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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. Evaluation of Community-Level Effects of Communities That Care on Adolescent Drug Use and Delinquency Using a Repeated Cross-Sectional Design.

    PubMed

    Rhew, Isaac C; Hawkins, J David; Murray, David M; Fagan, Abigail A; Oesterle, Sabrina; Abbott, Robert D; Catalano, Richard F

    2016-02-01

    The Communities That Care (CTC) prevention system has shown effects on reducing incidence and prevalence of problem behaviors among a panel of youth followed from 5th through 12th grade. The present report examines whether similar intervention effects could be observed using a repeated cross-sectional design in the same study. Data were from a community-randomized trial of 24 US towns. Cross-sectional samples of sixth, eighth, and tenth graders were surveyed at four waves. Two-stage ANCOVA analyses estimated differences between CTC and control communities in community-level prevalence of problem behaviors for each grade, adjusting for baseline prevalence. No statistically significant reductions in prevalence of problem behaviors were observed at any grade in CTC compared to control communities. Secondary analyses examined intervention effects within a “pseudo cohort” where cross-sectional data were used from sixth graders at baseline and tenth graders 4 years later. When examining effects within the pseudo cohort, CTC compared to control communities showed a significantly slower increase from sixth to tenth grade in lifetime smokeless tobacco use but not for other outcomes. Exploratory analyses showed significantly slower increases in lifetime problem behaviors within the pseudo cohort for CTC communities with high, but not low, prevention program saturation compared to control communities. Although CTC demonstrated effects in a longitudinal panel from the same community-randomized trial, we did not find similar effects on problem behaviors using a repeated cross-sectional design. These differences may be due to a reduced ability to detect effects because of potential cohort effects, accretion of those who were not exposed, and attrition of those who were exposed to CTC programming in the repeated cross-sectional sample. PMID:26462492

  3. Cross-Sectional and Longitudinal Comparisons of Adolescent Self-Esteem.

    ERIC Educational Resources Information Center

    Mullis, Ann K.; And Others

    1992-01-01

    Examined self-esteem of adolescents over three years of high school. Ninth graders (n=270) completed Coopersmith Self-Esteem Inventory for each of three years. Found grade level significantly related to self-esteem in longitudinal but not cross-sectional design. Mediational effects of gender and socioeconomic status were found to be minimal.…

  4. Cross-sectional and longitudinal comparisons of adolescent self-esteem.

    PubMed

    Mullis, A K; Mullis, R L; Normandin, D

    1992-01-01

    The purpose of this study was to examine the self-esteem of adolescents over three years of high school. The study was designed to allow for cross-sectional and longitudinal comparisons of adolescent self-esteem, including the effects of gender and socioeconomic status. Two hundred seventy ninth graders completed the Coopersmith Self-Esteem Inventory for each of three years. Grade level was found to be significantly related to self-esteem in the longitudinal but not the cross-sectional design. The mediational effects of gender and socioeconomic status were found to be minimal. Theoretical implications of these results are discussed, and implications for future research are indicated. PMID:1539501

  5. 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…

  6. 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…

  7. 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…

  8. 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

  9. Family leadership styles and adolescent dietary and physical activity behaviors: a cross-sectional study

    PubMed Central

    2012-01-01

    Background Transformational leadership is conceptualized as a set of behaviors designed to inspire, energize and motivate others to achieve higher levels of functioning, and is associated with salient health-related outcomes in organizational settings. Given (a) the similarities that exist between leadership within organizational settings and parenting within families, and (b) the importance of the family environment in the promotion of adolescent health-enhancing behaviors, the purpose of this exploratory study was to examine the cross-sectional relationships between parents’ transformational leadership behaviors and adolescent dietary and physical activity behaviors. Methods 857 adolescents (aged 13–15, mean age = 14.70 yrs) completed measures of transformational parenting behaviors, healthful dietary intake and leisure-time physical activity. Regression analyses were conducted to examine relationships between family transformational leadership and adolescent health outcomes. A further ‘extreme group analysis’ was conducted by clustering families based on quartile splits. A MANCOVA (controlling for child gender) was conducted to examine differences between families displaying (a) HIGH levels of transformational parenting (consistent HIGH TP), (b) LOW levels of transformational parenting (consistent LOW TP), and (c) inconsistent levels of transformational parenting (inconsistent HIGH-LOW TP). Results Results revealed that adolescents’ perceptions of family transformational parenting were associated with both healthy dietary intake and physical activity. Adolescents who perceived their families to display the highest levels of transformational parenting (HIGH TP group) displayed greater healthy eating and physical activity behaviors than adolescents who perceived their families to display the lowest levels of transformational parenting behaviors (LOW TP group). Adolescents who perceived their families to display inconsistent levels of transformational

  10. Prevalence and severity of micronutrient deficiency: a cross-sectional study among adolescents in Sri Lanka

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to determine the prevalence of micronutrient deficiencies (iron, zinc and folate) in Sri Lankan adolescent school children and the extent to which multiple micronutrient deficiencies exist in this population, a cross-sectional survey (2003) in the Galle district of the micronutrient and ant...

  11. Prevalence of child sexual abuse among adolescents in Geneva: results of a cross sectional survey.

    PubMed Central

    Halpérin, D. S.; Bouvier, P.; Jaffé, P. D.; Mounoud, R. L.; Pawlak, C. H.; Laederach, J.; Wicky, H. R.; Astié, F.

    1996-01-01

    OBJECTIVE--To measure the cumulative prevalence of child sexual abuse in a representative sample of the adolescent population of Geneva. DESIGN--Cross sectional survey with an anonymous self administered questionnaire centred on a factual description of sexual activities. SETTING--68 classes (17 schools) randomly selected from the 201 ninth grade classes of the public school system in Geneva. SUBJECTS--1193 adolescents aged 13-17 years, of whom 1116 (93.5%; 568 girls, 548 boys) consented to the study and returned completed questionnaires. RESULTS--192 (33.8%) girls and 60 (10.9%) boys reported having experienced at least one sexually abusive event. The prevalence of abuse involving physical contact was 20.4% (116 cases) among girls and 3.3% (18) among boys. The prevalence of abuse involving some form of penetration was 5.6% (32 cases) among girls and 1.1% (six) among boys. One third of the abused adolescents had experienced more than one abusive event and 46.5% (92/198) had experienced the first event before age 12. Abuse by a family member was reported by 20.5% (36/176) of abused girls and 6.3% (3/48) of abused boys. Abusers were known to victims in two thirds of cases. Ninety per cent of abusers were male and 35.3% (71/201) came from the victim's peer group. Over 80% of participants found the questionnaire interesting, clearly formulated, and useful. CONCLUSIONS--Child sexual abuse is a universal social phenomenon. Adolescents themselves can contribute to research and so help in the search for more efficient prevention and intervention strategies. PMID:8646043

  12. 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

  13. 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.

  14. Spinal pain and nutrition in adolescents - an exploratory cross-sectional study

    PubMed Central

    2010-01-01

    Background Spinal pain is an important health issue for adolescents resulting in functional limitations for many and increasing the risk of spinal pain in adulthood. Whilst human and animal studies suggest nutrition could influence spinal pain, this has not been investigated in adolescents. The objective of this exploratory cross sectional study was to evaluate associations between diet and adolescent spinal pain. Methods This study surveyed the spinal pain (neck and back) and nutrition (specific nutrients, broad food groups, diet quality and dietary pattern) of 1424 male and female adolescents at 14 years of age, in Western Australia. Results Back or neck pain were experienced by around half of the adolescents, with females more likely to experience spinal pain. Nutrition differed between sexes and deviated from optimal intakes. Vitamin B12, eggs, cereals and meat consumption were related to spinal pain in sex specific multivariate analyses including primary carer education level and adolescent waist girth and smoking. Conclusions The findings of this study suggest that certain aspects of diet may have an association with spinal pain in adolescence. PMID:20587071

  15. 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

  16. Predictors of sexual risk behaviour among adolescents from welfare institutions in Malaysia: a cross sectional study

    PubMed Central

    2014-01-01

    Background In welfare institutions, it is essential to address the health-related needs of adolescent populations who often engage in sexual activities. This study examines the association between individual and interpersonal factors concerning sexual risk behaviour (SRB) among adolescents in welfare institutions in Malaysia. Methods Data were derived from a cross-sectional study of 1082 adolescents in 22 welfare institutions located across Peninsular Malaysia in 2009. Using supervised self-administered questionnaires, adolescents were asked to assess their self-esteem and to complete questions on pubertal onset, substance use, family structure, family connectedness, parental monitoring, and peer pressure. SRB was measured through scoring of five items: sexual initiation, age of sexual debut, number of sexual partners, condom use, and sex with high-risk partners. Multivariate logistic regression analysis was used to examine the various predictors of sexual risk behaviour. Results The study showed that 55.1% (95%CI = 52.0-58.2) of the total sample was observed to practice sexual risk behaviours. Smoking was the strongest predictor of SRB among male adolescents (OR = 10.3, 95%CI = 1.25-83.9). Among females, high family connectedness (OR = 3.13, 95%CI = 1.64-5.95) seemed to predict the behaviour. Conclusion There were clear gender differences in predicting SRB. Thus, a gender-specific sexual and reproductive health intervention for institutionalised adolescents is recommended. PMID:25437631

  17. [Nursing needs of renal transplanted adolescents, a descriptive cross sectional study in a Swiss hospital].

    PubMed

    Kleinknecht, Michael; Neuhaus, Thomas J; Landolt, Markus A

    2009-06-01

    Various studies have demonstrated that the five-year graft survival of adolescents after renal transplantation is significantly lower than in children. This may be due to poor adherence to the post-transplant regime in adolescents. It has been shown that nurses can provide support to renal transplanted adolescents with positive effects on their adherence. The aim of this descriptive cross-sectional study was to gain knowledge about important topics of nurses' support to adolescent renal transplant patients. Twenty-seven adolescents between the ages of 12 and 18 years were interviewed and given a questionnaire based on a focus group discussion. Each of the provided 43 topics was rated on its importance. Results showed that responses corresponding to the judgment "very important" ranged from 20 % to 100 %. Information about illness and therapy was given highest priority, followed by the provision of support services as well as information and the support of planning and managing the personal way of living. These topics can be seen as a set of relevant variables that may be used for focused assessment, and for planning of nursing interventions. With regard to clinical practice it is necessary to develop nursing strategies and patient and family education programs based on the results of this study. PMID:19496030

  18. A Comparison of the Cross-Sectional and Sequential Designs when Assessing Longitudinal Mediation.

    PubMed

    Mitchell, Melissa A; Maxwell, Scott E

    2013-05-01

    Mediational studies are often of interest in psychology because they explore the underlying relationship between 2 constructs. Previous research has shown that cross-sectional designs are prone to biased estimates of longitudinal mediation parameters. The sequential design has become a popular alternative to the cross-sectional design for assessing mediation. This design is a compromise between the cross-sectional and longitudinal designs because it incorporates time in the model but has only 1 measurement each of X, M, and Y. As such, this design follows the recommendation of the MacArthur group approach, which stresses the importance of multiple waves of data for studying mediation. These 2 designs were compared to see whether the sequential design assesses longitudinal mediation more accurately than the cross-sectional design. Specifically, analytic expressions are derived for the bias of estimated direct and indirect effects as calculated from the sequential design when the actual mediational process follows a longitudinal autoregressive model. It was found that, in general, the sequential design does not assess longitudinal mediation more accurately than the cross-sectional design. As a result, neither design can be depended on to assess longitudinal mediation accurately. PMID:26741846

  19. 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. PMID:24853789

  20. 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

  1. Tentative evidence for striatal hyperactivity in adolescent cannabis-using boys: a cross-sectional multicenter fMRI study.

    PubMed

    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

  2. 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

  3. 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…

  4. 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

  5. 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

  6. Recreational Screen-Time Among Chinese Adolescents: A Cross-Sectional Study

    PubMed Central

    Jiang, Xiao-Xiao; Hardy, Louise L.; Ding, Ding; Baur, Louise A.; Shi, Hui-Jing

    2014-01-01

    Background Rapid urbanization in China has led to a proliferation of electronic entertainment media among youth. Prolonged screen time (ST; includes watching television and playing on computers, video game consoles, or mobile phones) is linked to poor health profiles. The aim of this study was to report recreational ST behaviors and ST correlates among Chinese adolescents living in two regions with different degrees of urbanization. Methods A cross-sectional, school-based survey (n = 3461 adolescents; aged 12–14 years old) living in inner-city Shanghai and a peri-urban region of Hangzhou. Students completed a questionnaire including family characteristics, daily ST, and information on family environment related to screen use. Recreational ST was categorized into two groups according to recommendations by the American Academy of Pediatrics (< or ≥2 h/day). Parents reported their own ST and also reported educational attainment as a proxy for socioeconomic status. Results ST was higher among boys than girls and on weekends than weekdays. Peri-urban girls were more likely to exceed 2 h/day ST compared to inner-city girls on weekends. Having a father with no university degree, mother’s TV viewing ≥2 h/day, no ST rules at home, and eating meals in front of the TV were associated with higher ST on both weekdays and weekends, and regional differences were found for weekend ST. Conclusions TV viewing and playing on the computer were the most prevalent ST behaviors among Chinese adolescents. Mobile phone playing was less prevalent but persistent throughout the week. More population-level surveillance and research is needed to monitor the trends in ST behaviors and to better understand the characteristics of those who are at risk. PMID:24930472

  7. Adolescent's perceptions and expectations of parental action on children's smoking and snus use; national cross sectional data from three decades

    PubMed Central

    Nilsson, Maria; Weinehall, Lars; Bergström, Erik; Stenlund, Hans; Janlert, Urban

    2009-01-01

    Background Parents play a vital role as children develop tobacco behaviours. Many parents feel unsure about their possibility to influence their teenager's lifestyle. Knowledge about young people's acceptance for parental intervention could increase parental involvement. The overall objective of this study was to explore adolescents' perceptions and expectations of parental action regarding children's smoking and snus use, and whether they have changed over time. To see if there were differences whether the adolescent was a tobacco user or not the adolescents' tobacco use was followed; and described to put the findings on their perceptions and expectations of parental action in a context. Methods The study used a repeated cross-sectional design, reporting Swedish national data from three decades. Data were collected in 1987, 1994 and 2003 by a questionnaire mailed to homes, in total to 13500 persons. The annual samples, which were random and national representative, consisted of 4500 young people aged 13, 15 and 17 yr, 1500 individuals per age group. The sampling and data collection procedures were done the same way during each survey. Chi2- tests were used to evaluate differences in distributions. Results Adolescents in all age groups became more positive toward parental action over time. In 2003, more then 86% of the adolescents, including both smokers and non-smokers, strongly supported parental action on their children's smoking by trying to persuade them not to smoke (94%), by not smoking themselves (87%) and by not allowing their children to smoke at home (86%). Both non-smokers and smokers supported the idea of parental action in a similar way. Reduced pocket money had a weak support (42%), especially from girls. Eighty-nine percent of the adolescents expected their parents to act against smoking and 85% against snus use. Smoking was stable at 8% in 1987 and 1994 but decreased to 4% in 2003. In 1987 the snus use prevalence was 4% and in 2003 it was 3%. Snus

  8. A cross-sectional study of factors related to gastrointestinal drug use in Korean adolescents.

    PubMed

    Lee, Kyung Eun; Hwang, Se Jung; Gwak, Hye Sun; Lee, Byung Koo; Bae, Seung Jin; Rhie, Sandy

    2013-10-01

    Adolescence is critical in the habituation of diverse lifestyles and is a base for future physical well-being. Although gastrointestinal disorders are frequently reported in adolescents, studies related to GI drug use or related factors in Korean adolescents are rare. Thus, this study examined Korean adolescents for the use of GI drugs for abdominal symptoms and analyzed the associated factors. This cross-sectional study was done with a total of 2,416 students who completed a given questionnaire. The health-related questions included GI medication intake, smoking, alcohol, caffeine, regular exercise, self-cognitive health level, GI symptom, non-steroidal anti-inflammatory drugs (NSAIDs) intake, and sleep problems. In questions about GI medication intake, drugs included digestives and antacids. And the intake of GI drugs more than once during the past 1 month was regarded as taking GI drugs. The sociodemographic questions included age, gender, grade, number of close friends, extracurricular activities, and school performance. The overall prevalence for taking GI drugs, including antacids and digestives, was 17.4 %. When students taking GI drugs were compared with those not taking GI drugs, the former group showed higher rates of girls (P < 0.001) and participants in extracurricular activities (P < 0.05) than the latter group. Factors including alcohol, caffeine, self-cognitive health levels, and GI symptoms showed statistical significance with the rate of GI drug intake. The rate of GI drug intake in NSAID users was 2.7 times higher than that in non-users (P < 0.001). The prevalence rate of every sleep problem was higher in students taking GI medications except snoring, witnessed apnea, and teeth grinding. From the multiple regression, it was found that gender (female), extracurricular activities, alcohol intake, self-cognitive health levels, NSAIDs intake, and nightmares were related factors to GI drug intake. Based on the results, it was conclude that

  9. A design method for entrance sections of transonic wind tunnels with rectangular cross sections

    NASA Technical Reports Server (NTRS)

    Lionel, L.; Mcdevitt, J. B.

    1975-01-01

    A mathematical technique developed to design entrance sections for transonic or high-speed subsonic wind tunnels with rectangular cross sections is discribed. The transition from a circular cross-section setting chamber to a rectangular test section is accomplished smoothly so as not to introduce secondary flows (vortices or boundary-layer separation) into a uniform test stream. The results of static-pressure measurements in the transition region and of static and total-pressure surveys in the test section of a pilot model for a new facility at the Ames Research Center are presented.

  10. 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

  11. Risk factors and psychosocial characteristics of potential problematic and problematic internet use among adolescents: A cross-sectional study

    PubMed Central

    2011-01-01

    Background Problematic internet use (PIU) is associated with a plethora of psychosocial adversities. The study objectives were to assess the determinants and psychosocial implications associated with potential PIU and PIU among adolescents. Methods A cross-sectional study design was applied among a random sample (n = 866) of Greek adolescents (mean age: 14.7 years). Self-completed questionnaires, including internet use characteristics, Young Internet Addiction Test, and Strengths and Difficulties Questionnaire, were utilized to examine the study objectives. Results Among the study population, the prevalence rates of potential PIU and PIU were 19.4% and 1.5%, respectively. Multinomial logistic regression indicated that male gender (Odds Ratio, OR: 2.01; 95% Confidence Interval, 95% CI: 1.35-3.00), as well as utilizing the internet for retrieving sexual information (OR: 2.52; 95% CI: 1.53-4.12), interactive game playing (OR: 1.85; 95% CI: 1.21-2.82), and socialization, including chat-room use (OR: 1.97; 95% CI: 1.36-2.86) and email (OR: 1.53; 95% CI: 1.05-2.24), were independently associated with potential PIU and PIU. Adolescents with potential PIU had an increased likelihood of concomitantly presenting with hyperactivity (OR: 4.39; 95% CI: 2.03-9.52) and conduct (OR: 2.56; 95% CI: 1.46-4.50) problems. Moreover, adolescent PIU was significantly associated with hyperactivity (OR: 9.96; 95% CI: 1.76-56.20) and conduct (OR: 8.39; 95% CI: 2.04-34.56) problems, as well as comprehensive psychosocial maladjustment (OR: 8.08; 95% CI: 1.44-45.34). Conclusions The determinants of potential PIU and PIU include accessing the internet for the purposes of retrieving sexual information, game playing, and socialization. Furthermore, both potential PIU and PIU are adversely associated with notable behavioral and social maladjustment among adolescents. PMID:21794167

  12. Obesity and elevated blood pressure among adolescents in Lagos, Nigeria: a cross-sectional study

    PubMed Central

    2012-01-01

    Background Childhood obesity and associated hypertension are major public health concerns globally. This study aimed to determine the prevalence of obesity and the associated risk of high blood pressure among Nigerian adolescents. Methods A cross-sectional school-based study of 885 apparently healthy adolescents was performed. Weight, height and blood pressure (BP) were measured using standard methods. Body mass index (BMI) was calculated and categorized by age, sex and percentile. Obesity and overweight were defined as: ≥ 95th and 85th to < 95th percentiles, respectively, for age, sex and height. Subjects were sub-categorized into age 10–13 years (A) and 14–17 years (B). The odds ratio for pre-hypertensive and hypertensive range BP by age and BMI were generated. Significance was set at P < 0.05. Results The prevalence of overweight and obesity were 13.8% and 9.4%, respectively. The prevalence of hypertensive range systolic BP in obese versus normal BMI females was 16% versus 23% (p=0.00) and 12.1% versus 6.4% (p=0.27) in males. The prevalence of hypertensive range diastolic BP in obese versus normal BMI females was 12% versus 1.4% (p=0.00) and 15.2% versus 3.5% (p=0.01) in males. BMI in group B was significantly associated with pre-hypertensive and hypertensive range systolic BP in overweight (P = 0.01, P = 0.002) and obese subjects (P = 0.00, P = 0.00) and with hypertensive range diastolic BP (P = 0.00) only in obese subjects. The only significant association in group A was between obesity and pre-hypertensive range diastolic BP (P = 0.00). Conclusion The prevalence of hypertensive range BP among obese Nigerian adolescents was high. Screening for childhood obesity and hypertension, and long-term follow-up of obese adolescents into adulthood are recommended. PMID:22867531

  13. 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. PMID:26717391

  14. Fast-food consumption and body mass index in children and adolescents: an international cross-sectional study

    PubMed Central

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

    2014-01-01

    Objective To investigate whether reported fast-food consumption over the previous year is associated with higher childhood or adolescent body mass index (BMI). Design Secondary analysis from a multicentre, multicountry cross-sectional study (International Study of Asthma and Allergies in Children (ISAAC) Phase Three). Subjects and methods Parents/guardians of children aged 6–7 completed questionnaires which included questions about their children's asthma and allergies, fast-food consumption, height and weight. Adolescents aged 13–14 completed the same questionnaire. The questionnaire asked “In the past 12 months, how often on average did you (your child) eat fast-food/burgers?” The responses were infrequent (never/only occasionally), frequent (once/twice a week) or very frequent (three or more times per week). A general linear mixed model was used to determine the association between BMI and fast-food consumption, adjusting for Gross National Income per capita by country, measurement type (whether heights/weights were reported or measured), age and sex. Results 72 900 children (17 countries) and 199 135 adolescents (36 countries) provided data. Frequent and very frequent fast-food consumption was reported in 23% and 4% of children, and 39% and 13% of adolescents, respectively. Children in the frequent and very frequent groups had a BMI that was 0.15 and 0.22 kg/m2 higher than those in the infrequent group (p<0.001). Male adolescents in the frequent and very frequent groups had a BMI that was 0.14 and 0.28 kg/m2 lower than those in the infrequent group (p<0.001). Female adolescents in the frequent and very frequent groups had a BMI that was 0.19 kg/m2 lower than those in the infrequent group (p<0.001). Conclusions Reported fast-food consumption is high in childhood and increases in adolescence. Compared with infrequent fast-food consumption, frequent and very frequent consumption is associated with a higher BMI in children. Owing to residual

  15. 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. PMID:26724066

  16. 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.

  17. 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

  18. Tracking the attentional blink profile: a cross-sectional study from childhood to adolescence

    PubMed Central

    Heim, Sabine; Benasich, April A.; Wirth, Nadine; Keil, Andreas

    2014-01-01

    This cross-sectional study is the first to examine the developmental trajectory of temporal attention control from childhood to adolescence. We used a rapid serial visual presentation paradigm, calling for the identification of two targets (T1 and T2) embedded in a distractor stream. In adults, manipulating the lag time within the target doublet typically leads to pronounced impairment in report for T2, when it follows T1 after approximately 200 ms, with one intervening distractor (lag 2); this is referred to as the attentional blink (AB). Participants, however, tend to identify T2 more often when the targets have occurred in a row (“lag-1 sparing”), or are separated by larger lag times, resulting in a hook-shaped accuracy profile. Here, we investigated the extent to which this AB profile undergoes systematic developmental changes in 204 students aged between 6 and 16 years (grades 1–10). T1–T2 lags varied from zero up to seven intervening distractors. Behavioral accuracy in younger children (grades 1–2) was found to follow a linear path, having its minimum at the earliest lag. Lag-1 sparing, accompanied by a relative accuracy loss in the AB interval, first appeared in grade 3, and became more robust in grade 4. From grades 5 to 6, the hook-shaped profile remained stable, with steady increases in overall performance up through the highest grades. This suggests that younger children’s performance is limited by processing speed, while from preadolescence on, children are increasingly able to identify rapid target sequences at the cost of an interference sensitive, higher control system. PMID:24337973

  19. Tracking the attentional blink profile: a cross-sectional study from childhood to adolescence.

    PubMed

    Heim, Sabine; Benasich, April A; Wirth, Nadine; Keil, Andreas

    2015-01-01

    This cross-sectional study is the first to examine the developmental trajectory of temporal attention control from childhood to adolescence. We used a rapid serial visual presentation paradigm, calling for the identification of two targets (T1 and T2) embedded in a distractor stream. In adults, manipulating the lag time within the target doublet typically leads to pronounced impairment in report for T2, when it follows T1 after approximately 200 ms, with one intervening distractor (lag 2); this is referred to as the attentional blink (AB). Participants, however, tend to identify T2 more often when the targets have occurred in a row ("lag-1 sparing"), or are separated by larger lag times, resulting in a hook-shaped accuracy profile. Here, we investigated the extent to which this AB profile undergoes systematic developmental changes in 204 students aged between 6 and 16 years (grades 1-10). T1-T2 lags varied from zero up to seven intervening distractors. Behavioral accuracy in younger children (grades 1-2) was found to follow a linear path, having its minimum at the earliest lag. Lag-1 sparing, accompanied by a relative accuracy loss in the AB interval, first appeared in grade 3, and became more robust in grade 4. From grades 5-6, the hook-shaped profile remained stable, with steady increases in overall performance up through the highest grades. This suggests that younger children's performance is limited by processing speed, while from preadolescence onwards, children are increasingly able to identify rapid target sequences at the cost of an interference sensitive, higher control system. PMID:24337973

  20. Prevalence and correlates of sleep disturbance and depressive symptoms among Chinese adolescents: a cross-sectional survey study

    PubMed Central

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

    2014-01-01

    Study objective To investigate the prevalence and the correlates of sleep disturbance and depressive symptoms among Chinese adolescents and to examine the association between the two problems. Design Cross-sectional survey. Participants A total of 3186 school students in grades 7–12 were sampled from the schools in Guangdong. A stratified-cluster random-sampling strategy was used to select the schools. Main outcome measures A self-administered questionnaire was used. The Pittsburgh Sleep Quality index (PSQI) was used to assess the occurrence of sleep disturbance, and the Center for Epidemiology Scale for Depression (CES-D) was used to identify whether individuals had depressive symptoms. Results The mean PSQI global score was 8.7 (±2.4) points, and 39.6% of the total sample had sleep disturbance. The mean CES-D score of students was 15.2 (±9.4) points, and 6.4% of the students had depressive symptoms. Additionally, girls and older adolescents were more likely to suffer from sleep disturbance, and the students who had depressive symptoms were 2.47 (95% CI 1.61 to 3.79) times more likely to suffer from sleep disturbance. Factors that were correlated with sleep disturbance and depressive symptoms were having a poor relationship with teachers, feeling lonely, suicide ideation and having run away from home. Conclusions Sleep disturbance was determined to be more prevalent among Chinese adolescents with depressive symptoms. Sleep disturbance and depressive symptoms were associated with each other, while school factors, family factors and psychosocial adjustment were comprehensively correlated with both. PMID:25079937

  1. Cross-sectional study on parental pro-drinking practices and adolescent alcohol drinking in Hong Kong

    PubMed Central

    Au, Wing Man; Ho, Sai Yin; Wang, Man Ping; Lo, Wing Sze; Tin, Sze Pui Pamela; Huang, Rong; Lam, Tai Hing

    2016-01-01

    Objectives To investigate the association between parental pro-drinking practices (PPDPs) and alcohol drinking in Hong Kong Chinese adolescents. Design A cross-sectional study. Setting 4 randomly selected secondary schools in Hong Kong. Participants 1738 students (mean age 14.6 years ±2.0, boys 67.8%). Main outcome measures Drinking status, drinking intention and exposure to 9 PPDPs (eg, seeing parents drunk, helping parents buy alcohol, encouraged to drink by parents) were reported by students. Logistic regression was used to compute adjusted ORs (AORs) of drinking and intention to drink by each PPDP and the number of PPDPs (0, 1–2, 3–4, 5 or above), adjusting for sociodemographic characteristics, parental drinking and school clustering. Results Nearly half (48.6%) of the students were ever-drinkers, 16.2% drank monthly (at least once per month) and 40.3% intended to drink in the next 12 months. Most PPDPs were significantly associated with ever drinking (AORs 1.40–6.20), monthly drinking (AORs 1.12–8.20) and intention to drink (AORs 1.40–5.02). Both ever and monthly drinking were most strongly associated with parental training of drinking capacity (ability to drink more without getting drunk) with AORs of 6.20 and 8.20 (both p<0.001), respectively. Adolescent drinking intention was most strongly associated with parental encouragement of drinking and training of drinking capacity with AORs of 3.19 and 5.02 (both p<0.001), respectively. Conclusions Exposure to PPDPs was associated with ever drinking, monthly drinking and drinking intention in Hong Kong Chinese adolescents. More studies, especially prospective studies, should be conducted to confirm these results, followed by interventional studies. PMID:26839012

  2. 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

  3. Dietary factors as the major determinants of overweight and obesity among Iranian adolescents. A cross-sectional study.

    PubMed

    Hatami, Monireh; Taib, Mohd Nasir Mohd; Jamaluddin, Rosita; Saad, Hazizi Abu; Djazayery, Abolghasem; Chamari, Maryam; Nazari, Mojgan

    2014-11-01

    This study investigated the determinants of overweight/obesity in adolescents. A cross-sectional survey was carried out on 1157 adolescents. Weight and height were measured. Information on socio-economic status (SES), dietary intakes, physical activity, and sedentary behaviours were collected by a self-administered questionnaire. Binary and multivariate binary logistic regressions were used to obtain the relationships and odds-ratios, respectively. The prevalence of overweight and obesity was higher among adolescents in low- or high-income families, adolescents whose mothers worked out of home, adolescents whose parents were both overweight, adolescents who watched a lot of TV or had excessive energy intake, adolescents with lower physical activity or lower intake of dietary fibre, those who skipped breakfast ≥ 4 times per week, and those with low and high fat intake. However, multiple logistic regression analysis showed that only energy intake was associated with increased odds and vegetables and fibre intake were associated with a reduction in the odds of being overweight (all p<0.05). Adolescents from middle SES showed a lower risk of overweight/obesity than low and high SES due to better dietary intakes and less sedentary behaviours. Therefore, in overweight/obesity prevention programs, adolescents with determined risk factors from families with low and high SES should receive attention. PMID:25068789

  4. 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

  5. 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. PMID:20728628

  6. Pain and pressure pain thresholds in adolescents with chronic fatigue syndrome and healthy controls: a cross-sectional study

    PubMed Central

    Winger, Anette; Kvarstein, Gunnvald; Wyller, Vegard Bruun; Sulheim, Dag; Fagermoen, Even; Småstuen, Milada Cvancarova; Helseth, Sølvi

    2014-01-01

    Objectives Although pain is a significant symptom in chronic fatigue syndrome (CFS), pain is poorly understood in adolescents with CFS. The aim of this study was to explore pain distribution and prevalence, pain intensity and its functional interference in everyday life, as well as pressure pain thresholds (PPT) in adolescents with CFS and compare this with a control group of healthy adolescents (HC). Methods This is a case–control, cross-sectional study on pain including 120 adolescents with CFS and 39 HCs, aged 12–18 years. We measured pain frequency, pain severity and pain interference using self-reporting questionnaires. PPT was measured using pressure algometry. Data were collected from March 2010 until October 2012 as part of the Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial. Results Adolescents with CFS had significantly lower PPTs compared with HCs (p<0.001). The Pain Severity Score and the Pain Interference Score were significantly higher in adolescents with CFS compared with HCs (p<0.001). Almost all adolescents with CFS experienced headache, abdominal pain and/or pain in muscles and joints. Moreover, in all sites, the pain intensity levels were significantly higher than in HCs (p<0.001). Conclusions We found a higher prevalence of severe pain among adolescents with CFS and lowered pain thresholds compared with HCs. The mechanisms, however, are still obscure. Large longitudinal population surveys are warranted measuring pain thresholds prior to the onset of CFS. Trial registration number Clinical Trials, NCT01040429; The Norwegian Study of Chronic Fatigue Syndrome in Adolescents: Pathophysiology and Intervention Trial (NorCAPITAL) http://www.clinicaltrials.gov. PMID:25287104

  7. 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…

  8. Characterization and design of tuned liquid dampers with floating roof considering arbitrary tank cross-sections

    NASA Astrophysics Data System (ADS)

    Ruiz, R. O.; Taflanidis, A. A.; Lopez-Garcia, D.

