Science.gov

Sample records for adolescents design cross-sectional

  1. Cigarette pack design and adolescent smoking susceptibility: a cross-sectional survey

    PubMed Central

    Ford, Allison; MacKintosh, Anne Marie; Moodie, Crawford; Richardson, Sol; Hastings, Gerard

    2013-01-01

    Objectives To compare adolescents’ responses to three different styles of cigarette packaging: novelty (branded packs designed with a distinctive shape, opening style or bright colour), regular (branded pack with no special design features) and plain (brown pack with a standard shape and opening and all branding removed, aside from brand name). Design Cross-sectional in-home survey. Setting UK. Participants Random location quota sample of 1025 never smokers aged 11–16 years. Main outcome measures Susceptibility to smoking and composite measures of pack appraisal and pack receptivity derived from 11 survey items. Results Mean responses to the three pack types were negative for all survey items. However, ‘novelty’ packs were rated significantly less negatively than the ‘regular’ pack on most items, and the novelty and regular packs were rated less negatively than the ‘plain’ pack. For the novelty packs, logistic regressions, controlling for factors known to influence youth smoking, showed that susceptibility was associated with positive appraisal and also receptivity. For example, those receptive to the innovative Silk Cut Superslims pack were more than four times as likely to be susceptible to smoking than those not receptive to this pack (AOR=4.42, 95% CI 2.50 to 7.81, p<0.001). For the regular pack, an association was found between positive appraisal and susceptibility but not with receptivity and susceptibility. There was no association with pack appraisal or receptivity for the plain pack. Conclusions Pack structure (shape and opening style) and colour are independently associated, not just with appreciation of and receptivity to the pack, but also with susceptibility to smoke. In other words, those who think most highly of novelty cigarette packaging are also the ones who indicate that they are most likely to go on to smoke. Plain packaging, in contrast, was found to directly reduce the appeal of smoking to adolescents. PMID:24056481

  2. Adolescent Idiopathic Scoliosis and Eating Disorders: Is There a Relation? Results of a Cross-Sectional Study

    ERIC Educational Resources Information Center

    Zaina, Fabio; Donzelli, Sabrina; Lusini, Monia; Vismara, Luca; Capodaglio, Paolo; Neri, Laura; Negrini, Stefano

    2013-01-01

    A recent study suggests a correlation between idiopathic scoliosis in adolescence and eating disorders. However, this does not correspond with our clinical experience in the same population. The aim of this study was to verify the correlation between scoliosis and eating disorders in adolescence. A cross-sectional study was designed including 187…

  3. Motivation Goals during Adolescence: A Cross-Sectional Perspective

    ERIC Educational Resources Information Center

    Mansfield, Caroline F.; Wosnitza, Marold

    2010-01-01

    Goal theory perspectives on motivation are at the forefront of research regarding adolescents' motivation in learning contexts, focusing on the purposes (both academic and social) individuals perceive for engaging in achievement related behaviour. Much research however, has focused on early adolescence, meaning there is limited research regarding…

  4. What Differentiates Adolescent Problematic Drinkers from Their Peers? Results from a Cross-Sectional Study in Northern Irish School Children

    ERIC Educational Resources Information Center

    McKay, Michael T.; Sumnall, Harry; Goudie, Andrew J.; Field, Matt; Cole, Jon C.

    2011-01-01

    Aim: To investigate whether or not a range of factors were associated with problematic drinking, as assessed using the Adolescent Alcohol Involvement Scale (AAIS) in a sample of 11-16-year olds in Northern Ireland. Methods: The study used a cross-sectional experimental design. Post-primary schools in the Eastern Health Board Area of Northern…

  5. A Cross-Sectional Study on the Diet and Nutritional Status of Adolescent Girls in Zambézia Province, Mozambique (the ZANE Study): Design, Methods, and Population Characteristics

    PubMed Central

    Freese, Riitta; Fidalgo, Lourdes; Selvester, Kerry; Ismael, Carina; Mutanen, Marja

    2014-01-01

    Background There is very little published work on dietary intake and nutritional status of Mozambicans. We conducted a population-based cross-sectional study on the diet and nutritional status of adolescent girls in different types of communities in Zambézia Province, Central Mozambique, in two distinct seasons. Objective The purpose of this paper is to present the design, methods, and study population characteristics of the Estudo do Estado Nutricional e da Dieta em Raparigas Adolescentes na Zambézia (the ZANE Study). Methods Data was collected in January-February 2010 ("hunger season") and in May-June 2010 ("harvest season"). A total of 551 girls in the age group 14-19 years old were recruited from one urban area and two districts (district towns and rural villages). The study protocol included a background interview, a 24-hour dietary recall interview, a food frequency questionnaire, anthropometric measurements, bioimpedance, hemoglobin measurement, and venous blood, urine, buccal cell, and fecal sampling. Results Adolescent motherhood was common in all study regions. Stunting prevalence for the total study population as a weighted percentage was 17.8% (95/549; 95% CI 14.3-22.0) with no regional differences. Overweight was found mainly in the urban area where the prevalence was 12.6% (20/159; 95% CI 7.5-17.6), thinness was rare. There were regional differences in the prevalence of malaria parasitemia and intestinal helminth infestation, but not human immunodeficiency virus. Conclusions The fully analyzed data from the ZANE Study will yield results useful for setting priorities in nutrition policy and further research on the diet and nutritional status in Mozambique and other countries with similar nutritional problems. Trial Registration ClinicalTrials.gov: NCT01944891; http://www.clinicaltrials.gov/ct2/show/NCT01944891 (Archived by WebCite at http://www.webcitation.org/6L9OUrsq8). PMID:24598035

  6. Association between maternal education and malocclusion in Mongolian adolescents: a cross-sectional study

    PubMed Central

    Tumurkhuu, Tsasan; Fujiwara, Takeo; Komazaki, Yuko; Kawaguchi, Yoko; Inazawa, Johji; Ganburged, Ganjargal; Bazar, Amarsaikhan; Ogawa, Takuya; Moriyama, Keiji

    2016-01-01

    Objective Malocclusion is a highly prevalent condition, affecting 20–60% of adolescents worldwide. Although its treatment is often expensive and unaffordable for disadvantaged individuals, few studies have examined the relationship between malocclusion and socioeconomic status. We investigated the prevalence of malocclusion among Mongolian adolescents and its association with maternal education in a community-based sample in Mongolia. Design Cross-sectional study. Settings 2 large secondary schools with different backgrounds in Ulaanbaatar, Mongolia. Participants Complete dental casts of 557 randomly recruited Mongolian schoolchildren aged 11–16 years were evaluated using the Dental Health Component of the Index of Orthodontic Treatment Need to dichotomise orthodontic treatment requirements. Exclusion criteria were the presence of orthodontic treatment history and absence of maternal educational status. Questionnaires were administered to caregivers to assess socioeconomic status. Poisson regression analysis was performed to examine the association between malocclusion and maternal educational status. Results The prevalence of malocclusion requiring orthodontic treatment among all adolescents was 35.2% (95% CI 31.2 to 39.2). In the unadjusted analysis, the prevalence ratio (PR) for malocclusion was higher (PR=1.46; 95% CI 0.96 to 2.20) among adolescents of mothers with a high educational background than among those of mothers with a low educational background. After adjusting for covariates, the PR remained significantly higher (PR=1.72; 95% CI 1.06 to 2.82) among adolescents of mothers with a high educational background. Other socioeconomic status variables, including family income and the educational level of the father, showed no association with malocclusion. Conclusions These findings suggest that malocclusion requiring orthodontic treatment in adolescents is more prevalent among children of mothers with high levels of education. Further studies are

  7. Family meal frequency and weight status among adolescents: cross-sectional and 5-year longitudinal associations.

    PubMed

    Fulkerson, Jayne A; Neumark-Sztainer, Dianne; Hannan, Peter J; Story, Mary

    2008-11-01

    This study examined cross-sectional and 5-year longitudinal associations between the frequency of family meals and overweight status (>85th percentile for age and gender) in a large, diverse population of adolescents (n = 2,516). The population included two cohorts (midadolescence to young adulthood, n = 1,710, and early adolescence to midadolescence, n = 806). Logistic regression models tested cross-sectional and longitudinal (1999-2004) associations between family meal frequency and overweight status. Two sets of models are presented: (i) models adjusted only for baseline demographic characteristics and (ii) models also adjusted for physical activity, sedentary behaviors, and energy intake. Longitudinal models adjusted for baseline overweight status. Although significant inverse associations between family meal frequency and overweight status were observed for early adolescent females in all cross-sectional models (P < 0.001), longitudinal associations were not significant. Neither cross-sectional nor longitudinal associations were significant for males of either cohort and older females in any models. Young adolescent females who do not eat meals with their families may be at risk for overweight; however, the increased risk may not persist over a 5-year period. Eating family meals during high school may not protect against overweight during young adulthood. Although previous longitudinal research has suggested significant dietary and psychosocial benefits related to family meal frequency, the weight-related benefits of family meals may be more complex and deserving of further study, including an examination of the quality and quantity of food consumed at family meals.

  8. Activation Cross Sections Improvements needed for IFE Power Reactors Designs

    SciTech Connect

    Rodriguez, A; Cabellos, O; Sanz, J; FalQuina, R; Latkowski, J; Reyes, S

    2003-10-02

    Uncertainties in the prediction of the neutron induced long-lived activity in the natural elements from H to Bi due to activation cross section uncertainties are estimated assuming as neutron environment those of the HYLIFE-II and Sombrero vessel structures. The latest available activation cross section data are employed. The random variables used in the uncertainty analysis have been the concentration limits (CL's) corresponding to hands-on recycling, remote recycling and shallow land burial, quantities typically considered in ranking elements under waste management considerations. The CL standard value (CL{sub nom}), i.e. without uncertainties, is compared with the 95th percentile CL value (CL95). The results of the analysis are very helpful in assessing the quality of the current activation data for IFE applications, providing a rational basis for programmatic priority assignments for new cross sections measurements or evaluations. The HYLIFE-II results shown that a significant error is estimated in predicting the activation of several elements. The estimated errors in the Sombrero case are much less important.

  9. Sodium and potassium urinary excretion and dietary intake: a cross-sectional analysis in adolescents

    PubMed Central

    Gonçalves, Carla; Abreu, Sandra; Padrão, Patrícia; Pinho, Olívia; Graça, Pedro; Breda, João; Santos, Rute; Moreira, Pedro

    2016-01-01

    Background Hypertension is the leading cause for heart disease and stroke, for mortality and morbidity worldwide, and a high sodium-to-potassium intake ratio is considered a stronger risk factor for hypertension than sodium alone. Objective This study aims to evaluate sodium and potassium urinary excretion, and assess the food sources of these nutrients in a sample of Portuguese adolescents. Design A cross-sectional study with a sample of 250 Portuguese adolescents. Sodium and potassium excretion were measured by one 24-h urinary collection, and the coefficient of creatinine was used to validate completeness of urine collections. Dietary sources of sodium and potassium were assessed using a 24-h dietary recall. Results Valid urine collections were provided by 200 adolescents (118 girls) with a median age of 14.0 in both sexes (p=0.295). Regarding sodium, the mean urinary excretion was 3,725 mg/day in boys and 3,062 mg/day in girls (p<0.01), and 9.8% of boys and 22% of girls met the World Health Organization (WHO) recommendations for sodium intake. Concerning potassium, the mean urinary excretion was 2,237 mg/day in boys and 1,904 mg/day in girls (p<0.01), and 6.1% of boys and 1.7% of girls met the WHO recommendations for potassium intake. Major dietary sources for sodium intake were cereal and cereal products (41%), meat products (16%), and milk and milk products (11%); and for potassium intake, main sources were milk and milk products (21%), meat products (17%), and vegetables (15%). Conclusions Adolescents had a high-sodium and low-potassium diet, well above the WHO recommendations. Health promotion interventions are needed in order to decrease sodium and increase potassium intake. PMID:27072344

  10. Section Builder: A finite element tool for analysis and design of composite beam cross-sections

    NASA Astrophysics Data System (ADS)

    Chakravarty, Uttam Kumar

    SectionBuilder is an innovative finite element based tool, developed for analysis and design of composite beam cross-sections. The tool can handle the cross-sections with parametric shapes and arbitrary configurations. It can also handle arbitrary lay-ups for predefined beam cross-section geometries in a consistent manner. The material properties for each layer of the cross-section can be defined on the basis of the design requirements. This tool is capable of dealing with multi-cell composite cross-sections with arbitrary lay-ups. It has also the benefit of handling the variation of thickness of skin and D-spars for beams such as rotor blades. A typical cross-section is considered as a collection of interconnected walls. Walls with arbitrary lay-ups based on predefined geometries and material properties are generated first. The complex composite beam cross-sections are developed by connecting the walls using various types of connectors. These connectors are compatible with the walls, i.e., the thickness of the layers of the walls must match with those of the connectors at the place of connection. Cross-sections are often reinforced by core material for constructing realistic rotor blade cross-sections. The tool has the ability to integrate core materials into the cross-sections. A mapped mesh is considered for meshing parametric shapes, walls and various connectors, whereas a free mesh is considered for meshing the core materials. A new algorithm based on the Delaunay refinement algorithm is developed for creating the best possible free mesh for core materials. After meshing the cross-section, the tool determines the sectional properties using finite element analysis. This tool computes sectional properties including stiffness matrix, compliance matrix, mass matrix, and principal axes. A visualization environment is integrated with the tool for visualizing the stress and strain distributions over the cross-section.

  11. Stress fracture and premenstrual syndrome in Japanese adolescent athletes: a cross-sectional study

    PubMed Central

    Imoto, Yoko; Nagasawa, Hiroyo; Takeshita, Atsuko; Shiina, Masami

    2016-01-01

    Objectives To investigate the relationship between the occurrence of stress fracture and premenstrual syndrome (PMS)/premenstrual dysphoric disorder (PMDD) in Japanese adolescent athletes. Design Cross-sectional study. Setting Osaka, Japan. Participants A school-based survey on menstruation and school life was conducted using a sample of 1818 Japanese female students who belonged to two public high schools in Japan. Among them, we recruited 394 athletes who had regular menstrual cycles (25–38 days) and completed a questionnaire about their premenstrual symptoms and their competitive career. Main outcome measure Premenstrual symptoms and the occurrence of stress fracture. Results The prevalences of moderate-to-severe PMS and PMDD were 8.9% and 1.3%, respectively, which were the same as in collegiate athletes in a previous study. Premenstrual symptoms disturbed ‘Work efficiency or productivity, home responsibilities’, ‘Relationships with coworkers or family’ and ‘Athletic performance in training or competition’ more severely than menstrual pain (p=0.031, p=0.004 and p<0.001, respectively). 66 athletes (16.8%) reported having experienced a stress fracture. The severity of ‘Overeating or food cravings’, ‘Physical symptoms’ and ‘Performance in training or competition’ in athletes with previous stress fractures were much higher than in those without a history of stress fractures (p=0.015, p=0.008 and p=0.006, respectively). In terms of premenstrual symptoms, ‘Physical symptoms’ was associated with an increased risk of stress fractures in athletes (OR 1.66, 95% CI 1.06 to 2.62). Conclusions The results from this study indicated that premenstrual symptoms may affect athletic performance and has the risk of stress fractures in adolescent athletes. PMID:27798029

  12. Socio-demographic correlates of sexual behaviours: a cross sectional survey of adolescents in Imo State secondary schools.

    PubMed

    Nwoke, E A; Okafor, J O; Chukwuocha, U M; Nworuh, B O

    2011-03-01

    The study was designed to determine the socio-demographic correlates of sexual behaviours of the adolescents in Imo State secondary schools. Three objectives and three hypotheses were formulated to guide the study. A cross sectional survey design was used and sample size was 3360 (2.2%) adolescents. A structured, validated and reliable questionnaire (r = 0.79) and focus group discussion were used as the instruments for data collection. Data analysis was done using mean and ANOVA statistics. The result generally, showed that the average sexual behaviours of the adolescents were below the decision mean of 2.50 and as such the adolescents were said to be sexually inactive. In Imo State secondary schools, various family sizes did not significantly influence the sexual behaviours of the adolescents (F-cal. 2.39, F-tab. 3.00 & P > 0.05), family structure significantly influenced their sexual behaviours (F-cal. 17.78, F-tab. 3.00 & P < 0.05) and different financial strengths influenced the adolescents sexual behaviours significantly (F-cal. 22.88, F-tab. 2.37 & P < 0.05. Of great worry is that unrestricted/uncontrolled adolescents sexual behaviours may expose them to sexually transmitted infections/HIV/AIDS, unwanted pregnancies, illegal abortion and dropping out of school. Thus comprehensive sex education was recommended.

  13. Positive associations between consumerism and tobacco and alcohol use in early adolescence: cross-sectional study

    PubMed Central

    Sweeting, Helen N; Bhaskar, Abita; Hunt, Kate

    2012-01-01

    Background There is concern about the negative impact of modern consumer culture on young people's mental health, but very few studies have investigated associations with substance use. In those which have, positive associations have been attributed to attempts to satisfy the unmet needs of more materialistic individuals. Objectives This study examines associations between different dimensions of consumerism and tobacco and alcohol use among Scottish early adolescents. Design Cross-sectional study. Setting and participants 2937 (92% of those eligible) secondary school pupils (ages 12–14) completed questionnaires in examination conditions. Analyses were restricted to those with complete data on all relevant variables (N=2736 smoking; N=2737 drinking). Measures Dependent variables comprised ever smoking and current drinking. Measures of consumerism comprised number of ‘premium’ (range 0–7) and ‘standard’ (range 0–5) material possessions and three Consumer Involvement subscales, ‘dissatisfaction’, ‘consumer orientation’ and ‘brand awareness’ (each range 3–12). Analyses also included school-year group and family affluence. Results Ever smoking and current drinking were both more prevalent among adolescents with more ‘premium’ and ‘standard’ material possessions, greater consumer ‘dissatisfaction’ and ‘brand awareness’ (mutually adjusted analyses including school-year group and family affluence). The strongest relationships occurred for ‘brand awareness’: for each unit increase in ‘brand awareness’ the ORs (95% CI) of ever smoking were 1.17 (1.08 to 1.26) and 1.23 (1.14 to 1.33) in males and females, respectively; and those for drinking were 1.15 (1.08 to 1.23) and 1.21 (1.13 to 1.30). ‘Brand awareness’ had an equal or stronger relationship with both smoking and drinking than did family affluence. Conclusions These results suggest aassociations between consumerism and both smoking and drinking might arise because

  14. Cross-Sectional Survey on Quitting Attempts among Adolescent Smokers in Dharan, Eastern Nepal

    PubMed Central

    Marahatta, Kedar

    2016-01-01

    Background. Adolescents frequently attempt smoking cessation but are unable to maintain long term abstinence because they are dependent on nicotine and experience withdrawal symptoms. Objectives. This study aimed to explore the quitting attempts among adolescent smokers in Dharan Municipality of Eastern Nepal. Methods. A cross-sectional study was conducted using pretested self-administered questionnaire adapted from Global Youth Tobacco Survey to assess current smokers and quitting attempts among 1312 adolescent students in middle (14-15 years) and late adolescence (16–19 years). Chi square test was used for association of various factors with quitting attempts. Results. The prevalence of current smoking was 13.7%. Among the current smokers, 66.5% had attempted to quit in the past because they believed smoking was harmful to health (35.5%). The median duration of quitting was 150 days. Nearly 8% of the current smokers were unwilling to quit in the future because they thought it is already a habit (60%). Smokers who are willing to quit smoking in the future were more likely to have made quitting attempts (OR = 1.36, 95% CI = 0.40–4.45). Conclusion. Relapse often occurs even after multiple quitting attempts. Tobacco focused interventions to support abstinence are important during adolescence to prevent habituation. PMID:27747130

  15. Internet addictive behavior in adolescence: a cross-sectional study in seven European countries.

    PubMed

    Tsitsika, Artemis; Janikian, Mari; Schoenmakers, Tim M; Tzavela, Eleni C; Olafsson, Kjartan; Wójcik, Szymon; Macarie, George Florian; Tzavara, Chara; Richardson, Clive

    2014-08-01

    A cross-sectional school-based survey study (N=13,284; 53% females; mean age 15.8±0.7) of 14-17-year-old adolescents was conducted in seven European countries (Greece, Spain, Poland, Germany, Romania, the Netherlands, and Iceland). The aim of the study was to investigate the prevalence of Internet addictive behavior (IAB) and related psychosocial characteristics among adolescents in the participating countries. In the study, we distinguish two problematic groups: adolescents with IAB, characterized by a loss of control over their Internet use, and adolescents "at risk for IAB," showing fewer or weaker symptoms of IAB. The two groups combined form a group of adolescents with dysfunctional Internet behavior (DIB). About 1% of adolescents exhibited IAB and an additional 12.7% were at risk for IAB; thus, in total, 13.9% displayed DIB. The prevalence of DIB was significantly higher among boys than among girls (15.2% vs. 12.7%, p<0.001) and varied widely between countries, from 7.9% in Iceland to 22.8% in Spain. Frequent use of specific online activities (e.g., gambling, social networking, gaming) at least 6 days/week was associated with greater probability of displaying DIB. Multiple logistic regression analysis indicated that DIB was more frequent among adolescents with a lower educational level of the parents, earlier age at first use of the Internet, and greater use of social networking sites and gaming sites. Multiple linear regression analysis showed that externalizing (i.e., behavioral) and internalizing (i.e., emotional) problems were associated with the presence of DIB.

  16. Low back pain in adolescent and associated factors: A cross sectional study with schoolchildren

    PubMed Central

    Silva, Mônica R. O. G. C. M.; Badaró, Ana Fátima V.; Dall'Agnol, Marinel M.

    2014-01-01

    Objective: To determine the prevalence of low back pain nonspecific and associated factors in schoolchildren. Method: This cross-sectional study investigated 343 adolescents, aged between 12 and 15 years, of both sexes of public schools. The questionnaire included questions regarding sociodemographic characteristics, type of school transportation, body mass index and low back pain. The outcome was defined as discomfort localized below the costal margin and above the inferior gluteal folds in the last 12 months. Results : The prevalence of low back pain in the last year was 57% (n=195) among participants, with no significant difference between the sexes (OR 1.13, 95% CI 0.93 to 1.37). Advancing age and body mass index were associated with the presence of low back pain in the bivariate analysis. The remaining seated at school in usual days was considered one of the main activities that trigger symptoms that lasted up to seven days for the majority (80%) of adolescents. Conclusions: The high prevalence of low back pain presented, indicating that it is a common condition among these adolescents. There was no difference between the sexes, but had influence of age and body mass index. Our results point to the need for the development epidemiological studies of low back pain among children and adolescents. PMID:25372002

  17. Low back pain in adolescent and associated factors: A cross sectional study with schoolchildren.

    PubMed

    Silva, Mônica R O G C M; Badaró, Ana Fátima V; Dall'Agnol, Marinel M

    2014-10-10

    Objective: To determine the prevalence of low back pain nonspecific and associated factors in schoolchildren. Method: This cross-sectional study investigated 343 adolescents, aged between 12 and 15 years, of both sexes of public schools. The questionnaire included questions regarding sociodemographic characteristics, type of school transportation, body mass index and low back pain. The outcome was defined as discomfort localized below the costal margin and above the inferior gluteal folds in the last 12 months. Results : The prevalence of low back pain in the last year was 57% (n=195) among participants, with no significant difference between the sexes (OR 1.13, 95% CI 0.93 to 1.37). Advancing age and body mass index were associated with the presence of low back pain in the bivariate analysis. The remaining seated at school in usual days was considered one of the main activities that trigger symptoms that lasted up to seven days for the majority (80%) of adolescents. Conclusions: The high prevalence of low back pain presented, indicating that it is a common condition among these adolescents. There was no difference between the sexes, but had influence of age and body mass index. Our results point to the need for the development epidemiological studies of low back pain among children and adolescents.

  18. The Cross-Sectional Association between Diet Quality and Depressive Symptomology amongst Fijian Adolescents

    PubMed Central

    Sinclair, Rachael; Millar, Lynne; Allender, Steven; Snowdon, Wendy; Waqa, Gade; Jacka, Felice; Moodie, Marj; Petersen, Solveig; Swinburn, Boyd

    2016-01-01

    Objective To examine the relationship between diet quality and depressive symptomology amongst a community-based sample of Fijian adolescents. Methods Participants included 7,237 adolescents (52.6% girls; mean age 15.6 years) at baseline (2005) and 2,948 (56% girls; mean age 17.4 years) at follow-up (2007/2008), from the Pacific Obesity Prevention in Communities Project. Intervention schools (n = 7) were selected from Nasinu, near Suva on the main Fijian island Viti Levu, and comparison schools (n = 11) were chosen from towns on the opposite, west side of the island. A dietary questionnaire was used to measure diet quality. Factor analysis clustered dietary variables into two unique and independent factors, referred to as healthy diet quality and unhealthy diet quality. Depressive symptomology was assessed via the emotional subscale of the Paediatric Quality of Life Inventory. Both measures were self-reported and self-administered. Multiple linear regression was used to test cross-sectional associations (at baseline and follow-up) between diet quality and depressive symptomology. Variables controlled for included gender, age, ethnicity, study condition, BMI-z scores, and physical activity. Findings Strong, positive dose-response associations between healthy diet and high emotional scores (lower depressive symptomology) were found in cross-sectional analyses at baseline and follow-up, among boys and girls. No association was found between emotional health and unhealthy diet. Conclusions This study suggests that cross-sectional relationships exist between a high quality diet during adolescence and less depressive symptoms, however more evidence is required to determine if these two variables are linked causally. Trial population health strategies that use dietary interventions as a mechanism for mental health promotion provide an opportunity to further test these associations. If this is indeed a true relationship, these forms of interventions have the potential to

  19. Tentative Evidence for Striatal Hyperactivity in Adolescent Cannabis Using Boys: A Cross-Sectional Multicenter fMRI Study

    PubMed Central

    Jager, Gerry; Block, Robert I.; Luijten, Maartje; Ramsey, Nick F.

    2013-01-01

    Adolescents' risk-taking behavior has been linked to a maturational imbalance between reward (“go”) and inhibitory-control (“stop”) related brain circuitry. This may drive adolescent drug-taking, such as cannabis use. In this study we assessed the non-acute effects of adolescent cannabis use on reward-related brain function. We performed a two-site (United States and Netherlands; pooled data) functional magnetic resonance imaging (fMRI) study with a cross-sectional design. Twenty-one abstinent but frequent cannabis-using boys were compared with 24 non-using peers on reward-related brain function, using a monetary incentive delay task with fMRI. Focus was on anticipatory and response stages of reward and brain areas critically involved in reward processing like the striatum. Performance in users was normal. Region-of-interest analysis indicated striatal hyperactivity during anticipatory stages of reward in users. Intriguingly, this effect was most pronounced during non-rewarding events. Striatal hyperactivity in adolescent cannabis users may signify an overly sensitive motivational brain circuitry. Frequent cannabis use during adolescence may induce diminished ability to disengage the motivational circuit when no reward can be obtained. This could strengthen the search for reinforcements like drugs of abuse, even when facing the negative (non-rewarding) consequences. PMID:23909003

  20. Deliberate Self-Harm in Adolescents Aged 12-18: A Cross-Sectional Survey of 18,104 Students

    ERIC Educational Resources Information Center

    Watanabe, Norio; Nishida, Atsushi; Shimodera, Shinji; Inoue, Ken; Oshima, Norihito; Sasaki, Tsukasa; Inoue, Shimpei; Akechi, Tatsuo; Furukawa, Toshi A.; Okazaki, Yuji

    2012-01-01

    Little is known about accurate prevalence and associated factors of deliberate self-harm (DSH) among adolescents in Asian countries. In this study, the prevalence and associated factors of DSH among adolescents in Japan were examined. Data were derived from a cross-sectional survey using an anonymous self-report questionnaire and enrolling 8,620…

  1. A probabilistic methodology for radar cross section prediction in conceptual aircraft design

    NASA Astrophysics Data System (ADS)

    Hines, Nathan Robert

    System effectiveness has increasingly become the prime metric for the evaluation of military aircraft. As such, it is the decision maker's/designer's goal to maximize system effectiveness. Industry and government research documents indicate that all future military aircraft will incorporate signature reduction as an attempt to improve system effectiveness and reduce the cost of attrition. Today's operating environments demand low observable aircraft which are able to reliably take out valuable, time critical targets. Thus it is desirable to be able to design vehicles that are balanced for increased effectiveness. Previous studies have shown that shaping of the vehicle is one of the most important contributors to radar cross section, a measure of radar signature, and must be considered from the very beginning of the design process. Radar cross section estimation should be incorporated into conceptual design to develop more capable systems. This research strives to meet these needs by developing a conceptual design tool that predicts radar cross section for parametric geometries. This tool predicts the absolute radar cross section of the vehicle as well as the impact of geometry changes, allowing for the simultaneous tradeoff of the aerodynamic, performance, and cost characteristics of the vehicle with the radar cross section. Furthermore, this tool can be linked to a campaign theater analysis code to demonstrate the changes in system and system of system effectiveness due to changes in aircraft geometry. A general methodology was developed and implemented and sample computer codes applied to prototype the proposed process. Studies utilizing this radar cross section tool were subsequently performed to demonstrate the capabilities of this method and show the impact that various inputs have on the outputs of these models. The F/A-18 aircraft configuration was chosen as a case study vehicle to perform a design space exercise and to investigate the relative impact of

  2. Cross-sectional and longitudinal associations between parenting style and adolescent girls’ physical activity

    PubMed Central

    2012-01-01

    Background Understanding the influences on physical activity is crucial, particularly among important target groups such as adolescent girls. This study describes cross-sectional and longitudinal associations between parenting style and girls’ participation in organized sport, walking/cycling trips and objectively assessed moderate to vigorous physical activity (MVPA). Methods Data were collected from adolescent girls (n=222) and their parents in 2004 and again in 2006. Parents self-reported their demographic characteristics and parenting style. Girls self-reported their organized sport participation and weekly walking/cycling trips, while MVPA was assessed using accelerometers. Linear regression and interaction analyses were performed. Interactions between socio-demographic factors and parenting style with organized sport, walking/cycling trips and MVPA are presented. Results There were cross-sectional associations between authoritative (B=−0.45, p=0.042) and indulgent (B=−0.56, p=0.002) parenting and the number of walking/cycling trips, and authoritarian (B=0.27, p=0.033) parenting and frequency of organized sport. Significant interactions included those between: family status, authoritative parenting and daily (p=0.048) and week day (p=0.013) MVPA; education, indulgent parenting and MVPA on weekend days (p=0.006); and, employment, authoritarian parenting and duration and frequency of organized sport (p=0.004), highlighting the complexity of these relationships. Longitudinal analyses revealed significant decreases in organized sport and MVPA, significant increases in walking/cycling trips and no significant associations between parenting and physical activity. Conclusion Parenting styles appear to influence walking and cycling trips among adolescent girls, though not physical activity within other domains. Socio-demographic characteristics interact with the relationships between parenting and physical activity. While these findings can inform the

  3. Temporomandibular Disorders and Related Factors in a Group of Iranian Adolescents: A Cross-sectional Survey

    PubMed Central

    Ebrahimi, Masoumeh; Dashti, Hossein; Mehrabkhani, Maryam; Arghavani, Mohammad; Daneshvar-Mozafari, Avideh

    2011-01-01

    Background and aims Temporomandibular disorders (TMDs) are the most common condition affecting the tem-poromandibular joint and associated structures. The aim of this study was the epidemiologic evaluation of TMDs and re-lated factors in a group of Iranian adolescents. Materials and methods This descriptive cross-sectional survey included a sample of800 high school students (400 girls and 400 boys) aged 14 to18 years, in Mashhad, Iran, selected using cluster sampling. Examiners completed question-naires and performed the clinical examinations. Data were analyzed with the Chi-square and Fisher exact tests. Results The prevalence of TMDs in the studied sample was 34.7%. The most common signs of TMDs were clicking, muscle tenderness and TMJ tenderness. The most prevalent predisposing factors of TMDs were clenching, premature con-tact in protrusive movement and bruxism. A clear predominance was seen in girls (40.5%) compared with boys (29%) (P = 0.001). Conclusion Signs and symptoms of TMDs were prevalent in Iranian adolescents with a clear female predominance. PMID:22991620

  4. Association between obesity and ECG variables in children and adolescents: A cross-sectional study

    PubMed Central

    SUN, GUO-ZHE; LI, YANG; ZHOU, XING-HU; GUO, XIAO-FAN; ZHANG, XIN-GANG; ZHENG, LI-QIANG; LI, YUAN; JIAO, YUN-DI; SUN, YING-XIAN

    2013-01-01

    Obesity exhibits a wide variety of electrocardiogram (ECG) abnormalities in adults, which often lead to cardiovascular events. However, there is currently no evidence of an association between obesity and ECG variables in children and adolescents. The present study aimed to explore the associations between obesity and ECG intervals and axes in children and adolescents. A cross-sectional observational study of 5,556 students aged 5–18 years was performed. Anthropometric data, blood pressure and standard 12-lead ECGs were collected for each participant. ECG variables were measured manually based on the temporal alignment of simultaneous 12 leads using a CV200 ECG Work Station. Overweight and obese groups demonstrated significantly longer PR intervals, wider QRS durations and leftward shifts of frontal P-wave, QRS and T-wave axes, while the obese group also demonstrated significantly higher heart rates, compared with normal weight groups within normotensive or hypertensive subjects (P<0.05). Abdominal obesity was also associated with longer PR intervals, wider QRS duration and a leftward shift of frontal ECG axes compared with normal waist circumference (WC) within normotensive or hypertensive subjects (P<0.05). Gender was a possible factor affecting the ECG variables. Furthermore, the ECG variables, including PR interval, QRS duration and frontal P-wave, QRS and T-wave axes, were significantly linearly correlated with body mass index, WC and waist-to-height ratio adjusted for age, gender, ethnicity and blood pressure. However, there was no significant association between obesity and the corrected QT interval (P>0.05). The results of the current study indicate that in children and adolescents, general and abdominal obesity is associated with longer PR intervals, wider QRS duration and a leftward shift of frontal P-wave, QRS and T-wave axes, independent of age, gender, ethnicity and blood pressure. PMID:24255675

  5. Prevalence of factors related to active reproductive health behavior: a cross-sectional study Indonesian adolescent

    PubMed Central

    Kimura, Rumiko; Tsuda, Akiko; Tabuchi, Noriko

    2016-01-01

    OBJECTIVES Complex and diverse factors are related to reproductive health (RH) behavior among adolescents according to the social and cultural context of each countries. This study examined the prevalence of active RH and factors related to active RH behavior among Indonesian adolescents. METHODS A cross-sectional study was conducted among 1,040 of students who were selected through a multi-stage random sampling technique. A self-administered questionnaire was developed, including the World Health Organization Illustrative Questionnaire for Interview-Surveys with Young People, pubertal development scale, and sexual activity scale, modified in accordance to the Indonesian context. The data were analyzed using descriptive and comparative statistics, as well as logistic regression analyses. RESULTS The prevalence of active RH behavior were more higher in boys (56.6%; 95% confidence interval [CI], 50.6% to 62.6%) than in girls (43.7%; 95% CI, 37.6% to 49.8%). Negative attitudes towards RH were a factor related to active RH behavior in both boys and girls. Smoking and kind relationship envisioned before marriage (pacaran [courtship] and nikah siri [non-registered marriage]) were factors related to active RH behavior in boys; whereas the absence of access to information on substance abuse was an additional factor in girls. Moreover, an interaction was found between access to information on development and smoking (boys) and attitudes on RH (girls) as independent variables associated with active RH behavior. CONCLUSIONS Sex education for adolescents in Indonesia, particularly in the context of a health promotion program, should be developed based on prevalent social, cultural, and religious values to prevent active RH behavior. Such programs should focus on the kind of relationship envisioned before marriage and smoking for boys and access to information on subtance abuse for girls. PMID:27866406

  6. Optimal hydraulic design of earth dam cross section using saturated-unsaturated seepage flow model

    NASA Astrophysics Data System (ADS)

    Xu, Y.-Q.; Unami, K.; Kawachi, T.

    An optimal hydraulic design problem regarding an earth dam cross section is formulated as an inverse problem for the steady model of saturated-unsaturated seepage flows in porous media. In the problem formulation, the choice of soil material to be used in each point of the dam cross sectional domain is considered as the control variable to be identified. The performance index used to evaluate the appropriateness of the design is defined as the sum of two square integral norms, which represent reducing the saturated zone and minimizing material costs. It is also shown that the first norm bounds the total seepage discharge through the earth dam. Since the governing variational boundary value problem as well as the adjoint problem is well-posed, a deterministic approach is taken. A numerical scheme including pseudo-unsteady terms is developed to calculate the optimal solution in an ideal earth dam cross section to be designed utilizing two different types of soil material. The results show that an inclined clay core of less hydraulic conductivity should be located on the upstream side of the cross section. The unsaturated zone turns out to play an important role in the flow field and the optimal design.

  7. Sexuality in Adolescents: have we Explored Enough! A Cross-sectional Study to Explore Adolescent Health in a City Slum in Northern India

    PubMed Central

    Mohan, Yogesh

    2014-01-01

    Context: Adolescent health is a relatively new focus area of India’s National health program. However, little evidence is available for the existing problems especially in adolescent slum population. A study was planned to explore the problems of adolescent pertaining to sexuality, physical health, tobacco and alcohol use in slums of Urban Meerut, and create evidence base for informed planning and decision making by the local health authorities. Aims: To study the adolescent health in the slums of Meerut City, India. Settings and Design: Entire slums of Urban Meerut, cross-sectional study. Materials and Methods: Study was done in the slums of Meerut city, in Northern India. WHO 30 cluster sampling technique was used. Thirty slums were selected from the list of all the slums of Meerut, 210 adolescents were selected with 7 adolescents from each slum. Statistical Analysis: Proportions and Chi-square test. Results: More than one third of the (36.7%) adolescents reported to have a current health problem, however only half of these sought medical help for treatment. Tweleve percent of adolescents reported history of alcohol or tobacoo use. Nine percent adolescents complained of stressful atmosphere at home. About 10% adolescents in the surveyed population gave history of sexual activity, but only one third of them had used condom during their last sexual intercourse. Conclusion: This study reflects the high morbidity and poor treatment seeking behaviour among adolescents in urban slums. A significant proportion of adolescents indulge in high risk sexual behavior, tobacco and alcohol use. There were significant gender differences with regards to treatment seeking behaviour, sexual behaviour, tobacco and alcohol use. The gender nuances must be taken into account while planning interventions for this section of population. PMID:25302222

  8. Respiratory effects associated with wood fuel use: a cross-sectional biomarker study among adolescents.

    PubMed

    Van Miert, Erik; Sardella, Antonia; Nickmilder, Marc; Bernard, Alfred

    2012-04-01

    The use of wood as heating and cooking fuel can result in elevated levels of indoor air pollution, but to what extent this is related to respiratory diseases and allergies is still inconclusive. Here, we report a cross-sectional study among 744 school adolescents (median age 15 years) using as main outcomes respiratory symptoms and diseases, exhaled nitric oxide, total and aeroallergen-specific IgE in serum, and two epithelial biomarkers in nasal lavage fluid (NALF) or serum, that is, Clara cell protein (CC16) and surfactant-associated protein D (SPD). Information about the wood fuel use and potential confounders was collected via a personal interview of the adolescent and a questionnaire filled out by the parents. Two approaches were used to limit the possible influence of confounders, that is, multivariate analysis using the complete study population or pairwise analysis of matched sub-populations obtained using an automated procedure. Wood fuel use was associated with a decrease of CC16 and an increase of SPD in serum, which resulted in a decreased serum CC16/SPD ratio (median -9%, P = 0.001). No consistent differences were observed for the biomarkers measured in exhaled breath or NALF. Wood fuel use was also associated with increased odds for asthma [odds ratio (OR) 2.2, 95% CI: 1.1-4.4, P = 0.02], hay fever (OR = 2.4, 95% CI: 1.4-4.3, P = 0.002), and sensitization against pollen allergens (OR = 2.1, 95% CI: 1.3-3.4, P = 0.002). The risks of respiratory tract infections, self-reported symptoms, and sensitization against house-dust mite were not increased by wood fuel use. The increased risks of asthma, hay fever and aeroallergen sensitization, and the changes of lung-specific biomarkers consistently pointed towards respiratory effects associated with the use of wood fuel.

  9. Psychosocial Problems Syndemically Increase Adolescent Substance Use: Findings From a Cross-sectional Survey of 82,812 Chinese Adolescents.

    PubMed

    Wu, Jie; Wu, Hong; Wang, Juan; Deng, Jianxiong; Gao, Xue; Xu, Yan; Huang, Guoliang; Huang, Jinghui; Guo, Lan; Lu, Ciyong

    2015-12-01

    A growing body of studies have indicated the associations between substance use and psychosocial problems in adolescents. However, few of them have examined whether these psychosocial problems form a syndemic, which means the co-occurrence of psychosocial problems accompanied by additional effects on substance use.We conducted a cross-sectional survey with 82,812 Chinese adolescents who were selected using a multistage random procedure. Bivariate associations were estimated between selected syndemic indicators and adolescent substance use. Multivariate logistic regression was used to estimate the association between the syndemic indicator count score (the count of syndemic indicators) and adolescent substance use. In addition, cluster analysis was used to partition participants reporting at least one of syndemic indicators to assess associations between resolved cluster memberships and adolescent substance use.All selected syndemic indicators were associated with each other and with adolescent substance use. As the number of syndemic indicators increases, stronger associations with substance use were found in our analysis: the range of adjusted OR was from 1.57 (95% CI: 1.38-1.79) for 1 syndemic indicator to 9.45 (95% CI: 7.60-11.76) for 5 or 6 syndemic indicators. There was no effect modification of gender on these additive associations. The multivariate logistic regression indicated that the cluster membership of nonlow SES academic failures has the highest odds of using substance (OR = 2.26, 95% CI: 2.12-2.41), compared to students reporting none syndemic indicators.Our findings support the syndemic hypothesis that adolescents bearing multiple psychosocial problems experience additive risks of using substance. Our findings support that a comprehensive approach to substance use prevention in adolescents would necessitate the involvement of a variety of providers.

  10. Design and optimization of a harmonic probe with step cross section in multifrequency atomic force microscopy.

    PubMed

    Cai, Jiandong; Wang, Michael Yu; Zhang, Li

    2015-12-01

    In multifrequency atomic force microscopy (AFM), probe's characteristic of assigning resonance frequencies to integer harmonics results in a remarkable improvement of detection sensitivity at specific harmonic components. The selection criterion of harmonic order is based on its amplitude's sensitivity on material properties, e.g., elasticity. Previous studies on designing harmonic probe are unable to provide a large design capability along with maintaining the structural integrity. Herein, we propose a harmonic probe with step cross section, in which it has variable width in top and bottom steps, while the middle step in cross section is kept constant. Higher order resonance frequencies are tailored to be integer times of fundamental resonance frequency. The probe design is implemented within a structural optimization framework. The optimally designed probe is micromachined using focused ion beam milling technique, and then measured with an AFM. The measurement results agree well with our resonance frequency assignment requirement.

  11. Design and optimization of a harmonic probe with step cross section in multifrequency atomic force microscopy

    SciTech Connect

    Cai, Jiandong; Zhang, Li; Wang, Michael Yu

    2015-12-15

    In multifrequency atomic force microscopy (AFM), probe’s characteristic of assigning resonance frequencies to integer harmonics results in a remarkable improvement of detection sensitivity at specific harmonic components. The selection criterion of harmonic order is based on its amplitude’s sensitivity on material properties, e.g., elasticity. Previous studies on designing harmonic probe are unable to provide a large design capability along with maintaining the structural integrity. Herein, we propose a harmonic probe with step cross section, in which it has variable width in top and bottom steps, while the middle step in cross section is kept constant. Higher order resonance frequencies are tailored to be integer times of fundamental resonance frequency. The probe design is implemented within a structural optimization framework. The optimally designed probe is micromachined using focused ion beam milling technique, and then measured with an AFM. The measurement results agree well with our resonance frequency assignment requirement.

  12. Vulnerability to unhealthy behaviours across different age groups in Swedish Adolescents: a cross-sectional study

    PubMed Central

    Paulsson Do, Ulrica; Edlund, Birgitta; Stenhammar, Christina; Westerling, Ragnar

    2014-01-01

    Purpose: There is lack of evidence on the effects of health-promoting programmes among adolescents. Health behaviour models and studies seldom compare the underlying factors of unhealthy behaviours between different adolescent age groups. The main objective of this study was to investigate factors including sociodemographic parameters that were associated with vulnerability to health-damaging behaviours and non-adoption of health-enhancing behaviours in different adolescent age groups. Methods: A survey was conducted among 10,590 pupils in the age groups of 13–14, 15–16 and 17–18 years. Structural equation modelling was performed to determine whether health-damaging behaviours (smoking and alcohol consumption) and non-adoption of health-enhancing behaviours (regular meal habits and physical activity) shared an underlying vulnerability. This method was also used to determine whether gender and socio-economic status were associated with an underlying vulnerability to unhealthy behaviours. Results: The findings gave rise to three models, which may reflect the underlying vulnerability to health-damaging behaviours and non-adoption of health-enhancing behaviours at different ages during adolescence. The four behaviours shared what was interpreted as an underlying vulnerability in the 15–16-year-old age group. In the youngest group, all behaviours except for non-participation in physical activity shared an underlying vulnerability. Similarly, alcohol consumption did not form part of the underlying vulnerability in the oldest group. Lower socio-economic status was associated with an underlying vulnerability in all the age groups; female gender was associated with vulnerability in the youngest adolescents and male gender among the oldest adolescents. Conclusions: These results suggest that intervention studies should investigate the benefits of health-promoting programmes designed to prevent health-damaging behaviours and promote health-enhancing behaviours in

  13. Comorbidities and Phenotypes of Rhinitis in Korean Children and Adolescents: A Cross-sectional, Multicenter Study

    PubMed Central

    Lee, Kyung Suk; Yum, Hye Yung; Sheen, Youn Ho; Park, Yong Mean; Lee, Yong Ju; Choi, Bong Seok; Jee, Hye Mi; Choi, Sun Hee; Kim, Hyun Hee; Park, Yang; Kim, Hyo-Bin

    2017-01-01

    Purpose Rhinitis is a nasal inflammatory disease in children and adolescents. However, little is known about the phenotypes and characteristics of allergic rhinitis (AR) in Korean children and adolescents. The objective of this study was to analyze the symptoms and comorbidities of rhinitis, to compare AR to non-allergic rhinitis (NAR), and to reveal the phenotypes and features of AR in a Korean pediatric population. Methods Patients under 18 years of age with rhinitis symptoms were recruited from January 2013 to January 2015 by pediatric allergists. We analyzed symptoms, phenotypes, comorbidities, and allergen sensitization in this cross-sectional, multicenter study. Results Medical records were collected from 11 hospitals. The AR group has 641 (68.3%) patients, with 63.2% of boys and 7.5 (±3.4) years of mean age. The NAR group has 136 (14.5%) patients, with 55.1% of boys and 5.5 (±2.9) years of mean age. Moderate-severe persistent AR affected 41.2% of AR patients. Nasal obstruction was more common in NAR patients (P<0.050), whereas AR patients sneezed more (P<0.050) and more commonly had conjunctivitis, asthma, and otitis media (P<0.050). Sinusitis was the most common comorbidity in both groups. Allergen sensitization was caused by house dust mites (HDMs) (90.2%), pollen (38.7%), and animal dander (24.8%) in AR patients. Pollen and animal dander sensitization significantly increased age-dependently (P<0.050), but 91.9% of AR patients were already sensitized to HDMs before 5 years old. Conclusions Our study revealed that AR was more prevalent than NAR and that 41.2% of AR presented with moderate-severe disease in Korean pediatric populations. Sinusitis was the most common comorbidity, and sleep disturbance was associated with the severity of rhinitis. The majority of AR patients were sensitized to HDMs in preschool ages. Further studies, including nationwide and longitudinal data, will help understand the relationship between these diseases. PMID:27826964

  14. SENSIT: a cross-section and design sensitivity and uncertainty analysis code. [In FORTRAN for CDC-7600, IBM 360

    SciTech Connect

    Gerstl, S.A.W.

    1980-01-01

    SENSIT computes the sensitivity and uncertainty of a calculated integral response (such as a dose rate) due to input cross sections and their uncertainties. Sensitivity profiles are computed for neutron and gamma-ray reaction cross sections of standard multigroup cross section sets and for secondary energy distributions (SEDs) of multigroup scattering matrices. In the design sensitivity mode, SENSIT computes changes in an integral response due to design changes and gives the appropriate sensitivity coefficients. Cross section uncertainty analyses are performed for three types of input data uncertainties: cross-section covariance matrices for pairs of multigroup reaction cross sections, spectral shape uncertainty parameters for secondary energy distributions (integral SED uncertainties), and covariance matrices for energy-dependent response functions. For all three types of data uncertainties SENSIT computes the resulting variance and estimated standard deviation in an integral response of interest, on the basis of generalized perturbation theory. SENSIT attempts to be more comprehensive than earlier sensitivity analysis codes, such as SWANLAKE.

  15. Sex Trafficking Related Knowledge, Awareness, and Attitudes among Adolescent Female Students in Nepal: A Cross-Sectional Study

    PubMed Central

    2015-01-01

    Background Sex trafficking has been a long-standing concern in Nepal. Very little has been achieved, however, in terms of actual reduction in the number of victims despite numerous anti-sex trafficking programs. This situation may be attributable to a lack of empirical evidence upon which to formulate anti-sexual trafficking interventions. This study aimed to assess sex trafficking-related knowledge, awareness and attitudes, and factors associated with sex trafficking awareness and attitudes towards the victims of sex trafficking and/or anti-sex trafficking campaigns among adolescent female students in Nepal. Methods A cross-sectional study was conducted between August–September 2013 among 292 adolescent female students (>10 years old) using systematic random sampling from three high schools in Sindhupalchowk district, Nepal. As an initial step, descriptive analyses were employed to characterize the data and multivariate logistic regression analyses were used to explore factors associated with sex trafficking awareness and related attitudes. Results Seventy-six percent of sampled students reported that they were aware of sex trafficking and 94.6% indicated media (i.e., radio or television) as the primary sources of their knowledge. Fifty-one percent mentioned relatives/friends as mediators of sex trafficking, 60.4% reported promise for better jobs as the primary attraction behind sex trafficking, and 48.6% mentioned adolescent females as the most vulnerable group for sex trafficking. Over half (56.8%) of the respondents had positive attitudes towards the victims of sex trafficking and/or anti-sex trafficking campaigns. Age (OR = 3.38, 95% CI:2.51–4.55), parents’ occupation (OR = 3.89, 95% CI:1.58–9.58), and having a radio/TV at home (OR = 6.67, 95% CI:3.99–9.54) were significantly associated with awareness, whereas being younger (OR = 0.67, 95% CI:0.55–0.79) and having joint-family (OR = 2.67, 95% CI:1.49–4.80) were significantly associated with

  16. Bidirectional cross-sectional and prospective associations between physical activity and body composition in adolescence: Birth cohort study

    PubMed Central

    Hallal, Pedro C.; Reichert, Felipe F.; Ekelund, Ulf; Dumith, Samuel C.; Menezes, Ana M.; Victora, Cesar G.; Wells, Jonathan

    2011-01-01

    The aim of this study was to investigate the cross-sectional and prospective associations between physical activity and body composition in adolescence. This is a prospective study, including 4,103 adolescents belonging to the Pelotas (Brazil) 1993 birth cohort, who were followed up at the mean ages of 11.3 and 14.7 years. Subsample analyses included 511 individuals with accelerometry and deuterium dilution data at 13.3 years. Sum of skinfolds at age 11.3 years was highly correlated with skinfolds at age 14.7 years (rho = 0.74, P < 0.001). More than 85% of participants remained in the same quintile or changed by not more than one quintile during the 3.4 year period. Tracking of physical activity was considerably lower, although still significant; the correlation was 0.24 (P < 0.001) and 61.4% of the adolescents moved one or less quintiles. In fully-adjusted models, no significant cross-sectional or longitudinal associations were found between physical activity and body composition, neither in boys nor in girls. These null results were confirmed in the 511 individuals with accelerometry and deuterium data. We provide evidence of tracking of physical activity and particularly body composition during adolescence. Our results do not support the hypothesis that physical activity and fatness are strongly related in adolescents. PMID:22141438

  17. Health-related quality of life in adolescents with chronic physical illness in northern Russia: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Health related quality of life (HRQoL) is an important subjectively evaluated outcome of adolescents physical, mental, and social functioning. It gives us the possibility to assess the disease impact on life of adolescents, and to sort out target groups of adolescents for future psychological interventions. The objective of this cross-sectional survey was to study HRQoL in 173 adolescents with chronic physical illness (CPI - diabetes, asthma, and epilepsy), and to find HRQoL predictors in each disease group. Methods Disease-specific questionnaires were completed by each adolescent recruited from the local outpatient clinic; mothers answered the questions on socioeconomic status (SES); and the patients’ clinicians evaluated the severity of the disease. Results A high proportion of adolescents in each disease specific sample reported moderate to high levels of HRQoL. Gender was the most prominent predictor of HRQoL in all three studied groups, while disease severity predicted HRQoL in the diabetic group and to some extent in the asthma group. Conclusions Our results provide evidence that adolescents with diabetes, asthma, and epilepsy in northern Russia maintain relatively moderate to high levels of HRQoL. The domains affecting HRQoL were related to both disease-specific (severity) and non-disease factors (gender and SES). Our study suggests that future psychosocial interventions should focus on aspects of CPI impacting adolescents in gendered ways, furthermore taking into account disease specific factors. PMID:24460738

  18. Self-reported quality of life of adolescents with cerebral palsy: a cross-sectional and longitudinal analysis

    PubMed Central

    Colver, Allan; Rapp, Marion; Eisemann, Nora; Ehlinger, Virginie; Thyen, Ute; Dickinson, Heather O; Parkes, Jackie; Parkinson, Kathryn; Nystrand, Malin; Fauconnier, Jérôme; Marcelli, Marco; Michelsen, Susan I; Arnaud, Catherine

    2015-01-01

    Summary Background Children with cerebral palsy who can self-report have similar quality of life (QoL) to their able-bodied peers. Is this similarity also found in adolescence? We examined how self-reported QoL of adolescents with cerebral palsy varies with impairment and compares with the general population, and how factors in childhood predict adolescent QoL. Methods We report QoL outcomes in a longitudinal follow-up and cross-sectional analysis of individuals included in the SPARCLE1 (childhood) and SPARCLE2 (adolescent) studies. In 2004 (SPARCLE1), a cohort of 818 children aged 8–12 years were randomly selected from population-based cerebral palsy registers in nine European regions. We gathered data from 500 participants about QoL with KIDSCREEN (ten domains); frequency of pain; child psychological problems (Strengths and Difficulties Questionnaire); and parenting stress (Parenting Stress Index). At follow-up in 2009 (SPARCLE2), 355 (71%) adolescents aged 13–17 years remained in the study and self-reported QoL (longitudinal sample). 76 additional adolescents self-reported QoL in 2009, providing data for 431 adolescents in the cross-sectional sample. Researchers gathered data at home visits. We compared QoL against matched controls in the general population. We used multivariable regression to relate QoL of adolescents with cerebral palsy to impairments (cross-sectional analysis) and to childhood QoL, pain, psychological problems, and parenting stress (longitudinal analysis). Findings Severity of impairment was significantly associated (p<0·01) with reduced adolescent QoL on only three domains (Moods and emotions, Autonomy, and Social support and peers); average differences in QoL between the least and most able groups were generally less than 0·5 SD. Adolescents with cerebral palsy had significantly lower QoL than did those in the general population in only one domain (Social support and peers; mean difference −2·7 [0·25 SD], 95% CI −4·3 to −1·4

  19. The role of integral experiments and nuclear cross section evaluations in space nuclear reactor design

    NASA Astrophysics Data System (ADS)

    Moses, David L.; McKnight, Richard D.

    The importance of the nuclear and neutronic properties of candidate space reactor materials to the design process has been acknowledged as has been the use of benchmark reactor physics experiments to verify and qualify analytical tools used in design, safety, and performance evaluation. Since June 1966, the Cross Section Evaluation Working Group (CSEWG) has acted as an interagency forum for the assessment and evaluation of nuclear reaction data used in the nuclear design process. CSEWG data testing has involved the specification and calculation of benchmark experiments which are used widely for commercial reactor design and safety analysis. These benchmark experiments preceded the issuance of the industry standards for acceptance, but the benchmarks exceed the minimum acceptance criteria for such data. Thus, a starting place has been provided in assuring the accuracy and uncertainty of nuclear data important to space reactor applications.

  20. Physical fitness among urban and rural Ecuadorian adolescents and its association with blood lipids: a cross sectional study

    PubMed Central

    2014-01-01

    Background Physical fitness has been proposed as a marker for health during adolescence. Currently, little is known about physical fitness and its association with blood lipid profile in adolescents from low and middle-income countries. The aim of this study is therefore to assess physical fitness among urban and rural adolescents and its associations with blood lipid profile in a middle-income country. Methods A cross-sectional study was conducted between January 2008 and April 2009 in 648 Ecuadorian adolescents (52.3% boys), aged 11 to 15 years, attending secondary schools in Cuenca (urban n = 490) and Nabón (rural n = 158). Data collection included anthropometric measures, application of the EUROFIT battery, dietary intake (2-day 24 h recall), socio-demographic characteristics, and blood samples from a subsample (n = 301). The FITNESGRAM standards were used to evaluate fitness. The associations of fitness and residential location with blood lipid profile were assessed by linear and logistic regression after adjusting for confounding factors. Results The majority (59%) of the adolescents exhibited low levels of aerobic capacity as defined by the FITNESSGRAM standards. Urban adolescents had significantly higher mean scores in five EUROFIT tests (20 m shuttle, speed shuttle run, plate tapping, sit-up and vertical jump) and significantly most favorable improved plasma lipid profile (triglycerides and HDL) as compared to rural adolescents. There was a weak association between blood lipid profile and physical fitness in both urban and rural adolescents, even after adjustment for confounding factors. Conclusions Physical fitness, in our sample of Ecuadorian adolescents, was generally poor. Urban adolescents had better physical fitness and blood lipid profiles than rural adolescents. The differences in fitness did not explain those in blood lipid profile between urban and rural adolescents. PMID:24745348

  1. Analyzing the influence of median cross-section design on highway safety using vehicle dynamics simulations.

    PubMed

    Stine, Jason S; Hamblin, Bridget C; Brennan, Sean N; Donnell, Eric T

    2010-11-01

    Although vehicle dynamics simulations have long been used in vehicle design and crash reconstruction, their use for highway design is rare. This paper investigates the safety of highway medians through iterative simulations of off-road median encroachments. The commercially available software CarSim was used to simulate over one hundred thousand encroachments, representing the entire passenger vehicle fleet and a wide range of encroachment angles, departure speeds, steering inputs, and braking inputs. Each individual simulation output was then weighted using data from previous studies to reflect the probability of each specific accident scenario occurring in a real-life median encroachment. Results of this analysis illustrate the relative influence of median cross-section geometry on the resulting accident outcomes. The simulations indicate that the overall safety of a highway median depends on the occurrence of both vehicle rollover and median crossover events, and the cross-section shape, slope, and width are all shown to greatly affect each of these incidents. An evaluation of the simulation results was conducted with vehicle trajectories from previous experimental crash tests. Further assessment of the aggregate simulation results to actual crash data was achieved through comparison with several databases of crash statistics. Both efforts showed a strong agreement between the simulations and the real-life crash data.

  2. Association between vertebral cross-sectional area and lumbar lordosis angle in adolescents

    PubMed Central

    Aggabao, Patricia C.; Poorghasamians, Ervin; Chavez, Thomas A.

    2017-01-01

    Lumbar lordosis (LL) is more prominent in women than in men, but the mechanisms responsible for this discrepancy are poorly defined. A recent study indicates that newborn girls have smaller vertebral cross-sectional area (CSA) when compared to boys—a difference that persists throughout life and is independent of body size. We determined the relations between vertebral cross-sectional area (CSA) and LL angle and whether sex differences in lumbar lordosis are related to sex differences in vertebral CSA. Using multi-planar magnetic resonance imaging (MRI), we measured vertebral cross-sectional area (CSA) and vertebral height of the spine of 40 healthy boys and 40 girls, ages 9–13 years. Measures of the CSA of the lumbar vertebrae significantly differed between sexes (9.38 ± 1.46 vs. 7.93 ± 0.69 in boys and girls, respectively; P < 0.0001), while the degree of LL was significantly greater in girls than in boys (23.7 ± 6.1 vs. 27.6 ± 8.0 in boys and girls, respectively; P = 0.02). When all subjects were analyzed together, values for LL angle were negatively correlated to vertebral CSA (r = -0.47; P < 0.0001); this was also true when boys and girls were analyzed separately. Multivariate regression analysis indicated that vertebral CSA was independently associated with LL, even after accounting for sex, age, height or vertebral height, and weight. Similar negative relations were present when thoracic vertebrae were analyzed (Model P < 0.0001, R2 = 0.37, thoracic vertebral CSA slope P < 0.0001), suggesting that deficient vertebral cross-sectional dimensions are not merely the consequence of the anterior lumbar curvature. We conclude that vertebral CSA is negatively associated with LL, and that the greater degree of LL in females could, at least in part, be due to smaller vertebral cross-sectional dimensions. Studies are needed to examine the potential relations between vertebral CSA and spinal conditions known to be associated with increased LL, such as

  3. Association between vertebral cross-sectional area and lumbar lordosis angle in adolescents.

    PubMed

    Wren, Tishya A L; Aggabao, Patricia C; Poorghasamians, Ervin; Chavez, Thomas A; Ponrartana, Skorn; Gilsanz, Vicente

    2017-01-01

    Lumbar lordosis (LL) is more prominent in women than in men, but the mechanisms responsible for this discrepancy are poorly defined. A recent study indicates that newborn girls have smaller vertebral cross-sectional area (CSA) when compared to boys-a difference that persists throughout life and is independent of body size. We determined the relations between vertebral cross-sectional area (CSA) and LL angle and whether sex differences in lumbar lordosis are related to sex differences in vertebral CSA. Using multi-planar magnetic resonance imaging (MRI), we measured vertebral cross-sectional area (CSA) and vertebral height of the spine of 40 healthy boys and 40 girls, ages 9-13 years. Measures of the CSA of the lumbar vertebrae significantly differed between sexes (9.38 ± 1.46 vs. 7.93 ± 0.69 in boys and girls, respectively; P < 0.0001), while the degree of LL was significantly greater in girls than in boys (23.7 ± 6.1 vs. 27.6 ± 8.0 in boys and girls, respectively; P = 0.02). When all subjects were analyzed together, values for LL angle were negatively correlated to vertebral CSA (r = -0.47; P < 0.0001); this was also true when boys and girls were analyzed separately. Multivariate regression analysis indicated that vertebral CSA was independently associated with LL, even after accounting for sex, age, height or vertebral height, and weight. Similar negative relations were present when thoracic vertebrae were analyzed (Model P < 0.0001, R2 = 0.37, thoracic vertebral CSA slope P < 0.0001), suggesting that deficient vertebral cross-sectional dimensions are not merely the consequence of the anterior lumbar curvature. We conclude that vertebral CSA is negatively associated with LL, and that the greater degree of LL in females could, at least in part, be due to smaller vertebral cross-sectional dimensions. Studies are needed to examine the potential relations between vertebral CSA and spinal conditions known to be associated with increased LL, such as spondylolysis

  4. Physical activity and self-reported health status among adolescents: a cross-sectional population-based study

    PubMed Central

    Galán, I; Boix, R; Medrano, M J; Ramos, P; Rivera, F; Pastor-Barriuso, R; Moreno, C

    2013-01-01

    Objectives Little is known about the dose–response relationship between physical activity and health benefits among young people. Our objective was to analyse the association between the frequency of undertaking moderate-to-vigorous physical activity (MVPA) and the self-reported health status of the adolescent population. Design Cross-sectional study. Setting All regions of Spain. Participants Students aged 11–18 years participating in the Spanish Health Behaviour in School-aged Children survey 2006. A total of 375 schools and 21 188 students were selected. Main outcomes The frequency of undertaking MVPA was measured by a questionnaire, with the following four health indicators: self-rated health, health complaints, satisfaction with life and health-related quality of life. Linear and logistic regression models were used to analyse the association, adjusting for potential confounding variables and the modelling of the dose–response relationship. Results As the frequency of MVPA increased, the association with health benefits was stronger. A linear trend (p<0.05) was found for self-rated health and health complaints in males and females and for satisfaction with life among females; for health-related quality of life this relationship was quadratic for both sexes (p<0.05). For self-reported health and health complaints, the effect was found to be of greater magnitude in males than in females and, in all scales, the benefits were observed from the lowest frequencies of MVPA, especially in males. Conclusions A protective effect of MVPA was found in both sexes for the four health indicators studied, and this activity had a gradient effect. Among males, health benefits were detected from very low levels of physical activity and the magnitude of the relationship was greater than that for females. PMID:23676798

  5. Mental Health Needs in Adolescents with Intellectual Disabilities: Cross-Sectional Survey of a Service Sample

    ERIC Educational Resources Information Center

    Hassiotis, A.; Turk, J.

