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Sample records for activity frequency questionnaire

  1. Food frequency questionnaires.

    PubMed

    Pérez Rodrigo, Carmen; Aranceta, Javier; Salvador, Gemma; Varela-Moreiras, Gregorio

    2015-02-26

    Food Frequency Questionnaires are dietary assessment tools widely used in epidemiological studies investigating the relationship between dietary intake and disease or risk factors since the early '90s. The three main components of these questionnaires are the list of foods, frequency of consumption and the portion size consumed. The food list should reflect the food habits of the study population at the time the data is collected. The frequency of consumption may be asked by open ended questions or by presenting frequency categories. Qualitative Food Frequency Questionnaires do not ask about the consumed portions; semi-quantitative include standard portions and quantitative questionnaires ask respondents to estimate the portion size consumed either in household measures or grams. The latter implies a greater participant burden. Some versions include only close-ended questions in a standardized format, while others add an open section with questions about some specific food habits and practices and admit additions to the food list for foods and beverages consumed which are not included. The method can be self-administered, on paper or web-based, or interview administered either face-to-face or by telephone. Due to the standard format, especially closed-ended versions, and method of administration, FFQs are highly cost-effective thus encouraging its widespread use in large scale epidemiological cohort studies and also in other study designs. Coding and processing data collected is also less costly and requires less nutrition expertise compared to other dietary intake assessment methods. However, the main limitations are systematic errors and biases in estimates. Important efforts are being developed to improve the quality of the information. It has been recommended the use of FFQs with other methods thus enabling the adjustments required.

  2. Usual Dietary Intakes: NHANES Food Frequency Questionnaire (FFQ)

    Cancer.gov

    NCI developed a new instrument called the NHANES Food Frequency Questionnaire (formerly called Food Propensity Questionnaire) and supported its application in the National Health and Nutrition Examination Survey (NHANES).

  3. Preliminary reliability of the five item physical activity questionnaire

    PubMed Central

    Cho, Min-Haeng

    2016-01-01

    [Purpose] The purpose of this study was to design a physical activity questionnaire reflecting on the basic principles and recommendations of exercise and to examine its reliability. [Subjects and Methods] 342 males and 374 females from the community centers (senior center, residential culture center, sport center, and YWCA center) participated in this study. [Results] The test-retest reliability of the physical activity questionnaire, measured with an interval of three months, being between 0.61 and 0.91 signifies that the questionnaire was useful instrument for assessing physical activity levels. [Conclusion] This study found that the simple physical activity questionnaire containing the frequency, duration, intensity, overall length, and type of activities that the person performed during their leisure time was reliable. PMID:28174459

  4. Preliminary reliability of the five item physical activity questionnaire.

    PubMed

    Cho, Min-Haeng

    2016-12-01

    [Purpose] The purpose of this study was to design a physical activity questionnaire reflecting on the basic principles and recommendations of exercise and to examine its reliability. [Subjects and Methods] 342 males and 374 females from the community centers (senior center, residential culture center, sport center, and YWCA center) participated in this study. [Results] The test-retest reliability of the physical activity questionnaire, measured with an interval of three months, being between 0.61 and 0.91 signifies that the questionnaire was useful instrument for assessing physical activity levels. [Conclusion] This study found that the simple physical activity questionnaire containing the frequency, duration, intensity, overall length, and type of activities that the person performed during their leisure time was reliable.

  5. Validation and reproducibility of an Australian caffeine food frequency questionnaire.

    PubMed

    Watson, E J; Kohler, M; Banks, S; Coates, A M

    2017-01-05

    The aim of this study was to measure validity and reproducibility of a caffeine food frequency questionnaire (C-FFQ) developed for the Australian population. The C-FFQ was designed to assess average daily caffeine consumption using four categories of food and beverages including; energy drinks; soft drinks/soda; coffee and tea and chocolate (food and drink). Participants completed a seven-day food diary immediately followed by the C-FFQ on two consecutive days. The questionnaire was first piloted in 20 adults, and then, a validity/reproducibility study was conducted (n = 90 adults). The C-FFQ showed moderate correlations (r = .60), fair agreement (mean difference 63 mg) and reasonable quintile rankings indicating fair to moderate agreement with the seven-day food diary. To test reproducibility, the C-FFQ was compared to itself and showed strong correlations (r = .90), good quintile rankings and strong kappa values (κ = 0.65), indicating strong reproducibility. The C-FFQ shows adequate validity and reproducibility and will aid researchers in Australia to quantify caffeine consumption.

  6. Relative Validity and Reproducibility of a Quantitative Food Frequency Questionnaire for Adolescents with Type 1 Diabetes: Validity of a Food Frequency Questionnaire

    PubMed Central

    Marques, Rosana de Moraes Borges; de Oliveira, Amanda Cristine; Teles, Sheylle Almeida da Silva; Stringuini, Maria Luiza Ferreira; Fornés, Nélida Shimid

    2014-01-01

    Background. Food frequency questionnaires are used to assess dietary intake in epidemiological studies. Objective. The aim of the study was to assess the relative validity and reproducibility of a quantitative food frequency questionnaire (QFFQ) for adolescents with type 1 diabetes. Methods: Validity was evaluated by comparing the data generated by QFFQs to those of 24-hour recalls (24 hrs). QFFQs were applied twice per patient to assess reproducibility. Statistical analysis included performing t-tests, obtaining Pearson correlation coefficients when necessary, correcting measurements for randomness by the weighted kappa method, calculating intraclass correlation coefficients, and generating Bland-Altman plots (P < 0,05). Results. The total energy and nutrient intake as estimated by the QFFQs were significantly higher than those from 24 hrs. Pearson correlation coefficients for energy-adjusted, deattenuated data ranged from 0.32 (protein) to 0.75 (lipid, unsaturated fat and calcium). Weighted kappa values ranged from 0.15 (vitamin C) to 0.45 (calcium). Bland-Altman plots indicated acceptable validity. As for reproducibility, intraclass correlation coefficients ranged from 0.24 (calcium) to 0.65 (lipid), and the Bland-Altman plots showed good agreement between the two questionnaires. Conclusion: The QFFQ presented an acceptable ability to classify correctly and with good reproducibility, adolescents with type 1 diabetes according to their levels of dietary intake. PMID:25250051

  7. Evaluation of a validated food frequency questionnaire for self-defined vegans in the United States.

    PubMed

    Dyett, Patricia; Rajaram, Sujatha; Haddad, Ella H; Sabate, Joan

    2014-07-08

    This study aimed to develop and validate a de novo food frequency questionnaire for self-defined vegans in the United States. Diet histories from pilot samples of vegans and a modified 'Block Method' using seven selected nutrients of concern in vegan diet patterns, were employed to generate the questionnaire food list. Food frequency responses of 100 vegans from 19 different U.S. states were obtained via completed mailed questionnaires and compared to multiple telephone-conducted diet recall interviews. Computerized diet analyses were performed. Correlation coefficients, t-tests, rank, cross-tabulations, and probability tests were used to validate and compare intake estimates and dietary reference intake (DRI) assessment trends between the two methods. A 369-item vegan-specific questionnaire was developed with 252 listed food frequency items. Calorie-adjusted correlation coefficients ranged from r = 0.374 to 0.600 (p < 0.001) for all analyzed nutrients except calcium. Estimates, ranks, trends and higher-level participant percentile placements for Vitamin B12 were similar with both methods. Questionnaire intakes were higher than recalls for most other nutrients. Both methods demonstrated similar trends in DRI adequacy assessment (e.g., significantly inadequate vitamin D intake among vegans). This vegan-specific questionnaire can be a useful assessment tool for health screening initiatives in U.S. vegan communities.

  8. Evaluation of a Validated Food Frequency Questionnaire for Self-Defined Vegans in the United States

    PubMed Central

    Dyett, Patricia; Rajaram, Sujatha; Haddad, Ella H.; Sabate, Joan

    2014-01-01

    This study aimed to develop and validate a de novo food frequency questionnaire for self-defined vegans in the United States. Diet histories from pilot samples of vegans and a modified ‘Block Method’ using seven selected nutrients of concern in vegan diet patterns, were employed to generate the questionnaire food list. Food frequency responses of 100 vegans from 19 different U.S. states were obtained via completed mailed questionnaires and compared to multiple telephone-conducted diet recall interviews. Computerized diet analyses were performed. Correlation coefficients, t-tests, rank, cross-tabulations, and probability tests were used to validate and compare intake estimates and dietary reference intake (DRI) assessment trends between the two methods. A 369-item vegan-specific questionnaire was developed with 252 listed food frequency items. Calorie-adjusted correlation coefficients ranged from r = 0.374 to 0.600 (p < 0.001) for all analyzed nutrients except calcium. Estimates, ranks, trends and higher-level participant percentile placements for Vitamin B12 were similar with both methods. Questionnaire intakes were higher than recalls for most other nutrients. Both methods demonstrated similar trends in DRI adequacy assessment (e.g., significantly inadequate vitamin D intake among vegans). This vegan-specific questionnaire can be a useful assessment tool for health screening initiatives in U.S. vegan communities. PMID:25006856

  9. Validation of a questionnaire assessing food frequency and nutritional intake in Greek adolescents.

    PubMed

    Papadopoulou, Sousana K; Barboukis, Vassilis; Dalkiranis, Anastasios; Hassapidou, Maria; Petridou, Anatoli; Mougios, Vassilis

    2008-03-01

    The aim of the study was to develop and validate a specific semi-quantitative food frequency questionnaire to assess nutritional intake of Greek adolescents. The sample of the study consisted of 250 pupils (15.3 +/- 0.7 years), who completed the Youth Adolescent Food Frequency Questionnaire enriched with 22 Greek foods and recipes to include ethnic and racial diversity. A 3-day weighed food recall was used as the criterion to test the validity of the questionnaire. The analysis of correlation revealed significant correlations between the two methods for almost all variables. The Pearson's coefficients ranged from 0.83 for energy intake to 0.34 for folate intake. Non-significant correlations were found for selenium and vitamin D intakes. The findings of the study provide evidence for the validity of the scale and its utility in assessing nutritional intake of Greek adolescents.

  10. Assessing dietary intake in childhood cancer survivors: Food frequency questionnaire versus 24-hour diet recalls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cancer diagnosis and treatment may influence dietary intake. The validity of using self-reported methods to quantify dietary intake has not been evaluated in childhood cancer survivors. We validated total energy intake (EI) reported from Food Frequency Questionnaire (FFQ) and repeated 24-hour diet r...

  11. Assessment of Dietary Intakes of Filipino-Americans: Implications for Food Frequency Questionnaire Design

    ERIC Educational Resources Information Center

    Johnson-Kozlow, Marilyn; Matt, Georg E.; Rock, Cheryl L.; de la Rosa, Ruth; Conway, Terry L.; Romero, Romina A.

    2011-01-01

    Objective: The purpose of this study was to describe food consumption practices of Filipino-American adults, to describe how they respond to a food frequency questionnaire (FFQ) as a function of acculturation and sex, and to suggest modifications to the FFQ to improve dietary assessment among Filipino-Americans. Methods: Twenty-one…

  12. Validation of a quantitative food frequency questionnaire developed to under graduate students.

    PubMed

    Komatsu, Tiemy Rosana; Oku, Simone Kimie; Gimeno, Suely Godoy Agostinho; Asakura, Leiko; Coelho, Luciola de Castro; Silva, Clarissa Viana Demezio da; Akutsu, Rita de Cassia Coelho Almeida; Sachs, Anita

    2013-12-01

    A validity test of a Food Frequency Questionnaire was carried out using 50 students of health occupation in São Paulo, Brazil. Therefore, a three day dietary record was used as reference method and variables such as energy, macronutrients and dietary fiber were analyzed. The accordance between the Food Frequency Questionnaire and average data from dietary record was tested with kappa statistics and intra-class correlation coefficients (ICC). Limits of agreement were estimated by the Bland-Altman's method. Better results were found for calories (ICC 0.43; 95%CI 0.17 - 0.63) and non-energy-adjusted nutrients, except dietary fiber (ICC 0.34; 95%CI 0.07 - 0.56). The percentage of individuals classified in the same category of consumption was nearly half (49.8%), while only 16% of them were classified in opposite categories. With the exception of lipids, other analyzed variables tended to be overestimated by the Food Frequency Questionnaire. The Food Frequency Questionnaire is recommended as a method of assessing food intake of university students in studies which focus on calorie estimates and also intend to classify groups into intake categories.

  13. Validity and Reliability of the School Physical Activity Environment Questionnaire

    ERIC Educational Resources Information Center

    Martin, Jeffrey J.; McCaughtry, Nate; Flory, Sara; Murphy, Anne; Wisdom, Kimberlydawn

    2011-01-01

    The goal of the current study was to establish the factor validity of the Questionnaire Assessing School Physical Activity Environment (Robertson-Wilson, Levesque, & Holden, 2007) using confirmatory factor analysis procedures. Another goal was to establish internal reliability and test-retest reliability. The confirmatory factor analysis…

  14. Validity and Reproducibility of a Habitual Dietary Fibre Intake Short Food Frequency Questionnaire.

    PubMed

    Healey, Genelle; Brough, Louise; Murphy, Rinki; Hedderley, Duncan; Butts, Chrissie; Coad, Jane

    2016-09-10

    Low dietary fibre intake has been associated with poorer health outcomes, therefore having the ability to be able to quickly assess an individual's dietary fibre intake would prove useful in clinical practice and for research purposes. Current dietary assessment methods such as food records and food frequency questionnaires are time-consuming and burdensome, and there are presently no published short dietary fibre intake questionnaires that can quantify an individual's total habitual dietary fibre intake and classify individuals as low, moderate or high habitual dietary fibre consumers. Therefore, we aimed to develop and validate a habitual dietary fibre intake short food frequency questionnaire (DFI-FFQ) which can quickly and accurately classify individuals based on their habitual dietary fibre intake. In this study the DFI-FFQ was validated against the Monash University comprehensive nutrition assessment questionnaire (CNAQ). Fifty-two healthy, normal weight male (n = 17) and female (n = 35) participants, aged between 21 and 61 years, completed the DFI-FFQ twice and the CNAQ once. All eligible participants completed the study, however the data from 46% of the participants were excluded from analysis secondary to misreporting. The DFI-FFQ cannot accurately quantify total habitual dietary fibre intakes, however, it is a quick, valid and reproducible tool in classifying individuals based on their habitual dietary fibre intakes.

  15. Validity and Reproducibility of a Habitual Dietary Fibre Intake Short Food Frequency Questionnaire

    PubMed Central

    Healey, Genelle; Brough, Louise; Murphy, Rinki; Hedderley, Duncan; Butts, Chrissie; Coad, Jane

    2016-01-01

    Low dietary fibre intake has been associated with poorer health outcomes, therefore having the ability to be able to quickly assess an individual’s dietary fibre intake would prove useful in clinical practice and for research purposes. Current dietary assessment methods such as food records and food frequency questionnaires are time-consuming and burdensome, and there are presently no published short dietary fibre intake questionnaires that can quantify an individual’s total habitual dietary fibre intake and classify individuals as low, moderate or high habitual dietary fibre consumers. Therefore, we aimed to develop and validate a habitual dietary fibre intake short food frequency questionnaire (DFI-FFQ) which can quickly and accurately classify individuals based on their habitual dietary fibre intake. In this study the DFI-FFQ was validated against the Monash University comprehensive nutrition assessment questionnaire (CNAQ). Fifty-two healthy, normal weight male (n = 17) and female (n = 35) participants, aged between 21 and 61 years, completed the DFI-FFQ twice and the CNAQ once. All eligible participants completed the study, however the data from 46% of the participants were excluded from analysis secondary to misreporting. The DFI-FFQ cannot accurately quantify total habitual dietary fibre intakes, however, it is a quick, valid and reproducible tool in classifying individuals based on their habitual dietary fibre intakes. PMID:27626442

  16. The effectiveness of a short food frequency questionnaire in determining vitamin D intake in children.

    PubMed

    Nucci, Anita M; Russell, Caitlin Sundby; Luo, Ruiyan; Ganji, Vijay; Olabopo, Flora; Hopkins, Barbara; Holick, Michael F; Rajakumar, Kumaravel

    2013-01-01

    Previous studies have found a high prevalence of vitamin D deficiency in children, yet few validated dietary vitamin D assessment tools are available for use in children. Our objective was to determine whether a short food frequency questionnaire (SFFQ) can effectively assess vitamin D intake in children. Vitamin D intake ascertained by a SFFQ was compared with assessments by a previously validated long food frequency questionnaire (LFFQ) in a population of 296 healthy 6- to 14-y-old children (54% male, 60% African American) from Pittsburgh, PA. The questionnaires were completed at two points 6 mo apart. Median reported daily vitamin D intake from the SFFQ (baseline: 380 IU, follow-up: 363 IU) was higher than the LFFQ (255 IU and 254 IU, respectively). Reported median dairy intake, including milk, cheese, and yogurt, was 3.7 cups/day, which meets the USDA recommendation for children. Vitamin D intake reported by the 2 questionnaires was modestly correlated at baseline and follow-up (r = 0.35 and r = 0.37, respectively; p < 0.001). These associations were stronger in Caucasians (r = 0.48 and r = 0.49, p < 0.001) than in African Americans (r = 0.27 and r = 0.31; p = 0.001). The sensitivity of the SFFQ for predicting daily vitamin D intake, defined as intake of ≥ 400 IU on both the SFFQ and LFFQ, was 65%. Specificity, defined as intake of < 400 IU on both questionnaires, was 42%. Vitamin D requirements may not be met despite adequate consumption of dairy products. The SFFQ was found to be a modestly valid and sensitive tool for dietary assessment of vitamin D intake in children.

  17. Development of a semiquantitative food frequency questionnaire to assess food, energy and nutrient intake in Denmark.

    PubMed

    Overvad, K; Tjønneland, A; Haraldsdóttir, J; Ewertz, M; Jensen, O M

    1991-12-01

    Foods to be included in a Danish self-administered semiquantitative food frequency questionnaire were identified from food tables developed, together with data collected, for the survey 'Dietary habits in Denmark, 1985'. The questionnaire was to be used in a prospective study on diet, cancer and health, and the aim was to rank individuals with regard to intake of 19 different nutrients considered of prime importance in human carcinogenesis. The questionnaire for the dietary survey included 247 foods and recipes. From stepwise multiple regression analyses with the intake of each of the 19 nutrients as the dependent variable and the intake of the 247 foods and recipes as independent variables, the foods in the models explaining 90% of the between-person variability were considered for the final questionnaire. All relevant analyses were performed for the study group as a whole, for men and women separately, and in each gender for subgroups of energy intake. Taken together, the models explaining 90% of the between-person variability identified a total of 74 foods or recipes, which were important predictors of the intake of one or more of the nutrients considered. A few foods were excluded and a few foods were added to the final questionnaire based on common biological background information, and on information on foods providing important amounts of given nutrients, but which failed to contribute to regression analyses. The 92 foods and recipes, which were included in the final questionnaire provided altogether 81% of the average total supply of the nutrients.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. Assessing Dietary Intake in Childhood Cancer Survivors: Food Frequency Questionnaire Versus 24-Hour Diet Recalls.

    PubMed

    Zhang, Fang Fang; Roberts, Susan B; Must, Aviva; Wong, William W; Gilhooly, Cheryl H; Kelly, Michael J; Parsons, Susan K; Saltzman, Edward

    2015-10-01

    Cancer diagnosis and treatment may influence dietary intake. The validity of using self-reported methods to quantify dietary intake has not been evaluated in childhood cancer survivors. We validated total energy intake (EI) reported from Food Frequency Questionnaire (FFQ) and repeated 24-hour diet recalls (24HRs) against total energy expenditure (TEE) measured using the doubly labeled water method in 16 childhood cancer survivors. Dietary underreporting, assessed by (EI-TEE)/TEE × 100%, was 22% for FFQ and 1% for repeated 24HRs. FFQ significantly underestimates dietary intake and should not be used to assess the absolute intake of foods and nutrients in childhood cancer survivors.

  19. 78 FR 38098 - Proposed Information Collection (Knee and Lower Leg Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-25

    ... AFFAIRS Proposed Information Collection (Knee and Lower Leg Disability Benefits Questionnaire) Activity... Disability Benefits Questionnaire)'' in any correspondence. During the comment period, comments may be viewed.... SUPPLEMENTARY INFORMATION: Title: Knee and Lower Leg Conditions Disability Benefits Questionnaire, VA Form...

  20. 78 FR 34708 - Proposed Information Collection (Ankle Conditions Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-10

    ... AFFAIRS Proposed Information Collection (Ankle Conditions Disability Benefits Questionnaire) Activity... Control No. 2900--NEW (Ankle Conditions Disability Benefits Questionnaire)'' in any correspondence. During... Conditions Disability Benefits Questionnaire, VA Form 21-0960M-2. OMB Control Number: 2900--NEW...

  1. Comparing the validity of 2 physical activity questionnaire formats in African-American and Hispanic women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study was to compare the validity of 2 physical activity questionnaire formats—one that lists activities (Checklist questionnaire) and one that assesses overall activities (Global questionnaire) by domain. Two questionnaire formats were validated among 260 African-American and Hi...

  2. Improving quality of Food Frequency Questionnaire response in low-income Mexican American children.

    PubMed

    Garcia-Dominic, Oralia; Treviño, Roberto P; Echon, Roger M; Mobley, Connie; Block, Torin; Bizzari, Ansam; Michalek, Joel

    2012-11-01

    The authors evaluated the validity and reliability of the Block Kids Food Frequency Questionnaire (BKFFQ) and the Block Kid Screener (BKScreener) in Mexican American children living along the Texas-Mexico border who participated in the National Institutes of Health-funded Proyecto Bienestar Laredo. The Bienestar/NEEMA health program is a school-based diabetes and obesity control program, and the Proyecto Bienestar Laredo is the translation of the Bienestar/NEEMA health program to 38 elementary schools in Laredo, Texas. Par ticipants included 2,376 eight-year-old boys (48%) and girls (52%) from two school districts in Laredo. Two Food Frequency Questionnaire (BKFFQ and BKScreener) dietary intakes were collected, and an expert panel of nutritionist assigned a classification response quality of "Good," "Questionable," and "Poor," based on playfulness (systematic or nonrandom) patterns and completion rates. In addition, both instruments were assessed for reliability (test-retest) in 138 students from a San Antonio School District. Children's height, weight, percentage body fat, reported family history of diabetes, and Texas Assessments of Knowledge and Skills in reading and mathematics scores were collected. This study showed that for Mexican American children living along the Texas-Mexico border, within the time constraints of the classroom, BKScreener yielded better data than the BKFFQ.

  3. The KOJACH food frequency questionnaire for Chaoshan, China: development and description.

    PubMed

    Li, Ke; Takezaki, Toshiro; Song, Feng-Yan; Yu, Ping; Lin, Xu-Kai; Yang, He-Lin; Deng, Xiao-Ling; Zhang, Yu-Qi; Lv, Lai-Wen; Huang, Xin-En; Tajima, Kazuo

    2006-01-01

    This paper aims to develop a data-based Semi-Quantitative Food Frequency Questionnaire (SQFFQ) covering both urban and rural areas in the Chaoshan region of Guangdong Province, China, for the investigation of relationships between food intake and lifestyle-related diseases among middle-aged Chinese. We recruited 417 subjects from the general population and performed an assessment of the diet, using a 3-day weighed dietary record survey. We employed contribution analysis (CA) and multiple regression analysis (MRA) to select food items covering up to a 90% contribution and a 0.90 R2, respectively. The total number of food items consumed was 523 (443 in the urban and 417 in the rural population) and the intake of 29 nutrients was calculated according to the actual consumption by foods/recipes. The CA selected 233, 194 and 183 foods/recipes for the combined, the urban and the rural areas, respectively, and then 196, 157 and 160 were chosen by the MRA. Finally, 125 foods/recipes were selected for the final questionnaire. The frequencies were classified into eight categories and standard portion sizes were also calculated. For adoption of the area-specific SQFFQ, Validity and reproducibility tests are now planned to determine how the combined SQFFQ performs in actual assessment of disease risk and benefit.

  4. Active Faraday optical frequency standard.

    PubMed

    Zhuang, Wei; Chen, Jingbiao

    2014-11-01

    We propose the mechanism of an active Faraday optical clock, and experimentally demonstrate an active Faraday optical frequency standard based on narrow bandwidth Faraday atomic filter by the method of velocity-selective optical pumping of cesium vapor. The center frequency of the active Faraday optical frequency standard is determined by the cesium 6 (2)S(1/2) F=4 to 6 (2)P(3/2) F'=4 and 5 crossover transition line. The optical heterodyne beat between two similar independent setups shows that the frequency linewidth reaches 281(23) Hz, which is 1.9×10(4) times smaller than the natural linewidth of the cesium 852-nm transition line. The maximum emitted light power reaches 75 μW. The active Faraday optical frequency standard reported here has advantages of narrow linewidth and reduced cavity pulling, which can readily be extended to other atomic transition lines of alkali and alkaline-earth metal atoms trapped in optical lattices at magic wavelengths, making it useful for new generation of optical atomic clocks.

  5. Frequency of methotrexate intolerance in rheumatoid arthritis patients using methotrexate intolerance severity score (MISS questionnaire).

    PubMed

    Fatimah, Nibah; Salim, Babur; Nasim, Amjad; Hussain, Kamran; Gul, Harris; Niazi, Sarah

    2016-05-01

    The objective of the study was to determine the frequency of methotrexate intolerance in rheumatoid arthritis (RA) patients by applying the methotrexate intolerance severity score (MISS) questionnaire and to see the effect of dose and concomitant use of other disease-modifying antirheumatic drugs (DMARDS) on methotrexate (MTX) intolerance. For the descriptive study, non-probability sampling was carried out in the Female Rheumatology Department of Fauji Foundation Hospital (FFH), Rawalpindi, Pakistan. One hundred and fifty diagnosed cases of RA using oral MTX were selected. The MISS questionnaire embodies five elements: abdominal pain, nausea, vomiting, fatigue and behavioural symptoms. The amplitude of each element was ranked from 0 to 3 being no complaint (0 points), mild (1 point), moderate (2 points) and severe (3 points). A cut-off score of 6 and above ascertained intolerance by the physicians. A total of 33.3 % of the subjects exhibited MTX intolerance according to the MISS questionnaire. Out of which, the most recurring symptom of all was behavioural with a value of 44 % whereas vomiting was least noticeable with a figure of 11 %. About 6.6 % of the women with intolerance were consuming DMARDs in conjunction with MTX. Those using the highest weekly dose of MTX (20 mg) had supreme intolerance with prevalence in 46.2 % of the patients. The frequency of intolerance decreased with a decrease in weekly dose to a minimum of 20 % with 7.5 mg of MTX. MTX intolerance has moderate prevalence in RA patients and if left undetected, the compliance to use of MTX as a first-line therapy will decrease. Methotrexate intolerance is directly proportional to the dose of MTX taken. Also, there is no upstroke seen in intolerance with the use of other disease-modifying agents.

  6. Development, validity, and reliability of a food frequency questionnaire for antioxidants in elderly Iranian people

    PubMed Central

    Malekahmadi, Mahsa; Naeini, Amirmansour Alavi; Shab-Bidar, Sakineh; Feizi, Awat; Djazayery, Abolghasem

    2016-01-01

    Background: The food frequency questionnaire (FFQ), as a way to assess the dietary intake in comparison with other methods, is easier to analyze and takes less time and is less costly. Our aim in this study was to develop and validate an FFQ for estimating the intakes of selected antioxidants in elderly Iranian people. Materials and Methods: A total of 185 elderly people were randomly selected. Three-day food records were completed by the subjects and collected every 2 months and dietary intake levels of zinc, selenium, carotenes and vitamins C and E were estimated. Based on the food records data, geographic location, and age, an FFQ was designed to estimate antioxidant intakes during 1 year. In addition, for controlling energy intake, 2-day food records were also collected with the food frequency questionnaire. To assess the reliability, 40 individuals were asked to complete the FFQ twice with an interval of 3 months in between. Results: Intraclass correlation coefficient (ICC) between the two FFQs for antioxidant C, antioxidant E, carotene, selenium, and zinc were 0.62, 0.47, 0.51, 0.54, and 0.58, respectively (P < 0.05). In addition, Pearson correlation coefficients between the FFQ and the food records, after controlling energy for vitamin C, vitamin E, carotene, selenium, and zinc, were 0.46, 0.48, 0.38, 0.55, and 0.47 respectively (P < 0.001). Conclusion: According to the results of this study, considering the fact that the FFQ was designed for the elderly and the special conditions (patience, memory, etc.) and vulnerability of this age group, the questionnaire is relatively valid and reliable to use. PMID:27904560

  7. Relative validity and reproducibility of a food frequency questionnaire to estimate intake of dietary phylloquinone and menaquinones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Several observational studies have investigated the relation of dietary phylloquinone and menaquinone intake with occurrence of chronic diseases. Most of these studies relied on food frequency questionnaires (FFQ) to estimate the intake of phylloquinone and menaquinones. However, none of...

  8. Validation of the Oxford Participation and Activities Questionnaire

    PubMed Central

    Morley, David; Dummett, Sarah; Kelly, Laura; Dawson, Jill; Fitzpatrick, Ray; Jenkinson, Crispin

    2016-01-01

    Purpose There is growing interest in the management of long-term conditions and in keeping people active and participating in the community. Testing the effectiveness of interventions that aim to affect activities and participation can be challenging without a well-developed, valid, and reliable instrument. This study therefore aims to develop a patient-reported outcome measure, the Oxford Participation and Activities Questionnaire (Ox-PAQ), which is theoretically grounded in the World Health Organization’s International Classification of Functioning, Disability, and Health (ICF) and fully compliant with current best practice guidelines. Methods Questionnaire items generated from patient interviews and based on the nine chapters of the ICF were administered by postal survey to 386 people with three neurological conditions: motor neuron disease, multiple sclerosis, and Parkinson’s disease. Participants also completed the Medical Outcomes Study (MOS) 36-Item Short Form Health Survey (SF-36) and EQ-5D-5L. Results Thus, 334 participants completed the survey, a response rate of 86.5%. Factor analysis techniques identified three Ox-PAQ domains, consisting of 23 items, accounting for 72.8% of variance. Internal reliability for the three domains was high (Cronbach’s α: 0.81–0.96), as was test–retest reliability (intraclass correlation: 0.83–0.92). Concurrent validity was demonstrated through highly significant relationships with relevant domains of the MOS SF-36 and the EQ- 5D-5L. Assessment of known-groups validity identified significant differences in Ox-PAQ scores among the three conditions included in the survey. Conclusion Results suggest that the Ox-PAQ is a valid and reliable measure of participation and activity. The measure will now be validated in a range of further conditions, and additional properties, such as responsiveness, will also be assessed in the next phase of the instrument’s development. PMID:27366108

  9. Protein intake in Parkinsonian patients using the EPIC food frequency questionnaire.

    PubMed

    Marczewska, Agnieszka; De Notaris, Roberta; Sieri, Sabina; Barichella, Michela; Fusconi, Elisabetta; Pezzoli, Gianni

    2006-08-01

    The dietary habits of 45 Italian patients with Parkinson's disease (PD) and their spouses were investigated using the EPIC food frequency questionnaire. Average daily energy intake was similar, but PD patients consumed significantly more vegetable proteins and carbohydrates (both +18%; P = 0.01 and P = 0.001, respectively). Daily protein intake, which interferes with levodopa absorption, was 50% higher than the recommended daily allowance (1.2 vs. 0.8 g/kg) in both PD patients and spouses and was significantly higher in patients with moderate/severe symptoms (1.27 +/- 0.29 vs. 1.07 +/- 0.28 g/kg; P < 0.001). In patients taking levodopa, there was a correlation between daily levodopa dosage and protein intake (P = 0.027). Dietary habits of patients with advanced and/or fluctuating PD should always be checked, with particular reference to protein intake.

  10. Evaluation of web-based, self-administered, graphical food frequency questionnaire.

    PubMed

    Kristal, Alan R; Kolar, Ann S; Fisher, James L; Plascak, Jesse J; Stumbo, Phyllis J; Weiss, Rick; Paskett, Electra D

    2014-04-01

    Computer-administered food frequency questionnaires (FFQs) can address limitations inherent in paper questionnaires by allowing very complex skip patterns, portion size estimation based on food pictures, and real-time error checking. We evaluated a web-based FFQ, the Graphical Food Frequency System (GraFFS). Participants completed the GraFFS, six telephone-administered 24-hour dietary recalls over the next 12 weeks, followed by a second GraFFS. Participants were 40 men and 34 women, aged 18 to 69 years, living in the Columbus, OH, area. Intakes of energy, macronutrients, and 17 micronutrients/food components were estimated from the GraFFS and the mean of all recalls. Bias (second GraFFS minus recalls) was -9%, -5%, +4%, and -4% for energy and percentages of energy from fat, carbohydrate, and protein, respectively. De-attenuated, energy-adjusted correlations (intermethod reliability) between the recalls and the second GraFFS for fat, carbohydrate, protein, and alcohol were 0.82, 0.79, 0.67, and 0.90, respectively; for micronutrients/food components the median was 0.61 and ranged from 0.40 for zinc to 0.92 for beta carotene. The correlations between the two administrations of the GraFFS (test-retest reliability) for fat, carbohydrate, protein, and alcohol were 0.60, 0.63, 0.73, and 0.87, respectively; among micronutrients/food components the median was 0.67 and ranged from 0.49 for vitamin B-12 to 0.82 for fiber. The measurement characteristics of the GraFFS were at least as good as those reported for most paper FFQs, and its high intermethod reliability suggests that further development of computer-administered FFQs is warranted.

  11. Evaluation of Web-Based, Self-Administered, Graphical Food Frequency Questionnaire

    PubMed Central

    Kristal, Alan R.; Kolar, Ann S.; Fisher, James L.; Plascak, Jesse J.; Stumbo, Phyllis J.; Weiss, Rick; Paskett, Electra D.

    2014-01-01

    Computer-administered food frequency questionnaires (FFQs) can address limitations inherent in paper questionnaires, by allowing very complex skip patterns, portion size estimation based on food pictures and real-time error checking. This manuscript evaluates a web-based FFQ, the Graphical Food Frequency System (GraFFS). Participants completed the GraFFS, six, telephone-administered 24-hr dietary recalls over the next 12 weeks, followed by a second GraFFS. Participants were 40 men and 34 women, ages 18–69, living in the Columbus, OH area. Intakes of energy, macronutrients and 17 micronutrients/food components were estimated from the GraFFS and the mean of all recalls. Bias (recalls minus the second GraFFS) was −9%, −5%, +4% and −4% for energy and percentages of energy from fat, carbohydrate and protein. De-attenuated, energy-adjusted correlations (inter-method reliability) between the recalls and the second GraFFS for fat, carbohydrate, protein and alcohol were 0.82, 0.79, 0.67 and 0.90; for micronutrients/food components the median was 0.61 and ranged from 0.40 for zinc to 0.92 for β-carotene. The correlations between the two administrations of the GraFFS (test-retest reliability) for fat, carbohydrate, protein and alcohol were 0.60, 0.63, 0.73 and 0.87; among micronutrients/food components the median was 0.67 and ranged from 0.49 for vitamin B12 to 0.82 for fiber. The measurement characteristics of the GraFFS were at least as good as those reported for most paper FFQs, and its high inter-method reliability suggests that further development of computer-administered FFQs is warranted. PMID:24462267

  12. Physical activity among dental health professionals in Hyderabad City: A questionnaire survey

    PubMed Central

    Srilatha, Adepu; Doshi, Dolar; Reddy, M. Padma; Kulkarni, Suhas; Reddy, B. Srikanth; Reddy, Sahithi

    2016-01-01

    Background: To assess and compare physical activity based on age, gender, marital status, education, and employment among dental health professionals in Hyderabad City, India. Materials and Methods: A cross-sectional questionnaire study was conducted among dentists and they were personally interviewed by a single trained interviewer. The frequency (in days) and time (in minutes) spent in doing vigorous- and moderate-intensity activity in a typical week in three domains and sedentary behavior were assessed using 16-item Global Physical Activity Questionnaire. Metabolic equivalents (METs) were used to express the intensity of physical activities. Results: Overall, 60.7% of the 313 respondents were physically active, with activity at work and commuting activity were the main contributors of physical activity. With increasing age, there was a decrease in physical activity with more sedentary behavior, professionals in age group of 21–30 years, who were single, those with Bachelor's Degree and those in teaching field performed activity at work, commuting, and recreational activity for more minutes with overall high MET minutes per week and least sedentary behavior. Conclusion: The prevalence of physical activity was high among dental health professionals. PMID:28182058

  13. The Oxford Participation and Activities Questionnaire: study protocol

    PubMed Central

    Morley, David; Dummett, Sarah; Kelly, Laura; Dawson, Jill; Fitzpatrick, Ray; Jenkinson, Crispin

    2014-01-01

    Background With an ageing population and increasing demands on health and social care services, there is growing importance attached to the management of long-term conditions, including maximizing the cost-effectiveness of treatments. In line with this, there is increasing emphasis on the need to keep people both active and participating in daily life. Consequently, it is essential that well developed and validated instruments that can meaningfully assess levels of participation and activity are widely available. Current measures, however, are largely focused on disability and rehabilitation, and there is no measure of activity or participation for generic use that fully meets the standards set by regulatory bodies such as the US Food and Drug Administration. Here we detail a protocol for the development and validation of a new patient-reported outcome measure (PROM) for assessment of participation and activity in people experiencing a variety of health conditions, ie, the Oxford Participation and Activities Questionnaire (Ox-PAQ). The stages incorporated in its development are entirely in line with current regulations and represent best practice in the development of PROMs. Methods Development of the Ox-PAQ is theoretically grounded in the World Health Organization International Classification of Functioning, Disability, and Health. The project incorporates a new strategy of engaging with stakeholders from the outset in an attempt to identify those characteristics of PROMs considered most important to a range of potential users. Items will be generated through interviews with patients from a range of conditions. Pretesting of the instrument will be via cognitive interviews and focus groups. A postal survey will be conducted, with data subject to factor and Rasch analysis in order to identify appropriate dimensions and redundant items. Reliability will be assessed by Cronbach’s alpha and item-total correlations. A second, large-scale postal survey will follow

  14. Development of a Quantitative Food Frequency Questionnaire for Use among the Yup'ik People of Western Alaska

    PubMed Central

    Kolahdooz, Fariba; Simeon, Desiree; Ferguson, Gary; Sharma, Sangita

    2014-01-01

    Alaska Native populations are experiencing a nutrition transition and a resulting decrease in diet quality. The present study aimed to develop a quantitative food frequency questionnaire to assess the diet of the Yup'ik people of Western Alaska. A cross-sectional survey was conducted using 24-hour recalls and the information collected served as a basis for developing a quantitative food frequency questionnaire. A total of 177 males and females, aged 13-88, in six western Alaska communities, completed up to three 24-hour recalls as part of the Alaska Native Dietary and Subsistence Food Assessment Project. The frequency of the foods reported in the 24-hour recalls was tabulated and used to create a draft quantitative food frequency questionnaire, which was pilot tested and finalized with input from community members. Store-bought foods high in fat and sugar were reported more frequently than traditional foods. Seven of the top 26 foods most frequently reported were traditional foods. A 150-item quantitative food frequency questionnaire was developed that included 14 breads and crackers; 3 cereals; 11 dairy products; 69 meats, poultry and fish; 13 fruit; 22 vegetables; 9 desserts and snacks; and 9 beverages. The quantitative food frequency questionnaire contains 39 traditional food items. This quantitative food frequency questionnaire can be used to assess the unique diet of the Alaska Native people of Western Alaska. This tool will allow for monitoring of dietary changes over time as well as the identification of foods and nutrients that could be promoted in a nutrition intervention program intended to reduce chronic disease. PMID:24963718

  15. Development of a quantitative food frequency questionnaire for Brazilian patients with type 2 diabetes

    PubMed Central

    2013-01-01

    Background To investigate the association between dietary components and development of chronic diabetic complications, the dietary evaluation should include a long period, months or years. The present manuscript aims to develop a quantitative food frequency questionnaire (FFQ) and a portfolio with food photos to assess the usual intake pattern of Brazilian patients with type 2 diabetes to be used in future studies. Methods Dietary data using 3-day weighed diet records (WDR) from 188 outpatients with type 2 diabetes were used to construct the list of usually consumed foods. Foods were initially clustered into eight groups: “cereals, tubers, roots, and derivatives”; “vegetables and legumes”; “fruits”; “beans”; “meat and eggs”; “milk and dairy products”; “oils and fats”, and “sugars and sweets”. The frequency of food intake and the relative contribution of each food item to the total energy and nutrient intakes were calculated. Portion sizes were determined according to the 25th, 50th, 75th, and 95th percentiles of intake for each food item. Results A total of 62 food items were selected based on the 3-day WDR and another 27 foods or how they are prepared and nine beverages were included after the expert examination. Also, a portfolio with food photos of each included food item and portion sizes was made to assist the patients in identifying the consumed portion. Conclusions We developed a practical quantitative FFQ and portfolio with photos of 98 food items covering those most commonly consumed in the past 12 months, to assess the usual diet pattern of patients with type 2 diabetes in Southern Brazil. PMID:23938026

  16. Development and Validation of a Mediterranean Oriented Culture-Specific Semi-Quantitative Food Frequency Questionnaire.

    PubMed

    Athanasiadou, Elpiniki; Kyrkou, Charikleia; Fotiou, Maria; Tsakoumaki, Foteini; Dimitropoulou, Aristea; Polychroniadou, Eleni; Menexes, Georgios; Athanasiadis, Apostolos P; Biliaderis, Costas G; Michaelidou, Alexandra-Maria

    2016-08-25

    The objectives were to develop a Mediterranean oriented semi-quantitative food frequency questionnaire (FFQ) and evaluate its validity in measuring energy and nutrient intakes. For FFQ development, the main challenge was to merge food items and practices reflecting cultural Mediterranean preferences with other food choices ensuing from diet transition to more westernized dietary patterns. FFQ validity was evaluated by comparing nutrient intakes against the average of two 24-h dietary recalls for 179 pregnant women. Although the mean intake values for most nutrients and energy tended to be higher when determined by the FFQ, the Cohen's d was below 0.3. Bland-Altman plots confirmed the agreement between the two methods. Positive significant correlations ranged from 0.35 to 0.77. The proportion of women classified correctly was between 73.2% and 92.2%, whereas gross misclassification was low. Weighted kappa values were between 0.31 and 0.78, while intraclass correlation coefficients were between 0.49 and 0.89. Our methodological approach for the development and validation of this FFQ provides reliable measurements of energy, macro- and micronutrient intakes. Overall, our culture-specific FFQ could serve as a useful assessment tool in studies aiming at monitoring dietary intakes, especially in the Mediterranean region, where countries share common cultural dietary habits.

  17. Zinc-specific food frequency questionnaire to assess college women's eating habits.

    PubMed

    Lacey, Janet M; Zotter, Deanne U

    2009-01-01

    Zinc deficiency has been reported in individuals with eating disorders, the risks of which increase during the adolescent and early adult years. A food frequency questionnaire (FFQ) specific for zinc-rich foods was tested for its usefulness in identifying problematic eating behaviour tendencies in college-age women. Ninety-two female students enrolled in a university introductory psychology course volunteered to complete demographic information, the Eating Attitudes Test (EAT-26), and a zinc-specific FFQ (ZnFFQ). Relationships among estimated zinc intakes, food/lifestyle habits, and eating attitude variables were examined. Twenty-five women had estimated intakes below the Recommended Dietary Allowance (RDA) for zinc. Individuals in the highest zinc intake group (over twice the RDA) had a tendency to score higher on the EAT-26 and the bulimia subscale. Vegetarians also scored high on the EAT-26. Although our data are limited, the ZnFFQ should be studied further to determine whether it could play a useful role in identifying individuals at risk for bulimia. The ZnFFQ is a simple, non-confrontational assessment tool and may be a helpful starting point for identifying women with unhealthy eating habits.

  18. A food frequency questionnaire validated for estimating dietary flavonoid intake in an Australian population.

    PubMed

    Somerset, Shawn; Papier, Keren

    2014-01-01

    Flavonoids, a broad category of nonnutrient food components, are potential protective dietary factors in the etiology of some cancers. However, previous epidemiological studies showing associations between flavonoid intake and cancer risk have used unvalidated intake assessment methods. A 62-item food frequency questionnaire (FFQ) based on usual intake of a representative Australian adult population sample was validated against a 3-day diet diary method in 60 young adults. Spearman's rank correlations showed 17 of 25 individual flavonoids, 3 of 5 flavonoid subgroups, and total flavonoids having strong/moderate correlation coefficients (0.40-0.70), and 8 of 25 individual flavonoids and 2 of 5 flavonoid subgroups having weak/insignificant correlations (0.01-0.39) between the 2 methods. Bland-Altman plots showed most subjects within ±1.96 SD for intakes of flavonoid subgroups and total flavonoids. The FFQ classified 73-90% of participants for all flavonoids except isorhamnetin, cyanidin, delphinidin, peonidin, and pelargonidin; 73.3-85.0% for all flavonoid subgroups except Anthocyanidins; and 86.7% for total flavonoid intake in the same/adjacent quartile determined by the 3-day diary. Weighted kappa values ranged from 0.00 (Isorhamnetin, Pelargonidin) to 0.60 (Myricetin) and were statistically significant for 18 of 25 individual flavonoids, 3 of 5 subgroups, and total flavonoids. This FFQ provides a simple and inexpensive means to estimate total flavonoid and flavonoid subgroup intake.

  19. Frequency and Influencing Factors of Rubber Dam Usage in Tianjin: A Questionnaire Survey.

    PubMed

    Zou, Huiru; Li, Yanni; Lian, Xiaoli; Yan, Yan; Dai, Xiaohua; Wang, Guanhua

    2016-01-01

    Objective. To investigate the frequency and influencing factors of rubber dam usage for endodontic procedures among general dentistry practitioners and specialized practitioners (endodontist) in Tianjin. Methods. Three hundred questionnaires were distributed among practitioners from 3 different types of medical institutions in Tianjin. Data were collected and analysed using Chi-square tests. Results. There were 63.3% of respondents who have used rubber dam (response rate 82.7%, valid response rate 76.3%). However, only 0.4% and 3.1% of them recognized using rubber dam "every time" during caries direct restoration and root canal therapy, respectively. There was no significant difference in rubber dam usage between male and female practitioners. Among the respondents, practitioners with working experience between 5 and 10 years showed the highest usage rate (76.3%), while practitioners working more than 20 years showed the lowest (53.2%). The endodontists gained the highest and the most frequent usage rate and the best rubber dam technique mastering skills. Practitioners working in those stomatological departments of general hospitals showed the lowest rubber dam usage rate. Conclusions. The prevalence of rubber dam usage in Tianjin city is still low. The practitioner's gender, years of professional experience, general or specialized field, and the type of dental setting they work for are the factors that need to be considered during making policy and executing training.

  20. Validity and reproducibility of a food frequency questionnaire to assess food group intake in adolescents.

    PubMed

    Martinez, Marcelle Flores; Philippi, Sonia Tucunduva; Estima, Camilla; Leal, Greisse

    2013-09-01

    The objective of this study was to assess the validity and reproducibility of a food frequency questionnaire to assess intake of the food groups included in the food guide pyramid for adolescents (FFQ-FP). The final version of the FFQ-FP consisted of 50 food items. The study was carried out with a sample of 109 adolescents over a period of four months. A 24hr recall (24hr) was conducted four times and the FFQ-FP was conducted twice. Validity was determined by comparing the second FFQ-FP and the mean of the four 24hrs, while reproducibility was verified by comparing the results of the two FFQ-FPs. Statistical analysis was carried out using medians, standard deviations, Pearson and intraclass correlations and Kappa statistics to assess concordance. Best results were achieved for the rice (including bread, grains and starches), meats and sugars groups. Weakest correlation was observed for the variable vitamin C. The validity and reproducibility of the FFQ-FP was satisfactory for most variables.

  1. Development and Validation of a Mediterranean Oriented Culture-Specific Semi-Quantitative Food Frequency Questionnaire

    PubMed Central

    Athanasiadou, Elpiniki; Kyrkou, Charikleia; Fotiou, Maria; Tsakoumaki, Foteini; Dimitropoulou, Aristea; Polychroniadou, Eleni; Menexes, Georgios; Athanasiadis, Apostolos P.; Biliaderis, Costas G.; Michaelidou, Alexandra-Maria

    2016-01-01

    The objectives were to develop a Mediterranean oriented semi-quantitative food frequency questionnaire (FFQ) and evaluate its validity in measuring energy and nutrient intakes. For FFQ development, the main challenge was to merge food items and practices reflecting cultural Mediterranean preferences with other food choices ensuing from diet transition to more westernized dietary patterns. FFQ validity was evaluated by comparing nutrient intakes against the average of two 24-h dietary recalls for 179 pregnant women. Although the mean intake values for most nutrients and energy tended to be higher when determined by the FFQ, the Cohen’s d was below 0.3. Bland-Altman plots confirmed the agreement between the two methods. Positive significant correlations ranged from 0.35 to 0.77. The proportion of women classified correctly was between 73.2% and 92.2%, whereas gross misclassification was low. Weighted kappa values were between 0.31 and 0.78, while intraclass correlation coefficients were between 0.49 and 0.89. Our methodological approach for the development and validation of this FFQ provides reliable measurements of energy, macro- and micronutrient intakes. Overall, our culture-specific FFQ could serve as a useful assessment tool in studies aiming at monitoring dietary intakes, especially in the Mediterranean region, where countries share common cultural dietary habits. PMID:27571097

  2. Reliability and Validity of the PAQ-C Questionnaire to Assess Physical Activity in Children

    ERIC Educational Resources Information Center

    Benítez-Porres, Javier; López-Fernández, Iván; Raya, Juan Francisco; Álvarez Carnero, Sabrina; Alvero-Cruz, José Ramón; Álvarez Carnero, Elvis

    2016-01-01

    Background: Physical activity (PA) assessment by questionnaire is a cornerstone in the field of sport epidemiology studies. The Physical Activity Questionnaire for Children (PAQ-C) has been used widely to assess PA in healthy school populations. The aim of this study was to evaluate the reliability and validity of the PAQ-C questionnaire in…

  3. 78 FR 34174 - Proposed Information Collection (Pension Claim Questionnaire for Farm Income) Activity: Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Pension Claim Questionnaire for Farm Income) Activity: Comment... techniques or the use of other forms of information technology. Title: Pension Claim Questionnaire for...

  4. 78 FR 57925 - Agency Information Collection (Pension Claim Questionnaire for Farm Income) Activity Under OMB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Pension Claim Questionnaire for Farm Income) Activity Under OMB... ``OMB Control No. 2900-0095.'' SUPPLEMENTARY INFORMATION: Title: Pension Claim Questionnaire for...

  5. 75 FR 62636 - Proposed Information Collection (Status of Dependents Questionnaire) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Status of Dependents Questionnaire) Activity: Comment Request... techniques or the use of other forms of information technology. Title: Status of Dependents Questionnaire,...

  6. 78 FR 46422 - Proposed Information Collection (Status of Dependents Questionnaire) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-31

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Status of Dependents Questionnaire) Activity: Comment Request... of Dependents Questionnaire, VA Form 21-0538. OMB Control Number: 2900-0500. Type of...

  7. Assessing adult leisure activities: an extension of a self-report activity questionnaire.

    PubMed

    Jopp, Daniela S; Hertzog, Christopher

    2010-03-01

    Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value, as they can inform diagnosis and interventions. In the present study, the authors enhanced the content validity of the Victoria Longitudinal Study activity questionnaire by adding items on physical and social activities and validated a shortened version of the questionnaire. The proposed leisure activity model included 11 activity categories: 3 types of social activities (i.e., activities with close social partners, group-centered public activity, religious activities), physical activities, developmental activities, experiential activities, crafts, game playing, TV watching, travel, and technology use. Confirmatory factor analyses validated the proposed factor structure in 2 independent samples. A higher order model with a general activity factor fitted the activity factor correlations with relatively little loss of fit. Convergent and discriminant validity for the activity scales were supported by patterns of their correlations with education, health, depression, cognition, and personality. In sum, the scores derived from of the augmented Victoria Longitudinal Study activity questionnaire demonstrate good reliability, and validity evidence supports their use as measures of leisure activities in young, middle-aged, and older individuals.

  8. Assessing Adult Leisure Activities: An Extension of a Self-Report Activity Questionnaire

    PubMed Central

    Jopp, Daniela; Hertzog, Christopher

    2009-01-01

    Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value as they can inform diagnosis and interventions. In the present study, we enhanced the content validity of the Victoria Longitudinal Study activity questionnaire by adding items on physical and social activities, and validated a shortened version of the questionnaire. Our proposed leisure activity model included 11 activity categories: three types of social activities (i.e., activities with close social partners, group-centered public activity, religious activities), physical, developmental, and experiential activities, crafts, game playing, TV watching, travel, and technology use. Confirmatory factor analyses validated the proposed factor structure in two independent samples. A higher-order model with a general activity factor fitted the activity factor correlations with relatively little loss of fit. Convergent and discriminant validity for the activity scales were supported by patterns of their correlations with education, health, depression, cognition, and personality. In sum, the scores derived from of the augmented VLS activity questionnaire demonstrate good reliability, and validity evidence supports their use as measure of leisure activities in young, middle-aged, and older individuals. PMID:20230157

  9. Validity of a Semi-Quantitative Food Frequency Questionnaire for Collegiate Athletes

    PubMed Central

    Sasaki, Kazuto; Suzuki, Yoshio; Oguma, Nobuhide; Ishihara, Junko; Nakai, Ayumi; Yasuda, Jun; Yokoyama, Yuri; Yoshizaki, Takahiro; Tada, Yuki; Hida, Azumi; Kawano, Yukari

    2016-01-01

    Background Food frequency questionnaires (FFQs) have been developed and validated for various populations. To our knowledge, however, no FFQ has been validated for young athletes. Here, we investigated whether an FFQ that was developed and validated to estimate dietary intake in middle-aged persons was also valid for estimating that in young athletes. Methods We applied an FFQ that had been developed for the Japan Public Health Center-based Prospective Cohort Study with modification to the duration of recollection. A total of 156 participants (92 males) completed the FFQ and a 3-day non-consecutive 24-hour dietary recall (24hDR). Validity of the mean estimates was evaluated by calculating the percentage differences between the 24hDR and FFQ. Ranking estimation was validated using Spearman’s correlation coefficient (CC), and the degree of miscategorization was determined by joint classification. Results The FFQ underestimated energy intake by approximately 10% for both males and females. For 35 nutrients, the median (range) deattenuated CC was 0.30 (0.10 to 0.57) for males and 0.32 (−0.08 to 0.62) for females. For 19 food groups, the median (range) deattenuated CC was 0.32 (0.17 to 0.72) for males and 0.34 (−0.11 to 0.58) for females. For both nutrient and food group intakes, cross-classification analysis indicated extreme miscategorization rates of 3% to 5%. Conclusions An FFQ developed and validated for middle-aged persons had comparable validity among young athletes. This FFQ might be useful for assessing habitual dietary intake in collegiate athletes, especially for calcium, vitamin C, vegetables, fruits, and milk and dairy products. PMID:26902164

  10. Reproducibility and relative validity of a food-frequency questionnaire among French adults and adolescents

    PubMed Central

    Deschamps, Valérie; De Lauzon-Guillain, Blandine; Lafay, Lionel; Borys, Jean-Michel; Charles, Marie-Aline; Romon, Monique

    2009-01-01

    Objective Our aim was to evaluate the reproducibility of a food frequency questionnaire (FFQ) developed in a French population, and its validity against four 24-hour dietary recalls (24-HR). Methods 57 adults (aged 18 to 63), 17 adolescents (aged 14 to 18), and 20 children (aged 10 to 14) completed four 24-HRs (one per season) and two FFQs over a 1-year interval. Reproducibility of the FFQ was estimated by intraclass correlation coefficients (ICCs). The validity of FFQ was assessed by comparison with the four 24-HRs. Results For most nutrients, the first FFQ measurements gave higher mean values than the second FFQ. The ICCs for nutrients ranged from 0.39 for total protein to 0.83 for alcohol. The ICCs were higher for food items consumed daily such as milk (0.80) or sugars and confectionnery (0.65), and lower for rarely eaten food such as inner organs (0.11). Nutrient intakes as assessed by FFQs were higher than those from the 24-HRs, except for alcohol. The de-attenuated Pearson’s correlation coefficient for nutrients varied from 0.25 (dietary fiber) to 0.90 (alcohol), but the adjustment for energy did not improve these coefficients. When nutrient intakes were categorized into quintiles, FFQ and 24-HRs produced agreement rates (same or adjacent quintile) between 55% (for PUFA) and 95% (for alcohol), while misclassification to an extreme quintile was rare (<5%). Conclusion The FFQ developed for the FLVS II Study can be used to classify adults or adolescents according to their nutrients and food intakes over a one-year period. PMID:17882132

  11. Repeatability and relative validity of a quantitative food-frequency questionnaire among French adults

    PubMed Central

    Barrat, Emmanuel; Aubineau, Nicolas; Maillot, Matthieu; Derbord, Élodie; Barthes, Pauline; Lescuyer, Jean-François; Boisseau, Nathalie; Peltier, Sébastien L.

    2012-01-01

    Background A 50-item self-administered food frequency questionnaire (FFQ) was developed for French adults, to assess the intake of energy, 10 macronutrients, 11 vitamins, and 11 minerals, and to be used in the context of a medical consultation. Objective To assess the repeatability and relative validity of this FFQ compared to a 7-day diet record (7-DR). Design A total of 54 and 100 French adults were included in the repeatability and validation studies, respectively. Repeatability was assessed using two FFQs, the second carried out 3 weeks after the first. In the validation study, subjects first completed the FFQ, then the 7-DR the following week. Energy and nutrient intakes were compared using Pearson correlation. The degree of misclassification by the FFQ, compared to the 7-DR, was calculated by a contingency table of quintiles. Bland–Altman plots assessed the correlation between FFQ and 7-DR across the intake range. Results Repeatability for intake, explored by Pearson correlation, was 0.62–0.90 (median: 0.81). Relative validity, as determined by Pearson correlation for the nutrient intake derived from the FFQ and 7-DR, was 0.36–0.80 (0.64). The FFQ tended to report higher fiber and micronutrient intake than 7-DR. Misclassification into opposite quintiles ranged 0–6% (1%), whereas classification into same or adjacent quintiles ranged 59–83% (74%). Bland–Altman plots showed good agreement for most nutrients across the range of intake. Conclusion This new FFQ showed a high repeatability and good relative validity, and thanks to its short length, should be a useful tool for rapidly evaluating the nutrient intake of French adults. PMID:23118710

  12. Biochemical Validation of the Older Australian’s Food Frequency Questionnaire Using Carotenoids and Vitamin E

    PubMed Central

    Lai, Jun S.; Attia, John; McEvoy, Mark; Hure, Alexis J.

    2014-01-01

    Background: Validation of a food frequency questionnaire (FFQ) is important, as inaccurate and imprecise information may affect the association between dietary exposure and health outcomes. Objective: This study assessed the validity of the Older Australian’s FFQ against plasma carotenoids and Vitamin E. Methods: A random subsample (n = 150) of 2420 participants in the Hunter Community Study, aged 55–85 years, were included. Correlations between crude and energy-adjusted FFQ estimates of carotenoids, Vitamin E, and fruit and vegetables with corresponding biomarkers were determined. Percentages of participants correctly classified in the same quartile, and in the same ± 1 quartile, by the two methods were calculated. Results: Significant correlations (P < 0.05) were observed for α-carotene (r = 0.26–0.28), β-carotene (r = 0.21–0.25), and β-cryptoxanthin (r = 0.21–0.23). Intakes of fruits and vegetables also showed similar correlations with these plasma carotenoids. Lycopene was only significantly correlated with fruit and vegetable intakes (r = 0.19–0.23). Weak correlations were observed for lutein + zeaxanthin (r = 0.12–0.16). For Vitamin E, significant correlation was observed for energy-adjusted FFQ estimate and biomarker (r = 0.20). More than 68% of individuals were correctly classified within the same or adjacent quartile, except for lutein + zeaxanthin. Conclusion: With the exception of lutein + zeaxanthin, the Older Australian’s FFQ provides reasonable rankings for individuals according to their carotenoids, Vitamin E, fruit and vegetable intakes. PMID:25383938

  13. Development and evaluation of a dish-based semiquantitative food frequency questionnaire for Korean adolescents

    PubMed Central

    Yum, Jinhee

    2016-01-01

    BACKGROUND/OBJECTIVES The purpose of this study was to develop a dish-based semiquantitative food frequency questionnaire s(FFQ) for Korean adolescents and evaluate its reproducibility and validity. SUBJECTS/METHODS Based on 24-hour dietary recall data from the 4th Korean National Health and Nutrition Examination Survey (KNHANES), we developed a FFQ with 71 items. From a quota sample of 160 adolescents recruited using gender and age group as stratification variables, 153 participated in the complete data collection process. The FFQ was administered to each subject twice, at an interval of 3-4 weeks, to evaluate the test-retest reliability. The validity of the FFQ was assessed relative to 8-day food record data. RESULTS The study findings demonstrated the FFQ's satisfactory reproducibility. Spearman correlation coefficients ranged from 0.64(for β-carotene) to 0.81(for protein). From cross-classification analyses, the proportion of subjects in the same intake quartile was highest for protein (65.4%) and lowest for vitamin A(47.1%). With regard to validity analysis, Spearman correlation coefficients ranged from 0.27(for vitamin A and fiber) to 0.90 (for energy). The proportions of subjects in the opposite categories between the first FFQ and the 8-day food record data were generally low within the range from 0.74% (for energy and carbohydrate) to 13.2% (for α-carotene). CONCLUSIONS In conclusion, the dish-based semiquantitative FFQ developed in this study can be useful for grouping Korean adolescents according to major macro- and micronutrient intakes with reasonable reproducibility and validity. PMID:27478551

  14. Reproducibility and validity of a food frequency questionnaire among pregnant women in a Mediterranean area

    PubMed Central

    2013-01-01

    Background Studies exploring the role of diet during pregnancy are still scarce, in part due to the complexity of measuring diet and to the lack of valid instruments. The aim of this study was to examine the reproducibility and validity (against biochemical biomarkers) of a semi-quantitative food frequency questionnaire (FFQ) in pregnant women. Methods Participants were 740 pregnant women from a population-based birth cohort study in Valencia (INMA Study). We compared nutrient and food intakes from FFQs estimated for two periods of pregnancy (reproducibility), and compared energy-adjusted intake of several carotenoids, folate, vitamin B12, vitamin C and α-tocopherol of the FFQ in the first trimester with their concentration in blood specimens (validity). Results Significant correlations for reproducibility were found for major food groups and nutrients but not for lycopene (r=0.06); the average correlation coefficients for daily intake were 0.51 for food groups and 0.61 for nutrients. For validity, statistically significant correlations were observed for vitamin C (0.18), α-carotene (0.32), β-carotene (0.22), lutein-zeaxantin (0.29) and β-cryptoxantin(0.26); non-significant correlations were observed for retinol, lycopene, α-tocopherol, vitamin B12 and folate (r≤0.12). When dietary supplement use was considered, correlations were substantially improved for folate (0.53) and to a lesser extent for vitamin B12 (0.12) and vitamin C (0.20). Conclusion This study supports that the FFQ has a good reproducibility for nutrient and food intake, and can provide a valid estimate of several important nutrients during pregnancy. PMID:23421854

  15. Qualitative attributes and measurement properties of physical activity questionnaires: a checklist.

    PubMed

    Terwee, Caroline B; Mokkink, Lidwine B; van Poppel, Mireille N M; Chinapaw, Mai J M; van Mechelen, Willem; de Vet, Henrica C W

    2010-07-01

    The large number of available physical activity (PA) questionnaires makes it difficult to select the most appropriate questionnaire for a certain purpose. This choice is further hampered by incomplete reporting and unsatisfactory evaluation of the content and measurement properties of the questionnaires. We provide a checklist for appraising the qualitative attributes and measurement properties of PA questionnaires, as a tool for selecting the most appropriate PA questionnaire for a certain target population and purpose. The checklist is called the Quality Assessment of Physical Activity Questionnaire (QAPAQ). This review is one of a group of four reviews in this issue of Sports Medicine on the content and measurement properties of physical activity questionnaires. Part 1 of the checklist can be used to appraise the qualitative attributes of PA questionnaires, i.e. the construct to be measured by the questionnaire, the purpose and target population for which it was developed, the format, interpretability and ease of use. Part 2 of the checklist can be used to appraise the measurement properties of a PA questionnaire, i.e. reliability (parameters of measurement error and reliability coefficients), validity (face and content validity, criterion validity and construct validity) and responsiveness. The QAPAQ can be used to select the most appropriate PA questionnaire for a certain purpose, but it can also be used to design or report a study on measurement properties of PA questionnaires. Using such a checklist will contribute to improving the assessment, reporting and appraisal of the content and measurement properties of PA questionnaires.