    2016-04-01

    A recently proposed new type of liquid mass damper, called Tuned Liquid Damper with Floating Roof (TLD-FR), is the focus of this paper. The TLD-FR consists of a traditional TLD (tank filled with liquid) with the addition of a floating roof. The sloshing of the liquid within the tank counteracts the motion of the primary structure it is placed on, offering the desired energy dissipation in the vibration of the latter, while the roof prevents wave breaking phenomena and introduces an essentially linear response. This creates a dynamic behavior that resembles other types of linear Tuned Mass dampers (TMDs). This investigation extends previous work of the authors to consider TLDs-FR with arbitrary tank cross-sections, whereas it additionally offers new insights on a variety of topics. In particular, the relationship between the tank geometry and the resultant vibratory characteristics is examined in detail, including the impact of the roof on these characteristics. An efficient mapping between these two is also developed, utilizing Kriging metamodeling concepts, to support the TLD-FR design. It is demonstrated that the overall behavior can be modeled through introduction of only four variables: the liquid mass, the frequency and damping ratio of the fundamental sloshing mode of the TLD-FR, and the efficiency index, which is related to the portion of the total mass that participates in this mode. Comparisons between TLDs-FR and other types of mass dampers are established through the use of the latter index. A design example is presented considering the dynamic response of a structure under stationary excitation. It is illustrated in this example that for complex tank cross-sectional geometries there exists a manifold of tank configurations leading to the same primary vibratory characteristics and therefore same efficiency of the TLD-FR. Considerations about excessive displacements of the roof can be then incorporated to indicate preference towards some of these

  9. 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. PMID:23713464

  10. Association between interleukin 1β and interleukin 10 concentrations: a cross-sectional study in young adolescents in Taiwan

    PubMed Central

    2013-01-01

    Background In adults, low circulating interleukin 10 (IL10) has been associated with obesity and type 2 diabetes. However, studies investigating IL10 in overweight and obese children have yielded conflicting results. The aim of this study was to investigate factors associated with serum IL10 concentration in young Chinese adolescents. Methods Young adolescents (n=325) ages 13.33±1.10 years were recruited into the cross-sectional study from 2010 to 2011. Parameters of obesity, individual components of MetS, iron status and serum IL10 were evaluated. Results Compared with their normal weight counterparts, overweight adolescents had lower serum IL10 but higher TNFα, nitric oxide (NO) and IL1β concentrations (all p<0.05). Obese adolescents had increased IL1β but decreased hepcidin concentration compared with normal weight (p<0.01 and p<0.05; respectively). A strong inverse relationship (p<0.0001) was found between IL10 and pro-inflammatory cytokines (TNFα and IL1β). Multivariate linear regression analysis showed serum IL1β was significantly correlated with IL10 (β=−0.156, p<0.0001). When overweight and obese adolescents were assessed separately from normal weight, only IL1β was inversely associated with serum IL10 (β=−0.231, p=0.0009). The association between IL10 and IL1β was weaker in adolescents with normal weight (β=−0.157, p=0.0002), after adjusting for gender, TNFα, IFNγ and NO. Conclusions Our study confirmed that low IL10 concentration is associated with overweight and obesity in young adolescents. We also demonstrated for the first time that pro-inflammatory cytokine IL1β is independently associated with IL10. A decline in IL10 concentration in overweight and obese adolescents may further contribute to the IL1β-mediated inflammatory environment associated with obesity. PMID:23941335

  11. Effects of the Communities That Care System on Cross-Sectional Profiles of Adolescent Substance Use and Delinquency

    PubMed Central

    Van Horn, M. Lee; Fagan, Abigail A.; Hawkins, J. David; Oesterle, Sabrina

    2014-01-01

    Introduction Adolescent substance use and delinquency are major public health problems. Although community–based prevention strategies have been recommended to produce population-level reductions in rates of substance use and delinquency, few models show evidence of effectiveness. Purpose To test the efficacy of a community–based prevention system, Communities That Care (CTC), in reducing community rates of problem behaviors, particularly effects on specific profiles of adolescent substance use and delinquency in eighth and tenth graders. Methods Twenty-four communities were randomized to CTC intervention or control groups. Data were collected from 14,099 eighth and tenth grade students in these communities using anonymous cross-sectional surveys in 2004 and 2010 and analyzed in 2012. Outcomes were four different profiles of self–reported substance use and delinquency in eighth grade and five profiles in tenth grade. Results In the cross-sectional 2010 data, there was no intervention effect on the probability of experimenting with substances or of substance use coupled with delinquent activities for either grade. However, tenth graders in intervention communities were significantly less likely to be alcohol users than those in control communities (OR=0.69, CI=0.48, 1.00). Conclusions Cross–sectional population surveys showed evidence of CTC effects in reducing tenth grade alcohol users but not experimenters. A community-wide reduction in adolescent alcohol use is important because alcohol is the most commonly used illicit substance during adolescence, and early initiation of alcohol use has been associated with alcohol-related disorders in adulthood. Failure to find hypothesized effects on experimenters qualifies these results. PMID:24986217

  12. Analysis and Design of Rectangular-Cross-Section Nozzles for Scramjet Engine Testing

    NASA Technical Reports Server (NTRS)

    Gaffney, Richard L., Jr.; Korte, John J.

    2004-01-01

    The flow in the square-cross-section Mach-6 nozzle used in the NASA Langley Research Center Arc-Heated Scramjet Test Facility has been analyzed using three-dimensional viscous CFD methods. The primary cause of the non-uniform flow exiting the nozzle is identified as cross-flow pressure gradients imposed on wall boundary layers. The cross-flow pressure gradients cause the boundary layer to roll up into counter-rotating vortex pairs on each of the four sides of the nozzle. These four vortex pairs produce significant non-uniformity in the nozzle-exit flow. In order to improve the quality of the test flow in the facility, two alternative nozzle designs (one axisymmetric and one rectangular with a 2-D contour) have been investigated. While the axisymmetric design produced the most uniform flow, the 2-D design also produced very good flow. The 2-D design was selected for further refinement, resulting in a new nozzle design which has been constructed and awaits calibration.

  13. Excessive TV viewing and cardiovascular disease risk factors in adolescents. The AVENA cross-sectional study

    PubMed Central

    2010-01-01

    Background Excessive television (TV) viewing might play an important role in the development of cardiovascular disease (CVD). The aim of this study was to examine the independent associations between TV viewing and CVD risk factors in adolescents. Methods A sample of 425 adolescents, aged 13- to 18.5-year-old, was included in this study. Body mass index (BMI), waist circumference (WC), glucose, total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein (apo) A-1, apo B-100, and lipoprotein(a) levels were determined. A composite CVD risk score was computed based on age-, sex-, sexual maturation- and race-standardized triglycerides, HDL-cholesterol, LDL-cholesterol and glucose. TV viewing was self-reported. Results Two hundred and twenty-five adolescents (53%) who spent >3 hrs/day watching TV were considered as the "high TV viewing" group. Ninety-nine adolescents (23%) from the total sample were classified as overweight according to International age- and sex-specific BMI values. The high TV viewing group had significantly less favorable values of HDL-cholesterol, glucose, apo A1 and CVD score, independent of age, sex, sexual maturation, race and weight status. There was a significant interaction effect of TV viewing × weight status (P = 0.002) on WC, and the negative influence of TV viewing on WC persisted in the overweight group (P = 0.031) but was attenuated in non-overweight adolescents (P > 0.05). Conclusion Excessive TV viewing seems to be related to an unfavorable CVD risk factors profile in adolescence. Reducing TV viewing in overweight adolescents might be beneficial to decrease abdominal body fat. PMID:20500845

  14. Psychosomatic complaints and sense of coherence among adolescents in a county in Sweden: a cross-sectional school survey

    PubMed Central

    Simonsson, Bo; Nilsson, Kent W; Leppert, Jerzy; Diwan, Vinod K

    2008-01-01

    Background Over the last five to ten years there has been an increase in psychosomatic complaints (PSC) in Swedish children. The objective of the study was to examine the relation between PSC and sense of coherence (SOC). Methods A cross-sectional school survey in the county of Västmanland, Sweden. All 16- and 19-year old adolescents present at school on the day of the survey were asked to complete a questionnaire in their classrooms during a one-lesson hour session under the supervision of their teachers. Totally 3,998 students in both private and public schools, studying in ninth grade elementary school or third grade secondary school participated. Results The results from our study show that there is a statistically significant relation between PSC and SOC among adolescents. It also shows that adolescents with a weak SOC score have more symptoms of PSC. Conclusion Our study indicates that SOC can help the adolescents to choose a coping strategy that is appropriate for the situation and thereby may prevent them from developing PSC. However, additional studies are needed to confirm our findings. PMID:18261203

  15. The emergence of sex differences in personality traits in early adolescence: A cross-sectional, cross-cultural study.

    PubMed

    De Bolle, Marleen; De Fruyt, Filip; McCrae, Robert R; Löckenhoff, Corinna E; Costa, Paul T; Aguilar-Vafaie, Maria E; Ahn, Chang-kyu; Ahn, Hyun-nie; Alcalay, Lidia; Allik, Jüri; Avdeyeva, Tatyana V; Bratko, Denis; Brunner-Sciarra, Marina; Cain, Thomas R; Chan, Wayne; Chittcharat, Niyada; Crawford, Jarret T; Fehr, Ryan; Ficková, Emília; Gelfand, Michele J; Graf, Sylvie; Gülgöz, Sami; Hřebíčková, Martina; Jussim, Lee; Klinkosz, Waldemar; Knežević, Goran; Leibovich de Figueroa, Nora; Lima, Margarida P; Martin, Thomas A; Marušić, Iris; Mastor, Khairul Anwar; Nakazato, Katsuharu; Nansubuga, Florence; Porrata, Jose; Purić, Danka; Realo, Anu; Reátegui, Norma; Rolland, Jean-Pierre; Schmidt, Vanina; Sekowski, Andrzej; Shakespeare-Finch, Jane; Shimonaka, Yoshiko; Simonetti, Franco; Siuta, Jerzy; Szmigielska, Barbara; Vanno, Vitanya; Wang, Lei; Yik, Michelle; Terracciano, Antonio

    2015-01-01

    Although large international studies have found consistent patterns of sex differences in personality traits among adults (i.e., women scoring higher on most facets), less is known about cross-cultural sex differences in adolescent personality and the role of culture and age in shaping them. The present study examines the NEO Personality Inventory-3 (McCrae, Costa, & Martin, 2005) informant ratings of adolescents from 23 cultures (N = 4,850), and investigates culture and age as sources of variability in sex differences of adolescents' personality. The effect for Neuroticism (with females scoring higher than males) begins to take on its adult form around age 14. Girls score higher on Openness to Experience and Conscientiousness at all ages between 12 and 17 years. A more complex pattern emerges for Extraversion and Agreeableness, although by age 17, sex differences for these traits are highly similar to those observed in adulthood. Cross-sectional data suggest that (a) with advancing age, sex differences found in adolescents increasingly converge toward adult patterns with respect to both direction and magnitude; (b) girls display sex-typed personality traits at an earlier age than boys; and (c) the emergence of sex differences was similar across cultures. Practical implications of the present findings are discussed. (PsycINFO Database Record (c) 2015 APA, all rights reserved). PMID:25603371

  16. 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. PMID:20974090

  17. Deliberate self-harm in adolescents aged 12-18: a cross-sectional survey of 18,104 students.

    PubMed

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

    2012-10-01

    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 adolescents aged 12-15 and 9,484 aged 15-18. DSH in the previous 12 months was reported by 3.3% (95% CI, 2.9-3.7) of junior and 4.3% (3.9%-4.7%) of senior high school respondents. The prevalence was more than four times as high among girls as among boys for both age groups. DSH was further strongly associated with having suicidal thoughts, having depression/anxiety symptoms, and having used recreational drugs. These associated factors were similar for both sexes and for both older and younger teenagers. A substantial minority of adolescents present with DSH, even among those aged 12-15. The prevalence of DSH in Japan was in the lower ranges of those reported for Western countries. The identified associated factors were not dissimilar from those reported in the West. PMID:22889157

  18. Design status of KOBRA for rare isotope production and direct measurements of radiative capture cross sections

    NASA Astrophysics Data System (ADS)

    Tshoo, K.; Chae, H.; Park, J.; Moon, J. Y.; Kwon, Y. K.; Souliotis, G. A.; Hashimoto, T.; Akers, C.; Berg, G. P. A.; Choi, S.; Jeong, S. C.; Kato, S.; Kim, Y. K.; Kubono, S.; Lee, K. B.; Moon, C.-B.

    2016-06-01

    KOBRA (KOrea Broad acceptance Recoil spectrometer and Apparatus) facility being designed at Rare Isotope Science Project in Korea will be utilized to produce rare isotope beams by employing multi-nucleon transfer reactions at about 20 MeV/nucleon for studies of nuclear structure. KOBRA will also provide high suppression of beam induced background for direct measurements of radiative-capture cross sections in the astrophysical energy range. The present design status of the KOBRA facility is reported along with a brief introduction to the facility. We have studied the feasibility of production of 44Ti based on the present design of KOBRA as an example, and calculated the intensity of 44Ti secondary beam, to be about 105 particles per second, for 1 pnA 46Ti primary beam with a carbon target for a beam energy of 25 MeV/nucleon. A Monte Carlo simulation with a ray-tracing code has been performed to show that recoil products 66Se are well separated from a 65As beam by KOBRA for the 65As (p, γ)66Se reaction at a beam energy of 1 MeV/nucleon.

  19. 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…

  20. Participation in Extracurricular Activities and Adolescent Adjustment: Cross-Sectional and Longitudinal Findings

    ERIC Educational Resources Information Center

    Darling, Nancy

    2005-01-01

    This study extends previous understanding of the association between adolescent extracurricular activity participation and adjustment by asking whether participation in school-based extracurricular activities is associated with lower substance use and depression, higher grades and academic aspirations, and more positive attitude toward school. In…

  1. Fitness level and body composition indices: cross-sectional study among Malaysian adolescent

    PubMed Central

    2014-01-01

    Background The importance of fitness level on the well-being of children and adolescent has long been recognised. The aim of this study was to investigate the fitness level of school-going Malaysian adolescent, and its association with body composition indices. Methods 1071 healthy secondary school students participated in the fitness assessment for the Malaysian Health and Adolescents Longitudinal Research Team (MyHEART) study. Body composition indices such as body mass index for age, waist circumference and waist height ratio were measured. Fitness level was assessed with Modified Harvard Step Test. Physical Fitness Score was calculated using total time of step test exercise and resting heart rates. Fitness levels were divided into 3 categories - unacceptable, marginally acceptable, and acceptable. Partial correlation analysis was used to determine the association between fitness score and body composition, by controlling age, gender, locality, ethnicity, smoking status and sexual maturation. Multiple regression analysis was conducted to determine which body composition was the strongest predictor for fitness. Results 43.3% of the participants were categorised into the unacceptable fitness group, 47.1% were considered marginally acceptable, and 9.6% were acceptable. There was a significant moderate inverse association (p < 0.001) between body composition with fitness score (r = -0.360, -0.413 and -0.403 for body mass index for age, waist circumference and waist height ratio, respectively). Waist circumference was the strongest and significant predictor for fitness (ß = -0.318, p = 0.002). Conclusion Only 9.6% of the students were fit. There was also an inverse association between body composition and fitness score among apparently healthy adolescents, with waist circumference indicated as the strongest predictor. The low fitness level among the Malaysian adolescent should necessitate the value of healthy lifestyle starting at a young age. PMID:25436933

  2. 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

  3. Overweight and its associated risk factors among urban school adolescents in Nepal: a cross-sectional study

    PubMed Central

    Baral, Kedar Prasad; Pradhan, Bandana; Poudyal, Amod Kumar

    2016-01-01

    Objectives The prevalence of non-communicable diseases is increasing in Nepal. Overweight and obesity are the major risk factors of many non-communicable diseases. Adolescence is a critical phase for development of overweight and obesity. Risk factors associated with overweight and obesity are not well understood in Nepal. The objective of the study was to identify the factors associated with overweight and obesity among adolescent students. Setting A cross-sectional descriptive study was carried out on higher secondary school students in the Lalitpur sub-metropolitan city, Nepal. Participants A random sample of 360 students aged 16–19 years from eight schools was included in the study. Results The prevalence of overweight among adolescent students was 12.2% (95% CI 8.9 to 15.5). Factors associated with being overweight included being male (adjusted OR (AOR) 2.64, 95% CI 1.18 to 4.88), studying in private school (AOR 2.10, 95% CI 1.03 to 4.28), high socioeconomic status family (AOR 4.77, 95% CI 1.36 to 16.72), watching television for more than 2 h per day (AOR 8.86, 95% CI 3.90 to 20.11), and consuming fruit four times or less per week (AOR 3.13, 95% CI 1.39 to 7.01). There was no statistically significant association between adolescent overweight and age, ethnicity, mother's education level, mother's occupation, number of siblings or family type. Conclusions Socioeconomic status, watching television for a longer time and consuming less fruit are major risk factors for overweight among adolescents in Nepal. Interventions are needed to increase awareness about the risk factors of adolescent overweight and obesity to decrease prevalence of overweight-associated non-communicable diseases. PMID:27207624

  4. 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

  5. The prevalence and correlates of behavioral risk factors for cardiovascular health among Southern Brazil adolescents: a cross-sectional study

    PubMed Central

    2012-01-01

    Background The adoption of health-related behaviors is an important part of adolescence. This study examined the prevalence and correlates of the isolated and simultaneous presence of behavioral risk factors for cardiovascular health (BRFCH) among adolescents in Curitiba, Southern Brazil. Methods A cross-sectional study was performed with 1,628 adolescents (aged 11-17.9 years, 52.5% males) that were randomly selected from 44 public schools. Self-report instruments were used to assess the variables. Six BRFCH were analyzed: insufficiently active, excessive TV watching, current alcohol and tobacco use, daily soft drinks consumption and inadequate fruit and vegetable consumption. Sociodemographic and behavioral variables were studied as possible correlates of the presence of BRFCH. Results The BRFCH with the highest prevalence were insufficiently active (50.5%, 95% confidence interval [95% CI]: 48.0-52.9) and daily soft drinks consumption (47.6%, 95% CI: 45.1-50.0). Approximately 30% of the adolescents presented three or more BRFCH simultaneously. Girls, adolescents who did not participate in organized physical activity, and who used computer/video games daily were the main high-risk subgroups for insufficiently active. Boys and those who used computer/video games daily were the high-risk subgroups for daily soft drinks consumption. For excessive TV watching, we identified to be at risk those who were from a high economic class, unemployed, and who used computer/video games daily. For current alcohol use, we identified older adolescents, who were from a high economic class and who worked to be at risk. Older adolescents, who worked and who spent little active time during a physical education class were the high-risk subgroups for current tobacco use. For inadequate fruit and vegetable consumption, we identified those who did not participate in organized physical activity to be at risk. Older adolescents, who were from a high economic class, who did not participate

  6. Anthropometric measurements for the prediction of the metabolic syndrome: a cross-sectional study on adolescents and young adults from southern india

    PubMed Central

    Vasan, S K; Thomas, N; Christopher, S; Geethanjali, F S; Paul, T V; Sanjeevi, C B

    2011-01-01

    Objectives To determine which anthropometric measurement correlates best with the metabolic abnormalities associated with the metabolic syndrome in adolescents and young adults. Design Cross-sectional study. Setting Schools, high schools and universities. Participants 1359 adolescents and young adults aged 14–25 years. Main outcome measures Anthropometric predictors of metabolic abnormalities as classified by International Diabetes Federation definition. Results The waist circumference (OR 1.56, 95% CI 1.0 to 2.43: p≤0.01) and the abdominal skin fold thickness (OR 1.44, 95% CI 1.02 to 2.04, p≤0.01) above the third quintile cut-offs were found to be significantly associated with metabolic abnormalities. The sensitivity of either one of these measurements in predicting metabolic abnormalities was 66.1% with a negative predictive value of 82.8%. Hyperglycaemia was significantly associated with an abdominal skin fold thickness over the fourth quintile alone (OR 1.63, 95% CI 1.24 to 2.1). All the anthropometric measurements correlated well with elevated triglycerides and hypertension. Conclusions In a large community-based cross-sectional survey of subjects aged 14–25 years, the waist circumference and the abdominal skin fold thickness are important predictors of the metabolic abnormalities associated with metabolic syndrome. This simple clinical tool may help in a primary care setting to identify subjects who require a further biochemical evaluation and would considerably reduce the cost of unwarranted testing. PMID:27325971

  7. Happiness and health behaviors in South Korean adolescents: a cross-sectional study

    PubMed Central

    2016-01-01

    OBJECTIVES: We examined the associations between happiness and a wide range of health behaviors in South Korean adolescents. METHODS: Study data were derived from the ninth Korea Youth Risk Behavior Web-based Survey administered from June to July 2013. In addition to happiness levels, the questionnaire included items on sociodemographics and health-related lifestyle factors (smoking, drinking, eating breakfast, fruit and vegetable consumption, physical activity, sedentary behavior, and hours of sleep). RESULTS: The multivariate analysis revealed that higher levels of happiness were associated with not smoking or drinking, eating breakfast, eating fruits daily, vegetable consumption, participating in at least 60 minutes of physical activity a day, avoiding sedentary behavior, and hours of sleep. Additionally, sex differences were found in relationships between happiness and eating fruit daily, participation in physical activity, and sedentary behavior. CONCLUSIONS: These results encourage public health professionals to consider the psychological aspects of adolescent life in working to improve their health behaviors and outcomes. PMID:27283139

  8. Adolescent substance use and peer use: a multilevel analysis of cross-sectional population data

    PubMed Central

    2013-01-01

    Background Limited evidence exists concerning the importance of social contexts in adolescent substance use prevention. In addition to the important role schools play in educating young people, they are important ecological platforms for adolescent health, development and behaviors. In this light, school community contexts represent an important, but largely neglected, area of research in adolescent substance use and prevention, particularly with regard to peer influences. This study sought to add to a growing body of literature into peer contexts by testing a model of peer substance use simultaneously on individual and school community levels while taking account of several well established individual level factors. Method We analyzed population-based data from the 2009 Youth in Iceland school survey, with 7,084 participants (response rate of 83.5%) nested within 140 schools across Iceland. Multilevel logistic regression models were used to analyze the data. Results School-level peer smoking and drunkenness were positively related to adolescent daily smoking and lifetime drunkenness after taking account of individual level peer smoking and drunkenness. These relationships held true for all respondents, irrespective of socio-economic status and other background variables, time spent with parents, academic performance, self-assessed peer respect for smoking and alcohol use, or if they have substance-using friends or not. On the other hand, the same relationships were not found with regard to individual and peer cannabis use. Conclusions The school-level findings in this study represent context effects that are over and above individual-level associations. This holds although we accounted for a large number of individual level variables that studies generally have not included. For the purpose of prevention, school communities should be targeted as a whole in substance use prevention programs in addition to reaching to individuals of particular concern. PMID:23902743

  9. A cross-sectional analysis of video games and attention deficit hyperactivity disorder symptoms in adolescents

    PubMed Central

    Chan, Philip A; Rabinowitz, Terry

    2006-01-01

    Background Excessive use of the Internet has been associated with attention deficit hyperactivity disorder (ADHD), but the relationship between video games and ADHD symptoms in adolescents is unknown. Method A survey of adolescents and parents (n = 72 adolescents, 72 parents) was performed assessing daily time spent on the Internet, television, console video games, and Internet video games, and their association with academic and social functioning. Subjects were high school students in the ninth and tenth grade. Students were administered a modified Young's Internet Addiction Scale (YIAS) and asked questions about exercise, grades, work, and school detentions. Parents were asked to complete the Conners' Parent Rating Scale (CPRS) and answer questions regarding medical/psychiatric conditions in their child. Results There was a significant association between time spent playing games for more than one hour a day and YIAS (p < 0.001), overall grade point average (p ≤ 0.019), and the "Inattention" and "ADHD" components of the CPRS (p ≤ 0.001 and p ≤ 0.020, respectively). No significant association was found between body mass index (BMI), exercise, number of detentions, or the "Oppositional" and "Hyperactivity" components of CPRS and video game use. Conclusion Adolescents who play more than one hour of console or Internet video games may have more or more intense symptoms of ADHD or inattention than those who do not. Given the possible negative effects these conditions may have on scholastic performance, the added consequences of more time spent on video games may also place these individuals at increased risk for problems in school. PMID:17059614

  10. Implicit Self-Esteem Decreases in Adolescence: A Cross-Sectional Study

    PubMed Central

    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 = 1.0×10−10. 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. PMID:24587169

  11. 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. PMID:24587169

  12. Assessment of health status of adolescent burn victims undergoing rehabilitation: a cross-sectional field study.

    PubMed

    Nicolosi, Júlia Teixeira; de Carvalho, Viviane Fernandes; Sabatés, Ana Llonch; Paggiaro, André Oliveira

    2013-01-01

    Teenagers may experience physiological and psychological changes when they suffer from a severe burn. The aim of this study was to assess the state of health of teenagers who were undergoing a rehabilitation process following a severe burn. A cross-sectional field study was carried out with 63 teenagers and young adults who had suffered burns. The tests applied were social, demographic, and clinical instruments. The specific tests included the Burn Specific Health Scale-Revised, Beck Depression Inventory, Rosenberg's Self-Esteem Scale, and Functional Independence Measurement. The results were analyzed by using descriptive statistics, multivariate analysis of variance, variance analysis, and Cronbach's reliability analysis. The social and demographic analysis of the population has shown a prevalence of female (60.3%), single subjects (93.7%), and ages between 12 and 20 years (mean age of 15.95 years). The mean total body surface area burn was 23.84%, with accidents as the main causative factor (92.10%). More than half (52.4%) reported functional and aesthetic effects after the burn, with 81% concerned about the visible scar. Cronbach's reliability analysis has shown statistically confident results for all the instruments as applied. The multivariate analysis showed a correlation between the work domain and marital status, whereas there was no evidence to show a correlation between sex, age, physical or aesthetic sequelae or visibility of burns, and depression, self-esteem, functional independence, or current state of health. The results obtained prove the reliability of the instruments applied, making it possible to assess the state of teenagers and young adults health during the rehabilitation process. PMID:24297081

  13. The Influence of Hand Preference on Grip Strength in Children and Adolescents; A Cross-Sectional Study of 2284 Children and Adolescents

    PubMed Central

    Hepping, Ann M.; Ploegmakers, Joris J. W.; Geertzen, Jan H. B.; Bulstra, Sjoerd K.; Stevens, Martin

    2015-01-01

    Introduction In adults the preferred hand is often considered to be around 10% stronger than the non-preferred hand. Whether the same is true for children and adolescents remains unclear. The objective of this study is therefore to determine whether there is a difference in grip strength between the preferred and non-preferred hand in developing children, to establish whether this difference is similar for children of a different gender or hand preference, and whether there is a difference in grip strength of the preferred hand of left-preferent (LP) and right-preferent (RP) children. Design Cross-sectional study. Participants Participants were recruited from schools in the northern provinces of the Netherlands. The study included healthy children and adolescents in the age range of 4–17 years. Outcome Measures Each child was allowed a total of four attempts using the JAMAR hand dynamometer, two attempts with each hand. All individual attempts were scored. Hand preference was determined by asking which hand was used to write, or in the case of 4- and 5-year-olds, which hand was used to draw a shape. Results The study population comprised 2284 children and adolescents. RP boys and girls scored significantly higher with their preferred hand, the difference amounting to 9.5 and 10.1% respectively. LP girls scored significantly higher with their preferred hand, but this difference was only 3.0%. For LP boys no significant difference was found in favor of either hand. LP children score higher with the non-preferred hand and tie scores on both hands more often than RP children. Conclusion The 10% rule of hand preference is applicable to RP children ranging in age between 4 and 17 years, but not to LP children. In contrast to LP boys, LP girls are generally significantly stronger with their preferred hand. PMID:26599429

  14. 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

  15. 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.

  16. Track Reconstruction in a Time Projection Chamber Designed to Make High Precision Fission Cross Section Measurements

    NASA Astrophysics Data System (ADS)

    Sharma, Sarvagya

    2010-10-01

    The TPC (Time Projection Chamber), being constructed by the NIFFTE (Neutron Induced Fission Fragment Tracking Experiment) collaboration will be used for high-precision fission cross-section measurements. These measurements will aid in the design of future generations of nuclear power plants. The NIFFTE track reconstruction effort has developed two approaches consisting of a variety of statistical estimators. The first, consists of traditional cluster and hit finding algorithms that are performed on 2D planes. A least squares is performed on the hits to produce a track in the TPC. The alternate approach uses the Hough Transform, a brute force attempt at finding tracks that isolates features in the TPC volume through data binning. To determine fit parameters, a Kalman Filter has been implemented that accounts for multiple scattering and kinks in the track. Comparing simulated and reconstructed tracks have shown the validity of these methods. The software uses open source packages to ensure re-usability for future TPC projects. In my talk, I will describe these methods in detail.

  17. 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

  18. 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

  19. 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

  20. The Emergence of Sex Differences in Personality Traits in Early Adolescence: A Cross-Sectional, Cross-Cultural Study

    PubMed Central

    De Bolle, Marleen; De Fruyt, Filip; McCrae, Robert R.; Löckenhoff, Corinna E.; Costa, Paul T.; Aguilar-Vafaie, Maria E.; Ahn, Chang-kyu; Ahn, Hyun-nie; Alcalay, Lidia; Allik, Jüri; Avdeyeva, Tatyana V.; Bratko, Denis; Brunner-Sciarra, Marina; Cain, Thomas R.; Chan, Wayne; Chittcharat, Niyada; Crawford, Jarret T.; Fehr, Ryan; Ficková, Emília; Gelfand, Michele J.; Graf, Sylvie; Gülgöz, Sami; Hřebíčková, Martina; Jussim, Lee; Klinkosz, Waldemar; Knežević, Goran; de Figueroa, Nora Leibovich; Lima, Margarida P.; Martin, Thomas A.; Marušić, Iris; Mastor, Khairul Anwar; Nakazato, Katsuharu; Nansubuga, Florence; Porrata, Jose; Purić, Danka; Realo, Anu; Reátegui, Norma; Rolland, Jean-Pierre; Schmidt, Vanina; Sekowski, Andrzej; Shakespeare-Finch, Jane; Shimonaka, Yoshiko; Simonetti, Franco; Siuta, Jerzy; Szmigielska, Barbara; Vanno, Vitanya; Wang, Lei; Yik, Michelle; Terracciano, Antonio

    2015-01-01

    Although large international studies have found consistent patterns of sex differences in personality traits among adults (i.e., women scoring higher on most facets), less is known about cross-cultural sex differences in adolescent personality and the role of culture and age in shaping them. The present study examines NEO Personality Inventory-3 (NEO-PI-3, McCrae, Costa, & Martin, 2005) informant ratings of adolescents from 23 cultures (N = 4,850) and investigates culture and age as sources of variability in sex differences of adolescents’ personality. The effect for Neuroticism (with females scoring higher than males) begins to take on its adult form around age 14. Girls score higher on Openness to Experience and Conscientiousness at all ages between 12 and 17 years. A more complex pattern emerges for Extraversion and Agreeableness, although by age 17, sex differences for these traits are highly similar to those observed in adulthood. Cross-sectional data suggest that (1) with advancing age, sex differences found in adolescents increasingly converge towards adult patterns with respect to both direction and magnitude; (2) girls display sex-typed personality traits at an earlier age than boys; and (3) the emergence of sex differences was similar across culture. Practical implications of the present findings are discussed. PMID:25603371

  1. 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. PMID:26327322

  2. 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

  3. 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

  4. Safe-sex belief and sexual risk behaviours among adolescents from three developing countries: a cross-sectional study

    PubMed Central

    Osorio, Alfonso; Lopez-del Burgo, Cristina; Ruiz-Canela, Miguel; Carlos, Silvia; de Irala, Jokin

    2015-01-01

    Objectives This study intends to evaluate whether the belief that condoms are 100% effective in protecting against HIV infection is associated with sexual risk behaviours among youth. Methods A cross-sectional study was performed in representative samples of high-school students in the Philippines, El Salvador and Peru. Participants completed a self-administered questionnaire. Students were asked about the risk of HIV transmission if one has sex using condoms. They were also asked to indicate whether they had ever had sexual relations and whether they used a condom in their first sexual relation. The sample was composed of 8994 students, aged 13–18. Results One out of seven adolescents believed condoms are 100% effective (safe-sex believers). Those adolescents were 82% more likely to have had sex than those without such belief, after adjusting for confounders (OR=1.82; 95% CI 1.51 to 2.21). On the contrary, no association was found between risk perception and condom use. Subgroup and sensitivity analyses produced similar results. Conclusions This is, to the best of our knowledge, the first study conducted specifically to evaluate this phenomenon and that has used the same questionnaire and the same data collection protocol in three different developing countries from Asia, Central and South America. These results reasonably suggest that there could be an association between safe sex beliefs and sexual initiation. Longitudinal studies are needed to better understand this possible association as it could influence how to better promote sexual health. PMID:25916489

  5. 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

  6. Built environment and physical activity in New Zealand adolescents: a protocol for a cross-sectional study

    PubMed Central

    Hinckson, Erica A; Duncan, Scott; Oliver, Melody; Mavoa, Suzanne; Cerin, Ester; Badland, Hannah; Stewart, Tom; Ivory, Vivienne; McPhee, Julia; Schofield, Grant

    2014-01-01

    Introduction Built-environment interventions have the potential to provide population-wide effects and the means for a sustained effect on behaviour change. Population-wide effects for adult physical activity have been shown with selected built environment attributes; however, the association between the built environment and adolescent health behaviours is less clear. This New Zealand study is part of an international project across 10 countries (International Physical Activity and the Environment Network–adolescents) that aims to characterise the links between built environment and adolescent health outcomes. Methods and analyses An observational, cross-sectional study of the associations between measures of the built environment with physical activity, sedentary behaviour, body size and social connectedness in 1600 New Zealand adolescents aged 12–18 years will be conducted in 2013–2014. Walkability and neighbourhood destination accessibility indices will be objectively measured using Geographic Information Systems (GIS). Physical activity and sedentary behaviours will be objectively measured using accelerometers over seven consecutive days. Body mass index will be calculated as weight divided by squared height. Demographics, socioeconomic status, active commuting behaviours and perceived neighbourhood walkability will be assessed using the Neighbourhood Environment Walkability Scale for Youth and psychosocial indicators. A web-based computer-assisted personal interview tool Visualisation and Evaluation of Route Itineraries, Travel Destinations, and Activity Spaces (VERITAS) and Global Positioning System (GPS) receivers will be used in a subsample of 300 participants. A qualitative research component will explore barriers and facilitators for physical activity in adolescents with respect to the built and social environment in a subsample of 80 participants. Ethics and dissemination The study received ethical approval from the Auckland University of

  7. Prevalence, Patterns and Correlates of Cigarette Smoking in Male Adolescents in Northern Jordan, and the Influence of Waterpipe Use and Asthma Diagnosis: A Descriptive Cross-Sectional Study

    PubMed Central

    Al-Sheyab, Nihaya; Alomari, Mahmoud A.; Shah, Smita; Gallagher, Patrick; Gallagher, Robyn

    2014-01-01

    Our study investigates the prevalence, patterns and predictors of tobacco smoking among early adolescent males in Northern Jordan and whether asthma diagnosis affects smoking patterns. A descriptive cross sectional design was used. Males in grades 7 and 8 from four randomly selected high schools in the city of Irbid were enrolled. Data on waterpipe (WP) use and cigarette smoking patterns were obtained (n = 815) using a survey in Arabic language. The overall prevalence of ever having smoked a cigarette was 35.6%, with 86.2% of this group smoking currently. Almost half of the sample reported WP use. The most common age in which adolescents started to experiment with cigarettes was 11–12 years old (49.1%), although 10 years was also common (25.3%). Significant predictors of male cigarette smoking were WP use (OR = 4.15, 95% CI = 2.99–5.76), asthma diagnosis (OR = 2.35, 95% CI = 1.46–3.78), grade 8 (OR = 1.52, 95% CI = 1.10–2.11), and having a sibling who smokes (OR = 2.23, 95% CI = 1.53–3.24). However, this cross-sectional study cannot establish causality, thus longitudinal studies are needed. Public health programs and school-based anti-tobacco smoking interventions that target children in early years at high schools are warranted to prevent the uptake of tobacco use among this vulnerable age group. High school students with asthma should be specifically targeted. PMID:25257355

  8. Agreement between parents and adolescents on emotional and behavioral problems and its associated factors among Chinese school adolescents: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Most studies about informant agreements on adolescents’ emotional and behavioral problems have been conducted in Western countries, but this subject has not been well researched in China. The aim of this study was to evaluate the pattern of parent–adolescent agreement on adolescents’ problems and its associated factors among school-age adolescents in China. Methods This cross-sectional study was conducted in November and December of 2010. A questionnaire including the Child Behavior Checklist (CBCL), the Youth Self-Report (YSR), the Family Environment Scale (FES) and the characteristics of the child (age and gender), parents (parent–adolescent relationship and parental expectations) and family (family structure, negative life events) was distributed to our study population. A total of 2,199 Chinese adolescents (aged 11–18) from 15 public schools in Liaoning Province, who completed the questionnaire, became our final participants. Pearson’s correlation coefficient was used to assess parent–adolescent agreement, and linear regression analysis was used to explore the associated factors of parent–adolescent discrepancies on emotional and behavioral problems. Results The parent–adolescent agreement on emotional and behavioral problems was high (mean r = 0.6). The scores of YSR were higher than those of CBCL. Factors that increased informant discrepancies on emotional and behavioral problems were boys, older age, the experience of negative life events, low levels of cohesion and organization, and high levels of conflict in the family. Conclusions A high level of parent–adolescent agreement on emotional and behavioral problems was found. Adolescents reported more problems than their parents did. Family environment is an important factor to be considered when interpreting informant discrepancies on the mental health of Chinese adolescents. PMID:24735388

  9. 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

  10. 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. PMID:23796145

  11. Does Chinese culture influence psychosocial factors for heroin use among young adolescents in China? A cross-sectional study

    PubMed Central

    2010-01-01

    Background Little empirical research has examined how cultural factors influence psychosocial factors for heroin drug use. The objectives of the study were to investigate the levels of individualism and collectivism among young adolescents and how cultural differences were associated with the constructs of the Theory of Planned Behavior and other psychosocial factors for heroin drug use. Methods A cross-sectional study was conducted among young adolescents in an HIV and heroin-stricken area in China. The Individualism-Collectivism Interpersonal Assessment Inventory (ICIAI) was used to measure cultural norms and values in the context of three social groups: family members, close friends, and classmates. Results A total of 220 boys and 241 girls were recruited and participated in an interview. Compared to boys, girls reported higher levels of the three specific-relationship ICIAIs, as well as higher levels of perceived behavioral control for heroin use, perceived peer control, and communication with parent about heroin use, but a lower level of favorable attitude towards heroin use. The levels of descriptive and subjective norms of heroin use were low in both girls and boys. Among boys, family ICIAI was positively associated with perceived behavioral control, and friend ICIAI was positively associated with perceived peer control and communication with parent. Among girls, family ICIAI was positively associated with perceived behavioral control and communication with parents about heroin use, but negatively with favorable attitudes to heroin use; friend ICIAI was positively associated with perceived peer control, and classmate ICIAI was negatively associated with favorable attitudes toward heroin use. Conclusions This study documents that collectivistic aspects of Chinese culture may influence psychosocial factors for heroin use, although the patterns are varied by gender. Findings provide an empirical basis for the development of culturally competent intervention

  12. 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.