    2012-01-01

    Background: Little research has been conducted on the mental health needs of adolescents with intellectual disability, despite the severity and rates of such needs being high throughout childhood and in adulthood. We have investigated the prevalence and predictors of mental health needs and service use in adolescents with intellectual…

  6. Health effects of perceived racial and religious bullying among urban adolescents in China: a cross-sectional national study.

    PubMed

    Pan, Stephen W; Spittal, Patricia M

    2013-07-01

    Research concerning ethnocultural bullying and adolescent health in China remains extremely limited. This study among Chinese urban adolescents examines associations between ethnocultural bullying and eight health-related outcomes: suicidal ideation, suicide planning, depressive symptomology, anxiety symptomatology, fighting, injury intentionally inflicted by another, smoking and moderate/heavy alcohol consumption. Data were obtained from the World Health Organisation's 2003 Chinese Global School-based Health Survey, a cross-sectional national survey of urban adolescents in four Chinese cities. The analytic sample size was n = 8182, which represented a sampling frame of 769,835 adolescents. Statistical analysis was conducted using generalised linear mixed effects models and sampling weights. Prevalence of ethnocultural bullying was significantly higher in Urumqi, Xinjiang province (2.08%) compared with Beijing municipality (0.72%) or Wuhan, Hubei province (0.67%). Compared to participants who were not bullied, religious bullying victimisation was significantly associated with suicidal ideation, injury intentionally inflicted by another and depressive symptomology. Racial bullying victimisation was significantly associated with suicidal ideation, injury intentionally inflicted by another and among females but not males, depressive symptomology. Health effects of ethnocultural bullying appear to be distinct from that of bullying in general. Additional research on ethnocultural adolescent health issues in China is warranted.

  7. Recruiting Chinese American adolescents to HIV/AIDS-related research: a lesson learned from a cross-sectional study.

    PubMed

    Lee, Yi-Hui; Salman, Ali; Wang, Fan

    2012-02-01

    The purpose of this article was to report identified barriers and challenges experienced in the recruiting process of Chinese American adolescents to a cross-sectional HIV/AIDS-related study. Snowball sampling method was used to recruit Chinese American adolescents from Chinese American communities in a U.S. Midwestern state. Barriers and challenges to recruitment were reviewed and analyzed from Chinese cultural perspectives in the hope of aiding researchers and health care providers understand and facilitate future recruitment of Chinese Americans for HIV/AIDS prevention studies. Barriers to recruitment were found related to the taboo topic of sexual issues in Chinese culture, unawareness and denial of HIV/AIDS risks, authoritarian parenting style in Chinese culture, and the required active consents. Facilitating factors of recruiting Chinese American adolescents to future HIV/AIDS prevention research or intervention programs are discussed. Information provided in this article may increase nurses' awareness of various barriers that they might encounter when they conduct research or address HIV/AIDS-related topics of Chinese American adolescents.

  8. Implicit self-esteem decreases in adolescence: a cross-sectional study.

    PubMed

    Cai, Huajian; Wu, Mingzheng; Luo, Yu L L; Yang, Jing

    2014-01-01

    Implicit self-esteem has remained an active research topic in both the areas of implicit social cognition and self-esteem in recent decades. The purpose of this study is to explore the development of implicit self-esteem in adolescents. A total of 599 adolescents from junior and senior high schools in East China participated in the study. They ranged in age from 11 to 18 years with a mean age of 14.10 (SD = 2.16). The degree of implicit self-esteem was assessed using the Implicit Association Test (IAT) with the improved D score as the index. Participants also completed the Rosenberg Self-Esteem Scale (α = 0.77). For all surveyed ages, implicit self-esteem was positively biased, all ts>8.59, all ps<0.001. The simple correlation between implicit self-esteem and age was significant, r =  -.25, p = 1. 10(-10). A regression with implicit self-esteem as the criterion variable, and age, gender, and age × gender interaction as predictors further revealed the significant negative linear relationship between age and implicit self-esteem, β = -0.19, t = -3.20, p = 0.001. However, explicit self-esteem manifested a reverse "U" shape throughout adolescence. Implicit self-esteem in adolescence manifests a declining trend with increasing age, suggesting that it is sensitive to developmental or age-related changes. This finding enriches our understanding of the development of implicit social cognition.

  9. Loneliness, Depressive Symptomatology, and Suicide Ideation in Adolescence: Cross-Sectional and Longitudinal Analyses

    ERIC Educational Resources Information Center

    Lasgaard, Mathias; Goossens, Luc; Elklit, Ask

    2011-01-01

    The paper presents the first known longitudinal study of the relationship between loneliness, depressive symptoms, and suicide ideation in adolescence, in a stratified sample of high school students (Time 1 N = 1009; 57% female; Time 2 N = 541; 60% female). Cross-lagged structural equation modeling indicated that depressive symptoms led to more…

  10. Where science meets policy: comparing longitudinal and cross-sectional designs to address diarrhoeal disease burden in the developing world

    PubMed Central

    Markovitz, Amanda R; Goldstick, Jason E; Levy, Karen; Cevallos, William; Mukherjee, Bhramar; Trostle, James A; Eisenberg, Joseph N S

    2012-01-01

    Background Longitudinal studies are considered preferable to cross-sectional studies for informing public health policy. However, when resources are limited, the trade-off between an accurate cross-section of the population and an understanding of the temporal variation should be optimized. When risk factors vary more across space at a fixed moment in time than at a fixed location across time, cross-sectional studies will tend to give more precise estimates of risk factor effects and thus may be a better source of data for policy judgments. Methods We conducted a diarrhoeal disease surveillance of 5616 individuals within 19 Ecuadorian villages. This data set was used to mimic cross-sectional and longitudinal studies by restricting focus to a single week and a single village, respectively. We compared the variability in risk factor effect estimates produced from each type of study. Results For household risk factors, the effect estimates produced by the longitudinal studies were more variable than their cross-sectional counterparts, which can be explained by greater spatial than temporal variability in the risk factor distribution. For example, the effect estimate of improved sanitation was almost twice as variable in longitudinal studies. Conclusions In our study, cross-sectional designs yielded more consistent evaluations of diarrhoea disease risk factors when those factors varied more between villages than over time. Cross-sectional studies can provide information that is representative across large geographic regions and therefore can provide insight for local, regional and national policy decisions. The value of the cross-sectional study should be reconsidered in the public health community. PMID:22253314

  11. Depression and Associated Factors among Adolescent Females in Riyadh, Kingdom of Saudi Arabia, A Cross-sectional Study

    PubMed Central

    Raheel, Hafsa

    2015-01-01

    Background: Adolescents who suffer from depression early in life, have an increase in suicidal tendency, anxiety, conduct disorders, substance abuse, and continue to be depressed, later on in life. This study was conducted to identify the prevalence and correlates of depression among adolescent girls in Riyadh city in order to carry out early intervention. Methods: A cross-sectional, school-based survey was conducted among 1028 adolescent girls aged 15–19 years in secondary schools of Riyadh city. Riyadh was divided into clusters and within each cluster, both public and private schools were enrolled. From the selected schools students from grade 10–12 were surveyed. Survey was conducted using a structured questionnaire including the beck depression inventory-II, and questions exploring the correlates of depression. Results: About 30% of participants were found to be depressed. Depression was more prevalent among female adolescents whose household income was <12,000 Saudi Riyal/month (odds ratio [OR] 2.17, confidence interval [CI] 0.97–6.84), did not have a good relationship with peers and family members (OR 4.63, CI 2.56–8.41), lived with single parent or alone (OR 1.77, CI 0.97–3.23), been emotionally abused (OR 3.45, CI 2.56–8.41), and those who had been subjected to physical violence, at least once (OR 3.34, CI 1.89–5.91). Conclusions: Strategies need to be developed to identify early signs and symptoms of depression among Saudi female adolescents. Training can be given to groups of students to help their peers, and also to the teachers to identify, and help students identify early signs of depression and provide them with better-coping strategies to combat progression of depression and anxiety among such adolescents. PMID:26445637

  12. The Worldwide Association between Television Viewing and Obesity in Children and Adolescents: Cross Sectional Study

    PubMed Central

    Braithwaite, Irene; Stewart, Alistair W.; Hancox, Robert J.; Beasley, Richard; Murphy, Rinki; Mitchell, Edwin A.

    2013-01-01

    Background Studies exploring the effect of television viewing on obesity throughout childhood are conflicting. Most studies have been confined to single high-income countries. Our aim was to examine the association between television viewing habits and Body Mass Index (BMI) in adolescents and children in a multicentre worldwide sample. Methods In the International Study of Asthma and Allergies in Children Phase Three, adolescents aged between 12 and 15 years completed questionnaires which included questions on television viewing habits, height and weight. Parents/guardians of children aged between 5 and 8 years completed the same questionnaire on behalf of their children. The questionnaire asked “During a normal week, how many hours a day (24 hours) do you (does your child) watch television?” Responses were categorised as; “short” (<1 hour), “moderate” (1 to ≤3 hours), “long” (3 to ≤5 hours) and “prolonged” (>5 hours). Findings 207,672 adolescents from 37 countries and 77,003 children from 18 countries provided data. Daily television viewing in excess of one hour was reported in 89% of adolescents and 79% of children. Compared with adolescents in the short viewing group, those in the moderate, long and prolonged groups had BMIs that were 0.14 kg/m2, 0.21 kg/m2, 0.30 kg/m2 and 0.08 kg/m2, 0.16 kg/m2 and 0.17 kg/m2 larger for females and males respectively (both P<0.001). Compared with children in the short viewing group, those in the moderate, long and prolonged groups had BMIs that were 0.24 kg/m2, 0.34 kg/m2, 0.36 kg/m2 and 0.19 kg/m2, 0.32 kg/m2 and 0.36 kg/m2 larger for females and males respectively (both P<0.001). Interpretation Increased television viewing hours were positively associated with BMI in both adolescents and children with an apparent dose response effect. These findings extend the evidence that television viewing contributes to increased BMI in childhood. PMID:24086327

  13. Health effects of family size: cross sectional survey in Chinese adolescents

    PubMed Central

    Hesketh, T; Qu, J; Tomkins, A

    2003-01-01

    Aims: To determine whether only children differ in terms of morbidity, nutritional status, risk behaviours, and utilisation of health services from children with siblings, in China. Methods: A cross sectional survey was carried out using self completion questionnaires, anthropometry, and haemoglobin measurement in middle schools (predominant age 12–16 years) in three distinct socioeconomic areas of Zhejiang province, eastern China. Results: Data were obtained for 4197 participants. No significant differences were found between only children and those with siblings for some key indicators: underweight 19% v 18%, suicide ideation 14% v 14%, and ever smoking 17% v 15%. Only children were more likely to be overweight (4.8% v 1.5%), and to have attended a doctor (71% v 63%) or dentist (17% v 10%) in the past year. Sibling children are significantly more likely to be anaemic (42% v 32%) and to admit to depression (41% v 21%) or anxiety (45% v 37%). However, after adjusting for area, sex, and parental education levels only two differences remained: sibling children are more likely to be bullied (OR 1.5, 1.1–2.0; p = 0.006) and are less likely to confide in parents (OR 0.6, 0.3–0.8, p = 0.009). There were no significant differences in the key parameters between first and second born children. Conclusions: We found no detrimental effects of being an only child using the indicators measured. Being an only child may confer some benefits, particularly in terms of socialisation. PMID:12765907

  14. Correspondence between theoretical models and dual energy x-ray absorptiometry measurements of femoral cross-sectional growth during adolescence

    NASA Technical Reports Server (NTRS)

    van der Meulen, M. C.; Marcus, R.; Bachrach, L. K.; Carter, D. R.

    1997-01-01

    We have developed an analytical model of long bone cross-sectional ontogeny in which appositional growth of the diaphysis is primarily driven by mechanical stimuli associated with increasing body mass during growth and development. In this study, our goal was to compare theoretical predictions of femoral diaphyseal structure from this model with measurements of femoral bone mineral and geometry by dual energy x-ray absorptiometry. Measurements of mid-diaphyseal femoral geometry and structure were made previously in 101 Caucasian adolescents and young adults 9-26 years of age. The data on measured bone mineral content and calculated section modulus were compared with the results of our analytical model of cross-sectional development of the human femur over the same age range. Both bone mineral content and section modulus showed good correspondence with experimental measurements when the relationships with age and body mass were examined. Strong linear relationships were evident for both parameters when examined as a function of body mass.

  15. Adolescents' leisure activities, parental monitoring and cigarette smoking - a cross-sectional study

    PubMed Central

    2011-01-01

    Background Adolescent participation in leisure activities is developmentally beneficial, but certain activities may increase health compromising behaviours, such as tobacco smoking. A limited range of leisure activities has been studied, with little research on out-of-school settings where parental supervision is a potential protective factor. Tobacco smoking is an important, potentially modifiable health determinant, so understanding associations between adolescent leisure activities, parental monitoring, demographic factors and daily smoking may inform preventive strategies. These associations are reported for a New Zealand adolescent sample. Methods Randomly selected schools (n = 145) participated in the 2006 Youth In-depth Survey, a national, biennial study of Year 10 students (predominantly 14-15 years). School classes were randomly selected and students completed a self-report questionnaire in class time. Adjustment for clustering at the school level was included in all analyses. Since parental monitoring and demographic variables potentially confound relations between adolescent leisure activities and smoking, variables were screened before multivariable modelling. Given prior indications of demographic differences, gender and ethnic specific regression models were built. Results and Discussion Overall, 8.5% of the 3,161 students were daily smokers, including more females (10.5%) than males (6.5%). In gender and ethnic specific multivariate analysis of associations with daily smoking (adjusted for age, school socioeconomic decile rating, leisure activities and ethnicity or gender, respectively), parental monitoring exhibited a consistently protective, dose response effect, although less strongly among Māori. Attending a place of worship and going to the movies were protective for non-Māori, as was watching sports, whereas playing team sport was protective for all, except males. Attending a skate park was a risk factor for females and Māori which

  16. Psychological reactions of adolescent schoolgirls to human papillomavirus vaccination in western Uganda: A comparative cross-sectional study.

    PubMed

    Turiho, Andrew Kampikaho; Okello, Elialilia S; Muhwezi, Wilson W; Nakasujja, Noeline; Katahoire, Anne R

    2015-07-01

    Schoolgirls in two Ugandan districts were recently vaccinated against human papillomavirus that causes most cervical cancer. This cross-sectional comparative study used mixed research methods to assess influence of human papillomavirus vaccination on adolescents' worrisome thoughts about being vaccinated and psychological distress. Vaccination predicted worrisome thoughts among the recently vaccinated (adjusted odds ratio: 1.65, confidence interval: 1.13-2.41; p = 0.01). Vaccination predicted distress (1.75, confidence interval: 1.09-2.82; p = 0.02), particularly among those recently vaccinated (1.92, confidence interval: 1.27-2.89; p = 0.001) and those who experienced worrisome thoughts (1.80, confidence interval: 1.06-3.07; p = 0.02). Parental communication mitigated distress (0.50, confidence interval: 0.35-0.72; p = 0.000).

  17. Does exposure to cigarette brands increase the likelihood of adolescent e-cigarette use? A cross-sectional study

    PubMed Central

    van der Sluijs, W; Haseen, F; Eadie, D; Stead, M; MacKintosh, AM; Pearce, J; Tisch, C; MacGregor, A; Amos, A; Miller, M; Frank, J; Haw, S

    2016-01-01

    Objective To examine the relationship between tobacco cigarette brand recognition, and e-cigarette use in adolescents. Design Cross-sectional observational study. Setting High schools in Scotland. Participants Questionnaires were administered to pupils in Secondary 2 (S2 mean age: 14.0 years) and Secondary 4 (S4 mean age: 15.9 years) across 4 communities in Scotland. An 86% response rate with a total sample of 1404 pupils was achieved. Main outcome measures Self-reported previous use of e-cigarettes and self-reported intention to try e-cigarettes in the next 6 months. Results 75% (1029/1377) of respondents had heard of e-cigarettes (69.5% S2, 81.1% S4), and of these, 17.3% (10.6% S2, 24.3% S4 n=1020) had ever tried an e-cigarette. 6.8% (3.7% S2, 10.0% S4 n=1019) reported that they intended to try an e-cigarette in the next 6 months. Recognition of more cigarette brands was associated with greater probability of previous e-cigarette use (OR 1.20, 99% CI 1.05 to 1.38) as was having a best friend who smoked (OR 3.17, 99% CI 1.42 to 7.09). Intention to try e-cigarettes was related to higher cigarette brand recognition (OR 1.41, 99% CI 1.07 to 1.87), hanging around in the street or park more than once a week (OR 3.78, 99% CI 1.93 to 7.39) and living in areas of high tobacco retail density (OR 1.20, 99% CI 1.08 to 1.34). Never having smoked was a protective factor for both future intention to try, and past e-cigarette use (OR 0.07, 99% CI 0.02 to 0.25; and OR 0.10, 99% CI 0.07 to 0.16, respectively). Conclusions Higher cigarette brand recognition was associated with increased probability of previous use and of intention to use e-cigarettes. The impact of tobacco control measures such as restricting point-of-sale displays on the uptake of e-cigarettes in young people should be evaluated. PMID:26908512

  18. Human Papillomavirus (HPV) Vaccination and Adolescent Girls' Knowledge and Sexuality in Western Uganda: A Comparative Cross-Sectional Study

    PubMed Central

    Turiho, Andrew Kampikaho

    2015-01-01

    The purpose of the study was to investigate the influence of human papillomavirus (HPV) vaccination on adolescent girls’ knowledge of HPV and HPV vaccine, perception of sexual risk and intentions for sexual debut. This cross-sectional comparative study was conducted in Ibanda and Mbarara districts. Data was collected using a standardized self-administered questionnaire and analyzed using the Statistical Package for the Social Sciences computer software. Univariate, bivariate, and logistic regression analyses were conducted with significance level set at p < .05. Results showed that HPV vaccination was associated with being knowledgeable (Crude OR: 5.26, CI: 2.32–11.93; p = 0.000). Vaccination against HPV did not predict perception of sexual risk. Knowledge was low (only 87/385 or 22.6% of vaccinated girls were knowledgeable), but predicted perception of a high sexual risk (Adjusted OR: 3.12, CI: 1.37–3.63; p = 0.008). HPV vaccination, knowledge and perceived sexual risk did not predict sexual behaviour intentions. High parental communication was associated with adolescent attitudes that support postponement of sexual debut in both bivariate and multiple regression analyses. In conclusion, findings of this study suggest that HPV vaccination is not likely to encourage adolescent sexual activity. Influence of knowledge on sexual behaviour intentions was not definitively explained. Prospective cohort studies were proposed to address the emerging questions. PMID:26327322

  19. Human Papillomavirus (HPV) Vaccination and Adolescent Girls' Knowledge and Sexuality in Western Uganda: A Comparative Cross-Sectional Study.

    PubMed

    Turiho, Andrew Kampikaho; Muhwezi, Wilson Winston; Okello, Elialilia Sarikiaeli; Tumwesigye, Nazarius Mbona; Banura, Cecil; Katahoire, Anne Ruhweza

    2015-01-01

    The purpose of the study was to investigate the influence of human papillomavirus (HPV) vaccination on adolescent girls' knowledge of HPV and HPV vaccine, perception of sexual risk and intentions for sexual debut. This cross-sectional comparative study was conducted in Ibanda and Mbarara districts. Data was collected using a standardized self-administered questionnaire and analyzed using the Statistical Package for the Social Sciences computer software. Univariate, bivariate, and logistic regression analyses were conducted with significance level set at p < .05. Results showed that HPV vaccination was associated with being knowledgeable (Crude OR: 5.26, CI: 2.32-11.93; p = 0.000). Vaccination against HPV did not predict perception of sexual risk. Knowledge was low (only 87/385 or 22.6% of vaccinated girls were knowledgeable), but predicted perception of a high sexual risk (Adjusted OR: 3.12, CI: 1.37-3.63; p = 0.008). HPV vaccination, knowledge and perceived sexual risk did not predict sexual behaviour intentions. High parental communication was associated with adolescent attitudes that support postponement of sexual debut in both bivariate and multiple regression analyses. In conclusion, findings of this study suggest that HPV vaccination is not likely to encourage adolescent sexual activity. Influence of knowledge on sexual behaviour intentions was not definitively explained. Prospective cohort studies were proposed to address the emerging questions.

  20. Cross-sectional reference values of upper arm anthropometry of the Khasi tribal adolescents of Meghalaya, India.

    PubMed

    Basu, Debashis; Sun, Deimaphishisha; Banerjee, Indraneel; Singh, Y Momo; Kalita, Jennifer G; Rao, Vadlamudi Raghavendra

    2010-01-01

    The Khasi tribal people in India with their distinct ethnic identity have relative geographic isolation from the rest of the country. Although chronic energy deficiency has been documented in this population, their nutritional status has not been re-evaluated following a decade of economic growth in India. In this study, the nutritional status of an ethno-homogenous sample of contemporary Khasi tribal adolescent cohort of age 11+ to 17+ years in the state of Meghalaya, India has been assessed by cross sectional analysis. This was achieved through the use of the following derived anthropometric measurements - total upper arm area (TUA), upper arm muscle area (UMA), upper arm fat area (UFA), and arm fat index (AFI). A total of 670 adolescents (335 boys; 335 girls) participated in this study. In comparison with North American NHANES 1999-2002 standards, UMA, a measure of upper arm muscle mass, was lower at all age groups in Khasi girls. Conversely, in Khasi boys, AFI, a marker of upper arm fat mass was lower at all age groups, thereby showing a gender dimorphic difference in upper limb muscle and fat proportions. We conclude that in upper arm indirect anthropometry, contemporary Khasi adolescent children remain nutritionally deficient with gender dimorphic muscle and fat proportions.

  1. Descriptive epidemiology of screen and non-screen sedentary time in adolescents: a cross sectional study

    PubMed Central

    2010-01-01

    Background Much attention has been paid to adolescents' screen time, however very few studies have examined non-screen sedentary time (NSST). This study aimed to (1) describe the magnitude and composition of screen sedentary time (SST) and NSST in Australian adolescents, (2) describe the socio-demographic correlates of SST and NSST, and (3) determine whether screen time is an adequate surrogate for total sedentary behaviour in this population. Methods 2200 9-16 year old Australians provided detailed use of time data for four days. Non-screen sedentary time (NSST) included time spent participating in activities expected to elicit <3 METs whilst seated or lying down (other than sleeping), excluding screen-based activities (television, playing videogames or using computers). Total sedentary time was the sum of screen time and NSST. Results Adolescents spent a mean (SD) of 345 (105) minutes/day in NSST, which constituted 60% of total sedentary time. School activities contributed 42% of NSST, socialising 19%, self-care (mainly eating) 16%, and passive transport 15%. Screen time and NSST showed opposite patterns in relation to key socio-demographic characteristics, including sex, age, weight status, household income, parental education and day type. Because screen time was negatively correlated with NSST (r = -0.58), and exhibited a moderate correlation (r = 0.53) with total sedentary time, screen time was only a moderately effective surrogate for total sedentary time. Conclusions To capture a complete picture of young people's sedentary time, studies should endeavour to measure both screen time and NSST. PMID:21194427

  2. Socioeconomic disparities in coverage of full immunisation among children of adolescent mothers in India, 1990–2006: a repeated cross-sectional analysis

    PubMed Central

    Kumar, Chandan; Singh, Prashant Kumar; Singh, Lucky; Rai, Rajesh Kumar

    2016-01-01

    Objective Studies have highlighted that children of adolescent (aged 15–19 years) mothers are likely to receive relatively poor healthcare. With an unacceptably high adolescent birth rate, India houses the highest number of adolescent mothers globally, putting children at risk of inadequate vaccination. This paper assesses trends and extent of socioeconomic disparities in the coverage of full immunisation among children of adolescent mothers in India. Design Repeated cross-sectional analytical study. Data sources 3 consecutive rounds of the National Family Health Survey (NFHS) conducted during 1992–1993, 1998–1999 and 2005–2006 were used. Besides, the required information is also extracted from the 2011 Indian Census. Participants Children (aged 12–23 months) of adolescent (aged 15–19 years) mothers. Sample inclusion criteria involved the last child of the adolescent eligible to avail full immunisation. Setting Nationally representative sample. Data analysis The Cochran-Armitage test, χ2 test and binary logistic regression methods were applied to attain the study objective. Results Between 1990 and 2006, a non-significant increase of 4 percentage points in full immunisation of children of adolescent mothers was estimated. During the same period, a large difference between the probability of children of adolescent mothers receiving full immunisation belonging to the least (predicted probability (PP): 0.196 in 1990–1993, and PP: 0.213 in 2003–2006) and the most (PP: 0.589 in 1990–1993, and PP: 0.645 in 2003–2006) socioeconomically privileged group was estimated, and this disparity persisted over the survey period. Conclusions During 1990–2006, an insufficient improvement in provision of full immunisation to children born to adolescent mothers was recorded. The study underscored the suboptimum immunisation of rural, illiterate and poor children of adolescent women. The programme and policymakers could focus on district-wise concentration

  3. Victimization After Meeting With Online Acquaintances: A Cross-Sectional Survey of Adolescents in Malaysia.

    PubMed

    Marret, Mary J; Choo, Wan-Yuen

    2016-01-18

    This study aimed to determine contact and privacy risks encountered by Malaysian adolescents with access to the Internet and mobile phones and factors associated with face-to-face meetings with online acquaintances as well as to estimate the prevalence of subsequent victimization. Secondary school students from randomly selected public schools in Selangor and Kuala Lumpur responded to an anonymous self-administered questionnaire (78% response rate). Out of 3,349 Internet or mobile phone users, 51% had been invited to meet offline with an online-meeting acquaintance and 30% complied. Of the 1,005 respondents who went to offline meetings, 55% had meetings with more than six people. Male gender, Malay ethnicity, online access at an Internet café, viewing pornography on the Internet, the absence of parental restrictions on visiting certain website and chat rooms, not being explicitly forbidden to meet strangers encountered online, and disclosure of personal information were significantly associated with increased odds of face-to-face meetings with online acquaintances. Verbal, physical, or sexual assaults were reported by 5.5% of the 1,005 including 13 males and five females who reported forced sexual intercourse. Similarities as well as differences in factors associated with risk-taking behavior compared with adolescents in Western countries have important implications on policy and intervention.

  4. Eating attitudes and food intakes of elite adolescent female figure skaters: a cross sectional study

    PubMed Central

    2012-01-01

    Background Elite adolescent female figure skaters compete in an aesthetic-based sport that values thin builds and lithe figures. To conform to the sport’s physical requirements, skaters may alter their eating patterns in unhealthful directions. This study assesses the eating attitudes and dietary intakes of elite adolescent female figure skaters to assess the potential nutritional risks among them. Methods Thirty-six elite competitive adolescent female figure skaters (mean age 16 ± 2.5 SD years) completed self-administered three-day records of dietary intake and simultaneous physical activity records during training season. Two months later, they attended a national training camp during which they completed the Eating Attitudes Test (EAT-40), provided fasting blood samples, and had heights and weights measured. Results Participants’ mean body mass index (BMI) was 19.8 ± 2.1 SD. Their BMIs were within the normal range, and the majority (70%) did not report a history of recent weight loss. The mean EAT-40 score was normal (19.5 ± 13.5 SD) and below the cut-off score of 30 that indicates clinically significant eating pathology. However, one-quarter of the skaters had EAT-40 scores above 30. The skaters reported a mean energy intake of 1491 ± 471 SD kcal/day (31 ± 10 SD kcal/kg), with 61.6% of calories from carbohydrate, 14.6% from protein, and 23.7% from fat. Their reported dietary intakes were high in carbohydrates but low in total energy, fat, and bone-building nutrients. Conclusions Although these highly active young women compete in a sport that prizes leanness, they had appropriate weights. The athletes reported dietary intakes that were far below estimated energy needs and were at moderate risk of disordered eating. Anticipatory guidance is warranted to improve their dietary intakes, particularly of bone-building nutrients. PMID:23237333

  5. Sedentary behaviours and its association with bone mass in adolescents: the HELENA cross-sectional study

    PubMed Central

    2012-01-01

    Background We aimed to examine whether time spent on different sedentary behaviours is associated with bone mineral content (BMC) in adolescents, after controlling for relevant confounders such as lean mass and objectively measured physical activity (PA), and if so, whether extra-curricular participation in osteogenic sports could have a role in this association. Methods Participants were 359 Spanish adolescents (12.5-17.5 yr, 178 boys,) from the HELENA-CSS (2006–07). Relationships of sedentary behaviours with bone variables were analysed by linear regression. The prevalence of low BMC (at least 1SD below the mean) and time spent on sedentary behaviours according to extracurricular sport participation was analysed by Chi-square tests. Results In boys, the use of internet for non-study was negatively associated with whole body BMC after adjustment for lean mass and moderate to vigorous PA (MVPA). In girls, the time spent studying was negatively associated with femoral neck BMC. Additional adjustment for lean mass slightly reduced the negative association between time spent studying and femoral neck BMC. The additional adjustment for MVPA did not change the results at this site. The percentage of girls having low femoral neck BMC was significantly smaller in those participating in osteogenic sports (≥ 3 h/week) than in the rest, independently of the cut-off selected for the time spent studying. Conclusions The use of internet for non-study (in boys) and the time spent studying (in girls) are negatively associated with whole body and femoral neck BMC, respectively. In addition, at least 3 h/week of extra-curricular osteogenic sports may help to counteract the negative association of time spent studying on bone health in girls. PMID:23148760

  6. Reproductive health knowledge and services utilization among rural adolescents in east Gojjam zone, Ethiopia: a community-based cross-sectional study

    PubMed Central

    2014-01-01

    Background According to World Health Organization, adolescents are people between 10 and 19 years of age; one-fifth of Ethiopian population constitutes adolescents and four-fifth live in rural areas. Local evidence about adolescents’ reproductive health knowledge, services utilization and associated factors are relevant to design age-appropriate program interventions and strategies. Hence, this study assessed the level of reproductive health knowledge and services utilization among rural adolescents in Machakel district, Northwest Ethiopia. Methods A community-based cross-sectional study was conducted to assess the level of reproductive health knowledge and services utilization of rural adolescents in Machakel district. The study employed both quantitative and qualitative methods. A systematic random sampling technique was used to select 415 adolescents from eligible households. Data were collected using pre-tested structured questionnaires and in-depth interview guides. The data were entered into Epi Info and analyzed by SPSS software for windows. Univariate, bivariate and multivariate analyses were done. Result More than two-third (67%) of the adolescents had knowledge about reproductive health. Age (AOR = 3.77, 95% CI: 3.1-8.98), living arrangement (AOR = 2.21, 95% CI: 1.81-6.04) and economic status (AOR = 3.37, 95% CI: 1.65-6.87) were associated with reproductive health knowledge. However, only one-fifth (21.5%) of the adolescents had ever used reproductive health services including family planning, sexually transmitted infections treatment and information, education and communication. Reproductive health services utilization was significantly associated with age (AOR = 2.18, 95% CI: 1.13-8.03) and knowledge for reproductive health (AOR = 1.23, 95% CI: 1.23-4.21). Parent disapproval, lack of basic information and pressure from partners were found to deter adolescents from accessing and using reproductive health services. Conclusion

  7. Insulin resistance in adolescents with Down syndrome: a cross-sectional study

    PubMed Central

    Fonseca, Cristina T; Amaral, Daniela M; Ribeiro, Márcia G; Beserra, Izabel CR; Guimarães, Marília M

    2005-01-01

    Background The prevalence of diabetes mellitus is higher in individuals with Down syndrome (DS) than in the general population; it may be due to the high prevalence of obesity presented by many of them. The aim of this study was to evaluate the insulin resistance (IR) using the HOMA (Homeostasis Model Assessment) method, in DS adolescents, describing it according to the sex, body mass index (BMI) and pubertal development. Methods 15 adolescents with DS (8 males and 7 females) were studied, aged 10 to 18 years, without history of disease or use of medication that could change the suggested laboratory evaluation. On physical examination, the pubertal signs, acanthosis nigricans (AN), weight and height were evaluated. Fasting plasma glucose and insulin were analysed by the colorimetric method and RIA-kit LINCO, respectively. IR was calculated using the HOMA method. The patients were grouped into obese, overweight and normal, according to their BMI percentiles. The EPIINFO 2004 software was used to calculate the BMI, its percentile and Z score. Results Five patients were adults (Tanner V or presence of menarche), 9 pubertal (Tanner II – IV) and 1 prepubertal (Tanner I). No one had AN. Two were obese, 4 overweight and 9 normal. Considering the total number of patients, HOMA was 1.7 ± 1.0, insulin 9.3 ± 4.8 μU/ml and glucose 74.4 ± 14.8 mg/dl. The HOMA values were 2.0 ± 1.0 in females and 1.5 ± 1.0 in males. Considering the nutritional classification, the values of HOMA and insulin were: HOMA: 3.3 ± 0.6, 2.0 ± 1.1 and 1.3 ± 0.6, and insulin: 18.15 ± 1.6 μU/ml, 10.3 ± 3.5 μU/ml and 6.8 ± 2.8 μU/ml, in the obese, overweight and normal groups respectively. Considering puberty, the values of HOMA and insulin were: HOMA: 2.5 ± 1.3, 1.4 ± 0.6 and 0.8 ± 0.0, and insulin: 13.0 ± 5.8 μU/ml, 7.8 ± 2.9 μU/ml and 4.0 ± 0.0 μU/ml, in the adult, pubertal and prepubertal groups respectively. Conclusion The obese and overweight, female and adult patients showed

  8. Exploring the bio-behavioural link between stress, allostatic load & micronutrient status: A cross-sectional study among adolescent boys

    PubMed Central

    Augustine, Little Flower; Nair, Krishnapillai Madhavan; Rao, Sylvia Fernandez; Rao, Mendu Vishnu Vardhana; Ravinder, Punjal; Laxmaiah, Avula

    2016-01-01

    Background & objectives: Allostatic load (AL) is a cumulative measure of physiological deregulation and is influenced by multiple factors including nutrition. The objectives of the study were to assess AL among adolescent boys (15-19 yr) and delineate its association with psychological stress and micronutrient status. Methods: A cross-sectional, school-based study was conducted among 370 adolescent boys of five higher secondary schools from Hyderabad, India. Perceived stress, adolescent life event stress (ALES), psychological morbidity and coping were measured. Biomarkers of AL included dehydroepiandrosterone sulphate, 12-h urinary cortisol, interleukin-6, C-reactive protein, lipid profile, body mass index and blood pressure. Micronutrient status with respect to iron (haemoglobin, ferritin, hepcidin, soluble transferrin receptor), folate, vitamins B12, C and A were analyzed in a sub-sample of 146 boys. AL score ≥3 was calculated from eight biomarkers. Results: Fourteen per cent participants had no AL but 34.3 per cent had AL score of ≥ 3. Unadjusted means of ALES scores were significantly different (P = 0.045) among participants with low [mean, 95% confidence interval (CI): 580, 531-629] and high (663, 605-721) AL. After controlling for confounders, the means were significantly different for controllable life event sub-scale of ALES (P = 0.048). Adjusted hepcidin concentrations were significantly higher among participants with high AL (means, 95% CI, 27.2, 24.0-30.8 for high AL; 22.1, 20.2-24.2 μg/l for low AL, P = 0.014). Interpretation & conclusions: Build-up of AL was found in adolescent boys and was positively associated with life event stress. Iron nutrition and stress exhibited a positive association through hepcidin. The study provides a link between iron nutrition, physiological deregulation and stress. PMID:28139536

  9. Comparison of Lateral Abdominal Muscle Thickness and Cross Sectional Area of Multifidus in Adolescent Soccer Players with and without Low Back Pain: A Case Control Study

    PubMed Central

    Noormohammadpour, Pardis; Hosseini Khezri, Alireza; Linek, Paweł; Mansournia, Mohammad Ali; Hassannejad, Alireza; Younesian, Ali; Farahbakhsh, Farzin; Kordi, Ramin

    2016-01-01

    Background Low back pain (LBP) is a common complaint amongst adolescent athletes. While different studies have shown association between LBP and trunk muscle thickness in the general population, few articles have studied it in adolescent athletes. Objectives The aim of this study is to compare lateral abdominal muscle thickness and function, and cross sectional area (CSA) of lumbar multifidus (LM) in adolescent soccer players with and without LBP. Methods In total, 28 adolescent soccer players with and without LBP, from the premier league participated in this study. The thickness of external oblique, internal oblique and transversus abdominis and the CSA of the LM muscles at L4 level on both sides were measured at rest and contraction via ultrasound imaging (USI). In addition, leg length discrepancy, hamstring flexibility, active lumbar forward flexion, and isometric muscle endurance of trunk extensors were measured in both groups. (study design/setting: case control study). Results The mean (SD) age in LBP group and non-LBP group were 14.0 (1.1) and 14.1 (0.9) years, respectively. There was no significant difference in baseline characteristics of participants between groups. Findings showed no significant difference between LBP and non-LBP groups comparing all measured variables. Conclusions The data obtained support that there is not a correlation between abdominal muscle thickness and CSA of the lumbar multifidi and LBP in adolescent soccer players. These findings suggest that other factors rather than the thickness of deep trunk muscles may play a more significant role in the etiology of LBP in adolescent soccer players. PMID:28144414

  10. Waist-to-Height Ratio Percentiles and Cutoffs for Obesity: A Cross-sectional Study in Brazilian Adolescents

    PubMed Central

    Zanetti Passos, Maria Aparecida; dos Santos, Luana Caroline; da Costa Machado, Helymar; Fisberg, Mauro

    2014-01-01

    ABSTRACT This study aimed to describe the distribution of waist-to-height ratio (WHtR) percentiles and cutoffs for obesity in Brazilian adolescents. A cross-sectional study including adolescents aged 10 to 15 years was conducted in the city of São Paulo, Brazil; anthropometric measurements (weight, height, and waist-circumference) were taken, and WHtRs were calculated and then divided into percentiles derived by using Least Median of Squares (LMS) regression. The receiver operating characteristic (ROC) curve was used in determining cutoffs for obesity (BMI ≥97th percentile) and Mann-Whitney and Kruskal-Wallis tests were used for comparing variables. The study included 8,019 adolescents from 43 schools, of whom 54.5% were female, and 74.8% attended public schools. Boys had higher mean WHtR than girls (0.45±0.06 vs 0.44±0.05; p=0.002) and higher WHtR at the 95th percentile (0.56 vs 0.54; p<0.05). The WHtR cutoffs according to the WHO criteria ranged from 0.467 to 0.506 and 0.463 to 0.496 among girls and boys respectively, with high sensitivity (82.8-95%) and specificity (84-95.5%). The WHtR was significantly associated with body adiposity measured by BMI. Its age-specific percentiles and cutoffs may be used as additional surrogate markers of central obesity and its co-morbidities. PMID:25395904

  11. Physical fitness status of children and adolescents in Tianjin of China during past three decades: a cross-sectional study

    PubMed Central

    Zhi, Xinyue; Xi, Wei; Gao, Lei; Huang, Junping; Yang, Xu; Dai, Wei; Deng, Yanmei; Zhang, Xin

    2015-01-01

    Background: Significant changes in the society and lifestyle have been observed in China, which influences the physical fitness status of children and adolescents. This study aimed to estimate the physical fitness status in Tianjin during the past three decades. Methods: Cross sectional survey was used in this study. The data were derived from the Chinese National Students’ Physical Health Survey database (1985-2010) using stratified cluster randomized sampling method. A total of 58,006 subjects aged 7-21 were recruited. The ethics approval was obtained from the Ethics Committee of Tianjin Medical University before collecting data from the children and adolescents, and/or their parents/guardians on behalf of them. Also written informed consent was obtained before collecting data from the patients. The secular trend of the physical fitness status, Levels of height, weight, body mass index, and chest circumference in China were calculated. The increase velocity of according indexes were analyzed, gender and rural/urban difference were discussed afterwards. SPSS16.0 was used in the analysis. Results: Levels of height, weight, body mass index, and chest circumference were obviously increased in 2010 compared to those levels in 1985, especially in the 9-13 age group. It was observed that the increase in the two crosses for height velocity between two genders of rural students was disappeared and the age of seven was important for the physical development. Conclusions: The circumstance was good for the physical development of the children and adolescents. The disappearance of the two crosses for height velocity between two genders of rural students in this study might be associated with factors such as nutritional status. PMID:26309589

  12. Mothers impose physical activity restrictions on their asthmatic children and adolescents: an analytical cross-sectional study

    PubMed Central

    2014-01-01

    Background Physical activities are important for children and adolescents, especially asthmatics. A significant proportion is considered less active than their non-asthmatic peers and mother’s beliefs about asthma are thought to be a determinant factor. The research objectives were to investigate whether mothers try to impose limitations on the physical activity (PA) of their asthmatic children/adolescents; identify associated factors; and explore if this attitude has any impact on children’s PA levels. Methods In this cross sectional investigation, we studied 115 asthmatics aged between 9 and 19 years and their mothers. Asthma severity, PA level and exercise induced bronchospasm (EIB) were evaluated. Mothers were questioned on their beliefs about physical activity in non-asthmatic and asthmatic children, if they imposed restrictions on their children’s physical activity, on EIB perception and personal levels of anxiety and depression. Results Ninety six percent of the mothers answered that PA are important for children and adolescents. Despite this, 37% of them admitted imposing restrictions to their children’s PA. This attitude was associated with mother’s negative opinions about asthmatics doing PA, perception of children’s dyspnea after running on a treadmill, mother’s anxiety level and children’s asthma severity. The mother’s restrictive attitudes were not associated with children’s lower PA levels. Conclusion A high proportion of the mothers said that they restrained their asthmatic children from engaging in physical activity. This fact should be recognized by health professionals and discussed with parents and caregivers as these negative beliefs may lead to conflicts and prejudiced attitudes that could discourage children’s involvement in physical activities and sports. PMID:24673939

  13. Design, Response Rates, and Population Characteristics of a Cross-Sectional Study in Zanzibar, Tanzania

    PubMed Central

    Nyangasa, Maria Adam; Kelm, Soerge; Sheikh, Mohammed Ali

    2016-01-01

    Background Data on nutritional status and correlates of noncommunicable diseases are scarce for resource-poor settings in sub-Saharan countries. With the scope of a project, “Access to Food and Nutrition Status of the Zanzibari Population,” data for investigating public health questions were collected using proven measurement and laboratory standards. Objective The present study aims at providing a descriptive overview of recruitment approaches, standardization, quality control measures, and data collection, with special attention to the design, responses, and participant characteristics of the overall project. Methods A cross-sectional study across 80 randomly selected Shehias (wards) was conducted in 2013 in Unguja Island, Zanzibar. Examinations included all members living in 1 household, face-to-face interviews and anthropometric measurements (weight, height, mid-upper arm circumference, waist and hip circumference, and body composition) were assessed for all household members, blood pressure was taken from participants older than 2 years, and biosamples (urine and blood) from eligible household members were collected. Data collected from the core sample included sociodemographic data, nutritional status, and medical history (hypertension). Physical activity data was collected from a subsample of children between 3 and 16 years of age. Results A total of 1314 participants (mean age 23.6 ± 18.9 years, 54.54% female) completed all anthropometric measurements and were included in the analysis. Out of which, 98.40% (1293/1314) completed the household member’s questionnaire, 93.32% (1229/1314) participants older than 2 years completed blood pressure measurements, and 64.31% (845/1314) blood samples were collected from participants older than 5 years. Underweight prevalence for the total study population was 36.53% (480/1314) with the highest prevalence in children under 14 years. Overweight and obesity was highest among females with the prevalence of 7

  14. Overweight and television and computer habits in Swedish school-age children and adolescents: a cross-sectional study.

    PubMed

    Garmy, Pernilla; Clausson, Eva K; Nyberg, Per; Jakobsson, Ulf

    2014-06-01

    The aim of this cross-sectional study was to investigate the prevalence of overweight and obesity in children and adolescents (6-16 years), and relationships between being overweight and sleep, experiencing of fatigue, enjoyment of school, and time spent in watching television and in sitting at the computer. Trained school nurses measured the weight and height of 2891 children aged 6, 7, 10, 14, and 16, and distributed a questionnaire to them regarding television and computer habits, sleep, and enjoyment of school. Overweight, obesity included, was present in 16.1% of the study population. Relationships between lifestyle factors and overweight were studied using multivariate logistic regression analysis. Having a bedroom television and spending more than 2 h a day watching television were found to be associated with overweight (OR 1.26 and 1.55 respectively). No association was found between overweight and time spent at the computer, short sleep duration, enjoyment of school, tiredness at school, or difficulties in sleeping and waking up. It is recommended that the school health service discuss with pupils their media habits so as to promote their maintaining a healthy lifestyle.

  15. THE ASSOCIATION BETWEEN MENSTRUAL CYCLE CHARACTERISTICS AND PERCEIVED BODY IMAGE: A CROSS-SECTIONAL SURVEY OF POLISH FEMALE ADOLESCENTS.

    PubMed

    Kaczmarek, Maria; Trambacz-Oleszak, Sylwia

    2016-05-01

    The increasing prevalence of negative body perceptions among adolescent girls and the tendency towards wishing to be thinner have become a cultural norm in Western culture. Adolescent girls are particularly vulnerable to developing a negative body image due to physical and sexual changes occurring during puberty. This study aimed to evaluate the association between different measures of body image perceptions and different phases of the menstrual cycle after controlling for weight status and other potential confounders in Polish adolescent girls aged 12-18 years. Three-hundred and thirty participants of a cross-sectional survey conducted in 2009, normally cycling and with no eating disorders, completed a background questionnaire and the Stunkard Figure Rating Scale, and their anthropometric measurements were collected. The dependent outcome variables were measures of body image (actual body image, ideal body image and ideal-self discrepancy) and dichotomous body image perception (satisfied versus dissatisfied) adjusted for other predictor factors: socio-demographic variables, menstrual history and cycle phases, and weight status. One-way ANOVA indicated that weight status, age at menarche and menstrual cycle phase were associated with actual body image and rate of ideal-self discrepancy. Ideal body image was associated with weight status and menstrual cycle phase. General logistic regression models were constructed to evaluate associations of body dissatisfaction and all potential predictor variables. The final selected model of the multiple logistic regression analysis using the backward elimination procedure revealed that adjusted for other factors, negative body image was significantly associated with different phases of the menstrual cycle (p trend=0.033) and increasing body weight status (p trend=0.0007). The likelihood of body dissatisfaction was greatest during the premenstrual phase of the menstrual cycle (OR=2.38; 95% CI 1.06, 5.32) and among girls in

  16. Energy Drink and Coffee Consumption and Psychopathology Symptoms Among Early Adolescents: Cross-Sectional and Longitudinal Associations.

    PubMed

    Marmorstein, Naomi R

    2016-06-01

    Background: Little is known about possible links between energy drink use and psychopathology among youth. This study examined cross-sectional and longitudinal associations between energy drink consumption and psychopathology among early adolescents. In addition, associations between psychopathology and coffee consumption were examined to assess whether findings were specific to energy drinks or also applied to another commonly used caffeinated beverage. Methods: One hundred forty-four youth who participated in the Camden Youth Development Study (72 males; mean age 11.9 at wave 1; 65% Hispanic, 30% African American) were assessed using self-report measures of frequency of energy drink and coffee consumption and depression, anxiety, conduct disorder (CD) symptoms, and teacher reports of attention-deficit hyperactivity disorder (ADHD). Youth (92%) were reassessed 16 months later. Results: Concurrently, energy drink and coffee consumption were associated with similar psychopathology symptoms; when the other beverage was adjusted for, energy drinks remained associated with CD and coffee remained associated with panic anxiety. Initial energy drink consumption predicted increasing ADHD and CD over time, though the association with CD dropped to a trend level of significance when coffee was adjusted for. Initial levels of hyperactive ADHD predicted increasing coffee consumption over time; this association remained when energy drinks were controlled. Social anxiety was associated with less increase in energy drink consumption over time, controlling for coffee. Conclusion: Energy drink and coffee consumption among early adolescents are concurrently associated with similar psychopathology symptoms. Longitudinally, the associations between these beverages and psychopathology differ, indicating that these substances have differing implications for development over time.

  17. Principle and Uncertainty Quantification of an Experiment Designed to Infer Actinide Neutron Capture Cross-Sections

    SciTech Connect

    G. Youinou; G. Palmiotti; M. Salvatorre; G. Imel; R. Pardo; F. Kondev; M. Paul

    2010-01-01

    An integral reactor physics experiment devoted to infer higher actinide (Am, Cm, Bk, Cf) neutron cross sections will take place in the US. This report presents the principle of the planned experiment as well as a first exercise aiming at quantifying the uncertainties related to the inferred quantities. It has been funded in part by the DOE Office of Science in the framework of the Recovery Act and has been given the name MANTRA for Measurement of Actinides Neutron TRAnsmutation. The principle is to irradiate different pure actinide samples in a test reactor like INL’s Advanced Test Reactor, and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after neutron irradiation allows the energy integrated neutron cross-sections to be inferred since the relation between the two are the well-known neutron-induced transmutation equations. This approach has been used in the past and the principal novelty of this experiment is that the atom densities of the different transmutation products will be determined with the Accelerator Mass Spectroscopy (AMS) facility located at ANL. While AMS facilities traditionally have been limited to the assay of low-to-medium atomic mass materials, i.e., A < 100, there has been recent progress in extending AMS to heavier isotopes – even to A > 200. The detection limit of AMS being orders of magnitude lower than that of standard mass spectroscopy techniques, more transmutation products could be measured and, potentially, more cross-sections could be inferred from the irradiation of a single sample. Furthermore, measurements will be carried out at the INL using more standard methods in order to have another set of totally uncorrelated information.

  18. Design and simulation of MEMS vector hydrophone with reduced cross section based meander beams

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Dutta, S.; Pal, Ramjay; Jain, K. K.; Gupta, Sudha; Bhan, R. K.

    2016-04-01

    MEMS based vector hydrophone is being one of the key device in the underwater communications. In this paper, we presented a bio-inspired MEMS vector hydrophone. The hydrophone structure consists of a proof mass suspended by four meander type beams with reduced cross-section. Modal patterns of the structure were studied. First three modal frequencies of the hydrophone structure were found to be 420 Hz, 420 Hz and 1646 Hz respectively. The deflection and stress of the hydrophone is found have linear behavior in the 1 µPa - 1Pa pressure range.

  19. ORIGEN-ARP Cross-Section Libraries for Magnox, Advanced Gas-Cooled, and VVER Reactor Designs

    SciTech Connect

    Murphy, BD

    2004-03-10

    Cross-section libraries for the ORIGEN-ARP system were extended to include four non-U.S. reactor types: the Magnox reactor, the Advanced Gas-Cooled Reactor, the VVER-440, and the VVER-1000. Typical design and operational parameters for these four reactor types were determined by an examination of a variety of published information sources. Burnup simulation models of the reactors were then developed using the SAS2H sequence from the Oak Ridge National Laboratory SCALE code system. In turn, these models were used to prepare the burnup-dependent cross-section libraries suitable for use with ORIGEN-ARP. The reactor designs together with the development of the SAS2H models are described, and a small number of validation results using spent-fuel assay data are reported.

  20. Alcohol use and alcohol-related problems among adolescents in China: A large-scale cross-sectional study.

    PubMed

    Guo, Lan; Deng, Jianxiong; He, Yuan; Deng, Xueqing; Huang, Jinghui; Huang, Guoliang; Gao, Xue; Zhang, Wei-Hong; Lu, Ciyong

    2016-09-01

    Alcohol misuse among adolescents is a common issue worldwide and is an emerging problem in China. This study aimed to investigate the prevalence of alcohol drinking and alcohol-related problems among Chinese adolescents and to explore their risk factors and connections.A cross-sectional study using an anonymous questionnaire was conducted among junior and senior high school students between 2010 and 2012. Data on self-reported alcohol use, alcohol-related problems, school factors, family factors, and psychosocial factors were collected. Descriptive analyses were made of the proportions of sociodemographics, family, school, and psychosocial factors. Multilevel logistic regression models were conducted to analyze the risk factors for alcohol drinking and alcohol-related problems.Of the 105,752 students who ranged in age from 9 to 21 years, the prevalence of current drinking among students was 7.3%, and 13.2% students reported having alcohol-related problems. Male students were 1.78 (95% confidence interval [CI] = 1.69-1.87) times more likely to be involved in current drinking and 1.86 (95% CI = 1.79-1.93) times more likely to have alcohol-related problems. Higher grade level students were at a higher risk of current drinking (adjusted odds ratio [AOR] = 1.09, 95% CI = 1.05-1.13) and having alcohol-related problems (AOR = 1.43, 95% CI = 1.42-1.58). Older students were more likely to report current drinking (AOR = 1.06, 95% CI = 1.04-1.17) and having alcohol-related problems (AOR = 1.83, 95% CI = 1.82-1.85). Having poor classmate relations (AOR = 1.28, 95% CI = 1.03-1.37), having poor relationships with teachers (AOR = 1.08, 95% CI = 1.00-1.16), and below average academic achievement (AOR = 1.50, 95% CI = 1.41-1.59) were positively associated with current drinking. Moreover, students with suicidal ideation were at a higher risk of current drinking (AOR = 1.70, 95% CI = 1.61-1.81) and having alcohol-related problems (AOR = 2.08, 95% CI = 1.98-2.16). Having higher Center

  1. Prevalence and correlates of sexual and gender-based violence against Chinese adolescent women who are involved in commercial sex: a cross-sectional study

    PubMed Central

    Zhang, Xu-Dong; Myers, Sierra; Yang, Hong-Juan; Li, Yun; Li, Ji-Hong; Luo, Wei; Luchters, Stanley

    2016-01-01

    Objectives Despite the vast quantity of research among Chinese female sex workers (FSWs) to address concerns regarding HIV/sexually transmitted infection (STI) risk, there is a paucity of research on issues of sexual and gender-based violence (SGBV) and the missed opportunity for sexual and reproductive health (SRH) promotion among young FSWs. Our research aimed to assess the prevalence and correlates of SGBV among Chinese adolescent FSWs, and to explore SRH service utilisation. Design and methods A cross-sectional study using a one-stage cluster sampling method was employed. A semistructured questionnaire was administered by trained peer educators or health workers. Multivariable logistic regression was conducted to determine individual and structural correlates of SGBV. Setting and participants Between July and September 2012, 310 adolescent women aged 15–20 years, and who self-reported having received money or gifts in exchange for sex in the past 6 months were recruited and completed their interview in Kunming, Yunnan Province, China. Results Findings confirm the high prevalence of SGBV against adolescent FSWs in China, with 38% (118/310) of participants affected in the past year. Moreover, our study demonstrated the low uptake of public health services and high rates of prior unwanted pregnancy (52%; 61/118), abortion (53%; 63/118) and self-reported STI symptoms (84%; 99/118) in participants who were exposed to SGBV. Forced sexual debut was reported by nearly a quarter of FSWs (23%; 70/310) and was independently associated with having had a drug-using intimate partner and younger age (<17 years old) at first abortion. When controlling for potential confounders, having experienced SGBV was associated with frequent alcohol use, having self-reported symptoms of STI, having an intimate partner and having an intimate partner with illicit drug use. Conclusions This study calls for effective and integrated interventions addressing adolescent FSWs

  2. The impact of knowledge about diabetes, resilience and depression on glycemic control: a cross-sectional study among adolescents and young adults with type 1 diabetes

    PubMed Central

    2013-01-01

    Background The purpose of this study is to evaluate the relationship between glycemic control and the factors of knowledge about diabetes, resilience, depression and anxiety among Brazilian adolescents and young adults with type 1 diabetes. Methods This cross-sectional study included 85 adolescents and young adults with type 1 diabetes, aged between 11–22 years, with an average age of 17.7 ± 3.72 years. Glycemic control degree was evaluated through HbA1c. To assess psychosocial factors, the following questionnaires were used: resilience (Resilience Scale, RS) and anxiety and depression (Hospital Anxiety and Depression Scale, HADS). The Diabetes Knowledge Assessment Scale (DKNA) was used to assess knowledge about diabetes. Results Significant correlations were found between HbA1c and resilience, anxiety and depression. Multiple linear regression analysis revealed that the only variable which presented significant association with the value of HbA1c was depression. Conclusions Depression has a significant association with higher HbA1c levels, as demonstrated in a regression analysis. The results suggest that depression, anxiety and resilience should be considered in the design of a multidisciplinary approach to type 1 diabetes, as these factors were significantly correlated with glycemic control. Glycemic control was not correlated with knowledge of diabetes, suggesting that theoretical or practical understanding of this disease is not by itself significantly associated with appropriate glycemic control (HbA1c ≤ 7.5%). PMID:24289093

  3. Subjective Health and Mental Well-Being of Adolescents and the Health Promoting School: A Cross-Sectional Multilevel Analysis

    ERIC Educational Resources Information Center

    Levin, Kate; Inchley, Jo; Currie, Dorothy; Currie, Candace

    2012-01-01

    Purpose: The aim of this paper is to examine the impact of the health promoting school (HPS) on adolescent well-being. Design/methodology/approach: Data from the 2006 Health Behaviour in School-aged Children: WHO-collaborative Study in Scotland were analysed using multilevel linear regression analyses for outcome measures: happiness, confidence,…

  4. Blood pressure and associated factors in a North African adolescent population. a national cross-sectional study in Tunisia

    PubMed Central

    2012-01-01

    Background In southern and eastern Mediterranean countries, changes in lifestyle and the increasing prevalence of excess weight in childhood are risk factors for high blood pressure (BP) during adolescence and adulthood. The aim of this study was to evaluate the BP status of Tunisian adolescents and to identify associated factors. Methods A cross-sectional study in 2005, based on a national, stratified, random cluster sample of 1294 boys and 1576 girls aged 15-19 surveyed in home visits. The socio-economic and behavioral characteristics of the adolescents were recorded. Overweight/obesity were assessed by Body Mass Index (BMI) from measured height and weight (WHO, 2007), abdominal obesity by waist circumference (WC). BP was measured twice during the same visit. Elevated BP was systolic (SBP) or diastolic blood pressure (DBP) ≥ 90th of the international reference or ≥ 120/80 mm Hg for 15-17 y., and SBP/DBP ≥ 120/80 mm Hg for 18-19 y.; hypertension was SBP/DBP ≥ 95th for 15-17 y. and ≥ 140/90 mm Hg for 18-19 y. Adjusted associations were assessed by logistic regression. Results The prevalence of elevated BP was 35.1%[32.9-37.4]: higher among boys (46.1% vs. 33.3%; P < 0.0001); 4.7%[3.8-5.9] of adolescents had hypertension. Associations adjusted for all covariates showed independent relationships with BMI and WC: - obesity vs. no excess weight increased elevated BP (boys OR = 2.1[1.0-4.2], girls OR = 2.3[1.3-3.9]) and hypertension (boys OR = 3.5[1.4-8.9], girls OR = 5.4[2.2-13.4]), - abdominal obesity (WC) was also associated with elevated BP in both genders (for boys: 2nd vs. 1st tertile OR = 1.7[1.3-2.3], 3rd vs.1st tertile OR = 2.8[1.9-4.2]; for girls: 2nd vs. 1st tertile OR = 1.6[1.2-2.1], 3rd vs.1st tertile OR = 2.1[1.5-3.0]) but only among boys for hypertension. Associations with other covariates were weaker: for boys, hypertension increased somewhat with sedentary lifestyle, while elevated BP was slightly more prevalent among urban girls and those not

  5. Correlates of sexual behaviors with health status and health perception in Chinese adolescents: a cross-sectional survey in schools.

