1.15-2.44) even after adjustment for AKI severity stage. The trajectory of SCr levels identifies AKI subphenotypes with different

Trajectory classes of cannabis use and heavy drinking among rural African American adolescents: multi-level predictors of class membership.

PubMed

Barton, Allen W; Brody, Gene H; Zapolski, Tamika C B; Goings, Trenette C; Kogan, Steven M; Windle, Michael; Yu, Tianyi

2018-02-17

To inform research on the etiology and prevention of substance use among rural African American youth by (a) identifying developmental trajectory classes of cannabis use and heavy drinking across adolescence and young adulthood and (b) examining associations between trajectory class membership and multi-level assessments of risk factors. A prospective study spanning 9 years with assessments of cannabis use and heavy drinking, the catecholamines epinephrine and norepinephrine, perceived stress and psychosocial risk factors. Rural communities in the southeastern United States. African American youth (n = 518). Participants were assessed for cannabis use and heavy drinking at seven assessments beginning at 16 years of age and continuing to 25 years of age. At age 19, participants provided overnight urine voids that were assayed for catecholamines, a biological marker of life stress resulting from sympathetic nervous system activation. At ages 16 and 19, participants provided information on malleable psychosocial risk factors. Latent class growth models revealed three distinct trajectory classes for cannabis use and for heavy drinking. Higher levels of circulating stress hormones and perceived stress were associated with classes reporting greater substance use over time (all Ps < 0.05). A composite of selected risk factors discriminated class membership (all Ps < 0.05). Trajectory classes characterized by rapid usage increases in early adulthood exhibited the greatest increase in deviant peer affiliations between ages 16 and 19 years. Rural African American youth's cannabis use and heavy drinking across adolescence and young adulthood demonstrate distinct developmental courses; a small number of risk factors and measures of biological and perceived stress differentiate class membership prognostically. Variability over time in these measures, specifically an increase in deviant peer affiliation, may help to account for steep increases in young adulthood. �

Categorizing natural history trajectories of ambulatory function measured by the 6-minute walk distance in patients with Duchenne muscular dystrophy.

PubMed

Mercuri, Eugenio; Signorovitch, James Edward; Swallow, Elyse; Song, Jinlin; Ward, Susan J

2016-09-01

High variability in patients' changes in 6 minute walk distance (6MWD) over time has complicated clinical trials of treatment efficacy in Duchenne muscular dystrophy (DMD). We assessed whether boys with DMD could be grouped into classes that shared similar ambulatory function trajectories as measured by 6MWD. Ambulatory boys aged 5 years or older with genetically confirmed DMD who were enrolled in a natural history study at 11 care centers throughout Italy were included. For each boy, standardized assessments of 6MWD were available at annual intervals spanning 3 years. Trajectories of 6MWD vs. age and trajectories of 6MWD vs. time from enrollment were examined using latent class analysis. A total of 96 boys were included. At enrollment, the mean age was 8.3 years (mean 6MWD: 374 meters). After accounting for age, baseline 6MWD, and steroid use, four latent trajectory classes were identified as explaining 3-year 6MWD outcomes significantly better than a single average trajectory. Patient trajectories of 6MWD change from enrollment were categorized as having fast decline (n = 25), moderate decline (n = 19), stable function (n = 37), and improving function (n = 15) during the 3-year follow-up. After accounting for trajectory classes, the standard deviation of variation in 6MWD was reduced by approximately 40%. The natural history of ambulatory function in DMD may be composed of distinct trajectory classes. The extent to which trajectories are associated with novel and established prognostic factors warrants further study. Reducing unexplained variation in patient outcomes could help to further improve DMD clinical trial design and analysis. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Comparative genomics identifies distinct lineages of S. Enteritidis from Queensland, Australia.

PubMed

Graham, Rikki M A; Hiley, Lester; Rathnayake, Irani U; Jennison, Amy V

2018-01-01

Salmonella enterica is a major cause of gastroenteritis and foodborne illness in Australia where notification rates in the state of Queensland are the highest in the country. S. Enteritidis is among the five most common serotypes reported in Queensland and it is a priority for epidemiological surveillance due to concerns regarding its emergence in Australia. Using whole genome sequencing, we have analysed the genomic epidemiology of 217 S. Enteritidis isolates from Queensland, and observed that they fall into three distinct clades, which we have differentiated as Clades A, B and C. Phage types and MLST sequence types differed between the clades and comparative genomic analysis has shown that each has a unique profile of prophage and genomic islands. Several of the phage regions present in the S. Enteritidis reference strain P125109 were absent in Clades A and C, and these clades also had difference in the presence of pathogenicity islands, containing complete SPI-6 and SPI-19 regions, while P125109 does not. Antimicrobial resistance markers were found in 39 isolates, all but one of which belonged to Clade B. Phylogenetic analysis of the Queensland isolates in the context of 170 international strains showed that Queensland Clade B isolates group together with the previously identified global clade, while the other two clades are distinct and appear largely restricted to Australia. Locally sourced environmental isolates included in this analysis all belonged to Clades A and C, which is consistent with the theory that these clades are a source of locally acquired infection, while Clade B isolates are mostly travel related.

Posttraumatic Stress Symptom Trajectories Among Children After Disaster Exposure: A Review

PubMed Central

Lai, Betty S.; Lewis, Rayleen; Livings, Michelle S.; La Greca, Annetate M.; Esnard, Ann-Margaret

2018-01-01

Natural disasters, such as hurricanes and floods, are increasing in frequency and scope. Youth exposed to disasters are at risk for developing posttraumatic stress symptoms (PTSS). However, not all youth who report initially elevated PTSS report persistent PTSS that last beyond the first three to six months postdisaster. Thus, it is crucial to understand how and why youth differ in their patterns of PTSS. This study reviewed the literature on children’s postdisaster PTSS, evaluating the typical number and types of patterns for children’s PTSS trajectories, as well as risk and protective factors predicting trajectory membership. This review identified eight empirical studies on youth PTSS trajectories following natural disasters; these studies included 8,306 children aged 3 to 18 years. All studies identified resilience, recovery, and chronic trajectories. Evidence for a delayed trajectory was mixed. Proportions of children falling into each trajectory varied widely across studies, but overall, resilience was the most prevalent trajectory. These findings were consistent across study factors (i.e., analytic strategy, assessment timing, and study selection criteria). Female gender, disaster exposure, negative coping, and lack of social support were significant risk factors for chronic trajectories across several studies. Future research should combine individual level participant data across studies of children’s responses to disasters to better understand PTSS trajectories. PMID:29193316

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

PubMed

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.

Glucose trajectories in cystic fibrosis and their association with pulmonary function.

PubMed

Reynaud, Quitterie; Rabilloud, Muriel; Roche, Sylvain; Poupon-Bourdy, Stéphanie; Iwaz, Jean; Nove-Josserand, Raphaële; Blond, Emilie; Laville, Martine; Llerena, Cathy; Quetant, Sébastien; Reix, Philippe; Touzet, Sandrine; Durieu, Isabelle

2018-05-01

The prevalence of cystic fibrosis-related diabetes is increasing. This condition is potentially responsible for respiratory decline. At inclusion, then yearly (over three years), 111 children and 117 adults with cystic fibrosis had oral glucose tolerance and insulin tests at one (G1) and 2h (G2). KmL analysis identified homogeneous G1 and G2 glucose trajectories. A linear mixed model quantified the relationships between trajectories and FEV1 changes. In children, there were three G1 and four G2 trajectories and FEV1 decrease was not significantly different between G1 or G2 trajectories. In adults, two G1 and four G2 trajectories were identified and FEV1 change was estimated at -0.85/year (95% CI: [-1.54; -0.17], p=0.01) whatever the G1 trajectory and found significantly faster in the high and increasing G2 trajectory (-2.1/year, [-3.9; -0.2], p=0.03). In case of persistent G2 abnormality, physicians should be alert for clinical deterioration and intensify patient surveillance. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

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

PubMed

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

Friendship networks and trajectories of adolescent tobacco use.

PubMed

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.

FVID: Fishing Vessel Type Identification Based on VMS Trajectories

NASA Astrophysics Data System (ADS)

Huang, Haiguang; Hong, Feng; Liu, Jing; Liu, Chao; Feng, Yuan; Guo, Zhongwen

2018-05-01

Vessel Monitoring System (VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels. However, one research problem is still calling for solutions, how to identify the fishing vessel type based on only VMS trajectories. This problem is important because it requires the fishing vessel type as a preliminary to recognize fishing activities from VMS trajectories. This paper proposes fishing vessel type identification scheme (FVID) based only on VMS trajectories. FVID exploits feature engineering and machine learning schemes of XGBoost as its two key blocks and classifies fishing vessels into nine types. The dataset contains all the fishing vessel trajectories in the East China Sea in March 2017, including 10031 pre-registered fishing vessels and 1350 unregistered vessels of unknown types. In order to verify type identification accuracy, we first conduct a 4-fold cross-validation on the trajectories of registered fishing vessels. The classification accuracy is 95.42%. We then apply FVID to the unregistered fishing vessels to identify their types. After classifying the unregistered fishing vessel types, their fishing activities are further recognized based upon their types. At last, we calculate and compare the fishing density distribution in the East China Sea before and after applying the unregistered fishing vessels, confirming the importance of type identification of unregistered fishing vessels.

Optimism and Pessimism as Predictors of Alcohol Use Trajectories in Adolescence

ERIC Educational Resources Information Center

Wray, Tyler B.; Dvorak, Rob D.; Hsia, Jennifer F.; Arens, Ashley M.; Schweinle, William E.

2013-01-01

A range of research has recognized the benefits of optimism in a variety of health-related outcomes. Pessimism has received less attention but may be a distinct concept that is uniquely related to certain health behaviors, including drug use. The present study examined relationships between optimism and pessimism and alcohol use trajectories of…

Method of interplanetary trajectory optimization for the spacecraft with low thrust and swing-bys

NASA Astrophysics Data System (ADS)

Konstantinov, M. S.; Thein, M.

2017-07-01

The method developed to avoid the complexity of solving the multipoint boundary value problem while optimizing interplanetary trajectories of the spacecraft with electric propulsion and a sequence of swing-bys is presented in the paper. This method is based on the use of the preliminary problem solutions for the impulsive trajectories. The preliminary problem analyzed at the first stage of the study is formulated so that the analysis and optimization of a particular flight path is considered as the unconstrained minimum in the space of the selectable parameters. The existing methods can effectively solve this problem and make it possible to identify rational flight paths (the sequence of swing-bys) to receive the initial approximation for the main characteristics of the flight path (dates, values of the hyperbolic excess velocity, etc.). These characteristics can be used to optimize the trajectory of the spacecraft with electric propulsion. The special feature of the work is the introduction of the second (intermediate) stage of the research. At this stage some characteristics of the analyzed flight path (e.g. dates of swing-bys) are fixed and the problem is formulated so that the trajectory of the spacecraft with electric propulsion is optimized on selected sites of the flight path. The end-to-end optimization is carried out at the third (final) stage of the research. The distinctive feature of this stage is the analysis of the full set of optimal conditions for the considered flight path. The analysis of the characteristics of the optimal flight trajectories to Jupiter with Earth, Venus and Mars swing-bys for the spacecraft with electric propulsion are presented. The paper shows that the spacecraft weighing more than 7150 kg can be delivered into the vicinity of Jupiter along the trajectory with two Earth swing-bys by use of the space transportation system based on the "Angara A5" rocket launcher, the chemical upper stage "KVTK" and the electric propulsion system

Trajectories of Sensation Seeking Among Puerto Rican Children and Youth.

PubMed

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.

Trajectories of quality of life, life satisfaction, and psychological adjustment after prostate cancer.

PubMed

Chambers, Suzanne K; Ng, Shu Kay; Baade, Peter; Aitken, Joanne F; Hyde, Melissa K; Wittert, Gary; Frydenberg, Mark; Dunn, Jeff

2017-10-01

To describe trajectories of health-related quality of life (QoL), life satisfaction, and psychological adjustment for men with prostate cancer over the medium to long term and identify predictors of poorer outcomes using growth mixture models. One-thousand sixty-four (82.4% response) men diagnosed with prostate cancer were recruited close to diagnosis and assessed over a 72-month (6-year) period with self-report assessment of health-related QoL, life satisfaction, cancer-related distress, and prostate specific antigen anxiety. Urinary, bowel, and sexual function were also assessed using validated questionnaires. Poorer physical QOL was predicted by older age, lower education, lower income, comorbidities, and receiving hormone therapy. Lower life satisfaction was related to younger age, lower income, not being partnered, and comorbidities. Poorer psychological trajectories were predicted by younger age, lower income, comorbidities, and receiving radical prostatectomy or brachytherapy. Better urinary, bowel, and sexual function were related to better global outcomes over time. Anxiety about prostate specific antigen testing was rare. Distinct trajectories exist for medium- to long-term QoL, life satisfaction, and psychological adjustment after prostate cancer; with age and socioeconomic deprivation playing a differential role in men's survivorship profile and the impact of functional status on outcomes increasing over time. These results reinforce the need for an appraisal of men's life course in addition to treatment side effects when planning survivorship care after cancer. © 2016 The Authors. Psycho-Oncology Published by John Wiley & Sons Ltd.

Integrative Genomic Analysis of Cholangiocarcinoma Identifies Distinct IDH-Mutant Molecular Profiles.

PubMed

Farshidfar, Farshad; Zheng, Siyuan; Gingras, Marie-Claude; Newton, Yulia; Shih, Juliann; Robertson, A Gordon; Hinoue, Toshinori; Hoadley, Katherine A; Gibb, Ewan A; Roszik, Jason; Covington, Kyle R; Wu, Chia-Chin; Shinbrot, Eve; Stransky, Nicolas; Hegde, Apurva; Yang, Ju Dong; Reznik, Ed; Sadeghi, Sara; Pedamallu, Chandra Sekhar; Ojesina, Akinyemi I; Hess, Julian M; Auman, J Todd; Rhie, Suhn K; Bowlby, Reanne; Borad, Mitesh J; Zhu, Andrew X; Stuart, Josh M; Sander, Chris; Akbani, Rehan; Cherniack, Andrew D; Deshpande, Vikram; Mounajjed, Taofic; Foo, Wai Chin; Torbenson, Michael S; Kleiner, David E; Laird, Peter W; Wheeler, David A; McRee, Autumn J; Bathe, Oliver F; Andersen, Jesper B; Bardeesy, Nabeel; Roberts, Lewis R; Kwong, Lawrence N

2017-03-14

Cholangiocarcinoma (CCA) is an aggressive malignancy of the bile ducts, with poor prognosis and limited treatment options. Here, we describe the integrated analysis of somatic mutations, RNA expression, copy number, and DNA methylation by The Cancer Genome Atlas of a set of predominantly intrahepatic CCA cases and propose a molecular classification scheme. We identified an IDH mutant-enriched subtype with distinct molecular features including low expression of chromatin modifiers, elevated expression of mitochondrial genes, and increased mitochondrial DNA copy number. Leveraging the multi-platform data, we observed that ARID1A exhibited DNA hypermethylation and decreased expression in the IDH mutant subtype. More broadly, we found that IDH mutations are associated with an expanded histological spectrum of liver tumors with molecular features that stratify with CCA. Our studies reveal insights into the molecular pathogenesis and heterogeneity of cholangiocarcinoma and provide classification information of potential therapeutic significance. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Life Events Trajectories, Allostatic Load, and the Moderating Role of Age at Arrival from Puerto Rico to the US Mainland

PubMed Central

Arévalo, Sandra P.; Tucker, Katherine L; Falcon, Luis M

2014-01-01

Our aim was to examine the effects of trajectories of stressful life events on allostatic load, measured over a two year time period, and to investigate the roles of language acculturation and age at migration in this association, in a sample of Puerto Rican migrants. We used data from the Boston Puerto Rican Health Study; a population-based prospective cohort of older Puerto Ricans recruited between the ages of 45 and 75 years. The Institutional Review Boards at Tufts Medical Center and Northeastern University approved the study. We used latent growth mixture modeling (LGMM) to identify different classes of two-year trajectories of stressful life events; analysis of variance to examine group differences by stress trajectory; and linear regression to test for the modifying effects of age at arrival on the association of stress trajectory with allostatic load at follow-up. In LGMM analysis, we identified three distinct stress trajectories; low, moderate ascending, and high. Unexpectedly, participants in the low stress group had the highest allostatic load at follow-up (F=4.4, p=0.01) relative to the other two groups. Age at arrival had a statistically significant moderating effect on the association. A reported two year period of moderate but repetitive and increasingly bad life events was associated with increases in allostatic load for participants who arrived to the U.S. mainland after the age of 5 years, and was particularly strong for those arriving between 6–11 years, but not for those arriving earlier or later. Results from this study highlight the complex effects of stress during the life course, and point to certain vulnerable periods for immigrant children that could modify long term effects of stress. PMID:25265208

Trajectories of Children's Social Interactions with their Infant Sibling in the First Year: A Multi-Dimensional Approach

PubMed Central

Oh, Wonjung; Volling, Brenda L.; Gonzalez, Richard

2015-01-01

Individual differences in longitudinal trajectories of children's social behaviors toward their infant sibling were examined simultaneously across multiple social dimensions: Positive engagement (moving toward), Antagonism (moving against), and Avoidance (moving away). Three distinct social patterns were identified: (C1) Positively-Engaged (n=107, 50%); (C2) Escalating-Antagonism (n=90, 42%); and (C3) Early-Onset Antagonism (n=16, 8%). Children in the positively-engaged class had high levels of positive engagement with their infant siblings, coupled with low levels of antagonism and avoidance. The escalating-antagonism class was positively engaged in sibling interaction with a steep escalation in antagonistic behavior and avoidance from 4 to 12 months. Children in the early-onset antagonism class displayed the highest level of antagonistic behavior starting as early as 4 months, and became increasingly avoidant over time. A path model, guided by a process × person × context × time model, revealed that low parental self-efficacy heightened by parenting stress and children's dysregulated temperament was directly related to the escalating-antagonism pattern. Punitive parenting in response to children's antagonistic behavior increased the likelihood of being in the early-onset antagonism class. Together, the results highlighted heterogeneity in the earliest emergence of sibling interaction patterns and the interplay of child and parent factors in predicting distinct sibling interaction trajectory patterns. PMID:25664367

Identification and prediction of health-related quality of life trajectories after a prostate cancer diagnosis.

PubMed

Farris, Megan S; Kopciuk, Karen A; Courneya, Kerry S; McGregor, S Elizabeth; Wang, Qinggang; Friedenreich, Christine M

2017-04-01

The aim of our study was to identify physical and mental health-related quality of life (HRQoL) trajectories after a prostate cancer diagnosis and systematically characterize trajectories by behaviours and prognostic factors. Prostate cancer survivors (n = 817) diagnosed between 1997 and 2000 were recruited between 2000 and 2002 into a prospective repeated measurements study. Behavioural/prognostic data were collected through in-person interviews and questionnaires. HRQoL was collected at three post-diagnosis time-points, approximately 2 years apart using the Short Form (SF)-36 validated questionnaire. To identify physical and mental HRQoL trajectories, group-based trajectory modelling was undertaken. Differences between groups were evaluated by assessing influential dropouts (mortality/poor health), behavioural/prognostic factors at diagnosis or during the follow-up. Three trajectories of physical HRQoL were identified including: average-maintaining HRQoL (32.2%), low-declining HRQoL (40.5%) and very low-maintaining HRQoL (27.3%). In addition, three trajectories for mental HRQoL were identified: average-increasing HRQoL (66.5%), above average-declining HRQoL (19.7%) and low-increasing HRQoL (13.8%). In both physical and mental HRQoL, dropout from mortality/poor health differed between trajectories, thus confirming HRQoL and mortality were related. Furthermore, increased Charlson comorbidity index score was consistently associated with physical and mental HRQoL group membership relative to average maintaining groups, while behaviours such as time-varying physical activity was associated with physical HRQoL trajectories but not mental HRQoL trajectories. It was possible to define three trajectories of physical and mental HRQoL after prostate cancer. These data provide insights regarding means for identifying subgroups of prostate cancer survivors with lower or declining HRQoL after diagnosis whom could be targeted for interventions aimed at improving HRQoL. �

Self-reported body silhouette trajectories across the lifespan and excessive daytime sleepiness in adulthood: a retrospective analysis. The Paris Prospective Study III

PubMed Central

Tafflet, Muriel; Charles, Marie-Aline; Thomas, Frédérique; Boutouyrie, Pierre; Guibout, Catherine; Haba-Rubio, José; Périer, Marie Cécile; Pannier, Bruno; Marques-Vidal, Pedro; Jouven, Xavier; Empana, Jean-Philippe

2018-01-01

Objectives Excessive daytime sleepiness (EDS) is a common sleep complaint in the population and is increasingly recognised as deleterious for health. Simple and sensitive tools allowing identifying individuals at greater risk of EDS would be of public health importance. Hence, we determined trajectories of body silhouette from early childhood to adulthood and evaluated their association with EDS in adulthood. Design A retrospective analysis in a prospective community-based study. Participants 6820 men and women self-reported their silhouette at ages 8, 15, 25, 35 and 45 using the body silhouettes proposed by Stunkard et al. EDS was defined by an Epworth Sleepiness Scale score ≥11. Main outcome measure Presence of EDS in adulthood. Results The study population comprised 6820 participants (mean age 59.8 years, 61.1% men). Five distinct body silhouettes trajectories over the lifespan were identified: 31.9% ‘lean stable’, 11.1% ‘lean increase’, 16.1% ‘lean-marked increase’, 32.5% ‘moderate stable’ and 8.4% ‘heavy stable’. Subjects with a ‘heavy-stable’ trajectory (OR 1.24, 95% CI 0.94 to 1.62) and those with a ‘lean-marked increase’ trajectory (OR 1.46, 95% CI 1.18 to 1.81) were more likely to have EDS when compared with the ‘lean-stable’ group after adjusting for confounding. Further adjustment for birth weight strengthened the magnitude of the ORs. Conclusion Increasing body silhouette and to a lesser extent constantly high body silhouette trajectory from childhood to adulthood are associated with increased likelihood of EDS, independently of major confounding variables. Trial registration number NCT00741728; Pre-results. PMID:29593025

IMP-27, a Unique Metallo-β-Lactamase Identified in Geographically Distinct Isolates of Proteus mirabilis.

PubMed

Dixon, Nyssa; Fowler, Randal C; Yoshizumi, A; Horiyama, Tsukasa; Ishii, Y; Harrison, Lucas; Geyer, Chelsie N; Moland, Ellen Smith; Thomson, Kenneth; Hanson, Nancy D

2016-10-01

A novel metallo-β-lactamase gene, blaIMP-27, was identified in unrelated Proteus mirabilis isolates from two geographically distinct locations in the United States. Both isolates harbor blaIMP-27 as part of the first gene cassette in a class 2 integron. Antimicrobial susceptibility testing indicated susceptibility to aztreonam, piperacillin-tazobactam, and ceftazidime but resistance to ertapenem. However, hydrolysis assays indicated that ceftazidime was a substrate for IMP-27. Copyright © 2016 Dixon et al.

Patterns of Adolescent Regulatory Responses during Family Conflict and Mental Health Trajectories

PubMed Central

Koss, Kalsea J.; Cummings, E. Mark; Davies, Patrick T.; Cicchetti, Dante

2016-01-01

Four distinct patterns of adolescents’ behavioral, emotional, and physiological responses to family conflict were identified during mother-father-adolescent (M=13.08 years) interactions. Most youth displayed adaptively-regulated patterns comprised of low overt and subjective distress. Under-controlled adolescents exhibited elevated observable and subjective anger. Over-controlled adolescents were withdrawn and reported heightened subjective distress. Physiologically reactive adolescents had elevated cortisol coupled with low overt and subjective distress. Regulation patterns were associated with unique mental health trajectories. Under-controlled adolescents had elevated conduct and peer problems whereas over-controlled adolescents had higher anxiety and depressive symptoms. Physiologically reactive adolescents had low concurrent, but increasing levels of depressive, anxiety, and peer problem symptoms. Findings underscore the importance of examining organizations of regulatory strategies in contributing to adolescent mental health. PMID:28498540

The relationship between lifetime health trajectories and socioeconomic attainment in middle age.

PubMed

Lee, Dohoon; Jackson, Margot

2015-11-01

A large literature demonstrates the direct and indirect influence of health on socioeconomic attainment, and reveals the ways in which health and socioeconomic background simultaneously and dynamically affect opportunities for attainment and mobility. Despite an increasing understanding of the effects of health on social processes, research to date remains limited in its conceptualization and measurement of the temporal dimensions of health, especially in the presence of socioeconomic circumstances that covary with health over time. Guided by life course theory, we use data from the British National Child Development Study, an ongoing panel study of a cohort born in 1958, to examine the association between lifetime health trajectories and socioeconomic attainment in middle age. We apply finite mixture modeling to identify distinct trajectories of health that simultaneously account for timing, duration and stability. Moreover, we employ propensity score weighting models to account for the presence of time-varying socioeconomic factors in estimating the impact of health trajectories. We find that, when poor health is limited to the childhood years, the disadvantage in socioeconomic attainment relative to being continuously healthy is either insignificant or largely explained by time-varying socioeconomic confounders. The socioeconomic impact of continuously deteriorating health over the life course is more persistent, however. Our results suggest that accounting for the timing, duration and stability of poor health throughout both childhood and adulthood is important for understanding how health works to produce social stratification. In addition, the findings highlight the importance of distinguishing between confounding and mediating effects of time-varying socioeconomic circumstances. Copyright © 2015 Elsevier Inc. All rights reserved.

The Relationship between Lifetime Health Trajectories and Socioeconomic Attainment in Middle Age

PubMed Central

Lee, Dohoon; Jackson, Margot

2015-01-01

A large literature demonstrates the direct and indirect influence of health on socioeconomic attainment, and reveals the ways in which health and socioeconomic background simultaneously and dynamically affect opportunities for attainment and mobility. Despite an increasing understanding of the effects of health on social processes, research to date remains limited in its conceptualization and measurement of the temporal dimensions of health, especially in the presence of socioeconomic circumstances that covary with health over time. Guided by life course theory, we use data from the British National Child Development Study, an ongoing panel study of a cohort born in 1958, to examine the association between lifetime health trajectories and socioeconomic attainment in middle age. We apply finite mixture modeling to identify distinct trajectories of health that simultaneously account for timing, duration and stability. Moreover, we employ propensity score weighting models to account for the presence of time-varying socioeconomic factors in estimating the impact of health trajectories. We find that, when poor health is limited to the childhood years, the disadvantage in socioeconomic attainment relative to being continuously healthy is either insignificant or largely explained by time-varying socioeconomic confounders. The socioeconomic impact of continuously deteriorating health over the life course is more persistent, however. Our results suggest that accounting for the timing, duration and stability of poor health throughout both childhood and adulthood is important for understanding how health works to produce social stratification. In addition, the findings highlight the importance of distinguishing between confounding and mediating effects of time-varying socioeconomic circumstances. PMID:26463537

Six-month trajectories of self-reported depressive symptoms in long-term care.