  13. 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.

  14. The design of equipment for optical power measurement in FSO link beam cross-section

    NASA Astrophysics Data System (ADS)

    Latal, Jan; David, Tomas; Wilfert, Otakar; Kolka, Zdenek; Koudelka, Petr; Hanacek, Frantisek; Vitasek, Jan; Siska, Petr; Skapa, Jan; Vasinek, Vladimir

    2012-06-01

    The free space optical links have found their major application in today's technological society. The demand for quality broadband is a must for all types of end users in these times. Because of the large jamming from wireless radio networks in non-licensed ISM bands, the free space optical links provide bridging of some densely populated urban areas. Their advantage is the high transmission rate for relatively long distances. However, the disadvantage is the dependence of free space optical links on atmospheric influences. Aired collimated optical beam passes through the atmospheric transmission environment and by its influence cause the deformation of the optical beam. Author's team decided to construct a special measuring device for measurement of optical power in FSO link beam cross-section. The equipment is mobile and can be rearranged and adjust according to the given location and placement of the FSO link at any time. The article describes the individual structural elements of the measuring equipment, its controlling and application for evaluation and adjustment of measuring steps. The graphs from optical power measurements in the beam cross-section of professional FSO links are presented at the end.

  15. Associations of short sleep duration with prehypertension and hypertension among Lithuanian children and adolescents: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Recent epidemiological studies have found that the prevalence of high blood pressure (BP) has significantly increased among children and adolescents. The aim of this study was to examine the associations between short sleep duration and prehypertension and hypertension in Lithuanian children and adolescents aged 12 to 15 years. Methods A cross-sectional study was conducted from November 2010 to April 2012. The participants with high BP (≥90th percentile) were screened on two separate occasions. Self-reported sleep duration was evaluated using questionnaires. Data on 6,940 subjects aged 12–15 years were analyzed. Adjusted odds ratios (aORs) with 95% confidence intervals for the associations were estimated using multivariate logistic regression models. Short sleep duration was defined as <8 hours per day (h/day). Results The prevalence of prehypertension and hypertension in the current sample was 12.6% and 22.5%, respectively. The percentages of the subjects with sleep durations of <7 (h/day), 7– < 8 h/day, and ≥8 h/day were 8.7%, 21.0%, and 70.3%, respectively. After adjusting for age, sex, body mass index, physical activity, and smoking, significant associations were found between short sleep duration and high BP, including prehypertension (7– < 8 h/day: aOR = 1.77; 95% CI, 1.48–2.12; <7 h/day: aOR = 2.18; 95% CI, 1.70–2.79) and hypertension (7– < 8 h/day: aOR = 1.99; 95% CI, 1.72–2.31; <7 h/day: aOR = 2.28; 95% CI, 1.85–2.80) (all P values <0.001), compared to participants who were sleeping longer (≥8 h/day). Conclusions Prehypertension and hypertension were associated with short sleep duration among Lithuanian children and adolescents aged 12 to 15 years. PMID:24628980

  16. 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.

  17. 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,…

  18. 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

  19. Factors associated with physical inactivity among female and male rural adolescents in Borneo - a cross-sectional study.

    PubMed

    Cheah, Whye Lian; Helmy, Hazmi; Chang, Ching Thon

    2014-01-01

    Rural communities have shown marked increase in metabolic syndrome among young people, with physical inactivity as one of the main contributing factors. This study aimed to determine factors associated with physical inactivity among male and female rural adolescents in a sample of schools in Malaysia. A cross-sectional study was conducted among 145 students aged 13-15 years. Data on socio-demographic, health-related, and psychosocial factors (perceived barriers, self-efficacy, social influences) were collected using a self-administered questionnaire. Anthropometric measurement was taken to generate body mass index (BMI)-for-age, while physical activity (PA) level was assessed using pedometers. The mean steps per day was 6251.37 (SD=3085.31) with males reported as being more active. About 27% of the respondents were either overweight or obese, with more females in this group. There was no significant difference in steps among males and females (p=0.212), and nutritional status (BMI-for-age) (p=0.439). Females consistently scored higher in most items under perceived barriers, but had significantly lower scores in self-efficacy's items. Males were more influenced by peers in terms of PA (p<0.001) and were more satisfied with their body parts (p=0.047). A significantly higher body size discrepancy score was found among females (p=0.034, CI -0.639, -0.026). PA level was low and almost one-third of the respondents were overweight and obese. Female students faced more barriers and had lower self-efficacy with regards PA. Based on the findings, it is recommended that interventions focus on reducing barriers while increasing support for PA. This is particularly important in improving the health status of the youth, especially among the females. PMID:24447982

  20. 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. PMID:20819144

  1. 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

  2. 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

  3. 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

  4. Mechanical design and analysis of the 2D cross-section of the SSC collider dipole magnet

    SciTech Connect

    Strait, J.; Kerby, J.; Bossert, R.; Carson, J.

    1991-05-01

    This paper describes the mechanical design of the two dimensional cross-section of the base-line collider dipole magnet for the Superconducting Super Collider. The components described here are the collar laminations, the tapered keys that lock the upper and lower collars, the yoke laminations, the cold mass shell. We describe in detail the shape of the outer surface of the collars which defines the yoke-collar interface, and the shape of the collar interior, which defines the conductor placement. Other features of the collar and yoke will be described in somewhat less detail. 20 refs., 12 figs. , 6 tabs.

  5. 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

  6. One-Dimensional, Multigroup Cross Section and Design Sensitivity and Uncertainty Analysis Code System - Generalized Perturbation Theory.

    1981-02-02

    Version: 00 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 (SED's) of multigroup scattering matrices.

  7. Prevalence and associated factors of suicidal ideation among school-going adolescents in Guyana: results from a cross sectional study

    PubMed Central

    2007-01-01

    Background Adolescent suicidal behaviour is a neglected public health issue especially in middle- and low-income countries. Informed policy decision-making on suicidal behaviour will need reliable information on the prevalence and correlates of suicidal ideation which is a determinant of suicidal behaviour. Methods We estimated the prevalence and associated factors of suicidal ideation among school-going adolescents using data from the Global School-Based Health Survey conducted in 2004 in Guyana. Results Of the 1197 respondents, 18.4% (14.9% males and 21.6% females)reported having seriously considered committing suicide in the last12 months. Males were less likely to seriously consider committingsuicide than females (OR = 0.45; 95% CI [0.30, 0.67]). Subjects whoreported having been bullied were more than twice as likely tocontemplate committing suicide as those who had not been bullied (OR = 2.46 [1.71, 3.54]). History of depression was positivelyassociated with suicidal ideation (OR = 2.67; 95% [1.87, 3.81] whilehaving close friends and understanding parents were negativelyassociated with suicide ideation (OR = 0.51; 95% CI [0.28, 0.94] and OR = 0.51; 95% CI [0.35, 0.76] respectively). Conclusion Suicidal ideation is a significant public health issue among in-school adolescents in Guyana that requires attention. The design, implementation and evaluation of suicidal behaviour interventions should incorporate our knowledge of these associated factors. PMID:17716374

  8. Parent-Adolescent Sexual and Reproductive Health Communication Is Very Limited and Associated with Adolescent Poor Behavioral Beliefs and Subjective Norms: Evidence from a Community Based Cross-Sectional Study in Eastern Ethiopia

    PubMed Central

    2015-01-01

    Introduction While parent-adolescent sexual and reproductive health (SRH) communication is one potential source of SRH information for adolescents, it appears to be inadequately practiced in Ethiopia. This study was designed to investigate the factors that limit or improve parent-adolescent SRH communication in Harar, Eastern Ethiopia. Methods A community based cross-sectional study was done on 4,559 adolescents of age 13–18. SRH communication was measured using a nine-item scale whose response ranged from “not at all” to “always.” Summated composite score ranging from 0–36 was generated; higher score indicates high SRH communication. A median value of the composite score was 4 out of the possible 36 with an Interquartile Range (IQR) of 7. Respondents were ranked as very poor, poor and satisfactory communicators based on 33rd and 67th percentiles values. Generalized ordered logit model was applied to investigate the factors associated with SRH communication. Results Results showed that the adolescents who were more likely to practice poor-very poor/very poor SRH communication were those who had poor behavioral beliefs on and poor subjective norms of communicating sexual issues with parents and those who perceived their parents’ reproductive health (RH) knowledge as poor. Nonetheless, the probability of poor-very poor/very poor SRH communication was less with high adolescent-parent communication quality, television co-viewing and discussions, and self-disclosure. Conclusions Curtailing the adolescents’ underlying poor beliefs and norms, and improving adolescent-parent communication quality, self-disclosure, and television co-viewing and discussions are essential to engage the parents in sexual and reproductive health education of the adolescents. PMID:26167860

  9. Design and construction of the RPI enhanced thermal neutron target and thermal cross-section measurements of rare earth isotopes

    SciTech Connect

    Danon, Y.

    1993-12-31

    In order to perform thermal cross section measurements the neutron flux in the RPI linac facility had to be increased. A new Enhanced Thermal Target (ETT) was designed, constructed and used. The thermal flux of the new target was up to six times higher than the previous RPI Bounce Target (BT). The ETT was also designed to be coupled to a cold moderator that will give an additional flux increase in the MeV energy region. Design calculations for the cold moderator including neutronics and cryogenics are also presented. The ETT was used for transmission measurements of rare earth metal samples of Ho, Er and Tm and enriched oxide samples of {sup 166}Er{sub 2}O{sub 3} and {sup 167}Er{sub 2}O{sub 3} in the energy range from 0.001 eV to 20 eV. The measurements were done with a 15 meter time-of-flight spectrometer and provide high quality data in the thermal and subthermal region as well as in the low energy resonance region. These measurements allowed a systematic study of paramagnetic scattering for the materials with Z = 67, 68 and 69 for which the paramagnetic scattering has the strongest effect. The paramagnetic scattering was inferred from the total cross section and compared to theoretical results and other experiments.

  10. Does socioeconomic status in adolescence predict low back pain in adulthood? A repeated cross-sectional study of 4,771 Danish adolescents.

    PubMed

    Hestbaek, Lise; Korsholm, Lars; Leboeuf-Yde, Charlotte; Kyvik, Kirsten Ohm

    2008-12-01

    Social and economic disadvantage is associated with general poor physical health. This relationship has been recognised for centuries, but it is unknown whether socioeconomic factors have a specific influence on low back pain (LBP). Furthermore, it is unknown how social and economic disadvantages in youth affect adult health. Therefore, the specific objectives of this study are to explore (1) the cross-sectional association between socioeconomic status (SES) and LBP in adolescence and (2) the longitudinal association between SES in adolescence and LBP in early adulthood. A database containing LBP data from 4,771 twins was merged with their parents' social and economic data, available from Statistics Denmark. Low back pain data ['any low back pain' and 'persistent low back pain (more than 30 days)'] were collected in 1994, when the subjects were 12-18 years of age, and collected again eight years later. Socioeconomic data of the parents (education, income, social class and long-term illness, all for both mother and father) were collected in 1994. Logistic regression analyses were used to estimate the associations between each parameter of parental SES in adolescence and LBP at baseline as well as at follow-up. Finally, the influence of a variable combining the different socioeconomic parameters was established. All estimates were controlled for smoking, alcohol consumption and body mass index at baseline. In the logistic regression models, only three of the 32 estimates were statistically significant. When merging the socioeconomic variables into a combined score, the results indicated that a good social background had a protective effect against the persistent LBP, while there was no association with any LBP. However, the statistical significance of this effect was unclear. We found no or very weak indications of possible relationships between social factors in adolescence and LBP at baseline and at follow-up. PMID:18830719

  11. Design of transmission-type phase holograms for a compact radar-cross-section measurement range at 650 GHz.

    PubMed

    Noponen, Eero; Tamminen, Aleksi; Vaaja, Matti

    2007-07-10

    A design formalism is presented for transmission-type phase holograms for use in a submillimeter-wave compact radar-cross-section (RCS) measurement range. The design method is based on rigorous electromagnetic grating theory combined with conventional hologram synthesis. Hologram structures consisting of a curved groove pattern on a 320 mmx280 mm Teflon plate are designed to transform an incoming spherical wave at 650 GHz into an output wave generating a 100 mm diameter planar field region (quiet zone) at a distance of 1 m. The reconstructed quiet-zone field is evaluated by a numerical simulation method. The uniformity of the quiet-zone field is further improved by reoptimizing the goal field. Measurement results are given for a test hologram fabricated on Teflon. PMID:17579673

  12. Computer-based designing of waveguide radiators of arbitrary cross section for antenna arrays

    NASA Astrophysics Data System (ADS)

    Voskresenskii, D. I.; Grinev, A. Iu.; Ilinskii, A. S.; Kotov, Iu. V.

    1980-02-01

    A multistep method is proposed for designing waveguide radiators for use in antenna arrays. A rigorous electrodynamic method for structure analysis is developed, along with a computer program and a numerical algorithm. The aperture performance of a quadruple-ridge rectangular waveguide in a phased array is examined, along with the directivity patterns of H-shaped, square, and circular radiators in antenna arrays.

  13. Symptomatic knee disorders in floor layers and graphic designers. A cross-sectional study

    PubMed Central

    2012-01-01

    Background Previous studies have described an increased risk of developing tibio-femoral osteoarthritis (TF OA), meniscal tears and bursitis among those with a trade as floor layers. The purpose of this study was to analyse symptomatic knee disorders among floor layers that were highly exposed to kneeling work tasks compared to graphic designers without knee-demanding work tasks. Methods Data on the Knee injury and Osteoarthritis Outcome Score (KOOS) were collected by questionnaires. In total 134 floor layers and 120 graphic designers had a bilateral radiographic knee examination to detect TF OA and patella-femoral (PF) OA. A random sample of 92 floor layers and 49 graphic designers had Magnetic Resonance Imaging (MRI) of both knees to examine meniscal tears. Means of the subscales of KOOS were compared by analysis of variance. The risk ratio of symptomatic knee disorders defined as a combination of radiological detected knee OA or MRI-detected meniscal tears combined with a low KOOS score was estimated by logistic regression in floor layers with 95% confidence interval (CI) and adjusted for age, body mass index, traumas, and knee-straining sports activities. Symptomatic knee OA or meniscal tears were defined as a combination of low KOOS-scores and radiographic or MRI pathology. Results Symptomatic TF and medial meniscal tears were found in floor layers compared to graphic designers with odds ratios 2.6 (95%CI 0.99-6.9) and 2.04 (95% CI 0.77-5.5), respectively. There were no differences in PF OA. Floor layers scored significantly lower on all KOOS subscales compared to graphic designers. Significantly lower scores on the KOOS subscales were also found for radiographic TF and PF OA regardless of trade but not for meniscal tears. Conclusions The study showed an overall increased risk of developing symptomatic TF OA in a group of floor layers with a substantial amount of kneeling work positions. Prevention would be appropriate to reduce the proportion of kneeling

  14. 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

  15. Exposure to secondhand smoke from neighbours and respiratory symptoms in never-smoking adolescents in Hong Kong: a cross-sectional study

    PubMed Central

    Leung, Lok Tung; Ho, Sai Yin; Wang, Man Ping; Lo, Wing Sze; Lam, Tai Hing

    2015-01-01

    Objectives To investigate secondhand smoke (SHS) exposure at home from neighbours in Hong Kong adolescents and its association with respiratory symptoms in never-smokers. Design A cross-sectional study. Setting 79 randomly selected secondary schools in Hong Kong. Participants 61 810 secondary 1 (USA grade 7) to 7 students, in which 50 762 never-smokers were identified and included in the analysis of the association between SHS exposure at home from neighbours and respiratory symptoms. Main outcome measures Smoking status, family smoking status, SHS exposure at home from inside the home and from neighbours in the past 7 days, respiratory symptoms and sociodemographic characteristics were reported. Adjusted ORs (AORs) of respiratory symptoms for SHS exposure from the 2 sources in never-smokers were calculated using logistic regression. Results In all students, 33.2% were exposed to SHS at home, including 16.2% from inside the home only, 10.0% from neighbours only and 7.0% from both. The prevalence of SHS exposure from neighbours was 17.1%, including 13.5% for 1–4 days/week and 3.6% for 5–7 days/week. In never-smokers (n=50 762), respiratory symptoms were significantly associated with SHS exposure from neighbours with AORs (95% CI) of 1.29 (1.20 to 1.39) for any exposure (p<0.001), 1.21 (1.12 to 1.31) for 1–4 days/week (p<0.001) and 1.63 (1.44 to 1.86) for 5–7 days/week (p<0.001) (P for trend <0.001). Compared with no SHS exposure at home from any source, the AORs were 1.16 (1.07 to 1.25) for SHS from inside the home only (p<0.001), 1.20 (1.11 to 1.31) from neighbours only (p<0.001), and 1.74 (1.56 to 1.94) from both (p<0.001). Conclusions SHS exposure at home from neighbours was prevalent in Hong Kong adolescents, and was associated with respiratory symptoms in never-smokers. SHS exposure at home may be underestimated by ignoring the neighbouring source. Smoke-free housing policy is needed to protect children and adolescents from harms of SHS

  16. Sensitivity Analysis of Neutron Cross-Sections Considered for Design and Safety Studies of Lfr and SFR Generation IV Systems

    NASA Astrophysics Data System (ADS)

    Tucek, Kamil; Carlsson, Johan; Wider, Hartmut

    2006-04-01

    We evaluated the sensitivity of several design and safety parameters with regard to five different nuclear data libraries, JEF2.2, JEFF3.0, ENDF/B-VI.8, JENDL3.2, and JENDL3.3. More specifically, the effective multiplication factor, burn-up reactivity swing and decay heat generation in available LFR and SFR designs were estimated. Monte Carlo codes MCNP and MCB were used in the analyses of the neutronic and burn-up performance of the systems. Thermo-hydraulic safety calculations were performed by the STAR-CD CFD code. For the LFR, ENDF/B-VI.8 and JEF2.2 showed to give a harder neutron spectrum than JEFF3.0, JENDL3.2, and JENDL3.3 data due to the lower inelastic scattering cross-section of lead in these libraries. Hence, the neutron economy of the system becomes more favourable and keff is higher when calculated with ENDF/B-VI.8 and JEF2.2 data. As for actinide cross-section data, the uncertainties in the keff values appeared to be mainly due to 239Pu, 240Pu and 241Am. Differences in the estimated burn-up reactivity swings proved to be significant, for an SFR as large as a factor of three (when comparing ENDF/B-VI.8 results to those of JENDL3.2). Uncertainties in the evaluation of short-term decay heat generation showed to be of the order of several per cent. Significant differences were, understandably, observed between decay heat generation data quoted in literature for LWR-UOX and those calculated for an LFR (U,TRU)O2 spent fuel. A corresponding difference in calculated core parameters (outlet coolant temperature) during protected total Loss-of-Power was evaluated.

  17. 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

  18. Environmental resources moderate the relationship between social support and school sports participation among adolescents: a cross-sectional analysis

    PubMed Central

    2011-01-01

    Background Most Americans are not active at recommended levels. Adolescence is a developmental period when physical activity (PA) decreases markedly. Methods This study investigates whether access to environmental PA resources moderates the relationship between psychosocial resources (social support and perceived competence) and PA among 192 adolescents. Results Environmental access to PA resources (determined via GIS-based assessment of the number of gyms, schools, trails, parks and athletic fields within 0.5 miles of each participant's home) moderated the association between social support and PA; among adolescents with high levels of environmental resources, greater social support was associated with students participating in a greater number of sports in school, whereas no such relationship emerged among adolescents with low environmental resources. Conclusions PA-promotion interventions should aim to enhance both social and environmental resources; targeting either one alone may be insufficient. PMID:21501504

  19. Role of gender, family, lifestyle and psychological factors in self-rated health among urban adolescents in Peru: a school-based cross-sectional survey

    PubMed Central

    Sharma, Bimala; Nam, Eun Woo; Kim, Dohyeong; Yoon, Young Min; Kim, Yeunju; Kim, Ha Yun

    2016-01-01

    Objective We examined the role of gender, family, lifestyle and psychological factors in self-rated health. Design Cross-sectional study. Setting A total of 970 randomly selected students from 11 secondary schools in Lima and Callao, Peru, participated in 2014. Main outcome measure Self-rated health was measured with a single item: ‘In general, how would you rate your health?’ Responses were arranged along a five-point Likert-type scale: ‘excellent’, ‘very good’, ‘good’, ‘fair’ and ‘poor’. The outcome variable was dichotomised as ‘good’ (excellent, very good or good) or ‘poor/fair’ (poor or fair). Methods We calculated adjusted ORs (AORs) and 95% CIs for poor/fair self-rated health using multivariate logistic regression analyses at 3-graded levels. Results 32.5% of the respondents had fair/poor self-rated health, 23.7% of the total males and 40.0% of the total female samples. Males were less likely to have poor/fair self-rated health (AOR 0.61; CI 0.41 to 0.91). Poor family support strongly increased the likelihood of having poor/fair self-rated health (no support, (AOR 3.15; CI 1.63 to 6.09); low support, (AOR 2.50; CI 1.29 to 4.85)). The other associated variables were missed meals due to a shortage of food (AOR 1.97; CI 1.15 to 3.36), television watching during leisure time (AOR 1.70; CI 1.09 to 2.67), low physical activity (AOR 1.49; CI 1.03 to 2.15), school absenteeism (AOR 1.54; CI 1.03 to 2.31) and perceived life satisfaction (AOR 0.28; CI 0.15 to 0.25). Conclusions Gender, missing meals due to a shortage of food, family support, physical activity and life satisfaction influenced self-rated health among adolescents in Peru. Interventions that focus on promoting physical activity for at least 1 h each day for 3 or more days per week, food security and strengthening supportive family roles may improve self-rated health during adolescence. PMID:26842274

  20. 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

  1. 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

  2. Vitamin D status in recently arrived immigrants from Africa and Asia: a cross-sectional study from Norway of children, adolescents and adults

    PubMed Central

    Eggemoen, Åse R; Knutsen, Kirsten V; Dalen, Ingvild; Jenum, Anne K

    2013-01-01

    Objectives To estimate the prevalence of vitamin D deficiency (25(OH)D) <50 nmol/L among recently arrived immigrants from Africa and Asia in Oslo, and to explore 25(OH)D levels according to origin, gender and age. Design A cross-sectional study. Setting Primary healthcare unit in Oslo, Norway, offering family immigrants, asylum seekers, United Nations (UN) refugees or individuals granted asylum a free medical examination on arrival. Participants All individuals from African and Asian countries (n=591) referred to the Centre of Migrant Health, Health Agency, Oslo, Norway in 2010, estimated to cover 60% of the targeted population. Results 25(OH)D <50 nmol/L was very prevalent in immigrants from the Middle East (81% (95% CI 75.4% to 86.6%)), South Sahara Africa (73% (CI 67.5% to 78.5%)) and South Asia (75% (CI 64.0% to 86.0%)), in contrast to East Asians (24% (CI 12.6% to 35.4%)), p<0.001 for differences. The prevalence of 25(OH)D<25 nmol/L was lower but followed the same pattern (Middle East: 38% (CI 31.1% to 45.0%), South Sahara Africa: 24% (CI 18.7% to 29.3%) and South Asia: 35% (CI 22.9% to 47.1%), although it was not observed in East Asians (p<0.001 for differences)). The ethnic differences persisted after adjusting for the duration of residence, seasonality and residence status in multiple linear regression analyses. Female adolescents from South Asia, the Middle East and South Sahara Africa had the lowest levels of 25(OH)D. Further, country-specific median levels of 25(OH)D were low (24–38 nmol/L) among groups from Somalia, Eritrea, Afghanistan and Iraq, the countries with the largest number of immigrants in our study. Conclusions The majority of recently settled immigrant groups from the Middle East, South Asia and Africa had 25(OH)D <50 nmol/L, in contrast to East Asians. Female adolescents from these regions had the lowest levels of 25(OH)D. PMID:24157818

  3. Indications for and use of antidepressants in child and adolescent psychiatry--a cross-sectional survey in Denmark.

    PubMed

    Buhl Sørensen, Christine; Bøhm Jepsen, Ea; Thomsen, Per Hove; Dalsgaard, Søren

    2003-06-01

    The prescription of antidepressants for children and adolescents is a controversial subject, and it has been documented that the practice has increased in the past decade in Denmark, the UK, and the USA. The aim of this study was to survey the indications for and use of antidepressants in child and adolescent psychiatry. Questionnaires were sent to all Danish child and adolescent psychiatric hospitals, out-patient clinics and privately practising psychiatrists treating children and adolescents under the age of 19 years (31 units in all). A 93.5 % response rate for the total of 382 questionnaires in the survey. The antidepressant serotonin selective re-uptake inhibitors (SSRIs) were the most prominently used agents in treating children and adolescents. The extent of their use represents 8 % of the total sample of individuals under the age of 19 years receiving any kind of psychiatric treatment - 0.03 % of the reference population in Denmark. It is only a surprisingly minor group of children and adolescents that are being treated with antidepressants despite the fact that 10 % of youth under the age of 19 are afflicted with diseases like depression, OCD, anxiety disorder and eating disorders. PMID:12768458

  4. Identifying the sociodemographic determinants of subjective health complaints in a cross-sectional study of Greek adolescents

    PubMed Central

    2012-01-01

    Background Experience of common health symptoms without a clear physical or psychological cause, such as headache or dizziness, is often reported in adolescence. The present study attempted to investigate associations of self-reported subjective health complaints (SHC) with a number of sociodemographic factors of Greek adolescents. Methods Questionnaires were administered to a Greek nationwide random school-based sample of adolescents aged 12 to 18 years and their parents in 2003. Data from 922 adolescent-parent pairs were analyzed (response rate = 63%). Adolescents’ reported subjective health complaints were assessed for their association with a number of sociodemographic factors: age, sex, type of area of residence according to level of urbanization, immigration background, parental education and employment status, family socioeconomic status and perceived quality of financial resources (PQFR). Multiple linear regression analysis was used to assess the association of the aforementioned factors with subjective health complaints as the dependent variable. Results Most sociodemographic variables, apart from area of residence and immigration background, were independently associated with subjective health complaints in the univariate analyses. The multiple linear regression analysis, however, limited the factors that could predict adolescents’ subjective health complaints to four (age, sex, Family Affluence Scale score and perceived quality of financial resources). Some considerations regarding parental employment status and immigration background are highlighted. Conclusions Our study highlights the sociodemographic components of subjective health complaints in the Greek adolescent population. The need to include adolescent-specific measures when collecting information on adolescents’ social background is underlined. Identifying vulnerable adolescent populations could lead to effective health promoting and preventive interventions. PMID:22748205

  5. Design of the Cross Section Shape of AN Aluminum Crash Box for Crashworthiness Enhancement of a CAR

    NASA Astrophysics Data System (ADS)

    Kim, S. B.; Huh, H.; Lee, G. H.; Yoo, J. S.; Lee, M. Y.

    This paper deals with the crashworthiness of an aluminum crash box for an auto-body with the various shapes of cross section such as a rectangle, a hexagon and an octagon. First, crash boxes with various cross sections were tested with numerical simulation to obtain the energy absorption capacity and the mean load. In case of the simple axial crush, the octagon shape shows higher mean load and energy absorption than the other two shapes. Secondly, the crash boxes were assembled to a simplified auto-body model for the overall crashworthiness. The model consists of a bumper, crash boxes, front side members and a sub-frame representing the behavior of a full car at the low speed impact. The analysis result shows that the rectangular cross section shows the best performance as a crash box which deforms prior to the front side member. The hexagonal and octagonal cross sections undergo torsion and local buckling as the width of cross section decreases while the rectangular cross section does not. The simulation result of the rectangular crash box was verified with the experimental result. The simulation result shows close tendency in the deformed shape and the load-displacement curve to the experimental result.

  6. Suicide Attempts and Associated Factors in Male and Female Korean Adolescents A Population-Based Cross-Sectional Survey.

    PubMed

    Chin, Young Ran; Choi, Kyungwon

    2015-10-01

    Using data from the Korea Youth Risk Behavior Web-based Survey, this study seeks to investigate associations of suicide attempts with family, individual, and behavioral factors on the basis of gender. Among male adolescents, those who did not live with their parents, who had poor subjective academic achievement, depression, experiences of smoking and sexual coitus, drug abuse, suicidal ideation and plans were more likely to attempt suicide. Among the female adolescents, those who did not live with their parents, had depression, low self-rated health, experiences of drug abuse and sexual coitus, and expressed unhappiness, suicidal ideation and suicide plans were more likely to attempt suicide. Thus, the development of a suicide prevention program for Korean adolescents requires different approaches for males and females. PMID:25812547

  7. 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.

  8. Estimating the Transitional Probabilities of Smoking Stages with Cross-sectional Data and 10-Year Projection for Smoking Behavior in Iranian Adolescents

    PubMed Central

    Khosravi, Ahmad; Mansournia, Mohammad Ali; Mahmoodi, Mahmood; Pouyan, Ali Akbar; Holakouie-Naieni, Kourosh

    2016-01-01

    Background: Cigarette smoking is one of the most important health-related risk factors in terms of morbidity and mortality. In this study, we introduced a new method for deriving the transitional probabilities of smoking stages from a cross-sectional study and simulated a long-term smoking behavior for adolescents. Methods: In this study in 2010, a total of 4853 high school students were randomly selected and were completed a self-administered questionnaire about cigarette smoking. We used smoothed age- and sex-specific prevalence of smoking stages in a probabilistic discrete event system for estimating of transitional probabilities. A nonhomogenous discrete time Markov chain analysis was used to model the progression of the smoking in 10 years ahead in the same population. The mean age of the students was 15.69 ± 0.73 years (range: 14–19). Results: The smoothed prevalence proportion of current smoking varies between 3.58 and 26.14%. The age-adjusted odds of initiation in boys is 8.9 (95% confidence interval [CI]: 7.9–10.0) times of the odds of initiation of smoking in girls. Our study predicted that the prevalence proportion of current smokers increased from 7.55% in 2010 to 20.31% (95% CI: 19.44–21.37) for 2019. Conclusions: The present study showed a moderately but concerning prevalence of current smoking in Iranian adolescents and introduced a novel method for estimation of transitional probabilities from a cross-sectional study. The increasing trend of cigarette use among adolescents indicated the necessity of paying more attention to this group. PMID:27625766

  9. 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…

  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. 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…

  12. 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.…

  13. Socioeconomic Inequality in Exposure to Bullying During Adolescence: A Comparative, Cross-Sectional, Multilevel Study in 35 Countries

    PubMed Central

    Merlo, Juan; Harel-Fisch, Yossi; Damsgaard, Mogens Trab; soc, Mag scient; Holstein, Bjørn E.; soc, Mag scient; Hetland, Jørn; Currie, Candace; Gabhainn, Saoirse Nic; de Matos, Margarida Gaspar; Lynch, John

    2009-01-01

    Objectives. We examined the socioeconomic distribution of adolescent exposure to bullying internationally and documented the contribution of the macroeconomic environment. Methods. We used an international survey of 162 305 students aged 11, 13, and 15 years from nationally representative samples of 5998 schools in 35 countries in Europe and North America for the 2001–2002 school year. The survey used standardized measures of exposure to bullying and socioeconomic affluence. Results. Adolescents from families of low affluence reported higher prevalence of being victims of bullying (odds ratio [OR] = 1.13; 95% confidence interval [CI] = 1.10, 1.16). International differences in prevalence of exposure to bullying were not associated with the economic level of the country (as measured by gross national income) or the school, but wide disparities in affluence at a school and large economic inequality (as measured by the Gini coefficient) at the national level were associated with an increased prevalence of exposure to bullying. Conclusions. There is socioeconomic inequality in exposure to bullying among adolescents, leaving children of greater socioeconomic disadvantage at higher risk of victimization. Adolescents who attend schools and live in countries where socioeconomic differences are larger are at higher risk of being bullied. PMID:19299676

  14. Relationship between Physical Attractiveness, Physical Effectiveness, and Self-Esteem: A Cross-Sectional Analysis among Adolescents.

    ERIC Educational Resources Information Center

    Thornton, Bill; Ryckman, Richard M.

    1991-01-01

    Examined contributions of physical attractiveness and physical effectiveness to self-esteem among adolescents in grades 7, 9, and 11, and college freshmen. Both attractiveness and effectiveness were significantly related to self-esteem of males and females. Attractiveness and effectiveness did not appear to be differentially important to…

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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

  20. Stressful Life Events as a Predictor for Nonsuicidal Self-Injury in Southern Chinese Adolescence: A Cross-Sectional Study.

