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Dive into the research topics where Julie A. Nelson is active.

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Featured researches published by Julie A. Nelson.


Medicine and Science in Sports and Exercise | 1993

Seven-day recall and other physical activity self-reports in children and adolescents.

James F. Sallis; Michael J. Buono; Julia J. Roby; Frank G. Micale; Julie A. Nelson

There is need to develop low cost, practical, and accurate measures of physical activity in children and adolescents, and self-report is a promising methodology for children that is applicable for large studies. The purpose of the present study was to assess the reliability and validity of several self-reports of physical activity. Subjects were 36 fifth-, 36 eighth-, and 30 eleventh-grade male and female students. The test-retest reliabilities were r = 0.77 for the 7-d recall interview, r = 0.81 for the Godin-Shephard self-administered survey, and r = 0.93 for a simple activity rating. For the former two measures, reliability improved with age but was significant at all ages, and for the last measure there were no age effects. Memory skills and obesity status were not related to the reliability of recall, but males were more reliable reporters than females. Validity of the 7-d recall was determined by comparing heart rate monitoring records with recalls of very hard activities on the same day. A correlation of 0.53 (P < 0.001) for the total group supported the validity of the reports. Validity improved with age, but validity coefficients were significant in all age groups. These data indicate that physical activity recalls of children as young as the fifth grade are of adequate reliability and validity to use in research on physical activity in children.


Health Psychology | 1993

Correlates of physical activity at home in Mexican-American and Anglo-American preschool children.

James F. Sallis; Philip R. Nader; Shelia L. Broyles; Charles C. Berry; John P. Elder; Thomas L. McKenzie; Julie A. Nelson

Twenty-two potential correlates of childrens physical activity were examined. Two hundred and one Mexican-American and 146 Anglo-American families with 4-year-old children were studied. Childrens physical activity was directly observed in the evening at home on 4 visits for 1 hr each time. Anglo-American children and male children were found to be more active. Demographic variables explained 11% of the variance in childrens physical activity. After adjusting for demographics, 3 childrens variables and 6 social-family variables did not account for significantly more variance. Five environmental variables accounted for 11% additional variance. Variables observed concurrently with physical activity, such as time spent outdoors and prompts to be active, were highly associated with childrens physical activity.


Journal of Developmental and Behavioral Pediatrics | 1992

Anglo- and Mexican-American preschoolers at home and at recess: activity patterns and environmental influences.

Thomas L. McKenzie; James F. Sallis; Philip R. Nader; Shelia L. Broyles; Julie A. Nelson

Habitual physical activity in children is related to physical fitness and appears to mediate cardiovascular disease (CVD) risk factors. We studied the physical activity patterns and associated variables of a large bi-ethnic cohort of 4-year-old children from low to middle socioeconomic families. Trained observers coded the behavior of 351 children (150 Anglo-American, 201 Mexican-American; 182 boys, 169 girls) during two 60-minute home visits and two unstructured recesses lasting up to 30 minutes each at 63 different preschools, Findings indicated that although children were much less active at home, there were low but significant correlations between their activity patterns at home and during recess (r = .13). Children who had activity-promoting toys at home also tended to have them available during preschool recess (r = .20). Ethnic differences were evident for both activity and environmental variables. Mexican-American children were less active than Anglo children at home (p < .002) and during recess (p < .03), thus adding to the adult literature that has found Mexican-Americans to be less active than Anglos, and supporting to the notion that physical activity life-style habits may be established in early childhood. In both settings, Mexican-American children spent more time in presence of adults (home, p < .04; recess, p < .03) and had access to fewer active toys (home, p < .001; recess, p < .05). Gender differences were also evident for both activity and environmental variables. Boys were more active both at home (p < .01) and during recess (p < .01) and at home watched television more frequently (p < .005). These data indicated some subgroups of preschool children are more active than others, and the findings may be useful for pediatricians and educators responsible for developing physical activity promotion programs for young children. J Dev Behav Pediatr 13:173–180, 1992. Index terms: preschool children, physical activity, systematic observation.