PubMed

McCusker, Jane; Cole, Martin G; Voyer, Philippe; Monette, Johanne; Champoux, Nathalie; Ciampi, Antonio; Vu, Minh; Belzile, Eric; Bai, Chun

2016-01-01

Depression is a common problem in long-term care (LTC) settings. We sought to characterize depression symptom trajectories over six months among older residents, and to identify resident characteristics at baseline that predict symptom trajectory. This study was a secondary analysis of data from a six-month prospective, observational, and multi-site study. Severity of depressive symptoms was assessed with the 15-item Geriatric Depression Scale (GDS) at baseline and with up to six monthly follow-up assessments. Participants were 130 residents with a Mini-Mental State Examination score of 15 or more at baseline and of at least two of the six monthly follow-up assessments. Individual resident GDS trajectories were grouped using hierarchical clustering. The baseline predictors of a more severe trajectory were identified using the Proportional Odds Model. Three clusters of depression symptom trajectory were found that described "lower," "intermediate," and "higher" levels of depressive symptoms over time (mean GDS scores for three clusters at baseline were 2.2, 4.9, and 9.0 respectively). The GDS scores in all groups were generally stable over time. Baseline predictors of a more severe trajectory were as follows: Initial GDS score of 7 or more, female sex, LTC residence for less than 12 months, and corrected visual impairment. The six-month course of depressive symptoms in LTC is generally stable. Most residents who experience a more severe symptom trajectory can be identified at baseline.

Elucidating distinct ion channel populations on the surface of hippocampal neurons via single-particle tracking recurrence analysis

NASA Astrophysics Data System (ADS)

Sikora, Grzegorz; Wyłomańska, Agnieszka; Gajda, Janusz; Solé, Laura; Akin, Elizabeth J.; Tamkun, Michael M.; Krapf, Diego

2017-12-01

Protein and lipid nanodomains are prevalent on the surface of mammalian cells. In particular, it has been recently recognized that ion channels assemble into surface nanoclusters in the soma of cultured neurons. However, the interactions of these molecules with surface nanodomains display a considerable degree of heterogeneity. Here, we investigate this heterogeneity and develop statistical tools based on the recurrence of individual trajectories to identify subpopulations within ion channels in the neuronal surface. We specifically study the dynamics of the K+ channel Kv1.4 and the Na+ channel Nav1.6 on the surface of cultured hippocampal neurons at the single-molecule level. We find that both these molecules are expressed in two different forms with distinct kinetics with regards to surface interactions, emphasizing the complex proteomic landscape of the neuronal surface. Further, the tools presented in this work provide new methods for the analysis of membrane nanodomains, transient confinement, and identification of populations within single-particle trajectories.

Online discourse on fibromyalgia: text-mining to identify clinical distinction and patient concerns.

PubMed

Park, Jungsik; Ryu, Young Uk

2014-10-07

The purpose of this study was to evaluate the possibility of using text-mining to identify clinical distinctions and patient concerns in online memoires posted by patients with fibromyalgia (FM). A total of 399 memoirs were collected from an FM group website. The unstructured data of memoirs associated with FM were collected through a crawling process and converted into structured data with a concordance, parts of speech tagging, and word frequency. We also conducted a lexical analysis and phrase pattern identification. After examining the data, a set of FM-related keywords were obtained and phrase net relationships were set through a web-based visualization tool. The clinical distinction of FM was verified. Pain is the biggest issue to the FM patients. The pains were affecting body parts including 'muscles,' 'leg,' 'neck,' 'back,' 'joints,' and 'shoulders' with accompanying symptoms such as 'spasms,' 'stiffness,' and 'aching,' and were described as 'sever,' 'chronic,' and 'constant.' This study also demonstrated that it was possible to understand the interests and concerns of FM patients through text-mining. FM patients wanted to escape from the pain and symptoms, so they were interested in medical treatment and help. Also, they seemed to have interest in their work and occupation, and hope to continue to live life through the relationships with the people around them. This research shows the potential for extracting keywords to confirm the clinical distinction of a certain disease, and text-mining can help objectively understand the concerns of patients by generalizing their large number of subjective illness experiences. However, it is believed that there are limitations to the processes and methods for organizing and classifying large amounts of text, so these limits have to be considered when analyzing the results. The development of research methodology to overcome these limitations is greatly needed.

Ascent trajectory dispersion analysis for WTR heads-up space shuttle trajectory

NASA Technical Reports Server (NTRS)

1986-01-01

The results of a Space Transportation System ascent trajectory dispersion analysis are discussed. The purpose is to provide critical trajectory parameter values for assessing the Space Shuttle in a heads-up configuration launched from the Western Test Range (STR). This analysis was conducted using a trajectory profile based on a launch from the WTR in December. The analysis consisted of the following steps: (1) nominal trajectories were simulated under the conditions as specified by baseline reference mission guidelines; (2) dispersion trajectories were simulated using predetermined parametric variations; (3) requirements for a system-related composite trajectory were determined by a root-sum-square (RSS) analysis of the positive deviations between values of the aerodynamic heating indicator (AHI) generated by the dispersion and nominal trajectories; (4) using the RSS assessment as a guideline, the system related composite trajectory was simulated by combinations of dispersion parameters which represented major contributors; (5) an assessment of environmental perturbations via a RSS analysis was made by the combination of plus or minus 2 sigma atmospheric density variation and 95% directional design wind dispersions; (6) maximum aerodynamic heating trajectories were simulated by variation of dispersion parameters which would emulate the summation of the system-related RSS and environmental RSS values of AHI. The maximum aerodynamic heating trajectories were simulated consistent with the directional winds used in the environmental analysis.

Trajectories of Work Disability and Economic Insecurity Approaching Retirement.

PubMed

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.

Cortisol response to an experimental stress paradigm prospectively predicts long-term distress and resilience trajectories in response to active police service

PubMed Central

Galatzer-Levy, Isaac R.; Steenkamp, Maria M.; Qian, Meng; Inslicht, Sabra; Henn-Haase, Clare; Otte, Christian; Yehuda, Rachel; Neylan, Thomas C.; Marmar, Charles R

2017-01-01

Heterogeneity in glucocorticoid response to experimental stress conditions has shown to differentiate individuals with healthy from maladaptive real-life stress responses in a number of distinct domains. However, it is not known if this heterogeneity influences the risk for developing stress related disorders or if it is a biological consequence of the stress response itself. Determining if glucocorticoid response to stress induction prospectively predicts psychological vulnerability to significant real life stressors can adjudicate this issue. To test this relationship, salivary cortisol as well as catecholamine responses to a laboratory stressor during academy training were examined as predictors of empirically identified distress trajectories through the subsequent 4 years of active duty among urban police officers routinely exposed to potentially traumatic events and routine life stressors (N = 234). During training, officers were exposed to a video vignette of police officers exposed to real-life trauma. Changes in salivary 3-methoxy-4-hydroxyphenylglycol (MHPG) and cortisol in response to this video challenge were examined as predictors of trajectory membership while controlling for age, gender, and baseline neuroendocrine levels. Officers who followed trajectories of resilience and recovery over 4 years mounted significant increases in cortisol in response to the experimental stressor, while those following a trajectory of chronic increasing distress had no significant cortisol change in response to the challenge. MHPG responses were not associated with distress trajectories. Cortisol response prospectively differentiated trajectories of distress response suggesting that a blunted cortisol response to a laboratory stressor is a risk factor for later vulnerability to distress following significant life stressors. PMID:24952936

Developmental trajectories of bullying and associated factors.

PubMed

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.

Dietary Fiber Intake in Relation to Knee Pain Trajectory.

PubMed

Dai, Zhaoli; Lu, Na; Niu, Jingbo; Felson, David T; Zhang, Yuqing

2017-09-01

Dietary fiber may reduce knee pain, in part by lowering body weight and reducing inflammation. In this study, we assessed whether fiber intake was associated with patterns of knee pain development. In a prospective, multicenter cohort of 4,796 men and women ages 45-79 years with or at risk of knee osteoarthritis, participants underwent annual followups for 8 years. Dietary fiber intake was estimated using a validated food frequency questionnaire at baseline. Group-based trajectory modeling was used to identify Western Ontario and McMaster Universities Osteoarthritis Index pain trajectories, which were assessed for associations with dietary fiber intake using polytomous regression models. Of the eligible participants (4,470 persons and 8,940 knees, mean ± SD age 61.3 ± 9.1 years, 58% women), 4.9% underwent knee replacement and were censored at the time of surgery. Four distinct knee pain patterns were identified: no pain (34.5%), mild pain (38.1%), moderate pain (21.2%), and severe pain (6.2%). Dietary total fiber was inversely related to membership in the moderate or severe pain groups (P ≤ 0.006 for trend for both). Subjects in the highest versus those in the lowest quartile of total fiber intake had a lower risk of belonging to the moderate pain pattern group (odds ratio [OR] 0.76 [95% confidence interval (95% CI) 0.61-0.93]) and severe pain pattern group (OR 0.56 [95% CI 0.41-0.78]). Similar results were found with grain fiber and these 2 pain pattern groups. Our findings suggest that a high intake of dietary total or grain fiber, particularly the recommended daily fiber average intake of 25 gm per day, is associated with a lower risk of developing moderate or severe knee pain over time. © 2016, American College of Rheumatology.

Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood.

PubMed

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.

Growth Trajectories of Health Behaviors from Adolescence through Young Adulthood

PubMed Central

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

Learning and Inferring "Dark Matter" and Predicting Human Intents and Trajectories in Videos.

PubMed

Xie, Dan; Shu, Tianmin; Todorovic, Sinisa; Zhu, Song-Chun

2018-07-01

This paper presents a method for localizing functional objects and predicting human intents and trajectories in surveillance videos of public spaces, under no supervision in training. People in public spaces are expected to intentionally take shortest paths (subject to obstacles) toward certain objects (e.g., vending machine, picnic table, dumpster etc.) where they can satisfy certain needs (e.g., quench thirst). Since these objects are typically very small or heavily occluded, they cannot be inferred by their visual appearance but indirectly by their influence on people's trajectories. Therefore, we call them "dark matter", by analogy to cosmology, since their presence can only be observed as attractive or repulsive "fields" in the public space. A person in the scene is modeled as an intelligent agent engaged in one of the "fields" selected depending his/her intent. An agent's trajectory is derived from an Agent-based Lagrangian Mechanics. The agents can change their intents in the middle of motion and thus alter the trajectory. For evaluation, we compiled and annotated a new dataset. The results demonstrate our effectiveness in predicting human intent behaviors and trajectories, and localizing and discovering distinct types of "dark matter" in wide public spaces.

Genome sequence of a distinct watermelon mosaic virus identified from ginseng (Panax ginseng) transcriptome.

PubMed

Park, D; Kim, H; Hahn, Y

Watermelon mosaic virus (WMV) is a member of the genus Potyvirus, which is the largest genus of plant viruses. WMV is a significant pathogen of crop plants, including Cucurbitaceae species. A WMV strain, designated as WMV-Pg, was identified in transcriptome data collected from ginseng (Panax ginseng) root. WMV-Pg showed 84% nucleotide sequence identity and 91% amino acid sequence identity with its closest related virus, WMV-Fr. A phylogenetic analysis of WMV-Pg with other WMVs and soybean mosaic viruses (SMVs) indicated that WMV-Pg is a distinct subtype of the WMV/SMV group of the genus Potyvirus in the family Potyviridae.

Accuracy of topographic index models at identifying ephemeral gully trajectories on agricultural fields

NASA Astrophysics Data System (ADS)

Sheshukov, Aleksey Y.; Sekaluvu, Lawrence; Hutchinson, Stacy L.

2018-04-01

Topographic index (TI) models have been widely used to predict trajectories and initiation points of ephemeral gullies (EGs) in agricultural landscapes. Prediction of EGs strongly relies on the selected value of critical TI threshold, and the accuracy depends on topographic features, agricultural management, and datasets of observed EGs. This study statistically evaluated the predictions by TI models in two paired watersheds in Central Kansas that had different levels of structural disturbances due to implemented conservation practices. Four TI models with sole dependency on topographic factors of slope, contributing area, and planform curvature were used in this study. The observed EGs were obtained by field reconnaissance and through the process of hydrological reconditioning of digital elevation models (DEMs). The Kernel Density Estimation analysis was used to evaluate TI distribution within a 10-m buffer of the observed EG trajectories. The EG occurrence within catchments was analyzed using kappa statistics of the error matrix approach, while the lengths of predicted EGs were compared with the observed dataset using the Nash-Sutcliffe Efficiency (NSE) statistics. The TI frequency analysis produced bi-modal distribution of topographic indexes with the pixels within the EG trajectory having a higher peak. The graphs of kappa and NSE versus critical TI threshold showed similar profile for all four TI models and both watersheds with the maximum value representing the best comparison with the observed data. The Compound Topographic Index (CTI) model presented the overall best accuracy with NSE of 0.55 and kappa of 0.32. The statistics for the disturbed watershed showed higher best critical TI threshold values than for the undisturbed watershed. Structural conservation practices implemented in the disturbed watershed reduced ephemeral channels in headwater catchments, thus producing less variability in catchments with EGs. The variation in critical thresholds for all

Adolescent Trajectories of Depressive Symptoms: Codevelopment of Behavioral and Academic Problems.

PubMed

Brière, Frédéric N; Janosz, Michel; Fallu, Jean-Sébastien; Morizot, Julien

2015-09-01

Increasing evidence suggests the existence of heterogeneity in the development of depressive symptoms during adolescence, but little remains known regarding the implications of this heterogeneity for the development of commonly co-occurring problems. In this study, we derived trajectories of depressive symptoms in adolescents and examined the codevelopment of multiple behavioral and academic problems in these trajectories. Participants were 6,910 students from secondary schools primarily located in disadvantaged areas of Quebec (Canada) who were assessed annually from the age 12 to 16 years. Trajectories were identified using growth mixture modeling. The course of behavioral (delinquency, substance use) and academic adjustment (school liking, academic achievement) in trajectories was examined by deriving latent growth curves for each covariate conditional on trajectory membership. We identified five trajectories of stable-low (68.1%), increasing (12.1%), decreasing (8.7%), transient (8.7%), and stable-high (2.4%) depressive symptoms. Examination of conditional latent growth curves revealed that the course of behavioral and academic problems closely mirrored the course of depressive symptoms in each trajectory. This pattern of results suggests that the course of depressive symptoms and other adjustment problems over time is likely to involve an important contribution of shared underlying developmental process(es). Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Parental Smoking Exposure and Adolescent Smoking Trajectories

PubMed Central

Gilman, Stephen E.; Rende, Richard; Luta, George; Tercyak, Kenneth P.; Niaura, Raymond S.

2014-01-01

OBJECTIVE: In a multigenerational study of smoking risk, the objective was to investigate the intergenerational transmission of smoking by examining if exposure to parental smoking and nicotine dependence predicts prospective smoking trajectories among adolescent offspring. METHODS: Adolescents (n = 406) ages 12 to 17 and a parent completed baseline interviews (2001–2004), and adolescents completed up to 2 follow-up interviews 1 and 5 years later. Baseline interviews gathered detailed information on parental smoking history, including timing and duration, current smoking, and nicotine dependence. Adolescent smoking and nicotine dependence were assessed at each time point. Latent Class Growth Analysis identified prospective smoking trajectory classes from adolescence into young adulthood. Logistic regression was used to examine relationships between parental smoking and adolescent smoking trajectories. RESULTS: Four adolescent smoking trajectory classes were identified: early regular smokers (6%), early experimenters (23%), late experimenters (41%), and nonsmokers (30%). Adolescents with parents who were nicotine-dependent smokers at baseline were more likely to be early regular smokers (odds ratio 1.18, 95% confidence interval 1.05–1.33) and early experimenters (odds ratio 1.04, 95% confidence interval 1.04–1.25) with each additional year of previous exposure to parental smoking. Parents’ current non-nicotine–dependent and former smoking were not associated with adolescent smoking trajectories. CONCLUSIONS: Exposure to parental nicotine dependence is a critical factor influencing intergenerational transmission of smoking. Adolescents with nicotine-dependent parents are susceptible to more intense smoking patterns and this risk increases with longer duration of exposure. Research is needed to optimize interventions to help nicotine-dependent parents quit smoking early in their children’s lifetime to reduce these risks. PMID:24819567

Lifecourse Childhood Adiposity Trajectories Associated With Adolescent Insulin Resistance

PubMed Central

Huang, Rae-Chi; de Klerk, Nicholas H.; Smith, Anne; Kendall, Garth E.; Landau, Louis I.; Mori, Trevor A.; Newnham, John P.; Stanley, Fiona J.; Oddy, Wendy H.; Hands, Beth; Beilin, Lawrence J.

2011-01-01

OBJECTIVE In light of the obesity epidemic, we aimed to characterize novel childhood adiposity trajectories from birth to age 14 years and to determine their relation to adolescent insulin resistance. RESEARCH DESIGN AND METHODS A total of 1,197 Australian children with cardiovascular/metabolic profiling at age 14 years were studied serially from birth to age 14 years. Semiparametric mixture modeling was applied to anthropometric data over eight time points to generate adiposity trajectories of z scores (weight-for-height and BMI). Fasting insulin and homeostasis model assessment of insulin resistance (HOMA-IR) were compared at age 14 years between adiposity trajectories. RESULTS Seven adiposity trajectories were identified. Three (two rising and one chronic high adiposity) trajectories comprised 32% of the population and were associated with significantly higher fasting insulin and HOMA-IR compared with a reference trajectory group (with longitudinal adiposity z scores of approximately zero). There was a significant sex by trajectory group interaction (P < 0.001). Girls within a rising trajectory from low to moderate adiposity did not show increased insulin resistance. Maternal obesity, excessive weight gain during pregnancy, and gestational diabetes were more prevalent in the chronic high adiposity trajectory. CONCLUSIONS A range of childhood adiposity trajectories exist. The greatest insulin resistance at age 14 years is seen in those with increasing trajectories regardless of birth weight and in high birth weight infants whose adiposity remains high. Public health professionals should urgently target both excessive weight gain in early childhood across all birth weights and maternal obesity and excessive weight gain during pregnancy. PMID:21378216

Sexual and general offending trajectories of men referred for civil commitment.

PubMed

Francis, Brian; Harris, Danielle Arlanda; Wallace, Stephanie; Knight, Raymond A; Soothill, Keith

2014-08-01

Policies aimed at managing high-risk offenders, which include sex offenders, often assume they are a homogeneous population. These policies also tend to assume the pattern of offending is the same for all sex offenders, and is stable. This study challenges these assumptions by examining the life course offending trajectories of 780 convicted adult male sexual offenders. The men were referred to the Massachusetts Treatment Center for civil commitment between 1959 and 1984. The changing number of both sexual and any offenses were examined by age using Group-Based Trajectory Modeling. We identified a four-trajectory model for all offending and a four-trajectory model for sexual offending. The identified groups varied in several offending patterns including criminal onset, length of criminal careers, age of peak offending, and time of entry into the treatment center. Late adult onset of sex offending was found to be associated with child molestation, whereas early-onset trajectories were associated with rape. Implications for future research and policy are discussed. © The Author(s) 2013.

Trajectories of Childhood Neighbourhood Cohesion and Adolescent Mental Health: Evidence from a National Canadian Cohort

PubMed Central

Kingsbury, Mila; Kirkbride, James B; McMartin, Seanna E; Wickham, Maeve E; Weeks, Murray; Colman, Ian

2017-01-01

Background The objective of this study was to examine associations between trajectories of childhood neighbourhood social cohesion and adolescent mental health and behaviour. Methods This study used data from the National Longitudinal Survey of Children and Youth, a nationally representative sample of Canadian children. The sample included 5577 children aged 0-3 in 1994/95, prospectively followed until age 12-15. Parental perceived neighbourhood cohesion was assessed every two years. Latent growth class modeling was used to identify trajectories of neighbourhood cohesion. Mental health and behavioural outcomes were self-reported at age 12-15 years. Logistic regression was used to examine associations between neighbourhood cohesion trajectories and outcomes, adjusting for potential confounders. Results Five distinct trajectories were identified: ‘stable low’ (4.2%); ‘moderate increasing’ (9.1%); ‘stable moderate’ (68.5%); ‘high falling’ (8.9%); and, ‘stable high’ (9.3%). Relative to those living in stable moderately cohesive neighbourhoods, those in stable low cohesive neighbourhoods were more likely to experience symptoms of anxiety/depression (OR=1.75; 95%CI: 1.05,2.92) and engage in indirect aggression (OR=1.59; 95%CI: 1.05,2.40). Those with improvements in neighbourhood cohesion had significantly lower odds of hyperactivity (OR=0.68; 95%CI: 0.46,0.99) and indirect aggression (OR=0.68; 95%CI: 0.49,0.95). In contrast, those with a decline in neighbourhood cohesion had increased odds of hyperactivity (OR=1.65; 95%CI: 1.20,2.27). Those in highly cohesive neighbourhoods in early childhood were more likely to engage in prosocial behaviour (‘high falling’: OR=1.95; 95%CI: 1.40,2.72; ‘stable high’: OR=1.91; 95%CI: 1.37,2.66). Conclusions These results suggest that neighbourhood cohesion in childhood may have time-sensitive effects on several domains of adolescent mental health and behaviour. PMID:26169730

Sexual risk trajectories among MSM in the United States: implications for pre-exposure prophylaxis delivery

PubMed Central

Pines, Heather A.; Gorbach, Pamina M.; Weiss, Robert E.; Shoptaw, Steve; Landovitz, Raphael J.; Javanbakht, Marjan; Ostrow, David G.; Stall, Ron D.; Plankey, Michael

2014-01-01

Background Despite evidence supporting pre-exposure prophylaxis (PrEP) efficacy, there are concerns regarding the feasibility of widespread PrEP implementation among men who have sex with men (MSM). To inform the development of targeted PrEP delivery guidelines, we characterized sexual risk trajectories among HIV-negative MSM. Methods At semiannual visits from 2003–2011, HIV-negative MSM (N=419) participating in the Multicenter AIDS Cohort Study provided data on sexual risk behaviors since their last visit. Based on reported behaviors, participants were assigned a sexual risk behavior (SRB) score at each visit as follows: (0) no insertive or receptive anal intercourse (IAI/RAI), (1) no unprotected IAI/RAI (UIAI/URAI), (2) only UIAI, (3) URAI with 1 HIV-negative partner, (4) condom-serosorting, (5) condom-seropositioning, and (6) no seroadaptive behaviors. Group-based trajectory modeling was used to examine SRB scores (<4 vs. ≥4) and identify groups with distinct sexual risk trajectories. Results Three sexual risk trajectory groups were identified: low risk (N=264; 63.0%), moderate risk (N=96; 22.9%; mean duration of consecutive high risk intervals~1 year), and high risk (N=59; 14.1%; mean duration of consecutive high risk intervals~2 years). Compared to low risk group membership, high risk group membership was associated with younger age (in years) (adjusted odds ratio [AOR]=0.92, 95% confidence interval [CI]: 0.88–0.96), being White (AOR=3.67, 95% CI: 1.48–9.11), earning an income ≥$20,000 (AOR=4.98, 95% CI: 2.13–11.64), distress/depression symptoms (CESD≥16) (AOR=2.36, 95% CI: 1.14–4.92), and substance use (AOR=2.00, 95% CI: 1.01–3.97). Conclusion Screening for the socio-demographic and behavioral factors described above may facilitate targeted PrEP delivery during high risk periods among MSM. PMID:24378726

The Impact of Parents, Child Care Providers, Teachers, and Peers on Early Externalizing Trajectories

PubMed Central

Silver, Rebecca B.; Measelle, Jeffrey R.; Armstrong, Jeffrey M.; Essex, Marilyn J.

2010-01-01

This study utilized growth mixture modeling to examine the impact of parents, child care providers, teachers, and peers on the prediction of distinct developmental patterns of classroom externalizing behavior in elementary school. Among 241 children, three groups were identified. 84.6% of children exhibited consistently low externalizing behavior. The externalizing behavior of the Chronic High group (5.8%) remained elevated throughout elementary school; it increased over time in the Low Increasing group (9.5%). Negative relationships with teachers and peers in the kindergarten classroom increased the odds of having chronically high externalizing behavior. Teacher–child conflict increased the likelihood of a developmental pattern of escalating externalizing behavior. Boys were overrepresented in the behaviorally risky groups, and no sex differences in trajectory types were found. PMID:21094398

Multiple Trajectories of Successful Aging of Older and Younger Cohorts

ERIC Educational Resources Information Center

Hsu, Hui-Chuan; Jones, Bobby L.

2012-01-01

Purpose: The purpose of this study was to apply group-based trajectory analysis to identify multiple successful aging trajectories by multiple indicators and to examine the factors related to successful aging among the elderly population in Taiwan. Design and Methods: Nation-representative longitudinal data collected from 1993 to 2007 and…

Impulsivity Trajectories and Gambling in Adolescence among Urban Male Youth

PubMed Central

Liu, Weiwei; Lee, Grace P.; Goldweber, Asha; Petras, Hanno; Storr, Carla L.; Ialongo, Nicholas S.; Martins, Silvia S.

2012-01-01

Aim Building on the recent emerging literature on the impulsivity trajectory-gambling association, this study investigated the association between developmental trajectories of teacher-rated impulsivity in early adolescence (ages 11–15) and subsequent gambling and gambling problems (i.e. at-risk and problem gambling) by age 19. Design Prospective cohort design. Setting Urban communities in Baltimore, Maryland. Participants The sample consists of 310 predominately minority (87%) and low SES (70%) males followed from first grade to late adolescence. Measurements Impulsivity was measured using teacher ratings of classroom behavior. Self-reported gambling behavior was assessed using the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA). Findings Results from a conventional growth model suggest the intercept of the impulsivity development (as measured by the repeated assessments of impulsivity across the entire developmental period) was significantly associated with gambling. Results from a general growth mixture model evidenced two distinct trajectories: a high impulsivity trajectory (41% the sample) and a low impulsivity trajectory (59% of the sample). Despite its non-significant association with any gambling, heterogeneity in impulsivity development was significantly associated with gambling problems. Specifically, being in the high impulsivity trajectory doubled the odds of meeting criteria for at-risk or problem gambling (OR= 2.09[1.02, 4.27]) and tripled the odds of meeting criteria for problem gambling (OR=2.84[1.02, 7.91]) Conclusions Development in impulsivity is strongly associated with problem/at-risk gambling in adolescence among urban male youth. Findings highlight the importance of distinguishing gambling problems from any gambling when evaluating programs aimed at reducing youth gambling problems through reducing impulsivity. PMID:23130867

Grouping and trajectories of neuropsychiatric symptoms in patients with Alzheimer's disease. Part II: two-year patient trajectories.

PubMed

Garre-Olmo, Josep; López-Pousa, Secundino; Vilalta-Franch, Joan; de Gracia Blanco, Manuel; Vilarrasa, Antoni Bulbena

2010-01-01

Behavioral and psychological symptoms of dementia (BPSD) are characterized by fluctuations in their frequency and severity as well as by differences in the concurrent presentation of different symptoms. The goal of the current study was to identify groups of patients with Alzheimer's disease (AD) that had similar trajectories in the expression of BPSD. Over a 24-month period, an observational study was conducted using a population of ambulatory patients with AD of mild or moderate severity. The Neuropsychiatric Inventory (NPI) was administered every 6 months to the patient's caregiver. To classify patients according to changes in the frequency and severity of BPSD, growth mixture models were fitted to the applied to the grouping of NPI subscales in the following three categories: psychotic syndrome (hallucinations and delusions), affective syndrome (depression, anxiety, irritability, and agitation), and behavioral syndrome (disinhibition, euphoria, apathy, and aberrant motor behavior). The sample population consisted of 491 patients (70.9% women) that had an average age of 75.2 years (SD=6.6). Different trajectory patterns were identified based on differences in changes over the time in the frequency (stable, increasing, decreasing, or fluctuating in course) and severity (low, moderate, or elevated severity) for psychotic syndrome, emotional syndrome, and behavior syndrome. Patients with AD display a high degree of variability in the evolutionary course of BPSD. It is possible to identify groups of patients with similar evolutionary trajectories in terms of changes in the frequency and severity of BPSD.