    PubMed

    Tang, Jie; Yang, Wei; Ahmed, Niman Isse; Ma, Ying; Liu, Hui-Yan; Wang, Jia-Ji; Wang, Pei-Xi; Du, Yu-Kai; Yu, Yi-Zhen

    2016-03-01

    Stressful life events have been implicated in the etiology of kinds of psychopathology related to nonsuicidal self-injury (NSSI); however, few studies have examined the association between NSSI and stressful life events directly in Chinese school adolescents. In this study, we aim to estimate the prevalence rate of NSSI and examine its association with stressful life events in Southern Chinese adolescents. A total sample of 4405 students with age ranged from 10 to 22 years was randomly selected from 12 schools in 3 cities of Guangdong Province, China. NSSI, stressful life events, self-esteem, emotional management, and coping methods were measured by structured questionnaires. Multinomial logistic regression was used to examine the association of NSSI with stressful life events. Results showed the 1 year self-reported NSSI was 29.2%, with 22.6% engaged in "minor" NSSI (including hitting self, pulling hair, biting self, inserting objects under nails or skin, picking at a wound) and 6.6% in "moderate/sever" NSSI (including cutting/carving, burning, self-tattooing, scraping, and erasing skin). Self-hitting (15.9%), pulling hair out (10.9%), and self-inserting objects under nails or skin picking areas to dram blood (18.3%) were the most frequent types of NSSI among adolescents. Results also showed that "Minor NSSI" was associated with stressful life events on interpersonal, loss and health adaption, and "moderate/severe NSSI" was associated with life events on interpersonal, health adaption in Southern Chinese adolescents, even after adjusted for sex, age, residence, self-esteem, coping style, and emotional management. Results further suggested stressful life events were significantly associated with less risk of NSSI in those who had good emotional management ability. PMID:26945351

  1. 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

  2. Sleep and Fatigue Symptoms in Children and Adolescents With CKD: A Cross-sectional Analysis From the Chronic Kidney Disease in Children (CKiD) Study

    PubMed Central

    Roumelioti, Maria-Eleni; Wentz, Alicia; Schneider, Michael F.; Gerson, Arlene C.; Hooper, Stephen; Benfield, Mark; Warady, Bradley A.; Furth, Susan L.; Unruh, Mark L.

    2010-01-01

    Background Although symptoms of sleepiness and fatigue are common among adults with Chronic Kidney Disease (CKD), little is known about the prevalence of these symptoms in children with CKD. Study Design Cross-sectional analysis within a cohort study. Setting & Participants We describe the frequency and severity of sleep problems and fatigue, and we assess the extent of their association with measured glomerular filtration rate (mGFR) and Health-Related Quality of Life (HRQOL) among 301 participants of the Chronic Kidney Disease in Children cohort. Outcomes and Measurements Sleep and fatigue-related items from the Pediatric Quality of Life Inventory 4.0 Generic Scales and the CKD-related Symptoms List were used. Results Median mGFR was 42.0 ml/min/1.73m2 (25th–75th percentiles, 31.2–53.2) [EF1]and median age was 13.9 years (25th–75th percentiles, 10.8–16.2). Children with mGFR 40-<50, 30-<40, or <30 had 2.07 (95% CI, 1.05–4.09), 2.35 (95% CI 1.17, 4.72) and 2.59 (95% CI 1.15, 5.85) higher odds of having more severe parent reports of low energy than children with mGFR ≥50. Compared to participants with mGFR ≥50, those with mGFR <30 had 3.92 (95% CI 1.37, 11.17) higher odds of reporting more severe weakness, and those with mGFR 40-<50 had 2.95 (95% CI 1.26, 6.88) higher odds of falling asleep during the day. Low energy, trouble sleeping and weakness were associated with lower HRQOL scores. Limitations Symptoms of sleep and fatigue represent the child or parent’s perception of symptom severity, while individual items can lead to imprecise measurements of sleep and fatigue. Conclusions Lower mGFR was associated with increased weakness, low energy, and daytime sleepiness. Furthermore, a strong association between trouble sleeping, low energy and weakness with decrements in overall HRQOL was observed. Detection and treatment of poor sleep and fatigue may improve the development and HRQOL of children and adolescents with CKD. PMID:20034719

  3. 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

  4. 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

    2016-01-01

    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

  5. 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

  6. The development and evaluation of the Australian child and adolescent recommended food score: a cross-sectional study

    PubMed Central

    2012-01-01

    Background Diet quality tools have been developed to assess the adequacy of dietary patterns for predicting future morbidity and mortality. This study describes the development and evaluation of a brief food-based diet quality index for use with children at the individual or population level. The Australian Child and Adolescent Recommended Food Score (ACARFS) was developed to reflect adherence to the Dietary Guidelines for Children and Adolescents in Australia and modelled on the approach of the US Recommended Food Score. Methods The ACARFS has eight sub-scales and is scored from zero to 73. The diet quality score was evaluated by assessing correlation (Spearman’s correlations) and agreement (weighted κ statistics) between ACARFS scores and nutrient intakes, derived from a food frequency questionnaire in 691 children (mean age 11.0, SD 1.1) in New South Wales, Australia. Nutrient intakes for ACARFS quartiles were compared with the relevant Australian nutrient reference values. Results ACARFS showed slight to substantial agreement (κ 0.13-0.64) with nutrient intakes, with statistically significant moderate to strong positive correlations with all vitamins, minerals and energy intake (r = 0.42-0.70). ACARFS was not related to BMI.Participants who scored less than the median ACARFS were more likely to have sub-optimal intakes of fibre, folic acid and calcium. Conclusion ACARFS demonstrated sufficient accuracy for use in future studies evaluating diet quality. Future research on its utility in targeting improvements in the nutritional quality of usual eating habits of children and adolescents is warranted. PMID:23164095

  7. 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. PMID:26844460

  8. Determinants of sexual health knowledge in adolescent girls in schools of Riyadh-Saudi Arabia: a cross sectional study

    PubMed Central

    2013-01-01

    Background There are many social and cultural factors affecting the sexual knowledge of adolescents. This study measured the sexual health knowledge level of adolescents and identified its association with role of parents, friends and school environment in adolescent girls in Riyadh, Saudi Arabia. Methods Four hundred and nineteen Saudi female students belonging to intermediate and secondary grades were randomly selected from four public and private girl schools. 255 (69.8%) students were ≤15 years and 164 (39.2%) were >15 years. A self-administered structured questionnaire comprising of socio-demographic information, role of parents and teachers, availability of school curriculum on sexual health was used. Sexual health knowledge was assessed through questions on identification of physical changes during puberty for ≤15 years and separate questions on sexually transmitted infections for >15 years. Results 54% of ≤15years and 70.7% of >15 years had poor sexual health knowledge. Multivariate analysis found determinants for poor sexual health education in ≤15years are: lower education level of both parents (OR 10.87; 95% CI 2.44–48.38), second birth order or more (OR 2.32; 95% CI 1.24–4.33) and absence of school curriculum on sexual health (OR 0.56; 95% CI 0.33–0.95). Determinants for >15 years of age are : mothers with low literacy (OR 3.08, 95% CI 1.42–6.71), as for sources of poor sexual knowledge : parents (OR 10.10; 95% CI 2.70–37.74), schools (OR 6.95; 95% CI 1.95–24.78) maids (OR 4.57; 95% CI 1.26–16.59) and media (OR 5.12; 95% CI 1.29–20.07) were statistically significant factors. Conclusion Government agencies with collaboration of all stake holders should develop policies and programs for implementing and evaluating integrated and comprehensive sexual educational programs for adolescents in Saudi Arabia. PMID:23587104

  9. 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. PMID:27391251

  10. 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…

  11. Association between regular participation in sports and leisure time behaviors in Brazilian adolescents: A cross-sectional study

    PubMed Central

    Fernandes, Rômulo Araújo; Júnior, Ismael Forte Freitas; Cardoso, Jefferson Rosa; Vaz Ronque, Enio Ricardo; Loch, Mathias Roberto; de Oliveira, Arli Ramos

    2008-01-01

    Background The belief that adolescents engaged in sports increase their overall physical activity level while simultaneously decreasing physical inactivity has been the foundation of many intervention programs in developing countries. The aim of this study was to analyze the association between regular participation in sports and both active behaviors and TV viewing during leisure time. Methods A total of 1752 Brazilian adolescents (812 = male and 940 = female) participated in this study. Regular participation in sports, as well as active behaviors (exemplified by walking or cycling) and TV viewing during leisure time were assessed by means of a questionnaire. The chi-square test analyzed the association between sports practice and leisure time behaviors, and the Poisson regression with robust variance indicated the magnitude of these associations. Results The prevalence of regular participation in sports was 14.8% (95% confidence interval 13.2% to 16.5%). After adjustment for all confounders, participation in sports was associated with, at the highest frequency, cycling (PR = 2.55 [1.80–3.60]) and walking (PR = 2.69 [1.98–3.64]) during leisure time. However, there was not an association between the participation in sports and frequency of TV viewing (PR = 1.28 [0.81–2.02]). Conclusion This study presented data indicating that the regular participation in sports is positively associated with a higher frequency of physically active behaviors during leisure time. However, the results did not support the hypothesis that the engagement in sports necessarily decreases leisure time spent in TV viewing. PMID:18811976

  12. Association between Weight Misperception Patterns and Depressive Symptoms in Korean Young Adolescents: National Cross-Sectional Study

    PubMed Central

    Byeon, Haewon

    2015-01-01

    Purpose Although distortion of weight perceptions has been known as a risk factor for adolescent depression, little has been known about the relationship between weight misperception patterns and depressive symptoms. This study explored the relationship between distortion of weight misperception patterns and depressive symptoms in Korean adolescents. Methods The subjects of this study were 109,373 middle school students who participated in the Korea Youth Risk Behavior Web-based Survey (KYRBWS) from 2011 to 2013. By comparing the difference between Body Mass Index (BMI) and subjective perceptions of body weight, misperceptions of weight were classified into two categories: misperception of underweight and misperception of overweight. Results When confounding variables were adjusted, the results of the logistic regression analysis revealed that male students who perceived themselves as underweight despite their normal weight were 110% more likely to have depressive symptoms (OR = 1.10, 95% CI: 1.03–1.18) than male students with accurate weight perceptions. On the contrary, for female students, misperceptions of underweight had no significant relationship with depression symptoms. Regarding misperceptions of overweight, female students who perceived themselves as overweight despite their normal weight were 107% (OR = 1.07, 95% CI: 1.02–1.11) more likely to have depressive symptoms than female students with accurate weight perceptions. Moreover, female students who perceived themselves as overweight when they were underweight were 137% (OR = 1.37, 95% CI: 1.18–1.58) more likely to have depressive symptoms. Conclusion Male students who underestimate their body weight and female students who overestimate their body weight were at a greater risk of depression emotions than students with accurate weight perceptions. PMID:26313680

  13. A cross-sectional study on attitudes toward gender equality, sexual behavior, positive sexual experiences, and communication about sex among sexually active and non-sexually active adolescents in Bolivia and Ecuador

    PubMed Central

    De Meyer, Sara; Jaruseviciene, Lina; Zaborskis, Apolinaras; Decat, Peter; Vega, Bernardo; Cordova, Kathya; Temmerman, Marleen; Degomme, Olivier; Michielsen, Kristien

    2014-01-01

    Background It is widely agreed upon that gender is a key aspect of sexuality however, questions remain on how gender exactly influences adolescents’ sexual health. Objective The aim of this research was to study correlations between gender equality attitudes and sexual behavior, sexual experiences and communication about sex among sexually active and non-sexually active adolescents in 2 Latin American countries. Design In 2011, a cross-sectional study was carried out among 5,913 adolescents aged 14–18 in 20 secondary schools in Cochabamba (Bolivia) and 6 secondary schools in Cuenca (Ecuador). Models were built using logistic regressions to assess the predictive value of attitudes toward gender equality on adolescents’ sexual behavior, on experiences and on communication. Results The analysis shows that sexually active adolescents who consider gender equality as important report higher current use of contraceptives within the couple. They are more likely to describe their last sexual intercourse as a positive experience and consider it easier to talk with their partner about sexuality than sexually experienced adolescents who are less positively inclined toward gender equality. These correlations remained consistent whether the respondent was a boy or a girl. Non-sexually active adolescents, who consider gender equality to be important, are more likely to think that sexual intercourse is a positive experience. They consider it less necessary to have sexual intercourse to maintain a relationship and find it easier to communicate with their girlfriend or boyfriend than sexually non-active adolescents who consider gender equality to be less important. Comparable results were found for boys and girls. Conclusions Our results suggest that gender equality attitudes have a positive impact on adolescents’ sexual and reproductive health (SRH) and wellbeing. Further research is necessary to better understand the relationship between gender attitudes and specific SRH

  14. 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…

  15. Correlation between basic physical fitness and pulmonary function in Korean children and adolescents: a cross-sectional survey.

    PubMed

    Bae, Ju Yong; Jang, Ki Sung; Kang, Sunghwun; Han, Don Hee; Yang, Wonho; Shin, Ki Ok

    2015-09-01

    [Purpose] The purpose of the present study was to determine whether there was a correlation between basic physical fitness and pulmonary function in Korean school students, to present an alternative method for improving their pulmonary function. [Subjects and Methods] Two hundred forty healthy students aged 6-17 years performed physical fitness tests of hand-grip strength, sit and reach, Sargent jump, single leg stance, and pulmonary function tests of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) using a Quark PFT. [Results] Muscle strength and power of boys improved in the late period of elementary school and middle school. Muscle strength of girls improved in the late period of elementary school. Analysis of factors affecting pulmonary function revealed that height, weight, BMI, and body fat significantly correlated with spirometric parameters. Right hand-grip strength, left hand-grip strength, and Sargent jump also significantly correlated with FVC and FEV1. [Conclusion] In order to improve the pulmonary function of children and adolescents, aerobic exercise and an exercise program to increase muscle strength and power is needed, and it should start in the late period of elementary school when muscle strength and power are rapidly increasing. PMID:26504269

  16. 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

  17. 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. PMID:27120264

  18. 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. PMID:25381268

  19. Sex differences in the association between body mass index and hypertension - a cross-sectional study in 717 812 adolescents.

    PubMed

    Gordon, B; Shamiss, A; Derazne, E; Tzur, D; Afek, A

    2016-08-01

    In order to examine sex-specific differences in the association of body mass index (BMI) and hypertension, we conducted a retrospective, cross-sectional study of 717 812 (402 914 men and 314 898 women) Israeli Jewish adolescents aged 16.0-19.99 years medically screened for military service. A diagnosis of hypertension was established per history or if a mean of 10 separate blood pressure measurements exceeded 140/90, following an initial measurement higher than 140/90. Weight and height were measured. Prevalence of hypertension was 0.42% in men and 0.05% in women. In men, BMI was significantly associated with hypertension from the third decile (odds ratio [OR] 1.67, 1.06-2.65) up to the 10th decile (OR 30.17, 20.83-43.69). In women, we observed a significantly increased risk for hypertension in the ninth decile (OR 3.82, 1.42-10.22) and in the 10th decile (OR 18.92, 7.7-46.51), with no visible trend in lower deciles. BMI effects on hypertension prevalence are different in male and female adolescents. PMID:25917570

  20. In vivo dosimetry of thyroid doses from different irradiated sites in children and adolescents: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Scattered radiation can be assessed by in vivo dosimetry. Thyroid tissue is sensitive to radiation, even at doses <10 cGy. This study compared the scattered dose to the thyroid measured by thermoluminescent dosimeters (TLDs) and the estimated one by treatment planning system (TPS). Methods During radiotherapy to sites other than the thyroid of 16 children and adolescents, seventy-two TLD measurements at the thyroid were compared with TPS estimation. Results The overall TPS/TLD bias was 1.02 (95% LA 0.05 to 21.09). When bias was stratified by treatment field, the TPS overestimated TLD values at doses <1 cGy and underestimated them at doses >10 cGy. The greatest bias was found in pelvis and abdomen: 15.01 (95% LA 9.16 to 24.61) and 5.12 (95% LA 3.04 to 8.63) respectively. There was good agreement in orbit, head, and spine: bias 1.52 (95% LA 0.48 to 4.79), 0.44 (95% LA 0.11 to 1.82) and 0.83 (0.39 to 1.76) respectively. There was small agreement with broad limits for lung and mediastinum: 1.13 (95% LA 0.03 to 40.90) and 0.39 (95% LA 0.02 to 7.14) respectively. Conclusions The scattered dose can be measured with TLDs, and TPS algorithms for outside structures should be improved. PMID:24479890

  1. Serum Ferritin Is Inversely Correlated with Testosterone in Boys and Young Male Adolescents: A Cross-Sectional Study in Taiwan

    PubMed Central

    Chao, Kuo-Ching; Chang, Chun-Chao; Chiou, Hung-Yi; Chang, Jung-Su

    2015-01-01

    Objective The transition from childhood to teenaged years is associated with increased testosterone and a decreased iron status. It is not clear whether higher testosterone levels cause the decreased iron status, and to what extent, obesity-related inflammation influences the iron-testosterone relationship. The aim of the present study was to examine relationships of testosterone, iron status, and anti-/proinflammatory cytokines in relation to nutritional status in boys and young adolescent Taiwanese males. Methods In total, 137 boys aged 7~13 yr were included. Parameters for obesity, the iron status, testosterone, and inflammatory markers were evaluated. Results Overweight and obese (ow/obese) boys had higher mean serum testosterone, interleukin (IL)-1β, and nitric oxide (NO) levels compared to their normal-weight counterparts (all p<0.05). Mean serum ferritin was slightly higher in ow/obese boys compared to normal-weight boys, but this did not reach statistical significance. A multiple linear regression showed that serum ferritin (β = -0.7470, p = 0.003) was inversely correlated with testosterone, while serum IL-10 (β = 0.3475, p = 0.009) was positively associated with testosterone after adjusting for covariates. When normal-weight boys were separately assessed from ow/obesity boys, the association between testosterone and serum ferritin became stronger (β = -0.9628, p<0.0001), but the association between testosterone and IL-10 became non-significant (β = 0.1140, p = 0.4065) after adjusting for covariates. In ow/obese boys, only IL-10 was weakly associated with serum testosterone (β = 0.6444, p = 0.051) after adjusting for age. Conclusions Testosterone and serum ferritin are intrinsically interrelated but this relationship is weaker in ow/obese boys after adjusting for age. PMID:26646112

  2. 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…

  3. 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

  4. 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

  5. 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

  6. Subjective health complaints in older adolescents are related to perceived stress, anxiety and gender – a cross-sectional school study in Northern Sweden

    PubMed Central

    2012-01-01

    Background Negative trends in adolescent mental and subjective health are a challenge to public health work in Sweden and worldwide. Self-reported mental and subjective health complaints such as pain, sleeping problems, anxiety, and various stress-related problems seem to have increased over time among older adolescents, especially girls. The aim of this study has therefore been to investigate perceived stress, mental and subjective health complaints among older adolescents in Northern Sweden. Methods Data were derived from a cross-sectional school-based survey with a sample consisting of 16–18 year olds (n = 1027), boys and girls, in the first two years of upper secondary school, from different vocational and academic programmes in three public upper secondary schools in a university town in northern Sweden. Prevalence of perceived stress, subjective health complaints, general self-rated health, anxiety, and depression were measured using a questionnaire, including the Hospital Anxiety and Depression Scale (HADS). Results A large proportion of both girls and boys reported health complaints and perceived stress. There was a clear gender difference: two to three times as many girls as boys reported subjective health complaints, such as headache, tiredness and sleeping difficulties and musculoskeletal pain, as well as sadness and anxiety. High pressure and demands from school were experienced by 63.6% of girls and 38.5% of boys. Perceived stress in the form of pressure and demands correlated strongly with reported health complaints (r = 0.71) and anxiety (r = 0.71). Conclusions The results indicate that mental and subjective health complaints are prevalent during adolescence, especially in girls, and furthermore, that perceived stress and demands may be important explanatory factors. Future studies should pay attention to the balance between gender-related demands, perceived control and social support, particularly in the school environment, in order

  7. 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

  8. 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

  9. 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

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

    PubMed

    Peltzer, Karl; Pengpid, Supa

    2016-01-01

    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

  11. 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

  12. 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

  13. Correlates of smoking susceptibility among adolescents in a peri-urban area of Nepal: a population-based cross-sectional study in the Jhaukhel-Duwakot Health Demographic Surveillance Site

    PubMed Central

    Aryal, Umesh R.; Petzold, Max; Bondjers, Göran; Krettek, Alexandra

    2014-01-01

    Background Susceptibility to smoking is defined as an absence of firm commitment not to smoke in the future or when offered a cigarette by best friends. Susceptibility begins in adolescence and is the first step in the transition to becoming an established smoker. Many scholars have hypothesized and studied whether psychosocial risk factors play a crucial role in preventing adolescent susceptibility to smoking or discourage susceptible adolescents from becoming established smokers. Our study examined sociodemographic and family and childhood environmental factors associated with smoking susceptibility among adolescents in a peri-urban area of Nepal. Design We conducted a population-based cross-sectional study during October–November 2011 in the Jhaukhel-Duwakot Health Demographic Surveillance Site (JD-HDSS) located in a peri-urban area near Kathmandu, the capital city of Nepal, where tobacco products are easily available. Trained local enumerators conducted face-to-face interviews with 352 respondents aged 14–16. We used stepwise logistic regression to assess sociodemographic and family and childhood environmental factors associated with smoking susceptibility. Results The percentage of smoking susceptibility among respondents was 49.70% (95% CI: 44.49; 54.93). Multivariable analysis demonstrated that smoking susceptibility was associated with smoking by exposure of adolescents to pro-tobacco advertisements (AOR [adjusted odds ratio] =2.49; 95% CI: 1.46–4.24), the teacher (2.45; 1.28–4.68), adolescents attending concerts/picnics (2.14; 1.13–4.04), and smoking by other family members/relatives (1.76; 1.05–2.95). Conclusions Smoking susceptible adolescents are prevalent in the JD-HDSS, a peri-urban community of Nepal. Several family and childhood environmental factors increased susceptibility to smoking among Nepalese non-smoking adolescents. Therefore, intervention efforts need to be focused on family and childhood environmental factors with emphasis on

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

    PubMed

    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

  15. 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

  16. 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

  17. 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.

    PubMed

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

    2010-08-01

    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

  18. Management of chronic immune thrombocytopenia in children and adolescents: lessons from an Austrian national cross-sectional study of 81 patients.

    PubMed

    Sipurzynski, J; Fahrner, B; Kerbl, R; Crazzolara, R; Jones, N; Ebetsberger, G; Jauk, B; Strenger, V; Wohlmuther, B; Schwinger, W; Lackner, H; Urban, C; Holter, W; Minkov, M; Kager, L; Benesch, M; Seidel, M G

    2016-04-01

    Chronic immune thrombocytopenia (cITP) is often associated with an underlying predisposition towards autoimmunity, recognition of which is relevant to guide treatment. International recommendations on diagnostic steps and therapeutic measures of cITP in childhood exist. However, due to the low prevalence (1-2/100,000) and a variation of availability of immunological and hematological tests and treatments across pediatric units, we postulated that these guidelines are not uniformly adhered to and that immune dysregulation syndromes remained undiscovered. To delineate the current management of children and adolescents with cITP in Austria, we performed a nationwide cross-sectional study. Between 2011 and 2014, 81 children with cITP were seen at seven centers (median age 8.75 years; range 1-17; female:male ratio 47:34) at 641 visits during 180 patient years after diagnosis of cITP (>12 months ITP duration). Additional diagnoses were noted, most frequently immune or autoimmune disorders, hematologic diseases, or infections (in 37.3%, including Evans syndrome, autoimmune lymphoproliferative syndrome, systemic lupus erythematosus, and Fanconi anemia), or other symptoms like bi- or pancytopenia (n=9), lymphoproliferation or granulomatous inflammation (n = 3). Both decision to treat as well as choice of treatment varied: smaller centers tended to observe more frequently, larger centers applied a pattern of treatment modalities that appeared to depend less on bleeding tendency than on center policy. More than 50% of therapeutic interventions occurred in bleedings scores ≤2 (of 5), suggesting a strong psychosocial intention to treat. Platelet increment upon 479 therapeutic interventions of eight types was evaluated, with multiple treatment approaches being pursued sequentially in refractory patients. These data confirm the hypothesis of heterogeneous diagnostic and therapeutic management of cITP in Austrian children and corroborate the need for (1) a precise panel of

  19. Patterns and trends of contraceptive use among sexually active adolescents in Burkina Faso, Ethiopia, and Nigeria: evidence from cross-sectional studies

    PubMed Central

    Hounton, Sennen; Barros, Aluisio J. D.; Amouzou, Agbessi; Shiferaw, Solomon; Maïga, Abdoulaye; Akinyemi, Akanni; Friedman, Howard; Koroma, Desmond

    2015-01-01

    Background The benefits of universal access to voluntary contraception have been widely documented in terms of maternal and newborn survival, women's empowerment, and human capital. Given population dynamics, the choices and opportunities adolescents have in terms of access to sexual and reproductive health information and services could significantly affect the burden of diseases and nations’ human capital. Objectives The objectives of this paper are to assess the patterns and trends of modern contraception use among sexually active adolescents by socio-economic characteristics and by birth spacing and parity; to explore predictors of use of modern contraception in relation to the health system; and to discuss implications of the findings for family planning policy and programmes. Design Data are from the last three Demographic and Health Surveys of Ethiopia, Burkina Faso, and Nigeria. The descriptive analysis focused on sexually active adolescents (15- to 19-year age group), used modern contraception as the dependent variable, and a series of contact points with the health system (antenatal care, institutional delivery, postnatal care, immunisation) as covariates. The multivariate analysis used the same covariates, adjusting for socio-economic variables. Results There are two different groups of sexually active adolescents: those married or in a union with very low use of modern contraception and lower socio-economic status, and those unmarried, among whom nearly 50% are using modern contraception. Younger adolescents have lower modern contraceptive prevalence. There are significant inequality issues in modern contraception use by education, residence, and wealth quintile. However, while there was no significant progress in Burkina Faso and Nigeria, the data in Ethiopia point to a significant and systematic reduction of inequalities. The narrowing of the equity gap was most notable for childbearing adolescents with no education or living in rural areas. In the

  20. 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

  1. The association of circulating 25-hydroxyvitamin D and calcium with cognitive performance in adolescents: cross-sectional study using data from the third National Health and Nutrition Examination Survey.

    PubMed

    Tolppanen, Anna-Maija; Williams, Dylan; Lawlor, Debbie A

    2011-01-01

    Studies in middle- and older-aged adults have shown positive associations between serum levels of 25-hydroxyvitamin D [25(OH)D] and cognitive function. Higher serum calcium levels have been associated with greater cognitive decline in older adults. There have been relatively few studies of the associations of 25(OH)D and calcium with cognitive function in adolescents. We investigated the cross sectional association between circulating levels of 25(OH)D and pH-normalised calcium with different domains of cognitive function (block design and digit span components from Wechsler Intelligence Scale for Children-revised and reading and mathematics subtests of Wide-range Achievement Test-revised) in adolescents (age 12-16.9 years) of the third National Health and Nutrition Examination Survey (NHANES III). Serum 25(OH)D was positively associated with performance in all four cognitive tests (e.g. 1 standard deviation (SD) change in digit span score per 1SD in 25(OH)D was 0.10 [95% confidence interval 0.03, 0.16]), but the association was attenuated to the null after adjusting for ethnicity/race and language used in test (1SD change in digit span per 1SD in 25(OH)D after adjusting for self-reported race/ethnicity and language used in test was 0.01[-0.06, 0.09]). pH-normalised calcium levels were not associated with any of the cognitive domains and adjustment for serum calcium levels did not alter the association between 25(OH)D and cognitive function. Thus, we found no evidence that the serum levels of 25(OH)D or calcium were associated with cognitive function in adolescents. A positive association of 25(OH)D with cognitive function was completely explained by confounding due to race/ethnicity. PMID:21133971

  2. Muscle torque relative to cross-sectional area and the functional muscle-bone unit in children and adolescents with chronic disease.

    PubMed

    Lee, Dale Y; Wetzsteon, Rachel J; Zemel, Babette S; Shults, Justine; Organ, Jason M; Foster, Bethany J; Herskovitz, Rita M; Foerster, Debbie L; Leonard, Mary B

    2015-03-01

    Measures of muscle mass or size are often used as surrogates of forces acting on bone. However, chronic diseases may be associated with abnormal muscle force relative to muscle size. The muscle-bone unit was examined in 64 children and adolescents with new-onset Crohn's disease (CD), 54 with chronic kidney disease (CKD), 51 treated with glucocorticoids for nephrotic syndrome (NS), and 264 healthy controls. Muscle torque was assessed by isometric ankle dynamometry. Calf muscle cross-sectional area (CSA) and tibia cortical section modulus (Zp) were assessed by quantitative CT. Log-linear regression was used to determine the relations among muscle CSA, muscle torque, and Zp, adjusted for tibia length, age, Tanner stage, sex, and race. Muscle CSA and muscle torque-relative-to-muscle CSA were significantly lower than controls in advanced CKD (CSA -8.7%, p = 0.01; torque -22.9%, p < 0.001) and moderate-to-severe CD (CSA -14.1%, p < 0.001; torque -7.6%, p = 0.05), but not in NS. Zp was 11.5% lower in advanced CKD (p = 0.005) compared to controls, and this deficit was attenuated to 6.7% (p = 0.05) with adjustment for muscle CSA. With additional adjustment for muscle torque and body weight, Zp was 5.9% lower and the difference with controls was no longer significant (p = 0.09). In participants with moderate-to-severe CD, Zp was 6.8% greater than predicted (p = 0.01) given muscle CSA and torque deficits (R(2)  = 0.92), likely due to acute muscle loss in newly-diagnosed patients. Zp did not differ in NS, compared with controls. In conclusion, muscle torque relative to muscle CSA was significantly lower in CKD and CD, compared with controls, and was independently associated with Zp. Future studies are needed to determine if abnormal muscle strength contributes to progressive bone deficits in chronic disease, independent of muscle area. © 2014 American Society for Bone and Mineral Research. PMID:25264231

  3. 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...

  4. Drug Susceptibility Patterns in MDR-TB Patients: Challenges for Future Regimen Design. A Cross-Sectional Study

    PubMed Central

    Stagg, Helen R.; Brown, James; Cīrule, Andra; Danilovitš, Manfred; Dravniece, Gunta; Jackson, Charlotte; White, Peter J.

    2015-01-01

    Globally, there is substantial concern regarding the challenges of treating complex drug resistance patterns in multidrug resistant tuberculosis cases. Utilising data from three different settings (Estonia, Latvia, Romania) we sought to contrast drug susceptibility profiles for multidrug resistant tuberculosis cases, highlight the difficulties in designing universal regimen, and inform future regimen selection. Demographic and microbiological surveillance data for multidrug resistant tuberculosis cases from 2004–13 were analysed. High levels of additional resistance to currently recommended second line drugs were seen in all settings, with extensive variability between countries. Accurate drug susceptibility testing and drug susceptibility testing data are vital to inform the development of comprehensive, flexible, multidrug resistant tuberculosis guidance. PMID:26558611

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. The total charm cross section

    SciTech Connect

    Vogt, R

    2007-09-14

    We assess the theoretical uncertainties on the total charm cross section. We discuss the importance of the quark mass, the scale choice and the parton densities on the estimate of the uncertainty. We conclude that the uncertainty on the total charm cross section is difficult to quantify.

  10. Revised cross section for RHIC dipole magnets

    SciTech Connect

    Thompson, P.A.; Gupta, R.C.; Kahn, S.A.; Hahn, H.; Morgan, G.H.; Wanderer, P.J.; Willen, E.

    1991-01-01

    Using the experience gained in designing and building Relativistic Heavy Ion Collider (RHIC) dipole prototype magnets an improved cross section has been developed. Significant features of this design include the use of only three wedges for field shaping and wedge cross sections which are sectors of an annulus. To aid in the understanding of the actual magnets, one has been sectioned, and detailed mechanical and photographic measurements made of the wire positions. The comparison of these measurements with the magnetic field measurements will is presented. 2 refs, 3 figs., 2 tabs.

  11. Cross sections at hadron colliders

    SciTech Connect

    Paige, F.E.

    1982-01-01

    The predicted cross sections are given for new Z'/sup 0/ bosons, for the Drell-Yan continuum of ..mu../sup +/..mu../sup -/ pairs, for high p/sub T/ hadron jets, for high p/sub T/ single photons, and for the associated production of heavy quarks. These processes have been selected not to cover the most interesting physics, but to provide a representative selection of cross sections for which to compare various energies and luminosities.

  12. 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

  13. Leisure time computer use and adolescent bone health—findings from the Tromsø Study, Fit Futures: a cross-sectional study

    PubMed Central

    Winther, Anne; Ahmed, Luai Awad; Furberg, Anne-Sofie; Grimnes, Guri; Jorde, Rolf; Nilsen, Ole Andreas; Dennison, Elaine; Emaus, Nina

    2015-01-01

    Objectives Low levels of physical activity may have considerable negative effects on bone health in adolescence, and increasing screen time in place of sporting activity during growth is worrying. This study explored the associations between self-reported screen time at weekends and bone mineral density (BMD). Design In 2010/2011, 1038 (93%) of the region’s first-year upper-secondary school students (15–18 years) attended the Tromsø Study, Fit Futures 1 (FF1). A follow-up survey (FF2) took place in 2012/2013. BMD at total hip, femoral neck and total body was measured as g/cm² by dual X-ray absorptiometry (GE Lunar prodigy). Lifestyle variables were self-reported, including questions on hours per day spent in front of television/computer during weekends and hours spent on leisure time physical activities. Complete data sets for 388/312 girls and 359/231 boys at FF1/FF2, respectively, were used in analyses. Sex stratified multiple regression analyses were performed. Results Many adolescents balanced 2–4 h screen time with moderate or high physical activity levels. Screen time was positively related to body mass index (BMI) in boys (p=0.002), who spent more time in front of the computer than girls did (p<0.001). In boys, screen time was adversely associated with BMDFF1 at all sites, and these associations remained robust to adjustments for age, puberty, height, BMI, physical activity, vitamin D levels, smoking, alcohol, calcium and carbonated drink consumption (p<0.05). Screen time was also negatively associated with total hip BMDFF2 (p=0.031). In contrast, girls who spent 4–6 h in front of the computer had higher BMD than the reference (<2 h). Conclusions In Norwegian boys, time spent on screen-based sedentary activity was negatively associated with BMD levels; this relationship persisted 2 years later. Such negative associations were not present among girls. Whether this surprising result is explained by biological differences remains unclear

  14. The influence of the root cross-section on the stress distribution in teeth restored with a positive-locking post and core design: a finite element study.