    PubMed

    Wong, William C W; Lee, Albert; Tsang, Kwong Ka

    2004-08-01

    Sexual intercourse remains taboo among adolescents in a Chinese society such as Hong Kong. It is not openly discussed and little research has been done on its impact on health, although it carries serious risks of contracting sexually transmitted diseases (STDs)/HIV. In 1999, a cross-sectional, self-report survey on youth risk behaviors was carried out on 8382 students 15-18 years of age from 48 schools in Hong Kong. Three hundred seventy-seven (4.69%) reported that they had had sexual intercourse. Among them, forced sex (16.94%) was common, most often happening to boys (52.38%). They were more likely to have consulted doctors in the last month (odds ration [OR] 1.41 in boys 95% confidence interval [CI] 1.03, 1.94; OR 2.46 in girls 95% CI 1.81, 3.30) and 6 months (OR 1.33 in boys 95% CI 0.98, 1.78; OR 2.66 in girls 95% CI 1.80, 3.91). They also perceived poorer and deteriorating health. The sexually active female students were 6.70 times (95% CI 4.65, 9.66) more likely to attempt suicide than the other group and were more likely to take sick leaves (OR 3.56 in girls 95% CI 2.35, 5.41). Parental education and occupation, place of birth, and type of housing did not correlate in the initiation of sexual intercourse. The sexually experienced group reported worse physical and psychological health as well as health perception. Some of the characteristics and patterns identified in our study were quite different from the findings in the West but further studies are required to determine the reason for this.

  6. The effects of insomnia and internet addiction on depression in Hong Kong Chinese adolescents: an exploratory cross-sectional analysis.

    PubMed

    Cheung, Lee M; Wong, Wing S

    2011-06-01

    The negative association of insomnia and internet addiction with mental health is widely documented in the literature, yet little is known about their inter-relationships. The primary aim of this study was to examine the inter-relationships between insomnia, internet addiction and depression. A total of 719 Chinese adolescents in Hong Kong participated in this school-based cross-sectional study. Participants completed the Chinese version of the Pittsburgh Sleep Quality Index (PSQI), the Chinese Internet Addiction Scale (CIAS), the 12-item version of General Health Questionnaire (GHQ-12) and questions assessing internet use pattern and sociodemographic characteristics. The classification of internet addiction and insomnia was based on the CIAS cutoff global score >63 and PSQI cutoff global score >5, respectively. Multiple regression analyses tested the effects of insomnia and internet addiction on depression. Among students with internet addiction (17.2%), 51.7% were also identified as insomniacs. Internet addicts scored significantly poorer on all PSQI components, except sleep duration, than their non-addicted counterparts. After adjustment for gender and internet use time, both internet addiction (β=0.05; Sobel test Z=6.50, P<0.001) and insomnia (β=0.59; Sobel test Z=4.49, P<0.001) demonstrated a significant association with depression. Overall, there is high comorbidity between internet addiction and insomnia. Both insomnia and internet addiction emerged as significant explanatory factors, but they exerted differential effects on depression. Future research should be directed at determining the causal relationship between internet addiction and insomnia, and its underlying mechanism with depression.

  7. Examining Childhood Maltreatment and School Bullying Among Adolescents: A Cross-Sectional Study From Anhui Province in China.

    PubMed

    Wang, Geng-Fu; Jiang, Liu; Wang, Lu-Han; Hu, Guo-Yun; Fang, Yu; Yuan, Shan-Shan; Wang, Xiu-Xiu; Su, Pu-Yu

    2016-05-03

    Although a body of research has established the relationship between childhood maltreatment and bullying in Western culture backgrounds, few studies have examined the association between childhood maltreatment experiences and bullying in China. Moreover, to date, the relationship between multiple types of childhood maltreatment and cyber bullying is poorly understood. This study examined the association between multiple types of childhood maltreatment (physical abuse, emotional abuse, sexual abuse, physical neglect, and emotional neglect) and multiple forms of school bullying (physical, verbal, relational, and cyber). A cross-sectional study using three-stage random cluster-sampling approach was conducted in Tongling, Chuzhou, and Fuyang, in Anhui Province. Self-reported questionnaires were completed by 5,726 middle school students to assess their school bullying involvement and childhood maltreatment experiences. A multivariable logistic regression analysis was used to explore the relationship between each single type of childhood maltreatment and each single form of school bullying. Each type of childhood maltreatment was associated with increased risk for involvement in each form of bullying as bullies, victims, and bully-victims. Specifically, both childhood physical neglect and emotional neglect were associated with increased risk for involvement in each form of school bullying. Each type of childhood maltreatment was associated with involvement in cyber bullying. Students who experienced multiple types of childhood maltreatment seem to report more forms of school bullying. Furthermore, multiple forms of school bullying caused the co-occurrence of several forms of school bullying. Our results indicated a significant association between school bullying and childhood maltreatment among adolescents. Interventions to reduce school bullying encompassing prevention toward childhood maltreatment might get better results in China.

  8. Mental health status among Burmese adolescent students living in boarding houses in Thailand: a cross-sectional study

    PubMed Central

    2013-01-01

    Background In Tak province of Thailand, a number of adolescent students who migrated from Burma have resided in the boarding houses of migrant schools. This study investigated mental health status and its relationship with perceived social support among such students. Methods This cross-sectional study surveyed 428 students, aged 12–18 years, who lived in boarding houses. The Hopkins Symptom Checklist (HSCL)-37 A, Stressful Life Events (SLE) and Reactions of Adolescents to Traumatic Stress (RATS) questionnaires were used to assess participants’ mental health status and experience of traumatic events. The Medical Outcome Study (MOS) Social Support Survey Scale was used to measure their perceived level of social support. Descriptive analysis was conducted to examine the distribution of sociodemographic characteristics, trauma experiences, and mental health status. Further, multivariate linear regression analysis was used to examine the association between such characteristics and participants’ mental health status. Results In total, 771 students were invited to participate in the study and 428 students chose to take part. Of these students, 304 completed the questionnaire. A large proportion (62.8%) indicated that both of their parents lived in Myanmar, while only 11.8% answered that both of their parents lived in Thailand. The mean total number of traumatic events experienced was 5.7 (standard deviation [SD] 2.9), mean total score on the HSCL-37A was 63.1 (SD 11.4), and mean total score on the RATS was 41.4 (SD 9.9). Multivariate linear regression analysis revealed that higher number of traumatic events was associated with more mental health problems. Conclusions Many students residing in boarding houses suffered from poor mental health in Thailand’s Tak province. The number of traumatic experiences reported was higher than expected. Furthermore, these traumatic experiences were associated with poorer mental health status. Rather than making a generalized

  9. Leptin status in adolescence is associated with academic performance in high school: a cross-sectional study in a Chilean birth cohort

    PubMed Central

    Correa-Burrows, Paulina; Blanco, Estela; Reyes, Marcela; Castillo, Marcela; Peirano, Patricio; Algarín, Cecilia; Lozoff, Betsy; Gahagan, Sheila; Burrows, Raquel

    2016-01-01

    Objective Leptin is a pleiotropic hormone associated with learning and memory via brain receptors. However, elevated plasma leptin levels may impair cognitive and memory functions. Since individual differences in memory performance affect students’ ability to learn, we aimed to study the relation between leptin status in adolescence and school performance. Design and setting We studied 568 adolescents aged 16–17 years from Santiago. A cross-sectional analysis was carried out on a birth cohort conducted in Santiago (Chile). Primary and secondary outcome measures We measured serum leptin concentration using an enzyme-linked immunosorbent assay. Cut-offs from the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study for 16-year-olds were used to define abnormally high leptin levels (hyperleptinaemia). Academic performance was measured using high-school grades and grade point average (GPA). Data were collected in 2009–2012; data analysis was performed in 2014. Results 15% of participants had hyperleptinaemia. They had significantly lower school grades and GPA compared with participants with normal leptin levels (eg, GPA mean difference=33.8 points). Leptin levels were negative and significantly correlated with school grades in 9th, 10th and 12th. Similarly, it was negatively correlated with high-school GPA. After controlling for health, sociodemographic and education confounders, the chances of having a performance ≥75th centile in students having hyperleptinaemia were 32% (95% CI 0.19% to 0.89%) that of students having normal serum leptin concentration. Conclusions In high school students, abnormally high levels of leptin were associated with poorer academic performance. These findings support the idea of a relationship between leptin and cognition. Further research is needed on the cognitive effects of leptin in younger populations. PMID:27797980

  10. Insomnia and Relationship with Anxiety in University Students: A Cross-Sectional Designed Study

    PubMed Central

    Choueiry, Nour; Salamoun, Tracy; Jabbour, Hicham; El Osta, Nada; Hajj, Aline; Rabbaa Khabbaz, Lydia

    2016-01-01

    Purpose Sleep disorders (SDs) are now recognized as a public health concern with considerable psychiatric and societal consequences specifically on the academic life of students. The aims of this study were to assess SDs in a group of university students in Lebanon and to examine the relationship between SDs and anxiety. Methods An observational cross-sectional study was conducted at Saint-Joseph University, Lebanon, during the academic year 2013–2014. Four questionnaires were face-to-face administered to 462 students after obtaining their written consent: Insomnia Severity Index (ISI), Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Generalized Anxiety Disorder 7-item scale (GAD-7). Results The prevalence of clinically significant insomnia was 10.6% (95% CI: 7.8–13.4%), more frequent in first year students. ISI mean score was 10.06 (SD = 3.76). 37.1% of the participants were poor sleepers. Excessive daytime sleepiness (EDS) and poor sleep were significantly more frequent among participants with clinical insomnia (p = 0.031 and 0.001 respectively). Clinically significant anxiety was more frequent in students suffering from clinical insomnia (p = 0.006) and in poor sleepers (p = 0.003). 50.8% of the participants with clinically significant anxiety presented EDS versus 30.9% of those with no clinically significant anxiety (p<0.0001). Conclusions The magnitude of SDs in this sample of Lebanese university students demonstrate the importance of examining sleep health in this population. Moreover, the link between SD and anxiety reminds us of the importance of treating anxiety as soon as detected and not simply targeting the reduction of sleep problems. PMID:26900686

  11. Neurobehavioral function and low-level exposure to brominated flame retardants in adolescents: a cross-sectional study

    PubMed Central

    2012-01-01

    Background Animal and in vitro studies demonstrated a neurotoxic potential of brominated flame retardants, a group of chemicals used in many household and commercial products to prevent fire. Although the first reports of detrimental neurobehavioral effects in rodents appeared more than ten years ago, human data are sparse. Methods As a part of a biomonitoring program for environmental health surveillance in Flanders, Belgium, we assessed the neurobehavioral function with the Neurobehavioral Evaluation System (NES-3), and collected blood samples in a group of high school students. Cross-sectional data on 515 adolescents (13.6-17 years of age) was available for the analysis. Multiple regression models accounting for potential confounders were used to investigate the associations between biomarkers of internal exposure to brominated flame retardants [serum levels of polybrominated diphenyl ether (PBDE) congeners 47, 99, 100, 153, 209, hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA)] and cognitive performance. In addition, we investigated the association between brominated flame retardants and serum levels of FT3, FT4, and TSH. Results A two-fold increase of the sum of serum PBDE’s was associated with a decrease of the number of taps with the preferred-hand in the Finger Tapping test by 5.31 (95% CI: 0.56 to 10.05, p = 0.029). The effects of the individual PBDE congeners on the motor speed were consistent. Serum levels above the level of quantification were associated with an average decrease of FT3 level by 0.18 pg/mL (95% CI: 0.03 to 0.34, p = 0.020) for PBDE-99 and by 0.15 pg/mL (95% CI: 0.004 to 0.29, p = 0.045) for PBDE-100, compared with concentrations below the level of quantification. PBDE-47 level above the level of quantification was associated with an average increase of TSH levels by 10.1% (95% CI: 0.8% to 20.2%, p = 0.033), compared with concentrations below the level of quantification. We did not observe effects of

  12. ARE HEALTH VISITORS' OBSERVATIONS OF EARLY PARENT-INFANT INTERACTIONS RELIABLE? A CROSS-SECTIONAL DESIGN.

    PubMed

    Kristensen, Ingeborg H; Trillingsgaard, Tea; Simonsen, Marianne; Kronborg, Hanne

    2017-03-01

    Health visitors need competences to promote healthy early parent-infant relationships. The aims of this study were to explore whether there are differences between groups of health visitors with and without additional parenting program education in terms of their knowledge of infant-parent interaction and their observation and assessment skills of such interactions. The cross-sectional study included 36 health visitors' certified Marte Meo therapists and 85 health visitors without additional parenting program education. Health visitors' observation skills were measured assessing five video-recorded mother-infant interactions. A questionnaire was used to measure their intention, self-efficacy, and knowledge. More certified Marte Meo therapists than health visitors without additional parenting program education reported a significantly higher mean level of knowledge of the early relationship, 6.42 (95% CI; 6.18-6.66) versus 5.05 (95% CI; 4.86-6.10), p = .04; and more certified Marte Meo therapists than health visitors without additional parenting program education reported a higher mean level of knowledge of infant self-regulation, 2.44 (95% CI; 2.18-2.71) versus 1.83 (95% CI; 1.62-2.03), p < .001. In the latter group, 54% (95% CI; 0.43-0.64) reported a significantly higher need for further education versus 22% (95% CI; 0.11-0.39), p = .001. Compared to health visitors without any parenting program education, health visitors certified as Marte Meo therapists reported a significantly higher frequency of correct assessment of mothers' sensitivity in two of five video-recordings, with 77.78% (95% CI; 0.61-0.87) compared to 45.88% (95% CI; 0.35-0.57) in Video 3, p = .001, and 69.44% (95% CI; 0.52-0.82) compared to 49.41% (95% CI; 0.39-0.60) in Video 4, p = .04, respectively. The results of the present study support the use of video-based education of health visitors to increase their knowledge of and skills in assessing parent-infant interactions. Randomized controlled

  13. Anemia and malnutrition in indigenous children and adolescents of the Peruvian Amazon in a context of lead exposure: a cross-sectional study

    PubMed Central

    Anticona, Cynthia; San Sebastian, Miguel

    2014-01-01

    Background Indigenous children and adolescents of the Peruvian Amazon live in precarious conditions that could increase the risk of malnutrition. A particular problem in the Corrientes river communities is the high exposure to lead among children and adolescents. Objective This study aimed to determine the nutritional status of children and adolescents in indigenous communities in the Corrientes river basin and examine risk factors for anemia, stunting, underweight, and wasting. Design This was a cross-sectional assessment in children and adolescents aged 0–17 years from six communities (n=330). Data collection included measurement of hemoglobin levels, anthropometrics, blood lead levels (BLLs); a parental questionnaire including demographic and dwelling information; parents’ occupation; and the child's duration of breastfeeding and food consumption. Analysis included univariate, bivariate, and logistic regression. Results Overall, anemia prevalence was 51.0%, stunting (proxy for chronic malnutrition) 50.0%, and underweight 20.0%. Bivariate analysis showed that anemia and underweight prevalence was higher in the 0–4 years group (p<0.05). No association was found between anemia, stunting, or underweight with gender, community exposure to oil activity, or consumption of river water. Stunting prevalence was higher in the group whose BLLs were >5 µg/dL (p<0.05). In the logistic regression analysis, no variable was associated with anemia or underweight. The group 5–11 years and >12 years had 1.9 and 3.1 times higher risk of stunting than the group under five years, respectively. Children and adolescents with BLLs >5 µg/dL had twice the risk of stunting compared to those with lower BLLs. Conclusions Half of the study population was found with anemia and stunting. Anemia was more prevalent in the 0- to 5-year age group and stunting in the 12- to 17-year group. The association between stunting and BLLs might be attributed to a direct effect of lead on human

  14. Loneliness and health risk behaviours among Russian and U.S. adolescents: a cross-sectional study

    PubMed Central

    2014-01-01

    girls in both Russia and the United States. Further research is now needed in both settings using quantitative and qualitative methods to better understand the association between loneliness and health risk behaviours so that effective interventions can be designed and implemented to mitigate loneliness and its effects on adolescent well-being. PMID:24735570

  15. Is Underweight Associated with more Positive Body Image? Results of a Cross-Sectional Study in Adolescent Girls and Boys.

    PubMed

    Kantanista, Adam; Król-Zielińska, Magdalena; Borowiec, Joanna; Osiński, Wiesław

    2017-02-09

    The aim of the study was to investigate the relationship between body image and prevalence of underweight, normal weight, and overweight in adolescents. The study included 1702 girls and 1547 boys, aged 14-16 years, who completed questionnaire assessing body satisfaction. The participants' BMI status: underweight, normal weight or overweight was determined on the basis of BMI cut-off values. Results revealed that more girls (p < .001) showed low body satisfaction (44.8%) and fewer girls (p < .001) had high body satisfaction (17.6%) compared to boys (28.5% and 29.0%, respectively). A two-way ANOVA revealed a significant interaction between BMI status and gender on body satisfaction F(2, 3243) = 4.10, p = .017, η2 = .003. In boys, body satisfaction was higher in normal weight and underweight in comparison to overweight individuals (p < .001). Underweight girls presented higher body satisfaction than those who were normal weight and overweight (p < .001). Our findings indicated that, in relation to gender, BMI status can be associated with different body satisfaction in adolescents. This should be taken into consideration when designing programs aimed at obesity and disordered eating prevention and body image improvement. Due to the fact that underweight girls and boys have high body satisfaction, this can lead to behaviors that maintain low body weight in adolescents and in turn this may have negative health consequences.

  16. Patterns of health-related behaviours among adolescents: a cross-sectional study based on the National Survey of School Health Brazil 2012

    PubMed Central

    Azeredo, Catarina Machado; Levy, Renata Bertazzi; Peres, Maria Fernanda Tourinho; Menezes, Paulo Rossi; Araya, Ricardo

    2016-01-01

    Objectives The aim of this study was to analyse the clustering of multiple health-related behaviours among adolescents and describe which socio-demographic characteristics are associated with these patterns. Design Cross-sectional study. Setting Brazilian schools assessed by the National Survey of School Health (PeNSE, 2012). Participants 104 109 Brazilian ninth-grade students from public and private schools (response rate=82.7%). Methods Exploratory and confirmatory factor analyses were performed to identify behaviour clustering and linear regression models were used to identify socio-demographic characteristics associated with each one of these behaviour patterns. Results We identified a good fit model with three behaviour patterns. The first was labelled ‘problem-behaviour’ and included aggressive behaviour, alcohol consumption, smoking, drug use and unsafe sex; the second was labelled ‘health-compromising diet and sedentary behaviours’ and included unhealthy food indicators and sedentary behaviour; and the third was labelled ‘health-promoting diet and physical activity’ and included healthy food indicators and physical activity. No differences in behaviour patterns were found between genders. The problem-behaviour pattern was associated with male gender, older age, more developed region (socially and economically) and public schools (compared with private). The ‘health-compromising diet and sedentary behaviours’ pattern was associated with female gender, older age, mothers with higher education level and more developed region. The ‘health-promoting diet and physical activity’ pattern was associated with male gender and mothers with higher education level. Conclusions Three health-related behaviour patterns were found among Brazilian adolescents. Interventions to decrease those negative patterns should take into account how these behaviours cluster together and the individuals most at risk. PMID:28186927

  17. Dieting status influences associations between dietary patterns and body composition in adolescents: a cross-sectional study

    PubMed Central

    2013-01-01

    significant for boys and not girls, nutrition messages designed to prevent obesity may be particularly important for adolescent boys. As an interaction between dieting status and ‘Treat Foods’ existed, future studies should also explore the role of dieting when investigating food choice and body composition. PMID:23617772

  18. Early Indication of Noise-induced Hearing Loss from PMP Use in Adolescents: A Cross-Sectional Analysis

    PubMed Central

    Colon, Diana C.; Verdugo-Raab, Ulla; Alvarez, Carmelo P.; Steffens, Thomas; Marcrum, Steven C.; Kolb, Stefanie; Herr, Caroline; Twardella, Dorothee

    2016-01-01

    Context: Distortion product otoacoustic emissions (DPOAEs) may indicate preclinical noise-induced hearing loss (NIHL) in adolescents from unsafe personal music player (PMP) use. Aims: The objective, therefore, was to observe preclinical signs of NIHL in 9th grade adolescents with clinically normal hearing by comparing DPOAE signals between different levels of A-weighted equivalent PMP exposure. Settings and Design: Subjects were recruited from all secondary-level schools located in the city of Regensburg, Germany during two academic years 2009/2010 and 2010/2011. Subjects and Methods: A-weighted equivalent sound pressure levels (SPLs) for a 40-hour work week (LAeq,40h) were estimated from questionnaire responses on output and duration of PMP use of the previous week. Subjects were then categorized into four levels of exposure: <80, 80–85, >85 to <90, and ≥90 A-weighted Decibel [dB(A)]. DPOAE signals were collected by trained audiological staff, applying a standard optimized protocol, at the Department of Otorhinolaryngology of the University Hospital Regensburg. Statistical Analysis Used: Mean DPOAE signals were compared between levels by unpaired t test. Novel linear regression models adjusting for other leisure noise exposures and with outcome variables DPoutcome and 4 kilo Hertz (kHz) DPOAEs estimated effects between levels. Results: A total of 1468 subjects (56% female, mostly aged 15 or 16 years) were available for analysis. Comparison of DPOAE means by PMP exposure typically showed no greater than 1 dB difference between groups. In fact, comparisons between ≥90 dB(A) and <80 dB(A) presented the least differences in magnitude. Both DPoutcome and 4 kHz linear regression models presented a weak association with the 4-level PMP exposure variable. An expected dose-response to PMP exposure was not observed in any analyses. Conclusions: DPOAE signal strength alone cannot indicate preclinical NIHL in adolescents. PMID:27991459

  19. Alcohol, Substance Use and Psychosocial Competence of Adolescents in Selected Secondary Schools in Uganda: A Cross Sectional Survey

    PubMed Central

    Abbo, Catherine; Okello, Elialilia S.; Muhwezi, Wilson; Akello, Grace; Ovuga, Emilio

    2016-01-01

    Aims 1) To determine the nature and extent of alcohol and substance use and 2) To describe the relationship between alcohol use and psychosocial competence among secondary school youths in Northern and Central Uganda. Study Design This was a cross-sectional study. Place and Duration of study Departments of Mental Health, Gulu University (Northern Uganda) and Department of Psychiatry, Makerere University College of Health Sciences (Central Uganda) between September 2011 and April 2012. Methodology Four (4) and eight (8) secondary schools located in the rural and urban areas of Gulu and Kampala districts respectively were randomly selected to participate in the survey. A total of 3,200 students aged 12 to 24 years were recruited by proportionate multistage sampling. Data was collected using a socio-demographic questionnaire that included questions about nature and frequency of alcohol and substance use. A pre-tested self-administered survey questionnaire with scales to measure components of psychosocial competence (PSC) was administered. Data was entered in Epidata, and exported to SPSS version 16.0 for analysis. Psychosocial competence was classified as high or low depending on the responses in the sub-scales of decision making, self efficacy, empathy, emotional awareness, coping with stress and emotions, and accurate self-assessment and self-confidence. Results A total of 2,902 questionnaires comprising of 2,502, (86.2%) from Kampala district and 400 (13.8%)) from Gulu district were analyzed. Male to female ratio was 1:1 with an age range of 12 to 24 years and a mean of 16.5. About 70.1% had ever used alcohol and substances. Only 39.1% used substances regularly. The commonest substance used was alcohol (23.3%), followed by kuber (10.8%), khat (10.5%), aviation fuel (10.1%), cannabis (9.2%) and cigarettes (5.9%). Respondents from the Gulu district were twice more likely to use all substances. Users and regular users from the North Northern Uganda had lower

  20. Performance on tasks of visuospatial memory and ability: A cross-sectional study in 330 adolescents aged 11 to 20.

    PubMed

    Burggraaf, Rudolf; Frens, Maarten A; Hooge, Ignace T C; van der Geest, Jos N

    2017-01-11

    Cognitive functions mature at different points in time between birth and adulthood. Of these functions, visuospatial skills, such as spatial memory and part-to-whole organization, have often been tested in children and adults but have been less frequently evaluated during adolescence. We studied visuospatial memory and ability during this critical developmental period, as well as the correlation between these abilities, in a large group of 330 participants (aged 11 to 20 years, 55% male). To assess visuospatial memory, the participants were asked to memorize and reproduce sequences of random locations within a grid using a computer. Visuospatial ability was tested using a variation of the Design Organization Test (DOT). In this paper-and-pencil test, the participants had one minute to reproduce as many visual patterns as possible using a numerical code. On the memory task, compared with younger participants, older participants correctly reproduced more locations overall and longer sequences of locations, made fewer mistakes and needed less time to reproduce the sequences. In the visuospatial ability task, the number of correctly reproduced patterns increased with age. We show that both visuospatial memory and ability improve significantly throughout adolescence and that performance on both tasks is significantly correlated.

  1. Investigating Sociodemographic Factors and HIV Risk Behaviors Associated With Social Networking Among Adolescents in Soweto, South Africa: A Cross-Sectional Survey

    PubMed Central

    Laher, Fatima; Hornschuh, Stefanie; Nkala, Busisiwe; Chimoyi, Lucy; Otwombe, Kennedy; Kaida, Angela; Gray, Glenda Elisabeth; Miller, Cari

    2016-01-01

    Background Internet access via mobile phones and computers facilitates interaction and potential health communication among individuals through social networking. Many South African adolescents own mobile phones and can access social networks via apps. Objective We investigated sociodemographic factors and HIV risk behaviors of adolescent social networking users in Soweto, South Africa. Methods We conducted an interviewer-administered, cross-sectional survey of adolescents aged 14-19 years. Independent covariates of social networking were assessed by multivariate logistic regression analysis. Results Of 830 adolescents, 57% (475/830) were females and the median age was found to be 18 years (interquartile range 17-18). Social networking was used by 60% of adolescents (494/830); more than half, that is, 87% (396/494) accessed social networks through mobile phones and 56% (275/494) spent more than 4 hours per day using their mobile phones. Social networking was independently associated with mobile usage 2-4 hours (adjusted odds ratio [AOR]: 3.06, CI: 1.69-5.51) and more than 4 hours per day (AOR: 6.16, CI: 3.46-10.9) and one (AOR: 3.35, CI: 1.79-6.27) or more sexual partner(s) (AOR: 2.58, CI: 1.05-6.36). Conclusions Mobile phone–based social networking is prevalent among sexually active adolescents living in Soweto and may be used as an entry point for health promotion and initiation of low-cost adolescent health interventions. PMID:27683173

  2. EuropeaN Energy balance Research to prevent excessive weight Gain among Youth (ENERGY) project: Design and methodology of the ENERGY cross-sectional survey

    PubMed Central

    2011-01-01

    Background Obesity treatment is by large ineffective long term, and more emphasis on the prevention of excessive weight gain in childhood and adolescence is warranted. To inform energy balance related behaviour (EBRB) change interventions, insight in the potential personal, family and school environmental correlates of these behaviours is needed. Studies on such multilevel correlates of EBRB among schoolchildren in Europe are lacking. The ENERGY survey aims to (1) provide up-to-date prevalence rates of measured overweight, obesity, self-reported engagement in EBRBs, and objective accelerometer-based assessment of physical activity and sedentary behaviour and blood-sample biomarkers of metabolic function in countries in different regions of Europe, (2) to identify personal, family and school environmental correlates of these EBRBs. This paper describes the design, methodology and protocol of the survey. Method/Design A school-based cross-sectional survey was carried out in 2010 in seven different European countries; Belgium, Greece, Hungary, the Netherlands, Norway, Slovenia, and Spain. The survey included measurements of anthropometrics, child, parent and school-staff questionnaires, and school observations to measure and assess outcomes (i.e. height, weight, and waist circumference), EBRBs and potential personal, family and school environmental correlates of these behaviours including the social-cultural, physical, political, and economic environmental factors. In addition, a selection of countries conducted accelerometer measurements to objectively assess physical activity and sedentary behaviour, and collected blood samples to assess several biomarkers of metabolic function. Discussion The ENERGY survey is a comprehensive cross-sectional study measuring anthropometrics and biomarkers as well as assessing a range of EBRBs and their potential correlates at the personal, family and school level, among 10-12 year old children in seven European countries. This study

  3. Association of breakfast intake with obesity, dietary and physical activity behavior among urban school-aged adolescents in Delhi, India: results of a cross-sectional study

    PubMed Central

    2012-01-01

    Background In developed countries, regular breakfast consumption is inversely associated with excess weight and directly associated with better dietary and improved physical activity behaviors. Our objective was to describe the frequency of breakfast consumption among school-going adolescents in Delhi and evaluate its association with overweight and obesity as well as other dietary, physical activity, and sedentary behaviors. Methods Design: Cross-sectional study. Setting: Eight schools (Private and Government) of Delhi in the year 2006. Participants: 1814 students from 8th and 10th grades; response rate was 87.2%; 55% were 8th graders, 60% were boys and 52% attended Private schools. Main outcome measures: Body mass index, self-reported breakfast consumption, diet and physical activity related behaviors, and psychosocial factors. Data analysis: Mixed effects regression models were employed, adjusting for age, gender, grade level and school type (SES). Results Significantly more Government school (lower SES) students consumed breakfast daily as compared to Private school (higher SES) students (73.8% vs. 66.3%; p<0.01). More 8th graders consumed breakfast daily vs.10th graders (72.3% vs. 67.0%; p<0.05). A dose–response relationship was observed such that overall prevalence of overweight and obesity among adolescents who consumed breakfast daily (14.6%) was significantly lower vs. those who only sometimes (15.2%) or never (22.9%) consumed breakfast (p<0.05 for trend). This relationship was statistically significant for boys (15.4 % vs. 16.5% vs. 26.0; p<0.05 for trend) but not for girls. Intake of dairy products, fruits and vegetables was 5.5 (95% CI 2.4-12.5), 1.7 (95% CI 1.1-2.5) and 2.2 (95% CI 1.3-3.5) times higher among those who consumed breakfast daily vs. those who never consumed breakfast. Breakfast consumption was associated with greater physical activity vs. those who never consumed breakfast. Positive values and beliefs about healthy eating; body image

  4. Seasonal variations in calcidiol and parathyroid hormone levels in healthy children and adolescents in Navarre, Spain: a cross-sectional study

    PubMed Central

    Gallinas-Victoriano, Fidel

    2016-01-01

    Objective To analyze the seasonal variations in calcidiol and parathyroid hormone serum levels along a natural year in a paediatric population living in a region of the north of Spain considering a normal nutrition status. Design A cross-sectional study. Setting Navarra Hospital Complex, Pamplona, Spain. Participants A total of 413 Caucasian individuals (aged 3.1 to 15.4 years): 227 school children (96 males and 131 females) and 186 adolescents (94 males and 92 females), with normal nutritional status. Main outcome measures Clinical examination (sex, age, weight, height and body mass index) and blood testing (calcium, phosphate, alkaline phosphatase, calcidiol and parathyroid hormone) during the year 2014. Results Calcidiol levels were lower during spring (25.96 ± 6.64 ng/mL) and reached its maximum level in summer (35.33 ± 7.51 ng/mL); parathyroid hormone levels were lower in summer (27.13 ± 7.89 pg/mL) and reached maximum level in autumn (34.73 ± 15.38 pg/mL). Hypovitaminosis D prevalence was 14.3% in summer and 75.3% in spring. Parathyroid hormone levels were compatible with secondary hyperparathyroidism in eight individuals (1.9%). There is a correlation (p < 0.01) between calcidiol and parathyroid hormone (r = −0.336). Logistic regression showed significant increased risk of hypovitaminosis in females (OR:1.63) and adolescents (OR:1.77), and when blood samples taken in autumn (OR:12.22), winter (OR:8.54) and spring (OR:19.72). Conclusions There is a high prevalence of hypovitaminosis D in the paediatric population with a healthy nutrition situation in Navarre, mainly during the months of autumn and winter, and, especially, in spring time. Given the difficulties in maintaining a sufficient amount of body vitamin D content along the year, it should be considered to give vitamin supplements and/or increase the intake of its natural dietary sources or vitamin D fortified foods. PMID:27066262

  5. Jet inclusive cross sections

    SciTech Connect

    Del Duca, V.

    1992-11-01

    Minijet production in jet inclusive cross sections at hadron colliders, with large rapidity intervals between the tagged jets, is evaluated by using the BFKL pomeron. We describe the jet inclusive cross section for an arbitrary number of tagged jets, and show that it behaves like a system of coupled pomerons.

  6. Relationship between attention-deficit/hyperactivity disorder and sedentary behavior in adolescence: a cross-sectional study.

    PubMed

    Suchert, Vivien; Pedersen, Anya; Hanewinkel, Reiner; Isensee, Barbara

    2017-04-04

    Existing studies reveal that high levels of sedentary behavior are associated with more inattention and hyperactivity problems. Since most previous studies used screen time as an indicator of sedentary behavior and assessed symptoms of attention-deficit/hyperactivity disorder (ADHD) by short screening measures which do not allow to distinguish between subtypes of ADHD, the current study aimed to investigate association between different types of sedentary behavior and symptoms and subtypes of ADHD. The current cross-sectional study analyzed data of 913 students (46.1% girls) aged 13-17 years (M = 15.0, SD = 0.6). Using a self-administered questionnaire, screen-based and non-screen-based sedentary behavior and ADHD symptoms were assessed. Linear and logistic regression analyses were conducted. All analyses were adjusted for age, gender, moderate to vigorous physical activity and body mass index. Screen time was related to the total ADHD score (p < 0.001) as well as to the subscales inattention (p ≤ 0.016) and hyperactivity/impulsivity (p ≤ 0.008). Sedentary time without screens was virtually not associated with ADHD. As far as ADHD symptoms are considered as a correlate of sedentary behavior, the type of activity which is pursued sedentarily seems to matter: screen time, but not other non-screen-based sedentary activities should be considered as being a risk factor for ADHD.

  7. Mental health clinicians' attitudes about consumer and consumer consultant participation in Australia: A cross-sectional survey design.

    PubMed

    McCann, Terence V; Clark, Eileen; Baird, John; Lu, Sai

    2008-06-01

    The purpose of this study was to assess mental health clinicians' attitudes about mental health consumer participation in inpatient psychiatric units. A cross-sectional survey design was used with a non-probability sample of 47 clinicians in the psychiatric units of a large Australian hospital. The results showed that gender, length of time as a clinician, and how long the staff worked in the units influenced their attitudes about consumer involvement. Females were more likely than males to support consumer participation in management and consumer consultants. Less experienced staff showed greater support than more experienced staff for mental health consumer involvement in treatment-related matters and consumer consultants in units. New staff members were more likely to register agreement-to-uncertainty regarding consumer involvement in treatment-related issues, whereas established staff members were more likely to record uncertainty about this issue. The findings showed that although reports and policies promoted participation, some clinicians were reluctant to accept consumer and consultant involvement.

  8. A Cross-Sectional and Follow-Up Functional MRI Study with a Working Memory Task in Adolescent Anorexia Nervosa

    ERIC Educational Resources Information Center

    Castro-Fornieles, Josefina; Caldu, Xavier; Andres-Perpina, Susana; Lazaro, Luisa; Bargallo, Nuria; Falcon, Carles; Plana, Maria Teresa; Junque, Carme

    2010-01-01

    Structural and functional brain abnormalities have been described in anorexia nervosa (AN). The objective of this study was to examine whether there is abnormal regional brain activation during a working memory task not associated with any emotional stimuli in adolescent patients with anorexia and to detect possible changes after weight recovery.…

  9. A Cross-Sectional Analysis of Social Engagement, Isolation and Loneliness for Children and Adolescents with Autism

    ERIC Educational Resources Information Center

    Mahjouri, Saara

    2011-01-01

    The first study examined the social and emotional experience of adolescents with autism spectrum disorders (ASDs) who are fully included in middle and high schools. Participants reported higher than average levels of loneliness and were observed to be isolated during most unstructured times. However, their depression and multidimensional anxiety…

  10. Cannabis Use and Memory Brain Function in Adolescent Boys: A Cross-Sectional Multicenter Functional Magnetic Resonance Imaging Study

    ERIC Educational Resources Information Center

    Jager, Gerry; Block, Robert I.; Luijten, Maartje; Ramsey, Nick F.

    2010-01-01

    Objective: Early-onset cannabis use has been associated with later use/abuse, mental health problems (psychosis, depression), and abnormal development of cognition and brain function. During adolescence, ongoing neurodevelopmental maturation and experience shape the neural circuitry underlying complex cognitive functions such as memory and…

  11. Mentoring Increases Connectedness and Knowledge: A Cross-Sectional Evaluation of Two Programs in Child and Adolescent Psychiatry

    ERIC Educational Resources Information Center

    Horner, Michelle S.; Miller, Susan Milam; Rettew, David C.; Althoff, Robert; Ehmann, Mary; Hudziak, James J.; Martin, Andres

    2008-01-01

    Objective: The authors assess changes in knowledge and feeling connected to the field of child and adolescent psychiatry (CAP) after participation in a brief mentoring program held at two CAP conferences. Methods: Similar mentorship programs were implemented at two CAP conferences, one national (N=119 participants), one international (N=53). The…

  12. Clustering of health-related behaviors, health outcomes and demographics in Dutch adolescents: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Recent studies show several health-related behaviors to cluster in adolescents. This has important implications for public health. Interrelated behaviors have been shown to be most effectively targeted by multimodal interventions addressing wider-ranging improvements in lifestyle instead of via separate interventions targeting individual behaviors. However, few previous studies have taken into account a broad, multi-disciplinary range of health-related behaviors and connected these behavioral patterns to health-related outcomes. This paper presents an analysis of the clustering of a broad range of health-related behaviors with relevant demographic factors and several health-related outcomes in adolescents. Methods Self-report questionnaire data were collected from a sample of 2,690 Dutch high school adolescents. Behavioral patterns were deducted via Principal Components Analysis. Subsequently a Two-Step Cluster Analysis was used to identify groups of adolescents with similar behavioral patterns and health-related outcomes. Results Four distinct behavioral patterns describe the analyzed individual behaviors: 1- risk-prone behavior, 2- bully behavior, 3- problematic screen time use, and 4- sedentary behavior. Subsequent cluster analysis identified four clusters of adolescents. Multi-problem behavior was associated with problematic physical and psychosocial health outcomes, as opposed to those exerting relatively few unhealthy behaviors. These associations were relatively independent of demographics such as ethnicity, gender and socio-economic status. Conclusions The results show that health-related behaviors tend to cluster, indicating that specific behavioral patterns underlie individual health behaviors. In addition, specific patterns of health-related behaviors were associated with specific health outcomes and demographic factors. In general, unhealthy behavior on account of multiple health-related behaviors was associated with both poor psychosocial

  13. Bullying behaviour in schools, socioeconomic position and psychiatric morbidity: a cross-sectional study in late adolescents in Greece

    PubMed Central

    2012-01-01

    Background Bullying is quite prevalent in the school setting and has been associated with the socioeconomic position and psychiatric morbidity of the pupils. The aim of the study was to investigate the association between bullying and socioeconomic status in a sample of Greek adolescents and to examine whether this is confounded by the presence of psychiatric morbidity, including sub-threshold forms of illness. Methods 5,614 adolescents aged 16-18 years old and attending 25 senior high schools were screened and a stratified random sample of 2,427 were selected for a detailed interview. Psychiatric morbidity was assessed with a fully structured psychiatric interview, the revised Clinical Interview Schedule (CIS-R), while bullying was assessed with the revised Olweus bully/victim questionnaire. The following socio-economic variables were assessed: parental educational level and employment status, financial difficulties of the family and adolescents' school performance. The associations were investigated using multinomial logit models. Results 26.4% of the pupils were involved in bullying-related behaviours at least once monthly either as victims, perpetrators or both, while more frequent involvement (at least once weekly) was reported by 4.1%. Psychiatric morbidity was associated with all types of bullying-related behaviours. No socioeconomic associations were reported for victimization. A lower school performance and unemployment of the father were significantly more likely among perpetrators, while economic inactivity of the mother was more likely in pupils who were both victims and perpetrators. These results were largely confirmed when we focused on high frequency behaviours only. In addition, being overweight increased the risk of frequent victimization. Conclusions The prevalence of bullying among Greek pupils is substantial. Perpetration was associated with some dimensions of adolescents' socioeconomic status, while victimization showed no socioeconomic

  14. Influence of health behaviours on the incidence of infection and allergy in adolescents: the AFINOS cross-sectional study

    PubMed Central

    2014-01-01

    Background Some health behaviours are liable to affect the incidence of allergies and/or common infections in young people; however, the extent and ways in which these might occur are mostly unknown. This study examines the association of health behaviours related to physical activity, sedentariness, diet and sleep with allergy and infection symptoms in adolescents, and also with biological markers that might mediate disease incidence. Methods The study comprised a total of 2054 adolescents (50.7% girls) from the Madrid region of Spain. The incidence of infection and allergy symptoms three months prior to the study was obtained from a self-administered questionnaire. Physical and sedentary activities, height and weight, food habits and sleep duration were also self-reported and their influence on infection and allergy incidence was assessed by logistic regression analysis. Blood biomarkers (IgE, eosinophil percentage, leptin, interleukin (IL)-2, IL-4, IL-5 and IL-10) were evaluated in a subsample of 198 subjects. Results Adequate sleep duration (OR = 0.79, 95%CI: 0.64 to 0.97) and unhealthy weight status (overweight/obesity) (OR = 1.35, 95%CI: 1.04-1.74) were independently associated with decreased and increased allergy incidence, respectively. No significant association was observed with infection incidence. IgE and leptin differed between adolescents with and without allergy symptoms. In regression models IgE was significantly associated with inadequate sleep duration and leptin with weight status. Conclusion Excess weight and inadequate sleep duration are independently associated with the incidence of allergy symptoms in adolescents. Adequate sleep duration and weight during adolescence might be relevant for a decreased risk of suffering allergy symptoms. PMID:24405509

  15. Intraclass correlation and design effect in BMI, physical activity and diet: a cross-sectional study of 56 countries

    PubMed Central

    Masood, Mohd; Reidpath, Daniel D

    2016-01-01

    Objectives Measuring the intraclass correlation coefficient (ICC) and design effect (DE) may help to modify the public health interventions for body mass index (BMI), physical activity and diet according to geographic targeting of interventions in different countries. The purpose of this study was to quantify the level of clustering and DE in BMI, physical activity and diet in 56 low-income, middle-income and high-income countries. Design Cross-sectional study design. Setting Multicountry national survey data. Methods The World Health Survey (WHS), 2003, data were used to examine clustering in BMI, physical activity in metabolic equivalent of task (MET) and diet in fruits and vegetables intake (FVI) from low-income, middle-income and high-income countries. Multistage sampling in the WHS used geographical clusters as primary sampling units (PSU). These PSUs were used as a clustering or grouping variable in this analysis. Multilevel intercept only regression models were used to calculate the ICC and DE for each country. Results The median ICC (0.039) and median DE (1.82) for BMI were low; however, FVI had a higher median ICC (0.189) and median DE (4.16). For MET, the median ICC was 0.141 and median DE was 4.59. In some countries, however, the ICC and DE for BMI were large. For instance, South Africa had the highest ICC (0.39) and DE (11.9) for BMI, whereas Uruguay had the highest ICC (0.434) for MET and Ethiopia had the highest ICC (0.471) for FVI. Conclusions This study shows that across a wide range of countries, there was low area level clustering for BMI, whereas MET and FVI showed high area level clustering. These results suggested that the country level clustering effect should be considered in developing preventive approaches for BMI, as well as improving physical activity and healthy diets for each country. PMID:26743697

  16. Parenting, identity development, internalizing symptoms, and alcohol use: a cross-sectional study in a group of Italian adolescents

    PubMed Central

    Pellerone, Monica; Tolini, Giacomo; Polopoli, Caterina

    2016-01-01

    Background Literature has demonstrated the adaptive function of identity development and parenting toward manifestation of problem behaviors in adolescence. These dimensions act on both internalizing and externalizing symptoms. Methods The objective is to investigate the relationship between identity status, parenting, and adolescent problems, which may manifest through internalized (phobias, obsessions, depression, eating disorders, entropy) and externalized modes (alcohol use and school discomfort). The research involved 198 Italian students (104 males and 94 females) in the 4th year (mean =16.94 years, standard deviation =0.35) and 5th year (mean =17.94 years, standard deviation =0.43) of senior secondary schools, who live in Caltanissetta, a town located in Sicily, Italy. The research lasted for 1 school year. The general group consisted of 225 students with a mortality rate of 12%. They completed an anamnestic questionnaire to provide 1) basic information, 2) alcohol consumption attitude in the past 30 days, and 3) their beliefs about alcohol; the “Ego Identity Process Questionnaire” to investigate identity development; the “Parental Bonding Instrument” to measure the perception of parenting during childhood; and the “Constraints of Mind” to value the presence of internalizing symptoms. Results Data show that identity status influences alcohol consumption. Low-profile identity and excessive maternal control affect the relational dependence and the tendency to perfectionism in adolescents. Among the predictors of alcohol use, there are socioeconomic status, parental control, and the presence of internalizing symptoms. Conclusion Family is the favored context of learning beliefs, patterns, and values that affect the broader regulatory social environment, and for this reason, it is considered the privileged context on which to intervene to reduce the adolescents’ behavior problems. This deviance could be an external manifestation of the difficulty

  17. Gingival proliferative lesions in children and adolescents in Brazil: A 15-year-period cross-sectional study

    PubMed Central

    daSilva, Fabiana Caroline; Piazzetta, Cleto Mariosvaldo; Torres-Pereira, Cassius Carvalho; Schussel, Juliana Lucena; Amenábar, José Miguel

    2016-01-01

    Background: Studies assessing the prevalence of oral lesions in children and adolescents, particularly in gingiva are scarce in the literature. The aim of the study was to describe the distribution of gingival proliferative lesions based on clinical and histopathological diagnoses in children and adolescents. Materials and Methods: A review of clinical charts of children and adolescents aged between 0 and 18 years old, admitted to the Oral Medicine Outpatient Unit, of Universidade Federal do Paraná, for 15 years (1994–2009) was performed. Results: Six hundred and sixty-nine out of 5,129 patients treated during this period were aged between 0 and 18 years old, and 45 of these had gingival lesions. The largest number of lesions was observed between 11 and 16 years old. The majority of the patients were referred by Curitiba's public health system. Pyogenic granuloma was the most frequent lesion (19 = 42.2%), followed by peripheral giant cell lesion (11 = 24.4%), gingival fibromatosis (10 = 22.2%), and peripheral ossifying fibroma (5 = 11.1%). Conclusion: Gingival proliferative lesions can show similar clinical characteristics. Appropriate clinical and histopathological diagnoses are necessary to guide the healthcare professional to establish the adequate treatment and to estimate the risk of recurrence. PMID:27041840

  18. Physical self-concept and self-esteem mediate cross-sectional relations of physical activity and sport participation with depression symptoms among adolescent girls.

    PubMed

    Dishman, Rod K; Hales, Derek P; Pfeiffer, Karin A; Felton, Gwen A; Saunders, Ruth; Ward, Dianne S; Dowda, Marsha; Pate, Russell R

    2006-05-01

    The authors tested whether physical self-concept and self-esteem would mediate cross-sectional relations of physical activity and sport participation with depression symptoms among 1,250 girls in 12th grade. There was a strong positive relation between global physical self-concept and self-esteem and a moderate inverse relation between self-esteem and depression symptoms. Physical activity and sport participation each had an indirect, positive relation with global physical self-concept that was independent of objective measures of cardiorespiratory fitness and body fatness. These correlational findings provide initial evidence suggesting that physical activity and sport participation might reduce depression risk among adolescent girls by unique, positive influences on physical self-concept that operate independently of fitness, body mass index, and perceptions of sports competence, body fat, and appearance.

  19. Breakfast Consumption and Its Associations with Health-Related Behaviors among School-Aged Adolescents: A Cross-Sectional Study in Zhejiang Province, China

    PubMed Central

    Wang, Meng; Zhong, Jie-Ming; Wang, Hao; Zhao, Ming; Gong, Wei-Wei; Pan, Jin; Fei, Fang-Rong; Wu, Hai-Bin; Yu, Min

    2016-01-01

    Evidence indicates that breakfast consumption is associated with a cluster of health-related behaviors, yet studies in mainland China are scarce. This study is conducted to describe the frequency of breakfast consumption among Chinese adolescents and examine its associations with other dietary, physical activity, sedentary, sleep, cigarette-smoking, and alcohol-drinking behaviors. Breakfast consumption and other health-related behaviors data was collected via a self-administered questionnaire in a cross-sectional study in Zhejiang Province, China. A total of 19,542 school-aged adolescents were recruited in this survey. The associations between breakfast consumption and other health-related behaviors were examined using logistic regression models. A significantly higher prevalence of daily breakfast consumption was found among students who were younger (p for trend <0.001), from urban schools (p < 0.001), and academic high schools (p < 0.001). More frequent vegetable and milk consumption, greater physical activity, and longer sleep duration were positively associated with daily breakfast consumption, while soft drinks and fast food consumption, computer use, cigarette-smoking and alcohol-drinking behaviors were inversely associated. The prevalence of irregular breakfast consumption was relatively high among Chinese adolescents in Zhejiang Province. Daily breakfast consumption was associated with a constellation of health-related behaviors. PMID:27472357

  20. Social capital in relation to alcohol consumption, smoking, and illicit drug use among adolescents: a cross-sectional study in Sweden

    PubMed Central

    2013-01-01

    Background Social capital has lately received much attention in public health research. However, few studies have examined the influence of social capital on alcohol consumption, smoking and drug use which have strong influence on public health. The present cross-sectional study investigated whether two measures of social capital were related to substance use in a large population of Swedish adolescents. Methods A total of 7757 13–18 year old students (participation rate: 78.2%) anonymously completed the Survey of Adolescent Life in Vestmanland 2008 which included questions on sociodemographic background, neighbourhood social capital, general social trust, alcohol consumption, smoking, and illicit drug use. Results Individuals within the group with low neighbourhood social capital had an approximately 60% increased odds of high alcohol consumption, more than three times increased odds of smoking and more than double the odds of having used illicit drugs compared with individuals with high neighbourhood social capital. Individuals within the group with low general social trust had approximately 50% increased odds of high alcohol consumption and double the odds of smoking and having used illicit drugs compared with individuals with high general social trust. However, social capital at the contextual level showed very weak effects on alcohol consumption, smoking, and illicit drug use. Conclusions Social capital may be an important factor in the future development of prevention programs concerning adolescent substance use. However, further replications of the results as well as identifications of direction of causality are needed. PMID:23688242

  1. Breakfast Consumption and Its Associations with Health-Related Behaviors among School-Aged Adolescents: A Cross-Sectional Study in Zhejiang Province, China.

    PubMed

    Wang, Meng; Zhong, Jie-Ming; Wang, Hao; Zhao, Ming; Gong, Wei-Wei; Pan, Jin; Fei, Fang-Rong; Wu, Hai-Bin; Yu, Min

    2016-07-27

    Evidence indicates that breakfast consumption is associated with a cluster of health-related behaviors, yet studies in mainland China are scarce. This study is conducted to describe the frequency of breakfast consumption among Chinese adolescents and examine its associations with other dietary, physical activity, sedentary, sleep, cigarette-smoking, and alcohol-drinking behaviors. Breakfast consumption and other health-related behaviors data was collected via a self-administered questionnaire in a cross-sectional study in Zhejiang Province, China. A total of 19,542 school-aged adolescents were recruited in this survey. The associations between breakfast consumption and other health-related behaviors were examined using logistic regression models. A significantly higher prevalence of daily breakfast consumption was found among students who were younger (p for trend <0.001), from urban schools (p < 0.001), and academic high schools (p < 0.001). More frequent vegetable and milk consumption, greater physical activity, and longer sleep duration were positively associated with daily breakfast consumption, while soft drinks and fast food consumption, computer use, cigarette-smoking and alcohol-drinking behaviors were inversely associated. The prevalence of irregular breakfast consumption was relatively high among Chinese adolescents in Zhejiang Province. Daily breakfast consumption was associated with a constellation of health-related behaviors.

  2. Bullying, Depression, and Suicidal Ideation Among Adolescents in the Fujian Province of China: A Cross-sectional Study.

    PubMed

    Hong, Lingyao; Guo, Lan; Wu, Hong; Li, Pengsheng; Xu, Yan; Gao, Xue; Deng, Jianxiong; Huang, Guoliang; Huang, Jinghui; Lu, Ciyong

    2016-02-01

    The relationship of bullying with suicidal ideation among adolescents is controversial. Although depression has been related to bullying and suicidal ideation, little is known about the combined impacts of depression and bullying on suicidal ideation.A sample of 20,509 high school students from Fujian Province were selected randomly by multistage stratified sampling. All participants completed an adolescent health status questionnaire. Three categories of bullying were assessed: perpetration, victimization, and both (victimization and perpetration). The associations of these 3 categories of bullying with depression and their interaction with suicidal ideation were examined in logistic models.After adjustment for potential confounders, all 3 categories of bullying (perpetration, victimization, and both) were related to increased risk of suicidal ideation with odds ratios (ORs) of 1.66 (95% confidence interval [CI] 1.20-2.30), 2.74 (95% CI 2.29-3.29), and 2.83 (95% CI 2.27-3.52), respectively. There was an interaction between depression and bullying (P = 0.001). Subgroup analyses showed a stronger association between perpetration and suicidal ideation in students with depression (odds ratio [OR] 2.97; 95% CI 1.44-6.09) than in those without depression (OR 1.65; 95% CI 1.19-2.28). The association between victimization and suicidal ideation was weaker in students with depression (OR 1.49; 95% CI 1.07-2.07) than in those without (OR 2.69; 95% CI 2.24-3.23). The association of both victimization and perpetration with suicidal ideation was weaker in students with depression (OR 2.22, 95% CI 1.43-3.47) than those without (OR 2.78; 95% CI 2.23-3.47).We observed an independent association of bullying with increased risk of suicidal ideation among adolescent students, and this association was affected by depression. Prospective studies should be conducted to confirm these findings.

  3. Cross-section and panel estimates of peer effects in early adolescent cannabis use: With a little help from my 'friends once removed'.

    PubMed

    Moriarty, John; McVicar, Duncan; Higgins, Kathryn

    2016-08-01

    Peer effects in adolescent cannabis are difficult to estimate, due in part to the lack of appropriate data on behaviour and social ties. This paper exploits survey data that have many desirable properties and have not previously been used for this purpose. The data set, collected from teenagers in three annual waves from 2002 to 2004 contains longitudinal information about friendship networks within schools (N = 5020). We exploit these data on network structure to estimate peer effects on adolescents from their nominated friends within school using two alternative approaches to identification. First, we present a cross-sectional instrumental variable (IV) estimate of peer effects that exploits network structure at the second degree, i.e. using information on friends of friends who are not themselves ego's friends to instrument for the cannabis use of friends. Second, we present an individual fixed effects estimate of peer effects using the full longitudinal structure of the data. Both innovations allow a greater degree of control for correlated effects than is commonly the case in the substance-use peer effects literature, improving our chances of obtaining estimates of peer effects than can be plausibly interpreted as causal. Both estimates suggest positive peer effects of non-trivial magnitude, although the IV estimate is imprecise. Furthermore, when we specify identical models with behaviour and characteristics of randomly selected school peers in place of friends', we find effectively zero effect from these 'placebo' peers, lending credence to our main estimates. We conclude that cross-sectional data can be used to estimate plausible positive peer effects on cannabis use where network structure information is available and appropriately exploited.

  4. C-reactive protein, physical activity and cardiorespiratory fitness in Portuguese adolescents: a cross-sectional study.

    PubMed

    Agostinis Sobrinho, Cesar Aparecido; Moreira, Carla Marisa Maia; Mota, Jorge Augusto Pinto da Silva; Santos, Rute Marina Roberto

    2015-09-01

    The goal of this study was to investigate the association of physical activity (PA) and cardiorespiratory fitness with C-reactive protein (CRP) concentration in adolescents. The sample included 386 Portuguese adolescents (n = 207, female), age 12-18 years, assessed in the year 2012. The PA was assessed with the use of accelerometers, and the cardiorespiratory fitness was assessed by the Fitnessgram Pacer test. Blood samples were collected after a 10-hour fasting, and high-sensitivity PCR concentration was further assessed. Significant associations between CRP and cardiorespiratory fitness were found for females (r = -0.313; p < 0.001) and males (r = -0.163; p < 0.05); however, when adjusted by the BMI, the associations remained significant only for females (r = -0.215; p < 0.001). Regarding the association between CRP and PA, no significant associations were found for both genders. Therefore, CRP is apparently negatively associated with cardiorespiratory fitness, with differences between males and females; for females it seems less dependent than BMI.

  5. Exploring the Relationship between Static and Dynamic Vertical Scaling from Cross-Sectional and Longitudinal Design Perspectives

    ERIC Educational Resources Information Center

    Wang, Shudong; Jiao, Hong; Jiang, Yanming

    2009-01-01

    The concept of dynamic vertical scaling (DVS) from longitudinal point of view has been proposed as comparing to traditional vertical scaling or static vertical scaling (SVS) from cross-sectional perspective. The effects of differences between DVS and SVS on large-scale student achievements have been investigated. The potential application of DVS…

  6. Adult Life-Span Patterns in WAIS-R Block Design Performance: Cross-Sectional versus Longitudinal Age Gradients and Relations to Demographic Factors

    ERIC Educational Resources Information Center

    Ronnlund, Michael; Nilsson, Lars-Goran

    2006-01-01

    Aging patterns in WAIS-R Block Design Test (BDT) were examined cross-sectionally and longitudinally. One sample (35-80 years, n=1000) was assessed in 1988-1990 and five years later (836 returned). An independent cohort-matched sample (n=974) was assessed at Time 2 to control for practice effects. Relations between BDT, gender, and education were…

  7. The association between adolescent risk behaviours and feelings of sadness or hopelessness: a cross-sectional survey of South African secondary school learners.

    PubMed

    James, Shamagonam; Reddy, Sasiragha Priscilla; Ellahebokus, Afzal; Sewpaul, Ronel; Naidoo, Pamela

    2017-03-14

    Poor mental health in adolescents has shown associations with engagement in other risk behaviours. However, evidence of this association in Sub-Saharan Africa, particularly South Africa, is lacking. This study examines the associations between pertinent risk behaviours and feelings of sadness or hopelessness amongst a nationally representative sample of South African school going adolescents. Data was analysed from the South African Youth Risk Behaviour Survey 2011 (n=10,997), a cross-sectional national survey among grades 8-11 school learners. Logistic regression examined the association of demographic, substance use, violent behaviour, sexual activity and suicidal plans and attempts with the primary outcome, feelings of sadness or hopelessness. Having feelings of sadness or hopelessness was significantly associated with more senior grades, being bullied (AOR:1.67, 95% CI: 1.42-1.96), being assaulted by a partner (1.33 [1.05-1.68]), forced sex (1.78 [1.37-2.32]); gang membership (1.32 [1.06-1.65]), binge drinking (1.37 [1.14-1.65]), ever having sex (1.23 [1.02-1.47]), having ≥1 partner/s in preceding three months (1.25 [1.02-1.53]), having made a plan to attempt suicide (2.50 [1.95-3.21]) and suicide attempt (1.49 [1.21-1.85]). Adolescents in South Africa are experiencing a multiple burden of risk. Health promotion strategies targeting adolescent mental health and risk behaviours need to be developed and implemented in a timely and comprehensive manner.

  8. Clinical Profile and Comorbidity of Obsessive-Compulsive Disorder among Children and Adolescents: A Cross-Sectional Observation in Bangladesh

    PubMed Central

    Chowdhury, Md. Hafizur Rahman; Mullick, Mohammad S. I.

    2016-01-01

    Obsessive compulsive disorder (OCD) is a common disorder characterised by persistent and unwanted intrusive thoughts, images, and urges and repetitive behaviours or mental acts and can cause pervasive impairments. In Bangladesh, the prevalence of OCD among children is 2% which is higher than in previous reporting. This study was aimed at looking into the type, frequency, and severity of symptoms of OCD and comorbidity among children and adolescents. A consecutive 60 OCD cases from a child mental health service with age range of 5–18 years were recruited and divided into below and above 12 years of age group. The assessment was carried out using standardized Bangla version of Development and Wellbeing Assessment and Children's Yale-Brown Obsessive Compulsive Scale was administered. Of the obsession, contamination was the highest followed by doubt, and of the compulsion, washing/cleaning was the highest followed by checking, repeating, and ordering rituals. More than half of the subjects had severe OCD and comorbidity was present in 58% subjects. Specific phobia, social phobia, major depressive disorder, and tic disorder were more prevalent. These symptoms and comorbidity profile can serve the baseline data for a country like Bangladesh and further large scale study would better generalize the study results. PMID:28070501

  9. Delinquent and Aggressive Behavior and Social Desirability Among Roma and Non-Roma Adolescents in Slovakia: A Cross-Sectional Study.

    PubMed

    Kolarcik, Peter; Madarasova Geckova, Andrea; Reijneveld, Sijmen A; van Dijk, Jitse P

    2016-02-01

    Rates of aggression and delinquency are assumed to be higher among Roma and other minorities, but sound evidence of this is lacking. Our aim was to assess delinquent and aggressive behavior among Roma and non-Roma adolescents and the effects on ethnic differences of parental education and social desirability. We conducted a cross-sectional study among Roma from separated and segregated settlements in the eastern part of Slovakia (N = 330; Mage = 14.50; interview) and non-Roma adolescents (N = 722; Mage = 14.86; questionnaire). The effect of ethnicity on antisocial behaviors was analyzed using linear regression (crude) and adjusted for gender, parental education, and social desirability. Adjustment for social desirability diminished the ethnic differences in delinquency (B = 1.08; 95% confidence interval [CI] = [2.12, -0.04]), led to an increase in the differences in hostility (B = 2.43; 95% CI = [0.87, 3.99]), and led to the disappearance of differences in physical aggression (B = 0.45; 95% CI = [1.14, 2.07]). Parental education did not affect the associations in an important way. Our findings indicate that Roma are not that much different from non-Roma, in terms of antisocial behavior, which contradicts the general perception of Roma. Our findings should be confirmed in other settings.

  10. Substance abuse in early adolescents and HIV preventive behaviors: findings from a school-based cross-sectional survey for the period from 2009 to 2013, Bangkok Thailand.

    PubMed

    Thepthien, B; Altaf, L; Chuchareon, P; Srivanichakron, S

    2016-10-01

    This study is first of its kind in Bangkok, and is a five-year (2009-2013) cross-sectional web-based survey to examine HIV preventive behaviors related to substance abuse among adolescents (N = 16,913). The questionnaire was self-administered. Logistic regression was used to analyze the data. The relationship between different types of substance abuse with risky and preventive behaviors was assessed. Male participants reported more substance abuse as compared to females. The risk behaviors observed among the substance abusers include increased sexual experience, multiple sex partners, no use of condoms, and injection drug use. The preventive behaviors include having a high self-risk assessment, going for HIV testing (highest in methamphetamine users), and screening for sexually transmitted infection. Logistic regression suggests that risky behaviors (e.g., sexual experience, injection drug use) are more common in substance abusers. Adolescents are clearly at a high risk. Behavioral preventive measures are needed to reduce or delay premature substance exposure to prevent a wide range of health problems and risks such as HIV and AIDS, injection drug use and unprotected sex.