Academic trajectories of newcomer immigrant youth.

PubMed

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

Analysis of the nucleoprotein gene identifies three distinct lineages of viral haemorrhagic septicemia virus (VHSV) within the European marine environment

USGS Publications Warehouse

Snow, M.; Cunningham, C.O.; Melvin, W.T.; Kurath, G.

1999-01-01

A ribonuclease (RNase) protection assay (RPA) has been used to detect nucleotide sequence variation within the nucleoprotein gene of 39 viral haemorrhagic septicaemia virus (VHSV) isolates of European marine origin. The classification of VHSV isolates based on RPA cleavage patterns permitted the identification of ten distinct groups of viruses based on differences at the molecular level. The nucleotide sequence of representatives of each of these groupings was determined and subjected to phylogenetic analysis. This revealed grouping of the European marine isolates of VHSV into three genotypes circulating within distinct geographic areas. A fourth genotype was identified comprising isolates originating from North America. Phylogenetic analyses indicated that VHSV isolates recovered from wild caught fish around the British Isles were genetically related to isolates responsible for losses in farmed turbot. Furthermore, a relationship between naturally occurring marine isolates and VHSV isolates causing mortality among rainbow trout in continental Europe was demonstrated. Analysis of the nucleoprotein gene identifies distinct lineages of viral haemorrhagic septicaemia virus within the European marine environment. Virus Res. 63, 35-44. Available from: 

Early and long-standing rheumatoid arthritis: distinct molecular signatures identified by gene-expression profiling in synovia

PubMed Central

Lequerré, Thierry; Bansard, Carine; Vittecoq, Olivier; Derambure, Céline; Hiron, Martine; Daveau, Maryvonne; Tron, François; Ayral, Xavier; Biga, Norman; Auquit-Auckbur, Isabelle; Chiocchia, Gilles; Le Loët, Xavier; Salier, Jean-Philippe

2009-01-01

Introduction Rheumatoid arthritis (RA) is a heterogeneous disease and its underlying molecular mechanisms are still poorly understood. Because previous microarray studies have only focused on long-standing (LS) RA compared to osteoarthritis, we aimed to compare the molecular profiles of early and LS RA versus control synovia. Methods Synovial biopsies were obtained by arthroscopy from 15 patients (4 early untreated RA, 4 treated LS RA and 7 controls, who had traumatic or mechanical lesions). Extracted mRNAs were used for large-scale gene-expression profiling. The different gene-expression combinations identified by comparison of profiles of early, LS RA and healthy synovia were linked to the biological processes involved in each situation. Results Three combinations of 719, 116 and 52 transcripts discriminated, respectively, early from LS RA, and early or LS RA from healthy synovia. We identified several gene clusters and distinct molecular signatures specifically expressed during early or LS RA, thereby suggesting the involvement of different pathophysiological mechanisms during the course of RA. Conclusions Early and LS RA have distinct molecular signatures with different biological processes participating at different times during the course of the disease. These results suggest that better knowledge of the main biological processes involved at a given RA stage might help to choose the most appropriate treatment. PMID:19563633

Identifying seasonal mobility profiles from anonymized and aggregated mobile phone data. Application in food security.

PubMed

Zufiria, Pedro J; Pastor-Escuredo, David; Úbeda-Medina, Luis; Hernandez-Medina, Miguel A; Barriales-Valbuena, Iker; Morales, Alfredo J; Jacques, Damien C; Nkwambi, Wilfred; Diop, M Bamba; Quinn, John; Hidalgo-Sanchís, Paula; Luengo-Oroz, Miguel

2018-01-01

We propose a framework for the systematic analysis of mobile phone data to identify relevant mobility profiles in a population. The proposed framework allows finding distinct human mobility profiles based on the digital trace of mobile phone users characterized by a Matrix of Individual Trajectories (IT-Matrix). This matrix gathers a consistent and regularized description of individual trajectories that enables multi-scale representations along time and space, which can be used to extract aggregated indicators such as a dynamic multi-scale population count. Unsupervised clustering of individual trajectories generates mobility profiles (clusters of similar individual trajectories) which characterize relevant group behaviors preserving optimal aggregation levels for detailed and privacy-secured mobility characterization. The application of the proposed framework is illustrated by analyzing fully anonymized data on human mobility from mobile phones in Senegal at the arrondissement level over a calendar year. The analysis of monthly mobility patterns at the livelihood zone resolution resulted in the discovery and characterization of seasonal mobility profiles related with economic activities, agricultural calendars and rainfalls. The use of these mobility profiles could support the timely identification of mobility changes in vulnerable populations in response to external shocks (such as natural disasters, civil conflicts or sudden increases of food prices) to monitor food security.

Predictors of Latent Trajectory Classes of Physical Dating Violence Victimization

ERIC Educational Resources Information Center

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…

Factors that Influence Trajectories of Delinquency Throughout Adolescence.

PubMed

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.

Trajectory Browser: An Online Tool for Interplanetary Trajectory Analysis and Visualization

NASA Technical Reports Server (NTRS)

Foster, Cyrus James

2013-01-01

The trajectory browser is a web-based tool developed at the NASA Ames Research Center for finding preliminary trajectories to planetary bodies and for providing relevant launch date, time-of-flight and (Delta)V requirements. The site hosts a database of transfer trajectories from Earth to planets and small-bodies 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.

A new trajectory concept for exploring the earth's geomagnetic tail

NASA Technical Reports Server (NTRS)

Farquhar, R. W.; Dunham, D. W.

1981-01-01

An innovative trajectory technique for a magnetotail mapping mission is described which can control the apsidal rotation of an elliptical earth orbit and keep its apogee segment inside the tail region. The required apsidal rotation rate of approximately 1 deg/day is achieved by using the moon to carry out a prescribed sequence of gravity-assist maneuvers. Apogee distances are alternately raised and lowered by the lunar-swingby maneuvers; several categories of the 'sun-synchronous' swingby trajectories are identified. The strength and flexibility of the new trajectory concept is demonstrated by using real-world simulations showing that a large variety of trajectory shapes can be used to explore the earth's geomagnetic tail between 60 and 250 R sub E.

Spatio-Temporal Pattern Mining on Trajectory Data Using Arm

NASA Astrophysics Data System (ADS)

Khoshahval, S.; Farnaghi, M.; Taleai, M.

2017-09-01

Preliminary mobile was considered to be a device to make human connections easier. But today the consumption of this device has been evolved to a platform for gaming, web surfing and GPS-enabled application capabilities. Embedding GPS in handheld devices, altered them to significant trajectory data gathering facilities. Raw GPS trajectory data is a series of points which contains hidden information. For revealing hidden information in traces, trajectory data analysis is needed. One of the most beneficial concealed information in trajectory data is user activity patterns. In each pattern, there are multiple stops and moves which identifies users visited places and tasks. This paper proposes an approach to discover user daily activity patterns from GPS trajectories using association rules. Finding user patterns needs extraction of user's visited places from stops and moves of GPS trajectories. In order to locate stops and moves, we have implemented a place recognition algorithm. After extraction of visited points an advanced association rule mining algorithm, called Apriori was used to extract user activity patterns. This study outlined that there are useful patterns in each trajectory that can be emerged from raw GPS data using association rule mining techniques in order to find out about multiple users' behaviour in a system and can be utilized in various location-based applications.

Clicker Score Trajectories and Concept Inventory Scores as Predictors for Early Warning Systems for Large STEM Classes

NASA Astrophysics Data System (ADS)

Lee, Un Jung; Sbeglia, Gena C.; Ha, Minsu; Finch, Stephen J.; Nehm, Ross H.

2015-12-01

Increasing the retention of STEM (science, technology, engineering, and mathematics) majors has recently emerged as a national priority in undergraduate education. Since poor performance in large introductory science and math courses is one significant factor in STEM dropout, early detection of struggling students is needed. Technology-supported "early warning systems" (EWSs) are being developed to meet these needs. Our study explores the utility of two commonly collected data sources—pre-course concept inventory scores and longitudinal clicker scores—for use in EWS, specifically, in determining the time points at which robust predictions of student success can first be established. The pre-course diagnostic assessments, administered to 287 students, included two concept inventories and one attitude assessment. Clicker question scores were also obtained for each of the 37 class sessions. Additionally, student characteristics (sex, ethnicity, and English facility) were gathered in a survey. Our analyses revealed that all variables were predictive of final grades. The correlation of the first 3 weeks of clicker scores with final grades was 0.53, suggesting that this set of variables could be used in an EWS starting at the third week. We also used group-based trajectory models to assess whether trajectory patterns were homogeneous in the class. The trajectory analysis identified three distinct clicker performance patterns that were also significant predictors of final grade. Trajectory analyses of clicker scores, student characteristics, and pre-course diagnostic assessment appear to be valuable data sources for EWS, although further studies in a diversity of instructional contexts are warranted.

Trajectory Browser Website

NASA Technical Reports Server (NTRS)

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.

An incremental DPMM-based method for trajectory clustering, modeling, and retrieval.

PubMed

Hu, Weiming; Li, Xi; Tian, Guodong; Maybank, Stephen; Zhang, Zhongfei

2013-05-01

Trajectory analysis is the basis for many applications, such as indexing of motion events in videos, activity recognition, and surveillance. In this paper, the Dirichlet process mixture model (DPMM) is applied to trajectory clustering, modeling, and retrieval. We propose an incremental version of a DPMM-based clustering algorithm and apply it to cluster trajectories. An appropriate number of trajectory clusters is determined automatically. When trajectories belonging to new clusters arrive, the new clusters can be identified online and added to the model without any retraining using the previous data. A time-sensitive Dirichlet process mixture model (tDPMM) is applied to each trajectory cluster for learning the trajectory pattern which represents the time-series characteristics of the trajectories in the cluster. Then, a parameterized index is constructed for each cluster. A novel likelihood estimation algorithm for the tDPMM is proposed, and a trajectory-based video retrieval model is developed. The tDPMM-based probabilistic matching method and the DPMM-based model growing method are combined to make the retrieval model scalable and adaptable. Experimental comparisons with state-of-the-art algorithms demonstrate the effectiveness of our algorithm.

Delineating the trajectories of social and occupational functioning of young people attending early intervention mental health services in Australia: a longitudinal study.

PubMed

Iorfino, Frank; Hermens, Daniel F; Cross, Shane Pm; Zmicerevska, Natalia; Nichles, Alissa; Badcock, Caro-Anne; Groot, Josine; Scott, Elizabeth M; Hickie, Ian B

2018-03-27

Mental disorders typically emerge during adolescence and young adulthood and put young people at risk for prolonged socioeconomic difficulties. This study describes the longitudinal course of social and occupational functioning of young people attending primary care-based, early intervention services. A longitudinal study of young people receiving mental healthcare. Data were collected between January 2005 and August 2017 from a designated primary care-based mental health service. 554 young people (54% women) aged 12-32 years. A systematic medical file audit collected clinical and functional information at predetermined time intervals (ie, 3 months to 5+ years) using a clinical pro forma. Group-based trajectory modelling (GBTM) was used to identify distinct trajectories of social and occupational functioning over time (median number of observations per person=4; median follow-up time=23 months). Between first clinical contact and time last seen, 15% of young people had reliably deteriorated, 23% improved and 62% did not demonstrate substantive change in function. Of the whole cohort, 69% had functional scores less than 70 at time last seen, indicative of ongoing and substantive impairment. GBTM identified six distinct functional trajectories whereby over 60% had moderate-to-serious functional impairment at entry and remained chronically impaired over time; 7% entered with serious impairment and deteriorated further; a quarter were mildly impaired at entry and functionally recovered and only a small minority (4%) presented with serious impairments and functionally improved over time. Not being in education, employment or training, previous hospitalisation and a younger age at baseline emerged as significant predictors of these functional trajectories. Young people with emerging mental disorders have significant functional impairment at presentation for care, and for the majority, it persists over the course of clinical care. In addition to providing clinical care

Trajectories of Sexual Risk from Middle Adolescence to Early Adulthood

ERIC Educational Resources Information Center

Moilanen, Kristin L.; Crockett, Lisa J.; Raffaelli, Marcela; Jones, Bobby L.

2010-01-01

Developmental trajectories of risky sexual behavior were identified in a multiethnic sample of 1,121 youth drawn from the Children of the National Longitudinal Survey of Youth data set (NLSY79). Group-based trajectory modeling of a composite index of sexual risk taking revealed four sexual risk groups from ages 16 to 22: low risk, decreasing risk,…

Trajectories of Callous-Unemotional Traits in Childhood Predict Different Forms of Peer Victimization in Adolescence.

PubMed

Fontaine, Nathalie M G; Hanscombe, Ken B; Berg, Mark T; McCrory, Eamon J; Viding, Essi

2018-01-01

Callous-unemotional (CU) traits (e.g., lack of empathy and guilt) differentiate a group of children at particularly high risk for engaging in aggressive behavior, notably bullying. However, little is known about whether youths with CU traits are at risk for being victimized by their peers. We examined the associations between trajectories of CU traits in childhood (between 7 and 12 years old) and peer victimization in adolescence (14 years old). The participants were drawn from the Twins Early Development Study, a longitudinal population-based study of twins born in England and in Wales. The trajectories of CU traits (i.e., stable high, increasing, decreasing and stable low) were identified through general growth mixture modeling. Four forms of peer victimization were considered: physical victimization, verbal victimization, social manipulation, and attacks on property. We found that youths with stable high levels, increasing levels, and decreasing levels of CU traits in childhood had higher levels of physical victimization in adolescence, not explained by other predictors at age 7 (e.g., conduct problems). Youths with increasing levels of CU traits, compared with the ones with stable low levels, also had higher levels of verbal victimization, social manipulation, and attacks on property. Our findings highlight the importance of distinct trajectories of CU traits in accounting for the experience of different forms of peer victimization. Youths with CU traits may benefit from bullying prevention programs, as they are likely to be the targets of peer victimization.

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

NASA Astrophysics Data System (ADS)

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.

Arctic sea-ice diffusion from observed and simulated Lagrangian trajectories

NASA Astrophysics Data System (ADS)

Rampal, Pierre; Bouillon, Sylvain; Bergh, Jon; Ólason, Einar

2016-07-01

We characterize sea-ice drift by applying a Lagrangian diffusion analysis to buoy trajectories from the International Arctic Buoy Programme (IABP) dataset and from two different models: the standalone Lagrangian sea-ice model neXtSIM and the Eulerian coupled ice-ocean model used for the TOPAZ reanalysis. By applying the diffusion analysis to the IABP buoy trajectories over the period 1979-2011, we confirm that sea-ice diffusion follows two distinct regimes (ballistic and Brownian) and we provide accurate values for the diffusivity and integral timescale that could be used in Eulerian or Lagrangian passive tracers models to simulate the transport and diffusion of particles moving with the ice. We discuss how these values are linked to the evolution of the fluctuating displacements variance and how this information could be used to define the size of the search area around the position predicted by the mean drift. By comparing observed and simulated sea-ice trajectories for three consecutive winter seasons (2007-2011), we show how the characteristics of the simulated motion may differ from or agree well with observations. This comparison illustrates the usefulness of first applying a diffusion analysis to evaluate the output of modeling systems that include a sea-ice model before using these in, e.g., oil spill trajectory models or, more generally, to simulate the transport of passive tracers in sea ice.

Effects of interventions on trajectories of health-related quality of life among older patients with hip fracture: a prospective randomized controlled trial.

PubMed

Tseng, Ming-Yueh; Liang, Jersey; Shyu, Yea-Ing L; Wu, Chi-Chuan; Cheng, Huey-Shinn; Chen, Ching-Yen; Yang, Shu-Fang

2016-03-03

Health-related quality of life (HRQoL) has been used to assess subjects' prognosis and recovery following hip fracture. However, evidence is mixed regarding the effectiveness of interventions to improve HRQoL of elders with hip fracture. The purposes of this study were to identify distinct HRQoL trajectories and to evaluate the effects of two care models on these trajectories over 12 months following hip-fracture surgery. For this secondary analysis, data came from a randomized controlled trial of subjects with hip fracture receiving three treatment care models: interdisciplinary care (n = 97), comprehensive care (n = 91), and usual care (n = 93). Interdisciplinary care consisted of geriatric consultation, discharge planning, and 4 months of in-home rehabilitation. Comprehensive care consisted of interdisciplinary care plus management of malnutrition and depressive symptoms, fall prevention, and 12 months of in-home rehabilitation. Usual care included only in-hospital rehabilitation and occasional discharge planning, without geriatric consultation and in-home rehabilitation. Mental and physical HRQoL were measured at 1, 3, 6, and 12 months after discharge by the physical component summary scale (PCS) and mental component summary scale (MCS), respectively, of the Medical Outcomes Study Short Form 36, Taiwan version. Latent class growth modeling was used to identify PCS and MCS trajectories and to evaluate how they were affected by the interdisciplinary and comprehensive care models. We identified three quadratic PCS trajectories: poor PCS (n = 103, 36.6 %), moderate PCS (n = 96, 34.2 %), and good PCS (n = 82, 29.2 %). In contrast, we found three linear MCS trajectories: poor MCS (n = 39, 13.9 %), moderate MCS (n = 84, 29.9 %), and good MCS (n = 158, 56.2 %). Subjects in the comprehensive care and interdisciplinary care groups were more likely to experience a good PCS trajectory (b = 0.99, odds ratio [OR] = 2

Cortisol response to an experimental stress paradigm prospectively predicts long-term distress and resilience trajectories in response to active police service.

PubMed

Galatzer-Levy, Isaac R; Steenkamp, Maria M; Brown, Adam D; Qian, Meng; Inslicht, Sabra; Henn-Haase, Clare; Otte, Christian; Yehuda, Rachel; Neylan, Thomas C; Marmar, Charles R

2014-09-01

Heterogeneity in glucocorticoid response to experimental stress conditions has shown to differentiate individuals with healthy from maladaptive real-life stress responses in a number of distinct domains. However, it is not known if this heterogeneity influences the risk for developing stress related disorders or if it is a biological consequence of the stress response itself. Determining if glucocorticoid response to stress induction prospectively predicts psychological vulnerability to significant real life stressors can adjudicate this issue. To test this relationship, salivary cortisol as well as catecholamine responses to a laboratory stressor during academy training were examined as predictors of empirically identified distress trajectories through the subsequent 4 years of active duty among urban police officers routinely exposed to potentially traumatic events and routine life stressors (N = 234). During training, officers were exposed to a video vignette of police officers exposed to real-life trauma. Changes in salivary 3-methoxy-4-hydroxyphenylglycol (MHPG) and cortisol in response to this video challenge were examined as predictors of trajectory membership while controlling for age, gender, and baseline neuroendocrine levels. Officers who followed trajectories of resilience and recovery over 4 years mounted significant increases in cortisol in response to the experimental stressor, while those following a trajectory of chronic increasing distress had no significant cortisol change in response to the challenge. MHPG responses were not associated with distress trajectories. Cortisol response prospectively differentiated trajectories of distress response suggesting that a blunted cortisol response to a laboratory stressor is a risk factor for later vulnerability to distress following significant life stressors. Copyright © 2014 Elsevier Ltd. All rights reserved.

Antecedents of transition patterns of depressive symptom trajectories from adolescence to young adulthood.

PubMed

Lee, Tae Kyoung; Wickrama, Kandauda A S; Kwon, Josephine A; Lorenz, Frederick O; Oshri, Assaf

2017-11-01

This study examined (a) transition patterns from adolescent-specific depressive symptom trajectory classes to young adult-specific trajectory classes (N = 537; 15-26 years) and (b) identified risk factors associated with these transition patterns. The latent classes and transition analyses identified three transitional patterns of depressive symptom trajectories, including a deteriorating pattern (8.2%), a recovering pattern (22.5%), and a consistently low pattern (69.3%). Additionally, the results showed that contextual risk factors (i.e., negative economic events, negative romantic relationships, and low college enrolment rates) in the transition period to young adulthood were more positively associated with deteriorated or recovered transition patterns of depressive symptom trajectories than with the consistently low transition patterns even after taking into account the effects of adolescent risk factors. The identification of dynamic transition patterns in depressive symptom trajectories from adolescence to young adulthood and risk factors provide useful tools for preventive and intervention efforts. Statement of contribution What is already known on this subject? Heterogeneous trajectories of depressive symptoms across adolescence and young adulthood have been reported. Psychosocial characteristics differentiate trajectories of depressive symptoms from adolescence to young adulthood. What does this study add? Dynamic transition patterns of depressive symptom trajectories are found between adolescence and young adulthood. Life experiences in the transition period are uniquely associated with the transition patterns of depressive symptom trajectories even after adjusting the effects of adolescent characteristics. © 2017 The British Psychological Society.

Management by Trajectory: Trajectory Management Study Report

NASA Technical Reports Server (NTRS)

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.

Identification and Prediction of Drinking Trajectories in Early and Mid-Adolescence

ERIC Educational Resources Information Center

Van Der Vorst, Haske; Vermulst, Ad A.; Meeus, Wim H. J.; Dekovic, Maja; Engels, Rutger C. M. E.

2009-01-01

The aim of this study was to identify subgroups of early and mid-adolescents with different drinking trajectories. In addition, we examined whether gender, parental, and peer factors predicted adolescents' membership of these drinking trajectories. We used longitudinal data of 428 families (fathers, mothers, mid-adolescents, and their younger…

Trajectories of Sleep Quality and Associations with Mood during the Perinatal Period

PubMed Central

Tomfohr, Lianne M.; Buliga, Elena; Letourneau, Nicole L.; Campbell, Tavis S.; Giesbrecht, Gerald F.

2015-01-01

Objective: The aim of this study was to investigate trajectories of sleep quality and associations with mood in the perinatal period. Although it is commonly accepted that subjective sleep quality declines during pregnancy and the transition to parenthood, some women may follow qualitatively distinct trajectories. Design, Setting, and Participants: Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Data were collected from 293 women at four time points: during early pregnancy, at Time 1 (T1; < 22 w gestational age [GA]; late pregnancy, at Time 2 (T2; 32 w GA); during the postnatal period at Time 3 (T3; 3 mo postpartum); and Time 4 (T4; 6 mo postpartum). A group-based semiparametric mixture model was used to estimate patterns of sleep quality throughout the perinatal period. Results: Four trajectory groups were identified, including patterns defined by high sleep quality throughout (21.5%), mild decrease in sleep quality (59.5%), significant decrease in sleep quality (12.3%) and a group with poor sleep quality throughout (6.7%). Women who had the worst sleep quality at Time 1 and those who experienced significant increases in sleep problems throughout pregnancy were also the groups who reported the highest levels of anxiety and depressive symptoms in early pregnancy and the lowest levels of social support. After controlling for covariates, the groups with worst subjective sleep quality during pregnancy were also the most likely to experience high symptoms of depression in the postpartum period. Conclusions: Most of the women in our sample reported mild sleep disturbances through the perinatal period. A subgroup of women reported a significant decline in sleep quality from early to late pregnancy and another reported poor subjective sleep quality throughout pregnancy; these groups had the greatest risk of experiencing high symptoms of depression in the postpartum period. Citation: Tomfohr LM, Buliga E, Letourneau NL, Campbell TS, Giesbrecht GF

Automated design of gravity-assist trajectories to Mars and the outer planets

NASA Technical Reports Server (NTRS)

Longuski, James M.; Williams, Steve N.

1991-01-01

In this paper, a new approach to planetary mission design is described which automates the search for gravity-assist trajectories. This method finds all conic solutions given a range of launch dates, a range of launch energies and a set of target planets. The new design tool is applied to the problems of finding multiple encounter trajectories to the outer planets and Venus gravity-assist trajectories to Mars. The last four-planet grand tour opportunity (until the year 2153) is identified. It requires an earth launch in 1996 and encounters Jupiter, Uranus, Neptune, and Pluto. Venus gravity-assist trajectories to Mars for the 30 year period 1995-2024 are examined. It is shown that in many cases these trajectories require less launch energy to reach Mars than direct ballistic trajectories.

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

PubMed

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.

Trajectories of Parent–Adolescent Relationship Quality Among At-Risk Youth: Parental Depression and Adolescent Developmental Outcomes

PubMed Central

Kim, JaHun; Thompson, Elaine Adams; Walsh, Elaine M.; Schepp, Karen G.

2015-01-01

Background Although the parent–adolescent relationship has been studied intensely, predictors and consequences of changes in the quality of the relationship across time have not been examined. Objectives This study examined the role of parent depression on changes in the parent–adolescent relationship, defined as support and conflict, and subsequent effects of relationship change on adolescent psychosocial outcomes including risky behavior, substance use, depressive symptoms, and hopelessness. Method Using data from a large prevention study, the sample included 110 youth at risk for high school drop out from the control condition; the sample was 48.2% of female, with a mean age of 15.9 years. The data, gathered from adolescents and their parents across a period of approximately 18 months, were analyzed using growth mixture modeling. Results Three distinct trajectories for parent–adolescent conflict (high-decreasing, low-increasing, low-stable trajectory) were identified as well as a single growth model for support, which revealed a slight decline in support across time. Parent depression was a significant predictor of perceived support, but not of membership in trajectories of conflict. Low parent–adolescent support was associated with adolescent depression and hopelessness measured 18 months post-baseline. Adolescents in the low but increasing conflict trajectory and those having a parent with depression reported increased depression and hopelessness 18 months later. Discussion Parent–Adolescent support and conflict were associated with adolescent emotional outcomes, particularly depression and hopelessness. The findings provide evidence that will inform prevention strategies to facilitate parent–adolescent support, minimize the negative impact of relationship conflict, and thereby promote healthy psychosocial outcomes for at-risk adolescence. PMID:26577559

Academic Trajectories of Newcomer Immigrant Youth

ERIC Educational Resources Information Center

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…

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

PubMed Central

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), p<0.01] greater odds of attempting suicide and 3.23[(CI=1.37,7.69), p=0.01] and 11.20[(CI=4.33,29.01), p<0.001] greater odds of rehospitalization relative to rapidly declining and subclinical groups, respectively. Higher baseline hopelessness was associated with persisting suicidal 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

Trading Robustness Requirements in Mars Entry Trajectory Design

NASA Technical Reports Server (NTRS)

Lafleur, Jarret M.

2009-01-01

One of the most important metrics characterizing an atmospheric entry trajectory in preliminary design is the size of its predicted landing ellipse. Often, requirements for this ellipse are set early in design and significantly influence both the expected scientific return from a particular mission and the cost of development. Requirements typically specify a certain probability level (6-level) for the prescribed ellipse, and frequently this latter requirement is taken at 36. However, searches for the justification of 36 as a robustness requirement suggest it is an empirical rule of thumb borrowed from non-aerospace fields. This paper presents an investigation into the sensitivity of trajectory performance to varying robustness (6-level) requirements. The treatment of robustness as a distinct objective is discussed, and an analysis framework is presented involving the manipulation of design variables to effect trades between performance and robustness objectives. The scenario for which this method is illustrated is the ballistic entry of an MSL-class Mars entry vehicle. Here, the design variable is entry flight path angle, and objectives are parachute deploy altitude performance and error ellipse robustness. Resulting plots show the sensitivities between these objectives and trends in the entry flight path angles required to design to these objectives. Relevance to the trajectory designer is discussed, as are potential steps for further development and use of this type of analysis.