  16. Development and Validation of a Quantitative Food Frequency Questionnaire among Rural- and Urban-Dwelling Adults in Colombia

    ERIC Educational Resources Information Center

    Dehghan, Mahshid; Lopez Jaramillo, Patricio; Duenas, Ruby; Anaya, Lilliam Lima; Garcia, Ronald G.; Zhang, Xiaohe; Islam, Shofiqul; Merchant, Anwar T.

    2012-01-01

    Objective: To validate a food frequency questionnaire (FFQ) against multiple 24-hour dietary recalls (DRs) that could be used for Colombian adults. Methods: A convenience sample of 219 individuals participated in the study. The validity of the FFQ was evaluated against multiple DRs. Four dietary recalls were collected during the year, and an FFQ…

  17. 78 FR 36643 - Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

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    ... AFFAIRS Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity... . Please refer to ``OMB Control No. 2900-NEW (Wrist Conditions Disability Benefits Questionnaire)'' in any... Conditions Disability Benefits Questionnaire, VA Form 21-0960M-16. OMB Control Number: 2900-NEW...

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  20. Associations between Diet and Cardiometabolic Risk among Yup’ik Alaska Native People using Food Frequency Questionnaire Dietary Patterns

    PubMed Central

    Ryman, TK; Boyer, BB; Hopkins, S; Philip, J; Beresford, SAA; Thompson, B; Heagerty, PJ; Pomeroy, JJ; Thummel, KE; Austin, MA

    2015-01-01

    Background and Aims In previous analyses, we identified three dietary patterns from food frequency questionnaire data among a sample of Yup’ik Alaska Native people living in Southwest Alaska: a “subsistence foods” dietary pattern and two market-based dietary patterns “processed foods” and “fruits and vegetables”. In this analysis, we aimed to characterize the association between the dietary patterns and cardiometabolic (CM) risk factors (lipids, blood pressure, glucose, adiposity). Methods and Results We used multilevel linear regression to estimate the mean of each CM risk factor, comparing participants in the 4th to the 1st quartile of each dietary pattern (n=637). Models were adjusted for age, sex, past smoking, current smoking, and physical activity. Mean log triglyceride levels were significantly higher among participants in the 4th compared to the 1st quartile of the processed foods dietary pattern (β=0.11). Mean HbA1c percent was significantly lower (β=−0.08) and mean diastolic blood pressure (DBP) mm Hg was significantly higher (β=2.87) among participants in the 4th compared to the 1st quartile of the fruits and vegetables dietary pattern. Finally, mean log triglyceride levels and mean DBP mm Hg were significantly lower among participants in the 4th compared to the 1st quartile of the subsistence foods dietary pattern (β=−0.10 and β=−3.99 respectively). Conclusions We found increased CM risk, as reflected by increased triglycerides, associated with eating a greater frequency of processed foods, and reduced CM risk, as reflected by lower triglycerides and DBP, associated with eating a greater frequency of subsistence foods. PMID:26607703

  1. Different ways to active optical frequency standards

    NASA Astrophysics Data System (ADS)

    Pan, Duo; Xue, Xiaobo; Zhang, Xiaogang; Chen, Jingbiao

    2016-06-01

    Active optical frequency standard, or active optical clock, is a new concept of optical frequency standard, where a weak feedback with phase coherence information in optical bad-cavity limitation is formed, and the continuous self-sustained coherent stimulated emission between two atomic transition levels with population inversion is realized. Through ten years of both theoretical and experimental exploration, the narrow linewidth and suppression of cavity pulling effect of active optical frequency standard have been initially proved. In this paper, after a simple review, we will mainly present the most recent experimental progresses of active optical frequency standards in Peking University, including 4-level cesium active optical frequency standards and active Faraday optical frequency standards. The future development of active optical frequency standards is also discussed.

  2. A simple food frequency questionnaire for Japanese diet--Part I. Development of the questionnaire, and reproducibility and validity for food groups.

    PubMed

    Wakai, K; Egami, I; Kato, K; Lin, Y; Kawamura, T; Tamakoshi, A; Aoki, R; Kojima, M; Nakayama, T; Wada, M; Ohno, Y

    1999-08-01

    We developed a simple food frequency questionnaire (FFQ) based on one-day dietary records (DRs) among 1001 subjects in Nagoya, Japan. A total of 97 foods and dishes were selected through a two-step procedure; first by ranking food items according to the contribution to the population intake of nutrient variables, and second by stepwise multiple regression analyses of individual food items as the independent variables and of total nutrient intake as the dependent variables. For simplicity, questions on portion sizes were not included except for a few selected food items, which resulted in short time (about 20 minutes) to complete the questionnaire. This FFQ was validated for food groups by referring to four 4-day DRs among 88 men and women in central Japan, from 1996 to 1997. The energy-, sex- and age-adjusted test-retest correlation coefficients between the two FFQs administered at an one year interval ranged from 0.34 to 0.78. The de-attenuated, energy-, sex- and age-adjusted correlation coefficients between the second FFQ and the DRs were larger than 0.40 for most food groups, indicating the usefulness of this simple FFQ with its sufficient validity in epidemiological surveys.

  3. Active-Q: Validation of the Web-Based Physical Activity Questionnaire Using Doubly Labeled Water

    PubMed Central

    Trolle Lagerros, Ylva; Christensen, Sara Elisabeth; Möller, Elisabeth; Wright, Antony; Sjölander, Arvid; Bälter, Katarina

    2012-01-01

    Background Increased use of the Internet provides new opportunities for collecting data in large studies. The aim of our new Web-based questionnaire, Active-Q, is to assess total physical activity and inactivity in adults. Active-Q assesses habitual activity during the past year via questions in four different domains: (1) daily occupation, (2) transportation to and from daily occupation, (3) leisure time activities, and (4) sporting activities. Objective The objective of our study is to validate Active-Q’s energy expenditure estimates using the doubly labeled water (DLW) method, and to assess the reproducibility of Active-Q by comparing the results of the questionnaire completed by the same group on two occasions. Methods The validity and reproducibility of Active-Q were assessed in a group of 37 individuals, aged 20 to 65 years. Active-Q was distributed via email to the participants. The total energy expenditure of the participants was assessed using DLW for 11 consecutive days. Results The median time to complete Active-Q was 6.1 minutes. The majority of participants (27/37, 73%) reported that the questionnaire was “easy” or “very easy” to answer. On average, Active-Q overestimated the total daily energy expenditure by 440 kJ compared with the DLW. The Spearman correlation between the two methods was r = 0.52 (P < .001). The intraclass correlation coefficient for total energy expenditure between the results of Active-Q completed on two occasions was 0.83 (95% CI 0.73-0.93). Conclusions Active-Q is a valid and reproducible method of assessing total energy expenditure. It is also a user-friendly method and suitable for Web-based data collection in large epidemiological studies. PMID:22356755

  4. Reproducibility and validity of an expanded self-administered semiquantitative food frequency questionnaire among male health professionals.

    PubMed

    Rimm, E B; Giovannucci, E L; Stampfer, M J; Colditz, G A; Litin, L B; Willett, W C

    1992-05-15

    The authors assessed the reproducibility and validity of an expanded 131-item semiquantitative food frequency questionnaire used in a prospective study among 51,529 men. The form was administered by mail twice to a sample of 127 participants at a one-year interval. During this interval, men completed two one-week diet records spaced approximately 6 months apart. Mean values for intake of most nutrients assessed by the two methods were similar. Intraclass correlation coefficients for nutrient intakes assessed by questionnaires one year apart ranged from 0.47 for vitamin E without supplements to 0.80 for vitamin C with supplements. Correlation coefficients between the energy-adjusted nutrient intakes measured by diet records and the second questionnaire (which asked about diet during the year encompassing the diet records) ranged from 0.28 for iron without supplements to 0.86 for vitamin C with supplements (mean r = 0.59). These correlations were higher after adjusting for week-to-week variation in diet record intakes (mean r = 0.65). These data indicate that the expanded semiquantitative food frequency questionnaire is reproducible and provides a useful measure of intake for many nutrients over a one-year period.

  5. Development of a Scottish physical activity questionnaire: a tool for use in physical activity interventions

    PubMed Central

    Lowther, M.; Mutrie, N.; Loughlan, C.; McFarlane, C.

    1999-01-01

    OBJECTIVES: Three studies were undertaken to establish the reliability and validity of the Scottish physical activity questionnaire (SPAQ), developed to aid seven day recall of leisure and occupational physical activity. METHODS: To establish reliability, SPAQs (n = 34) were completed on a Monday and the following Wednesday. Thus each questionnaire measured four identical days. To establish concurrent validity, 94 participants completed a SPAQ and an adapted stage of exercise behaviour change questionnaire. Responses to SPAQ were then analysed by stage of exercise behaviour change. In a further study of criterion validity, 30 volunteers wore a Caltrac motion sensor for four consecutive days, after which they completed a SPAQ. RESULTS: In the first study, total physical activity had a coefficient of repeatability (R) of 53 minutes. Occupational physical activity showed a similar variance (R = 54.6 minutes) but leisure physical activity was more reliable (R = 29.3 minutes). The main variation in occupational physical activity was found to be walking (R = 39.8 minutes). In study 2, a one way analysis of variance showed the expected relation between physical activity and stage of exercise behaviour change, confirming the concurrent validity of SPAQ with the stage of exercise behaviour change model. In study 3, several erroneous recordings affected both SPAQ and the Caltrac results (kcal). After relevant corrections had been made, the correlation between the two measurement devices was 0.52 (p < 0.05). CONCLUSIONS: SPAQ has been shown to be reliable and to hold strong concurrent validity and limited criterion validity. The main limitation in SPAQ appears to be the measurement of occupational walking. It is therefore recommended that further work be conducted to refine the measurement of this physical activity component. It is evident nonetheless that SPAQ can be used with confidence to measure outcomes in physical activity interventions when account is taken of its

  6. Comparison of IPAQ-SF and Two Other Physical Activity Questionnaires with Accelerometer in Adolescent Boys

    PubMed Central

    Mäestu, Jarek; Lätt, Evelin; Jürimäe, Jaak; Vainik, Uku

    2017-01-01

    Self-report measures of physical activity (PA) are easy to use and popular but their reliability is often questioned. Therefore, the general aim of the present study was to investigate the association of PA questionnaires with accelerometer derived PA, in a sample of adolescent boys. In total, 191 pubertal boys (mean age 14.0 years) completed three self-report questionnaires and wore an accelerometer (ActiGraph GT1M) for 7 consecutive days. The PA questionnaires were: International Physical Activity Questionnaire-Short Form (IPAQ-SF), Tartu Physical Activity Questionnaire (TPAQ), and the Inactivity subscale from Domain-Specific Impulsivity (DSI) scale. All three questionnaires were significantly correlated with accelerometer derived MVPA: the correlations were 0.31 for the IPAQ-SF MVPA, 0.34 for the TPAQ MVPA and -0.29 for the DSI Inactivity scale. Nevertheless, none of the questionnaires can be used as a reliable individual-level estimate of MVPA in male adolescents. The boys underreported their MVPA in IPAQ-SF as compared to accelerometer-derived MVPA (respective averages 43 and 56 minutes); underreporting was more marked in active boys with average daily MVPA at least 60 minutes, and was not significant in less active boys. Conversely, MVPA index from TPAQ overestimated the MVPA in less active boys but underestimated it in more active boys. The sedentary time reported in IPAQ-SF was an underestimate as compared to accelerometer-derived sedentary time (averages 519 and 545 minutes, respectively). PMID:28056080

  7. 78 FR 44625 - Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity... ``Wrist Conditions Disability Benefits Questionnaire, VA Form 21-0960M-16.'' On June 18, 2013 (78 FR...

  8. 76 FR 44087 - Agency Information Collection (Employment Questionnaire) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Employment Questionnaire) Activity Under OMB Review AGENCY... INFORMATION: Title: Employment Questionnaire, VA Forms 21-4140 and 21-4140-1. OMB Control Number:...

  9. 76 FR 27386 - Proposed Information Collection (Employment Questionnaire) Activity; Comment Request

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    2011-05-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Employment Questionnaire) Activity; Comment Request AGENCY...: Employment Questionnaire, VA Forms 21-4140 and 21-4140-1. OMB Control Number: 2900-0079. Type of...

  10. 75 FR 10027 - Proposed Information Collection (Marital Status Questionnaire) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Proposed Information Collection (Marital Status Questionnaire) Activity: Comment Request AGENCY.... Title: Marital Status Questionnaire, VA Form 21-0537. OMB Control Number: 2900-0495. Type of...

  11. 75 FR 80114 - Agency Information Collection (Status of Dependents Questionnaire) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Status of Dependents Questionnaire) Activity Under OMB Review... INFORMATION: Title: Status of Dependents Questionnaire, VA Form 21-0538. OMB Control Number: 2900-0500....

  12. 75 FR 26346 - Agency Information Collection (Marital Status Questionnaire) Activity Under OMB Review

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    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Marital Status Questionnaire) Activity Under OMB Review AGENCY...: Marital Status Questionnaire, VA Form 21-0537. OMB Control Number: 2900-0495. Type of Review: Extension...

  13. 78 FR 48941 - Agency Information Collection (Marital Status Questionnaire) Activity Under OMB Review

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    2013-08-12

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF VETERANS AFFAIRS Agency Information Collection (Marital Status Questionnaire) Activity Under OMB Review AGENCY... Questionnaire, VA Form 21-0537. OMB Control Number: 2900-0495. Type of Review: Extension of a currently...

  14. Validation in London of a physical activity questionnaire for use in a study of postmenopausal osteopaenia.

    PubMed Central

    Suleiman, S; Nelson, M

    1997-01-01

    STUDY OBJECTIVE: To determine the validity of a self administered physical activity questionnaire to be used as part of a screening device for postmenopausal osteopaenia (with additional questions on medical history and calcium intake). DESIGN: A questionnaire was posted to 86 perimenopausal women to enquire about weekly hours spent in non-sedentary activity at work, in the household, and during leisure hours. Subjects who returned the questionnaire were visited at home and asked to complete a four day activity diary and subsequently to undertake a submaximal estimate of VO2 MAX, carried out using a treadmill ergometer. They were interviewed to clarify questionnaire and diary entries. Questionnaire validity was assessed in comparison with the diary estimates of hours of activity and with VO2 MAX. PARTICIPANTS: A total of 86 perimenopausal women aged 43-54 years were randomly selected from a GP list in Hammersmith, London. Thirty five women (41%) returned the questionnaire. They were visited at home, given the diary to complete, and invited to attend the physiology laboratory for VO2 MAX measurements. Twenty six of the 35 (74%) completed the study and were included in the final analysis. MAIN RESULTS: Women spent an average of 51 hours per week in non-sedentary activities. Questionnaire and diary yielded similar results (51.05 versus 51.30 h/wk), and there was a good correlation between diary and questionnaire estimates of total weekly hours of non-sedentary activity (r = 0.45, p < 0.05). Other significant correlations were for standing (r = 0.69, p < 0.01), leisure activities (r = 0.66, p < 0.01), and for light household activities (r = 0.42, p < 0.05). Correlations were better for employed than non-employed subjects. In relation to the diary, the questionnaire correctly classified 60% into the top or bottom half of the distribution activity. Sensitivity and specificity of the questionnaire were both equal to 61.5%. CONCLUSIONS: The questionnaire is useful for

  15. Development and Initial Testing of the Penn Parkinson's Daily Activities Questionnaire

    PubMed Central

    Brennan, Laura; Siderowf, Andrew; Rubright, Jonathan D.; Rick, Jacqueline; Dahodwala, Nabila; Duda, John E.; Hurtig, Howard; Stern, Matthew; Xie, Sharon X.; Rennert, Lior; Karlawish, Jason; Shea, Judy A.; Trojanowski, John Q.; Weintraub, Daniel

    2015-01-01

    Objective The aim of this work was to describe the development and psychometric analysis of the Penn Parkinson's Daily Activities Questionnaire. The questionnaire is an item response theory-based tool for rating cognitive instrumental activities of daily living in PD. Methods Candidate items for the Penn Parkinson's Daily Activities Questionnaire were developed through literature review and focus groups of patients and knowledgeable informants. Item selection and calibration of item-response theory parameters were performed using responses from a cohort of PD patients and knowledgeable informants (n = 388). In independent cohorts of PD patients and knowledgeable informants, assessments of test-retest reliability (n = 50), and construct validity (n = 68) of the questionnaire were subsequently performed. Construct validity was assessed by correlating questionnaire scores with measures of motor function, cognition, an existing activities of daily living measure, and directly observed daily function. Results Fifty items were retained in the final questionnaire item bank. Items were excluded owing to redundancy, difficult reading level, and when item-response theory parameters could not be calculated. Test-retest reliability was high (intraclass correlation coefficient = 0.97; P < 0.001). The questionnaire correlated strongly with cognition (r = 0.68; P < 0.001) and directly observed daily function (r = 0.87; P < 0.001), but not with motor impairment (r = 0.08; P = 0.53). The questionnaire score accurately discriminated between PD patients with and without dementia (receiver operating characteristic curve = 0.91; 95% confidence interval: 0.85–0.97). Conclusions The Penn Parkinson's Daily Activities Questionnaire shows strong evidence of reliability and validity. Item response theory-based psychometric analysis suggests that this questionnaire can discriminate across a range of daily functions. PMID:26249849

  16. Validation of the Regicor Short Physical Activity Questionnaire for the Adult Population

    PubMed Central

    Molina, Luis; Sarmiento, Manuel; Peñafiel, Judith; Donaire, David; Garcia-Aymerich, Judith; Gomez, Miquel; Ble, Mireia; Ruiz, Sonia; Frances, Albert; Schröder, Helmut; Marrugat, Jaume; Elosua, Roberto

    2017-01-01

    Objective To develop and validate a short questionnaire to estimate physical activity (PA) practice and sedentary behavior for the adult population. Methods The short questionnaire was developed using data from a cross-sectional population-based survey (n = 6352) that included the Minnesota leisure-time PA questionnaire. Activities that explained a significant proportion of the variability of population PA practice were identified. Validation of the short questionnaire included a cross-sectional component to assess validity with respect to the data collected by accelerometers and a longitudinal component to assess reliability and sensitivity to detect changes (n = 114, aged 35 to 74 years). Results Six types of activities that accounted for 87% of population variability in PA estimated with the Minnesota questionnaire were selected. The short questionnaire estimates energy expenditure in total PA and by intensity (light, moderate, vigorous), and includes 2 questions about sedentary behavior and a question about occupational PA. The short questionnaire showed high reliability, with intraclass correlation coefficients ranging between 0.79 to 0.95. The Spearman correlation coefficients between estimated energy expenditure obtained with the questionnaire and the number of steps detected by the accelerometer were as follows: 0.36 for total PA, 0.40 for moderate intensity, and 0.26 for vigorous intensity. The questionnaire was sensitive to detect changes in moderate and vigorous PA (correlation coefficients ranging from 0.26 to 0.34). Conclusion The REGICOR short questionnaire is reliable, valid, and sensitive to detect changes in moderate and vigorous PA. This questionnaire could be used in daily clinical practice and epidemiological studies. PMID:28085886

  17. A measurement error model for physical activity level as measured by a questionnaire with application to the 1999-2006 NHANES questionnaire.

    PubMed

    Tooze, Janet A; Troiano, Richard P; Carroll, Raymond J; Moshfegh, Alanna J; Freedman, Laurence S

    2013-06-01

    Systematic investigations into the structure of measurement error of physical activity questionnaires are lacking. We propose a measurement error model for a physical activity questionnaire that uses physical activity level (the ratio of total energy expenditure to basal energy expenditure) to relate questionnaire-based reports of physical activity level to true physical activity levels. The 1999-2006 National Health and Nutrition Examination Survey physical activity questionnaire was administered to 433 participants aged 40-69 years in the Observing Protein and Energy Nutrition (OPEN) Study (Maryland, 1999-2000). Valid estimates of participants' total energy expenditure were also available from doubly labeled water, and basal energy expenditure was estimated from an equation; the ratio of those measures estimated true physical activity level ("truth"). We present a measurement error model that accommodates the mixture of errors that arise from assuming a classical measurement error model for doubly labeled water and a Berkson error model for the equation used to estimate basal energy expenditure. The method was then applied to the OPEN Study. Correlations between the questionnaire-based physical activity level and truth were modest (r = 0.32-0.41); attenuation factors (0.43-0.73) indicate that the use of questionnaire-based physical activity level would lead to attenuated estimates of effect size. Results suggest that sample sizes for estimating relationships between physical activity level and disease should be inflated, and that regression calibration can be used to provide measurement error-adjusted estimates of relationships between physical activity and disease.

  18. Active Mobility and Environment: A Pilot Qualitative Study for the Design of a New Questionnaire.

    PubMed

    Hess, Franck; Salze, Paul; Weber, Christiane; Feuillet, Thierry; Charreire, Hélène; Menai, Mehdi; Perchoux, Camille; Nazare, Julie-Anne; Simon, Chantal; Oppert, Jean-Michel; Enaux, Christophe

    2017-01-01

    It is generally accepted that active mobility, mainly walking and cycling, contributes to people's physical and mental health. One of the current challenges is to improve our understanding of this type of behaviour. This study aims to identify factors from the daily-life environment that may be related to active mobility behaviours, in order to design a new questionnaire for a quantitative study of a large adult population. The new questionnaire obtained through this pilot study combines information from interviews with existing questionnaires materials in order to introduce new factors while retaining the factors already assessed. This approach comprises three stages. The first was a content analysis (Reinert method) of interviews with a sample of participants about daily living activities as well as mobility. This stage led to a typology of factors suggested by interviews. The second was a scoping review of the literature in order to identify the active mobility questionnaires currently used in international literature. The last stage was a cross-tabulation of the factors resulting from the written interviews and the questionnaires. A table of the inter-relationships between the interview-based typology and the questionnaires shows discrepancies between factors considered by the existing questionnaires, and factors coming from individual interviews. Independent factors which were ignored in or absent from the questionnaires are the housing situation within the urban structure, overall consideration of the activity space beyond the limits of the residential neighbourhood, the perception of all the transportation modes, and the time scheduling impacting the modes actually used. Our new questionnaire integrates both the usual factors and the new factors that may be related to active mobility behaviours.

  19. Active Mobility and Environment: A Pilot Qualitative Study for the Design of a New Questionnaire

    PubMed Central

    Salze, Paul; Weber, Christiane; Feuillet, Thierry; Charreire, Hélène; Menai, Mehdi; Perchoux, Camille; Nazare, Julie-Anne; Simon, Chantal; Oppert, Jean-Michel

    2017-01-01

    It is generally accepted that active mobility, mainly walking and cycling, contributes to people’s physical and mental health. One of the current challenges is to improve our understanding of this type of behaviour. This study aims to identify factors from the daily-life environment that may be related to active mobility behaviours, in order to design a new questionnaire for a quantitative study of a large adult population. The new questionnaire obtained through this pilot study combines information from interviews with existing questionnaires materials in order to introduce new factors while retaining the factors already assessed. This approach comprises three stages. The first was a content analysis (Reinert method) of interviews with a sample of participants about daily living activities as well as mobility. This stage led to a typology of factors suggested by interviews. The second was a scoping review of the literature in order to identify the active mobility questionnaires currently used in international literature. The last stage was a cross-tabulation of the factors resulting from the written interviews and the questionnaires. A table of the inter-relationships between the interview-based typology and the questionnaires shows discrepancies between factors considered by the existing questionnaires, and factors coming from individual interviews. Independent factors which were ignored in or absent from the questionnaires are the housing situation within the urban structure, overall consideration of the activity space beyond the limits of the residential neighbourhood, the perception of all the transportation modes, and the time scheduling impacting the modes actually used. Our new questionnaire integrates both the usual factors and the new factors that may be related to active mobility behaviours. PMID:28052086

  20. Frequency requirements for active earth observation sensors

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The foundation and rationale for the selection of microwave frequencies for active remote sensing usage and for subsequent use in determination of sharing criteria and allocation strategies for the WARC-79 are presented.

  1. “How hard could it be?” A descriptive analysis of errors made on a validated lifetime physical activity questionnaire

    PubMed Central

    Anderton, Natalie; Newhouse, Megan E.; Ainsworth, Barbara E.; Nygaard, Ingrid E.; Egger, Marlene J.; Shaw, Janet M.

    2015-01-01

    Background Measuring historical physical activity in epidemiologic research depends on self-report. We aimed to describe data reporting errors women made in completing two validated questionnaires – Lifetime Physical Activity Questionnaire (LPAQ) and Occupational Questionnaire (OQ). Methods Participants, 229 women aged 38 – 65 years, completed questionnaires on paper (n=160) or by web interface (n=69). One research assistant collected questionnaire data, identified potential errors and contacted participants to trouble-shoot errors. Results Women made mean 9.7 (SD 11.2) errors on paper and 7.1 (SD 6.2) errors on electronic versions of the LPAQ and 2.6 (SD 3.8) and 1.1 (SD 1.4) errors on paper and electronic versions of the OQ, respectively. Fewer mistakes were made on electronic versions of both questionnaires combined (8.5±6.1) when compared to the paper versions (12.7±13.1). Only ~2% of the sample completed all questionnaires without detectable errors. The most common errors were reporting activities or frequencies inconsistently between past year survey and the current age epoch, reporting more years than allowed by age epoch and missing information. Conclusions Despite the implications of “self-report” questionnaires, we recommend researchers provide participants with additional instructions, either verbally or as written tip sheet or both, and follow-up after questionnaire completion to correct mistakes as needed. PMID:24809450

  2. The Turkish version of the pregnancy physical activity questionnaire: cross-cultural adaptation, reliability, and validity

    PubMed Central

    Tosun, Ozge Celiker; Solmaz, Ulas; Ekin, Atalay; Tosun, Gokhan; Mutlu, Ebru Kaya; Okyay, Emre; Adiyeke, Mehmet; Gezer, Cenk; Mat, Emre; Malkoc, Mehtap

    2015-01-01

    [Purpose] The aim of this study was to translate the Pregnancy Physical Activity Questionnaire, adapt it for use with Turkish subjects and determine its reliability and validity. [Subjects and Methods] The Pregnancy Physical Activity Questionnaire was translated into Turkish and administered twice at 7–14-day intervals to pregnant women to assess the test-retest reliability. Cronbach’s α was used for internal consistency, and the inter-rater correlation coefficient was used to calculate the test-retest reliability. The Turkish Short Form 36 Health Survey (SF-36) and the International Physical Activity Questionnaire were used to estimate validity. [Results] The internal consistency during the first and third trimesters of pregnancy was excellent, with Cronbach’s α values of 0.93 and 0.95, respectively. The mean interval between the two assessments was 11.1 ± 2.1 days. The correlation coefficient between the total activity measured by the Turkish version of the Pregnancy Physical Activity Questionnaire and the International Physical Activity Questionnaire estimates of the total metabolic equivalent were fair to poor during the first, second, and third trimesters of pregnancy (r = 0.17, r = 0.17, r = 0.21, respectively). The Turkish version of the Pregnancy Physical Activity Questionnaire showed fair correlations with the Short Form 36 Health Survey physical component score (r = −0.30) and mental component score (r = −0.37) for the first trimester of pregnancy. [Conclusion] The Turkish version of the Pregnancy Physical Activity Questionnaire was found to be reliable and valid for assessing a pregnant woman’s physical activity. PMID:26644678

  3. Pregnancy physical activity questionnaire (PPAQ): reliability and validity of Turkish version

    PubMed Central

    Çırak, Yasemin; Yılmaz, Gül Deniz; Demir, Yasemin Parlak; Dalkılınç, Murat; Yaman, Selen

    2015-01-01

    [Purpose] The aim of this study was to translate the Pregnancy Physical Activity Questionnaire into Turkish and test its reliability and validity among Turkish pregnant women. [Subjects and Methods] The subjects were 204 healthy, single pregnant women between the ages 18 and 40 who volunteered to participate in this study. Reliability was evaluated by measuring the one-week test-retest reliability with the intraclass correlation coefficient and Pearson’s correlation analysis. Concurrent validity was examined by comparing the Pregnancy Physical Activity Questionnaire with the long form of the International Physical Activity Questionnaire and step counts with pedometer. [Results] The mean age of the participants was 28.23±4.94 years, and the mean for BMI was 26.09±4.40. For test-retest reliability, r values were respectively 0.961, 0.934, 0.957 and 0.981 for self-reported sedentary, light, moderate, and vigorous activity, respectively. Intraclass correlation coefficient scores ranged from 0.924 to 0.993. For validity, the Pearson’s correlation coefficients between the Pregnancy Physical Activity Questionnaire and long form of the International Physical Activity Questionnaire ranged from moderate (r = 0.329) to high (r = 0.672). The correlation value between the total score of the Pregnancy Physical Activity Questionnaire and the step counts was 0.70. [Conclusion] The Turkish version of the Pregnancy Physical Activity Questionnaire is a valid and reliable tool for measurement of the physical activity level of pregnant women. PMID:26834336

  4. Fitting portion sizes in a self-administered food frequency questionnaire.

    PubMed

    Nöthlings, Ute; Hoffmann, Kurt; Bergmann, Manuela M; Boeing, Heiner

    2007-12-01

    For epidemiological studies, a simple semiquantitative FFQ was developed to assess the frequency of intake of food items demonstrated with graphically displayed portion sizes. As a validation study, a random sample of 393 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study completed 2 unannounced 24-h dietary recalls (24HDR) and the FFQ during 1 y. To calculate food and nutrient intakes, we compared the use of fitted portion sizes with the use of predefined portion sizes. Fitted portion sizes were calculated by summing food intakes over the 2 24HDR and dividing the sum by the frequency of intake reported in the FFQ for each FFQ food item, leading to similar mean intakes for FFQ and 24HDR. As predefined portion sizes, amounts that had been used in previous dietary assessments in EPIC-Potsdam were used. Mean intake of 12 food groups was 102% for men or women with fitted portion sizes and 79% for men and 95% for women with predefined portion sizes of intake measured with 2 24HDR. However, deattenuated, energy-adjusted correlation coefficients between FFQ and 24HDR were not better for 19 nutrients by the use of fitted portion sizes, with a mean correlation coefficient of 0.53 for men and 0.56 for women. Mean correlation coefficients for food groups also were similar for fitted and predefined portion sizes. Fitting portion sizes using recent reference data from a random sample of study participants improved the quantitative assessment of food and nutrient intake, but not ranking of study participants, compared with predefining portion sizes based on prior knowledge.

  5. Comparison of the Physical Activity and Sedentary Behaviour Assessment Questionnaire and the Short-Form International Physical Activity Questionnaire: An Analysis of Health Survey for England Data

    PubMed Central

    Scholes, Shaun; Bridges, Sally; Ng Fat, Linda; Mindell, Jennifer S.

    2016-01-01

    Background The Physical Activity and Sedentary Behaviour Assessment Questionnaire (PASBAQ), used within the Health Survey for England (HSE) at 5-yearly intervals, is not included annually due to funding and interview-length constraints. Policy-makers and data-users are keen to consider shorter instruments such as the Short-form International Physical Activity Questionnaire (IPAQ) for the annual survey. Both questionnaires were administered in HSE 2012, enabling comparative assessment in a random sample of 1252 adults. Methods Relative agreement using prevalence-adjusted bias-adjusted Kappa (PABAK) statistics was estimated for: sufficient aerobic activity (moderate-to-vigorous physical activity [MVPA] ≥150minutes/week); inactivity (MVPA<30minutes/week); and excessive sitting (≥540minutes/weekday). Cross-sectional associations with health outcomes were compared across tertiles of MVPA and tertiles of sitting time using logistic regression with tests for linear trend. Results Compared with PASBAQ data, IPAQ-assessed estimates of sufficient aerobic activity and inactivity were higher and lower, respectively; estimates of excessive sitting were higher. Demographic patterns in prevalence were similar. Agreement using PABAK statistics was fair-to-moderate for sufficient aerobic activity (0.32–0.49), moderate-to-substantial for inactivity (0.42–0.74), and moderate-to-substantial for excessive sitting (0.49–0.75). As with the PASBAQ, IPAQ-assessed MVPA and sitting each showed graded associations with mental well-being (women: P for trend = 0.003 and 0.004, respectively) and obesity (women: P for trend = 0.007 and 0.014, respectively). Conclusions Capturing habitual physical activity and sedentary behaviour through brief questionnaires is complex. Differences in prevalence estimates can reflect differences in questionnaire structure and content rather than differences in reported behaviour. Treating all IPAQ-assessed walking as moderate-intensity contributed to the

  6. Non-Exercise Estimation of VO[subscript 2]max Using the International Physical Activity Questionnaire

    ERIC Educational Resources Information Center

    Schembre, Susan M.; Riebe, Deborah A.

    2011-01-01

    Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO[subscript 2]max) as well as sub-maximal exercise testing. The International Physical Activity Questionnaire is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO[subscript…

  7. Validity and Reliability of the Persian Version of Baecke Habitual Physical Activity Questionnaire in Healthy Subjects

    PubMed Central

    Sadeghisani, Meissam; Dehghan Manshadi, Farideh; Azimi, Hadi; Montazeri, Ali

    2016-01-01

    Background Baecke Habitual Physical Activity Questionnaire (BHPAQ) has widely been employed in clinical and laboratorial studies as a tool for measuring subjects' physical activities. But, the reliability and validity of this questionnaire have not been investigated among Persian speakers. Objectives Therefore, the aim of the current study was examining the reliability and validity of the Persian version of the BHPAQ in healthy Persian adults. Materials and Methods After following the process of forward-backward translation, 32 subjects were invited to fill out the Persian version of the questionnaire in two independent sessions (3 - 7 days after the first session) in order to determine the reliability index. Also, the validity of the questionnaire was assessed through concurrent validity by 126 subjects (66 males and 60 females) answering both the Baecke and the International Physical Activity Questionnaire (IPAQ). Results An acceptable level of intraclass correlation coefficient (ICC of work score = 0.95, sport score = 0.93, and leisure score = 0.77) was achieved for the Persian Baecke questionnaire. Correlations between Persian Baecke and IPAQ with and without the score for sitting position were found to be 0.19 and 0.36, respectively. Conclusions The Persian version of the BHPAQ is a reliable and valid instrument that can be used to measure the level of habitual functional activities in Persian-speaking subjects. PMID:27826396

  8. Psychometric Properties of the Modified RESIDE Physical Activity Questionnaire among Low-Income Overweight Women

    PubMed Central

    Jones, Sydney A.; Evenson, Kelly R.; Johnston, Larry F.; Trost, Stewart G.; Samuel-Hodge, Carmen; Jewell, David A.; Kraschnewski, Jennifer L.; Keyserling, Thomas C.

    2014-01-01

    Objective This study explored the criterion-related validity and test-retest reliability of the modified RESIDential Enviroment (RESIDE) physical activity questionnaire and whether the instrument’s validity varied by body mass index (BMI), education, race/ethnicity, or employment status. Design Validation study using baseline data collected for randomized trial of a weight loss intervention. Method Participants recruited from health departments wore an ActiGraph accelerometer and self-reported non-occupational walking, moderate and vigorous physical activity on the modified RESIDE questionnaire. We assessed validity (n=152) using Spearman correlation coefficients (SCC), and reliability (n=57) using intraclass correlation coefficients (ICC). Results When compared to steps, moderate physical activity, and bouts of moderate/vigorous physical activity measured by accelerometer, these questionnaire measures showed fair evidence for validity: recreational walking (SCC 0.23–0.36), total walking (SCC 0.24–0.37), and total moderate physical activity (SCC 0.18–0.36). Correlations for self-reported walking and moderate physical activity were higher among unemployed participants and women with lower BMIs. Generally no other variability in the validity of the instrument was found. Evidence for reliability of RESIDE measures of recreational walking, total walking, and total moderate physical activity was substantial (ICC 0.56–0.68). Conclusions Evidence for questionnaire validity and reliability varied by activity domain and was strongest for walking measures. The questionnaire may capture physical activity less accurately among women with higher BMIs and employed participants. Capturing occupational activity, specifically walking at work, may improve questionnaire validity. PMID:24462117

  9. Critical incident history questionnaire replication: frequency and severity of trauma exposure among officers from small and midsize police agencies.

    PubMed

    Chopko, Brian A; Palmieri, Patrick A; Adams, Richard E

    2015-04-01

    Frequency and severity of trauma exposure are thought to influence posttraumatic reactions. Weiss et al.'s Critical Incident History Questionnaire (CIHQ; 2010) measures these variables among law enforcement officers; they reported findings using a sample of officers from large urban departments. We noted the need for replication studies utilizing samples from smaller and rural police agencies. The purpose of this study was to replicate the CIHQ findings from Weiss et al. using a sample (N = 193) of officers from small and midsize police departments and officers whose duties include policing rural and isolated jurisdictions. Frequency and severity findings were similar to those reported by Weiss et al. (). Regarding frequency, the present study found the critical incident exposure mean score was 188.5, compared to 168.5 from Weiss et al. (). Making a mistake that kills or injures a colleague had the highest mean nomothetic severity rating in both studies. Among the various variables examined in this study, PTSD symptoms demonstrated the strongest association with the exposure indices, based on Spearman rank correlations (r = .26-.46).

  10. Substance and Alcohol use in Young Adults in Turkey as Indicated by the CAGE Questionnaire and Drinking Frequency

    PubMed Central

    DEMİRBAŞ, Hatice

    2015-01-01

    Introduction The purpose of this study was to determine drinking problems and to analyze the socio-demographic factors associated with problematic alcohol use in young adults. Methods The study included 262 students who were surveyed for substance use problems in a postgraduate program using the Cut down, Annoyed, Guilty, Eye opener (CAGE) Questionnaire. The relationships between socio-demographic variables and alcohol use were assessed using both univariate and multivariate analyses. Results Of the whole sample, 56.11% reported that they had tried drinking alcohol and 1.91% had tried cannabis. The prevalence of problematic alcohol use was 15.3% and 29.7% according to CAGE1+ and past-year drinking frequency, respectively. Alcohol use by mothers was an important differentiating factor for alcohol use by their daughters. Graduating from a university located in the Eastern/Southeastern Anatolia regions, graduating from a private high school, and having average academic performance levels were determinants of problematic alcohol use according to CAGE1+ and frequency of drinking. Conclusion This study suggests there is need for early intervention to prevent exposure to the risk factors for problematic alcohol use in young adults, emphasizing that probable presence of an alcohol use disorder and high frequency of drinking are related to socio-demographic factors (high school type, geographical location of the university, and family structure).

  11. Validation of the Physical Activity Questionnaire for Older Children (PAQ-C) among Chinese children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study initially validates the Chinese version of the Physical Activity Questionnaire for Older Children (PAQ-C), which has been identified as a potentially valid instrument to assess moderate-to-vigorous physical activity (MVPA) in children among diverse racial groups. The psychometric properti...

  12. Validity of a Questionnaire to Assess the Physical Activity Level in Coronary Artery Disease Patients

    ERIC Educational Resources Information Center

    Guiraud, Thibaut; Granger, Richard; Bousquet, Marc; Gremeaux, Vincent

    2012-01-01

    The aim of the study is to compare, in coronary artery disease patients, physical activity (PA) assessed with the Dijon Physical Activity Questionnaire (DPAQ) and the true PA objectively measured using an accelerometer. Seventy patients wore an accelerometer (MyWellness Key actimeter) throughout 1 week after a cardiac rehabilitation program that…

  13. Validation Evidence for the Netherlands Physical Activity Questionnaire for Young Children: The Iowa Bone Development Study

    ERIC Educational Resources Information Center

    Janz, Kathleen F.; Broffitt, Barbara; Levy, Steven M.

    2005-01-01

    In this paper, the authors present reliability and validity information for the Netherlands (Health Education Project) Physical Activity Questionnaire (NPAQ), a global proxy report of children's everyday activity preferences (Montoye, Kemper, Saris, & Washburn, 1996). In this study, the authors examined the measurement properties of a global…

  14. Reliability and Validity of the Flemish Physical Activity Computerized Questionnaire in Adults

    ERIC Educational Resources Information Center

    Matton, Lynn; Wijndaele, Katrien; Duvigneaud, Nathalie; Duquet, William; Philippaerts, Renaat; Thomis, Martine; Lefevre, Johan

    2007-01-01

    The purpose of this study was to investigate the test-retest reliability and concurrent validity of the Flemish Physical Activity Computerized Questionnaire (FPACQ) in employed/unemployed and retired people. The FPACQ was developed to assess detailed information on several dimensions of physical activity and sedentary behavior over a usual week. A…

  15. Physical Activity and Adiposity Markers at Older Ages: Accelerometer Vs Questionnaire Data

    PubMed Central

    Sabia, Séverine; Cogranne, Pol; van Hees, Vincent T.; Bell, Joshua A.; Elbaz, Alexis; Kivimaki, Mika; Singh-Manoux, Archana

    2015-01-01

    Objective Physical activity is critically important for successful aging, but its effect on adiposity markers at older ages is unclear as much of the evidence comes from self-reported data on physical activity. We assessed the associations of questionnaire-assessed and accelerometer-assessed physical activity with adiposity markers in older adults. Design/Setting/Participants This was a cross-sectional study on 3940 participants (age range 60-83 years) of the Whitehall II study who completed a 20-item physical activity questionnaire and wore a wrist-mounted accelerometer for 9 days in 2012 and 2013. Measurements Total physical activity was estimated using metabolic equivalent hours/week for the questionnaire and mean acceleration for the accelerometer. Time spent in moderate-and-vigorous physical activity (MVPA) was also assessed by questionnaire and accelerometer. Adiposity assessment included body mass index, waist circumference, and fat mass index. Fat mass index was calculated as fat mass/height² (kg/m²), with fat mass estimated using bioimpedance. Results Greater total physical activity was associated with lower adiposity for all adiposity markers in a dose-response manner. In men, the strength of this association was 2.4 to 2.8 times stronger with the accelerometer than with questionnaire data. In women, it was 1.9 to 2.3 times stronger. For MVPA, questionnaire data in men suggested no further benefit for adiposity markers past 1 hour/week of activity. This was not the case for accelerometer-assessed MVPA where, for example, compared with men undertaking <1 hour/week of accelerometer-assessed MVPA, waist circumference was 3.06 (95% confidence interval 2.06–4.06) cm lower in those performing MVPA 1–2.5 hours/week, 4.69 (3.47–5.91) cm lower in those undertaking 2.5–4 hours/week, and 7.11 (5.93–8.29) cm lower in those performing ≥4 hours/week. Conclusions The association of physical activity with adiposity markers in older adults was

  16. Evaluation of the Relative Validity of the Short Diet Questionnaire for Assessing Usual Consumption Frequencies of Selected Nutrients and Foods.

    PubMed

    Shatenstein, Bryna; Payette, Hélène

    2015-08-04

    A 36-item Short Diet Questionnaire (SDQ) was developed to assess usual consumption frequencies of foods providing fats, fibre, calcium, vitamin D, in addition to fruits and vegetables. It was pretested among 30 community-dwelling participants from the Québec Longitudinal Study on Nutrition and Successful Aging, "NuAge" (n = 1793, 52.4% women), recruited in three age groups (70 ± 2 years; 75 ± 2 years; 80 ± 2 years). Following revision, the SDQ was administered to 527 NuAge participants (55% female), distributed among the three age groups, both sexes and languages (French, English) prior to the second of three non-consecutive 24 h diet recalls (24HR) and validated relative to the mean of three 24HR. Full data were available for 396 participants. Most SDQ nutrients and fruit and vegetable servings were lower than 24HR estimates (p < 0.05) except calcium, vitamin D, and saturated and trans fats. Spearman correlations between the SDQ and 24HR were modest and significant (p < 0.01), ranging from 0.19 (cholesterol) to 0.45 (fruits and vegetables). Cross-classification into quartiles showed 33% of items were jointly classified into identical quartiles of the distribution, 73% into identical and contiguous quartiles, and only 7% were frankly misclassified. The SDQ is a reasonably accurate, rapid approach for ranking usual frequencies of selected nutrients and foods. Further testing is needed in a broader age range.

  17. Evaluation of the Relative Validity of the Short Diet Questionnaire for Assessing Usual Consumption Frequencies of Selected Nutrients and Foods

    PubMed Central

    Shatenstein, Bryna; Payette, Hélène

    2015-01-01

    A 36-item Short Diet Questionnaire (SDQ) was developed to assess usual consumption frequencies of foods providing fats, fibre, calcium, vitamin D, in addition to fruits and vegetables. It was pretested among 30 community-dwelling participants from the Québec Longitudinal Study on Nutrition and Successful Aging, “NuAge” (n = 1793, 52.4% women), recruited in three age groups (70 ± 2 years; 75 ± 2 years; 80 ± 2 years). Following revision, the SDQ was administered to 527 NuAge participants (55% female), distributed among the three age groups, both sexes and languages (French, English) prior to the second of three non-consecutive 24 h diet recalls (24HR) and validated relative to the mean of three 24HR. Full data were available for 396 participants. Most SDQ nutrients and fruit and vegetable servings were lower than 24HR estimates (p < 0.05) except calcium, vitamin D, and saturated and trans fats. Spearman correlations between the SDQ and 24HR were modest and significant (p < 0.01), ranging from 0.19 (cholesterol) to 0.45 (fruits and vegetables). Cross-classification into quartiles showed 33% of items were jointly classified into identical quartiles of the distribution, 73% into identical and contiguous quartiles, and only 7% were frankly misclassified. The SDQ is a reasonably accurate, rapid approach for ranking usual frequencies of selected nutrients and foods. Further testing is needed in a broader age range. PMID:26247965

  18. Solar activity and oscillation frequency splittings

    NASA Technical Reports Server (NTRS)

    Woodard, M. F.; Libbrecht, K. G.

    1993-01-01

    Solar p-mode frequency splittings, parameterized by the coefficients through order N = 12 of a Legendre polynomial expansion of the mode frequencies as a function of m/L, were obtained from an analysis of helioseismology data taken at Big Bear Solar Observatory during the 4 years 1986 and 1988-1990 (approximately solar minimum to maximum). Inversion of the even-index splitting coefficients confirms that there is a significant contribution to the frequency splittings originating near the solar poles. The strength of the polar contribution is anti correlated with the overall level or solar activity in the active latitudes, suggesting a relation to polar faculae. From an analysis of the odd-index splitting coefficients we infer an uppor limit to changes in the solar equatorial near-surface rotatinal velocity of less than 1.9 m/s (3 sigma limit) between solar minimum and maximum.

  19. Validation of Self-Report Measures of Physical Activity: A Case Study Using the New Zealand Physical Activity Questionnaire

    ERIC Educational Resources Information Center

    Mackay, Lisa M.; Schofield, Grant M.; Schluter, Philip J.

    2007-01-01

    Accurate measurement of physical activity is fundamentally important in epidemiological research of physical activity behavior. A widely used telephone-based physical activity questionnaire was compared with other methods of administration and objective measures (pedometers and accelerometers) among 80 adults (43 women). The telephone…

  20. Differential Item Functioning Analysis of the 2003-04 NHANES Physical Activity Questionnaire

    ERIC Educational Resources Information Center

    Gao, Yong; Zhu, Weimo

    2011-01-01

    Using differential item functioning (DIF) analyses, this study examined whether there were any DIF items in the National Health and Nutrition Examination Survey (NHANES) physical activity (PA) questionnaire. A subset of adult data from the 2003-04 NHANES study (n = 3,083) was used. PA items related to respondents' occupational, transportation,…

  1. Validation of a food frequency questionnaire for retrospective estimation of diet during the first 2 years of life

    PubMed Central

    Mejía-Rodríguez, Fabiola; Neufeld, Lynnette M.; García-Guerra, Armando; Quezada-Sanchez, Amado D.; Orjuela, Manuela A.

    2013-01-01

    Objective This study aims to validate a Food Frequency Questionnaire (FFQ), specifically designed to retrospectively estimate dietary intake and supplement consumption during the first two years of life in children from resource poor households in semi-rural Mexico. Methods The FFQ querying about diet during the first 2 years of life was administered to mothers of children (N=84), who participated in a prospective study 3 to 5 years earlier, in which complementary feeding practice questionnaires and 24-hour recall (24hrR) were collected at several time points during the first 2 years of life to evaluate dietary and vitamin supplement intake. The resulting FFQ data were compared to intake data collected during the original study using Spearman correlations, deattenuated correlations and Wilcoxon signed-rank tests. Results Total energy intake, as estimated by the retrospective and original instruments, did not differ in the second year (Yr2); correlations between the measures were significant (r=0.40, p<0.001). The 24hrR and FFQ-Yr2 were significantly correlated for dietary intake of vitamins B6, B12 (p<0.001) and folate (p<0.01); however, after including vitamin supplement intake, the two dietary instruments were correlated only for vitamins A and B12 (p<0.05). Conclusions The FFQ provides a reasonable estimate of a child’s dietary intake of energy and key micronutrients during the second year of life, and permits accurate ranking of intake 3 to 5 years after birth. PMID:23532627

  2. Physical Activity Characteristics across GOLD Quadrants Depend on the Questionnaire Used

    PubMed Central

    Demeyer, Heleen; Gimeno-Santos, Elena; Rabinovich, Roberto A.; Hornikx, Miek; Louvaris, Zafeiris; de Boer, Willem I.; Karlsson, Niklas; de Jong, Corina; Van der Molen, Thys; Vogiatzis, Ioannis; Janssens, Wim; Garcia-Aymerich, Judith; Troosters, Thierry; Polkey, Michael I.

    2016-01-01

    Background The GOLD multidimensional classification of COPD severity combines the exacerbation risk with the symptom experience, for which 3 different questionnaires are permitted. This study investigated differences in physical activity (PA) in the different GOLD quadrants and patient’s distribution in relation to the questionnaire used. Methods 136 COPD patients (58±21% FEV1 predicted, 34F/102M) completed COPD assessment test (CAT), clinical COPD questionnaire (CCQ) and modified Medical Research Council (mMRC) questionnaire. Exacerbation history, spirometry and 6MWD were collected. PA was objectively measured for 2 periods of 1 week, 6 months apart, in 5 European centres; to minimise seasonal and clinical variation the average of these two periods was used for analysis. Results GOLD quadrants C+D had reduced PA compared with A+B (3824 [2976] vs. 5508 [4671] steps.d-1, p<0.0001). The choice of questionnaire yielded different patient distributions (agreement mMRC-CAT κ = 0.57; CCQ-mMRC κ = 0.71; CCQ-CAT κ = 0.72) with different clinical characteristics. PA was notably lower in patients with an mMRC score ≥2 (3430 [2537] vs. 5443 [3776] steps.d-1, p <0.001) in both the low and high risk quadrants. Conclusions Using different questionnaires changes the patient distribution and results in different clinical characteristics. Therefore, standardization of the questionnaire used for classification is critical to allow comparison of different studies using this as an entry criterion. Clinical Trial Registration ClinicalTrials.gov NCT01388218 PMID:26974332

  3. Active Reading Experience Questionnaire: Development and Validation of an Instrument for Studying Active Reading Activities

    ERIC Educational Resources Information Center

    Palilonis, Jennifer; Butler, Darrell

    2015-01-01

    The increasing adoption of mobile platforms and digital textbooks in university classrooms continues to have a profound impact on higher education. Advocates believe that providing students digital textbooks with built-in annotation features and interactive study tools will improve learning by facilitating active reading, a task essential to…

  4. Assessment of Diet and Physical Activity of Brazilian Schoolchildren: Usability Testing of a Web-Based Questionnaire

    PubMed Central

    2013-01-01

    Background Information and communication technology (ICT) has been used with increasing frequency for the assessment of diet and physical activity in health surveys. A number of Web-based questionnaires have been developed for children and adolescents. However, their usability characteristics have scarcely been reported, despite their potential importance for improving the feasibility and validity of ICT-based methods. Objective The objective of this study was to describe the usability evaluation of the Consumo Alimentar e Atividade Física de Escolares (CAAFE) questionnaire (Food Consumption and Physical Activity Questionnaire for schoolchildren), a new Web-based survey tool for the self-assessment of diet and physical activity by schoolchildren. Methods A total of 114 schoolchildren aged 6 to 12 years took part in questionnaire usability testing carried out in computer classrooms at five elementary schools in the city of Florianopolis, Brazil. Schoolchildren used a personal computer (PC) equipped with software for recording what is on the computer screen and the children’s speech during usability testing. Quantitative and qualitative analyses took into account objective usability metrics such as error counts and time to complete a task. Data on the main difficulties in accomplishing the task and the level of satisfaction expressed by the children were assessed by the observers using a standardized form and interviews with the children. Descriptive statistics and content analysis were used to summarize both the quantitative and the qualitative aspects of the data obtained. Results The mean time for completing the questionnaire was 13.7 minutes (SD 3.68). Compared to the children in 2nd or 3rd grades, those in 4th or 5th grades spent less time completing the questionnaire (median 12.4 vs 13.3 minutes, P=.022), asked for help less frequently (median 0 vs 1.0 count, P=.005), had a lower error count (median 2.0 vs 8.0 count, P<.001), and obtained a higher overall

  5. Reliability and validity of an internet-based questionnaire measuring lifetime physical activity.

    PubMed

    De Vera, Mary A; Ratzlaff, Charles; Doerfling, Paul; Kopec, Jacek

    2010-11-15

    Lifetime exposure to physical activity is an important construct for evaluating associations between physical activity and disease outcomes, given the long induction periods in many chronic diseases. The authors' objective in this study was to evaluate the measurement properties of the Lifetime Physical Activity Questionnaire (L-PAQ), a novel Internet-based, self-administered instrument measuring lifetime physical activity, among Canadian men and women in 2005-2006. Reliability was examined using a test-retest study. Validity was examined in a 2-part study consisting of 1) comparisons with previously validated instruments measuring similar constructs, the Lifetime Total Physical Activity Questionnaire (LT-PAQ) and the Chasan-Taber Physical Activity Questionnaire (CT-PAQ), and 2) a priori hypothesis tests of constructs measured by the L-PAQ. The L-PAQ demonstrated good reliability, with intraclass correlation coefficients ranging from 0.67 (household activity) to 0.89 (sports/recreation). Comparison between the L-PAQ and the LT-PAQ resulted in Spearman correlation coefficients ranging from 0.41 (total activity) to 0.71 (household activity); comparison between the L-PAQ and the CT-PAQ yielded coefficients of 0.58 (sports/recreation), 0.56 (household activity), and 0.50 (total activity). L-PAQ validity was further supported by observed relations between the L-PAQ and sociodemographic variables, consistent with a priori hypotheses. Overall, the L-PAQ is a useful instrument for assessing multiple domains of lifetime physical activity with acceptable reliability and validity.

  6. The Work and Home Activities Questionnaire: Energy Expenditure Estimates and Association With Percent Body Fat

    PubMed Central

    Block, Gladys; Jensen, Christopher D.; Block, Torin J.; Norris, Jean; Dalvi, Tapashi B.; Fung, Ellen B.

    2015-01-01

    Background Understanding and increasing physical activity requires assessment of occupational, home, leisure and sedentary activities. Methods A physical activity questionnaire was developed using data from a large representative U.S. sample; includes occupational, leisure and home-based domains; and produces estimates of energy expenditure, percent body fat, minutes in various domains, and meeting recommendations. It was tested in 396 persons, mean age 44 years. Estimates were evaluated in relation to percent body fat measured by dual-energy x-ray absorptiometry. Results Median energy expenditure was 2,365 kcal (women) and 2.960 kcal (men). Women spent 35.1 minutes/day in moderate household activities, 13.0 minutes in moderate leisure and 4.0 minutes in vigorous activities. Men spent 18.0, 22.5 and 15.6 minutes/day in those activities, respectively. Men and women spent 276.4 and 257.0 minutes/day in sedentary activities. Respondents who met recommendations through vigorous activities had significantly lower percent body fat than those who did not, while meeting recommendations only through moderate activities was not associated with percent body fat. Predicted and observed percent body fat correlated at r = .73 and r = .82 for men and women respectively, P < .0001. Conclusions This questionnaire may be useful for understanding health effects of different components of activity, and for interventions to increase activity levels. PMID:19998851

  7. Reproducibility and Relative Validity of a Short Food Frequency Questionnaire in 9–10 Year-Old Children

    PubMed Central

    Saeedi, Pouya; Skeaff, Sheila A.; Wong, Jyh Eiin; Skidmore, Paula M. L.

    2016-01-01

    The aim of this study was to assess the reproducibility and validity of a non-quantitative 28-item food frequency questionnaire (FFQ). Children aged 9–10 years (n = 50) from three schools in Dunedin, New Zealand, completed the FFQ twice and a four-day estimated food diary (4DEFD) over a two-week period. Intraclass correlation coefficients (ICC) and Spearman’s correlation coefficients (SCC) were used to determine reproducibility and validity of the FFQ, respectively. Weekly intakes were estimated for each food item and aggregated into 23 food items/groups. More than half of the food items/groups (52.2%) had an ICC ≥0.5. The median SCC between FFQ administrations was 0.66 (ranging from 0.40 for processed meat to 0.82 for sweets and non-dairy drinks). Cross-classification analysis between the first FFQ and 4DEFD for ranking participants into thirds showed that breakfast cereals had the highest agreement (54.0%) and pasta the lowest (34.0%). In validity analyses, 70% of food items/groups had a SCC ≥0.3. Results indicate that the FFQ is a useful tool for ranking children according to food items/groups intake. The low respondent burden and relative simplicity of the FFQ makes it suitable for use in large cohort studies of 9–10 year-old children in New Zealand. PMID:27164137

  8. Dietary quality varies according to data collection instrument: a comparison between a food frequency questionnaire and 24-hour recall.

    PubMed

    Rodrigues, Paulo Rogério Melo; de Souza, Rita Adriana Gomes; De Cnop, Mara Lima; Monteiro, Luana Silva; Coura, Camila Pinheiro; Brito, Alessandra Page; Pereira, Rosangela Alves

    2016-02-01

    The objective of this study was to assess the agreement between the Brazilian Healthy Eating Index - Revised (BHEI-R), estimated by a food frequency questionnaire (FFQ) and multiple 24-hour recalls (24h-R). The Wilcoxon paired test, partial correlations (PC), intraclass correlation coefficient (ICC), and Bland-Altman method were used. The total BHEI-R scores and its components ("total fruits", "whole fruits", "total vegetables", "integral cereals", "saturated fat", "sodium", and "energy intake derived from solid fat, added sugar, and alcoholic beverages") were statistically different, with the ICC and PC indicating poor concordance and correlation. The mean concordance estimated for the total BHEI-R and its components varied from 68% for "integral cereals" to 147% for "whole fruits". The suitable concordance limits were violated for most of the components of the BHEI-R. Poor concordance was observed between the BHEI-R estimated by the FFQ and by multiple 24h-R, which indicated a strong reliability of the BHEI-R on the instrument used to collect information on food consumption.

  9. Fruit and vegetable intake assessed by food frequency questionnaire and plasma carotenoids: a validation study in adults.

    PubMed

    Burrows, Tracy L; Hutchesson, Melinda J; Rollo, Megan E; Boggess, May M; Guest, Maya; Collins, Clare E

    2015-05-06

    Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (α- and β-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for α-carotene, β-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of α-carotene, β-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence.

  10. Food frequency questionnaire is a valid tool for the assessment of dietary habits of South Indian pregnant women.

    PubMed

    Dwarkanath, Pratibha; Soares, Mario J; Thomas, Tinku; Vaz, Mario; Swaminathan, Sumathi; Kurpad, Anura V

    2014-09-01

    The food frequency questionnaire (FFQ) was validated against multiple 24-hour dietary recalls (24-HDRs) and for a few blood biomarkers in 154 pregnant women at the obstetrics and gynecology department of St John's Medical College Hospital, Bangalore, India. Absolute nutrient intakes from the FFQ correlated positively with the average 24-HDR during pregnancy. Energy-adjusted nutrients from the FFQ in all trimesters, except proteins, carbohydrate, folate intake, and vitamin B6 in the third trimester, correlated positively with average 24-HDR. Overestimation by the FFQ compared with the 24-HDR ranged from 9% to 41%. Vitamin B12 status in the first and second trimesters positively correlated with energy-adjusted and absolute vitamin B12 intakes from the FFQ. The Bland Altman plots showed a pattern such that a trend was seen toward underreporting of intakes through the FFQ, with increasing mean intakes by the 2 methods, considering 24-HDR as the reference tool. We conclude that the FFQ is a valid tool to measure dietary intakes during pregnancy.

  11. Reproducibility and validity of semi-quantitative food frequency questionnaire measuring dietary trans-fatty acids intake among Korean adults

    PubMed Central

    Oh, Seung-Won; Lee, Eun

    2015-01-01

    BACKGROUND/OBJECTIVES Compelling evidence indicates that consumption of trans-fatty acids (TFA) is associated with a wide range of diseases. However, few validated tools for TFA intake assessment are available in Korea. We aimed to validate a food frequency questionnaire (FFQ) estimating usual intake of TFA in Korean adults. MATERIALS/METHODS Eighty-two healthy adults completed an FFQ with a 3-day diet record (3DDR), and 58 completed a second FFQ at a 1-month interval. To assess the reproducibility of the FFQ, we compared estimated TFA intakes from each FFQ. To assess the validity, we compared estimates from the FFQ with those from the 3DDR. RESULTS The FFQ was reproducible (Spearman r = 0.71) and provided modest correlations with the 3DDR (Spearman r = 0.38). After adjustment for total energy intake, the correlations increased (r = 0.45). Measurement-error correction also de-attenuated the correlations (r = 0.57). When quintiles of the FFQ and 3DDR were joint-classified, 9% on average were misclassified into extreme quintiles. CONCLUSIONS Our findings suggest that the developed FFQ is reproducible and reasonably valid in categorizing individuals according to TFA intakes among healthy young and middle aged adults in Korea. PMID:25671075

  12. Fruit and Vegetable Intake Assessed by Food Frequency Questionnaire and Plasma Carotenoids: A Validation Study in Adults

    PubMed Central

    Burrows, Tracy L.; Hutchesson, Melinda J.; Rollo, Megan E.; Boggess, May M.; Guest, Maya; Collins, Clare E.