  11. Adolescent Bullying Involvement and Psychosocial Aspects of Family and School Life: A Cross-Sectional Study from Guangdong Province in China

    PubMed Central

    Lu, Ciyong; Wu, Jie; Deng, Xueqing; Hong, Lingyao; Gao, Xue; He, Yuan

    2012-01-01

    Background School bullying is an emerging problem in China. The present study aimed to measure the prevalence of bullying behaviors among Chinese adolescents and to examine the association of bullying and being bullied with family factors, school factors and indicators of psychosocial adjustment. Methods A cross-sectional study was conducted. A total of 8,342 middle school students were surveyed in four cities in the Guangdong Province. Self-reports on bullying involvement and information regarding family factors, school factors and psychosocial adjustment were collected. Descriptive statistics and multi-level logistic regression analysis were used to evaluate the prevalence of school bullying and explore potentially influential factors. Results Of the total sample, 20.83% (1,738) reported being involved in bullying behaviors. Of the respondents, 18.99% were victims of bullying, 8.60% were bullies and 6.74% both bullied themselves and bullied others. Factors that were determined to be correlated with bullying behaviors included grade, parental caring, consideration of suicide, running away from home, time spent online per day and being in a physical fight. Conclusion Bullying was determined to be prevalent among Chinese adolescents. Given the concurrent psychosocial adjustment, family and school factors associated with bullying, as well as the potential long-term negative outcomes for these youth, this issue merits serious attention, both for future research and preventive intervention. PMID:22815693

  12. Relational Factors of Vulnerability and Protection for Adolescent Pregnancy: A Cross-Sectional Comparative Study of Portuguese Pregnant and Nonpregnant Adolescents of Low Socioeconomic Status

    ERIC Educational Resources Information Center

    Pereira, Ana I. F.; Canavarro, Maria C.; Cardoso, Margarida F.; Mendonca, Denisa

    2005-01-01

    This study explores multiple relational contexts that promote vulnerability and protection against early pregnancy in a potential risk group of Portuguese adolescents. A comparative analysis was made between two groups of female adolescents of low socioeconomic status: pregnant adolescents (n = 57) and adolescents without a history of pregnancy (n…

  13. Family Structure, Mother-Child Communication, Father-Child Communication, and Adolescent Life Satisfaction: A Cross-Sectional Multilevel Analysis

    ERIC Educational Resources Information Center

    Levin, Kate A.; Currie, Candace

    2010-01-01

    Purpose: The purpose of this paper is to investigate the association between mother-child and father-child communication and children's life satisfaction, and the moderating effect of communication with stepparents. Design/methodology/approach: Data from the 2006 Health Behaviour in School-aged Children: WHO-collaborative Study in Scotland…

  14. Self-Reported Speech Problems in Adolescents and Young Adults with 22q11.2 Deletion Syndrome: A Cross-Sectional Cohort Study

    PubMed Central

    Vorstman, Jacob AS; Kon, Moshe; Mink van der Molen, Aebele B

    2014-01-01

    Background Speech problems are a common clinical feature of the 22q11.2 deletion syndrome. The objectives of this study were to inventory the speech history and current self-reported speech rating of adolescents and young adults, and examine the possible variables influencing the current speech ratings, including cleft palate, surgery, speech and language therapy, intelligence quotient, and age at assessment. Methods In this cross-sectional cohort study, 50 adolescents and young adults with the 22q11.2 deletion syndrome (ages, 12-26 years, 67% female) filled out questionnaires. A neuropsychologist administered an age-appropriate intelligence quotient test. The demographics, histories, and intelligence of patients with normal speech (speech rating=1) were compared to those of patients with different speech (speech rating>1). Results Of the 50 patients, a minority (26%) had a cleft palate, nearly half (46%) underwent a pharyngoplasty, and all (100%) had speech and language therapy. Poorer speech ratings were correlated with more years of speech and language therapy (Spearman's correlation= 0.418, P=0.004; 95% confidence interval, 0.145-0.632). Only 34% had normal speech ratings. The groups with normal and different speech were not significantly different with respect to the demographic variables; a history of cleft palate, surgery, or speech and language therapy; and the intelligence quotient. Conclusions All adolescents and young adults with the 22q11.2 deletion syndrome had undergone speech and language therapy, and nearly half of them underwent pharyngoplasty. Only 34% attained normal speech ratings. Those with poorer speech ratings had speech and language therapy for more years. PMID:25276637

  15. Activation in Context: Differential Conclusions Drawn from Cross-Sectional and Longitudinal Analyses of Adolescents' Cognitive Control-Related Neural Activity.

    PubMed

    McCormick, Ethan M; Qu, Yang; Telzer, Eva H

    2017-01-01

    Although immature cognitive control, subserved by late-developing prefrontal regions, has been proposed to underlie increased risk taking during adolescence, it remains unclear what patterns of PFC activation represent mature brain states: more or less activation? One challenge to drawing cogent conclusions from extant work stems from its reliance on single-time point neuroimaging and cross-sectional comparisons, which are ill-suited for assessing the complex changes that characterize adolescence. This necessitates longitudinal fMRI work to track within-subject changes in PFC function and links to risk-taking behavior, which can serve as an external marker for maturation of neural systems involved in cognitive control. In the current study, 20 healthy adolescents (13 males) completed a go/nogo task during two fMRI scans, once at age 14 years and again at age 15 years. We found that the association between cognitive control-related VLPFC activation and risk-taking behavior reversed when examining wave 1 (W1) versus longitudinal change (W2 > W1) and wave 2 (W2) in neural activation, such that increased VLPFC activation at W1 was associated with lower risk taking, whereas longitudinal increases in cognitive control-related VLPFC activation as well as heightened VLPFC activation at W2 were associated with greater risk taking. Several steps were taken to disentangle potential alternative accounts that might explain these disparate results across time. Findings highlight the necessity of considering brain-behavior relationships in the context of ongoing developmental changes and suggests that using neuroimaging data at a single time point to predict behavioral changes can introduce interpretation errors when failing to account for changes in neural trajectories.

  16. Disturbed eating behavior in Iranian adolescent and young females with type-1 diabetes compared to non diabetic peers: A cross-sectional study

    PubMed Central

    Roohafza, Hamid Reza; Abdeyazdan, Zahra; Amini, Parvaneh; Pahlavanzadeh, Saied; Shokouh, Pedram

    2016-01-01

    Background: An association of eating disorder with diabetes mellitus may lead to a serious lack of metabolic control, higher mortality and morbidity. There is no recent study conducted in the Iranian population about eating disorder and its variants. The aim of the present study is investigation of frequency of disturbed eating behaviors in adolescent girls with type 1 diabetes mellitus (T1DM) compared to non-diabetics. Materials and Methods: In this cross-sectional study, disturbed eating behavior were evaluated and compared in two groups of 12–22 year old adolescent and young females (126 with diabetes and 325 without diabetes). A self-report questionnaire including demographic data, Children's Depression Inventory (CDI), and Eating Attitude Test (EAT-26) was used for data gathering. Independent t-test, Chi-square test, and logistic regression [odds ratio (OR)] were used for data analyses in SPSS 15. Results: Findings revealed that higher percentage of diabetic girls are likely to have eating disturbances (67.9% vs. 53.8%, P = 0.01). Diabetic group obtained higher scores in both dieting (14.95 ± 6.28 vs. 11.79 ± 5.62, P < 0.001) and bulimia scales (4.9 ± 3.13 vs. 4.12 ± 2.89, P = 0.017), which supports a role for T1DM in inducing the symptoms. Diabetic girls were at more than double the risk of developing eating disturbance. Conclusions: The results indicate that a significantly higher percentage of diabetic girls are likely to have eating disturbances. Also, diabetic subjects had an increased probability of getting higher scores in all three EAT-26 subscales. Therefore, healthcare professionals, especially diabetic nurses, should be aware of the potential effects of the subclinical and clinical eating behaviors on adolescents with T1DM and evaluate them for these disturbances. PMID:27904642

  17. The association of nonalcoholic fatty liver disease with central and peripheral blood pressure in adolescence: findings from a cross-sectional study

    PubMed Central

    Patel, Sumaiya; Lawlor, Debbie A.; Ferreira, Diana L.S.; Hughes, Alun D.; Chaturvedi, Nish; Callaway, Mark; Day, Chris; Sattar, Naveed; Fraser, Abigail

    2015-01-01

    Objectives: We aimed to determine the association of nonalcoholic fatty liver disease (NAFLD) with central and peripheral blood pressure (BP), in a general adolescent population and to examine whether associations are independent of adiposity. Methods: Using cross-sectional data from a subsample (N = 1904) of a UK birth cohort, we assessed markers of NAFLD including ultrasound scan (USS) determined fatty liver, shear velocity (marker of liver fibrosis), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) at a mean age of 17.8 years. These were related to BP [central and peripheral SBP and DBP and mean arterial pressure (MAP)]. Results: Fatty liver was positively associated with central and peripheral SBP, DBP and MAP in models adjusting for age, sex, social class, puberty and alcohol intake. These positive associations were attenuated to the null when fat mass was included. For example, in confounder-adjusted models, not including fat mass, mean central SBP was 3.74 mmHg [95% confidence interval (CI) 1.12 to 6.36] higher in adolescents with USS fatty liver than in those without; with additional adjustment for fat mass, the association attenuated to the null value (−0.37 mmHg; 95% CI –3.09 to 2.36). Similar patterns were found for associations of ALT and GGT with central and peripheral BP. There was no consistent evidence of associations of shear velocity or AST with BP measurements. Fatty liver was not consistently associated with central pulse pressure (PP), peripheral PP and Aix@75. Conclusion: NAFLD is not associated with higher central or peripheral BP in adolescents once confounding by adiposity is taken into account. PMID:25426570

  18. Thinking dimensional: prevalence of DSM-5 early adolescent full syndrome, partial and subthreshold eating disorders in a cross-sectional survey in German schools

    PubMed Central

    Hammerle, Florian; Huss, Michael; Ernst, Verena; Bürger, Arne

    2016-01-01

    Objectives Investigating for the first time in Germany Diagnostic and Statistical Manual Fifth Edition (DSM-5) prevalences of adolescent full syndrome, Other Specified Feeding or Eating Disorder (OSFED), partial and subthreshold anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED). Method A national school-based cross-sectional survey with nine schools in Germany was undertaken that was aimed at students from grades 7 and 8. Of the 1775 students who were contacted to participate in the study, 1654 participated (participation rate: 93.2%). The sample consisted of 873 female and 781 male adolescents (mean age=13.4 years). Prevalence rates were established using direct symptom criteria with a structured inventory (SIAB-S) and an additional self-report questionnaire (Eating Disorder Inventory 2 (EDI-2)). Results Prevalences for full syndrome were 0.3% for AN, 0.4% for BN, 0.5% for BED and 3.6% for OSFED-atypical AN, 0% for BN (low frequency/limited duration), 0% for BED (low frequency/limited duration) and 1.9% for purging disorder (PD). Prevalences of partial syndrome were 10.9% for AN (7.1% established with cognitive symptoms only, excluding weight criteria), 0.2% for BN and 2.1% for BED, and of subthreshold syndrome were 0.8% for AN, 0.3% for BN and 0.2% for BED. Cases on EDI-2 scales were much more pronounced with 12.6–21.1% of the participants with significant sex differences. Conclusions The findings were in accordance with corresponding international studies but were in contrast to other German studies showing much higher prevalence rates. The study provides, for the first time, estimates for DSM-5 prevalences of eating disorders in adolescents for Germany, and evidence in favour of using valid measures for improving prevalence estimates. Trial registration number DRKS00005050; Results. PMID:27150185

  19. Relational factors of vulnerability and protection for adolescent pregnancy: a cross-sectional comparative study of Portuguese pregnant and nonpregnant adolescents of low socioeconomic status.

    PubMed

    Pereira, Ana I F; Canavarro, Maria C; Cardoso, Margarida F; Mendonça, Denisa

    2005-01-01

    This study explores multiple relational contexts that promote vulnerability and protection against early pregnancy in a potential risk group of Portuguese adolescents. A comparative analysis was made between two groups of female adolescents of low socioeconomic status: pregnant adolescents (n=57) and adolescents without a history of pregnancy (n=81). Results suggest that several variables belonging to different contexts-family and school and peer relations--are important in the characterization of the two groups. Lower levels of mother's overprotection and father's emotional support, presence of early pregnancy in adolescent's mother, lower level of emotional proximity to peer relations, and higher number of school failures are significantly associated with adolescent pregnancy.

  20. The Relationship between Post-Traumatic Symptoms, Parenting Style, and Resilience among Adolescents in Liaoning, China: A Cross-Sectional Study

    PubMed Central

    Zhai, Yanxue; Liu, Kun; Zhang, Lin; Gao, Han; Chen, Zhuo; Du, Siyi; Zhang, Lili; Guo, Yu

    2015-01-01

    Background In China, a growing number of adolescents have experienced traumatic events that have resulted in PTSD (post-traumatic stress disorder). Post-traumatic symptoms are common psychological problems in adolescents who have experienced traumatic events. However, existing studies tend to focus on the factors influencing PTSD, such as the response styles and social support, and studies on the relationships between parenting style, resilience and post-traumatic symptoms are still rare. Objectives To analyze the relationships between parenting style, resilience and post-traumatic symptoms among adolescents in China. Methods A cross-sectional survey was conducted from June to December 2013 in the Liaoning Province, China. N = 5765 adolescents (aged 12 to 18 years old) were ultimately chosen to participate. The Chinese version of the Essen Trauma Inventory for Kids and Juveniles (ETI-KJ), a modified version of the Parental Authority Questionnaire, and the Chinese Resilience Scale were used to estimate the post-traumatic symptoms, parenting style, and resilience, respectively. Pearson’s correlations, multiple linear regression analyses and structural equation modeling (SEM) were applied to analyze the data. Results Of the adolescents, 39.76% (N = 2292) had been exposed to traumatic events during their lives. The prevalence of probable PTSD at the time of the interview (one-month-prevalence) was 12.65%. Parenting style and resilience were significantly associated with post-traumatic symptoms. According to the SEM, parenting style had a significant direct effect on resilience (0.70, P<0.01) and post-traumatic symptoms (-0.15, P<0.05), and resilience had a significant direct effect on the post-traumatic symptoms (-0.43, P<0.01). Furthermore, parenting style had a significant indirect effect (-0.43×0.70 = -0.30. P<0.01) on the post-traumatic symptoms through resilience. The SEM significantly explained 49% of the variance in resilience and 30% of the variance in post

  1. Cross-sectional examination of the association of co-occurring alcohol misuse and traumatic brain injury on mental health and conduct problems in adolescents in Ontario, Canada

    PubMed Central

    Ilie, Gabriela; Mann, Robert E; Boak, Angela; Adlaf, Edward M; Hamilton, Hayley; Asbridge, Mark; Rehm, Jürgen; Cusimano, Michael D

    2016-01-01

    Objective This study describes the impact of traumatic brain injury (TBI) and hazardous drinking on mental health and behavioural issues among Ontario adolescents. In particular, we assessed the incremental co-occurrence of hazardous drinking with a history of TBI, in comparison to experiencing just one of these conditions. Methods A cross-sectional subsample of 3130 Ontario adolescents attending grades 9–12, and aged 10–21 were surveyed in 2013 as a part of the Centre for Addiction and Mental Health's Ontario Student Drug Use and Health Survey. Recent (past year) and former (lifetime and excluding the last year) TBI were defined as trauma to the head that resulted in loss of consciousness for at least 5 min or overnight hospitalisation. Current hazardous drinking was derived using the Alcohol Use Disorders Identification Test (AUDIT). Results An estimated 11.8% of Ontario adolescents (95% CI 10.1% to 13.8%) reported a history of former TBI and were not hazardous drinkers; 4.0% (95% CI 2.9% to 5.5%) reported recent TBI and were not hazardous drinkers; 13.7% (95% CI 12.3% to 15.3%) were hazardous drinkers who never had a TBI; 4.1% (95% CI 2.9% to 5.8%) had former TBI with co-occurring hazardous drinking; and 2.2% (95% CI 1.6% to 3.0%) had recent TBI with co-occurring hazardous drinking. Most odds increased significantly and were two to three times higher for reporting compromised mental health, violent and non-violent conduct behaviours, and reported victimisation for classifying as a hazardous drinker at the time of testing with co-occurring either former or recent TBI compared to classifying as not having either of these conditions. Adolescents classified as hazardous drinkers with former TBI had numerous and higher ORs for conduct behaviours than those with recent TBI. Conclusions Results emphasise the strong interplay between TBI and hazardous drinking and point to the need for integrating prevention efforts to reduce these conditions and their co

  2. Family Health Climate and Adolescents’ Physical Activity and Healthy Eating: A Cross-Sectional Study with Mother-Father-Adolescent Triads

    PubMed Central

    Niermann, Christina Y. N.; Kremers, Stef P. J.; Renner, Britta; Woll, Alexander

    2015-01-01

    Introduction The importance of the family environment for children’s and adolescents’ health behavior has been demonstrated, the underlying mechanisms of this influence remain unclear. Therefore, the aim of the study was to investigate the relationship between family environmental and individual determinants. It was hypothesized that the Family Health Climate (FHC) is associated with adolescents’ physical activity and dietary behavior and that intrinsic motivation mediates this association. Methods Cross-sectional data were collected from 198 families (mother, father, and child) using questionnaires. Perceptions of FHC of mothers, fathers, and their children were assessed using the FHC-scales for physical activity (FHC-PA) and nutrition (FHC-NU). The adolescents also rated their intrinsic motivation for exercise and healthy eating, their physical activity and consumption of healthful food. A structural equation model was analyzed and a bootstrapping procedure was used to test direct and indirect effects. Results The FHC-PA was related to the amount of weekly physical activity and the FHC-NU to the consumption of fruit, vegetables and salad. These effects were mediated by adolescents’ intrinsic motivation; the indirect effects were significant for both behaviors. Discussion These results emphasize the importance of the FHC in shaping adolescents’ physical activity and dietary behavior. Individual motivational factors are potential mediators of family and parental influences. Considering family-level variables and their interaction with individual factors contributes to the understanding of adolescents’ health behavior. PMID:26606157

  3. Independent and Combined Effects of Physical Activity and Sedentary Behavior on Blood Pressure in Adolescents: Gender Differences in Two Cross-Sectional Studies

    PubMed Central

    de Moraes, Augusto César Ferreira; Carvalho, Heráclito Barbosa; Rey-López, Juan Pablo; Gracia-Marco, Luis; Beghin, Laurent; Kafatos, Anthony; Jiménez-Pavón, David; Molnar, Dénes; De Henauw, Stefaan; Manios, Yannis; Widhalm, Kurt; Ruiz, Jonatan R.; Ortega, Francisco B.; Sjöström, Michael; Polito, Angela; Pedrero-Chamizo, Raquel; Marcos, Ascensión; Gottrand, Frederic; Moreno, Luis A.

    2013-01-01

    Objectives To examine the independent and combined association of physical activity (PA) and sedentary behavior (SB) on both systolic (SBP) and diastolic blood pressure (DBP) in adolescents from two observational studies. Methods Participants from two cross-sectional studies, one conducted in Europe (n = 3,308; HELENA study) and the other in Brazil (n = 991; BRACAH study), were selected by complex sampling. Systolic and diastolic blood pressure (outcomes), PA and SB, both independently and combined, and potential confounders were analyzed. Associations were examined by multilevel linear regression. Results Performing the recommended amount of PA (≥60 min/d) attenuated the effect of SB on DBP in BRACAH study girls and in boys from both studies. In contrast, PA did not attenuate the effects of SB on the SBP of girls in the HELENA study. The combination of less than recommended levels of PA with 2–4 h/d of sedentary behavior was found to be associated with increased SBP in boys from both studies. Conclusions Meeting current PA recommendations could mediate the association between SB and DBP in both sexes. In boys, the joint effect of low levels of PA and excessive sedentary activity increases SBP levels. Longitudinal studies are required to confirm these findings. PMID:23650506

  4. Health Risk Behaviour among In-School Adolescents in the Philippines: Trends between 2003, 2007 and 2011, A Cross-Sectional Study

    PubMed Central

    Peltzer, Karl; Pengpid, Supa

    2015-01-01

    Intermittent monitoring of health risk behaviours at the population level is important for the planning and evaluation of national health promotion intervention programmes. The study aimed to provide trend estimates on the prevalence of various health risk behaviours assessed in the Global School-based Health Survey in 2003, 2007 and 2011 in the Philippines. Three waves of cross-sectional data included 18,285 school-going adolescents, 47.4% male and 52.6% female, aged between 11 years or younger and 16 years or older, with a mean age of about 14.7 years (SD = 1.2), and mainly in second to fourth year study Grade. Significant improvements in health risk and risk behaviours (overweight or obese and smokeless tobacco use among boys, being in a physical fight, troubles from alcohol drinking, mental health, oral and hand hygiene among both boys and girls) but also increases in health risk behaviour (bullying victimization, injury and loneliness) among both boys and girls were found in this large study over a period of eight years in the Philippines. High prevalences of health risk behaviours and increases in some of them should call for intensified school health promotion programmes to reduce such risk behaviours. PMID:26712770

  5. Adverse life events and delinquent behavior among Kenyan adolescents: a cross-sectional study on the protective role of parental monitoring, religiosity, and self-esteem

    PubMed Central

    2014-01-01

    Background Past research provides strong evidence that adverse life events heighten the risk of delinquent behavior among adolescents. Urban informal (slum) settlements in sub-Saharan Africa are marked by extreme adversity. However, the prevalence and consequences of adverse life events as well as protective factors that can mitigate the effects of exposure to these events in slum settlements is largely understudied. We examine two research questions. First, are adverse life events experienced at the individual and household level associated with a higher likelihood of delinquent behavior among adolescents living in two slums in Nairobi, Kenya? Second, are parental monitoring, religiosity, and self-esteem protective against delinquency in a context of high adversity? Methods We used cross-sectional data from 3,064 males and females aged 12–19 years who participated in the Transitions to Adulthood Study. We examined the extent to which a composite index of adverse life events was associated with delinquent behavior (measured using a composite index derived from nine items). We also examined the direct and moderating effects of three protective factors: parental monitoring, religiosity, and self-esteem. Results Fifty-four percent of adolescents reported at least one adverse life event, while 18% reported three or more adverse events. For both males and females, adversity was positively and significantly associated with delinquency in bivariate and multivariate models. Negative associations were observed between the protective factors and delinquency. Significant adverse events × protective factor interaction terms were observed for parental monitoring (females and males), religiosity (males), and self-esteem (females). Conclusions Similar to research in high income countries, adverse life events are associated with an increased likelihood of delinquent behavior among adolescents living in urban slums in Kenya, a low-income country. However, parental monitoring

  6. Mental Health Inequalities in Adolescents Growing Up in Post-Apartheid South Africa: Cross-Sectional Survey, SHaW Study

    PubMed Central

    Das-Munshi, Jayati; Lund, Crick; Mathews, Catherine; Clark, Charlotte; Rothon, Catherine; Stansfeld, Stephen

    2016-01-01

    Background South Africa is one of the most ‘unequal’ societies in the world. Despite apartheid ending more than 20 years ago, material inequalities remain interwoven with ethnic/racial inequalities. There is limited research on the prevalence/predictors of common mental disorders (CMD) among young people. Adolescence is a unique time-point during which intervention may lead to improved mental health and reduced social problems later. The study objective was to assess mental health disparities in a representative sample of adolescents growing up in South Africa. Methods Cross-sectional associations of race/ethnicity and material disadvantage with CMD and Post Traumatic Stress Disorder (PTSD) were assessed in a stratified random sample representative of school-attendees, aged 14–15 years, in a large metropolitan area of Cape Town. Validated instruments assessed mental disorders; these included: Harvard Trauma Questionnaire (PTSD); Short Moods and Feelings Questionnaire (depression); Zung self-rated anxiety scale (anxiety). Self-ascribed ethnicity was determined using procedures similar to the South African census and previous national surveys. Results Response rate was 88% (1034 of 1169 individuals). Adolescents experienced a high prevalence of depression (41%), anxiety (16%) and PTSD (21%). A gradient between material disadvantage and CMD/ PTSD was evident across all ethnic/racial groups. Respondents self-identifying as ‘black’ or ‘coloured’ were disadvantaged across most indicators. After adjusting for confounders, relative to white children, relative risk (RR) of CMD in black children was 2.27 (95% CI:1.24, 4.15) and for PTSD was RR: 2.21 (95% CI:1.73, 2.83). Relative risk of CMD was elevated in children self-identifying as ‘coloured’ (RR: 1.73, 95% CI:1.11, 2.70). Putative mediators (violence, racially motivated bullying, social support, self-esteem) partially accounted for differences in CMD and fully for PTSD. Conclusions Adolescent mental

  7. Is soy intake related to age at onset of menarche? A cross-sectional study among adolescents with a wide range of soy food consumption

    PubMed Central

    2014-01-01

    Background Early onset of menarche may negatively influence the future health of adolescent girls. Several factors affect the timing of menarche but it is not clear if soy foods consumption around pubertal years plays a role; thus, we examined its relation to age at onset of menarche (AOM) in a high soy-consuming population. Methods We conducted a cross-sectional study on 339 girls ages 12–18 years attending middle and high schools near two Seventh-day Adventist universities in California and Michigan using a web-based dietary questionnaire and physical development tool. Soy consumption (categorized as total soy, meat alternatives, tofu/traditional soy, and soy beverages) was estimated from the questionnaire, while AOM was self-reported. Data analyses included descriptive statistics, Cox proportional hazards ratios, Kaplan-Meier curves and Poisson regression with adjustment for relevant confounders. Results Mean (SD) intakes were: total soy,12.9 (14.4) servings/week; meat alternatives, 7.0 (8.9) servings/week; tofu/traditional soy foods, 2.1 (3.8) servings/week; soy beverages, 3.8 (6.3) servings/week. Mean AOM was 12.5 (1.4) y for those who reached menarche. Consumption of total soy and the 3 types of soy foods was not significantly associated with AOM and with the odds for early- or late-AOM. Adjustment for demographic and dietary factors did not change the results. Conclusion Soy intake is not associated with AOM in a population of adolescent girls who have a wide range of, and relatively higher, soy intake than the general US population. Our finding suggests that the increasing popularity of soy in the US may not be associated with AOM. PMID:24889551

  8. Assessment of Oral Health Knowledge, Attitude and Self-Care Practice Among Adolescents - A State Wide Cross- Sectional Study in Manipur, North Eastern India

    PubMed Central

    Kshetrimayum, Nandita; Wahengbam, Brucelee Singh; Nandkeoliar, Tanya; Lyngdoh, Daiasharailang

    2016-01-01

    Introduction The World Health Organization global strategy of promoting oral health have shown vast improvements in developed countries but the scenario is glum among underprivileged communities due to lacunae in implementation of these promotional programs. Manipur, a North Eastern state in India, is one such marginalized area. Aim The study aimed to evaluate Knowledge, Attitude and Practice (KAP) towards oral health in 15-18 year adolescents residing in Manipur together with the association of these variables to sociodemographic factors. Materials and Methods This cross-sectional study included 810 healthy adolescents drawn from various primary health care centers spanning in all the nine districts of Manipur. A closed ended questionnaire for the purpose of collecting data was used in the survey. Results Of the total participants 90.9% had high knowledge, 79.8% had favorable attitude and 70.4% had adequate practice towards oral health. Education of the parents and respondents was the only factor significantly associated with all three variables, knowledge, attitude and practice. Significant and positive linear correlation between knowledge-attitude (r=0.369, p<0.01) knowledge-practice (r=0.405, p<0.01) and attitude-practice (r =0.353, p<0.01), were observed. Conclusion An overwhelming majority of the respondents had high knowledge, favorable attitude and sound practice with respect to oral health. A positive linear correlation exists between the knowledge, attitude and practice. Evidence based reinforcement programs should be introduced to further reduce the gap between knowledge, attitude and practice. The study will also serve as a reference value for use in future evaluation to help measure the effectiveness of the planned activities. Future research needs to focus on establishing the dental caries prevalence and oral hygiene status of Manipuri youth. PMID:27504414

  9. Design and producing of fine-group cross section library HENDL3.0/FG for subcritical system

    SciTech Connect

    Zou, J.; Zeng, Q.; Xu, D.; Hu, L.; Long, P.

    2012-07-01

    To improve the accuracy of the neutron analyses for subcritical system with thermal fission blanket, a coupled neutron and photon (315 n + 42{gamma}) fine-group cross section library HENDL3.0/FG based on ENDF/B-VII, JEFF3.1 and JENDL3.3 was produced by FDS team. In order to test the availability and reliability of the HENDL3.0/FG data library, shielding and critical safety benchmarks were performed with VisualBUS code. The testing results indicated that the discrepancy between calculation and experimental values of nuclear parameters fell in a reasonable range. It showed that the nuclear data library had accuracy and availability. (authors)

  10. MMPI-2 Profile of French Transsexuals: The Role of Sociodemographic and Clinical Factors. A cross-sectional design

    PubMed Central

    Bonierbale, Mireille; Baumstarck, Karine; Maquigneau, Aurélie; Gorin-Lazard, Audrey; Boyer, Laurent; Loundou, Anderson; Auquier, Pascal; Lançon, Christophe

    2016-01-01

    The assessment of co-existing psychological and psychiatric disorders is advocated in the Standards of Care for the health of transsexual people. This study aimed to determine the psychopathological characteristics of transsexuals based on a large sample of French individuals and to identify whether these characteristics differed according to the individual’s sociodemographic or clinical characteristics. The aim of this study was to determine the psychopathological characteristics of transsexuals from a large sample of French individuals and whether these differed by sociodemographic or clinical characteristics. This cross-sectional study was conducted in a French public university hospital. The inclusion criteria were 18 years or older, diagnosis of gender dysphoria, and eligibility for a standardized sex reassignment procedure. Personality characteristics were assessed using the Minnesota Multiphasic Personality Inventory 2 (MMPI-2). A total of 108 individuals provided a valid MMPI-2 between January 2007 and December 2010. The final sample had a median age of 31 years and included 54 (50%) Female-to-Male individuals. In multivariate models, hormonal therapy status was significantly related to the scales of MMPI-2 (Psychasthenia and Masculinity/Femininity). Personality assessment can help a multidisciplinary gender dysphoria team detect potential psychopathological factors of vulnerability. PMID:27068099

  11. Validation of Cross-Sectional Time Series and Multivariate Adaptive Regression Splines Models for the Prediction of Energy Expenditure in Children and Adolescents Using Doubly Labeled Water12

    PubMed Central

    Butte, Nancy F.; Wong, William W.; Adolph, Anne L.; Puyau, Maurice R.; Vohra, Firoz A.; Zakeri, Issa F.

    2010-01-01

    Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant characteristics, heart rate (HR), and accelerometer counts (AC) for prediction of minute-by-minute EE, and hence 24-h total EE (TEE), against a 7-d doubly labeled water (DLW) method in children and adolescents. Our secondary aim was to demonstrate the utility of CSTS and MARS to predict awake EE, sleep EE, and activity EE (AEE) from 7-d HR and AC records, because these shorter periods are not verifiable by DLW, which provides an estimate of the individual's mean TEE over a 7-d interval. CSTS and MARS models were validated in 60 normal-weight and overweight participants (ages 5–18 y). The Actiheart monitor was used to simultaneously measure HR and AC. For prediction of TEE, mean absolute errors were 10.7 ± 307 kcal/d and 18.7 ± 252 kcal/d for CSTS and MARS models, respectively, relative to DLW. Corresponding root mean square error values were 305 and 251 kcal/d for CSTS and MARS models, respectively. Bland-Altman plots indicated that the predicted values were in good agreement with the DLW-derived TEE values. Validation of CSTS and MARS models based on participant characteristics, HR monitoring, and accelerometry for the prediction of minute-by-minute EE, and hence 24-h TEE, against the DLW method indicated no systematic bias and acceptable limits of agreement for pediatric groups and individuals under free-living conditions. PMID:20573939

  12. Environment factors associated with adolescents' body mass index, physical activity and physical fitness in Kuching South City, Sarawak: a cross-sectional study.

    PubMed

    Cheah, Whye L; Chang, Ching T; Saimon, Rosalia

    2012-01-01

    This study examined the relationship between perceived built environment attributes and physical activity, physical fitness and body weight among adolescents aged 14-16 years in Sarawak. This was a cross-sectional study, using multi-stage sampling. A set of questionnaires consisting of socio-demographic information, a self-administered physical activity checklist and a Neighborhood Environment Walkability Scale-Youth (NEWS-Y) was used. Body mass index (BMI) was measured and physical fitness was tested using a maximal multistage 20 m shuttle run test. Data analysis was done using SPSS version 17.0. A total of 316 respondents participated. The mean BMI for boys was almost equal to the mean BMI for girls. Only 7.9% of the sampled population was found to be overweight or obese. The overall mean duration spent per day on physical activity was 128.4 min (SD 118.43), with mean of 56.1 min (SD 73.94) after school time. Girls reported to spend longer each day taking physical activity before and during school. Boys were found to have significantly higher VO2max of 27.79±5.91 mL/kg/min as compared to girls (t=11.22, p<0.000). Based on comparison with other countries, the NEWS-Y scores indicated a mixture of low and high walkability neighborhoods. Respondents who had lower BMIs reported living in lower residential density areas and less risk of crime, and respondents who had better physical fitness reported less suitable infrastructure for walking. Promotion of exercise at all levels should be continuously encouraged as it would lead to improvement in the well-being of an individual.

  13. Cross-sectional reference values for mid-upper arm circumference, triceps skinfold thickness and arm fat area of Turkish children and adolescents.

    PubMed

    Ozturk, Ahmet; Budak, Nurten; Cicek, Betul; Mazicioglu, M Mumtaz; Bayram, Fahri; Kurtoglu, Selim

    2009-06-01

    The aim of the study was to establish cross-sectional reference values for the mid-upper arm circumference (MUAC), triceps skinfold thickness (TSF) and arm fat area (AFA) of Turkish children and adolescents. In total 5,553 students aged between 6 and 17 years were selected by a multistage sampling method from schools representing city centre, rural and urban areas of Kayseri, Central Anatolia. The MUAC and TSF were measured, and the arm muscle area, arm area, AFA and fat percentage (%) were calculated. The LMS method was employed to calculate the MUAC, TSF and AFA curve parameters. The MUAC, TSF, AFA and fat percentage in each age group were significantly higher in girls than in boys. In boys, the TSF 50th percentile ranged from 7.6 mm at 17 years to 9.0 mm at 11 years; whereas in girls this ranged from 9.4 mm at 6 years to 14.6 mm at 17 years. The MUAC 50th percentile ranged from 17.0 to 23.6 cm in boys, and from 15.6 cm to 20.9 cm in girls. The AFA 50th percentile measurements ranged from 4.5 cm at 6 years to 5.8 cm at 12-14 years in boys; and ranged from 7.2 cm at 6 years to 14.8 cm at 17 years in girls. The percentile distribution was more disperse towards higher TSF and AFA values in boys than in girls.

  14. Socio-demographic disparity in oral health among the poor: a cross sectional study of early adolescents in Kilwa district, Tanzania

    PubMed Central

    2010-01-01

    Background There is a lack of studies considering social disparity in oral health emanating from adolescents in low-income countries. This study aimed to assess socio-demographic disparities in clinical- and self reported oral health status and a number of oral health behaviors. The extent to which oral health related behaviors might account for socio-demographic disparities in oral health status was also examined. Methods A cross-sectional study was conducted in Kilwa district in 2008. One thousand seven hundred and forty five schoolchildren completed an interview and a full mouth clinical examination. Caries experience was recorded using WHO criteria, whilst type of treatment need was categorized using the ART approach. Results The majority of students were caries free (79.8%) and presented with a low need for dental treatment (89.3%). Compared to their counterparts in opposite groups, rural residents and those from less poor households presented more frequently with caries experience (DMT>0), high need for dental treatment and poor oral hygiene behavior, but were less likely to report poor oral health status. Stepwise logistic regressions revealed that social and behavioral variables varied systematically with caries experience, high need for dental treatment and poor self reported oral health. Socio-demographic disparities in oral health outcomes persisted after adjusting for oral health behaviors. Conclusions Socio-demographic disparities in oral health outcomes and oral health behaviors do exist. Socio-demographic disparities in oral health outcomes were marginally accounted for by oral health behaviors. Developing policies and programs targeting both social and individual determinants of oral health should be an urgent public health strategy in Tanzania. PMID:20406452

  15. New Arsenic Cross Section Calculations

    SciTech Connect

    Kawano, Toshihiko

    2015-03-04

    This report presents calculations for the new arsenic cross section. Cross sections for 73,74,75 As above the resonance range were calculated with a newly developed Hauser-Feshbach code, CoH3.

  16. The Influence of Witnessing Inter-parental Violence and Bullying Victimization in Involvement in Fighting among Adolescents: Evidence from a School-based Cross-sectional Survey in Peru

    PubMed Central

    Sharma, Bimala; Nam, Eun Woo; Kim, Ha Yun; Kim, Jong Koo

    2016-01-01

    Background Witnessing inter-parental violence and bullying victimization is common for many children and adolescents. This study examines the role of witnessing inter-parental violence and bullying victimization in involvement in physical fighting among Peruvian adolescents. Methods A cross-sectional study was conducted among 1,368 randomly selected adolescents in 2015. We conducted logistic regression analyses to obtain crude and adjusted odds ratios with 95% confidence intervals for involvement in fighting among male and female adolescents. Results Among all adolescents, 35.8% had been involved in fighting in the last 12 months, 32.9% had been victim of verbal bullying and 37.9% had been the victim of physical bullying. Additionally, 39.2% and 27.8% of adolescents witnessed violence against their mother and father, respectively, at least once in their lives. Multivariate logistic regression analyses found that late adolescence, participation in economic activities, being the victim of verbal bullying, stress, and witnessing violence against the father among male adolescents, and self-rated academic performance and being the victim of physical or verbal bullying among female adolescents were associated with higher odds of being involved in fighting. Conclusion Verbal bullying victimization and witnessing violence against the father in males and bullying victimization in females were associated with greater odds of adolescents being involved in fighting. Creating a non-violent environment at both home and school would be an effective strategy for reducing fighting among the adolescent population. PMID:27358837

  17. Associations between school difficulties and health-related problems and risky behaviours in early adolescence: A cross-sectional study in middle-school adolescents in France.

    PubMed

    Chau, Kénora; Kabuth, Bernard; Causin-Brice, Odile; Delacour, Yves; Richoux-Picard, Catherine; Verdin, Monique; Armand, Isabelle; Chau, Nearkasen

    2016-10-30

    Health-related problems and risky behaviours (substance use) are frequent in adolescents, may alter their physical and mental capabilities, and may thus generate school absenteeism, low academic performance, and school dropout ideation. This study assessed their associations and the contribution of socioeconomic factors among 1559 middle-school adolescents (mean age 13.5+1.3) from north-eastern France. They completed a questionnaire including socioeconomic characteristics, health-related problems (poor physical health, psychological health, social relationships, and living environment) assessed with the World Health Organization's quality of life measure (score<25th percentile), risky behaviours, school absences during the present school year, last-trimester academic performance, and school dropout ideation. Data were analysed using logistic regression models. School absenteeism was frequent (12.6% of subjects for 8-14 days, and 6.0% for ≥15 days); 8.2% of subjects had low academic performance (average school-mark <10/20) and 3.9% school dropout ideation. All school difficulties were strongly associated with all health-related problems (gender-age-school-level-adjusted odds ratios gasOR between 1.5 and 4.2), and with risky behaviours (gasOR between 1.4 and 14). Socioeconomic factors differently contributed to these associations (contribution reaching 77%). Policy makers, schools, physicians and parents should be more aware of the problems and help adolescents to reduce health-related problems and risky behaviours and to increase resilience.

  18. Validity and reliability of the Oral Impacts on Daily Performance (OIDP) frequency scale: a cross-sectional study of adolescents in Uganda

    PubMed Central

    Åstrøm, Anne Nordrehaug; Okullo, Isaac

    2003-01-01

    Background Assessing oral health related quality of life impact of mouth in adolescents is a relatively ignored area in dental research. This study aimed to examine reliability and validity of an abbreviated version of the oral impact of daily performance (OIDP) questionnaire and to analyse the interrelationship among OIDP scores, socio-demographic characteristics and oral health status in Uganda. Method 1146 adolescents (mean age 15.8, response rate 87%) attending secondary schools in Kampala (urban) and Lira (rural) completed a survey instrument designed to measure subjective oral health indicators including the eight-item OIDP frequency scores. A clinical examination was conducted among 372 students (mean age 16.3, response rate 72%) and caries was assessed following the World Health Organisation criteria (1997). Results 62% of the students experienced at least one oral impact during the 6 months preceding the survey. Cronbach's alpha for the OIDP frequency items was 0.91 and the corrected item-total correlation ranged from 0.62 to 0.75. Discriminant and construct validity were demonstrated in that the OIDP scores varied systematically in the expected direction with missing teeth and self-report indicators of oral health status, respectively. Socio-demographics and dental attendance did not predict OIDP through interaction with clinical indicators but varied systematically and independently with OIDP frequency scores in the multivariate analysis. Conclusion the OIDP frequency score have acceptable psychometric properties in the context of an oral health survey among Ugandan adolescents. Some evidence of the importance of social and personal characteristics in shaping adolescents' responses to oral disorders was provided. PMID:12943555

  19. Validation of cross-sectional time series and multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents using doubly labeled water

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant cha...

  20. Radar cross section of insects

    NASA Astrophysics Data System (ADS)

    Riley, J. R.

    1985-02-01

    X-band measurements of radar cross section as a function of the angle between insect body axis and the plane of polarization are presented. A finding of particular interest is that in larger insects, maximum cross section occurs when the E-vector is perpendicular to the body axis. A new range of measurements on small insects (aphids, and planthoppers) is also described, and a comprehensive summary of insect cross-section data at X-band is given.

  1. Protocol Design for Large-Scale Cross-Sectional Studies of Sexual Abuse and Associated Factors in Individual Sports: Feasibility Study in Swedish Athletics

    PubMed Central

    Timpka, Toomas; Janson, Staffan; Jacobsson, Jenny; Ekberg, Joakim; Dahlström, Örjan; Kowalski, Jan; Bargoria, Victor; Mountjoy, Margo; Svedin, Carl G.

    2015-01-01

    To ensure health and well-being for their athletes, sports organizations must offer preventive measures against sexual abuse. The aim of this study was to design and evaluate feasibility of a research protocol for cross-sectional epidemiological studies of sexual abuse in athletics. Examination of the requirements on the study of sexual abuse in athletics was followed by iterated drafting of protocol specifications and formative evaluations. The feasibility of the resulting protocol was evaluated in a national-level study among elite athletics athletes (n = 507) in Sweden. The definition of sexual abuse, the ethical soundness of the protocol, reference populations and study of co-morbidity, and the means for athlete-level data collection were identified as particularly complex issues in the requirements analyses. The web-based survey defined by the protocol facilitates anonymous athlete self-reporting of data on exposure to sexual abuse. 198 athletes (39%) fully completed the feasibility survey. 89% (n = 177) reported that they agreed with that the questions in the survey were important, and 95% (n = 189) reported that they answered truthfully to all questions. Similarly, 91% (n = 180) reported that they did not agree with that the questions were unpleasant for them. However, 16% (n = 32) reported that they did not find the survey to be of personal value, and 12% (n = 23) reported that the survey had caused them to think about issues that they did not want to think about. Responding that participation was not personally gratifying was associated with training more hours (p = 0.01). There is a scarcity of research on the prevention of sexual abuse in individual sports. The present protocol should be regarded as a means to overcome this shortcoming in athletics. When implementing the protocol, it is necessary to encourage athlete compliance and to adapt the web-based survey to the particular infrastructural conditions in the sports setting at hand. Key points A

  2. Protocol design for large-scale cross-sectional studies of sexual abuse and associated factors in individual sports: feasibility study in Swedish athletics.

    PubMed

    Timpka, Toomas; Janson, Staffan; Jacobsson, Jenny; Ekberg, Joakim; Dahlström, Örjan; Kowalski, Jan; Bargoria, Victor; Mountjoy, Margo; Svedin, Carl G

    2015-03-01

    To ensure health and well-being for their athletes, sports organizations must offer preventive measures against sexual abuse. The aim of this study was to design and evaluate feasibility of a research protocol for cross-sectional epidemiological studies of sexual abuse in athletics. Examination of the requirements on the study of sexual abuse in athletics was followed by iterated drafting of protocol specifications and formative evaluations. The feasibility of the resulting protocol was evaluated in a national-level study among elite athletics athletes (n = 507) in Sweden. The definition of sexual abuse, the ethical soundness of the protocol, reference populations and study of co-morbidity, and the means for athlete-level data collection were identified as particularly complex issues in the requirements analyses. The web-based survey defined by the protocol facilitates anonymous athlete self-reporting of data on exposure to sexual abuse. 198 athletes (39%) fully completed the feasibility survey. 89% (n = 177) reported that they agreed with that the questions in the survey were important, and 95% (n = 189) reported that they answered truthfully to all questions. Similarly, 91% (n = 180) reported that they did not agree with that the questions were unpleasant for them. However, 16% (n = 32) reported that they did not find the survey to be of personal value, and 12% (n = 23) reported that the survey had caused them to think about issues that they did not want to think about. Responding that participation was not personally gratifying was associated with training more hours (p = 0.01). There is a scarcity of research on the prevention of sexual abuse in individual sports. The present protocol should be regarded as a means to overcome this shortcoming in athletics. When implementing the protocol, it is necessary to encourage athlete compliance and to adapt the web-based survey to the particular infrastructural conditions in the sports setting at hand. Key points

  3. XCOM: Photon Cross Sections Database

    National Institute of Standards and Technology Data Gateway

    SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

  4. A cross-sectional analysis of HIV and hepatitis C clinical trials 2007 to 2010: the relationship between industry sponsorship and randomized study design

    PubMed Central

    2014-01-01

    Background The proportion of clinical research sponsored by industry will likely continue to expand as federal funds for academic research decreases, particularly in the fields of HIV/AIDS and hepatitis C (HCV). While HIV and HCV continue to burden the US population, insufficient data exists as to how industry sponsorship affects clinical trials involving these infectious diseases. Debate exists about whether pharmaceutical companies undertake more market-driven research practices to promote therapeutics, or instead conduct more rigorous trials than their non-industry counterparts because of increased resources and scrutiny. The ClinicalTrials.gov registry, which allows investigators to fulfill a federal mandate for public trial registration, provides an opportunity for critical evaluation of study designs for industry-sponsored trials, independent of publication status. As part of a large public policy effort, the Clinical Trials Transformation Initiative (CTTI) recently transformed the ClinicalTrials.gov registry into a searchable dataset to facilitate research on clinical trials themselves. Methods We conducted a cross-sectional analysis of 477 HIV and HCV drug treatment trials, registered with ClinicalTrials.gov from 1 October 2007 to 27 September 2010, to study the relationship of study sponsorship with randomized study design. The likelihood of using randomization given industry (versus non-industry) sponsorship was reported with prevalence ratios (PR). PRs were estimated using crude and stratified tabular analysis and Poisson regression adjusting for presence of a data monitoring committee, enrollment size, study phase, number of study sites, inclusion of foreign study sites, exclusion of persons older than age 65, and disease condition. Results The crude PR was 1.17 (95% CI 0.94, 1.45). Adjusted Poisson models produced a PR of 1.13 (95% CI 0.82, 1.56). There was a trend toward mild effect measure modification by study phase, but this was not statistically

  5. Precise neutron inelastic cross section measurements

    SciTech Connect

    Negret, Alexandru

    2012-11-20

    The design of a new generation of nuclear reactors requires the development of a very precise neutron cross section database. Ongoing experiments performed at dedicated facilities aim to the measurement of such cross sections with an unprecedented uncertainty of the order of 5% or even smaller. We give an overview of such a facility: the Gamma Array for Inelastic Neutron Scattering (GAINS) installed at the GELINA neutron source of IRMM, Belgium. Some of the most challenging difficulties of the experimental approach are emphasized and recent results are shown.

  6. Contextualized theory-based predictors of intention to practice monogamy among adolescents in Botswana junior secondary schools: Results of focus group sessions and a cross-sectional study.

    PubMed

    Chilisa, Bagele; Mohiemang, Irene; Mpeta, Kolentino Nyamadzapasi; Malinga, Tumane; Ntshwarang, Poloko; Koyabe, Bramwell Walela; Heeren, G Anita

    2016-01-01

    Culture and tradition influences behaviour. Multiple partner and concurrent relationships are made responsible for the increase of HIV infection in Sub-Saharan Africa. A contextualized "Theory of Planned Behaviour" was used to identify predictors of intention to practice monogamy. A mixed method design using qualitative data from focus groups, stories and a survey were analyzed for quantitative data. The qualitative data added to the behavioural beliefs a socio-cultural belief domain as well as attitudes, subjective norms, and perceived behavioural control predicted the intention to practice monogamy. The adolescents showed a tendency towards having more than one sexual partner. The normative beliefs and the socio cultural beliefs also predicted intentions while hedonistic belief and partner reaction did not. In contextualizing theory-based interventions, it is important to draw from stories and the langauage that circulate in a community about a given behaviour. More studies are needed on ways to combine qualitative approaches with quantitative approaches to inform the development of theory based culturally appropriate and context specific intervention strategies to reduce the risk of HIV.

  7. [Fast neutron cross section measurements

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

  8. Is poor self-rated health associated with low-grade inflammation in 43 110 late adolescent men of the general population? A cross-sectional study

    PubMed Central

    Warnoff, Carin; Lekander, Mats; Hemmingsson, Tomas; Sorjonen, Kimmo; Melin, Bo; Andreasson, Anna

    2016-01-01

    Objective Self-rated health is a powerful predictor of long-term health and mortality, hence the importance of a better understanding of its biological determinants. Previous studies have shown that low-grade inflammation is associated with poor self-rated health in clinical and healthy populations, but the evidence is sparse in men and completely lacking for men in late adolescence. The aim of this study was to investigate the association between low-grade inflammation and self-rated health among conscripts. It was hypothesised that high levels of inflammatory factors would be associated with poor self-rated health. Design Data from 49 321 men (18–21 years) conscripted for military service in 1969 and 1970 were used. Inflammation had been measured through erythrocyte sedimentation rate (ESR). Self-rated health had been assessed on a five-point scale, and was dichotomised into Good (‘Very good’/‘Good’/‘Fair’) versus Poor (‘Poor’/‘Very poor’). Data from 43 110 conscripts with normal levels of ESR, and who reported self-rated health remained after exclusion of those with ESR <1 and >11 mm/h. Associations were calculated using logistic regression analyses. Adjustments were made for body mass index, socioeconomic position, inflammatory disease, emotion regulation, smoking, risky use of alcohol and physical activity. Results High levels of ESR were associated with higher odds for poor self-rated health (OR: 1.077 for each unit mm/h increase in ESR, 95% CI 1.049 to 1.105). Conclusions The present study shows for the first time a significant association between a marker of inflammation and self-rated health in late adolescent men, adding to evidence of an association between low-grade inflammation and subjective health perception also in men, as previously demonstrated in women. Further support for inflammation as part of a general psychobiological process that underpins subjective health perception is hereby provided. PMID:27113233

  9. An Examination of the Ethnicity-Specific Prevalence of and Factors Associated with Substance Use and Misuse: Cross-Sectional Analysis of Croatian and Bosniak Adolescents in Bosnia and Herzegovina

    PubMed Central

    Bjelica, Dusko; Idrizovic, Kemal; Popovic, Stevo; Sisic, Nedim; Sekulic, Damir; Ostojic, Ljerka; Spasic, Miodrag; Zenic, Natasa

    2016-01-01

    Substance use and misuse (SUM) in adolescence is a significant public health problem and the extent to which adolescents exhibit SUM behaviors differs across ethnicity. This study aimed to explore the ethnicity-specific and gender-specific associations among sports factors, familial factors, and personal satisfaction with physical appearance (i.e., covariates) and SUM in a sample of adolescents from Federation of Bosnia and Herzegovina. In this cross-sectional study the participants were 1742 adolescents (17–18 years of age) from Bosnia and Herzegovina who were in their last year of high school education (high school seniors). The sample comprised 772 Croatian (558 females) and 970 Bosniak (485 females) adolescents. Variables were collected using a previously developed and validated questionnaire that included questions on SUM (alcohol drinking, cigarette smoking, and consumption of other drugs), sport factors, parental education, socioeconomic status, and satisfaction with physical appearance and body weight. The consumption of cigarettes remains high (37% of adolescents smoke cigarettes), with a higher prevalence among Croatians. Harmful drinking is also alarming (evidenced in 28.4% of adolescents). The consumption of illicit drugs remains low with 5.7% of adolescents who consume drugs, with a higher prevalence among Bosniaks. A higher likelihood of engaging in SUM is found among children who quit sports (for smoking and drinking), boys who perceive themselves to be good looking (for smoking), and girls who are not satisfied with their body weight (for smoking). Higher maternal education is systematically found to be associated with greater SUM in Bosniak girls. Information on the associations presented herein could be discretely disseminated as a part of regular school administrative functions. The results warrant future prospective studies that more precisely identify the causality among certain variables. PMID:27690078

  10. A Cross-Sectional Study on Attitudes to and Understanding of Risk of Acquisition of HIV: Design, Methods and Participant Characteristics

    PubMed Central

    Speakman, Andrew; Phillips, Andrew N; Lampe, Fiona C; Miltz, Ada; Gilson, Richard; Asboe, David; Nwokolo, Nneka; Scott, Christopher; Day, Sara; Clarke, Amanda; Anderson, Jane; O'Connell, Rebecca; Apea, Vanessa; Dhairyawan, Rageshri; Gompels, Mark; Farazmand, Paymaneh; Allan, Sris; Mann, Susan; Dhar, Jyoti; Tang, Alan; Sadiq, S Tariq; Taylor, Stephen; Collins, Simon; Sherr, Lorraine; Hart, Graham; Johnson, Anne M; Miners, Alec; Elford, Jonathan; Rodger, Alison

    2016-01-01

    Background The annual number of new human immunodeficiency virus (HIV) infections in the United Kingdom among men who have sex with men (MSM) has risen, and remains high among heterosexuals. Increasing HIV transmission among MSM is consistent with evidence of ongoing sexual risk behavior in this group, and targeted prevention strategies are needed for those at risk of acquiring HIV. Objective The Attitudes to and Understanding of Risk of Acquisition of HIV (AURAH) study was designed to collect information on HIV negative adults at risk of HIV infection in the United Kingdom, based on the following parameters: physical and mental health, lifestyle, patterns of sexual behaviour, and attitudes to sexual risk. Methods Cross-sectional questionnaire study of HIV negative or undiagnosed sexual health clinic attendees in the United Kingdom from 2013-2014. Results Of 2630 participants in the AURAH study, 2064 (78%) were in the key subgroups of interest; 580 were black Africans (325 females and 255 males) and 1484 were MSM, with 27 participants belonging to both categories. Conclusions The results from AURAH will be a significant resource to understand the attitudes and sexual behaviour of those at risk of acquiring HIV within the United Kingdom. AURAH will inform future prevention efforts and targeted health promotion initiatives in the HIV negative population. PMID:27091769

  11. Decreased levels of physical activity in adolescents with down syndrome are related with low bone mineral density: a cross-sectional study

    PubMed Central

    2013-01-01

    Background Down syndrome (DS) has been described as one of the main contributors for low bone mineral density (BMD). Physical activity (PA) is a key factor in skeletal health and thus, PA levels might be associated to the risk of developing osteoporosis. Therefore, the aims were (1) to describe PA patterns in adolescents with DS compared to their counterparts and (2) to determine the relationships between PA and the risk of having low bone mass in adolescents with DS. Methods Nineteen adolescents (10 girls) with DS and 14 without disabilities (7 girls) participated in the study. Minutes in different PA intensities were objectively assessed with accelerometers (ActiTrainer). Moreover adolescents with DS were classified into PA tertiles taking into account the amount of total minutes of PA at any intensity, resulting in those performing low, medium or high of PA (lowPA, medPA and highPA). BMD was measured at the whole body, hip and lumbar spine with dual-energy X-ray absorptiometry and the BMD Z-score was calculated for each region taking into account age- and sex-matched reference data. Student’s unpaired t-tests and analysis of covariance were used to compare variables between different conditions (DS vs. control) and PA levels (low, medium and high). Results None of the adolescents with DS achieved the minimum of 60 min of daily moderate to vigorous PA (VPA) intensity recommended by PA guidelines; adolescents with DS group spent less time in sedentary and in VPA and more time in light PA than those without DS (p < 0.05). Adolescents with DS showed lower BMD Z-score values than those without (p < 0.05). Those adolescents with DS allocated in the lowPA tertile showed significant lower BMD Z-score at the hip and a general tendency towards lower BMD Z-score was found at whole body and lumbar spine compared to those in highPA tertile and (p < 0.05). Conclusions Adolescents with DS in the highPA tertile showed lower risk of developing future osteoporosis by having

  12. Accurate Cross Sections for Microanalysis

    PubMed Central

    Rez, Peter

    2002-01-01

    To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V. PMID:27446747

  13. Social support as a mediator between problem behaviour and gambling: a cross-sectional study among 14–16-year-old Finnish adolescents

    PubMed Central

    Lintonen, Tomi; Tolvanen, Asko; Konu, Anne

    2016-01-01

    Background During the adolescent period, risk-taking behaviour increases. These behaviours can compromise the successful transition from adolescence to adulthood. The purpose of this study was to examine social support as a mediator of the relation between problem behaviour and gambling frequency among Finnish adolescents. Methods Data were obtained from the national School Health Promotion Study (SHPS) from the years 2010 and 2011 (N=102 545). Adolescents were classified in the most homogeneous groups based on their problem behaviour via latent class analysis. Results Path analysis indicated that social support was negatively associated with problem behaviour, and problem behaviour and social support were negatively related (except for social support from friends among boys) to gambling. Social support from parents and school mediated, albeit weakly, the relations between problem behaviour and gambling among girls and boys. Conclusions Problem behaviour may affect gambling through social support from school and parents. Thus prevention and intervention strategies should focus on strengthening adolescents' social support. In addition, because of the clustering of different problem behaviours instead of concentrating on a single form of problem behaviour multiple-behaviour interventions may have a much greater impact on public health. PMID:28007707

  14. Decreasing the number of small eating occasions (<15 % of total energy intake) regardless of the time of day may be important to improve diet quality but not adiposity: a cross-sectional study in British children and adolescents.

    PubMed

    Murakami, Kentaro; Livingstone, M Barbara E

    2016-01-28

    Evidence of associations between meal frequency (MF) and snack frequency (SF) and diet and obesity in young populations is limited. This cross-sectional study examined MF and SF in relation to dietary intake and adiposity measures in British children aged 4-10 years (n 818) and adolescents aged 11-18 years (n 818). Based on data from a 7-d weighed dietary record, all eating occasions were divided into meals or snacks on the basis of contribution to energy intake (≥15 or <15 %) or time (06.00-10.00, 12.00-15.00 and 18.00-21.00 hours or others). All measures of MF and SF showed positive associations with energy intake, except for MF based on energy contribution in children. Irrespective of the definition of snacks, SF was associated with higher intakes of soft drinks, confectionery and total sugar, lower intakes of cereals, fish, meat, protein, PUFA, starch and dietary fibre, and a lower diet quality (assessed by the Mediterranean diet score, except for SF based on energy contribution in adolescents). MF based on time, but not based on energy contribution, was associated with higher intakes of confectionery and total sugar, lower intakes of fish, protein, PUFA and starch, and, only in children, a lower diet quality. All measures of MF and SF showed no association with adiposity measures. In conclusion, this cross-sectional study in British children and adolescents suggests that decreasing the number of small eating occasions (<15 % of total energy intake) regardless of the time of day may be important to improve diet quality but not adiposity.

  15. Obesity-related behaviours and BMI in five urban regions across Europe: sampling design and results from the SPOTLIGHT cross-sectional survey

    PubMed Central

    Lakerveld, Jeroen; Ben Rebah, Maher; Mackenbach, Joreintje D; Charreire, Hélène; Compernolle, Sofie; Glonti, Ketevan; Bardos, Helga; Rutter, Harry; De Bourdeaudhuij, Ilse; Brug, Johannes; Oppert, Jean-Michel

    2015-01-01

    Objectives To describe the design, methods and first results of a survey on obesity-related behaviours and body mass index (BMI) in adults living in neighbourhoods from five urban regions across Europe. Design A cross-sectional observational study in the framework of an European Union-funded project on obesogenic environments (SPOTLIGHT). Setting 60 urban neighbourhoods (12 per country) were randomly selected in large urban zones in Belgium, France, Hungary, the Netherlands and the UK, based on high or low values for median household income (socioeconomic status, SES) and residential area density. Participants A total of 6037 adults (mean age 52 years, 56% female) participated in the online survey. Outcome measures Self-reported physical activity, sedentary behaviours, dietary habits and BMI. Other measures included general health; barriers and motivations for a healthy lifestyle, perceived social and physical environmental characteristics; the availability of transport modes and their use to specific destinations; self-defined neighbourhood boundaries and items related to residential selection. Results Across five countries, residents from low-SES neighbourhoods ate less fruit and vegetables, drank more sugary drinks and had a consistently higher BMI. SES differences in sedentary behaviours were observed in France, with residents from higher SES neighbourhoods reporting to sit more. Residents from low-density neighbourhoods were less physically active than those from high-density neighbourhoods; during leisure time and (most pronounced) for transport (except for Belgium). BMI differences by residential density were inconsistent across all countries. Conclusions The SPOTLIGHT survey provides an original approach for investigating relations between environmental characteristics, obesity-related behaviours and obesity in Europe. First descriptive results indicate considerable differences in health behaviours and BMI between countries and neighbourhood types. PMID

  16. Neutrino cross-sections: Experiments

    SciTech Connect

    Sánchez, F.

    2015-07-15

    Neutrino-nucleus cross-sections are as of today the main source of systematic errors for oscillation experiments together with neutrino flux uncertainties. Despite recent experimental and theoretical developments, future experiments require even higher precisions in their search of CP violation. We will review the experimental status and explore possible future developments required by next generation of experiments.

  17. Photoneutron cross sections for Au

    SciTech Connect

    Itoh, O.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Kamata, M.; Toyokawa, H.; Harada, H.; Kitatani, F.; Goko, S.; Nair, C.; Lui, Y.-W.

    2011-10-28

    Photoneutron cross sections were measured for Au in the entire energy range of the ({gamma},n) channel based on a direct neutron-counting technique with quasimonochromatic {gamma} rays produced in inverse Compton-scattering of laser photons with relativistic electrons. We present results of the measurement in comparison with the past data.