Zero- vs. one-dimensional, parametric vs. non-parametric, and confidence interval vs. hypothesis testing procedures in one-dimensional biomechanical trajectory analysis.

PubMed

Pataky, Todd C; Vanrenterghem, Jos; Robinson, Mark A

2015-05-01

Biomechanical processes are often manifested as one-dimensional (1D) trajectories. It has been shown that 1D confidence intervals (CIs) are biased when based on 0D statistical procedures, and the non-parametric 1D bootstrap CI has emerged in the Biomechanics literature as a viable solution. The primary purpose of this paper was to clarify that, for 1D biomechanics datasets, the distinction between 0D and 1D methods is much more important than the distinction between parametric and non-parametric procedures. A secondary purpose was to demonstrate that a parametric equivalent to the 1D bootstrap exists in the form of a random field theory (RFT) correction for multiple comparisons. To emphasize these points we analyzed six datasets consisting of force and kinematic trajectories in one-sample, paired, two-sample and regression designs. Results showed, first, that the 1D bootstrap and other 1D non-parametric CIs were qualitatively identical to RFT CIs, and all were very different from 0D CIs. Second, 1D parametric and 1D non-parametric hypothesis testing results were qualitatively identical for all six datasets. Last, we highlight the limitations of 1D CIs by demonstrating that they are complex, design-dependent, and thus non-generalizable. These results suggest that (i) analyses of 1D data based on 0D models of randomness are generally biased unless one explicitly identifies 0D variables before the experiment, and (ii) parametric and non-parametric 1D hypothesis testing provide an unambiguous framework for analysis when one׳s hypothesis explicitly or implicitly pertains to whole 1D trajectories. Copyright © 2015 Elsevier Ltd. All rights reserved.

An Efficient Universal Trajectory Language

NASA Technical Reports Server (NTRS)

Hagen, George E.; Guerreiro, Nelson M.; Maddalon, Jeffrey M.; Butler, Ricky W.

2017-01-01

The Efficient Universal Trajectory Language (EUTL) is a language for specifying and representing trajectories for Air Traffic Management (ATM) concepts such as Trajectory-Based Operations (TBO). In these concepts, the communication of a trajectory between an aircraft and ground automation is fundamental. Historically, this trajectory exchange has not been done, leading to trajectory definitions that have been centered around particular application domains and, therefore, are not well suited for TBO applications. The EUTL trajectory language has been defined in the Prototype Verification System (PVS) formal specification language, which provides an operational semantics for the EUTL language. The hope is that EUTL will provide a foundation for mathematically verified algorithms that manipulate trajectories. Additionally, the EUTL language provides well-defined methods to unambiguously determine position and velocity information between the reported trajectory points. In this paper, we present the EUTL trajectory language in mathematical detail.

Trajectories of attachment in older age: interpersonal trauma and its consequences.

PubMed

Bachem, Rahel; Levin, Yafit; Solomon, Zahava

2018-06-04

Previous studies suggest that attachment insecurities may increase after trauma exposure, an effect documented only at a group level. This study explores the heterogeneity of changes over time and examines the associations of the nature of the traumatic event (interpersonal and nonpersonal), and its consequences (posttraumatic stress disorder [PTSD] and loneliness) with attachment trajectories. Two groups of Israeli veterans participated: 164 former prisoners-of-war and 185 combat veterans. Attachment was assessed at four points (1991-2015). Risk factors were evaluated in 1991. Using latent growth mixture modeling, trajectories of attachment insecurities were explored. Three avoidance trajectories (stability, decrease, inverse u-shaped) and two anxiety trajectories (stability, decrease) were identified. The inverse u-shaped avoidance trajectory was associated with captivity, humiliation, loneliness, and PTSD, and stable avoidance was associated with loneliness. Stable anxiety was associated with captivity and loneliness. Attachment insecurities can change during aging and persist decades after a trauma. Trauma-related risk factors are related to more deleterious trajectories.

Blast and ballistic trajectories in combat casualties: a preliminary analysis using a cartesian positioning system with MDCT.

PubMed

Folio, Les R; Fischer, Tatjana; Shogan, Paul; Frew, Michael; Dwyer, Andrew; Provenzale, James M

2011-08-01

The purpose of this study is to determine the agreement with which radiologists identify wound paths in vivo on MDCT and calculate missile trajectories on the basis of Cartesian coordinates using a Cartesian positioning system (CPS). Three radiologists retrospectively identified 25 trajectories on MDCT in 19 casualties who sustained penetrating trauma in Iraq. Trajectories were described qualitatively in terms of directional path descriptors and quantitatively as trajectory vectors. Directional descriptors, trajectory angles, and angles between trajectories were calculated based on Cartesian coordinates of entrance and terminus or exit recorded in x, y image and table space (z) using a Trajectory Calculator created using spreadsheet software. The consistency of qualitative descriptor determinations was assessed in terms of frequency of observer agreement and multirater kappa statistics. Consistency of trajectory vectors was evaluated in terms of distribution of magnitude of the angles between vectors and the differences between their paraaxial and parasagittal angles. In 68% of trajectories, the observers' visual assessment of qualitative descriptors was congruent. Calculated descriptors agreed across observers in 60% of the trajectories. Estimated kappa also showed good agreement (0.65-0.79, p < 0.001); 70% of calculated paraaxial and parasagittal angles were within 20° across observers, and 61.3% of angles between trajectory vectors were within 20° across observers. Results show agreement of visually assessed and calculated qualitative descriptors and trajectory angles among observers. The Trajectory Calculator describes trajectories qualitatively similar to radiologists' visual assessment, showing the potential feasibility of automated trajectory analysis.

Finding shelter: two-year housing trajectories among homeless youth.

PubMed

Tevendale, Heather D; Comulada, W Scott; Lightfoot, Marguerita A

2011-12-01

The aim of this study was to (1) identify trajectories of homeless youth remaining sheltered or returning to shelter over a period of 2 years, and (2) to identify predictors of these trajectories. A sample of 426 individuals aged 14-24 years receiving services at homeless youth serving agencies completed six assessments over 2 years. Latent class growth analysis was applied to the reports of whether youth had been inconsistently sheltered (i.e., living on the street or in a squat, abandoned building, or automobile) or consistently sheltered (i.e., not living in any of those settings) during the past 3 months. Three trajectories of homeless youth remaining sheltered or returning to shelter were identified: consistently sheltered (approximately 41% of the sample); inconsistently sheltered, short-term (approximately 20%); and inconsistently sheltered, long-term (approximately 39%). Being able to go home and having not left of one's own accord predicted greater likelihood of membership in the short-term versus the long-term inconsistently sheltered trajectory. Younger age, not using drugs other than alcohol or marijuana, less involvement in informal sector activities, being able to go home, and having been homeless for <1 year predicted membership in the consistently sheltered groups versus the long-term inconsistently sheltered groups in the multivariate analyses. Findings suggest that being able to return home is more important than the degree of individual impairment (e.g., substance use or mental health problems) when determining the likelihood that a homeless youth follows a more or a less chronically homeless pathway. Copyright © 2011. Published by Elsevier Inc.

Reading and math achievement profiles and longitudinal growth trajectories of children with an autism spectrum disorder.

PubMed

Wei, Xin; Christiano, Elizabeth R A; Yu, Jennifer W; Wagner, Mary; Spiker, Donna

2015-02-01

This study examined the reading and math achievement profiles and longitudinal growth trajectories of a nationally representative sample of children ages 6 through 9 with an autism spectrum disorder. Four distinct achievement profiles were identified: higher-achieving (39%), hyperlexia (9%), hypercalculia (20%) and lower-achieving (32%). Children with hypercalculia and lower-achieving profiles were more likely to be from low socioeconomic families and had lower functional cognitive skills than the higher-achieving profile. All four profiles lost ground in passage comprehension over time. Slower improvement occurred for the higher-achieving group on letter-word identification, the hyperlexia group on conversation abilities and the hypercalculia group on calculation and functional cognitive skills relative to the lower-achieving group. © The Author(s) 2014.

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

PubMed

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.

Learning probabilistic models of hydrogen bond stability from molecular dynamics simulation trajectories.

PubMed

Chikalov, Igor; Yao, Peggy; Moshkov, Mikhail; Latombe, Jean-Claude

2011-02-15

Hydrogen bonds (H-bonds) play a key role in both the formation and stabilization of protein structures. They form and break while a protein deforms, for instance during the transition from a non-functional to a functional state. The intrinsic strength of an individual H-bond has been studied from an energetic viewpoint, but energy alone may not be a very good predictor. This paper describes inductive learning methods to train protein-independent probabilistic models of H-bond stability from molecular dynamics (MD) simulation trajectories of various proteins. The training data contains 32 input attributes (predictors) that describe an H-bond and its local environment in a conformation c and the output attribute is the probability that the H-bond will be present in an arbitrary conformation of this protein achievable from c within a time duration Δ. We model dependence of the output variable on the predictors by a regression tree. Several models are built using 6 MD simulation trajectories containing over 4000 distinct H-bonds (millions of occurrences). Experimental results demonstrate that such models can predict H-bond stability quite well. They perform roughly 20% better than models based on H-bond energy alone. In addition, they can accurately identify a large fraction of the least stable H-bonds in a conformation. In most tests, about 80% of the 10% H-bonds predicted as the least stable are actually among the 10% truly least stable. The important attributes identified during the tree construction are consistent with previous findings. We use inductive learning methods to build protein-independent probabilistic models to study H-bond stability, and demonstrate that the models perform better than H-bond energy alone.

The Effect of a Depression Prevention Program on Negative Cognitive Style Trajectories in Early Adolescents

ERIC Educational Resources Information Center

Kindt, Karlijn C. M.; Kleinjan, Marloes; Janssens, Jan M. A. M.; Scholte, Ron H. J.

2016-01-01

As restructuring a negative cognitive style is a central skill taught in many depression prevention programs, we tested whether a universal prevention program evoked a change in negative cognitive style in adolescents. In addition, we examined distinct developmental trajectories of negative cognitive styles and assessed whether research condition…

Early Childhood Precursors and School age Correlates of Different Internalising Problem Trajectories Among Young Children.

PubMed

Parkes, Alison; Sweeting, Helen; Wight, Daniel

2016-10-01

It is unclear why trajectories of internalising problems vary between groups of young children. This is the first attempt in the United Kingdom to identify and explain different trajectories of internalising problems from 46 to 94 months. Using both mother- and child-reported data from the large Growing Up in Scotland (GUS) birth cohort (N = 2901; male N = 1497, female N = 1404), we applied growth mixture modelling and multivariable multinomial regression models. Three trajectories were identified: low-stable, high-decreasing and medium-increasing. There were no gender differences in trajectory shape, membership, or importance of covariates. Children from both elevated trajectories shared several early risk factors (low income, poor maternal mental health, poor partner relationship, pre-school behaviour problems) and school-age covariates (low mother-child warmth and initial school maladjustment) and reported fewer supportive friendships at 94 months. However, there were also differences in covariates between the two elevated trajectories. Minority ethnic status and pre-school conduct problems were more strongly associated with the high-decreasing trajectory; and covariates measured after school entry (behaviour problems, mother-child conflict and school maladjustment) with the medium-increasing trajectory. This suggests a greater burden of early risk for the high-decreasing trajectory, and that children with moderate early problem levels were more vulnerable to influences after school transition. Our findings largely support the sparse existing international evidence and are strengthened by the use of child-reported data. They highlight the need to identify protective factors for children with moderate, as well as high, levels of internalising problems at pre-school age, but suggest different approaches may be required.

Girls’ childhood trajectories of disruptive behavior predict adjustment problems in early adolescence

PubMed Central

van der Molen, Elsa; Blokland, Arjan A. J.; Hipwell, Alison E.; Vermeiren, Robert R.J.M.; Doreleijers, Theo A.H.; Loeber, Rolf

2014-01-01

Background It is widely recognized that early onset of disruptive behavior is linked to a variety of detrimental outcomes in males later in life. In contrast, little is known about the association between girls’ childhood trajectories of disruptive behavior and adjustment problems in early adolescence. Methods The current study used 9 waves of data from the ongoing Pittsburgh Girls Study. A semi-parametric group based model was used to identify trajectories of disruptive behavior in 1,513 girls from age 6 to 12 years. Adjustment problems were characterized by depression, self-harm, PTSD, substance use, interpersonal aggression, sexual behavior, affiliation with delinquent peers, and academic achievement at ages 13 and 14. Results Three trajectories of childhood disruptive behavior were identified: low, medium, and high. Girls in the high group were at increased risk for depression, self-harm, PTSD, illegal substance use, interpersonal aggression, early and risky sexual behavior, and lower academic achievement. The likelihood of multiple adjustment problems increased with trajectories reflecting higher levels of disruptive behavior. Conclusion Girls following the high childhood trajectory of disruptive behavior require early intervention programs to prevent multiple, adverse outcomes in adolescence and further escalation in adulthood. PMID:25302849

Distinct Trajectories of Separation Anxiety in the Preschool Years: Persistence at School Entry and Early-Life Associated Factors

ERIC Educational Resources Information Center

Battaglia, Marco; Touchette, Évelyne; Garon-Carrier, Gabrielle; Dionne, Ginette; Côté, Sylvana M.; Vitaro, Frank; Tremblay, Richard E.; Boivin, Michel

2016-01-01

Background: Little is known about how children differ in the onset and evolution of separation anxiety (SA) symptoms during the preschool years, and how SA develops into separation anxiety disorder. In a large, representative population-based sample, we investigated the developmental trajectories of SA symptoms from infancy to school entry, their…

Anti-MDA5 autoantibodies in juvenile dermatomyositis identify a distinct clinical phenotype: a prospective cohort study

PubMed Central

2014-01-01

Introduction The aim of this study was to define the frequency and associated clinical phenotype of anti-MDA5 autoantibodies in a large UK based, predominantly Caucasian, cohort of patients with juvenile dermatomyositis (JDM). Methods Serum samples and clinical data were obtained from 285 patients with JDM recruited to the UK Juvenile Dermatomyositis Cohort and Biomarker Study. The presence of anti-MDA5 antibodies was determined by immunoprecipitation and confirmed by ELISA using recombinant MDA5 protein. Results were compared with matched clinical data, muscle biopsies (scored by an experienced paediatric neuropathologist) and chest imaging (reviewed by an experienced paediatric radiologist). Results Anti-MDA5 antibodies were identified in 7.4% of JDM patients and were associated with a distinct clinical phenotype including skin ulceration (P = 0.03) oral ulceration (P = 0.01), arthritis (P <0.01) and milder muscle disease both clinically (as determined by Childhood Myositis Assessment Score (P = 0.03)) and histologically (as determined by a lower JDM muscle biopsy score (P <0.01)) than patients who did not have anti-MDA5 antibodies. A greater proportion of children with anti-MDA5 autoantibodies achieved disease inactivity at two years post-diagnosis according to PRINTO criteria (P = 0.02). A total of 4 out of 21 children with anti-MDA5 had interstitial lung disease; none had rapidly progressive interstitial lung disease. Conclusions Anti-MDA5 antibodies can be identified in a small but significant proportion of patients with JDM and identify a distinctive clinical sub-group. Screening for anti-MDA5 autoantibodies at diagnosis would be useful to guide further investigation for lung disease, inform on prognosis and potentially confirm the diagnosis, as subtle biopsy changes could otherwise be missed. PMID:24989778

Trajectories of Sleep Quality and Associations with Mood during the Perinatal Period.

PubMed

Tomfohr, Lianne M; Buliga, Elena; Letourneau, Nicole L; Campbell, Tavis S; Giesbrecht, Gerald F

2015-08-01

The aim of this study was to investigate trajectories of sleep quality and associations with mood in the perinatal period. Although it is commonly accepted that subjective sleep quality declines during pregnancy and the transition to parenthood, some women may follow qualitatively distinct trajectories. Sleep quality was assessed by the Pittsburgh Sleep Quality Index (PSQI). Data were collected from 293 women at four time points: during early pregnancy, at Time 1 (T1; < 22 w gestational age [GA]; late pregnancy, at Time 2 (T2; 32 w GA); during the postnatal period at Time 3 (T3; 3 mo postpartum); and Time 4 (T4; 6 mo postpartum). A group-based semiparametric mixture model was used to estimate patterns of sleep quality throughout the perinatal period. Four trajectory groups were identified, including patterns defined by high sleep quality throughout (21.5%), mild decrease in sleep quality (59.5%), significant decrease in sleep quality (12.3%) and a group with poor sleep quality throughout (6.7%). Women who had the worst sleep quality at Time 1 and those who experienced significant increases in sleep problems throughout pregnancy were also the groups who reported the highest levels of anxiety and depressive symptoms in early pregnancy and the lowest levels of social support. After controlling for covariates, the groups with worst subjective sleep quality during pregnancy were also the most likely to experience high symptoms of depression in the postpartum period. Most of the women in our sample reported mild sleep disturbances through the perinatal period. A subgroup of women reported a significant decline in sleep quality from early to late pregnancy and another reported poor subjective sleep quality throughout pregnancy; these groups had the greatest risk of experiencing high symptoms of depression in the postpartum period. © 2015 Associated Professional Sleep Societies, LLC.

Diffusion-weighted MRI derived apparent diffusion coefficient identifies prognostically distinct subgroups of pediatric diffuse intrinsic pontine glioma.

PubMed

Lober, Robert M; Cho, Yoon-Jae; Tang, Yujie; Barnes, Patrick D; Edwards, Michael S; Vogel, Hannes; Fisher, Paul G; Monje, Michelle; Yeom, Kristen W

2014-03-01

While pediatric diffuse intrinsic pontine gliomas (DIPG) remain fatal, recent data have shown subgroups with distinct molecular biology and clinical behavior. We hypothesized that diffusion-weighted MRI can be used as a prognostic marker to stratify DIPG subsets with distinct clinical behavior. Apparent diffusion coefficient (ADC) values derived from diffusion-weighted MRI were computed in 20 consecutive children with treatment-naïve DIPG tumors. The median ADC for the cohort was used to stratify the tumors into low and high ADC groups. Survival, gender, therapy, and potential steroid effects were compared between the ADC groups. Median age at diagnosis was 6.6 (range 2.3-13.2) years, with median follow-up seven (range 1-36) months. There were 14 boys and six girls. Seventeen patients received radiotherapy, five received chemotherapy, and six underwent cerebrospinal fluid diversion. The median ADC of 1,295 × 10(-6) mm(2)/s for the cohort partitioned tumors into low or high diffusion groups, which had distinct median survivals of 3 and 13 months, respectively (log-rank p < 0.001). Low ADC tumors were found only in boys, whereas high ADC tumors were found in both boys and girls. Available tissue specimens in three low ADC tumors demonstrated high-grade histology, whereas one high ADC tumor demonstrated low-grade histology with a histone H3.1 K27M mutation and high-grade metastatic lesion at autopsy. ADC derived from diffusion-weighted MRI may identify prognostically distinct subgroups of pediatric DIPG.

Functionally distinct amygdala subregions identified using DTI and high-resolution fMRI

PubMed Central

Balderston, Nicholas L.; Schultz, Douglas H.; Hopkins, Lauren

2015-01-01

Although the amygdala is often directly linked with fear and emotion, amygdala neurons are activated by a wide variety of emotional and non-emotional stimuli. Different subregions within the amygdala may be engaged preferentially by different aspects of emotional and non-emotional tasks. To test this hypothesis, we measured and compared the effects of novelty and fear on amygdala activity. We used high-resolution blood oxygenation level-dependent (BOLD) imaging and streamline tractography to subdivide the amygdala into three distinct functional subunits. We identified a laterobasal subregion connected with the visual cortex that responds generally to visual stimuli, a non-projecting region that responds to salient visual stimuli, and a centromedial subregion connected with the diencephalon that responds only when a visual stimulus predicts an aversive outcome. We provide anatomical and functional support for a model of amygdala function where information enters through the laterobasal subregion, is processed by intrinsic circuits in the interspersed tissue, and is then passed to the centromedial subregion, where activation leads to behavioral output. PMID:25969533

Comparison between Mean Forces and Swarms-of-Trajectories String Methods.

PubMed

Maragliano, Luca; Roux, Benoît; Vanden-Eijnden, Eric

2014-02-11

The original formulation of the string method in collective variable space is compared with a recent variant called string method with swarms-of-trajectories. The assumptions made in the original method are revisited and the significance of the minimum free energy path (MFEP) is discussed in the context of reactive events. These assumptions are compared to those made in the string method with swarms-of-trajectories, and shown to be equivalent in a certain regime: in particular an expression for the path identified by the swarms-of-trajectories method is given and shown to be closely related to the MFEP. Finally, the algorithmic aspects of both methods are compared.

Comparison of Two Alternative Methods for Tracking Toe Trajectory

NASA Technical Reports Server (NTRS)

Miller, Chris; Peters, Brian; Brady, Rachel; Mulavara, Ajitkumar; Warren, Liz; Feiveson, Al; Bloomberg, Jacob

2007-01-01

Toe trajectory during the swing phase of locomotion has been identified as a precise motor control task (Karst, et al., 1999). The standard method for tracking toe trajectory is to place a marker on the superior aspect of the distal end of the 2nd toe itself (Karst, et al., 1999; Winter, 1992). However, others have based their toe trajectory results either on a marker positioned on the lateral aspect of the 5th metatarsal head (Dingwell, et al., 1999; Osaki, et al., 2007), or on a virtual toe marker computed at the anterior tip of the second toe based on the positions of other real foot markers (Miller, et al., 2006). While these methods for tracking the toe may seem similar, their results may not be directly comparable. The purpose of this study was to compute toe trajectory parameters using a 5th metatarsal marker and a virtual toe marker, and compare their results with those of the standard toe marker.

Convergent Metabolic Specialization through Distinct Evolutionary Paths in Pseudomonas aeruginosa.

PubMed

La Rosa, Ruggero; Johansen, Helle Krogh; Molin, Søren

2018-04-10

Evolution by natural selection under complex and dynamic environmental conditions occurs through intricate and often counterintuitive trajectories affecting many genes and metabolic solutions. To study short- and long-term evolution of bacteria in vivo , we used the natural model system of cystic fibrosis (CF) infection. In this work, we investigated how and through which trajectories evolution of Pseudomonas aeruginosa occurs when migrating from the environment to the airways of CF patients, and specifically, we determined reduction of growth rate and metabolic specialization as signatures of adaptive evolution. We show that central metabolic pathways of three distinct Pseudomonas aeruginosa lineages coevolving within the same environment become restructured at the cost of versatility during long-term colonization. Cell physiology changes from naive to adapted phenotypes resulted in (i) alteration of growth potential that particularly converged to a slow-growth phenotype, (ii) alteration of nutritional requirements due to auxotrophy, (iii) tailored preference for carbon source assimilation from CF sputum, (iv) reduced arginine and pyruvate fermentation processes, and (v) increased oxygen requirements. Interestingly, although convergence was evidenced at the phenotypic level of metabolic specialization, comparative genomics disclosed diverse mutational patterns underlying the different evolutionary trajectories. Therefore, distinct combinations of genetic and regulatory changes converge to common metabolic adaptive trajectories leading to within-host metabolic specialization. This study gives new insight into bacterial metabolic evolution during long-term colonization of a new environmental niche. IMPORTANCE Only a few examples of real-time evolutionary investigations in environments outside the laboratory are described in the scientific literature. Remembering that biological evolution, as it has progressed in nature, has not taken place in test tubes, it is not

Trajectories of Achievement within Race/Ethnicity: "Catching Up" in Achievement across Time

ERIC Educational Resources Information Center

Davis-Kean, Pamela E.; Jager, Justin

2014-01-01

The achievement gap has long been the focus of educational research, policy, and intervention. The authors took a new approach to examining the achievement gap by examining achievement trajectories within each racial group. To identify these trajectories they used the Early Childhood Longitudinal Study-Kindergarten Cohort, which is a nationally…

The effect of a depression prevention program on negative cognitive style trajectories in early adolescents.

PubMed

Kindt, Karlijn C M; Kleinjan, Marloes; Janssens, Jan M A M; Scholte, Ron H J

2016-10-01

As restructuring a negative cognitive style is a central skill taught in many depression prevention programs, we tested whether a universal prevention program evoked a change in negative cognitive style in adolescents. In addition, we examined distinct developmental trajectories of negative cognitive styles and assessed whether research condition (intervention versus control) predicted these trajectories. Young adolescents (n = 1343; Mean age = 13.4 years; SD = 0.77; 52.3% girls) were randomly allocated to a cognitive behavioral therapy (CBT)-based depression prevention program or a care as usual control condition. A negative cognitive style was assessed at baseline, post-treatment and 6- and 12-months follow-up. Adolescents who received the intervention did not differ in their negative cognitive style from the control group at any time-point. We found four distinctive trajectories of negative cognitive style: normative, increasing, decreasing and stable high, which were not predicted by intervention condition and were not moderated by gender. Yet, the results revealed a trend, which indicated that adolescents who followed the program tended to show an increasing than a normative developmental pattern. We concluded that the CBT-based depression prevention program did not reduce or prevent an increase in negative cognitive style. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Assessing the Relationship Between Chronic Health Conditions and Productivity Loss Trajectories

PubMed Central

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

Trajectories of health-related quality of life in children with epilepsy: a cohort study.

PubMed

Ferro, Mark A; Camfield, Carol S; Levin, Simon D; Smith, Mary Lou; Wiebe, Samuel; Zou, Guangyong; Speechley, Kathy N

2013-11-01

Little is known about subgroups of children with epilepsy who may experience less favorable outcomes over time. The objectives of this study were to document trajectories of health-related quality of life (HRQL) and to identify predictors of the trajectory group in children with new-onset epilepsy. Data were obtained from the Health Related Quality of Life in Children with Epilepsy Study, a prospective multisite study of children 4-12 years old with new-onset epilepsy followed for 24 months. Health-related quality of life was measured using the Quality of Life in Childhood Epilepsy questionnaire. Trajectories of HRQL were investigated using latent class trajectory modeling. Multinomial logistic regression was used to identify child, parent, and family predictors of HRQL trajectories. A total of 374 families responded at baseline and 283 (76%) completed the study. Five HRQL trajectories were observed: low-increasing (4%), moderate-decreasing (12%), moderate-increasing (22%), high-increasing (32%), and high-stable (30%). Many children in the low-increasing, moderate-increasing, high-increasing, and high-stable had clinically meaningful improvements in HRQL: 82%, 47%, 63%, and 44%, respectively. In contrast, the majority of children in the moderate-decreasing group (56%) experienced clinically meaningful declines in their HRQL. Factors predicting trajectories were number of antiepileptic drugs prescribed, presence of comorbid behavior or cognitive problems, parent depression, and family functioning and demands. Results suggested that children with epilepsy are not homogenous but rather consist of groups with different trajectories and unique predictors of HRQL. Problems associated with child behavior and cognition were the strongest predictors identified. Given that several risk factors are modifiable, it is important to examine these as potential targets within a family-centered framework to improve HRQL of children with new-onset epilepsy. Wiley Periodicals, Inc. �

In situ data analytics and indexing of protein trajectories.