Research Quarterly for Exercise and Sport | 1990

Reliability of Interviewers Using the Seven-Day Physical Activity Recall

Lisa D. Gross; James F. Sallis; Michael J. Buono; Julia J. Roby; Julie A. Nelson

The Seven-Day Physical Activity Recall interview is commonly used in epidemiologic research, but the methods of training and certifying interviewers have not been studied or standardized. The purpose of this study was to examine the reliability of the Seven-Day Physical Activity Recall interviews after a structured training program. Twenty-one volunteer interviewers participated in a five-session group training program that targeted standardized interview techniques and scoring procedures. Interviewers scored eight videotaped interviews on two occasions to assess scoring skills. Across all videotapes and interviewers, the test-retest reliability was .99. Two interviewers independently interviewed the same person on the same day, and the reliability of kilocalorie expenditure across interviewers was .86. It was concluded that naive individuals can be taught to reliably conduct and score the Seven-Day Physical Activity Recall interview in a brief training program.


Journal of Developmental and Behavioral Pediatrics | 1991

Blood pressure reactivity to exercise: stability, determinants, family aggregation, and prediction.

James F. Sallis; Shelia L. Broyles; Philip R. Nader; Michael J. Buono; Ian Abramson; Thomas L. Patterson; Julie A. Nelson

Previous studies have shown blood pressure reactivity to exercise predicts future resting blood pressure. Subjects in this study were 206 healthy Mexican-American and Anglo-American families with fifth or sixth grade children. A total of 539 children (mean age = 12 years) and parents (mean age = 37 years) had complete data at baseline, and 79% were remeasured 48 months later. Blood pressure was measured during a submaximal cycle ergometer fitness test. Reactivity measures included systolic blood pressure at 70% of maximal heart rate (SBP70) and slope of the blood pressure-heart rate association during exercise (SLOPE). Stability of reactivity measures over 24 months varied from .22 to .63 (all p < 0.001). Correlates of blood pressure reactivity in parents included resting heart rate, gender, age, and sodium intake. Correlates of reactivity in children included resting heart rate, body mass index, and age. Modest but significant levels of family aggregation of blood pressure reactivity were observed. In stepwise multiple regression analyses, SBP70 at baseline predicted resting blood pressure 48 months later in parents but not in children. The present results confirm previous studies indicating systolic blood pressure reactivity to exercise is a significant predictor of later resting blood pressure.


Sexually Transmitted Diseases | 1997

Neurocognitive impairment in human immunodeficiency virus infection is correlated with sexually transmitted disease history.

Mark R. Wallace; Robert K. Heaton; McCutchan Ja; Malone Jl; Robert A. Velin; Julie A. Nelson; Miller Lk; Weiss Pj; Oldfield Ec rd; Igor Grant

Background and Objectives: Neurocognitive impairment is common in human immunodeficiency virus (HIV)‐infected subjects. The relationship of sexually transmitted diseases to neurocognitive changes is unknown. Goal: To establish whether HIV‐infected patients with a history of syphilis or gonorrhea have a higher rate of neurocognitive dysfunction. Study Design: Neurocognitive function was measured by a battery of quantitative tests in a 453‐person HIV‐infected cohort and a 219‐person HIV‐seronegative control group. Neurocognitive function was then correlated with histories of either syphilis or gonorrhea to assess for possible relationships between these sexually transmitted diseases and neurologic impairment. Results: Human immunodeficiency virus‐infected subjects with a history of either syphilis or gonorrhea tended to perform worse on neurocognitive testing than their counterparts. This difference could not be explained by educational attainment, age, race or CD4 cell count, and was not noted in the HIV‐uninfected control subjects. Conclusions: Sexually transmitted diseases in HIV‐infected subjects are correlated with neurocognitive impairment through an unidentified mechanism.