  18. Blood pressure patterns in relation to geographic area of residence: a cross-sectional study of adolescents in Kogi state, Nigeria

    PubMed Central

    Ejike, Chukwunonso ECC; Ugwu, Chidi E; Ezeanyika, Lawrence US; Olayemi, Ayo T

    2008-01-01

    Background The prevalence of hypertension, an important risk factor for cardiovascular disease (CVD), is increasing in the developing countries and this may be connected with the economic transition in those countries. Adult hypertension is thought to be related to childhood and adolescent increases in blood pressure, and hence the need to monitor patterns in early life. This study investigates the BP patterns, and their correlates, of adolescents from different geographic areas of residence in Nigeria. Methods A total of 1,088 Nigerian adolescents from different geographic areas of residence were recruited for the study. Their blood pressures and anthropometric indices were measured using standard procedures. The association of blood pressure with height, weight, body mass index (BMI) and geographic area of residence was assessed. Results Male and female urban-dwelling adolescents had significantly (p < 0.05) higher systolic blood pressure (117.45 ± 21.53 mmHg and 114.82 ± 17.95 mmHg respectively) compared to their counterparts living in the non-urban areas (108.20 ± 12.12 mmHg and 106.03 ± 13.06 mmHg respectively), even after adjusting for age and height. Conversely, non-urban boys (but not the girls) had significantly (p < 0.05) higher diastolic blood pressure compared to their urban counterparts. Adolescents in the urban areas had higher BMI (20.74 ± 3.27 kg/m2 for males and 21.35 ± 3.37 kg/m2 for females) than those in the non-urban areas (20.33 ± 3.11 kg/m2 for males and 21.35 ± 3.37 kg/m2 for females) though the difference was significant (p < 0.05) only in the females. Blood pressures were found to increase with age, and to be associated with BMI. Conclusion These findings underscore the need for efforts to be made towards addressing adolescent blood pressure elevation (in both urban and non-urban areas) as they are a reflection of adult morbidity and mortality from hypertension and the associated disorders. PMID:19087334

  19. Prevalence and Factors Associated with Substance Use and Misuse among Kosovar Adolescents; Cross Sectional Study of Scholastic, Familial-, and Sports-Related Factors of Influence

    PubMed Central

    Tahiraj, Enver; Cubela, Mladen; Ostojic, Ljerka; Rodek, Jelena; Zenic, Natasa; Sekulic, Damir; Lesnik, Blaz

    2016-01-01

    Adolescence is considered to be the most important period for the prevention of substance use and misuse (SUM). The aim of this study was to investigate the problem of SUM and to establish potentially important factors associated with SUM in Kosovar adolescents. Multi-stage simple random sampling was used to select participants. At the end of their high school education, 980 adolescents (623 females) ages 17 to 19 years old were enrolled in the study. The prevalence of smoking, alcohol consumption (measured by Alcohol Use Disorder Identification Test–AUDIT), and illegal drug use (dependent variables), as well as socio-demographic, scholastic, familial, and sports-related factors (independent variables), were assessed. Boys smoke cigarettes more often than girls with daily-smoking prevalence of 16% among boys and 9% among girls (OR = 1.85, 95% = CI 1.25–2.75). The prevalence of harmful drinking (i.e., AUDIT scores of >10) is found to be alarming (41% and 37% for boys and girls, respectively; OR = 1.13, 95% CI = 0.87–1.48), while 17% of boys and 9% of girls used illegal drugs (OR = 2.01, 95% CI = 1.35–2.95). The behavioral grade (observed as: excellent–average-poor) is the factor that was most significantly correlated with SUM both in boys and girls, with lower behavioral grades among those adolescents who consume substances. In girls, lower maternal education levels were associated with a decreased likelihood of SUM, whereas sports achievement was negatively associated with risky drinking. In boys, sports achievement decreased the likelihood of daily smoking. Information on the factors associated with SUM should be disseminated among sports and school authorities. PMID:27196918

  20. Associations of Overweight, Obesity and Related Factors with Sleep-Related Breathing Disorders and Snoring in Adolescents: A Cross-Sectional Survey

    PubMed Central

    Ma, Yue; Peng, Liping; Kou, Changgui; Hua, Shucheng; Yuan, Haibo

    2017-01-01

    Background: Sleep-related breathing disorders (SRBD) have been identified as a major public health problem closely related to adolescent obesity. We aimed to estimate the prevalences of SRBD and snoring in adolescents in Changchun City, Northeastern China, and to evaluate the associated factors in this population. Methods: In total, 1955 adolescents aged 11–18 years were recruited in Changchun City using stratified cluster sampling. Parents and caretakers of children completed the questionnaires, which included demographic characteristics, anthropometric parameters and a pediatric sleep questionnaire (SRBD scale). Logistic regression was used to analyze the relationship between SRBD, snoring and other factors. Results: The prevalences of SRBD and snoring in our population were 3.7% and 3.3%, respectively, and the prevalences of overweight and obesity were 12.6% and 4.9%. Multivariate logistic regression showed that urban residence (OR = 2.356, 95%CI: 1.251–4.435) and post-term birth (OR = 3.275, 95%CI: 1.396–7.683) were significantly associated with SRBD. Preterm birth (OR = 2.255, 95%CI: 1.021–4.980) and parental education level of university and above (OR = 0.265, 95%CI: 0.083–0.850) were significantly associated with snoring. Overweight (OR = 2.063, 95%CI: 1.062–4.006) was also related to snoring. Conclusions: The prevalences of SRBD and snoring were similar to those reported in previous studies. Urban residence and post-term birth were important influencing factors for SRBD; overweight, highest parental education level (university and above) and preterm birth were key factors affecting snoring in adolescents. PMID:28212303

  1. Prevalence, correlates, and prospective predictors of non-suicidal self-injury among New Zealand adolescents: cross-sectional and longitudinal survey data.

    PubMed

    Garisch, Jessica Anne; Wilson, Marc Stewart

    2015-01-01

    Non-suicidal self-injury (NSSI) is common among adolescents and linked to many maladaptive outcomes. This study aimed to assess the prevalence and correlates of NSSI among a community sample of New Zealand adolescents. A self-report questionnaire was administered to adolescents at time 1 (N = 1162, mean age = 16.35), and approximately five months later (time 2, N = 830, mean age = 16.49). Prevalence and bivariate correlations were assessed at both time points, and cross-lag correlations using matched data (N = 495, mean age = 16.23). Lifetime history of NSSI was 48.7 % (females 49.4 %, males 48 %). Consistent with previous international research, NSSI was associated with higher Alexithymia, depression, anxiety, bullying, impulsivity, substance abuse, abuse history and sexuality concerns and lower mindfulness, resilience and self-esteem. Cross-lag correlations suggested NSSI is directly (perhaps causally) related to psychological vulnerability in various domains (e.g., increased depression and lower self-esteem), while bullying may be more distal to NSSI, rather than a proximal predictor.

  2. Gender differences in the association between cigarette smoking, alcohol consumption and depressive symptoms: a cross-sectional study among Chinese adolescents

    PubMed Central

    Yue, Yue; Hong, Lingyao; Guo, Lan; Gao, Xue; Deng, Jianxiong; Huang, Jinghui; Huang, Guoliang; Lu, Ciyong

    2015-01-01

    The aim of this study was to examine the association between cigarette smoking, alcohol consumption and depressive symptoms among adolescents, with a particular focus on gender differences. A total of 19,578 middle and high school students in Chongqing Province were surveyed. Self-reported cigarette smoking, alcohol consumption, depressive symptoms, and family- and school-related factors were assessed. A total of 8.8% adolescents reported smoking cigarettes. Tobacco use by boys (16.5%) was significantly higher than by girls (1.9%). Approximately 23.5% of adolescents reported alcohol consumption. Consumption in boys (31.5%) was significantly higher than in girls (16.2%). Depressive symptoms were prevalent in 9.1% of the sample. Girls reported significantly more symptoms (10.4%) than boys (7.7%). Multiple logistic regression analyses showed that the association between alcohol consumption and depressive symptoms was stronger among girls (AOR = 2.1, 95% CI = 1.8–2.5) than boys (AOR = 1.7, 95% CI = 1.4–2.1). A significant association (AOR = 2.3, 95% CI = 1.6–3.4) between cigarette smoking and depressive symptoms was revealed in girls only. The significant gender differences found above may provide a basis for the early identification of individuals at high risk for depression. PMID:26639938

  3. How often do German children and adolescents show signs of common mental health problems? Results from different methodological approaches – a cross-sectional study

    PubMed Central

    2014-01-01

    Background Child and adolescent mental health problems are ubiquitous and burdensome. Their impact on functional disability, the high rates of accompanying medical illnesses and the potential to last until adulthood make them a major public health issue. While methodological factors cause variability of the results from epidemiological studies, there is a lack of prevalence rates of mental health problems in children and adolescents according to ICD-10 criteria from nationally representative samples. International findings suggest only a small proportion of children with function impairing mental health problems receive treatment, but information about the health care situation of children and adolescents is scarce. The aim of this epidemiological study was a) to classify symptoms of common mental health problems according to ICD-10 criteria in order to compare the statistical and clinical case definition strategies using a single set of data and b) to report ICD-10 codes from health insurance claims data. Methods a) Based on a clinical expert rating, questionnaire items were mapped on ICD-10 criteria; data from the Mental Health Module (BELLA study) were analyzed for relevant ICD-10 and cut-off criteria; b) Claims data were analyzed for relevant ICD-10 codes. Results According to parent report 7.5% (n = 208) met the ICD-10 criteria of a mild depressive episode and 11% (n = 305) showed symptoms of depression according to cut-off score; Anxiety is reported in 5.6% (n = 156) and 11.6% (n = 323), conduct disorder in 15.2% (n = 373) and 14.6% (n = 357). Self-reported symptoms in 11 to 17 year olds resulted in 15% (n = 279) reporting signs of a mild depression according to ICD-10 criteria (vs. 16.7% (n = 307) based on cut-off) and 10.9% (n = 201) reported symptoms of anxiety (vs. 15.4% (n = 283)). Results from routine data identify 0.9% (n = 1,196) with a depression diagnosis, 3.1% (n = 6,729) with anxiety and 1.4% (n

  4. Measurement of the argon-38(n,2n)argon-37 and calcium- 40(n,alpha)argon-37 cross sections, and National Ignition Facility concrete activation using the rotating target neutron source. The design of an experiment to measure the beryllium-9(n,gamma)beryllium-10 cross section at 14 MeV

    NASA Astrophysics Data System (ADS)

    Belian, Anthony Paul

    were recorded as a function of time after irradiation. These dose rates were compared to those calculated using the Monte Carlo code TART and the activation code ACAB. It was found that 95.8% of the comparisons agreed within the experimental uncertainty. The 40Ca(n,α)37Ar reaction was of interest for the detection of clandestine underground nuclear detonations. Since calcium is naturally abundant in the earth's crust, and since 37Ar is an inert gas and is not found naturally, the 40Ca(n, α) 37Ar reaction is a good candidate for detecting a nuclear detonation. An accurate cross section is needed to estimate the yield of the nuclear device. The average cross sections measured were: 175.6 +/- 9.2 millibarns (mb) at 13.2 +/- 0.6 MeV and 122.1 +/- 4.6 mb at 15.2 +/- 0.12 MeV. One of the current NIF pellet designs uses beryllium as the ablation layer, and the target positioner will be made of a beryllium/copper alloy. The reaction product, 10Be, from the 9Be(n,γ) 10Be reaction will be generated, although probably in very small quantities, during the lifetime of the NIF. This cross section has not been measured at 14 MeV, but should be measured to estimate the amount of 10Be produced at the NIF.

  5. BMI is a Better Indicator of Cardiac Risk Factors, as against Elevated Blood Pressure in Apparently Healthy Female Adolescents and Young Adult Students: Results From a Cross-Sectional Study in Tripura

    PubMed Central

    Debnath, Surajit

    2016-01-01

    Background: Anthropometric measures are used as indicators of elevated blood pressure, but reported to have variable sensitivity among populations. This study was undertaken to identify the better indicator of Cardiac-risk factors by statistical comparison of BMI, Waist circumference, and Waist to Height (WtHr) ratio in apparently healthy adolescents and young adult female students of Tripura. Materials and Methods: A cross-sectional study was conducted in a resource limited setup on 210 apparently healthy female adolescents and young adult students in Tripura. Mean (±SD) of all parameters were compared (ANOVA) to recognize significant independent (anthropometric measures) and dependent factors (blood pressure indices and so on). Correlation (r) analysis was used to identify the better (p) indicator of blood pressure indices (dependent variable) and its impact was assessed by Multiple Regression analysis. Results: blood pressure indices are comparatively higher in obese and overweight participants with statistically significant (95.5% confidence) mean differences. Significant correlation with dependent factors is observed with BMI followed by WtHr and Waist Circumference. Impact of anthropometric measures with blood pressure Indices is most significant for BMI (P ≤ 0.020) followed by WtHr (P ≤ 0.500) and waist circumference (P ≤ 0.520). Conclusion: BMI is a superior indicator of blood pressure indices and can identify participants at risk even in apparently healthy adolescent and young adult females. PMID:27890980

  6. A Western dietary pattern is associated with overweight and obesity in a national sample of Lebanese adolescents (13-19 years): a cross-sectional study.

    PubMed

    Naja, Farah; Hwalla, Nahla; Itani, Leila; Karam, Sabine; Sibai, Abla Mehio; Nasreddine, Lara

    2015-12-14

    Adolescent obesity is associated with both immediate and longer-term health implications. This study aims to identify dietary patterns among a nationally representative sample of Lebanese adolescents aged between 13 and 19 years (n 446) and to assess the association of these patterns with overweight and obesity. Through face-to-face interviews, socio-demographic, lifestyle and anthropometric variables were collected. Dietary intake was assessed using a sixty-one-item FFQ. Dietary patterns were derived by factor analysis. The following two dietary patterns were identified: Western and traditional Lebanese. The Western pattern was characterised by high consumption of red meat, eggs and fast-food sandwiches. The traditional Lebanese pattern reflected high intakes of fruits and vegetables, legumes and fish. Female sex and a higher maternal education level were associated with a greater adherence to the traditional Lebanese pattern. As for the Western pattern, the scores were negatively associated with crowding index, physical activity and frequency of breakfast consumption. After adjustment, subjects belonging to the 3rd tertile of the Western pattern scores had significantly higher odds of overweight compared with those belonging to the 1st tertile (OR 2·3; 95% CI 1·12, 4·73). In conclusion, two distinct dietary patterns were identified among adolescents in Lebanon: the traditional Lebanese and the Western, with the latter pattern being associated with an increased risk of overweight. The findings of this study may be used to guide the development of evidence-based preventive nutrition interventions to curb the obesity epidemic in this age group.

  7. Validation of the Brazilian version of the pediatric outcomes data collection instrument: a cross-sectional evaluation in children and adolescents with juvenile idiopathic arthritis

    PubMed Central

    2013-01-01

    Background There is a lack of health-related quality of life (HRQOL) questionnaires to evaluate pediatric musculoskeletal diseases in Brazil. The Pediatric Outcome Data Collection Instrument (PODCI) is widely used elsewhere for pediatric patients with musculoskeletal disorders, but it has not been fully validated in Brazil. Validation of the PODCI in the Brazilian Portuguese language is important to improve the assessment of pediatric patients with musculoskeletal diseases and to compare Brazilian study results with results from the international literature. This study aimed to analyze the test–re-test reliability and the convergent validity indicators for the quality of life scores obtained by application of the PODCI to children and adolescents with juvenile idiopathic arthritis (JIA). Methods The PODCI underwent translation, transcultural adaptation, and field testing. Fifty-seven children and adolescents with JIA were administered the PODCI questionnaire. The Child Health Questionnaire - Parent Form 28 (CHQ PF-28) was used as the gold standard. Pain scales were employed, clinical examinations were performed, and laboratory inflammatory activity tests were conducted. Results The three versions of the PODCI exhibited good internal consistency (Cronbach’s alpha coefficient >0.70), good reproducibility (p < 0.05), and good correlation compared with the gold standard (CHQ), as shown by a Spearman coefficient (Rho) >0.40 (p < 0.05). Conclusions The PODCI was validated in patients with JIA in Brazil. This questionnaire was found to be valid, precise, and reliable. It can be successfully applied in research conducted by healthcare professionals who work with children and adolescents with musculoskeletal system disorders. PMID:24171906

  8. Executive functions and basic symptoms in adolescent antisocial behavior: a cross-sectional study on an Italian sample of late-onset offenders.

    PubMed

    Muscatello, Maria Rosaria A; Scimeca, Giuseppe; Pandolfo, Gianluca; Micò, Umberto; Romeo, Vincenzo M; Mallamace, Domenico; Mento, Carmela; Zoccali, Rocco; Bruno, Antonio

    2014-04-01

    Executive cognitive functions (ECFs) and other cognitive impairments, such as lower IQ and verbal deficits, have been associated with the pattern of antisocial and delinquent behavior starting in childhood (early-onset), but not with late-onset antisocial behavior. Beyond objective measures of ECF, basic symptoms are prodromal, subjectively experienced cognitive, perceptual, affective, and social disturbances, associated with a range of psychiatric disorders, mainly with psychosis. The goal of the present study was to examine ECF and basic symptoms in a sample of late-onset juvenile delinquents. Two-hundred nine male adolescents (aged 15-20 years) characterized by a pattern of late-onset delinquent behavior with no antecedents of Conduct Disorder, were consecutively recruited from the Social Services of the Department of Juvenile Justice of the city of Messina (Italy), and compared with nonantisocial controls matched for age, educational level, and socio-demographic features on measures for ECF dysfunction and basic symptoms. Significant differences between late-onset offenders (completers=147) and control group (n=150) were found on ECF and basic symptoms measures. Chi-square analysis showed that a significantly greater number of late-onset offending participants scored in the clinical range on several ECF measures. Executive cognitive impairment, even subtle and subclinical, along with subjective symptoms of cognitive dysfunction (basic symptom), may be contributing factor in the development and persistence of antisocial behaviors displayed by late-onset adolescent delinquents. The findings also suggest the need for additional research aimed to assess a broader range of cognitive abilities and specific vulnerability and risk factors for late-onset adolescent offenders.

  9. Discontent with Financial Situation, Self-rated Health, and Well-being of Adolescents in Bosnia and Herzegovina: Cross-sectional Study in Tuzla Canton

    PubMed Central

    Pranjić, Nurka; Brković, Aida; Beganlić, Azijada

    2007-01-01

    Aim To examine the relationship between quality of life, self-rated health, and well-being and to establish the relationship between discontent with familial financial situation and health in adolescents living in the Tuzla Canton. Method The study comprised a random sample of 356 high school students aged 16, coming from 15 different classes of 16 high schools in the Tuzla municipality. Data were obtained using a validated self-reporting questionnaire on demographic and socioeconomic background, structure, and dynamics of the adolescent’s family, life-style, perception, and satisfaction with the financial situation and current health status, as well as social relationships and health care provided in school settings. Results In 11% (n = 40) of students’ households several poverty indicators were present. Twenty three percent (n = 82) of the examinees were dissatisfied with the financial situation in their families, and 73% of them came from local, non-refugee families. They presented with progressive symptoms of unhappiness and expressed discontent with their health condition, and even self-hate in comparison with adolescents who were satisfied with the financial situation in their families (χ2 = 21.5; P = 0.001). The prevalence of self-rated mental symptoms was significantly lower among adolescents who were satisfied with their financial situation than in those who were dissatisfied (symptoms of depression 57/274 vs 40/82, P = 0.001; sadness 73/274 vs 45/82, P = 0.001; moroseness 34/274 vs 19/82, P = 0.001; under-sedation 29/274 vs 18/82, P = 0.001; bad marks and school failures 31/274 vs 20/82, P = 0.001; suicidal attempts 11/274 vs 7/82, P = 0.001, respectively). Using linear regression analysis we found that adolescents’ satisfaction with the financial situation was a major factor predicting depression (OR, 1.57; 95% CI, 1.158-1.855), loss of appetite (OR, 0.82; 95% CI, 0.561-1.235), distraction (OR, 1.19; 95% CI

  10. Adolescent gender differences in the determinants of tobacco smoking: a cross sectional survey among high school students in São Paulo

    PubMed Central

    2010-01-01

    Background Diverse psychosocial factors have been associated with the use of cigarettes by adolescents. We investigated gender differences in tobacco smoking, and factors correlated with smoking among boys and girls. Methods Data was collected on recent cigarette smoking (CS) and related factors, with a focus on religious beliefs, leisure activities, family structure, relationships and parental monitoring from 2,691 private school-attending youths from 28 schools in São Paulo, Brazil, selected via probability sampling. Estimates were derived via weighted hierarchical logistic regression models. Results There was no difference in the prevalence of recent cigarette smoking between boys and girls (14.2%). Older age (aORboys = 1.71[1.33-2.21]; aORgirls = 1.73[1.35-2.23]), second-hand smoke exposure at home (aORboys = 1.52[1.00-2.29]; aORgirls = 1.74[1.13-2.68]) and not having a religion (aORboys = 1.99[1.41-2.81]; aORgirls = 1.78[1.14-2.78]) were associated with CS in boys and girls. Adolescents who went out often at night were more likely to be tobacco smokers (aORboys = 8.82[3.96-19.67]; aORgirls = 14.20[6.64-30.37]). For girls, data suggest that CS was also associated with a lack of parental attention and care (aORgirls = 4.37[1.19-16.04]) and no participation in youth religious activities (aORgirls = 2.76[1.49-5.12]). For boys, CS was additionally associated with the loss of one or both parents (aORboys = 3.75[1.78-7.85]). Conclusions Although older age, living with smokers at home and lack of religion were common contributing factors to cigarette smoking among all adolescents, girls were influenced to a greater degree by family relationships and religiosity than boys. The study results may be materially important to the development of prevention programs that influence determinants connected to gender and the implementation of single-core models of prevention; gender differences must be considered in order to reduce adolescent CS. PMID:21129177

  11. Social capital in relation to depression, musculoskeletal pain, and psychosomatic symptoms: a cross-sectional study of a large population-based cohort of Swedish adolescents

    PubMed Central

    2010-01-01

    Background Social capital has lately received much attention in health research. The present study investigated whether two measures of subjective social capital were related to psychosomatic symptoms, musculoskeletal pain, and depression in a large population of Swedish adolescents. Methods A total of 7757 13-18 year old students anonymously completed the Survey of Adolescent Life in Vestmanland 2008 which included questions on sociodemographic background, neighbourhood social capital, general social trust, and ill health. Results Low neighbourhood social capital and low general social trust were associated with higher rates of psychosomatic symptoms, musculoskeletal pain, and depression. Individuals with low general social trust had more than three times increased odds of being depressed, three times increased odds of having many psychosomatic symptoms, and double the odds of having many symptoms of musculoskeletal pain. Conclusions The findings make an important contribution to the social capital - health debate by demonstrating relations between social capital factors and self-reported ill health in a young population. PMID:21092130

  12. Screening for non-alcoholic fatty liver disease in children and adolescents with type 1 diabetes mellitus: a cross-sectional analysis.

    PubMed

    Kummer, Sebastian; Klee, Dirk; Kircheis, Gerald; Friedt, Michael; Schaper, Joerg; Häussinger, Dieter; Mayatepek, Ertan; Meissner, Thomas

    2017-04-01

    The liver is intensely involved in glucose metabolism and is thereby closely related to diabetes pathophysiology. Adult patients with type 1 diabetes mellitus (DM) are at an increased risk for non-alcoholic fatty liver disease (NAFLD). Here, we studied the prevalence of NAFLD in a cohort of children and adolescents with type 1 DM in a tertiary care paediatric diabetes centre in Germany. We screened 93 children and adolescents with type 1 DM using ultrasound, laboratory investigations, and liver stiffness measurements (Fibroscan® [FS] and acoustic radiation force imaging [ARFI]). Of these, 82 (88.1%) had completely normal results in all examined aspects. Only one patient (1.1%) fulfilled the criteria as potential NAFLD with ALT > twice the upper limit of normal. Ten of the 93 patients (10.8%) showed any mild abnormality in at least one examined category including ALT, conventional ultrasounds and liver stiffness measurements. However, none of these ten fulfilled the NAFLD case definition criteria. Therefore, these slightly abnormal results were judged to be unspecific or at least of unknown significance in terms of NAFLD indication.

  13. Characteristics of chronic non-specific musculoskeletal pain in children and adolescents attending a rheumatology outpatients clinic: a cross-sectional study

    PubMed Central

    2011-01-01

    Background Chronic non-specific musculoskeletal pain (CNSMSP) may develop in childhood and adolescence, leading to disability and reduced quality of life that continues into adulthood. The purpose of the study was to build a biopsychosocial profile of children and adolescents with CNSMSP. Methods CNSMSP subjects (n = 30, 18 females, age 7-18) were compared with age matched pain free controls across a number of biopsychosocial domains. Results In the psychosocial domain CNSMSP subjects had increased levels of anxiety and depression, and had more somatic pain complaints. In the lifestyle domain CNSMSP subjects had lower physical activity levels, but no difference in television or computer use compared to pain free subjects. Physically, CNSMSP subjects tended to sit with a more slumped spinal posture, had reduced back muscle endurance, increased presence of joint hypermobility and poorer gross motor skills. Conclusion These findings support the notion that CNSMSP is a multidimensional biopsychosocial disorder. Further research is needed to increase understanding of how the psychosocial, lifestyle and physical factors develop and interact in CNSMSP. PMID:21247439

  14. Cross Sections for Planetary Escape

    NASA Astrophysics Data System (ADS)

    Tully, C.

    2001-05-01

    Energetic charged-particle bombardment, dissociative recombination and photodissociation processes produce energetic recoil atoms which heat the thermosphere and can lead to escape from a planet affecting the evolution of the atmosphere. In describing these processes by Monte Carlo methods, many of the critical cross sections are not available in the energy range of interest, a few eV to 1 keV. Here we present our recent results for elastic collision and collisional dissociation cross sections relevant to Titan, Triton, Europa and the terrestrial planets [1,2]. Elastic and diffusion cross sections were calculated using both quantum mechanical techniques and the semiclassical JWKB approximation for the collision of ground state oxygen atoms in the energy range 1-10eV [2]. This involved calculation of phase shifts for each of the 18 molecular energy states of O2 which separate to two ground state O atoms. For an O thermosphere the total elastic cross section is close to that typically assumed but the escape depths are shown to be larger than those typically used. Dissociation cross sections of N + N2 were calculated using a semiclassical method, in the energy range 0-30eV. This required treating the vibrational motion quantum mechanically while the rotational and the relative translational motion were treated classically. The evolution of the system was calculated by simultaneous propagation of the classical as well as the quantal degrees of freedom. The solution to the classical part was carried out by solving Hamilton equations of motion using an effective London-Eyring-Polanyi-Sato potential energy surface, calculated by Laganá et al [3]. Propagation of the quantal wavefunction was carried out by solving the time dependent Schrödinger equation using the split operator technique with the help of the fast fourier transform which was used to calculate the second derivatives arising from the kinetic energy operator. This work was supported by NASA's Planetary

  15. Identity development, intelligence structure, and interests: a cross-sectional study in a group of Italian adolescents during the decision-making process

    PubMed Central

    Pellerone, Monica; Passanisi, Alessia; Bellomo, Mario Filippo Paolo

    2015-01-01

    Background Forming one’s identity is thought to be the key developmental task of adolescence, but profound changes in personality traits also occur in this period. The negotiation of complex social settings, the creation of an integrated identity, and career choice are major tasks of adolescence. The adolescent, having to make choices for his or her future, has not only to consider his or her own aspirations and interests but also to possess a capacity for exploration and commitment; in fact, career commitments can be considered as a fit between the study or career that is chosen and personal values, skills, and preferences. Methods The objective of the study reported here was to investigate the role of identity on profile of interests; the relation between identity and decisional style; the correlation between identity, aptitudes, interests, and school performance; and the predictive variables to school success. The research involved 417 Italian students who live in Enna, a small city located in Sicily, Italy, aged 16–19 years (197 males and 220 females) in the fourth year (mean =17.2, standard deviation =0.52) and the fifth year (mean =18.2, standard deviation =0.64) of senior secondary school. The research lasted for one school year; the general group of participants consisted of 470 students, and although all participants agreed to be part of the research, there was a dropout rate of 11.28%. They completed the Ego Identity Process Questionnaire to measure their identity development, the Intelligence Structure Test to investigate aptitudes, the Self-Directed Search to value interests, and General Decision Making Style questionnaire to describe their individual decisional style. Results The data showed that high-school performance was positively associated with rational decision-making style and identity diffusion predicted the use of avoidant style. Interests were related to identity exploration; the differentiation of preferences was related to identity

  16. A national cross-sectional study among drug-users in France: epidemiology of HCV and highlight on practical and statistical aspects of the design

    PubMed Central

    2009-01-01

    Background Epidemiology of HCV infection among drug users (DUs) has been widely studied. Prevalence and sociobehavioural data among DUs are therefore available in most countries but no study has taken into account in the sampling weights one important aspect of the way of life of DUs, namely that they can use one or more specialized services during the study period. In 2004–2005, we conducted a national seroepidemiologic survey of DUs, based on a random sampling design using the Generalised Weight Share Method (GWSM) and on blood testing. Methods A cross-sectional multicenter survey was done among DUs having injected or snorted drugs at least once in their life. We conducted a two stage random survey of DUs selected to represent the diversity of drug use. The fact that DUs can use more than one structure during the study period has an impact on their inclusion probabilities. To calculate a correct sampling weight, we used the GWSM. A sociobehavioral questionnaire was administered by interviewers. Selected DUs were asked to self-collect a fingerprick blood sample on blotting paper. Results Of all DUs selected, 1462 (75%) accepted to participate. HCV seroprevalence was 59.8% [95% CI: 50.7–68.3]. Of DUs under 30 years, 28% were HCV seropositive. Of HCV-infected DUs, 27% were unaware of their status. In the month prior to interview, 13% of DUs shared a syringe, 38% other injection parapharnelia and 81% shared a crack pipe. In multivariate analysis, factors independently associated with HCV seropositivity were age over 30, HIV seropositivity, having ever injected drugs, opiate substitution treatment (OST), crack use, and precarious housing. Conclusion This is the first time that blood testing combined to GWSM is applied to a DUs population, which improve the estimate of HCV prevalence. HCV seroprevalence is high, indeed by the youngest DUs. And a large proportion of DUs are not aware of their status. Our multivariate analysis identifies risk factors such as crack

  17. Utility of the modified ATP III defined metabolic syndrome and severe obesity as predictors of insulin resistance in overweight children and adolescents: a cross-sectional study

    PubMed Central

    Dhuper, Sarita; Cohen, Hillel W; Daniel, Josephine; Gumidyala, Padmasree; Agarwalla, Vipin; St Victor, Rosemarie; Dhuper, Sunil

    2007-01-01

    Background The rising prevalence of obesity and metabolic syndrome (MetS) has received increased attention since both place individuals at risk for Type II diabetes and cardiovascular disease. Insulin resistance (IR) has been implicated in the pathogenesis of obesity and MetS in both children and adults and is a known independent cardiovascular risk factor. However measures of IR are not routinely performed in children while MetS or severe obesity when present, are considered as clinical markers for IR. Objective The study was undertaken to assess the utility of ATPIII defined metabolic syndrome (MetS) and severe obesity as predictors of insulin resistance (IR) in a group of 576 overweight children and adolescents attending a pediatric obesity clinic in Brooklyn. Methods Inclusion criteria were children ages 3–19, and body mass index > 95th percentile for age. MetS was defined using ATP III criteria, modified for age. IR was defined as upper tertile of homeostasis model assessment (HOMA) within 3 age groups (3–8, n = 122; 9–11, n = 164; 12–19, n = 290). Sensitivity, specificity, positive predictive values and odds ratios (OR) with 95% confidence intervals (CI) were calculated within age groups for predicting IR using MetS and severe obesity respectively. Results MetS was present in 45%, 48% and 42% of the respective age groups and significantly predicted IR only in the oldest group (OR = 2.0, 95% CI 1.2, 3.4; p = .006). Sensitivities were <55%; specificities <63% and positive predictive values ≤ 42% in all groups. Severe obesity was significantly associated with IR in both the 9–11 (p = .002) and 12–18 (p = .01) groups but positive predictive values were nonetheless ≤ 51% for all groups. Conclusion The expression of IR in overweight children and adolescents is heterogeneous and MetS or severe obesity may not be sufficiently sensitive and specific indicators of insulin resistance. In addition to screening for MetS in overweight children markers for

  18. A cross-sectional survey of complementary and alternative medicine use by children and adolescents attending the University Hospital of Wales

    PubMed Central

    Crawford, Nigel W; Cincotta, Domenic R; Lim, Alissa; Powell, Colin VE

    2006-01-01

    Background A high prevalence of CAM use has been documented worldwide in children and adolescents with chronic illnesses. Only a small number of studies, however, have been conducted in the United Kingdom. The primary aim of this study was to examine the use of CAM by children and adolescents with a wide spectrum of acute and chronic medical problems in a tertiary children's hospital in Wales. Methods Structured personal interviews of 100 inpatients and 400 outpatients were conducted over a 2-month period in 2004. The yearly and monthly prevalence of CAM use were assessed and divided into medicinal and non-medicinal therapies. This use was correlated with socio-demographic factors. Results There were 580 patients approached to attain 500 completed questionnaires. The use of at least one type of CAM in the past year was 41% (95% CI 37–46%) and past month 26% (95% CI 23–30%). The yearly prevalence of medicinal CAM was 38% and non-medicinal 12%. The users were more likely to have parents that were tertiary educated (mother: OR = 2.3, 95%CI 1.6–3.3) and a higher family income (Pearson chi-square for trend = 14.3, p < 0.001). The most common medicinal types of CAM were non-prescribed vitamins and minerals (23%) and herbal therapies (10%). Aromatherapy (5%) and reflexology (3%) were the most prevalent non-medicinal CAMs. None of the inpatient medical records documented CAM use in the past month. Fifty-two percent of medicinal and 38% of non-medicinal CAM users felt their doctor did not need to know about CAM use. Sixty-six percent of CAM users did not disclose the fact to their doctor. Three percent of all participants were using herbs and prescription medicines concurrently. Conclusion There is a high prevalence of CAM use in our study population. Paediatricians need to ensure that they ask parents and older children about their CAM usage and advise caution with regard to potential interactions. CAM is a rapidly expanding industry that requires further evidence

  19. Parents Support Implementation of HIV Testing and Counseling at School: Cross-Sectional Study with Parents of Adolescent Attending High School in Gauteng and North West Provinces, South Africa

    PubMed Central

    Mokgatle, Mathildah

    2016-01-01

    Background. A formative assessment of the implementation of HIV testing and counseling (HTC) at school showed high acceptability and willingness to test among learners. However, the success of the proposed HTC depends on the support and acceptability of key stakeholders, including the parents. The aim of the study was to assess the opinions and acceptability of the implementation of HTC at school among parents of adolescents in high school. Methods. This was a cross-sectional household survey conducted with parents of adolescents attending high schools in educational districts in North West and Gauteng provinces, South Africa. Results. A total of 804 parents participated, and 548 (68.3%) were biological mothers, 85 (10.6%) were fathers, and the remaining were other relatives including grandmothers. Almost all (n = 742, 92.9%) parents were in support of implementation and provision of HTC at school, 701 (87.7%) would allow their children to be tested at school, 365 (46%) felt that parental consent was not needed to test at school, and 39.4% preferred to receive the HIV test results with their children. Conclusion. Parents accept the roll-out of an HTC program at school and have a role to play in supporting children who test positive for HIV. PMID:27807481

  20. A cross-sectional study of adolescent non-suicidal self-injury: support for a specific distress-function relationship

    PubMed Central

    2014-01-01

    Background This study has investigated the specific relationship between childhood adversities, individual trauma symptoms and the functions of non-suicidal self-injury (NSSI). The aim was to examine whether different self-reported adverse experiences and trauma symptoms predict the need to engage in NSSI, either to regulate emotions or to communicate with and influence others. Method The participants were a community sample of 816 adolescents aged 15–17 years with NSSI. Hierarchical multiple regression was used, controlling for NSSI frequency and gender. The dependent variables were the automatic and social functions of NSSI, respectively. The predictors entered in the model were several different maltreatment and adversity experiences as well as individual trauma symptoms. Mediation analyses were also performed using the bootstrapping method with bias-corrected confidence estimates. Results Frequency of NSSI, gender (female), emotional abuse, prolonged illness or handicap during upbringing and symptoms of depression uniquely predicted the automatic functions of NSSI in the final regression model, but not the social functions. Symptoms of anxiety uniquely predicted social but not automatic functions. Having experienced physical abuse, having made a suicide attempt and symptoms of dissociation were significant predictors in both final models. The model for automatic functions explained more of the variance (62%) than the social model (28%). The relationship between childhood emotional, physical and sexual abuse and performing NSSI for automatic reasons was mediated by symptoms of depression and dissociation. The relationship between physical abuse and the social functions of NSSI was mediated by symptoms of anxiety and dissociation. Conclusions It is important to understand the specific context in which NSSI has developed and is maintained. Experiences of emotional abuse and symptoms of depression could guide clinical work in the direction of emotion regulation

  1. The association between state bans on soda only and adolescent substitution with other sugar-sweetened beverages: a cross-sectional study

    PubMed Central

    2015-01-01

    Background Across the United States, many states have actively banned the sale of soda in high schools, and evidence suggests that students’ in-school access to soda has declined as a result. However, schools may be substituting soda with other sugar-sweetened beverages (SSBs), and national trends indicate that adolescents are consuming more sports drinks and energy drinks. This study examined whether students consumed more non-soda SSBs in states that banned the sale of soda in school. Methods Student data on consumption of various SSBs and in-school access to vending machines that sold SSBs were obtained from the National Youth Physical Activity and Nutrition Study (NYPANS), conducted in 2010. Student data were linked to state laws regarding the sale of soda in school in 2010. Students were cross-classified based on their access to vending machines and whether their state banned soda in school, creating 4 comparison groups. Zero-inflated negative binomial models were used to compare these 4 groups with respect to students’ self-reported consumption of diet soda, sports drinks, energy drinks, coffee/tea, or other SSBs. Students who had access to vending machines in a state that did not ban soda were the reference group. Models were adjusted for race/ethnicity, sex, grade, home food access, state median income, and U.S. Census region. Results Students consumed more servings of sports drinks, energy drinks, coffee/tea, and other SSBs if they resided in a state that banned soda in school but attended a school with vending machines that sold other SSBs. Similar results were observed where schools did not have vending machines but the state allowed soda to be sold in school. Intake was generally not elevated where both states and schools limited SSB availability – i.e., states banned soda and schools did not have SSB vending machines. Conclusion State laws that ban soda but allow other SSBs may lead students to substitute other non-soda SSBs. Additional

  2. Electron-Impact Ionization Cross Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

  3. Physical activity and screen-based media use: cross-sectional associations with health-related quality of life and the role of body satisfaction in a representative sample of German adolescents.

    PubMed

    Finne, Emily; Bucksch, Jens; Lampert, Thomas; Kolip, Petra

    2013-01-01

    Purpose: Although it is widely accepted that physical activity (PA) positively, and screen-based media use (SBM) negatively, affects well-being, there is a lack of studies relating PA and SBM to health-related quality of life (HRQoL) in adolescents. We examined these associations in German adolescents for different HRQoL subdomains and explored the role of body satisfaction as a possible mediator. Methods: The 11-17-year-old subsample of the German Health Interview and Examination Survey (2003-2006) was analysed (N = 6813; 51.3% male). Cross-sectional associations of self-reported PA frequency and amount of daily SBM with HRQoL subscale scores (according to KINDL-R) were examined by hierarchical linear regression models, adjusting for the clustering of the sample and for a variety of possible confounders. The size and significance of indirect effects via body (dis)satisfaction (BDS) were examined by mediation analyses. Results: Higher PA frequency was significantly associated with higher HRQoL on nearly all subscales and dose-response-relationships were observable. Variations were greatest in terms of social well-being in boys (effect size d = 0.59) and physical well-being in girls (d = 0.43). Higher SBM was related to lower HRQoL on all subscales in girls and on some subscales in boys, with the largest effects for school functioning in both genders (d = 0.31 and 0.37, respectively). The mediated effects for PA and SBM were significant in both genders, but the sizes and the proportions of total effects mediated by body satisfaction were rather small. Conclusions: Higher PA frequency was associated with higher self-reported HRQoL, and higher SBM was associated with lower self-reported HRQoL in both genders, even after adjusting for relevant covariates. The results support the assumption of independent health impacts of both behaviours, although no causal relationship can be confirmed with these cross-sectional data. Mechanisms other than body satisfaction must

  4. Neutron cross sections: Book of curves

    SciTech Connect

    McLane, V.; Dunford, C.L.; Rose, P.F.

    1988-01-01

    Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs.

  5. Photoproduction total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, F.; García Canal, C. A.; Grau, A.; Pancheri, G.; Sciutto, S. J.

    2015-12-01

    The total photoproduction cross section at ultrahigh energies is obtained using a model based on QCD minijets and soft-gluon resummation and the ansatz that infrared gluons limit the rise of total cross sections. This cross section is introduced into the Monte Carlo system AIRES to simulate extended air showers initiated by cosmic ray photons. The impact of the new photoproduction cross section on common shower observables, especially those related to muon production, is compared with previous results.

  6. Cross-section adjustment techniques for BWR adaptive simulation

    NASA Astrophysics Data System (ADS)

    Jessee, Matthew Anderson

    Computational capability has been developed to adjust multi-group neutron cross-sections to improve the fidelity of boiling water reactor (BWR) modeling and simulation. The method involves propagating multi-group neutron cross-section uncertainties through BWR computational models to evaluate uncertainties in key core attributes such as core k-effective, nodal power distributions, thermal margins, and in-core detector readings. Uncertainty-based inverse theory methods are then employed to adjust multi-group cross-sections to minimize the disagreement between BWR modeling predictions and measured plant data. For this work, measured plant data were virtually simulated in the form of perturbed 3-D nodal power distributions with discrepancies with predictions of the same order of magnitude as expected from plant data. Using the simulated plant data, multi-group cross-section adjustment reduces the error in core k-effective to less than 0.2% and the RMS error in nodal power to 4% (i.e. the noise level of the in-core instrumentation). To ensure that the adapted BWR model predictions are robust, Tikhonov regularization is utilized to control the magnitude of the cross-section adjustment. In contrast to few-group cross-section adjustment, which was the focus of previous research on BWR adaptive simulation, multigroup cross-section adjustment allows for future fuel cycle design optimization to include the determination of optimal fresh fuel assembly designs using the adjusted multi-group cross-sections. The major focus of this work is to efficiently propagate multi-group neutron cross-section uncertainty through BWR lattice physics calculations. Basic neutron cross-section uncertainties are provided in the form of multi-group cross-section covariance matrices. For energy groups in the resolved resonance energy range, the cross-section uncertainties are computed using an infinitely-dilute approximation of the neutron flux. In order to accurately account for spatial and

  7. SNL RML recommended dosimetry cross section compendium

    SciTech Connect

    Griffin, P.J.; Kelly, J.G.; Luera, T.F.; VanDenburg, J.

    1993-11-01

    A compendium of dosimetry cross sections is presented for use in the characterization of fission reactor spectrum and fluence. The contents of this cross section library are based upon the ENDF/B-VI and IRDF-90 cross section libraries and are recommended as a replacement for the DOSCROS84 multigroup library that is widely used by the dosimetry community. Documentation is provided on the rationale for the choice of the cross sections selected for inclusion in this library and on the uncertainty and variation in cross sections presented by state-of-the-art evaluations.

  8. Cross Section Sensitivity and Propagated Errors in HZE Exposures

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Wilson, John W.; Blatnig, Steve R.; Qualls, Garry D.; Badavi, Francis F.; Cucinotta, Francis A.

    2005-01-01

    It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates.

  9. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

    NASA Astrophysics Data System (ADS)

    Baltov, Anguel; Yanakieva, Ana

    2015-12-01

    Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

  10. Experimental nuclear cross sections for spacecraft shield analysis

    NASA Technical Reports Server (NTRS)

    Peelle, R. W.

    1972-01-01

    Experiments have been performed to validate and to supplement the intranuclear cascade model as a method for estimating cross sections of importance to spacecraft shield design. The experimental situation is inconclusive particularly for neutron-producing reactions, but is relatively sound for reaction cross sections and for proton spectra at several hundred MeV at medium forward angles. Secondary photon contributions are imprecisely known.

  11. Internet Addiction and Relationships with Insomnia, Anxiety, Depression, Stress and Self-Esteem in University Students: A Cross-Sectional Designed Study

    PubMed Central

    Jabbour, Hicham; El Osta, Nada; Karam, Latife; Hajj, Aline; Rabbaa Khabbaz, Lydia

    2016-01-01

    Background and Aims Internet addiction (IA) could be a major concern in university medical students aiming to develop into health professionals. The implications of this addiction as well as its association with sleep, mood disorders and self-esteem can hinder their studies, impact their long-term career goals and have wide and detrimental consequences for society as a whole. The objectives of this study were to: 1) Assess potential IA in university medical students, as well as factors associated with it; 2) Assess the relationships between potential IA, insomnia, depression, anxiety, stress and self-esteem. Methods Our study was a cross-sectional questionnaire-based survey conducted among 600 students of three faculties: medicine, dentistry and pharmacy at Saint-Joseph University. Four validated and reliable questionnaires were used: the Young Internet Addiction Test, the Insomnia Severity Index, the Depression Anxiety Stress Scales (DASS 21), and the Rosenberg Self Esteem Scale (RSES). Results The average YIAT score was 30 ± 18.474; Potential IA prevalence rate was 16.8% (95% confidence interval: 13.81–19.79%) and it was significantly different between males and females (p-value = 0.003), with a higher prevalence in males (23.6% versus 13.9%). Significant correlations were found between potential IA and insomnia, stress, anxiety, depression and self-esteem (p-value < 0.001); ISI and DASS sub-scores were higher and self-esteem lower in students with potential IA. Conclusions Identifying students with potential IA is important because this addiction often coexists with other psychological problems. Therefore, interventions should include not only IA management but also associated psychosocial stressors such as insomnia, anxiety, depression, stress, and self-esteem. PMID:27618306

  12. The relationship between age of menarche and mental distress in Norwegian adolescent girls and girls from different immigrant groups in Norway: results from an urban city cross-sectional survey.

    PubMed

    Lien, Lars; Dalgard, Florence; Heyerdahl, Sonja; Thoresen, Magne; Bjertness, Espen

    2006-07-01

    Lower age of menarche has been associated with increased mental distress among adolescent girls. The association might be mediated via body image, as girls with early menarche tend to have higher weight than those with late onset menarche. Many of the existing studies of menarche and mental distress are based on samples of white, western girls. The aim of the study was to analyze the association between age of menarche and mental distress among Norwegian girls and girls from different immigrant groups, and to study the effect of body mass index (BMI) and the difference between current and desired weight, on the relationship between age of menarche and mental distress. The study was a cross-sectional population-based self-report survey of all 10th grade pupils in Oslo for two consecutive years. A total of 3694 girls (91%) participated, one quarter of which were first or second generation immigrants. The Hopkins Symptom Checklist-10 was used to measure mental distress. An inverse, linear association between age of menarche and mental distress was found for both Norwegian girls and girls from all the immigrant groups. Regardless of immigrant status, girls with early onset menarche had higher BMI and higher difference in current and desired weight than those with late onset menarche. In linear regression, the difference in current and desired weight was more strongly associated with mental distress both among the Norwegian girls and girls from immigrant groups than age of menarche and BMI when controlling for social and behavioral factors. Early age of menarche might serve as a predictor for psychopathology in Norwegians girls as well as in girls from different immigrant groups. The association between age of menarche and mental distress might be mediated via differences in current and desired weight.

  13. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  14. Absolute cross sections of compound nucleus reactions

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.

    1993-11-01

    The program SEEF is a Fortran IV computer code for the extraction of absolute cross sections of compound nucleus reactions. When the evaporation residue is fed by its parents, only cumulative cross sections will be obtained from off-line gamma ray measurements. But, if one has the parent excitation function (experimental or calculated), this code will make it possible to determine absolute cross sections of any exit channel.

  15. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  16. Cross Sections for Electron Collisions with Acetylene

    NASA Astrophysics Data System (ADS)

    Song, Mi-Young; Yoon, Jung-Sik; Cho, Hyuck; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2017-03-01

    Cross section data are compiled from the literature for electron collisions with the acetylene (HCCH) molecule. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2016.

  17. Cross Sections for Electron Collisions with Methane

    SciTech Connect

    Song, Mi-Young Yoon, Jung-Sik; Cho, Hyuck; Itikawa, Yukikazu; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2015-06-15

    Cross section data are compiled from the literature for electron collisions with methane (CH{sub 4}) molecules. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2014.

  18. Rationale and cross-sectional study design of the Research on Obesity and type 2 Diabetes among African Migrants: the RODAM study

    PubMed Central

    Agyemang, Charles; Beune, Erik; Meeks, Karlijn; Owusu-Dabo, Ellis; Agyei-Baffour, Peter; Aikins, Ama de-Graft; Dodoo, Francis; Smeeth, Liam; Addo, Juliet; Mockenhaupt, Frank P; Amoah, Stephen K; Schulze, Matthias B; Danquah, Ina; Spranger, Joachim; Nicolaou, Mary; Klipstein-Grobusch, Kerstin; Burr, Tom; Henneman, Peter; Mannens, Marcel M; van Straalen, Jan P; Bahendeka, Silver; Zwinderman, A H; Kunst, Anton E; Stronks, Karien

    2014-01-01

    Introduction Obesity and type 2 diabetes (T2D) are highly prevalent among African migrants compared with European descent populations. The underlying reasons still remain a puzzle. Gene–environmental interaction is now seen as a potential plausible factor contributing to the high prevalence of obesity and T2D, but has not yet been investigated. The overall aim of the Research on Obesity and Diabetes among African Migrants (RODAM) project is to understand the reasons for the high prevalence of obesity and T2D among sub-Saharan Africans in diaspora by (1) studying the complex interplay between environment (eg, lifestyle), healthcare, biochemical and (epi)genetic factors, and their relative contributions to the high prevalence of obesity and T2D; (2) to identify specific risk factors within these broad categories to guide intervention programmes and (3) to provide a basic knowledge for improving diagnosis and treatment. Methods and analysis RODAM is a multicentre cross-sectional study among homogenous sub-Saharan African participants (ie, Ghanaians) aged >25 years living in rural and urban Ghana, the Netherlands, Germany and the UK (http://rod-am.eu/). Standardised data on the main outcomes, genetic and non-genetic factors are collected in all locations. The aim is to recruit 6250 individuals comprising five subgroups of 1250 individuals from each site. In Ghana, Kumasi and Obuasi (urban stratum) and villages in the Ashanti region (rural stratum) are served as recruitment sites. In Europe, Ghanaian migrants are selected through the municipality or Ghanaian organisations registers. Ethics and dissemination Ethical approval has been obtained in all sites. This paper gives an overview of the rationale, conceptual framework and methods of the study. The differences across locations will allow us to gain insight into genetic and non-genetic factors contributing to the occurrence of obesity and T2D and will inform targeted intervention and prevention programmes, and

  19. Examination of the community-specific prevalence of and factors associated with substance use and misuse among Rural and Urban adolescents: a cross-sectional analysis in Bosnia and Herzegovina

    PubMed Central

    Zenic, Natasa; Ostojic, Ljerka; Sisic, Nedim; Pojskic, Haris; Peric, Mia; Uljevic, Ognjen; Sekulic, Damir

    2015-01-01

    Objective The community of residence (ie, urban vs rural) is one of the known factors of influence on substance use and misuse (SUM). The aim of this study was to explore the community-specific prevalence of SUM and the associations that exist between scholastic, familial, sports and sociodemographic factors with SUM in adolescents from Bosnia and Herzegovina. Methods In this cross-sectional study, which was completed between November and December 2014, the participants were 957 adolescents (aged 17 to 18 years) from Bosnia and Herzegovina (485; 50.6% females). The independent variables were sociodemographic, academic, sport and familial factors. The dependent variables consisted of questions on cigarette smoking and alcohol consumption. We have calculated differences between groups of participants (gender, community), while the logistic regressions were applied to define associations between the independent and dependent variables. Results In the urban community, cigarette smoking is more prevalent in girls (OR=2.05; 95% CI 1.27 to 3.35), while harmful drinking is more prevalent in boys (OR=2.07; 95% CI 1.59 to 2.73). When data are weighted by gender and community, harmful drinking is more prevalent in urban boys (OR=1.97; 95% CI 1.31 to 2.95), cigarette smoking is more frequent in rural boys (OR=1.61; 95% CI 1.04 to 2.39), and urban girls misuse substances to a greater extent than rural girls (OR=1.70; 95% CI 1.16 to 2.51,OR=2.85; 95% CI 1.88 to 4.31,OR=2.78; 95% CI 1.67 to 4.61 for cigarette smoking, harmful drinking and simultaneous smoking-drinking, respectively). Academic failure is strongly associated with a higher likelihood of SUM. The associations between parental factors and SUM are more evident in urban youth. Sports factors are specifically correlated with SUM for urban girls. Conclusions Living in an urban environment should be considered as a higher risk factor for SUM in girls. Parental variables are more strongly associated with SUM among urban

  20. Neutron capture cross section of 102Pd

    NASA Astrophysics Data System (ADS)

    Duncan, C. L.; Krane, K. S.

    2005-05-01

    The cross sections for radiative neutron capture by 102Pd have been deduced from a measurement of the γ rays emitted by 17.0-d 103Pd. The thermal cross section has been determined to be σ=1.82±0.20 b, and the effective resonance integral is I=23±4 b. We also report thermal and resonance capture cross sections for 108Pd and note possible inconsistencies with the presently accepted values of the 110Pd cross sections.

  1. Neutrino Cross Sections at Solar Energies

    NASA Astrophysics Data System (ADS)

    Strigari, Louis

    2017-01-01

    I will review neutrino nucleus cross section measurements and uncertainties for energies applicable to solar neutrinos. I will discuss how these cross sections are important for interpreting solar neutrino experimental data, and highlight the most important neutrino-nucleus interactions that will be relevant for forthcoming dark matter direct detection experiments. NSF PHY-1522717.

  2. Neutrino flux predictions for cross section measurements

    SciTech Connect

    Hartz, Mark

    2015-05-15

    Experiments that measure neutrino interaction cross sections using accelerator neutrino sources require a prediction of the neutrino flux to extract the interaction cross section from the measured neutrino interaction rate. This article summarizes methods of estimating the neutrino flux using in-situ and ex-situ measurements. The application of these methods by current and recent experiments is discussed.

  3. Measured data used in the Watusi cross-section sets

    SciTech Connect

    Mustafa, M; Nethaway, D R

    1999-02-09

    In this document we list the experimental data that were used to make up the major cross- section sets that we use in the Watusi code to calculate the amount of detector activation in device tests. In order to use experimental data to make up a cross-section set, it is often necessary to extrapolate the cross sections down to either the threshold energy or to 0.01 keV, and to extrapolate up to 20 MeV. We then fit the data to a function so that we can get a smoothed set of interpolated values at up to 321 energy points. The combined data are then processed with the Hiroshima code into flux-weighted, group-averaged cross sections for use with the output from the different physics design codes. We typically use the standard 53 or 175 energy group structures. In a recent companion memo 1 we described the make up of all of the cross-section sets in detail, giving references to both the experimental data and the theoretical calculations that were used. The following sections have the experimental data, in the form of energy-cross section pairs, for the titanium, chromium, bromine, krypton, yttrium, zirconium, iodine, europium, lutetium, and bismuth sets. The other cross-section sets are not directly based on enough experimental data to warrant their listing here. Many of the reactions used in these sets are based on calculated cross sections. In making these calculations certain parameters are sometimes adjusted so that the calculated cross sections match experimental data. In some of these cases we have made a further normalization to give a closer agreement to selected experimental data, and such normalizations are noted in this document. In other cases no further normalization was made. In Table 1 we summarize the reactions for which we present the experimental data given in Tables 2-46. In Figs. 1-35 we show plots of the experimental data together with the actual excitation functions used in the cross-section sets. Some reactions in the current sets are based on

  4. Nucleon-Nucleon Total Cross Section

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2008-01-01

    The total proton-proton and neutron-proton cross sections currently used in the transport code HZETRN show significant disagreement with experiment in the GeV and EeV energy ranges. The GeV range is near the region of maximum cosmic ray intensity. It is therefore important to correct these cross sections, so that predictions of space radiation environments will be accurate. Parameterizations of nucleon-nucleon total cross sections are developed which are accurate over the entire energy range of the cosmic ray spectrum.

  5. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Chyzh, A.; Couture, A.; Henderson, R.; Jandel, M.; Kwan, E.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Wu, C. Y.

    2014-05-01

    The Detector for Advanced Neutron Capture Experiments (DANCE) has been used to measure the 239Pu(n,γ) cross section from 10 eV to the keV region. Three experimental run conditions were used to characterize the prompt fission γ-ray spectrum across the entire energy regime, measure the cross section in the resolved resonance region, and obtain necessary count rate well into the keV region. The preliminary cross sections are in good agreement with current evaluations from 10 eV to 80 keV.

  6. K-shell photoionization cross-sections.

    NASA Technical Reports Server (NTRS)

    Daltabuit, E.; Cox, D. P.

    1972-01-01

    Approximate values for the threshold energies, threshold cross sections, and energy dependence of the cross sections for K-shell photoionization are tabulated for H, He, C, N, O, Ne, Mg, Si, and S in all stages of ionization. The approximation of these data is based on the assumptions that the threshold energy is a simple function of the nuclear charge and the number of electrons present in the atom, and that the threshold values and energy dependence of the cross sections are determined only by the threshold energy.

  7. Cross-sectional anatomy for computed tomography

    SciTech Connect

    Farkas, M.L.

    1988-01-01

    This self-study guide recognizes that evaluation and interpretation of CT-images demands a firm understanding of both cross-sectional anatomy and the principles of computed tomography. The objectives of this book are: to discuss the basic principles of CT, to stress the importance of cross-sectional anatomy to CT through study of selected cardinal transverse sections of head, neck, and trunk, to explain orientation and interpretation of CT-images with the aid of corresponding cross-sectional preparations.

  8. Cross Section Evaluations for Arsenic Isotopes

    SciTech Connect

    Pruet, J; McNabb, D P; Ormand, W E

    2005-03-10

    The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

  9. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    SciTech Connect

    Schulte, Elaine

    2002-05-01

    New measurements of the high energy deuteron photodisintegration differential cross section were made at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Two experiments were performed. Experiment E96-003 was performed in experimental Hall C. The measurements were designed to extend the highest energy differential cross section values to 5.5 GeV incident photon energy at forward angles. This builds upon previous high energy measurements in which scaling consistent with the pQCD constituent counting rules was observed at 90 degrees and 70 degrees in the center of mass. From the new measurements, a threshold for the onset of constituent counting rule scaling seems present at transverse momentum approximately 1.3 GeV/c. The second experiment, E99-008, was performed in experimental Hall A. The measurements were designed to explore the angular distribution of the differential cross section at constant energy. The measurements were made symmetric about 90 degrees

  10. Benchmark cross sections for bottom quark production

    SciTech Connect

    Berger, E.L.

    1988-01-07

    A summary is presented of theoretical expectations for the total cross sections for bottom quark production, for longitudinal and transverse momentum distributions, and for b, /bar b/ momentum correlations at Fermilab fixed target and collider energies.

  11. Bibliography of photoabsorption cross-section data

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.; Kieffer, L. J.

    1970-01-01

    This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

  12. A nuclear cross section data handbook

    SciTech Connect

    Fisher, H.O.M.

    1989-12-01

    Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and thermal energy. Other information about the evaluations and their availability in continuous-energy, discrete-reaction, and multigroup forms is provided. The evaluations come from ENDF/B-V, ENDL85, and the Los Alamos Applied Nuclear Science Group T-2. Graphs of all neutron and photon production cross-section reactions for these nuclides have been categorized and plotted. 21 refs., 5 tabs.

  13. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1982-01-01

    A solution is presented for the backscatter (nonstatic) radar cross section of dielectric disks of arbitrary shape, thickness and dielectric constant. The result is obtained by employing a Kirchhoff type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner is shown to agree with known results in the special cases of normal incidence, thin disks and perfect conductivity. The solution can also be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff type approximation without additional assumptions.

  14. Energy dependence of fusion cross sections

    SciTech Connect

    Bang, J.M.; Ferreira, L.S.; Maglione, E.; Hansteen, J.M.

    1996-01-01

    Observed enhancements of fusion cross sections at low energies are explained as caused by an underestimate of beam energy due to an overestimate of the stopping energy loss. {copyright} {ital 1996 The American Physical Society.}

  15. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  16. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Le Vine, D. M.

    1984-01-01

    A solution is presented for the backscatter (monostatic) radar cross section of dielectric disks of arbitrary shape, thickness, and dielectric constant. The result is obtained by employing a Kirchhoff-type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner will be shown to agree with known results in the special cases of normal incidence, thin disks, and perfect conductivity. It will also be shown that the solution can be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff-type approximation without additional assumptions.

  17. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  18. QuickSite Cross Section Processing

    SciTech Connect

    Richard Becker, ANL

    2003-05-27

    This AGEM-developed system produces cross sections by inputting data in both standard and custom file formats and outputting a graphic file that can be printed or further modified in a commercial graphic program. The system has evolved over several years in order to combine and visualize a changing set of field data more rapidly than was possible with commercially available cross section software packages. It uses some commercial packages to produce the input and to modify the output files. Flexibility is provided by a dynamic set of programs that are customized to accept varying input and accomodate varying output requirements. There are two basic types of routines: conversion routines and cross section generation routines. The conversion routines convery various data files to logger file format which is compatible with a standard file format for LogPlot 98, a commonly used commercial log plotting program. The cross section routines generate cross sections and apply topography to these cross sections. All of the generation routines produce a standard graphic DXF file, which is the format used in AutoCAD and can then be modified in a number of available graphics programs.

  19. Situation-specific factors predicting nonadherence to methadone maintenance treatment: a cross-sectional study using the case-crossover design in Guangzhou, China.