PubMed

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.

Predictors and Outcomes Associated with Trajectories of Revenge Goals from Fourth Grade through Seventh Grade

ERIC Educational Resources Information Center

McDonald, Kristina L.; Lochman, John E.

2012-01-01

The present study identified longitudinal trajectories of revenge goals in a sample of at-risk youth (N = 240; 63.3% male) followed from fourth grade through seventh grade. Three revenge goal trajectory groups were identified: a low-stable group, an increasing group, and a decreasing group. The increasing and decreasing groups were initially more…

Trajectories of post-traumatic stress disorder symptoms among youth exposed to both natural and technological disasters.

PubMed

Osofsky, Joy D; Osofsky, Howard J; Weems, Carl F; King, Lucy S; Hansel, Tonya C

2015-12-01

Theorists and researchers have demonstrated multiple trajectories of symptoms following disasters (Ecology and Society, 13, 2008, 9), highlighting the importance of obtaining more knowledge about exposed youth who demonstrate resilience as well as those who suffer chronic difficulties. This paper examines trajectories of post-traumatic stress disorder (PTSD) symptoms following exposure to hurricanes and the Deepwater Horizon Oil Spill to increase understanding of resilience and chronic reactions to both natural and technological disasters. A multiwave longitudinal design was used to follow N = 4,619 youth who were evaluated for PTSD symptoms, hurricane exposure, and oil spill exposure/stress at four time points over a period of 4 years. Trajectories were identified with cluster analyses and multilevel modeling. Individual trajectories were statistically identified consistent with theory. The largest group exhibited stable-low symptoms (52%), a second group showed steep declines following initial symptoms (21%), a third group exhibited increasing symptoms (18%), and a fourth group showed stable-high symptoms (9%). Both hurricane exposure and oil spill stress predicted trajectories and overall levels of PTSD symptoms. Results identified an effect of oil spill stress and hurricane exposure on symptom levels and trajectories of exposed youth. Results provide prospective data to support theories of multiple symptom trajectories following disasters and reinforce the importance of research that utilizes a developmental perspective to consider the long-term effects of disasters in youth. Findings highlight the importance of identifying symptoms and predictors of resilience as well as factors that contribute to resilience. © 2015 Association for Child and Adolescent Mental Health.

Querying databases of trajectories of differential equations: Data structures for trajectories

NASA Technical Reports Server (NTRS)

Grossman, Robert

1989-01-01

One approach to qualitative reasoning about dynamical systems is to extract qualitative information by searching or making queries on databases containing very large numbers of trajectories. The efficiency of such queries depends crucially upon finding an appropriate data structure for trajectories of dynamical systems. Suppose that a large number of parameterized trajectories gamma of a dynamical system evolving in R sup N are stored in a database. Let Eta is contained in set R sup N denote a parameterized path in Euclidean Space, and let the Euclidean Norm denote a norm on the space of paths. A data structure is defined to represent trajectories of dynamical systems, and an algorithm is sketched which answers queries.

Psychological and sociocultural adjustment of first-year international students: Trajectories and predictors.

PubMed

Hirai, Reiko; Frazier, Patricia; Syed, Moin

2015-07-01

Despite the increasing number of international students in U.S. universities, the temporal course of international students' adjustment has not been adequately tested, and only 1 study to date has examined multiple trajectories of adjustment. Therefore, the first goal of the current study was to explore multiple trajectories of adjustment among first-year international students using a broader range of adjustment measures (i.e., psychological distress, positive psychological adjustment, sociocultural adjustment). The second goal was to identify important predictors of trajectories. A wide range of individual and interpersonal predictor variables was examined, including academic stress and perceived control over academic stress, personality, social relationships, and language-related factors. Undergraduate and graduate international students in their first semester at a large midwestern university participated in this 5-wave longitudinal study (N = 248) that spanned 1 academic year. Multiple trajectories emerged, and the trajectories varied across the 3 adjustment measures. Average trajectories masked the trajectories of small groups of students who maintained or increased in terms of adjustment difficulties across outcomes. Contrary to popular theories, the U-shape adjustment trajectory (characterized by initial euphoria, distress, and then recovery) did not emerge. The most consistent predictors of adjustment trajectories were perceived present control over academic stress and Neuroticism. (c) 2015 APA, all rights reserved).

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

ERIC Educational Resources Information Center

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…

Survey and Method for Determination of Trajectory Predictor Requirements

NASA Technical Reports Server (NTRS)

Rentas, Tamika L.; Green, Steven M.; Cate, Karen Tung

2009-01-01

A survey of air-traffic-management researchers, representing a broad range of automation applications, was conducted to document trajectory-predictor requirements for future decision-support systems. Results indicated that the researchers were unable to articulate a basic set of trajectory-prediction requirements for their automation concepts. Survey responses showed the need to establish a process to help developers determine the trajectory-predictor-performance requirements for their concepts. Two methods for determining trajectory-predictor requirements are introduced. A fast-time simulation method is discussed that captures the sensitivity of a concept to the performance of its trajectory-prediction capability. A characterization method is proposed to provide quicker, yet less precise results, based on analysis and simulation to characterize the trajectory-prediction errors associated with key modeling options for a specific concept. Concept developers can then identify the relative sizes of errors associated with key modeling options, and qualitatively determine which options lead to significant errors. The characterization method is demonstrated for a case study involving future airport surface traffic management automation. Of the top four sources of error, results indicated that the error associated with accelerations to and from turn speeds was unacceptable, the error associated with the turn path model was acceptable, and the error associated with taxi-speed estimation was of concern and needed a higher fidelity concept simulation to obtain a more precise result

US Decadal Survey Outer Solar System Missions: Trajectory Options

NASA Astrophysics Data System (ADS)

Spilker, T. R.; Atkinson, D. H.; Strange, N. J.; Landau, D.

2012-04-01

The report of the US Planetary Science Decadal Survey (PSDS), released in draft form March 7, 2011, identifies several mission concepts involving travel to high-priority outer solar system (OSS) destinations. These include missions to Europa and Jupiter, Saturn and two of its satellites, and Uranus. Because travel to the OSS involves much larger distances and larger excursions out of the sun's gravitational potential well than inner solar system (ISS) missions, transfer trajectories for OSS missions are stronger drivers of mission schedule and resource requirements than for ISS missions. Various characteristics of each planet system, such as obliquity, radiation belts, rings, deep gravity wells, etc., carry ramifications for approach trajectories or trajectories within the systems. The maturity of trajectory studies for each of these destinations varies significantly. Europa has been the focus of studies for well over a decade. Transfer trajectory options from Earth to Jupiter are well understood. Current studies focus on trajectories within the Jovian system that could reduce the total mission cost of a Europa orbiter mission. Three missions to the Saturn system received high priority ratings in the PSDS report: two flagship orbital missions, one to Titan and one to Enceladus, and a Saturn atmospheric entry probe mission for NASA's New Frontiers Program. The Titan Saturn System Mission (TSSM) studies of 2007-2009 advanced our understanding of trajectory options for transfers to Saturn, including solar electric propulsion (SEP) trajectories. But SEP trajectories depend more on details of spacecraft and propulsion system characteristics than chemical trajectories, and the maturity of SEP trajectory search tools has not yet caught up with chemical trajectory tools, so there is still more useful research to be done on Saturn transfers. The TSSM studies revealed much about Saturn-orbiting trajectories that yield efficient and timely delivery to Titan or Enceladus

Examining the Differential Effectiveness of a Life Skills Program (IPSY) on Alcohol Use Trajectories in Early Adolescence

ERIC Educational Resources Information Center

Spaeth, Michael; Weichold, Karina; Silbereisen, Rainer K.; Wiesner, Margit

2010-01-01

Objective: This study investigated whether a universal school-based life skills program--IPSY (Information + Psychosocial Competence = Protection)--against substance misuse exerted the same effectiveness for young adolescents (10.5-13 years) from distinct alcohol use trajectories characterized by late childhood risk factors (temperament,…

Girls' childhood trajectories of disruptive behavior predict adjustment problems in early adolescence.

PubMed

van der Molen, Elsa; Blokland, Arjan A J; Hipwell, Alison E; Vermeiren, Robert R J M; Doreleijers, Theo A H; Loeber, Rolf

2015-07-01

It is widely recognized that early onset of disruptive behavior is linked to a variety of detrimental outcomes in males, later in life. In contrast, little is known about the association between girls' childhood trajectories of disruptive behavior and adjustment problems in early adolescence. This study used nine waves of data from the ongoing Pittsburgh Girls Study. A semiparametric group-based model was used to identify trajectories of disruptive behavior in 1,513 girls from age 6 to 12 years. Adjustment problems were characterized by depression, self-harm, Post Traumatic Stress Disorder (PTSD), substance use, interpersonal aggression, sexual behavior, affiliation with delinquent peers, and academic achievement at ages 13 and 14. Three trajectories of childhood disruptive behavior were identified: low, medium, and high. Girls in the high group were at increased risk for depression, self-harm, PTSD, illegal substance use, interpersonal aggression, early and risky sexual behavior, and lower academic achievement. The likelihood of multiple adjustment problems increased with trajectories reflecting higher levels of disruptive behavior. Girls following the high childhood trajectory of disruptive behavior require early intervention programs to prevent multiple, adverse outcomes in adolescence and further escalation in adulthood. © 2014 Association for Child and Adolescent Mental Health.

Definition and Demonstration of a Methodology for Validating Aircraft Trajectory Predictors

NASA Technical Reports Server (NTRS)

Vivona, Robert A.; Paglione, Mike M.; Cate, Karen T.; Enea, Gabriele

2010-01-01

This paper presents a new methodology for validating an aircraft trajectory predictor, inspired by the lessons learned from a number of field trials, flight tests and simulation experiments for the development of trajectory-predictor-based automation. The methodology introduces new techniques and a new multi-staged approach to reduce the effort in identifying and resolving validation failures, avoiding the potentially large costs associated with failures during a single-stage, pass/fail approach. As a case study, the validation effort performed by the Federal Aviation Administration for its En Route Automation Modernization (ERAM) system is analyzed to illustrate the real-world applicability of this methodology. During this validation effort, ERAM initially failed to achieve six of its eight requirements associated with trajectory prediction and conflict probe. The ERAM validation issues have since been addressed, but to illustrate how the methodology could have benefited the FAA effort, additional techniques are presented that could have been used to resolve some of these issues. Using data from the ERAM validation effort, it is demonstrated that these new techniques could have identified trajectory prediction error sources that contributed to several of the unmet ERAM requirements.

Developmental Trajectories of Adolescent Substance Use

ERIC Educational Resources Information Center

Yamada, Samantha; Pepler, Debra; Jiang, Depeng; Cappadocia, M. Catherine; Craig, Wendy; Connolly, Jennifer

2016-01-01

Longitudinal data from 746 adolescents in Toronto, Canada (54% females), was gathered in eight waves over seven years (1995 through 2001), beginning when the youths were 10 to 12 years old (mean age = 11.8, SD = 1.2 years). Five trajectories of substance use were identified: chronic-high, childhood onset-rapid high, childhood onset-moderate,…

Developmental Trajectories for Children With Dyslexia and Low IQ Poor Readers

PubMed Central

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

Selection and trajectory design to mission secondary targets

NASA Astrophysics Data System (ADS)

Victorino Sarli, Bruno; Kawakatsu, Yasuhiro

2017-02-01

Recently, with new trajectory design techniques and use of low-thrust propulsion systems, missions have become more efficient and cheaper with respect to propellant. As a way to increase the mission's value and scientific return, secondary targets close to the main trajectory are often added with a small change in the transfer trajectory. As a result of their large number, importance and facility to perform a flyby, asteroids are commonly used as such targets. This work uses the Primer Vector theory to define the direction and magnitude of the thrust for a minimum fuel consumption problem. The design of a low-thrust trajectory with a midcourse asteroid flyby is not only challenging for the low-thrust problem solution, but also with respect to the selection of a target and its flyby point. Currently more than 700,000 minor bodies have been identified, which generates a very large number of possible flyby points. This work uses a combination of reachability, reference orbit, and linear theory to select appropriate candidates, drastically reducing the simulation time, to be later included in the main trajectory and optimized. Two test cases are presented using the aforementioned selection process and optimization to add and design a secondary flyby to a mission with the primary objective of 3200 Phaethon flyby and 25143 Itokawa rendezvous.

Trajectories of Childbearing among HIV Infected Indian Women: A Sequence Analysis Approach

PubMed Central

Darak, Shrinivas; Mills, Melinda; Kulkarni, Vinay; Kulkarni, Sanjeevani; Hutter, Inge; Janssen, Fanny

2015-01-01

Background HIV infection closely relates to and deeply affects the reproductive career of those infected. However, little is known about the reproductive career trajectories, specifically the interaction of the timing of HIV diagnosis with the timing and sequencing of reproductive events among HIV infected women. This is the first study to describe and typify this interaction. Methods Retrospective calendar data of ever married HIV infected women aged 15-45 attending a HIV clinic in Pune, Maharashtra, Western India (N=622) on reproductive events such as marriage, cohabitation with the partner, use of contraception, pregnancy, childbirth and HIV diagnosis were analyzed using sequence analysis and multinomial logistic regression. Results Optimal matching revealed three distinct trajectories: 1) HIV diagnosis concurrent with childbearing (40.7%), 2) HIV diagnosis after childbearing (32.1%), and 3) HIV diagnosis after husband’s death (27.2%). Multinomial logistic regression (trajectory 1 = baseline) showed that women who got married before the age of 21 years and who had no or primary level education had a significantly higher risk of knowing their HIV status either after childbearing or close to their husband’s death. The risk of HIV diagnosis after husband’s death was also higher among rural women and those who were diagnosed before 2005. Conclusions Three distinct patterns of interaction of timing of HIV diagnosis with timing and sequencing of events in the reproductive career were observed that have clear implications for (i) understanding of the individual life planning process in the context of HIV, (ii) formulation of assumptions for estimating HIV infected women in need of PMTCT services, and (iii) provision of care services. PMID:25906185

Exploring the complexity of quantum control optimization trajectories.

PubMed

Nanduri, Arun; Shir, Ofer M; Donovan, Ashley; Ho, Tak-San; Rabitz, Herschel

2015-01-07

The control of quantum system dynamics is generally performed by seeking a suitable applied field. The physical objective as a functional of the field forms the quantum control landscape, whose topology, under certain conditions, has been shown to contain no critical point suboptimal traps, thereby enabling effective searches for fields that give the global maximum of the objective. This paper addresses the structure of the landscape as a complement to topological critical point features. Recent work showed that landscape structure is highly favorable for optimization of state-to-state transition probabilities, in that gradient-based control trajectories to the global maximum value are nearly straight paths. The landscape structure is codified in the metric R ≥ 1.0, defined as the ratio of the length of the control trajectory to the Euclidean distance between the initial and optimal controls. A value of R = 1 would indicate an exactly straight trajectory to the optimal observable value. This paper extends the state-to-state transition probability results to the quantum ensemble and unitary transformation control landscapes. Again, nearly straight trajectories predominate, and we demonstrate that R can take values approaching 1.0 with high precision. However, the interplay of optimization trajectories with critical saddle submanifolds is found to influence landscape structure. A fundamental relationship necessary for perfectly straight gradient-based control trajectories is derived, wherein the gradient on the quantum control landscape must be an eigenfunction of the Hessian. This relation is an indicator of landscape structure and may provide a means to identify physical conditions when control trajectories can achieve perfect linearity. The collective favorable landscape topology and structure provide a foundation to understand why optimal quantum control can be readily achieved.

Maternal posttraumatic stress disorder symptom trajectories following Hurricane Katrina: An initial examination of the impact of maternal trajectories on the well-being of disaster-exposed youth.

PubMed

Self-Brown, Shannon; Lai, Betty S; Harbin, Shannon; Kelley, Mary Lou

2014-12-01

This study examined trajectories of posttraumatic stress disorder symptoms in impoverished mothers impacted by Hurricane Katrina, as well as how predictive the maternal trajectories were for youth posttraumatic stress symptoms 2 years post-Katrina. 360 mother participants displaced by Hurricane Katrina completed self-report measures across four time points related to Hurricane exposure, trauma history, and posttraumatic stress symptoms. Additionally, the youth offspring completed a self-report measure of posttraumatic stress symptoms. Latent Class Growth Analysis demonstrated three primary trajectories emerged among females impacted by Katrina, namely, (1) chronic (4 %), (2) recovering (30 %), and (3) resilient (66 %), respectively. These trajectories were significantly impacted by prior trauma history, but not hurricane exposure. Additionally, data indicated that children whose parents fell into the chronic PTS trajectory also reported high levels of PTS symptoms. This study identified three main trajectories typical of female PTS symptoms following disaster and was the first known study to document associations between PTS outcomes among adults and their offspring impacted by a large natural disaster. Future research is warranted and should explore additional risk and protective factors that impact both the parental and child outcomes.

Impact trajectories of the asteroid Apophis in the 21st century

NASA Astrophysics Data System (ADS)

Sokolov, L. L.; Bashakov, A. A.; Borisova, T. P.; Petrov, N. A.; Pitjev, N. P.; Shaidulin, V. S.

2012-07-01

The asteroid Apophis is one of the most hazardous near-Earth asteroids. As a result of the scattering of Apophis' potential trajectories after its close approach in 2029, and its possible approach in 2036, there are many dangerous trajectories including impact trajectories after 2036. The purpose of this study is to identify and investigate these trajectories. We use the Everhart integrator; the DE405, DE423, and EPM2008 ephemerides; and two sets of initial data for Apophis (those collected by NASA in 2006 and by the IAA in 2010). More than 50 possible encounters in this century are presented, including 13 encounters between 2036 and 2050. The minimum geocentric distances obtained using a different ephemeris and initial conditions differ little between themselves. Analogous results in (Yeomans et al., 2009) are consistent with our results.

Characterization of Metering, Merging and Spacing Requirements for Future Trajectory-Based Operations

NASA Technical Reports Server (NTRS)

Johnson, Sally

2017-01-01

Trajectory-Based Operations (TBO) is one of the essential paradigm shifts in the NextGen transformation of the National Airspace System. Under TBO, aircraft are managed by 4-dimensional trajectories, and airborne and ground-based metering, merging, and spacing operations are key to managing those trajectories. This paper presents the results of a study of potential metering, merging, and spacing operations within a future TBO environment. A number of operational scenarios for tactical and strategic uses of metering, merging, and spacing are described, and interdependencies between concurrent tactical and strategic operations are identified.

Profiling human breast epithelial cells using single cell RNA sequencing identifies cell diversity.

PubMed

Nguyen, Quy H; Pervolarakis, Nicholas; Blake, Kerrigan; Ma, Dennis; Davis, Ryan Tevia; James, Nathan; Phung, Anh T; Willey, Elizabeth; Kumar, Raj; Jabart, Eric; Driver, Ian; Rock, Jason; Goga, Andrei; Khan, Seema A; Lawson, Devon A; Werb, Zena; Kessenbrock, Kai

2018-05-23

Breast cancer arises from breast epithelial cells that acquire genetic alterations leading to subsequent loss of tissue homeostasis. Several distinct epithelial subpopulations have been proposed, but complete understanding of the spectrum of heterogeneity and differentiation hierarchy in the human breast remains elusive. Here, we use single-cell mRNA sequencing (scRNAseq) to profile the transcriptomes of 25,790 primary human breast epithelial cells isolated from reduction mammoplasties of seven individuals. Unbiased clustering analysis reveals the existence of three distinct epithelial cell populations, one basal and two luminal cell types, which we identify as secretory L1- and hormone-responsive L2-type cells. Pseudotemporal reconstruction of differentiation trajectories produces one continuous lineage hierarchy that closely connects the basal lineage to the two differentiated luminal branches. Our comprehensive cell atlas provides insights into the cellular blueprint of the human breast epithelium and will form the foundation to understand how the system goes awry during breast cancer.

Flight Evaluation of Center-TRACON Automation System Trajectory Prediction Process

NASA Technical Reports Server (NTRS)

Williams, David H.; Green, Steven M.

1998-01-01

Two flight experiments (Phase 1 in October 1992 and Phase 2 in September 1994) were conducted to evaluate the accuracy of the Center-TRACON Automation System (CTAS) trajectory prediction process. The Transport Systems Research Vehicle (TSRV) Boeing 737 based at Langley Research Center flew 57 arrival trajectories that included cruise and descent segments; at the same time, descent clearance advisories from CTAS were followed. Actual trajectories of the airplane were compared with the trajectories predicted by the CTAS trajectory synthesis algorithms and airplane Flight Management System (FMS). Trajectory prediction accuracy was evaluated over several levels of cockpit automation that ranged from a conventional cockpit to performance-based FMS vertical navigation (VNAV). Error sources and their magnitudes were identified and measured from the flight data. The major source of error during these tests was found to be the predicted winds aloft used by CTAS. The most significant effect related to flight guidance was the cross-track and turn-overshoot errors associated with conventional VOR guidance. FMS lateral navigation (LNAV) guidance significantly reduced both the cross-track and turn-overshoot error. Pilot procedures and VNAV guidance were found to significantly reduce the vertical profile errors associated with atmospheric and airplane performance model errors.

An Exponential Growth Learning Trajectory: Students' Emerging Understanding of Exponential Growth through Covariation

ERIC Educational Resources Information Center

Ellis, Amy B.; Ozgur, Zekiye; Kulow, Torrey; Dogan, Muhammed F.; Amidon, Joel

2016-01-01

This article presents an Exponential Growth Learning Trajectory (EGLT), a trajectory identifying and characterizing middle grade students' initial and developing understanding of exponential growth as a result of an instructional emphasis on covariation. The EGLT explicates students' thinking and learning over time in relation to a set of tasks…

Trajectories and Risk Factors for Post-Traumatic Stress Symptoms following Pediatric Concussion.

PubMed

Truss, Katherine; Godfrey, Celia; Takagi, Michael; Babl, Franz E; Bressan, Silvia; Hearps, Stephen; Clarke, Cathriona; Dunne, Kevin; Anderson, Vicki

2017-07-15

A substantial minority of children experience post-traumatic stress symptoms (PTSS) following injury. Research indicates variation in the trajectory of PTSS following pediatric injury, but investigation of PTSS following concussion has assumed homogeneity. This study aimed to identify differential trajectories of PTSS following pediatric concussion and to investigate risk factors, including acute post-concussive symptoms (PCS), associated with these trajectories. A total of 120 children ages 8-18 years reported PTSS for 3 months following concussion diagnosis using the Child PTSD Symptom Scale, with a score of 16 or above indicating probable post-traumatic stress disorder diagnosis. Age, gender, injury mechanism, loss of consciousness, previous concussions, prior hospitalization, prior diagnosis of depression or anxiety, and acute PCS were assessed as risk factors. Data were analyzed using group-based trajectory modeling. Results revealed 16% of children had clinically significant PTSS 2 weeks post-concussion, declining to 10% at 1 month and 6% at 3 months post-injury. Group-based trajectory modeling identified three trajectories of PTSS post-concussion: "resilient" (70%); "recovering" (25%), in which children experienced elevated acute symptoms that declined over time; and "chronic symptomatology" (5%). Due to small size, the chronic group should be interpreted with caution. Higher acute PCS and prior diagnosis of depression or anxiety both significantly increased predicted probability of recovering trajectory group membership. These findings establish that most children are resilient to PTSS following concussion, but that PTSS do occur acutely in a substantial minority of children. The study indicates mental health factors, particularly PTSS, depression, and anxiety, should be considered integral to models of concussion management and treatment.

Trajectory Design of the Lunar Impactor Mission Concept

NASA Technical Reports Server (NTRS)

Chung, Min-Kun J.; McElrath, Timothy P.; Roncoli, Ralph B.

2006-01-01

The National Aeronautics and Space Administration (NASA) solicited proposals in 2006 for an opportunity to include a small secondary payload with the launch of the Lunar Reconnaissance Orbiter (LRO) scheduled for October 2008. The cost cap of the proposal was between $50 and $80M, and the mass cap was 1,000 kilograms. JPL proposed a Lunar Impactor (LI) concept for this solicitation. The mission objective of LI was to impact the permanently shadowed region of a South polar crater ultimately to detect the presence of water. The detection of water ice would prove to be an important factor on future lunar exploration. NASA Ames Research Center also proposed a similar concept, the Lunar Crater observation and Sensing Satellite (LCROSS), which was selected by NASA for the mission. However, in this paper, the trajectory design of the LI proposed by JPL is considered. Since the LI spacecraft was to be launched on the LRO launch vehicle as a secondary payload, its initial trajectory must be diverted at some later time from the LRO trans-lunar trajectory for the subsequent impact. Several such trajectories have been considered, where each trajectory option fields some specific values for the mission parameters. The mission parameters include the availability of LRO instruments at the time of impact for the observation by LRO, the mission duration, the impact velocity, the impact angle, etc. It is possible for the LI to be deflected with a relatively low delta-V to impact a South polar crater at a reasonable impact velocity and impact angle directly with no delay. However, the instruments on-board LRO may not be ready for observation. Thus, several delayed trajectory options have been considered further. The lunar phase at the time of impact may also play an important factor for observation, especially from Earth. Several lunar flyby trajectory maneuvers have been identified to arrive at the Moon for impact at the desired lunar phase. By using a combination of these

Ballistic projectile trajectory determining system

DOEpatents

Karr, T.J.

1997-05-20

A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile. 8 figs.

Ballistic projectile trajectory determining system

DOEpatents

Karr, Thomas J.

1997-01-01

A computer controlled system determines the three-dimensional trajectory of a ballistic projectile. To initialize the system, predictions of state parameters for a ballistic projectile are received at an estimator. The estimator uses the predictions of the state parameters to estimate first trajectory characteristics of the ballistic projectile. A single stationary monocular sensor then observes the actual first trajectory characteristics of the ballistic projectile. A comparator generates an error value related to the predicted state parameters by comparing the estimated first trajectory characteristics of the ballistic projectile with the observed first trajectory characteristics of the ballistic projectile. If the error value is equal to or greater than a selected limit, the predictions of the state parameters are adjusted. New estimates for the trajectory characteristics of the ballistic projectile are made and are then compared with actual observed trajectory characteristics. This process is repeated until the error value is less than the selected limit. Once the error value is less than the selected limit, a calculator calculates trajectory characteristics such a the origin and destination of the ballistic projectile.

Marijuana use trajectories and academic outcomes among college students.