    2015-01-01

    Dietary validation studies of self-reported fruit and vegetable intake should ideally include measurement of plasma biomarkers of intake. The aim was to conduct a validation study of self-reported fruit and vegetable intakes in adults, using the Australian Eating Survey (AES) food frequency questionnaire (FFQ), against a range of plasma carotenoids. Dietary intakes were assessed using the semi-quantitative 120 item AES FFQ. Fasting plasma carotenoids (α- and β-carotene, lutein/zeaxanthin, lycopene and cryptoxanthin) were assessed using high performance liquid chromatography in a sample of 38 adult volunteers (66% female). Significant positive correlations were found between FFQ and plasma carotenoids for α-carotene, β-carotene and lutein/zeaxanthin (52%, 47%, 26%, p < 0.001, 0.003, 0.041; respectively) and relationships between plasma carotenoids (except lycopene) and weight status metrics (BMI, waist circumference, fat mass) were negative and highly significant. The results of the current study demonstrate that carotenoid intakes as assessed by the AES FFQ are significantly related to plasma concentrations of α-carotene, β-carotene and lutein/zeaxanthin, the carotenoids commonly found in fruit and vegetables. Lower levels of all plasma carotenoids, except lycopene, were found in individuals with higher BMI. We conclude that the AES can be used to measure fruit and vegetable intakes with confidence. PMID:25954899

  13. The e-EPIDEMIOLOGY Mobile Phone App for Dietary Intake Assessment: Comparison with a Food Frequency Questionnaire

    PubMed Central

    Sharp, Brett Northrop; García-Perea, María Dolores

    2016-01-01

    Background There is a great necessity for new methods of evaluation of dietary intake that overcome the limitations of traditional self-reporting methods. Objective The objective of this study was to develop a new method, based on an app for mobile phones called e-EPIDEMIOLOGY, which was designed to collect individual consumption data for a series of foods/drinks, and to compare this app with a previously validated paper food frequency questionnaire (FFQ). Methods University students >18 years of age recorded the consumption of certain foods/drinks using e-EPIDEMIOLOGY during 28 consecutive days and then filled out a paper FFQ at the end of the study period. To evaluate the agreement between the categories of habitual consumption for each of the foods/drinks included in the study, cross-classification analysis and a weighted kappa statistic were used. Results A total of 119 participants completed the study (71% female, 85/119; 29% male, 34/119). Cross-classification analysis showed that 79.8% of the participants were correctly classified into the same category and just 1.1% were misclassified into opposite categories. The average weighted kappa statistic was good (κ=.64). Conclusions The results indicate that e-EPIDEMIOLOGY generated ranks of dietary intakes that were highly comparable with the previously validated paper FFQ. However, it was noted that further testing of e-EPIDEMIOLOGY is required to establish its wider utility. PMID:27806922

  14. Development and Validation of a Data-Based Food Frequency Questionnaire for Adults in Eastern Rural Area of Rwanda

    PubMed Central

    Yanagisawa, Ayumi; Sudo, Noriko; Amitani, Yukiko; Caballero, Yuko; Sekiyama, Makiko; Mukamugema, Christine; Matsuoka, Takuya; Imanishi, Hiroaki; Sasaki, Takayo; Matsuda, Hirotaka

    2016-01-01

    This study aimed to develop and evaluate the validity of a food frequency questionnaire (FFQ) for rural Rwandans. Since our FFQ was developed to assess malnutrition, it measured energy, protein, vitamin A, and iron intakes only. We collected 260 weighed food records (WFRs) from a total of 162 Rwandans. Based on the WFR data, we developed a tentative FFQ and examined the food list by percent contribution to energy and nutrient intakes. To assess the validity, nutrient intakes estimated from the FFQ were compared with those calculated from three-day WFRs by correlation coefficient and cross-classification for 17 adults. Cumulative contributions of the 18-item FFQ to the total intakes of energy and nutrients reached nearly 100%. Crude and energy-adjusted correlation coefficients ranged from −0.09 (vitamin A) to 0.58 (protein) and from −0.19 (vitamin A) to 0.68 (iron), respectively. About 50%–60% of the participants were classified into the same tertile. Our FFQ provided acceptable validity for energy and iron intakes and could rank Rwandan adults in eastern rural area correctly according to their energy and iron intakes. PMID:27429558

  15. Validity and Reliability of International Physical Activity Questionnaire-Short Form in Chinese Youth

    ERIC Educational Resources Information Center

    Wang, Chao; Chen, Peijie; Zhuang, Jie

    2013-01-01

    Purpose: The psychometric profiles of the widely used International Physical Activity Questionnaire-Short Form (IPAQ-SF) in Chinese youth have not been reported. The purpose of this study was to examine the validity and reliability of the IPAQ-SF using a sample of Chinese youth. Method: One thousand and twenty-one youth (M[subscript age] = 14.26 ±…

  16. Development of estimates of dietary nitrates, nitrites, and nitrosamines for use with the short willet food frequency questionnaire

    PubMed Central

    Griesenbeck, John S; Steck, Michelle D; Huber, John C; Sharkey, Joseph R; Rene, Antonio A; Brender, Jean D

    2009-01-01

    Background Studies have suggested that nitrates, nitrites, and nitrosamines have an etiologic role in adverse pregnancy outcomes and chronic diseases such as cancer. Although an extensive body of literature exists on estimates of these compounds in foods, the extant data varies in quality, quantified estimates, and relevance. Methods We developed estimates of nitrates, nitrites, and nitrosamines for food items listed in the Short Willet Food Frequency Questionnaire (WFFQ) as adapted for use in the National Birth Defects Prevention Study. Multiple reference databases were searched for published literature reflecting nitrate, nitrite, and nitrosamine values in foods. Relevant published literature was reviewed; only publications reporting results for items listed on the WFFQ were selected for inclusion. The references selected were prioritized according to relevance to the U.S. population. Results Based on our estimates, vegetable products contain the highest levels of nitrate, contributing as much as 189 mg/serving. Meat and bean products contain the highest levels of nitrites with values up to 1.84 mg/serving. Alcohol, meat and dairy products contain the highest values of nitrosamines with a maximum value of 0.531 μg/serving. The estimates of dietary nitrates, nitrites, and nitrosamines generated in this study are based on the published values currently available. Conclusion To our knowledge, these are the only estimates specifically designed for use with the adapted WFFQ and generated to represent food items available to the U.S. population. The estimates provided may be useful in other research studies, specifically in those exploring the relation between exposure to these compounds in foods and adverse health outcomes. PMID:19348679

  17. Eating habits of preschool children with high migrant status in Switzerland according to a new food frequency questionnaire.

    PubMed

    Ebenegger, Vincent; Marques-Vidal, Pedro; Barral, Jérôme; Kriemler, Susi; Puder, Jardena J; Nydegger, Andreas

    2010-02-01

    Assessment of eating habits in young children from multicultural backgrounds has seldom been conducted. Our objectives were to study the reproducibility and the results of a food frequency questionnaire (FFQ) developed to assess changes in eating habits of preschool children with a high migrant population, in the context of a multidisciplinary multilevel lifestyle intervention. Three kindergarten classes (53% from migrant backgrounds) in French-speaking Switzerland were randomly selected and included 16 girls and 28 boys (mean age +/- SD, 5.4 +/- 0.7 years). The FFQ was filled out twice within a 4-week interval by the parents. Spearman rank correlations between the first and the second FFQ for the 39 items of the food questions were as follows: low (r < 0.50) for 8 (7 P < .05 and 1 nonsignificant), moderate (0.50 or= 0.70) for 9 (all P < .01). In addition, 28 of 39 intraclass correlation coefficients were high (>0.50, all P < .01). Eighty-six percent of the children ate breakfast at home daily, but only 67% had lunch at home. The percentages of children eating at least once a week in front of the TV were as follows: 50% for breakfast, 33% for lunch, 38% for dinner, and 48% for snacks. Forty percent of children asked their parents to buy food previously seen in advertisements and ate fast food between once a week and once a month. Children generally consumed foods with a high-energy content. The FFQ yielded good test-retest reproducibility for most items of the food questions and gave relevant findings about the eating habits of preschool children in areas with a high migrant population.

  18. Validity and Reliability of a Self-administered Food Frequency Questionnaire to Assess Vitamin K Intake in Korean Adults

    PubMed Central

    Kim, Eunsu; Kim, Misung

    2016-01-01

    This study was conducted to validate a food frequency questionnaire (FFQ) to assess vitamin K intake in clinical and research settings based on data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V). We collected a subset of data on informative food items using the 24-hour recall method from adults aged 19 to 64 years from KNHANES V. The cumulative percent contribution and cumulative multiple regression coefficients for vitamin K intake from each food were computed. Twenty-five foods items were selected for the FFQ to assess vitamin K intake. The FFQ was validated against intakes derived from a 5-day food record (5DR) (n = 48). To assess the reliability of the FFQ, participants completed the self-administered FFQ (FFQ1) and a second FFQ (FFQ2) after a 6-month period (n = 54). Data were analyzed using Pearson's correlation coefficients, the cross-classification method, and Bland-Altman plots. Mean intakes were similar for vitamin K between the FFQ and dietary records, with significant correlations observed (r = 0.652), and cross-classification analyses demonstrated no major misclassification of participants into intake quartiles. Bland-Altman plots showed no serious systematic bias between the administrations of the two dietary assessment methods over the range of mean intakes. FFQ reliability was high, with a Pearson's correlation coefficient of 0.560. This pilot study shows promising validation and reliability evidence for the use of this FFQ, which is focused on vitamin K intake in adults, as an efficient screening tool in clinical and research settings. PMID:27482519

  19. Relative validity of adolescent dietary patterns: comparison of a food frequency questionnaire and 3-day food record

    PubMed Central

    Ambrosini, Gina L; O’Sullivan, Therese A; de Klerk, Nicholas H; Mori, Trevor A; Beilin, Lawrence J; Oddy, Wendy H

    2012-01-01

    Interest in empirically derived dietary patterns has increased over the past decade. However, relatively few studies have evaluated dietary patterns using different dietary methods, or in young populations. We quantitatively compared dietary patterns from a food frequency questionnaire (FFQ) with those from a 3-day food record (FR) in a cohort of adolescents. Subjects from the Western Australian Pregnancy Cohort (Raine) Study completed a semi-quantitative FFQ and a 3-day FR at 14 y of age (n=783). Major dietary patterns were identified using exploratory factor analysis on 38 food groups. Dietary pattern z-scores were compared using 95% limits of agreement (LOA) and Spearman’s r. Two major dietary patterns were identified in the FFQ and FR. A ‘Healthy’ pattern was high in fresh fruit, vegetables, whole grains and grilled or canned fish. A ‘Western’ pattern was high in takeaway foods, confectionery, soft drinks, crisps and fried potato. The nutrient profiles of these dietary patterns were similar when estimated by the FFQ and FR. The LOA between dietary pattern scores from the FFQ and FR were -1.69 to 1.75 (‘Healthy’) and -1.89 to 1.82 (‘Western’). Minor differences in agreement were observed when boys and girls were analysed separately. Spearman’s correlation coefficients between the FFQ and FR were r=0.45 (‘Healthy’) and r=0.36 (‘Western’). Comparable dietary patterns may be obtained from a FFQ and FR using exploratory factor analysis. This supports the use of major dietary patterns identified using a FFQ in this adolescent cohort. PMID:21269548

  20. Reliability and validity of the Flemish Physical Activity Computerized Questionnaire in adults.

    PubMed

    Matton, Lynn; Wijndaele, Katrien; Duvigneaud, Nathalie; Duquet, William; Philippaerts, Renaat; Thomis, Martine; Lefevre, Johan

    2007-09-01

    The purpose of this study was to investigate the test-retest reliability and concurrent validity of the Flemish Physical Activity Computerized Questionnaire (FPACQ) in employed/unemployed and retired people. The FPACQ was developed to assess detailed information on several dimensions of physical activity and sedentary behavior over a usual week. A triaxial accelerometer, the RT3 Triaxial Research Tracker (RT3), in combination with a written 7-day activity record, was used as the objective criterion measure. In employed/unemployed people, 2-week test-retest reliability for several activity variables calculated from the FPACQ was good to excellent with intraclass correlations (ICCs) ranging from .67 to .99. In retired people ICCs were lower but, except for time spent eating, still fair to excellent, ranging from .57 to .96. Except for time spent in leisure time activities for men and the average energy expenditure related to sports participation in women, correlations between the RT3 and the FPACQ generally supported the relative validity of the FPACQ for employed/unemployed people (r ranging from .37 to .88). Values for retired people were somewhat lower (r ranging from .15 to .85), but most variables still reached at least moderate correlations. Concerning absolute validity, the FPACQ generally overestimated physical activity and underestimated sedentary behavior compared to the RT3. From this study, it can be concluded that the FPACQ is a reliable and reasonably valid questionnaire for assessing different dimensions of physical activity and sedentary behavior.

  1. The relationship between interviewer-respondent race match and reporting of energy intake using food frequency questionnaires in the rural South United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of the observational study was to determine whether interviewer race influences food frequency questionnaire (FFQ) reporting accuracy in a Deep South, largely African American cohort. A secondary analysis was conducted to investigate the influence of interviewer race on energy reporting ...

  2. Reported frequency of physical activity in a large epidemiological study: relationship to specific activities and repeatability over time

    PubMed Central

    2011-01-01

    Background How overall physical activity relates to specific activities and how reported activity changes over time may influence interpretation of observed associations between physical activity and health. We examine the relationships between various physical activities self-reported at different times in a large cohort study of middle-aged UK women. Methods At recruitment, Million Women Study participants completed a baseline questionnaire including questions on frequency of strenuous and of any physical activity. About 3 years later 589,896 women also completed a follow-up questionnaire reporting the hours they spent on a range of specific activities. Time spent on each activity was used to estimate the associated excess metabolic equivalent hours (MET-hours) and this value was compared across categories of physical activity reported at recruitment. Additionally, 18,655 women completed the baseline questionnaire twice, at intervals of up to 4 years; repeatability over time was assessed using the weighted kappa coefficient (κweighted) and absolute percentage agreement. Results The average number of hours per week women reported doing specific activities was 14.0 for housework, 4.5 for walking, 3.0 for gardening, 0.2 for cycling, and 1.4 for all strenuous activity. Time spent and the estimated excess MET-hours associated with each activity increased with increasing frequency of any or strenuous physical activity reported at baseline (tests for trend, P < 0.003), although the associations for housework were by far the weakest (Spearman correlations, 0.01 and -0.03 respectively for housework, and 0.11-0.37 for all other activities). Repeatability of responses to physical activity questions on the baseline questionnaire declined significantly over time. For strenuous activity, absolute agreement was 64% (κweighted = 0.71) for questionnaires administered less than 6 months apart, and 52% (κweighted = 0.51) for questionnaires more than 2 years apart. Corresponding

  3. Development of the Oxford Participation and Activities Questionnaire: constructing an item pool

    PubMed Central

    Kelly, Laura; Jenkinson, Crispin; Dummett, Sarah; Dawson, Jill; Fitzpatrick, Ray; Morley, David

    2015-01-01

    Purpose The Oxford Participation and Activities Questionnaire is a patient-reported outcome measure in development that is grounded on the World Health Organization International Classification of Functioning, Disability, and Health (ICF). The study reported here aimed to inform and generate an item pool for the new measure, which is specifically designed for the assessment of participation and activity in patients experiencing a range of health conditions. Methods Items were informed through in-depth interviews conducted with 37 participants spanning a range of conditions. Interviews aimed to identify how their condition impacted their ability to participate in meaningful activities. Conditions included arthritis, cancer, chronic back pain, diabetes, motor neuron disease, multiple sclerosis, Parkinson’s disease, and spinal cord injury. Transcripts were analyzed using the framework method. Statements relating to ICF themes were recast as questionnaire items and shown for review to an expert panel. Cognitive debrief interviews (n=13) were used to assess items for face and content validity. Results ICF themes relevant to activities and participation in everyday life were explored, and a total of 222 items formed the initial item pool. This item pool was refined by the research team and 28 generic items were mapped onto all nine chapters of the ICF construct, detailing activity and participation. Cognitive interviewing confirmed the questionnaire instructions, items, and response options were acceptable to participants. Conclusion Using a clear conceptual basis to inform item generation, 28 items have been identified as suitable to undergo further psychometric testing. A large-scale postal survey will follow in order to refine the instrument further and to assess its psychometric properties. The final instrument is intended for use in clinical trials and interventions targeted at maintaining or improving activity and participation. PMID:26056503

  4. Assessing Metacognitive Activities: The In-Depth Comparison of a Task-Specific Questionnaire with Think-Aloud Protocols

    ERIC Educational Resources Information Center

    Schellings, Gonny L.; van Hout-Wolters, Bernadette H. A .M.; Veenman, Marcel V. J.; Meijer, Joost

    2013-01-01

    Teaching and assessing metacognitive activities are important educational objectives, and teachers are calling for efficient instruments. The advantages of questionnaires in measuring metacognitive activities are obvious, but serious validity issues appear. For example, correlations of questionnaire data with think-aloud measures are generally…

  5. A self-efficacy questionnaire regarding leisure time physical activity: Psychometric properties among Iranian male adolescents

    PubMed Central

    Abasi, Mohammad Hadi; Eslami, Ahmad Ali; Rakhshani, Fatemeh; Shiri, Mansoor

    2016-01-01

    Background: Attention to different aspects of self-efficacy leads to actual evaluation of self-efficacy about physical activity. This study was carried out in order to design and determine psychometric characteristics of a questionnaire for evaluation of self-efficacy about leisure time physical activity (SELPA) among Iranian adolescent boys, with an emphasis on regulatory self-efficacy. Materials and Methods: This descriptive–analytic study was conducted in 734 male adolescents aged 15–19 years in Isfahan. After item generation and item selection based on review of literature and other questionnaires, content validity index (CVI) and content validity ratio (CVR) were determined and items were modified employing the opinions of expert panel (N = 10). Comprehensibility of the questionnaire was determined by members of target group (N = 35). Exploratory factors analysis (EFA) was operated on sample 1 (N1 = 325) and confirmatory factors analysis (CFA) on sample 2 (N2 = 347). Reliability of SELPA was estimated via internal consistency method. Results: According to EFA, barrier self-efficacy and scheduling self-efficacy are the two main aspects of SELPA with the total variance of 65%. The suggested model was confirmed by CFA and all fitness indices of the corrected model were good. Cronbach's alpha was totally estimated as 0.89 and for barrier and scheduling self-efficacy, it was 0.86 and 0.81, respectively. Conclusions: The results provide some evidence for acceptable validity and reliability of SELPA in Iranian adolescent boys. However, further investigations, especially for evaluation of predictive power of the questionnaire, are necessary. PMID:26985219

  6. Psychometric properties of the Brazilian version of Pfeffer's Functional Activities Questionnaire

    PubMed Central

    Assis, Luciana de Oliveira; de Paula, Jonas J.; Assis, Marcella G.; de Moraes, Edgar N.; Malloy-Diniz, Leandro F.

    2014-01-01

    Pfeffer's Functional Activities Questionnaire (FAQ) is one of the most commonly employed tools in studies on pathological cognitive aging. Despite the different versions of the questionnaire translated for use in clinical practice, few studies have analyzed the psychometric properties of the Brazilian version of the FAQ (P-FAQ). Thus, the aim of the present study was to analyze the P-FAQ with regard to internal consistency, factorial structure and associations with demographic factors (age, sex, and schooling), depressive symptoms, cognitive measures and other measures of functionality. One hundred sixty-one older adults were divided into four groups (91 with dementia, 46 with mild cognitive impairment, 11 with psychiatric disorders and 13 healthy controls). All participants were evaluated by cognitive, behavioral and functional tests and scales. Their caregivers answered the P-FAQ. The questionnaire showed high internal consistency (α = 0.91). Factor analysis revealed a two-factor structure, which, accounted for 66% of the total variance. The P-FAQ was not correlated with demographic factors, was weakly correlated with depressive symptoms (ϱ = 0.271, p < 0.01, R2 = 7%) and strongly correlated with cognitive measures (Matttis Dementia Rating Scale total score: ϱ = −0.574, p < 0.01, R2 = 33%) as well as complex instrumental activities of daily living (ϱ = −0.845, p < 0.01, R2 = 71%). Cognitive performance and depression status were independent predictors of P-FAQ scores in regression models. The present findings indicate that the P-FAQ has satisfactory reliability, internal consistency, construct validity and ecological validity. Therefore, this questionnaire can be used in clinical practice and research involving the Brazilian population of older adults. PMID:25309432

  7. Validity of a food frequency questionnaire to estimate long-chain polyunsaturated fatty acid intake among Japanese women in early and late pregnancy

    PubMed Central

    Kobayashi, Minatsu; Jwa, Seung Chik; Ogawa, Kohei; Morisaki, Naho

    2016-01-01

    Background The relative validity of food frequency questionnaires for estimating long-chain polyunsaturated fatty acid (LC-PUFA) intake among pregnant Japanese women is currently unclear. The aim of this study was to verify the external validity of a food frequency questionnaire, originally developed for non-pregnant adults, to assess the dietary intake of LC-PUFA using dietary records and serum phospholipid levels among Japanese women in early and late pregnancy. Methods A validation study involving 188 participants in early pregnancy and 169 participants in late pregnancy was conducted. Intake LC-PUFA was estimated using a food frequency questionnaire and evaluated using a 3-day dietary record and serum phospholipid concentrations in both early and late pregnancy. Results The food frequency questionnaire provided estimates of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake with higher precision than dietary records in both early and late pregnancy. Significant correlations were observed for LC-PUFA intake estimated using dietary records in both early and late pregnancy, particularly for EPA and DHA (correlation coefficients ranged from 0.34 to 0.40, p < 0.0001). Similarly, high correlations for EPA and DHA in serum phospholipid composition were also observed in both early and late pregnancy (correlation coefficients ranged 0.27 to 0.34, p < 0.0001). Conclusions Our findings suggest that the food frequency questionnaire, which was originally designed for non-pregnant adults and was evaluated in this study against dietary records and biological markers, has good validity for assessing LC-PUFA intake, especially EPA and DHA intake, among Japanese women in early and late pregnancy. PMID:28135195

  8. Development and evaluation of the physical activity questionnaire for elderly Japanese: the Nakanojo study.

    PubMed

    Yasunaga, Akitomo; Park, Hyuntae; Watanabe, Eiji; Togo, Fumiharu; Park, Sungjin; Shephard, Roy J; Aoyagi, Yukitoshi

    2007-10-01

    The Physical Activity Questionnaire for Elderly Japanese (PAQ-EJ) is a self-administered physical activity questionnaire for elderly Japanese; the authors report here on its repeatability and direct and indirect validity. Reliability was assessed by repeat administration after 1 month. Direct validation was based on accelerometer data collected every 4 s for 1 month in 147 individuals age 65-85 years. Indirect validation against a 10-item Barthel index (activities of daily living [ADL]) was completed in 3,084 individuals age 65-99 years. The test-retest coefficient was high (r = .64-.71). Total and subtotal scores for lower (transportation, housework, and labor) and higher intensity activities (exercise/sports) were significantly correlated with step counts and durations of physical activity <3 and >or=3 METs (r = .41, .28, .53), respectively. Controlling for age and ADL, scores for transportation, exercise/sports, and labor were greater in men, but women performed more housework. Sex- and ADL- or age-adjusted PAQ-EJ scores were significantly lower in older and dependent people. PAQ-EJ repeatability and validity seem comparable to those of instruments used in Western epidemiological studies.

  9. 76 FR 8846 - Proposed Information Collection (Disability Benefits Questionnaires-Group 1) Activity: Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    .... Titles: a. Hematologic and Lymphatic Conditions, Including Leukemia Disability Benefits Questionnaire, VA... Cancer and Leukemias) Disability Benefits Questionnaire, VA Form 21-0960O-1. l. Eating...

  10. Reproducibility and Validity of a Food Frequency Questionnaire Designed to Assess Diet in Children Aged 4-5 Years

    PubMed Central

    Vioque, Jesus; Gimenez-Monzo, Daniel; Navarrete-Muñoz, Eva Maria; Garcia-de-la-Hera, Manuela; Gonzalez-Palacios, Sandra; Rebagliato, Marisa; Ballester, Ferran; Murcia, Mario; Iñiguez, Carmen; Granado, Fernando

    2016-01-01

    Background The food frequency questionnaire (FFQ) is the most efficient and cost-effective method to investigate the relationship between usual diet and disease in epidemiologic studies. Although FFQs have been validated in many adult populations worldwide, the number of valid FFQ in preschool children is very scarce. The aim of this study was to evaluate the reproducibility and validity of a semi-quantitative FFQ designed for children aged 4 to 5 years. Materials and methods In this study, we have included 169 children aged 4–5 years from the INMA project in Valencia, a population-based prospective cohort study of mothers and children in Spain. The 105-items FFQ was administered twice to the parents or care-givers of children over a 9-month period. Reproducibility was explored by comparing intake of nutrients by the FFQs, while validity was examined by comparing the nutrient values from the FFQs with the average nutrient values of three 24 hour dietary recall (24hDR) taken in the period, and also, with the concentration in blood specimens for several vitamins (carotenoids, folate, vitamin B12, vitamin C and α-tocopherol). Pearson correlation coefficients and de-attenuated correlation coefficients were calculated and we also evaluated misclassification by quintile distribution. Results All correlation coefficients for reproducibility for nutrients and major food groups were statistically significant; the average correlation coefficients for daily intake were 0.43 for food groups and 0.41 for nutrients. The average correlation coefficients for validity for daily intakes against 24hDR was r = 0.30, and the average for de-attenuated correlation coefficients was r = 0.44. When evaluating validity against the blood concentration of vitamins, statistically significant correlations were observed for vitamin C (0.35), lycopene (0.31), β-Cryptoxantin (0.40), and vitamin E (0.29); the average of correlation coefficients was r = 0.21. Conclusion Despite some low to

  11. Validation of a novel method for retrospectively estimating nutrient intake during pregnancy using a semi-quantitative food frequency questionnaire

    PubMed Central

    Mejía-Rodríguez, Fabiola; Orjuela, Manuela A.; García-Guerra, Armando; Quezada-Sanchez, Amado David; Neufeld, Lynnette M.

    2011-01-01

    Objective Case control studies evaluating the relationship between dietary intake of specific nutrients and risk of congenital, neonatal or early childhood disease require the ability to rank relative maternal dietary intake during pregnancy. Such studies are limited by the lack of validated instruments for assessing gestational dietary intake several years post-partum. This study aims to validate a semi-quantitative interview-administered food frequency questionnaire (FFQ) for retrospectively estimating nutrient intake at two critical time points during pregnancy. Methods The FFQ was administered to women (N=84), who 4 to 6 years earlier had participated in a prospective study to evaluate dietary intake during pregnancy. The FFQ queried participants about intake during the previous month (FFQ-month). This was then used as a reference point to estimate consumption by trimester (FFQ-pregnancy). The resulting data were compared to data collected during the original study from two 24-hour recalls (24hr-original) using Spearman correlation and Wilcoxon sign-rank-test. Results Total energy intake as estimated by the retrospective and original instruments did not differ and was only weakly correlated in the trimesters (1st & 3rd) as a whole (r = 0.18-32), though more strongly correlated when restricted to the first half of the 1st trimester (r=0.32) and later half of the 3rd trimester (r=0.87). After energy adjustment, correlation between the 24hR-original and FFQ-pregnancy in the 3rd trimester were r=0.25 (p<0.05) for dietary intake of vitamin A, and r=0.26 (p<0.05) for folate, and r= 0.23-0.77 (p<0.005) for folate, and vitamins A, B6 and B12 in the 1st and 3rd trimester after including vitamin supplement intake. Conclusions The FFQ-pregnancy provides a consistent estimate of maternal intake of key micronutrients during pregnancy and permits accurate ranking of intake 4-6 years post-partum. PMID:22116778

  12. Relative validity and reproducibility of a food frequency questionnaire to assess dietary fiber intake in Danish adults

    PubMed Central

    Vuholm, Stine; Lorenzen, Janne K.; Kristensen, Mette

    2014-01-01

    Background Differences in habitual dietary fiber intake may modify effects of dietary fiber interventions, thus measurement of habitual dietary fiber intake is relevant to apply in intervention studies on fiber-rich foods, and food frequency questionnaire (FFQ) is a commonly used method. Rye bread is the major contributor of dietary fiber in the Danish population, and a nation-specific FFQ is therefore needed. Objective The aim of this study was to assess the relative validity and reproducibility of a self-administered quantitative FFQ designed to assess total dietary fiber intake among Danish adults. Design In order to assess the relative validity of the FFQ, a total of 125 participants completed both a 7-day weighed dietary recording (DR) and an FFQ consisting of 60 questions. To evaluate the reproducibility of the FFQ, a sub-group of 12 participants subsequently completed an FFQ approximately 6 months later. Results Estimates of mean dietary fiber intake were 24.9±9.8 and 28.1±9.4 g/day when applying the FFQ and DR, respectively, where FFQ estimates were ~12% lower (p<0.001). Pearson's correlation coefficient between the estimated dietary fiber intake of the two methods was r=0.63 (p<0.001), and 62% of the participants were grouped into the same tertile of intake according to the two methods. The estimates of mean dietary intake of first and second FFQ were very similar (22.2±4.0 and 23.3±4.1 g/day, respectively, p=0.42) and showed a correlation of r=0.95 (95% CI 0.83–0.99). Conclusion The developed FFQ showed moderate underestimation of dietary fiber intake (g/day), adequate ranking of subjects according to their dietary fiber intake, and good reproducibility. The FFQ is therefore believed to be a valuable tool for epidemiology and screening in human interventions, where intake of dietary fibers is of specific interest. PMID:25490961

  13. The Self-Presentation Motives for Physical Activity Questionnaire: Instrument Development and Preliminary Construct Validity Evidence.

    PubMed

    Howle, Timothy C; Dimmock, James A; Whipp, Peter R; Jackson, Ben

    2015-06-01

    With the aim of advancing the literature on impression management in physical activity settings, we developed a theoretically derived 2 by 2 instrument that was designed to measure different types of context-specific self-presentation motives. Following item generation and expert review (Study 1), the instrument was completed by 206 group exercise class attendees (Study 2) and 463 high school physical education students (Study 3). Our analyses supported the intended factor structure (i.e., reflecting acquisitive-agentic, acquisitive-communal, protective-agentic, and protective-communal motives). We found some support for construct validity, and the self-presentation motives were associated with variables of theoretical and applied interest (e.g., impression motivation and construction, social anxiety, social and achievement goals, efficacy beliefs, engagement). Taken together, the results indicate that the Self-presentation Motives for Physical Activity Questionnaire (SMPAQ) may be useful for measuring various types of self-presentation motives in physical activity settings.

  14. Measuring and validating physical activity and sedentary behavior comparing a parental questionnaire to accelerometer data and diaries.

    PubMed

    Bringolf-Isler, Bettina; Mäder, Urs; Ruch, Nicole; Kriemler, Susi; Grize, Leticia; Braun-Fahrländer, Charlotte

    2012-05-01

    Accurately measuring children's physical activity and their sedentary behavior is challenging. The present study compared 189 parental responses to a questionnaire surveying physical activity and sedentary behavior of children aged 6-14 years, to accelerometer outputs and time activity diaries for the same group. Responses were analyzed taking age, sex and maternal education into account. Correlation coefficients between questionnaire reports and accelerometer-based physical activity across all age groups were acceptable (up to r = .55). Yet, adjustment for age markedly attenuated these associations, suggesting concomitant influences of biological and behavioral processes linked to age. The comparisons of general time indications in the questionnaire with 24h-diary records suggested that parents tended to under- and over-report single activities, possibly due to social desirability. We conclude that physical activity questionnaires need to be designed for specific age groups and be administered in combination with objective measurements.

  15. 76 FR 33417 - Agency Information Collection (Disability Benefits Questionnaires-Group 2) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... Questionnaire, VA Form 21-0960A-4. d. Diabetic Peripheral Neuropathy (Diabetic Sensory-Motor Peripheral.... Flatfoot (PES PLANUS) Disability Benefits Questionnaire, VA Form 21-0960M-5. l. Foot Miscellaneous...

  16. Physical activity parenting: A systematic review of questionnaires and their associations with child activity levels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Insufficient physical activity (PA) is considered a critical contributor to childhood overweight. Parents are a key in influencing their child's PA through various mechanisms of PA parenting, including support, restriction of PA, and facilitation of enrollment in PA classes or activities. However, s...

  17. Psychometric properties of the 7-Day Physical Activity Recall questionnaire in individuals with severe mental illness.

    PubMed

    Soundy, Andy; Taylor, Adrian; Faulkner, Guy; Rowlands, Ann

    2007-12-01

    Few self-report measures of physical activity have been validated in individuals with severe mental illness. The purpose of this study was to examine the validity and reliability of a 7-day recall measure (7DR: [Blair, S. N. (1984). How to assess exercise habits and physical fitness. In J. D. Matarazzo, N. E. Miller, & S. M. Weiss, (Eds.), Behavioural health: A handbook of health enhancement and disease prevention (pp. 424-447). New York: Wiley.]) through comparison with RT3 triaxial accelerometry data. Fourteen individuals took part in the study. Validity was considered by Kendall's tau correlation and (Bland, J. M., & Altman, D. G. (1986). Statistical-methods for assessing agreement between 2 methods of clinical measurement. Lancet, 1(8476), 307-310) limits of agreement and test-retest reliability was measured by ICC. The only significant correlation between measures was total energy expenditure (tau = 0.43). The 7-DR over reported moderate physical activity by 16.9 +/- 52.3 min/day, but under reported vigorous physical activity by -10.4 +/- 24.3 min/day. Test retest ICC was significant for all outcome measures. Overall, the 7-DR was reliable but exhibited questionable validity. The use of self-report questionnaires such as the 7-DR may inaccurately estimate the levels of physical activity in this population, and may not be sensitive to monitoring intervention-related changes in physical activity.

  18. Test-retest reliability of a questionnaire to assess physical environmental factors pertaining to physical activity

    PubMed Central

    Evenson, Kelly R; McGinn, Aileen P

    2005-01-01

    Background Despite the documented benefits of physical activity, many adults do not obtain the recommended amounts. Barriers to physical activity occur at multiple levels, including at the individual, interpersonal, and environmental levels. Only until more recently has there been a concerted focus on how the physical environment might affect physical activity behavior. With this new area of study, self-report measures should be psychometrically tested before use in research studies. Therefore the objective of this study was to document the test-retest reliability of a questionnaire designed to assess physical environmental factors that might be associated with physical activity in a diverse adult population. Methods Test and retest surveys were conducted over the telephone with 106 African American and White women and men living in either Forsyth County, North Carolina or Jackson, Mississippi. Reliability of self-reported environmental factors across four domains (e.g., access to facilities and destinations, functionality and safety, aesthetics, natural environment) was determined using intraclass correlation coefficients (ICC) overall and separately by gender and race. Results Generally items displayed moderate and sometimes substantial reliability (ICC between 0.4 to 0.8), with a few differences by gender or race, across each of the domains. Conclusion This study provides some psychometric evidence for the use of many of these questions in studies examining the effect of self-reported physical environmental measures on physical activity behaviors, among African American and White women and men. PMID:15958168

  19. Validation of the SQUASH Physical Activity Questionnaire in a Multi-Ethnic Population: The HELIUS Study

    PubMed Central

    Gademan, M. G. J.; Snijder, M. B.; Engelbert, R. H. H.; Dijkshoorn, H.; Terwee, C. B.; Stronks, K.

    2016-01-01

    Purpose To investigate the reliability and validity of the SQUASH physical activity (PA) questionnaire in a multi-ethnic population living in the Netherlands. Methods We included participants from the HELIUS study, a population-based cohort study. In this study we included Dutch (n = 114), Turkish (n = 88), Moroccan (n = 74), South-Asian Surinamese (n = 98) and African Surinamese (n = 91) adults, aged 18–70 years. The SQUASH was self-administered twice to assess test-re-test reliability (mean interval 6–7 weeks) and participants wore an accelerometer and heart rate monitor (Actiheart) to enable assessment of construct validity. Results We observed low test-re-test reliability; Intra class correlation coefficients ranged from low (0.05 for moderate/high intensity PA in African Surinamese women) to acceptable (0.78 for light intensity PA in Moroccan women). The discrepancy between self-reported and measured PA differed on the basis of the intensity of activity: self-reported light intensity PA was lower than measured but self-reported moderate/high intensity PA was higher than measured, with wide limits of agreement. The discrepancy between questionnaire and Actiheart measures of moderate intensity PA did not differ between ethnic minority and Dutch participants with correction for relevant confounders. Additionally, the SQUASH overestimated the number of participants meeting the Dutch PA norm; Cohen’s kappas for the agreement were poor, the highest being 0.30 in Dutch women. Conclusion We found considerable variation in the test-re-test reliability and validity of self-reported PA with no consistency based on ethnic origin. Our findings imply that the SQUASH does not provide a valid basis for comparison of PA between ethnic groups. PMID:27575490

  20. Assessing Adult Leisure Activities: An Extension of a Self-Report Activity Questionnaire

    ERIC Educational Resources Information Center

    Jopp, Daniela S.; Hertzog, Christopher

    2010-01-01

    Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value, as they can inform diagnosis and interventions. In the present study, the authors enhanced…

  1. 76 FR 61149 - Agency Information Collection (Disability Benefits Questionnaires-Group 4) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... Form 21- 0960-I-5. Urinary Tract (including Bladder & Urethra) Conditions (excluding Male Reproductive System) Disability Benefits Questionnaire, VA Form 21- 0960-J-4. Respiratory Conditions (other...

  2. Dissecting gamma frequency activity during human memory processing.

    PubMed

    Kucewicz, Michal T; Berry, Brent M; Kremen, Vaclav; Brinkmann, Benjamin H; Sperling, Michael R; Jobst, Barbara C; Gross, Robert E; Lega, Bradley; Sheth, Sameer A; Stein, Joel M; Das, Sandthitsu R; Gorniak, Richard; Stead, S Matthew; Rizzuto, Daniel S; Kahana, Michael J; Worrell, Gregory A

    2017-03-13

    Gamma frequency activity (30-150 Hz) is induced in cognitive tasks and is thought to reflect underlying neural processes. Gamma frequency activity can be recorded directly from the human brain using intracranial electrodes implanted in patients undergoing treatment for drug-resistant epilepsy. Previous studies have independently explored narrowband oscillations in the local field potential and broadband power increases. It is not clear, however, which processes contribute to human brain gamma frequency activity, or their dynamics and roles during memory processing. Here a large dataset of intracranial recordings obtained during encoding of words from 101 patients was used to detect, characterize and compare induced gamma frequency activity events. Individual bursts of gamma frequency activity were isolated in the time-frequency domain to determine their spectral features, including peak frequency, amplitude, frequency span, and duration. We found two distinct types of gamma frequency activity events that showed either narrowband or broadband frequency spans revealing characteristic spectral properties. Narrowband events, the predominant type, were induced by word presentations following an initial induction of broadband events, which were temporally separated and selectively correlated with evoked response potentials, suggesting that they reflect different neural activities and play different roles during memory encoding. The two gamma frequency activity types were differentially modulated during encoding of subsequently recalled and forgotten words. In conclusion, we found evidence for two distinct activity types induced in the gamma frequency range during cognitive processing. Separating these two gamma frequency activity components contributes to the current understanding of electrophysiological biomarkers, and may prove useful for emerging neurotechnologies targeting, mapping and modulating distinct neurophysiological processes in normal and epileptogenic brain.

  3. Frequency dispersion of electrokinetically activated Janus particles

    NASA Astrophysics Data System (ADS)

    Boymelgreen, Alicia; Balli, Tov; Yossifon, Gilad; Miloh, Touvia

    2015-11-01

    We examine the influence of the applied frequency of the electric field on the induced-charge electroosmotic flow around a metallo-dielectric Janus particle. Previously, we have used three dimensional-two component micro-particle-image-velocimetry (3D-2C μ PIV) around a stagnant particle, to illustrate the presence of a number of competing effects including dielectrophoresis and electrohydrodynamic flow which distort both the strength and shape of the frequency dispersion predicted for pure induced-charge effects. Here, we extend this work by examining the frequency dispersion of mobile Janus particles of different sizes (3 - 15 μm in diameter) at different electrolyte concentrations. In all cases, towards the DC limit, and in the frequency domain where previously EHD flow was shown to dominate, the velocity of a mobile particle decays to zero. At the same time significant variations in the frequency dispersion, including its shape and the value for maximum velocity are recorded as a function of both electrolyte concentration and particle size. This work is of both fundamental and practical importance and may be used to further refine non-linear electrokinetic theory and optimize the application of Janus particles as carriers in lab-on-a-chip analysis systems.

  4. The 'Technology - Activities of Daily Living Questionnaire': a version with a technology-related subscale

    PubMed Central

    Muñoz-Neira, Carlos; López, Oscar L.; Riveros, Rodrigo; Nuñez-Huasaf, Javier; Flores, Patricia; Slachevsky, Andrea

    2016-01-01

    Background Information and communication technology (ICT) has become an increasingly important part of daily life. The ability to use technology is becoming essential for autonomous functioning in society. Current functional scales for patients with cognitive impairment do not evaluate the use of technology. The objective of this study was to develop and validate a new version of the Activities of Daily Living Questionnaire (ADLQ) that incorporates an ICT subscale. Method A new technology-based subscale was incorporated into the Spanish Version of the ADLQ (SV-ADLQ), entitled The Technology Version of the ADLQ (T-ADLQ). The T-ADLQ was administered to 63 caregivers of dementia patients, 21 proxies of mild cognitive impairment patients and 44 proxies of normal elderly subjects (mean age of the sample ± SD: 73.5 ± 8.30). We analysed the convergent validity, internal consistency, reliability cut-off point, sensitivity and specificity of the T-ADLQ. The results of the T-ADLQ were compared to the SV-ADLQ. Results The T-ADLQ showed significant correlations with the Mini-mental Test (MMSE), the Frontal Assesment Battery (FAB) as well as other measures of functional impairment and dementia severity (MMSE: r = −0.70; FAB: r = −0.65; Functional Assessment Questionnaire: r = 0.77; Instrumental Activities of Daily Living Scale: r = −0.75; Clinical Dementia Rating Scale: r = 0.72; p<0.001). The T-ADLQ showed a good reliability with a relatively high Cronbach’s alpha coefficient (Cronbach’s alpha = 0.861). When considering a functional impairment cut-off point greater than 29.25%, the sensitivity and specificity of the T-ADLQ were 82% and 90%, respectively. The area under the ROC curve (AUC) was 0.937 for the T-ADLQ and 0.932 for the original version of the test. Conclusions The T-ADLQ revealed adequate indicators of validity and reliability for the functional assessment of activities of daily living in dementia patients. However, the inclusion of technology items in

  5. Accelerometer-Determined Physical Activity and Its Comparison with the International Physical Activity Questionnaire in a Sample of Nigerian Adults

    PubMed Central

    Oyeyemi, Adewale L.; Umar, Maimuna; Oguche, Friday; Aliyu, Salamatu U.; Oyeyemi, Adetoyeje Y.

    2014-01-01

    Introduction Accurate assessment of physical activity to identify current levels and changes within the population is dependent on the precision of the measurement tools. The aim of this study was to compare components of physical activity measured with an adapted version of the International Physical Activity Questionnaire (Hausa IPAQ-SF) and the accelerometer in a sample of Nigeria adults. Methods One hundred and forty-four participants (Mean age = 32.6±9.9 years, 40.3% women) in a cross-sectional study wore an accelerometer for seven consecutive days and completed the Hausa IPAQ-SF questionnaire on the eighth day. Total physical activity, time spent in moderate-to-vigorous activity (MVPA) and sedentary time assessed by Hausa IPAQ-SF and accelerometer were compared. The absolute and criterion- related validity of the Hausa IPAQ-SF was assessed by Bland-Altman analysis and Spearman Correlation Coefficients, respectively. Specificity and sensitivity were calculated to classify individuals according to the global standard guideline for sufficient physical activity. Results Compared with the accelerometer, higher time in MVPA and total physical activity were reported on the Hausa IPAQ-SF (p<0.001), while low to moderate correlations (Rs = 0.03–0.38) were found between the two methods. The 95% limits of agreement were wide between methods for total physical activity (−23019 to 20375 METmin.d−1) and sedentary time (−510 to 150 min.d−1). The sensitivity (76.2%) of Hausa IPAQ-SF to identify insufficiently active people was good, but its specificity (33.3%) to correctly classify sufficiently active people was low. Conclusions The Hausa IPAQ-SF overestimated components of physical activity among Nigerian adults, and demonstrated poor to moderate evidence of absolute and criterion validity. Further evaluation of IPAQ and other self-report physical activity instruments in other Africa populations could enhance accurate evaluation of physical activity data

  6. Measuring physical activity-related environmental factors: reliability and predictive validity of the European environmental questionnaire ALPHA

    PubMed Central

    2010-01-01

    Background A questionnaire to assess physical activity related environmental factors in the European population (a 49-item and an 11-item version) was created as part of the framework of the EU-funded project "Instruments for Assessing Levels of PHysical Activity and fitness (ALPHA)". This paper reports on the development and assessment of the questionnaire's test-retest stability, predictive validity, and applicability to European adults. Methods The first pilot test was conducted in Belgium, France and the UK. In total 190 adults completed both forms of the ALPHA questionnaire twice with a one-week interval. Physical activity was concurrently measured (i) by administration of the long version of the International Physical Activity Questionnaire (IPAQ) by interview and (ii) by accelerometry (Actigraph™ device). After adaptations, the second field test took place in Belgium, the UK and Austria; 166 adults completed the adapted questionnaire at two time points, with minimum one-week interval. In both field studies intraclass correlation coefficients (ICC) and proportion of agreement were computed to assess the stability of the two test scores. Predictive validity was examined in the first field test by correlating the results of the questionnaires with physical activity data from accelerometry and long IPAQ-last 7 days. Results The reliability scores of the ALPHA questionnaire were moderate-to good in the first field testing (ICC range 0.66 - 0.86) and good in the second field testing (ICC range 0.71 - 0.87). The proportion of agreement for the ALPHA short increased significantly from the first (range 50 - 83%) to the second field testing (range 85 - 95%). Environmental scales from both versions of the ALPHA questionnaire were significantly associated with self-reported minutes of transport-related walking, and objectively measured low intensity physical activity levels, particularly in women. Both versions were easily administered with an average completion time

  7. Reliability of questionnaires to assess the healthy eating and activity environment of a child's home and school.

    PubMed

    Wilson, Annabelle; Magarey, Anthea; Mastersson, Nadia

    2013-01-01

    Childhood overweight and obesity are a growing concern globally, and environments, including the home and school, can contribute to this epidemic. This paper assesses the reliability of two questionnaires (parent and teacher) used in the evaluation of a community-based childhood obesity prevention intervention, the eat well be active (ewba) Community Programs. Parents and teachers were recruited from two primary schools and they completed the same questionnaire twice in 2008 and 2009. Data from both questionnaires were classified into outcomes relevant to healthy eating and activity, and target outcomes, based on the goals of the ewba Community Programs, were identified. Fourteen and 12 outcomes were developed from the parent and teacher questionnaires, respectively. Sixty parents and 28 teachers participated in the reliability study. Intraclass correlation coefficients for outcomes ranged from 0.37 to 0.92 (parent) (P < 0.05) and from 0.42 to 0.86 (teacher) (P < 0.05). Internal consistency, measured by Cronbach's alpha, of teacher scores ranged from 0.11 to 0.91 and 0.13 to 0.78 for scores from the parent questionnaire. The parent and teacher questionnaires are moderately reliable tools for simultaneously assessing child intakes, environments, attitudes, and knowledge associated with healthy eating and physical activity in the home and school and may be useful for evaluation of similar programs.

  8. 78 FR 35661 - Proposed Information Collection (Disability Benefits Questionnaires) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-13

    .... Hairy Cell and Other B-Cell Leukemias Disability Benefits Questionnaire, VA Form 21-0960b-1. c... exposure: Hairy Cell and ] Other Chronic B-cell Leukemias, Parkinson's and Ischemic Heart diseases.... Hairy Cell and Other B-Cell Leukemias Disability Benefits Questionnaire, VA Form 21-0960b-1-500....

  9. 75 FR 60170 - Proposed Information Collection (Disability Benefits Questionnaires) Activity: Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-29

    ...-0960a-1. b. Hairy Cell and Other B-Cell Leukemias Disability Benefits Questionnaire, VA Form 21-0960b-1... on herbicide exposure: Hairy Cell and Other Chronic B-cell Leukemias, Parkinson's and Ischemic Heart...,750. b. Hairy Cell and Other B-Cell Leukemias Disability Benefits Questionnaire, VA Form...

  10. 75 FR 76081 - Agency Information Collection (Disability Benefits Questionnaires) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    .... Hairy Cell and Other B-Cell Leukemias Disability Benefits Questionnaire, VA Form 21-0960b-1. c... exposure: Hairy Cell and Other Chronic B-cell Leukemias, Parkinson's and Ischemic Heart diseases. Veterans... Form 21-0960a-1--13,750. b. Hairy Cell and Other B-Cell Leukemias Disability Benefits Questionnaire,...

  11. Development of the parents' perception of their involvement in their child's tennis activity questionnaire (Q-PPICTA).

    PubMed

    Hurtel, V; Lacassagne, M-F

    2013-08-01

    The purpose of this study was to develop and validate a questionnaire for assessing parents' perception of their involvement in their children's tennis activity (Q-PPICTA). The validation required four successive studies. In study 1, a preliminary version of the questionnaire was formulated after selecting and adapting items taken from existing questionnaires and interviews conducted with the parents of 36 young tennis players. Three factors for measuring parental involvement in sport were identified and retained: emotional, logistic, and informational supports. In study 2, exploratory factor analyses were performed on data collected from 214 parents of tennis players. Results attested the questionnaire's three-factor structure and ascertained its internal consistency. In study 3, a confirmatory factor analysis as well as tests on convergent and discriminant validity were carried out on data gathered from a different sample of 220 parents of tennis players. Statistics confirmed the questionnaire's three-factor structure and reliability. In study 4, the questionnaire's external construct validity was compared with another sample consisting of 192 parents and their children. Overall, results underlined satisfactory psychometric properties for the Q-PPICTA. Nevertheless, further studies are required to confirm the questionnaire's accuracy, reliability, and temporal validity.

  12. The effect of dietary estimates calculated using food frequency questionnaires on micronuclei formation in European pregnant women: a NewGeneris study.

    PubMed

    Vande Loock, Kim; Botsivali, Maria; Zangogianni, Marina; Anderson, Diana; Baumgartner, Adolph; Fthenou, Eleni; Chatzi, Leda; Marcos, Ricard; Agramunt, Sylvia; Namork, Ellen; Granum, Berit; Knudsen, Lisbeth E; Nielssen, Jeanette K S; Meltzer, Helle Margrete; Haugen, Margaretha; Kyrtopoulos, Soterios A; Decordier, Ilse; Plas, Gina; Roelants, Mathieu; Merlo, Franco; Kleinjans, Jos; Kogevinas, Manolis; Kirsch-Volders, Micheline

    2014-11-01

    The use of biomarkers of early genetic effects, predictive for cancer, such as micronuclei (MN) in lymphocytes, may help to investigate the association between diet and cancer. We hypothesised that the presence of mutagens in the diet may increase MN formation. A 'pooled' standardised analysis was performed by applying the same experimental protocol for the cytokinesis block micronucleus assay in 625 young healthy women after delivery from five European study populations (Greece, Denmark, UK, Spain and Norway). We assessed MN frequencies in mono- and binucleated T-lymphocytes (MNMONO and MNBN) and the cytokinesis blocked proliferation index using a semi-automated image analysis system. Food frequency questionnaires (FFQs) were used to estimate intake of fatty acids and a broad range of immunotoxic and genotoxic/carcinogenic compounds through the diet. Pooled difference based on delivery type revealed higher MNMONO frequencies in caesarean than in vaginal delivery (P = 0.002). Statistical analysis showed a decrease in MNMONO frequencies with increasing calculated omega-6 PUFA concentrations and a decrease in MNBN frequencies with increasing calculated omega-3 PUFA concentrations. The expected toxic compounds estimated by FFQs were not associated with MN formation in mothers after delivery. In pregnant women, an omega-3 and -6 rich diet estimated by FFQ is associated with lower MN formation during pregnancy and delivery.

  13. Assessing Activity Limitations in Patients with Neuromuscular Diseases: Is the ACTIVLIM Questionnaire Linked to ICF and ICF-CY?

    ERIC Educational Resources Information Center

    Raggi, Alberto; Leonardi, Matilde

    2009-01-01

    The objective of this study was to explore to what extent the ACTIVLIM questionnaire, designed to evaluate limitations in activities involving upper and lower limbs in adults and children with neuromuscular diseases, is linked to the domains of the Activities and Participation of the International Classification of Functioning, Disability and…

  14. A systematic review of reliability and objective criterion-related validity of physical activity questionnaires

    PubMed Central

    2012-01-01

    Physical inactivity is one of the four leading risk factors for global mortality. Accurate measurement of physical activity (PA) and in particular by physical activity questionnaires (PAQs) remains a challenge. The aim of this paper is to provide an updated systematic review of the reliability and validity characteristics of existing and more recently developed PAQs and to quantitatively compare the performance between existing and newly developed PAQs. A literature search of electronic databases was performed for studies assessing reliability and validity data of PAQs using an objective criterion measurement of PA between January 1997 and December 2011. Articles meeting the inclusion criteria were screened and data were extracted to provide a systematic overview of measurement properties. Due to differences in reported outcomes and criterion methods a quantitative meta-analysis was not possible. In total, 31 studies testing 34 newly developed PAQs, and 65 studies examining 96 existing PAQs were included. Very few PAQs showed good results on both reliability and validity. Median reliability correlation coefficients were 0.62–0.71 for existing, and 0.74–0.76 for new PAQs. Median validity coefficients ranged from 0.30–0.39 for existing, and from 0.25–0.41 for new PAQs. Although the majority of PAQs appear to have acceptable reliability, the validity is moderate at best. Newly developed PAQs do not appear to perform substantially better than existing PAQs in terms of reliability and validity. Future PAQ studies should include measures of absolute validity and the error structure of the instrument. PMID:22938557

  15. Validation of an Online Food Frequency Questionnaire against Doubly Labelled Water and 24 h Dietary Recalls in Pre-School Children

    PubMed Central

    Delisle Nyström, Christine; Henriksson, Hanna; Alexandrou, Christina; Bergström, Anna; Bonn, Stephanie; Bälter, Katarina; Löf, Marie

    2017-01-01

    The development of easy-to-use and accurate methods to assess the intake of energy, foods and nutrients in pre-school children is needed. KidMeal-Q is an online food frequency questionnaire developed for the LifeGene prospective cohort study in Sweden. The aims of this study were to compare: (i) energy intake (EI) obtained using KidMeal-Q to total energy expenditure (TEE) measured via doubly labelled water and (ii) the intake of certain foods measured using KidMeal-Q to intakes acquired by means of 24 h dietary recalls in 38 children aged 5.5 years. The mean EI calculated using KidMeal-Q was statistically different (p < 0.001) from TEE (4670 ± 1430 kJ/24 h and 6070 ± 690 kJ/24 h, respectively). Significant correlations were observed for vegetables, fruit juice and candy between KidMeal-Q and 24 h dietary recalls. Only sweetened beverage consumption was significantly different in mean intake (p < 0.001), as measured by KidMeal-Q and 24 h dietary recalls. In conclusion, KidMeal-Q had a relatively short answering time and comparative validity to other food frequency questionnaires. However, its accuracy needs to be improved before it can be used in studies in pre-school children. PMID:28098765

  16. 76 FR 16478 - Proposed Information Collection (Disability Benefits Questionnaires-Group 2) Activity: Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... Form 21-0960A-4. d. Diabetic Peripheral Neuropathy (Diabetic Sensory-Motor Peripheral Neuropathy.... Flatfoot (PES PLANUS) Disability Benefits Questionnaire, VA Form 21-0960M-5. l. Foot Miscellaneous...

  17. 76 FR 35950 - Agency Information Collection (Disability Benefits Questionnaires-Group 3) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    .... Breast Conditions and Disorders Disability Benefits Questionnaire, VA Form 21-0960K-1. m. Gynecological.... Osteomyelitis Disability Benefits Questionnaire, VA Form 21- 0960M-11. q. Ear Conditions (Including Vestibular.... n. VA Form 21-0960L-2--1,250. o. VA Form 21-0960M-3--25,000. p. VA Form 21-0960M-11--10,000. q....

  18. Validity of the Physical Activity Questionnaires IPAQ-SF and GPAQ for Cancer Survivors: Insights from a Spanish Cohort.

    PubMed

    Ruiz-Casado, A; Alejo, L B; Santos-Lozano, A; Soria, A; Ortega, M J; Pagola, I; Fiuza-Luces, C; Palomo, I; Garatachea, N; Cebolla, H; Lucia, A

    2016-11-01

    Regular physical activity (PA) decreases mortality risk in survivors of breast and colorectal cancer. Such impacts of exercise have prompted initiatives designed both to promote and adequately monitor PA in cancer survivors. This study examines the validity of 2 widely used self-report methods for PA determination, the International Physical Activity Questionnaire short version (IPAQ-SF) and Global Physical Activity Questionnaire (GPAQ). Both instruments were compared with the triaxial accelerometry (Actigraph) method as an objective reference standard. Study participants were 204 cancer survivors (both sexes, aged 18-79 years). Compared with accelerometry, both questionnaires significantly overestimated PA levels (across all intensities) and underestimated physical inactivity levels. No differences were detected between the 2 questionnaires except for a shorter inactivity time estimated by GPAQ (p=0.001). The Bland and Altman method confirmed that both questionnaires overestimated all PA levels. Receiver operating characteristic (ROC) analysis classified IPAQ and GPAQ as fair and poor predictors, respectively, of the proportions of survivors fulfilling international PA recommendations (≥150 min·week(-1) of moderate-vigorous PA). IPAQ-SF showed a higher sensitivity but lower specificity than GPAQ. Our data do not support the use of IPAQ-SF or GPAQ to determine PA or inactivity levels in cancer survivors.

  19. Validity and Reproducibility of a Dietary Questionnaire for Consumption Frequencies of Foods during Pregnancy in the Born in Guangzhou Cohort Study (BIGCS)

    PubMed Central

    Yuan, Ming-Yang; He, Jian-Rong; Chen, Nian-Nian; Lu, Jin-Hua; Shen, Song-Ying; Xiao, Wan-Qing; Hu, Fang; Xiao, Hui-Yun; Wu, Yan-Yan; Xia, Xiao-Yan; Liu, Yu; Qiu, Lan; Wu, Ying-Fang; Hu, Cui-Yue; Xia, Hui-Min; Qiu, Xiu

    2016-01-01

    This study aimed to examine the reproducibility and validity of a new food frequency questionnaire (FFQ) used in a birth cohort study to estimate the usual consumption frequencies of foods during pregnancy. The reference measure was the average of three inconsecutive 24 h diet recalls (24 HR) administrated between two FFQs, and the reproducibility was measured by repeating the first FFQ (FFQ1) approximately eight weeks later (FFQ2). A total of 210 pregnant women from the Born in Guangzhou Cohort Study (BIGCS) with full data were included in the analysis. The Spearman’s correlation coefficients of FFQ1 and FFQ2 ranged from 0.33 to 0.71. The intraclass correlation coefficients of the two FFQs ranged from 0.22 to 0.71. The Spearman’s correlation coefficients of the 24 HR and FFQ2 ranged from 0.23 to 0.62. Cross-classification analysis showed 65.1% of participants were classified into same and contiguous quintiles, while only 3.2% were misclassified into the distant quintiles. Bland-Altman methods showed good agreement for most food groups across the range of frequencies between FFQ1 and FFQ2. Our findings indicated that the reproducibility and validity of the FFQ used in BIGCS for assessing the usual consumption frequencies of foods during pregnancy were acceptable. PMID:27483304

  20. Introducing an Outcome Expectation Questionnaire and Its Psychometric Properties Regarding Leisure Time Physical Activity for Iranian Male Adolescent

    PubMed Central

    Abasi, Mohammad Hadi; Eslami, Ahmad Ali; Rakhshani, Fatemeh

    2015-01-01

    Background: Outcome expectation (OE) is known as a psychosocial determinant of leisure time physical activity (LTPA). Despite importance of this construct evaluation, there is no evidence of special questionnaire for measuring OE in Persian speaking Iranian male adolescents. Objectives: This article reports development and psychometric evaluation process of a specific questionnaire that evaluates OE about LTPA among Iranian male adolescents. Materials and Methods: Literature review and group discussions were used to select 26 items of this questionnaire based on 3 dimensions of OE (self-evaluation, social expectancy, and physical expectancy). All Participants (n = 720) were divided into two groups randomly after evaluating comprehensibility, face and content validity, and items analysis. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were separately operated on one of these groups for evaluation of the construct validity of questionnaire. The reliability of the questionnaire was estimated by the Cronbach α. Results: EFA extracted 3 main factors explained 45.80%, 10.31%, and 7.51% of OE variance, respectively. Almost all fit indexes in CFA were acceptable (CMIN = 107.39, CMIN/DF = 2.619, CFI = 0.938, PCFI = 0.699, RMSEA = 0.067, PCLOSE = 0.034). Finally 11 items remained in the questionnaire, which showed excellent reliability on main study (α = 0.85). Conclusions: This study provided evidence regarding the reliability and validity of the Iranian male adolescent outcome expectation about leisure time physical activity (IMAO-PAC) and illustrated that this new questionnaire can be used to measure the perceived exercise benefits among target group in observational and interventional studies. PMID:26082851

  1. Validation of a simplified food frequency questionnaire for the assessment of dietary habits in Iranian adults: Isfahan Healthy Heart Program, Iran

    PubMed Central

    Mohammadifard, Noushin; Sajjadi, Firouzeh; Maghroun, Maryam; Alikhasi, Hassan; Nilforoushzadeh, Farzaneh; Sarrafzadegan, Nizal

    2015-01-01

    BACKGROUND Dietary assessment is the first step of dietary modification in community-based interventional programs. This study was performed to validate a simple food frequency questionnaire (SFFQ) for assessment of selected food items in epidemiological studies with a large sample size as well as community trails. METHODS This validation study was carried out on 264 healthy adults aged ≥ 41 years old living in 3 district central of Iran, including Isfahan, Najafabad, and Arak. Selected food intakes were assessed using a 48-item food frequency questionnaire (FFQ). The FFQ was interviewer-administered, which was completed twice; at the beginning of the study and 2 weeks thereafter. The validity of this SFFQ was examined compared to estimated amount by single 24 h dietary recall and 2 days dietary record. Validation of the FFQ was determined using Spearman correlation coefficients between daily frequency consumption of food groups as assessed by the FFQ and the qualitative amount of daily food groups intake accessed by dietary reference method was applied to evaluate validity. Intraclass correlation coefficients (ICC) were used to determine the reproducibility. RESULTS Spearman correlation coefficient between the estimated amount of food groups intake by examined and reference methods ranged from 0.105 (P = 0.378) in pickles to 0.48 (P < 0.001) in plant protein. ICC for reproducibility of FFQ were between 0.47-0.69 in different food groups (P < 0.001). CONCLUSION The designed SFFQ has a good relative validity and reproducibility for assessment of selected food groups intake. Thus, it can serve as a valid tool in epidemiological studies and clinical trial with large participants. PMID:26405443

  2. Nutrition and Physical Activity Knowledge Assessment: Development of Questionnaires and Evaluation of Reliability in African American and Latino Children

    ERIC Educational Resources Information Center

    Roberts, Lindsay S.; Sharma, Sushma; Hudes, Mark L.; Fleming, Sharon E.

    2012-01-01

    Background: African-American and Latino children living in neighborhoods with a low-socioeconomic index are more at risk of obesity-associated metabolic disease than their higher socioeconomic index and/or white peers. Currently, consistent and reliable questionnaires to evaluate nutrition and physical activity knowledge in these children are…

  3. Construct Validation of Physical Activity Surveys in Culturally Diverse Older Adults: A Comparison of Four Commonly Used Questionnaires

    ERIC Educational Resources Information Center

    Moore, Delilah S.; Ellis, Rebecca; Allen, Priscilla D.; Cherry, Katie E.; Monroe, Pamela A.; O'Neil, Carol E.; Wood, Robert H.