    PubMed

    Schilling, Kai-Uwe; Rottner, Kurt; Boldt, Julian; Proff, Peter; Gredes, Tomasz; Richter, Ernst-Jürgen; Reicheneder, Claudia

    2008-10-01

    Human teeth with substantial coronal defects are subject to reconstruction by means of post and core restorations. Typically, such a restoration comprises a slightly cylindrical post onto which an abutment of varying shape, depending on the designated restoration, is attached. As clinical results are not satisfactory to date, we proposed a new proprietary post and core design which makes use of positive locking. As this prefabricated system is not customised to an individual root's cross-sectional geometry (usually oval), a varying amount of radicular dentin is left in periphery of the core's outer edge. The aim of this study was to assess the implications of this fact, i.e., whether the root has to endure higher overall stress levels which ultimately may lead to failure of one of the components involved. A series of finite element simulations were performed to evaluate stress and strain on the system, in which the proposed post and core was embedded into a virtual dentin cylinder of different diameters, ranging from flush mounting of the restoration to a dentin excess of 4 mm, and subsequently loaded with forces with two angles of attack (90 degrees and 130 degrees ). The results show that flush mounting yields an agreeable stress and strain distribution within the radicular dentin, but overall stress levels drop significantly with an excess of 0.5 mm of surrounding dentin. More than 1 mm excess was not found to have profound positive effects. PMID:18803526

  15. Propensity score matching in estimating the effect of managerial education on academic planning behavior. Study design: a cross-sectional study

    PubMed Central

    2011-01-01

    Background In many academic settings teaching a particular topic is applied to every student enrolled in the same academic year, it is a difficult task for researchers to design a randomized control group study. This research aimed to estimate the effect of teaching management and planning on increasing academic planning behavior (APB), using propensity score matching (PSM). Methods In a cross-sectional survey utilizing a self-reported structured questionnaire on a systematic random sample of 421 students in Hanoi Medical University, one of the eight medical schools in Vietnam, this evaluation study adopted regression procedures to assess model fit, then PSM to create a matched control group in order to allow for evaluating the effect of management education. Results The study showed both direct and indirect effects of the education on behavior. After PSM to adjust for the possible confounders to balance statistically two groups - with and without management education, there is statistically a significant difference in APB between these two groups, making a net difference of 18.60% (p < .05). The estimated 18.6 percentage point increase can be translated into the practice of APB by 670 students in the population. This number of academic planners can be attributed to a high recall of important management and planning education. Conclusions The study provided theoretical as well as practical implications to guide the design of the education and evaluation of teaching. PMID:22151539

  16. 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.

  17. Electron Photon Interaction Cross Sections

    2014-11-01

    Version 00 The Electron Photon Interaction Cross Sections, EPICS, provides the atomic data needed to perform coupled Electron-Photon transport calculations, to produce accurate macroscopic results, such as energy deposit and dose. Atomic data is provided for elements, Z = 1 to 100, over the energy range 10 eV to 100 GeV; note that nuclear data, such as photo-nuclear, and data for compounds, are not included. All data is in a simple computer independent text formatmore » that is standard and presented to a high precision that can be easily read by computer codes written in any computer language, e.g., C, C++, and FORTRAN. EPICS includes four separate data bases that are designed to be used in combination, these include, • The Evaluated Electron Data Library (EEDL), to describe the interaction of electrons with matter. • The Evaluated Photon Data Library (EPDL), to describe the interaction of photons with matter. • The Evaluated Atomic Data Library (EADL), to describe the emission of electrons and photons back to neutrality following an ionizing event, caused by either electron or photon interactions. • The Evaluated Excitation Data Library (EXDL), to describe the excitation of atoms due to photon interaction. All of these are available in the Extended ENDL format (ENDLX) in which the evaluations were originally performed. The first three are also available in the ENDF format; as yet ENDF does not include formats to handle excitation data (EXDL).« less

  18. Electron Photon Interaction Cross Sections

    SciTech Connect

    Cullen, D. E.

    2014-11-01

    Version 00 The Electron Photon Interaction Cross Sections, EPICS, provides the atomic data needed to perform coupled Electron-Photon transport calculations, to produce accurate macroscopic results, such as energy deposit and dose. Atomic data is provided for elements, Z = 1 to 100, over the energy range 10 eV to 100 GeV; note that nuclear data, such as photo-nuclear, and data for compounds, are not included. All data is in a simple computer independent text format that is standard and presented to a high precision that can be easily read by computer codes written in any computer language, e.g., C, C++, and FORTRAN. EPICS includes four separate data bases that are designed to be used in combination, these include, • The Evaluated Electron Data Library (EEDL), to describe the interaction of electrons with matter. • The Evaluated Photon Data Library (EPDL), to describe the interaction of photons with matter. • The Evaluated Atomic Data Library (EADL), to describe the emission of electrons and photons back to neutrality following an ionizing event, caused by either electron or photon interactions. • The Evaluated Excitation Data Library (EXDL), to describe the excitation of atoms due to photon interaction. All of these are available in the Extended ENDL format (ENDLX) in which the evaluations were originally performed. The first three are also available in the ENDF format; as yet ENDF does not include formats to handle excitation data (EXDL).

  19. [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.

  20. 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

  1. Presence of Cardiometabolic Risk Factors Is Not Associated with Microalbuminuria in 14-to-20-Years Old Slovak Adolescents: A Cross-Sectional, Population Study

    PubMed Central

    Gurecká, Radana; Koborová, Ivana; Šebek, Jozef; Šebeková, Katarína

    2015-01-01

    Introduction In adults, microalbuminuria indicates generalized endothelial dysfunction, and is an independent risk factor for cardiovascular and all cause mortality. Slovak adults present one of the highest cardiovascular mortality rates in Europe. Thus Slovak adolescents are on a high-risk to develop cardiovascular afflictions early, and screening for microalbuminuria might be useful in early assessment of their cardiovascular risk. We aimed to study the prevalence of microalbuminuria in Slovak adolescents, and the association of urinary albumin-to-creatinine ratio (ACR) to cardiovascular risk factors. Subjects and methods Anthropometric data, blood pressure, blood count, glucose homeostasis, lipid profile, renal function, inflammatory status, concentrations of homocysteine and uric acid were determined and associated with ACR in 2 666 adolescents (49.4% boys, 51.6% girls) aged 14-to-20 years. Microalbuminuria was classified as ACR 2.5–25.0 mg/mmol in boys and 3.5–35.0 mg/mmol in girls. Results Prevalence of microalbuminuria in both genders reached 3.3%, and did not differ significantly between lean and centrally obese subjects. Girls presented higher ACR than boys (normoalbuminuric: 0.6±0.5 mg/mmol vs. 0.5±0.4 mg/mmol, p>0.001; microalbuminuric: 9.3±7.3 mg/mmol vs. 5.0±3.8 mg/mmol; p>0.001). Microalbuminuric adolescents and those presenting normoalbuminuria within the upper ACR quartile were slimmer than their normoalbuminuric counterparts or adolescents with normoalbuminuria within the lower quartile, respectively. No association between microalbuminuria and cardiovascular risk markers was revealed. Conclusion Results obtained in this study do not support our assumption that ACR associates with cardiometabolic risk factors in apparently healthy adolescents. Follow-up studies until adulthood are needed to estimate the potential cardiometabolic risk of apparently healthy microalbuminuric adolescents. PMID:26046923

  2. 242Amm fission cross section

    NASA Astrophysics Data System (ADS)

    Browne, J. C.; White, R. M.; Howe, R. E.; Landrum, J. H.; Dougan, R. J.; Dupzyk, R. J.

    1984-06-01

    The neutron-induced fission cross section of 242Amm has been measured over the energy region from 10-3 eV to ~20 MeV in a series of experiments utilizing a linac-produced "white" neutron source and a monoenergetic source of 14.1 MeV neutrons. The cross section was measured relative to that of 235U in the thermal (0.001 to ~3 eV) and high energy (1 keV to ~20 MeV) regions and normalized to the ENDF/B-V 235U(n,f) evaluated cross section. In the resonance energy region (0.5 eV to 10 keV) the neutron flux was measured using thin lithium glass scintillators and the relative cross section thus obtained was normalized to the thermal energy measurement. This procedure allowed a consistency check between the thermal and high energy data. The cross section data have a statistical accuracy of ~0.5% at thermal energies and in the 1-MeV energy region, and a systematic uncertainty of ~5%. We confirmed that 242Amm has the largest thermal fission cross section known with a 2200 m/sec value of 6328 b. Results of a Breit-Wigner sum-of-single-levels analysis of 48 fission resonances up to 20 eV are presented and the connection of these resonance properties to the large thermal cross section is discussed. Our measurements are compared with previously reported results.

  3. Influences of socioeconomic factors on childhood and adolescent overweight by gender in Korea: cross-sectional analysis of nationally representative sample

    PubMed Central

    2014-01-01

    Background Childhood and adolescent overweight is a recognized public health concern as the prevalence is already high and continues to increase. The purpose of this study was to examine the relationship between socioeconomic status (SES) and overweight status by gender among Korean children and adolescents. Methods The data used in this study were taken from the 2009 Korean Survey on the Obesity of Youth and Children. Underweight individuals (n = 1,010) and children and adolescents whose age, height, or weight information was missing (n = 591) were excluded from the data set, resulting in a total of 8,555 subjects who were included in this analysis. Subjective SES, parental education level, parental occupational status, and family structure were used to measure parental SES. Chi-squared tests were used for univariable analysis and multiple logistic regression analysis was conducted for multivariable analysis. Results After adjusting for subject’s characteristics including gender, age, parental interest in weight management of children, parental body shape, economic status variables that significantly influenced childhood overweight were identified. Low economic status increased the probability of childhood overweight (odds ratio, 1.3; 95% confidence interval, 1.1-1.5). Conclusions There is an inverse association between parental SES variables and the overweight status of children and adolescents. Additionally, parental body shape is an important factor that influences childhood and adolescent overweight. PMID:24708879

  4. Comparison of the Schwartz and CKD-EPI Equations for Estimating Glomerular Filtration Rate in Children, Adolescents, and Adults: A Retrospective Cross-Sectional Study

    PubMed Central

    Selistre, Luciano; Rabilloud, Muriel; Cochat, Pierre; de Souza, Vandréa; Iwaz, Jean; Lemoine, Sandrine; Beyerle, Françoise; Poli-de-Figueiredo, Carlos E.; Dubourg, Laurence

    2016-01-01

    aged ≥65 y, the CKD-EPI equation performed better than the Schwartz equation (IQR: 0.33 [95% CI 0.31; 0.34] versus 0.40 [95% CI 0.38; 0.41]; P30: 77.6 [95% CI 75.7; 79.5] versus 67.5 [95% CI 65.4; 69.7], respectively). In children and adolescents (2–17 y), the Schwartz equation was superior to the CKD-EPI equation (IQR: 0.23 [95% CI 0.21; 0.24] versus 0.33 [95% CI 0.31; 0.34]; P30: 88.6 [95% CI 86.7; 90.4] versus 29.4 [95% CI 26.8; 32.0]). This study is limited by its retrospective design, single-center setting with few non-white patients, and small number of patients with severe chronic kidney disease. Conclusions The results from this study suggest that the Schwartz equation may be more reliable than the CKD-EPI equation for estimating GFR in children and adolescents and in adults with mild to moderate kidney impairment up to age 40 y. PMID:27023756

  5. 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

  6. 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. PMID:26568443

  7. 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

  8. 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

  9. Impact of socioeconomic and risk factors on cardiovascular disease and type II diabetes in Australia: comparison of results from longitudinal and cross-sectional designs

    PubMed Central

    Li, Jinjing; Kinfu, Yohannes

    2016-01-01

    Objective Existing large-scale studies do not take into account comorbidity or control for selection and endogeneity biases. This study addresses these shortcomings. Participants We use information on individuals aged between 35 and 70 years from a nationally representative longitudinal survey conducted in Australia between 2001 and 2013. Participants were approached annually, and updates on their characteristics, including health status, were ascertained through self-reporting. Method We develop three different analytical designs. The first model is a cross-sectional analysis against which our improved models are compared. In the second model, we follow the same approach but control for prior health conditions. The last preferred model additionally adjusts for characteristics and risk profile of respondents prior to onset of conditions. It also allows for comorbidity and controls for selection bias. Results Once comorbidity and changes over time in the participant's characteristics are controlled for, body mass index (BMI), alcohol consumption and physical activity exhibit a stronger impact than in the models without these controls. A unit increase in BMI increases the risk of developing a cardiovascular disease (CVD) condition within 2 years by 1.3 percentage points (β=0.11, 95% CI 0.05 to 0.16) and regular alcohol intake increases the risk of CVD by 3.0 percentage points (β=0.24, 95% CI 0.09 to 0.39). Both factors lose significance without proper control for endogenous behavioural change. We also note that frequent physical activity reduces the risk of developing diabetes by 0.9 percentage point (β=−0.40, 95% CI −0.72 to −0.07). Conclusions Our result shows a greater importance of certain lifestyle and risk factors than was previously suggested. PMID:27053269

  10. The impact of the built environment on health across the life course: design of a cross-sectional data linkage study

    PubMed Central

    Villanueva, Karen; Pereira, Gavin; Knuiman, Matthew; Bull, Fiona; Wood, Lisa; Christian, Hayley; Foster, Sarah; Boruff, Bryan J; Beesley, Bridget; Hickey, Sharyn; Joyce, Sarah; Nathan, Andrea; Saarloos, Dick; Giles-Corti, Billie

    2013-01-01

    Introduction The built environment is increasingly recognised as being associated with health outcomes. Relationships between the built environment and health differ among age groups, especially between children and adults, but also between younger, mid-age and older adults. Yet few address differences across life stage groups within a single population study. Moreover, existing research mostly focuses on physical activity behaviours, with few studying objective clinical and mental health outcomes. The Life Course Built Environment and Health (LCBEH) project explores the impact of the built environment on self-reported and objectively measured health outcomes in a random sample of people across the life course. Methods and analysis This cross-sectional data linkage study involves 15 954 children (0–15 years), young adults (16–24 years), adults (25–64 years) and older adults (65+years) from the Perth metropolitan region who completed the Health and Wellbeing Surveillance System survey administered by the Department of Health of Western Australia from 2003 to 2009. Survey data were linked to Western Australia's (WA) Hospital Morbidity Database System (hospital admission) and Mental Health Information System (mental health system outpatient) data. Participants’ residential address was geocoded and features of their ‘neighbourhood’ were measured using Geographic Information Systems software. Associations between the built environment and self-reported and clinical health outcomes will be explored across varying geographic scales and life stages. Ethics and dissemination The University of Western Australia's Human Research Ethics Committee and the Department of Health of Western Australia approved the study protocol (#2010/1). Findings will be published in peer-reviewed journals and presented at local, national and international conferences, thus contributing to the evidence base informing the design of healthy neighbourhoods for all residents. PMID

  11. Self-reported depression is increasing among socio-economically disadvantaged adolescents – repeated cross-sectional surveys from Finland from 2000 to 2011

    PubMed Central

    2014-01-01

    Background Adolescent depression is more common in lower socio-economic groups. Whether this pattern has changed over time, is not known. We examined the prevalence of self-reported depression and its changes in socio-economic groups from 2000 to 2011 among Finnish adolescents. Methods Data were based on classroom surveys every second year from 2000–2001 to 2010–2011 using nationwide samples of 14–16-year old Finns (n = 618,084). Data were collected using self-administered questionnaires including questions on health, health behaviours, and school experiences. Depression was measured with a Finnish modification of the 13-item Beck Depression Inventory, and divided into no, mild, moderate and severe depression. The association between depression and the social background (parents’ education and employment) over time was studied using a multinomial regression analysis. Results The prevalence of self-reported severe depression slightly increased from 2000–2001 to 2010–2011 in girls. In boys a slight increase was observed when adjusting for background variables. The differences in the prevalence of depression between the social background groups persisted over the entire study period. In both sexes, severe depression nearly doubled among those adolescents whose parents were unemployed and had a low education level; among boys, the prevalence was 6.5% in 2000–2001 and 12.8% in 2010–2011, and among girls 6.4% and 11.4% respectively. Conclusion The largest increases in prevalence of severe depression are seen among socio-economically disadvantaged adolescents. This suggests that inequalities in mental health may become an increasing concern. PMID:24775269

  12. 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

  13. 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

    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

  14. 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

  15. 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. PMID:26157484

  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. 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. PMID:24405775

  18. 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. PMID:26431469

  19. Can negative life events and coping style help explain socioeconomic differences in perceived stress among adolescents? A cross-sectional study based on the West Jutland cohort study

    PubMed Central

    2013-01-01

    Background Previous research suggests that perceived stress in adolescence is socially patterned, but that this relationship may depend on the measure of socioeconomic status (SES) used. This study examines if social gradients in perceived stress, negative life events, and coping exist amongst Danish adolescents, and, if life events and coping strategies can partly account for an association between SES and perceived stress. These relationships are studied separately for two different measures of SES. Methods Questionnaire data were collected from 3054 14–15 year old youths (83% response rate) during baseline measurement in the West Jutland birth cohort study. Parents were identified via the Central Office of Civil Registration in which the respondents are linked to their parents or guardians via their CPR-number, a personal identification number given to everyone in Denmark. The study employs data from two independent sources, adolescent self-report data (stress, life events and coping) and national registers (parental educational level, household income and confounder variables). Ordinary Least Squares regression estimated the effects of parental SES, negative life events and coping on perceived stress. Analyses were stratified by gender. Results Girls reported more perceived stress than boys. SES accounted for a small but significant amount of the variance in perceived stress. Lower parental education and lower household income were associated with higher stress levels irrespective of gender, but the social gradient was strongest amongst girls when parents’ education was used to measure SES, and strongest for boys when income was used. Life events and coping were also found to be associated with SES and both mediated part of the SES-perceived stress relationship. In general, the social gradient in perceived stress was accounted for by the study variables to a higher degree among girls than among boys. Conclusions Lower parental education and household

  20. Association between societal costs and treatment response in children and adolescents with ADHD and their parents. A cross-sectional study in the Netherlands.

    PubMed

    van der Kolk, Annemarie; Bouwmans, Clazien Am; Schawo, Saskia J; Buitelaar, Jan K; van Agthoven, Michel; Hakkaart-van Roijen, Leona

    2015-01-01

    Attention Deficit Hyperactivity Disorder (ADHD) is associated with considerable burden of illness at a patient, family and societal level. Although pharmacological treatment is recommended by authoritative guidelines, evidence on its influence on the broader burden of illness is limited. As treatment induces costs, proper healthcare decision making requires evidence on the associated societal costs or benefits and particularly the difference that response to treatment can make. Data on ADHD related resource use of patients 8-18 years and parents were collected by means of a cross-sectional, online survey amongst members of the Dutch parent association. Children were stratified to responders and non-responders to treatment according to pre-defined expert definitions. Analyses were performed on 618 questionnaires (428 responders; 190 non-responders to treatment). Children were 11.8 years on average and mainly boys (82 %). Total monthly costs for children were €578 and €839 for responders and non-responders, respectively (p = 0.021), with a breakdown to direct medical costs (€322 vs. €512; p = 0.068), direct non-medical costs (€222 vs. €296; p = 0.090), and indirect non-medical costs (€34 vs. €57; p < 0.001). For parents, total costs were €246 vs. €399 for the responding and non-responding children, respectively (p = 0.006), with a breakdown to direct medical costs (€130 vs. €211; p = 0.010) and indirect non-medical costs (€116 vs. €181; p = 0.092). Total monthly costs of children and their parents together were €824 and €1228 for responders and non-responders to treatment, respectively (p = 0.002). These results stress the importance of a focus on response to treatment, not only beneficial for patients and their family, but also resulting in considerable societal benefits. PMID:26155437

  1. An empirical investigation of the structure of anxiety and depressive symptoms in late adolescence: cross-sectional study using the Greek version of the revised Clinical Interview Schedule.

    PubMed

    Skapinakis, Petros; Anagnostopoulos, Fotios; Bellos, Stefanos; Magklara, Konstantina; Lewis, Glyn; Mavreas, Venetsanos

    2011-04-30

    Several studies in the past have examined whether the hierarchical structure of anxiety and depressive symptoms can explain the high comorbidity between them but more studies are needed from other settings and with different methods. The present study aimed to examine the structure of common anxiety and depressive symptoms in adolescents 16-18 years old attending secondary schools using the Greek version of the revised Clinical Interview Schedule (CIS-R), a fully structured psychiatric interview. A total of 2431 adolescents were interviewed with the computerized version of the CIS-R. The hierarchical structure of 12 depressive and anxiety symptoms was examined with confirmatory factor analytical methods. Four alternative models of increasing complexity were tested. The best-fitting model included three first-order factors, representing the dimensions of anxiety, depression and non-specific distress respectively. A model with a higher-order factor representing the broader internalizing dimension was less supported by the data. The findings of this and other studies should be taken into account in future classifications of psychiatric disorders and may have clinical practical implications. PMID:20846727

  2. 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

  3. Parenting Style and Family Meals: Cross-Sectional and 5-year Longitudinal Associations

    PubMed Central

    Berge, Jerica M.; Wall, Melanie; Neumark-Sztainer, Dianne; Larson, Nicole; Story, Mary

    2010-01-01

    Background Research on family meals in the last decade has shown a positive association between family meal frequency and adolescent healthy dietary intake. However, less is known about factors within the home environment, such as parenting style, which may be associated with family meal patterns. Objective The purpose of this study is to test cross-sectional and five-year longitudinal associations between parenting styles (authoritative, authoritarian, permissive, neglectful) and the frequency of family meals among adolescents. Study Design Data were from Project EAT (Eating Among Teens), a population-based study comprised of youth from diverse ethnic/racial and socioeconomic backgrounds. Two cohorts of adolescents (middle school, high school) completed in-class surveys in 1999 (Time 1) and mailed surveys in 2004 (Time 2). Multiple linear regression models were used to predict mean frequency of family meals at Time 1 and Time 2 from adolescent report of parenting style (both mother and father) at Time 1. Cross-sectional analyses included both adolescent cohorts (n = 4,746) and longitudinal analyses included only the younger cohort (n = 806) because family meal frequency was not assessed in the older cohort at Time 2. Results Cross-sectional results for adolescent girls indicated a positive association between maternal and paternal authoritative parenting style and frequency of family meals. For adolescent boys, maternal authoritative parenting style was associated with more frequent family meals. Longitudinal results indicated that authoritative parenting style predicted higher frequency of family meals five years later, but only between opposite sex parent/adolescent dyads. Conclusions Future research should identify additional factors within the home environment that are associated with family meal frequency in order to develop effective interventions that result in increased family meals for youth. Also, future research should investigate the mealtime behaviors

  4. 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

  5. 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

  6. Cross sections required for FMIT dosimetry

    SciTech Connect

    Gold, R.; McElroy, W.N.; Lippincott, E.P.; Mann, F.M.; Oberg, D.L.; Roberts, J.H.; Ruddy, F.H.

    1980-05-02

    The Fusion Materials Irradiation Test (FMIT) facility, currently under construction, is designed to produce a high flux of high energy neutrons for irradiation effects experiments on fusion reactor materials. Characterization of the flux-fluence-spectrum in this rapidly varying neutron field requires adaptation and extension of currently available dosimetry techniques. This characterization will be carried out by a combination of active, passive, and calculational dosimetry. The goal is to provide the experimenter with accurate neutron flux-fluence-spectra at all positions in the test cell. Plans have been completed for a number of experimental dosimetry stations and provision for these facilities has been incorporated into the FMIT design. Overall needs of the FMIT irradiation damage program delineate goal accuracies for dosimetry that, in turn, create new requirements for high energy neutron cross section data. Recommendations based on these needs have been derived for required cross section data and accuracies.

  7. 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

  8. Design and construction of a large area detector system and neutron total cross section measurements in the energy range 0.4 to 20 MeV

    NASA Astrophysics Data System (ADS)

    Rapp, Michael James

    In an effort to extend the measurement capabilities of the Gaerttner LINAC Laboratory at Rensselaer Polytechnic Institute (RPI) into the MeV region, a new detector system and analysis methods were developed. A large volume modular proton recoil detector was constructed and placed in a collimated neutron beam at an effective distance of 99.95 meters from the neutron source. Transmission measurements were done on natural carbon (graphite), beryllium, molybdenum, zirconium, titanium and tantalum using the time-of-flight method. Combining the long flight path, fast detector response and electronics, and a narrow neutron pulse width, provided good energy resolution, enabling some of the measurements to resolve structure in neutron total cross section never before seen. In order to obtain accurate transmission calculations, a method was developed to determine the time-dependent background component associated with the measurement, using a combination of experimental data and Monte Carlo methods. This background, combined with the high neutron flux provided by the RPI LINAC, generated high signal-to-background ratios. This signal-to-background and low counting statistics error resulted in low uncertainties and highly accurate data, with uncertainties of less than one percent seen through much of the measured energy range. The carbon measurement, which has a well measured and agreed upon neutron total cross section in the energy range 0.4 to 20 MeV, provided verification of the accuracy in the measurement and analytical methods used, with an average difference of less than one percent seen between the experimental and evaluated data. The measurements of beryllium, molybdenum, zirconium, titanium and tantalum, also resulted in accurate measurements of neutron total cross section. These high-resolution, high-accuracy results showed that improvements can be made in the current neutron total cross section evaluations, some of which show differences up to 10 %. The experimental

  9. DBCC Software as Database for Collisional Cross-Sections

    NASA Astrophysics Data System (ADS)

    Moroz, Daniel; Moroz, Paul

    2014-10-01

    Interactions of species, such as atoms, radicals, molecules, electrons, and photons, in plasmas used for materials processing could be very complex, and many of them could be described in terms of collisional cross-sections. Researchers involved in plasma simulations must select reasonable cross-sections for collisional processes for implementing them into their simulation codes to be able to correctly simulate plasmas. However, collisional cross-section data are difficult to obtain, and, for some collisional processes, the cross-sections are still not known. Data on collisional cross-sections can be obtained from numerous sources including numerical calculations, experiments, journal articles, conference proceedings, scientific reports, various universities' websites, national labs and centers specifically devoted to collecting data on cross-sections. The cross-sections data received from different sources could be partial, corresponding to limited energy ranges, or could even not be in agreement. The DBCC software package was designed to help researchers in collecting, comparing, and selecting cross-sections, some of which could be constructed from others or chosen as defaults. This is important as different researchers may place trust in different cross-sections or in different sources. We will discuss the details of DBCC and demonstrate how it works and why it is beneficial to researchers working on plasma simulations.

  10. 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

  11. 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

  12. Recommended Dosimetry Cross Section Compendium.

    1994-07-11

    Version 00 The data is recommended for spectrum determination applications and for the prediction of neutron activation of typical radiation sensor materials. The library has been tested for consistency of the cross sections in a wide variety of neutron environments. The results and cautions from this testing have been documented. The data has been interfaced with radiation transport codes, such as TWODANT-SYS (CCC-547) and MCNP (CCC-200), in order to compare calculated and measured activities formore » benchmark reactor experiments.« less

  13. 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 Central

    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

  14. 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.

  15. (Fast neutron cross section measurements)

    SciTech Connect

    Not Available

    1991-01-01

    In the 14 MeV Neutron Laboratory, we have continued the development of a facility that is now the only one of its kind in operation in the United States. We have refined the klystron bunching system described in last year's report to the point that 1.2 nanosecond pulses have been directly measured. We have tested the pulse shape discrimination capability of our primary NE 213 neutron detector. We have converted the RF sweeper section of the beamline to a frequency of 1 MHz to replace the function of the high voltage pulser described in last year's report which proved to be difficult to maintain and unreliable in its operation. We have also overcome several other significant experimental difficulties, including a major problem with a vacuum leak in the main accelerator column. We have completed additional testing to prove the remainder of the generation and measurement systems, but overcoming some of these experimental difficulties has delayed the start of actual data taking. We are now in a position to begin our first series of ring geometry elastic scattering measurements, and these will be underway before the end of the current contract year. As part of our longer term planning, we are continuing the conceptual analysis of several schemes to improve the intensity of our current pulsed beam. These include the provision of a duoplasmatron ion source and/or the provision of preacceleration bunching. Additional details are given later in this report. A series of measurements were carried out at the Tandem Dynamatron Facility involving the irradiation of a series of yttrium foils and the determination of activation cross sections using absolute counting techniques. The experimental work has been completed, and final analysis of the cross section data will be completed within several months.

  16. 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.

  17. Recent fission cross section standards measurements

    SciTech Connect

    Wasson, O.A.

    1985-01-01

    The /sup 235/U(n,f) reaction is the standard by which most neutron induced fission cross sections are determined. Most of these cross sections are derived from relatively easy ratio measurements to /sup 235/U. However, the more difficult /sup 235/U(n,f) cross section measurements require the use of advanced neutron detectors for the determination of the incident neutron fluence. Examples of recent standard cross section measurements are discussed, various neutron detectors are described, and the status of the /sup 235/U(n,f) cross section standard is assessed. 23 refs., 8 figs., 4 tabs.

  18. 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.

  19. Methodology Series Module 3: Cross-sectional Studies

    PubMed Central

    Setia, Maninder Singh

    2016-01-01

    Cross-sectional study design is a type of observational study design. In a cross-sectional study, the investigator measures the outcome and the exposures in the study participants at the same time. Unlike in case–control studies (participants selected based on the outcome status) or cohort studies (participants selected based on the exposure status), the participants in a cross-sectional study are just selected based on the inclusion and exclusion criteria set for the study. Once the participants have been selected for the study, the investigator follows the study to assess the exposure and the outcomes. Cross-sectional designs are used for population-based surveys and to assess the prevalence of diseases in clinic-based samples. These studies can usually be conducted relatively faster and are inexpensive. They may be conducted either before planning a cohort study or a baseline in a cohort study. These types of designs will give us information about the prevalence of outcomes or exposures; this information will be useful for designing the cohort study. However, since this is a 1-time measurement of exposure and outcome, it is difficult to derive causal relationships from cross-sectional analysis. We can estimate the prevalence of disease in cross-sectional studies. Furthermore, we will also be able to estimate the odds ratios to study the association between exposure and the outcomes in this design. PMID:27293245

  20. Liquid-metal MHD flow in a duct whose cross section changes from a rectangle to a trapezoid, with applications in fusion blanket designs

    SciTech Connect

    Walker, J.S.

    1986-04-01

    This paper treats the liquid-metal MHD flow in a semi-infinite rectangular duct and a semi-infinite trapezoidal duct, which are connected by a finite-length transition duct. There is a strong, transverse, uniform magnetic field. The walls parallel to the magnetic field (sides) remain parallel, while the walls intersecting the magnetic field are twisted in the transition duct to provide the change in cross sectional shape. The left side has a constant height, while the height of the right side increases or decreases in the transition duct. This geometry gives a skewed velocity profile with a high velocity near the left side, provided the right side is relatively thick. All walls are thin and electrically conducting, but the sides are considerably thicker than the other walls. The application is to fusion-reactor blankets in which a high velocity near the first wall (separating the plasma chamber from the coolant) improves the thermal performance. Junctions of different ducts with walls parallel to the magnetic field are treated for the first time. In expansions, contractions and other geometric transition ducts, as well as in straight ducts with axially varying magnetic fields, the fluid flow and electric currents are concentrated in boundary layers adjacent to the sides and in the side. At a junction with a straight duct with a uniform magnetic field, the flow and current must transfer from the boundary layers adn sides to the core regions. These transfers at junctions play a key role in any three-dimensional flow.

  1. 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.

  2. 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).

  3. Actinide Targets for Neutron Cross Section Measurements

    SciTech Connect

    John D. Baker; Christopher A. McGrath

    2006-10-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from "minor" actinides that currently have poorly known or in some cases not measured (n,?) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  4. 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

  5. Design and Validation of a Novel Method to Measure Cross-Sectional Area of Neck Muscles Included during Routine MR Brain Volume Imaging

    PubMed Central

    Kilgour, Alixe H. M.; Subedi, Deepak; Gray, Calum D.; Deary, Ian J.; Lawrie, Stephen M.; Wardlaw, Joanna M.; Starr, John M.

    2012-01-01

    Introduction Low muscle mass secondary to disease and ageing is an important cause of excess mortality and morbidity. Many studies include a MR brain scan but no peripheral measure of muscle mass. We developed a technique to measure posterior neck muscle cross-sectional area (CSA) on volumetric MR brain scans enabling brain and muscle size to be measured simultaneously. Methods We performed four studies to develop and test: feasibility, inter-rater reliability, repeatability and external validity. We used T1-weighted MR brain imaging from young and older subjects, obtained on different scanners, and collected mid-thigh MR data. Results After developing the technique and demonstrating feasibility, we tested it for inter-rater reliability in 40 subjects. Intraclass correlation coefficients (ICC) between raters were 0.99 (95% confidence intervals (CI) 0.98–1.00) for the combined group (trapezius, splenius and semispinalis), 0.92 (CI 0.85–0.96) for obliquus and 0.92 (CI 0.85–0.96) for sternocleidomastoid. The first unrotated principal component explained 72.2% of total neck muscle CSA variance and correlated positively with both right (r = 0.52, p = .001) and left (r = 0.50, p = .002) grip strength. The 14 subjects in the repeatability study had had two MR brain scans on three different scanners. The ICC for between scanner variation for total neck muscle CSA was high at 0.94 (CI 0.86–0.98). The ICCs for within scanner variations were also high, with values of 0.95 (CI 0.86–0.98), 0.97 (CI 0.92–0.99) and 0.96 (CI 0.86–0.99) for the three scanners. The external validity study found a correlation coefficient for total thigh CSA and total neck CSA of 0.88. Discussion We present a feasible, valid and reliable method for measuring neck muscle CSA on T1-weighted MR brain scans. Larger studies are needed to validate and apply our technique with subjects differing in age, ethnicity and geographical location. PMID:22509305

  6. 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

  7. 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.

  8. Topological Optimization of Beam Cross Section by Employing Extrusion Constraint

    NASA Astrophysics Data System (ADS)

    Zuberi, Rehan H.; Zhengxing, Zuo; Kai, Long

    2010-05-01

    Optimal cross-section design of beams plays a characteristic role which signifies the rigidity of the member in bending, shear and torsion load conditions. Practically modern overhead crane girders, railway bridge girders or rail tracks etc. require constant cross-section along the axial direction. Conventional topological optimization modeling procedures in such cases prove inadequate for the reason that these procedures generate non-uniform topologies along the axis of the bending member. To examine optimal topology of those structural bending members which commonly possess constant cross-section along the axis the topology optimization with extrusion constraint is more appropriate. The extrusion constraint method suggests a fresh approach to investigate optimal topologies of beam cross-section under the influence of realistic loading condition across the section at the beginning of design cycle. Presented study is focused upon the influence of various configuration and location of the load and boundary conditions on the topology of the of the beam cross-section which was not possible prior to the materialization of the extrusion or stamping constraint method. Several realistic loads and boundary conditions have been applied on the 3D beam model and optimal cross-section topologies obtained have uniform compliance history and convergent solutions. The lowest compliance criteria have been suggested to choose topologies as furthers shape and size optimization candidates during beam design process.