    PubMed

    Gu, Jing; Xu, Huifang; Lau, Joseph T F; Chen, Long; Wang, Zixin; Hao, Chun; Hao, Yuantao

    2014-01-01

    Methadone maintenance treatment (MMT) is a key risk reduction measure for controlling HIV transmission among drug users. Studies using traditional methods exist to distinguish between drop outs and nondrop outs. However, many nondrop outs use MMT discontinuously and no study has identified situation-specific factors predicting their showing or not showing up. This study used a case-crossover design comparing situation-specific factors appearing on the last episode of attendance versus those of the last episode of nonattendance. A total of 133 participants were recruited from two MMT clinics in Guangzhou, China. Participants were asked separately whether various situation-specific factors existed in the last episodes of nonattendance and attendance of MMT. Matched odds ratios (ORs) based on conditional logistic regression analysis were presented. The results showed that the participants attended the MMT clinics on average for 25 days in the last month. Situation-specific factors significantly predicting nonattendance included: (1) physical and mental health status: in illness (OR = 33.0, P < 0.001), in a bad mood (OR = 7.5, P < 0.001), and occurrence of an unhappy event (OR = 18.0, P < 0.001); (2) other engagement: work engagement (OR = 40.0, P < 0.001), trip to other places (OR = 83.0, P < 0.001), and social activities (OR = 10.0, P = 0.012); (3) interpersonal relationship: conflicts with family (OR = 19.0, P = 0.004); and (4) structural situational factors: financial difficulty (OR = 19.0, P = 0.004) and worrying about police arrest (OR = 12.0, P = 0.003). Other factors such as interaction with drug users and heroin use were marginally significant, while reduced methadone dosage was nonsignificant. Interventions to improve MMT adherence need to consider situation-specific factors. Ancillary psychosocial services should be integrated with current MMT; MMT should also provide more flexible services to the clients. Furthermore, efforts should be taken to build up

  20. Pion photoproduction cross section at large momentum transfer

    SciTech Connect

    Sjoegren, Johan

    2015-02-27

    The Real Compton Scattering experiment was performed in Hall A at the Thomas Jefferson National Accelerator Facility. It was designed to measure, for Compton scattering and π0-photoproduction, the differential cross section over a range of kinematic points and the polarisation transfer to the proton at a single kinematic point. The full range of the experiment in Mandelstam variables t and s was 1.6-6.46 GeV2 and 4.82-10.92 GeV2 respectively with beam energies of 2-6 GeV. The motivation for the experiment is to test the cross section and polarisation transfer predictions of perturbative QCD versus that of predictions from Generalised Parton Distribution models. This thesis will give an overview of the pertinent theory, experimental setup in Hall A and the extracting of the π0-photoproduction cross section.

  1. [Fast neutron cross section measurements]. Progress report

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ``clean`` and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ``data production`` phase.

  2. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    SciTech Connect

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.; Giardina, G.; Eidelman, S.; Venanzoni, G.; Battaglieri, M.; Mandaglio, G.

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  3. Simultaneous evaluation of interrelated cross sections by generalized least-squares and related data file requirements

    SciTech Connect

    Poenitz, W.P.

    1984-10-25

    Though several cross sections have been designated as standards, they are not basic units and are interrelated by ratio measurements. Moreover, as such interactions as /sup 6/Li + n and /sup 10/B + n involve only two and three cross sections respectively, total cross section data become useful for the evaluation process. The problem can be resolved by a simultaneous evaluation of the available absolute and shape data for cross sections, ratios, sums, and average cross sections by generalized least-squares. A data file is required for such evaluation which contains the originally measured quantities and their uncertainty components. Establishing such a file is a substantial task because data were frequently reported as absolute cross sections where ratios were measured without sufficient information on which reference cross section and which normalization were utilized. Reporting of uncertainties is often missing or incomplete. The requirements for data reporting will be discussed.

  4. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    SciTech Connect

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-05-14

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used in the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.

  5. Reduction Methods for Total Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Gomes, P. R. S.; Mendes Junior, D. R.; Canto, L. F.; Lubian, J.; de Faria, P. N.

    2016-03-01

    The most frequently used methods to reduce fusion and total reaction excitation functions were investigated in a very recent paper Canto et al. (Phys Rev C 92:014626, 2015). These methods are widely used to eliminate the influence of masses and charges in comparisons of cross sections for weakly bound and tightly bound systems. This study reached two main conclusions. The first is that the fusion function method is the most successful procedure to reduce fusion cross sections. Applying this method to theoretical cross sections of single channel calculations, one obtains a system independent curve (the fusion function), that can be used as a benchmark to fusion data. The second conclusion was that none of the reduction methods available in the literature is able to provide a universal curve for total reaction cross sections. The reduced single channel cross sections keep a strong dependence of the atomic and mass numbers of the collision partners, except for systems in the same mass range. In the present work we pursue this problem further, applying the reduction methods to systems within a limited mass range. We show that, under these circumstances, the reduction of reaction data may be very useful.

  6. Prospects for Precision Neutrino Cross Section Measurements

    SciTech Connect

    Harris, Deborah A.

    2016-01-28

    The need for precision cross section measurements is more urgent now than ever before, given the central role neutrino oscillation measurements play in the field of particle physics. The definition of precision is something worth considering, however. In order to build the best model for an oscillation experiment, cross section measurements should span a broad range of energies, neutrino interaction channels, and target nuclei. Precision might better be defined not in the final uncertainty associated with any one measurement but rather with the breadth of measurements that are available to constrain models. Current experience shows that models are better constrained by 10 measurements across different processes and energies with 10% uncertainties than by one measurement of one process on one nucleus with a 1% uncertainty. This article describes the current status of and future prospects for the field of precision cross section measurements considering the metric of how many processes, energies, and nuclei have been studied.

  7. The cross section for double Compton scattering

    NASA Technical Reports Server (NTRS)

    Gould, R. J.

    1984-01-01

    Employing elementary methods in nonrelativistic quantum electrodynamics, the cross section for gamma sub 0 + e yields e + gamma + gamma is computed for arbitrary energy in the spectrum of the outgoing photons. The final result is given, differential in the energy of one of these photons, for the case where the incident photon is unpolarized and has energy E sub 0 much less than mc-squared, a polarization sum and angular integration being performed for the final-state photons. The cross section has a simple algebraic form resulting from contributions from the sum of squared direct and exchange amplitudes; interference terms from these amplitudes do not contribute to the angular-integrated cross section.

  8. Optical Model and Cross Section Uncertainties

    SciTech Connect

    Herman,M.W.; Pigni, M.T.; Dietrich, F.S.; Oblozinsky, P.

    2009-10-05

    Distinct minima and maxima in the neutron total cross section uncertainties were observed in model calculations using spherical optical potential. We found this oscillating structure to be a general feature of quantum mechanical wave scattering. Specifically, we analyzed neutron interaction with 56Fe from 1 keV up to 65 MeV, and investigated physical origin of the minima.We discuss their potential importance for practical applications as well as the implications for the uncertainties in total and absorption cross sections.

  9. Universal Parameterization of Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1999-01-01

    Our prior nuclear absorption cross sections model is extended for light systems (A less than or equal to 4) where either both projectile and target are light particles or one is a light particle and the other is a medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium, and heavy systems, a very valuable input for radiation protection studies.

  10. Covariance Evaluation Methodology for Neutron Cross Sections

    SciTech Connect

    Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

    2008-09-01

    We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

  11. Total cross sections for +/-atom collisions

    NASA Astrophysics Data System (ADS)

    Gien, T. T.

    1987-03-01

    The total cross sections for electron and positron scatterings by lithium, sodium, and potassium in the intermediate energy range from 40 to 1000 eV are calculated using the modified Glauber and second Born approximations. A model potential approach is developed to enable an exact inclusion of the core-interaction effects. Within this approach, the positron cross sections are predicted to be somewhat smaller than those of electron scattering. Calculations have also been performed with the consideration of the inert-core and frozen-core assumption and the use of the Clementi wave function to represent the target electrons. Comparison to existing experimental data is made.

  12. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Couture, A.; Jandel, M.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Chyzh, A.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2014-09-01

    The 239Pu(n,γ) cross section has been measured over the energy range 10 eV - 10 keV using the Detector for Advanced Neutron Capture Experiments (DANCE) as part of a campaign to produce precision (n,γ) measurements on 239Pu in the keV region. Fission coincidences were measured with a PPAC and used to characterize the prompt fission γ-ray spectrum in this region. The resulting spectra will be used to better characterize the fission component of another experiment with a thicker target to extend the (n,γ) cross section measurement well into the keV region.

  13. New Parameterization of Neutron Absorption Cross Sections

    NASA Astrophysics Data System (ADS)

    Tripathi, Ram K.; Wilson, John W.; Cucinotta, Francis A.

    1997-06-01

    Recent parameterization of absorption cross sections for any system of charged ion collisions, including proton-nucleus collisions, is extended for neutron-nucleus collisions valid from approx. 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pairs (charged or uncharged). The parameters are associated with the physics of the problem. At lower energies, optical potential at the surface is important, and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  14. Infrared absorption cross sections of alternative CFCs

    NASA Technical Reports Server (NTRS)

    Clerbaux, Cathy; Colin, Reginald; Simon, Paul C.

    1994-01-01

    Absorption cross sections have obtained in the infrared atmospheric window, between 600 and 1500 cm(exp -1), for 10 alternative hydrohalocarbons: HCFC-22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCFC-225ca, HCFC-225cb, HFC-125, HFC-134a, and HFC-152a. The measurements were made at three temperatures (287K, 270K and 253K) with a Fourier transform spectrometer operating at 0.03 cm(exp -1) apodized resolution. Integrated cross sections are also derived for use in radiative models to calculate the global warming potentials.

  15. New Parameterization of Neutron Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, Ram K.; Wilson, John W.; Cucinotta, Francis A.

    1997-01-01

    Recent parameterization of absorption cross sections for any system of charged ion collisions, including proton-nucleus collisions, is extended for neutron-nucleus collisions valid from approx. 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pairs (charged or uncharged). The parameters are associated with the physics of the problem. At lower energies, optical potential at the surface is important, and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  16. Cotton fibre cross-section properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    From a structural perspective the cotton fibre is a singularly discrete, elongated plant cell with no junctions or inter-cellular boundaries. Its form in nature is essentially unadulterated from the field to the spinning mill where its cross-section properties, as for any textile fibre, are central ...

  17. Cross Sections From Scalar Field Theory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

    2008-01-01

    A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

  18. Testing (Validating?) Cross Sections with ICSBEP Benchmarks

    SciTech Connect

    Kahler, Albert C. III

    2012-06-28

    We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

  19. Neutron capture cross section of Am241

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. Γn neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  20. Cross-sectional structural parameters from densitometry

    NASA Technical Reports Server (NTRS)

    Cleek, Tammy M.; Whalen, Robert T.

    2002-01-01

    Bone densitometry has previously been used to obtain cross-sectional properties of bone from a single X-ray projection across the bone width. Using three unique projections, we have extended the method to obtain the principal area moments of inertia and orientations of the principal axes at each scan cross-section along the length of the scan. Various aluminum phantoms were used to examine scanner characteristics to develop the highest accuracy possible for in vitro non-invasive analysis of cross-sectional properties. Factors considered included X-ray photon energy, initial scan orientation, the angle spanned by the three scans (included angle), and I(min)/I(max) ratios. Principal moments of inertia were accurate to within +/-3.1% and principal angles were within +/-1 degrees of the expected value for phantoms scanned with included angles of 60 degrees and 90 degrees at the higher X-ray photon energy (140 kVp). Low standard deviations in the error (0.68-1.84%) also indicate high precision of calculated measurements with these included angles. Accuracy and precision decreased slightly when the included angle was reduced to 30 degrees. The method was then successfully applied to a pair of excised cadaveric tibiae. The accuracy and insensitivity of the algorithms to cross-sectional shape and changing isotropy (I(min)/I(max)) values when various included angles are used make this technique viable for future in vivo studies.

  1. Reaction cross section of 22C

    NASA Astrophysics Data System (ADS)

    Togano, Yasuhiro; Samurai Collaboration

    2014-09-01

    Reaction cross section of 22C on a carbon target at an energy of 240 MeV/nucleon have been measured by using the transmission method. The most neutron-rich carbon isotopes 22C is a candidate of a two-neutron halo nucleus. Tanaka et al. [1] measured the reaction cross section of 22C on a hydrogen target at 40 MeV/nucleon. It is showed 22C to have a large matter radius of 5 . 9 +/- 0 . 9 fm, which is much larger than the ones of carbon isotopes with N <= 14 , suggesting 22C is the halo nucleus. This reported radius has a large uncertainty due to a lack of statistics. To deduce a more accurate matter radius of 22C, the measurement of reaction cross section with higher statistics at a higher beam energy are required. The experiment was performed by using the SAMURAI spectrometer at RIBF. The 22C beam at 240 MeV/nucleon was impinged on a carbon target, and the reaction product was identified by using SAMURAI spectrometer. In the present talk, the extracted reaction cross section and derived matter density distribution of 22C will be presented.

  2. Associations between Poor Health and School-Related Behavior Problems at the Child and Family Levels: A Cross-Sectional Study of Migrant Children and Adolescents in Southwest Urban China

    ERIC Educational Resources Information Center

    Zhang, Jing-Jing; Li, Ning-Xiu; Liu, Chao-Jie

    2010-01-01

    Background: Due to urbanization in China, the numbers of migrant children and adolescents in urban environments have increased. Previous studies have indicated that children and adolescents are more likely to suffer from health problems and poor school achievement. The present study identified associations between poor health and school-related…

  3. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  4. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  5. Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

    NASA Technical Reports Server (NTRS)

    Townsend, L. W.; Wilson, J. W.

    1985-01-01

    A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

  6. Tables of nuclear cross sections for galactic cosmic rays: Absorption cross sections

    NASA Astrophysics Data System (ADS)

    Townsend, L. W.; Wilson, J. W.

    1985-05-01

    A simple but comprehensive theory of nuclear reactions is presented. Extensive tables of nucleon, deuteron, and heavy-ion absorption cross sections over a broad range of energies are generated for use in cosmic ray shielding studies. Numerous comparisons of the calculated values with available experimental data show agreement to within 3 percent for energies above 80 MeV/nucleon and within approximately 10 percent for energies as low as 30 MeV/nucleon. These tables represent the culmination of the development of the absorption cross section formalism and supersede the preliminary absorption cross sections published previously in NASA TN D-8107, NASA TP-2138, and NASA TM-84636.

  7. Proton Pair Production Cross Sections at BESIII

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaorong

    Using data samples collected with the BESIII detector at the BEPCII collider, the Born cross section of e + e - to pbar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV is provided. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal. In addition, the ratio of electric to magnetic form factors are extracted for the data samples with larger statistics. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BaBar results in the same q2 region.

  8. Extinction cross section of a dielectric strip

    NASA Astrophysics Data System (ADS)

    Dowerah, Subratananda; Chakrabarti, Aloknath

    1988-05-01

    The problem of scattering of a plane electromagnetic wave by a dielectric strip is formulated in terms of an uncoupled system of three-part Wiener-Hopf equations by using a set of approximate boundary conditions derived and utilized recently. The resulting Wiener-Hopf problems are solved approximately for sufficiently large values of the width of the strip by using Jones' method (1964). An analytical formula is derived for the excitation cross section of the strip under consideration from which numerical values are obtained in specific situations and the results are presented graphically. The radar cross section of the strip is also computed for several special circumstances and these are presented separately.

  9. Universal Parameterization of Absorption Cross Sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Cucinotta, Francis A.; Wilson, John W.

    1997-01-01

    This paper presents a simple universal parameterization of total reaction cross sections for any system of colliding nuclei that is valid for the entire energy range from a few AMeV to a few AGeV. The universal picture presented here treats proton-nucleus collision as a special case of nucleus-nucleus collision, where the projectile has charge and mass number of one. The parameters are associated with the physics of the collision system. In general terms, Coulomb interaction modifies cross sections at lower energies, and the effects of Pauli blocking are important at higher energies. The agreement between the calculated and experimental data is better than all earlier published results.

  10. Rotational averaging of multiphoton absorption cross sections

    NASA Astrophysics Data System (ADS)

    Friese, Daniel H.; Beerepoot, Maarten T. P.; Ruud, Kenneth

    2014-11-01

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  11. Rotational averaging of multiphoton absorption cross sections.

    PubMed

    Friese, Daniel H; Beerepoot, Maarten T P; Ruud, Kenneth

    2014-11-28

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  12. {sup 231}Pa photofission cross section

    SciTech Connect

    Soldatov, A.S.; Rudnikov, V.E.; Smirenkin, G.N.

    1995-12-01

    The measurements of the {sup 231}Pa yield and cross section photofission in the energy range 7-9 MeV are presented. These measurements are a continuation of similar measurements performed for the {gamma}-ray energy range 4.8-7 MeV. The entire collection of experimental data which combine the results obtained in the present work and in Ref. 1 was analyzed.

  13. How to Calculate Colourful Cross Sections Efficiently

    SciTech Connect

    Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

    2008-09-03

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  14. Fusion cross sections measurements with MUSIC

    NASA Astrophysics Data System (ADS)

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  15. Fusion cross sections and the new dynamics

    SciTech Connect

    Swiatecki, W.J.

    1981-05-01

    The prediction of the need for an extra push over the interaction barrier in order to make the heavier nuclei fuse is made the basis of a simple algebraic theory for the energy-dependence of the fusion cross-section. A comparison with recent experiments promises to provide a quantitative test of the New Dynamics (the theory of macroscopic nuclear shape evolutions based on the one-body dissipation concept).

  16. Inclusive jet cross section measurement at CDF

    SciTech Connect

    Pagliarone, C.

    1996-08-01

    The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

  17. Quality Quantification of Evaluated Cross Section Covariances

    SciTech Connect

    Varet, S.; Dossantos-Uzarralde, P.

    2015-01-15

    Presently, several methods are used to estimate the covariance matrix of evaluated nuclear cross sections. Because the resulting covariance matrices can be different according to the method used and according to the assumptions of the method, we propose a general and objective approach to quantify the quality of the covariance estimation for evaluated cross sections. The first step consists in defining an objective criterion. The second step is computation of the criterion. In this paper the Kullback-Leibler distance is proposed for the quality quantification of a covariance matrix estimation and its inverse. It is based on the distance to the true covariance matrix. A method based on the bootstrap is presented for the estimation of this criterion, which can be applied with most methods for covariance matrix estimation and without the knowledge of the true covariance matrix. The full approach is illustrated on the {sup 85}Rb nucleus evaluations and the results are then used for a discussion on scoring and Monte Carlo approaches for covariance matrix estimation of the cross section evaluations.

  18. Designing Deeply Engaging Online Communities for Adolescents

    ERIC Educational Resources Information Center

    Gurzick, David

    2009-01-01

    American adolescents have experienced growth in their use of online communities; yet, it was unknown whether the current understanding of online-community design applied to the design of communities specific to adolescents. This study bridged this gap, examining (a) How adolescents interact in an online community designed in accordance with…

  19. Accurate Development of Thermal Neutron Scattering Cross Section Libraries

    SciTech Connect

    Hawari, Ayman; Dunn, Michael

    2014-06-10

    The objective of this project is to develop a holistic (fundamental and accurate) approach for generating thermal neutron scattering cross section libraries for a collection of important enutron moderators and reflectors. The primary components of this approach are the physcial accuracy and completeness of the generated data libraries. Consequently, for the first time, thermal neutron scattering cross section data libraries will be generated that are based on accurate theoretical models, that are carefully benchmarked against experimental and computational data, and that contain complete covariance information that can be used in propagating the data uncertainties through the various components of the nuclear design and execution process. To achieve this objective, computational and experimental investigations will be performed on a carefully selected subset of materials that play a key role in all stages of the nuclear fuel cycle.

  20. Prevalence and Predictors of Somatic Symptoms among Child and Adolescents with Probable Posttraumatic Stress Disorder: A Cross-Sectional Study Conducted in 21 Primary and Secondary Schools after an Earthquake

    PubMed Central

    Zhang, Ye; Zhu, Shenyue; Du, Changhui

    2015-01-01

    Purpose To explore the prevalence rates and predictors of somatic symptoms among child and adolescent survivors with probable posttraumatic stress disorder (PTSD) after an earthquake. Methods A total of 3053 students from 21 primary and secondary schools in Baoxing County were administered the Patient Health Questionnaire-13 (PHQ-13), a short version of PHQ-15 without the two items about sexuality and menstruation, the Children's Revised Impact of Event Scale (CRIES), and the self-made Earthquake-Related Experience Questionnaire 3 months after the Lushan earthquake. Results Among child and adolescent survivors, the prevalence rates of all somatic symptoms were higher in the probable PTSD group compared with the controls. The most frequent somatic symptoms were trouble sleeping (83.2%), feeling tired or having low energy (74.4%), stomach pain (63.2%), dizziness (58.1%), and headache (57.7%) in the probable PTSD group. Older age, having lost family members, having witnessed someone get seriously injured, and having witnessed someone get buried were predictors for somatic symptoms among child and adolescent survivors with probable PTSD. Conclusions Somatic symptoms among child and adolescent earthquake survivors with probable PTSD in schools were common, and predictors of these somatic symptoms were identified. These findings may help those providing psychological health programs to find the child and adolescent students with probable PTSD who are at high risk of somatic symptoms in schools after an earthquake in China. PMID:26327455

  1. A nationwide population-based cross-sectional survey of health-related quality of life in patients with myeloproliferative neoplasms in Denmark (MPNhealthSurvey): survey design and characteristics of respondents and nonrespondents

    PubMed Central

    Brochmann, Nana; Flachs, Esben Meulengracht; Christensen, Anne Illemann; Andersen, Christen Lykkegaard; Juel, Knud; Hasselbalch, Hans Carl; Zwisler, Ann-Dorthe

    2017-01-01

    Objective The Department of Hematology, Zealand University Hospital, Denmark, and the National Institute of Public Health, University of Southern Denmark, created the first nationwide, population-based, and the most comprehensive cross-sectional health-related quality of life (HRQoL) survey of patients with myeloproliferative neoplasms (MPNs). In Denmark, all MPN patients are treated in public hospitals and treatments received are free of charge for these patients. Therefore, MPN patients receive the best available treatment to the extent of its suitability for them and if they wish to receive the treatment. The aims of this article are to describe the survey design and the characteristics of respondents and nonrespondents. Material and methods Individuals with MPN diagnoses registered in the Danish National Patient Register (NPR) were invited to participate. The registers of the Danish Civil Registration System and Statistics Denmark provided information regarding demographics. The survey contained 120 questions: validated patient-reported outcome (PRO) questionnaires and additional questions addressing lifestyle. Results A total of 4,704 individuals were registered with MPN diagnoses in the NPR of whom 4,236 were eligible for participation and 2,613 (62%) responded. Overall, the respondents covered the broad spectrum of MPN patients, but patients 70–79 years old, living with someone, of a Danish/Western ethnicity, and with a higher level of education exhibited the highest response rate. Conclusion A nationwide, population-based, and comprehensive HRQoL survey of MPN patients in Denmark was undertaken (MPNhealthSurvey). We believe that the respondents broadly represent the MPN population in Denmark. However, the differences between respondents and nonrespondents have to be taken into consideration when examining PROs from the respondents. The results of the investigation of the respondents’ HRQoL in this survey will follow in future articles. PMID:28280390

  2. Averaging cross section data so we can fit it

    SciTech Connect

    Brown, D.

    2014-10-23

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  3. Nuclear interaction cross sections for proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.; Jones, D. T. L.; Arendse, G. J.; Cowley, A. A.; Richter, W. A.; Lawrie, J. J.; Newman, R. T.; Pilcher, J. V.; Smit, F. D.; Steyn, G. F.; Koen, JW; Stander, JA

    Model calculations of proton-induced nuclear reaction cross sections are described for biologically-important targets. Measurements made at the National Accelerator Centre are presented for double-differential proton, deuteron, triton, helium-3 and alpha particle spectra, for 150 and 200 MeV protons incident on C, N, and O. These data are needed for Monte Carlo simulations of radiation transport and absorbed dose in proton therapy. Data relevant to the use of positron emission tomography to locate the Bragg peak are also described.

  4. Critical behavior of cross sections at LHC

    NASA Astrophysics Data System (ADS)

    Dremin, I. M.

    2016-07-01

    Recent experimental data on elastic scattering of high energy protons show that the critical regime has been reached at LHC energies. The approach to criticality is demonstrated by increase of the ratio of elastic to total cross sections from ISR to LHC energies. At LHC it reaches the value which can result in principal change of the character of proton interactions. The treatment of new physics of hollowed toroid-like hadrons requires usage of another branch of the unitarity condition. Its further fate is speculated and interpreted with the help of the unitarity condition in combination with present experimental data. The gedanken experiments to distinguish between different possibilities are proposed.

  5. Neutron absorption cross section of uranium-236

    SciTech Connect

    Macklin, R.L.; Alexander, C.W.

    1988-11-01

    U-236 neutron absorption was measured as a function of neutron time-of-flight from 20 eV to 1 MeV. The neutron flux was monitored with a /sup 6/Li glass scintillator. Average cross sections from 3 keV to 1 MeV were derived. Estimated uncertainties were less than 5% below 600 keV and increased to 9.5% at 1 MeV. Resonance parametrization from 20 eV to a few keV remains to be done. 17 refs., 5 figs., 3 tabs.

  6. Application of cross-sectional time series modeling for the prediction of energy expenditure from heart rate and accelerometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurate estimation of energy expenditure (EE) in children and adolescents is required for a better understanding of physiological, behavioral, and environmental factors affecting energy balance. Cross-sectional time series (CSTS) models, which account for correlation structure of repeated observati...

  7. Traditional and cyberbullying victimization as correlates of psychosocial distress and barriers to a healthy lifestyle among severely obese adolescents – a matched case–control study on prevalence and results from a cross-sectional study

    PubMed Central

    2014-01-01

    Background Obese youth are at increased risk for peer victimization, which may heighten their risk of psychosocial problems and physical activity avoidance, and lower the effectiveness of professional and lifestyle weight-loss initiatives. Little is known about obese adolescents’ risk for victimization from cyber-bullying and how this relates to psychosocial functioning and healthy lifestyle barriers. The purpose of the study was to assess traditional and cyber-victimization among adolescents with severe obesity and its relation to psychosocial distress and barriers to healthy lifestyles. Methods A sample of 102 obese adolescents (mean age = 15.32 ±1.71) in residential treatment was matched with 102 normal-weight youngsters from the Health Behavior in School-aged Children (HBSC) study (mean age = 15.30 ±1.73). Results Adolescents with obesity were significantly more often cyber-victimized than normal-weight peers. Obese youth victimized by traditional bullying experienced lower quality of life, lower motivation for physical activity and higher avoidance and emotional coping towards healthy lifestyles than those non-victimized. Obese cyber-victims experienced significantly higher suicidal ideation. Conclusions Traditional and cyber-victimization may hinder treatment effectiveness and healthy lifestyle change in adolescents with obesity. Health professionals should pro-actively address peer victimization and psychosocial functioning during multidisciplinary obesity treatment. Schools could contribute to a better physical and psychosocial health of obese youth by implementing multi-behavioral health-promotion programs. PMID:24593118

  8. Origami tubes with reconfigurable polygonal cross-sections

    PubMed Central

    Filipov, E. T.; Paulino, G. H.; Tachi, T.

    2016-01-01

    Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings. PMID:26997894

  9. A study of radar cross section measurement techniques

    NASA Technical Reports Server (NTRS)

    Mcdonald, Malcolm W.

    1986-01-01

    Past, present, and proposed future technologies for the measurement of radar cross section were studied. The purpose was to determine which method(s) could most advantageously be implemented in the large microwave anechoic chamber facility which is operated at the antenna test range site. The progression toward performing radar cross section measurements of space vehicles with which the Orbital Maneuvering Vehicle will be called upon to rendezvous and dock is a natural outgrowth of previous work conducted in recent years of developing a high accuracy range and velocity sensing radar system. The radar system was designed to support the rendezvous and docking of the Orbital Maneuvering Vehicle with various other space vehicles. The measurement of radar cross sections of space vehicles will be necessary in order to plan properly for Orbital Maneuvering Vehicle rendezvous and docking assignments. The methods which were studied include: standard far-field measurements; reflector-type compact range measurements; lens-type compact range measurement; near field/far field transformations; and computer predictive modeling. The feasibility of each approach is examined.

  10. Origami tubes with reconfigurable polygonal cross-sections.

    PubMed

    Filipov, E T; Paulino, G H; Tachi, T

    2016-01-01

    Thin sheets can be assembled into origami tubes to create a variety of deployable, reconfigurable and mechanistically unique three-dimensional structures. We introduce and explore origami tubes with polygonal, translational symmetric cross-sections that can reconfigure into numerous geometries. The tubular structures satisfy the mathematical definitions for flat and rigid foldability, meaning that they can fully unfold from a flattened state with deformations occurring only at the fold lines. The tubes do not need to be straight and can be constructed to follow a non-linear curved line when deployed. The cross-section and kinematics of the tubular structures can be reprogrammed by changing the direction of folding at some folds. We discuss the variety of tubular structures that can be conceived and we show limitations that govern the geometric design. We quantify the global stiffness of the origami tubes through eigenvalue and structural analyses and highlight the mechanical characteristics of these systems. The two-scale nature of this work indicates that, from a local viewpoint, the cross-sections of the polygonal tubes are reconfigurable while, from a global viewpoint, deployable tubes of desired shapes are achieved. This class of tubes has potential applications ranging from pipes and micro-robotics to deployable architecture in buildings.

  11. Accurate universal parameterization of absorption cross sections II--neutron absorption cross sections

    NASA Technical Reports Server (NTRS)

    Tripathi, R. K.; Wilson, J. W.; Cucinotta, F. A.

    1997-01-01

    A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from approximately 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  12. Accurate universal parameterization of absorption cross sections II — neutron absorption cross sections

    NASA Astrophysics Data System (ADS)

    Tripathi, R. K.; Wilson, John W.; Cucinotta, Francis A.

    1997-06-01

    A recent parameterization (here after referred as paper I, Ref. [4]) of absorption cross sections for any system of charged ions collisions including proton -nucleus collisions, is extended for neutron-nucleus collisions valid from ˜ 1 MeV to a few GeV, thus providing a comprehensive picture of absorption cross sections for any system of collision pair (charged and/or uncharged). The parameters are associated with the physics of the problem. At lower energies, the optical potential at the surface is important and the Pauli operator plays an increasingly important role at intermediate energies. The agreement between the calculated and experimental data is better than earlier published results.

  13. Current situation of asthma-COPD overlap syndrome (ACOS) in Chinese patients older than 40 years with airflow limitation: rationale and design for a multicenter, cross-sectional trial (study protocol)

    PubMed Central

    Yao, Wanzhen; Cai, Baiqiang; Chen, Ping; Ling, Xia; Shang, Hongyan

    2016-01-01

    Background Asthma and chronic obstructive pulmonary disease (COPD) are the frequently occurring chronic airway diseases, and the overlapping syndrome observed in the majority of patients has been recently defined as asthma-COPD overlap syndrome (ACOS) by the Global Initiative for Chronic Obstructive Lung (GOLD, 2014) and Global initiative for Asthma (GINA, 2015). The proportion, features, and clinical practice of ACOS still remain elusive in China. We are conducting this multicenter, cross-sectional, observational study (NCT02600221) to investigate the distributions of chronic obstructive diseases in patients >40 years of age with chronic airflow limitation in China along with determination of the main clinical practice and features of these diseases. The study will also explore the factors that may influence the exacerbations and severity of ACOS in Chinese patients (>40 years of age). Methods A total of 2,000 patients (age, ≥40 years; either sex) who are clinically diagnosed as having asthma, COPD/chronic bronchitis/emphysema, or ACOS for at least 12 months with airflow limitation [post-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC): <0.7] will be enrolled from approximately 20 sites in China between December 2015 and December 2016. The proportion of ACOS among patients older than 40 years based on GINA 2015 and GOLD 2014 definitions is the primary variable. Following were the secondary variables: the proportions of COPD and asthma among the patients, distributions of the severity of airflow limitation, distribution of groups according to GOLD 2011 group definition (A, B, C, D), and the distribution of medication by drug class in patients with ACOS, asthma, and COPD. Acute exacerbation history, hospitalization, and severity of ACOS as evaluated using COPD Assessment Test, Asthma Control Questionnaire-5, and Modified British Medical Research Council in patients with ACOS were also assessed. Implications This will be the

  14. Neutrino Cross Sections at Supernova Energies

    NASA Astrophysics Data System (ADS)

    Scholberg, Kate

    2017-01-01

    Neutrinos with energies between a few and a few tens of MeV are relevant for a number of physics topics. Notably, this is the energy range corresponding to emission of neutrinos from supernovae. In addition, it is relevant for studies of solar, reactor and atmospheric neutrinos, as well as for physics using accelerator-produced neutrinos from pions or radioactive nuclei decaying at rest. Surprisingly, with the exception of interactions on electrons and protons, the interactions of neutrinos with matter in this energy range are quite poorly understood, both theoretically and experimentally. This talk will describe neutrino physics and astrophysics in the supernova-neutrino energy range, the state of knowledge of cross sections on relevant nuclei, and initiatives for experimental measurements.

  15. Lunar Radar Cross Section at Low Frequency

    NASA Technical Reports Server (NTRS)

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  16. Absolute photoneutron cross sections of Sm isotopes

    SciTech Connect

    Gheorghe, I.; Glodariu, T.; Utsunomiya, H.; Filipescu, D.; Nyhus, H.-T.; Renstrom, T.; Tesileanu, O.; Shima, T.; Takahisa, K.; Miyamoto, S.

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  17. Angle-averaged Compton cross sections

    SciTech Connect

    Nickel, G.H.

    1983-01-01

    The scattering of a photon by an individual free electron is characterized by six quantities: ..cap alpha.. = initial photon energy in units of m/sub 0/c/sup 2/; ..cap alpha../sub s/ = scattered photon energy in units of m/sub 0/c/sup 2/; ..beta.. = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV.

  18. Top cross section measurement at CDF

    SciTech Connect

    Compostella, Gabriele; /INFN, CNAF /Padua U.

    2010-01-01

    This paper describes the latest measurements of the t{bar t} pair production cross section performed by the CDF Collaboration analyzing p{bar p} collisions at a center-of-mass energy of 1.96 TeV from Fermilab Tevatron, as presented at the XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects. In order to test Standard Model predictions, several analysis methods are explored and all the top decay channels are considered, to better constrain the properties of the top quark and to search for possible sources of new physics affecting the pair production mechanism. Experimental results using an integrated luminosity up to 5.1 fb{sup -1} are presented.

  19. Preliminary cross section of Englebright Lake sediments

    USGS Publications Warehouse

    Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Overview -- The Upper Yuba River Studies Program is a CALFED-funded, multidisciplinary investigation of the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. Englebright Lake (Figure 1 on poster) is a narrow, 14-km-long reservoir located in the northern Sierra Nevada, northeast of Marysville, CA. The dam was completed in 1941 for the primary purpose of trapping sediment derived from mining operations in the Yuba River watershed. Possible management scenarios include lowering or removing Englebright Dam, which could cause the release of stored sediments and associated contaminants, such as mercury used extensively in 19th-century hydraulic gold mining. Transport of released sediment to downstream areas could increase existing problems including flooding and mercury bioaccumulation in sport fish. To characterize the extent, grain size, and chemistry of this sediment, a coring campaign was done in Englebright Lake in May and June 2002. More than twenty holes were drilled at 7 different locations along the longitudinal axis of the reservoir (Figure 4 on poster), recovering 6 complete sequences of post-reservoir deposition and progradation. Here, a longitudinal cross section of Englebright Lake is presented (Figure 5 on poster), including pre-dam and present-day topographic profiles, and sedimentologic sections for each coring site. This figure shows the deltaic form of the reservoir deposit, with a thick upper section consisting of sand and gravel overlying silt, a steep front, and a thinner lower section dominated by silt. The methodologies used to create the reservoir cross section are discussed in the lower part of this poster.

  20. Single-level resonance parameters fit nuclear cross-sections

    NASA Technical Reports Server (NTRS)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  1. Total and ionization cross sections of electron scattering by fluorocarbons

    NASA Astrophysics Data System (ADS)

    Antony, B. K.; Joshipura, K. N.; Mason, N. J.

    2005-02-01

    Electron impact total cross sections (50-2000 eV) and total ionization cross sections (threshold to 2000 eV) are calculated for typical plasma etching molecules CF4, C2F4, C2F6, C3F8 and CF3I and the CFx (x = 1-3) radicals. The total elastic and inelastic cross sections are determined in the spherical complex potential formalism. The sum of the two gives the total cross section and the total inelastic cross section is used to calculate the total ionization cross sections. The present total and ionization cross sections are found to be consistent with other theories and experimental measurements, where they exist. Our total cross section results for CFx (x = 1-3) radicals presented here are first estimates on these species.

  2. Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

    1957-07-22

    In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

  3. MOX Cross-Section Libraries for ORIGEN-ARP

    SciTech Connect

    Gauld, I.C.

    2003-07-01

    The use of mixed-oxide (MOX) fuel in commercial nuclear power reactors operated in Europe has expanded rapidly over the past decade. The predicted characteristics of MOX fuel such as the nuclide inventories, thermal power from decay heat, and radiation sources are required for design and safety evaluations, and can provide valuable information for non-destructive safeguards verification activities. This report describes the development of computational methods and cross-section libraries suitable for the analysis of irradiated MOX fuel with the widely-used and recognized ORIGEN-ARP isotope generation and depletion code of the SCALE (Standardized Computer Analyses for Licensing Evaluation) code system. The MOX libraries are designed to be used with the Automatic Rapid Processing (ARP) module of SCALE that interpolates appropriate values of the cross sections from a database of parameterized cross-section libraries to create a problem-dependent library for the burnup analysis. The methods in ORIGEN-ARP, originally designed for uranium-based fuels only, have been significantly upgraded to handle the larger number of interpolation parameters associated with MOX fuels. The new methods have been incorporated in a new version of the ARP code that can generate libraries for low-enriched uranium (LEU) and MOX fuel types. The MOX data libraries and interpolation algorithms in ORIGEN-ARP have been verified using a database of declared isotopic concentrations for 1042 European MOX fuel assemblies. The methods and data are validated using a numerical MOX fuel benchmark established by the Organization for Economic Cooperation and Development (OECD) Working Group on burnup credit and nuclide assay measurements for irradiated MOX fuel performed as part of the Belgonucleaire ARIANE International Program.

  4. Electron Elastic-Scattering Cross-Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 64 NIST Electron Elastic-Scattering Cross-Section Database (PC database, no charge)   This database provides values of differential elastic-scattering cross sections, corresponding total elastic-scattering cross sections, phase shifts, and transport cross sections for elements with atomic numbers from 1 to 96 and for electron energies between 50 eV and 20,000 eV (in steps of 1 eV).

  5. SCALE system cross-section validation for criticality safety analysis

    SciTech Connect

    Hathout, A M; Westfall, R M; Dodds, Jr, H L

    1980-01-01

    The purpose of this study is to test selected data from three cross-section libraries for use in the criticality safety analysis of UO/sub 2/ fuel rod lattices. The libraries, which are distributed with the SCALE system, are used to analyze potential criticality problems which could arise in the industrial fuel cycle for PWR and BWR reactors. Fuel lattice criticality problems could occur in pool storage, dry storage with accidental moderation, shearing and dissolution of irradiated elements, and in fuel transport and storage due to inadequate packing and shipping cask design. The data were tested by using the SCALE system to analyze 25 recently performed critical experiments.

  6. Mental Visualization of Objects from Cross-Sectional Images

    ERIC Educational Resources Information Center

    Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

    2012-01-01

    We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

  7. APPARATUS FOR MEASURING TOTAL NEUTRON CROSS SECTIONS

    DOEpatents

    Cranberg, L.

    1959-10-13

    An apparatus is described for measuring high-resolution total neutron cross sections at high counting rate in the range above 50-kev neutron energy. The pulsed-beam time-of-flight technique is used to identify the neutrons of interest which are produced in the target of an electrostatic accelerator. Energy modulation of the accelerator . makes it possible to make observations at 100 energy points simultaneously. 761O An apparatus is described for monitoring the proton resonance of a liquid which is particulariy useful in the continuous purity analysis of heavy water. A hollow shell with parallel sides defines a meander chamber positioned within a uniform magnetic fieid. The liquid passes through an inlet at the outer edge of the chamber and through a spiral channel to the central region of the chamber where an outlet tube extends into the chamber perpendicular to the magnetic field. The radiofrequency energy for the monitor is coupled to a coil positioned coaxially with the outlet tube at its entrance point within the chamber. The improvement lies in the compact mechanical arrangement of the monitor unit whereby the liquid under analysis is subjected to the same magnetic field in the storage and sensing areas, and the entire unit is shielded from external electrostatic influences.

  8. Normalization of experimental electron cross sections.

    NASA Astrophysics Data System (ADS)

    Avdonina, N.; Felfli, Z.; Msezane, A. Z.

    1997-10-01

    Absolute experimental electron-impact differential cross sections (DCSs) can be obtained through an extrapolation of the relative generalized oscillator strength (GOS) values at some given impact energy E to zero momentum transfer squared K^2, the optical oscillator strength (OOS) [1]. We propose to normalize the relative experimental DCS data to the corresponding OOS value by extrapolating the GOS to K^2 = 0 without involving the nonphysical region. This is possible only by simultaneously increasing E and decreasing K^2 so that K^2 = 0 corresponds to E = ∞. Thus is avoided a divergence of fracd(GOS)d(K^2) at K^2 = 0 [2]. Another advantage of our method is that, over a wide range of small K^2 values the contribution of higher order terms of the Born series to the GOS function is negligible, contrary to the constant E case in which even order K^2 terms are non-Born [2]. Thus first Born approximation can be used to normalize relative experimental DCSs to the OOS. This method is applicable to both the excitation and ionization of atomic and molecular targets by electron impact. The latter case generalizes the method of ref. [3]. ^*Supported by AFOSR, NSF and DoE Div. of Chemical Sciences, OBES. ^1 E. N. Lassettre et al., J. Chem. Phys \\underline50, (1829) ^2 W. M. Huo, J. Chem. Phys \\underline71, 1593 (1979) ^3 A. Saenz, W Weyrich and P. Froelich, J. Phys. B \\underline29, 97 (1996)

  9. Spectroscopy and Photoabsorption Cross Sections of FNO

    NASA Astrophysics Data System (ADS)

    Burley, J. D.; Miller, C. E.; Johnston, H. S.

    1993-04-01

    The spectroscopy and photoabsorption cross sections of nitrosyl fluoride are investigated in the spectral region 350-180 nm. Results for 350-250 nm are in good agreement with the initial measurements of Johnston and Bertin and later measurements from Solgadi and Flament and Huber et al. The spectrum is assigned to a series of vibrational progressions which arise from (0, 0, 0)″ and involve excitation of the ν' 1 mode. Excitations to ( n, 0, 0)' and ( n, 0, 1)' make up the bulk of the spectrum, with promotions to ( n, 1, 0)', ( n, 0, 2)', and ( n, 1, 2)' becoming dominant at higher energies. Analysis of the spectrum results in values of ν' 1 = 1096 cm -1, ν' 2 = 480cm -1 and ν' 3 = 349 cm -1 for the excited state FNO frequencies. The experimental basis for the assignment of ν' 1 and ν' 3 is distinctly stronger than that for ν' 2. Below 250 nm, a broad, featureless continuum absorption is observed, which rises in intensity from σ = 1.77 × 10 -20cm 2 at 245 nm to 5.24 × 10 -19cm 2 at 180 nm.

  10. Cross-sectional imaging in Crohn disease.

    PubMed

    Furukawa, Akira; Saotome, Takao; Yamasaki, Michio; Maeda, Kiyosumi; Nitta, Norihisa; Takahashi, Masashi; Tsujikawa, Tomoyuki; Fujiyama, Yoshihide; Murata, Kiyoshi; Sakamoto, Tsutomu

    2004-01-01

    The role of cross-sectional imaging in the diagnosis of Crohn disease has expanded with recent technologic advances in computed tomography (CT) and magnetic resonance (MR) imaging that allow rapid acquisition of high-resolution images of the intestines. To acquire images of diagnostic quality, administration of a fairly large amount of intraluminal contrast agent prior to examination and scanning with intravenous contrast material injection are necessary. Both CT and MR imaging are reported to have a sensitivity of over 95% for the detection of Crohn disease; however, they may not allow early diagnosis. Colonoscopy and conventional enteroclysis studies are indicated for patients with early-stage disease. At more advanced stages, CT and MR imaging can help identify and characterize pathologically altered bowel segments as well as extraluminal lesions (eg, fistulas, abscesses, fibrofatty proliferation, increased vascularity of the vasa recta, mesenteric lymphadenopathy). These modalities can also clearly depict inflammatory lesion activity and conditions that require elective gastrointestinal surgery, thereby aiding in treatment planning. In the clinical setting, CT is currently the imaging modality of choice at most institutions; however, it is expected that MR imaging will soon play a comparable role. CT or MR imaging should be included in a comprehensive evaluation of patients with Crohn disease, along with conventional imaging and clinical and laboratory tests.

  11. Abdominal sarcoidosis: cross-sectional imaging findings

    PubMed Central

    Gezer, Naciye Sinem; Başara, Işıl; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%–70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  12. Shape optimization of the total scattering cross section for cylindrical scatterers

    NASA Astrophysics Data System (ADS)

    Jacobsson, Per; Rylander, Thomas

    2009-08-01

    We propose and test a gradient-based shape optimization algorithm for the total scattering cross section of infinitely long cylinders, by means of changing the shape of the cylinder's cross section. On the basis of the optical theorem, we derive sensitivity expressions for both dielectric and metal cylinders given an incident plane wave, where the wave vector is perpendicular to the cylinder axis. Both the transverse electric (TE) case and the transverse magnetic case are considered. The sensitivity expressions are based on the continuum form of Maxwell's equations, and they provide the sensitivity with respect to an arbitrary number of shape parameters in terms of the field solution of the original scattering problem and an adjoint scattering problem. These results are used to construct a gradient-based optimization algorithm that we exploit for the reduction of the total scattering cross section in the TE case for metal cylinders, e.g., struts used in reflector antennas. We present optimized cross sections that are oblong in the direction of the incident wave vector, and some of these designs feature corrugations that are parallel to the cylinder axis. We show designs with asymmetric cross sections that yield a low monostatic scattering cross section for certain directions in combination with a low total scattering cross section, which can be used to reduce the noise temperature contributions from the upper strut in an inverted Y tripod reflector antenna.

  13. Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

    SciTech Connect

    Soran, P.D.; Seamon, R.E.

    1980-05-01

    Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ..nu.., the average number of neutrons per fission, are also given.

  14. Cross-section generation methodology for three-dimensional transient reactor simulation

    SciTech Connect

    Watson, J.; Ivanov, K.; Macian, R.; Baratta, A.

    1997-12-01

    An important aspect of three-dimensional transient reactor calculations is the cross-section modeling algorithm. Based on our experience in transient simulations of different accident scenarios with Pennsylvania State University`s coupled code TRAC-PF1/NEM, an original cross-section generation methodology was developed and tested. Well-known features were combined with new developments to achieve an accurate and efficient coupled three-dimensional kinetics/thermal-hydraulic system modeling. Our approach is designed to describe both initial steady state and the entire range of conditions expected during a transient. It differs from the existing cross-section generation procedures in both history and instantaneous models.

  15. PWR Cross Section Libraries for ORIGEN-ARP

    SciTech Connect

    McGraw, Carolyn; Ilas, Germina

    2012-01-01

    New pressurized water reactor (PWR) cross-section libraries were generated for use with the ORIGEN-ARP depletion sequence in the SCALE nuclear analysis code system. These libraries are based on ENDF/B-VII nuclear data and were generated using the two-dimensional depletion sequence, TRITON/NEWT, in SCALE 6.1. The libraries contain multiple burnup-dependent cross-sections for seven PWR fuel designs, with enrichments ranging from 1.5 to 6 wt% 235U. The burnup range has been extended from the 72 GWd/MTU used in previous versions of the libraries to 90 GWd/MTU. Validation of the libraries using radiochemical assay measurements and decay heat measurements for PWR spent fuel showed good agreement between calculated and experimental data. Verification against detailed TRITON simulations for the considered assembly designs showed that depletion calculations performed in ORIGEN-ARP with the pre-generated libraries provide similar results as obtained with direct TRITON depletion, while greatly reducing the computation time.

  16. Consumers’ estimation of calorie content at fast food restaurants: cross sectional observational study

    PubMed Central

    Condon, Suzanne K; Kleinman, Ken; Mullen, Jewel; Linakis, Stephanie; Rifas-Shiman, Sheryl; Gillman, Matthew W

    2013-01-01

    Objective To investigate estimation of calorie (energy) content of meals from fast food restaurants in adults, adolescents, and school age children. Design Cross sectional study of repeated visits to fast food restaurant chains. Setting 89 fast food restaurants in four cities in New England, United States: McDonald’s, Burger King, Subway, Wendy’s, KFC, Dunkin’ Donuts. Participants 1877 adults and 330 school age children visiting restaurants at dinnertime (evening meal) in 2010 and 2011; 1178 adolescents visiting restaurants after school or at lunchtime in 2010 and 2011. Main outcome measure Estimated calorie content of purchased meals. Results Among adults, adolescents, and school age children, the mean actual calorie content of meals was 836 calories (SD 465), 756 calories (SD 455), and 733 calories (SD 359), respectively. A calorie is equivalent to 4.18 kJ. Compared with the actual figures, participants underestimated calorie content by means of 175 calories (95% confidence interval 145 to 205), 259 calories (227 to 291), and 175 calories (108 to 242), respectively. In multivariable linear regression models, underestimation of calorie content increased substantially as the actual meal calorie content increased. Adults and adolescents eating at Subway estimated 20% and 25% lower calorie content than McDonald’s diners (relative change 0.80, 95% confidence interval 0.66 to 0.96; 0.75, 0.57 to 0.99). Conclusions People eating at fast food restaurants underestimate the calorie content of meals, especially large meals. Education of consumers through calorie menu labeling and other outreach efforts might reduce the large degree of underestimation. PMID:23704170

  17. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    NASA Astrophysics Data System (ADS)

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-08-01

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (∼ 50 MeV to ∼ 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used in the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are available now. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results. Our current results indicate this is, in fact, the case.

  18. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    DOE PAGES

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-05-14

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used inmore » the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.« less

  19. Work Values of Singaporean Adolescents.

    ERIC Educational Resources Information Center

    Tan, Esther

    This study attempted to determine the predominant work values among Singaporean students, possible changes in the work values of adolescents as they proceed from early to late adolescence, and the role of gender in forming work values. Using a cross-sectional design and stratified random sampling techniques, a sample of 645 boys and 735 girls was…

  20. Loneliness Predicts Reduced Physical Activity: Cross-Sectional & Longitudinal Analyses

    PubMed Central

    Hawkley, Louise C.; Thisted, Ronald A.; Cacioppo, John T.

    2009-01-01

    Objective To determine cross-sectional and prospective associations between loneliness and physical activity, and to evaluate the roles of social control and emotion regulation as mediators of these associations. Design A population-based sample of 229 White, Black, and Hispanic men and women, age 50 to 68 years at study onset, were tested annually for each of 3 years. Main Outcome Measures Physical activity probability, and changes in physical activity probability over a 3-year period. Results Replicating and extending prior cross-sectional research, loneliness was associated with a significantly reduced odds of physical activity (OR = 0.65 per SD of loneliness) net of sociodemographic variables (age, gender, ethnicity, education, income), psychosocial variables (depressive symptoms, perceived stress, hostility, social support), and self-rated health. This association was mediated by hedonic emotion regulation, but not by social control as indexed by measures of social network size, marital status, contact with close ties, group membership, or religious group affiliation. Longitudinal analyses revealed that loneliness predicted diminished odds of physical activity in the next two years (OR = 0.61), and greater likelihood of transitioning from physical activity to inactivity (OR = 1.58). Conclusion Loneliness among middle and older age adults is an independent risk factor for physical inactivity and increases the likelihood that physical activity will be discontinued over time. PMID:19450042

  1. Realizing the Opportunities of Neutron Cross Section Measurements at RIA

    SciTech Connect

    Ahle, L; Hausmann, M; Reifarth, R; Roberts, K; Roeben, M; Rusnak, B; Vieira, D

    2004-10-13

    The Rare Isotope Accelerator will produce many isotopes at never before seen rates. This will allow for the first time measurements on isotopes very far from stability and new measurement opportunities for unstable nuclei near stability. In fact, the production rates are such that it should be possible to collect 10 micrograms of many isotopes with a half-life of 1 day or more. This ability to make targets of short-lived nuclei enables the possibility of making neutron cross-section measurements important to the astrophysics and the stockpile stewardship communities. But to fully realize this opportunity, the appropriate infrastructure must be included at the RIA facility. This includes isotope harvesting capabilities, radiochemical areas for processing collected material, and an intense, ''mono-energetic'', tunable neutron source. As such, we have been developing a design for neutron source facility to be included at the RIA site. This facility would produce neutrons via intense beams of deuterons and protons on a variety of targets. The facility would also include the necessary radiochemical facilities for target processing. These infrastructure needs will be discussed in addition to the methods that would be employed at RIA for measuring these neutron cross-sections.

  2. Family food involvement and frequency of family dinner meals among Australian children aged 10-12years. Cross-sectional and longitudinal associations with dietary patterns.

    PubMed

    Leech, Rebecca M; McNaughton, Sarah A; Crawford, David A; Campbell, Karen J; Pearson, Natalie; Timperio, Anna

    2014-04-01

    Involvement in meal preparation and eating meals with the family are associated with better dietary patterns in adolescents, however little research has included older children or longitudinal study designs. This 3-year longitudinal study examines cross-sectional and longitudinal associations between family food involvement, family dinner meal frequency and dietary patterns during late childhood. Questionnaires were completed by parents of 188 children from Greater Melbourne, Australia at baseline in 2002 (mean age=11.25years) and at follow-up in 2006 (mean age=14.16years). Principal components analysis (PCA) was used to identify dietary patterns. Factor analysis (FA) was used to determine the principal factors from six indicators of family food involvement. Multiple linear regression models were used to predict the dietary patterns of children and adolescents at baseline and at follow-up, 3years later, from baseline indicators of family food involvement and frequency of family dinner meals. PCA revealed two dietary patterns, labeled a healthful pattern and an energy-dense pattern. FA revealed one factor for family food involvement. Cross-sectionally among boys, family food involvement score (β=0.55, 95% CI: 0.02, 1.07) and eating family dinner meals daily (β=1.11, 95% CI: 0.27, 1.96) during late childhood were positively associated with the healthful pattern. Eating family dinner meals daily was inversely associated with the energy-dense pattern, cross-sectionally among boys (β=-0.56, 95% CI: -1.06, -0.06). No significant cross-sectional associations were found among girls and no significant longitudinal associations were found for either gender. Involvement in family food and eating dinner with the family during late childhood may have a positive influence on dietary patterns of boys. No evidence was found to suggest the effects on dietary patterns persist into adolescence.

  3. Effects of space-dependent cross sections on core physics parameters for compact fast spectrum space power reactors

    NASA Astrophysics Data System (ADS)

    Lell, R. M.; Hanan, N. A.

    Effects of multigroup neutron cross section generation procedures on core physics parameters for compact fast spectrum reactors were examined. Homogeneous and space dependent multigroup cross section set were generated in 11 and 27 groups for a representative fast reactor core. These cross sections were used to compute various reactor physics parameters for the reference core. Coarse group structure and neglect of space dependence in the generation procedure resulted in inaccurate computations of reactor flux and power distributions and in significant errors regarding estimates of core reactivity and control system worth. Delayed neutron fraction was insensitive to cross section treatment, and computed reactivity coefficients were only slightly sensitive. However, neutron lifetime was found to be very sensitive to cross section treatment. Deficiencies in multigroup cross sections are reflected in core nuclear design and, consequently, in system mechanical design.

  4. Damage accumulation in closed cross-section, laminated, composite structures

    NASA Technical Reports Server (NTRS)

    Bucinell, Ronald B.

    1996-01-01

    . Space structures typically have closed cross-sections, absent of free edges. As a result, composite material characterization data generated using finite width flat specimens does not accurately reflect the performance of the composite materials used in a closed cross-section structural configuration. Several investigators have recognized the need to develop characterization techniques for composite materials in closed cross-sectioned structures. In these investigations test methods were developed and cylindrical specimens were evaluated. The behavior of the cylindrical specimens were observed to depart from behavior typical of flat coupons. However, no attempts were made to identify and monitor the progression of damage in these cylindrical specimens during loading. The identification and monitoring of damage is fundamental to the characterization of composite materials in closed cross-section configurations. In the study reported here, a closed cross-sectioned test method was developed to monitor damage progression in 2 in. diameter cylindrical specimens and 1.5 in. finite width flat coupons subjected to quasi-static, tensile loading conditions. Damage in these specimen configurations was monitored using pulse echo ultrasonic, acoustic emission, and X-ray techniques.

  5. Coupled multigroup cross sections for hydrogen interactions in plasmas

    NASA Astrophysics Data System (ADS)

    Wienke, B. R.; Morel, J. E.; Cayton, T. E.; Howell, R. B.

    1985-10-01

    Using analytical fits to the experimental cross sections for H 3 H 2, and H 2+ interactions in plasmas, developed by Gryzinski, Riviere, Jones, and Freeman, we obtain coupled multigroup cross sections and rate coefficients for hydrogen transport applications. Multigroup cross sections and rate coefficients, for specified energy group boundaries, plasma particle and temperature profiles, and cylindrical plasma confinement radius, are generated against a spatially dependent, local Maxwellian scattering background. Cross sections are formatted for direct use in production multigroup S n, Monte Carlo, or specific transport applications. Ten coupled hydrogen reactions are included and resulting cross sections for ionization, scattering, and production can be coupled or decoupled. Reactions treated include H, H 2 ionization by electrons and protons, H, H 2 charge exchange, and H 2, H 2+ dissociative mechanisms. We detail the formalism used to compute effective cross sections and rates and give practicle results for two fusion reactors.

  6. Total and partial photoneutron cross sections for Pb isotopes

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Utsunomiya, H.; Goriely, S.; Daoutidis, I.; Iwamoto, C.; Akimune, H.; Okamoto, A.; Yamagata, T.; Kamata, M.; Itoh, O.; Toyokawa, H.; Lui, Y.-W.; Harada, H.; Kitatani, F.; Hilaire, S.; Koning, A. J.

    2012-07-01

    Using quasimonochromatic laser-Compton scattering γ rays, total photoneutron cross sections were measured for 206,207,208Pb near neutron threshold with a high-efficiency 4π neutron detector. Partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near threshold by measuring anisotropies in photoneutron emission with linearly polarized γ rays. The E1 strength dominates over the M1 strength in the neutron channel where E1 photoneutron cross sections show extra strength of the pygmy dipole resonance in 207,208Pb near the neutron threshold corresponding to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to an M1 cross section less than 10% of the total photoneutron cross section.

  7. Color dipole cross section and inelastic structure function

    NASA Astrophysics Data System (ADS)

    Jeong, Yu Seon; Kim, C. S.; Luu, Minh Vu; Reno, Mary Hall

    2014-11-01

    Instead of starting from a theoretically motivated form of the color dipole cross section in the dipole picture of deep inelastic scattering, we start with a parametrization of the deep inelastic structure function for electromagnetic scattering with protons, and then extract the color dipole cross section. Using the parametrizations of F 2(ξ = x or W 2 , Q 2) by Donnachie-Landshoff and Block et al., we find the dipole cross section from an approximate form of the presumed dipole cross section convoluted with the perturbative photon wave function for virtual photon splitting into a color dipole with massless quarks. The color dipole cross section determined this way reproduces the original structure function within about 10% for 0 .1 GeV2 ≤ Q 2 ≤10 GeV2. We discuss the dipole cross section at large and small dipole sizes and compare our results with other parametrizations.

  8. Crosstalk in rectangular cross-section heterogeneous multicore fiber

    NASA Astrophysics Data System (ADS)

    Egorova, Olga N.; Astapovich, Maxim S.; Semjonov, Sergey L.

    2016-09-01

    Using neighboring cores with different mode propagation constants (indexes) is a well-known way to reduce crosstalk in multicore fiber (MCF). However, in actual field-deployed fiber, random bends can cause a reduction in the difference between the mode indexes of neighboring cores, which consequently increases crosstalk. The level of crosstalk induced by bending in both rectangular cross-section and circular cross-section heterogeneous MCF with cores arranged in a line was investigated. The experimental results obtained indicate that in contrast to circular cross-section MCF, no bending-induced crosstalk occurs in rectangular cross-section MCF wound on the mandrel without special control of cross-section orientation. Thus, to eliminate undesirable bending-induced crosstalk in heterogeneous MCF a rectangular cross-section should be employed.

  9. Partial Photoneutron Cross Sections for 207,208Pb

    NASA Astrophysics Data System (ADS)

    Kondo, T.; Utsunomiya, H.; Goriely, S.; Iwamoto, C.; Akimune, H.; Yamagata, T.; Toyokawa, H.; Harada, H.; Kitatani, F.; Lui, Y.-W.; Hilaire, S.; Koning, A. J.

    2014-05-01

    Using linearly-polarized laser-Compton scattering γ-rays, partial E1 and M1 photoneutron cross sections along with total cross sections were determined for 207,208Pb at four energies near neutron threshold by measuring anisotropies in photoneutron emission. Separately, total photoneutron cross sections were measured for 207,208Pb with a high-efficiency 4π neutron detector. The partial cross section measurement provides direct evidence for the presence of pygmy dipole resonance (PDR) in 207,208Pb in the vicinity of neutron threshold. The strength of PDR amounts to 0.32%-0.42% of the Thomas-Reiche-Kuhn sum rule. Several μN2 units of B(M1)↑ strength were observed in 207,208Pb just above neutron threshold, which correspond to M1 cross sections less than 10% of the total photoneutron cross sections.

  10. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  11. Measured microwave scattering cross sections of three meteorite specimens

    NASA Technical Reports Server (NTRS)

    Hughes, W. E.

    1972-01-01

    Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

  12. Left atrial vascularised thrombus diagnosed by transoesophageal cross sectional echocardiography.

    PubMed Central

    Taams, M A; Gussenhoven, E J; Lancée, C T

    1987-01-01

    This report describes a patient with a Björk-Shiley mitral valve prosthesis in whom transoesophageal cross sectional echocardiography revealed a large vascularised mass within the left atrial appendage with smoke-like opacification of blood flow in the left atrium. Transoesophageal cross sectional echocardiography gave a detailed image of the lesion which was unobtainable with precordial cross sectional echocardiography. Images Fig 1 Fig 2 PMID:3426904

  13. Analytical formulation of the quantum electromagnetic cross section

    NASA Astrophysics Data System (ADS)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2016-05-01

    It has been found that the quantum radar cross section (QRCS) equation can be written in terms of the Fourier transform of the surface atom distribution of the object. This paper uses this form to provide an analytical formulation of the quantum radar cross section by deriving closed form expressions for various geometries. These expressions are compared to the classical radar cross section (RCS) expressions and the quantum advantages are discerned from the differences in the equations. Multiphoton illumination is also briefly discussed.

  14. Giant dipole resonance parameters with uncertainties from photonuclear cross sections

    NASA Astrophysics Data System (ADS)

    Plujko, V. A.; Capote, R.; Gorbachenko, O. M.