    2008-01-01

    The purpose of this study was to establish validity evidence of four physical activity (PA) questionnaires in culturally diverse older adults by comparing self-report PA with performance-based physical function. Participants were 54 older adults who completed the Continuous Scale Physical Functional Performance 10-item Test (CS-PFP10), Physical…

  4. The patient-specific functional scale is more responsive than the Roland Morris disability questionnaire when activity limitation is low.

    PubMed

    Hall, Amanda M; Maher, Chris G; Latimer, Jane; Ferreira, Manuela L; Costa, Leonardo O P

    2011-01-01

    The primary objective of this study was to determine which questionnaire, the Roland Morris disability questionnaire (RMDQ) or the patient-specific functional scale (PSFS), was better at detecting change in activity limitation in a large cohort of patients with low back pain undergoing rehabilitation. A secondary aim was to determine if the responsiveness of the questionnaires was influenced by the patient's level of activity limitation at baseline. Responsiveness statistics, including effect size statistics, Pearson's r correlations and receiver operative characteristic (ROC) curve analysis were used to determine ability to detect change in activity limitation on 831 patients with low back pain. Data were analysed at two time points; directly after treatment (termed short-term) and several weeks post-treatment (termed mid-term). The data were subsequently re-analysed on sub-sets of the full cohort according to the level of activity limitation from RMDQ baseline scores. In the total cohort we found that the PSFS was more responsive than the RMDQ; however, in the subgroup with high activity limitation this pattern was not observed. This is true for time points up to 6 months post-treatment. In conclusion, the RMDQ and PSFS both demonstrate good responsiveness according to the definitions given in previous guidelines. The PSFS is more responsive than the RMDQ for patients with low levels of activity limitation but not for patients with high levels of activity limitation.

  5. 76 FR 80965 - Agency Information Collection Activities; Proposed collection: Applicant Questionnaire: Race...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-27

    ... Questionnaire: Race, National Origin, Gender, and Disability Demographics; Revision of a Currently Approved...: Race, National Origin, Gender and Disability Demographics (3) The agency form number, if any, and the... information on race, national origin, gender and disability of an applicant/or employee in accordance with...

  6. Development, relative validity, and reliability of a food frequency questionnaire for a case-control study on dietary advanced glycation end products and diabetes complications.

    PubMed

    Luevano-Contreras, Claudia; Durkin, Taylor; Pauls, Maria; Chapman-Novakofski, Karen

    2013-12-01

    Dietary advanced glycation end products (dAGEs) could be involved on diabetes complications, yet their quantification is not standardized. The objective of this study was to design a food frequency questionnaire (FFQ) for dAGEs, and to assess its reliability and validity. For the design, data from 30 subjects was used. The final instrument had 90 food items. To measure reliability and validity, 20 participants with type 2 diabetes filled out twice the FFQ (FFQ-T1, FFQ-T2) and 7-day food records (7-dFR). The Shrout-Fleiss coefficient was 0.98 showing good reliability. For validation, the results for the weighted kappa were 0.55 (moderate agreement) for FFQ-T1 and 0.64 (good agreement) for FFQ-T2, and 75% and 80% of subjects respectively were correctly classified into tertiles; Bland-Altman graphics showed no systematic bias. This FFQ is comparable to 7-dFR for measuring dAGEs. To our knowledge, this is the first questionnaire designed to measure specifically dAGEs.

  7. Relative validity of a web-based food frequency questionnaire for patients with type 1 and type 2 diabetes in Denmark

    PubMed Central

    Bentzen, S M R; Knudsen, V K; Christiensen, T; Ewers, B

    2016-01-01

    Background: Diet has an important role in the management of diabetes. However, little is known about dietary intake in Danish diabetes patients. A food frequency questionnaire (FFQ) focusing on most relevant nutrients in diabetes including carbohydrates, dietary fibres and simple sugars was developed and validated. Objectives: To examine the relative validity of nutrients calculated by a web-based food frequency questionnaire for patients with diabetes. Design: The FFQ was validated against a 4-day pre-coded food diary (FD). Intakes of nutrients were calculated. Means of intake were compared and cross-classifications of individuals according to intake were performed. To assess the agreement between the two methods, Pearson and Spearman's correlation coefficients and weighted kappa coefficients were calculated. Subjects: Ninety patients (64 with type 1 diabetes and 26 with type 2 diabetes) accepted to participate in the study. Twenty-six were excluded from the final study population. Setting: 64 volunteer diabetes patients at the Steno Diabetes Center. Results: Intakes of carbohydrates, simple sugars, dietary fibres and total energy were higher according to the FFQ compared with the FD. However, intakes of nutrients were grossly classified in the same or adjacent quartiles with an average of 82% of the selected nutrients when comparing the two methods. In general, moderate agreement between the two methods was found. Conclusion: The FFQ was validated for assessment of a range of nutrients. Comparing the intakes of selected nutrients (carbohydrates, dietary fibres and simple sugars), patients were classified correctly according to low and high intakes. The FFQ is a reliable dietary assessment tool to use in research and evaluation of patient education for patients with diabetes. PMID:27669176

  8. Factors modifying the frequency of spontaneous activity in gastric muscle.

    PubMed

    Suzuki, H; Kito, Y; Hashitani, H; Nakamura, E

    2006-11-01

    The cellular mechanisms that determine the frequency of spontaneous activity were investigated in gastric smooth muscles isolated from the guinea-pig. Intact antral muscle generated slow waves periodically; the interval between slow waves was decreased exponentially by depolarization of the membrane to reach a steady interval value of about 7 s. Isolated circular muscle bundles produced slow potentials spontaneously or were evoked by depolarizing current stimuli. Evoked slow potentials appeared in an all-or-none fashion, with a refractory period of approximately 2-3 s. Low concentrations of chemicals that modify intracellular signalling revealed that the refractory period was causally related to the activity of protein kinase C (PKC). Activation of PKC increased and inhibition of PKC activity decreased the frequency of slow potentials. Chemicals that inhibit mitochondrial functions reduced the frequency of slow waves. Inhibition of internal Ca(2+)-store activity decreased the amplitude, but not the frequency of slow potentials, suggesting that the amplitude is causally related to Ca(2+) release from the internal store. The results suggest that changes in [Ca(2+)](i) caused by the activity of mitochondria may play a key role in determining the frequency of spontaneous activity in gastric pacemaker cells.

  9. Frequencies of Inaudible High-Frequency Sounds Differentially Affect Brain Activity: Positive and Negative Hypersonic Effects

    PubMed Central

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10–13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC. PMID:24788141

  10. Prediction of VO[subscript 2]max in Children and Adolescents Using Exercise Testing and Physical Activity Questionnaire Data

    ERIC Educational Resources Information Center

    Black, Nate E.; Vehrs, Pat R.; Fellingham, Gilbert W.; George, James D.; Hager, Ron

    2016-01-01

    Purpose: The purpose of this study was to evaluate the use of a treadmill walk-jog-run exercise test previously validated in adults and physical activity questionnaire data to estimate maximum oxygen consumption (VO[subscript 2]max) in boys (n = 62) and girls (n = 66) aged 12 to 17 years old. Methods: Data were collected from Physical Activity…

  11. Relative and biomarker-based validity of a food frequency questionnaire that measures the intakes of vitamin B(12), folate, iron, and zinc in young women.

    PubMed

    Fayet, Flavia; Flood, Victoria; Petocz, Peter; Samman, Samir

    2011-01-01

    Folate, vitamin B(12), iron, and zinc are particularly important nutrients for women of childbearing age. We tested the hypothesis that an electronic, 235-item, semiquantitative food frequency questionnaire (FFQ) is a valid measure of dietary intake when compared with repeat dietary 24-hour recalls. Biomarkers of folate, vitamin B(12), iron, and zinc were determined because their measurement errors are unrelated to errors in dietary questionnaires. Female adults (N = 256) aged 18 to 35 years completed the FFQ, and a representative subset (n = 53) completed repeat dietary 24-hour recalls. The FFQ estimates (mean ± SD) were 315 ± 132 μg for folate, 3.1 ± 2.1 μg for vitamin B(12), 15.4 ± 5.6 mg for iron, and 15.1 ± 6.4 mg for zinc. The percentage of women classified within the same ±1 quartile for energy intake by the 2 methods was 77.3%. There was moderate agreement between the 2 dietary methods, and no systematic bias was noted for energy, folate, vitamin B(12), and zinc. The deattenuated energy-adjusted correlation coefficients ranged from 0.41 (dietary folate equivalents) to 0.60 (folate). Significant correlations between biomarker and nutrient intakes were found for folate (r = 0.37, P < .01) and vitamin B(12) (r = 0.27, P < .01). The electronic FFQ developed in the present study is a relatively valid tool that was able to adequately assess and rank individuals according to their nutrient intakes.

  12. Validity of the Food Frequency Questionnaire Assessing the Folate Intake in Women of Reproductive Age Living in a Country without Food Fortification: Application of the Method of Triads

    PubMed Central

    Zekovic, Milica; Djekic-Ivankovic, Marija; Nikolic, Marina; Gurinovic, Mirjana; Krajnovic, Dusanka; Glibetic, Marija

    2017-01-01

    The study aimed to examine the external validity of the Folate Food Frequency Questionnaire (F-FFQ) designed for assessing the folate intake in Serbian women of reproductive age. The F-FFQ was tested against repeated 24 h dietary recalls and correspondent nutritional biomarkers (red blood cells (RBC) and serum folate concentrations) using the method of triads. In a cross sectional study, 503 women aged 18–49 years completed dietary questionnaires and representative validation subsample (n = 50) provided fasting blood samples for biomarker analyses. Correlation coefficients were calculated between each of the dietary methods and three pair-wise correlations were applied for the calculation of validity coefficients. Correlation coefficients observed between F-FFQ and three 24 h recalls were r = 0.56 (p < 0.001) and r = 0.57 (p < 0.001) for total sample and validation group, respectively. Bland–Altman plot and cross-classification analyses indicated good agreement between methods. High validity coefficients were determined between the true intake (I) and dietary assessment methods, F-FFQ (Q) and 24 h dietary recalls (R) (ρQIrbc = 0.871 and ρQIser = 0.814; ρRIrbc = 0.652 and ρRIser = 0.698), and moderate ones for biomarkers (B) (ρBIrbc = 0.428 and ρBIser = 0.421). The F-FFQ is valid instrument for the assessment of dietary folate intake in women living in Serbia, a country without mandatory folic acid food fortification. PMID:28208817

  13. Validity of a Self-Administered Food Frequency Questionnaire for Middle-Aged Urban Cancer Screenees: Comparison With 4-Day Weighed Dietary Records

    PubMed Central

    Takachi, Ribeka; Ishihara, Junko; Iwasaki, Motoki; Hosoi, Satoko; Ishii, Yuri; Sasazuki, Shizuka; Sawada, Norie; Yamaji, Taiki; Shimazu, Taichi; Inoue, Manami; Tsugane, Shoichiro

    2011-01-01

    Background The validity of estimates of dietary intake calculated using a food frequency questionnaire (FFQ) depends on the specific population. The 138-item FFQ used in the 5-year follow-up survey for the Japan Public Health Center-based Prospective Study was initially developed for and validated in rural residents. However, the validity of estimates based on this FFQ for urban residents, whose diet and lifestyle differ from those of rural residents, has not been clarified. We examined the validity of ranking individuals according to level of dietary consumption, as estimated by this FFQ, among an urban population in Japan. Methods Among 896 candidates randomly selected from examinees of cancer screening provided by the National Cancer Center, Japan, 144 participated in the study. In 2007–2008, at an average 2.7 years after cancer screening, participants were asked to respond to the questionnaire and to provide 4-day weighed diet records (4d-DRs) for use as the reference intake. Spearman correlation coefficients (CCs) between the FFQ and 4d-DR estimates were calculated, after correction for intraindividual variation of 4d-DRs. Results The median (range) deattenuated CC for men and women was 0.57 (0.23 to 0.89) and 0.47 (0.08 to 0.94), respectively, across 45 nutrients and 0.51 (0.10 to 0.98) and 0.51 (−0.36 to 0.88) for 43 food groups. Conclusions Although the FFQ was developed for a rural population, it provided reasonably valid measures of consumption for many nutrients and food groups in middle-aged screenees living in urban areas in Japan. PMID:21963789

  14. Sexual health in women with pelvic floor disorders: measuring the sexual activity and function with questionnaires--a summary.

    PubMed

    Espuña Pons, Montserrat

    2009-05-01

    The integration of sexual health into the health care services is important. In women attending urogynecological clinics, the urinary function, anorectal function, and anatomical defects are more often evaluated than those related to sexual activity and function. A group of experts in urogynecology, sexuality, and patient reported outcome development, met in a roundtable with the final objective of reviewing what is currently available and what is needed to accurately evaluate sexual function in women with pelvic floor dysfunction. An article was prepared for each of the issued presented during the roundtable and combined into this supplement. This article is a summary of all articles included in this supplement. The pathophysiology of sexual dysfunction as related to pelvic floor disorders has not been well established. Sexuality questionnaires and scales play an integral role in the diagnosis and treatment of female sexual dysfunction. The Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ) is the only validated female sexual function questionnaire specifically developed to assess sexual function in women with urinary incontinence and/or pelvic organ prolapse; however, the PISQ does not screen for sexual activity. The effects of treatments for pelvic floor problems on sexual function have received little attention. There is a need for a validated sexual function measure that evaluates not only the impact of pelvic floor dysfunction on sexual function but also the impact on sexual activity.

  15. Development of a Questionnaire Designed To Evaluate the Employee Development Activities at Paradise Valley Community College Center: Politics, Law, and Economics of Higher Education.

    ERIC Educational Resources Information Center

    Cristiano, Marilyn J.; Nellis, Deo E.

    This paper describes the development of a questionnaire for evaluating the activities of the Employee Development Program (EDP) at Paradise Valley Community College Center (PVCCC) in Phoenix (Arizona). Four major goals of the evaluation of the activities of the EDP, and a means for ensuring the content validity of the questionnaire are described.…

  16. Development of a Semi-Quantitative Food Frequency Questionnaire to Assess the Dietary Intake of a Multi-Ethnic Urban Asian Population.

    PubMed

    Neelakantan, Nithya; Whitton, Clare; Seah, Sharna; Koh, Hiromi; Rebello, Salome A; Lim, Jia Yi; Chen, Shiqi; Chan, Mei Fen; Chew, Ling; van Dam, Rob M

    2016-08-27

    Assessing habitual food consumption is challenging in multi-ethnic cosmopolitan settings. We systematically developed a semi-quantitative food frequency questionnaire (FFQ) in a multi-ethnic population in Singapore, using data from two 24-h dietary recalls from a nationally representative sample of 805 Singapore residents of Chinese, Malay and Indian ethnicity aged 18-79 years. Key steps included combining reported items on 24-h recalls into standardized food groups, developing a food list for the FFQ, pilot testing of different question formats, and cognitive interviews. Percentage contribution analysis and stepwise regression analysis were used to identify foods contributing cumulatively ≥90% to intakes and individually ≥1% to intake variance of key nutrients, for the total study population and for each ethnic group separately. Differences between ethnic groups were observed in proportions of consumers of certain foods (e.g., lentil stews, 1%-47%; and pork dishes, 0%-50%). The number of foods needed to explain variability in nutrient intakes differed substantially by ethnic groups and was substantially larger for the total population than for separate ethnic groups. A 163-item FFQ covered >95% of total population intake for all key nutrients. The methodological insights provided in this paper may be useful in developing similar FFQs in other multi-ethnic settings.

  17. Development of a Semi-Quantitative Food Frequency Questionnaire to Assess the Dietary Intake of a Multi-Ethnic Urban Asian Population

    PubMed Central

    Neelakantan, Nithya; Whitton, Clare; Seah, Sharna; Koh, Hiromi; Rebello, Salome A.; Lim, Jia Yi; Chen, Shiqi; Chan, Mei Fen; Chew, Ling; van Dam, Rob M.

    2016-01-01

    Assessing habitual food consumption is challenging in multi-ethnic cosmopolitan settings. We systematically developed a semi-quantitative food frequency questionnaire (FFQ) in a multi-ethnic population in Singapore, using data from two 24-h dietary recalls from a nationally representative sample of 805 Singapore residents of Chinese, Malay and Indian ethnicity aged 18–79 years. Key steps included combining reported items on 24-h recalls into standardized food groups, developing a food list for the FFQ, pilot testing of different question formats, and cognitive interviews. Percentage contribution analysis and stepwise regression analysis were used to identify foods contributing cumulatively ≥90% to intakes and individually ≥1% to intake variance of key nutrients, for the total study population and for each ethnic group separately. Differences between ethnic groups were observed in proportions of consumers of certain foods (e.g., lentil stews, 1%–47%; and pork dishes, 0%–50%). The number of foods needed to explain variability in nutrient intakes differed substantially by ethnic groups and was substantially larger for the total population than for separate ethnic groups. A 163-item FFQ covered >95% of total population intake for all key nutrients. The methodological insights provided in this paper may be useful in developing similar FFQs in other multi-ethnic settings. PMID:27618909

  18. The relationship between interviewer–respondent race match and reporting of energy intake using food frequency questionnaires in the rural South United States

    PubMed Central

    Lemacks, Jennifer L.; Huye, Holly; Rupp, Renee; Connell, Carol

    2015-01-01

    Objective The purpose of the observational study was to determine whether interviewer race influences food frequency questionnaire (FFQ) reporting accuracy in a Deep South, largely African American cohort. Methods A secondary analysis was conducted to investigate the influence of interviewer race on energy reporting of 319 African Americans who participated in the Mississippi Communities for Healthy Living intervention in May–June 2011, a community-based and USDA-funded project. Reported energy intake was compared to total energy expenditure to identify normal (ENR), under-(EUR) and over-reporters (EOR). Multivariate logistic regression models determined the relationship between race match and energy misreporting, accounting for confounding variables (educational level, health status perception, BMI, gender, and age) identified using chi-square/correlation analyses. Results The sample included 278 African Americans with 165 EURs, 26 EORs, and 87 ENRs identified. Logistic regression analyses revealed that there was no relationship between race-matched participants and EUR or EOR; controlling factors, BMI and perceived health status were significant in the model. Conclusion This study is the first to our knowledge to examine whether race influences dietary intake reporting which may influence assessment data used for comparison with health outcomes. This may have important implications for research conducted in health disparate populations, particularly rural, Southern populations. PMID:26844114

  19. The Development of the Lunchtime Enjoyment of Activity and Play Questionnaire

    ERIC Educational Resources Information Center

    Hyndman, Brendon; Telford, Amanda; Finch, Caroline; Ullah, Shahid; Benson, Amanda C.

    2013-01-01

    Background: Enjoyment of physical activity is as an important determinant of children's participation in physical activity. Despite this, there is an absence of reliable measures for assessing children's enjoyment of play activities during school lunchtime. The purpose of this study was to develop and assess the reliability of the Lunchtime…

  20. Joint amplitude and frequency analysis of tremor activity.

    PubMed

    Foerster, F; Smeja, M

    1999-01-01

    Clinical tremor analysis mostly is used for the measurement of tremor frequency. The analysis is based on short segments of EMG recordings and on clinical ratings of tremor intensity. Accelerometry appears to have some practical advantages. The present study was concerned with the development of a methodology for assessing tremor activity using the three parameters, frequency (Hz), amplitude (g), and occurrence of tremor (in per cent of time). These parameters were derived from joint amplitude frequency analysis of the calibrated accelerometer raw signal and from appropriate decision rules. This methodology was used in connection with 27 patients with Parkinson's disease, to investigate the aforesaid parameters of tremor activity. Postural tremor had a higher occurrence time (right-hand only) and higher frequency (left-hand only) than resting tremor, however, the average amplitudes did not differ. The correlations between right-hand and left-hand measures were higher during postural tremor test. Frequency was not correlated to amplitude or occurrence time, however, moderate correlations did exist between amplitude and occurrence time. In addition to the assessment of tremor activity, multi-channel accelerometry may be used for the detection of posture and motion. Further applications of this methodology, for example, in 24 hr ambulatory monitoring of tremor, are discussed.

  1. Development and psychometric properties of a belief-based Physical Activity Questionnaire for Diabetic Patients (PAQ-DP)

    PubMed Central

    2010-01-01

    Background This study carried out to develop a scale for assessing diabetic patients' perceptions about physical activity and to test its psychometric properties (The Physical Activity Questionnaire for Diabetic Patients-PAQ-DP). Methods An item pool extracted from the Theory of Planned Behavior literature was generated. Then an expert panel evaluated the items by assessing content validity index and content validity ratio. Consequently exploratory factor analysis (EFA) was performed to indicate the scale constructs. In addition reliability analyses including internal consistency and test-retest analysis were carried out. Results In all a sample of 127 women with diabetes participated in the study. Twenty-two items were initially extracted from the literature. A six-factor solution (containing 19 items) emerged as a result of an exploratory factor analysis namely: instrumental attitude, subjective norm, perceived behavioral control, affective attitude, self-identity, and intention explaining 60.30% of the variance observed. Additional analyses indicated satisfactory results for internal consistency (Cronbach's alpha ranging from 0.54 to 0.8) and intraclass correlation coefficients (ranging from 0.40 to 0.92). Conclusions The Physical Activity Questionnaire for Diabetic Patients (PAQ-DP) is the first instrument that applies the Theory of Planned Behavior in its constructs. The findings indicated that the PAQ-DP is a reliable and valid measure for assessing physical activity perceptions and now is available and can be used in future studies. PMID:21062466

  2. Validation of Veterans Specific Activity Questionnaire to assess exercise tolerance of Chinese elderly with coronary heart disease

    PubMed Central

    Wang, Yan; Shi, Jing-Jing; Wang, Bo-Zhong

    2016-01-01

    Objective The Veterans Specific Activity Questionnaire (VSAQ) has been used to assess exercise tolerance. Nevertheless, there is no validated Chinese version. The aim of this study is to determine whether a questionnaire-based method using the Chinese version of VSAQ (the modified VSAQ) is a practical tool to assess exercise tolerance of Chinese elderly with coronary heart disease. Methods One hundred thirty consecutive elderly patients who were diagnosed with coronary heart disease (CHD) (mean age 68.9 ± 6.0 years) referred for treadmill exercise testing (TET) for clinical reasons were included in the study. They were asked to complete a questionnaire for clinical characteristics information on age, sex, history, exercise habits, medications, the original VSAQ and the modified VSAQ. We investigated the relationship between exercise tolerance in metabolic equivalents (METs) estimated by VSAQ and that obtained by TET. Results The METs by the original VSAQ and the modified VSAQ did not difference significantly (P = 0.528). The modified VSAQ scores were significantly correlated with the METs obtained by TET (r = 0.819, 95% CI: 0.753–0.873, P < 0.01), and the scores of original VSAQ also correlated with the METs by TET (r = 0.804, 95% CI: 0.745–0.854, P < 0.01). The Bland-Altman graph analysis showed few values outside the limits of agreement, suggesting good precision between the METs estimated by questionnaire and the METs obtained by TET. Conclusions The Chinese version of the VSAQ confirmed its validity and equivalence to the original version, especially when evaluating individuals with coronary heart disease and older adults. The results showed that the VSAQ is a valuable tool to assess the exercise tolerance. PMID:28321240

  3. Evidence for the validity of the Children's Attraction to Physical Activity questionnaire (CAPA) with young children.

    PubMed

    Rose, Elizabeth; Larkin, Dawne; Hands, Beth; Howard, Barbara; Parker, Helen

    2009-09-01

    Attraction to physical activity is important to an individual's intrinsic motivation to engage in play, games and sports. While there are instruments designed to measure attraction to physical activity in middle childhood years, the lack of authentic measures in young children has impeded research in this area. In this study we sought to address the validity of a scale to tap young children's attraction to physical activity. Evidence for validity was based on internal consistency, content analysis, and factor structure. Australian school children (180 boys and 154 girls) from school year two, aged 6-8 years, were individually administered a modified version of the Children's Attraction to Physical Activity Scale (CAPA) [Brustad RJ. Who will go out to play? Parental and psychological influences on children's attraction to physical activity. Pediatr Exerc Sci 1993;5:210-23; Brustad RJ. Attraction to physical activity in urban school children: parental socialization and gender influences. Res Q Exerc Sport 1996;67:316-23]. The results indicated that internal consistency was acceptable for most of the subscales when negative statements were excluded from the analyses. Factor analysis revealed that the liking of games and sports, liking of physical exertion and exercise, and the importance of exercise subscales were more robust. Second order factor analysis indicated that the overall construct of attraction to physical activity was viable in this age group. With some modifications, the scale appears to provide a valid approach to the measurement of attraction to physical activity in young children.

  4. Spatial frequency components influence cell activity in the inferotemporal cortex.

    PubMed

    Bermudez, Maria A; Vicente, Ana F; Romero, Maria C; Perez, Rogelio; Gonzalez, Francisco

    2009-01-01

    We studied the correlation between the spatial frequency of complex stimuli and neuronal activity in the monkey inferotemporal (IT) cortex while performing a task that required visual recognition. Single-cell activity was recorded from the right IT cortex. The frequency components of the images used as stimuli were analyzed by using a fast Fourier transform, and a modulus was obtained for 40 spatial frequency ranges from 0.3 to 11.1 cycles/deg. We recorded 82 cells showing statistically significant responses (analysis of variance, P < 0.05) to at least one of the images used as a stimulus. Seventy-eight percent of these cells (n = 64) showed significant responses to at least three images, and in two thirds of them (n = 42), we found a statistically significant correlation (P < 0.05) between cell response and the modulus amplitude of at least one frequency range present in the images. Our results suggest that information about spatial frequency of the visual images is present in the IT cortex.

  5. Sexual Dysfunction in Breast Cancer Survivors: Cross-Cultural Adaptation of the Sexual Activity Questionnaire for Use in Portugal.

    PubMed

    da Costa, Filipa Alves; Ribeiro, Manuel Castro; Braga, Sofia; Carvalho, Elisabete; Francisco, Fátima; Miranda, Ana Costa; Moreira, António; Fallowfield, Lesley

    2016-09-01

    Introdução: A crescente população de sobreviventes de cancro da mama tem redireccionado o interesse investigacional e prático para o impacto da doença e do seu tratamento nas várias áreas da qualidade de vida. A falta de questionários para avaliar de forma objectiva a disfunção sexual conduziu à necessidade de adaptar e validar culturalmente o Sexual Activity Questionnaire para utilização em Portugal. Material e Métodos: O Sexual Activity Questionnaire foi traduzido e retrovertido, sua versão de consenso refinada após teste de compreensão, e subsequentemente auto-administrado a uma amostra alargada de sobreviventes de cancro da mama em dois momentos, espaçados 15 dias, para julgar a sua validade e fiabilidade. Resultados: Após alterações minor à versão de consenso, o Sexual Activity Questionnaire foi aplicado a 134 doentes. Obteve-se uma estrutura de três factores (75,5% da variância), compreendendo as escalas do Prazer, Hábito e Desconforto, todas com boa consistência interna (α de Cronbach > 0,70), boa validade concorrente com o FACt-An e a checklist BCPT (r de Spearman > 0,65; p-value < 0,001) e estabilidade temporal aceitável (k de Cohen > 0,44). Foi identificada inactividade sexual em 23,9% das mulheres, devido a falta de interesse ou ao facto de não ter parceiro. Discussão: Os dados reportados pelos doentes conduziram a alterações nos cuidados prestados, que passaram a contemplar a oncosexologia. Estudos futuros deverão focar-se na aplicabilidade deste questionário a amostras com diferentes características e mesmo à população global, para se poderem generalizar os resultados. Conclusão: A versão obtida do Sexual Activity Questionnaire é válida para avaliar a função sexual em sobreviventes de cancro da mama em Portugal.

  6. Spatial frequency multiplier with active linearly tapered slot antenna array

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1994-01-01

    A frequency multiplier with active linearly tapered slot antennas (LTSA's) has been demonstrated at the second harmonic frequency. In each antenna element, a GaAs monolithic microwave integrated circuit (MMIC) distributed amplifier is integrated with two LTSA's. The multiplier has a very wide bandwidth and large dynamic range. The fundamental-to-second harmonic conversion efficiency is 8.1 percent. The spatially combined second harmonic signal is 50 dB above the noise level. The design is suitable for constructing a large array using monolithic integration techniques.

  7. Validity of a new food frequency questionnaire for pregnant women in the Norwegian Mother and Child Cohort Study (MoBa).

    PubMed

    Brantsaeter, Anne Lise; Haugen, Margaretha; Alexander, Jan; Meltzer, Helle Margrete

    2008-01-01

    The aim of the present study was to examine the relative validity of foods and nutrients calculated by a new food frequency questionnaire (FFQ) in the Norwegian Mother and Child Cohort Study (MoBa). Reference measures were a 4-day weighed food diary (FD), a motion sensor for measuring total energy expenditure, one 24-h urine collection for analysis of nitrogen and iodine excretion, and a venous blood specimen for analysis of plasma 25-hydroxy-vitamin D and serum folate. A total of 119 women participated in the validation study, and 112 completed the motion sensor registration. Overall, the level of agreement between the FFQ and the FD was satisfactory, and significant correlations were found for all major food groups and for all nutrients except vitamin E. The average correlation coefficient between the FFQ and the FD for daily intake was 0.48 for foods and 0.36 for nutrients, and on average, 68% of the participants were classified into the same or adjacent quintiles by the two methods. Estimated total energy expenditure indicated that under-reporting of energy intake was more extensive with the FD than with the FFQ. The biological markers confirmed that the FFQ was able to distinguish between high and low intakes of nutrients, as measured by vitamin D, folate, protein and iodine. This validation study indicates that the MoBa FFQ produces reasonable valid intake estimates and is a valid tool to rank pregnant women according to low and high intakes of energy, nutrients and foods.

  8. Validation of a Food Frequency Questionnaire for Estimating Micronutrient Intakes in an Urban US Sample of Multi-Ethnic Pregnant Women

    PubMed Central

    Kannan, Srimathi; Ni, Yu-Ming; Gennings, Chris; Ganguri, Harish B.; Wright, Rosalind J.

    2016-01-01

    Objective(s) To validate the Block98 food frequency questionnaire (FFQ) for estimating antioxidant, methyl-nutrient and polyunsaturated fatty acids (PUFA) intakes in a pregnant sample of ethnic/racial minority women in the United States (US). Methods Participants (n = 42) were from the Programming of Intergenerational Stress Mechanisms study. Total micronutrient intakes from food and supplements was ascertained using the modified Block98 FFQ and two 24-h dietary recalls collected at random on nonconsecutive days subsequent to completion of the FFQ in mid-pregnancy. Correlation coefficients (r) corrected for attenuation from within-person variation in the recalls were calculated for antioxidants (n = 7), methyl-nutrients (n = 8), and PUFAs (n = 2). Result(s) The sample was largely ethnic minorities (38 % Black, 33 % Hispanic) with 21 % being foreign born and 41 % having less than or equal to a high school degree. Significant and adequate deattenuated correlations (r ≥ 0.40) for total dietary intakes of antioxidants were observed for vitamin C, vitamin E, magnesium, and zinc. Reasonable deattenuated correlations were also observed for methyl-nutrient intakes of vitamin B6, betaine, iron, and n:6 PUFAs; however, they did not reach significance. Most women were classified into the same or adjacent quartiles (≥70 %) for total (dietary + supplements) estimates of antioxidants (5 out of 7) and methyl-nutrients (4 out of 5). Conclusions The Block98 FFQ is an appropriate dietary method for evaluating antioxidants in pregnant ethnic/minorities in the US; it may be less efficient in measuring methyl-nutrient and PUFA intakes. PMID:26511128

  9. Validity and reproducibility of an interviewer-administered food frequency questionnaire in Austrian adults at risk of or with overt diabetes mellitus.

    PubMed

    Farukuoye, Michaela; Strassburger, Klaus; Kacerovsky-Bielesz, Gertrud; Giani, Guido; Roden, Michael

    2014-05-01

    Food frequency questionnaires (FFQs) provide an inexpensive tool for dietary assessment. Given the scarcity of data on their validity for nutritional analysis in persons with overt diabetes mellitus or with increased risk of diabetes (relatives of patients with diabetes), this study tests the hypothesis that an FFQ, adapted to local dietary habits, yields a reliable estimate of nutrient intake when compared with 7-day food record (7DR) in healthy, prediabetes, and diabetes cohorts. One hundred three volunteers (50 persons with overt diabetes mellitus, 24 relatives of patients with diabetes, and 29 nondiabetic individuals without a family history of diabetes) completed both FFQ and 7DR. A second FFQ was completed by 100 of these volunteers after 3 months to evaluate its reproducibility. Data were compared by correlation and Bland-Altman analyses. Across the entire group, estimates for gram intakes of nutrients and total energy were associated with wide limits of agreement between FFQ and 7DR (correlation coefficients, 0.23-0.72; P < .02). Compared with 7DR, the FFQ overestimated intakes of saturated fat in the entire group (+6.6 ± 14 g; P < .001) and in persons with overt diabetes mellitus (+7.6 ± 15 g; P < .001) but underestimated protein intake in relatives of patients with diabetes (-16.36 ± 31 g; P = .01). The repeated FFQ revealed variable agreement (correlation coefficients, 0.34-0.72; P < .001) and underestimated (P < .01) macronutrient and total energy intakes, with slightly better performance in persons with overt diabetes mellitus and relatives of patients with diabetes than in nondiabetic individuals without a family history of diabetes. Hence, the FFQ allows measuring intakes of total energy and macronutrients in prediabetes and diabetes cohorts but reveals limitations when assessing dietary composition.

  10. Validation of a food frequency questionnaire to assess intake of n-3 polyunsaturated fatty acids in subjects with and without major depressive disorder.

    PubMed

    Sublette, M Elizabeth; Segal-Isaacson, C J; Cooper, Thomas B; Fekri, Shiva; Vanegas, Nora; Galfalvy, Hanga C; Oquendo, Maria A; Mann, J John

    2011-01-01

    The role of n-3 polyunsaturated fatty acids (PUFAs) in psychiatric illness is a topic of public health importance. This report describes development and biomarker validation of a 21-item, self-report food frequency questionnaire (FFQ) intended for use in psychiatric research to assess intake of α-linolenic acid (18:3n-3 [ALA]), docosahexaenoic acid (22:6n-3 [DHA]), and eicosapentaenoic acid (20:5n-3 [EPA]). In a cross-sectional study conducted from September 2006 to September 2008, sixty-one ethnically diverse adult participants with (n=34) and without (n=27) major depressive disorder completed this n-3 PUFA FFQ and provided a plasma sample. Plasma levels of n-3 PUFAs EPA and DHA, and n-6 PUFA arachidonic acid (20:4n-6 [AA]) were quantified by gas chromatography. Using Spearman's ρ, FFQ-estimated intake correlated with plasma levels of DHA (r=0.50; P<0.0001) and EPA (r=0.38; P=0.002), but not with ALA levels (r=0.22; P=0.086). Participants were classified into quartiles by FFQ-estimated intake and plasma PUFA concentrations. Efficacy of the FFQ to rank individuals into same or adjacent plasma quartiles was 83% for DHA, 78.1% for EPA, and 70.6% for ALA; misclassification into extreme quartiles was 4.9% for DHA, 6.5% for EPA, and 8.2% for ALA. FFQ-estimated EPA intake and plasma EPA were superior to plasma AA levels as predictors of the plasma AA to EPA ratio. This brief FFQ can provide researchers and clinicians with valuable information concerning dietary intake of DHA and EPA.

  11. Validity and reproducibility of a food frequency questionnaire to assess dietary nutrients for prevention and management of metabolic syndrome in Korea

    PubMed Central

    Bae, Yun-Jung; Choi, Hae-Yeon; Sung, Mi-Kyung; Kim, Mi-Kyung

    2010-01-01

    Little data exists on metabolic syndrome (MetS) related with intake, especially for the South Korean. The purpose of this study was to develop and evaluate a food frequency questionnaire (FFQ) for nutritional assessment in the population with MetS in South Korea. Randomly selected female participants, mean age 21.9 years (n = 38) were invited to answer the FFQ twice (FFQ1 and FFQ2) over a nine-month interval and to complete twelve-day diet records (DR) during the months between in South Korea. The correlation coefficients for nutrient intake between FFQ1 and FFQ2 varied from 0.253 (niacin) to 0.573 (cholesterol), and the energy intake-adjusted correlation coefficients ranged from 0.187 for protein to 0.662 for iron. The energy intake-adjusted and de-attenuated correlation coefficients for comparison of FFQ1 and the DRs ranged between 0.277 (vitamin B1) and 0.768 (fiber), and between 0.229 (zinc) and 0.859 (fat) for comparison of DRs with FFQ2. The percentages of study subjects classified into the same quartiles in both the DRs and FFQ1 ranged from 15.8% (vitamin B6) to 47.4% (calcium), and for the same quartiles in DRs and FFQ2 from 13.2% (vitamin B1) to 44.7% (potassium). The FFQ has reasonably good validity and reproducibility. Further research is needed for an assessment of reproducibility and validation of present FFQ in the subjects with MetS. PMID:20461200

  12. Development and validation of a food frequency questionnaire for dietary intake assessment among multi-ethnic primary school-aged children

    PubMed Central

    Fatihah, Fadil; Ng, Boon Koon; Hazwanie, Husin; Norimah, A Karim; Shanita, Safii Nik; Ruzita, Abd Talib; Poh, Bee Koon

    2015-01-01

    INTRODUCTION This study aimed to develop and validate a food frequency questionnaire (FFQ) to assess habitual diets of multi-ethnic Malaysian children aged 7–12 years. METHODS A total of 236 primary school children participated in the development of the FFQ and 209 subjects participated in the validation study, with a subsample of 30 subjects participating in the reproducibility study. The FFQ, consisting of 94 food items from 12 food groups, was compared with a three-day dietary record (3DR) as the reference method. The reproducibility of the FFQ was assessed through repeat administration (FFQ2), seven days after the first administration (FFQ1). RESULTS The results of the validation study demonstrated good acceptance of the FFQ. Mean intake of macronutrients in FFQ1 and 3DR correlated well, although the FFQ intake data tended to be higher. Cross-classification of nutrient intake between the two methods showed that < 7% of subjects were grossly misclassified. Moderate correlations noted between the two methods ranged from r = 0.310 (p < 0.001) for fat to r = 0.497 (p < 0.001) for energy. The reproducibility of the FFQ, as assessed by Cronbach’s alpha, ranged from 0.61 (protein) to 0.70 (energy, carbohydrates and fat). Spearman’s correlations between FFQ1 and FFQ2 ranged from rho = 0.333 (p = 0.072) for protein to rho = 0.479 (p < 0.01) for fat. CONCLUSION These findings indicate that the FFQ is valid and reliable for measuring the average intake of energy and macronutrients in a population of multi-ethnic children aged 7–12 years in Malaysia. PMID:26702165

  13. Reproducibility and Relative Validity of Food Group Intake in a Food Frequency Questionnaire Developed for the Tehran Lipid and Glucose Study

    PubMed Central

    Hosseini Esfahani, Firoozeh; Asghari, Golaleh; Mirmiran, Parvin; Azizi, Fereidoun

    2010-01-01

    Objective To examine the validity and reproducibility of food groups in the semi-quantitative food frequency questionnaire (FFQ) developed for the Tehran Lipid and Glucose Study (TLGS). Methods To evaluate the reproducibility of food groups included in the FFQ, 132 subjects (61 men and 71 women) aged 20 years or older twice completed a 168-item FFQ (FFQ1, FFQ2), with a 14-month interval between FFQ1 and FFQ2. Over the 1-year interval, 12 dietary recalls (DRs) were collected (1 each month) to assess the validity of the FFQ. Seventeen food groups were derived from the FFQ based on methods described in previous studies. Age-adjusted and deattenuated Spearman correlation coefficients were used to assess the validity of the FFQ. Results The mean (SD) age and body mass index of subjects were 35.5 (16.8) years and 25.5 (5.2) kg/m2, respectively. Validity correlation coefficients ranged from 0.03 (liquid oil) to 0.77 (simple sugars) in men (median, 0.44), and from 0.12 (snacks) to 0.79 (simple sugars) in women (median, 0.37). The energy-adjusted intraclass correlation coefficient, which reflects the reproducibility of the FFQ, was 0.51 in men and was highest for tea and coffee (0.91); in women it was 0.59 and was highest for simple sugars (0.74). The highest percentage of complete agreement and disagreement was observed for snacks and desserts (60.6%) and potatoes and dairy products (12.8%), respectively, in men, and tea and coffee (62.9%) and legumes (15.7%) in women. Conclusions The FFQ that was designed for the TLGS was found to be reliable and valid for assessing the intake of several food groups. PMID:20154450

  14. Acrylamide exposure measured by food frequency questionnaire and hemoglobin adduct levels and prostate cancer risk in the Cancer of the Prostate in Sweden Study

    PubMed Central

    Wilson, Kathryn M.; Bälter, Katarina; Adami, Hans-Olov; Grönberg, Henrik; Vikström, Anna C.; Paulsson, Birgit; Törnqvist, Margareta; Mucci, Lorelei A.

    2010-01-01

    Acrylamide, a probable human carcinogen, is formed during the cooking of many commonly consumed foods. Data are scant on whether dietary acrylamide represents an important cancer risk in humans. We studied the association between acrylamide and prostate cancer risk using two measures of acrylamide exposure: intake from a food frequency questionnaire (FFQ) and acrylamide adducts to hemoglobin. We also studied the correlation between these two exposure measures. We used data from the population-based case-control study Cancer of the Prostate in Sweden (CAPS). Dietary data was available for 1499 cases and 1118 controls. Hemoglobin adducts of acrylamide were measured in blood samples from a subset of 170 cases and 161 controls. We calculated odds ratios (ORs) for the risk of prostate cancer in high versus low quantiles of acrylamide exposure using logistic regression. The correlation between FFQ acrylamide intake and acrylamide adducts in non-smokers was 0.25 (95% confidence interval: 0.14–0.35), adjusted for age, region, energy intake, and laboratory batch. Among controls the correlation was 0.35 (95% CI: 0.21–0.48); among cases it was 0.15 (95% CI: 0.00–0.30). The OR of prostate cancer for the highest versus lowest quartile of acrylamide adducts was 0.93 (95% CI: 0.47–1.85, p-value for trend=0.98). For FFQ acrylamide, the OR of prostate cancer for the highest versus lowest quintile was 0.97 (95% CI: 0.75–1.27, p trend=0.67). No significant associations were found between acrylamide exposure and risk of prostate cancer by stage, grade, or PSA level. Acrylamide adducts to hemoglobin and FFQ-measured acrylamide intake were moderately correlated. Neither measure of acrylamide exposure – hemoglobin adducts or FFQ – was associated with risk of prostate cancer. PMID:19142870

  15. Mechanical stress-controlled tunable active frequency-selective surface

    NASA Astrophysics Data System (ADS)

    Huang, Bo-Cin; Hong, Jian-Wei; Lo, Cheng-Yao

    2017-01-01

    This study proposes a tunable active frequency-selective surface (AFSS) realized by mechanically expanding or contracting a split-ring resonator (SRR) array. The proposed AFSS transfers mechanical stress from its elastic substrate to the top of the SRR, thereby achieving electromagnetic (EM) modulation without the need for an additional external power supply, meeting the requirements for the target application: the invisibility cloak. The operating mechanism of the proposed AFSS differs from those of other AFSSs, supporting modulations in arbitrary frequencies in the target range. The proposed stress-controlled or strain-induced EM modulation proves the existence of an identical and linear relationship between the strain gradient and the frequency shift, implying its suitability for other EM modulation ranges and applications.

  16. Assessing face validity of a physical activity questionnaire for Spanish-speaking women in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: A review of the literature produced no rigorously tested and validated Spanish-language physical activity survey or evaluation tools for use by USDA’s food assistance and education programs. The purpose of the current study was to develop and evaluate the face validity of a visually enha...

  17. Reliability and Validity of the International Physical Activity Questionnaire for Assessing Walking

    ERIC Educational Resources Information Center

    van der Ploeg, Hidde P.; Tudor-Locke, Catrine; Marshall, Alison L.; Craig, Cora; Hagstromer, Maria; Sjostrom, Michael; Bauman, Adrian

    2010-01-01

    The single most commonly reported physical activity in public health surveys is walking. As evidence accumulates that walking is important for preventing weight gain and reducing the risk of diabetes, there is increased need to capture this behavior in a valid and reliable manner. Although the disadvantages of a self-report methodology are well…

  18. Conversion of Questionnaire Data

    SciTech Connect

    Powell, Danny H; Elwood Jr, Robert H

    2011-01-01

    During the survey, respondents are asked to provide qualitative answers (well, adequate, needs improvement) on how well material control and accountability (MC&A) functions are being performed. These responses can be used to develop failure probabilities for basic events performed during routine operation of the MC&A systems. The failure frequencies for individual events may be used to estimate total system effectiveness using a fault tree in a probabilistic risk analysis (PRA). Numeric risk values are required for the PRA fault tree calculations that are performed to evaluate system effectiveness. So, the performance ratings in the questionnaire must be converted to relative risk values for all of the basic MC&A tasks performed in the facility. If a specific material protection, control, and accountability (MPC&A) task is being performed at the 'perfect' level, the task is considered to have a near zero risk of failure. If the task is performed at a less than perfect level, the deficiency in performance represents some risk of failure for the event. As the degree of deficiency in performance increases, the risk of failure increases. If a task that should be performed is not being performed, that task is in a state of failure. The failure probabilities of all basic events contribute to the total system risk. Conversion of questionnaire MPC&A system performance data to numeric values is a separate function from the process of completing the questionnaire. When specific questions in the questionnaire are answered, the focus is on correctly assessing and reporting, in an adjectival manner, the actual performance of the related MC&A function. Prior to conversion, consideration should not be given to the numeric value that will be assigned during the conversion process. In the conversion process, adjectival responses to questions on system performance are quantified based on a log normal scale typically used in human error analysis (see A.D. Swain and H.E. Guttmann

  19. Measuring the Environment for Friendliness Toward Physical Activity: A Comparison of the Reliability of 3 Questionnaires

    PubMed Central

    Brownson, Ross C.; Chang, Jen Jen; Eyler, Amy A.; Ainsworth, Barbara E.; Kirtland, Karen A.; Saelens, Brian E.; Sallis, James F.

    2004-01-01

    Objectives. We tested the reliability of 3 instruments that assessed social and physical environments. Methods. We conducted a test–retest study among US adults (n = 289). We used telephone survey methods to measure suitableness of the perceived (vs objective) environment for recreational physical activity and nonmotorized transportation. Results. Most questions in our surveys that attempted to measure specific characteristics of the built environment showed moderate to high reliability. Questions about the social environment showed lower reliability than those that assessed the physical environment. Certain blocks of questions appeared to be selectively more reliable for urban or rural respondents. Conclusions. Despite differences in content and in response formats, all 3 surveys showed evidence of reliability, and most items are now ready for use in research and in public health surveillance. PMID:14998817

  20. Frequency Based Volcanic Activity Detection through Remotely Sensed Data

    NASA Astrophysics Data System (ADS)

    Worden, A. K.; Dehn, J.; Webley, P. W.

    2015-12-01

    Satellite remote sensing has proved to offer a useful and relatively inexpensive method for monitoring large areas where field work is logistically unrealistic, and potentially dangerous. Current sensors are able to detect the majority of explosive volcanic activity; those that tend to effect and represent larger scale changes in the volcanic systems, eventually relating to ash producing periods of extended eruptive activity, and effusive activity. As new spaceborne sensors are developed, the ability to detect activity improves so that a system to gauge the frequency of volcanic activity can be used as a useful monitoring tool. Four volcanoes were chosen for development and testing of a method to monitor explosive activity: Stromboli (Italy); Shishaldin and Cleveland (Alaska, USA); and Karymsky (Kamchatka, Russia). Each volcano studied had similar but unique signatures of pre-cursory and eruptive activity. This study has shown that this monitoring tool could be applied to a wide range of volcanoes and still produce useful and robust data. Our method deals specifically with the detection of small scale explosive activity. The method described here could be useful in an operational setting, especially at remote volcanoes that have the potential to impact populations, infrastructure, and the aviation community. A number of important factors will affect the validity of application of this method. They are: (1) the availability of a continuous and continually populated dataset; (2) appropriate and reasonable sensor resolutions; (3) a recorded history of the volcano's previous activity; and, if available, (4) some ground-based monitoring system. We aim to develop the method further to be able to capture and evaluate the frequency of other volcanic processes such as lava flows, phreatomagmatic eruptions and dome growth and collapse. The work shown here has served to illustrate the capability of this method and monitoring tool for use at remote, un-instrumented volcanoes.

  1. Biomarkers of Dietary Intake Are Correlated with Corresponding Measures from Repeated Dietary Recalls and Food-Frequency Questionnaires in the Adventist Health Study-2123

    PubMed Central

    Fan, Jing; Knutsen, Synnove F; Sabaté, Joan; Bennett, Hannelore

    2016-01-01

    Background: Accurate assessment of diet in study populations is still a challenge. Some statistical strategies that use biomarkers of dietary intake attempt to compensate for the biasing effects of reporting errors. Objective: The objective was to correlate biomarkers of dietary intake with 2 direct measures of dietary intake. Methods: Subjects provided repeated 24-h dietary recalls and 2 food-frequency questionnaires (FFQs) separated by ∼3 y. Correlations between biomarkers and reported dietary intakes as measured by the recalls and FFQs were de-attenuated for within-person variability. The Adventist Health Study-2 (AHS-2) has a large database of biomarkers of dietary intake (blood, urine, adipose tissue) from a calibration study (909 analytic subjects) representing the cohort. Participants were black and non-black Adventists in the United States and Canada. Results: Dietary items with higher-valued de-attenuated correlations (≥0.50) between biomarkers and recalls included some fatty acids (FAs), the non-fish meats, fruit (non-black subjects), some carotenoids, vitamin B-12 (non-black subjects), and vitamin E. Moderately valued correlations (0.30–0.49) were found for very long chain ω-3 (n–3) FAs, some carotenoids, folate, isoflavones, cruciferous vegetables, fruit (black subjects), and calcium. The highest correlation values in non-black and black subjects were 0.69 (urinary 1-methyl-histidine and meat consumption) and 0.72 (adipose and dietary 18:2 ω-6), respectively. Correlations comparing biomarkers with recalls were generally similar for black and non-black subjects, but correlations between biomarkers and the FFQ were slightly lower than corresponding recall correlations. Correlations between biomarkers and a single FFQ estimate (the usual cohort situation) were generally much lower. Conclusions: Many biomarkers that have relatively high-valued correlations with dietary intake were identified and were usually of similar value in black and non

  2. Reproducibility and Validity of a Food Frequency Questionnaire for Assessing Dietary Consumption via the Dietary Pattern Method in a Chinese Rural Population

    PubMed Central

    Liu, Xudong; Wang, Xiaorong; Lin, Sihao; Song, Qingkun; Lao, Xiangqian; Yu, Ignatius Tak-Sun

    2015-01-01

    Objective This study was conducted to assess the reproducibility and validity of a food frequency questionnaire (FFQ) that was developed to assess the overall dietary consumption via dietary pattern method in a rural population in southwest China. Methods A total of 179 participants aged between 40 and 70 years old were included in this study. Participants administered FFQ at baseline (FFQ1) and one year later (FFQ2) to assess the reproducibility. Six 3-day 24-hour recalls (24HRs) were completed between the administrations of two FFQs to determine the validity. Dietary patterns from three separate dietary sources were derived by using principle component factor analysis. Comparisons between dietary pattern scores were made by using Pearson or intraclass correlation coefficient, cross-classification analysis, weighted kappa (κ) statistic and Bland-Altman analysis. The de-attenuated method was adopted to correct the monthly and seasonally variation and the partial correlation analysis was used correct the influence by total energy intake. Results Two major dietary factors, labeled as prudent pattern and processed food pattern, were identified. The prudent pattern was characterized by higher factor loadings of wheat, rice, fresh vegetables, bean products, nuts, red meat, white meat and fresh eggs; and the processed food pattern was characterized by higher factor loadings of pickled vegetables, preserved vegetables and salted meat. Between Two FFQs, intraclass correlation coefficients were 0.57 for prudent pattern and 0.55 for processed food pattern, partial Pearson correlation coefficients were 0.51 for the prudent pattern and 0.56 for the processed food pattern; weighted κ statistic ranged from 0.45 (for the prudent pattern) to 0.56 (for the processed food pattern). Between FFQs and 24HRs, de-attenuated correlation coefficients ranged from 0.54 to 0.78 for the prudent pattern and from 0.55 to 0.61 for the processed food pattern; partial Pearson correlation

  3. Comparative validity of the ASSO–Food Frequency Questionnaire for the web-based assessment of food and nutrients intake in adolescents

    PubMed Central

    Tabacchi, Garden; Filippi, Anna Rita; Breda, João; Censi, Laura; Amodio, Emanuele; Napoli, Giuseppe; Bianco, Antonino; Jemni, Monèm; Firenze, Alberto; Mammina, Caterina

    2015-01-01

    Background A new web-based food frequency questionnaire (the ASSO–FFQ) was developed within the ASSO Project funded by the Italian Ministry of Health. Objective The aim of the present study is to assess the validity of the ASSO–FFQ at food groups, energy, and nutrients level. Design and subjects The validation study compared the ASSO–FFQ against a weighted food record (WFR) measuring foods, beverages and supplements intake, compiled during the week following the ASSO–FFQ administration. Ninety-two subjects aged 14–17, recruited from secondary schools in Palermo (Italy), completed the ASSO–FFQ and WFR. The intake of 24 food groups, energy, and 52 nutrients were taken as main outcomes. Tests for paired observations, Spearman and Pearson’s correlation coefficients (cc), kappa statistics and classification in quintiles, Bland–Altman plots and multiple regressions, on untransformed and transformed data were used for the statistical analysis. Results High cc (≥0.40) were found for soft drinks, milk, tea/coffee, vegetables, and lactose; fair energy-adjusted cc (0.25–0.40) for water, alcoholic drinks, breakfast cereals, fishery products, savory food, fruit juice, eggs, and 19 nutrients. The subjects classified in the same or adjacent quintile for food groups ranged from 40% (alcoholic drinks) to 100% (dried fruit); for energy and nutrients from 43% (phosphorus, thiamin, niacin) to 77% (lactose). Mean differences were not significant for water, soft drinks, meat, sweets, animal fats, milk and white bread, and vitamin B12 and folate. Limits of Agreement were broad for all food groups and nutrients. School, gender, alcohol consumption and between meals mainly affected most food groups’ intake differences. Gender stratification showed females had increased Pearson’s cc for energy and 28 nutrients, such as almost all fats, carbohydrates, vitamins and minerals. Conclusions The ASSO–FFQ could be applied in epidemiological studies for the assessment of

  4. Adaptation and reliability of neighborhood environment walkability scale (NEWS) for Iran: A questionnaire for assessing environmental correlates of physical activity

    PubMed Central

    Hakimian, Pantea; Lak, Azadeh

    2016-01-01

    Background: In spite of the increased range of inactivity and obesity among Iranian adults, insufficient research has been done on environmental factors influencing physical activity. As a result adapting a subjective (self-report) measurement tool for assessment of physical environment in Iran is critical. Accordingly, in this study Neighborhood Environment Walkability Scale (NEWS) was adapted for Iran and also its reliability was evaluated. Methods: This study was conducted using a systematic adaptation method consisting of 3 steps: translate-back translation procedures, revision by a multidisciplinary panel of local experts and a cognitive study. Then NEWS-Iran was completed among adults aged 18 to 65 years (N=19) with an interval of 15 days. Intra-Class Coefficient (ICC) was used to evaluate the reliability of the adapted questionnaire. Results: NEWS-Iran is an adapted version of NEWS-A (abbreviated) and in the adaptation process five items were added from other versions of NEWS, two subscales were significantly modified for a shorter and more effective questionnaire, and five new items were added about climate factors and site-specific uses. NEWS-Iran showed almost perfect reliability (ICCs: more than 0.8) for all subscales, with items having moderate to almost perfect reliability scores (ICCs: 0.56-0.96). Conclusion: This study introduced NEWS-Iran, which is a reliable version of NEWS for measuring environmental perceptions related to physical activity behavior adapted for Iran. It is the first adapted version of NEWS which demonstrates a systematic adaptation process used by earlier studies. It can be used for other developing countries with similar environmental, social and cultural context. PMID:28210592

  5. Adaptation and reliability of neighborhood environment walkability scale (NEWS) for Iran: A questionnaire for assessing environmental correlates of physical activity.

    PubMed

    Hakimian, Pantea; Lak, Azadeh

    2016-01-01

    Background: In spite of the increased range of inactivity and obesity among Iranian adults, insufficient research has been done on environmental factors influencing physical activity. As a result adapting a subjective (self-report) measurement tool for assessment of physical environment in Iran is critical. Accordingly, in this study Neighborhood Environment Walkability Scale (NEWS) was adapted for Iran and also its reliability was evaluated. Methods: This study was conducted using a systematic adaptation method consisting of 3 steps: translate-back translation procedures, revision by a multidisciplinary panel of local experts and a cognitive study. Then NEWS-Iran was completed among adults aged 18 to 65 years (N=19) with an interval of 15 days. Intra-Class Coefficient (ICC) was used to evaluate the reliability of the adapted questionnaire. Results: NEWS-Iran is an adapted version of NEWS-A (abbreviated) and in the adaptation process five items were added from other versions of NEWS, two subscales were significantly modified for a shorter and more effective questionnaire, and five new items were added about climate factors and site-specific uses. NEWS-Iran showed almost perfect reliability (ICCs: more than 0.8) for all subscales, with items having moderate to almost perfect reliability scores (ICCs: 0.56-0.96). Conclusion: This study introduced NEWS-Iran, which is a reliable version of NEWS for measuring environmental perceptions related to physical activity behavior adapted for Iran. It is the first adapted version of NEWS which demonstrates a systematic adaptation process used by earlier studies. It can be used for other developing countries with similar environmental, social and cultural context.

  6. Manipulating neuronal activity with low frequency transcranial ultrasound

    NASA Astrophysics Data System (ADS)

    Moore, Michele Elizabeth

    Stimulation of the rodent cerebral cortex is used to investigate the underlying biological basis for the restorative effects of slow wave sleep. Neuronal activation by optogenetic and ultrasound stimulation elicits changes in action potentials across the cerebral cortex that are recorded as electroencephalograms. Optogenetic stimulation requires an invasive implantation procedure limiting its application in human studies. We sought to determine whether ultrasound stimulation could be as effective as optogenetic techniques currently used, in an effort to further understand the physiological and metabolic requirements of sleep. We successfully recorded electroencephalograms in response to transcranial ultrasound stimulation of the barrel cortex at 1 and 7 Hz frequencies, comparing them to those recorded in response to optogenetic stimuli applied at the same frequencies. Our results showed application of a 473 nm blue LED positioned 6 cm above the skull and ultrasound stimulation at an output voltage of 1000 mVpp produced electroencephalograms with physiological responses of similar amplitude. We concluded that there exists an intensity-proportionate response in the optogenetic stimulation, but not with ultrasound stimulation at the frequencies we surveyed. Activation of neuronal cells in response to optogenetic stimulation in a Thy1-ChR2 transgenic mouse line is specifically targeted to pyramidal cells in the cerebral cortex. ChR2 responses to optogenetic stimulation are mediated by a focal activation of neuronal ion channels. We measured electrophysiological responses to ultrasound stimulation, comparing them to those recorded from optogenetic stimuli. Our results show striking similarities between ultrasound-induced responses and optogenetically-induced responses, which may indicate that transcranial ultrasound stimulation is also mediated by ion channel dependent processes in cerebral cortical neurons. The biophysical substrates for electrical excitability of

  7. Assessing practice-based influences on adolescent psychosocial development in sport: the activity context in youth sport questionnaire.

    PubMed

    García Bengoechea, Enrique; Sabiston, Catherine M; Wilson, Philip M

    2017-01-01

    The aim of this study was to provide initial evidence of validity and reliability of scores derived from the Activity Context in Youth Sport Questionnaire (ACYSQ), an instrument designed to offer a comprehensive assessment of the activities adolescents take part in during sport practices. Two studies were designed for the purposes of item development and selection, and to provide evidence of structural and criterion validity of ACYSQ scores, respectively (N = 334; M age = 14.93, SD = 1.76 years). Confirmatory factor analysis (CFA) supported the adequacy of a 20-item ACYSQ measurement model, which was invariant across gender, and comprised the following dimensions: (1) stimulation; (2) usefulness-value; (3) authenticity; (4) repetition-boredom; and (5) ineffectiveness. Internal consistency reliability estimates and composite reliability estimates for ACYSQ subscale scores ranged from 0.72 to 0.91. In regression analyses, stimulation predicted enjoyment and perceived competence, ineffectiveness was significantly associated with perceived competence and authenticity emerged as a predictor of commitment in sport. These findings indicate that the ACYSQ displays adequate psychometric properties and the use of the instrument may be useful for studying selected activity-based features of the practice environment and their motivational consequences in youth sport.