  9. 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.

  10. 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.

  11. Theoretical antideuteron-nucleus absorptive cross sections

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Antideuteron-nucleus absorptive cross sections for intermediate to high energies are calculated using an ion-ion optical model. Good agreement with experiment (within 15 percent) is obtained in this same model for (bar p)-nucleus cross sections at laboratory energies up to 15 GeV. We describe a technique for estimating antinucleus-nucleus cross sections from NN data and suggest that further cosmic ray studies to search for antideuterons and other antinuclei be undertaken.

  12. 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.

  13. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  14. 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.

  15. Thermoelastic damping in microrings with circular cross-section

    NASA Astrophysics Data System (ADS)

    Li, Pu; Fang, Yuming; Zhang, Jianrun

    2016-01-01

    Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular cross-section. The temperature field in the rectangular cross-section is one-dimensional. This paper deals with TED in the microrings with circular cross-section. The temperature field in the circular cross-section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with circular cross-section. Only the two-dimensional heat conduction in the circular cross-section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

  16. Design, fabrication, and characterization of a planar, silicon-based, monolithically integrated micro laminar flow fuel cell with a bridge-shaped microchannel cross-section

    NASA Astrophysics Data System (ADS)

    López-Montesinos, P. O.; Yossakda, N.; Schmidt, A.; Brushett, F. R.; Pelton, W. E.; Kenis, P. J. A.

    2011-05-01

    We report the fabrication of a planar, silicon-based, monolithically integrated micro laminar flow fuel cell (μLFFC) using standard MEMS and IC-compatible fabrication technologies. The μLFFC operates with acid supported solutions of formic acid and potassium permanganate, as a fuel and oxidant respectively. The micro-fuel cell design features two in-plane anodic and cathodic microchannels connected via a bridge to confine the diffusive liquid-liquid interface away from the electrode areas and to minimize crossover. Palladium high-active-surface-area catalyst was selectively integrated into the anodic microchannel by electrodeposition, whereas no catalyst was required in the cathodic microchannel. A three-dimensional (3D) diffusion-convection model was developed to study the behavior of the diffusion zone and to extract appropriate cell-design parameters and operating conditions. Experimentally, we observed peak power densities as high as 26 mW cm-2 when operating single cells at a flow rate of 60 μL min-1 at room temperature. The miniature membraneless fuel cell design presented herein offers potential for on-chip power generation, which has long been prohibited by integration complexities associated with the membrane.

  17. 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.

  18. 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.

  19. Cross-sectional survey comparing HIV risk behaviours of adolescent and young adult men who have sex with men only and men who have sex with men and women in the US and Puerto Rico

    PubMed Central

    Ellen, Jonathan M; Greenberg, Lauren; Willard, Nancy; Stines, Stephanie; Korelitz, James; Boyer, Cherrie B

    2015-01-01

    Objective To examine the HIV risk behaviours of men who have sex with men only (MSMO) and men who have sex with men and women (MSMW), aged 12–24 years, in five US cities and in San Juan, Puerto Rico. Methods Data were collected through four annual cross-sectional anonymous surveys at community venues and included questions about sexual partnerships, sexual practices including condom use and substance use. Demographic and risk profiles were summarised for both groups. Results A total of 1198 men were included in this analysis, including 565 MSMO and 633 MSMW. There were statistically significant differences between the two groups for many risk factors examined in multivariable models. MSMW were more likely to identify as bisexual, be in a long-term relationship, have a history of homelessness, have ever used marijuana, have ever been tested for HIV and to have been tested for HIV within the past 6 months. MSMW may be more likely to ever exchange sex for money and ever have a sexually transmitted infection than MSMO. Conclusions MSMW were more likely to report several markers of socioeconomic vulnerability or behaviours associated with increased risk for HIV than MSMO. MSMW contribute to HIV prevalence in the USA, and better understanding of the risk profile of this group is essential to understand heterosexual HIV transmission. MSMW, particularly those who identify as bisexual or questioning, may feel uncomfortable participating in programmes that are designed for gay-identified men. Therefore, prevention strategies need to target distinct subgroups that compose the population of MSM. PMID:25587181

  20. Health-Related Quality of Life in Children and Adolescents with Hereditary Bleeding Disorders and in Children and Adolescents with Stroke: Cross-Sectional Comparison to Siblings and Peers

    PubMed Central

    Neuner, Bruno; von Mackensen, Sylvia; Holzhauer, Susanne; Funk, Stephanie; Klamroth, Robert; Kurnik, Karin; Krümpel, Anne; Halimeh, Susan; Reinke, Sarah; Frühwald, Michael; Nowak-Göttl, Ulrike

    2016-01-01

    Objectives. To investigate self-reported health-related quality of life (HrQoL) in children and adolescents with chronic medical conditions compared with siblings/peers. Methods. Group 1 (6 treatment centers) consisted of 74 children/adolescents aged 8–16 years with hereditary bleeding disorders (HBD), 12 siblings, and 34 peers. Group 2 (one treatment center) consisted of 70 children/adolescents with stroke/transient ischemic attack, 14 siblings, and 72 peers. HrQoL was assessed with the “revised KINDer Lebensqualitätsfragebogen” (KINDL-R) questionnaire. Multivariate analyses within groups were done by one-way ANOVA and post hoc pairwise single comparisons by Student's t-tests. Adjusted pairwise comparisons were done by hierarchical linear regressions with individuals nested within treatment centers (group 1) and by linear regressions (group 2), respectively. Results. No differences were found in multivariate analyses of self-reported HrQoL in group 1, while in group 2 differences occurred in overall wellbeing and all subdimensions. These differences were due to differences between patients and peers. After adjusting for age, gender, number of siblings, and treatment center these differences persisted regarding self-worth (p = .0040) and friend-related wellbeing (p < .001). Conclusions. In children with HBD, HrQoL was comparable to siblings and peers. In children with stroke/TIA HrQoL was comparable to siblings while peers, independently of relevant confounder, showed better self-worth and friend-related wellbeing. PMID:27294108

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

    SciTech Connect

    Elaine Schulte

    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

  2. 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.

  3. 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.

  4. 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.

  5. International Evaluation of Neutron Cross Section Standards

    NASA Astrophysics Data System (ADS)

    Carlson, A. D.; Pronyaev, V. G.; Smith, D. L.; Larson, N. M.; Chen, Zhenpeng; Hale, G. M.; Hambsch, F.-J.; Gai, E. V.; Oh, Soo-Youl; Badikov, S. A.; Kawano, T.; Hofmann, H. M.; Vonach, H.; Tagesen, S.

    2009-12-01

    Neutron cross section standards are the basis for the determination of most neutron cross sections. They are used for both measurements and evaluations of neutron cross sections. Not many cross sections can be obtained absolutely - most cross sections are measured relative to the cross section standards and converted using evaluations of the standards. The previous complete evaluation of the neutron cross section standards was finished in 1987 and disseminated as the NEANDC/INDC and ENDF/B-VI standards. R-matrix model fits for the light elements and non-model least-squares fits for all the cross sections in the evaluation were the basis of the combined fits for all of the data. Some important reactions and constants are not standards, but they assist greatly in the determination of the standard cross sections and reduce their uncertainties - these data were also included in the combined fits. The largest experimental database used in the evaluation was prepared by Poenitz and included about 400 sets of experimental data with covariance matrices of uncertainties that account for all cross-energy, cross-reaction and cross-material correlations. For the evaluation GMA, a least-squares code developed by Poenitz, was used to fit all types of cross sections (absolute and shape), their ratios, spectrum-averaged cross sections and thermal constants in one full analysis. But, the uncertainties derived in this manner, and especially those obtained in the R-matrix model fits, have been judged to be too low and unrealistic. These uncertainties were substantially increased prior to their release in the recommended data files of 1987. Modified percentage uncertainties were reassigned by the United States Cross Section Evaluation Working Group's Standards Subcommittee for a wide range of energies, and no covariance (or correlation) matrices were supplied at that time. The need to re-evaluate the cross section standards is based on the appearance of a significant amount of precise

  6. Absorption cross section of canonical acoustic holes

    SciTech Connect

    Crispino, Luis C. B.; Oliveira, Ednilton S.; Matsas, George E. A.

    2007-11-15

    We compute numerically the absorption cross section of a canonical acoustic hole for sound waves with arbitrary frequencies. Our outputs are in full agreement with the expected low- and high-frequency limits.

  7. 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.

  8. Shuttle orbiter radar cross-sectional analysis

    NASA Technical Reports Server (NTRS)

    Cooper, D. W.; James, R.

    1979-01-01

    Theoretical and model simulation studies on signal to noise levels and shuttle radar cross section are described. Pre-mission system calibrations, system configuration, and postmission system calibration of the tracking radars are described. Conversion of target range, azimuth, and elevation into radar centered east north vertical position coordinates are evaluated. The location of the impinging rf energy with respect to the target vehicles body axis triad is calculated. Cross section correlation between the two radars is presented.

  9. Reaction cross sections of unstable nuclei

    SciTech Connect

    Ozawa, Akira

    2006-11-02

    Experimental studies on reaction cross sections are reviewed. The recent developments of radioactive nuclear beams have enabled us to measure reaction cross-sections for unstable nuclei. Using Glauber-model analysis, effective nuclear matter density distributions of unstable nuclei can be studied. Recent measurements in RIBLL at IMP and RIPS at RIKEN are introduced. The effective matter density distributions for 14-18C are also mentioned.

  10. 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.

  11. Path forward for dosimetry cross sections

    SciTech Connect

    Griffin, P.J.; Peters, C.D.

    2011-07-01

    In the 1980's the dosimetry community embraced the need for a high fidelity quantification of uncertainty in nuclear data used for dosimetry applications. This led to the adoption of energy-dependent covariance matrices as the accepted manner of quantifying the uncertainty data. The trend for the dosimetry community to require high fidelity treatment of uncertainty estimates has continued to the current time where requirements on nuclear data are codified in standards such as ASTM E 1018. This paper surveys the current state of the dosimetry cross sections and investigates the quality of the current dosimetry cross section evaluations by examining calculated-to-experimental ratios in neutron benchmark fields. In recent years more nuclear-related technical areas are placing an emphasis on uncertainty quantification. With the availability of model-based cross sections and covariance matrices produced by nuclear data codes, some nuclear-related communities are considering the role these covariance matrices should play. While funding within the dosimetry community for cross section evaluations has been very meager, other areas, such as the solar-related astrophysics community and the US Nuclear Criticality Safety Program, have been supporting research in the area of neutron cross sections. The Cross Section Evaluation Working Group (CSEWG) is responsible for the creation and maintenance of the ENDF/B library which has been the mainstay for the reactor dosimetry community. Given the new trends in cross section evaluations, this paper explores the path forward for the US nuclear reactor dosimetry community and its use of the ENDF/B cross-sections. The major concern is maintenance of the sufficiency and accuracy of the uncertainty estimate when used for dosimetry applications. The two major areas of deficiency in the proposed ENDF/B approach are: 1) the use of unrelated covariance matrices in ENDF/B evaluations and 2) the lack of 'due consideration' of experimental data

  12. Cross sections for actinide burner reactors

    SciTech Connect

    Difilippo, F.C.

    1991-01-01

    Recent studies have shown the feasibility of burning higher actinides (i.e., transuranium (TRU) elements excluding plutonium) in ad hoc designed reactors (Actinide Burner Reactors: ABR) which, because of their hard neutron spectra, enhance the fission of TRU. The transmutation of long-lived radionuclides into stable or short-lived isotopes reduces considerably the burden of handling high-level waste from either LWR or Fast Breeder Reactors (FBR) fuels. Because of the large concentrations of higher actinides in these novel reactor designs the Doppler effect due to TRU materials is the most important temperature coefficient from the point of view of reactor safety. Here we report calculations of energy group-averaged capture and fission cross sections as function of temperature and dilution for higher actinides in the resolved and unresolved resonance regions. The calculations were done with the codes SAMMY in the resolved region and URR in the unresolved regions and compared with an independent calculation. 4 refs., 2 figs., 2 tabs.

  13. Predicting the Total Charm Cross Section

    SciTech Connect

    Vogt, R

    2008-05-29

    We discuss the energy dependence of the total charm cross section and some of its theoretical uncertainties including the quark mass, scale choice and the parton densities. Extracting the total charm cross section from data is a non-trivial task. To go from a finite number of measured D mesons in a particular decay channel to the total c{bar c} cross section one must: divide by the branching ratio for that channel; correct for the luminosity, {sigma}{sub D} = N{sub D}/Lt; extrapolate to full phase space from the finite detector acceptance; divide by two to get the pair cross section from the single Ds; and multiply by a correction factor to account for unmeasured charm hadrons. Early fixed-target data were at rather low p{sub T}, making the charm quark mass the most relevant scale. At proton and ion colliders, although the RHIC experiments can access the full pT range and thus the total cross section, the data reach rather high p{sub T}, p{sub T} >> m, making p{sub T} (m{sub T}) the most relevant scale. Here we focus on the total cross section calculation where the quark mass is the only relevant scale.

  14. QuickSite Cross Section Processing

    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 tomore » 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.« less

  15. [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.

  16. Actinide cross section program at ORELA

    SciTech Connect

    Dabbs, J.W.T.

    1980-01-01

    The actinide cross section program at ORELA, the Oak Ridge Electron Linear Accelerator, is aimed at obtaining accurate neutron cross sections (primarily fission, capture, and total) for actinide nuclides which occur in fission reactors. Such cross sections, measured as a function of neutron energy over as wide a range of energies as feasible, comprise a data base that permits calculated predictions of the formation and removal of these nuclides in reactors. The present program is funded by the Division of Basic Energy Sciences of DOE, and has components in several divisions at ORNL. For intensively ..cap alpha..-active nuclides, many of the existing fission cross section data have been provided by underground explosions. New measurement techniques, developed at ORELA, now permit linac measurements on fissionable nuclides with alpha half-lives as short as 28 years. Capture and capture-plus-fission measurements utilize scintillation detectors (of capture ..gamma.. rays and fission neutrons) in which pulse shape discrimination plays an important role. Total cross sections can be measured at ORELA on samples of only a few milligrams. A simultaneous program of chemical and isotopic analyses of samples irradiated in EBR-II is in progress to provide benchmarks for the existing differential measurements. These analyses are being studied with updated versions of ORIGEN and with sensitivity determinations. Calculations of the sensitivity to cross section changes of various aspects of the nuclear fuel cycle are also being made. Even in this relatively mature field, many cross sections still require improvements to provide an adequate data base. Examples of recent techniques and measurements are presented. 12 figures, 3 tables.

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

    DOE PAGESBeta

    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.; et al

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

    2015-06-01

    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.

  19. Undergraduate Measurements of Neutron Cross Sections

    NASA Astrophysics Data System (ADS)

    Hicks, S. F.; Vanhoy, J. R.; French, A. J.; Santonil, Z. C.; Crider, B. P.; Peters, E. E.; McEllistrem, M. T.; Prados-Estévez, F. M.; Ross, T. J.; Yates, S. W.

    Undergraduate students at the University of Dallas have investigated basic properties of nuclei through γ-ray and neutron spectroscopy following neutron scattering. The former has been used primarily for nuclear structure investigations, while the latter has been used to measure neutron scattering cross sections important for fission reactor applications. A series of (n,n') and (n,n'γ) measurements have been made on 54Fe and 56Fe to determine neutron cross sections for scattering to excited levels in these nuclei. The former provides the cross sections directly and the latter are used to deduce inelastic neutron scattering cross sections by measuring the γ-ray production cross sections to states not easily resolved in neutron spectroscopy. All measurements have been completed at the University of Kentucky Accelerator Laboratory using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. Students participate in accelerator operation, experimental setup, data acquisition, and data analyses. An overview of the research program and student contributions is presented.

  20. 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.

  1. Modeling the heavy ion upset cross section

    NASA Astrophysics Data System (ADS)

    Connell, L. W.; McDaniel, P. J.; Prinja, A. K.; Sexton, F. W.

    1995-04-01

    The standard Rectangular Parallelepiped (RPP) construct is used to derive a closed form expression for, sigma-bar (theta, phi, L) the directional-spectral heavy ion upset cross section. This is an expected value model obtained by integrating the point-value cross section model, sigma (theta, phi, L, E), also developed here, with the Weibull density function, f(E), assumed to govern the stochastic behavior of the upset threshold energy, E. A comparison of sigma-bar (theta, phi, L) with experimental data show good agreement, lending strong credibility to the hypothesis that E-randomness is responsible for the shape of the upset cross section curve. The expected value model is used as the basis for a new, rigorous mathematical formulation of the effective cross section concept. The generalized formulation unifies previous corrections to the inverse cosine scaling, collapsing to Petersen's correction, (cos theta - (h/l) sin theta)(sup -1), near threshold and Sexton's, (cos theta + (h/l) sin theta)(sup -1), near saturation. The expected value cross section model therefore has useful applications in both upset rate prediction and test data analysis.

  2. 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.

  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. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  5. Algorithmic analysis of quantum radar cross sections

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco; Venegas-Andraca, Salvador

    2015-05-01

    Sidelobe structures on classical radar cross section graphs are a consequence of discontinuities in the surface currents. In contrast, quantum radar theory states that sidelobe structures on quantum radar cross section graphs are due to quantum interference. Moreover, it is conjectured that quantum sidelobe structures may be used to detect targets oriented off the specular direction. Because of the high data bandwidth expected from quantum radar, it may be necessary to use sophisticated quantum signal analysis algorithms to determine the presence of stealth targets through the sidelobe structures. In this paper we introduce three potential quantum algorithmic techniques to compute classical and quantum radar cross sections. It is our purpose to develop a computer science-oriented tool for further physical analysis of quantum radar models as well as applications of quantum radar technology in various fields.

  6. 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.

  7. Top differential cross section measurements (Tevatron)

    SciTech Connect

    Jung, Andreas W.

    2012-01-01

    Differential cross sections in the top quark sector measured at the Fermilab Tevatron collider are presented. CDF used 2.7 fb{sup -1} of data and measured the differential cross section as a function of the invariant mass of the t{bar t} system. The measurement shows good agreement with the standard model and furthermore is used to derive limits on the ratio {kappa}/M{sub Pl} for gravitons which decay to top quarks in the Randall-Sundrum model. D0 used 1.0 fb{sup -1} of data to measure the differential cross section as a function of the transverse momentum of the top-quark. The measurement shows a good agreement to the next-to-leading order perturbative QCD prediction and various other standard model predictions.

  8. 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…

  9. 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.

  10. Cross sections of neutron-induced reactions

    SciTech Connect

    Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N.

    2010-10-15

    We study the properties of the neutron-nucleus total and reaction cross sections for several nuclei. We have applied an analytical model, the nuclear Ramsauer model, justified it from the nuclear reaction theory approach, and extracted the values of 12 parameters used in the model. The given parametrization has an advantage as phenomenological optical model potentials are limited up to 150-200 MeV. The present model provides good estimates of the total cross sections for several nuclei particularly at high energies.

  11. Improved cross section calculations for astrophysical applications

    NASA Technical Reports Server (NTRS)

    Silberberg, R.; Tsao, C. H.; Letaw, J. R.

    1985-01-01

    Modifications are proposed for the semiempirical equations and parameters of Silberberg and Tsao (1973) for partial cross section calculations of proton-nucleus reactions in cosmic rays. These modifications include: adjustment of general parameters; modification of energy dependence; effects of nuclear alpha-particle structure, deuteron emission, and even-charged products; peripheral reactions; fission reactions; averaging cross sections near boundaries of different parameters; elimination of certain special cases; and treatment of the Pt to Pb group that cannot yet be generalized to Z(t) less than 76.

  12. 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.

  13. Neutron capture cross section of 136 Xe

    NASA Astrophysics Data System (ADS)

    Daugherty, Sean; Albert, Joshua; Johnson, Tessa; O'Conner, Thomasina; Kaufman, Lisa

    2015-04-01

    136 Xe is an important 0 νββ candidate, studied in experiments such as EXO-200 and, in the future, nEXO. These experiments require a precise study of neutron capture for their background models. The neutron capture cross section of 136 Xe has been measured at the Detector for Advanced Capture Experiments (DANCE) at the Los Alamos Neutron Science Center. A neutron beam ranging from thermal energy to 100 keV was incident on a gas cell filled with isotopically pure 136 Xe . We will discuss the measurement of partial neutron capture cross sections at thermal and first neutron resonance energies along with corresponding capture gamma cascades.

  14. 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.

  15. 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.

  16. 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.

  17. 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).

  18. 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.

  19. Cross sections relevant to gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Dyer, P.; Bodansky, D.; Maxson, D. R.

    1978-01-01

    Gamma-ray production cross sections were measured for protons and alpha particles incident on targets consisting of nuclei of high cosmic abundance: C-12, N-14, O-16, Ne-20, Mg-24, Si-28 and Fe-56. Solid or gaseous targets were bombarded by monoenergetic beams of protons and alpha particles, and gamma rays were detected by two Ge(Li) detectors. The proton energy for each target was varied from threshold to about 24 MeV (lab); for alphas the range was from threshold to about 27 MeV. For most transitions, it was possible to measure the total cross section by placing the detectors at 30.5 deg and 109.9 deg where the fourth-order Legendre polynomial is zero. For the case of the 16O (E sub gamma = 6.13 MeV, multipolarity E3) cross sections, yields were measured at four angles. Absolute cross sections were obtained by integrating the beam current and by measuring target thicknesses and detector efficiencies. The Ge(Li) detector resolution was a few keV (although the peak widths were greater, due to Doppler broadening).

  20. Photoelectric absorption cross sections with variable abundances

    NASA Technical Reports Server (NTRS)

    Balucinska-Church, Monika; Mccammon, Dan

    1992-01-01

    Polynomial fit coefficients have been obtained for the energy dependences of the photoelectric absorption cross sections of 17 astrophysically important elements. These results allow the calculation of X-ray absorption in the energy range 0.03-10 keV in material with noncosmic abundances.

  1. 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.

  2. Neutron Capture Cross Sections for Radioactive Nuclei

    NASA Astrophysics Data System (ADS)

    Tonchev, Anton; Bedrossian, Peter; Escher, Jutta; Scielzo, Nicholas

    2015-10-01

    Accurate neutron-capture cross sections for radioactive nuclei near or far away from the line of beta stability are crucial for understanding the nucleosynthesis of heavy elements. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining observables that can constrain Hauser-Feshbach statistical model calculations of capture cross sections. Specifically, we will consider photon scattering, transfer reactions, and beta-delayed neutron emission. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes far from stability will be discussed. This work was performed under the auspices of US DOE by LLNL under contract DE-AC52-07NA27344. Funding was provided via the LDRD-ERD-069 project.

  3. Electron impact excitation cross sections for carbon

    NASA Astrophysics Data System (ADS)

    Ganas, P. S.

    1981-04-01

    A realistic analytic atomic independent particle model is used to generate wave functions for the valence and excited states of carbon. Using these wave functions in conjunction with the Born approximation and the Russell-Saunders LS-coupling scheme, we calculate generalized oscillator strengths and integrated cross sections for various excitations from the 2p 2( 3P O) valence state.

  4. 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…

  5. Report on 238Pu(n,x) surrogate cross section measurement

    SciTech Connect

    Burke, J T; Ressler, J J; Henderson, R A; Scielzo, N D; Escher, J E; Thompson, I J; Gostic, J; Bleuel, D; Weideking, M; Bernstein, L A

    2010-03-31

    The goal of this year's effort is to measure the {sup 238}Pu(n,f) and {sup 238}Pu(n,2n) cross section from 100 keV to 20 MeV. We designed a surrogate experiment that used the reaction {sup 239}Pu(a,a{prime}x) as a surrogate for {sup 238}Pu(n,x). The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in January 2010. A description of the experiment and status of the data analysis is given. In order to obtain a reliable {sup 238}Pu(n,x) cross section we designed the experiment using the surrogate ratio technique. This technique allows one to measure a desired, unknown, cross section relative to a known cross section. In the present example, the {sup 238}Pu(n,x) cross section of interest is determined relative to the known {sup 235}U(n,x) cross section. To increase confidence in the results, and to reduce overall uncertainties, we are also determining the {sup 238}Pu(n,x) cross section relative to the known {sup 234}U(n,x) cross section. The compound nuclei of interest for this experiment were produced using inelastic alpha scattering. For example, {sup 236}U(a,a{prime}x) served as a surrogate for {sup 235}U(n,x); analogous reactions were considered for the other cross sections. Surrogate experiments determine the probabilities for the decay of the compound nuclei into the various channels of interest (fission, gamma decay) by measuring particle-fission (p-f) or particle?gamma (p?g) reaction spectra. By comparing the decay probabilities associated with the unknown cross section to that of a known cross section it is possible to obtain the ratio of these cross sections and thus determine the unknown, desired cross section.

  6. 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.

  7. 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.

  8. 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.

  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. Calculation of improved spallation cross sections

    NASA Technical Reports Server (NTRS)

    Tsao, C. H.; Silberberg, R.; Letaw, J. R.

    1985-01-01

    Several research groups have recently carried out highly precise measurements (to about 10 percent) of high-energy nuclear spallation cross sections. These measurements, above 5 GeV, cover a broad range of elements: V, Fe, Cu, Ag, Ta and Au. Even the small cross sections far off the peak of the isotopic distribution curves have been measured. The semiempirical calculations are compared with the measured values. Preliminary comparisons indicate that the parameters of our spallation relations (Silberberg and Tsao, 1973) for atomic numbers 20 to 83 need modifications, e.g. a reduced slope of the mass yield distribution, broader isotopic distributions, and a shift of the isotopic distribution toward the neutron-deficient side. The required modifications are negligible near Fe and Cu, but increase with increasing target mass.

  11. Inclusive jet cross section at D0

    SciTech Connect

    Bhattacharjee, M.

    1996-09-01

    Preliminary measurement of the central ({vert_bar}{eta}{vert_bar} {<=} 0.5) inclusive jet cross sections for jet cone sizes of 1.0, 0.7, and 0.5 at D{null} based on the 1992-1993 (13.7 {ital pb}{sup -1}) and 1994-1995 (90 {ital pb}{sup -1}) data samples are presented. Comparisons to Next-to-Leading Order (NLO) Quantum Chromodynamics (QCD) calculations are made.

  12. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1985-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  13. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  14. {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.

  15. Neutron cross section standards and instrumentation

    NASA Astrophysics Data System (ADS)

    1992-09-01

    This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the second year of a three-year interagency agreement. This program includes a broad range of data measurements and evaluations. An emphasis has been focused on the (sup 10)B cross sections where serious discrepancies in the nuclear data base remain. In particular, there are important problems with the interpretation of the helium gas production associated with diagnostic measurements of interest in nuclear technology. The enhanced use of this isotope for medical treatment is also of significance. New measurements of neutron reaction cross sections for (sup 10)B are in progress in collaboration with scientists at the Oak Ridge National Laboratory. New experiments are in progress on the important dosimetry standards (sup 237)Np(n,f) and (sup 239)Pu(n,f) below 1 MeV neutron energy. In addition, new measurements of charged-particle production in basic biological elements for medical applications are underway. Further measurements are planned or in progress in collaborations which include fission fragment energy and angular distributions, and neutron energy spectra and angular distributions from neutron-induced fission. Also measurements of angular distributions of neutrons from scattering on protons, and determinations of capture cross section of gold are planned for a later time. Data evaluation will shift to include a unified international effort to motivate new measurements and evaluations. In response to the requests of the measurement community, NIST is beginning the formation of a national depository for fissionable isotope mass standards. This action will preserve for future measurements the valuable and irreplaceable critical samples whose masses and composition have been carefully determined and documented over the past 30 years of the nuclear program.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. Correlation analysis of optical absorption cross section and rate coefficient measurements in reacting systems

    SciTech Connect

    Hessler, J.P.; Ogren, P.J.

    1992-08-31

    A technique was developed for determining relative importance and correlation between reactions making up a complex kinetic system. This technique was used to investigate measurements of optical absorption cross sections and the correlation between cross sections and measured rate coefficients. It is concluded that (1) species, initial conditions, and temporal regions may be identified where cross sections may be measured without interference from the kinetic behavior of the observed species and (2) experiments designed to measure rate coefficients will always be correlated with the absorption cross section of the observed species. This correlation may reduce the accuracy of rate coefficient measurements.

  2. 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

  3. 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.

  4. 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...

  5. Quantifying and predicting interpretational uncertainty in cross-sections

    NASA Astrophysics Data System (ADS)

    Randle, Charles; Bond, Clare; Monaghan, Alison; Lark, Murray

    2015-04-01

    Cross-sections are often constructed from data to create a visual impression of the geologist's interpretation of the sub-surface geology. However as with all interpretations, this vision of the sub-surface geology is uncertain. We have designed and carried out an experiment with the aim of quantifying the uncertainty in geological cross-sections created by experts interpreting borehole data. By analysing different attributes of the data and interpretations we reflect on the main controls on uncertainty. A group of ten expert modellers at the British Geological Survey were asked to interpret an 11.4 km long cross-section from south-east Glasgow, UK. The data provided consisted of map and borehole data of the superficial deposits and shallow bedrock. Each modeller had a unique set of 11 boreholes removed from their dataset, to which their interpretations of the top of the bedrock were compared. This methodology allowed quantification of how far from the 'correct answer' each interpretation is at 11 points along each interpreted cross-section line; through comparison of the interpreted and actual bedrock elevations in the boreholes. This resulted in the collection of 110 measurements of the error to use in further analysis. To determine the potential control on uncertainty various attributes relating to the modeller, the interpretation and the data were recorded. Modellers were asked to fill out a questionnaire asking for information; such as how much 3D modelling experience they had, and how long it took them to complete the interpretation. They were also asked to record their confidence in their interpretations graphically, in the form of a confidence level drawn onto the cross-section. Initial analysis showed the majority of the experts' interpreted bedrock elevations within 5 metres of those recorded in the withheld boreholes. Their distribution is peaked and symmetrical about a mean of zero, indicating that there was no tendency for the experts to either under

  6. 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).

  7. The calculation of radar cross sections

    NASA Astrophysics Data System (ADS)

    Pizer, R.

    1980-04-01

    The FORTRAN program CHAOS, used for calculating cross sections is described including the physical approximations used to simplify Maxwell's equations. The scattering bodies are extended to both open and closed surfaces. The numerical methods used are supplied. The problems of wire junctions, of finite conductivity and the attaching of lumped loads to the structure are considered. Techniques for dealing with bodies having rotational or left-right symmetries are examined as well as the sparse matrix approximation and the complex frequency version of CHAOS. The formula used to calculate the impedance matrix elements, and the conventions adopted concerning coordinate systems and polarization are included.

  8. Correlation among soluble receptors for advanced glycation end-products, soluble vascular adhesion protein-1/semicarbazide-sensitive amine oxidase (sVAP-1) and cardiometabolic risk markers in apparently healthy adolescents: a cross-sectional study.

    PubMed

    Gurecká, Radana; Koborová, Ivana; Csongová, Melinda; Šebek, Jozef; Šebeková, Katarína

    2016-08-01

    In non-diabetics, low levels of soluble receptor for advanced glycations end products (sRAGE) associate with an increased risk of development of diabetes, cardiovascular afflictions, or death. The majority of studies in non-diabetics report an inverse relationship between measures of obesity, cardiometabolic risk factors and sRAGE and/or endogenous secretory RAGE (esRAGE) levels. To elucidate whether this inconsistency is related to the metabolically healthy obese phenotype, or a different impact of the risk factors in presence and absence of obesity, we analyzed data from 2206 apparently healthy adolescents (51 % girls) aged 15-to-19 years. The association of sRAGE levels with soluble vascular adhesion protein-1/semicarbazide sensitive amine oxidase (sVAP-1/SSAO) was also investigated. Centrally obese, including metabolically healthy, adolescents present significantly lower sRAGE and esRAGE, but not sVAP-1, levels in comparison with their lean counterparts. An increasing number of cardiometabolic risk factors did not associate with significant changes in sRAGE, esRAGE or sVAP-1 levels either in lean or in obese subjects. In multivariate analyses, WHtR, hsCRP, markers of glucose homeostasis, renal function, adiponectin, and sVAP-1 associated significantly with sRAGE and esRAGE. SVAP-1 correlated significantly with glycemia, adiponectin, hsCRP, and sRAGE. Thus, in adolescents, a decline in sRAGE and esRAGE precedes the development of metabolic syndrome. When combined, standard and non-standard cardiometabolic risk factors explain only minor proportion in a variability of sRAGE and esRAGE (8 %-11 %); or sVAP-1 (12 %-20 %). Elucidation of pathogenetic mechanisms underlying early decline in sRAGE and esRAGE levels in obese adolescents and their clinical impact with regard to future cardiometabolic health requires further studies. PMID:27300745

  9. The Thyroid Status of Children and Adolescents in Fukushima Prefecture Examined during 20–30 Months after the Fukushima Nuclear Power Plant Disaster: A Cross-Sectional, Observational Study

    PubMed Central

    Watanobe, Hajime; Furutani, Tomoyuki; Nihei, Masahiko; Sakuma, Yu; Yanai, Rie; Takahashi, Miyuki; Sato, Hideo; Sagawa, Fumihiko

    2014-01-01

    Background A possible increase in thyroid cancer in the young represents the most critical health problem to be considered after the nuclear accident in Fukushima, Japan (March 2011), which is an important lesson from the Chernobyl disaster (April 1986). Although it was reported that childhood thyroid cancer had started to increase 3–5 yr after the Chernobyl accident, we speculate that the actual period of latency might have been shorter than reported, considering the delay in initiating thyroid surveillance in the then Soviet Union and also the lower quality of ultrasonographic testing in the 1980s. Our primary objectives in the present study were to identify any possible thyroid abnormality in young Fukushima citizens at a relatively early timepoint (20–30 months) after the accident, and also to strive to find a possible relationship among thyroid ultrasonographic findings, thyroid-relevant biochemical markers, and iodine-131 ground deposition in the locations of residence where they stayed during very early days after the accident. Methods and Findings This is a cross-sectional study. We targeted the Fukushima residents who were 18 yr old or younger (including fetuses) at the time of the accident. Our examinations comprised a questionnaire, thyroid ultrasonography, thyroid-related blood tests, and urinary iodine measurement. We analyzed a possible relationship among thyroid ultrasonographic findings (1,137 subjects), serum hormonal data (731 subjects), urinary iodine concentrations (770 subjects), and iodine-131 ground deposition (1,137 subjects). We did not find any significant relationship among these indicators, and no participant was diagnosed to contract thyroid cancer. Conclusions At the timepoint of 20–30 months after the accident, we did not confirm any discernible deleterious effects of the emitted radioactivity on the thyroid of young Fukushima residents. This is the first report in English detailing the thyroid status of young Fukushima

  10. Windowed multipole for cross section Doppler broadening

    NASA Astrophysics Data System (ADS)

    Josey, C.; Ducru, P.; Forget, B.; Smith, K.