    2011-09-01

    Updated values and corresponding uncertainties of isovector giant dipole resonance (IVGDR or GDR) model parameters are presented that are obtained by the least-squares fitting of theoretical photoabsorption cross sections to experimental data. The theoretical photoabsorption cross section is taken as a sum of the components corresponding to excitation of the GDR and quasideuteron contribution to the experimental photoabsorption cross section. The present compilation covers experimental data as of January 2010.

  15. High E{sub T} jet cross sections at CDF

    SciTech Connect

    Flaugher, B.; CDF Collaboration

    1996-08-01

    The inclusive jet cross section for {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the {Sigma} E{sub T} cross section at {radical}s = 1.8 TeV and the central inclusive jet cross section at {radical}s = 0.630 TeV will also be shown.

  16. Cross section dependence of event rates at neutrino telescopes.

    PubMed

    Hussain, S; Marfatia, D; McKay, D W; Seckel, D

    2006-10-20

    We examine the dependence of event rates at neutrino telescopes on the neutrino-nucleon cross section for neutrinos with energy above 1 PeV, and contrast the results with those for cosmic ray experiments. Scaling of the standard model cross sections leaves the rate of upward events essentially unchanged. Details, such as detector depth and cross section inelasticity, can influence rates. Numerical estimates of upward shower, muon, and tau event rates in the IceCube detector confirm these results.

  17. Error Assessment of Homogenized Cross Sections Generation for Whole Core Neutronic Calculation

    SciTech Connect

    Hursin, Mathieu; Kochunas, Brendan; Downar, Thomas J.

    2007-10-26

    The objective of the work here was to assess the errors introduced by using 2D, few group homogenized cross sections to perform neutronic analysis of BWR problems with significant axial heterogeneities. The 3D method of characteristics code DeCART is used to generate 2-group assembly homogenized cross sections first using a conventional 2D lattice model and then using a full 3D solution of the assembly. A single BWR fuel assembly model based on an advanced BWR lattice design is used with a typical void distribution applied to the fuel channel coolant. This model is validated against an MCNP model. A comparison of the cross sections is performed for the assembly homogenized planar cross sections from the DeCART 3D and DeCART 2D solutions.

  18. Neutron capture cross section of {sup 102}Pd

    SciTech Connect

    Duncan, C.L.; Krane, K.S.

    2005-05-01

    The cross sections for radiative neutron capture by {sup 102}Pd have been deduced from a measurement of the {gamma} rays emitted by 17.0-d {sup 103}Pd. The thermal cross section has been determined to be {sigma}=1.82{+-}0.20 b, and the effective resonance integral is I=23{+-}4 b. We also report thermal and resonance capture cross sections for {sup 108}Pd and note possible inconsistencies with the presently accepted values of the {sup 110}Pd cross sections.

  19. Inclusive Cross Section Production of J/ψ in LEP

    NASA Astrophysics Data System (ADS)

    Osati, T.; Abubakri, B.

    2017-02-01

    Cross section production is one of the observable quantities in the hadronic systems. Inclusive cross section production J/ψ may be calculated through the use of the fragmentation c → J/ψ. In this paper we calculate the inclusive cross section production J/ψ about the pole of Z 0 in the e + e ‑ annihilation, through the lowest order regim of perturbative of QCD ananlyticaly. The obtained results arrive an excellent agreement with the exprimental data to produce the inclusive cross section production c → J/ψ.

  20. Flow in tubes of non-circular cross-sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    Laminar, viscous, incompressible flow in tubes of noncircular cross sections is investigated. The specific aims of the investigation are (1) to look at the problems of both developing flow and fully developed flow, (2) to consider noncircular cross sections in a more systematic manner than has been done in the past, and (3) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent-shaped cross sections, and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the corresponding exact

  1. Thermal Neutron Capture Cross Section of {sup 22}Ne

    SciTech Connect

    Belgya, T.; Uberseder, E.; Petrich, D.; Kaeppeler, F.

    2009-01-28

    The radiative thermal neutron capture cross section of the astrophysically important {sup 22}Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched {sup 22}Ne and CH{sub 4} were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7{+-}0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

  2. Neutron-capture Cross Sections from Indirect Measurements

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  3. Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

    SciTech Connect

    Younes, W; Britt, H C

    2003-07-10

    In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated cross sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.

  4. SCWR Once-Through Calculations for Transmutation and Cross Sections

    SciTech Connect

    ganda, francesco

    2012-07-01

    It is the purpose of this report to document the calculation of (1) the isotopic evolution and of (2) the 1-group cross sections as a function of burnup of the reference Super Critical Water Reactor (SCWR), in a format suitable for the Fuel Cycle Option Campaign Transmutation Data Library. The reference SCWR design was chosen to be that described in [McDonald, 2005]. Super Critical Water Reactors (SCWR) are intended to operate with super-critical water (i.e. H2O at a pressure above 22 MPa and a temperature above 373oC) as a cooling – and possibly also moderating – fluid. The main mission of the SCWR is to generate lower cost electricity, as compared to current standard Light Water Reactors (LWR). Because of the high operating pressure and temperature, SCWR feature a substantially higher thermal conversion efficiency than standard LWR – i.e. about 45% versus 33%, mostly due to an increase in the exit water temperature from ~300oC to ~500oC – potentially resulting in a lower cost of generated electricity. The coolant remains single phase throughout the reactor and the energy conversion system, thus eliminating the need for pressurizers, steam generators, steam separators and dryers, further potentially reducing the reactor construction capital cost. The SCWR concept presented here is based on existing LWR technology and on a large number of existing fossil-fired supercritical boilers. However, it was concluded in [McDonald, 2005], that: “Based on the results of this study, it appears that the reference SCWR design is not feasible.” This conclusion appears based on the strong sensitivity of the design to small deviations in nominal conditions leading to small effects having a potentially large impact on the peak cladding temperature of some fuel rods. “This was considered a major feasibility issue for the SCWR” [McDonald, 2005]. After a description of the reference SCWR design, the Keno V 3-D single assembly model used for this analysis, as well as the

  5. Characterization of radar cross section of carbon fiber composite materials

    NASA Astrophysics Data System (ADS)

    Riley, Elliot J.; Lenzing, Erik H.; Narayanan, Ram M.

    2015-05-01

    Carbon fiber composite (CFC) materials have been used for many structural applications for decades. Their electromagnetic properties are also of great interest and are being quantified by recent research. This research explores shielding effectiveness, antenna design, conductivity, reflection, and absorption properties. The work in this paper specifically characterizes the radar cross section (RCS) of CFC structures. Various CFC planar samples were created using a wet layup method and vacuum bagging techniques. These samples were then placed in an anechoic chamber and their RCS values were measured at normal incidence. These measured values were compared to those of aluminum samples made into the same shape as the CFC samples. All of the measurements were made over 7 - 12 GHz frequency range. The RCS of the CFC samples show some interesting results. The fiber direction in the CFC samples had great influence on the RCS. Theories and reasoning for the results are presented and discussed.

  6. Gamma Efficiency Simulations towards Coincidence Measurements for Fusion Cross Sections

    NASA Astrophysics Data System (ADS)

    Heine, M.; Courtin, S.; Fruet, G.; Jenkins, D. G.; Montanari, D.; Morris, L.; Regan, P. H.; Rudigier, M.; Symochko, D.

    2016-10-01

    With the experimental station STELLA (STELlar LAboratory) we will measure fusion cross sections of astrophysical relevance making use of the coincident detection of charged particles and gamma rays for background reduction. For the measurement of gamma rays from the de-excitation of fusion products a compact array of 36 UK FATIMA LaBr3 detectors is designed based on efficiency studies with Geant4. The photo peak efficiency in the region of interest compares to other gamma detection systems used in this field. The features of the internal decay of 138La is used in a background study to obtain an online calibration of the gamma detectors. Background data are fit to the Monte Carlo model of the self activity assuming crude exponential behavior of external background. Accuracy in the region of interest is of the order of some keV in this first study.

  7. Radar cross section prediction and reduction for naval ships

    NASA Astrophysics Data System (ADS)

    Khan, Jawad; Duan, Wenyang; Sherbaz, Salma

    2012-06-01

    Radar cross section (RCS) is the measurement of the reflective strength of a target. Reducing the RCS of a naval ship enables its late detection, which is useful for capitalizing on elements of surprise and initiative. Thus, the RCS of a naval ship has become a very important design factor for achieving surprise, initiative, and survivability. Consequently, accurate RCS determination and RCS reduction are of extreme importance for a naval ship. The purpose of this paper is to provide an understanding of the theoretical background and engineering approach to deal with RCS prediction and reduction for naval ships. The importance of RCS, radar fundamentals, RCS basics, RCS prediction methods, and RCS reduction methods for naval ships is also discussed.

  8. Cross Sections for Inner-Shell Ionization by Electron Impact

    SciTech Connect

    Llovet, Xavier; Powell, Cedric J.; Salvat, Francesc; Jablonski, Aleksander

    2014-03-15

    An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

  9. Total cross sections for positrons scattered elastically from helium based on new measurements of total ionization cross sections

    NASA Technical Reports Server (NTRS)

    Diana, L. M.; Chaplin, R. L.; Brooks, D. L.; Adams, J. T.; Reyna, L. K.

    1990-01-01

    An improved technique is presented for employing the 2.3m spectrometer to measure total ionization cross sections, Q sub ion, for positrons incident on He. The new ionization cross section agree with the values reported earlier. Estimates are also presented of total elastic scattering cross section, Q sub el, obtained by subtracting from total scattering cross sections, Q sub tot, reported in the literature, the Q sub ion and Q sub Ps (total positronium formation cross sections) and total excitation cross sections, Q sub ex, published by another researcher. The Q sub ion and Q sub el measured with the 3m high resolution time-of-flight spectrometer for 54.9eV positrons are in accord with the results from the 2.3m spectrometer. The ionization cross sections are in fair agreement with theory tending for the most part to be higher, especially at 76.3 and 88.5eV. The elastic cross section agree quite well with theory to the vicinity of 50eV, but at 60eV and above the experimental elastic cross sections climb to and remain at about 0.30 pi a sub o sq while the theoretical values steadily decrease.

  10. Cross Sections for Electron Collisions with Carbon Monoxide

    SciTech Connect

    Itikawa, Yukikazu

    2015-03-15

    Cross section data are collected and reviewed for electron collisions with carbon monoxide. Collision processes included are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational and electronic states, ionization, and dissociation. For each process, recommended values of the cross sections are presented, when possible. The literature has been surveyed through to the end of 2013.

  11. Analysis of cross sections using various nuclear potential

    SciTech Connect

    Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

    2014-05-02

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

  12. Learning of Cross-Sectional Anatomy Using Clay Models

    ERIC Educational Resources Information Center

    Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

    2009-01-01

    We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

  13. Benchmark Calculations of Electron-Impact Differential Cross Sections

    SciTech Connect

    Bray, I.; Bostock, C. J.; Fursa, D. V.; Hines, C. W.; Kadyrov, A. S.; Stelbovics, A. T.

    2011-05-11

    The calculation of electron-atom excitation and ionization cross section is considered in both the non-relativistic and relativistic scattering theory. We consider electron collisions with H, He, Cs, and Hg. Differential cross sections for elastic scattering and ionization are presented.

  14. Cross sections for scattering of electrons on BF_3

    NASA Astrophysics Data System (ADS)

    Radmilovic-Radjenovic, M.; Varambhia, H. N.; Vranic, M.; Tennyson, J.; Petrovic, Z. Lj.

    2008-07-01

    We calculate cross sections for elastic scattering and electronic excitation of BF_3 molecules by low energy electrons. The R-Matrix code Quantemol-N has been used for calculations. The cross sections indicate the presence of a shape resonance of symmetry B_1 (A_2'' in D_3h) at around 4.5 eV.

  15. Electron induced inelastic and ionization cross section for plasma modeling

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Mahato, Dibyendu; Kaur, Jaspreet; Antony, Bobby

    2016-09-01

    The present paper reports electron impact total inelastic and ionization cross section for silicon, germanium, and tin tetrahalides at energies varying from ionization threshold of the target to 5000 eV. These cross section data over a wide energy domain are very essential to understand the physico-chemical processes involved in various environments such as plasma modeling, semiconductor etching, atmospheric sciences, biological sciences, and radiation physics. However, the cross section data on the above mentioned molecules are scarce. In the present article, we report the computation of total inelastic cross section using spherical complex optical potential formalism and the estimation of ionization cross section through a semi-empirical method. The present ionization cross section result obtained for SiCl4 shows excellent agreement with previous measurements, while other molecules have not yet been investigated experimentally. Present results show more consistent behaviour than previous theoretical estimates. Besides cross sections, we have also studied the correlation of maximum ionization cross section with the square root of the ratio of polarizability to ionization potential for the molecules with known polarizabilities. A linear relation is observed between these quantities. This correlation is used to obtain approximate polarizability volumes for SiBr4, SiI4, GeCl4, GeBr4, and GeI4 molecules.

  16. DPA Cross Section Library FermiDPA 1.0

    SciTech Connect

    Pronskikh, V. S.; Mokhov, N. V.

    2013-06-05

    DPA cross section library FermiDPA 1.0 based on the industry standard NRT model calculations is described. The library contains DPA cross sections for neutrons in the energy range 10$^{-5}$ eV 20 (150) MeV. Calculations used neutron-induced reaction cross sections from ENDFB-VII database of evaluated nuclear data. The NJOY99 nuclear data processing system's module HEATR was applied to calculate NRT model radiation damage cross sections. The FermiDPA 1.0 library is a database of 395 text files (for 395 known isotopes) with DPA cross sections. It is code-independent and can be implemented in any transport code.

  17. Temperature-dependent high resolution absorption cross sections of propane

    NASA Astrophysics Data System (ADS)

    Beale, Christopher A.; Hargreaves, Robert J.; Bernath, Peter F.

    2016-10-01

    High resolution (0.005 cm-1) absorption cross sections have been measured for pure propane (C3H8). These cross sections cover the 2550-3500 cm-1 region at five temperatures (from 296 to 700 K) and were measured using a Fourier transform spectrometer and a quartz cell heated by a tube furnace. Calibrations were made by comparison to the integrated cross sections of propane from the Pacific Northwest National Laboratory. These are the first high resolution absorption cross sections of propane for the 3 μm region at elevated temperatures. The cross sections provided may be used to monitor propane in combustion environments and in astronomical sources such as the auroral regions of Jupiter, brown dwarfs and exoplanets.

  18. Fission cross section measurements of actinides at LANSCE

    SciTech Connect

    Tovesson, Fredrik; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

  19. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  20. Analytical approximations for X-ray cross sections 3

    NASA Astrophysics Data System (ADS)

    Biggs, Frank; Lighthill, Ruth

    1988-08-01

    This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energies greater than or equal to 10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically.

  1. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Astrophysics Data System (ADS)

    Nicovich, J. M.; Wine, P. H.

    1988-03-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  2. Proton Radiography: Cross Section Measurements and Detector Development

    SciTech Connect

    Michael J. Longo; H. R. Gustafson: Durga Rajaram; Turgun Nigmanov

    2010-04-16

    Proton radiography has become an important tool for predicting the performance of stockpiled nuclear weapons. Current proton radiography experiments at LANSCE are confined to relatively small targets on the order of centimeters in size because of the low beam energy. LANL scientists have made radiographs with 12 and 24 GeV protons produced by the accelerator at Brookhaven National Laboratory. These energies are in the range required for hydrotest radiography. The design of a facility for hydrotest radiography requires knowledge of the cross sections for producing high-energy particles in the forward direction, which are incorporated into the Monte Carlo simulation used in designing the beam and detectors. There are few existing measurements of neutron production cross sections for proton-nuclei interactions in the 50 GeV range, and almost no data exist for forward neutron production, especially for heavy target nuclei. Thus the data from the MIPP EMCAL and HCAL, for which our group was responsible, are critical to proton radiography. Since neutrons and photons cannot be focused by magnets, they cause a background “fog” on the images. This problem can be minimized by careful design of the focusing system and detectors. The purpose of our research was to measure forward production of neutrons produced by high-energy proton beams striking a variety of targets. The forward-going particles carry most of the energy from a high-energy proton interaction, so these are the most important to proton radiography. This work was carried out in conjunction with the Fermilab E-907 (MIPP) collaboration. Our group was responsible for designing and building the E907 forward neutron and photon calorimeters. With the support of our Stewardship Science Academic Alliances grants, we were able to design, build, and commission the calorimeters on budget and ahead of schedule. The MIPP experiment accumulated a large amount of data in the first run that ended in early 2006. Our group has

  3. Advanced Neutron Source Cross Section Libraries (ANSL-V): ENDF/B-V based multigroup cross-section libraries for advanced neutron source (ANS) reactor studies

    SciTech Connect

    Ford, W.E. III; Arwood, J.W.; Greene, N.M.; Moses, D.L.; Petrie, L.M.; Primm, R.T. III; Slater, C.O.; Westfall, R.M.; Wright, R.Q.

    1990-09-01

    Pseudo-problem-independent, multigroup cross-section libraries were generated to support Advanced Neutron Source (ANS) Reactor design studies. The ANS is a proposed reactor which would be fueled with highly enriched uranium and cooled with heavy water. The libraries, designated ANSL-V (Advanced Neutron Source Cross Section Libraries based on ENDF/B-V), are data bases in AMPX master format for subsequent generation of problem-dependent cross-sections for use with codes such as KENO, ANISN, XSDRNPM, VENTURE, DOT, DORT, TORT, and MORSE. Included in ANSL-V are 99-group and 39-group neutron, 39-neutron-group 44-gamma-ray-group secondary gamma-ray production (SGRP), 44-group gamma-ray interaction (GRI), and coupled, 39-neutron group 44-gamma-ray group (CNG) cross-section libraries. The neutron and SGRP libraries were generated primarily from ENDF/B-V data; the GRI library was generated from DLC-99/HUGO data, which is recognized as the ENDF/B-V photon interaction data. Modules from the AMPX and NJOY systems were used to process the multigroup data. Validity of selected data from the fine- and broad-group neutron libraries was satisfactorily tested in performance parameter calculations.

  4. Comprehensive neutron cross-section and secondary energy distribution uncertainty analysis for a fusion reactor

    SciTech Connect

    Gerstl, S.A.W.; LaBauve, R.J.; Young, P.G.

    1980-05-01

    On the example of General Atomic's well-documented Power Generating Fusion Reactor (PGFR) design, this report exercises a comprehensive neutron cross-section and secondary energy distribution (SED) uncertainty analysis. The LASL sensitivity and uncertainty analysis code SENSIT is used to calculate reaction cross-section sensitivity profiles and integral SED sensitivity coefficients. These are then folded with covariance matrices and integral SED uncertainties to obtain the resulting uncertainties of three calculated neutronics design parameters: two critical radiation damage rates and a nuclear heating rate. The report documents the first sensitivity-based data uncertainty analysis, which incorporates a quantitative treatment of the effects of SED uncertainties. The results demonstrate quantitatively that the ENDF/B-V cross-section data files for C, H, and O, including their SED data, are fully adequate for this design application, while the data for Fe and Ni are at best marginally adequate because they give rise to response uncertainties up to 25%. Much higher response uncertainties are caused by cross-section and SED data uncertainties in Cu (26 to 45%), tungsten (24 to 54%), and Cr (up to 98%). Specific recommendations are given for re-evaluations of certain reaction cross-sections, secondary energy distributions, and uncertainty estimates.

  5. Diffusion cross sections for potassium ? and ? levels in rare gases

    NASA Astrophysics Data System (ADS)

    Yahyaei-Moayyed, F.; Hickman, A. P.; Streater, A. D.

    1996-02-01

    We have used a light-induced drift (LID) experiment to determine ratios of cross sections for diffusion of potassium in the excited 0953-4075/29/3/011/img3, 0953-4075/29/3/011/img4 and the ground 0953-4075/29/3/011/img5 levels in five rare gases. The measured ratios are combined with the ground-state cross sections and statistically averaged excited cross sections, available from a previously reported light induced diffusive pulling experiment, to obtain the absolute cross sections for individual fine structure levels. We also report calculated cross sections based on available potential curves and a coupled-channel theory. Rough qualitative agreement is generally found between the absolute cross sections inferred from experiment and the theoretical values. The light-induced drift experiments, however, measure ratios of cross section differences that are highly sensitive to the potential curves. It is found that the available potential curves are not adequate for predicting these measured ratios.

  6. Scottish adolescents’ sun-related behaviours, tanning attitudes and associations with skin cancer awareness: a cross-sectional study

    PubMed Central

    Kyle, Richard G; MacMillan, Iona; Forbat, Liz; Neal, Richard D; O'Carroll, Ronan E; Haw, Sally; Hubbard, Gill

    2014-01-01

    Objectives To describe Scottish adolescents’ sun-related behaviours and tanning attitudes and assess associations with skin cancer awareness. Design Cross-sectional study. Setting 20 state secondary schools in one Scottish local authority (Glasgow City). Participants 2173 adolescents (females: 50.7%, n=1102) with a mean age of 12.4 (SD=0.55). Outcome measures Sun-related behaviour (suntan, sunbathing, sunburn, sunscreen use, sunbed use), tanning attitudes, skin cancer-related symptom and risk factor awareness. Results Adolescents reported poor sun-related practice: 51% of adolescents reported sunburn the previous summer of whom 38% indicated sunburn on more than one occasion. Skin cancer awareness was low: 45% recognised ‘change in the appearance of a mole’ as a cancer symptom, and 39% agreed that ‘getting sunburnt more than once as a child’ increased cancer risk. 42% and 26% of adolescents, respectively, reported that friends and family held protanning attitudes. Compared with males, females were statistically significantly more likely to: report sunbathing (p<0.001), use of lotions or oil to aid tanning (p=0.009) and sunburn (p<0.001); know that changes in the appearance of a mole was a skin cancer symptom (p=0.036) and sunburn more than once as a child was a skin cancer risk factor (p=0.005); perceive their friends to hold protanning attitudes (p<0.001) and indicate that a tan made them feel better about themselves (p<0.001), more attractive to others (p=0.011) and healthier (p<0.001). Conclusions Scottish adolescents had poor sun protection practice and low skin cancer awareness. Girls adopted riskier sun-related behaviour despite greater awareness of skin cancer-related risk. Urgent action is required to promote positive sun-related behaviour and increase skin cancer awareness among Scottish adolescents. However, further research is needed to inform the development of effective sun-safe interventions. PMID:24793258

  7. Electron impact ionization cross sections of beryllium-tungsten clusters*

    NASA Astrophysics Data System (ADS)

    Sukuba, Ivan; Kaiser, Alexander; Huber, Stefan E.; Urban, Jan; Probst, Michael

    2016-01-01

    We report calculated electron impact ionization cross sections (EICSs) of beryllium-tungsten clusters, BenW with n = 1,...,12, from the ionization threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The positions of the maxima of DM and BEB cross sections are mostly close to each other. The DM cross sections are more sensitive with respect to the cluster size. For the clusters smaller than Be4W they yield smaller cross sections than BEB and vice versa larger cross sections than BEB for clusters larger than Be6W. The maximum cross section values for the singlet-spin groundstate clusters range from 7.0 × 10-16 cm2 at 28 eV (BeW) to 54.2 × 10-16 cm2 at 43 eV (Be12W) for the DM cross sections and from 13.5 × 10-16 cm2 at 43 eV (BeW) to 38.9 × 10-16 cm2 at 43 eV (Be12W) for the BEB cross sections. Differences of the EICSs in different isomers and between singlet and triplet states are also explored. Both the DM and BEB cross sections could be fitted perfectly to a simple expression used in modeling and simulation codes in the framework of nuclear fusion research. Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2015-60583-7

  8. Review of electron impact excitation cross sections for copper atom

    SciTech Connect

    Winter, N.W.; Hazi, A.U.

    1982-02-01

    Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different cross sections, and the uncertainty in the correct normalization of the data has been a source of confusion and concern for the kinetic modeling efforts. This difficulty has motivated us to review previous work on the electron impact excitation of copper atom and to perform new calculations of the inelastic cross sections using the impact parameter method. In this memorandum we review the previous attempts to normalize the experimental data and provide a critical assessment of the accuracy of the resulting cross sections. We also present new theoretical cross sections for the electron impact excitation of the /sup 2/S ..-->.. /sup 2/P/sup 0/ and /sup 2/S ..-->.. /sup 2/D transitions in copper. When the experimental cross sections are renormalized to the results of the impact parameter calculations, they are a factor of three smaller than those published in the latest paper of Trajmar et. al. At impact energies above 60 eV the excitation cross sections obtained with the impact parameter method agree well with the results of the very recent, unpublished, close-coupling calculations of Henry. This agreement suggests that the present normalization of the experimental cross sections is probably the most reliable one obtained to date.

  9. Fission cross sections in the intermediate energy region

    SciTech Connect

    Lisowski, P.W.; Gavron, A.; Parker, W.E.; Ullmann, J.L.; Balestrini, S.J. ); Carlson, A.D.; Wasson, O.A. ); Hill, N.W. )

    1991-01-01

    Until recently there has been very little cross section data for neutron-induced fission in the intermediate energy region, primarily because no suitable neutron source has existed. At Los Alamos, the WNR target-4 facility provides a high-intensity source of neutrons nearly ideal for fission measurements extending from a fraction of a MeV to several hundred MeV. This paper summarizes the status of fission cross section data in the intermediate energy range (En > 30 MeV) and presents our fission cross section data for {sup 235}U and {sup 238}U compared to intranuclear cascade and statistical model predictions.

  10. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  11. Antinucleus-Nucleus Cross Sections Implemented in Geant4

    SciTech Connect

    Uzhinsky, V.; Apostolakis, J.; Galoyan, A.; Folger, G.; Grichine, V.M.; Ivanchenko, V.N.; Wright, D.H.; /SLAC

    2012-04-26

    Cross sections of antinucleus ({bar p}, {bar d}, {bar t}, {sup 3}{ovr He}, {sup 4}{ovr He}) interactions with nuclei in the energy range 100 MeV/c to 1000 GeV/c per antinucleon are calculated in the Glauber approximation which provides good description of all known {bar p}Across sections. The results were obtained using a new parameterization of the total and elastic {bar p}p cross sections. Simple parameterizations of the antinucleus-nucleus cross sections are proposed for use in estimating the efficiency of antinucleus detection and tracking in cosmic rays and accelerator experiments. These parameterizations are implemented in the Geant4 toolkit.

  12. Lower socioeconomic status, adiposity and negative health behaviours in youth: a cross-sectional observational study

    PubMed Central

    Lord, Sarah; Manlhiot, Cedric; Tyrrell, Pascal N; Dobbin, Stafford; Gibson, Don; Chahal, Nita; Stearne, Karen; Fisher, Amanda; McCrindle, Brian W

    2015-01-01

    Objective Understanding obesity and its modifiable risk factors in youth is key to addressing the burden of cardiovascular disease later in life. Our aim was to examine the associations among adiposity, negative health behaviours and socioeconomic status in youth from the Niagara Region. Design, setting and participants Cross-sectional observational study of 3467 grade 9 students during their mandatory health and physical education class to investigate the association between socioeconomic status (postal code), self-reported health behaviour and adiposity in the Niagara Region, Ontario, Canada. Results Median household income was $63 696 and overall percentage below the after-tax low-income cut-off was 4.2%. Negative health behaviours (especially skipped meals, lower fruit and vegetable consumption, higher screen time) were associated with lower income neighbourhoods, however, the absolute effect was small. Those participants in the lowest income quintile had a significantly greater body mass index z-score than those in the highest (0.72±1.19 vs 0.53±1.12), but the overall trend across quintiles was not statistically significant. A similar trend was noted for waist-to-height ratio. The lowest income neighbourhoods according to after-tax low-income cut-off had small but statistically significant associations with higher adiposity compared with the middle or highest income neighbourhoods. Conclusions Obesity prevention efforts should target modifiable behaviours, with particular attention to adolescents from lower income families and neighbourhoods. PMID:25986642

  13. MALOCCLUSIONS AND QUALITY OF LIFE. Cross-sectional and longitudinal studies in children.

    PubMed

    Dimberg, Lillemor

    2015-01-01

    There are few longitudinal studies of the prevalence of malocclusions and possible self-correction of malocclusions during the development of the dentition. Early intervention might be unnecessary if self-correction of the malocclusion occurs during the transition from the primary to the permanent dentition. Most studies are cross-sectional and in those of longitudinal design, the results are inconsistent and difficult to interpret. Malocclusions may or may not influence the quality of life in children and adolescents. Thus, evaluations of the influence of different malocclusions on quality of life will certainly underpin a broader understanding and knowledge about how malocclusions affect the daily life of young patients. This information may also be important when it comes to assessing the most appropriate time for starting orthodontic treatment, not only from a professional point of view, but also, most importantly, from the patients' perspective. The overall aim of this thesis was therefore to evaluate the prevalence of malocclusions, and to document changes occurring during the development of the dentition, from the primary dentition stage at age 3, through the mixed dentition at age 7, to the early permanent dentition at age 11.5 years. Further aims were to review the current state of knowledge about the impact of malocclusions on oral health related quality of life (OHRQoL) and to investigate how malocclusions affect the quality of life in a cohort of children, aged 11.5 years, whose dental care is provided by the Swedish Public Dental Service.

  14. An evaluation of wind turbine blade cross section analysis techniques.

    SciTech Connect

    Paquette, Joshua A.; Griffith, Daniel Todd; Laird, Daniel L.; Resor, Brian Ray

    2010-03-01

    The blades of a modern wind turbine are critical components central to capturing and transmitting most of the load experienced by the system. They are complex structural items composed of many layers of fiber and resin composite material and typically, one or more shear webs. Large turbine blades being developed today are beyond the point of effective trial-and-error design of the past and design for reliability is always extremely important. Section analysis tools are used to reduce the three-dimensional continuum blade structure to a simpler beam representation for use in system response calculations to support full system design and certification. One model simplification approach is to analyze the two-dimensional blade cross sections to determine the properties for the beam. Another technique is to determine beam properties using static deflections of a full three-dimensional finite element model of a blade. This paper provides insight into discrepancies observed in outputs from each approach. Simple two-dimensional geometries and three-dimensional blade models are analyzed in this investigation. Finally, a subset of computational and experimental section properties for a full turbine blade are compared.

  15. Bistatic and Multistatic Radar: Surveillance, Countermeasures, and Radar Cross Sections. (Latest citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The bibliography contains citations concerning the design, development, testing, and evaluation of bistatic and multistatic radar used in surveillance and countermeasure technology. Citations discuss radar cross sections, target recognition and characteristics, ghost recognition, motion image compensation, and wavelet analysis. Stealth aircraft design, stealth target tracking, synthetic aperture radar, and space applications are examined.

  16. Bistatic and Multistatic Radar: Surveillance, Countermeasures, and Radar Cross Sections. (Latest Citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The bibliography contains citations concerning the design, development, testing, and evaluation of bistatic and multistatic radar used in surveillance and countermeasure technology. Citations discuss radar cross sections, target recognition and characteristics, ghost recognition, motion image compensation, and wavelet analysis. Stealth aircraft design, stealth target tracking, synthetic aperture radar, and space applications are examined.

  17. Surrogate Measurements of Actinide (n,2n) Cross Sections with NeutronSTARS

    SciTech Connect

    Casperson, R. J.; Burke, J. T.; Hughes, R. O.; Akindele, O. A.; Koglin, J. D.; Wang, B.; Tamashiro, A.

    2016-09-27

    Directly measuring (n,2n) cross sections on short-lived actinides presents a number of experimental challenges. The surrogate reaction technique is an experimental method for measuring cross sections on short-­lived isotopes, and it provides a unique solution for measuring (n,2n) cross sections. This technique involves measuring a charged-­particle reaction cross section, where the reaction populates the same compound nucleus as the reaction of interest. To perform these surrogate (n,2n) cross section measurements, a silicon telescope array has been placed along a beam line at the Texas A&M University Cyclotron Institute, which is surrounded by a large tank of gadolinium-doped liquid scintillator, which acts as a neutron detector. The combination of the charge-particle and neutron-detector arrays is referred to as NeutronSTARS. In the analysis procedure for calculating the (n,2n) cross section, the neutron detection efficiency and time structure plays an important role. Due to the lack of availability of isotropic, mono-energetic neutron sources, modeling is an important component in establishing this efficiency and time structure. This report describes the NeutronSTARS array, which was designed and commissioned during this project. It also describes the surrogate reaction technique, specifically referencing a 235U(n,2n) commissioning measurement that was fielded during the past year. Advanced multiplicity analysis techniques have been developed for this work, which should allow for efficient analysis of 241Pu(n,2n) and 239Pu(n,2n) cross section measurements

  18. XSECT: A computer code for generating fuselage cross sections - user's manual

    NASA Technical Reports Server (NTRS)

    Ames, K. R.

    1982-01-01

    A computer code, XSECT, has been developed to generate fuselage cross sections from a given area distribution and wing definition. The cross sections are generated to match the wing definition while conforming to the area requirement. An iterative procedure is used to generate each cross section. Fuselage area balancing may be included in this procedure if desired. The code is intended as an aid for engineers who must first design a wing under certain aerodynamic constraints and then design a fuselage for the wing such that the contraints remain satisfied. This report contains the information necessary for accessing and executing the code, which is written in FORTRAN to execute on the Cyber 170 series computers (NOS operating system) and produces graphical output for a Tektronix 4014 CRT. The LRC graphics software is used in combination with the interface between this software and the PLOT 10 software.

  19. 28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE INTERNAL STRUCTURE OF THE OVEN. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  20. 12. CLOSEUP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. CLOSE-UP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET FROM LAKESHORE, SHOWING REMAINS OF SPILLWAY TIMBERS, LOOKING WEST - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  1. Stellar (n ,γ ) cross sections of 23Na

    NASA Astrophysics Data System (ADS)

    Uberseder, E.; Heil, M.; Käppeler, F.; Lederer, C.; Mengoni, A.; Bisterzo, S.; Pignatari, M.; Wiescher, M.

    2017-02-01

    The cross section of the 23Na(n ,γ )24Na reaction was measured via the activation method at the Karlsruhe 3.7 MV Van de Graaff accelerator. NaCl samples were exposed to quasistellar neutron spectra at k T =5.1 and 25 keV produced via the 18O(p ,n )18F and 7Li(p ,n )7Be reactions, respectively. The derived capture cross sections <σ> kT =5 keV=9.1 ±0.3 mb and <σ> kT =25 keV=2.03 ±0.05 mb are significantly lower than reported in literature. These results were used to substantially revise the radiative width of the first 23Na resonance and to establish an improved set of Maxwellian average cross sections. The implications of the lower capture cross section for current models of s -process nucleosynthesis are discussed.

  2. 8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  3. Photocopy of "sheet 6 of 8" showing cross section of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of "sheet 6 of 8" showing cross section of house, front elevation, fire finder stand, hip roof cap, and shiplap roof sheathing. - Badger Mountain Lookout, .125 mile northwest of Badger Mountain summit, East Wenatchee, Douglas County, WA

  4. A new technique for dosimetry reaction cross-section evaluation

    SciTech Connect

    Badikov, S.A.

    2011-07-01

    Document available in abstract form only, full text of document follows: An objective of this paper is a unification of the procedure for dosimetry reaction cross-section evaluation. A set of requirements for the unified evaluation procedure is presented. A new code (ORTHO) was developed in order to meet these requirements. A statistical model, an algorithm, and the basic formulae employed in the code are described. The code was used for Ti48(n,p) reaction cross-section evaluation. The results of the evaluation are compared to International Reactor Dosimetry File (IRDF)-2002 data. The evaluated cross-sections and their correlations from this work are in good agreement with the IRDF-2002 evaluated data, whereas the uncertainties of the evaluated cross-sections are inconsistent. (authors)

  5. 4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR FACINGS LINED WITH RUBBLE BACKING AND EARTH INFILL, LOOKING EAST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  6. Theory in Evaluation of Actinide Fission and Capture Cross Sections

    SciTech Connect

    Lynn, J. Eric

    2005-05-24

    We discuss the possibilities and limitations of the use of theory as a tool in the evaluation of actinide fission and capture cross sections. We consider especially the target 235U as an example. We emphasize the roles of intermediate structure in the fission cross section and of level width fluctuations in both intermediate structure and fine structure, noting that these lead to a breakdown of Hauser-Feshbach theory at sub-barrier and near-barrier energies. At higher energies (where fluctuation-averaged Hauser-Feshbach theory is applicable) semi-quantitative and intuitive representations of transition state spectra and barrier level density functions have to be tested against experimental data wherever these are available. Adjustment of the fission cross section against inelastic scattering to the much better known levels of the residual nucleus should then lead to a fairly sound estimate of the capture cross section. We compare such estimates with evaluated and experimental data for 235U.

  7. Superstructure Main Bridge, Cross Sections, Cantilever Structure Huey ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Superstructure - Main Bridge, Cross Sections, Cantilever Structure - Huey P. Long Bridge, Spanning Mississippi River approximately midway between nine & twelve mile points upstream from & west of New Orleans, Jefferson, Jefferson Parish, LA

  8. Total cross sections for ultracold neutrons scattered from gases

    DOE PAGES

    Seestrom, Susan Joyce; Adamek, Evan R.; Barlow, Dave; ...

    2017-01-30

    Here, we have followed up on our previous measurements of upscattering of ultracold neutrons (UCNs) from a series of gases by making measurements of total cross sections on the following gases hydrogen, ethane, methane, isobutene, n-butane, ethylene, water vapor, propane, neopentane, isopropyl alcohol, and 3He. The values of these cross sections are important for estimating the loss rate of trapped neutrons due to residual gas and are relevant to neutron lifetime measurements using UCNs. The effects of the UCN velocity and path-length distributions were accounted for in the analysis using a Monte Carlo transport code. Results are compared to ourmore » previous measurements and with the known absorption cross section for 3He scaled to our UCN energy. We find that the total cross sections for the hydrocarbon gases are reasonably described by a function linear in the number of hydrogen atoms in the molecule.« less

  9. Total cross sections for ultracold neutrons scattered from gases

    NASA Astrophysics Data System (ADS)

    Seestrom, S. J.; Adamek, E. R.; Barlow, D.; Blatnik, M.; Broussard, L. J.; Callahan, N. B.; Clayton, S. M.; Cude-Woods, C.; Currie, S.; Dees, E. B.; Fox, W.; Hoffbauer, M.; Hickerson, K. P.; Holley, A. T.; Liu, C.-Y.; Makela, M.; Medina, J.; Morley, D. J.; Morris, C. L.; Pattie, R. W.; Ramsey, J.; Roberts, A.; Salvat, D. J.; Saunders, A.; Sharapov, E. I.; Sjue, S. K. L.; Slaughter, B. A.; Walstrom, P. L.; Wang, Z.; Wexler, J.; Womack, T. L.; Young, A. R.; Vanderwerp, J.; Zeck, B. A.

    2017-01-01

    We have followed up on our previous measurements of upscattering of ultracold neutrons (UCNs) from a series of gases by making measurements of total cross sections on the following gases hydrogen, ethane, methane, isobutene, n -butane, ethylene, water vapor, propane, neopentane, isopropyl alcohol, and 3He . The values of these cross sections are important for estimating the loss rate of trapped neutrons due to residual gas and are relevant to neutron lifetime measurements using UCNs. The effects of the UCN velocity and path-length distributions were accounted for in the analysis using a Monte Carlo transport code. Results are compared to our previous measurements and with the known absorption cross section for 3He scaled to our UCN energy. We find that the total cross sections for the hydrocarbon gases are reasonably described by a function linear in the number of hydrogen atoms in the molecule.

  10. Scaling Cross Sections for Ion-atom Impact Ionization

    SciTech Connect

    Igor D. Kaganovich; Edward Startsev; Ronald C. Davidson

    2003-06-06

    The values of ion-atom ionization cross sections are frequently needed for many applications that utilize the propagation of fast ions through matter. When experimental data and theoretical calculations are not available, approximate formulas are frequently used. This paper briefly summarizes the most important theoretical results and approaches to cross section calculations in order to place the discussion in historical perspective and offer a concise introduction to the topic. Based on experimental data and theoretical predictions, a new fit for ionization cross sections is proposed. The range of validity and accuracy of several frequently used approximations (classical trajectory, the Born approximation, and so forth) are discussed using, as examples, the ionization cross sections of hydrogen and helium atoms by various fully stripped ions.

  11. 36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  12. 20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY SUPERSTRUCTURE AND CONCRETE PLACEMENT LINES August 2, 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  13. Radiative neutron capture cross sections on 176Lu at DANCE

    NASA Astrophysics Data System (ADS)

    Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

    2016-03-01

    The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

  14. Automating the Modeling of the SEE Cross Section's Angular Dependence

    NASA Technical Reports Server (NTRS)

    Patterson, J. D.; Edmonds, L. D.

    2003-01-01

    An algorithm that automates the application of the alpha law in any SEE analysis is presented. This automation is essential for the widespread acceptance of the sophisticated cross section angular dependence model.

  15. Electron-Impact Total Ionization Cross Sections of Hydrocarbon Ions

    PubMed Central

    Irikura, Karl K.; Kim, Yong-Ki; Ali, M. A.

    2002-01-01

    The Binary-Encounter-Bethe (BEB) model for electron-impact total ionization cross sections has been applied to CH2+, CH3+, CH4+, C2H2+, C2H4+, C2H6+ and H3O+. The cross sections for the hydrocarbon ions are needed for modeling cool plasmas in fusion devices. No experimental data are available for direct comparison. Molecular constants to generate total ionization cross sections at arbitrary incident electron energies using the BEB formula are presented. A recent experimental result on the ionization of H3O+ is found to be almost 1/20 of the present theory at the cross section peak. PMID:27446718

  16. Methodology for safety optimization of highway cross-sections for horizontal curves with restricted sight distance.

    PubMed

    Ibrahim, Shewkar E; Sayed, Tarek; Ismail, Karim

    2012-11-01

    Several earlier studies have noted the shortcomings with existing geometric design guides which provide deterministic standards. In these standards the safety margin of the design output is generally unknown and there is little knowledge of the safety implications of deviating from the standards. To mitigate these shortcomings, probabilistic geometric design has been advocated where reliability analysis can be used to account for the uncertainty in the design parameters and to provide a mechanism for risk measurement to evaluate the safety impact of deviations from design standards. This paper applies reliability analysis for optimizing the safety of highway cross-sections. The paper presents an original methodology to select a suitable combination of cross-section elements with restricted sight distance to result in reduced collisions and consistent risk levels. The purpose of this optimization method is to provide designers with a proactive approach to the design of cross-section elements in order to (i) minimize the risk associated with restricted sight distance, (ii) balance the risk across the two carriageways of the highway, and (iii) reduce the expected collision frequency. A case study involving nine cross-sections that are parts of two major highway developments in British Columbia, Canada, was presented. The results showed that an additional reduction in collisions can be realized by incorporating the reliability component, P(nc) (denoting the probability of non-compliance), in the optimization process. The proposed approach results in reduced and consistent risk levels for both travel directions in addition to further collision reductions.

  17. Top Quark Pair Production Cross Section at the Tevatron

    SciTech Connect

    Peters, Reinhild Yvonne

    2015-09-25

    The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production cross sections using the full Tevatron data sample. In these proceedings, the latest results on inclusive and differential measurements of top-antitop quark production cross sections at the Tevatron are reported.

  18. Differential cross sections for positron-xenon elastic scattering

    SciTech Connect

    Marler, J. P.; Surko, C. M.; McEachran, R. P.; Stauffer, A. D.

    2006-06-15

    Absolute measurements of differential cross sections for the elastic scattering of positrons from xenon are made at 2, 5 and 8 eV using a trap-based beam and the technique of measuring scattering cross sections in a strong magnetic field. Calculations are carried out using the relativistic Dirac equations with a static plus polarization potential. Generally good absolute agreement is found between experiment and theory.

  19. A Cross-Sectional Comparison of Army Advertising Attributes

    DTIC Science & Technology

    1990-11-01

    that identifies the needs and characteristics of individuals in the Armys’ prime market , as well as their exposure to Army advertising . One way the Army...U.S. Army Research Institute for the Behavioral and Social Sciences N Research Report 1578 A Cross-Sectional Comparison I of Army Advertising ...62785A 791 2105 H01 11. TITLE (Include Security Classification) A Cross-Sectional Comparison of Army Advertising Attributes 12. PERSONAL AUTHOR(S

  20. Relativistic corrections in K-shell ionization cross sections

    SciTech Connect

    Sheth, C.V.

    1984-03-01

    Relativistic effects on a modified version of Rutherford's scattering cross section are considered up to first-order in the Born approximation for relativistic velocities in the binary-encounter approximation (BEA). The predicted cross sections with protons as projectile are lower than the previous theoretical values at low energies and are seen to be in better agreement with measurements. An approximate relativistic correction factor which accounts for orbital electrons only is compared with exact Dirac corrections, within the BEA model.

  1. Enhancing the optical cross section of quantum antenna

    NASA Astrophysics Data System (ADS)

    Liu, Jingfeng; Zhou, Ming; Ying, Lei; Chen, Xuewen; Yu, Zongfu

    2017-01-01

    The classical radio-frequency antenna theory indicates that large cross sections can be realized through directional radiation. In this paper, a similar principle is applied in quantum systems, in which quantum antennas, constructed by a cluster of quantum two-level systems, explore the collective excitation of two-level systems to realize large directivity. Both the optical cross section and the coherent time can be dramatically enhanced in free space, far exceeding the case of a single two-level system.

  2. Photoproduction models for total cross section and shower development

    NASA Astrophysics Data System (ADS)

    Cornet, Fernando; Garcia Canal, Carlos; Grau, Agnes; Pancheri, Giulia; Sciutto, Sergio

    2015-08-01

    A model for the total photoproduction cross section, based on the ansatz that resummation of infrared gluons limits the rise induced by QCD minijets in all the total cross-sections, is used to simulate extended air showers initiated by cosmic rays with the AIRES simulation program. The impact on common shower observables, especially those related with muon production, is analysed and compared with the corresponding results obtained with previous photoproduction models.

  3. Absorption cross sections of the ClO dimer

    NASA Technical Reports Server (NTRS)

    Huder, K. J.; DeMore, W. B.

    1995-01-01

    The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%.

  4. Associations between Parental Concern for Adolescent Weight and the Home Food Environment and Dietary Intake

    ERIC Educational Resources Information Center

    MacFarlane, Abbie; Crawford, David; Worsley, Anthony

    2010-01-01

    Objective: Examine associations between parental concern about adolescent weight and adolescent perceptions of their dietary intake, home food availability, family mealtime environment, and parents' feeding practices. Design: Cross-sectional study. Setting: Adolescents, aged 12-15 years from 37 secondary schools in Victoria, Australia, and their…

  5. Photodissociation cross section of ClOOCl at 330 nm.

    PubMed

    Jin, Bing; Chen, I-Cheng; Huang, Wen-Tsung; Lien, Chien-Yu; Guchhait, Nikhil; Lin, Jim J

    2010-04-15

    The photolysis rate of ClOOCl is crucial in the catalytic destruction of polar stratospheric ozone. In this work, we determined the photodissociation cross section of ClOOCl at 330 nm with a molecular beam and with mass-resolved detection. The photodissociation cross section is the product of the absorption cross section and the dissociation quantum yield. We formed an effusive molecular beam of ClOOCl at a nozzle temperature of 200 or 250 K and determined its photodissociation probability by measuring the decrease of the ClOOCl intensity upon laser irradiation. By comparing with a reference molecule (Cl(2)), of which the absorption cross section and dissociation quantum yield are well-known, we determined the absolute photodissociation cross section of ClOOCl at 330 nm to be (2.31 +/- 0.11) x 10(-19) cm(2) at 200 K and (2.47 +/- 0.12) x 10(-19) cm(2) at 250 K. Impurity interference has been a well-recognized problem in conventional spectroscopic studies of ClOOCl; our mass-resolved measurement directly overcomes such a problem. This measurement of the ClOOCl photolysis cross section at 330 nm is particularly useful in constraining its atmospheric photolysis rate, which in the polar stratosphere peaks near this wavelength.

  6. A genetic algorithm to reduce stream channel cross section data

    USGS Publications Warehouse

    Berenbrock, C.

    2006-01-01

    A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near-optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.

  7. Coulomb and nuclear effects in breakup and reaction cross sections

    NASA Astrophysics Data System (ADS)

    Descouvemont, P.; Canto, L. F.; Hussein, M. S.

    2017-01-01

    We use a three-body continuum discretized coupled channel (CDCC) model to investigate Coulomb and nuclear effects in breakup and reaction cross sections. The breakup of the projectile is simulated by a finite number of square integrable wave functions. First we show that the scattering matrices can be split in a nuclear term and in a Coulomb term. This decomposition is based on the Lippmann-Schwinger equation and requires the scattering wave functions. We present two different methods to separate both effects. Then, we apply this separation to breakup and reaction cross sections of 7Li+208Pb . For breakup, we investigate various aspects, such as the role of the α +t continuum, the angular-momentum distribution, and the balance between Coulomb and nuclear effects. We show that there is a large ambiguity in defining the Coulomb and nuclear breakup cross sections, since both techniques, although providing the same total breakup cross sections, strongly differ for the individual components. We suggest a third method which could be efficiently used to address convergence problems at large angular momentum. For reaction cross sections, interference effects are smaller, and the nuclear contribution is dominant above the Coulomb barrier. We also draw attention to different definitions of the reaction cross section which exist in the literature and which may induce small, but significant, differences in the numerical values.

  8. Krypton charge exchange cross sections for Hall effect thruster models

    SciTech Connect

    Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

    2013-04-28

    Following discharge from a Hall effect thruster, charge exchange occurs between ions and un-ionized propellant atoms. The low-energy cations produced can disturb operation of onboard instrumentation or the thruster itself. Charge-exchange cross sections for both singly and doubly charged propellant atoms are required to model these interactions. While xenon is the most common propellant currently used in Hall effect thrusters, other propellants are being considered, in particular, krypton. We present here guided-ion beam measurements and comparisons to semiclassical calculations for Kr{sup +} + Kr and Kr{sup 2+} + Kr cross sections. The measurements of symmetric Kr{sup +} + Kr charge exchange are in good agreement with both the calculations including spin-orbit effects and previous measurements. For the symmetric Kr{sup 2+} + Kr reaction, we present cross section measurements for center-of-mass energies between 1 eV and 300 eV, which spans energies not previously examined experimentally. These cross section measurements compare well with a simple one-electron transfer model. Finally, cross sections for the asymmetric Kr{sup 2+} + Kr {yields} Kr{sup +} + Kr{sup +} reaction show an onset near 12 eV, reaching cross sections near constant value of 1.6 A{sup 2} with an exception near 70-80 eV.

  9. General Constraints on Cross Sections Deduced from Surrogate Reactions

    SciTech Connect

    Younes, W

    2003-08-14

    Cross sections that cannot be measured in the laboratory, e.g. because the target lifetime is too short, can be inferred indirectly from a different reaction forming the same compound system, but with a more accessible beam/target combination (the ''surrogate-reaction'' technique). The reactions share the same compound system and a common decay mechanism, but they involve different formation processes. Therefore, an implicit constraint is imposed on the inferred cross section deduced from the measured surrogate-reaction data, through the common decay mechanism. In this paper, the mathematical consequences of this implicit constraint are investigated. General formulas are derived from upper and lower bounds on the inferred cross section, estimated from surrogate data in a procedure which does not require any modeling of the common decay process. As an example, the formulas developed here are applied to the case of the {sup 235}U(n,f) cross section, deduced from {sup 234}U(t,pf) surrogate data. The calculated bounds are not very tight in this particular case. However, by introducing a few qualitative assumptions about the physics of the fission process, meaningful bounds on the deduced cross section are obtained. Upper and lower limits for the cross-section ratio of the (n,f) reaction on the {sup 235}U isomer at E{sub x} = 77 eV relative to the (n,f) reaction on the ground state are also calculated. The generalization of this technique to other surrogate reactions is discussed.

  10. Electron cross-sections and transport in liquids and biomolecules

    NASA Astrophysics Data System (ADS)

    White, Ronald; Casey, M.; Cocks, D.; Konvalov, D.; Brunger, M. J.; Garcia, G.; Petrovic, Z.; McEachran, R.; Buckman, S. J.; de Urquijo, J.

    2016-09-01

    Modelling of electron induced processes in plasma medicine and radiation damage is reliant on accurate self-consistent sets of cross-sections for electrons in tissue. These cross-sections (and associated transport theory) must accurately account not only the electron-biomolecule interactions but also for the soft-condensed nature of tissue. In this presentation, we report on recent swarm experiments for electrons in gaseous water and tetrahydrofuran using the pulsed-Townsend experiment, and the associated development of self-consistent cross-section sets that arise from them. We also report on the necessary modifications to gas-phase cross-sections required to accurately treat electron transport in liquids. These modifications involve the treatment of coherent scattering and screening of the electron interaction potential as well as the development of a new transport theory to accommodate these cross-sections. The accuracy of the ab-initio cross-sections is highlighted through comparison of theory and experiment for electrons in liquid argon and xenon.

  11. Status of the Neutron Cross-Section Standards Database

    NASA Astrophysics Data System (ADS)

    Hambsch, Franz-Josef; Carlson, Allan D.; Vonach, Herbert

    2005-05-01

    A new evaluation of the neutron cross-section standards is now underway. This evaluation has been supported by the Working Party on International Evaluation Cooperation (WPEC), the Cross Section Evaluation Working Group (CSEWG), and an International Atomic Energy Agency Coordinated Research Program (CRP). The CRP has had the dominant role in producing these evaluations. An important goal is to produce the standards needed for the upcoming new ENDF/B-VII library. Since most neutron cross-section measurements are made relative to neutron cross-section standards, the standards evaluation is of crucial importance. The standard reactions to be evaluated are: H(n,n), 3He(n,p), 6Li(n,t), 10B(n,α), 10B(n,α1γ), C(n,n), Au(n,γ), 235U(n,f), and 238U(n,f). These standards should receive international acceptance to ensure that all evaluation projects use the same set of standards. The last complete evaluation of the standards dates back almost 20 years. In the meantime quite a number of new and improved measurements have occurred for the cross-section standards. International efforts are presently underway to update the experimental database and to improve the evaluation process. Due to the need for high-energy standards, the energy range is being extended to 200 MeV for some of the cross-section standards.

  12. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-07-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been reevaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding fifty years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  13. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-12-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  14. A cross-section plotting program (CSPP) for gridded (map) data

    USGS Publications Warehouse

    Wells, Richard B.; Faust, Charles R.; Mercer, James W.

    1976-01-01

    A FORTRAN program that prepares the Calcomp plotter tape for drawing cross-sections from gridded map data is described and documented. The program accepts gridded data of the form Z(x,y), where Z is the value at the grid intersection, (x,y). Up to 10 sets of Z(x,y) data for a given grid may be drawn on the same section. The positions of the end points of the cross-section are arbitrary. A bilinear interpolation scheme is used to obtain the Z(x,y) values along the specified cross-section. The program was designed to provide a visual aid for interpreting input and output data for two-dimensional (areal) finite-difference models used in aquifer analysis and geothermal reservoir simulation. The program should, however, be useful for drawing cross-sections of any multiple Z(x,y) gridded data. The computer code is called CSPP standing for Cross-Section Plotting Program.

  15. Temperature- and pressure-dependent absorption cross sections of gaseous hydrocarbons at 3.39 µm

    NASA Astrophysics Data System (ADS)

    Klingbeil, A. E.; Jeffries, J. B.; Hanson, R. K.

    2006-07-01

    The pressure- and temperature-dependent absorption cross sections of several neat hydrocarbons and multi-component fuels are measured using a 3.39 µm helium-neon laser. Absorption cross section measurements are reported for methane, ethylene, propane, n-heptane, iso-octane, n-decane, n-dodecane, JP-10, gasoline and jet-A with an estimated uncertainty of less than 3.5%. The experimental conditions range from 298 to 673 K and from 500 to 2000 Torr with nitrogen as the bath gas. An apparatus is designed to facilitate these measurements, and specific care is taken to ensure the compositional accuracy of the hydrocarbon/N2 mixtures. The absorption cross sections of the smallest hydrocarbons, methane and ethylene, vary with temperature and pressure. The cross sections of larger hydrocarbons show negligible dependence on pressure and only a weak dependence on temperature. The reported data increase the range of conditions and the number of hydrocarbons for which cross section measurements are available at the HeNe laser wavelength.

  16. Comparison of Performances of Scramjet-Driven Experimental DCW-MHD Generators with Different Cross-Section

    NASA Astrophysics Data System (ADS)

    Niwa, Naoyuki; Takahashi, Toru; Fujino, Takayasu; Ishikawa, Motoo

    The purpose of this study is to examine the influence of shape of cross-section of scramjet engine driven experimental DCW-MHD generator on generator performance by three-dimensional numerical analyses. We have designed the MHD generators with symmetric square and circular cross-section, based on the experimental MHD generator with asymmetric square cross-section. Under the optimum load condition, the electric power output becomes 26.6kW for the asymmetric square cross-section, 24.6kW for the symmetric square cross-section, and 22.4kW for the circular cross-section. The highest output is obtained for the experimental generator with asymmetric square cross-section. The difference of electric power output is induced by the difference of flow velocity and boundary layer thickness. For the generator with asymmetric square cross-section, the average flow velocity becomes the highest and the boundary layer becomes the thinnest. The compression wave is generated depending on the channel shape. The difference of flow velocity and boundary layer thickness is induced by the superposition of compression wave.

  17. Performing Neutron Cross-Section Measurements at RIA

    SciTech Connect

    Ahle, L E

    2003-05-20

    The Rare Isotope Accelerator (RIA) is a proposed accelerator for the low energy nuclear physics community. Its goal is to understand the natural abundances of the elements heavier than iron, explore the nuclear force in systems far from stability, and study symmetry violation and fundamental physics in nuclei. To achieve these scientific goals, RIA promises to produce isotopes far from stability in sufficient quantities to allow experiments. It would also produce near stability isotopes at never before seen production rates, as much as 10{sup 12} pps. Included in these isotopes are many that are important to stockpile stewardship, such as {sup 87}Y, {sup 146-50}Eu, and {sup 231}Th. Given the expected production rates at RIA and a reasonably intense neutron source, one can expect to make {approx} 10 {micro}g targets of nuclei with a half-life of {approx}1 day. Thus, it will be possible at RIA to obtain experimental information on the neutron cross section for isotopes that have to date only been determined by theory. There are two methods to perform neutron cross-section measurements, prompt and delayed. The prompt method tries to measure each reaction as it happens. The exact technique employed will depend on the reaction of interest, (n,2n), (n,{gamma}), (n,p), etc. The biggest challenge with this method is designing a detector system that can handle the gamma ray background from the target. The delayed method, which is the traditional radiochemistry method for determining the cross-section, irradiates the targets and then counts the reaction products after the fact. While this allows one to avoid the target background, the allowed fraction of target impurities is extremely low. This is especially true for the desired reaction product with the required impurity fraction on the order of 10{sup -9}. This is particularly problematic for (n,2n) and (n,{gamma}) reactions, whose reaction production cannot be chemically separated from the target. In either case, the

  18. Profile variation impact on FIB cross-section metrology

    NASA Astrophysics Data System (ADS)

    Cordes, Aaron; Bunday, Benjamin; Nadeau, Jim

    2012-03-01

    The focused ion beam (FIB) milling tool is an important component of reference metrology and process characterization, both as a supporting instrument for bulk sample preparation before forwarding to the transmission electron microscope (TEM) and other instruments and as an in situ measurement instrument using angled scanning electron microscopy. As features grow denser, deeper and more demanding, full-profile reference metrology is needed, and this methodology will only grow in importance. Thus, the ability to extract accurate dimensional and profile information out of the crosssectional faces produced by FIB milling is critical. For features that demonstrate perfect symmetry in the plane of the cross section, analyzing images and extracting metrology data are straightforward. However, for industrial materials, symmetry is not a safe assumption: as features shrink, the line edge and sidewall roughness increases as a percentage of the overall feature dimension. Furthermore, with the introduction of more complex architectures such as 3D memory and FinFETs, the areas of greatest interest, such as the intersections of wrap-around gates, cannot be assumed to be symmetrical in any given plane if cut placement is not precisely controlled. Therefore it is important to establish the exact location and repeatability of the cross-section plane, both in terms of coordinate placement and effective angle of the milled surface. To this end, we prepared designed-in line edge roughness samples in the Albany Nanotech facility using SEMATECH's AMAG6 metrology reticle. The samples were thoroughly characterized before being milled by a non-destructive, sidewall-scanning atomic force microscope (AFM). These samples are then milled and measured under varying process and setup parameters using a single-beam FIB with angled SEM. We established methodologies that allow precise alignment of the cut planes of slice-and-view FIB milling to 3D-AFM scan lines to compare repeated sections

  19. Modal characteristics in a single-nanowire cavity with a triangular cross section.

    PubMed

    Seo, Min-Kyo; Yang, Jin-Kyu; Jeong, Kwang-Yong; Park, Hong-Gyu; Qian, Fang; Ee, Ho-Seok; No, You-Shin; Leet, Yong-Hee

    2008-12-01

    In this study, the modal characteristics of a single-GaN nanowire cavity with a triangular cross section surrounded by air or located on a silicon dioxide substrate have been analyzed. Two transverse resonant modes, transverse electric-like and transverse magnetic-like modes, are dominantly excited for nanowire cavities that have a small cross-sectional size of <300 nm and length of 10 microm. Using the three-dimensional finite-difference time-domain simulation method, quality factors, confinement factors, single-mode conditions, and far-field emission patterns are investigated for a nanowire cavity as a function of one length of the triangular cross section. The results of these simulations provide information that will be vital for the design and development of efficient nanowire lasers and light sources in ultracompact nanophotonic integrated circuits.

  20. RIA R&D for Enabling Direct Neutron Cross-Section Measurements

    SciTech Connect

    Ahle, L E; Rusnak, B; Stoyer, M

    2003-08-22

    The expected production rates at RIA imply it should be possible to collect 10-{micro}g of a one-day half-life isotope. The amount of material should be sufficient to enable direct neutron cross-section measurements for many unstable isotopes. This capability is crucial for many of the stockpile stewardship and some of the astrophysical cross-section measurements. Enabling this capability at RIA requires the ability to harvest the desired isotopes, process highly radioactive material into targets, and irradiate targets with neutrons. This paper will discuss the changes and additions to the RIA complex that are necessary in order to enable direct neutron cross-section measurements. This will include a discussion of harvesting as well as a conceptual design for a co-located experimental facility with radiochemistry capability and a variable 'mono-energetic' neutron source.