  8. The reliability and validity of the English version of the Evaluation of Daily Activity Questionnaire for people with rheumatoid arthritis

    PubMed Central

    Tennant, Alan; Tyson, Sarah F.; Nordenskiöld, Ulla; Hawkins, Ruth; Prior, Yeliz

    2015-01-01

    Objectives. The Evaluation of Daily Activity Questionnaire (EDAQ) includes 138 items in 14 domains identified as important by people with RA. The aim of this study was to test the validity and reliability of the English EDAQ. Methods. A total of 502 participants completed two questionnaires 3 weeks apart. The first consisted of the EDAQ, HAQ, RA Quality of Life (RAQoL) and the Medical Outcomes Scale (MOS) 36-item Short-Form Health Survey (SF-36v2), and the second consisted of the EDAQ only. The 14 EDAQ domains were tested for: unidimensionality—using confirmatory factor analysis; fit, response dependency, invariance across groups (differential item functioning)—using Rasch analysis; internal consistency [Person Separation Index (PSI)]; concurrent validity—by correlations with the HAQ, SF-36v2 and RAQoL; and test–retest reliability (Spearman’s correlations). Results. Confirmatory factor analysis of the 14 EDAQ domains indicated unidimensionality, after adjustment for local dependency in each domain. All domains achieved a root mean square error of approximation <0.10 and satisfied Rasch model expectations for local dependency. DIF by age, gender and employment status was largely absent. The PSI was consistent with individual use (PSI = 0.94 for all 14 domains). For all domains, except Caring, concurrent validity was good: HAQ (rs = 0.72–0.91), RAQoL (rs = 0.67–0.82) and SF36v2 Physical Function scale (rs = −0.60 to −0.84) and test–retest reliability was good (rs = 0.70–0.89). Conclusion. Analysis supported a 14-domain, two-component structure (Self care and Mobility) of the EDAQ, where each domain, and both components, satisfied Rasch model requirements, and have robust reliability and validity. PMID:25863045

  9. Online Dietary Intake Estimation: Reproducibility and Validity of the Food4Me Food Frequency Questionnaire Against a 4-Day Weighed Food Record

    PubMed Central

    Fallaize, Rosalind; Forster, Hannah; Macready, Anna L; Walsh, Marianne C; Mathers, John C; Brennan, Lorraine; Gibney, Eileen R; Gibney, Michael J

    2014-01-01

    Background Advances in nutritional assessment are continuing to embrace developments in computer technology. The online Food4Me food frequency questionnaire (FFQ) was created as an electronic system for the collection of nutrient intake data. To ensure its accuracy in assessing both nutrient and food group intake, further validation against data obtained using a reliable, but independent, instrument and assessment of its reproducibility are required. Objective The aim was to assess the reproducibility and validity of the Food4Me FFQ against a 4-day weighed food record (WFR). Methods Reproducibility of the Food4Me FFQ was assessed using test-retest methodology by asking participants to complete the FFQ on 2 occasions 4 weeks apart. To assess the validity of the Food4Me FFQ against the 4-day WFR, half the participants were also asked to complete a 4-day WFR 1 week after the first administration of the Food4Me FFQ. Level of agreement between nutrient and food group intakes estimated by the repeated Food4Me FFQ and the Food4Me FFQ and 4-day WFR were evaluated using Bland-Altman methodology and classification into quartiles of daily intake. Crude unadjusted correlation coefficients were also calculated for nutrient and food group intakes. Results In total, 100 people participated in the assessment of reproducibility (mean age 32, SD 12 years), and 49 of these (mean age 27, SD 8 years) also took part in the assessment of validity. Crude unadjusted correlations for repeated Food4Me FFQ ranged from .65 (vitamin D) to .90 (alcohol). The mean cross-classification into “exact agreement plus adjacent” was 92% for both nutrient and food group intakes, and Bland-Altman plots showed good agreement for energy-adjusted macronutrient intakes. Agreement between the Food4Me FFQ and 4-day WFR varied, with crude unadjusted correlations ranging from .23 (vitamin D) to .65 (protein, % total energy) for nutrient intakes and .11 (soups, sauces and miscellaneous foods) to .73 (yogurts

  10. Performance of the international physical activity questionnaire (short form) in subgroups of the Hong Kong chinese population

    PubMed Central

    2011-01-01

    Background The International Physical Activity Questionnaire (IPAQ-SF) has been validated and recommended as an efficient method to assess physical activity, but its validity has not been investigated in different population subgroups. We examined variations in IPAQ validity in the Hong Kong Chinese population by six factors: sex, age, job status, educational level, body mass index (BMI), and visceral fat level (VFL). Methods A total of 1,270 adults (aged 42.9 ± SD 14.4 years, 46.1% male) completed the Chinese version of IPAQ (IPAQ-C) and wore an accelerometer (ActiGraph) for four days afterwards. The IPAQ-C and the ActiGraph were compared in terms of estimated Metabolic Equivalent Task minutes per week (MET-min/wk), minutes spent in activity of moderate or vigorous intensity (MVPA), and agreement in the classification of physical activity. Results The overall Spearman correlation (ρ) of between the IPAQ-C and ActiGraph was low (0.11 ± 0.03; range in subgroups 0.06-0.24) and was the highest among high VFL participants (0.24 ± 0.05). Difference between self-reported and ActiGraph-derived MET-min/wk (overall 2966 ± 140) was the smallest among participants with tertiary education (1804 ± 208). When physical activity was categorized into over or under 150 min/wk, overall agreement between self-report and accelerometer was 81.3% (± 1.1%; subgroup range: 77.2%-91.4%); agreement was the highest among those who were employed full-time in physically demanding jobs (91.4% ± 2.7%). Conclusions Sex, age, job status, educational level, and obesity were found to influence the criterion validity of IPAQ-C, yet none of the subgroups showed good validity (ρ = 0.06 to 0.24). IPAQ-SF validity is questionable in our Chinese population. PMID:21801461

  11. Parvalbumin Interneurons of Hippocampus Tune Population Activity at Theta Frequency.

    PubMed

    Amilhon, Bénédicte; Huh, Carey Y L; Manseau, Frédéric; Ducharme, Guillaume; Nichol, Heather; Adamantidis, Antoine; Williams, Sylvain

    2015-06-03

    Hippocampal theta rhythm arises from a combination of recently described intrinsic theta oscillators and inputs from multiple brain areas. Interneurons expressing the markers parvalbumin (PV) and somatostatin (SOM) are leading candidates to participate in intrinsic rhythm generation and principal cell (PC) coordination in distal CA1 and subiculum. We tested their involvement by optogenetically activating and silencing PV or SOM interneurons in an intact hippocampus preparation that preserves intrinsic connections and oscillates spontaneously at theta frequencies. Despite evidence suggesting that SOM interneurons are crucial for theta, optogenetic manipulation of these interneurons modestly influenced theta rhythm. However, SOM interneurons were able to strongly modulate temporoammonic inputs. In contrast, activation of PV interneurons powerfully controlled PC network and rhythm generation optimally at 8 Hz, while continuously silencing them disrupted theta. Our results thus demonstrate a pivotal role of PV but not SOM interneurons for PC synchronization and the emergence of intrinsic hippocampal theta.

  12. Development and Validation of a Short Form of the Valued Life Activities Disability Questionnaire for Rheumatoid Arthritis

    PubMed Central

    Katz, Patricia P.; Radvanski, Diane C.; Allen, Diane; Buyske, Steven; Schiff, Samuel; Nadkarni, Anagha; Rosenblatt, Lisa; Maclean, Ross; Hassett, Afton L.

    2011-01-01

    Objective Develop and validate a shortened version of the Valued Life Activities disability and accommodations scale (VLA) for individuals with rheumatoid arthritis (RA). Methods To shorten the existing VLA measure, item response theory analyses were conducted using data from 449 patients with RA. Next, the resulting 14-item shortened version of the VLA scale (S-VLA) was evaluated by structured interviews among 20 RA patients. Lastly, the S-VLA was administered to 150 RA patients along with other measures including the Health Assessment Questionnaire (HAQ) and SF-36. A random sample of 50 patients completed the S-VLA two weeks later to assess reliability. Item statistics were calculated to evaluate correlations between individual items and S-VLA total score. Correlations between the S-VLA and other measures were used to evaluate validity. Results Test–retest reliability was 0.91, while Cronbach’s alpha for the S-VLA was 0.95. None of the 14 items were associated with improved alpha coefficients when omitted. All items were strongly correlated with the S-VLA total score. S-VLA scores were highly positively correlated with HAQ (r=0.81; p≤0.001), patient-reported disease activity (r=0.71; p≤0.001), satisfaction with abilities (r=0.82; p≤0.001), and number of days with activity limitations (r=0.65; p≤0.001). In addition, as hypothesized, the S-VLA was inversely correlated with SF-36 Physical Component Summary score (r=−0.78; p≤0.001) and subscales: Physical Functioning (r=−0.80; p≤0.001), Role Physical (r=−0.67; p≤0.001) and Social Functioning (r=−0.72; p≤0.001). Conclusions The S-VLA is a short, valid, and reliable instrument that may prove useful for monitoring disability among individuals with RA. PMID:21905253

  13. Is a single question of the Global Physical Activity Questionnaire (GPAQ) valid for measuring sedentary behaviour in the Chilean population?

    PubMed

    Aguilar-Farias, Nicolas; Leppe Zamora, Jaime

    2016-09-08

    A study was conducted to assess the validity of the Global Physical Activity Questionnaire (GPAQ) for measuring sedentary behaviour (SB) in the Chilean adult population. About 217 adults (93/124 male/female, 43.8 ± 15.75 years) who were randomly selected during National Health Survey 2009-2010 completed the protocol. The participants wore an ActiGraph GT3X (AG) for 7 consecutive days and then completed the GPAQ (single-item question for measuring time spent sitting in a usual day). Validity was examined using Spearman's correlation, mean bias and limits of agreement (LoA), with AG (vertical axis <100 counts · min(-1)) as the reference standard for estimates of SB in bouts of 1 (AG1), 5 (AG5) and 10 (AG10) min. Agreement between the GPAQ and AG for classifying data into quartiles and tertiles was assessed with kappa method. The GPAQ showed fair correlation with AG1, AG5 and AG10 (range = 0.23-0.26), with large mean biases (range = -293.9, -76.12 min · day(-1)). Agreement between the GPAQ and AG1, AG5 and AG10 was poor for categorising time spent in SB into tertiles and quartiles. The single question from the GPAQ has shown fair validity for measuring SB and poor ability for correctly classifying individuals into tertiles or quartiles of SB in a Chilean population.

  14. Psychometric properties of the Social Cognitive Theory questionnaire for physical activity in a sample of Iranian adolescent girl students.

    PubMed

    Ardestani, M S; Niknami, S; Hidarnia, A; Hajizadeh, E

    2016-08-18

    This research examined the validity and reliability of a researcher-developed questionnaire based on Social Cognitive Theory (SCT) to assess the physical activity behaviour of Iranian adolescent girls (SCT-PAIAGS). Psychometric properties of the SCT-PAIAGS were assessed by determining its face validity, content and construct validity as well as its reliability. In order to evaluate factor structure, cross-sectional research was conducted on 400 high-school girls in Tehran. Content validity index, content validity ratio and impact score for the SCT-PAIAGS varied between 0.97-1, 0.91-1 and 4.6-4.9 respectively. Confirmatory factor analysis approved a six-factor structure comprising self-efficacy, self-regulation, family support, friend support, outcome expectancy and self-efficacy to overcoming impediments. Factor loadings, t-values and fit indices showed that the SCT model was fitted to the data. Cronbach's α-coefficient ranged from 0.78 to 0.85 and intraclass correlation coefficient from 0.73 to 0.90.

  15. Active Control of High-Frequency Combustor Instability Demonstrated

    NASA Technical Reports Server (NTRS)

    DeLaat, John C.; Chang, Clarence T.

    2003-01-01

    To reduce the environmental impact of aerospace propulsion systems, extensive research is being done in the development of lean-burning (low fuel-to-air ratio) combustors that can reduce emissions throughout the mission cycle. However, these lean-burning combustors have an increased susceptibility to thermoacoustic instabilities-high-pressure oscillations much like sound waves that can cause severe high-frequency vibrations in the combustor. These pressure waves can fatigue the combustor components and even the downstream turbine blades. This can significantly decrease the combustor and turbine safe operating life. Thus, suppression of the thermoacoustic combustor instabilities is an enabling technology for lean, low-emissions combustors. Under the Propulsion and Power Program, the NASA Glenn Research Center in partnership with Pratt & Whitney, United Technologies Research Center, and Georgia Institute of Technology is developing technologies for the active control of combustion instabilities.

  16. 78 FR 70567 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-26

    ... Frequency (UHF) Sound Navigation and Ranging (SONAR) Technology and Finding of No Significant Impact (FONSI..., day or night regardless of visibility and in air and water temperatures and thermoclines normal...

  17. Delphinid behavioral responses to incidental mid-frequency active sonar.

    PubMed

    Henderson, E Elizabeth; Smith, Michael H; Gassmann, Martin; Wiggins, Sean M; Douglas, Annie B; Hildebrand, John A

    2014-10-01

    Opportunistic observations of behavioral responses by delphinids to incidental mid-frequency active (MFA) sonar were recorded in the Southern California Bight from 2004 through 2008 using visual focal follows, static hydrophones, and autonomous recorders. Sound pressure levels were calculated between 2 and 8 kHz. Surface behavioral responses were observed in 26 groups from at least three species of 46 groups out of five species encountered during MFA sonar incidents. Responses included changes in behavioral state or direction of travel, changes in vocalization rates and call intensity, or a lack of vocalizations while MFA sonar occurred. However, 46% of focal groups not exposed to sonar also changed their behavior, and 43% of focal groups exposed to sonar did not change their behavior. Mean peak sound pressure levels when a behavioral response occurred were around 122 dB re: 1 μPa. Acoustic localizations of dolphin groups exhibiting a response gave insight into nighttime movement patterns and provided evidence that impacts of sonar may be mediated by behavioral state. The lack of response in some cases may indicate a tolerance of or habituation to MFA sonar by local populations; however, the responses that occur at lower received levels may point to some sensitization as well.

  18. Resting Brain Activity Varies with Dream Recall Frequency Between Subjects

    PubMed Central

    Eichenlaub, Jean-Baptiste; Nicolas, Alain; Daltrozzo, Jérôme; Redouté, Jérôme; Costes, Nicolas; Ruby, Perrine

    2014-01-01

    Dreaming is still poorly understood. Notably, its cerebral underpinning remains unclear. Neuropsychological studies have shown that lesions in the temporoparietal junction (TPJ) and/or the white matter of the medial prefrontal cortex (MPFC) lead to the global cessation of dream reports, suggesting that these regions of the default mode network have key roles in the dreaming process (forebrain ‘dream-on' hypothesis). To test this hypothesis, we measured regional cerebral blood flow (rCBF) using [15O]H2O positron emission tomography in healthy subjects with high and low dream recall frequencies (DRFs) during wakefulness (rest) and sleep (rapid eye movement (REM) sleep, N2, and N3). Compared with Low recallers (0.5±0.3 dream recall per week in average), High recallers (5.2±1.4) showed higher rCBF in the TPJ during REM sleep, N3, and wakefulness, and in the MPFC during REM sleep and wakefulness. We demonstrate that the resting states of High recallers and Low recallers differ during sleep and wakefulness. It coheres with previous ERP results and confirms that a high/low DRF is associated with a specific functional organization of the brain. These results support the forebrain ‘dream-on' hypothesis and suggest that TPJ and MPFC are not only involved in dream recall during wakefulness but also have a role in dreaming during sleep (production and/or encoding). Increased activity in the TPJ and MPFC might promote the mental imagery and/or memory encoding of dreams. Notably, increased activity in TPJ might facilitate attention orienting toward external stimuli and promote intrasleep wakefulness, facilitating the encoding of the dreams in memory. PMID:24549103

  19. Resting brain activity varies with dream recall frequency between subjects.

    PubMed

    Eichenlaub, Jean-Baptiste; Nicolas, Alain; Daltrozzo, Jérôme; Redouté, Jérôme; Costes, Nicolas; Ruby, Perrine

    2014-06-01

    Dreaming is still poorly understood. Notably, its cerebral underpinning remains unclear. Neuropsychological studies have shown that lesions in the temporoparietal junction (TPJ) and/or the white matter of the medial prefrontal cortex (MPFC) lead to the global cessation of dream reports, suggesting that these regions of the default mode network have key roles in the dreaming process (forebrain 'dream-on' hypothesis). To test this hypothesis, we measured regional cerebral blood flow (rCBF) using [(15)O]H2O positron emission tomography in healthy subjects with high and low dream recall frequencies (DRFs) during wakefulness (rest) and sleep (rapid eye movement (REM) sleep, N2, and N3). Compared with Low recallers (0.5 ± 0.3 dream recall per week in average), High recallers (5.2 ± 1.4) showed higher rCBF in the TPJ during REM sleep, N3, and wakefulness, and in the MPFC during REM sleep and wakefulness. We demonstrate that the resting states of High recallers and Low recallers differ during sleep and wakefulness. It coheres with previous ERP results and confirms that a high/low DRF is associated with a specific functional organization of the brain. These results support the forebrain 'dream-on' hypothesis and suggest that TPJ and MPFC are not only involved in dream recall during wakefulness but also have a role in dreaming during sleep (production and/or encoding). Increased activity in the TPJ and MPFC might promote the mental imagery and/or memory encoding of dreams. Notably, increased activity in TPJ might facilitate attention orienting toward external stimuli and promote intrasleep wakefulness, facilitating the encoding of the dreams in memory.

  20. Development of a novel questionnaire evaluating disability in activities of daily living in the upper extremities of patients undergoing maintenance hemodialysis.

    PubMed

    Kutsuna, Toshiki; Matsunaga, Atsuhiko; Takagi, Yutaka; Motohashi, Sachiko; Yamamoto, Kazuya; Matsumoto, Takuya; Ishii, Akira; Takahira, Naonobu; Yoshida, Atsushi; Masuda, Takashi

    2011-04-01

    The aim of the present study was to develop a novel questionnaire evaluating disability in the activities of daily living in the upper extremities of hemodialysis (HD) patients (QDUE-HD). We recruited 83 patients (40 males and 43 females) aged 66 ± 8 years, and measured their muscle strength and range of motion in the upper extremities. Moreover, 14 patients performed a six-week exercise training regimen (the exercise group) and were compared with 15 patients not performing such training (the control group). In an initial questionnaire consisting of 37 items, 30 were taken from the Disabilities of the Arm, Shoulder and Hand questionnaire and the Activities of Daily Living Test, and the remaining seven were selected from activities that HD patients perceived as impossible or extremely difficult to perform. The principal factor analysis focused on 11 items, as 26 showing floor and ceiling effects were excluded. These 11 items were divided into two categories consisting of six items termed "light work" and five termed "holding activities". The scores for light work and holding activities correlated significantly and positively with both muscle strength and range of motion in the upper extremities. These scores increased significantly after the six-week exercise training as compared with those before training in the exercise group. We conclude that the QDUE-HD is clinically useful for evaluating disability in activities of daily living in the upper extremities of HD patients because of its high reliability, validity and responsiveness.

  1. 75 FR 81284 - Nationwide Use of High Frequency and Ultra High Frequency Active SONAR Technology; Draft...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... SONAR technologies that operate at frequencies of 50 kiloHertz (kHz) and greater from mobile platforms... proposes to use HF and UHF SONAR technology from mobile platforms nationwide. Mobile platforms include...-specific, non-mobile operating scenarios or newly developed technologies fall outside of the scope of...

  2. Time and Frequency Activities at the JHU Applied Physics Laboratory

    DTIC Science & Technology

    2010-11-01

    mass ejections (STEREO) to the examination of the outer planets and the Kuiper Belt objects (New Horizons). This support includes providing precise...missions that span our solar system from the study of the Sun’s coronal mass ejections (STEREO) to the examination of the outer planets and the Kuiper ... Belt objects (New Horizons). This support includes providing precise time and frequency to the integration and testing of flight hardware, frequency

  3. The Sedentary Time and Activity Reporting Questionnaire (STAR-Q): reliability and validity against doubly labeled water and 7-day activity diaries.

    PubMed

    Csizmadi, Ilona; Neilson, Heather K; Kopciuk, Karen A; Khandwala, Farah; Liu, Andrew; Friedenreich, Christine M; Yasui, Yutaka; Rabasa-Lhoret, Rémi; Bryant, Heather E; Lau, David C W; Robson, Paula J

    2014-08-15

    We determined measurement properties of the Sedentary Time and Activity Reporting Questionnaire (STAR-Q), which was designed to estimate past-month activity energy expenditure (AEE). STAR-Q validity and reliability were assessed in 102 adults in Alberta, Canada (2009-2011), who completed 14-day doubly labeled water (DLW) protocols, 7-day activity diaries on day 15, and the STAR-Q on day 14 and again at 3 and 6 months. Three-month reliability was substantial for total energy expenditure (TEE) and AEE (intraclass correlation coefficients of 0.84 and 0.73, respectively), while 6-month reliability was moderate. STAR-Q-derived TEE and AEE were moderately correlated with DLW estimates (Spearman's ρs of 0.53 and 0.40, respectively; P < 0.001), and on average, the STAR-Q overestimated TEE and AEE (median differences were 367 kcal/day and 293 kcal/day, respectively). Body mass index-, age-, sex-, and season-adjusted concordance correlation coefficients (CCCs) were 0.24 (95% confidence interval (CI): 0.07, 0.36) and 0.21 (95% CI: 0.11, 0.32) for STAR-Q-derived versus DLW-derived TEE and AEE, respectively. Agreement between the diaries and STAR-Q (metabolic equivalent-hours/day) was strongest for occupational sedentary time (adjusted CCC = 0.76, 95% CI: 0.64, 0.85) and overall strenuous activity (adjusted CCC = 0.64, 95% CI: 0.49, 0.76). The STAR-Q demonstrated substantial validity for estimating occupational sedentary time and strenuous activity and fair validity for ranking individuals by AEE.

  4. Decoding of the sound frequency from the steady-state neural activities in rat auditory cortex.

    PubMed

    Shiramatsu, Tomoyo I; Noda, Takahiro; Kanzaki, Ryohei; Takahashi, Hirokazu

    2013-01-01

    In the auditory cortex, onset activities have been extensively investigated as a cortical representation of sound information such as sound frequency. Yet, less attention has been paid to date to steady-state activities following the onset activities. In this study, we used machine learning to investigate whether steady-state activities in the presence of continuous sounds represent the sound frequency. Sparse Logistic Regression (SLR) decoded the sound frequency from band specific power or phase locking value (PLV) of local field potentials (LFP) from the fourth layer of the auditory cortex of anesthetized rats. Consequently, we found that SLR was able to decode the sound frequency from steady-state neural activities as well as onset activities. This result demonstrates that the steady-state activities contain information about the sound such as sound frequency.

  5. Exoskeleton control for lower-extremity assistance based on adaptive frequency oscillators: adaptation of muscle activation and movement frequency.

    PubMed

    Aguirre-Ollinger, Gabriel

    2015-01-01

    In this article, we analyze a novel strategy for assisting the lower extremities based on adaptive frequency oscillators. Our aim is to use the control algorithm presented here as a building block for the control of powered lower-limb exoskeletons. The algorithm assists cyclic movements of the human extremities by synchronizing actuator torques with the estimated net torque exerted by the muscles. Synchronization is produced by a nonlinear dynamical system combining an adaptive frequency oscillator with a form of adaptive Fourier analysis. The system extracts, in real time, the fundamental frequency component of the net muscle torque acting on a specific joint. Said component, nearly sinusoidal in shape, is the basis for the assistive torque waveform delivered by the exoskeleton. The action of the exoskeleton can be interpreted as a virtual reduction in the mechanical impedance of the leg. We studied the ability of human subjects to adapt their muscle activation to the assistive torque. Ten subjects swung their extended leg while coupled to a stationary hip joint exoskeleton. The experiment yielded a significant decrease, with respect to unassisted movement, of the activation levels of an agonist/antagonist pair of muscles controlling the hip joint's motion, which suggests the exoskeleton control has potential for assisting human gait. A moderate increase in swing frequency was observed as well. We theorize that the increase in frequency can be explained by the impedance model of the assisted leg. Per this model, subjects adjust their swing frequency in order to control the amount of reduction in net muscle torque.

  6. School Social Worker's Perceptions of the Frequency of Actual and Preferred Engagement in Role Related Activities

    ERIC Educational Resources Information Center

    Arthur, Elizabeth

    2009-01-01

    The purpose of this study was (1) to determine the frequency in which school social workers in Virginia engage in and prefer to engage in social work related activities and (2) to determine if the frequency in which the social work related activities the school social workers engage in is related to select variables. After a comprehensive review…

  7. 77 FR 52317 - Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active Sonar

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Navy Record of Decision for Surveillance Towed Array Sensor System Low Frequency Active... Array Sensor System Low Frequency Active (SURTASS LFA) sonar systems with certain...

  8. Validity and Reproducibility of a Self-Administered Semi-Quantitative Food-Frequency Questionnaire for Estimating Usual Daily Fat, Fibre, Alcohol, Caffeine and Theobromine Intakes among Belgian Post-Menopausal Women

    PubMed Central

    Bolca, Selin; Huybrechts, Inge; Verschraegen, Mia; De Henauw, Stefaan; Van de Wiele, Tom

    2009-01-01

    A novel food-frequency questionnaire (FFQ) was developed and validated to assess the usual daily fat, saturated, mono-unsaturated and poly-unsaturated fatty acid, fibre, alcohol, caffeine, and theobromine intakes among Belgian post-menopausal women participating in dietary intervention trials with phyto-oestrogens. The relative validity of the FFQ was estimated by comparison with 7 day (d) estimated diet records (EDR, n 64) and its reproducibility was evaluated by repeated administrations 6 weeks apart (n 79). Although the questionnaire underestimated significantly all intakes compared to the 7 d EDR, it had a good ranking ability (r 0.47–0.94; weighted κ 0.25–0.66) and it could reliably distinguish extreme intakes for all the estimated nutrients, except for saturated fatty acids. Furthermore, the correlation between repeated administrations was high (r 0.71–0.87) with a maximal misclassification of 7% (weighted κ 0.33–0.80). In conclusion, these results compare favourably with those reported by others and indicate that the FFQ is a satisfactorily reliable and valid instrument for ranking individuals within this study population. PMID:19440274

  9. Validation of a new questionnaire to assess the impact of Whiplash Associated Disorders: The Whiplash Activity and participation List (WAL).

    PubMed

    Stenneberg, Martijn S; Schmitt, Maarten A; van Trijffel, Emiel; Schröder, Carin D; Lindeboom, Robert

    2015-02-01

    Valid questionnaires for measuring functional limitations in patients with Whiplash Associated Disorders (WAD) are lacking, since existing measures are not suitable for addressing the specific limitations of these patients and because of cross contamination between theoretical constructs. The objective of this study was to evaluate dimensionality, test-retest reliability, measurement error, construct validity, and responsiveness of a new condition-specific questionnaire for WAD as well as to estimate the minimally important change score. Patients with WAD grade I or II were recruited from physical therapy practices and rehabilitation centers. Dimensionality was examined by internal consistency analysis (Cronbach's alpha) and factor analysis. Test-retest reliability was estimated by intraclass correlations and measurement error was calculated by the minimal detectable change (MDC) scores. Construct validity was investigated by testing predefined hypotheses on correlations of the WAL scores with generic health measures and by using the known group method. Responsiveness was expressed as the minimal clinically important change (MCIC) score. 73 patients (53 women) were included. Cronbach's alpha was high (0.95) and unidimensionality was plausible because factor analysis showed 40.3% variance explained by one dominant factor, which was more than 4.5 times larger than the second largest factor. Test-retest reliability was excellent (0.92, 95% CI 0.87-0.95). Construct validity was supported by 14 out of 15 confirmed hypotheses and the WAL showed statistically significant differences between known groups. MDC was 16 points while the MCIC was 18 points. In conclusion, the present study suggests that the WAL has adequate measurement properties, but additional research is needed.

  10. Spatial Frequency Components of Images Modulate Neuronal Activity in Monkey Amygdala.

    PubMed

    Montes-Lourido, Pilar; Bermudez, M A; Romero, M C; Vicente, A F; Gonzalez, F

    2016-04-01

    Processing the spatial frequency components of an image is a crucial feature for visual perception, especially in recognition of faces. Here, we study the correlation between spatial frequency components of images of faces and neuronal activity in monkey amygdala while performing a visual recognition task. The frequency components of the images were analyzed using a fast Fourier transform for 40 spatial frequency ranges. We recorded 65 neurons showing statistically significant responses to at least one of the images used as a stimulus. A total of 37 of these neurons (n = 37) showed significant responses to at least three images, and in eight of them (8/37, 22%), we found a statistically significant correlation between neuron response and the modulus amplitude of at least one frequency range present in the images. Our results indicate that high spatial frequency and low spatial frequency components of images influence the activity of amygdala neurons.

  11. THE ACOUSTIC CUTOFF FREQUENCY OF THE SUN AND THE SOLAR MAGNETIC ACTIVITY CYCLE

    SciTech Connect

    Jimenez, A.; Palle, P. L.; Garcia, R. A.

    2011-12-20

    The acoustic cutoff frequency-the highest frequency for acoustic solar eigenmodes-is an important parameter of the solar atmosphere as it determines the upper boundary of the p-mode resonant cavities. At frequencies beyond this value, acoustic disturbances are no longer trapped but are traveling waves. Interference among them gives rise to higher-frequency peaks-the pseudomodes-in the solar acoustic spectrum. The pseudomodes are shifted slightly in frequency with respect to p-modes, making possible the use of pseudomodes to determine the acoustic cutoff frequency. Using data from the GOLF and VIRGO instruments on board the Solar and Heliospheric Observatory spacecraft, we calculate the acoustic cutoff frequency using the coherence function between both the velocity and intensity sets of data. By using data gathered by these instruments during the entire lifetime of the mission (1996 until the present), a variation in the acoustic cutoff frequency with the solar magnetic activity cycle is found.

  12. Visible frequency magnetic activity in silver nanocluster metamaterial.

    PubMed

    Tamma, Venkata Ananth; Lee, Jin-Hyoung; Wu, Qi; Park, Wounjhang

    2010-03-01

    We experimentally observe magnetic resonance in the visible frequency region from self-assembled silver nanocluster metamaterials. Extensive numerical modeling studies were conducted to find the optimal nanocluster dimensions. Self-assembly of silver nanoparticles coated with nanoscale silica coating was then performed on polymer templates fabricated by laser interference lithography. The nanoclusters supported magnetic resonance in the visible region, and the extracted effective permeability exhibited Lorentz-like resonance. The experimentally observed lowest value for the real part of permeability was 0.06. The nanocluster metamaterial represents a practical metamaterial architecture that is compatible with the scalable bottom-up manufacturing process.

  13. Time and Frequency Activities at the JHU Applied Physics Laboratory

    DTIC Science & Technology

    2009-11-01

    Resolution Offset Generator  2 GPS Time Transfer Receivers Time and Frequency Dissemination  1 MHz, 5 MHz, 10 MHz, 100 MHz  1 PPS  IRIG ...B APL Local Time  IRIG -B UTC  Common View GPS Time Transfer •NIST, USNO, BIPM 41 st Annual Precise Time and Time Interval (PTTI) Meeting...MASER* CESIUM 3 MICROPHASE STEPPER 5 MHZ DISTRIBUTION APL TIMESCALE PROCESSOR PREDICTION ALGORITHM TIMECODE 1PPS & IRIG 8 CHANNEL GPS A

  14. Sampling frequency affects the processing of Actigraph raw acceleration data to activity counts.

    PubMed

    Brønd, Jan Christian; Arvidsson, Daniel

    2016-02-01

    ActiGraph acceleration data are processed through several steps (including band-pass filtering to attenuate unwanted signal frequencies) to generate the activity counts commonly used in physical activity research. We performed three experiments to investigate the effect of sampling frequency on the generation of activity counts. Ideal acceleration signals were produced in the MATLAB software. Thereafter, ActiGraph GT3X+ monitors were spun in a mechanical setup. Finally, 20 subjects performed walking and running wearing GT3X+ monitors. Acceleration data from all experiments were collected with different sampling frequencies, and activity counts were generated with the ActiLife software. With the default 30-Hz (or 60-Hz, 90-Hz) sampling frequency, the generation of activity counts was performed as intended with 50% attenuation of acceleration signals with a frequency of 2.5 Hz by the signal frequency band-pass filter. Frequencies above 5 Hz were eliminated totally. However, with other sampling frequencies, acceleration signals above 5 Hz escaped the band-pass filter to a varied degree and contributed to additional activity counts. Similar results were found for the spinning of the GT3X+ monitors, although the amount of activity counts generated was less, indicating that raw data stored in the GT3X+ monitor is processed. Between 600 and 1,600 more counts per minute were generated with the sampling frequencies 40 and 100 Hz compared with 30 Hz during running. Sampling frequency affects the processing of ActiGraph acceleration data to activity counts. Researchers need to be aware of this error when selecting sampling frequencies other than the default 30 Hz.

  15. Sudden synchrony leaps accompanied by frequency multiplications in neuronal activity

    PubMed Central

    Vardi, Roni; Goldental, Amir; Guberman, Shoshana; Kalmanovich, Alexander; Marmari, Hagar; Kanter, Ido

    2013-01-01

    A classical view of neural coding relies on temporal firing synchrony among functional groups of neurons, however, the underlying mechanism remains an enigma. Here we experimentally demonstrate a mechanism where time-lags among neuronal spiking leap from several tens of milliseconds to nearly zero-lag synchrony. It also allows sudden leaps out of synchrony, hence forming short epochs of synchrony. Our results are based on an experimental procedure where conditioned stimulations were enforced on circuits of neurons embedded within a large-scale network of cortical cells in vitro and are corroborated by simulations of neuronal populations. The underlying biological mechanisms are the unavoidable increase of the neuronal response latency to ongoing stimulations and temporal or spatial summation required to generate evoked spikes. These sudden leaps in and out of synchrony may be accompanied by multiplications of the neuronal firing frequency, hence offering reliable information-bearing indicators which may bridge between the two principal neuronal coding paradigms. PMID:24198764

  16. High-frequency underwater plasma discharge application in antibacterial activity

    NASA Astrophysics Data System (ADS)

    Ahmed, M. W.; Choi, S.; Lyakhov, K.; Shaislamov, U.; Mongre, R. K.; Jeong, D. K.; Suresh, R.; Lee, H. J.

    2017-03-01

    Plasma discharge is a novel disinfection and effectual inactivation approach to treat microorganisms in aqueous systems. Inactivation of Gram-negative Escherichia coli (E. coli) by generating high-frequency, high-voltage, oxygen (O2) injected and hydrogen peroxide (H2O2) added discharge in water was achieved. The effect of H2O2 dose and oxygen injection rate on electrical characteristics of discharge and E. coli disinfection has been reported. Microbial log reduction dependent on H2O2 addition with O2 injection was observed. The time variation of the inactivation efficiency quantified by the log reduction of the initial E. coli population on the basis of optical density measurement was reported. The analysis of emission spectrum recorded after discharge occurrence illustrated the formation of oxidant species (OH•, H, and O). Interestingly, the results demonstrated that O2 injected and H2O2 added, underwater plasma discharge had fabulous impact on the E. coli sterilization. The oxygen injection notably reduced the voltage needed for generating breakdown in flowing water and escalated the power of discharge pulses. No impact of hydrogen peroxide addition on breakdown voltage was observed. A significant role of oxidant species in bacterial inactivation also has been identified. Furthermore the E. coli survivability in plasma treated water with oxygen injection and hydrogen peroxide addition drastically reduced to zero. The time course study also showed that the retardant effect on E. coli colony multiplication in plasma treated water was favorable, observed after long time. High-frequency underwater plasma discharge based biological applications is technically relevant and would act as baseline data for the development of novel antibacterial processing strategies.

  17. The Survey Questionnaire

    ERIC Educational Resources Information Center

    Ritter, Lois A. Ed.; Sue, Valerie M., Ed.

    2007-01-01

    Internet-based surveys are still relatively new, and researchers are just beginning to articulate best practices for questionnaire design. Online questionnaire design has generally been guided by the principles applying to other self-administered instruments, such as paper-based questionnaires. Web-based questionnaires, however, have the potential…

  18. Coherence and frequency in the reticular activating system (RAS).

    PubMed

    Garcia-Rill, Edgar; Kezunovic, Nebojsa; Hyde, James; Simon, Christen; Beck, Paige; Urbano, Francisco J

    2013-06-01

    This review considers recent evidence showing that cells in the reticular activating system (RAS) exhibit (1) electrical coupling mainly in GABAergic cells, and (2) gamma band activity in virtually all of the cells. Specifically, cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine dorsal subcoeruleus nucleus dorsalis (SubCD) (1) show electrical coupling, and (2) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanism behind electrical coupling is important because the stimulant modafinil was shown to increase electrical coupling. We also provide recent findings demonstrating that all cells in the PPN and Pf have high threshold, voltage-dependent P/Q-type calcium channels that are essential to gamma band activity. On the other hand, all SubCD, and some PPN, cells manifested sodium-dependent subthreshold oscillations. A novel mechanism for sleep-wake control based on transmitter interactions, electrical coupling, and gamma band activity is described. We speculate that continuous sensory input will modulate coupling and induce gamma band activity in the RAS that could participate in the processes of preconscious awareness, and provide the essential stream of information for the formulation of many of our actions.

  19. Database of Standardized Questionnaires About Walking & Bicycling

    Cancer.gov

    This database contains questionnaire items and a list of validation studies for standardized items related to walking and biking. The items come from multiple national and international physical activity questionnaires.

  20. Criterion-Related Validity of the Short Form of the International Physical Activity Questionnaire in Adults Who Are Blind

    ERIC Educational Resources Information Center

    Marmeleira, Jose; Laranjo, Luis; Marques, Olga; Batalha, Nuno

    2013-01-01

    This article describes the results of a recommendation from the World Health Organization (2004) that it was important to examine whether high-risk groups meet the current general recommendation of at least 30 minutes of moderate or greater physical activity per day. Doing so required an accurate measurement of physical activity for supporting the…

  1. Development of new physical activity and sedentary behavior change self-efficacy questionnaires using item response modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theoretically, increased levels of physical activity self-efficacy (PASE) should lead to increased physical activity, but few studies have reported this effect among youth. This failure may be at least partially attributable to measurement limitations. In this study, Item Response Modeling (IRM) was...

  2. A novel design of semi-active hydraulic mount with wide-band tunable notch frequency

    NASA Astrophysics Data System (ADS)

    Wang, Min; Yao, Guo-feng; Zhao, Jing-zhou; Qin, Min

    2014-04-01

    Hydraulic engine mount is advanced vibration isolator with superior performance to reduce vibration transferred from engine to chassis. As the stiffness at notch frequency is small, some semi-active or active hydraulic mounts tune some parameters to let notch frequency coincide with exciting frequency for better vibration isolation performance. It is discovered the current semi-active mounts can tune the notch frequency in narrow frequency band when only one parameter is tuned. A novel semi-active hydraulic engine mount design which introduces screw thread is proposed and researched in the paper. This hydraulic mount can control both cross section area and the length of inertia track and the theoretical tunable notch frequency band is [0, ∞). Theoretical work is carried out to uncover the capability for the proposed design to tune notch frequency. Simulation work is performed to understand its high vibration isolation performance. For the purpose of energy conservation, the friction self-locking is introduced. This denotes once the mount is tuned at optimal condition, the energy can be cut off and the optimal condition will never change. We also determine the best time to tune the parameters of the proposed mount in order to decrease the acting force. The proposed semi-active mount has capability to obtain wide band tunable notch frequency and has merit of energy conservation.

  3. Driving an Active Vibration Balancer to Minimize Vibrations at the Fundamental and Harmonic Frequencies

    NASA Technical Reports Server (NTRS)

    Holliday, Ezekiel S. (Inventor)

    2014-01-01

    Vibrations of a principal machine are reduced at the fundamental and harmonic frequencies by driving the drive motor of an active balancer with balancing signals at the fundamental and selected harmonics. Vibrations are sensed to provide a signal representing the mechanical vibrations. A balancing signal generator for the fundamental and for each selected harmonic processes the sensed vibration signal with adaptive filter algorithms of adaptive filters for each frequency to generate a balancing signal for each frequency. Reference inputs for each frequency are applied to the adaptive filter algorithms of each balancing signal generator at the frequency assigned to the generator. The harmonic balancing signals for all of the frequencies are summed and applied to drive the drive motor. The harmonic balancing signals drive the drive motor with a drive voltage component in opposition to the vibration at each frequency.

  4. Deep brain stimulation suppresses pallidal low frequency activity in patients with phasic dystonic movements.

    PubMed

    Barow, Ewgenia; Neumann, Wolf-Julian; Brücke, Christof; Huebl, Julius; Horn, Andreas; Brown, Peter; Krauss, Joachim K; Schneider, Gerd-Helge; Kühn, Andrea A

    2014-11-01

    Deep brain stimulation of the globus pallidus internus alleviates involuntary movements in patients with dystonia. However, the mechanism is still not entirely understood. One hypothesis is that deep brain stimulation suppresses abnormally enhanced synchronized oscillatory activity within the motor cortico-basal ganglia network. Here, we explore deep brain stimulation-induced modulation of pathological low frequency (4-12 Hz) pallidal activity that has been described in local field potential recordings in patients with dystonia. Therefore, local field potentials were recorded from 16 hemispheres in 12 patients undergoing deep brain stimulation for severe dystonia using a specially designed amplifier allowing simultaneous high frequency stimulation at therapeutic parameter settings and local field potential recordings. For coherence analysis electroencephalographic activity (EEG) over motor areas and electromyographic activity (EMG) from affected neck muscles were recorded before and immediately after cessation of high frequency stimulation. High frequency stimulation led to a significant reduction of mean power in the 4-12 Hz band by 24.8 ± 7.0% in patients with predominantly phasic dystonia. A significant decrease of coherence between cortical EEG and pallidal local field potential activity in the 4-12 Hz range was revealed for the time period of 30 s after switching off high frequency stimulation. Coherence between EMG activity and pallidal activity was mainly found in patients with phasic dystonic movements where it was suppressed after high frequency stimulation. Our findings suggest that high frequency stimulation may suppress pathologically enhanced low frequency activity in patients with phasic dystonia. These dystonic features are the quickest to respond to high frequency stimulation and may thus directly relate to modulation of pathological basal ganglia activity, whereas improvement in tonic features may depend on long-term plastic changes within the

  5. Liking and wanting of drug and nondrug rewards in active cocaine users: the STRAP-R questionnaire

    SciTech Connect

    Goldstein, R.Z.; Goldstein, R.Z.; Woicik, P.A..; Moeller, S.J.; Telang, F.; Jayne, M.; Wong, C.; Wang, G-J.; Fowler, J.S.; Volkow, N.D.

    2008-10-01

    Few studies have examined the subjective value attributed to drug rewards specifically as it compares with the value attributed to primary non-drug rewards in addicted individuals. The objective of this study is to assess liking and wanting of expected drug rewards as compared to food and sex while respondents report about three different situations (current, and hypothetical in general, and under drug influence). In all, 20 cocaine-addicted individuals (mean abstinence = 2 days) and 20 healthy control subjects were administered the STRAP-R (Sensitivity To Reinforcement of Addictive and other Primary Rewards) questionnaire after receiving an oral dose of the dopamine agonist methylphenidate (20 mg) or placebo. The reinforcers relative value changed within the addicted sample when reporting about the under drug influence situation (drug > food; otherwise, drug < food). This change was highest in the addicted individuals with the youngest age of cocaine use onset. Moreover, drug wanting exceeded drug liking in the addicted subjects when reporting about this situation during methylphenidate. Thus, cocaine-addicted individuals assign the highest subjective valence to drug rewards but only when recalling cue-related situations. When recalling this situation, they also report higher drug wanting than hedonic liking, a motivational shift that was only significant during methylphenidate. Together, these valence shifts may underlie compulsive stimulant abuse upon pharmacological or behavioural cue exposure in addicted individuals. Additional studies are required to assess the reliability of the STRAP-R in larger samples and to examine its validity in measuring the subjective value attributed to experienced reinforcers or in predicting behaviour.

  6. Temperature dependence of the Raman-active phonon frequencies in indium sulfide

    NASA Astrophysics Data System (ADS)

    Gasanly, N. M.; Özkan, H.; Aydinli, A.; Yilmaz, İ.

    1999-03-01

    The temperature dependence of the Raman-active mode frequencies in indium sulfide was measured in the range from 10 to 300 K. The analysis of the temperature dependence of the A g intralayer optical modes show that Raman frequency shift results from the change of harmonic frequency with volume expansion and anharmonic coupling to phonons of other branches. The pure-temperature contribution (phonon-phonon coupling) is due to three- and four-phonon processes.

  7. Development of the young spine questionnaire

    PubMed Central

    2013-01-01

    Background Back pain in children is common and early onset of back pain has been shown to increase the risk of back pain significantly in adulthood. Consequently, preventive efforts must be targeted the young population but research relating to spinal problems in this age group is scarce. Focus has primarily been on the working age population, and therefore specific questionnaires to measure spinal pain and its consequences, specifically aimed at children and adolescents are absent. The purpose of this study was to develop a questionnaire for schoolchildren filling this gap. Methods The Young Spine Questionnaire (YSQ) was developed in three phases – a conceptualisation, development and testing phase. The conceptualisation phase followed the Wilson and Cleary model and included questions regarding spinal prevalence estimates, pain frequency and intensity, activity restrictions, care seeking behaviour and influence of parental back trouble. Items from existing questionnaires and the “Revised Faces Pain Scale” (rFPS) were included during the development phase. The testing phase consisted of a mixed quantitative and qualitative iterative method carried out in two pilot tests using 4th grade children and focusing on assessment of spinal area location and item validity. Results The testing phase resulted in omission of the pain drawings and the questions and answer categories were simplified in several questions. Agreement between the questionnaire prevalence estimates and the interviews ranged between 83.7% (cervical pain today) and 97.9% (thoracic pain today). To improve the understanding of the spinal boundaries we added bony landmarks to the spinal drawings after pilot test I. This resulted in an improved sense of spinal boundary location in pilot test II. Correlations between the rFPS and the interview pain score ranged between 0.67 (cervical spine) and 0.79 (lumbar spine). Conclusions The Young Spine Questionnaire contains questions that assess spinal pain

  8. Evidence for an Activation Locus of the Word-Frequency Effect in Lexical Decision

    ERIC Educational Resources Information Center

    Allen, Philip A.; Smith, Albert F.; Lien, Mei-Ching; Grabbe, Jeremy; Murphy, Martin D.

    2005-01-01

    The authors report a lexical decision experiment designed to determine whether activation is the locus of the word-frequency effect. K. R. Paap and L. S. Johansen (1994) reported that word frequency did not affect lexical decisions when exposure durations were brief; they accounted for this by proposing that data-limited conditions prevented…

  9. The Event-Related Low-Frequency Activity of Highly and Average Intelligent Children

    ERIC Educational Resources Information Center

    Liu, Tongran; Shi, Jiannong; Zhao, Daheng; Yang, Jie

    2008-01-01

    Using time-frequency analysis techniques to investigate the event-related low-frequency (delta: 0.5-4 Hz; theta: 4-8 Hz) activity of auditory event-related potentials (ERPs) data of highly and average intelligent children, 18 intellectually gifted children, and 18 intellectually average children participated the present study. Present findings…

  10. The Diabetes Self-Management Questionnaire (DSMQ): development and evaluation of an instrument to assess diabetes self-care activities associated with glycaemic control

    PubMed Central

    2013-01-01

    Background Though several questionnaires on self-care and regimen adherence have been introduced, the evaluations do not always report consistent and substantial correlations with measures of glycaemic control. Small ability to explain variance in HbA1c constitutes a significant limitation of an instrument’s use for scientific purposes as well as clinical practice. In order to assess self-care activities which can predict glycaemic control, the Diabetes Self-Management Questionnaire (DSMQ) was designed. Methods A 16 item questionnaire to assess self-care activities associated with glycaemic control was developed, based on theoretical considerations and a process of empirical improvements. Four subscales, ‘Glucose Management’ (GM), ‘Dietary Control’ (DC), ‘Physical Activity’ (PA), and ‘Health-Care Use’ (HU), as well as a ‘Sum Scale’ (SS) as a global measure of self-care were derived. To evaluate its psychometric quality, 261 patients with type 1 or 2 diabetes were assessed with the DSMQ and an established analogous scale, the Summary of Diabetes Self-Care Activities Measure (SDSCA). The DSMQ’s item and scale characteristics as well as factorial and convergent validity were analysed, and its convergence with HbA1c was compared to the SDSCA. Results The items showed appropriate characteristics (mean item-total-correlation: 0.46 ± 0.12; mean correlation with HbA1c: -0.23 ± 0.09). Overall internal consistency (Cronbach’s alpha) was good (0.84), consistencies of the subscales were acceptable (GM: 0.77; DC: 0.77; PA: 0.76; HU: 0.60). Principal component analysis indicated a four factor structure and confirmed the designed scale structure. Confirmatory factor analysis indicated appropriate fit of the four factor model. The DSMQ scales showed significant convergent correlations with their parallel SDSCA scales (GM: 0.57; DC: 0.52; PA: 0.58; HU: n/a; SS: 0.57) and HbA1c (GM: -0.39; DC: -0.30; PA: -0.15; HU: -0.22; SS: -0.40). All correlations with

  11. The Manchester Respiratory Activities of Daily Living questionnaire for use in COPD patients: translation into Portuguese and cross-cultural adaptation for use in Brazil

    PubMed Central

    Junkes-Cunha, Maíra; Mayer, Anamaria Fleig; Reis, Cardine; Yohannes, Abebaw M.; Maurici, Rosemeri

    2016-01-01

    Objective : To translate The Manchester Respiratory Activities of Daily Living (MRADL) questionnaire into Portuguese and to create a version of the MRADL that is cross-culturally adapted for use in Brazil. Methods : The English-language version of the MRADL was translated into Portuguese by two health care researchers who were fluent in English. A consensus version was obtained by other two researchers and a pulmonologist. That version was back-translated into English by another translator who was a native speaker of English and fluent in Portuguese. The cognitive debriefing process consisted in having 10 COPD patients complete the translated questionnaire in order to test its understandability, clarity, and acceptability in the target population. On the basis of the results, the final Portuguese-language version of the MRADL was produced and approved by the committee and one of the authors of the original questionnaire. Results : The author of the MRADL questioned only a few items in the translated version, and some changes were made to the mobility and personal hygiene domains. Cultural differences regarding the domestic activities domain were found, in particular regarding the item "Do you have the ability to do a full clothes wash and hang them out to dry?", due to socioeconomic and climatic issues. The item "Do you take care of your garden?" was questioned by the participants who lived in apartments, being modified to "Do you take care of your garden or plants in your apartment?" Conclusions : The final Portuguese-language version of the MRADL adapted for use in Brazil was found to be easy to understand and easily applied. PMID:26982036

  12. Validity and reliability of questionnaires measuring physical activity self-efficacy, enjoyment, social support among Hong Kong Chinese children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physical activity (PA) correlates have not been extensively studied in Hong Kong children. The aim of this study is to assess the validity and reliability of translated scales to measure PA related self-efficacy, enjoyment and social support in Hong Kong Chinese children. Sample 1 (n=273, aged 8–12 ...

  13. Frequency translating phase conjugation circuit for active retrodirective antenna array

    NASA Astrophysics Data System (ADS)

    Chernoff, R.

    1980-11-01

    An active retrodirective antenna array which has central phasing from a reference antenna element through a "tree" structured network of transmission lines utilizes a number of phase conjugate circuits (PCCs) at each node and a phase reference regeneration circuit (PRR) at each node except the initial node. Each node virtually coincides with an element of the array. A PCC generates the exact conjugate phase of an incident signal using a phase locked loop which combines the phases in an up converter, divides the sum by 2 and mixes the result with the phase in a down converter for phase detection. The PRR extracts the phase from the conjugate phase. Both the PCC and the PRR are not only exact but also free from mixer degeneracy.

  14. Effect of electric current frequency on the activation kinetics of raw charcoal

    SciTech Connect

    Shevchenko, A.O.; Ivakhnyuk, G.K.; Fedorov, N.F.

    1993-12-10

    The effect of electric current frequency on the kinetics of raw charcoal activation with water vapor has been investigated. It was established that under the effect of alternating current the rate constant increases under otherwise equal conditions. A dependence of the reaction rate on the current frequency was found. It was discovered that under the effect of alternating current the activation energy of interaction with water vapor diminishes.

  15. Behavioral Assessment: Questionnaires.

    ERIC Educational Resources Information Center

    Wilson, C. Chrisman

    1980-01-01

    This is a general discussion of the validity, reliability, function, and format of questionnaires designed to measure problem behavior, noncompliance, anxiety, social interaction, hyperactivity, drug use, and sexual behavior. Commonly used questionnaires are cited. (CP)

  16. Frequency domain active vibration control of a flexible plate based on neural networks

    NASA Astrophysics Data System (ADS)

    Liu, Jinxin; Chen, Xuefeng; He, Zhengjia

    2013-06-01

    A neural-network (NN)-based active control system was proposed to reduce the low frequency noise radiation of the simply supported flexible plate. Feedback control system was built, in which neural network controller (NNC) and neural network identifier (NNI) were applied. Multi-frequency control in frequency domain was achieved by simulation through the NN-based control systems. A pre-testing experiment of the control system on a real simply supported plate was conducted. The NN-based control algorithm was shown to perform effectively. These works lay a solid foundation for the active vibration control of mechanical structures.

  17. Strings on a Violin: Location Dependence of Frequency Tuning in Active Dendrites

    PubMed Central

    Das, Anindita; Rathour, Rahul K.; Narayanan, Rishikesh

    2017-01-01

    Strings on a violin are tuned to generate distinct sound frequencies in a manner that is firmly dependent on finger location along the fingerboard. Sound frequencies emerging from different violins could be very different based on their architecture, the nature of strings and their tuning. Analogously, active neuronal dendrites, dendrites endowed with active channel conductances, are tuned to distinct input frequencies in a manner that is dependent on the dendritic location of the synaptic inputs. Further, disparate channel expression profiles and differences in morphological characteristics could result in dendrites on different neurons of the same subtype tuned to distinct frequency ranges. Alternately, similar location-dependence along dendritic structures could be achieved through disparate combinations of channel profiles and morphological characteristics, leading to degeneracy in active dendritic spectral tuning. Akin to strings on a violin being tuned to different frequencies than those on a viola or a cello, different neuronal subtypes exhibit distinct channel profiles and disparate morphological characteristics endowing each neuronal subtype with unique location-dependent frequency selectivity. Finally, similar to the tunability of musical instruments to elicit distinct location-dependent sounds, neuronal frequency selectivity and its location-dependence are tunable through activity-dependent plasticity of ion channels and morphology. In this morceau, we explore the origins of neuronal frequency selectivity, and survey the literature on the mechanisms behind the emergence of location-dependence in distinct forms of frequency tuning. As a coda to this composition, we present some future directions for this exciting convergence of biophysical mechanisms that endow a neuron with frequency multiplexing capabilities. PMID:28348519

  18. Questionnaire Construction Manual

    DTIC Science & Technology

    1976-07-01

    Questionnaire Results A. Overview 8. Social De ■* ability and Acquiescence Response Sets C. Other Response Sets or Errors D. Effects of General Pretest...Attitudes of Respondents E. Effects of Demographic Characteristics of Responses XIII. Evaluating Questionnaire Results A. Overview B. Scoring...34questionnaire" refers to an ordered arrangement of items (questions, in effect ) intended to elicit the evaluations, judgments, comparisons, attitudes

  19. Test–retest reliability and validity of a web-based food-frequency questionnaire for adolescents aged 13–14 to be used in the Norwegian Mother and Child Cohort Study (MoBa)

    PubMed Central

    Øverby, Nina Cecilie; Johannesen, Elisabeth; Jensen, Grete; Skjaevesland, Anne-Kirsti; Haugen, Margaretha

    2014-01-01

    Background The assessment of food intake is challenging and prone to errors; it is therefore important to consider the reliability and validity of the assessment methods. Objective The aim of this study was to analyze the reproducibility and validity of a developed food-frequency questionnaire (FFQ) for use among adolescents. Design In total, 58 students (aged 13–14) from four different schools in the southern part of Norway participated in the reproducibility study of filling out the FFQ 4 weeks apart. In addition, 93 students participated in the relative validity study where the FFQ was compared to 2×24-hour dietary recalls, while 92 students participated in the absolute validity study where the intakes of fatty acids and vitamin D from the FFQ were compared to fatty acids and 25-hydroxy-vitamin D3 in whole blood. Results The median Spearman correlation coefficient for all nutrients in the test–retest reliability study was 0.57. The median Spearman correlation for all nutrients in the relative validity study was 0.26, while the correlations coefficients were low in the absolute validity study with n-3 fatty acid coefficients ranging from 0.05 to 0.25, and absent for vitamin D (r=0.000). Conclusion The test–retest reproducibility was considered good, the relative validity was considered poor to good, and the absolute validity was considered poor. However, the results are comparable to other studies among adolescents. PMID:25371661

  20. Validity of a self-administered food frequency questionnaire used in the 5-year follow-up survey of the JPHC Study Cohort I to assess dietary fiber intake: comparison with dietary records.

    PubMed

    Sasaki, Satoshi; Matsumura, Yasuhiro; Ishihara, Junko; Tsugane, Shoichiro

    2003-01-01

    We examined the validity of a food frequency questionnaire (FFQ) used in the 5-year follow-up survey of the JPHC study for estimation of dietary fiber intake by comparing the intake estimated with dietary records (DR). We developed a food composition table for dietary fiber for the food items included in the FFQ using a substitution method. The Spearman correlation coefficients were slightly higher in crude values (0.48-0.51 in men, 0.40-0.45 in women) than in energy-adjusted values (0.43-0.44 in men, 0.36-0.40 in women). The correlation coefficients of food group-specific dietary fiber (crude) were 0.26 and 0.27 for vegetables, and 0.62 and 0.49 for fruits in men and women, respectively. The mean intakes assessed with the FFQ and DR were not statistically different either for water-soluble or -insoluble fiber in both men and women. However, the fruit fiber assessed with FFQ was significantly over- and the vegetable fiber was underestimated compared with those assessed with DRs. The FFQ can be used for ranking individuals for dietary fiber intakes in epidemiologic studies, despite the difficulty in estimating mean intake.

  1. Short-term changes in solar oscillation frequencies and solar activity

    NASA Technical Reports Server (NTRS)

    Woodard, M. F.; Libbrecht, K. G.; Kuhn, J. R.; Murray, N.

    1991-01-01

    It is shown that the frequencies of solar rho-mode oscillations change significantly over periods as short as one month. These changes correlate significantly with variations in the strength of surface solar activity as measured by the average, over the sun's visible surface, of the magnitude of the line-of-sight magnetic field component from magnetograms. The frequency and mean magnetic variations are found to obey a linear relationship. It is seen that the mean frequency shift at any time depends on the history of solar activity over an interval of, at most, several months prior to the measurement and conclude that the dominant mechanism of the frequency shift is correlated with surface magnetic activity.

  2. Diverse impact of neuronal activity at θ frequency on hippocampal long-term plasticity.

    PubMed

    Wójtowicz, Tomasz; Mozrzymas, Jerzy W

    2015-09-01

    Brain oscillatory activity is considered an essential aspect of brain function, and its frequency can vary from <1 Hz to >200 Hz, depending on the brain states and projection. Episodes of rhythmic activity accompany hippocampus-dependent learning and memory in vivo. Therefore, long-term synaptic potentiation (LTP) and long-term depression, which are considered viable substrates of learning and memory, are often experimentally studied in paradigms of patterned high-frequency (>50 Hz) and low-frequency (<5 Hz) stimulation. However, the impact of intermediate frequencies on neuronal plasticity remains less well understood. In particular, hippocampal neurons are specifically tuned for activity at θ frequency (4-8 Hz); this band contributes significantly to electroencephalographic signals, and it is likely to be involved in shaping synaptic strength in hippocampal circuits. Here, we review in vitro and in vivo studies showing that variation of θ-activity duration may affect long-term modification of synaptic strength and neuronal excitability in the hippocampus. Such θ-pulse-induced neuronal plasticity 1) is long-lasting, 2) may be built on previously stabilized potentiation in the synapse, 3) may produce opposite changes in synaptic strength, and 4) requires complex molecular machinery. Apparently innocuous episodes of low-frequency synaptic activity may have a profound impact on network signaling, thereby contributing to information processing in the hippocampus and beyond. In addition, θ-pulse-induced LTP might be an advantageous protocol in studies of specific molecular mechanisms of synaptic plasticity.

  3. Activation of attention networks using frequency analysis of a simple auditory-motor paradigm.

    PubMed

    Astrakas, Loukas G; Teicher, Martin; Tzika, A Aria

    2002-04-01

    The purpose of this study was to devise a paradigm that stimulates attention using a frequency-based analysis of the data acquired during a motor task. Six adults (30-40 years of age) and one child (10 years) were studied. Each subject was requested to attend to "start" and "stop" commands every 20 s alternatively and had to respond with the motor task every second time. Attention was stimulated during a block-designed, motor paradigm in which a start-stop commands cycle produced activation at the fourth harmonic of the motor frequency. We disentangled the motor and attention functions using statistical analysis with subspaces spanned by vectors generated by a truncated trigonometric series of motor and attention frequency. During our auditory-motor paradigm, all subjects showed activation in areas that belong to an extensive attention network. Attention and motor functions were coactivated but with different frequencies. While the motor-task-related areas were activated with slower frequency than attention, the activation in the attention-related areas was enhanced every time the subject had to start or end the motor task. We suggest that although a simple block-designed, auditory-motor paradigm stimulates the attention network, motor preparation, and motor inhibition concurrently, a frequency-based analysis can distinguish attention from motor functions. Due to its simplicity the paradigm can be valuable in studying children with attention deficit disorders.

  4. Validation of soy protein estimates from a food-frequency questionnaire with repeated 24-h recalls and isoflavonoid excretion in overnight urine in a Western population with a wide range of soy intakes2

    PubMed Central

    Jaceldo-Siegl, Karen; Fraser, Gary E; Chan, Jacqueline; Franke, Adrian; Sabaté, Joan

    2013-01-01

    Background Evidence of the benefits of soy on cancer risk in Western populations is inconsistent, in part because of the low intake of soy in these groups. Objective We assessed the validity of soy protein estimates from food-frequency questionnaires (FFQs) in a sample of Adventist Health Study-2 participants with a wide range of soy intakes. Design We obtained dietary intake data from 100 men and women (43 blacks and 57 nonblacks). Soy protein estimates from FFQs were compared against repeated 24-h recalls and urinary excretion of daidzein, genistein, total isoflavonoids (TIFLs), and equol (measured by HPLC/photodiode array/mass spectrometry) as reference criteria. We calculated Pearson and Spearman correlation coefficients (with 95% CIs) for FFQ–24-h recall, 24 h-recall–urinary excretion, and FFQ–urinary excretion pairs. Results Among soy users, mean (± SD) soy protein values were 12.12 ± 10.80 g/d from 24-h recalls and 9.43 ± 7.83 g/d from FFQs. The unattenuated correlation (95% CI) between soy protein estimates from 24-h recalls and FFQs was 0.57 (0.32, 0.75). Correlation coefficients between soy protein intake from 24-h recalls and urinary isoflavonoids were 0.72 (0.43, 0.96) for daidzein, 0.67 (0.43, 0.91) for genistein, and 0.72 (0.47, 0.98) for TIFLs. Between FFQs and urinary excretion, these were 0.50 (0.32, 0.65), 0.48 (0.29, 0.61), and 0.50 (0.32, 0.64) for daidzein, genistein, and TIFLs, respectively. Conclusions Soy protein estimates from questionnaire were significantly correlated with soy protein from 24-h recalls and urinary excretion of daidzein, genistein, and TIFLs. The Adventist Health Study-2 FFQ is a valid instrument for assessing soy protein in a population with a wide range of soy intakes. PMID:18469267

  5. Development of narrow-band low-frequency active filters for DC railway vehicles

    SciTech Connect

    Weem, J. van der

    1994-12-31

    To avoid failures in the signalling systems of light-rail plants low frequency components of the line current may often not exceed specified limits. These limits are in the range of 0.1% of the line current. Presently the low frequency components are damped with passive filters. This paper proposes an active filter to reduce the low frequency components of the line current. A method for dimensioning a digital control algorithm for active filters, which are implemented in the railway vehicle, is presented. Time domain simulations are carried out. They predicted a good behaviour of the active filter for all kinds of vehicles and different realistic conditions. The active filter was realized with an IGBT-inverter and the filter algorithm was implemented in a microcontroller, to ensure a high flexibility. The measurements presented in this paper prove the validity of the simulations. 19 refs.

  6. Decreases in Theta and Increases in High Frequency Activity Underlie Associative Memory Encoding

    PubMed Central

    Greenberg, Jeffrey A.; Burke, John F.; Haque, Rafi; Kahana, Michael J.; Zaghloul, Kareem A.

    2015-01-01

    Episodic memory encoding refers to the cognitive process by which items and their associated contexts are stored in memory. To investigate changes directly attributed to the formation of explicit associations, we examined oscillatory power captured through intracranial electroencephalography (iEEG) as 27 neurosurgical patients receiving subdural and depth electrodes for seizure monitoring participated in a paired associates memory task. We examined low (3–8 Hz) and high (45–95 Hz) frequency activity, and found that the successful formation of new associations was accompanied by broad decreases in low frequency activity and a posterior to anterior progression of increases in high frequency activity in the left hemisphere. These data suggest that the observed patterns of activity may reflect the neural mechanisms underlying the formation of novel item-item associations. PMID:25862266

  7. Relationship between Frequency and Intensity of Physical Activity and Health Behaviors of Adolescents

    ERIC Educational Resources Information Center

    Delisle, Tony T.; Werch, Chudley E.; Wong, Alvin H.; Bian, Hui; Weiler, Robert

    2010-01-01

    Background: While studies have determined the importance of physical activity in advancing health outcomes, relatively few have explored the relationship between exercise and various health behaviors of adolescents. The purpose of this study is to examine the relationship between frequency and intensity of physical activity and both health risk…

  8. A study of amplitude information-frequency characteristics for underwater active electrolocation system.

    PubMed

    Peng, Jiegang

    2015-11-04

    Weakly electric fish sense their surroundings in complete darkness by their active electrolocation system. For biologists, the active electrolocation system has been investigated for near 60 years. And for engineers, bio-inspired active electrolocation sensor has been investigated for about 20 years. But how the amplitude information response will be affected by frequencies of detecting electric fields in the active electrolocation system was rarely investigated. In this paper, an electrolocation experiment system has been built. The amplitude information-frequency characteristics (AIFC) of the electrolocation system for sinusoidal electric fields of varying frequencies have been investigated. We find that AIFC of the electrolocation system have relevance to the material properties and geometric features of the probed object and conductivity of surrounding water. Detect frequency dead zone (DFDZ) and frequency inflection point (FIP) of AIFC for the electrolocation system were found. The analysis model of the electrolocation system has been investigated for many years, but DFDZ and FIP of AIFC can be difficult to explain by those models. In order to explain those AIFC phenomena for the electrolocation system, a simple relaxation model based on Cole-Cole model which is not only a mathematical explanation but it is a physical one for the electrolocation system was advanced. We also advance a hypothesis for physical mechanism of weakly electrical fish electrolocation system. It may have reference value for physical mechanism of weakly electrical fish active electrolocation system.