    2016-02-01

    This paper presents an in-depth analysis on the accuracy and performance of the windowed multipole Doppler broadening method. The basic theory behind cross section data is described, along with the basic multipole formalism followed by the approximations leading to windowed multipole method and the algorithm used to efficiently evaluate Doppler broadened cross sections. The method is tested by simulating the BEAVRS benchmark with a windowed multipole library composed of 70 nuclides. Accuracy of the method is demonstrated on a single assembly case where total neutron production rates and 238U capture rates compare within 0.1% to ACE format files at the same temperature. With regards to performance, clock cycle counts and cache misses were measured for single temperature ACE table lookup and for windowed multipole. The windowed multipole method was found to require 39.6% more clock cycles to evaluate, translating to a 7.9% performance loss overall. However, the algorithm has significantly better last-level cache performance, with 3 fewer misses per evaluation, or a 65% reduction in last-level misses. This is due to the small memory footprint of the windowed multipole method and better memory access pattern of the algorithm.

  11. Neutronic Cross Section Calculations on Fluorine Nucleus

    NASA Astrophysics Data System (ADS)

    Kara, A.; Tel, E.

    2013-06-01

    Certain light nuclei such as Lithium (Li), Beryllium (Be), Fluorine (F) (which are known as FLİBE) and its molten salt compounds (LiF, BeF2 and NaF) can serve as a coolant which can be used at high temperatures without reaching a high vapor pressure. These molten salt compounds are also a good neutron moderator. In this study, cross sections of neutron induced reactions have been calculated for fluorine target nucleus. The new calculations on the excitation functions of 19F( n, 2n), 19F( n, p), 19F( n, xn), 19F( n, xp) have been made. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the full exciton model and the cascade exciton model. The equilibrium effects are calculated according to the Weisskopf-Ewing model. Also in the present work, the ( n, 2n) and ( n, p) reaction cross sections have calculated by using evaluated empirical formulas developed by Tel et al. at 14-15 MeV energy. The multiple pre-equilibrium mean free path constant from internal transition have been investigated for 19F nucleus. The obtained results have been discussed and compared with the available experimental data.

  12. A study of radar cross section measurement techniques

    NASA Astrophysics Data System (ADS)

    McDonald, Malcolm W.

    1986-11-01

    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.

  13. Summary of the Workshop on Neutron Cross Section Covariances

    SciTech Connect

    Smith, Donald L.

    2008-12-15

    A Workshop on Neutron Cross Section Covariances was held from June 24-27, 2008, in Port Jefferson, New York. This Workshop was organized by the National Nuclear Data Center, Brookhaven National Laboratory, to provide a forum for reporting on the status of the growing field of neutron cross section covariances for applications and for discussing future directions of the work in this field. The Workshop focused on the following four major topical areas: covariance methodology, recent covariance evaluations, covariance applications, and user perspectives. Attention was given to the entire spectrum of neutron cross section covariance concerns ranging from light nuclei to the actinides, and from the thermal energy region to 20 MeV. The papers presented at this conference explored topics ranging from fundamental nuclear physics concerns to very specific applications in advanced reactor design and nuclear criticality safety. This paper provides a summary of this workshop. Brief comments on the highlights of each Workshop contribution are provided. In addition, a perspective on the achievements and shortcomings of the Workshop as well as on the future direction of research in this field is offered.

  14. 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.

  15. Hydrogen and Nitrogen Broadened Ethane and Propane Absorption Cross Sections

    NASA Astrophysics Data System (ADS)

    Hargreaves, Robert J.; Appadoo, Dominique; Billinghurst, Brant E.; Bernath, Peter F.

    2015-06-01

    High-resolution infrared absorption cross sections are presented for the ν9 band of ethane (C2H6) at 823 cm-1. These cross sections make use of spectra recorded at the Australian Synchrotron using a Fourier transform infrared spectrometer with maximum resolution of 0.00096 cm-1. The spectra have been recorded at 150, 120 and 90 K for hydrogen and nitrogen broadened C2H6. They cover appropriate temperatures, pressures and broadening gases associated with the atmospheres of the Outer Planets and Titan, and will improve atmospheric retrievals. The THz/Far-IR beamline at the Australian Synchrotron is unique in combining a high-resolution Fourier transform spectrometer with an 'enclosive flow cooling' (EFC) cell designed to study molecules at low temperatures. The EFC cell is advantageous at temperatures for which the vapor pressure is very low, such as C2H6 at 90 K. Hydrogen broadened absorption cross sections of propane between 700 and 1200 cm-1 will also be presented based on spectra obtained at the Canadian Light Source.

  16. A novel, open access, elliptical cross-section magnet for paediatric MRI

    NASA Astrophysics Data System (ADS)

    Crozier, Stuart; Forbes, Lawrence K.; Doddrell, David M.

    1998-01-01

    Almost all clinical magnetic resonance imaging systems are based on circular cross-section magnets. Recent advances in elliptical cross-section RF probe and gradient coil hardware raise the question of the possibility of using elliptical cross-section magnet systems. This paper presents a methodology for calculating rapidly the magnetic fields generated by a multi-turn coil of elliptical cross-section and incorporates this in a stochastic optimization method for magnet design. An open magnet system of elliptical cross-section is designed that both reduces the claustrophobia for the patients and allows ready access by attending physicians. The magnet system is optimized for paediatric use. The coil geometry produced by the optimization method has several novel features.

  17. 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.

  18. Correlation cross sections along the international border

    SciTech Connect

    Martiniuk, C.D. ); Le Fever, J.A.; Anderson, S.B. )

    1991-06-01

    The Manitoba-North Dakota (Canada-US) stratigraphic correlation project is a joint study between the Petroleum Branch of Manitoba Energy and Mines and the North Dakota Geological Survey. It is an attempt to correlate the differing stratigraphic terminologies established in the two jurisdictions by providing a reference cross section across the international boundary. The study involves the subsurface correlation of logs of the Paleozoic and Mesozoic sequences in the Manitoba and North Dakota portions of the Williston basin. The Paleozoic and Mesozoic sequences are subdivided for presentation into the following stratigraphic intervals: (a) Cambrian-Ordovician-Silurian, (b) Devonian, (c) Mississippian, (d) Jurassic, and (e) Cretaceous. Wireline logs show the actual stratigraphic correlations. A nomenclature chart is also presented from each sequence. In addition, the sections include a generalized description of lithologies, thicknesses, environments of deposition, and petroleum potential for each geographic area.

  19. Photofission cross section of /sup 232/Th

    SciTech Connect

    Zhang, H.X.; Yeh, T.R.; Lancman, H.

    1986-10-01

    The photofission cross section of /sup 232/Th was measured in the 5.8-12 MeV energy range with an average photon energy resolution of 600 eV. Intermediate structure was observed at 5.91, 5.97, and 6.31 MeV. The experimental fission probability and various properties of the intermediate structure were compared with calculated values based on a double-humped fission barrier as well as a triple-humped one. The results favor, though not decisively, the presence of a shallow third well in the barrier. Certain features of both barriers, a rather high first hump and a deep secondary well, are quite different from those predicted by current theoretical barrier calculations.

  20. 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.

  1. 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.

  2. 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.

  3. Geophysical Fluid Flow Cell (GFFC) Cross Section

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This drawing shows a cross-section view of the test cell at the heart of the Geophysical Fluid Flow Cell (GFFC) that flew on two Spacelab missions. The middle and lower drawings depict the volume of the silicone oil layer that served as the atmosphere as the steel ball rotated and an electrostatic field pulled the oil inward to mimic gravity's effects during the experiments. The GFFC thus produced flow patterns that simulated conditions inside the atmospheres of Jupiter and the Sun and other stars. The principal investigator was John Hart of the University of Colorado at Boulder. It was managed by NASA's Marshall Space Flight Center (MSFC). An Acrobat PDF copy of this drawing is available at http://microgravity.nasa.gov/gallery. (Credit: NASA/Marshall Space Flight Center)

  4. Collision cross sections for structural proteomics.

    PubMed

    Marklund, Erik G; Degiacomi, Matteo T; Robinson, Carol V; Baldwin, Andrew J; Benesch, Justin L P

    2015-04-01

    Ion mobility mass spectrometry (IM-MS) allows the structural interrogation of biomolecules by reporting their collision cross sections (CCSs). The major bottleneck for exploiting IM-MS in structural proteomics lies in the lack of speed at which structures and models can be related to experimental data. Here we present IMPACT (Ion Mobility Projection Approximation Calculation Tool), which overcomes these twin challenges, providing accurate CCSs up to 10(6) times faster than alternative methods. This allows us to assess the CCS space presented by the entire structural proteome, interrogate ensembles of protein conformers, and monitor molecular dynamics trajectories. Our data demonstrate that the CCS is a highly informative parameter and that IM-MS is of considerable practical value to structural biologists. PMID:25800554

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Thermal neutron cross section of liquid and solid mesitylene

    NASA Astrophysics Data System (ADS)

    Cantargi, F.; Blostein, J. J.; Torres, L.; Granada, J. R.

    2006-08-01

    Total cross sections of mesitylene at 293 K and at 89 K were measured at the electron LINAC based pulsed neutron source of Centro Atómico Bariloche. Preliminary frequency spectra were proposed for liquid and solid mesitylene at those temperatures combining experimental and synthetic contributions. Scattering law data files were generated with the NJOY nuclear data processing system. Good agreement between experiments and calculations is found, which represents a primary validation of the scattering kernels which are now being used for the design and optimization of a cold moderator employing that material.

  10. 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).

  11. Electron cross section set for CHF{sub 3}

    SciTech Connect

    Morgan, W. Lowell; Winstead, Carl; McKoy, Vincent

    2001-08-15

    We describe the development of a consistent set of low-energy electron collision cross sections for trifluoromethane, CHF{sub 3}. First-principles calculations are used to obtain key elastic and inelastic cross sections. These are combined with literature values of the ionization cross section and with vibrational excitation cross sections obtained from the Born approximation to form a preliminary set, which is then adjusted to achieve consistency with measured swarm parameters. {copyright} 2001 American Institute of Physics.

  12. Influence of strut cross-section of stents on local hemodynamics in stented arteries

    NASA Astrophysics Data System (ADS)

    Jiang, Yongfei; Zhang, Jun; Zhao, Wanhua

    2016-05-01

    Stenting is a very effective treatment for stenotic vascular diseases, but vascular geometries altered by stent implantation may lead to flow disturbances which play an important role in the initiation and progression of restenosis, especially in the near wall in stented arterial regions. So stent designs have become one of the indispensable factors needed to be considered for reducing the flow disturbances. In this paper, the structural designs of strut cross-section are considered as an aspect of stent designs to be studied in details. Six virtual stents with different strut cross-section are designed for deployments in the same ideal arterial model. Computational fluid dynamics (CFD) methods are performed to study how the shape and the aspect ratio (AR) of strut cross-section modified the local hemodynamics in the stented segments. The results indicate that stents with different strut cross-sections have different influence on the hemodynamics. Stents with streamlined cross-sectional struts for circular arc or elliptical arc can significantly enhance wall shear stress (WSS) in the stented segments, and reduce the flow disturbances around stent struts. The performances of stents with streamlined cross-sectional struts are better than that of stents with non-streamlined cross-sectional struts for rectangle. The results also show that stents with a larger AR cross-section are more conductive to improve the blood flow. The present study provides an understanding of the flow physics in the vicinity of stent struts and indicates that the shape and AR of strut cross-section ought to be considered as important factors to minimize flow disturbance in stent designs.

  13. Influence of strut cross-section of stents on local hemodynamics in stented arteries

    NASA Astrophysics Data System (ADS)

    Jiang, Yongfei; Zhang, Jun; Zhao, Wanhua

    2016-04-01

    Stenting is a very effective treatment for stenotic vascular diseases, but vascular geometries altered by stent implantation may lead to flow disturbances which play an important role in the initiation and progression of restenosis, especially in the near wall in stented arterial regions. So stent designs have become one of the indispensable factors needed to be considered for reducing the flow disturbances. In this paper, the structural designs of strut cross-section are considered as an aspect of stent designs to be studied in details. Six virtual stents with different strut cross-section are designed for deployments in the same ideal arterial model. Computational fluid dynamics (CFD) methods are performed to study how the shape and the aspect ratio (AR) of strut cross-section modified the local hemodynamics in the stented segments. The results indicate that stents with different strut cross-sections have different influence on the hemodynamics. Stents with streamlined cross-sectional struts for circular arc or elliptical arc can significantly enhance wall shear stress (WSS) in the stented segments, and reduce the flow disturbances around stent struts. The performances of stents with streamlined cross-sectional struts are better than that of stents with non-streamlined cross-sectional struts for rectangle. The results also show that stents with a larger AR cross-section are more conductive to improve the blood flow. The present study provides an understanding of the flow physics in the vicinity of stent struts and indicates that the shape and AR of strut cross-section ought to be considered as important factors to minimize flow disturbance in stent designs.

  14. 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…

  15. A simple approach to SEU cross section evaluation

    SciTech Connect

    Miroshkin, V.V.; Tverskoy, M.G.

    1998-12-01

    The simplified method for determination of proton induced SEU cross section is presented. The method is based on results of the analysis of experimental SEU cross sections initiated by fast nucleons. The possibility of SEU cross section measurement at single proton energy for SEU rate prediction is shown.

  16. Viscous Flow through Pipes of Various Cross-Sections

    ERIC Educational Resources Information Center

    Lekner, John

    2007-01-01

    An interesting variety of pipe cross-sectional shapes can be generated, for which the Navier-Stokes equations can be solved exactly. The simplest cases include the known solutions for elliptical and equilateral triangle cross-sections. Students can find pipe cross-sections from solutions of Laplace's equation in two dimensions, and then plot the…

  17. Cross-sectional study of violence in emerging adulthood.

    PubMed

    Marcus, Robert F

    2009-01-01

    Theories of emerging adulthood, the evolutionary perspective, and the presence of turning points in the lives of 19-25-year olds were examined in relation to serious perpetrated violence for a cross-sectional sample of men and women (n=14,098) from the National Longitudinal Study of Adolescent Health (Add Health), Wave III. Perpetrated, self-reported violence included armed robbery, gang fighting, using a weapon in a fight, pulling a knife or gun on someone, or shooting or stabbing someone. Results showed that 11.3% of emergent adults had perpetrated at least one of these behaviors in the past year. Hierarchical logistic regression analysis partially supported the three theories for both men and women, beyond the contribution of violence in adolescence. The presence of Wave III violence was more likely given the unique contributions of unmarried status and economic risk. Moreover, and consistent with the theory of emerging adulthood, both sensation seeking and depression declined with age and contributed to the acknowledgement of Wave III violence, beyond the contribution of controls for Wave I violence (6 years earlier), demographics, age, gender, unmarried status, and economic risk. Findings of age-related declines and gender differences in prevalence rates were consistent with previous research on nationally representative samples, and with the predictions of the three theories. PMID:19067362

  18. 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)

  19. 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.

  20. Electron-impact-ionization cross section for the hydrogen atom

    NASA Astrophysics Data System (ADS)

    Hu, W.; Fang, D.; Wang, Y.; Yang, F.

    1994-02-01

    A distorted-wave Born exchange approximation was used to calculate the cross section for electron-impact ionization of the hydrogen atoms. Both the integral and energy-differential cross section were calculated. The results were compared with the latest experimental data and other theoretical calculations. Comparison shows that the calculations agree with differential cross-section measurements in general. For integral cross sections the calculation shows a better agreement with an earlier measurement [M.B. Shah, D. S. Elliott, and H. B. Gilbody, J. Phys. B 20, 3501 (1987)] in which the cross sections are normalized to the first Born approximation.

  1. 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

  2. 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.

  3. Aerodynamic characteristics of a monoplanar missile concept with bodies of circular and elliptical cross sections

    NASA Technical Reports Server (NTRS)

    Graves, E. B.

    1977-01-01

    Experimental aerodynamic characteristics of a low-drag missile concept with a body of circular cross section were compared to one with a body of 3:1 elliptical cross section, the bodies having identical cross section area distributions. The concepts were of monowing design with constant wing span. Tail surfaces were located flush at the body base with plus or minus 30 deg dihedral. Wind tunnel tests were performed at Mach numbers from 0.5 to 4.63 and at angles of attack from about -5 deg to 28 deg.

  4. Elastic and inelastic vibrational cross sections for positron scattering by carbon monoxide

    NASA Astrophysics Data System (ADS)

    Tenfen, W.; Arretche, F.; Michelin, S. E.; Mazon, K. T.

    2015-11-01

    The vibrational cross sections of the CO molecule induced by positron impact is the focus of this work. The positron-molecule interaction is represented by the static potential plus a model potential designed to take into account the positron-target correlations. To calculate the vibrational cross sections, we applied the multichannel version of the continued fractions method in the close-coupling scheme. We present vibrational excitation cross sections and elastic ones, for the ground and excited vibrational states. The results are interpreted in terms of the vibrational coupling-scheme used in the scattering model.

  5. Radioactive targets for neutron-induced cross section measurements

    SciTech Connect

    Kronenberg, A.; Bond, E. M.; Glover, S. E.; Rundberg, R. S.; Vieira, D. J.; Esch, E. I.; Reifarth, R.; Ullmann, J. L.; Haight, Robert C.; Rochmann, D.

    2004-01-01

    Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high detection efficiency of DANCE, combined with the high TOF-neutron flux available at the Lujan Center provides a versatile tool for measuring many important cross section data using radioactive and isotopically enriched targets of about 1 milligram. Another powerful instrument is the Lead-slowing down spectrometer (LSDS), which will enable the measurement of neutron-induced fission cross-section of U-235m and other short-lived actinides in a energy range from 1-200 keV with sample sizes down to 10 nanograms. Due to the short half-life of the U-235m isomer (T{sub 1/2} = 26 minutes), the samples must be rapidly and repeatedly extracted from its {sup 239}Pu parent. Since {sup 239}Pu is itself highly fissile, the separation must not only be rapid, but must also be of very high purity (the Pu must be removed from the U with a decontamination factor >10{sup 12}). Once extracted and purified, the {sup 235m}U isomer would be electrodeposited on solar cells as a fission detector and placed within the LSDS for direct (n,f) cross section measurements. The

  6. 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.

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

    DOE PAGESBeta

    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

  8. Actinide Targets for Neutron Cross Section Measurements (C)

    SciTech Connect

    J. D. Baker; C. A. McGrath

    2006-04-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from “minor” actinides that currently have poorly known (n,g) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  9. 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.

  10. 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.

  11. Experimental verification of theoretical cross sections for FIB PIXE

    NASA Astrophysics Data System (ADS)

    Streib, Kenneth L.; Alford, Terry L.; Mayer, James W.

    2006-08-01

    X-ray production cross sections were found for films of Cr, Cu, Ge, Ag, W and Au, using incident H+ and Be+ ions at energies from 300 keV to 3.5 MeV. These experimental cross section results were compared with the cross section results obtained using software which calculates inner shell ionization and X-ray production cross sections. The software uses the ECPSSR-UA approach to finding X-ray production cross sections. This program was found to be useful for predicting cross sections for H+ and Be+ ions at the energies in this study. The software was then used to predict results for Li+, Be+ and B+ ions at 280 keV, energies available in the Arizona State University focused ion beam laboratory.

  12. 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.

  13. Charge exchange cross sections for the Io plasma torus

    NASA Astrophysics Data System (ADS)

    McGrath, M. A.; Johnson, R. E.

    1989-03-01

    An impact parameter method for calculating cross sections as a function of incident ion energy is used in conjunction with an improved exchange energy formulation to update several of the charge exchange cross sections currently used in Io plasma torus modeling. New cross sections for S(+) + S(2+) yielding S(2+) + S(+) and Na(+) on neutral targets, useful in analyzing the fast Na jets observed at Io, are also calculated.

  14. 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.

  15. 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.

  16. Single event upset cross sections at various data rates

    SciTech Connect

    Reed, R.A.; Marshall, C.J.; McMorrow, D.; Carts, M.A.; Marshall, P.W.; Buchner, S.; La Macchia, M.; Mathes, B.

    1996-12-01

    The authors present data which show that Single Event Upset (SEU) cross section varies linearly with frequency for most devices tested. They show that the SEU cross section can increase dramatically away from a linear relationship when the test setup is not optimized, or when testing near the maximum operating frequency. They also observe non-linear behavior in some complex circuit topologies. Knowledge of the relationship between SEU cross section and frequency is important for estimates of on-orbit SEU rates.

  17. 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.

  18. 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.

  19. 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.

  20. Rapid and accurate broadband absorption cross-section measurement of human bodies in a reverberation chamber

    NASA Astrophysics Data System (ADS)

    Flintoft, Ian D.; Melia, Gregory C. R.; Robinson, Martin P.; Dawson, John F.; Marvin, Andy C.

    2015-06-01

    A measurement methodology for polarization and angle of incidence averaged electromagnetic absorption cross-section using a reverberation chamber is presented. The method is optimized for simultaneous rapid and accurate determination of average absorption cross-section over the frequency range 1-15 GHz, making it suitable for use in human absorption and exposure studies. The typical measurement time of the subject is about 8 min with a corresponding statistical uncertainty of about 3% in the measured absorption cross-section. The method is validated by comparing measurements on a spherical phantom with Mie series calculations. The efficacy of the method is demonstrated with measurements of the posture dependence of the absorption cross-section of a human subject and an investigation of the effects of clothing on the measured absorption which are important considerations for the practical design of experiments for studies on human subjects.

  1. Positive Scattering Cross Sections using Constrained Least Squares

    SciTech Connect

    Dahl, J.A.; Ganapol, B.D.; Morel, J.E.

    1999-09-27

    A method which creates a positive Legendre expansion from truncated Legendre cross section libraries is presented. The cross section moments of order two and greater are modified by a constrained least squares algorithm, subject to the constraints that the zeroth and first moments remain constant, and that the standard discrete ordinate scattering matrix is positive. A method using the maximum entropy representation of the cross section which reduces the error of these modified moments is also presented. These methods are implemented in PARTISN, and numerical results from a transport calculation using highly anisotropic scattering cross sections with the exponential discontinuous spatial scheme is presented.

  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. Documentation of Uncertainties in Experimental Cross Sections for EXFOR

    SciTech Connect

    Otuka, N.; Smith, D.L.

    2014-06-15

    Documentation of uncertainties and covariances in experimental nuclear reaction cross sections has been assessed. Following consideration of the importance of covariances for nuclear data in various nuclear applications, and presentation of a simple numerical example to demonstrate this point, the minimum basic concepts (mean, covariance, standard derivation, partial uncertainties, micro- and macro-correlation coefficients) are introduced. A deterministic approach to propagating the covariances in primary measured parameters (e.g., counts) to the derived cross sections is discussed, using a neutron-induced activation cross section measurement as an example. Finally, various approaches to documentation (publication, compilation) of experimental cross sections to facilitate their use in future evaluations are mentioned.

  4. 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.

  5. Derivation of reaction cross sections from experimental elastic backscattering probabilities

    NASA Astrophysics Data System (ADS)

    Sargsyan, V. V.; Adamian, G. G.; Antonenko, N. V.; Gomes, P. R. S.

    2013-10-01

    The relationship between the backward elastic scattering probabilities and the reaction cross sections is derived. This is a very simple and useful method to extract reaction cross sections for heavy-ion systems. We compare the results of our method with those that use the traditional full elastic scattering angular distributions for several systems at energies near and above the Coulomb barrier. From the calculated reaction and capture cross sections that use the present method, we derive the cross sections of other mechanisms for weak nearly spherical systems.

  6. The correction of pebble bed reactor nodal cross sections for the effects of leakage and depletion history

    NASA Astrophysics Data System (ADS)

    Hudson, Nathanael Harrison

    cross-section generator for two PBR reactor designs.

  7. OBSERVED, GIS, AND SELF-REPORTED ENVIRONMENTAL FEATURES AND ADOLESCENT PHYSICAL ACTIVITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Purpose: Examine associations among observed, self-reported, and Geographical Information Systems (GIS) environmental features and physical activity among adolescent males. Design: Cross-sectional study. Setting: Boy Scout troops and neighborhoods in Houston, Texas. Subjects: Two hundred and ten ...

  8. 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.

  9. 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

  10. Extracting forward strong amplitudes from elastic differential cross sections

    SciTech Connect

    C.M. Chen; D.J. Ernst; Mikkel B. Johnson

    2001-07-01

    The feasibility of a model-independent extraction of the forward strong amplitude from elastic nuclear cross section data in the Coulomb-nuclear interference region is assessed for {pi} and K{sup +} scattering at intermediate energies. Theoretically-generated ''data'' are analyzed to provide criteria for optimally designing experiments to measure these amplitudes, whose energy dependence (particularly that of the real parts) is needed for disentangling various sources of medium modifications of the projectile-nucleon interaction. The issues considered include determining the angular region over which to make the measurements, the role of the most forward angles measured, and the effects of statistical and systematic errors. We find that there is a region near the forward direction where Coulomb-nuclear interference allows reliable extraction of the strong forward amplitude for both pions and the K{sup +} from .3 to 1 GeV/c.

  11. 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.

  12. Determination of Electron Collision Cross Sections Set for Tetramethysilane

    NASA Astrophysics Data System (ADS)

    Bordage, Marie-Claude

    2007-12-01

    A swarm analysis technique based on the solution of the Boltzmann equation is used to derive low energy electron collision cross sections for tetramethylsilane (TMS). The calculated swarm parameters with this first available cross sections set is consistent with measured values of the swarm parameters. Calculations of transport parameters in mixtures of TMS with argon are also presented.

  13. Temperature dependence of the HNO3 UV absorption cross sections

    NASA Technical Reports Server (NTRS)

    Burkholder, James B.; Talukdar, Ranajit K.; Ravishankara, A. R.; Solomon, Susan

    1993-01-01

    The temperature dependence of the HNO3 absorption cross sections between 240 and 360 K over the wavelength range 195 to 350 nm has been measured using a diode array spectrometer. Absorption cross sections were determined using both (1) absolute pressure measurements at 298 K and (2) a dual absorption cell arrangement in which the absorption spectrum at various temperatures is measured relative to the room temperature absorption spectrum. The HNO3 absorption spectrum showed a temperature dependence which is weak at short wavelengths but stronger at longer wavelengths which are important for photolysis in the lower stratosphere. The 298 K absorption cross sections were found to be larger than the values currently recommended for atmospheric modeling (DeMore et al., 1992). Our absorption cross section data are critically compared with the previous measurements of both room temperature and temperature-dependent absorption cross sections. Temperature-dependent absorption cross sections of HNO3 are recommended for use in atmospheric modeling. These temperature dependent HNO3 absorption cross sections were used in a two-dimensional dynamical-photochemical model to demonstrate the effects of the revised absorption cross sections on loss rate of HNO3 and the abundance of NO2 in the stratosphere.

  14. 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.

  15. 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.

  16. The energy dependence of the total charm cross section

    SciTech Connect

    Vogt, R

    2007-10-18

    We discuss the energy dependence of the total charm cross section and some of its theoretical uncertainties including the quark mass, scale choice and the parton densities. We compare the next-to-leading order calculation of the total cross section with results obtained using PYTHIA.

  17. 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.

  18. 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…

  19. Calculation of cross sections for binary reactions between heavy ion projectiles and heavy actinide targets

    SciTech Connect

    Hoffman, D.C.; Hoffman, M.M.

    1990-11-01

    The computer program, described in this report, is identified as PWAVED5. It was developed to calculate cross sections for nucleon transfer reactions in low energy heavy ion bombardments. The objective was to calculate cross sections that agree with experimental results for ions of different charge and mass and to develop a predictive capability. It was undertaken because previous heavy ion calculations, for which programs were readily available, appeared to focus primarily on reactions resulting in compound nucleus formation and were not particularly applicable to calculations of binary reaction cross sections at low interaction energies. There are to principal areas in which this computation differs from several other partial wave calculations of heavy-ion reaction cross sections. First, this program is designed specifically to calculate cross sections for nucleon exchange interactions and to exclude interactions that are expected to result in fusion of the two nuclei. A second major difference in this calculation is the use of a statistical distribution to assign the total interaction cross section to individual final mass states.

  20. Design of the Trial of Activity in Adolescent Girls (TAAG)

    PubMed Central

    Stevens, June; Murray, David M.; Catellier, Diane J.; Hannan, Peter J.; Lytle, Leslie A.; Elder, John P.; Young, Deborah R.; Simons-Morton, Denise G.; Webber, Larry S.

    2005-01-01

    The primary aim of the Trial of Activity in Adolescent Girls (TAAG) is to test an intervention to reduce by half the age-related decline in moderate to vigorous physical activity (MVPA) in middle school girls. The intervention will be evaluated using a group-randomized trial involving 36 middle schools. The primary endpoint is the mean difference in intensity-weighted minutes (i.e., MET-minutes) of MVPA between intervention and comparison schools assessed using accelerometry. The TAAG study design calls for two cross-sectional samples, one drawn from 6th graders at the beginning of the study and the second drawn from 8th graders at the end of the study following the 2-year implementation of the intervention. An important strength of this design over a cohort design is the consistency with the goals of TAAG, which focus on environmental-level rather than individual-level interventions to produce change. The study design specifies a recruitment rate of 80% and a smaller sample of girls at baseline (n=48 per school) than at follow-up (n=96 per school). A two-stage model will be used to test the primary hypothesis. In the first stage, MET-weighted minutes of MVPA will be regressed on school, time (baseline or follow-up), their interaction, ethnicity and week of data collection. The second stage analysis will be conducted on the 72 adjusted means from the first stage. In the main-effects model, we will regress the follow-up school mean MET-weighted minutes of MVPA on study condition, adjusting for the baseline school mean. The TAAG study addresses an important health behavior, and also advances the field of group-randomized trials through the use of a study design and analysis plan tailored to serve the main study hypothesis. PMID:15837442

  1. 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.

  2. Consistent set of electron cross sections for methane

    NASA Astrophysics Data System (ADS)

    Alves, L. L.; Guerra, V.; Pintassilgo, C. D.

    2013-09-01

    This contribution presents a complete consistent set of electron-impact cross sections for methane (CH4) , recently made available on the IST-LISBON database with the LXCat website. The set is based on the cross sections originally compiled and adjusted in and first used in. The elementary processes taken into account are elastic momentum-transfer, vibrational excitation of the (1,3) and (2,4) modes, total dissociation into neutrals, and ionization producing CH4+and CH3++ H. For the latter two processes we have adjusted the partial ionization cross section of Chatham et al. as to reproduce their measured total ionization. The new cross-section set is validated by comparing calculated and measured electron swarm parameters for E / N = 0.1-400 Td. A discussion of similarities and differences with sets of CH4 cross sections from other databases is also presented. Work partially supported by FCT (Pest-OE/SADG/LA0010/2011).

  3. 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.

  4. 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.

  5. Alpha Induced Reaction Cross Section Calculations of Tantalum Nucleus

    NASA Astrophysics Data System (ADS)

    Tel, E.; Ugur, F. A.; Gokce, A. A.

    2013-04-01

    The fusion energy is attractive as an energy source because the fusion will not produce CO2 or SO2 and so fusion will not contribute to environmental problems, such as particulate pollution and excessive CO2 in the atmosphere. The fusion reaction does not produce radioactive nuclides and it is not self-sustaining, as is a fission reaction when a critical mass of fissionable material is assembled. Since the fusion reaction is easily and quickly quenched the primary sources of heat to drive such an accident are heat from radioactive decay and heat from chemical reactions. Both the magnitude and time dependence of the generation of heat from radioactive decay can be controlled by proper selection and design of materials. Tantalum is one of the candidate materials for the first wall of fusion reactors and for component parts of irradiation chambers. Accurate experimental cross-section data of alpha induced reactions on Tantalum are also of great importance for thermonuclear reaction rate determinations since the models used in the study of stellar nucleosynthesis are strongly dependent on these rates (Santos et al. in J Phys G 26:301, 2000). In this study, neutron-production cross sections for target nuclei 181Ta have been investigated up to 100 MeV alpha energy. The excitation functions for (α, xn) reactions (x = 1, 2, 3) have been calculated by pre-equilibrium reaction mechanism. And also neutron emission spectra for 181Ta (α, xn) reactions at 26.8 and 45.2 MeV have been calculated. The mean free path multiplier parameters has been investigated. The pre-equilibrium results have been calculated by using the hybrid model, the geometry dependent hybrid (GDH) model. Calculation results have been also compared with the available measurements in literature.

  6. 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

  7. 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…

  8. 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.

  9. Electron impact rotationally elastic total cross section for formamide

    SciTech Connect

    Vinodkumar, Minaxi; Limbachiya, Chetan; Desai, Hardik Vinodkumar, P. C.

    2014-09-28

    This paper reports computational results of the total cross sections for electron impact on formamide (HCONH₂) over a wide range of energies from 0.01 eV to 5 keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77 eV and 14.9 eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results.

  10. Electron impact rotationally elastic total cross section for formamide

    NASA Astrophysics Data System (ADS)

    Vinodkumar, Minaxi; Limbachiya, Chetan; Desai, Hardik; Vinodkumar, P. C.

    2014-09-01

    This paper reports computational results of the total cross sections for electron impact on formamide (HCONH2) over a wide range of energies from 0.01 eV to 5 keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77 eV and 14.9 eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results.

  11. Modeling elastic momentum transfer cross-sections from mobility data

    NASA Astrophysics Data System (ADS)

    Nikitović, Ž. D.; Stojanović, V. D.; Raspopović, Z. M.

    2016-04-01

    In this letter we present a new method to simply obtain the elastic momentum transfer cross-section which predicts a maximum of reduced mobility and its sensitivity to the temperature variation at low energies. We first determined the transport cross-section which resembles mobility data for similar closed-shell systems by using the Monte Carlo method. Second, we selected the most probable reactive processes and compiled cross-sections from experimental and theoretical data. At the end, an elastic momentum transfer cross-section is obtained by subtracting the compiled cross-sections from the momentum transfer cross-section, taking into account the effects of the angular scattering distributions. Finally, the cross-section set determined in such a way is used as an input in a final Monte Carlo code run, to calculate the flux and bulk reduced mobility for Ne+ + CF4 which were discussed as functions of the reduced electric field E/N (N is the gas density) for the temperature T = 300 K.

  12. Cross sections for electron scattering by atomic potassium

    SciTech Connect

    Msezane, A.Z.; Awuah, P.; Hiamang, S. Center for Theoretical Studies of Physical Systems, Clark Atlanta University, Atlanta, Georgia 30314 ); Allotey, F.K.A. )

    1992-12-01

    Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith (Comput. Phys. Commun. 23, 233 (1981)) in the electron energy range 4{le}{ital E}{le}200 eV. Configuration-interaction target wave functions that take account of correlation and polarization effects are used to represent the ground state and the six lowest excited states 4{ital p} {sup 2}{ital P}{degree}, 5{ital s} {sup 2}{ital S}, 3{ital d} {sup 2}{ital D}, 5{ital p} {sup 2}{ital P}{degree}, 4{ital d} {sup 2}{ital D}, and 6{ital s} {sup 2}{ital S}. Elastic and discrete excitation cross sections are obtained in a seven-state close-coupling (7CC) approximation. The 7CC elastic and excitation cross sections are compared and contrasted. Near threshold the elastic cross section dominates the resonance, 4{ital s} {sup 2}{ital S}{r arrow}4{ital p} {sup 2}{ital P}{degree}, and the sum of the other remaining excitation cross sections. Comparison of our total cross sections with some available experimental and theoretical data is also effected. The discrepancy between the recent measurement of the total cross section by Kwan {ital et} {ital al}. (Phys. Rev. A 44, 1620 (1991)) on the one hand and other measurements near threshold on the other hand is explained.