PubMed

Suerken, Cynthia K; Reboussin, Beth A; Egan, Kathleen L; Sutfin, Erin L; Wagoner, Kimberly G; Spangler, John; Wolfson, Mark

2016-05-01

Marijuana is the most commonly used illicit drug by college students. Prior studies have established an association between marijuana use and poor academic performance in college, but research on the frequency of marijuana use over the entire college career is limited. The study objective was to examine the association of marijuana use trajectories on academic outcomes, including senior year enrollment, plans to graduate on time, and GPA. Data were collected from a cohort of 3146 students from 11 colleges in North Carolina and Virginia at six time points across the college career. Group-based trajectory models were used to characterize longitudinal marijuana use patterns during college. Associations between marijuana trajectory groups and academic outcomes were modeled using random-effects linear and logistic regressions. Five marijuana trajectory groups were identified: non-users (69.0%), infrequent users (16.6%), decreasing users (4.7%), increasing users (5.8%), and frequent users (3.9%). Decreasing users and frequent users were more likely to drop out of college and plan to delay graduation when compared to non-users. All marijuana user groups reported lower GPAs, on average, than non-users. These results identify marijuana use patterns that put students at risk for poor academic performance in college. Students who use marijuana frequently at the beginning of the college career are especially at risk for lower academic achievement than non-users, suggesting that early intervention is critical. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Marijuana Use Trajectories and Academic Outcomes among College Students

PubMed Central

Suerken, Cynthia K.; Reboussin, Beth A.; Egan, Kathleen L.; Sutfin, Erin L.; Wagoner, Kimberly G.; Spangler, John; Wolfson, Mark

2016-01-01

Background Marijuana is the most commonly used illicit drug by college students. Prior studies have established an association between marijuana use and poor academic performance in college, but research on the frequency of marijuana use over the entire college career is limited. The study objective was to examine the association of marijuana use trajectories on academic outcomes, including senior year enrollment, plans to graduate on time, and GPA. Methods Data were collected from a cohort of 3,146 students from 11 colleges in North Carolina and Virginia at six time points across the college career. Group-based trajectory models were used to characterize longitudinal marijuana use patterns during college. Associations between marijuana trajectory groups and academic outcomes were modeled using random-effects linear and logistic regressions. Results Five marijuana trajectory groups were identified: non-users (69.0%), infrequent users (16.6%), decreasing users (4.7%), increasing users (5.8%), and frequent users (3.9%). Decreasing users and frequent users were more likely to drop out of college and plan to delay graduation when compared to non-users. All marijuana user groups reported lower GPAs, on average, than non-users. Conclusion These results identify marijuana use patterns that put students at risk for poor academic performance in college. Students who use marijuana frequently at the beginning of the college career are especially at risk for lower academic achievement than non-users, suggesting that early intervention is critical. PMID:27020322

Trajectories of dental anxiety in a birth cohort

PubMed Central

Thomson, W. M.; Broadbent, J. M.; Locker, D.; Poulton, R.

2010-01-01

Objective To examine predictors of dental anxiety trajectories in a longitudinal study of New Zealanders. Methods Prospective study of a complete birth cohort born in 1972/73 in Dunedin, New Zealand, with dental anxiety scale (DAS) scores and dental utilization determined at ages 15, 18, 26 and 32 years. Personality traits were assessed at a superfactor and (more fine-grained) subscale level via the Multidimensional Personality Questionnaire at age 18 years. Group-based trajectory analysis was used to identify dental anxiety trajectories. Results DAS scores from at least three assessments were available for 828 participants. Six dental anxiety trajectories were observed: stable nonanxious low (39.6%); stable nonanxious medium (37.9%); recovery (1.6%); adult-onset anxious (7.7%); stable anxious (7.2%) and adolescent-onset anxious (5.9%). Multivariate analysis showed that males and those with higher DMFS at age 15 years were more likely to be in the stable nonanxious low trajectory group. Membership of the stable nonanxious medium group was predicted by the dental caries experience at age 15 years. Participants who had lost one or more teeth between ages 26 and 32 years had almost twice the relative risk for membership of the adult-onset anxious group. Personality traits predicted group membership. Specifically, high scorers (via median split) on the ‘stress reaction’ subscale had over twice the risk of being in the stable anxious group; low scorers on the traditionalism subscale were more likely to be members of the recovery trajectory group; and high scorers on the ‘social closeness’ subscale had half the risk of being in the stable anxious group. Dental caries experience at age 5 years was also a predictor for the stable anxious group. Membership of the late-adolescent-onset anxious group was predicted by higher dental caries experience by age 15 years, but none of the other predictors was significant. Conclusion Six discrete trajectories of dental anxiety

Work–Family Trajectories and the Higher Cardiovascular Risk of American Women Relative to Women in 13 European Countries

PubMed Central

van Hedel, Karen; Mejía-Guevara, Iván; Avendaño, Mauricio; Sabbath, Erika L.; Berkman, Lisa F.; Mackenbach, Johan P.

2016-01-01

Objectives. To investigate whether less-healthy work–family life histories contribute to the higher cardiovascular disease prevalence in older American compared with European women. Methods. We used sequence analysis to identify distinct work–family typologies for women born between 1935 and 1956 in the United States and 13 European countries. Data came from the US Health and Retirement Study (1992–2006) and the Survey of Health, Aging, and Retirement in Europe (2004–2009). Results. Work–family typologies were similarly distributed in the United States and Europe. Being a lone working mother predicted a higher risk of heart disease, stroke, and smoking among American women, and smoking for European women. Lone working motherhood was more common and had a marginally stronger association with stroke in the United States than in Europe. Simulations indicated that the higher stroke risk among American women would only be marginally reduced if American women had experienced the same work–family trajectories as European women. Conclusions. Combining work and lone motherhood was more common in the United States, but differences in work–family trajectories explained only a small fraction of the higher cardiovascular risk of American relative to European women. PMID:27310346

Work-Family Trajectories and the Higher Cardiovascular Risk of American Women Relative to Women in 13 European Countries.

PubMed

van Hedel, Karen; Mejía-Guevara, Iván; Avendaño, Mauricio; Sabbath, Erika L; Berkman, Lisa F; Mackenbach, Johan P; van Lenthe, Frank J

2016-08-01

To investigate whether less-healthy work-family life histories contribute to the higher cardiovascular disease prevalence in older American compared with European women. We used sequence analysis to identify distinct work-family typologies for women born between 1935 and 1956 in the United States and 13 European countries. Data came from the US Health and Retirement Study (1992-2006) and the Survey of Health, Aging, and Retirement in Europe (2004-2009). Work-family typologies were similarly distributed in the United States and Europe. Being a lone working mother predicted a higher risk of heart disease, stroke, and smoking among American women, and smoking for European women. Lone working motherhood was more common and had a marginally stronger association with stroke in the United States than in Europe. Simulations indicated that the higher stroke risk among American women would only be marginally reduced if American women had experienced the same work-family trajectories as European women. Combining work and lone motherhood was more common in the United States, but differences in work-family trajectories explained only a small fraction of the higher cardiovascular risk of American relative to European women.

Aeroassisted orbit transfer vehicle trajectory analysis

NASA Technical Reports Server (NTRS)

Braun, Robert D.; Suit, William T.

1988-01-01

The emphasis in this study was on the use of multiple pass trajectories for aerobraking. However, for comparison, single pass trajectories, trajectories using ballutes, and trajectories corrupted by atmospheric anomolies were run. A two-pass trajectory was chosen to determine the relation between sensitivity to errors and payload to orbit. Trajectories that used only aerodynamic forces for maneuvering could put more weight into the target orbits but were very sensitive to variations from the planned trajectors. Using some thrust control resulted in less payload to orbit, but greatly reduced the sensitivity to variations from nominal trajectories. When compared to the non-thrusting trajectories investigated, the judicious use of thrusting resulted in multiple pass trajectories that gave 97 percent of the payload to orbit with almost none of the sensitivity to variations from the nominal.

Differential expression of vesicular glutamate transporters 1 and 2 may identify distinct modes of glutamatergic transmission in the macaque visual system

PubMed Central

Balaram, Pooja; Hackett, Troy A.; Kaas, Jon H.

2013-01-01

Glutamate is the primary neurotransmitter utilized by the mammalian visual system for excitatory neurotransmission. The sequestration of glutamate into synaptic vesicles, and the subsequent transport of filled vesicles to the presynaptic terminal membrane, is regulated by a family of proteins known as vesicular glutamate transporters (VGLUTs). Two VGLUT proteins, VGLUT1 and VGLUT2, characterize distinct sets of glutamatergic projections between visual structures in rodents and prosimian primates, yet little is known about their distributions in the visual system of anthropoid primates. We have examined the mRNA and protein expression patterns of VGLUT1 and VGLUT2 in the visual system of macaque monkeys, an Old World anthropoid primate, in order to determine their relative distributions in the superior colliculus, lateral geniculate nucleus, pulvinar complex, V1 and V2. Distinct expression patterns for both VGLUT1 and VGLUT2 identified architectonic boundaries in all structures, as well as anatomical subdivisions of the superior colliculus, pulvinar complex, and V1. These results suggest that VGLUT1 and VGLUT2 clearly identify regions of glutamatergic input in visual structures, and may identify common architectonic features of visual areas and nuclei across the primate radiation. Additionally, we find that VGLUT1 and VGLUT2 characterize distinct subsets of glutamatergic projections in the macaque visual system; VGLUT2 predominates in driving or feedforward projections from lower order to higher order visual structures while VGLUT1 predominates in modulatory or feedback projections from higher order to lower order visual structures. The distribution of these two proteins suggests that VGLUT1 and VGLUT2 may identify class 1 and class 2 type glutamatergic projections within the primate visual system (Sherman and Guillery, 2006). PMID:23524295

Differential expression of vesicular glutamate transporters 1 and 2 may identify distinct modes of glutamatergic transmission in the macaque visual system.

PubMed

Balaram, Pooja; Hackett, Troy A; Kaas, Jon H

2013-05-01

Glutamate is the primary neurotransmitter utilized by the mammalian visual system for excitatory neurotransmission. The sequestration of glutamate into synaptic vesicles, and the subsequent transport of filled vesicles to the presynaptic terminal membrane, is regulated by a family of proteins known as vesicular glutamate transporters (VGLUTs). Two VGLUT proteins, VGLUT1 and VGLUT2, characterize distinct sets of glutamatergic projections between visual structures in rodents and prosimian primates, yet little is known about their distributions in the visual system of anthropoid primates. We have examined the mRNA and protein expression patterns of VGLUT1 and VGLUT2 in the visual system of macaque monkeys, an Old World anthropoid primate, in order to determine their relative distributions in the superior colliculus, lateral geniculate nucleus, pulvinar complex, V1 and V2. Distinct expression patterns for both VGLUT1 and VGLUT2 identified architectonic boundaries in all structures, as well as anatomical subdivisions of the superior colliculus, pulvinar complex, and V1. These results suggest that VGLUT1 and VGLUT2 clearly identify regions of glutamatergic input in visual structures, and may identify common architectonic features of visual areas and nuclei across the primate radiation. Additionally, we find that VGLUT1 and VGLUT2 characterize distinct subsets of glutamatergic projections in the macaque visual system; VGLUT2 predominates in driving or feedforward projections from lower order to higher order visual structures while VGLUT1 predominates in modulatory or feedback projections from higher order to lower order visual structures. The distribution of these two proteins suggests that VGLUT1 and VGLUT2 may identify class 1 and class 2 type glutamatergic projections within the primate visual system (Sherman and Guillery, 2006). Copyright © 2013 Elsevier B.V. All rights reserved.

Trajectories of Marijuana Use During the Transition to Adulthood: The Big Picture Based on National Panel Data

PubMed Central

Schulenberg, John E.; Merline, Alicia C.; Johnston, Lloyd D.; O'Malley, Patrick M.; Bachman, Jerald G.; Laetz, Virginia B.

2005-01-01

The purposes of this study were to: a) identify trajectory groups of frequent marijuana use during emerging adulthood, b) distinguish among trajectory groups according to demographic and lifestyle characteristics, and c) examine how the trajectory groups relate to behavioral, attitudinal, and social-emotional correlates over time. National panel data from the Monitoring the Future study were used: 18 cohorts of high school seniors (classes of 1977-94) were followed biennially through age 24. Frequent marijuana use was defined as 3+ occasions of use in past month and/or 20 to 40+ occasions in past year. Based on four waves of complete longitudinal data (N=19,952), six frequent marijuana use trajectory groups were identified: chronic, decreased, increased, fling, rare, and abstain. Categorical analyses revealed trajectory group differences in demographic and lifestyle characteristics at senior year and age 24. The trajectory groups varied significantly in longitudinal patterns of other substance use, problem behaviors, and well-being. PMID:16534532

LONGITUDINAL TRAJECTORIES OF GESTATIONAL THYROID FUNCTION: A NEW APPROACH TO BETTER UNDERSTAND CHANGES IN THYROID FUNCTION.

PubMed

Pop, Victor; Broeren, Maarten; Wijnen, Hennie; Endendijk, Joyce; van Baar, Anneloes; Wiersinga, Wilmar; Williams, Graham R

2018-05-28

Most studies of thyroid function changes during pregnancy use a cross-sectional design comparing means between groups rather than similarities within groups. Latent class growth analysis (LCGA) is a novel approach to investigate longitudinal changes that provide dynamic understanding of the relationship between thyroid status and advancing pregnancy. Prospective observational study with repeated assessments. General community. 1100 healthy pregnant women who were included at their first antenatal visit at 12 weeks gestation. Statistically defined distinct groups based on determined specific changing trajectories by LCGA of both fT4 and TSH at each trimester. LCGA revealed three trajectory classes. Class 1 (n = 1019, 92.4%), a 'Low increasing TSH' reference group, had a gradual increase in TSH throughout gestation (from 1.1 to 1.3 IU/l). Class 2 (n = 30, 2.8%), 'High increasing TSH'', displayed the largest increase in TSH (from 1.9 to 3.3 IU/l); Class 3 (n = 51, 4.6%), 'Decreasing TSH', had the largest fall in TSH (from 3.2 to 2.4 IU/l). (Sub)clinical hypothyroidism at 12 weeks occurred in up to 60% of class 3 women and was accompanied by elevated TPO-Ab titres (50%) and a parental history of thyroid dysfunction (23%). 70% of class 2 women were nulliparous compared to 46% and 49% in classes 1 and 3. LCGA revealed distinct trajectories of longitudinal changes of fT4 and TSH levels during pregnancy in 7.4% of women. These trajectories were correlated with parity and TPO-Ab status and followed patterns that might reflect differences in pregnancy-specific immune tolerance between nulliparous and multiparous women.

TrackTable Trajectory Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Andrew T.

Tracktable is designed for analysis and rendering of the trajectories of moving objects such as planes, trains, automobiles and ships. Its purpose is to operate on large sets of trajectories (millions) to help a user detect, analyze and display patterns. It will also be used to disseminate trajectory research results from Sandia's PANTHER Grand Challenge LDRD.

Body mass trajectories, diabetes mellitus, and mortality in a large cohort of Austrian adults.

PubMed

Peter, Raphael Simon; Keller, Ferdinand; Klenk, Jochen; Concin, Hans; Nagel, Gabriele

2016-12-01

There are only few studies on latent trajectories of body mass index (BMI) and their association with diabetes incidence and mortality in adults.We used data of the Vorarlberg Health Monitoring & Prevention Program and included individuals (N=24,875) with BMI measurements over a 12-year period. Trajectory classes were identified using growth mixture modeling for predefined age groups (<50, 50-65, >65 years of age) and men, women separately. Poisson models were applied to estimate incidence and prevalence of diabetes for each trajectory class. Relative all-cause mortality and diabetes-related mortality was estimated using Cox proportional hazard regression.We identified 4 trajectory classes for the age groups <50 years and 50 to 65 years, and 3 for age groups >65 years. For all age groups, a stable BMI trajectory class was the largest, with about 90% of men and 70% to 80% of women. For the low stable BMI classes, the corresponding fasting glucose levels were the lowest. The highest diabetes prevalences were observed for decreasing trajectories. During subsequent follow-up of mean 8.1 (SD 2.0) years, 2741 individuals died. For men <50 years, highest mortality was observed for steady weight gainers. For all other age-sex groups, mortality was the highest for decreasing trajectories.We found considerably heterogeneity in BMI trajectories by sex and age. Stable weight, however, was the largest class over all age and sex groups, and was associated with the lowest diabetes incidence and mortality suggesting that maintaining weight at a moderate level is an important public health goal.

Prospective post-traumatic stress disorder symptom trajectories in active duty and separated military personnel.

PubMed

Porter, Ben; Bonanno, George A; Frasco, Melissa A; Dursa, Erin K; Boyko, Edward J

2017-06-01

Post-traumatic stress disorder (PTSD) is a serious mental illness that affects current and former military service members at a disproportionately higher rate than the civilian population. Prior studies have shown that PTSD symptoms follow multiple trajectories in civilians and military personnel. The current study examines whether the trajectories of PTSD symptoms of veterans separated from the military are similar to continuously serving military personnel. The Millennium Cohort Study is a population-based study of military service members that commenced in 2001 with follow-up assessments occurring approximately every 3 years thereafter. PTSD symptoms were assessed at each time point using the PTSD Checklist. Latent growth mixture modeling was used to compare PTSD symptom trajectories between personnel who separated (veterans; n = 5292) and personnel who remained in military service (active duty; n = 16,788). Four distinct classes (resilient, delayed-onset, improving, and elevated-recovering) described PTSD symptoms trajectories in both veterans and active duty personnel. Trajectory shapes were qualitatively similar between active duty and veterans. However, within the resilient, improving, and elevated recovering classes, the shapes were statistically different. Although the low-symptom class was the most common in both groups (veterans: 82%; active duty: 87%), veterans were more likely to be classified in the other three classes (in all cases, p < 0.01). The shape of each trajectory was highly similar between the two groups despite differences in military and civilian life. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Monte Carlo Analysis as a Trajectory Design Driver for the TESS Mission

NASA Technical Reports Server (NTRS)

Nickel, Craig; Lebois, Ryan; Lutz, Stephen; Dichmann, Donald; Parker, Joel

2016-01-01

The Transiting Exoplanet Survey Satellite (TESS) will be injected into a highly eccentric Earth orbit and fly 3.5 phasing loops followed by a lunar flyby to enter a mission orbit with lunar 2:1 resonance. Through the phasing loops and mission orbit, the trajectory is significantly affected by lunar and solar gravity. We have developed a trajectory design to achieve the mission orbit and meet mission constraints, including eclipse avoidance and a 30-year geostationary orbit avoidance requirement. A parallelized Monte Carlo simulation was performed to validate the trajectory after injecting common perturbations, including launch dispersions, orbit determination errors, and maneuver execution errors. The Monte Carlo analysis helped identify mission risks and is used in the trajectory selection process.

Sca-1 Identifies a Distinct Androgen-Independent Murine Prostatic Luminal Cell Lineage with Bipotent Potential

PubMed Central

Kwon, Oh-Joon; Zhang, Li; Xin, Li

2016-01-01

Recent lineage tracing studies support the existence of prostate luminal progenitors that possess extensive regenerative capacity, but their identity remains unknown. We show that Sca-1 (Stem Cell Antigen-1) identifies a small population of murine prostate luminal cells that reside in the proximal prostatic ducts adjacent to the urethra. Sca-1+ luminal cells do not express Nkx3.1. They do not carry the secretory function, although they express the androgen receptor. These cells are enriched in the prostates of castrated mice. In the in vitro prostate organoid assay, a small fraction of the Sca-1+ luminal cells are capable of generating budding organoids that are morphologically distinct from those derived from other cell lineages. Histologically, this type of organoid is composed of multiple inner layers of luminal cells surrounded by multiple outer layers of basal cells. When passaged, these organoids retain their morphological and histological features. Finally, the Sca-1+ luminal cells are capable of forming small prostate glands containing both basal and luminal cells in an in vivo prostate regeneration assay. Collectively, our study establishes the androgen-independent and bipotent organoid-forming Sca-1+ luminal cells as a functionally distinct cellular entity. These cells may represent a putative luminal progenitor population and serve as a cellular origin for castration resistant prostate cancer. PMID:26418304

Trajectories of Maternal Depressive Symptoms, Maternal Sensitivity, and Children's Functioning at School Entry

ERIC Educational Resources Information Center

Campbell, Susan B.; Matestic, Patricia; von Stauffenberg, Camilla; Mohan, Roli; Kirchner, Thomas

2007-01-01

Using data from the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development, the authors modeled trajectories of maternal depressive symptoms from infant age 1 month to 7 years. The authors identified 6 trajectories of maternal depressive symptoms: high-chronic, moderate-increasing, high-decreasing,…

TRAJECTORIES OF SUBSTANCE USE FREQUENCY AMONG ADOLESCENTS SEEN IN PRIMARY CARE: IMPLICATIONS FOR SCREENING

PubMed Central

Hadland, Scott E.; Copelas, Sarah H.; Harris, Sion K.

2017-01-01

Objective Anticipating how adolescents’ substance use may escalate is critical for primary care clinicians. We identified trajectories of use in a prospective cohort of adolescent primary care patients one year after a clinic visit. Study Design We recruited 12- to 18-year-olds from 9 New England practices between 2005–2008 and identified 5 trajectories of substance use. We first distinguished adolescents with no past-year use at a baseline clinic visit and at 12-month follow-up (trajectory A). For adolescents who used substances, we assessed past-90-day use at both timepoints, and identified the remaining 4 trajectories based on frequency of use. Trajectories included: trajectory B), trajectory A). The remainder were classified into trajectories B (23.8%), C (9.5%), D (5.7%), and E (8.3%). Those who abstained were least likely to have substance-involved parents (adjusted odds ratio [AOR]=0.58; 95% confidence interval [95%CI]=0.46–0.72), siblings (AOR=0.49; 95%CI=0.40–0.60), or peers (AOR=0.44; 95%CI=0.37–0.52). Those increasing from

Parent and Peer Links to Trajectories of Anxious Withdrawal From Grades 5 to 8

PubMed Central

Booth-LaForce, Cathryn; Oh, Wonjung; Kennedy, Amy E.; Rubin, Kenneth H.; Rose-Krasnor, Linda; Laursen, Brett

2013-01-01

Individual differences in trajectories of anxious withdrawal were examined from Grades 5 to 8 across the transition to middle school in a community sample (N = 283), using General Growth Mixture Modeling. Three distinct pathways of anxious withdrawal were identified: low-stable (78%), high-decreasing (12%), and high-increasing (10%). In Grade 6, relative to the low-stable class, greater peer exclusion and more free time spent with mother predicted membership in the high-decreasing class; higher peer exclusion predicted membership in the high-increasing class. Within the high-increasing class, the growth of anxious withdrawal was predicted by lower parental autonomy-granting, less free time with mother, both nurturing and restrictive parenting, and greater peer exclusion. Results highlight the role of both parent–child relationship and peer difficulties in increasing the adjustment risk among youth who are anxiously withdrawn prior to the middle-school transition. PMID:22417188

Trajectories of life satisfaction after TBI: Influence of life roles, age, cognitive disability, and depressive symptoms

PubMed Central

Juengst, Shannon B.; Adams, Leah M.; Bogner, Jennifer A.; Arenth, Patricia M.; O’Neil-Pirozzi, Therese M.; Dreer, Laura E.; Hart, Tessa; Bergquist, Thomas F.; Bombardier, Charles H.; Dijkers, Marcel P.; Wagner, Amy K.

2015-01-01

Objectives 1) Identify life satisfaction trajectories after moderate to severe traumatic brain injury (TBI), 2) establish a predictive model for these trajectories across the first 5 years post-injury, and 3) describe differences in these life satisfaction trajectory groups, focusing on age, depressive symptoms, disability, and participation in specific life roles,. Research Method Analysis of the longitudinal TBI Model Systems National Database was performed on data collected prospectively at 1, 2, and 5 years post-TBI. Participants (n=3,012) had a moderate to severe TBI and were 16 years old and older. Results Four life satisfaction trajectories were identified across the first 5 years post-injury, including: Stable Satisfaction, Initial Satisfaction Declining, Initial Dissatisfaction Improving, and Stable Dissatisfaction. Age, depressive symptoms, cognitive disability, and life role participation as a worker, leisure participant, and/ or religious participant at one year post-injury significantly predicted trajectory group membership. Life role participation and depressive symptoms were strong predictors of life satisfaction trajectories across the first 5 years post TBI. Conclusions The previously documented loss of life roles and prevalence of depression after a moderate to severe TBI make this a vulnerable population for whom low or declining life satisfaction is a particularly high risk. Examining individual life role participation may help to identify relevant foci for community-based rehabilitation interventions or supports. PMID:26618215

Work functioning trajectories in cancer patients: Results from the longitudinal Work Life after Cancer (WOLICA) study.

PubMed

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.

Developmental Trajectories of Irritability and Bidirectional Associations With Maternal Depression

PubMed Central

Wiggins, Jillian Lee; Mitchell, Colter; Stringaris, Argyris; Leibenluft, Ellen

2014-01-01

Objective 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 (1) identifies classes of irritability trajectories from toddlerhood to middle childhood; (2) characterizes maternal depression and other family, social environment, and child variables within each irritability trajectory class; and (3) as a more exploratory analysis, examines bidirectional associations between maternal depression and child irritability. Method 4,898 families from the Fragile Families and Child Wellbeing Study reported on irritability symptoms at ages 3, 5, and 9, 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, 9. Results A latent class growth analysis identified five 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 use, as well as maternal drug and alcohol use, 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 is associated with increased mother depression at 5 and 9, respectively. Conversely, mother depression at child ages 1 and 3 is associated with increased child irritability at 3 and 5. Conclusion Irritability development across toddlerhood and middle childhood has five main trajectory types, which differ on

Developmental trajectories of irritability and bidirectional associations with maternal depression.

PubMed

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

Trajectories of physical activity and risk factors among Taiwanese older adults.

PubMed

Pan, Ling-Yen; Hsu, Hui-Chuan; Chang, Wen-Chiung; Luh, Dih-Ling

2015-02-01

The significance of physical activity has been noticed. However, the dynamic change and the heterogeneity of physical activity patterns among older people are little explored. This study aimed to identify the trajectory patterns of engaging in physical activity over time and its related factors. Nationally representative four-wave panel data from Taiwanese older adults, gathered between 1996 and 2007, were used (n = 4,018). The participants ranged in age from 50 to 96 years old. "Being physically active" was defined as performing physical activity in sports or exercises at least three times per week and lasting for at least 30 min each time. Group-based trajectory analysis was performed for analyzing the data. Four trajectory patterns were identified: inactive (47.83%), decreasing (12.21%), increasing (23.36%), and active (16.60%). Older respondents and those with more education were more likely to be active. Those respondents having more depressive symptoms, having more physical functional limitations, and having jobs were less likely to be physically active in the decreasing, increasing, and active patterns. There is heterogeneity among the trajectory patterns of physical activity across time in the older adults. Different strategies of physical activity promotion for the older people should be developed by the group characteristics.

Four-body trajectory optimization

NASA Technical Reports Server (NTRS)

Pu, C. L.; Edelbaum, T. N.

1974-01-01

A comprehensive optimization program has been developed for computing fuel-optimal trajectories between the earth and a point in the sun-earth-moon system. It presents methods for generating fuel optimal two-impulse trajectories which may originate at the earth or a point in space and fuel optimal three-impulse trajectories between two points in space. The extrapolation of the state vector and the computation of the state transition matrix are accomplished by the Stumpff-Weiss method. The cost and constraint gradients are computed analytically in terms of the terminal state and the state transition matrix. The 4-body Lambert problem is solved by using the Newton-Raphson method. An accelerated gradient projection method is used to optimize a 2-impulse trajectory with terminal constraint. The Davidon's Variance Method is used both in the accelerated gradient projection method and the outer loop of a 3-impulse trajectory optimization problem.

The Trajectory Synthesizer Generalized Profile Interface

NASA Technical Reports Server (NTRS)

Lee, Alan G.; Bouyssounouse, Xavier; Murphy, James R.

2010-01-01

The Trajectory Synthesizer is a software program that generates aircraft predictions for Air Traffic Management decision support tools. The Trajectory Synthesizer being used by researchers at NASA Ames Research Center was restricted in the number of trajectory types that could be generated. This limitation was not sufficient to support the rapidly changing Air Traffic Management research requirements. The Generalized Profile Interface was developed to address this issue. It provides a flexible approach to describe the constraints applied to trajectory generation and may provide a method for interoperability between trajectory generators. It also supports the request and generation of new types of trajectory profiles not possible with the previous interface to the Trajectory Synthesizer. Other enhancements allow the Trajectory Synthesizer to meet the current and future needs of Air Traffic Management research.