  9. Low Frequency Stimulation Decreases Seizure Activity in a Mutation Model of Epilepsy

    PubMed Central

    Kile, Kara Buehrer; Tian, Nan; Durand, Dominique M.

    2013-01-01

    Summary Purpose To investigate brain electrical activity in Q54 mice that display spontaneous seizures because of a gain-of-function mutation of the Scn2a sodium channel gene, and to evaluate the efficacy of low frequency deep brain stimulation (DBS) for seizure frequency reduction. Methods EEG, EMG, and hippocampal deep electrodes were implanted into Q54 mice expressing an epileptic phenotype (n = 6). Chronic six channel recordings (wideband, 0.1–300 Hz) were stored 24 hours a day for more than 12 days. Low Frequency stimulation (LFS) (3Hz, square wave, biphasic, 100μs, 400μA) was applied to the ventral hippocampal commisure (VHC) in alternating five minute cycles (on or off) 24 hours a day for a period of four days. Results LFS (3Hz) resulted in a significant reduction in seizure frequency and duration (21% and 35%, p<0.05), when applied to the VHC of epileptic Q54 mice (n = 6). Seizure frequency was not directly affected by stimulation state (“on” versus “off”). Conclusion LFS applied at a frequency of 3Hz significantly reduced seizure frequency and duration in the Q54 model. Furthermore, the reduction of seizure frequency and duration by LFS was not immediate but had a delayed and lasting effect, supporting complex, indirect mechanisms of action. PMID:20659150

  10. Active vibration control using optimized modified acceleration feedback with Adaptive Line Enhancer for frequency tracking

    NASA Astrophysics Data System (ADS)

    Nima Mahmoodi, S.; Craft, Michael J.; Southward, Steve C.; Ahmadian, Mehdi

    2011-03-01

    Modified acceleration feedback (MAF) control, an active vibration control method that uses collocated piezoelectric actuators and accelerometer is developed and its gains optimized using an optimal controller. The control system consists of two main parts: (1) frequency adaptation that uses Adaptive Line Enhancer (ALE) and (2) an optimized controller. Frequency adaptation method tracks the frequency of vibrations using ALE. The obtained frequency is then fed to MAF compensators. This provides a unique feature for MAF, by extending its domain of capabilities from controlling a certain mode of vibrations to any excited mode. The optimized MAF controller can provide optimal sets of gains for a wide range of frequencies, based on the characteristics of the system. The experimental results show that the frequency tracking method works quite well and fast enough to be used in a real-time controller. ALE parameters are numerically and experimentally investigated and tuned for optimized frequency tracking. The results also indicate that the MAF can provide significant vibration reduction using the optimized controller. The control power varies for vibration suppression at different resonance frequencies; however, it is always optimized.

  11. Reliability and validity of the modified child and adolescent physical activity and nutrition survey (CAPANS-C) questionnaire examining potential correlates of physical activity participation among Chinese-Australian youth

    PubMed Central

    2014-01-01

    Background To date, few questionnaires examining psychosocial influences of physical activity (PA) participation have been psychometrically tested among Culturally and Linguistically Diverse (CALD) youth. An understanding of these influences may help explain the observed differences in PA among CALD youth. Therefore, this study examined the reliability and predictive validity of a brief self-report questionnaire examining potential psychological and social correlates of physical activity among a sample of Chinese-Australian youth. Methods Two Chinese-weekend cultural schools from eastern metropolitan Melbourne consented to participate in this study. In total, 505 students aged 11 to 16 years were eligible for inclusion in the present study, and of these, 106 students agreed to participate (21% response rate). Participants completed at 37-item self-report questionnaire examining perceived psychological and social influences on physical activity participation twice, with a test–retest interval of 7 days. Predictive validity, internal consistency and test–retest reliability were evaluated using exploratory factor analyses, Cronbach’s α coefficient, and the intraclass correlation coefficient (ICC) respectively. Predictive validity was assessed by correlating responses against duration spent in self-reported moderate-to-vigorous physical activity (MVPA). Results The exploratory factor analysis revealed a nine factor structure, with the majority of factors exhibiting high internal consistency (α ≥ 0.6). In addition, four of the nine factors had an ICC ≥ 0.6. Spearman rank-order correlations coefficients between the nine factors and self-reported minutes spent in MVPA ranged from -0.5 to 0.3 for all participants. Conclusion This is the first study to examine the psychometric properties of a potential psychological and social correlates questionnaire among Chinese-Australian youth. The questionnaire was found to provide reliable estimates on a range

  12. Noninvasive Imaging of the High Frequency Brain Activity in Focal Epilepsy Patients

    PubMed Central

    Lu, Yunfeng; Worrell, Gregory A.; Zhang, Huishi Clara; Yang, Lin; Brinkmann, Benjamin; Nelson, Cindy

    2014-01-01

    High frequency (HF) activity represents a potential biomarker of the epileptogenic zone in epilepsy patients, the removal of which is considered to be crucial for seizure-free surgical outcome. We proposed a high frequency source imaging (HFSI) approach to noninvasively image the brain sources of scalp recorded high frequency EEG activity. Both computer simulation and clinical patient data analysis were performed to investigate the feasibility of using the HFSI approach to image the sources of HF activity from noninvasive scalp EEG recordings. The HF activity was identified from high-density scalp recordings after high-pass filtering the EEG data and the EEG segments with HF activity were concatenated together to form repetitive HF activity. Independent component analysis was utilized to extract the components corresponding to the HF activity. Noninvasive EEG source imaging using realistic geometric boundary element head modeling was then applied to image the sources of the pathological HF brain activity. Five medically intractable focal epilepsy patients were studied and the estimated sources were found to be concordant with the surgical resection or intracranial recordings of the patients. The present study demonstrates, for the first time, that source imaging from the scalp HF activity could help to localize the seizure onset zone (SOZ) and provide a novel noninvasive way of studying the epileptic brain in humans. This study also indicates the potential application of studying HF activity in the pre-surgical planning of medically intractable epilepsy patients. PMID:24845275

  13. Validity of a Self-Administered Food-Frequency Questionnaire for Assessing Amino Acid Intake in Japan: Comparison With Intake From 4-Day Weighed Dietary Records and Plasma Levels

    PubMed Central

    Iwasaki, Motoki; Ishihara, Junko; Takachi, Ribeka; Todoriki, Hidemi; Yamamoto, Hiroshi; Miyano, Hiroshi; Yamaji, Taiki; Tsugane, Shoichiro

    2016-01-01

    Background Interest in the physiological roles of amino acids and their impact on health outcomes is substantial and growing. This interest has prompted assessment of the habitual intake of amino acids for use in epidemiologic studies and in clarifying the association between habitual intake and plasma levels of amino acids. Here, we investigated the validity of ranking individuals according to dietary amino acid intake as estimated using a food frequency questionnaire (FFQ) in comparison with intakes from dietary records (DRs) and plasma levels. Methods A total of 139 men and women selected from examinees of the cancer screening program at the Research Center for Cancer Prevention and Screening, National Cancer Center, Japan, provided 4-day weighed DRs, a semi-quantitative FFQ, and plasma samples. Plasma levels of amino acids were measured using the UF-Amino Station system. Results Spearman rank correlation coefficients of energy-adjusted intake of amino acids from the DR and FFQ ranged from 0.40 to 0.65 for men and from 0.35 to 0.46 for women. Correlation coefficients of energy-adjusted intake from the DR and plasma levels ranged from −0.40 to 0.25 for men and from −0.16 to 0.11 for women. Similarly, no significant positive correlation coefficients were observed between intake from the FFQ and plasma levels for either men or women. Conclusions We confirmed that this FFQ has moderate validity in estimating amino acid intake when 4-day weighed DRs are used as a reference method, suggesting that it is suitable for ranking individuals living in urban areas in Japan by amino acid intake. PMID:26277881

  14. Active shielding to reduce low frequency disturbances in direct current near biomagnetic measurements

    NASA Astrophysics Data System (ADS)

    Platzek, D.; Nowak, H.; Giessler, F.; Röther, J.; Eiselt, M.

    1999-05-01

    Measurements of dc near biomagnetic fields are disturbed by low frequency noise that is not reduced sufficiently by most of the magnetically shielded rooms or gradiometers. For this reason an active shielding system has been developed at the Biomagnetic Center of the University of Jena. This work describes the principle of the active shielding system and demonstrates its properties concerning the attenuation of disturbing fields, frequency range, and some applications in biomedical measurements. We achieved a reduction of external low frequency magnetic fields by more than 50 dB and an attenuation of the field gradient by about 25 dB. This active shielding enables measurements of near dc biomagnetic fields in investigations of periinfarct depolarizations after ischemic stroke and spreading depression in migraine patients.

  15. Low-frequency absorption using a two-layer system with active control of input impedance.

    PubMed

    Cobo, Pedro; Fernández, Alejandro; Doutres, Olivier

    2003-12-01

    Broadband noise absorption, including low frequencies, may be obtained by a hybrid passive-active two-layer system. A porous layer in front of an air layer provides passive absorption, at medium and high frequencies. Active control of the input impedance of the two-layer system yields absorption at low frequencies. The active control system can implement either pressure-release or impedance-matching conditions. A simple analytical model based upon plane waves propagating in a tube permits the comparison of both control strategies. The results of this simple model show that the pressure-release condition affords higher absorption than the impedance-matching condition for some combinations of geometrical and material parameters. Experimental results corroborate the good performance of the pressure-release condition under the prescribed geometrical setup.

  16. Operational Definition of Active and Healthy Aging (AHA): The European Innovation Partnership (EIP) on AHA Reference Site Questionnaire: Montpellier October 20-21, 2014, Lisbon July 2, 2015.

    PubMed

    Bousquet, Jean; Malva, Joao; Nogues, Michel; Mañas, Leocadio Rodriguez; Vellas, Bruno; Farrell, John

    2015-12-01

    A core operational definition of active and healthy aging (AHA) is needed to conduct comparisons. A conceptual AHA framework proposed by the European Innovation Partnership on Active and Healthy Ageing Reference Site Network includes several items such as functioning (individual capability and underlying body systems), well-being, activities and participation, and diseases (including noncommunicable diseases, frailty, mental and oral health disorders). The instruments proposed to assess the conceptual framework of AHA have common applicability and availability attributes. The approach includes core and optional domains/instruments depending on the needs and the questions. A major common domain is function, as measured by the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). WHODAS 2.0 can be used across all diseases and healthy individuals. It covers many of the AHA dimensions proposed by the Reference Site network. However, WHODAS 2.0 does not include all dimensions proposed for AHA assessment. The second common domain is health-related quality of life (HRQoL). A report of the AHA questionnaire in the form of a spider net has been proposed to facilitate usual comparisons across individuals and groups of interest.

  17. Concurrent fast and slow synchronized efferent phrenic activities in time and frequency domain.

    PubMed

    Schmid, K; Böhmer, G; Weichel, T

    1990-09-24

    In urethane-anesthetized or decerebrated vagotomized rabbits efferent multifiber activity of the phrenic nerve was investigated for synchronized activities both in time and frequency domains. When respiratory drive was steadily increased by either an elevation of end-tidal CO2 concentration or i.v. administration of 4-aminopyridine, medium-frequency oscillations (MFO) first increased, then decreased and finally became absent. The power of high-frequency oscillations (HFO) steadily rose with increasing respiratory drive. In contrast to HFO which revealed a unimodal spectral peak of mostly small bandwidth, the MFO spectrum in most cases consisted of a broad complex. This complex in some cases was composed of two distinct peaks, i.e. MFO were heterogenous. The low- and high-frequency fractions of the MFO complex were related predominantly to the first and last third of inspiration, respectively. Examination of the on-going multifiber activity of the phrenic nerve with an expanded time scale revealed that lower frequency MFO probably result from synchronized ramp-like wave activity during early and mid-inspiration. The duration of the observed ramps well matched the corresponding MFO frequency. We suggest that these ramps might result from propagated synchronized waves of high-threshold phrenic motoneurons. During the last part of inspiration, however, MFO, like HFO, resulted from burst-like synchronized discharge of phenic motoneurons. Thus HFO are superimposed on ramp-like and burst-like activity of the MFO. It is assumed that the decline of MFO at high respiratory drive may be due to the increasing strength of HFO bursts which interrupt ramp activity in the MFO range and thus let MFO appear 'invisible' to the recording electrode. Both MFO and HFO were visually detectable in postinspiration.

  18. Comparison of psychometric properties between usual-week and past-week self-reported physical activity questionnaires: a systematic review.

    PubMed

    Doma, Kenji; Speyer, Renée; Leicht, Anthony S; Cordier, Reinie

    2017-01-31

    The aim was to critically appraise the methodological quality of studies and determine the psychometric qualities of Past-week and Usual-week Physical Activity Questionnaires (PAQs). Data sources were obtained from Pubmed and Embase. The eligibility criteria for selecting studies included: 1) at least one psychometric property of PAQs was examined in adults; 2) the PAQs either had a recall period of usual 7-days (Usual-week PAQs) within the past 12 months or during the past 7-days (Past-week PAQs); and 3) PAQs were self-administered. Study quality was evaluated using the COSMIN taxonomy and the overall psychometric qualities evaluated using pre-established psychometric criteria. Overall, 45 studies were reviewed to assess the psychometric properties of 21 PAQs with the methodological quality of most studies showing good to excellent ratings. When the relationship between PAQs and other instruments (i.e., convergent validity) were compared between recall methods, Past-week PAQs appeared to have stronger correlations than Usual-week PAQs. For the overall psychometric quality, the Incidental and Planned Exercise Questionnaire for the Usual-week (IPEQ-WA) and for the Past-week (IPEQ-W) had the greatest number of positive ratings. For all included PAQs, very few psychometric properties were assessed with poor ratings for the majority of the overall qualities of psychometric properties indicating the limitation of current PAQs. More research that covers a greater spectrum of psychometric properties is required to gain a better understanding of the qualities of current PAQs.

  19. Physician Enabling Skills Questionnaire

    PubMed Central

    Hudon, Catherine; Lambert, Mireille; Almirall, José

    2015-01-01

    Abstract Objective To evaluate the reliability and validity of the newly developed Physician Enabling Skills Questionnaire (PESQ) by assessing its internal consistency, test-retest reliability, concurrent validity with patient-centred care, and predictive validity with patient activation and patient enablement. Design Validation study. Setting Saguenay, Que. Participants One hundred patients with at least 1 chronic disease who presented in a waiting room of a regional health centre family medicine unit. Main outcome measures Family physicians’ enabling skills, measured with the PESQ at 2 points in time (ie, while in the waiting room at the family medicine unit and 2 weeks later through a mail survey); patient-centred care, assessed with the Patient Perception of Patient-Centredness instrument; patient activation, assessed with the Patient Activation Measure; and patient enablement, assessed with the Patient Enablement Instrument. Results The internal consistency of the 6 subscales of the PESQ was adequate (Cronbach α = .69 to .92). The test-retest reliability was very good (r = 0.90; 95% CI 0.84 to 0.93). Concurrent validity with the Patient Perception of Patient-Centredness instrument was good (r = −0.67; 95% CI −0.78 to −0.53; P < .001). The PESQ accounts for 11% of the total variance with the Patient Activation Measure (r2 = 0.11; P = .002) and 19% of the variance with the Patient Enablement Instrument (r2 = 0.19; P < .001). Conclusion The newly developed PESQ presents good psychometric properties, allowing for its use in practice and research. PMID:26889507

  20. Medium-frequency impulsive-thrust-activated liquid hydrogen reorientation with Geyser

    NASA Technical Reports Server (NTRS)

    Hung, R. J.; Shyu, K. L.

    1992-01-01

    Efficient technique are studied for accomplishing propellant resettling through the minimization of propellant usage through impulsive thrust. A comparison between the use of constant-thrust and impulsive-thrust accelerations for the activation of propellant resettlement shows that impulsive thrust is superior to constant thrust for liquid reorientation in a reduced-gravity environment. This study shows that when impulsive thrust with 0.1-1.0-, and 10-Hz frequencies for liquid-fill levels in the range between 30-80 percent is considered, the selection of 1.0-Hz-frequency impulsive thrust over the other frequency ranges of impulsive thrust is the optimum. Characteristics of the slosh waves excited during the course of 1.0-Hz-frequency impulsive-thrust liquid reorientation were also analyzed.

  1. Utah Drug Use Questionnaire.

    ERIC Educational Resources Information Center

    Governor's Citizen Advisory Committee on Drugs, Salt Lake City, UT.

    This questionnaire assesses drug use practices in junior and senior high school students. The 21 multiple choice items pertain to drug use practices, use history, available of drugs, main reason for drug use, and demographic data. The questionnaire is untimed, group administered, and may be given by the classroom teacher in about 10 minutes. Item…

  2. Write Your Own Questionnaire

    ERIC Educational Resources Information Center

    Cook, David I.

    1975-01-01

    Contends that student evaluative questionnaires should be designed by instructors themselves to help improve their classroom performance and therefore should contain only questions that students are capable of answering objectively and not, for instance, questions about the relevancy of the course. Contains a sample questionnaire. (GH)

  3. Wesleyan University Student Questionnaire.

    ERIC Educational Resources Information Center

    Haagen, C. Hess

    This questionnaire assesses marijuana use practices in college students. The 30 items (multiple choice or free response) are concerned with personal and demographic data, marijuana smoking practices, use history, effects from smoking marijuana, present attitude toward the substance, and use of other drugs. The Questionnaire is untimed and…

  4. Increased frequency of social interaction is associated with enjoyment enhancement and reward system activation.

    PubMed

    Kawamichi, Hiroaki; Sugawara, Sho K; Hamano, Yuki H; Makita, Kai; Kochiyama, Takanori; Sadato, Norihiro

    2016-04-19

    Positive social interactions contribute to the sense that one's life has meaning. Enjoyment of feelings associated through social interaction motivates humans to build social connections according to their personal preferences. Therefore, we hypothesized that social interaction itself activates the reward system in a manner that depends upon individual interaction preferences. To test this hypothesis, we conducted a functional magnetic resonance imaging (fMRI) study in which 38 participants played a virtual ball-toss game in which the number of ball tosses to the participant was either similar to (normal-frequency condition) or higher than (high-frequency condition) the number of tosses to the other players. Participants reported greater-than-anticipated enjoyment during the high-frequency condition, suggesting that receiving a social reward led to unexpected positive feelings. Consistent with this, the high-frequency condition produced stronger activation in the ventral striatum, which is part of the reward system, and the precuneus, representing positive self-image, which might be translated to social reward. Furthermore, ventral striatal activation covaried with individual participants' preference for interactions with others. These findings suggest that an elevated frequency of social interaction is represented as a social reward, which might motivate individuals to promote social interaction in a manner that is modulated by personal preference.

  5. Increased frequency of social interaction is associated with enjoyment enhancement and reward system activation

    PubMed Central

    Kawamichi, Hiroaki; Sugawara, Sho K.; Hamano, Yuki H.; Makita, Kai; Kochiyama, Takanori; Sadato, Norihiro

    2016-01-01

    Positive social interactions contribute to the sense that one’s life has meaning. Enjoyment of feelings associated through social interaction motivates humans to build social connections according to their personal preferences. Therefore, we hypothesized that social interaction itself activates the reward system in a manner that depends upon individual interaction preferences. To test this hypothesis, we conducted a functional magnetic resonance imaging (fMRI) study in which 38 participants played a virtual ball-toss game in which the number of ball tosses to the participant was either similar to (normal-frequency condition) or higher than (high-frequency condition) the number of tosses to the other players. Participants reported greater-than-anticipated enjoyment during the high-frequency condition, suggesting that receiving a social reward led to unexpected positive feelings. Consistent with this, the high-frequency condition produced stronger activation in the ventral striatum, which is part of the reward system, and the precuneus, representing positive self-image, which might be translated to social reward. Furthermore, ventral striatal activation covaried with individual participants’ preference for interactions with others. These findings suggest that an elevated frequency of social interaction is represented as a social reward, which might motivate individuals to promote social interaction in a manner that is modulated by personal preference. PMID:27090501

  6. NO signalling decodes frequency of neuronal activity and generates synapse-specific plasticity in mouse cerebellum

    PubMed Central

    Namiki, Shigeyuki; Kakizawa, Sho; Hirose, Kenzo; Iino, Masamitsu

    2005-01-01

    Nitric oxide (NO) is an intercellular messenger regulating neuronal functions. To visualize NO signalling in the brain, we generated a novel fluorescent NO indicator, which consists of the heme-binding region (HBR) of soluble guanylyl cyclase and the green fluorescent protein. The indicator (HBR–GFP) was expressed in the Purkinje cells of the mouse cerebellum and we imaged NO signals in acute cerebellar slices upon parallel fibre (PF) activation with a train of burst stimulations (BS, each BS consisting of five pulses at 50 Hz). Our results showed that the intensity of synaptic NO signal decays steeply with the distance from the synaptic input near PF–Purkinje cell synapses and generates synapse-specific long-term potentiation (LTP). Furthermore, the NO release level has a bell-shaped dependence on the frequency of PF activity. At an optimal frequency (1 Hz), but not at a low frequency (0.25 Hz) of a train of 60 BS, NO release as well as LTP was induced. However, both NO release and LTP were significantly reduced at higher frequencies (2–4 Hz) of BS train due to cannabinoid receptor-mediated retrograde inhibition of NO generation at the PF terminals. These results suggest that synaptic NO signalling decodes the frequency of neuronal activity to mediate synaptic plasticity at the PF–Purkinje cell synapse. PMID:15919714

  7. Evaluation of multiple-frequency, active and passive acoustics as surrogates for bedload transport

    USGS Publications Warehouse

    Wood, Molly S.; Fosness, Ryan L.; Pachman, Gregory; Lorang, Mark; Tonolla, Diego

    2015-01-01

    The use of multiple-frequency, active acoustics through deployment of acoustic Doppler current profilers (ADCPs) shows potential for estimating bedload in selected grain size categories. The U.S. Geological Survey (USGS), in cooperation with the University of Montana (UM), evaluated the use of multiple-frequency, active and passive acoustics as surrogates for bedload transport during a pilot study on the Kootenai River, Idaho, May 17-18, 2012. Four ADCPs with frequencies ranging from 600 to 2000 kHz were used to measure apparent moving bed velocities at 20 stations across the river in conjunction with physical bedload samples. Additionally, UM scientists measured the sound frequencies of moving particles with two hydrophones, considered passive acoustics, along longitudinal transects in the study reach. Some patterns emerged in the preliminary analysis which show promise for future studies. Statistically significant relations were successfully developed between apparent moving bed velocities measured by ADCPs with frequencies 1000 and 1200 kHz and bedload in 0.5 to 2.0 mm grain size categories. The 600 kHz ADCP seemed somewhat sensitive to the movement of gravel bedload in the size range 8.0 to 31.5 mm, but the relation was not statistically significant. The passive hydrophone surveys corroborated the sample results and could be used to map spatial variability in bedload transport and to select a measurement cross-section with moving bedload for active acoustic surveys and physical samples.

  8. Accumulated source imaging of brain activity with both low and high-frequency neuromagnetic signals

    PubMed Central

    Xiang, Jing; Luo, Qian; Kotecha, Rupesh; Korman, Abraham; Zhang, Fawen; Luo, Huan; Fujiwara, Hisako; Hemasilpin, Nat; Rose, Douglas F.

    2014-01-01

    Recent studies have revealed the importance of high-frequency brain signals (>70 Hz). One challenge of high-frequency signal analysis is that the size of time-frequency representation of high-frequency brain signals could be larger than 1 terabytes (TB), which is beyond the upper limits of a typical computer workstation's memory (<196 GB). The aim of the present study is to develop a new method to provide greater sensitivity in detecting high-frequency magnetoencephalography (MEG) signals in a single automated and versatile interface, rather than the more traditional, time-intensive visual inspection methods, which may take up to several days. To address the aim, we developed a new method, accumulated source imaging, defined as the volumetric summation of source activity over a period of time. This method analyzes signals in both low- (1~70 Hz) and high-frequency (70~200 Hz) ranges at source levels. To extract meaningful information from MEG signals at sensor space, the signals were decomposed to channel-cross-channel matrix (CxC) representing the spatiotemporal patterns of every possible sensor-pair. A new algorithm was developed and tested by calculating the optimal CxC and source location-orientation weights for volumetric source imaging, thereby minimizing multi-source interference and reducing computational cost. The new method was implemented in C/C++ and tested with MEG data recorded from clinical epilepsy patients. The results of experimental data demonstrated that accumulated source imaging could effectively summarize and visualize MEG recordings within 12.7 h by using approximately 10 GB of computer memory. In contrast to the conventional method of visually identifying multi-frequency epileptic activities that traditionally took 2–3 days and used 1–2 TB storage, the new approach can quantify epileptic abnormalities in both low- and high-frequency ranges at source levels, using much less time and computer memory. PMID:24904402

  9. Hemodynamic low-frequency oscillation reflects resting-state neuronal activity in rodent brain

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Liu, Peng; Li, James; Pan, Yingtian; Du, Congwu

    2015-03-01

    Brain functional connectivity is mapped using spontaneous low-frequency oscillations (LFOs) in blood-oxygen-leveldependent (BOLD) signals using fMRI. However, the origin of spontaneous BOLD oscillations remains elusive. Specifically, the coupling of regional hemodynamic LFOs to neuronal activity in a resting brain is rarely examined directly. Here we present a method based on instantaneous-frequency (IF) analysis to detect regional LFOs of cerebral blood flow (CBF) along with local-field potential (LFP) changes of neurons in resting state to study neurovascular coupling. CBF and LFP were simultaneously acquired using laser Doppler flowmetry (LDF) and electroencephalography in the rat's somatosensory cortex with high temporal resolution (i.e., 20Hz for CBF and 2kHz for LDF, respectively). Instead of fast Fourier transform analysis, a peak-detection algorithm was used to define the LFP activities and CBF spontaneous oscillations in the time domain and the time lapses were used to calculate the IFs of hemodynamic (i.e., CBF) oscillations and neuronal (i.e., LFP) activities. Our results showed that the CBF mostly oscillated at ~0.1Hz with a full-half-bandwidth of [0.08Hz, 0.15Hz]. In addition, the maximal frequency of LFP firings was also approximately at 0.1Hz, which collaborated with to the frequency of CBF oscillations. Interestingly, CBF increased linearly with the LFP activity up to 0.15Hz (r=0.93), and both signals then decreased rapidly as a function of activity frequency. This indicates the spontaneous hemodynamic LFOs were associated with neuronal activities, thus confirming the neuronal origin of the hemodynamic oscillations.

  10. Theta and High-Frequency Activity Mark Spontaneous Recall of Episodic Memories

    PubMed Central

    Burke, John F.; Sharan, Ashwini D.; Sperling, Michael R.; Ramayya, Ashwin G.; Evans, James J.; Healey, M. Karl; Beck, Erin N.; Davis, Kathryn A.; Lucas, Timothy H.

    2014-01-01

    Humans possess the remarkable ability to search their memory, allowing specific past episodes to be re-experienced spontaneously. Here, we administered a free recall test to 114 neurosurgical patients and used intracranial theta and high-frequency activity (HFA) to identify the spatiotemporal pattern of neural activity underlying spontaneous episodic retrieval. We found that retrieval evolved in three electrophysiological stages composed of: (1) early theta oscillations in the right temporal cortex, (2) increased HFA in the left hemisphere including the medial temporal lobe (MTL), left inferior frontal gyrus, as well as the ventrolateral temporal cortex, and (3) motor/language activation during vocalization of the retrieved item. Of these responses, increased HFA in the left MTL predicted recall performance. These results suggest that spontaneous recall of verbal episodic memories involves a spatiotemporal pattern of spectral changes across the brain; however, high-frequency activity in the left MTL represents a final common pathway of episodic retrieval. PMID:25143616

  11. Physical Activity Levels, Frequency, and Type Among Adolescents with and Without Autism Spectrum Disorder.

    PubMed

    Stanish, Heidi I; Curtin, Carol; Must, Aviva; Phillips, Sarah; Maslin, Melissa; Bandini, Linda G

    2017-03-01

    We compared time spent in moderate and vigorous physical activity (MVPA), type, and frequency of participation in physical activities between adolescents with ASD (n = 35) and typically developing (TD) adolescents (n = 60). Accelerometers measured MVPA and participants were interviewed about engagement in physical activities. Adolescents with ASD spent less time in MVPA compared to TD adolescents (29 min/day vs. 50 min/day, p < 0.001) and fewer met the Physical Activity Guidelines for Americans (14 vs. 29%, p > 0.05). Among adolescents <16 years old, those with ASD participated in fewer activities than TD adolescents (5.3 vs. 7.1 activities, p < 0.03). Walking/hiking and active video gaming were among the top activities for both groups. Findings support the need for interventions that meet the needs of youth with ASD.

  12. Frequencies and cyclical pattern of the human sphincter of Oddi phasic activity.

    PubMed Central

    Torsoli, A; Corazziari, E; Habib, F I; De Masi, E; Biliotti, D; Mazzarella, R; Giubilei, D; Fegiz, G

    1986-01-01

    Basal frequency of sphincter of Oddi phasic contractility has been repeatedly measured during endoscopic manometry and reported to range, in control subjects, from (M +/- SE) 3.0 +/- 0.6 to 7.5 +/- 0.7 c/min. Recently, high frequency (greater than 8 c/min) phasic contractions or absence of phasic activity were recorded in patients with postcholecystectomy or pancreatic complaints, possibly suggesting a sphincter of Oddi dysfunction. In the present study, sphincter of Oddi (biliary tract) phasic contractility was measured by perendoscopic manometry in 13 subjects without specific clinical symptoms of biliopancreatic disease and with a normal common bile and pancreatic duct at ERCP. Four T-tube patients with no evidence of common bile duct stones or papillary stenosis were studied for comparison (transductal sphincter of Oddi manometry). Basal frequency was found to range from 0 to 7 c/min (M +/- SE: 2.99 +/- 0.46) in perendoscopic manometry (85 min of recording time) and from 0 to 12 c/min (2.0 +/- 0.3) in transductal manometry (2546 min of recording time). Long lasting transductal recordings also showed that frequency of activity derived from the sphincter area varied cyclically in close relation with the duodenal migrating motor complex. It is concluded that the sphincter of Oddi in man is likely to participate in the interdigestive gastrointestinal motor activity and that short perendoscopic recordings may not be representative of the overall sphincter of Oddi activity. PMID:3957107

  13. Dynamic Docking Test System (DDTS) active table frequency response test results. [Apollo Soyuz Test Project

    NASA Technical Reports Server (NTRS)

    Gates, R. M.

    1974-01-01

    Results are presented of the frequency response test performed on the dynamic docking test system (DDTS) active table. Sinusoidal displacement commands were applied to the table and the dynamic response determined from measured actuator responses and accelerometers mounted to the table and one actuator.

  14. Active Flutter Suppression Using Cooperative, High Frequency, Dynamic-Resonant Aero-Effectors

    DTIC Science & Technology

    2006-12-13

    Final 06/15/03-09/14/06 4. TITLE AND SUBTITLE Sa . CONTRACT NUMBER Active Flutter Suppression Using Cooperative, High Frequency, Dynamic Resonant Aero...maneuvering performance. Conventional active vibration control and flutter suppression systems are servo -hydraulic. Conventional servo -hydraulic...technology is burdened by a set of undesirable characteristics that effectively restrict their use to large aircraft. The servo -hydraulic based systems have

  15. The reliability and validity of a short food frequency questionnaire among 9–11-year olds: a multinational study on three middle-income and high-income countries

    PubMed Central

    Saloheimo, T; González, S A; Erkkola, M; Milauskas, D M; Meisel, J D; Champagne, C M; Tudor-Locke, C; Sarmiento, O; Katzmarzyk, P T; Fogelholm, M

    2015-01-01

    Objective: The main aim of this study was to assess the reliability and validity of a food frequency questionnaire with 23 food groups (I-FFQ) among a sample of 9–11-year-old children from three different countries that differ on economical development and income distribution, and to assess differences between country sites. Furthermore, we assessed factors associated with I-FFQ's performance. Methods: This was an ancillary study of the International Study of Childhood Obesity, Lifestyle and the Environment. Reliability (n=321) and validity (n=282) components of this study had the same participants. Participation rates were 95% and 70%, respectively. Participants completed two I-FFQs with a mean interval of 4.9 weeks to assess reliability. A 3-day pre-coded food diary (PFD) was used as the reference method in the validity analyses. Wilcoxon signed-rank tests, intraclass correlation coefficients and cross-classifications were used to assess the reliability of I-FFQ. Spearman correlation coefficients, percentage difference and cross-classifications were used to assess the validity of I-FFQ. A logistic regression model was used to assess the relation of selected variables with the estimate of validity. Analyses based on information in the PFDs were performed to assess how participants interpreted food groups. Results: Reliability correlation coefficients ranged from 0.37 to 0.78 and gross misclassification for all food groups was <5%. Validity correlation coefficients were below 0.5 for 22/23 food groups, and they differed among country sites. For validity, gross misclassification was <5% for 22/23 food groups. Over- or underestimation did not appear for 19/23 food groups. Logistic regression showed that country of participation and parental education were associated (P⩽0.05) with the validity of I-FFQ. Analyses of children's interpretation of food groups suggested that the meaning of most food groups was understood by the children. Conclusion: I-FFQ is a

  16. Accelerometer tags: detecting and identifying activities in fish and the effect of sampling frequency.

    PubMed

    Broell, Franziska; Noda, Takuji; Wright, Serena; Domenici, Paolo; Steffensen, John Fleng; Auclair, Jean-Pierre; Taggart, Christopher T

    2013-04-01

    Monitoring and measuring the behaviour and movement of aquatic animals in the wild is typically challenging, though micro-accelerometer (archival or telemetry) tags now provide the means to remotely identify and quantify behavioural states and rates such as resting, swimming and migrating, and to estimate activity and energy budgets. Most studies use low-frequency (≤32 Hz) accelerometer sampling because of battery and data-archiving constraints. In this study we assessed the effect of sampling frequency (aliasing) on activity detection probability using the great sculpin (Myoxocephalus polyacanthoceaphalus) as a model species. Feeding strikes and escape responses (fast-start activities) and spontaneous movements among seven different great sculpin were triggered, observed and recorded using video records and a tri-axial accelerometer sampling at 100 Hz. We demonstrate that multiple parameters in the time and probability domains can statistically differentiate between activities with high detection (90%) and identification (80%) probabilities. Detection probability for feeding and escape activities decreased by 50% when sampling at <10 Hz. Our analyses illustrate additional problems associated with aliasing and how activity and energy-budget estimates can be compromised and misinterpreted. We recommend that high-frequency (>30 Hz) accelerometer sampling be used in similar laboratory and field studies. If battery and/or data storage is limited, we also recommend archiving the events via an on-board algorithm that determines the highest likelihood and subsequent archiving of the various event classes of interest.

  17. Effect of moderate electric field frequency on growth kinetics and metabolic activity of Lactobacillus acidophilus.

    PubMed

    Loghavi, Laleh; Sastry, Sudhir K; Yousef, Ahmed E

    2008-01-01

    Moderate electric fields (MEF) have been previously shown to alter the metabolic activity of microbial cells; thus, the effect of frequency and electric field would be of considerable interest. We investigated herein the effects of MEF frequency on microbial growth kinetics and bacteriocin (Lacidin A) production of Lactobacillus acidophilus OSU 133 during fermentation. The following fermentation treatments were compared: conventional (for 40 h), MEF (1 V cm(-1), for 40 h), combination of MEF (1 V cm(-1), for the first 5 h) and conventional (for 35 h) at various frequency levels (45, 60, and 90 Hz) all at 30 degrees C, and control (conventional) fermentation at 37 degrees C. MEF treatments with purely sinusoidal waveforms at all frequencies at 30 degrees C produced a shorter lag phase than conventional fermentation. However, no lag phase reduction was found for a 60 Hz waveform that contained high-frequency harmonics. There was, however, a significant increase in the bacteriocin production under early MEF treatment at 60 Hz with high-frequency harmonics. On the basis of these observations, the fermentation process is accelerated by applying pure sinusoidal MEF at the early stage of growth while a significant increase in the bacteriocin production occurs when sinusoidal field at 60 Hz with harmonics is applied at the early stage of the growth.

  18. Simultaneous measurement of noise-activated middle-ear muscle reflex and stimulus frequency otoacoustic emissions.

    PubMed

    Goodman, Shawn S; Keefe, Douglas H

    2006-06-01

    Otoacoustic emissions serve as a noninvasive probe of the medial olivocochlear (MOC) reflex. Stimulus frequency otoacoustic emissions (SFOAEs) elicited by a low-level probe tone may be the optimal type of emission for studying MOC effects because at low levels, the probe itself does not elicit the MOC reflex [Guinan et al. (2003) J. Assoc. Res. Otolaryngol. 4:521]. Based on anatomical considerations, the MOC reflex activated by ipsilateral acoustic stimulation (mediated by the crossed olivocochlear bundle) is predicted to be stronger than the reflex to contralateral stimulation. Broadband noise is an effective activator of the MOC reflex; however, it is also an effective activator of the middle-ear muscle (MEM) reflex, which can make results difficult to interpret. The MEM reflex may be activated at lower levels than measured clinically, and most previous human studies have not explicitly included measurements to rule out MEM reflex contamination. The current study addressed these issues using a higher-frequency SFOAE probe tone to test for cochlear changes mediated by the MOC reflex, while simultaneously monitoring the MEM reflex using a low-frequency probe tone. Broadband notched noise was presented ipsilaterally at various levels to elicit probe-tone shifts. Measurements are reported for 15 normal-hearing subjects. With the higher-frequency probe near 1.5 kHz, only 20% of subjects showed shifts consistent with an MOC reflex in the absence of an MEM-induced shift. With the higher-frequency probe near 3.5 kHz, up to 40% of subjects showed shifts in the absence of an MEM-induced shift. However, these responses had longer time courses than expected for MOC-induced shifts, and may have been dominated by other cochlear processes, rather than MOC reflex. These results suggest caution in the interpretation of effects observed using ipsilaterally presented acoustic activators intended to excite the MOC reflex.

  19. Different dynamic resting state fMRI patterns are linked to different frequencies of neural activity.

    PubMed

    Thompson, Garth John; Pan, Wen-Ju; Keilholz, Shella Dawn

    2015-07-01

    Resting state functional magnetic resonance imaging (rsfMRI) results have indicated that network mapping can contribute to understanding behavior and disease, but it has been difficult to translate the maps created with rsfMRI to neuroelectrical states in the brain. Recently, dynamic analyses have revealed multiple patterns in the rsfMRI signal that are strongly associated with particular bands of neural activity. To further investigate these findings, simultaneously recorded invasive electrophysiology and rsfMRI from rats were used to examine two types of electrical activity (directly measured low-frequency/infraslow activity and band-limited power of higher frequencies) and two types of dynamic rsfMRI (quasi-periodic patterns or QPP, and sliding window correlation or SWC). The relationship between neural activity and dynamic rsfMRI was tested under three anesthetic states in rats: dexmedetomidine and high and low doses of isoflurane. Under dexmedetomidine, the lightest anesthetic, infraslow electrophysiology correlated with QPP but not SWC, whereas band-limited power in higher frequencies correlated with SWC but not QPP. Results were similar under isoflurane; however, the QPP was also correlated to band-limited power, possibly due to the burst-suppression state induced by the anesthetic agent. The results provide additional support for the hypothesis that the two types of dynamic rsfMRI are linked to different frequencies of neural activity, but isoflurane anesthesia may make this relationship more complicated. Understanding which neural frequency bands appear as particular dynamic patterns in rsfMRI may ultimately help isolate components of the rsfMRI signal that are of interest to disorders such as schizophrenia and attention deficit disorder.

  20. Different dynamic resting state fMRI patterns are linked to different frequencies of neural activity

    PubMed Central

    Thompson, Garth John; Pan, Wen-Ju

    2015-01-01

    Resting state functional magnetic resonance imaging (rsfMRI) results have indicated that network mapping can contribute to understanding behavior and disease, but it has been difficult to translate the maps created with rsfMRI to neuroelectrical states in the brain. Recently, dynamic analyses have revealed multiple patterns in the rsfMRI signal that are strongly associated with particular bands of neural activity. To further investigate these findings, simultaneously recorded invasive electrophysiology and rsfMRI from rats were used to examine two types of electrical activity (directly measured low-frequency/infraslow activity and band-limited power of higher frequencies) and two types of dynamic rsfMRI (quasi-periodic patterns or QPP, and sliding window correlation or SWC). The relationship between neural activity and dynamic rsfMRI was tested under three anesthetic states in rats: dexmedetomidine and high and low doses of isoflurane. Under dexmedetomidine, the lightest anesthetic, infraslow electrophysiology correlated with QPP but not SWC, whereas band-limited power in higher frequencies correlated with SWC but not QPP. Results were similar under isoflurane; however, the QPP was also correlated to band-limited power, possibly due to the burst-suppression state induced by the anesthetic agent. The results provide additional support for the hypothesis that the two types of dynamic rsfMRI are linked to different frequencies of neural activity, but isoflurane anesthesia may make this relationship more complicated. Understanding which neural frequency bands appear as particular dynamic patterns in rsfMRI may ultimately help isolate components of the rsfMRI signal that are of interest to disorders such as schizophrenia and attention deficit disorder. PMID:26041826

  1. Mesoscale infraslow spontaneous membrane potential fluctuations recapitulate high-frequency activity cortical motifs.

    PubMed

    Chan, Allen W; Mohajerani, Majid H; LeDue, Jeffrey M; Wang, Yu Tian; Murphy, Timothy H

    2015-07-20

    Neuroimaging of spontaneous, resting-state infraslow (<0.1 Hz) brain activity has been used to reveal the regional functional organization of the brain and may lead to the identification of novel biomarkers of neurological disease. However, these imaging studies generally rely on indirect measures of neuronal activity and the nature of the neuronal activity correlate remains unclear. Here we show, using wide-field, voltage-sensitive dye imaging, the mesoscale spatiotemporal structure and pharmacological dependence of spontaneous, infraslow cortical activity in anaesthetized and awake mice. Spontaneous infraslow activity is regionally distinct, correlates with electroencephalography and local field potential recordings, and shows bilateral symmetry between cortical hemispheres. Infraslow activity is attenuated and its functional structure abolished after treatment with voltage-gated sodium channel and glutamate receptor antagonists. Correlation analysis reveals patterns of infraslow regional connectivity that are analogous to cortical motifs observed from higher-frequency spontaneous activity and reflect the underlying framework of intracortical axonal projections.

  2. Human intracranial high-frequency activity maps episodic memory formation in space and time

    PubMed Central

    Burke, John F.; Long, Nicole M.; Zaghloul, Kareem A.; Sharan, Ashwini D.; Sperling, Michael R.; Kahana, Michael J.

    2013-01-01

    Noninvasive neuroimaging studies have revealed a network of brain regions that activate during human memory encoding; however, the relative timing of such activations remains unknown. Here we used intracranially recorded high-frequency activity (HFA) to first identify regions that activate during successful encoding. Then, we leveraged the high-temporal precision of HFA to investigate the timing of such activations. We found that memory encoding invokes two spatiotemporally distinct activations: early increases in HFA that involve the ventral visual pathway as well as the medial temporal lobe and late increases in HFA that involve the left inferior frontal gyrus, left posterior parietal cortex and left ventrolateral temporal cortex. We speculate that these activations reflect higher-order visual processing and top-down modulation of attention/semantic information, respectively. PMID:23827329

  3. Mesoscale infraslow spontaneous membrane potential fluctuations recapitulate high-frequency activity cortical motifs

    PubMed Central

    Chan, Allen W.; Mohajerani, Majid H.; LeDue, Jeffrey M.; Wang, Yu Tian; Murphy, Timothy H.

    2016-01-01

    Neuroimaging of spontaneous, resting-state infraslow (<0.1 Hz) brain activity has been used to reveal the regional functional organization of the brain and may lead to the identification of novel biomarkers of neurological disease. However, these imaging studies generally rely on indirect measures of neuronal activity and the nature of the neuronal activity correlate remains unclear. Here we show, using wide-field, voltage-sensitive dye imaging, the mesoscale spatiotemporal structure and pharmacological dependence of spontaneous, infraslow cortical activity in anaesthetized and awake mice. Spontaneous infraslow activity is regionally distinct, correlates with electroencephalography and local field potential recordings, and shows bilateral symmetry between cortical hemispheres. Infraslow activity is attenuated and its functional structure abolished after treatment with voltage-gated sodium channel and glutamate receptor antagonists. Correlation analysis reveals patterns of infraslow regional connectivity that are analogous to cortical motifs observed from higher-frequency spontaneous activity and reflect the underlying framework of intracortical axonal projections. PMID:26190168

  4. Temporal evolution of neural activity underlying auditory discrimination of frequency increase and decrease.

    PubMed

    Noguchi, Yasuki; Fujiwara, Mana; Hamano, Saki

    2015-05-01

    Discriminating a direction of frequency change is an important ability of the human auditory system, although temporal dynamics of neural activity underlying this discrimination remains unclear. In the present study, we recorded auditory-evoked potentials when human subjects explicitly judged a direction of a relative frequency change between two successive tones. A comparison of two types of trials with ascending and descending tone pairs revealed that neural activity discriminating a direction of frequency changes appeared as early as the P1 component of auditory-evoked potentials (latency 50 ms). Those differences between the ascending and descending trials were also observed in subsequent electroencephalographic components such as the N1 (100 ms) and P2 (200 ms). Furthermore, amplitudes of the P2 were significantly modulated by behavioral responses (upward/downward judgments) of subjects in the direction discrimination task, while those of the P1 were not. Those results indicate that, while the neural responses encoding a direction of frequency changes can be observed in an early component of electroencephalographic responses (50 ms after the change), the activity associated (correlated) with behavioral judgments evolves over time, being shaped in a later time period (around 200 ms) of the auditory processing.

  5. Five-dimensional neuroimaging: Localization of the time-frequency dynamics of cortical activity

    PubMed Central

    Dalal, Sarang S.; Guggisberg, Adrian G.; Edwards, Erik; Sekihara, Kensuke; Findlay, Anne M.; Canolty, Ryan T.; Berger, Mitchel S.; Knight, Robert T.; Barbaro, Nicholas M.; Kirsch, Heidi E.; Nagarajan, Srikantan S.

    2008-01-01

    The spatiotemporal dynamics of cortical oscillations across human brain regions remain poorly understood because of a lack of adequately validated methods for reconstructing such activity from noninvasive electrophysiological data. In this paper, we present a novel adaptive spatial filtering algorithm optimized for robust source time-frequency reconstruction from magnetoencephalography (MEG) and electroencephalography (EEG) data. The efficacy of the method is demonstrated with simulated sources and is also applied to real MEG data from a self-paced finger movement task. The algorithm reliably reveals modulations both in the beta band (12–30 Hz) and high gamma band (65–90 Hz) in sensorimotor cortex. The performance is validated by both across-subjects statistical comparisons and by intracranial electrocorticography (ECoG) data from two epilepsy patients. Interestingly, we also reliably observed high frequency activity (30–300 Hz) in the cerebellum, though with variable locations and frequencies across subjects. The proposed algorithm is highly parallelizable and runs efficiently on modern high performance computing clusters. This method enables the ultimate promise of MEG and EEG for five-dimensional imaging of space, time, and frequency activity in the brain and renders it applicable for widespread studies of human cortical dynamics during cognition. PMID:18356081

  6. Is bone formation induced by high-frequency mechanical signals modulated by muscle activity?

    PubMed

    Judex, S; Rubin, C T

    2010-03-01

    Bone formation and resorption are sensitive to both external loads arising from gravitational loading as well to internal loads generated by muscular activity. The question as to which of the two sources provides the dominant stimulus for bone homeostasis and new bone accretion is arguably tied to the specific type of activity and anatomical site but it is often assumed that, because of their purportedly greater magnitude, muscle loads modulate changes in bone morphology. High-frequency mechanical signals may provide benefits at low- (<1g) and high- (>1g) acceleration magnitudes. While the mechanisms by which cells perceive high-frequency signals are largely unknown, higher magnitude vibrations can cause large muscle loads and may therefore be sensed by pathways similar to those associated with exercise. Here, we review experimental data to examine whether vibrations applied at very low magnitudes may be sensed directly by transmittance of the signal through the skeleton or whether muscle activity modulates, and perhaps amplifies, the externally applied mechanical stimulus. Current data indicate that the anabolic and anti-catabolic effects of whole body vibrations on the skeleton are unlikely to require muscular activity to become effective. Even high-frequency signals that induce bone matrix deformations of far less than five microstrain can promote bone formation in the absence of muscular activity. This independence of cells on large strains suggests that mechanical interventions can be designed that are both safe and effective.

  7. Reconstruction of human brain spontaneous activity based on frequency-pattern analysis of magnetoencephalography data

    PubMed Central

    Llinás, Rodolfo R.; Ustinin, Mikhail N.; Rykunov, Stanislav D.; Boyko, Anna I.; Sychev, Vyacheslav V.; Walton, Kerry D.; Rabello, Guilherme M.; Garcia, John

    2015-01-01

    A new method for the analysis and localization of brain activity has been developed, based on multichannel magnetic field recordings, over minutes, superimposed on the MRI of the individual. Here, a high resolution Fourier Transform is obtained over the entire recording period, leading to a detailed multi-frequency spectrum. Further analysis implements a total decomposition of the frequency components into functionally invariant entities, each having an invariant field pattern localizable in recording space. The method, addressed as functional tomography, makes it possible to find the distribution of magnetic field sources in space. Here, the method is applied to the analysis of simulated data, to oscillating signals activating a physical current dipoles phantom, and to recordings of spontaneous brain activity in 10 healthy adults. In the analysis of simulated data, 61 dipoles are localized with 0.7 mm precision. Concerning the physical phantom the method is able to localize three simultaneously activated current dipoles with 1 mm precision. Spatial resolution 3 mm was attained when localizing spontaneous alpha rhythm activity in 10 healthy adults, where the alpha peak was specified for each subject individually. Co-registration of the functional tomograms with each subject's head MRI localized alpha range activity to the occipital and/or posterior parietal brain region. This is the first application of this new functional tomography to human brain activity. The method successfully provides an overall view of brain electrical activity, a detailed spectral description and, combined with MRI, the localization of sources in anatomical brain space. PMID:26528119

  8. Psychometric Properties of the Physical Activity Questionnaire for Older Children in Italy: Testing the Validity among a General and Clinical Pediatric Population

    PubMed Central

    Gobbi, Erica; Elliot, Catherine; Varnier, Maurizio; Carraro, Attilio

    2016-01-01

    The purpose of this research was to assess an Italian version of the Physical Activity Questionnaire for Older Children (PAQ-C-It). Three separate studies were conducted, whereby testing general psychometric properties, construct validity, concurrent validity and the factor structure of the PAQ-C-It among general and clinical pediatric population. Study 1 (n = 1170) examined the psychometric properties, internal consistency, factor structure (exploratory factor analysis, EFA) and construct validity with enjoyment perception during physical activity. Study 2 (n = 59) reported on reliability, construct validity with enjoyment and BMI, and on cross-sectional concurrent validity with objectively measured MVPA (tri-axial accelerometry) over the span of seven consecutive days. Study 3 (n = 58) examined the PAQ-C-It reliability, construct validity with BMI and VO2max as the objective measurement among a population of children with congenital heart defects (CHD). In study 2 and 3, the factor structure of the PAQ-C-It was then re-examined with an EFA. The PAQ-C-It showed acceptable to good reliability (alpha .70 to .83). Results on construct validity showed moderate but significant association with enjoyment perception (r = .30 and .36), with BMI (r = -.30 and -.79 for CHD simple form), and with the VO2max (r = .55 for CHD simple form). Significant concurrent validity with the objectively measured MVPA was reported (rho = .30, p < .05). Findings of the EFA suggested a two-factor structure for the PAQ-C-It, with items 2, 3, and 4 contributing little to the total score. This study supports the PAQ-C-It as an appropriate instrument to assess the MVPA levels of Italian children, including children with simple forms of CHD. Support is given to the possible instrument effectiveness on a large international perspective in order to level out data gathering across the globe. PMID:27228050

  9. Human intracranial high-frequency activity during memory processing: neural oscillations or stochastic volatility?

    PubMed

    Burke, John F; Ramayya, Ashwin G; Kahana, Michael J

    2015-04-01

    Intracranial high-frequency activity (HFA), which refers to fast fluctuations in electrophysiological recordings, increases during memory processing. Two views have emerged to explain this effect: (1) HFA reflects a synchronous signal, related to underlying gamma oscillations, that plays a mechanistic role in human memory and (2) HFA reflects an asynchronous signal that is a non-specific marker of brain activation. We review recent data supporting each of these views and conclude that HFA during memory processing is more consistent with an asynchronous signal. Memory-related HFA is therefore best conceptualized as a biomarker of neural activation that can functionally map memory with high spatial and temporal precision.

  10. Li2MoO4 crystal growth from solution activated by low-frequency vibrations

    NASA Astrophysics Data System (ADS)

    Barinova, Olga; Sadovskiy, Andrey; Ermochenkov, Ivan; Kirsanova, Svetlana; Sukhanova, Ekaterina; Kostikov, Vladimir; Belov, Stanislav; Mozhevitina, Elena; Khomyakov, Andrew; Kuchuk, Zhanna; Zharikov, Eugeny; Avetissov, Igor

    2017-01-01

    The possibility of Li2MoO4 crystal growth from aqueous solutions activated by axial vibrational control (AVC) technique was investigated. It was found out that a low-frequency mechanical activation of the solution led to an increase of Li2MoO4 equilibrium solubility in aqueous solution for 11 rel% in the 25-29 °C temperature range. The changes in solution structure were analyzed in situ by Raman study of the solution. The AVC activation of solution resulted in a re-faceting of growing crystals, a smoothing of a face surface morphology and reduction of water content in the crystal.

  11. Active notch filter network with variable notch depth, width and frequency

    NASA Technical Reports Server (NTRS)

    Black, J. M. (Inventor)

    1980-01-01

    An active notch filter having independently adjustable notch frequency, width, and depth is provided by three equal capacitors connected in series with an operational amplifier (connected in a voltage follower configuration), a potentiometer across the series connected capacitors for notch depth adjustment, and a potentiometer (for notch frequency connected across the center capacitor); with its tap connected to receive a voltage feedback signal from a variable voltage divider comprised of another potentiometer for notch width. Adjusting the voltage dividing potentiometer will independently set the notch width, and adjusting the tap on the potentiometer across the center capacitor will independently adjust the notch frequency of the filter. A second operational amplifier connected in a voltage follower configuration may be used to connect the voltage divider output to the adjustable tap of the potentiometer across the center capacitor.

  12. Are spatial frequency cues used for whisker-based active discrimination?

    PubMed Central

    Georgieva, Petya; Brugger, Dominik; Schwarz, Cornelius

    2014-01-01

    Rats are highly skilled in discriminating objects and textures by palpatory movements of their whiskers. If they used spatial frequency cues, they would be able to optimize performance in a stimulus dependent way—by moving their whisker faster or slower across the texture surface, thereby shifting the frequency content of the neuronal signal toward an optimal working range for perception. We tested this idea by measuring discrimination performance of head-fixed rats that were trained to actively sample from virtual grids. The virtual grid mimicked discrete and repetitive whisker deflections generated by real objects (e.g., grove patterns) with single electrical microstimulation pulses delivered directly to the barrel cortex, and provided the critical advantage that stimuli could be controlled at highest precision. Surprisingly, rats failed to use the spatial frequency cue for discrimination as a matter of course, and also failed to adapt whisking patterns in order to optimally exploit frequency differences. In striking contrast they could be easily trained to discriminate stimuli differing in electrical pulse amplitudes, a stimulus property that is not malleable by whisking. Intermingling these “easy-to-discriminate” discriminanda with others that solely offered frequency/positional cues, rats could be guided to base discrimination on frequency and/or position, albeit on a lower level of performance. Following this training, abolishment of electrical amplitude cues and reducing positional cues led to initial good performance which, however, was unstable and ran down to very low levels over the course of hundreds of trials. These results clearly demonstrate that frequency cues, while definitely perceived by rats, are of minor importance and they are not able to support consistent modulation of whisking patterns to optimize performance. PMID:25404903

  13. Are spatial frequency cues used for whisker-based active discrimination?

    PubMed

    Georgieva, Petya; Brugger, Dominik; Schwarz, Cornelius

    2014-01-01

    Rats are highly skilled in discriminating objects and textures by palpatory movements of their whiskers. If they used spatial frequency cues, they would be able to optimize performance in a stimulus dependent way-by moving their whisker faster or slower across the texture surface, thereby shifting the frequency content of the neuronal signal toward an optimal working range for perception. We tested this idea by measuring discrimination performance of head-fixed rats that were trained to actively sample from virtual grids. The virtual grid mimicked discrete and repetitive whisker deflections generated by real objects (e.g., grove patterns) with single electrical microstimulation pulses delivered directly to the barrel cortex, and provided the critical advantage that stimuli could be controlled at highest precision. Surprisingly, rats failed to use the spatial frequency cue for discrimination as a matter of course, and also failed to adapt whisking patterns in order to optimally exploit frequency differences. In striking contrast they could be easily trained to discriminate stimuli differing in electrical pulse amplitudes, a stimulus property that is not malleable by whisking. Intermingling these "easy-to-discriminate" discriminanda with others that solely offered frequency/positional cues, rats could be guided to base discrimination on frequency and/or position, albeit on a lower level of performance. Following this training, abolishment of electrical amplitude cues and reducing positional cues led to initial good performance which, however, was unstable and ran down to very low levels over the course of hundreds of trials. These results clearly demonstrate that frequency cues, while definitely perceived by rats, are of minor importance and they are not able to support consistent modulation of whisking patterns to optimize performance.

  14. Low-frequency sound affects active micromechanics in the human inner ear.

    PubMed

    Kugler, Kathrin; Wiegrebe, Lutz; Grothe, Benedikt; Kössl, Manfred; Gürkov, Robert; Krause, Eike; Drexl, Markus

    2014-10-01

    Noise-induced hearing loss is one of the most common auditory pathologies, resulting from overstimulation of the human cochlea, an exquisitely sensitive micromechanical device. At very low frequencies (less than 250 Hz), however, the sensitivity of human hearing, and therefore the perceived loudness is poor. The perceived loudness is mediated by the inner hair cells of the cochlea which are driven very inadequately at low frequencies. To assess the impact of low-frequency (LF) sound, we exploited a by-product of the active amplification of sound outer hair cells (OHCs) perform, so-called spontaneous otoacoustic emissions. These are faint sounds produced by the inner ear that can be used to detect changes of cochlear physiology. We show that a short exposure to perceptually unobtrusive, LF sounds significantly affects OHCs: a 90 s, 80 dB(A) LF sound induced slow, concordant and positively correlated frequency and level oscillations of spontaneous otoacoustic emissions that lasted for about 2 min after LF sound offset. LF sounds, contrary to their unobtrusive perception, strongly stimulate the human cochlea and affect amplification processes in the most sensitive and important frequency range of human hearing.

  15. Intratympanic manganese administration revealed sound intensity and frequency dependent functional activity in rat auditory pathway.

    PubMed

    Jin, Seong-Uk; Lee, Jae-Jun; Hong, Kwan Soo; Han, Mun; Park, Jang-Woo; Lee, Hui Joong; Lee, Sangheun; Lee, Kyu-Yup; Shin, Kyung Min; Cho, Jin Ho; Cheong, Chaejoon; Chang, Yongmin

    2013-09-01

    The cochlear plays a vital role in the sense and sensitivity of hearing; however, there is currently a lack of knowledge regarding the relationships between mechanical transduction of sound at different intensities and frequencies in the cochlear and the neurochemical processes that lead to neuronal responses in the central auditory system. In the current study, we introduced manganese-enhanced MRI (MEMRI), a convenient in vivo imaging method, for investigation of how sound, at different intensities and frequencies, is propagated from the cochlear to the central auditory system. Using MEMRI with intratympanic administration, we demonstrated differential manganese signal enhancements according to sound intensity and frequencies in the ascending auditory pathway of the rat after administration of intratympanic MnCl2.Compared to signal enhancement without explicit sound stimuli, auditory structures in the ascending auditory pathway showed stronger signal enhancement in rats who received sound stimuli of 10 and 40 kHz. In addition, signal enhancement with a stimulation frequency of 40 kHz was stronger than that with 10 kHz. Therefore, the results of this study seem to suggest that, in order to achieve an effective response to high sound intensity or frequency, more firing of auditory neurons, or firing of many auditory neurons together for the pooled neural activity is needed.

  16. Active low-frequency vertical vibration isolation system for precision measurements

    NASA Astrophysics Data System (ADS)

    Wu, Kang; Li, Gang; Hu, Hua; Wang, Lijun

    2017-01-01

    Low-frequency vertical vibration isolation systems play important roles in precision measurements to reduce seismic and environmental vibration noise. Several types of active vibration isolation systems have been developed. However, few researches focus on how to optimize the test mass install position in order to improve the vibration transmissibility. An active low-frequency vertical vibration isolation system based on an earlier instrument, the Super Spring, is designed and implemented. The system, which is simple and compact, consists of two stages: a parallelogram-shaped linkage to ensure vertical motion, and a simple spring-mass system. The theoretical analysis of the vibration isolation system is presented, including terms erroneously ignored before. By carefully choosing the mechanical parameters according to the above analysis and using feedback control, the resonance frequency of the system is reduced from 2.3 to 0.03 Hz, a reduction by a factor of more than 75. The vibration isolation system is installed as an inertial reference in an absolute gravimeter, where it improved the scatter of the absolute gravity values by a factor of 5. The experimental results verifies the improved performance of the isolation system, making it particularly suitable for precision experiments. The improved vertical vibration isolation system can be used as a prototype for designing high-performance active vertical isolation systems. An improved theoretical model of this active vibration isolation system with beam-pivot configuration is proposed, providing fundamental guidelines for vibration isolator design and assembling.

  17. Increased Low- and High-Frequency Oscillatory Activity in the Prefrontal Cortex of Fibromyalgia Patients

    PubMed Central

    Lim, Manyoel; Kim, June Sic; Kim, Dajung J.; Chung, Chun Kee

    2016-01-01

    Recent human neuroimaging studies have suggested that fibromyalgia (FM), a chronic widespread pain disorder, exhibits altered thalamic structure and function. Since the thalamus has extensive reciprocal connection with the cortex, structural and functional thalamic alterations in FM might be linked to aberrant thalamocortical oscillation. This study investigated the presence of abnormal brain rhythmicity in low- and high-frequency bands during resting state in patients with FM and their relationship to clinical pain symptom. Spontaneous magnetoencephalography (MEG) activity was recorded in 18 females with FM and 18 age- and sex-matched healthy control (HC) subjects. The most remarkable finding was that FM patients had general increases in theta, beta and gamma power along with a slowing of the dominant alpha peak. Increased spectral powers in the theta-band were primarily localized to the left dorsolateral prefrontal (DLPFC) and orbitofrontal cortex (OFC). Beta and gamma over-activation were localized to insular, primary motor and primary and secondary somatosensory (S2) cortices, as well as the DLPFC and OFC. Furthermore, enhanced high-frequency oscillatory activities in the DLPFC and OFC were associated with higher affective pain scores in patients with FM. Our results demonstrate that FM patients feature enhanced low- and high-frequency oscillatory activity in the brain areas related to cognitive and emotional modulation of pain. Increased low- and high-frequency activity of the prefrontal cortex may contribute to persistent perception of pain in FM. Therapeutic intervention based on manipulating neural oscillation to restore normal thalamocortical rhythmicity may be beneficial to pain relief in FM. PMID:27014041

  18. Cholinergic and glutamatergic agonists induce gamma frequency activity in dorsal subcoeruleus nucleus neurons

    PubMed Central

    Simon, Christen; Kezunovic, Nebojsa; Williams, D. Keith; Urbano, Francisco J.