  1. Cross-sectional study of malocclusion in Spanish children

    PubMed Central

    Montiel-Company, José M.; Bellot-Arcís, Carlos; Puertes-Fernández, Neus

    2014-01-01

    Objectives: This study was conducted to determine the orthodontic treatment need of the child population of the Valencia region of Spain, employing the DAI and the IOTN, to examine the relations between treatment need, socio-economic data and gender and to assess the diagnostic agreement between the two indices. Study Design: A cross-sectional descriptive study was conducted in a random representative sample of the schoolchild population of the Valencia region of Spain. The sample size was a total of 765 children aged 12 and 15 years at 39 schools. Results: The orthodontic treatment need assessed by the DAI was 21.7% at 12 years of age and 14.1% at 15 years. The orthodontic treatment need assessed by the IOTN DHC was 20.9% at 12 years of age and 12.7% at 15 years. The diagnostic agreement between the DAI and the modified IOTN was moderate, with Kappa scores of 0.426 at 12 years of age and 0.415 for the 15-year-old group. Conclusions: Approximately 20% of the children needed orthodontic treatment. Neither gender nor social class appeared to exert a significant influence on orthodontic treatment need. Key words:Orthodontics, epidemiology, children, malocclusion. PMID:23986013

  2. Grit and Work Engagement: A Cross-Sectional Study

    PubMed Central

    Asahi, Kentaro; Ishikawa, Yoshiki

    2015-01-01

    Grit, defined as perseverance of effort and consistency of interest, has attracted attention as a predictor of success in various fields beyond IQ and the Big Five personality dimension of Conscientiousness. The purpose of the current study was to examine previously uninvestigated questions regarding grit using a cross-sectional design among a large number of working adults in Japan. First, we tested geographical generalizability of associations between grit and orientations towards happiness by comparing previous studies in the U.S. and the current study in Japan. It was confirmed that orientation towards meaning rather than orientation towards engagement had a stronger positive correlation with grit in our sample of Japanese people. This result is inconsistent with previous studies in the U.S. Furthermore, the Big Five dimension of Openness to Experience was newly confirmed as having a positive association with grit. Second, we examined the association between grit and work engagement, which is considered as an outcome indicator for work performance. In this analysis, grit was a strong predictor for work performance as well as academic performance. PMID:26335001

  3. Radar-cross-section reduction of wind turbines. part 1.

    SciTech Connect

    Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K.; Allen, Steven E.; Clem, Paul Gilbert; Patitz, Ward E.

    2012-03-05

    In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report.

  4. ANSL-V: ENDF/B-V based multigroup cross-section libraries for Advanced Neutron Source (ANS) reactor studies

    SciTech Connect

    Ford, W.E. III; Arwood, J.W.; Greene, N.M.; Petrie, L.M.; Primm, R.T. III; Waddell, M.W.; Webster, C.C.; Westfall, R.M.; Wright, R.Q.

    1987-01-01

    Multigroup P3 neutron, P0-P3 secondary gamma ray production (SGRP), and P6 gamma ray interaction (GRI) cross section libraries have been generated to support design work on the Advanced Neutron Source (ANS) reactor. The libraries, designated ANSL-V (Advanced Neutron Source Cross-Section Libraries), are data bases in a format suitable for subsequent generation of problem dependent cross sections. The ANSL-V libraries are available on magnetic tape from the Radiation Shielding Information Center at Oak Ridge National Laboratory.

  5. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  6. Slow Wave Vane Structure with Elliptical Cross-Section Slots, an Analysis

    NASA Technical Reports Server (NTRS)

    Kosmahl, Henry G.

    1994-01-01

    Mathematical analysis of the wave equation in cylinders with elliptical cross-section slots was performed. Compared to slow wave structures with rectangular slots higher impedance and lower power dissipation losses are evident. These features could lead to improved designs of traveling wave magnetrons and gigahertz backward-wave oscillators as well as linear traveling wave tubes with relatively shallow slots.

  7. A Simple and Efficient Device for Demonstrating Cross-Sectional Anatomy of the Head

    ERIC Educational Resources Information Center

    Zamarioli, Ariane; Demaman, Aline Santos; Bim, Waldeci Roberto; Homem, Jefferson Mallman; Thomazini, Jose Antonio

    2010-01-01

    Described in this article is a novel device that facilitates study of the cross-sectional anatomy of the human head. In designing our device, we aimed to protect sections of the head from the destructive action of handling during anatomy laboratory while also ensuring excellent visualization of the anatomic structures. We used an electric saw to…

  8. Psychological Problems in Children with Cerebral Palsy: A Cross-Sectional European Study

    ERIC Educational Resources Information Center

    Parkes, Jackie; White-Koning, Melanie; Dickinson, Heather O.; Thyen, Ute; Arnaud, Catherine; Beckung, Eva; Fauconnier, Jerome; Marcelli, Marco; McManus, Vicki; Michelsen, Susan I.; Parkinson, Kathryn; Colver, Allan

    2008-01-01

    Objectives: To describe psychological symptoms in 8-12-year-old children with cerebral palsy; to investigate predictors of these symptoms and their impact on the child and family. Design: A cross-sectional multi-centre survey. Participants: Eight hundred and eighteen children with cerebral palsy, aged 8-12 years, identified from population-based…

  9. Factors Associated with Women's Antenatal Plans to Use a Baby Walker: A Cross Sectional Study

    ERIC Educational Resources Information Center

    Illingworth, Rachel; Kendrick, Denise; Collier, Jacqueline; Woods, Amanda; Wattse, Kim; Dewey, Michael; Chen, Chih-Mei

    2006-01-01

    Objective: The objective of these analyses was to explore maternal antenatal decisions about baby walker use, factors associated with these decisions and the relationship between antenatal plans to use a walker and postnatal walker use. Design: Cross sectional study. Setting: Mothers-to-be (n = 1174) participating in a cluster randomised…

  10. The Effect of Using Dynamic Mathematics Software: Cross Section and Visualization

    ERIC Educational Resources Information Center

    Kösa, Temel

    2016-01-01

    The main purpose of this study is to determine the effects of using dynamic mathematics software on pre-service mathematics teachers' ability to infer the shape of a cross section of a three-dimensional solid, as well as on their spatial visualization skills. The study employed a quasi-experimental design with a control group; the Purdue Spatial…

  11. PBL and Critical Thinking Disposition in Chinese Medical Students--A Randomized Cross-Sectional Study

    ERIC Educational Resources Information Center

    Du, XiangYun; Emmersen, Jeppe; Toft, Egon; Sun, Baozhi

    2013-01-01

    The purpose of this study was to explore the relationship of problem-based learning (PBL) and the development of critical thinking disposition (CT) and academic achievement in Chinese medical students using a cross-sectional randomized design. Medical students from China Medical University (CMU) were randomized to PBL or non-PBL teaching at the…

  12. Behaviour of Reinforced Concrete Columns of Various Cross-Sections Subjected to Fire

    NASA Astrophysics Data System (ADS)

    Balaji, Aneesha; Muhamed Luquman, K.; Nagarajan, Praveen; Madhavan Pillai, T. M.

    2016-09-01

    Fire resistance is one of the crucial design regulations which are now mandatory in most of the design codes. Therefore, a thorough knowledge of behaviour of structures exposed to fire is required in this aspect. Columns are the most vulnerable structural member to fire as it can be exposed to fire from all sides. However, the data available for fire resistant design for columns are limited. Hence the present work is focused on the effect of cross-sectional shape of column in fire resistance design. The various cross-sections considered are Square, Ell (L), Tee (T), and Plus (`+') shape. Also the effect of size and shape and distribution of steel reinforcement on fire resistance of columns is studied. As the procedure for determining fire resistance is not mentioned in Indian Standard code IS 456 (2000), the simplified method (500 °C isotherm method) recommended in EN 1992-1-2:2004 (E) (Eurocode 2) is adopted. The temperature profiles for various cross-sections are developed using finite element method and these profiles are used to predict fire resistance capability of compression members. The fire resistance based on both numerical and code based methods are evaluated and compared for various types of cross-section.

  13. The Longitudinal and Cross-Section Approach to a Descriptive Ethnography of Schooling.

    ERIC Educational Resources Information Center

    Johnson, Norris Brock

    A research design is described which refines standard classroom observation schedules and techniques in order to reveal the social organization of schooling as the environment for processes of cultural transmission. The author believes a combination of longitudinal and cross-sectional study of classrooms and grade levels is the most effective way…

  14. Determining the partial photoionization cross-sections of ethyl radicals.

    PubMed

    FitzPatrick, B L; Maienschein-Cline, M; Butler, L J; Lee, S-H; Lin, J J

    2007-12-13

    Using a crossed laser-molecular beam scattering apparatus, these experiments photodissociate ethyl chloride at 193 nm and detect the Cl and ethyl products, resolved by their center-of-mass recoil velocities, with vacuum ultraviolet photoionization. The data determine the relative partial cross-sections for the photoionization of ethyl radicals to form C2H5+, C2H4+, and C2H3+ at 12.1 and 13.8 eV. The data also determine the internal energy distribution of the ethyl radical prior to photoionization, so we can assess the internal energy dependence of the photoionization cross-sections. The results show that the C2H4++H and C2H3++H2 dissociative photoionization cross-sections strongly depend on the photoionization energy. Calibrating the ethyl radical partial photoionization cross-sections relative to the bandwidth-averaged photoionization cross-section of Cl atoms near 13.8 eV allows us to use these data in conjunction with literature estimates of the Cl atom photoionization cross-sections to put the present bandwidth-averaged cross-sections on an absolute scale. The resulting bandwidth-averaged cross-section for the photoionization of ethyl radicals to C2H5+ near 13.8 eV is 8+/-2 Mb. Comparison of our 12.1 eV data with high-resolution ethyl radical photoionization spectra allows us to roughly put the high-resolution spectrum on the same absolute scale. Thus, one obtains the photoionization cross-section of ethyl radicals to C2H5+ from threshold to 12.1 eV. The data show that the onset of the C2H4++H dissociative photoionization channel is above 12.1 eV; this result offers a simple way to determine whether the signal observed in photoionization experiments on complex mixtures is due to ethyl radicals. We discuss an application of the results for resolving the product branching in the O+allyl bimolecular reaction.

  15. Inclined Bodies of Various Cross Sections at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H.

    1958-01-01

    To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

  16. Electromagnetic Dissociation Cross Sections using Weisskopf-Ewing Theory

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne M.; Norbury, John W.

    2011-01-01

    It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes exist to predict the radiation environment, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate Electromagnetic Dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable, but mainly better agreement with data than the energy independent branching ratio. Furthermore, EMD cross sections for single neutron, proton, and alpha particle removal are calculated using WE theory and an energy independent branching ratio used in NUCFRG2 and compared to experimental data.

  17. Experience With the SCALE Criticality Safety Cross Section Libraries

    SciTech Connect

    Bowman, S.M.

    2000-08-21

    This report provides detailed information on the SCALE criticality safety cross-section libraries. Areas covered include the origins of the libraries, the data on which they are based, how they were generated, past experience and validations, and performance comparisons with measured critical experiments and numerical benchmarks. The performance of the SCALE criticality safety cross-section libraries on various types of fissile systems are examined in detail. Most of the performance areas are demonstrated by examining the performance of the libraries vs critical experiments to show general trends and weaknesses. In areas where directly applicable critical experiments do not exist, performance is examined based on the general knowledge of the strengths and weaknesses of the cross sections. In this case, the experience in the use of the cross sections and comparisons with the results of other libraries on the same systems are relied on for establishing acceptability of application of a particular SCALE library to a particular fissile system. This report should aid in establishing when a SCALE cross-section library would be expected to perform acceptably and where there are known or suspected deficiencies that would cause the calculations to be less reliable. To determine the acceptability of a library for a particular application, the calculational bias of the library should be established by directly applicable critical experiments.

  18. Theoretical Formalism To Estimate the Positron Scattering Cross Section.

    PubMed

    Singh, Suvam; Dutta, Sangita; Naghma, Rahla; Antony, Bobby

    2016-07-21

    A theoretical formalism is introduced in this article to calculate the total cross sections for positron scattering. This method incorporates positron-target interaction in the spherical complex optical potential formalism. The study of positron collision has been quite subtle until now. However, recently, it has emerged as an interesting area due to its role in atomic and molecular structure physics, astrophysics, and medicine. With the present method, the total cross sections for simple atoms C, N, and O and their diatomic molecules C2, N2, and O2 are obtained and compared with existing data. The total cross section obtained in the present work gives a more consistent shape and magnitude than existing theories. The characteristic dip below 10 eV is identified due to the positronium formation. The deviation of the present cross section with measurements at energies below 10 eV is attributed to the neglect of forward angle-discrimination effects in experiments, the inefficiency of additivity rule for molecules, empirical treatment of positronium formation, and the neglect of annihilation reactions. In spite of these deficiencies, the present results show consistent behavior and reasonable agreement with previous data, wherever available. Besides, this is the first computational model to report positron scattering cross sections over the energy range from 1 to 5000 eV.

  19. Improved empirical parameterization for projectile fragmentation cross sections

    NASA Astrophysics Data System (ADS)

    Mei, B.

    2017-03-01

    A new empirical parametrization is developed for calculating the fragment cross sections in projectile fragmentation reactions at high energies (>100 MeV/nucleon). The new parametrization, FRACS, consists of two main parts, i.e., the mass yield and the isobaric distribution, on the basis of previous parametrizations. The formalism for the mass yield is improved to describe the target and the projectile energy dependences observed in measured fragmentation cross sections. The parametrization of the isobaric distribution is also modified to reproduce recent experimental data. Furthermore, an additional term is proposed and first implemented in the FRACS parametrization to account for the evident odd-even staggering effect observed in many experimental cross sections. Comparisons with extensive cross sections measured in various fragmentation reactions reveal that FRACS is in much better agreement with experimental data and can reproduce measured cross sections in most cases within a factor of 1.84, which is a much smaller rms deviation as compared to that of the recent parametrization EPAX3.

  20. Electron Impact Ionization Cross Sections in Rb and Cs.

    NASA Astrophysics Data System (ADS)

    Reddish, T. J.; Lukomski, M.; Sutton, S.; Kedzierski, W.; McConkey, J. W.; Bartschat, K.; Bartlett, P. L.; Stelbovics, A. T.; Bray, I.

    2006-05-01

    We present a new atom trapping technique for determining absolute, total ionisation cross sections (TICS) out of an excited atom. The novel feature of this method is in utilizing Doppler cooling of neutral atoms to determine ionisation cross sections. This fluorescence-monitoring experiment, which is a variant of the `trap loss' technique, has enabled us to obtain the experimental electron impact ionisation cross sections out of the Cs 6^2P3/2 excited state between 7 - 400 eV. New CCC, R-Matrix with Pseudo-States (RMPS), and Born approximation single ionisation cross sections (SICS) are also presented for both the ground and excited states of Cs and Rb, and compared with the available experimental data. The comparison of the results reveals the importance of the autoionisation and multiple ionisation contributions to the TICS. The autoionisation contribution appears to be substantial for ionisation out of the Cs 6^2P and Rb 5^2P excited states; ˜ 3-4 larger than the direct ionisation contribution predicted by CCC at ˜ 30-50 eV. This surprising result shows the importance of multi-electron processes in determining the ionisation cross sections of heavy alkali atoms.

  1. Progress on FP13 Total Cross Section Measurements Capability

    SciTech Connect

    Ullmann, John Leonard; Couture, Aaron Joseph; Koehler, Paul E.; Mocko, Michal; Mosby, Shea Morgan; Wender, Stephen Arthur

    2016-09-26

    An accurate knowledge of the neutron capture cross section is important for many applications. Experimental measurements are important since theoretical calculations of capture have been notoriously difficult, with the ratio of measured to calculated cross sections often a factor of 2 or more in the 10 keV to 1 MeV region. However, a direct measurement of capture cannot be made on many interesting radioactive nuclides because of their short half-life or backgrounds caused by their nuclear decay. On the other hand, neutron transmission measurements of the total cross section are feasible for a wide range of radioactive nuclides since the detectors are far from the sample, and often are less sensitive to decay radiation. The parameters extracted from a total cross section measurement, which include the average resonance spacing, the neutron strength function, and the average total radiation width, (Γγ), provide tight constraints on the calculation of the capture cross section, and when applied produce much more accurate results. These measurements can be made using the intense epithermal neutron flux at the Lujan Center on relatively small quantities of target material. It was the purpose of this project to investigate and develop the capability to make these measurements. A great deal of progress was made towards establishing this capability during 2016, including setting up the flight path and obtaining preliminary results, but more work remains to be done.

  2. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    NASA Astrophysics Data System (ADS)

    Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; Blyth, D.; Bowman, J. D.; Calarco, J.; Crawford, C.; Craycraft, K.; Evans, D.; Fomin, N.; Fry, J.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Hamblen, J.; Hayes, C.; Kucuker, S.; Mahurin, R.; Maldonado-Velázquez, M.; Martin, E.; McCrea, M.; Mueller, P. E.; Musgrave, M.; Nann, H.; Penttilä, S. I.; Snow, W. M.; Tang, Z.; Wilburn, W. S.

    2015-05-01

    Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. Unfortunately, the pair correlation function g (r ) inferred from neutron scattering measurements of the differential cross section d/σ d Ω from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43 and 16.1 meV on liquid hydrogen at 15.6 K (which is dominated by the parahydrogen component) using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1 meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra nonequilibrium component of orthohydrogen. Liquid parahydrogen is also a widely used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. We describe our measurements and compare them with previous work.

  3. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    SciTech Connect

    Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; Blyth, D.; Bowman, J. D.; Calarco, J.; Crawford, C.; Craycraft, K.; Evans, D.; Fomin, N.; Fry, J.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Hamblen, J.; Hayes, C.; Kucuker, S.; Mahurin, R.; Maldonado-Velázquez, M.; Martin, E.; McCrea, M.; Mueller, P. E.; Musgrave, M.; Nann, H.; Penttilä, S. I.; Snow, W. M.; Tang, Z.; Wilburn, W. S.

    2015-05-08

    Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. Unfortunately, the pair correlation function g(r) inferred from neutron scattering measurements of the differential cross section dσ/dΩ from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43 and 16.1 meV on liquid hydrogen at 15.6 K (which is dominated by the parahydrogen component) using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1 meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra nonequilibrium component of orthohydrogen. Liquid parahydrogen is also a widely used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. Furthermore, we describe our measurements and compare them with previous work.

  4. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    DOE PAGES

    Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; ...

    2015-05-08

    Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. Unfortunately, the pair correlation function g(r) inferred from neutron scattering measurements of the differential cross section dσ/dΩ from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43 and 16.1 meV on liquid hydrogen at 15.6 K (which is dominated by the parahydrogen component)more » using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1 meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra nonequilibrium component of orthohydrogen. Liquid parahydrogen is also a widely used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. Furthermore, we describe our measurements and compare them with previous work.« less

  5. A simple and efficient device for demonstrating cross-sectional anatomy of the head.

    PubMed

    Zamarioli, Ariane; Demaman, Aline Santos; Bim, Waldeci Roberto; Homem, Jefferson Mallman; Thomazini, Jose Antonio

    2010-01-01

    Described in this article is a novel device that facilitates study of the cross-sectional anatomy of the human head. In designing our device, we aimed to protect sections of the head from the destructive action of handling during anatomy laboratory while also ensuring excellent visualization of the anatomic structures. We used an electric saw to create 15-mm sections of three cadaver heads in the three traditional anatomic planes and inserted each section into a thin, perforated display box made of transparent acrylic material. The thin display boxes with head sections are kept in anatomical order in a larger transparent acrylic storage box containing formaldehyde solution, which preserves the specimens but also permits direct observation of the structures and their anatomic relationships to each other. This box-within-box design allows students to easily view sections of a head in its anatomical position as well as to examine internal structures by manipulating individual display boxes without altering the integrity of the preparations. This methodology for demonstrating cross-section anatomy allows efficient use of cadaveric material and technician time while also giving learners the best possible handling and visualization of complex anatomic structures. Our approach to teaching cross-sectional anatomy of the head can be applied to any part of human body, and the value of our device design will only increase as more complicated understandings of cross-sectional anatomy are required by advances and proliferation of imaging technology.

  6. Inelastic cross sections for positron scattering from atomic hydrogen

    SciTech Connect

    Weber, M.; Hofmann, A.; Raith, W.; Sperber, W.; Jacobsen, F.; Lynn, K.G.

    1994-12-31

    Positronium formation (Ps) cross sections for positrons impinging on atomic hydrogen were measured in the impact energy range from 13eV to 255eV at the High Intensity Positron (HIP) beam at Brookhaven National Laboratory (BNL). The Ps-formation cross section was found to rise rapidly from the threshold at 6.8eV to a maximum value of (2.98 {plus_minus} 0.18) {times} 10{sup {minus}16} cm{sup 2} for {approx} 15eV positrons. By 75eV it drops below the detection limit of 0.17 {times} 10{sup {minus}16} cm{sup 2} which is the present level of statistical uncertainty. The experiment was modified to enable the measurement of doubly differential scattering cross sections.

  7. Pion Total Cross Section in Nucleon - Nucleon Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2009-01-01

    Total cross section parameterizations for neutral and charged pion production in nucleon - nucleon collisions are compared to experimental data over the projectile momentum range from threshold to 300 GeV. Both proton - proton and proton - neutron reactions are considered. Overall excellent agreement between parameterizations and experiment is found, except for notable disagreements near threshold. In addition, the hypothesis that the neutral pion production cross section can be obtained from the average charged pion cross section is checked. The theoretical formulas presented in the paper obey this hypothesis for projectile momenta below 500 GeV. The results presented provide a test of engineering tools used to calculate the pion component of space radiation.

  8. Cross-Sectional Transport Imaging in a Multijunction Solar Cell

    SciTech Connect

    Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

    2015-06-14

    Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

  9. Cross section versus time delay and trapping probability

    NASA Astrophysics Data System (ADS)

    Luna-Acosta, G. A.; Fernández-Marín, A. A.; Méndez-Bermúdez, J. A.; Poli, Charles

    2016-07-01

    We study the behavior of the s-wave partial cross section σ (k), the Wigner-Smith time delay τ (k), and the trapping probability P (k) as function of the wave number k. The s-wave central square well is used for concreteness, simplicity, and to elucidate the controversy whether it shows true resonances. It is shown that, except for very sharp structures, the resonance part of the cross section, the trapping probability, and the time delay, reach their local maxima at different values of k. We show numerically that τ (k) > 0 at its local maxima, occurring just before the resonant part of the cross section reaches its local maxima. These results are discussed in the light of the standard definition of resonance.

  10. Accurate universal parameterization of absorption cross sections III - light systems

    NASA Astrophysics Data System (ADS)

    Tripathi, R. K.; Cucinotta, F. A.; Wilson, J. W.

    1999-09-01

    Our prior nuclear absorption cross sections model [R.K. Tripathi, F.A. Cucinotta, J.W. Wilson, Nucl. Instr. and Meth. B 117 (1996) 347; R.K. Tripathi, J.W. Wilson, F.A. Cucinotta, Nucl. Instr. and Meth. B 129 (1997) 11] is extended for light systems ( A ⩽ 4) where either both projectile and target are light particles or one is light particle and the other is medium or heavy nucleus. The agreement with experiment is excellent for these cases as well. Present work in combination with our original model provides a comprehensive picture of absorption cross sections for light, medium and heavy systems. As a result the extended model can reliably be used in all studies where there is a need for absorption cross sections.

  11. Photoabsorption cross section of acetylene in the EUV region

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Judge, D. L.

    1985-01-01

    The measurement of the absolute photoabsorption cross sections of C2H2 in the 175-740 A region by means of a double ionization chamber is reported. The continuum background source is the synchrotron radiation emitted by the Wisconsin 240 MeV electron storage ring. It is found that the cross sections range from 2 to a maximum of 36 Mb. Two new Rydberg series are identified and the cross section data are applied in the analysis of various sum rules. From the rules, it is shown that the data of C2H2 in the 580-1088 A range may be too low, while the measured ionization transition moment may be too high.

  12. Phenomenological barrier parameters for total reaction cross section

    NASA Astrophysics Data System (ADS)

    Phookan, C. K.; Kalita, K.

    2016-01-01

    A phenomenological formula for total reaction cross section is introduced for reactions induced by three types of projectiles. The formula is based on Wong's formula in which, the barrier parameters are calculated from the Bass, Aage Winther and the Akyuz Winther potentials. For the reactions studied, we find that a uniform correction of the barrier parameters can account for the total reaction cross section satisfactorily. An unusually large deviation of the barrier parameters is noticed for the reaction {}8{B} + {}^{58}{Ni}. Arguments are given that most likely the radius of the proton halo nucleus {}8{B} is not well accounted by the above potentials and hence, an increase in the effective radius of {}^8{B} is proposed. Analysis is also presented for the reaction {}^{11}{Li} + {}^{208}{Pb} by making the assumption that its reduced total reaction cross section lies on the same trajectory as that for other halo reactions.

  13. New Resonance Parameter Evaluation of Cl Neutron Cross Sections

    SciTech Connect

    Sayer, R.O.; Guber, K.H.; Leal, L.C.; Larson, N.M.

    2005-05-24

    Better measurements and evaluations are needed for many elements where the existing evaluations or the underlying nuclear cross-section data are not sufficiently accurate for reliable calculation of criticality safety margins. Deficiencies in the existing ENDF/B-VI data evaluation for Cl led to our resonance parameter evaluation of Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Our evaluation takes advantage of recent high-resolution capture and transmission measurements at the Oak Ridge Electron Linear Accelerator (ORELA) as well as older total cross-section measurements at Karlsruhe (KFK) to extend the resolved resonance energy range to 1.2 MeV with much more accurate representation of the data than previous evaluations.

  14. Large cross sections for transitions with a small energy difference

    NASA Astrophysics Data System (ADS)

    McGuire, J. H.; Shakov, Kh. Kh.

    2009-05-01

    Cross sections for transitions between states with small differences in energy can be quite large. An example is the 1s-2p transition in atomic hydrogen caused by the impact of a fast charged particle [1] or a photon [3]. In such cases the actual cross section may become much larger than the simple geometric cross section. Such transitions are often difficult to observe in the laboratory. However, they can be evaluated numerically. This effect can be significant in analysis of astrophysical data, as pointed out by T. Nandi [2]. I discuss a few examples of calculations and give a physical explanation for this effect. [4pt] [1] J.H. McGuire, D. J. Land, J. G. Brennan and G. Basbas, Phys. Rev. A19, 2180 (1979).[0pt] [2] Kh.Kh. Shakov and J.H. McGuire, Phys. Rev. A67 033405 (2003). [0pt] [3] T. Nandi, private communication, 2008.

  15. Absorption Cross-Sections of Sodium Diatomic Molecules

    NASA Technical Reports Server (NTRS)

    Fong, Zeng-Shevan

    1985-01-01

    The absorption cross sections of sodium dimers were studied using a heat pipe over operating in the non-heat-pipe mode. Three wavelength regions were observed. They are in the red, the green-blue, and the near ultraviolet regions. The absorption cross section depends on the wavelength of the incident light. Representative peak values for the v"=0 progression in the red and green-blue regions are 2.59 A sup 2 (average value) and 11.77 A sup 2 (T sub ave=624 K). The value for the C greater than X transitions is several tenths A sup 2. The cross sections were measured from absorption spectra taken as a function of temperature.

  16. Reaction cross sections of the deformed halo nucleus 31Ne

    NASA Astrophysics Data System (ADS)

    Urata, Y.; Hagino, K.; Sagawa, H.

    2012-10-01

    Using the Glauber theory, we calculate reaction cross sections for the deformed halo nucleus 31Ne. To this end, we assume that the 31Ne nucleus takes the 30Ne+n structure. To take into account the rotational excitation of the core nucleus 30Ne, we employ the particle-rotor model (PRM). We compare the results to those in the adiabatic limit of PRM, that is, the Nilsson model, and show that the Nilsson model works reasonably well for the reaction cross sections of 31Ne. We also investigate the dependence of the reaction cross sections on the ground-state properties of 31Ne, such as the deformation parameter and the p-wave component in the ground-state wave function.

  17. 63Ni (n ,γ ) cross sections measured with DANCE

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Bredeweg, T. A.; Couture, A.; Göbel, K.; Heftrich, T.; Jandel, M.; Käppeler, F.; Lederer, C.; Kivel, N.; Korschinek, G.; Krtička, M.; O'Donnell, J. M.; Ostermöller, J.; Plag, R.; Reifarth, R.; Schumann, D.; Ullmann, J. L.; Wallner, A.

    2015-10-01

    The neutron capture cross section of the s -process branch nucleus 63Ni affects the abundances of other nuclei in its region, especially 63Cu and 64Zn. In order to determine the energy-dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4 π BaF2 array DANCE. The (n ,γ ) cross section of 63Ni has been determined relative to the well-known 197Au standard with uncertainties below 15%. Various 63Ni resonances have been identified based on the Q value. Furthermore, the s -process sensitivity of the new values was analyzed with the new network calculation tool NETZ.

  18. Neutron Capture Cross Section Calculations with the Statistical Model

    NASA Astrophysics Data System (ADS)

    Beard, Mary; Uberseder, Ethan; Wiescher, Michael

    2014-09-01

    Hauser-Feshbach (HF) cross sections are of enormous importance for a wide range of applications, from waste transmutation and nuclear technologies, to medical applications, and nuclear astrophysics. It is a well observed result that different nuclear input models sensitively affect HF cross section calculations. Less well-known however are the effects on calculations originating from model-specific implementation details (such as level density parameter, matching energy, backshift and giant dipole parameters), as well as effects from non-model aspects, such as experimental data truncation and transmission function energy binning. To investigate the effects or these various aspects, Maxwellian-averaged neutron capture cross sections have been calculated for approximately 340 nuclei. The relative effects of these model details will be discussed.

  19. Cross-sectional geometry of the dentary in bats.

    PubMed

    Dumont, Elizabeth R; Nicolay, Christopher W

    2006-01-01

    Bats exhibit remarkable diversity in dietary habits, with species specializing on insects, fruit, nectar, vertebrates and blood. Studies of larger mammals have shown that structural differences in dentary cross-sectional properties exist among species with different diets. Unfortunately, few of these studies have considered the role of phylogeny in shaping these apparent form-function associations. Here we ask whether a relationship exists between diet and dentary structure in bats when phylogenetic history is factored into the analysis. To answer this question, we compared results from phylogenetic generalized least squares (PGLS) and traditional (nonphylogenetic) regression analyses of dentary cross-sectional shape in frugivorous, nectarivorous, and insectivorous bats (253 individuals representing 72 species). Cross-sectional moments of inertia of the dentary between M(1) and M(2) were computed from bone densitometry scans of skeletal specimens. Traditional regressions of cross-sectional parameters against dentary length detected significant departures from isometry among frugivores. In contrast, PGLS analyses indicated that cross-sectional variables for each dietary group scaled with isometry. Thus, the allometric patterns illuminated by traditional statistics are linked to the phylogenetic structure of the sample. Identical patterns of significant differences in slopes and intercepts between frugivores and nectarivores emerged from both traditional and PGLS analyses. As predicted, the cross-sectional shape of the dentary in frugivores is consistent with increased resistance to torsion and bending, while that of nectarivores suggested a less resistant dentary. Although traditional and PGLS analyses yielded some similar results, the phylogenetic structure of a sample can drive apparent patterns of scaling and should be considered in comparative functional analyses.

  20. Stellar neutron capture cross sections of the Ba isotopes

    NASA Astrophysics Data System (ADS)

    Voss, F.; Wisshak, K.; Guber, K.; Käppeler, F.; Reffo, G.

    1994-11-01

    The neutron capture cross sections of 134Ba, 135Ba, 136Ba, and 137Ba were measured in the energy range from 5 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the 7Li (p,n)7 Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4π barium fluoride detector. The cross section ratios were determined with an overall uncertainty of ~3%, an improvement by factors of 5 to 8 compared to existing data. Severe discrepancies were found with respect to previous results. As a new possibility in time of flight experiments, isomeric cross section ratios could be determined for 135Ba, 136Ba, and 137Ba. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT=10 keV and 100 keV. These stellar cross sections were used in an s-process analysis. For the s-only isotopes 134Ba and 136Ba the Ns<σ> ratio was determined to 0.875+/-0.025. Hence, a significant branching of the s-process path at 134Cs can be claimed for the first time, in contrast to predictions from the classical approach. This branching yields information on the s-process temperature, indicating values around T8=2. The new cross sections are also important for the interpretation of barium isotopic anomalies, which were recently discovered in SiC grains of carbonaceous chondrite meteorites. Together with the results from previous experiments on tellurium and samarium, a general improvement of the Ns<σ> systematics in the mass range A=120-150 is achieved. This yields a more reliable separation of s- and r-process contributions for comparison with stellar observations, but reveals a 20% discrepancy with respect to the solar barium abundance.

  1. The solar neutrino capture cross section for 81Br

    NASA Astrophysics Data System (ADS)

    Haxton, W. C.

    1981-09-01

    The solar neutrino capture rate for the reaction 81Br + νe --> 81Kr + e- is calculated for the standard solar and weak interaction models. The results show that the capture cross section is dominated by the lowest Gamow-Teller transition to the metastable 1/2- (0.190 MeV) state in 81Kr. As the inverse electron capture rate for this transition has been measured recently, one can then argue that the cross section is well determined experimentally. Thus uncertainties in nuclear physics should not be an obstacle to the recently proposed 81Br radiochemical measurement of the 7Be solar neutrino flux. Present address.

  2. Charge Influence on Mini Black Hole's Cross Section

    NASA Astrophysics Data System (ADS)

    Caraça, R. S.; Malheiro, M.

    In this work we study the electric charge effect on the cross section production of charged mini black holes (MBH) in accelerators. We analyze the charged MBH solution using the fat brane approximation in the context of the ADD model. The maximum charge-mass ratio condition for the existence of a horizon radius is discussed. We show that the electric charge causes a decrease in this radius and, consequently, in the cross section. This reduction is negligible for protons and light-ions but can be important for heavy-ions.

  3. Uncertainty quantification in fission cross section measurements at LANSCE

    DOE PAGES

    Tovesson, F.

    2015-01-09

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  4. The 237U(n,f) Cross Section

    SciTech Connect

    Younes, W; Britt, H C; Wilhelmy, J B

    2003-03-03

    The purpose of this note is to combine existing information on the {sup 237}U(n,f) cross section to determine if some consistency can be obtained for the neutron induced fission excitation of {sup 237}U. The neutron induced fission cross section of the 6.8 day {sup 237}U was measured directly by McNally et al. in 1968 using the Pommard nuclear device test. At the same time critical assembly measurements were done at Los Alamos using the Flattop assembly. A previous measurement was also made at LASL in 1954 with two different neutron sources, each peaked near 200 keV. The results were 0.66 {+-} 0.10 b and 0.70 {+-} 0.07 b for the (n,f) cross section. More recently Younes and Britt have reanalyzed direct reaction charged particle data of Cramer and Britt that had determined the fission probability of the {sup 238}U compound nucleus as a function of nuclear excitation energy. They have combined fission probabilities with calculated neutron absorption cross sections, including corrections for the differences in angular momentum between the direct and neutron induced reactions. From this analysis they have extracted equivalent {sup 237}U(n,f) cross sections. The technique for extracting surrogate (n,f) cross sections from (t,pf) data has been demonstrated in a recent publication for the test case {sup 235}U(n,f). In addition to this experimental information, Lynn and Hayes have recently done a new theoretical study of the fission cross sections for a series of isotopes in this region. A summary plot of the data is shown in Fig. 1. Below 0.5 MeV the McNally, Cowan, and Younes-Britt results are in reasonable agreement. The average cross section in the Younes-Britt results, for En = 0.1 to 0.4 MeV, is 0.80 times the McNally values which is well within the errors of the McNally experiment. Above 0.5 MeV the McNally results diverge toward higher values. It should be noted that this divergence begins approximately at the {sup 237}Np threshold and that {sup 237}Np is the

  5. Ozone absorption cross section measurements in the Wulf bands

    NASA Technical Reports Server (NTRS)

    Anderson, Stuart M.; Hupalo, Peter; Mauersberger, Konrad

    1993-01-01

    A tandem dual-beam spectrometer has been developed to determine ozone absorption cross sections for 13 selected wavelengths between 750 and 975 nm at room temperature. The increasingly pronounced structure in this region may interfere with atmospheric trace gas transitions that are useful for remote sensing and complicate the measurement of aerosols. Ozone concentrations were determined by absorption at the common HeNe laser transition near 632.8 nm using the absolute cross section reported previously. The overall accuracy of these room temperature measurements is generally better than 2 percent. A synoptic near-IR spectrum scaled to these measurements is employed for comparison with results of previous studies.

  6. Cross-sectional imaging of the thyroid gland.

    PubMed

    Loevner, Laurie A; Kaplan, Summer L; Cunnane, Mary Elizabeth; Moonis, Gul

    2008-08-01

    Directed imaging is useful in assessing the thyroid gland. Nuclear scintigraphy reveals functional information about the thyroid gland, while cross-sectional imaging, including ultrasound, CT, and MR imaging provide important adjunctive anatomic information about the thyroid as well as about related structures in the neck, including the presence or absence of cervical and mediastinal lymphadenopathy, or extension of thyroid disease into adjacent soft tissues or the mediastinum. This article reviews the anatomy and physiology of the thyroid gland and addresses issues related to diseases affecting the thyroid gland, with an emphasis on neoplasms and the role of cross-sectional MR and CT imaging in the assessment of thyroid neoplasia.

  7. Absolute Photoionization Cross Sections of Two Cyclic Ketones: Cyclopentanone & Cyclohexanone.

    PubMed

    Price, Chelsea; Fathi, Yasmin; Meloni, Giovanni

    2017-02-23

    Absolute photoionization cross sections for cyclopentanone and cyclohexanone, as well as partial ionization cross sections for the dissociative ionized fragments, are presented in this investigation. Experiments are performed via a multiplexed photoionization mass spectrometer utilizing VUV synchrotron radiation supplied by the Advanced Light Source of Lawrence Berkeley National Laboratory. These results allow the quantification of these species that is relevant to investigate the kinetics and combustion reactions of potential biofuels. The CBS-QB3 calculated values for the adiabatic ionization energies agree well with the experimental values and the identification of possible dissociative fragments is discussed for both systems.

  8. Neutron removal cross section as a measure of neutron skin

    SciTech Connect

    Fang, D. Q.; Ma, Y. G.; Cai, X. Z.; Tian, W. D.; Wang, H. W.

    2010-04-15

    We study the relation between neutron removal cross section (sigma{sub -N}) and neutron skin thickness for finite neutron-rich nuclei using the statistical abrasion ablation model. Different sizes of neutron skin are obtained by adjusting the diffuseness parameter of neutrons in the Fermi distribution. It is demonstrated that there is a good linear correlation between sigma{sub -N} and the neutron skin thickness for neutron-rich nuclei. Further analysis suggests that the relative increase of neutron removal cross section could be used as a quantitative measure for neutron skin thickness in neutron-rich nuclei.

  9. Iterative cross section sequence graph for handwritten character segmentation.

    PubMed

    Dawoud, Amer

    2007-08-01

    The iterative cross section sequence graph (ICSSG) is an algorithm for handwritten character segmentation. It expands the cross section sequence graph concept by applying it iteratively at equally spaced thresholds. The iterative thresholding reduces the effect of information loss associated with image binarization. ICSSG preserves the characters' skeletal structure by preventing the interference of pixels that causes flooding of adjacent characters' segments. Improving the structural quality of the characters' skeleton facilitates better feature extraction and classification, which improves the overall performance of optical character recognition (OCR). Experimental results showed significant improvements in OCR recognition rates compared to other well-established segmentation algorithms.

  10. Cross section expansion for direct neutron radiative capture

    SciTech Connect

    Baye, D.

    2004-07-01

    Cross sections for neutron radiative capture multiplied by the relative velocity can be expressed as a Taylor expansion in powers of the relative energy. The coefficients of this expansion are expressed in the potential model as integrals involving solutions of the radial Schroedinger equation and of its inhomogeneous energy derivatives calculated at zero energy. Similarities and differences with charged-particle capture are emphasized. The {sup 12}C(n,{gamma}){sup 13}C capture reaction is treated as an example. The coefficients of the Taylor expansion lead to simple parametrizations of the experimental partial cross sections for neutron capture to each {sup 13}C bound state.

  11. Total cross section of electron scattering by fluorocarbon molecules

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Ushiroda, S.; Kondo, Y.

    2008-12-01

    A compact linear electron transmission apparatus was used for the measurement of the total electron scattering cross section at 4-500 eV. Total cross sections of chlorofluorocarbon (CCl2F2), hydrochlorofluorocarbon (CHClF2), perfluoropropane (C3F8), perfluoro-n-pentane (C5F12), perfluoro-n-hexane (C6F14) and perfluoro-n-octane (C8F18) were obtained experimentally and compared with the values obtained from a theoretical calculation and semi-empirical model calculation.

  12. abo-cross: Hydrogen broadening cross-section calculator

    NASA Astrophysics Data System (ADS)

    Barklem, P. S.; Anstee, S. D.; O'Mara, B. J.

    2015-07-01

    Line broadening cross sections for the broadening of spectral lines by collisions with neutral hydrogen atoms have been tabulated by Anstee & O'Mara (1995), Barklem & O'Mara (1997) and Barklem, O'Mara & Ross (1998) for s-p, p-s, p-d, d-p, d-f and f-d transitions. abo-cross, written in Fortran, interpolates in these tabulations to make these data more accessible to the end user. This code can be incorporated into existing spectrum synthesis programs or used it in a stand-alone mode to compute line broadening cross sections for specific transitions.

  13. Measurements of (n,{gamma}) cross sections with small samples

    SciTech Connect

    Koehler, P.E.; Kaeppeler, F.

    1995-02-05

    Neutron capture cross section data for certain isotopes of very small natural abundance are crucial for a better understanding of the s- and p-processes of nucleosynthesis. Also, recent work has shown that many previous (n,{gamma}) measurements need to be extended to lower neutron energies and that the accuracy of some previous data need to be improved. At Los Alamos we have developed a system for measuring (n,{gamma}) cross sections on samples as small as 1 mg. We give examples of measurements made with this apparatus and discuss the nuclear astrophysics motivation for these and future measurements.

  14. Measurements of (n,{gamma}) cross sections with small samples

    SciTech Connect

    Koehler, P.E.; Kaeppeler, F.

    1994-09-01

    Neutron capture cross section data for certain isotopes of very small natural abundance are crucial for a better understanding of the s- and p-processes of nucleosynthesis. Also, recent work has shown that many previous (n,{gamma}) measurements need to be extended to lower neutron energies and that the accuracy of some previous data need to be improved. At Los Alamos the authors have developed a system for measuring (n,{gamma}) cross sections on samples as small as 1 mg. They give examples of measurements made with this apparatus and discuss the nuclear astrophysics motivation for these and future measurements.

  15. Hadronic absorption cross sections of B{sub c}

    SciTech Connect

    Lodhi, M. A. K.; Akram, Faisal; Irfan, Shaheen

    2011-09-15

    The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

  16. SU-E-I-43: Photoelectric Cross Section Revisited

    SciTech Connect

    Haga, A; Nakagawa, K; Kotoku, J; Horikawa, Y

    2015-06-15

    Purpose: The importance of the precision in photoelectric cross-section value increases for recent developed technology such as dual energy computed tomography, in which some reconstruction algorithms require the energy dependence of the photo-absorption in each material composition of human being. In this study, we revisited the photoelectric cross-section calculation by self-consistent relativistic Hartree-Fock (HF) atomic model and compared with that widely distributed as “XCOM database” in National Institute of Standards and Technology, which was evaluated with localdensity approximation for electron-exchange (Fock)z potential. Methods: The photoelectric cross section can be calculated with the electron wave functions in initial atomic state (bound electron) and final continuum state (photoelectron). These electron states were constructed based on the selfconsistent HF calculation, where the repulsive Coulomb potential from the electron charge distribution (Hartree term) and the electron exchange potential with full electromagnetic interaction (Fock term) were included for the electron-electron interaction. The photoelectric cross sections were evaluated for He (Z=2), Be (Z=4), C (Z=6), O (Z=8), and Ne (Z=10) in energy range of 10keV to 1MeV. The Result was compared with XCOM database. Results: The difference of the photoelectric cross section between the present calculation and XCOM database was 8% at a maximum (in 10keV for Be). The agreement tends to be better as the atomic number increases. The contribution from each atomic shell has a considerable discrepancy with XCOM database except for K-shell. However, because the photoelectric cross section arising from K-shell is dominant, the net photoelectric cross section was almost insensitive to the different handling in Fock potential. Conclusion: The photoelectric cross-section program has been developed based on the fully self-consistent relativistic HF atomic model. Due to small effect on the Fock

  17. Differential Cross Sections for Proton-Proton Elastic Scattering

    NASA Technical Reports Server (NTRS)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  18. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L. F.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The ray is also drawn through the same leaf cross section with cell wall and air as the only optical mediums. The values of the reflection and transmission found from the ray tracing tests agree closely with the experimental results obtained using a Beckman Dk-2A Spectroreflector.

  19. Neutron capture cross section standards for BNL 325, Fourth Edition

    SciTech Connect

    Holden, N.E.

    1981-01-01

    This report evaluates the experimental data and recommends values for the thermal neutron cross sections and resonance integrals for the neutron capture reactions: /sup 55/Mn(n,..gamma..), /sup 59/Co(n,..gamma..) and /sup 197/Au(n,..gamma..). The failure of lithium and boron as standards due to the natural variation of the absorption cross sections of these elements is discussed. The Westcott convention, which describes the neutron spectrum as a thermal Maxwellian distribution with an epithermal component, is also discussed.

  20. Prevalence of Depressive Symptoms among Urban Adolescents of South India

    ERIC Educational Resources Information Center

    Mohanraj, Rani; Subbaiah, Karunanidhi

    2010-01-01

    Aim: This study aimed to find the prevalence of depressive symptoms among adolescents studying in schools in Chennai. Settings and Design: The study was a school based cross-sectional survey in which data were collected through a self-administered questionnaire from adolescents studying in classes X, XI and XII. Material: Beck Depression Inventory…

  1. Adolescent-Friendly Technologies as Potential Adjuncts for Health Promotion

    ERIC Educational Resources Information Center

    Dietrich, Janan J.; Coetzee, Jenny; Otwombe, Kennedy; Hornschuh, Stefanie; Mdanda, Sanele; Nkala, Busisiwe; Makongoza, Matamela; Tshabalala, Celokhuhle; Soon, Christine N.; Kaida, Angela; Hogg, Robert; Gray, Glenda E.; Miller, Cari L.

    2014-01-01

    Purpose: The purpose of this paper is to measure prevalence and predictors of mobile phone access and use among adolescents in Soweto, South Africa. Design/Methodology/Approach: The current study was an interviewer-administered, cross-sectional survey among adolescents 14-19 years living in a hyper-endemic human immunodeficiency virus (HIV)…

  2. Adolescent Sexual Education: Designing Curriculum That Works

    ERIC Educational Resources Information Center

    Quincy, Michael L.

    2009-01-01

    The purpose of this review paper, "Adolescent Sexual Education: Designing Curriculum That Works", is to present some basic curriculum necessities for developing an in-school sexual education program that results in decreasing the number of teenagers initiating sex, thus reducing the number of teen pregnancies and cases of sexually transmitted…

  3. Health effects of environmental exposure to cadmium: objectives, design and organization of the cadmibel study: a cross-sectional morbidity study carried out in Belgium from 1985 to 1989

    PubMed Central

    Lauwerys, Robert; Amery, Antoon; Bernard, Alfred; Bruaux, Pierre; Buchet, Jean-Pierre; Claeys, Françoise; De Plaen, Pierre; Ducoffre, Geneviève; Fagard, Robert; Lijnen, Paul; Nick, Laurence; Roels, Harry; Rondia, Désiré; Saint-Remy, Annie; Sartor, Francis; Staessen, Jan

    1990-01-01

    Cadmium is a cumulative environmental pollutant. For the general population mainly exposed by the oral route and through tobacco smoke inhalation, the kidney is the critical organ. Belgium is the principal producer of cadmium in Europe, and certain areas of the country are polluted by cadmium mainly because of past emissions from nonferrous industries. Preliminary studies carried out in one polluted area have suggested that environmental pollution might lead to an increased uptake of cadmium by the human body and possibly to health effects. Thus, a large-scale morbidity study has been initiated to assess the validity of this hypothesis. The present paper describes the protocol of this study. Its main objectives are to determine to what extent environmental exposure to cadmium resulting from industrial emissions may lead to accumulation of the metal in the human organism; to establish whether or not environmental exposure may induce renal changes and/or influence blood pressure; and to assess the acceptable internal dose of cadmium for the general population. The study design takes advantage of the fact that biological indicators of exposure, body burden, and early nephrotoxic effects of cadmium are available, which increase the likelihood of detecting a cause-effect relationship. PMID:2269233

  4. Acquiring credentials in bedside ultrasound: a cross-sectional survey

    PubMed Central

    Lewiss, Resa E; Saul, Turandot; Del Rios, Marina

    2013-01-01

    Objective Although there are training guidelines to credential emergency physicians in bedside ultrasound, many faculty groups have members who completed residency without a mandatory curriculum. These physicians are therefore required to learn bedside ultrasound while out in practice. The objective of this descriptive report is to illustrate a single academic facility's experience with acquiring credentials for emergency physicians in bedside ultrasound and the faculty's impressions on the motivators of and barriers to completion of the requirements. Design Cross-sectional survey. Setting Two urban teaching hospitals with a combined volume of 170 000 visits a year. Participants 41 emergency medicine attending physicians. Intervention Emergency medicine attending physicians underwent training and credentialing in the applications of aorta and pelvic ultrasound over a 9-month period. Outcome measure After the credentialing period, we conducted a survey to evaluate the physicians’ perceptions of this process. Results There were 41 faculty members during the credentialing survey period. 11 of the faculty members were exempt from ultrasound training. We asked attending physicians (N=41 exempt and non-exempt) to complete a web-based survey after the completion of the credentialing period. Questions about the potential barriers and incentives were listed and responders were asked to rank answers on a five-point Likert scale. Of the 31 respondents, 21 (67.7%) completed the credentialing requirements by the 9-month deadline. 19 of 26 emergency medicine residency trained physicians completed the requirements compared with 2/5 of those that were not emergency medicine residency trained. Our pilot study data suggest an association between fewer years in practice and completion of the requirements. Conclusions This is a report on a single academic institution's experience with a faculty credentialing programme in bedside ultrasound for physicians with a diversity of prior

  5. Capture cross sections for the astrophysical p process

    NASA Astrophysics Data System (ADS)

    Quinn, Stephen J.

    This dissertation includes the design and development of the Summing NaI (SuN) 4pi gamma-ray detector at the National Superconducting Cyclotron Laboratory to measure proton and alpha radiative capture reactions relevant in the astrophysical p process. Discussions of p-process nucleosynthesis, the relevant nuclear reaction theory, experimental details, and analysis procedures are included. All reaction measurements were performed at the Nuclear Science Laboratory of the University of Notre Dame. The commissioning experiments in both regular and inverse kinematics were done using known resonances in the 27Al(p,gamma)28Si and 58Ni(p,gamma) 59Cu reactions, and the results agree well with previous literature values. The success of these proof-of-principle measurements marks the first time that the gamma-summing technique has been implemented in inverse kinematics. Furthermore, in an effort to investigate the synthesis of the light p-process nuclei, the 74Ge(p,gamma)75As, 74Ge(alpha,gamma) 78Se, and 90,92Zr(alpha,gamma)94,96Mo reactions were measured and compared to theoretical calculations using the nuclear statistical model. It was found that the new 74Ge(p,gamma) 75As measurements cause an enhancement in the overproduction of 74Se in p-process models, and that the updated 90Zr(alpha,gamma) 94Mo reaction rate seems to confirms the p-process branching point at 94Mo. Finally, the 58Ni(alpha,gamma) 62Zn reaction was measured for its role in nucleosynthesis in type Ia supernovae. The measurements here lower the reaction rate used in astrophysical models, which leads to a 5% reduction in the calculated abundances of several isotopes. All of the measurements in this dissertation greatly reduce the uncertainty in the reaction cross section.

  6. Cross-sectional observations on the natural history of asthma.

    PubMed Central

    Neville, R G; McCowan, C; Hoskins, G; Thomas, G

    2001-01-01

    BACKGROUND: Asthma is a major health care problem that affects all ages. It is uncertain whether asthma is a single clinical entity or a grouping of separate clinical syndromes that share a common set of treatment guidelines. AIM: To observe the symptoms, treatment step, and health service utilisation of a population of patients throughout the United Kingdom (UK) listed on an asthma register. DESIGN OF STUDY: A cross-sectional study and clinical assessment of asthma patients. SETTING: A total of 12,203 patients from 393 general practices throughout the UK. METHOD: A database was used to observe the symptoms, treatment step, and health service utilisation of the asthma patients. RESULTS: Children aged up to four years had a distinctive profile of symptoms, including night time cough. They also experienced increased health service utilisation including a high hospital admission rate. Symptoms in adults became more common with increasing age. The pattern of symptoms in patients aged 45 years and over suggest many patients on asthma registers may have chronic obstructive pulmonary disease. Patients aged 16 to 30 years showed a different pattern of health service usage to those aged 5 to 15 years and 31 to 45 years, relying more on unscheduled use of health services rather than a review-based management plan. Patients aged 16 to 30 years used less anti-asthma medication than those aged 5 to 15 years and 31 to 45 years. CONCLUSIONS: Databases may be a useful tool with which to study the natural history of asthma, but there are problems with bias. Several clinical subgroups exist within the broad diagnosis label of asthma. Knowledge of how these subgroups of doctor-diagnosed asthma use health services may help clinicians to create individual care plans for groups of patients. PMID:11360699

  7. Fission, total and neutron capture cross section measurements at ORELA

    SciTech Connect

    Guber, K.H.; Spencer, R.R.; Leal, L.C.; Larson, D.C.; Dos Santos, G.; Harvey, J.A.; Hill, N.W.

    1998-08-01

    In support of the Nuclear Criticality Predictability Program established in response to the Defense Nuclear Facility Safety Board Recommendation 93-2, time-of-flight (TOF) measurements of the fission cross sections of {sup 233}U in the neutron energy range from 0.36 eV to several hundred keV have been initiated at the Oak Ridge Electron Linear Accelerator (ORELA). Also total and capture cross sections of Al, Cl, and K in the energy range from about 100 eV to several hundred keV have been measured or are under way. The goal is to derive accurate cross section representations for the materials involved in criticality calculations of fuel storage, transportation, etc., configurations. Additional high-resolution measurements of the total cross sections of {sup 233}U below a few keV neutron energy are being planned for 1998, as well as for the other involved material. Evaluated data files in ENDF-6 format will be processed into formats for use in criticality analysis and utilized in benchmark data testing. Finally the data will be submitted for inclusion in ENDF/B.

  8. Electron-silane scattering cross section for plasma assisted processes

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Kaur, Jaspreet; Antony, Bobby

    2017-03-01

    Silane is an important molecule with numerous applications to natural and technological plasmas. In such environments, where plasma assisted processes are vital, electron induced reactions play a major role in its chemistry. In view of this, electron induced scattering of molecules such as silane finds significance. This article reports a comprehensive study of electron impact cross sections for silane over a wide energy range. In particular, the emphasis is given in providing a complete dataset for various electron scattering events possible with silane. Such dataset is the need for the plasma modeling community. Moreover, literature survey shows that the cross section database for silane is fragmentary. To fill this void, we have computed the differential elastic, total, rotational excitation, and momentum transfer cross sections. Two formalisms that are reliable in their energy domain are employed to accomplish the task: the R-matrix method through QUANTEMOL-N at low incident energies and the spherical complex optical potential formalism at intermediate to high energies. Interestingly, the comparison of the present cross section exhibits a good concurrence with the previous data, wherever available.

  9. The total neutron cross section of liquid para-hydrogen

    NASA Astrophysics Data System (ADS)

    Celli, M.; Rhodes, N.; Soper, A. K.; Zoppi, M.

    1999-12-01

    We have measured, using the pulsed neutron source ISIS, the total neutron cross section of liquid para-hydrogen in the vicinity of the triple point. The experimental results compare only qualitatively with the results of the Young and Koppel theory. However, a much better agreement is found once modifications are included in the model which effectively take into account the intermolecular interactions.

  10. 45. Cross Section through the Power House, from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Cross Section through the Power House, from Construction Drawing 2042-F-23, entitled General Arrangement of Power Plant, Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  11. Cross Section; Half Longitudinal Section Showing Middle Wall Reinforced with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Section; Half Longitudinal Section Showing Middle Wall Reinforced with Arch; Part Long Section Showing Inside of External Side Wall; East Entrance; Part Side South External; Part Reflected Plan of Soffite of Floor; Part Reflected Plan of Soffite of Roof - Blenheim Covered Bridge, Spanning Schoharie River, North Blenheim, Schoharie County, NY

  12. Skin Diseases: Cross-section of human skin

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Skin Diseases Cross-section of human skin Past Issues / Fall 2008 Table of Contents For ... Logical Images, Inc. I n the areas of skin health and skin diseases, the NIH's National Institute ...

  13. 35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December 1941 by John Brackett, Consulting Engineer, to Public Works Department, Bureau of Yards & Docks. PW Drawing 3874-46, Y&D Drawing 190848. Scale 1/8' = 1'. - Naval Torpedo Station, Firing Pier, North end of Gould Island in Narragansett Bay, Newport, Newport County, RI

  14. Stellar neutron capture cross sections of the Lu isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.

    2006-01-15

    The neutron capture cross sections of {sup 175}Lu and {sup 176}Lu have been measured in the energy range 3-225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li(p,n){sup 7}Be reaction by bombarding metallic Li targets with a pulsed proton beam, and capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The cross sections were determined relative to the gold standard using isotopically enriched as well as natural lutetium oxide samples. Overall uncertainties of {approx}1% could be achieved in the final cross section ratios to the gold standard, about a factor of 5 smaller than in previous works. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 and 100 keV. These values are systematically larger by {approx}7% than those reported in recent evaluations. These results are of crucial importance for the assessment of the s-process branchings at A 175/176.

  15. Stellar neutron capture cross sections of the tin isotopes

    SciTech Connect

    Wisshak, K.; Voss, F.; Theis, C.; Kaeppeler, F.; Guber, K.; Kazakov, L.; Kornilov, N.; Reffo, G.

    1996-09-01

    The neutron capture cross sections of {sup 114}Sn, {sup 115}Sn, {sup 116}Sn, {sup 117}Sn, {sup 118}Sn, and {sup 120}Sn were measured in the energy range from 3 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the {sup 7}Li({ital p},{ital n}){sup 7}Be reaction using a pulsed proton beam. Capture events were registered with the Karlsruhe 4{pi} barium fluoride detector. The experiment was complicated by the small ({ital n},{gamma}) cross sections of the proton magic tin isotopes and by the comparably low enrichment of the rare isotopes {sup 114}Sn and {sup 115}Sn. Despite significant corrections for capture of scattered neutrons and for isotopic impurities, the high efficiency and the spectroscopic quality of the BaF{sub 2} detector allowed the determination of the cross-section ratios with overall uncertainties of 1{endash}2{percent}, five times smaller compared to existing data. Based on these results, Maxwellian averaged ({ital n},{gamma}) cross sections were calculated for thermal energies between {ital kT}=10 and 100 keV. These data are used for a discussion of the solar tin abundance and for an improved determination of the isotopic {ital s}- and {ital r}-process components. {copyright} {ital 1996 The American Physical Society.}

  16. RZ calculations for self shielded multigroup cross sections

    SciTech Connect

    Li, M.; Sanchez, R.; Zmijarevic, I.; Stankovski, Z.

    2006-07-01

    A collision probability method has been implemented for RZ geometries. The method accounts for white albedo, specular and translation boundary condition on the top and bottom surfaces of the geometry and for a white albedo condition on the outer radial surface. We have applied the RZ CP method to the calculation of multigroup self shielded cross sections for Gadolinia absorbers in BWRs. (authors)

  17. Cross Sections: No 6 Hold Section at Fr 178 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No 6 Hold Section at Fr 178 Looking Fwd, No 7 Hold Section at No 154 Looking Fwd, No 7 Hold Section at Fr 195 Looking Fwd Showing Trans 194, No 7 Hold Section at Fr 198 Looking Fwd - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  18. Cross Sections: No. 1 Hold section at Fr 24 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No. 1 Hold section at Fr 24 Looking Fwd, No 1 Hold Section at Fr 28 Looking Aft, No 2 Hold Section at Fr 48 Looking Aft, No 3 Hold Section at Fr 70 Looking Aft, No 4 Hold Section at Fr 90 Looking Aft - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  19. Electron Impact Ionization Cross Sections of n-decane

    NASA Astrophysics Data System (ADS)

    Jiao, Charles; Dejoseph, Charles; Garscadden, Alan

    2001-10-01

    The ionization and dissociation of hydrocarbon fuels with various plasma excitation schemes including pulsed high E/n discharges have been proposed to alleviate the problem of ignition in supersonic flow combustors and operations at high altitudes. The fuel which is also used for cooling, must not pyrolyse at operational temperatures. We have examined the electron ionization collision processes in n-decane using high resolution Fourier transform mass spectrometry that permits measurements of the 24 ions with cross sections larger than 10-19cm2. These generally fall into two broad categories: those with five or more carbon atoms whose ionization cross sections rise rapidly and essentially saturate within twice the appearance potential and those with four carbon atoms and less whose cross sections rise more gradually and are only saturating at energies above 70 eV. The total ionization cross section is large, rising to 7x10-16cm2. Studies were made with deuterated samples to distinguish the potential mechanisms in fragment ion induced dissociation of the parent gas. The results are compared with similar data for octane.

  20. Pion Charge Exchange Cross Section on Liquid Argon

    NASA Astrophysics Data System (ADS)

    Nelson, Kevin; LArIAT (FNAL T-1034) Collaboration

    2017-01-01

    The observation of neutrino oscillations allows charge parity violation to be probed in the neutrino sector. Detectors with high calorimetric energy resolution and high spatial resolution will provide precise measurements of neutrino oscillations. By measuring small π+/- cross sections for individual interaction channels, specifically charge exchange, we will make a measurement in the first of its kind on liquid Argon and demonstrate the physics capabilities of a relatively new detector technology: the Liquid Argon Time Projection Chamber (LAr TPC). This analysis will report on the thin slab cross section measurement technique and the Monte Carlo cross section measurements in the energy range of 0.2 - 1.0 GeV. This analysis is the first iteration in classifying charge exchange events from a sample of incident pions, and it aims to identify events in which a π0 was produced without any charged pions leaving the interaction vertex. We will also report on the methodology and efficiency of this algorithm in identifying particles and their interactions in liquid argon. This analysis will inform a future measurement of the π+/- charge exchange cross section on liquid argon. This work was supported in part by the National Science Foundation under Grant No. PHY-1359364.