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

NASA Astrophysics Data System (ADS)

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.

Direct and interactive effects of parent, friend and schoolmate drinking on alcohol use trajectories.

PubMed

Lynch, Alicia Doyle; Coley, Rebekah Levine; Sims, Jacqueline; Lombardi, Caitlin McPherran; Mahalik, James R

2015-01-01

This study considered the unique and interactive roles of social norms from parents, friends and schools in predicting developmental trajectories of adolescent drinking and intoxication. Using data from the National Longitudinal Study of Adolescent Health, which followed adolescents (N = 18,921) for 13 years, we used discrete mixture modelling to identify unique developmental trajectories of drinking and of intoxication. Next, multilevel multinomial regression models examined the role of alcohol-related social norms from parents, friends and schoolmates in the prediction of youths' trajectory group membership. Results demonstrated that social norms from parents, friends and schoolmates that were favourable towards alcohol use uniquely predicted drinking and intoxication trajectory group membership. Interactions between social norms revealed that schoolmate drinking played an important moderating role, frequently augmenting social norms from parents and friends. The current findings suggest that social norms from multiple sources (parents, friends and schools) work both independently and interactively to predict longitudinal trajectories of adolescent alcohol use. Results highlight the need to identify and understand social messages from multiple developmental contexts in efforts to reduce adolescent alcohol consumption and alcohol-related risk-taking.

Marriage Trajectories and Health Risk Behaviors Throughout Adulthood Among Urban African Americans

PubMed Central

Green, Kerry M.; Doherty, Elaine E.; Fothergill, Kate E.; Ensminger, Margaret E.

2015-01-01

Although previous studies have identified a protective effect of marriage on risky health behaviors, gaps remain in our understanding of how marriage improves health, particularly among African Americans. This study uses longitudinal data to take selection into account and examines whether marital trajectories that incorporate timing, stability, and duration of marriage affect health risk behaviors among a community cohort of urban African Americans followed for 35 years (N = 1,049). For both men and women, we find six marital trajectories. Men and women in consistently married trajectories are less likely to smoke, drink heavily (women only), and use illegal drugs than those in unmarried or previously married trajectories. Late marrying men do not fare worse in midlife than men in earlier marrying trajectories, but late marrying women show increased risk of midlife drug use. Results suggest policies supporting marriage may have an impact on health but only if stable unions are achieved. PMID:26136611

Similar bowtie structures and distinct largest strong components are identified in the transcriptional regulatory networks of Arabidopsis thaliana during photomorphogenesis and heat shock.

PubMed

Luo, Shitao; Zhang, Fengming; Ruan, Yingfei; Li, Jie; Zhang, Zheng; Sun, Yan; Deng, Shixiong; Peng, Rui

2018-06-01

Photomorphogenesis and heat shock are critical biological processes of plants. A recent research constructed the transcriptional regulatory networks (TRNs) of Arabidopsis thaliana during these processes using DNase-seq. In this study, by strong decomposition, we revealed that each of these TRNs can be represented as a similar bowtie structure with only one non-trivial and distinct strong component. We further identified distinct patterns of variation of a few light-related genes in these bowtie structures during photomorphogenesis. These results suggest that bowtie structure may be a common property of TRNs of plants, and distinct variation patterns of genes in bowtie structures of TRNs during biological processes may reflect distinct functions. Overall, our study provides an insight into the molecular mechanisms underlying photomorphogenesis and heat shock, and emphasizes the necessity to investigate the strong connectivity structures while studying TRNs. Copyright © 2018 Elsevier B.V. All rights reserved.

Developmental Trajectories of Bullying and Associated Factors

ERIC Educational Resources Information Center

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…

Linear growth trajectories in Zimbabwean infants12

PubMed Central

Gough, Ethan K; Moodie, Erica EM; Prendergast, Andrew J; Ntozini, Robert; Moulton, Lawrence H; Humphrey, Jean H; Manges, Amee R

2016-01-01

Background: Undernutrition in early life underlies 45% of child deaths globally. Stunting malnutrition (suboptimal linear growth) also has long-term negative effects on childhood development. Linear growth deficits accrue in the first 1000 d of life. Understanding the patterns and timing of linear growth faltering or recovery during this period is critical to inform interventions to improve infant nutritional status. Objective: We aimed to identify the pattern and determinants of linear growth trajectories from birth through 24 mo of age in a cohort of Zimbabwean infants. Design: We performed a secondary analysis of longitudinal data from a subset of 3338 HIV-unexposed infants in the Zimbabwe Vitamin A for Mothers and Babies trial. We used k-means clustering for longitudinal data to identify linear growth trajectories and multinomial logistic regression to identify covariates that were associated with each trajectory group. Results: For the entire population, the mean length-for-age z score declined from −0.6 to −1.4 between birth and 24 mo of age. Within the population, 4 growth patterns were identified that were each characterized by worsening linear growth restriction but varied in the timing and severity of growth declines. In our multivariable model, 1-U increments in maternal height and education and infant birth weight and length were associated with greater relative odds of membership in the least–growth restricted groups (A and B) and reduced odds of membership in the more–growth restricted groups (C and D). Male infant sex was associated with reduced odds of membership in groups A and B but with increased odds of membership in groups C and D. Conclusion: In this population, all children were experiencing growth restriction but differences in magnitude were influenced by maternal height and education and infant sex, birth weight, and birth length, which suggest that key determinants of linear growth may already be established by the time of birth

Trajectory analyses of sickness absence among industrial and municipal employees.

PubMed

Virtanen, P; Siukola, A; Lipiäinen, L; Liukkonen, V; Pentti, J; Vahtera, J

2017-03-01

Compared with the public sector, the private sector is more susceptible to changes in the economic environment and associated threats of downsizing, outsourcing and transfers of production. This might be assumed to be associated with more restrictive sickness absence practices. To investigate whether this difference is reflected in higher sickness absence rates in the public sector and to explore the potential of trajectory analysis in researching such absences. The sample consisted of industrial and municipal employees. Latent groups of differential sickness absence during a 6-year study period were searched with a two-response trajectory analysis that jointly captured the spells and the days. Multinomial logistic regressions were used to assess associations of the labour market sector with the set of trajectories obtained. There were 2207 industrial and 3477 municipal employees in the study group. The analysis assigned the employees to three trajectory groups, the 'low-level', 'middle-range' and 'high-range' groups. The relative risk ratios for the middle-range and the high-range trajectories of public sector employees were not higher after controlling for age, gender and occupational. In this study, the labour market sector was not a major independent determinant of sickness absence practices. Trajectory analysis can be recommended as a way to determine differential absence practices. The trajectory approach might help occupational health services to identify more accurately the employees who need support to maintain their work ability. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Trajectories of change in cognitive function in people with chronic obstructive pulmonary disease.

PubMed

Park, Soo Kyung

2018-04-01

To describe changes in cognitive function, as measured by the trail making test; to identify distinct patterns of change in cognitive function; and to examine predictors of change in cognitive function in people with severe chronic obstructive pulmonary disease. How cognitive function changes in people with chronic obstructive pulmonary disease and what factors influence those changes over time is not well known, despite the fact that it declines rapidly in this population and significantly impacts functional decline in healthy older adults. A secondary analysis and longitudinal study with a follow-up period of 3 years. A data set from the National Emphysema Treatment Trial provided participant data. Patients with severe chronic obstructive pulmonary disease (n = 307) were recruited at a clinical site. Several demographic and clinical measures were assessed at baseline. Trail making test scores were measured at baseline, 1, 2 and 3 years. Cognitive function was stable for 3 years in people with chronic obstructive pulmonary disease. However, four distinct patterns of change in cognitive function were identified. Age, education, 6-min walk distance and cognitive impairment scores at baseline on the trail making test Part B were significant predictors of worsening cognitive function and below-average cognitive function over 3 years. These findings suggest that increasing exercise capacity improves cognitive function and delays deterioration of cognitive function in people with COPD. Understanding the trajectories of change in cognitive function and predictors of change in cognitive function over 3 years may enable health care providers to identify patients at greatest risk of developing mental deterioration and those who might benefit from interventions to improve cognitive function. Health care providers should periodically assess and frequently screen people with COPD for cognitive function. © 2018 John Wiley & Sons Ltd.

Mapping concentrations of posttraumatic stress and depression trajectories following Hurricane Ike

PubMed Central

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

2016-01-01

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. PMID:27558011

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

PubMed

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.

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

PubMed

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 Depressive Symptoms in Older Adults and Risk of Dementia

PubMed Central

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

2016-01-01

IMPORTANCE 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. OBJECTIVE To investigate the association between trajectories of depressive symptoms and risk of dementia in older adults. DESIGN, SETTING, AND PARTICIPANTS 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. MAIN OUTCOMES AND MEASURES 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). RESULTS 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

Trajectories of maternal weight from before pregnancy through postpartum and associations with childhood obesity.

PubMed

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

Developmental Trajectories of Chinese Adolescents' Relational Aggression: Associations With Changes in Social-Psychological Adjustment.

PubMed

Chen, Liang; Zhang, Wenxin; Ji, Linqin; Deater-Deckard, Kirby

2018-05-25

This study investigated the development of relational aggression (RA) in a sample of Chinese youth (N = 2,274, 52% boys) from fourth (M age  = 10.27 years) to ninth grade. Using latent class growth analysis, four trajectories were identified for both peer- and teacher-rated RA: a no aggression trajectory, a low-increasing trajectory, a moderate-decreasing trajectory, and a chronically high trajectory. Chronically high RA showed a chronicity effect on adolescent peer acceptance, rejection, and rule-breaking behaviors. Adolescents showed worse adjustment as RA increased, but they did not necessarily evidence significant improvement in adjustment even if their RA decreased. Findings reveal the maladaptive nature of RA and highlight the importance of considering cultural context in understanding RA. © 2018 Society for Research in Child Development.

Optimal trajectories of aircraft and spacecraft

NASA Technical Reports Server (NTRS)

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

Aggressive Delinquency among North American Indigenous Adolescents: Trajectories and Predictors

PubMed Central

Sittner, Kelley J.; Hautala, Dane

2016-01-01

Aggressive delinquency is a salient social problem for many North American Indigenous (American Indian, Canadian First Nations) communities, and can have deleterious consequences later in life. Yet there is a paucity of research on Indigenous delinquency. Group-based trajectory modeling is used to prospectively examine trajectories of aggressive delinquency over the course of adolescence using data from 646 Indigenous adolescents from a single culture, spanning the ages of 10 to 19. Five aggression trajectory groups were identified, characterized by different levels and ages of onset and desistence: non-offenders (22.1%), moderate desistors (19.9%), adolescent-limited offenders (22.2%), high desistors (16.7%), and chronic offenders (19.2%). Using the social development model of antisocial behavior, we selected relevant risk and protective factors predicted to discriminate among those most and least likely to engage in more aggressive behavior. Higher levels of risk (i.e., parent rejection, delinquent peers, substance use, and early dating) in early adolescence were associated with being in the two groups with the highest levels of aggressive delinquency. Positive school adjustment, the only significant protective factor, was associated with being in the lowest aggression trajectory groups. The results provide important information that could be used in developing prevention and intervention programs, particularly regarding vulnerable ages as well as malleable risk factors. Identifying those youth most at risk of engaging in higher levels of aggression may be key to preventing delinquency and reducing the overrepresentation of Indigenous youth in the justice system. PMID:26350331

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

PubMed

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.

New method for finding multiple meaningful trajectories

NASA Astrophysics Data System (ADS)

Bao, Zhonghao; Flachs, Gerald M.; Jordan, Jay B.

1995-07-01

Mathematical foundations and algorithms for efficiently finding multiple meaningful trajectories (FMMT) in a sequence of digital images are presented. A meaningful trajectory is motion created by a sentient being or by a device under the control of a sentient being. It is smooth and predictable over short time intervals. A meaningful trajectory can suddenly appear or disappear in sequence images. The development of the FMMT is based on these assumptions. A finite state machine in the FMMT is used to model the trajectories under the conditions of occlusions and false targets. Each possible trajectory is associated with an initial state of a finite state machine. When two frames of data are available, a linear predictor is used to predict the locations of all possible trajectories. All trajectories within a certain error bound are moved to a monitoring trajectory state. When trajectories attain three consecutive good predictions, they are moved to a valid trajectory state and considered to be locked into a tracking mode. If an object is occluded while in the valid trajectory state, the predicted position is used to continue to track; however, the confidence in the trajectory is lowered. If the trajectory confidence falls below a lower limit, the trajectory is terminated. Results are presented that illustrate the FMMT applied to track multiple munitions fired from a missile in a sequence of images. Accurate trajectories are determined even in poor images where the probabilities of miss and false alarm are very high.

Developmental Trajectories and Antecedents of Distal Parental Supervision

ERIC Educational Resources Information Center

Laird, Robert D.; Criss, Michael M.; Pettit, Gregory S.; Bates, John E.; Dodge, Kenneth A.

2009-01-01

Groups of adolescents were identified on the basis of developmental trajectories of their families' rules and their parents' knowledge of their activities. Characteristics of the adolescent, peer antisociality, and family context were tested as antecedents. In sum, 404 parent-adolescent dyads provided data for adolescents aged 10-16. Most…

Mining spatiotemporal patterns of urban dwellers from taxi trajectory data

NASA Astrophysics Data System (ADS)

Mao, Feng; Ji, Minhe; Liu, Ting

2016-06-01

With the widespread adoption of locationaware technology, obtaining long-sequence, massive and high-accuracy spatiotemporal trajectory data of individuals has become increasingly popular in various geographic studies. Trajectory data of taxis, one of the most widely used inner-city travel modes, contain rich information about both road network traffic and travel behavior of passengers. Such data can be used to study the microscopic activity patterns of individuals as well as the macro system of urban spatial structures. This paper focuses on trajectories obtained from GPS-enabled taxis and their applications for mining urban commuting patterns. A novel approach is proposed to discover spatiotemporal patterns of household travel from the taxi trajectory dataset with a large number of point locations. The approach involves three critical steps: spatial clustering of taxi origin-destination (OD) based on urban traffic grids to discover potentially meaningful places, identifying threshold values from statistics of the OD clusters to extract urban jobs-housing structures, and visualization of analytic results to understand the spatial distribution and temporal trends of the revealed urban structures and implied household commuting behavior. A case study with a taxi trajectory dataset in Shanghai, China is presented to demonstrate and evaluate the proposed method.

Joint-specific DNA methylation and transcriptome signatures in rheumatoid arthritis identify distinct pathogenic processes

PubMed Central

Ai, Rizi; Hammaker, Deepa; Boyle, David L.; Morgan, Rachel; Walsh, Alice M.; Fan, Shicai; Firestein, Gary S.; Wang, Wei

2016-01-01

Stratifying patients on the basis of molecular signatures could facilitate development of therapeutics that target pathways specific to a particular disease or tissue location. Previous studies suggest that pathogenesis of rheumatoid arthritis (RA) is similar in all affected joints. Here we show that distinct DNA methylation and transcriptome signatures not only discriminate RA fibroblast-like synoviocytes (FLS) from osteoarthritis FLS, but also distinguish RA FLS isolated from knees and hips. Using genome-wide methods, we show differences between RA knee and hip FLS in the methylation of genes encoding biological pathways, such as IL-6 signalling via JAK-STAT pathway. Furthermore, differentially expressed genes are identified between knee and hip FLS using RNA-sequencing. Double-evidenced genes that are both differentially methylated and expressed include multiple HOX genes. Joint-specific DNA signatures suggest that RA disease mechanisms might vary from joint to joint, thus potentially explaining some of the diversity of drug responses in RA patients. PMID:27282753

Co-Translational Folding Trajectory of the HemK Helical Domain.

PubMed

Mercier, Evan; Rodnina, Marina V

2018-06-26

Protein folding begins co-translationally within the restricted space of the peptide exit tunnel of the ribosome. We have already shown that the N-terminal α-helical domain of the universally conserved N 5 -glutamine methyltransferase HemK is compacted within the exit tunnel and rearranges into the native fold upon emerging from the ribosome. However, the exact folding pathway of the domain remained unclear. Here we analyzed the rapid kinetics of translation and folding monitored by fluorescence resonance energy transfer and photoinduced electron transfer using global fitting to a model for synthesis of the 112-amino acid HemK fragment. Our results suggest that the co-translational folding trajectory of HemK starts within the tunnel and passes through four kinetically distinct folding intermediates that may represent sequential docking of helices to a growing compact core. The kinetics of the process is defined entirely by translation. The results show how analysis of ensemble kinetic data can be used to dissect complex trajectories of rapid conformational rearrangements in multicomponent systems.

Barrier scattering with complex-valued quantum trajectories: Taxonomy and analysis of isochrones

DOE Office of Scientific and Technical Information (OSTI.GOV)

David, Julianne K.; Wyatt, Robert E.

2008-03-07

To facilitate the search for isochrones when using complex-valued trajectory methods for quantum barrier scattering calculations, the structure and shape of isochrones in the complex plane were studied. Isochrone segments were categorized based on their distinguishing features, which are shared by each situation studied: High and low energy wave packets, scattering from both thick and thin Gaussian and Eckart barriers of varying height. The characteristic shape of the isochrone is a trifurcated system: Trajectories that transmit the barrier are launched from the lower branch (T), while the middle and upper branches form the segments for reflected trajectories (F and B).more » In addition, a model is presented for the curved section of the lower branch (from which transmitted trajectories are launched), and important features of the complex extension of the initial wave packet are identified.« less

Comparison of the brain development trajectory between Chinese and U.S. children and adolescents

PubMed Central

Xie, Wanze; Richards, John E.; Lei, Du; Lee, Kang; Gong, Qiyong

2015-01-01

This current study investigated brain development of Chinese and American children and adolescents from 8 to 16 years of age using structural magnetic resonance imaging (MRI) techniques. Analyses comparing Chinese and U.S. children brain/head MR images were performed to explore similarities and differences in the trajectory of brain development between these two groups. Our results revealed regional and age differences in both brain/head morphological and tissue level development between Chinese and U.S. children. Chinese children's brains and heads were shorter, wider, and taller than those of U.S. children. There were significant differences in the gray matter (GM) and white matter (WM) intensity between the two nationalities. Development trajectories for cerebral volume, GM, and several key brain structures were also distinct between these two populations. PMID:25698941

Detection of Diffusion Heterogeneity in Single Particle Tracking Trajectories Using a Hidden Markov Model with Measurement Noise Propagation

PubMed Central

Slator, Paddy J.; Cairo, Christopher W.; Burroughs, Nigel J.

2015-01-01

We develop a Bayesian analysis framework to detect heterogeneity in the diffusive behaviour of single particle trajectories on cells, implementing model selection to classify trajectories as either consistent with Brownian motion or with a two-state (diffusion coefficient) switching model. The incorporation of localisation accuracy is essential, as otherwise false detection of switching within a trajectory was observed and diffusion coefficient estimates were inflated. Since our analysis is on a single trajectory basis, we are able to examine heterogeneity between trajectories in a quantitative manner. Applying our method to the lymphocyte function-associated antigen 1 (LFA-1) receptor tagged with latex beads (4 s trajectories at 1000 frames s−1), both intra- and inter-trajectory heterogeneity were detected; 12–26% of trajectories display clear switching between diffusive states dependent on condition, whilst the inter-trajectory variability is highly structured with the diffusion coefficients being related by D 1 = 0.68D 0 − 1.5 × 104 nm2 s−1, suggestive that on these time scales we are detecting switching due to a single process. Further, the inter-trajectory variability of the diffusion coefficient estimates (1.6 × 102 − 2.6 × 105 nm2 s−1) is very much larger than the measurement uncertainty within trajectories, suggesting that LFA-1 aggregation and cytoskeletal interactions are significantly affecting mobility, whilst the timescales of these processes are distinctly different giving rise to inter- and intra-trajectory variability. There is also an ‘immobile’ state (defined as D < 3.0 × 103 nm2 s−1) that is rarely involved in switching, immobility occurring with the highest frequency (47%) under T cell activation (phorbol-12-myristate-13-acetate (PMA) treatment) with enhanced cytoskeletal attachment (calpain inhibition). Such ‘immobile’ states frequently display slow linear drift, potentially reflecting binding to a dynamic actin cortex

WE-AB-209-06: Dynamic Collimator Trajectory Algorithm for Use in VMAT Treatment Deliveries

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacDonald, L; Thomas, C; Syme, A

2016-06-15

Purpose: To develop advanced dynamic collimator positioning algorithms for optimal beam’s-eye-view (BEV) fitting of targets in VMAT procedures, including multiple metastases stereotactic radiosurgery procedures. Methods: A trajectory algorithm was developed, which can dynamically modify the angle of the collimator as a function of VMAT control point to provide optimized collimation of target volume(s). Central to this algorithm is a concept denoted “whitespace”, defined as area within the jaw-defined BEV field, outside of the PTV, and not shielded by the MLC when fit to the PTV. Calculating whitespace at all collimator angles and every control point, a two-dimensional topographical map depictingmore » the tightness-of-fit of the MLC was generated. A variety of novel searching algorithms identified a number of candidate trajectories of continuous collimator motion. Ranking these candidate trajectories according to their accrued whitespace value produced an optimal solution for navigation of this map. Results: All trajectories were normalized to minimum possible (i.e. calculated without consideration of collimator motion constraints) accrued whitespace. On an acoustic neuroma case, a random walk algorithm generated a trajectory with 151% whitespace; random walk including a mandatory anchor point improved this to 148%; gradient search produced a trajectory with 137%; and bi-directional gradient search generated a trajectory with 130% whitespace. For comparison, a fixed collimator angle of 30° and 330° accumulated 272% and 228% of whitespace, respectively. The algorithm was tested on a clinical case with two metastases (single isocentre) and identified collimator angles that allow for simultaneous irradiation of the PTVs while minimizing normal tissue irradiation. Conclusion: Dynamic collimator trajectories have the potential to improve VMAT deliveries through increased efficiency and reduced normal tissue dose, especially in treatment of multiple cranial

Interplanetary program to optimize simulated trajectories (IPOST). Volume 4: Sample cases

NASA Technical Reports Server (NTRS)

Hong, P. E.; Kent, P. D; Olson, D. W.; Vallado, C. A.

1992-01-01

The Interplanetary Program to Optimize Simulated Trajectories (IPOST) is intended to support many analysis phases, from early interplanetary feasibility studies through spacecraft development and operations. The IPOST output provides information for sizing and understanding mission impacts related to propulsion, guidance, communications, sensor/actuators, payload, and other dynamic and geometric environments. IPOST models three degree of freedom trajectory events, such as launch/ascent, orbital coast, propulsive maneuvering (impulsive and finite burn), gravity assist, and atmospheric entry. Trajectory propagation is performed using a choice of Cowell, Encke, Multiconic, Onestep, or Conic methods. The user identifies a desired sequence of trajectory events, and selects which parameters are independent (controls) and dependent (targets), as well as other constraints and the cost function. Targeting and optimization are performed using the Standard NPSOL algorithm. The IPOST structure allows sub-problems within a master optimization problem to aid in the general constrained parameter optimization solution. An alternate optimization method uses implicit simulation and collocation techniques.

Interplanetary Program to Optimize Simulated Trajectories (IPOST). Volume 2: Analytic manual

NASA Technical Reports Server (NTRS)

Hong, P. E.; Kent, P. D.; Olson, D. W.; Vallado, C. A.

1992-01-01

The Interplanetary Program to Optimize Space Trajectories (IPOST) is intended to support many analysis phases, from early interplanetary feasibility studies through spacecraft development and operations. The IPOST output provides information for sizing and understanding mission impacts related to propulsion, guidance, communications, sensor/actuators, payload, and other dynamic and geometric environments. IPOST models three degree of freedom trajectory events, such as launch/ascent, orbital coast, propulsive maneuvering (impulsive and finite burn), gravity assist, and atmospheric entry. Trajectory propagation is performed using a choice of Cowell, Encke, Multiconic, Onestep, or Conic methods. The user identifies a desired sequence of trajectory events, and selects which parameters are independent (controls) and dependent (targets), as well as other constraints and the cost function. Targeting and optimization is performed using the Stanford NPSOL algorithm. IPOST structure allows subproblems within a master optimization problem to aid in the general constrained parameter optimization solution. An alternate optimization method uses implicit simulation and collocation techniques.

Rapid Design of Gravity Assist Trajectories

NASA Technical Reports Server (NTRS)

Carrico, J.; Hooper, H. L.; Roszman, L.; Gramling, C.

1991-01-01

Several International Solar Terrestrial Physics (ISTP) missions require the design of complex gravity assisted trajectories in order to investigate the interaction of the solar wind with the Earth's magnetic field. These trajectories present a formidable trajectory design and optimization problem. The philosophy and methodology that enable an analyst to design and analyse such trajectories are discussed. The so called 'floating end point' targeting, which allows the inherently nonlinear multiple body problem to be solved with simple linear techniques, is described. The combination of floating end point targeting with analytic approximations with a Newton method targeter to achieve trajectory design goals quickly, even for the very sensitive double lunar swingby trajectories used by the ISTP missions, is demonstrated. A multiconic orbit integration scheme allows fast and accurate orbit propagation. A prototype software tool, Swingby, built for trajectory design and launch window analysis, is described.

Educational Aspirations Trajectories in England

ERIC Educational Resources Information Center

McCulloch, Andrew

2017-01-01

This study used latent class analysis to examine the trajectories followed by young people's educational aspirations in England over the age range from 13 to 16 years and their relationship to educational achievement. The results suggested that young people's aspirations followed six trajectories. Four trajectories showed overall patterns of…

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

PubMed

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.

Persistent arm pain is distinct from persistent breast pain following breast cancer surgery.

PubMed

Langford, Dale J; Paul, Steven M; West, Claudia; Abrams, Gary; Elboim, Charles; Levine, Jon D; Hamolsky, Deborah; Luce, Judith A; Kober, Kord M; Neuhaus, John M; Cooper, Bruce A; Aouizerat, Bradley E; Miaskowski, Christine

2014-12-01

Persistent pain following breast cancer surgery is well documented. However, it is not well characterized in terms of the anatomic site affected (ie, breast, arm). In 2 separate growth mixture modeling analyses, we identified subgroups of women (N = 398) with distinct breast pain and arm pain trajectories. The fact that these latent classes differed by anatomic site, types of tissue affected, and neural innervation patterns suggests the need for separate evaluations of these distinct persistent pain conditions. The purposes of this companion study were to identify demographic and clinical characteristics that differed between the 2 arm pain classes and determine if differences existed over time in sensitivity in the upper inner arm and axillary lymph node dissection sites, pain qualities, pain interference, and hand and arm function, as well as to compare findings with persistent breast pain. Higher occurrence rates for depression and lymphedema were found in the moderate arm pain class. Regardless of pain group membership, sensory loss was observed in the upper inner arm and axillary lymph node dissection site. Arm pain was described similarly to neuropathic pain and interfered with daily functioning. Persistent arm pain was associated with sustained impairments in shoulder mobility. For persistent breast and arm pain, changes in sensation following breast cancer surgery were notable. Persistent arm pain was associated with sustained interference with daily functioning and upper body mobility impairments. Long-term management of persistent pain following breast cancer surgery is warranted to improve the quality of survivorship for these women. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.