    2011-01-01

    The dorsal subcoeruleus nucleus (SubCD) is involved in generating two signs of rapid eye movement (REM) sleep: muscle atonia and ponto-geniculo-occipital (PGO) waves. We tested the hypothesis that single cell and/or population responses of SubCD neurons are capable of generating gamma frequency activity in response to intracellular stimulation or receptor agonist activation. Whole cell patch clamp recordings (immersion chamber) and population responses (interface chamber) were conducted on 9- to 20-day-old rat brain stem slices. All SubCD neurons (n = 103) fired at gamma frequency when subjected to depolarizing steps. Two statistically distinct populations of neurons were observed, which were distinguished by their high (>80 Hz, n = 24) versus low (35–80 Hz, n = 16) initial firing frequencies. Both cell types exhibited subthreshold oscillations in the gamma range (n = 43), which may underlie the gamma band firing properties of these neurons. The subthreshold oscillations were blocked by the sodium channel blockers tetrodotoxin (TTX, n = 21) extracellularly and N-(2,6-dimethylphenylcarbamoylmethyl)triethylammonium bromide (QX-314) intracellularly (n = 5), indicating they were sodium channel dependent. Gamma frequency subthreshold oscillations were observed in response to the nonspecific cholinergic receptor agonist carbachol (CAR, n = 11, d = 1.08) and the glutamate receptor agonists N-methyl-d-aspartic acid (NMDA, n = 12, d = 1.09) and kainic acid (KA, n = 13, d = 0.96), indicating that cholinergic and glutamatergic inputs may be involved in the activation of these subthreshold currents. Gamma band activity also was observed in population responses following application of CAR (n = 4, P < 0.05), NMDA (n = 4, P < 0.05) and KA (n = 4, P < 0.05). Voltage-sensitive, sodium channel-dependent gamma band activity appears to be a part of the intrinsic membrane properties of SubCD neurons. PMID:21543743

  19. National questionnaire survey of TMA.

    PubMed

    Ito, Naomi; Wada, Hideo; Matsumoto, Masanori; Fujimura, Yoshihiro; Murata, Mitsuru; Izuno, Takashi; Sugita, Minoru; Ikeda, Yasuo

    2009-10-01

    A questionnaire survey of Japanese patients with thrombotic microangiopathy (TMA) was carried out to investigate the frequency, laboratory abnormalities, and outcome in 2004. Out of 185 patients, there were 13 with familial TMA and 172 with acquired TMA. In acquired TMA, there were 66 with Escherichia coli O-157 infection (O-157)-related TMA, 35 with ADAMTS13-related TMA, and 22 with other types of TMA. The frequency of TMA in O-157-related TMA was high in patients from 0- to 15-year-old, and acquired TMA without O-157 was frequently observed in patients ranging from 31 to 65 years of age. In the treatment of acquired TMA, including plasma exchange (PE), steroid, antiplatelet agent, and anticoagulant, PE was carried out in 94.3% of ADAMTS13-related TMA, 77.3% of other TMA, and 7.6% of O-157-related TMA. The efficacy of PE and steroid therapy tended to be higher in ADAMTS13 TMA than in other types of TMA. The complete remission rate is the highest in O-157 TMA. The mortality rate was the lowest for O-157 TMA, and this rate also tended to be lower in ADAMTS13-related TMA than in other types of TMA. However, the determination of ADAMTS13 was not universal in Japan at the time of this questionnaire.

  20. High-frequency neural activity predicts word parsing in ambiguous speech streams.

    PubMed

    Kösem, Anne; Basirat, Anahita; Azizi, Leila; van Wassenhove, Virginie

    2016-12-01

    During speech listening, the brain parses a continuous acoustic stream of information into computational units (e.g., syllables or words) necessary for speech comprehension. Recent neuroscientific hypotheses have proposed that neural oscillations contribute to speech parsing, but whether they do so on the basis of acoustic cues (bottom-up acoustic parsing) or as a function of available linguistic representations (top-down linguistic parsing) is unknown. In this magnetoencephalography study, we contrasted acoustic and linguistic parsing using bistable speech sequences. While listening to the speech sequences, participants were asked to maintain one of the two possible speech percepts through volitional control. We predicted that the tracking of speech dynamics by neural oscillations would not only follow the acoustic properties but also shift in time according to the participant's conscious speech percept. Our results show that the latency of high-frequency activity (specifically, beta and gamma bands) varied as a function of the perceptual report. In contrast, the phase of low-frequency oscillations was not strongly affected by top-down control. Whereas changes in low-frequency neural oscillations were compatible with the encoding of prelexical segmentation cues, high-frequency activity specifically informed on an individual's conscious speech percept.

  1. Applying Learning Strategy Questionnaires: Problems and Possibilities

    ERIC Educational Resources Information Center

    Schellings, Gonny

    2011-01-01

    This article discusses measuring learning strategies by means of questionnaires. In "multi-method" research, in which think-aloud measures are compared with questionnaires, low or moderate correlations are found. A conclusion often drawn is that learners are not able to verbally report on their learning activities. Alternative explanations concern…

  2. A Nutritional Questionnaire for Older Adults.

    ERIC Educational Resources Information Center

    Fanelli, Marie T.; Abernethy, Marilyn M.

    1986-01-01

    Describes a questionnaire assessing nutritional knowledge and eating behaviors of older adults. The questionnaire consists of six sections: demographic and personal information, food resources, food consumption patterns, dietary practices related to health, activity patterns, and nutritional knowledge. Study results demonstrating the…

  3. Localized, Non-Harmonic Active Flap Motions for Low Frequency In-Plane Rotor Noise Reduction

    NASA Technical Reports Server (NTRS)

    Sim, Ben W.; Potsdam, Mark; Kitaplioglu, Cahit; LeMasurier, Philip; Lorber, Peter; Andrews, Joseph

    2012-01-01

    A first-of-its-kind demonstration of the use of localized, non-harmonic active flap motions, for suppressing low frequency, in-plane rotor noise, is reported in this paper. Operational feasibility is verified via testing of the full-scale AATD/Sikorsky/UTRC active flap demonstration rotor in the NFAC's 40- by 80-Foot anechoic wind tunnel. Effectiveness of using localized, non-harmonic active flap motions are compared to conventional four-per-rev harmonic flap motions, and also active flap motions derived from closed-loop acoustics implementations. All three approaches resulted in approximately the same noise reductions over an in-plane three-by-three microphone array installed forward and near in-plane of the rotor in the nearfield. It is also reported that using an active flap in this localized, non-harmonic manner, resulted in no more that 2% rotor performance penalty, but had the tendency to incur higher hub vibration levels.

  4. Frequency analysis of a semi-active suspension with magneto-rheological dampers

    NASA Astrophysics Data System (ADS)

    Andronic, Florin; Mihai, Ioan; Suciu, Cornel; Beniuga, Marius

    2015-02-01

    Suspension systems for motor vehicles are constantly evolving in order to ensure vehicle stability and traffic safety under all driving conditions. The present work aims to highlight the influence factors in the case of a quarter car model for semi-active suspensions. The functions that must be met by such suspension systems are first presented. Mathematical models for passive systems are first illustrated and then customized for the semi-active case. A simulation diagram was conceived for Matlab Simulink. The obtained simulation results allow conducting a frequency analysis of the passive and semi-active cases of the quarter car model. Various charts for Passive Suspension Transmissibility and for the Effect of Damping on Vertical Acceleration Response were obtained for both passive and semi-active situations. Analysis of obtained results allowed evaluating of the suspension systems behavior and their frequency dependence. Significant differences were found between the behaviors of passive and semi-active suspensions. It was found that semi-active suspensions ensure damping in accordance to the chosen control method, and are much more efficient than passive ones.

  5. Investigation of frequency response of microwave active ring resonator based on ferrite film

    NASA Astrophysics Data System (ADS)

    Martynov, M. I.; Nikitin, A. A.; Ustinov, A. B.; Kalinikos, B. A.

    2016-11-01

    The complex transmission coefficient of active ring resonators based on ferrite-film delay lines was investigated both theoretically and experimentally. Influence of the parameters of the delay line on the transmission coefficients was investigated. It was shown that the resonant frequencies of the ring depend on the ferrite film thickness and the distance between spin-wave antennae. These dependences give possibility to control the shape of the transmission coefficient that in combination with magnetic tuning provide flexibility for microwave applications.

  6. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2004-09-01

    35th Annual Precise Time and Time Interval (PTTI) Meeting 23 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios...Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U. S. Naval Observatory (USNO) has provided... timing for the Navy and the Department of Defense since 1830 and, in cooperation with other institutions, has also provided timing for the United

  7. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2009-11-01

    41 st Annual Precise Time and Time Interval (PTTI) Meeting 261 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY...Demetrios Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has...provided timing for the Navy since 1830 and, via DoD Directive 4650.05, is the sole source of timing for the Department of Defense. In cooperation

  8. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2007-01-01

    38th Annual Precise Time and Time Interval (PTTI) Meeting TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios...Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has provided timing ...for the Navy and the Department of Defense since 1830 and, in cooperation with other institutions, has also provided timing for the United States

  9. Time and Frequency Activities at The U.S. Naval Observatory

    DTIC Science & Technology

    2011-01-01

    43 rd Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting 107 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL...OBSERVATORY Demetrios Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory...USNO) has provided timing for the Navy since 1830 and via DoD Directives 4650.05 and 4650.07 is the sole source of timing for the Department of

  10. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2005-08-01

    TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios Matsakis Time Service Department U.S. Naval Observatory...Washington, DC 20392, USA Abstract: The U.S. Naval Observatory (USNO) has provided timing for the Navy and the Department of Defense since 1830...and, in cooperation with other institutions, has also provided timing for the United States and the international community. Its Master Clock (MC

  11. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2004-12-01

    36th Annual Precise Time and Time Interval (PTTI) Meeting 215 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios...Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has provided... timing for the Navy and the Department of Defense since 1830 and, in cooperation with other institutions, has also provided timing for the United

  12. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2002-12-01

    34th Annual Precise Time and Time Interval (PTTI) Meeting 437 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios...Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20391-5420, USA E-mail: dnm@usno.navy.mil Abstract The U. S. Naval...Observatory (USNO) has provided timing for the Navy and the Department of Defense since 1830 and, in cooperation with other institutions, has also

  13. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2008-12-01

    40th Annual Precise Time and Time Interval (PTTI) Meeting 605 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY...Demetrios Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has...provided timing for the Navy since 1830 and, in cooperation with other institutions, has also provided timing for the United States and the international

  14. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2005-01-01

    36th Annual Precise Time and Time Interval (PTTI) Meeting 215 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios...Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has provided... timing for the Navy and the Department of Defense since 1830 and, in cooperation with other institutions, has also provided timing for the United

  15. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2007-11-01

    39th Annual Precise Time and Time Interval (PTTI) Meeting TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY Demetrios...Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has provided... timing for the Navy since 1830 and, in cooperation with other institutions, has also provided timing for the United States and the international

  16. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2010-01-01

    42 nd Annual Precise Time and Time Interval (PTTI) Meeting 11 TIME AND FREQUENCY ACTIVITIES AT THE U.S. NAVAL OBSERVATORY...Demetrios Matsakis Time Service Department U.S. Naval Observatory Washington, DC 20392, USA Abstract The U.S. Naval Observatory (USNO) has...provided timing for the Navy since 1830 and, via DoD Directive 4650.05, is the sole source of timing for the Department of Defense. In cooperation

  17. Semantic Wavelet-Induced Frequency-Tagging (SWIFT) Periodically Activates Category Selective Areas While Steadily Activating Early Visual Areas

    PubMed Central

    Koenig-Robert, Roger; VanRullen, Rufin; Tsuchiya, Naotsugu

    2015-01-01

    Primate visual systems process natural images in a hierarchical manner: at the early stage, neurons are tuned to local image features, while neurons in high-level areas are tuned to abstract object categories. Standard models of visual processing assume that the transition of tuning from image features to object categories emerges gradually along the visual hierarchy. Direct tests of such models remain difficult due to confounding alteration in low-level image properties when contrasting distinct object categories. When such contrast is performed in a classic functional localizer method, the desired activation in high-level visual areas is typically accompanied with activation in early visual areas. Here we used a novel image-modulation method called SWIFT (semantic wavelet-induced frequency-tagging), a variant of frequency-tagging techniques. Natural images modulated by SWIFT reveal object semantics periodically while keeping low-level properties constant. Using functional magnetic resonance imaging (fMRI), we indeed found that faces and scenes modulated with SWIFT periodically activated the prototypical category-selective areas while they elicited sustained and constant responses in early visual areas. SWIFT and the localizer were selective and specific to a similar extent in activating category-selective areas. Only SWIFT progressively activated the visual pathway from low- to high-level areas, consistent with predictions from standard hierarchical models. We confirmed these results with criterion-free methods, generalizing the validity of our approach and show that it is possible to dissociate neural activation in early and category-selective areas. Our results provide direct evidence for the hierarchical nature of the representation of visual objects along the visual stream and open up future applications of frequency-tagging methods in fMRI. PMID:26691722

  18. Semantic Wavelet-Induced Frequency-Tagging (SWIFT) Periodically Activates Category Selective Areas While Steadily Activating Early Visual Areas.

    PubMed

    Koenig-Robert, Roger; VanRullen, Rufin; Tsuchiya, Naotsugu

    2015-01-01

    Primate visual systems process natural images in a hierarchical manner: at the early stage, neurons are tuned to local image features, while neurons in high-level areas are tuned to abstract object categories. Standard models of visual processing assume that the transition of tuning from image features to object categories emerges gradually along the visual hierarchy. Direct tests of such models remain difficult due to confounding alteration in low-level image properties when contrasting distinct object categories. When such contrast is performed in a classic functional localizer method, the desired activation in high-level visual areas is typically accompanied with activation in early visual areas. Here we used a novel image-modulation method called SWIFT (semantic wavelet-induced frequency-tagging), a variant of frequency-tagging techniques. Natural images modulated by SWIFT reveal object semantics periodically while keeping low-level properties constant. Using functional magnetic resonance imaging (fMRI), we indeed found that faces and scenes modulated with SWIFT periodically activated the prototypical category-selective areas while they elicited sustained and constant responses in early visual areas. SWIFT and the localizer were selective and specific to a similar extent in activating category-selective areas. Only SWIFT progressively activated the visual pathway from low- to high-level areas, consistent with predictions from standard hierarchical models. We confirmed these results with criterion-free methods, generalizing the validity of our approach and show that it is possible to dissociate neural activation in early and category-selective areas. Our results provide direct evidence for the hierarchical nature of the representation of visual objects along the visual stream and open up future applications of frequency-tagging methods in fMRI.

  19. An Extended Forecast of the Frequencies of North Atlantic Basin Tropical Cyclone Activity for 2009

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2009-01-01

    An extended forecast of the frequencies for the 2009 North Atlantic basin hurricane season is presented. Continued increased activity during the 2009 season with numbers of tropical cyclones, hurricanes, and major hurricanes exceeding long-term averages are indicated. Poisson statistics for the combined high-activity intervals (1950-1965 and 1995-2008) give the central 50% intervals to be 9-14, 5-8, and 2-4, respectively, for the number of tropical cyclones, hurricanes, and major hurricanes, with a 23.4% chance of exceeding 14 tropical cyclones, a 28% chance of exceeding 8 hurricanes, and a 31.9% chance of exceeding 4 major hurricanes. Based strictly on the statistics of the current high-activity interval (1995-2008), the central 50% intervals for the numbers of tropical cyclones, hurricanes, and major hurricanes are 12-18, 6-10, and 3-5, respectively, with only a 5% chance of exceeding 23, 13, or 7 storms, respectively. Also examined are the first differences in 10-yr moving averages and the effects of global warming and decadal-length oscillations on the frequencies of occurrence for North Atlantic basin tropical cyclones. In particular, temperature now appears to be the principal driver of increased activity and storm strength during the current high-activity interval, with near-record values possible during the 2009 season.

  20. Comparison of the EPIC Physical Activity Questionnaire with Combined Heart Rate and Movement Sensing in a Nationally Representative Sample of Older British Adults

    PubMed Central

    España-Romero, Vanesa; Golubic, Rajna; Martin, Kathryn R.; Hardy, Rebecca; Ekelund, Ulf; Kuh, Diana; Wareham, Nicholas J.; Cooper, Rachel; Brage, Soren

    2014-01-01

    Objectives To compare physical activity (PA) subcomponents from EPIC Physical Activity Questionnaire (EPAQ2) and combined heart rate and movement sensing in older adults. Methods Participants aged 60–64y from the MRC National Survey of Health and Development in Great Britain completed EPAQ2, which assesses self-report PA in 4 domains (leisure time, occupation, transportation and domestic life) during the past year and wore a combined sensor for 5 consecutive days. Estimates of PA energy expenditure (PAEE), sedentary behaviour, light (LPA) and moderate-to-vigorous PA (MVPA) were obtained from EPAQ2 and combined sensing and compared. Complete data were available in 1689 participants (52% women). Results EPAQ2 estimates of PAEE and MVPA were higher than objective estimates and sedentary time and LPA estimates were lower [bias (95% limits of agreement) in men and women were 32.3 (−61.5 to 122.6) and 29.0 (−39.2 to 94.6) kJ/kg/day for PAEE; −4.6 (−10.6 to 1.3) and −6.0 (−10.9 to −1.0) h/day for sedentary time; −171.8 (−454.5 to 110.8) and −60.4 (−367.5 to 246.6) min/day for LPA; 91.1 (−159.5 to 341.8) and 55.4 (−117.2 to 228.0) min/day for MVPA]. There were significant positive correlations between all self-reported and objectively assessed PA subcomponents (rho  = 0.12 to 0.36); the strongest were observed for MVPA (rho = 0.30 men; rho = 0.36 women) and PAEE (rho = 0.26 men; rho = 0.25 women). Conclusion EPAQ2 produces higher estimates of PAEE and MVPA and lower estimates of sedentary and LPA than objective assessment. However, both methodologies rank individuals similarly, suggesting that EPAQ2 may be used in etiological studies in this population. PMID:24516543

  1. Performance and mechanism of low-frequency ultrasound to regenerate the biological activated carbon.

    PubMed

    Liu, Cheng; Sun, Yakun; Wang, Dongying; Sun, Zhehao; Chen, Ming; Zhou, Zhi; Chen, Wei

    2017-01-01

    Biological activated carbon (BAC) filter has been widely used as an effective water treatment but regenerations of BAC are costly. Ultrasound has been successfully applied for regeneration of activated carbon but has been less frequently applied to the regenerate the BAC. In this study, bench-scale and pilot-scale experiments were conducted to evaluate the regeneration performance and mechanism of BAC with low-frequency ultrasound. Adsorption indices, microbiological parameters, pore structure and removal efficiencies were further investigated. The results showed that low-frequency ultrasound could regenerate the BAC effectively. The regeneration effects were significantly affected by the frequency, sonication intensity, sonication time, and water temperature, but not the usage time of the BAC. The optimized conditions were identified as 40kHz of frequency, 115×10(-3)W/cm(3) of sonication intensity, 25-30°C of water temperature and 5min of sonication time. The iodine value and methylene blue value increased from 480mg/g and 100mg/g to 680mg/g and 133mg/g respectively, the biomass decreased from 310nmolP/gC to 245nmolP/gC, while the biological activity increased from 0.03mg O2/hgC to 0.0355mg O2/hgC under the optimized condition. After three months of continuous operation, removal efficiencies of regenerated BAC were still high for the removal of organic contaminants, atrazine, and 2-MIB. Analysis of pore structure, BET surface area, and scanning electron microscopy indicated that ultrasound mainly acted on surface and macro-pores of BAC through the high-speed microjets and high-pressure microstreams resulted from the collapse of cavitation bubbles.

  2. Active Control of High Frequency Combustion Instability in Aircraft Gas-Turbine Engines

    NASA Technical Reports Server (NTRS)

    Corrigan, Bob (Technical Monitor); DeLaat, John C.; Chang, Clarence T.

    2003-01-01

    Active control of high-frequency (greater than 500 Hz) combustion instability has been demonstrated in the NASA single-nozzle combustor rig at United Technologies Research Center. The combustor rig emulates an actual engine instability and has many of the complexities of a real engine combustor (i.e. actual fuel nozzle and swirler, dilution cooling, etc.) In order to demonstrate control, a high-frequency fuel valve capable of modulating the fuel flow at up to 1kHz was developed. Characterization of the fuel delivery system was accomplished in a custom dynamic flow rig developed for that purpose. Two instability control methods, one model-based and one based on adaptive phase-shifting, were developed and evaluated against reduced order models and a Sectored-1-dimensional model of the combustor rig. Open-loop fuel modulation testing in the rig demonstrated sufficient fuel modulation authority to proceed with closed-loop testing. During closed-loop testing, both control methods were able to identify the instability from the background noise and were shown to reduce the pressure oscillations at the instability frequency by 30%. This is the first known successful demonstration of high-frequency combustion instability suppression in a realistic aero-engine environment. Future plans are to carry these technologies forward to demonstration on an advanced low-emission combustor.

  3. Active noise control using noise source having adaptive resonant frequency tuning through stress variation

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor); Renshaw, Anthony A. (Inventor); Hedeen, Robert A. (Inventor)

    1995-01-01

    A noise source for an aircraft engine active noise cancellation system in which the resonant frequency of a noise radiating element is tuned to permit noise cancellation over a wide range of frequencies. The resonant frequency of the noise radiating element is tuned by an expandable ring embedded in the noise radiating element. Excitation of the ring causes expansion or contraction of the ring, thereby varying the stress in the noise radiating element. The ring is actuated by a controller which receives input of a feedback signal proportional to displacement of the noise radiating element and a signal corresponding to the blade passage frequency of the engine's fan. In response, the controller determines a control signal which is sent to the ring, causing the ring to expand or contract. Instead of a single ring embedded in the noise radiating panel, a first expandable ring can be bonded to one side of the noise radiating element, and a second expandable ring can be bonded to the other side.

  4. Active noise control using noise source having adaptive resonant frequency tuning through variable ring loading

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor); Renshaw, Anthony A. (Inventor); Hedeen, Robert A. (Inventor)

    1995-01-01

    A noise source for an aircraft engine active noise cancellation system in which the resonant frequency of noise radiating structure is tuned to permit noise cancellation over a wide range of frequencies. The resonant frequency of the noise radiating structure is tuned by a plurality of drivers arranged to contact the noise radiating structure. Excitation of the drivers causes expansion or contraction of the drivers, thereby varying the edge loading applied to the noise radiating structure. The drivers are actuated by a controller which receives input of a feedback signal proportional to displacement of the noise radiating element and a signal corresponding to the blade passage frequency of the engine's fan. In response, the controller determines a control signal which is sent to the drivers, causing them to expand or contract. The noise radiating structure may be either the outer shroud of the engine or a ring mounted flush with an inner wall of the shroud or disposed in the interior of the shroud.

  5. Active noise control using noise source having adaptive resonant frequency tuning through stiffness variation

    NASA Technical Reports Server (NTRS)

    Pla, Frederic G. (Inventor); Rajiyah, Harindra (Inventor); Renshaw, Anthony A. (Inventor); Hedeen, Robert A. (Inventor)

    1995-01-01

    A noise source for an aircraft engine active noise cancellation system in which the resonant frequency of a noise radiating element is tuned to permit noise cancellation over a wide range of frequencies. The resonant frequency of the noise radiating element is tuned by a plurality of force transmitting mechanisms which contact the noise radiating element. Each one of the force transmitting mechanisms includes an expandable element and a spring in contact with the noise radiating element so that excitation of the element varies the spring force applied to the noise radiating element. The elements are actuated by a controller which receives input of a signal proportional to displacement of the noise radiating element and a signal corresponding to the blade passage frequency of the engine's fan. In response, the controller determines a control signal which is sent to the elements and causes the spring force applied to the noise radiating element to be varied. The force transmitting mechanisms can be arranged to either produce bending or linear stiffness variations in the noise radiating element.

  6. Questionnaire typography and production.

    PubMed

    Gray, M

    1975-06-01

    This article describes the typographic principles and practice which provide the basis of good design and print, the relevant printing processes which can be used, and the graphic designer's function in questionnaire production. As they impose constraints on design decisions to be discussed later in the text, the various methods of printing and production are discussed first.

  7. EEG frequency tagging to explore the cortical activity related to the tactile exploration of natural textures

    PubMed Central

    Moungou, Athanasia; Thonnard, Jean-Louis; Mouraux, André

    2016-01-01

    When sliding our fingertip against a textured surface, complex vibrations are produced in the skin. It is increasingly recognised that the neural transduction and processing of these vibrations plays an important role in the dynamic tactile perception of textures. The aim of the present study was to develop a novel means to tag the cortical activity related to the processing of these vibrations, by periodically modulating the amplitude of texture exploration-induced vibrations such as to record a steady-state evoked potential (SS-EP). The EEG was recorded while the right index fingertip was scanned against four different textures using a constant exploration velocity. Amplitude modulation of the elicited vibrations was achieved by periodically modulating the force applied against the finger. Frequency analysis of the recorded EEG signals showed that modulation of the vibrations induced by the fingertip-texture interactions elicited an SS-EP at the frequency of modulation (3 Hz) as well as its second harmonic (6 Hz), maximal over parietal regions contralateral to the stimulated side. Textures generating stronger vibrations also generated SS-EPs of greater magnitude. Our results suggest that frequency tagging using SS-EPs can be used to isolate and explore the brain activity related to the tactile exploration of natural textures. PMID:26853820

  8. High-frequency, resonance-enhanced microactuators with active structures for high-speed flow control

    NASA Astrophysics Data System (ADS)

    Kreth, Phillip Andrew

    The need for actuators that are adaptable for use in a wide array of applications has been the motivation behind actuator development research over the past few years. Recent developments at the Advanced Aero-Propulsion Laboratory (AAPL) at Florida State University have produced a microactuator that uses the unsteadiness of a small-scale impinging jet to produce pulsed, supersonic microjets -- this is referred to as the Resonance-Enhanced Microjet (REM) actuator. Prior studies on these actuators at AAPL have been somewhat limited in that the actuator response has only been characterized through pressure/acoustic measurements and qualitative flow visualizations. Highly-magnified particle image velocimetry (PIV) measurements were performed to measure the velocity fields of both a 1 mm underexpanded jet and an REM actuator. The results demonstrate that this type of microactuator is capable of producing pulsed, supersonic microjets that have velocities of approximately 400 m/s that are sustained for significant portions of their cycles (> 60 %). These are the first direct velocity measurements of these flowfields, and they allow for a greater understanding of the flow physics associated with this microactuator. The previous studies on the REM actuators have shown that the microactuator volume is among the principal parameters in determining the actuator's maximum-amplitude frequency component. In order to use this actuator in a closed-loop, feedback control system, a modified design that incorporates smart materials is studied. The smart materials (specifically piezoelectric ceramic stack actuators) have been implemented into the microactuator to actively change its geometry, thus permitting controllable changes in the microactuator's resonant frequency. The distinct feature of this design is that the smart materials are not used to produce the primary perturbation or flow from the actuator (which has in the past limited the control authority of other designs) but to

  9. Polymorph characterization of active pharmaceutical ingredients (APIs) using low-frequency Raman spectroscopy.

    PubMed

    Larkin, Peter J; Dabros, Marta; Sarsfield, Beth; Chan, Eric; Carriere, James T; Smith, Brian C

    2014-01-01

    Polymorph detection, identification, and quantitation in crystalline materials are of great importance to the pharmaceutical industry. Vibrational spectroscopic techniques used for this purpose include Fourier transform mid-infrared (FT-MIR) spectroscopy, Fourier transform near-infrared (FT-NIR) spectroscopy, Raman spectroscopy, and terahertz (THz) and far-infrared (FIR) spectroscopy. Typically, the fundamental molecular vibrations accessed using high-frequency Raman and MIR spectroscopy or the overtone and combination of bands in the NIR spectra are used to monitor the solid-state forms of active pharmaceutical ingredients (APIs). The local environmental sensitivity of the fundamental molecular vibrations provides an indirect probe of the long-range order in molecular crystals. However, low-frequency vibrational spectroscopy provides access to the lattice vibrations of molecular crystals and, hence, has the potential to more directly probe intermolecular interactions in the solid state. Recent advances in filter technology enable high-quality, low-frequency Raman spectra to be acquired using a single-stage spectrograph. This innovation enables the cost-effective collection of high-quality Raman spectra in the 200-10 cm(-1) region. In this study, we demonstrate the potential of low-frequency Raman spectroscopy for the polymorphic characterization of APIs. This approach provides several benefits over existing techniques, including ease of sampling and more intense, information-rich band structures that can potentially discriminate among crystalline forms. An improved understanding of the relationship between the crystalline structure and the low-frequency vibrational spectrum is needed for the more widespread use of the technique.

  10. Design of a multilevel Active Power Filter for More Electrical Airplane variable frequency systems

    NASA Astrophysics Data System (ADS)

    Guerreiro, Joel Filipe; Pomilio, Jose Antenor; Busarello, Tiago Davi Curi

    This paper presents the design and simulation of an Aeronautical Active Power Filter (AAPF) for a Variable Speed Variable Frequency (VSVF) advanced aircraft electric power system. The purposes of the AAPF are to mitigate current harmonics, to improve the source power factor and to mitigate the effects of unbalanced loads. Regarding the fact that the Aircraft Electrical Power System (AEPS) frequency may vary between 360 Hz and 900 Hz, and the load dynamics is often modified, an enhanced filtering technique is required. The designed AAPF topology is an asymmetrical multilevel inverter (AMI), which control strategy is based on the Conservative Power Theory (CPT) and synchronized by a Kalman Filter Phase-Locked Loop (KF-PLL). The above configuration renders the AAPF very robust and effective to its purpose. Accurate simulation results on Matlab/Simulink platform verify the feasibility of the proposed AAPF and the high performance of the control strategy during steady-state and dynamic operations.

  11. Active control of low-frequency sound radiation by cylindrical shell with piezoelectric stack force actuators

    NASA Astrophysics Data System (ADS)

    Cao, Yin; Sun, Hongling; An, Fengyan; Li, Xiaodong

    2012-05-01

    A novel active control method of sound radiation from a cylindrical shell under axial excitations is proposed and theoretically analyzed. This control method is based on a pair of piezoelectric stack force actuators which are installed on the shell and parallel to the axial direction. The actuators are driven in phase and generate the same forces to control the vibration and the sound radiation of the cylindrical shell. The model considered is a fluid-loaded finite stiffened cylindrical shell with rigid end-caps and only low-frequency axial vibration modes are involved. Numerical simulations are performed to explore the required control forces and the optimal mounting positions of actuators under different cost functions. The results show that the proposed force actuators can reduce the radiated sound pressure of low-frequency axial modes in all directions.

  12. Frequency domain stability analysis of nonlinear active disturbance rejection control system.

    PubMed

    Li, Jie; Qi, Xiaohui; Xia, Yuanqing; Pu, Fan; Chang, Kai

    2015-05-01

    This paper applies three methods (i.e., root locus analysis, describing function method and extended circle criterion) to approach the frequency domain stability analysis of the fast tool servo system using nonlinear active disturbance rejection control (ADRC) algorithm. Root locus qualitative analysis shows that limit cycle is generated because the gain of the nonlinear function used in ADRC varies with its input. The parameters in the nonlinear function are adjustable to suppress limit cycle. In the process of root locus analysis, the nonlinear function is transformed based on the concept of equivalent gain. Then, frequency domain description of the nonlinear function via describing function is presented and limit cycle quantitative analysis including estimating prediction error is presented, which virtually and theoretically demonstrates that the describing function method cannot guarantee enough precision in this case. Furthermore, absolute stability analysis based on extended circle criterion is investigated as a complement.

  13. Limits on information transduction through amplitude and frequency regulation of transcription factor activity.

    PubMed

    Hansen, Anders S; O'Shea, Erin K

    2015-05-18

    Signaling pathways often transmit multiple signals through a single shared transcription factor (TF) and encode signal information by differentially regulating TF dynamics. However, signal information will be lost unless it can be reliably decoded by downstream genes. To understand the limits on dynamic information transduction, we apply information theory to quantify how much gene expression information the yeast TF Msn2 can transduce to target genes in the amplitude or frequency of its activation dynamics. We find that although the amount of information transmitted by Msn2 to single target genes is limited, information transduction can be increased by modulating promoter cis-elements or by integrating information from multiple genes. By correcting for extrinsic noise, we estimate an upper bound on information transduction. Overall, we find that information transduction through amplitude and frequency regulation of Msn2 is limited to error-free transduction of signal identity, but not signal intensity information.

  14. Recurrence and Frequency of Disturbance have Cumulative Effect on Methanotrophic Activity, Abundance, and Community Structure

    PubMed Central

    Ho, Adrian; van den Brink, Erik; Reim, Andreas; Krause, Sascha M. B.; Bodelier, Paul L. E.

    2016-01-01

    Alternate prolonged drought and heavy rainfall is predicted to intensify with global warming. Desiccation-rewetting events alter the soil quality and nutrient concentrations which drive microbial-mediated processes, including methane oxidation, a key biogeochemical process catalyzed by methanotrophic bacteria. Although aerobic methanotrophs showed remarkable resilience to a suite of physical disturbances induced as a single event, their resilience to recurring disturbances is less known. Here, using a rice field soil in a microcosm study, we determined whether recurrence and frequency of desiccation-rewetting impose an accumulating effect on the methanotrophic activity. The response of key aerobic methanotroph subgroups (type Ia, Ib, and II) were monitored using qPCR assays, and was supported by a t-RFLP analysis. The methanotrophic activity was resilient to recurring desiccation-rewetting, but increasing the frequency of the disturbance by twofold significantly decreased methane uptake rate. Both the qPCR and t-RFLP analyses were congruent, showing the dominance of type Ia/Ib methanotrophs prior to disturbance, and after disturbance, the recovering community was predominantly comprised of type Ia (Methylobacter) methanotrophs. Both type Ib and type II (Methylosinus/Methylocystis) methanotrophs were adversely affected by the disturbance, but type II methanotrophs showed recovery over time, indicating relatively higher resilience to the disturbance. This revealed distinct, yet unrecognized traits among the methanotroph community members. Our results show that recurring desiccation-rewetting before a recovery in community abundance had an accumulated effect, compromising methanotrophic activity. While methanotrophs may recover well following sporadic disturbances, their resilience may reach a ‘tipping point’ where activity no longer recovered if disturbance persists and increase in frequency. PMID:26779148

  15. Low-Frequency Mode Activity of Heme: Femtosecond Coherence Spectroscopy of Iron Porphine Halides and Nitrophorin

    PubMed Central

    Kubo, Minoru; Gruia, Flaviu; Benabbas, Abdelkrim; Barabanschikov, Alexander; Montfort, William R.; Maes, Estelle M.; Champion, Paul M.

    2009-01-01

    The low-frequency mode activity of metalloporphyrins has been studied for iron porphine-halides (Fe(P)(X), X = Cl, Br) and nitrophorin 4 (NP4) using femtosecond coherence spectroscopy (FCS) in combination with polarized resonance Raman spectroscopy and density functional theory (DFT). It is confirmed that the mode symmetry selection rules for FCS are the same as for Raman scattering and that both Franck-Condon and Jahn-Teller mode activities are observed for Fe(P)(X) under Soret resonance conditions. The DFT-calculated low-frequency (20-400 cm-1) modes, and their frequency shifts upon halide substitution, are in good agreement with experimental Raman and coherence data, so that mode assignments can be made. The doming mode is located at ~80 cm-1 for Fe(P)(Cl) and at ~60 cm-1 for Fe(P)(Br). NP4 is also studied with coherence techniques, and the NO-bound species of ferric and ferrous NP4 display a mode at ~30-40 cm-1 that is associated with transient heme doming motion following NO photolysis. The coherence spectra of three ferric derivatives of NP4 with different degrees of heme ruffling distortion are also investigated. We find a mode at ~60 cm-1 whose relative intensity in the coherence spectra depends quadratically on the magnitude of the ruffling distortion. To quantitatively account for this correlation, a new “distortion-induced” Raman enhancement mechanism is presented. This mechanism is unique to low-frequency “soft modes” of the molecular framework that can be distorted by environmental forces. These results demonstrate the potential of FCS as a sensitive probe of dynamic and functionally important nonplanar heme vibrational excitations that are induced by the protein environmental forces or by the chemical reactions in the aqueous phase. PMID:18597456

  16. Reduced frequency of memory T cells and increased Th17 responses in patients with active tuberculosis.

    PubMed

    Marín, Nancy D; París, Sara C; Rojas, Mauricio; García, Luis F

    2012-10-01

    Phenotypic and functional alterations in Mycobacterium tuberculosis T cell subsets have been reported in patients with active tuberculosis. A better understanding of these alterations will increase the knowledge about immunopathogenesis and also may contribute to the development of new diagnostics and prophylactic strategies. Here, the ex vivo phenotype of CD4(+) and CD8(+) T cells and the frequency and phenotype of gamma interferon (IFN-γ)- and interleukin 17 (IL-17)-producing cells elicited in short-term and long-term cultures following CFP-10 and purified protein derivative (PPD) stimulation were determined in noninfected persons (non-TBi), latently infected persons (LTBi), and patients with active tuberculosis (ATB). Phenotypic characterization of T cells was done based on the expression of CD45RO and CD27. Results show that ATB had a reduced frequency of circulating CD4(+) CD45RO(+) CD27(+) T cells and an increased frequency of CD4(+) CD45RO(-) CD27(+) T cells. ATB also had a higher frequency of circulating IL-17-producing CD4(+) T cells than did LTBi after PPD stimulation, whereas LTBi had more IFN-γ-producing CD4(+) T cells than did non-TBi. The phenotype of IFN-γ-producing cells at 24 h differs from the phenotype of IL-17-producing cells with no differences between LTBi and ATB. At 144 h, IFN-γ- and IL-17-producing cells were mainly CD45RO(+) CD27(+) T cells and they were more frequent in ATB. These results suggest that M. tuberculosis infection induces alterations in T cells which interfere with an adequate specific immune response.

  17. Reduced Frequency of Memory T Cells and Increased Th17 Responses in Patients with Active Tuberculosis

    PubMed Central

    Marín, Nancy D.; París, Sara C.; Rojas, Mauricio

    2012-01-01

    Phenotypic and functional alterations in Mycobacterium tuberculosis T cell subsets have been reported in patients with active tuberculosis. A better understanding of these alterations will increase the knowledge about immunopathogenesis and also may contribute to the development of new diagnostics and prophylactic strategies. Here, the ex vivo phenotype of CD4+ and CD8+ T cells and the frequency and phenotype of gamma interferon (IFN-γ)- and interleukin 17 (IL-17)-producing cells elicited in short-term and long-term cultures following CFP-10 and purified protein derivative (PPD) stimulation were determined in noninfected persons (non-TBi), latently infected persons (LTBi), and patients with active tuberculosis (ATB). Phenotypic characterization of T cells was done based on the expression of CD45RO and CD27. Results show that ATB had a reduced frequency of circulating CD4+ CD45RO+ CD27+ T cells and an increased frequency of CD4+ CD45RO− CD27+ T cells. ATB also had a higher frequency of circulating IL-17-producing CD4+ T cells than did LTBi after PPD stimulation, whereas LTBi had more IFN-γ-producing CD4+ T cells than did non-TBi. The phenotype of IFN-γ-producing cells at 24 h differs from the phenotype of IL-17-producing cells with no differences between LTBi and ATB. At 144 h, IFN-γ- and IL-17-producing cells were mainly CD45RO+ CD27+ T cells and they were more frequent in ATB. These results suggest that M. tuberculosis infection induces alterations in T cells which interfere with an adequate specific immune response. PMID:22914361

  18. Evolution of anatase surface active sites probed by in situ sum-frequency phonon spectroscopy.

    PubMed

    Cao, Yue; Chen, Shiyou; Li, Yadong; Gao, Yi; Yang, Deheng; Shen, Yuen Ron; Liu, Wei-Tao

    2016-09-01

    Surface active sites of crystals often govern their relevant surface chemistry, yet to monitor them in situ in real atmosphere remains a challenge. Using surface-specific sum-frequency spectroscopy, we identified the surface phonon mode associated with the active sites of undercoordinated titanium ions and conjoint oxygen vacancies, and used it to monitor them on anatase (TiO2) (101) under ambient conditions. In conjunction with theory, we determined related surface structure around the active sites and tracked the evolution of oxygen vacancies under ultraviolet irradiation. We further found that unlike in vacuum, the surface oxygen vacancies, which dominate the surface reactivity, are strongly regulated by ambient gas molecules, including methanol and water, as well as weakly associated species, such as nitrogen and hydrogen. The result revealed a rich interplay between prevailing ambient species and surface reactivity, which can be omnipresent in environmental and catalytic applications of titanium dioxides.

  19. Evolution of anatase surface active sites probed by in situ sum-frequency phonon spectroscopy

    PubMed Central

    Cao, Yue; Chen, Shiyou; Li, Yadong; Gao, Yi; Yang, Deheng; Shen, Yuen Ron; Liu, Wei-Tao

    2016-01-01

    Surface active sites of crystals often govern their relevant surface chemistry, yet to monitor them in situ in real atmosphere remains a challenge. Using surface-specific sum-frequency spectroscopy, we identified the surface phonon mode associated with the active sites of undercoordinated titanium ions and conjoint oxygen vacancies, and used it to monitor them on anatase (TiO2) (101) under ambient conditions. In conjunction with theory, we determined related surface structure around the active sites and tracked the evolution of oxygen vacancies under ultraviolet irradiation. We further found that unlike in vacuum, the surface oxygen vacancies, which dominate the surface reactivity, are strongly regulated by ambient gas molecules, including methanol and water, as well as weakly associated species, such as nitrogen and hydrogen. The result revealed a rich interplay between prevailing ambient species and surface reactivity, which can be omnipresent in environmental and catalytic applications of titanium dioxides. PMID:27704049

  20. Shared genetic influences on ADHD symptoms and very low-frequency EEG activity: a twin study

    PubMed Central

    Tye, Charlotte; Rijsdijk, Frühling; Greven, Corina U.; Kuntsi, Jonna; Asherson, Philip; McLoughlin, Gráinne

    2013-01-01

    Background ADHD is a common and highly heritable neurodevelopmental disorder with a complex aetiology. The identification of candidate intermediate phenotypes that are both heritable and genetically linked to ADHD may facilitate the detection of susceptibility genes and elucidate aetiological pathways. Very low-frequency (VLF; <0.5Hz) electroencephalographic (EEG) activity represents a promising indicator of risk for ADHD, but it is currently unclear whether it is heritable or genetically linked to the disorder. Methods Direct-current (DC)-EEG was recorded during a cognitive activation condition in 30 monozygotic and dizygotic adolescent twin pairs concordant or discordant for high ADHD symptom scores, and 37 monozygotic and dizygotic matched-control twin pairs with low ADHD symptom scores. Structural equation modelling was used to quantify the genetic and environmental contributions to the phenotypic covariance between ADHD and VLF activity. Results ADHD was significantly associated with reduced VLF power during cognitive activation, which suggests reduced synchronisation of widespread neuronal activity. VLF power demonstrated modest heritability (0.31) and the genetic correlation (−0.80) indicated a substantial degree of overlap in genetic influences on ADHD and VLF activity. Conclusions Altered VLF activity is a potential candidate intermediate phenotype of ADHD, which warrants further investigation of underlying neurobiological and genetic mechanisms. PMID:22118296

  1. Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation

    PubMed Central

    Kobayashi, Katsuya; Matsumoto, Riki; Matsuhashi, Masao; Usami, Kiyohide; Shimotake, Akihiro; Kunieda, Takeharu; Kikuchi, Takayuki; Mikuni, Nobuhiro; Miyamoto, Susumu; Fukuyama, Hidenao; Takahashi, Ryosuke; Ikeda, Akio

    2015-01-01

    Physiological high frequency activities (HFA) are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections), or different terminal layers (layer IV vs. layer II/III) affect its frequency, we, in the primary somatosensory cortex (SI), compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response) and N80 (late response) of somatosensory evoked potentials (HFASEP(N20) and HFASEP(N80)) and compared those overriding N1 and N2 (first and second responses) of cortico-cortical evoked potentials (HFACCEP(N1) and HFACCEP(N2)). HFASEP(N20) showed the power peak in the frequency above 200 Hz, while HFACCEP(N1) had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFACCEP(N1) and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions. PMID:26087042

  2. Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation.

    PubMed

    Kobayashi, Katsuya; Matsumoto, Riki; Matsuhashi, Masao; Usami, Kiyohide; Shimotake, Akihiro; Kunieda, Takeharu; Kikuchi, Takayuki; Mikuni, Nobuhiro; Miyamoto, Susumu; Fukuyama, Hidenao; Takahashi, Ryosuke; Ikeda, Akio

    2015-01-01

    Physiological high frequency activities (HFA) are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections), or different terminal layers (layer IV vs. layer II/III) affect its frequency, we, in the primary somatosensory cortex (SI), compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response) and N80 (late response) of somatosensory evoked potentials (HFA(SEP(N20)) and HFA(SEP(N80))) and compared those overriding N1 and N2 (first and second responses) of cortico-cortical evoked potentials (HFA(CCEP(N1)) and HFA(CCEP(N2))). HFA(SEP(N20)) showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1)) had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1)) and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

  3. Selective attention modulates high-frequency activity in the face-processing network.

    PubMed

    Müsch, Kathrin; Hamamé, Carlos M; Perrone-Bertolotti, Marcela; Minotti, Lorella; Kahane, Philippe; Engel, Andreas K; Lachaux, Jean-Philippe; Schneider, Till R

    2014-11-01

    Face processing depends on the orchestrated activity of a large-scale neuronal network. Its activity can be modulated by attention as a function of task demands. However, it remains largely unknown whether voluntary, endogenous attention and reflexive, exogenous attention to facial expressions equally affect all regions of the face-processing network, and whether such effects primarily modify the strength of the neuronal response, the latency, the duration, or the spectral characteristics. We exploited the good temporal and spatial resolution of intracranial electroencephalography (iEEG) and recorded from depth electrodes to uncover the fast dynamics of emotional face processing. We investigated frequency-specific responses and event-related potentials (ERP) in the ventral occipito-temporal cortex (VOTC), ventral temporal cortex (VTC), anterior insula, orbitofrontal cortex (OFC), and amygdala when facial expressions were task-relevant or task-irrelevant. All investigated regions of interest (ROI) were clearly modulated by task demands and exhibited stronger changes in stimulus-induced gamma band activity (50-150 Hz) when facial expressions were task-relevant. Observed latencies demonstrate that the activation is temporally coordinated across the network, rather than serially proceeding along a processing hierarchy. Early and sustained responses to task-relevant faces in VOTC and VTC corroborate their role for the core system of face processing, but they also occurred in the anterior insula. Strong attentional modulation in the OFC and amygdala (300 msec) suggests that the extended system of the face-processing network is only recruited if the task demands active face processing. Contrary to our expectation, we rarely observed differences between fearful and neutral faces. Our results demonstrate that activity in the face-processing network is susceptible to the deployment of selective attention. Moreover, we show that endogenous attention operates along the whole

  4. Reduced In-Plane, Low Frequency Helicopter Noise of an Active Flap Rotor

    NASA Technical Reports Server (NTRS)

    Sim, Ben W.; Janakiram, Ram D.; Barbely, Natasha L.; Solis, Eduardo

    2009-01-01

    Results from a recent joint DARPA/Boeing/NASA/Army wind tunnel test demonstrated the ability to reduce in-plane, low frequency noise of the full-scale Boeing-SMART rotor using active flaps. Test data reported in this paper illustrated that acoustic energy in the first six blade-passing harmonics could be reduced by up to 6 decibels at a moderate airspeed, level flight condition corresponding to advance ratio of 0.30. Reduced noise levels were attributed to selective active flap schedules that modified in-plane blade airloads on the advancing side of the rotor, in a manner, which generated counteracting acoustic pulses that partially offset the negative pressure peaks associated with in-plane, steady thickness noise. These favorable reduced-noise operating states are a strong function of the active flap actuation amplitude, frequency and phase. The associated noise reductions resulted in reduced aural detection distance by up to 18%, but incurred significant vibratory load penalties due to increased hub shear forces. Small reductions in rotor lift-to-drag ratios, of no more than 3%, were also measured

  5. Effects of high-frequency oscillatory ventilation on vagal and phrenic nerve activities.

    PubMed

    Man, G C; Man, S F; Kappagoda, C T

    1983-02-01

    This study was undertaken to define the mechanism for the respiratory inhibition observed during high-frequency oscillatory ventilation (HFOV). The effects of HFOV on the activities of single units in the vagus (Vna) and phrenic nerves (Pna) were examined in pentobarbital-anesthetized dogs. The animals were either ventilated by intermittent positive-pressure ventilation (IPPV) with and without positive end-expiratory pressure (PEEP), or by HFOV at a frequency of 25 Hz and pump displacement volume of 3 ml/kg. In 13 vagal units the Vna was much higher during HFOV than during IPPV or airway occlusion at a matched airway pressure. Ten units in the phrenic nerves were examined, and Pna (expressed as bursts/min) was attenuated by HFOV in all of them. In four of them, the effect of cooling the vagi to 8-10 degrees C on Pna was examined, and it was found that HFOV failed to alter the Pna. We conclude that 1) HFOV stimulates the pulmonary vagal afferent fibers continuously and to a degree greater than that due to static lung inflation and increased airway pressure and 2) the increased vagal activity during HFOV probably causes phrenic nerve activity inhibition.

  6. Effects of surveillance towed array sensor system (SURTASS) low frequency active sonar on fish

    NASA Astrophysics Data System (ADS)

    Popper, Arthur N.; Halvorsen, Michele B.; Miller, Diane; Smith, Michael E.; Song, Jiakun; Wysocki, Lidia E.; Hastings, Mardi C.; Kane, Andrew S.; Stein, Peter

    2005-04-01

    We investigated the effects of exposure to Low Frequency Active (LFA) sonar on rainbow trout (a hearing non-specialist related to several endangered salmonids) and channel catfish (a hearing specialist), using an element of the standard SURTASS LFA source array. We measured hearing sensitivity using auditory brainstem response, effects on inner ear structure using scanning electron microscopy, effects on non-auditory tissues using general pathology and histopathology, and behavioral effects with video monitoring. Exposure to 193 dB re 1 microPa (rms received level) in the LFA frequency band for 324 seconds resulted in a TTS of 20 dB at 400 Hz in rainbow trout, with less TTS at 100 and 200 Hz. TTS in catfish ranged from 6 to 12 dB at frequencies from 200 to 1000 Hz. Both species recovered from hearing loss in several days. Inner ears sensory tissues appeared unaffected by acoustic exposure. Gross pathology indicated no damage to non-auditory tissues, including the swim bladder. Both species showed consistent startle responses at sound onsets and changed their position relative to the sound source during exposures. There was no fish death attributable to sound exposure even up to four days post-exposure. [Work supported by Chief of Naval Operations.

  7. Active power control of solar PV generation for large interconnection frequency regulation and oscillation damping

    DOE PAGES

    Liu, Yong; Zhu, Lin; Zhan, Lingwei; ...

    2015-06-23

    Because of zero greenhouse gas emission and decreased manufacture cost, solar photovoltaic (PV) generation is expected to account for a significant portion of future power grid generation portfolio. Because it is indirectly connected to the power grid via power electronic devices, solar PV generation system is fully decoupled from the power grid, which will influence the interconnected power grid dynamic characteristics as a result. In this study, the impact of solar PV penetration on large interconnected power system frequency response and inter-area oscillation is evaluated, taking the United States Eastern Interconnection (EI) as an example. Furthermore, based on the constructedmore » solar PV electrical control model with additional active power control loops, the potential contributions of solar PV generation to power system frequency regulation and oscillation damping are examined. The advantages of solar PV frequency support over that of wind generator are also discussed. Finally, simulation results demonstrate that solar PV generations can effectively work as ‘actuators’ in alleviating the negative impacts they bring about.« less

  8. Active power control of solar PV generation for large interconnection frequency regulation and oscillation damping

    SciTech Connect

    Liu, Yong; Zhu, Lin; Zhan, Lingwei; Gracia, Jose R.; King, Thomas Jr.; Liu, Yilu

    2015-06-23

    Because of zero greenhouse gas emission and decreased manufacture cost, solar photovoltaic (PV) generation is expected to account for a significant portion of future power grid generation portfolio. Because it is indirectly connected to the power grid via power electronic devices, solar PV generation system is fully decoupled from the power grid, which will influence the interconnected power grid dynamic characteristics as a result. In this study, the impact of solar PV penetration on large interconnected power system frequency response and inter-area oscillation is evaluated, taking the United States Eastern Interconnection (EI) as an example. Furthermore, based on the constructed solar PV electrical control model with additional active power control loops, the potential contributions of solar PV generation to power system frequency regulation and oscillation damping are examined. The advantages of solar PV frequency support over that of wind generator are also discussed. Finally, simulation results demonstrate that solar PV generations can effectively work as ‘actuators’ in alleviating the negative impacts they bring about.

  9. Effect of Turning Frequency on Composting of Empty Fruit Bunches Mixed with Activated Liquid Organic Fertilizer

    NASA Astrophysics Data System (ADS)

    Trisakti, B.; Lubis, J.; Husaini, T.; Irvan

    2017-03-01

    Composting of Empty Fruit Bunch (EFB) by mixing it with activated liquid organic fertilizer (ALOF) is an alternative way in the utilization of solid waste produced from the palm oil mill (POM). This research was to determine the effect of turning frequency on the rate of composting of EFB mixed with ALOF in a basket composter. The composting process was started with cutting the EFB into pieces with size 1-3 cm, inserting the EFB pieces into basket composter (33 cm W × 28 cm L × 40 cm H), and adding ALOF until moisture content (MC) in the range of 55-65%. During composting, the MC was maintained at 55-65% range by adding the ALOF. The turning frequency on each composter was varied i.e. once in every 1, 2, 3, 4, and 5 days. The parameters analysed during composting were temperature, pH, MC, compost weight, water holding capacity (WHC), CN ratio, and the quality of the final compost. Composting was carried out for 40 days and the best result obtained at turning frequency was 3 days. The best compost characteristic was pH 9.0; MC 57.24%; WHC 76%; CN ratio 12.15%; P 0.58%; and K 0. 95%.

  10. Frequency Count Attribute Oriented Induction of Corporate Network Data for Mapping Business Activity

    NASA Astrophysics Data System (ADS)

    Tanutama, Lukas

    2014-03-01

    Companies increasingly rely on Internet for effective and efficient business communication. As Information Technology infrastructure backbone for business activities, corporate network connects the company to Internet and enables its activities globally. It carries data packets generated by the activities of the users performing their business tasks. Traditionally, infrastructure operations mainly maintain data carrying capacity and network devices performance. It would be advantageous if a company knows what activities are running in its network. The research provides a simple method of mapping the business activity reflected by the network data. To map corporate users' activities, a slightly modified Attribute Oriented Induction (AOI) approach to mine the network data was applied. The frequency of each protocol invoked were counted to show what the user intended to do. The collected data was samples taken within a certain sampling period. Samples were taken due to the enormous data packets generated. Protocols of interest are only Internet related while intranet protocols are ignored. It can be concluded that the method could provide the management a general overview of the usage of its infrastructure and lead to efficient, effective and secure ICT infrastructure.

  11. Neurone bioelectric activity under magnetic fields of variable frequency in the range of 0.1-80 Hz

    NASA Astrophysics Data System (ADS)

    Pérez Bruzón, R. N.; Azanza, María. J.; Calvo, Ana C.; del Moral, A.

    2004-05-01

    Intracellular recordings from single unit molluscan neurones under exposure to ELF-MF (1 mT, 0.1-80 Hz), show that neurone frequency activity, f, decreases with the applied magnetic field frequency, fM, a phenomenon which indicates a frequency-window effect for the neurone membrane response. The HMHW of the window amounts between 2-10 Hz. An explanation of this phenomenon is proposed.

  12. Trade-off between frequency and precision during stepping movements: Kinematic and BOLD brain activation patterns.

    PubMed

    Martínez, Martin; Valencia, Miguel; Vidorreta, Marta; Luis, Elkin O; Castellanos, Gabriel; Villagra, Federico; Fernández-Seara, Maria A; Pastor, Maria A

    2016-05-01

    The central nervous system has the ability to adapt our locomotor pattern to produce a wide range of gait modalities and velocities. In reacting to external pacing stimuli, deviations from an individual preferred cadence provoke a concurrent decrease in accuracy that suggests the existence of a trade-off between frequency and precision; a compromise that could result from the specialization within the control centers of locomotion to ensure a stable transition and optimal adaptation to changing environment. Here, we explore the neural correlates of such adaptive mechanisms by visually guiding a group of healthy subjects to follow three comfortable stepping frequencies while simultaneously recording their BOLD responses and lower limb kinematics with the use of a custom-built treadmill device. In following the visual stimuli, subjects adopt a common pattern of symmetric and anti-phase movements across pace conditions. However, when increasing the stimulus frequency, an improvement in motor performance (precision and stability) was found, which suggests a change in the control mode from reactive to predictive schemes. Brain activity patterns showed similar BOLD responses across pace conditions though significant differences were observed in parietal and cerebellar regions. Neural correlates of stepping precision were found in the insula, cerebellum, dorsolateral pons and inferior olivary nucleus, whereas neural correlates of stepping stability were found in a distributed network, suggesting a transition in the control strategy across the stimulated range of frequencies: from unstable/reactive at lower paces (i.e., stepping stability managed by subcortical regions) to stable/predictive at higher paces (i.e., stability managed by cortical regions). Hum Brain Mapp 37:1722-1737, 2016. © 2016 Wiley Periodicals, Inc.

  13. Frequency-dependent changes in cerebral metabolic rate of oxygen during activation of human visual cortex.

    PubMed

    Vafaee, M S; Meyer, E; Marrett, S; Paus, T; Evans, A C; Gjedde, A

    1999-03-01

    To test the hypothesis that brain oxidative metabolism is significantly increased upon adequate stimulation, we varied the presentation of a visual stimulus to determine the frequency at which the metabolic response would be at maximum. The authors measured regional CMR(O2) in 12 healthy normal volunteers with the ECAT EXACT HR+ (CTI/Siemens, Knoxville, TN, U.S.A.) three-dimensional whole-body positron emission tomograph (PET). In seven successive activating conditions, subjects viewed a yellow-blue annular checkerboard reversing its contrast at frequencies of 0, 1, 4, 8, 16, 32, and 50 Hz. Stimulation began 4 minutes before and continued throughout the 3-minute dynamic scan. In the baseline condition, the subjects began fixating a cross hair 30 seconds before the scan and continued to do so for the duration of the 3-minute scan. At the start of each scan, the subjects inhaled 20 mCi of (15)O-O2 in a single breath. The CMR(O2) value was calculated using a two-compartment, weighted integration method. Normalized PET images were averaged across subjects and coregistered with the subjects' magnetic resonance imaging in stereotaxic space. Mean subtracted image volumes (activation minus baseline) of CMR(O2) then were obtained and converted to z statistic volumes. The authors found a statistically significant focal change of CMR(O2) in the striate cortex (x = 9; y = -89; z = -1) that reached a maximum at 4 Hz and dropped off sharply at higher stimulus frequencies.

  14. Time-frequency intracranial source localization of feedback-related EEG activity in hypothesis testing.

    PubMed

    Papo, David; Douiri, Abdel; Bouchet, Florence; Bourzeix, Jean-Claude; Caverni, Jean-Paul; Baudonnière, Pierre-Marie

    2007-06-01

    The neural correlates of the response to performance feedback have been the object of numerous neuroimaging studies. However, the precise timing and functional meaning of the resulting activations are poorly understood. We studied the electroencephalographic response time locked to positive and negative performance feedback in a hypothesis testing paradigm. The signal was convoluted with a family of complex wavelets. Intracranial sources of activity at various narrow-band frequencies were estimated in the 100- to 400-ms time window following feedback onset. Positive and negative feedback were associated to 1) early parahippocampo-cingular sources of alpha oscillations, more posteriorly located and long lasting for negative feedback and to 2) late partially overlapping neural circuits comprising regions in prefrontal, cingular, and temporal cortices but operating at feedback-specific latencies and frequencies. The results were interpreted in the light of neurophysiological models of feedback and were used to discuss methodological issues in the study of high-level cognitive functions, including reasoning and decision making.

  15. Active control of high-frequency vibration: Optimisation using the hybrid modelling method

    NASA Astrophysics Data System (ADS)

    Muthalif, Asan G. A.; Langley, Robin S.

    2012-06-01

    This work presents active control of high-frequency vibration using skyhook dampers. The choice of the damper gain and its optimal location is crucial for the effective implementation of active vibration control. In vibration control, certain sensor/actuator locations are preferable for reducing structural vibration while using minimum control effort. In order to perform optimisation on a general built-up structure to control vibration, it is necessary to have a good modelling technique to predict the performance of the controller. The present work exploits the hybrid modelling approach, which combines the finite element method (FEM) and statistical energy analysis (SEA) to provide efficient response predictions at medium to high frequencies. The hybrid method is implemented here for a general network of plates, coupled via springs, to allow study of a variety of generic control design problems. By combining the hybrid method with numerical optimisation using a genetic algorithm, optimal skyhook damper gains and locations are obtained. The optimal controller gain and location found from the hybrid method are compared with results from a deterministic modelling method. Good agreement between the results is observed, whereas results from the hybrid method are found in a significantly reduced amount of time.

  16. Do Productive Activities Reduce Inflammation in Later Life? Multiple Roles, Frequency of Activities, and C-Reactive Protein

    PubMed Central

    Kim, Seoyoun; Ferraro, Kenneth F.

    2014-01-01

    Purpose of the Study: The study investigates whether productive activities by older adults reduce bodily inflammation, as indicated by C-reactive protein (CRP), a biomeasure associated with the risk of cardiovascular diseases. Design and Methods: The study uses a representative survey of adults aged 57–85 from the National Social Life, Health, and Aging Project (N = 1,790). Linear regression models were used to analyze the effects of multiple roles (employment, volunteering, attending meetings, and caregiving) and the frequency of activity within each role on log values of CRP concentration (mg/L) drawn from assayed blood samples. Results: Number of roles for productive activities was associated with lower levels of CRP net of chronic conditions, lifestyle factors, and socioeconomic resources. When specific types of activity were examined, volunteering manifested the strongest association with lower levels of inflammation, particularly in the 70+ group. There was no evidence that frequent engagement in volunteer activity was associated with heightened inflammation. Implications: Productive activities—and frequent volunteering in particular—may protect individuals from inflammation that is associated with increased risk of hypertension and cardiovascular disease. PMID:23969258

  17. [Effect of electromagnetic field of extremely low frequency on ATPase activity of actomyosin].