Ophthalmic Surgery and Lasers | 1997

Retinal Findings and Characteristics in AIDS Patients With Systemic Mycobacterium avium-intracellulare Complex and Toxoplasmic Encephalitis

J. Fernando Arevalo; Jose I. Quiceno; Roberto Garcia; J. Allen McCutchan; David Munguia; Julie A. Nelson; William R. Freeman

BACKGROUND AND OBJECTIVE The purpose of this study was to evaluate the incidence and characteristics of retinal and choroidal manifestations of toxoplasmosis and/or Mycobacterium avium-intracellulare complex (MAC) in patients with acquired immunodeficiency syndrome (AIDS). PATIENTS AND METHODS The authors analyzed their prospectively collected data and found 120 patients with new retinal lesions (group A) that were diagnosed 3 months or longer following the diagnosis of MAC and/or toxoplasmic encephalitis. The authors also performed a point prevalence study of retinal/choroidal findings in 25 consecutive AIDS patients (group B) without known eye disease who had been recently treated for toxoplasmic encephalitis and/or disseminated MAC infections. In addition, the characteristics of retinochoroidal toxoplasmosis scars in 5 AIDS patients were studied and compared with the characteristics of scars in 18 immunocompetent patients. RESULTS In this study the incidence of ocular manifestations of MAC was zero (95% confidence interval [CI] 0.0% to 3.8%). Two of 25 patients (8%) (95% CI 1% to 26%) in group A and 2 of 11 patients (18.1%) (95% CI 3.3% to 51.8%) in group B had toxoplasmic retinochoroiditis. CONCLUSION In AIDS patients, ocular manifestations of toxoplasmosis are more common than ocular MAC. In addition, when compared with immunocompetent patients, AIDS patients tend to have retinochoroidal scars with less retinal pigment epithelium hyperplasia (1.8+ vs 3+) (P = .03).


Scandinavian Journal of Infectious Diseases | 2001

Bartonella henselae Serostatus is not Correlated with Neurocognitive Decline in HIV Infection

Mark R. Wallace; David H. Persing; J. Allen McCutchan; Jenifer Magara; Julie A. Nelson; Robert K. Heaton; Sybil A. Tasker; Igor Grant

Bartonella henselae has been implicated as a significant cause of HIV-associated dementia. We attempted to confirm this association by utilizing the database of the San Diego HIV Neurobehavioral Research Center, which collects longitudinal neurocognitive and laboratory data on over 500 HIV-infected participants. Utilizing an immunofluorescent assay we found that 11% of 177 subjects, half of whom had documented neurocognitive decline, were seropositive for B. henselae. There was no correlation between B. henselae seropositivity and neurocognitive decline. The role of B. henselae in HIV-associated dementia remains ambiguous.Bartonella henselae has been implicated as a significant cause of HIV-associated dementia. We attempted to confirm this association by utilizing the database of the San Diego HIV Neurobehavioral Research Center, which collects longitudinal neurocognitive and laboratory data on over 500 HIV-infected participants. Utilizing an immunofluorescent assay we found that 11% of 177 subjects, half of whom had documented neurocognitive decline, were seropositive for B. hensalae. There was no correlation between B. hensalae seropositivity and neurocognitive decline. The role of B. hensalae in HIV-associated dementia remains ambiguous.


Annals of Neurology | 1997

Dendritic injury is a pathological substrate for human immunodeficiency virus—related cognitive disorders

Eliezer Masliah; Robert K. Heaton; Thomas D. Marcotte; Ronald J. Ellis; Clayton A. Wiley; Margaret Mallory; Cristian L. Achim; McCutchan Ja; Julie A. Nelson; Atkinson Jh; Igor Grant


Annals of Neurology | 1997

Cerebrospinal fluid human immunodeficiency virus type 1 RNA levels are elevated in neurocognitively impaired individuals with acquired immunodeficiency syndrome

Ronald J. Ellis; Karen Hsia; Stephen A. Spector; Julie A. Nelson; Robert K. Heaton; Mark R. Wallace; Ian Abramson; Atkinson Jh; Igor Grant; McCutchan Ja

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Igor Grant

University of California

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McCutchan Ja

University of California

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Atkinson Jh

University of California

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Mark R. Wallace

Naval Medical Center San Diego

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Michael J. Buono

San Diego State University

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Ian Abramson

University of California

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