  13. Cross-Sectional Drawing Techniques And The Artist

    NASA Astrophysics Data System (ADS)

    Berry, William A.

    1980-07-01

    Although Democritus, a Greek pholosopher of the fifth century B.C. described the use of cross-sections in analyzing a solid form, this method was not extensively developed in art until the Renaissance. The earliest treatise documenting the integration of the cross-section and linear perspective is Piero della Francesca's De prospective pingendi (c. 1480), in which a drawing of the human head is mathematically conceived and plotted by means of cross-section contours. Piero's method anticipates contemporary biostereometric techniques and current theories of visual perception. Outside of theoretical treatises the complete cross-section rarely occurs in art, though certain pictorial elements such as the religious halo can be interpreted as cross-sections. The chan-ging representation of the halo in art of the Medieval, Renaissance and Baroque periods parallels the development of the artist's concepts and techniques for representing form and space. During the Renaissance and Baroque periods the widespread use of contour hatching, a drawing technique based on the cross-section, indicates that the cross-section concept has played a greater role in pictorial representation than has generally been recognized.

  14. 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

  15. 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. PMID:26642595

  16. 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.

  17. 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

  18. Relative charge transfer cross section from Rb (4d)

    NASA Astrophysics Data System (ADS)

    Shah, M. H.; Camp, H. A.; Trachy, M. L.; Fléchard, X.; Gearba, M. A.; Nguyen, H.; Brédy, R.; Lundeen, S. R.; Depaola, B. D.

    2005-08-01

    Relative charge transfer cross section measurements for the excited state Rb(4d) with 7keV Na+ is reported. The specific channels reported are Na++Rb(4d5/2)→Na(nl)+Rb+ , where the dominant transfer cross sections channels were nl=3d and 4s . Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na++Rb(5s,5p) systems at the same collision energy.

  19. Relative charge transfer cross section from Rb(4d)

    SciTech Connect

    Shah, M.H.; Camp, H.A.; Trachy, M.L.; De Paola, B.D.; Flechard, X.; Gearba, M.A.; Nguyen, H.; Bredy, R.; Lundeen, S.R.

    2005-08-15

    Relative charge transfer cross section measurements for the excited state Rb(4d) with 7 keV Na{sup +} is reported. The specific channels reported are Na{sup +}+Rb(4d{sub 5/2}){yields}Na(nl)+Rb{sup +}, where the dominant transfer cross sections channels were nl=3d and 4s. Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na{sup +}+Rb(5s,5p) systems at the same collision energy.

  20. Momentum transfer cross sections for the heavy noble gases

    NASA Astrophysics Data System (ADS)

    McEachran, R. P.; Stauffer, A. D.

    2014-06-01

    We present momentum transfer cross sections for elastic electron scattering from argon, krypton and xenon atoms over the energy range from zero to 1 keV. These have been calculated using the Dirac equations with a relativistic complex optical potential which includes polarization of the target atom by the incident electron and allows for the absorption of some of the incident electron flux into channels representing excitation and ionization of the atom. In order to aid in plasma modelling calculations, we provide simple analytic fits to these cross sections as well as to the elastic scattering cross sections. Comparisons are made with previous experimental and theoretical results.

  1. 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.

  2. Cross sections for electron scattering from α-tetrahydrofurfuryl alcohol

    NASA Astrophysics Data System (ADS)

    Duque, H. V.; Chiari, L.; Jones, D. B.; Thorn, P. A.; Pettifer, Z.; da Silva, G. B.; Limão-Vieira, P.; Duflot, D.; Hubin-Franskin, M.-J.; Delwiche, J.; Blanco, F.; García, G.; Lopes, M. C. A.; Ratnavelu, K.; White, R. D.; Brunger, M. J.

    2014-07-01

    We report on measurements of integral cross sections (ICSs) for electron impact excitation of a series of Rydberg electronic-states in α-tetrahydrofurfuryl alcohol. The energy range of these experiments was 20-50 eV. There are currently no other results against which we can directly compare those measured data. We also report results from our independent atom model with screened additivity rule correction computations, namely for the total cross section, elastic ICS, inelastic ICS (all discrete electronic states and neutral dissociation) and the total ionisation ICS. Where possible, our calculated cross sections are compared to the limited available data of each scattering process.

  3. 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.

  4. 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.

  5. 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…

  6. 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.

  7. 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.

  8. Importance of sarcomere length when determining muscle physiological cross-sectional area: a spine example.

    PubMed

    Brown, Stephen H M; Gerling, Michael E

    2012-05-01

    Muscle physiological cross-sectional area predicts the maximum capability of a muscle to generate isometric force. Biomechanical models often use estimates of individual muscle physiological cross-sectional area to partition internal forces among different muscles and predict joint forces and stability. In the spine literature, these physiological cross-sectional area values are generally obtained from imaging or cadaveric studies that have not accounted for a potential lengthened or shortened (and thus thinned or thickened, respectively) state of the muscles in question. Sarcomere length measurements can be used to normalize muscle lengths and correct for these length discrepancies. This article was designed to demonstrate potential effects of not accounting for instantaneous sarcomere length when calculating the physiological cross-sectional area of muscles of the spine region. Because some muscles of the spine region appear to be shortened and others lengthened in the neutral spine posture, both over- and under-estimations of physiological cross-sectional area are possible. Specifically, it is shown that the muscle physiological cross-sectional area could be over-estimated or under-estimated by as much as + 36% (multifidus) and -21% (rectus abdominis), respectively. This differential error effect poses difficulties in accurately estimating individual muscle forces and subsequent spine forces and stability that result from biomechanical models incorporating physiological cross-sectional area data obtained in the absence of sarcomere length measurements. Future work is needed to measure the dynamic range of sarcomere lengths of all spinal muscles to ensure correct inputs to biomechanical models. PMID:22720391

  9. 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.

  10. Differential cross sections of positron–hydrogen collisions

    NASA Astrophysics Data System (ADS)

    Rong-Mei, Yu; Chun-Ying, Pu; Xiao-Yu, Huang; Fu-Rong, Yin; Xu-Yan, Liu; Li-Guang, Jiao; Ya-Jun, Zhou

    2016-07-01

    We make a detailed study on the angular differential cross sections of positron–hydrogen collisions by using the momentum-space coupled-channels optical (CCO) method for incident energies below the H ionization threshold. The target continuum and the positronium (Ps) formation channels are included in the coupled-channels calculations via a complex equivalent-local optical potential. The critical points, which show minima in the differential cross sections, as a function of the scattering angle and the incident energy are investigated. The resonances in the angular differential cross sections are reported for the first time in this energy range. The effects of the target continuum and the Ps formation channels on the different cross sections are discussed. Project supported by the Nanyang Normal University Science Foundation of China (Grant No. ZX2013017) and the National Natural Science Foundation of China (Grant Nos. 11174066, 61306007, and U1304114).

  11. 56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 1. SCE drawing no. 5206856 (no date; FERC no. 1933-46). - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

  12. Photocopy of longitudinal, cross sections and roof plan of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of longitudinal, cross sections and roof plan of the C.B. & Q. R.R. roundhouse and locomotive shops. June 1980. - Chicago, Burlington & Quincy Railroad, Roundhouse & Shops, Broadway & Spring Streets, Aurora, Kane County, IL

  13. 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

  14. 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

  15. 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

  16. Viscosity cross sections for the heavy noble gases

    NASA Astrophysics Data System (ADS)

    McEachran, Robert P.; Stauffer, Allan Daniel

    2015-04-01

    We have calculated viscosity cross sections for argon, krypton and xenon from zero to 1 keV using the phase shifts from our previous publication [R.P. McEachran, A.D. Stauffer, Eur. Phys. J. D 68, 153 (2014)] which presented total elastic and momentum transfer cross sections for these gases. As previously, we present simple analytic fits to our results to aid in modelling plasmas containing these atoms. By using the current results and those in reference [R.P. McEachran, A.D. Stauffer, Eur. Phys. J. D 68, 153 (2014)] the first two `partial cross sections' used in the general moment method of solving the Boltzmann equation can be obtained. The agreement of our viscosity cross sections with experimentally derived results indicates the overall reliability of our calculations.

  17. 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

  18. 15. Power plant elevations and cross sections, sheet 64 of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Power plant elevations and cross sections, sheet 64 of 130 - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  19. Photoionization cross section for He in the hyperspherical coordinate method

    SciTech Connect

    Miller, D.L.; Starace, A.F.

    1980-01-01

    In order to more fully explore the role of electron correlations in the photoionization process the hyperspherical coordinate method of Macek was employed in calculating photoionization cross sections of He. Results are presented and discussed. (WHK)

  20. 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.

  1. 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.

  2. Totem Results on Elastic Scattering and Total Cross-Section

    NASA Astrophysics Data System (ADS)

    Kašpar, Jan

    2015-06-01

    TOTEM is an LHC experiment dedicated to forward hadronic physics. In this contribution, an update on two main parts of its physics programme is given: proton-proton elastic scattering and total cross-section.

  3. 56. CROSS SECTIONS OF CANAL AND TUNNELS. POWER CANAL, SALT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. CROSS SECTIONS OF CANAL AND TUNNELS. POWER CANAL, SALT RIVER RESERVOIR Courtesy of U.S.G.S., Reclamation Service - Roosevelt Power Canal & Diversion Dam, Parallels Salt River, Roosevelt, Gila County, AZ

  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. 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

  6. 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

  7. Extraordinarily Large Optical Cross Section for Localized Single Nanoresonator

    NASA Astrophysics Data System (ADS)

    Zhou, Ming; Shi, Lei; Zi, Jian; Yu, Zongfu

    2015-07-01

    Using an optical nanoresonator to realize extreme concentration of light at subwavelength nanoscale dimensions is of both fundamental and practical significance. Unfortunately, the optical cross section of an isotropic nanoresonator is determined by the resonant wavelength, which unfavorably limits the highest concentration ratio. Here we show that the cross section of a localized subwavelength resonator can be drastically enhanced by orders of magnitude. A single microscopic nanoresonator could exhibit a macroscopic optical cross section. We further show that the enhancement can be implemented in simple dielectric structures that are readily compatible with optoelectronic integration. The giant optical cross section of a nano-object provides a versatile platform to create extremely strong light-matter interactions at the nanoscale.

  8. Nucleon-nucleon cross sections in nuclear matter

    SciTech Connect

    Schulze, H.; Schnell, A.; Roepke, G.; Lombardo, U.

    1997-06-01

    We provide a microscopic calculation of neutron-proton and neutron-neutron cross sections in symmetric nuclear matter at various densities, using the Brueckner-Hartree-Fock approximation scheme with the Paris potential. We investigate separately the medium effects on the effective mass and on the scattering amplitude. We determine average cross sections suitable for application in the dynamical simulation of heavy ion collisions, including a parametrization of their energy and density dependence. {copyright} {ital 1997} {ital The American Physical Society}

  9. Differential double capture cross sections in p+He collisions

    SciTech Connect

    Schulz, M.; Brand, J. A.; Vajnai, T.

    2007-02-15

    We have measured differential double capture cross sections for 15 to 150 keV p+He collisions. We also analyzed differential double to single capture ratios, where we find pronounced peak structures. An explanation of these structures probably requires a quantum-mechanical description of elastic scattering between the projectile and the target nucleus. Strong final-state correlations have a large effect on the magnitude of the double capture cross sections.

  10. 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.

  11. 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%.

  12. Studies of 54,56Fe Neutron Scattering Cross Sections

    NASA Astrophysics Data System (ADS)

    Hicks, S. F.; Vanhoy, J. R.; French, A. J.; Henderson, S. L.; Howard, T. J.; Pecha, R. L.; Santonil, Z. C.; Crider, B. P.; Liu, S.; McEllistrem, M. T.; Peters, E. E.; Prados-Estévez, F. M.; Ross, T. J.; Yates, S. W.

    2015-05-01

    Elastic and inelastic neutron scattering differential cross sections and γ-ray production cross sections have been measured on 54,56Fe at several incident energies in the fast neutron region between 1.5 and 4.7 MeV. All measurements were completed at the University of Kentucky Accelerator Laboratory (UKAL) using a 7-MV Model CN Van de Graaff accelerator, along with the neutron production and neutron and γ-ray detection systems located there. The facilities at UKAL allow the investigation of both elastic and inelastic scattering with nearly mono-energetic incident neutrons. Time-of-flight techniques were used to detect the scattered neutrons for the differential cross section measurements. The measured cross sections are important for fission reactor applications and also for testing global model calculations such as those found at ENDF, since describing both the elastic and inelastic scattering is important for determining the direct and compound components of the scattering mechanism. The γ-ray production cross sections are used to determine cross sections to unresolved levels in the neutron scattering experiments. Results from our measurements and comparisons to model calculations are presented.

  13. Updating the IST-LISBON electron cross sections for nitrogen

    NASA Astrophysics Data System (ADS)

    Alves, L. L.; Sombreireiro, L.; Viegas, P.; Guerra, V.

    2013-09-01

    In this work we update the complete and consistent set of nitrogen (N2) electron-impact cross-section with the IST-LISBON database, available on the LXCat website. The update has extended, in energy scale up to 1 keV, the cross sections for effective momentum-transfer, excitation to electronic states and ionization. The set further accounts for excitation to rotational and vibrational excited states. Calculations using BOLSIG + with the new cross sections give swarm parameters in very good agreement with available experimental data for the reduced mobility, the characteristic energy and the reduced ionization coefficient, for a very extended E / N range up to 1000 Td. The influence of rotational excitations/de-excitations at low E / N and different rotational temperatures is discussed. A critical evaluation of similarities and differences with sets of N2 cross sections from other databases is carried out. Moreover, the procedure to de-convolute global cross sections into state-to-state vibrational level dependent cross sections is outlined and discussed. Work partially supported by FCT (Pest-OE/SADG/LA0010/2011).

  14. Absolute cross section for recoil detection of deuterium

    NASA Astrophysics Data System (ADS)

    Besenbacher, F.; Stensgaard, I.; Vase, P.

    1986-04-01

    The D( 4He, D) 4He cross section used for recoil detection of deuterium (D) has been calibrated on an absolute scale against the cross section of the D( 3He, α)p nuclear reaction which is often used for D profiling. For 4He energies ranging from 0.8 to ~1.8 MeV. the D( 4He, D) 4He cross section varies only slightly with incident energy and recoil angle θ (for 0° ⩽ 8 ⩽ 35°) and has a value of ~ 500 mb/sr which is significantly higher than the ~ 65 mb/sr c.m.s. cross section of the D( 3He, α)p nuclear reaction. For 4He energies ranging from ~ 1.9 to ~ 2.3 MeV, the D( 4He,D) 4He cross section exhibits a fairly narrow resonance peak (fwhm ~ 70 keV), with a maximum value (for θ = 0°) of ~ 8.5 b/sr, corresponding to a 4He energy of ~ 2130 keV. The large values of the cross section in connection with the described energy dependence makes the use of forward-recoil detection of D attractive for many purposes, e.g., D Jepth profiling (with an extreme gain in sensitivity), absolute concentration or coverage measurements, and lattice-location experiments by transmission channeling.

  15. Mental visualization of objects from cross-sectional images

    PubMed Central

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

    2011-01-01

    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 representation. Participants used a hand-held device to reveal a hidden object as a sequence of cross-sectional images. The process of localization was manipulated by contrasting two displays, in-situ vs. ex-situ, which differed in whether cross sections were presented at their source locations or displaced to a remote screen. The process of integration was manipulated by varying the structural complexity of target objects and their components. Experiments 1 and 2 demonstrated visualization of 2D and 3D line-segment objects and verified predictions about display and complexity effects. In Experiments 3 and 4, the visualized forms were familiar letters and numbers. Errors and orientation effects showed that displacing cross-sectional images to a remote display (ex-situ viewing) impeded the ability to determine spatial relationships among pattern components, a failure of integration at the object level. PMID:22217386

  16. Differential Cross Sections for Positrons Scattered from Molecules

    NASA Astrophysics Data System (ADS)

    Przybyla, D. A.; Addo-Asah, W.; Kauppila, W. E.; Stein, T. S.

    1998-05-01

    We have measured relative quasi-elastic (elastic scattering plus vibrational and rotational excitations) differential cross sections (DCS's) for positrons scattered at 30^o to 135^o from CH_4, N_2, O_2, CO, CO2 , and SF6 at energies extending from below the positronium (Ps) formation thresholds to well above them.(D. A. Przybyla, Nucl. Instr. and Meth. in Phys. Res. B, to be pub.) For each molecule we find (by extrapolating our DCS's to 0^o and 180^o) that below the Ps formation threshold there are significant large angle contributions to the total quasi-elastic cross sections. This observation is consistent with Ps formation cross sections measured by our group(C. K. Kwan, Nucl. Instr. and Meth. in Phys. Res. B, to be pub.), where we make "upper limit" measurements using a beam-transmisson technique with the angular discrimination deliberately made as poor as possible. In that case, there are still significant upper limit cross section values below the Ps formation threshold which must be due to elastically scattered positrons removed from the beam by scattering into large angles and the backward hemisphere. Below the Ps formation threshold, molecules with the greatest large angle DCS's have "upper limit" cross sections that are the greatest percentage of the total cross section.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. The Neutron Time-of-Flight Cross Section Program at the University of Kentucky - Adventures in Analysis II

    NASA Astrophysics Data System (ADS)

    Vanhoy, J. R.; Hicks, S. F.; Combs, B. C.; Crider, B. P.; French, A. J.; Garza, E. A.; Henderson, S. L.; Howard, T. J.; Liu, S. H.; Nigam, S.; Pecha, R. L.; Peters, E. E.; Prados-Estévez, F. M.; McEllistrem, M. T.; Rice, B. J.; Ross, T. J.; Santonil, Z. C.; Sidwell, L. C.; Steves, J. L.; Yates, S. W.

    2015-05-01

    Elastic and inelastic neutron differential cross sections are measured at the University of Kentucky Accelerator Laboratory (www.pa.uky.edu/accelerator/) at incident energies in the fast neutron region. The labo- ratorys facilities and instrumentation will be described and our measurement and analysis procedures outlined. Many corrections are required for neutron scattering experiments and the analysis utilizes information from many other cross section data sets and model calculations. Exploring and understanding the limitations of the foundational information and procedures are important for controlling the accuracy of the cross section results. We are examining the limitations in neutron detection efficiency, the normalization of (n,n'γ) cross sections,background reduction, spectrum stripping techniques, and attenuation and multiple scattering corrections. The resulting differential cross sections provide information on the compound elastic and coupled channels reaction mechanisms important for advanced reactor designs

  5. 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.

  6. 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

  7. 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

  8. 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.

  9. Determination of Minor Actinides Fission Cross Sections by Means of Transfer Reactions

    NASA Astrophysics Data System (ADS)

    Aiche, M.; Barreau, G.; Boyer, S.; Czajkowski, S.; Dassié, D.; Grosjean, C.; Guiral, A.; Haas, B.; Jurado, B.; Osmanov, B.; Bauge, E.; Petit, M.; Berthoumieux, E.; Gunsing, F.; Perrot, L.; Theisen, C.; Michel-Sendis, F.; Billebaud, A.; Wilson, J. N.; Ahmad, I.; Greene, J. P.; Janssens, R. V. F.

    2006-04-01

    An inventive method that allows to determine neutron-induced cross sections of very short-lived minor actinides is presented. We have successfully applied this method, based on the use of transfer reactions, to 233Pa, a key nucleus in the 232Th-233U fuel cycle. A recent experiment using this technique has also been performed in order to obtain the neutron-induced fission cross sections of 242, 243, 244Cm and 241Am which are present in the nuclear waste of the current U-Pu fuel cycle. These cross sections are highly relevant for the design of reactors capable to incinerate minor actinides. Preliminary experimental results will be presented.

  10. 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

  11. Grit and Work Engagement: A Cross-Sectional Study.

    PubMed

    Suzuki, Yuhei; Tamesue, Dai; 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

  12. 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.

  13. A Multigroup Reaction Cross-Section Collapsing Code and Library of 154-Group Fission-Product Cross Sections.

    1983-03-23

    Version 01/02 The code reads multigroup cross sections from a compatible data file and collapses user-selected reaction cross sections to any few-group structure using one of a variety of user neutron flux spectrum options given below: Option Flux description 1 Built-in function including Maxwellian, fission, fusion and slowing-down regions and requiring user-specified parameters and energy-region boundaries. 2 Set of log-log flux-energy interpolation points read from input cross-section data file. 3 Set of log-log flux-energy interpolationmore » points read from user-supplied card input. 4 - 6 Histogram flux values read from user-supplied card input in arbitrary group structure in units of flux-per unit-energy, flux-per-unit lethargy, or integral group flux. LAFPX-E may be used to collapse any set of multigroup reaction cross sections furnished in the required format. However, the code was developed for, and is furnished with, a library of 154-group fission-product cross sections processed from ENDF/B-IV with a typical light water reactor (LWR) flux spectrum and temperature. Four-group radiative capture cross sections produced for LWR calculations are tabulated in the code documentation and are incorporated in the EPRI-CINDER data library, RSIC Code Package CCC-309.« less

  14. /sup 242/Am/sup m/ fission cross section

    SciTech Connect

    Browne, J.C.; White, R.M.; Howe, R.E.; Landrum, J.H.; Dougan, R.J.; Dupzyk, R.J.

    1984-06-01

    The neutron-induced fission cross section of /sup 242/Am/sup m/ has been measured over the energy region from 10/sup -3/ eV to approx.20 MeV in a series of experiments utilizing a linac-produced ''white'' neutron source and a monoenergetic source of 14.1 MeV neutrons. The cross section was measured relative to that of /sup 235/U in the thermal (0.001 to approx.3 eV) and high energy (1 keV to approx.20 MeV) regions and normalized to the ENDF/B-V /sup 235/U(n,f) evaluated cross section. In the resonance energy region (0.5 eV to 10 keV) the neutron flux was measured using thin lithium glass scintillators and the relative cross section thus obtained was normalized to the thermal energy measurement. This procedure allowed a consistency check between the thermal and high energy data. The cross section data have a statistical accuracy of approx.0.5% at thermal energies and in the 1-MeV energy region, and a systematic uncertainty of approx.5%. We confirmed that /sup 242/Am/sup m/ has the largest thermal fission cross section known with a 2200 m/sec value of 6328 b. Results of a Breit-Wigner sum-of-single-levels analysis of 48 fission resonances up to 20 eV are presented and the connection of these resonance properties to the large thermal cross section is discussed. Our measurements are compared with previously reported results.

  15. ACTIV87: Fast Neutron Activation Cross Section File

    1993-08-01

    4. HISTORICAL BACKGROUND AND INFORMATION ACTIV87 is a compilation of fast neutron induced activation reaction cross-sections. The compilation covers energies from threshold to 20 MeV and is based on evaluated data taken from other evaluated data libraries and individual evaluations. The majority of these evaluations were performed by using available experimental data. The aforementioned available experimental data were used in the selection of needed parameters for theoretical computations and for normalizing the results of suchmore » computations. Theoretical calculations were also used for interpolation and extrapolation of experimental cross-section data. All of the evaluated data curves were compared with experimental data that had been reported over the four year period preceding 1987. Only those cross-sections not in contradiction with experimental data that was current in 1987 were retained in the activation file, ACTIV87. In cases of several conflicting evaluations, that evaluation was chosen which best corresponded to the experimental data. A few evaluated curves were renormalized in accordance with the results of the latest precision measurements. 5. APPLICATION OF THE DATA 6. SOURCE AND SCOPE OF DATA The following libraries and individual files of evaluated neutron cross-section data were used for the selection of the activation cross-sections: the BOSPOR Library, the Activation File of the Evaluated Nuclear Data Library, the Evaluated Neutron Data File (ENDF/B-V) Activation File, the International Reactor Dosimetry File (IRDF-82), and individual evaluations carried out under various IAEA research contracts. The file of selected reactions contains 206 evaluated cross-section curves of the (n,2n), (n,p) and (n,a) reactions which lead to radioactive products and may be used in many practical applications of neutron activation analysis. Some competing activation reactions, usually with low cross-section values, are given for completeness.« less

  16. 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).

  17. 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)…

  18. 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.

  19. 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…

  20. 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…

  1. 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…

  2. Cross Section Sensitivity and Uncertainty Analysis Including Secondary Neutron Energy and Angular Distributions.

    1991-03-12

    Version 00 SUSD calculates sensitivity coefficients for one- and two-dimensional transport problems. Variance and standard deviation of detector responses or design parameters can be obtained using cross-section covariance matrices. In neutron transport problems, this code can perform sensitivity-uncertainty analysis for secondary angular distribution (SAD) or secondary energy distribution (SED).

  3. 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…

  4. About creation of machines for rock destruction with formation of apertures of various cross-sections

    NASA Astrophysics Data System (ADS)

    Zhukov, I. A.; Dvornikov, L. T.; Nikitenko, S. M.

    2016-04-01

    The article presents the results of the experimental research of the high strength rock destruction by a bladeless tool. Rational circuit designs of disposing of indenters in the impact part of the drill bits and a diamond tool are justified. New constructive solutions of reinforcing bladeless drill bits, which allow drilling blast-holes of the various cross-section, are shown.

  5. 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.

  6. 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.

  7. 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. PMID:27333337

  8. Updated compilation of electron-Cl2 scattering cross sections

    NASA Astrophysics Data System (ADS)

    Gregório, J.; Pitchford, L. C.

    2012-06-01

    We present a set of cross sections for electron scattering from ground state neutral chlorine molecules in the energy range from 0.01 to 100 eV. This cross section set is based on the recommendations in the review paper by Christophorou and Olthoff (1999 J. Phys. Chem. Ref. Data 28 131) and on more recently published theoretical and experimental results. These cross sections are used as input to a Boltzmann equation solver to yield the electron energy distribution as a function of E/N, the ratio of the electric field strength to neutral density, from which electron transport and rate coefficients (swarm parameters) in gas mixtures containing Cl2 are obtained. Reasonable agreement with the more reliable of the measured swarm parameters is obtained after slightly adjusting the magnitudes of some of the cross sections. While this agreement validates to some extent the cross section set, it is important to note that swarm data in Cl2-containing mixtures are limited and that there is a critical need for further measurements.

  9. Electron collision cross sections for H{sub 2} II

    SciTech Connect

    Itoh, H.; Wada, H.; Ikuta, N.

    1993-12-01

    It is now an open but serious problem that the vibrational excitation cross sections of H{sub 2} molecule theoretically obtained by Morrison and that deduced by England from the swarm data disagree to each other. The results of beam experiment, on the other hand, agree with the theoretical cross section. Examinations in order to find the cause of these discrepancies have been carried out using the FTI method. The authors obtained the cross sections which fit to the drift velocity data and the D{sub {tau}}/{mu} data independently, but it has been impossible to obtain a cross section that fits to both of them. Theoretically derived cross section for vibrational excitation by Morrison can not give swarm parameters that agree with the data of swarm experiments. These facts show that there may be a fault in the present swarm theory. A possible cause of errors is the anisotropy in scatterings which has not been strictly included to the analyses.

  10. EDDIX--a database of ionisation double differential cross sections.

    PubMed

    MacGibbon, J H; Emerson, S; Liamsuwan, T; Nikjoo, H

    2011-02-01

    The use of Monte Carlo track structure is a choice method in biophysical modelling and calculations. To precisely model 3D and 4D tracks, the cross section for the ionisation by an incoming ion, double differential in the outgoing electron energy and angle, is required. However, the double differential cross section cannot be theoretically modelled over the full range of parameters. To address this issue, a database of all available experimental data has been constructed. Currently, the database of Experimental Double Differential Ionisation Cross sections (EDDIX) contains over 1200 digitalised experimentally measured datasets from the 1960s to present date, covering all available ion species (hydrogen to uranium) and all available target species. Double differential cross sections are also presented with the aid of an eight parameter functions fitted to the cross sections. The parameters include projectile species and charge, target nuclear charge and atomic mass, projectile atomic mass and energy, electron energy and deflection angle. It is planned to freely distribute EDDIX and make it available to the radiation research community for use in the analytical and numerical modelling of track structure. PMID:21113060

  11. Simulation of multistatic and backscattering cross sections for airborne radar

    NASA Astrophysics Data System (ADS)

    Biggs, Albert W.

    1986-07-01

    In order to determine susceptibilities of airborne radar to electronic countermeasures and electronic counter-countermeasures simulations of multistatic and backscattering cross sections were developed as digital modules in the form of algorithms. Cross section algorithms are described for prolate (cigar shape) and oblate (disk shape) spheroids. Backscattering cross section algorithms are also described for different categories of terrain. Backscattering cross section computer programs were written for terrain categorized as vegetation, sea ice, glacial ice, geological (rocks, sand, hills, etc.), oceans, man-made structures, and water bodies. PROGRAM SIGTERRA is a file for backscattering cross section modules of terrain (TERRA) such as vegetation (AGCROP), oceans (OCEAN), Arctic sea ice (SEAICE), glacial snow (GLASNO), geological structures (GEOL), man-made structures (MAMMAD), or water bodies (WATER). AGCROP describes agricultural crops, trees or forests, prairies or grassland, and shrubs or bush cover. OCEAN has the SLAR or SAR looking downwind, upwind, and crosswind at the ocean surface. SEAICE looks at winter ice and old or polar ice. GLASNO is divided into a glacial ice and snow or snowfields. MANMAD includes buildings, houses, roads, railroad tracks, airfields and hangars, telephone and power lines, barges, trucks, trains, and automobiles. WATER has lakes, rivers, canals, and swamps. PROGRAM SIGAIR is a similar file for airborne targets such as prolate and oblate spheroids.

  12. Can cross sections be accurately known for priori?

    SciTech Connect

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

    2008-06-24

    Distinct maxima and minima in the neutron total cross section uncertainties were observed in our large scale covariance calculations using a spherical optical potential. In this contribution we investigate the physical origin of this oscillating structure. Specifically, we analyze the case of neutron reactions on {sup 56}Fe, for which total cross section uncertainties are characterized by the presence of five distinct minima at 0.1, 1.1, 5, 25, and 70 MeV. To investigate their origin, we calculated total cross sections by perturbing the real volume depth V{sub v} by its expected uncertainty {+-}{Delta}V{sub v}. Inspecting the effect of this perturbation on the partial wave cross sections we found that the first minimum (at 0.1 MeV) is exclusively due to the contribution of the s-wave. On the other hand, the same analysis at 1.1 MeV showed that the minimum is the result of the interplay between s-, p-, and d-waves; namely the change in the s-wave happens to be counterbalanced by changes in the p- and d-waves. Similar considerations can be extended for the third minimum, although it can be also explained in terms of the Ramsauer effect as well as the other ones (at 25 and 70 MeV). We discuss the potential importance of these minima for practical applications as well as the implications of this work for the uncertainties in total and absorption cross sections.

  13. 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.

  14. 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.

  15. Systematic analysis of reaction cross sections of carbon isotopes

    SciTech Connect

    Horiuchi, W.; Suzuki, Y.; Abu-Ibrahim, B.; Kohama, A.

    2007-04-15

    We systematically analyze total reaction cross sections of carbon isotopes with N= 6-16 on a {sup 12}C target for wide range of incident energy. The intrinsic structure of the carbon isotope is described by a Slater determinant generated from a phenomenological mean-field potential, which reasonably well reproduces the ground-state properties for most of the even N isotopes. We need separate studies not only for odd nuclei but also for {sup 16}C and {sup 22}C to improve their wave functions. The density of the carbon isotope is constructed by eliminating the effect of the center-of-mass motion. For the calculations of the cross sections, we take two schemes, the Glauber approximation and the eikonal model using a global optical potential. Both the reaction models successfully reproduce low and high incident energy data on the cross sections of {sup 12}C, {sup 13}C, and {sup 16}C on {sup 12}C. The calculated reaction cross sections of {sup 15}C are found to be considerably smaller than the empirical values observed at low energy. We find a consistent parametrization of the nucleon-nucleon scattering amplitude, differently from previous ones. Finally, we predict the total reaction cross section of {sup 22}C on {sup 12}C.

  16. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    DOE PAGESBeta

    Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; Blyth, D.; Bowman, J. D.; Calarco, J.; Crawford, C.; Craycraft, K.; Evans, D.; Fomin, N.; et al

    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

  17. 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.

  18. Characterization of Cross-Sectioned Gallium Nitride High-Electron-Mobility Transistors with In Situ Biasing

    NASA Astrophysics Data System (ADS)

    Hilton, A. M.; Brown, J. L.; Moore, E. A.; Hoelscher, J. A.; Heller, E. R.; Dorsey, D. L.

    2015-10-01

    AlGaN/GaN high-electron-mobility transistors (HEMTs) were characterized in cross-section by Kelvin probe force microscopy (KPFM) during in situ biasing. The HEMTs used in this study were specially designed to maintain full and representative transistor functionality after cross-sectioning perpendicular to the gate width dimension to expose the active channel from source to drain. A cross-sectioning procedure was established that produces samples with high-quality surfaces and minimal degradation in initial transistor performance. A detailed description of the cross-sectioning procedure is provided. Samples were characterized by KPFM, effectively mapping the surface potential of the device in two-dimensional cross-section, including under metallization layers (i.e., gate, field plates, and ohmic contacts). Under the gate and field plate layers are where electric field, temperature, and temperature gradients are all most commonly predicted to have peak values, and where degradation and failure are most likely, and so this is where direct measurements are most critical. In this work, the surface potential of the operating device was mapped in cross-section by KPFM. Charge redistribution was observed during and after biasing, and the surface potential was seen to decay with time back to the prebias condition. This work is a first step toward directly mapping and localizing the steady-state and transient charge distribution due to point defects (traps) before, during, and after device operation, including normally inaccessible regions such as under metallization layers. Such measurements have not previously been demonstrated for GaN HEMT technology.

  19. 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.

  20. Measurement of the NP Elastic Cross Section by Neutron Transmission

    NASA Astrophysics Data System (ADS)

    Daub, Brian; Kovash, Michael; Henzl, Vladimir; Shoniyozov, Khayrullo

    2010-11-01

    There are very few previous measurements of the cross section for neutron-proton elastic scattering at energies between 200 and 500 keV. To improve this situation, we used a pulsed proton beam from the Van de Graaff accelerator at the University of Kentucky to produce 200-800 keV neutrons via the ^7Li(p,n)^7Be reaction. We determined the total n-p elastic cross section by measuring the transmission of the neutron beam in samples of CH2 and carbon, using a BC501 liquid scintillator. The cross section obtained by taking ratios between normalized sample-in and sample-out yields is independent of both detector efficiency and dead time.