PERSISTENT ARM PAIN IS DISTINCT FROM PERSISTENT BREAST PAIN FOLLOWING BREAST CANCER SURGERY

PubMed Central

Langford, Dale J.; Paul, Steven M.; West, Claudia; Abrams, Gary; Elboim, Charles; Levine, Jon D.; Hamolsky, Deborah; Luce, Judith A.; Kober, Kord M.; Neuhaus, John M.; Cooper, Bruce A.; Aouizerat, Bradley E.; Miaskowski, Christine

2014-01-01

Persistent pain following breast cancer surgery is well-documented. However, it is not well characterized in terms of the anatomic site effected (i.e., breast, arm). In two separate growth mixture modeling analyses, we identified subgroups of women (n=398) with distinct breast pain and arm pain trajectories. Based on the fact that these latent classes differed by anatomic site, types if tissue affected, and neural innervation patterns suggests the need for separate evaluations of these distinct persistent pain conditions. Purposes of this companion study were to identify demographic and clinical characteristics that differed between the two arm pain classes and determine if differences existed over time in sensitivity in the upper inner arm and axillary lymph node dissection (ALND) sites, pain qualities, pain interference, and hand and arm function; as well as to compare findings with persistent breast pain. Higher occurrence rates for depression and lymphedema were found in the Moderate Arm pain class. Regardless of pain group membership, sensory loss was observed in the upper inner arm and ALND site. Arm pain was described similarly to neuropathic pain and interfered with daily functioning. Persistent arm pain was associated with sustained impairments in shoulder mobility. Perspective: For persistent breast and arm pain, changes in sensation following breast cancer surgery were notable. Persistent arm pain was associated with sustained interference with daily functioning and upper body mobility impairments. Long-term management of persistent pain following breast cancer surgery is warranted to improve the quality of survivorship for these women. PMID:25439319

Revealing nonergodic dynamics in living cells from a single particle trajectory

NASA Astrophysics Data System (ADS)

Lanoiselée, Yann; Grebenkov, Denis S.

2016-05-01

We propose the improved ergodicity and mixing estimators to identify nonergodic dynamics from a single particle trajectory. The estimators are based on the time-averaged characteristic function of the increments and can thus capture additional information on the process as compared to the conventional time-averaged mean-square displacement. The estimators are first investigated and validated for several models of anomalous diffusion, such as ergodic fractional Brownian motion and diffusion on percolating clusters, and nonergodic continuous-time random walks and scaled Brownian motion. The estimators are then applied to two sets of earlier published trajectories of mRNA molecules inside live Escherichia coli cells and of Kv2.1 potassium channels in the plasma membrane. These statistical tests did not reveal nonergodic features in the former set, while some trajectories of the latter set could be classified as nonergodic. Time averages along such trajectories are thus not representative and may be strongly misleading. Since the estimators do not rely on ensemble averages, the nonergodic features can be revealed separately for each trajectory, providing a more flexible and reliable analysis of single-particle tracking experiments in microbiology.

The development of creative cognition across adolescence: distinct trajectories for insight and divergent thinking.

PubMed

Kleibeuker, Sietske W; De Dreu, Carsten K W; Crone, Eveline A

2013-01-01

We examined developmental trajectories of creative cognition across adolescence. Participants (N = 98), divided into four age groups (12/13 yrs, 15/16 yrs, 18/19 yrs, and 25-30 yrs), were subjected to a battery of tasks gauging creative insight (visual; verbal) and divergent thinking (verbal; visuo-spatial). The two older age groups outperformed the two younger age groups on insight tasks. The 25-30-year-olds outperformed the two youngest age groups on the originality measure of verbal divergent thinking. No age-group differences were observed for verbal divergent thinking fluency and flexibility. On divergent thinking in the visuo-spatial domain, however, only 15/16-year-olds outperformed 12/13-year-olds; a model with peak performance for 15/16-years-old showed the best fit. The results for the different creativity processes are discussed in relation to cognitive and related neurobiological models. We conclude that mid-adolescence is a period of not only immaturities but also of creative potentials in the visuo-spatial domain, possibly related to developing control functions and explorative behavior. © 2012 Blackwell Publishing Ltd.

Trajectory Design to Mitigate Risk on the Transiting Exoplanet Survey Satellite (TESS) Mission

NASA Technical Reports Server (NTRS)

Dichmann, Donald

2016-01-01

The Transiting Exoplanet Survey Satellite (TESS) will employ a highly eccentric Earth orbit, in 2:1 lunar resonance, reached with a lunar flyby preceded by 3.5 phasing loops. The TESS mission has limited propellant and several orbit constraints. Based on analysis and simulation, we have designed the phasing loops to reduce delta-V and to mitigate risk due to maneuver execution errors. We have automated the trajectory design process and use distributed processing to generate and to optimize nominal trajectories, check constraint satisfaction, and finally model the effects of maneuver errors to identify trajectories that best meet the mission requirements.

Ethnic Variations of Trajectories in Suicide Ideation and Attempt: From Middle School to High School.

PubMed

Kim, Jahun; Pike, Kenneth; McCauley, Elizabeth; Vander Stoep, Ann

2018-02-14

The purpose of this study was to compare patterns of suicide ideation and suicide attempt in three ethnic groups. We analyzed data from 463 students with ethnic backgrounds of African American (AA), Asian American (ASA), and European American (EA) for 6 years. The best fit model was a three-trajectory class model for all groups. The majority of adolescents belonged in the nonideators trajectory. The high level of ideation was found in the high ideators (4%), high-fluctuating ideators (8%), and high-decreasing ideators (4%) trajectory in AA, ASA, and EA, respectively. In the AA group, being a member of ideators was not a significant predictor of suicide attempt. In the ASA group, being a member of high-fluctuating ideators was a significant predictor. In the EA group, being a member of both ideators predicted suicide attempt. The timing of onset, patterns of change, and peak time in the ideators trajectories in the three ethnic groups were markedly different. The high level of attempts found in the ASA-AA group was not explained by having suicide ideation. Findings suggest the need for in-depth examination of suicide behaviors across ethnic groups and culturally adapted preventive efforts with distinct developmental timing for adolescents from different ethnic backgrounds. © 2018 The American Association of Suicidology.

Symptom-specific course trajectories and their determinants in primary care patients with Major Depressive Disorder: Evidence for two etiologically distinct prototypes.

PubMed

Wardenaar, K J; Monden, R; Conradi, H J; de Jonge, P

2015-07-01

The course-heterogeneity of Major Depressive Disorder (MDD) hampers development of better prognostic models. Although latent class growth analyses (LCGA) have been used to explain course-heterogeneity, such analyses have failed to also account for symptom-heterogeneity of depressive symptoms. Therefore, the aim was to identify more specific data-driven subgroups based on patterns of course-trajectories on different depressive symptom domains. In primary care MDD patients (n=205), the presence of the MDD criterion symptoms was determined for each week during a year. Weekly 'mood/cognition' (MC) and 'somatic' (SOM) scores were computed and parallel processes-LCGA (PP-LCGA) was used to identify subgroups based on the course on these domains. The classes׳ associations with baseline predictors and 2-/3-year outcomes were investigated. PP-LCGA identified four classes: quick recovery, persisting SOM, persisting MC, and persisting SOM+MC (chronic). Persisting SOM was specifically predicted by higher baseline somatic symptomatology and somatization, and was associated with more somatic depressive symptomatology at long-term follow-up. Persisting MC was specifically predicted by higher depressive severity, thinking insufficiencies, neuroticism, loneliness and lower self-esteem, and was associated with lower mental health related quality of life and more mood/cognitive depressive symptomatology at follow-up. The sample was small and contained only primary care MDD patients. The weekly depression assessments were collected retrospectively at 3-month intervals. The results indicate that there are two specific prototypes of depression, characterized by either persisting MC or persisting SOM, which have different sets of associated prognostic factors and long-term outcomes, and could have different etiological mechanisms. Copyright © 2015 Elsevier B.V. All rights reserved.

Optimal solar sail planetocentric trajectories

NASA Technical Reports Server (NTRS)

Sackett, L. L.

1977-01-01

The analysis of solar sail planetocentric optimal trajectory problem is described. A computer program was produced to calculate optimal trajectories for a limited performance analysis. A square sail model is included and some consideration is given to a heliogyro sail model. Orbit to a subescape point and orbit to orbit transfer are considered. Trajectories about the four inner planets can be calculated and shadowing, oblateness, and solar motion may be included. Equinoctial orbital elements are used to avoid the classical singularities, and the method of averaging is applied to increase computational speed. Solution of the two-point boundary value problem which arises from the application of optimization theory is accomplished with a Newton procedure. Time optimal trajectories are emphasized, but a penalty function has been considered to prevent trajectories which intersect a planet's surface.

Regional source identification using Lagrangian stochastic particle dispersion and HYSPLIT backward-trajectory models.

PubMed

Koracin, Darko; Vellore, Ramesh; Lowenthal, Douglas H; Watson, John G; Koracin, Julide; McCord, Travis; DuBois, David W; Chen, L W Antony; Kumar, Naresh; Knipping, Eladio M; Wheeler, Neil J M; Craig, Kenneth; Reid, Stephen

2011-06-01

The main objective of this study was to investigate the capabilities of the receptor-oriented inverse mode Lagrangian Stochastic Particle Dispersion Model (LSPDM) with the 12-km resolution Mesoscale Model 5 (MM5) wind field input for the assessment of source identification from seven regions impacting two receptors located in the eastern United States. The LSPDM analysis was compared with a standard version of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) single-particle backward-trajectory analysis using inputs from MM5 and the Eta Data Assimilation System (EDAS) with horizontal grid resolutions of 12 and 80 km, respectively. The analysis included four 7-day summertime events in 2002; residence times in the modeling domain were computed from the inverse LSPDM runs and HYPSLIT-simulated backward trajectories started from receptor-source heights of 100, 500, 1000, 1500, and 3000 m. Statistics were derived using normalized values of LSPDM- and HYSPLIT-predicted residence times versus Community Multiscale Air Quality model-predicted sulfate concentrations used as baseline information. From 40 cases considered, the LSPDM identified first- and second-ranked emission region influences in 37 cases, whereas HYSPLIT-MM5 (HYSPLIT-EDAS) identified the sources in 21 (16) cases. The LSPDM produced a higher overall correlation coefficient (0.89) compared with HYSPLIT (0.55-0.62). The improvement of using the LSPDM is also seen in the overall normalized root mean square error values of 0.17 for LSPDM compared with 0.30-0.32 for HYSPLIT. The HYSPLIT backward trajectories generally tend to underestimate near-receptor sources because of a lack of stochastic dispersion of the backward trajectories and to overestimate distant sources because of a lack of treatment of dispersion. Additionally, the HYSPLIT backward trajectories showed a lack of consistency in the results obtained from different single vertical levels for starting the backward trajectories. To

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

PubMed

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.

Posttraumatic stress symptom trajectories among children exposed to violence.

PubMed

Miller-Graff, Laura E; Howell, Kathryn H

2015-02-01

Little research has examined the developmental course of posttraumatic stress symptoms (PTSS) in children. The current study aimed to identify developmental trajectories of PTSS in childhood and to examine predictors of symptom presentation in 1,178 children from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN) studies, a consortium of studies focusing on the causes and effects of child maltreatment. Most children had a history of documented reports with Child Protective Services (CPS) and all were identified as living in high-risk environments. Using group-based trajectory modeling, 3 unique developmental trajectories were identified: Resilient, Clinical-Improving (PTSS in the clinical range at baseline then declining over time), and Borderline-Stable (chronically subclinical PTSS). Children in the Clinical-Improving group were more likely than children in the Resilient group to have reports of physical abuse (RRR = 1.76), emotional abuse (RRR = 2.55), neglect (RRR = 1.57), and exposure to violence at home and in the community (RRR = 1.04). Children in the Borderline-Stable group were more likely than children in the Resilient group to have a CPS history of neglect (RRR = 2.44) and exposure to violence at home and in the community (RRR = 1.04). Many children living in high-risk environments exhibit resilience to PTSS, but exposure to witnessed violence and neglect appear to put children at chronic risk for poor adjustment. These children may require more intensive, integrated clinical services that attend to multiple adverse experiences. Copyright © 2015 International Society for Traumatic Stress Studies.

Transition paths of Met-enkephalin from Markov state modeling of a molecular dynamics trajectory.

PubMed

Banerjee, Rahul; Cukier, Robert I

2014-03-20

Conformational states and their interconversion pathways of the zwitterionic form of the pentapeptide Met-enkephalin (MetEnk) are identified. An explicit solvent molecular dynamics (MD) trajectory is used to construct a Markov state model (MSM) based on dihedral space clustering of the trajectory, and transition path theory (TPT) is applied to identify pathways between open and closed conformers. In the MD trajectory, only four of the eight backbone dihedrals exhibit bistable behavior. Defining a conformer as the string XXXX with X = "+" or "-" denoting, respectively, positive or negative values of a given dihedral angle and obtaining the populations of these conformers shows that only four conformers are highly populated, implying a strong correlation among these dihedrals. Clustering in dihedral space to construct the MSM finds the same four bistable dihedral angles. These state populations are very similar to those found directly from the MD trajectory. TPT is used to obtain pathways, parametrized by committor values, in dihedral state space that are followed in transitioning from closed to open states. Pathway costs are estimated by introducing a kinetics-based procedure that orders pathways from least (shortest) to greater cost paths. The least costly pathways in dihedral space are found to only involve the same XXXX set of dihedral angles, and the conformers accessed in the closed to open transition pathways are identified. For these major pathways, a correlation between reaction path progress (committors) and the end-to-end distance is identified. A dihedral space principal component analysis of the MD trajectory shows that the first three modes capture most of the overall fluctuation, and pick out the same four dihedrals having essentially all the weight in those modes. A MSM based on root-mean-square backbone clustering was also carried out, with good agreement found with dihedral clustering for the static information, but with results that differ

Gaussian Processes for Prediction of Homing Pigeon Flight Trajectories

NASA Astrophysics Data System (ADS)

Mann, Richard; Freeman, Robin; Osborne, Michael; Garnett, Roman; Meade, Jessica; Armstrong, Chris; Biro, Dora; Guilford, Tim; Roberts, Stephen

2009-12-01

We construct and apply a stochastic Gaussian Process (GP) model of flight trajectory generation for pigeons trained to home from specific release sites. The model shows increasing predictive power as the birds become familiar with the sites, mirroring the animal's learning process. We show how the increasing similarity between successive flight trajectories can be used to infer, with increasing accuracy, an idealised route that captures the repeated spatial aspects of the bird's flight. We subsequently use techniques associated with reduced-rank GP approximations to objectively identify the key waypoints used by each bird to memorise its idiosyncratic habitual route between the release site and the home loft.

Group-based trajectory modeling of fear of disease recurrence among women recently diagnosed with gynecological cancers.

PubMed

Manne, Sharon L; Myers-Virtue, Shannon; Kissane, David; Ozga, Melissa L; Kashy, Deborah A; Rubin, Stephen C; Rosenblum, Norman G; Heckman, Carolyn J

2017-11-01

Fear of cancer recurrence is an important clinical phenomenon and is associated with decrements in life domains. The study goals were to characterize patterns of global fear of recurrence (FOR) and 4 domains of fear (health, role, womanhood, and death worry) over time in women who were diagnosed with gynecological cancer and to identify demographic, medical, and psychological predictors of FOR. One hundred eighteen women participating in the usual care arm of a randomized trial completed the Concerns about Recurrence scale as well as measures of depressive symptoms, cancer-specific distress, coping, coping efficacy, and social network responses at 4 time points. The majority of the sample was diagnosed with stage 3 ovarian cancer. Group-based trajectory modeling identified subgroups of women with high-stable (49.1%), high-decreasing (25.3%), and low-stable (25.5%) trajectories for global FOR. For role worries, 3 similar group trajectories were identified. For health worries, modeling identified subgroups with high-decreasing (19.1%) and low-increasing (80.9%) trajectories. For womanhood worries, modeling identified subgroups with high-increasing (15.7%) and low-decreasing (84.2%) trajectories. Young age, metastatic cancer, depression, cancer distress, holding back, and lower coping efficacy were associated with the high-stable global FOR and at least 1 domain of FOR. Almost half of the women recently diagnosed with gynecological cancer evidence persistently elevated FOR over the 6-month period postdiagnosis. Psychological interventions to reduce FOR may be more effective if they focus on teaching patients coping skills, as well as greater comfort expressing cancer-specific concerns to others. Copyright © 2016 John Wiley & Sons, Ltd.

[Suicide among the French National Police forces: Implication of life events and life trajectories].

PubMed

Encrenaz, G; Miras, A; Contrand, B; Séguin, M; Moulki, M; Queinec, R; René, J-S; Fériot, A; Mougin, M; Bonfils, M; Marien, P; Michel, G; Lagarde, E

2016-08-01

Research indicates that suicide rates are high among members of law enforcement. Our objectives were: (1) to determine life events implicated in suicide mortality among French law enforcement; and (2) to describe the different life trajectories of police officers who deceased by suicide. All suicides of police officers which occurred during 2008 (n=49) were explored using the psychological autopsy method. Key informants were: a supervisor, a colleague and a member of the family or a close friend. Each of them were interviewed by trained psychologists using standardized questionnaires exploring: sociodemographic characteristics, life events, social integration and support, health service use, mental health with the Composite International Diagnostic Interview short form (CIDI-SF), occupational stress with the Spielberger Inventory, impulsiveness with the Barratt Impulsiveness Scale and aggressiveness with the Brown-Goodwin Lifetime Aggression Scale. Information was then summarized in a timetable life trajectory of all life areas. All cases were finally appraised by at least two experts in order to identify the determinants of the suicide and to determine psychiatric diagnoses. For each period of time, a burdensomeness score was determined, from 6 (no adversity) to 1 (adversities in each sphere of life). Of the 49 cases of suicide, two were excluded and 39 were investigated and appraised (response rate: 39/47=83%). Eighty-two percent of the suicide cases were men and the mean age at death was 35years. In more than half of the cases, police officers used their service weapon to commit suicide. All deceased police officers were suffering from mental health symptoms (primarily depression). Of them, two thirds had used healthcare for this distress. The main other cause of suicide was problems in the married life (70% of the cases). Four distinct types of life trajectories of adversities could be identified by a qualitative analysis. It is the first time such a study was

Adaptive estimation of hand movement trajectory in an EEG based brain-computer interface system

NASA Astrophysics Data System (ADS)

Robinson, Neethu; Guan, Cuntai; Vinod, A. P.

2015-12-01

Objective. The various parameters that define a hand movement such as its trajectory, speed, etc, are encoded in distinct brain activities. Decoding this information from neurophysiological recordings is a less explored area of brain-computer interface (BCI) research. Applying non-invasive recordings such as electroencephalography (EEG) for decoding makes the problem more challenging, as the encoding is assumed to be deep within the brain and not easily accessible by scalp recordings. Approach. EEG based BCI systems can be developed to identify the neural features underlying movement parameters that can be further utilized to provide a detailed and well defined control command set to a BCI output device. A real-time continuous control is better suited for practical BCI systems, and can be achieved by continuous adaptive reconstruction of movement trajectory than discrete brain activity classifications. In this work, we adaptively reconstruct/estimate the parameters of two-dimensional hand movement trajectory, namely movement speed and position, from multi-channel EEG recordings. The data for analysis is collected by performing an experiment that involved center-out right-hand movement tasks in four different directions at two different speeds in random order. We estimate movement trajectory using a Kalman filter that models the relation between brain activity and recorded parameters based on a set of defined predictors. We propose a method to define these predictor variables that includes spatial, spectral and temporally localized neural information and to select optimally informative variables. Main results. The proposed method yielded correlation of (0.60 ± 0.07) between recorded and estimated data. Further, incorporating the proposed predictor subset selection, the correlation achieved is (0.57 ± 0.07, p {\\lt }0.004) with significant gain in stability of the system, as well as dramatic reduction in number of predictors (76%) for the savings of computational

Developmental Trajectories of Peer-Reported Aggressive Behavior: The Role of Friendship Understanding, Friendship Quality, and Friends' Aggressive Behavior.

PubMed

Malti, Tina; McDonald, Kristina; Rubin, Kenneth H; Rose-Krasnor, Linda; Booth-LaForce, Cathryn

2015-10-01

To investigate developmental trajectories in peer-reported aggressive behavior across the transition from elementary-to-middle school, and whether aggressive behavior trajectories were associated with friendship quality, friends' aggressive behavior, and the ways in which children think about their friendships. Participants included a community sample of 230 5 th grade children who were assessed when they made a transition from elementary-to-middle school (6 th grade). Peer nominations were used to assess the target child's and friend's aggressive behavior. Self- and friend reports were used to measure friendship quality; friendship understanding was assessed via a structured interview. General Growth Mixture Modeling (GGMM) revealed three distinct trajectories of peer-reported aggressive behavior across the school transition: low-stable, decreasing, and increasing. Adolescents' understanding of friendship formation differentiated the decreasing from the low-stable aggressive behavior trajectories, and the understanding of friendship trust differentiated the increasing from the low-stable aggressive and decreasing aggressive behavior trajectories. The findings indicated that a sophisticated understanding of friendship may serve as a protective factor for initially aggressive adolescents as they transition into middle school. Promoting a deepened understanding of friendship relations and their role in one's own and others' well-being may serve as an important prevention and intervention strategy to reduce aggressive behavior.

Developmental Trajectories of Aggression from Late Childhood through Adolescence: Similarities and Differences across Gender

PubMed Central

Xie, Hongling; Drabick, Deborah A. G.; Chen, Diane

2015-01-01

Although numerous investigations of overt aggressive and antisocial trajectories have been undertaken, there is a dearth of literature examining gender differences and similarities in trajectory patterns and their correlates. To address these gaps, we investigated gender differences in the prevalence rates, predictive validity during transition to adulthood, childhood risk factors, and adolescent correlates of different trajectories of teacher-reported overt aggression (i.e., fights, argues, gets in trouble) among 220 participants (116 girls and 104 boys) evaluated annually from grade 4 to grade 12. Four patterns of trajectories were identified: low, increasing (i.e., adolescent-onset), decreasing (i.e., childhood-limited), and high (i.e., childhood-onset). majority large proportion of youth, particularly girls, displayed low levels of aggression over time. A small proportion followed the childhood-onset trajectory. Across gender, the childhood-onset trajectory was associated with the highest rates of maladjustment during the transition to adulthood, the highest number of childhood risk factors, and multiple problems during adolescence. The adolescent-onset trajectory was associated with few childhood risk factors, but with high levels of independent status during adolescence. In contrast, the childhood-limited trajectory was associated with several childhood risk factors, but high levels of parental monitoring and school engagement during adolescence. Romantic involvement differentiated the adolescent-onset and childhood-limited trajectories among girls. PMID:21748751

Developmental trajectories of aggression from late childhood through adolescence: similarities and differences across gender.

PubMed

Xie, Hongling; Drabick, Deborah A G; Chen, Diane

2011-01-01

Although numerous investigations of overt aggressive and antisocial trajectories have been undertaken, there is a dearth of literature examining gender differences and similarities in trajectory patterns and their correlates. To address these gaps, we investigated gender differences in the prevalence rates, predictive validity during transition to adulthood, childhood risk factors, and adolescent correlates of different trajectories of teacher-reported overt aggression (i.e., fights, argues, gets in trouble) among 220 participants (116 girls and 104 boys) evaluated annually from grade 4 to grade 12. Four patterns of trajectories were identified: low, increasing (i.e., adolescent-onset), decreasing (i.e., childhood-limited), and high (i.e., childhood-onset). A large proportion of youth, particularly girls, displayed low levels of aggression over time. A small proportion followed the childhood-onset trajectory. Across gender, the childhood-onset trajectory was associated with the highest rates of maladjustment during the transition to adulthood, the highest number of childhood risk factors, and multiple problems during adolescence. The adolescent-onset trajectory was associated with few childhood risk factors, but with high levels of independent status during adolescence. In contrast, the childhood-limited trajectory was associated with several childhood risk factors, but high levels of parental monitoring and school engagement during adolescence. Romantic involvement differentiated the adolescent-onset and childhood-limited trajectories among girls. © 2011 Wiley-Liss, Inc.

Aggressive delinquency among north American indigenous adolescents: Trajectories and predictors.

PubMed

Sittner, Kelley J; Hautala, Dane

2016-01-01

Aggressive delinquency is a salient social problem for many North American Indigenous (American Indian, Canadian First Nations) communities, and can have deleterious consequences later in life. Yet there is a paucity of research on Indigenous delinquency. Group-based trajectory modeling is used to prospectively examine trajectories of aggressive delinquency over the course of adolescence using data from 646 Indigenous adolescents from a single culture, spanning the ages of 10-19. Five aggression trajectory groups were identified, characterized by different levels and ages of onset and desistence: non-offenders (22.1%), moderate desistors (19.9%), adolescent-limited offenders (22.2%), high desistors (16.7%), and chronic offenders (19.2%). Using the social development model of antisocial behavior, we selected relevant risk and protective factors predicted to discriminate among those most and least likely to engage in more aggressive behavior. Higher levels of risk (i.e., parent rejection, delinquent peers, substance use, and early dating) in early adolescence were associated with being in the two groups with the highest levels of aggressive delinquency. Positive school adjustment, the only significant protective factor, was associated with being in the lowest aggression trajectory groups. The results provide important information that could be used in developing prevention and intervention programs, particularly regarding vulnerable ages as well as malleable risk factors. Identifying those youth most at risk of engaging in higher levels of aggression may be key to preventing delinquency and reducing the over-representation of Indigenous youth in the justice system. © 2015 Wiley Periodicals, Inc.

Constrained Multi-Level Algorithm for Trajectory Optimization

NASA Astrophysics Data System (ADS)

Adimurthy, V.; Tandon, S. R.; Jessy, Antony; Kumar, C. Ravi

The emphasis on low cost access to space inspired many recent developments in the methodology of trajectory optimization. Ref.1 uses a spectral patching method for optimization, where global orthogonal polynomials are used to describe the dynamical constraints. A two-tier approach of optimization is used in Ref.2 for a missile mid-course trajectory optimization. A hybrid analytical/numerical approach is described in Ref.3, where an initial analytical vacuum solution is taken and gradually atmospheric effects are introduced. Ref.4 emphasizes the fact that the nonlinear constraints which occur in the initial and middle portions of the trajectory behave very nonlinearly with respect the variables making the optimization very difficult to solve in the direct and indirect shooting methods. The problem is further made complex when different phases of the trajectory have different objectives of optimization and also have different path constraints. Such problems can be effectively addressed by multi-level optimization. In the multi-level methods reported so far, optimization is first done in identified sub-level problems, where some coordination variables are kept fixed for global iteration. After all the sub optimizations are completed, higher-level optimization iteration with all the coordination and main variables is done. This is followed by further sub system optimizations with new coordination variables. This process is continued until convergence. In this paper we use a multi-level constrained optimization algorithm which avoids the repeated local sub system optimizations and which also removes the problem of non-linear sensitivity inherent in the single step approaches. Fall-zone constraints, structural load constraints and thermal constraints are considered. In this algorithm, there is only a single multi-level sequence of state and multiplier updates in a framework of an augmented Lagrangian. Han Tapia multiplier updates are used in view of their special role in