    PubMed

    Tseĭslier, Iu V; Sheliuk, O V; Martyniuk, V S; Nuryshchenko, N Ie

    2012-01-01

    The Mg2+/Ca2+ and K(+)-ATPase actomyosin activity of rabbit skeletal muscle was evaluated by the Fiske-Subbarow method during a five-hour exposition of protein solutions in electromagnetic field of extremely low frequency of 8 Hz and 25 microT induction. The results of the study of the ATPase activity of actomyosin upon electromagnetic exposure have shown statistically significant changes that are characterized by a rather complex time dynamics. After 1, 2 and 4 hours of exposure of protein solutions the effect of ELF EMF exposure inhibits the ATPase activity compared to control samples, which are not exposed to the magnetic field. By the third and fifth hours of exposure to the electromagnetic field, there is a significant increase in the ATPase activity of actomyosin. It should be noted that a similar pattern of change in enzyme activity was universal, both for the environment by Mg2+ and Ca2+, and in the absence of these ions in the buffer. This can evidence for Ca(2+)-independent ways of the infuence of electromagnetic field (EMP) on biologic objects. In our opinion, the above effects are explained by EMP influence on the dynamic properties of actomyosin solutions, which are based on the processes of spontaneous dynamic formation of structure.

  18. No differences of butyrylcholinesterase protein activity and allele frequency in Lewy body diseases.

    PubMed

    Maetzler, Walter; Keller, Stefanie; Michelis, Joan; Koehler, Niklas; Stransky, Elke; Becker, Clemens; Schulte, Claudia; Melms, Arthur; Gasser, Thomas; Berg, Daniela

    2009-08-01

    Butyrylcholinesterase (BChE) genotypes and protein (BuChE) activity, especially in combination with Apolipoprotein E4 (ApoE4), have been investigated as risk factors for developing Alzheimer disease (AD) and may be associated with the rate of progression of cognitive decline. Despite similar pathologic (e.g. amyloid deposition) and neurochemical (e.g. cholinergic deficits) aspects between AD and Lewy body diseases (LBD), scarce data is obtainable about BChE genotypes and BuChE activity in LBD. We measured BuChE activity levels in serum and cerebrospinal fluid (CSF) of 114 LBD subjects (59 of them were demented) and 31 elderly controls. We found higher CSF BuChE activity in males compared to females, and a negative correlation of serum BuChE activity with age and cognitive function. Demented LBD patients, non-demented LBD patients and controls did not differ significantly with regard to serum and CSF BuChE activity. Furthermore, BChE K variant and ApoE4 allele frequencies were determined. The BChE K variant was significantly associated with lower serum activity; the same trend was observable in CSF. The subgroups did not differ significantly with regard to BChE K/ApoE4 occurrence. These data confirm and extend previous results on the relationship between BChE gene and BuChE activity, and argue rather against a major impact of BuChE on LBD-associated pathologies.

  19. The Toronto Empathy Questionnaire

    PubMed Central

    Spreng, R. Nathan; McKinnon, Margaret C.; Mar, Raymond A.; Levine, Brian

    2008-01-01

    In order to formulate a parsimonious tool to assess empathy, we used factor analysis on a combination of self-report measures to examine consensus and developed a brief self-report measure of this common factor. The Toronto Empathy Questionnaire (TEQ) represents empathy as a primarily emotional process. In three studies, the TEQ demonstrated strong convergent validity, correlating positively with behavioral measures of social decoding, self-report measures of empathy, and negatively with a measure of Autism symptomatology. Moreover, it exhibited good internal consistency and high test-retest reliability. The TEQ is a brief, reliable, and valid instrument for the assessment of empathy. PMID:19085285

  20. Effect of solar activity on the frequency of occurrence of major anomalies in the Arctic. [weather forecasting

    NASA Technical Reports Server (NTRS)

    Bolotinskaya, M. S.

    1978-01-01

    Major air pressure and temperature anomalies in certain arctic regions were studied with a view toward predicting their occurrence. Correlations are sought between the frequency of arctic anomalies and solar activity, or specifically the Wolf number and the index of geomagnetic disturbance. Graphic techniques are used to show that solar activity has a definite influence on the frequency of occurrence of major anomalies of pressure and temperature in the Arctic.

  1. Beware: Recruitment of Muscle Activity by the EEG-Neurofeedback Trainings of High Frequencies.

    PubMed

    Paluch, Katarzyna; Jurewicz, Katarzyna; Rogala, Jacek; Krauz, Rafał; Szczypińska, Marta; Mikicin, Mirosław; Wróbel, Andrzej; Kublik, Ewa

    2017-01-01

    EEG-neurofeedback (NFB) became a very popular method aimed at improving cognitive and behavioral performance. However, the EMG frequency spectrum overlies the higher EEG oscillations and the NFB trainings focusing on these frequencies is hindered by the problem of EMG load in the information fed back to the subjects. In such a complex signal, it is highly probable that the most controllable component will form the basis for operant conditioning. This might cause different effects in the case of various training protocols and therefore needs to be carefully assessed before designing training protocols and algorithms. In the current experiment a group of healthy adults (n = 14) was trained by professional trainers to up-regulate their beta1 (15-22 Hz) band for eight sessions. The control group (n = 18) underwent the same training regime but without rewards for increasing beta. In half of the participants trained to up-regulate beta1 band (n = 7) a systematic increase in tonic EMG activity was identified offline, implying that muscle activity became a foundation for reinforcement in the trainings. The remaining participants did not present any specific increase of the trained beta1 band amplitude. The training was perceived effective by both trainers and the trainees in all groups. These results indicate the necessity of proper control of muscle activity as a requirement for the genuine EEG-NFB training, especially in protocols that do not aim at the participants' relaxation. The specificity of the information fed back to the participants should be of highest interest to all therapists and researchers, as it might irreversibly alter the results of the training.

  2. Beware: Recruitment of Muscle Activity by the EEG-Neurofeedback Trainings of High Frequencies

    PubMed Central

    Paluch, Katarzyna; Jurewicz, Katarzyna; Rogala, Jacek; Krauz, Rafał; Szczypińska, Marta; Mikicin, Mirosław; Wróbel, Andrzej; Kublik, Ewa

    2017-01-01

    EEG-neurofeedback (NFB) became a very popular method aimed at improving cognitive and behavioral performance. However, the EMG frequency spectrum overlies the higher EEG oscillations and the NFB trainings focusing on these frequencies is hindered by the problem of EMG load in the information fed back to the subjects. In such a complex signal, it is highly probable that the most controllable component will form the basis for operant conditioning. This might cause different effects in the case of various training protocols and therefore needs to be carefully assessed before designing training protocols and algorithms. In the current experiment a group of healthy adults (n = 14) was trained by professional trainers to up-regulate their beta1 (15–22 Hz) band for eight sessions. The control group (n = 18) underwent the same training regime but without rewards for increasing beta. In half of the participants trained to up-regulate beta1 band (n = 7) a systematic increase in tonic EMG activity was identified offline, implying that muscle activity became a foundation for reinforcement in the trainings. The remaining participants did not present any specific increase of the trained beta1 band amplitude. The training was perceived effective by both trainers and the trainees in all groups. These results indicate the necessity of proper control of muscle activity as a requirement for the genuine EEG-NFB training, especially in protocols that do not aim at the participants’ relaxation. The specificity of the information fed back to the participants should be of highest interest to all therapists and researchers, as it might irreversibly alter the results of the training. PMID:28373836

  3. A thorough analysis of the short- and mid-term activity-related variations in the solar acoustic frequencies

    NASA Astrophysics Data System (ADS)

    Santos, A. R. G.; Cunha, M. S.; Avelino, P. P.; Chaplin, W. J.; Campante, T. L.

    2017-02-01

    The frequencies of the solar acoustic oscillations vary over the activity cycle. The variations in other activity proxies are found to be well correlated with the variations in the acoustic frequencies. However, each proxy has a slightly different time behaviour. Our goal is to characterize the differences between the time behaviour of the frequency shifts and of two other activity proxies, namely the area covered by sunspots and the 10.7-cm flux. We define a new observable that is particularly sensitive to the short-term frequency variations. We then compare the observable when computed from model frequency shifts and from observed frequency shifts obtained with the Global Oscillation Network Group (GONG) for cycle 23. Our analysis shows that on the shortest time-scales, the variations in the frequency shifts seen in the GONG observations are strongly correlated with the variations in the area covered by sunspots. However, a significant loss of correlation is still found. We verify that the times when the frequency shifts and the sunspot area do not vary in a similar way tend to coincide with the times of the maxima of the quasi-biennial variations seen in the solar seismic data. A similar analysis of the relation between the 10.7-cm flux and the frequency shifts reveals that the short-time variations in the frequency shifts follow even more closely those of the 10.7-cm flux than those of the sunspot area. However, a loss of correlation between frequency shifts and 10.7-cm flux variations is still found around the same times.

  4. Questionnaire Translation and Questionnaire Validation: Are They the Same?

    ERIC Educational Resources Information Center

    Griffee, Dale T.

    The purpose of this paper is to give evidence for the thesis that if teachers using a questionnaire as a data collection instrument have the questionnaire items translated from one language into another, they cannot assume that the translated items are valid simply because they were translated. Even if the original questionnaire items were…

  5. Frequency of Maternal Touch Predicts Resting Activity and Connectivity of the Developing Social Brain

    PubMed Central

    Brauer, Jens; Xiao, Yaqiong; Poulain, Tanja; Friederici, Angela D.; Schirmer, Annett

    2016-01-01

    Previous behavioral research points to a positive relationship between maternal touch and early social development. Here, we explored the brain correlates of this relationship. The frequency of maternal touch was recorded for 43 five-year-old children during a 10 min standardized play session. Additionally, all children completed a resting-state functional magnetic resonance imaging session. Investigating the default mode network revealed a positive relation between the frequency of maternal touch and activity in the right posterior superior temporal sulcus (pSTS) extending into the temporo-parietal junction. Using this effect as a seed in a functional connectivity analysis identified a network including extended bilateral regions along the temporal lobe, bilateral frontal cortex, and left insula. Compared with children with low maternal touch, children with high maternal touch showed additional connectivity with the right dorso-medial prefrontal cortex. Together these results support the notion that childhood tactile experiences shape the developing “social brain” with a particular emphasis on a network involved in mentalizing. PMID:27230216

  6. Examination into the maximum rotational frequency for an in-plane switched active waveplate device

    NASA Astrophysics Data System (ADS)

    Davidson, A. J.; Elston, S. J.; Raynes, E. P.

    2005-05-01

    An examination of an active waveplate device using a one-dimensional model, giving numerical and analytical results, is presented. The model calculates the director and twist configuration by minimizing the free energy of the system with simple homeotropic boundary conditions. The effect of varying the in-plane electric field in both magnitude and direction is examined, and it is shown that the twist through the cell is constant in time as the field is rotated. As the electric field is rotated, the director field lags behind by an angle which increases as the frequency of the electric field rotation increases. When this angle reaches approximately π/4 the director field no longer follows the electric field in a uniform way. Using mathematical analysis it is shown that the conditions on which the director profile will fail to follow the rotating electric field depend on the frequency of electric field rotation, the magnitude of the electric field, the dielectric anisotropy and the viscosity of the liquid crystal.

  7. Visualization and optimization of cavitation activity at a solid surface in high frequency ultrasound fields.

    PubMed

    Kauer, Markus; Belova-Magri, Valentina; Cairós, Carlos; Schreier, Hans-Jürgen; Mettin, Robert

    2017-01-01

    Despite the increasing use of high frequency ultrasound in heterogeneous reactions, knowledge about the spatial distribution of cavitation bubbles at the irradiated solid surface is still lacking. This gap hinders controllable surface sonoreactions. Here we present an optimization study of the cavitation bubble distribution at a solid sample using sonoluminescence and sonochemiluminescence imaging. The experiments were performed at three ultrasound frequencies, namely 580, 860 and 1142kHz. We found that position and orientation of the sample to the transducer, as well as its material properties influence the distribution of active cavitation bubbles at the sample surface in the reactor. The reason is a significant modification of the acoustic field due to reflections and absorption of the ultrasonic wave by the solid. This is retraced by numerical simulations employing the Finite Element Method, yielding reasonable agreement of luminescent zones and high acoustic pressure amplitudes in 2D simulations. A homogeneous coverage of the test sample surface with cavitation is finally reached at nearly vertical inclination with respect to the incident wave.

  8. Tutorial of Wind Turbine Control for Supporting Grid Frequency through Active Power Control: Preprint

    SciTech Connect

    Aho, J.; Buckspan, A.; Laks, J.; Fleming, P.; Jeong, Y.; Dunne, F.; Churchfield, M.; Pao, L.; Johnson, K.

    2012-03-01

    As wind energy becomes a larger portion of the world's energy portfolio and wind turbines become larger and more expensive, wind turbine control systems play an ever more prominent role in the design and deployment of wind turbines. The goals of traditional wind turbine control systems are maximizing energy production while protecting the wind turbine components. As more wind generation is installed there is an increasing interest in wind turbines actively controlling their power output in order to meet power setpoints and to participate in frequency regulation for the utility grid. This capability will be beneficial for grid operators, as it seems possible that wind turbines can be more effective at providing some of these services than traditional power plants. Furthermore, establishing an ancillary market for such regulation can be beneficial for wind plant owner/operators and manufacturers that provide such services. In this tutorial paper we provide an overview of basic wind turbine control systems and highlight recent industry trends and research in wind turbine control systems for grid integration and frequency stability.

  9. Simulated vibrational sum frequency generation from a multilayer thin film system with two active interfaces.

    PubMed

    O'Brien, Daniel B; Massari, Aaron M

    2013-04-21

    In the field of surface-specific vibrational sum frequency generation spectroscopy (VSFG) on organic thin films, optical interferences combined with the two-interface problem presents a challenge in terms of qualitative assessment of the data and quantitative modeling. The difficulty is amplified when considering systems comprised of more than a single material thin film layer. Recently, in our lab we have developed a generalized model that describes thin film interference in interface-specific nonlinear optical spectroscopies from arbitrary multilayer systems. Here, we apply the model to simulate VSFG spectra from the simplest multilayer: a system of two thin films, one of which is an organic small molecule and the other is a dielectric layer on a semiconductor substrate system where we idealize that the organic interfaces are equally VSFG active. Specifically, we consider the molecule N,N'-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) deposited on a silicon wafer with a thermally grown oxide dielectric. We present results for the four polarization experiments that sample the nonzero nonlinear susceptibility elements of macroscopically centrosymmetric materials (ssp, sps, pss, and ppp) and in two mIR frequency windows (the imide carbonyl stretches around 1680 cm(-1) and the alkyl stretches around 2900 cm(-1)) as a function of both thin film thicknesses with fixed input beam angles. We use frequency dependent refractive indices for all materials. The goal is to illustrate some of the intricacies contained in the intensity data of such systems. Of particular interest is the effect of the relative polar orientation of modes at the interfaces and the possibility of designing a system where the collected signal is exclusively attributable to a single interface. Our calculations indicate that in order to unambiguously identify the relative polar orientation one must experimentally vary an additional system parameter such as thin film thickness or input beam angle

  10. Active loaded plasmonic antennas at terahertz frequencies: Optical control of their capacitive-inductive coupling

    NASA Astrophysics Data System (ADS)

    Georgiou, G.; Tserkezis, C.; Schaafsma, M. C.; Aizpurua, J.; Gómez Rivas, J.

    2015-03-01

    We demonstrate the photogeneration of loaded dipole plasmonic antennas resonating at THz frequencies. This is achieved by the patterned optical illumination of a semiconductor surface using a spatial light modulator. Our experimental results indicate the existence of capacitive and inductive coupling of localized surface plasmon polaritons. By varying the load in the antenna gap we are able to switch between both coupling regimes. Furthermore, we determine experimentally the effective impedance of the antenna load and verify that this load can be effectively expressed as a LC resonance formed by a THz inductor and capacitor connected in a parallel circuit configuration. These findings are theoretically supported by full electrodynamic calculations and by simple concepts of lumped circuit theory. Our results open new possibilities for the design of active THz circuits for optoelectronic devices.

  11. A flexible active and reactive power control strategy for a variable speed constant frequency generating system

    SciTech Connect

    Tang, Y.; Xu, L.

    1995-07-01

    Variable-speed constant-frequency generating systems are used in wind power, hydro power, aerospace, and naval power generations to enhance efficiency and reduce friction. In these applications, an attractive candidate is the slip power recovery system comprising of doubly excited induction machine or doubly excited brushless reluctance machine and PWM converters with a dc link. In this paper, a flexible active and reactive power control strategy is developed, such that the optimal torque-speed profile of the turbine can be followed and overall reactive power can be controlled, while the machine copper losses have been minimized. At the same time, harmonics injected into the power network has also been minimized. In this manner, the system can function as both a high-efficient power generator and a flexible reactive power compensator.

  12. High frequency oscillatory ventilation attenuates the activation of alveolar macrophages and neutrophils in lung injury.

    PubMed

    Shimaoka; Fujino; Taenaka; Hiroi; Kiyono; Yoshiya

    1998-01-01

    BACKGROUND: Recent investigations have shown that leukocyte activation is involved in the pathogenesis of ventilator-associated lung injury. This study was designed to investigate whether the inflammatory responses and deterioration of oxygenation in ventilator-associated lung injury are attenuated by high-frequency oscillatory ventilation (HFO). We analyzed the effects of HFO compared with conventional mechanical ventilation (CMV) on the activation of pulmonary macrophages and neutrophils in 10 female rabbits. RESULTS: After surfactant depletion, the rabbits were ventilated by CMV or HFO at the same mean airway pressure. Surfactant-depletion followed by 4 h mechanical ventilation hindered pulmonary oxygenation in both groups. Impairment of oxygenation was less severe in the HFO group than in the CMV group. In the HFO group the infiltration of granulocytes into alveolar spaces occurred more readily than in the CMV group. Compared with CMV, HFO resulted in greater attenuation of beta2-integrin expression, not only on granulocytes, but also on macrophages. CONCLUSIONS: In the surfactant-depleted lung, the activation of leukocytes was attenuated by HFO. Reduced inflammatory response correlated with decreased impairment of oxygenation. HFO may reduce lung injury via the attenuation of pulmonary inflammation.

  13. Thiamethoxam: Assessing flight activity of honeybees foraging on treated oilseed rape using radio frequency identification technology.

    PubMed

    Thompson, Helen; Coulson, Mike; Ruddle, Natalie; Wilkins, Selwyn; Harkin, Sarah

    2016-02-01

    The present study was designed to assess homing behavior of bees foraging on winter oilseed rape grown from seed treated with thiamethoxam (as Cruiser OSR), with 1 field drilled with thiamethoxam-treated seed and 2 control fields drilled with fungicide-only-treated seed. Twelve honeybee colonies were used per treatment group, 4 each located at the field edge (on-field site), at approximately 500 m and 1000 m from the field. A total of nearly 300 newly emerged bees per colony were fitted (tagged) with Mic3 radio frequency identification (RFID) transponders and introduced into each of the 36 study hives. The RFID readers fitted to the entrances of the test colonies were used to monitor the activity of the tagged bees for the duration of the 5-wk flowering period of the crop. These activity data were analyzed to assess any impact on flight activity of bees foraging on the treated compared with untreated crops. Honeybees were seen to be actively foraging within all 3 treatment groups during the exposure period. The data for the more than 3000 RFID-tagged bees and more than 90 000 foraging flights monitored throughout the exposure phase for the study follow the same trends across the treatment and controls and at each of the 3 apiary distances, indicating that there were no effects from foraging on the treated crop. Under the experimental conditions, there was no effect of foraging on thiamethoxam-treated oilseed rape on honeybee flight activity or on their ability to return to the hive.

  14. Questionnaire Surveys in Educational Planning.

    ERIC Educational Resources Information Center

    Psacharopoulos, George

    1980-01-01

    This paper reviews and discusses some critical issues related to the use of questionnaire surveys in educational planning. Ten brief sections discuss survey objectives, coverage, questionnaire design, administration, validity, nonresponse, cost considerations, coding, statistical analysis, and interpretation. Five illustrative questionnaire…

  15. Diet History Questionnaire: Suggested Citations

    Cancer.gov

    Use of the Diet History Questionnaire and Diet*Calc Analysis Software for publication purposes should contain a citation which includes version information for the software, questionnaire, and nutrient database.

  16. Diet History Questionnaire: International Applications

    Cancer.gov

    ARP staff adapted the Diet History Questionnaire (DHQ) for use by Canadian populations in collaboration with the Alberta Cancer Board. This questionnaire takes into account the different food fortification polices of the U.S. and Canada.

  17. The Drug-Abuse Questionnaire.

    ERIC Educational Resources Information Center

    Ferneau, E.; Mueller, S.

    The drug-abuse questionnaire used to survey college student attitudes on the subject is provided. It is identical to the alcoholism questionnaire except for word changes appropriate to the subject matter. The questionnaire consists of 40 statements about drug abuse and drug abusers, with 7 possible responses: (1) completely disagree; (2) mostly…

  18. Diet History Questionnaire II & Canadian Diet History Questionnaire II: Web-based DHQ

    Cancer.gov

    The Web-based versions of DHQ II and C-DHQ II are identical in content to the paper forms. By automating the DHQ II and providing versions on the Web for public use, researchers have another tool to collect and analyze food frequency questionnaire data.

  19. Frequency-Dependent Activation of Glucose Utilization in the Superior Cervical Ganglion by Electrical Stimulation of Cervical Sympathetic Trunk

    NASA Astrophysics Data System (ADS)

    Yarowsky, Paul; Kadekaro, Massako; Sokoloff, Louis

    1983-07-01

    Electrical stimulation of the distal stump of the transected cervical sympathetic trunk produces a frequency-dependent activation of glucose utilization, measured by the deoxy[14C]glucose method, in the superior cervical ganglion of the urethane-anesthetized rat. The frequency dependence falls between 0-15 Hz; at 20 Hz the activation of glucose utilization is no greater than at 15 Hz. Deafferentation of the superior cervical ganglion by transection of the cervical sympathetic trunk does not diminish the rate of glucose utilization in the ganglion in the urethane-anesthetized rat. These results indicate that the rate of energy metabolism in an innervated neural structure is, at least in part, regulated by the impulse frequency of the electrical input to the structure, and this regulation may be an essential component of the mechanism of the coupling of metabolic activity to functional activity in the nervous system.

  20. Neurosteroids modulate epileptiform activity and associated high-frequency oscillations in the piriform cortex.

    PubMed

    Herrington, R; Lévesque, M; Avoli, M

    2014-01-03

    Allotetrahydrodeoxycorticosterone (THDOC) belongs to a class of pregnane neurosteroidal compounds that enhance brain inhibition by interacting directly with GABAA signaling, mainly through an increase in tonic inhibitory current. Here, we addressed the role of THDOC in the modulation of interictal- and ictal-like activity and associated high-frequency oscillations (HFOs, 80-500 Hz; ripples: 80-200 Hz, fast ripples: 250-500 Hz) recorded in vitro in the rat piriform cortex, a highly excitable brain structure that is implicated in seizure generation and maintenance. We found that THDOC: (i) increased the duration of interictal discharges in the anterior piriform cortex while decreasing ictal discharge duration in both anterior and posterior piriform cortices; (ii) reduced the occurrence of HFOs associated to both interictal and ictal discharges; and (iii) prolonged the duration of 4-aminopyridine-induced, glutamatergic independent synchronous field potentials that are known to mainly result from the activation of GABAA receptors. Our results indicate that THDOC can modulate epileptiform synchronization in the piriform cortex presumably by potentiating GABAA receptor-mediated signaling. This evidence supports the view that neurosteroids regulate neuronal excitability and thus control the occurrence of seizures.

  1. Movement-related frequency modulation of beta oscillatory activity in the human subthalamic nucleus.

    PubMed

    Foffani, G; Bianchi, A M; Baselli, G; Priori, A

    2005-10-15

    Event-related changes of brain electrical rhythms are typically analysed as amplitude modulations of local field potential (LFP) oscillations, like radio amplitude modulation broadcasting. In telecommunications, frequency modulation (FM) is less susceptible to interference than amplitude modulation (AM) and is therefore preferred for high-fidelity transmissions. Here we hypothesized that LFP rhythms detected from deep brain stimulation (DBS) electrodes implanted in the subthalamic nucleus (STN) in patients with Parkinson's disease could represent movement-related activity not only in AM but also in FM. By combining adaptive autoregressive identification with spectral power decomposition, we were able to show that FM of low-beta (13-20 Hz) and high-beta (20-35 Hz) rhythms significantly contributes to the involvement of the human STN in movement preparation, execution and recovery, and that the FM patterns are regulated by the dopamine levels in the system. Movement-related FM of beta oscillatory activity in the human subthalamic nucleus therefore provides a novel informational domain for rhythm-based pathophysiological models of cortico-basal ganglia processing.

  2. Dual-frequency plasmon lasing modes in active three-layered bimetallic Ag/Au nanoshells

    NASA Astrophysics Data System (ADS)

    Wu, DaJian; Wu, XueWei; Cheng, Ying; Jin, BiaoBing; Liu, XiaoJun

    2015-11-01

    The optical properties of three-layered silver-gold-silica (SGS) nanoshells with gain have been investigated theoretically by using Mie theory. Surface plasmon amplification by stimulated emission of radiation (spaser) phenomena can be observed at two plasmon modes of the active SGS nanoshell in the visible region. It is found with the decrease in the radius of the inner Ag core that the critical value of ɛg″(ωg ) for the super-resonance of the low-energy mode increases first and then decreases while that for the high-energy mode decreases. An interesting overlap between the two curves for the critical value of ɛg″(ωg ) can be found at a special core radius. At this point, two super-resonances can be achieved concurrently at the low- and high-energy modes of the active SGS nanoshell with the same gain coefficient. This dual-frequency spaser based on the bimetallic Ag/Au nanoshell may be an efficient candidate for designing the nanolaser.

  3. Movement-related frequency modulation of beta oscillatory activity in the human subthalamic nucleus

    PubMed Central

    Foffani, G; Bianchi, AM; Baselli, G; Priori, A

    2005-01-01

    Event-related changes of brain electrical rhythms are typically analysed as amplitude modulations of local field potential (LFP) oscillations, like radio amplitude modulation broadcasting. In telecommunications, frequency modulation (FM) is less susceptible to interference than amplitude modulation (AM) and is therefore preferred for high-fidelity transmissions. Here we hypothesized that LFP rhythms detected from deep brain stimulation (DBS) electrodes implanted in the subthalamic nucleus (STN) in patients with Parkinson's disease could represent movement-related activity not only in AM but also in FM. By combining adaptive autoregressive identification with spectral power decomposition, we were able to show that FM of low-beta (13–20 Hz) and high-beta (20–35 Hz) rhythms significantly contributes to the involvement of the human STN in movement preparation, execution and recovery, and that the FM patterns are regulated by the dopamine levels in the system. Movement-related FM of beta oscillatory activity in the human subthalamic nucleus therefore provides a novel informational domain for rhythm-based pathophysiological models of cortico-basal ganglia processing. PMID:16123109

  4. Impact of lung inflation cycle frequency on rat muscle and skin sympathetic activity recorded using suction electrodes

    PubMed Central

    Huang, Chunhua; Marina, Nephtali; Gilbey, Michael P.

    2009-01-01

    Microneurography has been used in humans to study sympathetic activity supplying targets within skeletal muscle and skin. Comparable animal studies are relatively few, probably due to the technical demands of traditional fibre picking techniques. Here we apply a simple suction electrode technique to record cutaneous (CVC) and muscle (MVC) vasoconstrictor activities and describe and investigate the basis of the frequency dependence of lung inflation related modulation. Hindlimb MVC and CVC activities were recorded concurrently. The magnitude of MVC and CVC activities at the lung inflation cycle frequency was significantly less at 2.0 Hz than at lung inflation cycle frequencies ≤ 1.0 Hz. As lung inflation cycle frequency was increased the coherence between lung inflation cycle or BP and MVC or CVC waveforms decreased. Consistent with the hypothesis that much of the coherence between lung inflation cycle and nerve activity waveforms is secondary to oscillating baroreceptor activity attributable to BP waves, partialization with the BP waveform significantly decreased the coherence between lung inflation cycle and nerve waveforms, and there was an absence of coherence between these waveforms following sinus and aortic denervation. Our data extend findings from other laboratories and establish the value of a suction electrode technique for recording MVC and CVC activities. Furthermore, our observations describe the rates of positive pressure ventilation that avoid strong and regular gating of sympathetic activity. PMID:19457723

  5. Feeding frequency, but not dietary water content, affects voluntary physical activity in young lean adult female cats.

    PubMed

    de Godoy, M R C; Ochi, K; de Oliveira Mateus, L F; de Justino, A C C; Swanson, K S

    2015-05-01

    The objective of this study was to investigate whether increased dietary water content and feeding frequency increased voluntary physical activity of young, lean adult female cats. A replicated 4 × 4 Latin square design with a 2 × 2 factorial treatment arrangement (feeding frequency and water content) was used. The 4 treatments consisted of 1 meal daily dry pet food without added water (1D; 12% moisture as is), 1 meal daily dry pet food with added water (1W; 70% total water content), 4 meals daily dry pet food without added water (4D; 12% moisture as is), and 4 meals daily dry pet food with added water (4W; 70% total water content). Eight healthy adult, lean, intact, young, female domestic shorthair cats were used in this experiment. Voluntary physical activity was evaluated using Actical activity monitors placed on collars and worn around the cats' necks for the last 7 d of each experimental period of 14 d. Food anticipatory activity (FAA) was calculated based on 2 h prior to feeding periods and expressed as a percentage of total daily voluntary physical activity. Increased feeding frequency (4 vs. 1 meal daily) resulted in greater average daily activity (P = 0.0147), activity during the light period (P = 0.0023), and light:dark activity ratio (P = 0.0002). In contrast, physical activity during the dark period was not altered by feeding frequency (P > 0.05). Cats fed 4 meals daily had increased afternoon FAA (P= 0.0029) compared with cats fed once daily. Dietary water content did not affect any measure of voluntary physical activity. Increased feeding frequency is an effective strategy to increase the voluntary physical activity of cats. Thus, it may assist in the prevention and management of obesity.

  6. Effects of controlled-frequency moderate electric fields on pectin methylesterase and polygalacturonase activities in tomato homogenate.

    PubMed

    Samaranayake, Chaminda P; Sastry, Sudhir K

    2016-05-15

    The effect of controlled-frequency moderate electric field treatments on pectin methylesterase and polygalcturonase activities in tomato homogenate was investigated by subjecting identically treated control and electrically-treated samples to the same temperature history. Additionally, a model was developed for the motion of the enzyme molecules subjected to an electric field. Results show that the application of electric fields at a low field strength (0.4V/cm) constant temperature (65°C) has a statistically significant effect on pectin methylesterase activity, typically at or lower than 60 Hz. At higher frequencies, the effects are negligible. Molecular motion simulations suggest that the efficacy at low frequencies may be due to the amplitude of motion being of the order of the intermolecular distance for water. Higher frequencies result in small overall displacements due to rapid reversals in the direction of motion.

  7. [S-II symptom questionnaire].

    PubMed

    Aleksandrowicz, J W

    2000-01-01

    "S-II" Symptom Check-list which allows for a fast diagnosis of neurotic disorders. A result of 165 points suggests the incidence of such disorders with the probability of 90%. The methodology of the construction of the check-list intends for the application of questions most common in those ill due to neurotic disorders (owing to the change in frequency) and the most possibly equal amount of questions on the symptoms common to women and men. Thanks to this the norm for women and men is identical. SCL S-II Symptom Check-list is a shortened and actualised version of the "O" Symptom Check-list, developed in 1975. It is similar to the SCL-90 and highly correlated with it, but it does not contain the variables concerning the psychotic symptoms. Thanks to this, its' accuracy (specificity) in the diagnosis of neurotic disorders is high. 4 pairs of questions allow for the judgement of answer reliability. 10 scales were singled out in the questionnaire. They are only of a helpful value and do not allow for a one-sided diagnosis of the type of the disorder, listed in the ICD-10. The scale results can, however make the correct diagnosis easier.

  8. Skilled adult readers activate the meanings of high-frequency words using phonology: Evidence from eye tracking.

    PubMed

    Jared, Debra; O'Donnell, Katrina

    2017-02-01

    We examined whether highly skilled adult readers activate the meanings of high-frequency words using phonology when reading sentences for meaning. A homophone-error paradigm was used. Sentences were written to fit 1 member of a homophone pair, and then 2 other versions were created in which the homophone was replaced by its mate or a spelling-control word. The error words were all high-frequency words, and the correct homophones were either higher-frequency words or low-frequency words-that is, the homophone errors were either the subordinate or dominant member of the pair. Participants read sentences as their eye movements were tracked. When the high-frequency homophone error words were the subordinate member of the homophone pair, participants had shorter immediate eye-fixation latencies on these words than on matched spelling-control words. In contrast, when the high-frequency homophone error words were the dominant member of the homophone pair, a difference between these words and spelling controls was delayed. These findings provide clear evidence that the meanings of high-frequency words are activated by phonological representations when skilled readers read sentences for meaning. Explanations of the differing patterns of results depending on homophone dominance are discussed.

  9. Frequency-specific electrocorticographic correlates of working memory delay period fMRI activity.

    PubMed

    Khursheed, Faraz; Tandon, Nitin; Tertel, Kathrin; Pieters, Thomas A; Disano, Michael A; Ellmore, Timothy M

    2011-06-01

    Electrocorticography (ECoG) and functional MRI (BOLD-fMRI) have been used previously to measure brain activity during working memory delay periods. These studies have separately reported oscillation changes in the theta (4-8 Hz) band and BOLD-fMRI increases during delay periods when information is maintained in memory. However, it is not known how intracranial cortical field potential (CFP) changes relate to BOLD-fMRI responses during delay periods. To answer this question, fMRI was obtained from six epilepsy patients during a visual working memory task. Then, following subdural macroelectrode implant, continuous ECoG was used to record CFPs during the same task. Time-frequency analyses showed delay period gamma band oscillation amplitude increases on electrodes located near fMRI activity, while in the theta band changes were higher for electrodes located away from fMRI activation. The amplitude of the ECoG gamma band response was significantly positively correlated with the fMRI response, while a negative correlation was found for the theta band. The findings are consistent with previous reports of local field potential (LFP) coupling in the gamma band with BOLD-fMRI responses during visual stimulation in monkeys, but are novel in that the relationship reported here persists after the disappearance of visual stimuli while information is being maintained in memory. We conclude that there is a relationship between BOLD-fMRI increases and human working memory delay period gamma oscillation increases and theta decreases. The spectral profile change provides a basis for comparison of working memory delay period BOLD-fMRI with field potential recordings in animals and other human intracranial EEG studies.

  10. Low frequency electromagnetic signals in the atmosphere caused by geodynamics and solar activity

    NASA Astrophysics Data System (ADS)

    Novik, Oleg; Ruzhin, Yuri; Ershov, Sergey; Volgin, Max; Smirnov, Fedor

    Due to the composed structure of the medium and large portions of energy transferred, a seismic excitation in the oceanic or continental lithosphere disturbs all types of geophysical fields. To investigate the problem of electromagnetic (EM) forcing on the atmosphere from the seismically activated lithosphere, we have formulated two mathematical models of interaction of fields of different physical nature resulting in arising of the low-frequency (from 0.1 to 10 Hz by amplitude of a few hundreds of pT) EM signals in the atmosphere. First we have considered the EM field generation in the moving oceanic lithosphere and then in the moving continental one. For both cases, the main physical principles and geological data were applied for formulation of the model and characteristics of the computed signals of different nature agree with measurements of other authors. On the basis of the 2D model of the seismo-hydro-EM-temperature interaction in a lithosphere-Ocean-atmosphere domain, a block-scheme of a multisensory vertically distributed (from a seafloor up to the ionosphere) tsunami precursors’ detection system is described. On the basis of the 3D model of the seismo-EM interaction in a lithosphere-atmosphere domain, we explain effect of location of the future seismic epicenter area (obtained by Prof. Kopytenko, Yu. A. from Inst. IZMIRAN of Russian Acad. Sci. and co-authors) as the result of the magnetic field measurements in the atmosphere near the earth’s surface. We believe that the biosphere effects of forcing on the atmosphere may not be ignored. We formulate the result of our measurements with the system of micro-voltmeters: low-frequency EM disturbances of the atmosphere caused by solar activity (namely, geomagnetic storms with the geomagnetic index values K = 5 and K = 6), are decreasing temporarily the coherence of oscillations of the electric potentials of different points on the surface of a head, i.e. the coherence of the human brain EM processes. We are

  11. Voltage-clamp frequency domain analysis of NMDA-activated neurons.

    PubMed

    Moore, L E; Hill, R H; Grillner, S

    1993-02-01

    1. Voltage and current-clamp steps were added to a sum of sine waves to measure the tetrodotoxin-insensitive membrane properties of neurons in the intact lamprey spinal cord. A systems analysis in the frequency domain was carried out on two types of cells that have very different morphologies in order to investigate the structural dependence of their electrophysiological properties. The method explicitly takes into account the geometrical shapes of (i) nearly spherical dorsal cells with one or two processes and (ii) motoneurons and interneurons that have branched dendritic structures. Impedance functions were analysed to obtain the cable properties of these in situ neurons. These measurements show that branched neurons are not isopotential and, therefore, a conventional voltage-clamp analysis is not valid. 2. The electrophysiological data from branched neurons were curve-fitted with a lumped soma-equivalent cylinder model consisting of eight equal compartments coupled to an isopotential cell body to obtain membrane parameters for both passive and active properties. The analysis provides a quantitative description of both the passive electrical properties imposed by the geometrical structure of neurons and the voltage-dependent ionic conductances determined by ion channel kinetics. The model fitting of dorsal cells was dominated by a one-compartment resistance and capacitance in parallel (RC) corresponding to the spherical, non-branched shape of these cells. Branched neurons required a model that contained both an RC compartment and a cable that reflected the structure of the cells. At rest, the electrotonic length of the cable was about two. Uniformly distributed voltage-dependent ionic conductance sites were adequate to describe the data at different membrane potentials. 3. The frequency domain admittance method in conjunction with a step voltage clamp was used to control and measure the oscillatory behavior induced by N-methyl-D-aspartate (NMDA) on lamprey spinal

  12. Determining the Posture and Vibration Frequency that Maximize Pelvic Floor Muscle Activity During Whole-Body Vibration

    PubMed Central

    Lee, Juhyun; Lee, Kyeongjin; Song, Changho

    2016-01-01

    Background The aim of this study was to investigate the electromyogram (EMG) response of pelvic floor muscle (PFM) to whole-body vibration (WBV) while using different body posture and vibration frequencies. Material/Methods Thirteen healthy adults (7 men, 6 women) voluntarily participated in this cross-sectional study in which EMG data from PFM were collected in a total of 12 trials for each subject (4 body postures, 3 vibration frequencies). Pelvic floor EMG activity was recorded using an anal probe. The rating of perceived exertion (RPE) was assessed with a modified Borg scale. Results We found that vibration frequency, body posture, and muscle stimulated had a significant effect on the EMG response. The PFM had high activation at 12 Hz and 26 Hz (p<0.05). PFM activation significantly increased with knee flexion (p<0.05). The RPE significantly increased with increased frequency (p<0.05). Conclusions The knee flexion angle of 40° at 12 Hz frequency can be readily promoted in improving muscle activation during WBV, and exercise would be performed effectively. Based on the results of the present investigation, sports trainers and physiotherapists may be able to optimize PFM training programs involving WBV. PMID:27787476

  13. Muscle activation of patients suffering from asymmetric ankle osteoarthritis during isometric contractions and level walking - a time-frequency analysis.

    PubMed

    Nüesch, Corina; Huber, Cora; Pagenstert, Geert; von Tscharner, Vinzenz; Valderrabano, Victor

    2012-12-01

    Asymmetric osteoarthritis (OA) is a common type of OA in the ankle joint. OA also influences the muscles surrounding a joint, however, little is known about the muscle activation in asymmetric ankle OA. Therefore, the aim of this study was to characterize the patients' muscle activation during isometric ankle torque measurements and level walking. Surface electromyography (EMG) was measured of gastrocnemius medialis (GM) and lateralis (GL), soleus (SO), tibialis anterior (TA), and peroneus longus (PL) in 12 healthy subjects and 12 ankle OA patients. To obtain time and frequency components of the EMG power a wavelet transformation was performed. Furthermore, entropy was introduced to characterize the homogeneity of the wavelet patterns. Patients produced lower plantar- and dorsiflexion torques and their TA wavelet spectrum was shifted towards lower frequencies. While walking, the patients' muscles were active with a lower intensity and over a broader time-frequency region. In contrast to controls and varus OA patients, maximal GM activity of valgus OA patients lagged behind the activity of GL and SO. In both tasks, PL of the valgus patients contained more low frequency power. The results of this study will help to assess whether surgical interventions of ankle OA can reestablish the muscle activation patterns.

  14. Impact of major and minor mode on EEG frequency range activities of music processing as a function of expertise.

    PubMed

    Jenni, Raoul; Oechslin, Mathias S; James, Clara E

    2017-04-24

    Processing western tonal music may yield distinct brain responses depending on the mode of the musical compositions. Although subjective feelings in response to major and minor mode are well described, the underlying brain mechanisms and their development with increasing expertise have not been thoroughly examined. Using high-density electroencephalography, the present study investigated neuronal activities in the frequency domain in response to polyphone musical compositions in major and minor mode in non-musicians, amateurs and experts. During active listening decrease of theta- and gamma-frequency range activities occurred with increasing expertise in right posterior regions, possibly reflecting enhanced processing efficiency. Moreover, minor and major compositions distinctively modulated synchronization of neuronal activities in high frequency ranges (beta and gamma) in frontal regions, with increased activity in response to minor compositions in musicians and in experts in particular. These results suggest that high-frequency electroencephalographic (EEG) activities carry information about musical mode, showing gradual increase of processing efficiency and sensitivity with musical expertise.

  15. A Time-Frequency Analysis of the Effects of Solar Activities on Tropospheric Thermodynamics

    NASA Technical Reports Server (NTRS)

    Kiang, Richard K.; Kyle, H. Lee; Wharton, Stephen W. (Technical Monitor)

    2001-01-01

    Whether the Sun has significantly influenced the climate during the last century has been under extensive debates for almost two decades. Since the solar irradiance varies very little in a solar cycle, it is puzzling that some geophysical parameters show proportionally large variations which appear to be responding to the solar cycles. For example, variation in low altitude clouds is shown correlated with solar cycle, and the onset of Forbush decrease is shown correlated with the reduction of the vorticity area index. A possible sun-climate connection is that galactic cosmic rays modulated by solar activities influence cloud formation. In this paper, we apply wavelet transform to satellite and surface data to examine this hypothesis. Data analyzed include the time series for solar irradiance, sunspots, UV index, temperature, cloud coverage, and neutron counter measurements. The interactions among the elements in the Earth System under the external and internal forcings give out very complex signals.The periodicity of the forcings or signals could range widely. Since wavelet transforms can analyze multi-scale phenomena that are both localized in frequency and time, it is a very useful technique for detecting, understanding and monitoring climate changes.

  16. First direct measurements of behavioural responses by Cuvier's beaked whales to mid-frequency active sonar.

    PubMed

    DeRuiter, Stacy L; Southall, Brandon L; Calambokidis, John; Zimmer, Walter M X; Sadykova, Dinara; Falcone, Erin A; Friedlaender, Ari S; Joseph, John E; Moretti, David; Schorr, Gregory S; Thomas, Len; Tyack, Peter L

    2013-08-23

    Most marine mammal- strandings coincident with naval sonar exercises have involved Cuvier's beaked whales (Ziphius cavirostris). We recorded animal movement and acoustic data on two tagged Ziphius and obtained the first direct measurements of behavioural responses of this species to mid-frequency active (MFA) sonar signals. Each recording included a 30-min playback (one 1.6-s simulated MFA sonar signal repeated every 25 s); one whale was also incidentally exposed to MFA sonar from distant naval exercises. Whales responded strongly to playbacks at low received levels (RLs; 89-127 dB re 1 µPa): after ceasing normal fluking and echolocation, they swam rapidly, silently away, extending both dive duration and subsequent non-foraging interval. Distant sonar exercises (78-106 dB re 1 µPa) did not elicit such responses, suggesting that context may moderate reactions. The observed responses to playback occurred at RLs well below current regulatory thresholds; equivalent responses to operational sonars could elevate stranding risk and reduce foraging efficiency.

  17. A frequency-duty cycle equation for the ACGIH hand activity level.

    PubMed

    Radwin, Robert G; Azari, David P; Lindstrom, Mary J; Ulin, Sheryl S; Armstrong, Thomas J; Rempel, David

    2015-01-01

    A new equation for predicting the hand activity level (HAL) used in the American Conference for Government Industrial Hygienists threshold limit value®(TLV®) was based on exertion frequency (F) and percentage duty cycle (D). The TLV® includes a table for estimating HAL from F and D originating from data in Latko et al. (Latko WA, Armstrong TJ, Foulke JA, Herrin GD, Rabourn RA, Ulin SS, Development and evaluation of an observational method for assessing repetition in hand tasks. American Industrial Hygiene Association Journal, 58(4):278-285, 1997) and post hoc adjustments that include extrapolations outside of the data range. Multimedia video task analysis determined D for two additional jobs from Latko's study not in the original data-set, and a new nonlinear regression equation was developed to better fit the data and create a more accurate table. The equation, HAL = 6:56 ln D[F(1:31) /1+3:18 F(1:31), generally matches the TLV® HAL lookup table, and is a substantial improvement over the linear model, particularly for F>1.25 Hz and D>60% jobs. The equation more closely fits the data and applies the TLV® using a continuous function.

  18. Improvement of photocatalytic activity of silver nanoparticles by radio frequency oxygen plasma irradiation

    NASA Astrophysics Data System (ADS)

    Fang, Yingcui; Zhang, Bing; Hong, Liu; Yao, Damao; Xie, Zhiqiang; Jiang, Yang

    2015-07-01

    Photocatalytic activity (PA) of silver nanoparticles (AgNPs) induced by radio frequency (RF) oxygen plasma irradiation (OPI) is investigated in this paper. An improvement in PA by 365% and 181% has been achieved when 15 nm AgNPs irradiated by oxygen plasma for 2 s were used to degrade 10-5 M Rhodamine 6 G (R6G) under ultraviolet (UV) and visible lights, respectively. The PA caused by OPI is better than that induced by the localized surface plasma resonance (LSPR) of AgNPs. The mechanism for the improvement was explored by scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and UV-vis absorption spectra. The OPI-induced formation of AgO/AgNP and Ag2O/AgNP-heterogeneous photocatalysts and electrophilic oxygen are considered to be responsible for the PA improvement. This investigation deepens our understanding of oxygen-assisted photocatalysis of AgNPs and provides a practical approach using solar light for broad spectra photocatalysis with high efficiency.

  19. Myelinating satellite oligodendrocytes are integrated in a glial syncytium constraining neuronal high-frequency activity

    PubMed Central

    Battefeld, Arne; Klooster, Jan; Kole, Maarten H. P.

    2016-01-01

    Satellite oligodendrocytes (s-OLs) are closely apposed to the soma of neocortical layer 5 pyramidal neurons but their properties and functional roles remain unresolved. Here we show that s-OLs form compact myelin and action potentials of the host neuron evoke precisely timed Ba2+-sensitive K+ inward rectifying (Kir) currents in the s-OL. Unexpectedly, the glial K+ inward current does not require oligodendrocytic Kir4.1. Action potential-evoked Kir currents are in part mediated by gap–junction coupling with neighbouring OLs and astrocytes that form a syncytium around the pyramidal cell body. Computational modelling predicts that glial Kir constrains the perisomatic [K+]o increase most importantly during high-frequency action potentials. Consistent with these predictions neurons with s-OLs showed a reduced probability for action potential burst firing during [K+]o elevations. These data suggest that s-OLs are integrated into a glial syncytium for the millisecond rapid K+ uptake limiting activity-dependent [K+]o increase in the perisomatic neuron domain. PMID:27161034

  20. Low-frequency wave activity related to dipolarization fronts detected by MMS in the magnetotail

    NASA Astrophysics Data System (ADS)

    Le Contel, O.; Retino, A.; Breuillard, H.; Mirioni, L.; Roux, A.; Chust, T.; Chasapis, A.; Lavraud, B.; Lindqvist, P. A.; Khotyaintsev, Y. V.; Vaivads, A.; Fu, H.; Marklund, G. T.; Nakamura, R.; Burch, J. L.; Torbert, R. B.; Moore, T. E.; Ergun, R.; Goodrich, K.; Needell, J.; Chutter, M.; Rau, D.; Dors, I.; Russell, C. T.; Magnes, W.; Strangeway, R. J.; Le, G.; Bromund, K. R.; Plaschke, F.; Fischer, D.; Leinweber, H. K.; Anderson, B. J.; Argall, M. R.; Slavin, J. A.; Kepko, L.; Baumjohann, W.; Pollock, C. J.; Mauk, B.; Fuselier, S. A.

    2015-12-01

    Dipolarization fronts are often associated to reconnection jets in the magnetotail current sheet and are sites of important energy dissipation and particle energization. Since the launch on March 12th and until the 9th of July 2015, the MMS constellation has been moving from dawn to dusk in a string of pearls formation. Although particle instruments were rarely operating and only FIELDS instrument suite was often gathering data, the MMS spacecraft have detected numerous dipolarization fronts, in particular on May 15th. Since 9th of July, the MMS evolved into a tetrahedral configuration with an average inter-satellite distance of 160 km and was still able to detect dipolarization fronts in the dusk magnetotail. As the Larmor radius of thermal protons is about 500 km in this region and dipolarization fronts have a typical thickness of the order of the Larmor radius, such a separation allows us to investigate in detail the microphysics of dipolarization fronts. In this study, we focus in particular on low-frequency electromagnetic wave activity related to the fronts and discuss possible mechanisms of particle heating and acceleration both at large scales (string of pearls configuration) and at kinetic scales (tetrahedral configuration).

  1. Comparison of a web-based food record tool and a food-frequency questionnaire and objective validation using the doubly labelled water technique in a Swedish middle-aged population.

    PubMed

    Nybacka, Sanna; Bertéus Forslund, Heléne; Wirfält, Elisabet; Larsson, Ingrid; Ericson, Ulrika; Warensjö Lemming, Eva; Bergström, Göran; Hedblad, Bo; Winkvist, Anna; Lindroos, Anna Karin

    2016-01-01

    Two web-based dietary assessment tools have been developed for use in large-scale studies: the Riksmaten method (4-d food record) and MiniMeal-Q (food-frequency method). The aim of the present study was to examine the ability of these methods to capture energy intake against objectively measured total energy expenditure (TEE) with the doubly labelled water technique (TEEDLW), and to compare reported energy and macronutrient intake. This study was conducted within the pilot study of the Swedish CArdioPulmonary bioImage Study (SCAPIS), which included 1111 randomly selected men and women aged 50-64 years from the Gothenburg general population. Of these, 200 were enrolled in the SCAPIS diet substudy. TEEDLW was measured in a subsample (n 40). Compared with TEEDLW, both methods underestimated energy intake: -2·5 (sd  2·9) MJ with the Riksmaten method; -2·3 (sd 3·6) MJ with MiniMeal-Q. Mean reporting accuracy was 80 and 82 %, respectively. The correlation between reported energy intake and TEEDLW was r 0·4 for the Riksmaten method (P < 0·05) and r 0·28 (non-significant) for MiniMeal-Q. Women reported similar average intake of energy and macronutrients in both methods whereas men reported higher intakes with the Riksmaten method. Energy-adjusted correlations ranged from 0·14 (polyunsaturated fat) to 0·77 (alcohol). Bland-Altman plots showed acceptable agreement for energy and energy-adjusted protein and carbohydrate intake, whereas the agreement for fat intake was poorer. According to energy intake data, both methods displayed similar precision on energy intake reporting. However, MiniMeal-Q was less successful in ranking individuals than the Riksmaten method. The development of methods to achieve limited under-reporting is a major challenge for future research.

  2. Frequency stabilization of the zero-phonon line of a quantum dot via phonon-assisted active feedback

    SciTech Connect

    Hansom, Jack; Schulte, Carsten H. H.; Matthiesen, Clemens; Stanley, Megan J.; Atatüre, Mete

    2014-10-27

    We report on the feedback stabilization of the zero-phonon emission frequency of a single InAs quantum dot. The spectral separation of the phonon-assisted component of the resonance fluorescence provides a probe of the detuning between the zero-phonon transition and the resonant driving laser. Using this probe in combination with active feedback, we stabilize the zero-phonon transition frequency against environmental fluctuations. This protocol reduces the zero-phonon fluorescence intensity noise by a factor of 22 by correcting for environmental noise with a bandwidth of 191 Hz, limited by the experimental collection efficiency. The associated sub-Hz fluctuations in the zero-phonon central frequency are reduced by a factor of 7. This technique provides a means of stabilizing the quantum dot emission frequency without requiring access to the zero-phonon emission.

  3. Effects of Lexicality and Word Frequency on Brain Activation in Dyslexic Readers

    ERIC Educational Resources Information Center

    Heim, Stefan; Wehnelt, Anke; Grande, Marion; Huber, Walter; Amunts, Katrin

    2013-01-01

    We investigated the neural basis of lexical access to written stimuli in adult dyslexics and normal readers via the Lexicality effect (pseudowords greater than words) and the Frequency effect (low greater than high frequent words). The participants read aloud German words (with low or high lexical frequency) or pseudowords while being scanned. In…

  4. Frequency decoding of periodically timed action potentials through distinct activity patterns in a random neural network

    NASA Astrophysics Data System (ADS)

    Reichenbach, Tobias; Hudspeth, A. J.

    2012-11-01

    Frequency discrimination is a fundamental task of the auditory system. The mammalian inner ear, or cochlea, provides a place code in which different frequencies are detected at different spatial locations. However, a temporal code based on spike timing is also available: action potentials evoked in an auditory-nerve fiber by a low-frequency tone occur at a preferred phase of the stimulus—they exhibit phase locking—and thus provide temporal information about the tone's frequency. Humans employ this temporal information for discrimination of low frequencies. How might such temporal information be read out in the brain? Here we employ statistical and numerical methods to demonstrate that recurrent random neural networks in which connections between neurons introduce characteristic time delays, and in which neurons require temporally coinciding inputs for spike initiation, can perform sharp frequency discrimination when stimulated with phase-locked inputs. Although the frequency resolution achieved by such networks is limited by the noise in phase locking, the resolution for realistic values reaches the tiny frequency difference of 0.2% that has been measured in humans.

  5. Activities and Updates at the State Time and Frequency Standard of Russia

    DTIC Science & Technology

    2009-11-01

    m, is depicted in Figure 9. This is a Michelson interferometer with a one-arm length of more than 60 meters and a two- mode laser as a light...program on time and frequency transfer by optical fiber links. The goal is to achieve a transfer accuracy of ə10 -17 in frequency and ə ns in

  6. Rapid feedback regulation of synaptic efficacy during high-frequency activity at the Drosophila larval neuromuscular junction.

    PubMed

    Kauwe, Grant; Isacoff, Ehud Y

    2013-05-28

    High-frequency firing of neurons depresses transmitter release at many synapses. At the glutamatergic synapse of the Drosophila larval neuromuscular junction, we find that presynaptic depression is modulated by postsynaptic ionotropic glutamate receptor (iGluR) activity. Although basal release at low frequency was insensitive to postsynaptic iGluR activity, recovery from depression elicited by high-frequency presynaptic trains decreased with partial block of native iGluRs. Moreover, recovery from depression increased with optical activation of the light-gated mammalian iGluR6 (LiGluR) expressed postsynaptically. The enhancement of recovery from depression occurred within 2 min of optical activation of LiGluR and persisted for minutes after optical deactivation. This effect depended on cAMP-dependent presynaptic recruitment of vesicles from the reserve pool. Our findings reveal a unique dimension to postsynaptic iGluR activity: fast retrograde signaling that preserves transmission efficacy during high-frequency presynaptic firing.

  7. Paper to Electronic Questionnaires: Effects on Structured Questionnaire Forms

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.

    2009-01-01

    With the use of computers, paper questionnaires are being replaced by electronic questionnaires. The formats of traditional paper questionnaires have been found to effect a subject's rating. Consequently, the transition from paper to electronic format can subtly change results. The research presented begins to determine how electronic questionnaire formats change subjective ratings. For formats where subjects used a flow chart to arrive at their rating, starting at the worst and middle ratings of the flow charts were the most accurate but subjects took slightly more time to arrive at their answers. Except for the electronic paper format, starting at the worst rating was the most preferred. The paper and electronic paper versions had the worst accuracy. Therefore, for flowchart type of questionnaires, flowcharts should start at the worst rating and work their way up to better ratings.

  8. In vitro Neurons in Mammalian Cortical Layer 4 Exhibit Intrinsic Oscillatory Activity in the 10- to 50-Hz Frequency Range

    NASA Astrophysics Data System (ADS)

    Llinas, Rodolfo R.; Grace, Anthony A.; Yarom, Yosef

    1991-02-01

    We report here the presence of fast subthreshold oscillatory potentials recorded in vitro from neurons within layer 4 of the guinea pig frontal cortex. Two types of oscillatory neurons were recorded: (i) One type exhibited subthreshold oscillations whose frequency increased with membrane depolarization and encompassed a range of 10-45 Hz. Action potentials in this type of neuron demonstrated clear after-hyperpolarizations. (ii) The second type of neuron was characterized by narrow-frequency oscillations near 35-50 Hz. These oscillations often outlasted the initiating depolarizing stimulus. No calcium component could be identified in their action potential. In both types of cell the subthreshold oscillations were tetrodotoxin-sensitive, indicating that the depolarizing phase of the oscillation was generated by a voltage-dependent sodium conductance. The initial depolarizing phase was followed by a potassium conductance responsible for the falling phase of the oscillatory wave. In both types of cell, the subthreshold oscillation could trigger spikes at the oscillatory frequency, if the membrane was sufficiently depolarized. Combining intracellular recordings with Lucifer yellow staining showed that the narrow-frequency oscillatory activity was produced by a sparsely spinous interneuron located in layer 4 of the cortex. This neuron has extensive local axonal collaterals that ramify in layers 3 and 4 such that they may contribute to the columnar synchronization of activity in the 40- to 50-Hz range. Cortical activity in this frequency range has been proposed as the basis for the "conjunctive properties" of central nervous system networks.

  9. The Ca2+-activated chloride channel anoctamin-2 mediates spike-frequency adaptation and regulates sensory transmission in thalamocortical neurons

    PubMed Central

    Ha, Go Eun; Lee, Jaekwang; Kwak, Hankyul; Song, Kiyeong; Kwon, Jea; Jung, Soon-Young; Hong, Joohyeon; Chang, Gyeong-Eon; Hwang, Eun Mi; Shin, Hee-Sup; Lee, C. Justin; Cheong, Eunji

    2016-01-01

    Neuronal firing patterns, which are crucial for determining the nature of encoded information, have been widely studied; however, the molecular identity and cellular mechanisms of spike-frequency adaptation are still not fully understood. Here we show that spike-frequency adaptation in thalamocortical (TC) neurons is mediated by the Ca2+-activated Cl− channel (CACC) anoctamin-2 (ANO2). Knockdown of ANO2 in TC neurons results in significantly reduced spike-frequency adaptation along with increased tonic spiking. Moreover, thalamus-specific knockdown of ANO2 increases visceral pain responses. These results indicate that ANO2 contributes to reductions in spike generation in highly activated TC neurons and thereby restricts persistent information transmission. PMID:27991499

  10. Frequency-dependent spatiotemporal profiles of visual responses recorded with subdural ECoG electrodes in awake monkeys: Differences between high- and low-frequency activity.

    PubMed

    Takaura, Kana; Tsuchiya, Naotsugu; Fujii, Naotaka

    2016-01-01

    Electrocorticography (ECoG) constitutes a powerful and promising neural recording modality in humans and animals. ECoG signals are often decomposed into several frequency bands, among which the so-called high-gamma band (80-250Hz) has been proposed to reflect local cortical functions near the cortical surface below the ECoG electrodes. It is typically assumed that the lower the frequency bands, the lower the spatial resolution of the signals; thus, there is not much to gain by analyzing the event-related changes of the ECoG signals in the lower-frequency bands. However, differences across frequency bands have not been systematically investigated. To address this issue, we recorded ECoG activity from two awake monkeys performing a retinotopic mapping task. We characterized the spatiotemporal profiles of the visual responses in the time-frequency domain. We defined the preferred spatial position, receptive field (RF), and response latencies of band-limited power (BLP) (i.e., alpha [3.9-11.7Hz], beta [15.6-23.4Hz], low [30-80Hz] and high [80-250Hz] gamma) for each electrode and compared them across bands and time-domain visual evoked potentials (VEPs). At the population level, we found that the spatial preferences were comparable across bands and VEPs. The high-gamma power showed a smaller RF than the other bands and VEPs. The response latencies for the alpha band were always longer than the latencies for the other bands and fastest in VEPs. Comparing the response profiles in both space and time for each cortical region (V1, V4+, and TEO/TE) revealed regional idiosyncrasies. Although the latencies of visual responses in the beta, low-, and high-gamma bands were almost identical in V1 and V4+, beta and low-gamma BLP occurred about 17ms earlier than high-gamma power in TEO/TE. Furthermore, TEO/TE exhibited a unique pattern in the spatial response profile: the alpha and high-gamma responses tended to prefer the foveal regions, whereas the beta and low-gamma responses

  11. Basal ganglia dysfunction in OCD: subthalamic neuronal activity correlates with symptoms severity and predicts high-frequency stimulation efficacy.

    PubMed

    Welter, M-L; Burbaud, P; Fernandez-Vidal, S; Bardinet, E; Coste, J; Piallat, B; Borg, M; Besnard, S; Sauleau, P; Devaux, B; Pidoux, B; Chaynes, P; Tézenas du Montcel, S; Bastian, A; Langbour, N; Teillant, A; Haynes, W; Yelnik, J; Karachi, C; Mallet, L

    2011-05-03

    Functional and connectivity changes in corticostriatal systems have been reported in the brains of patients with obsessive-compulsive disorder (OCD); however, the relationship between basal ganglia activity and OCD severity has never been adequately established. We recently showed that deep brain stimulation of the subthalamic nucleus (STN), a central basal ganglia nucleus, improves OCD. Here, single-unit subthalamic neuronal activity was analysed in 12 OCD patients, in relation to the severity of obsessions and compulsions and response to STN stimulation, and compared with that obtained in 12 patients with Parkinson's disease (PD). STN neurons in OCD patients had lower discharge frequency than those in PD patients, with a similar proportion of burst-type activity (69 vs 67%). Oscillatory activity was present in 46 and 68% of neurons in OCD and PD patients, respectively, predominantly in the low-frequency band (1-8 Hz). In OCD patients, the bursty and oscillatory subthalamic neuronal activity was mainly located in the associative-limbic part. Both OCD severity and clinical improvement following STN stimulation were related to the STN neuronal activity. In patients with the most severe OCD, STN neurons exhibited bursts with shorter duration and interburst interval, but higher intraburst frequency, and more oscillations in the low-frequency bands. In patients with best clinical outcome with STN stimulation, STN neurons displayed higher mean discharge, burst and intraburst frequencies, and lower interburst interval. These findings are consistent with the hypothesis of a dysfunction in the associative-limbic subdivision of the basal ganglia circuitry in OCD's pathophysiology.

  12. Frequencies, Laboratory Features, and Granulocyte Activation in Chinese Patients with CALR-Mutated Myeloproliferative Neoplasms

    PubMed Central

    Tian, Ruiyuan; Chang, Jianmei; Li, Jianlan; Tan, Yanhong; Xu, Zhifang; Ren, Fanggang; Zhao, Junxia; Pan, Jie; Zhang, Na; Wang, Xiaojuan; He, Jianxia; Yang, Wanfang; Wang, Hongwei

    2015-01-01

    Somatic mutations in the CALR gene have been recently identified as acquired alterations in myeloproliferative neoplasms (MPNs). In this study, we evaluated mutation frequencies, laboratory features, and granulocyte activation in Chinese patients with MPNs. A combination of qualitative allele-specific polymerase chain reaction and Sanger sequencing was used to detect three driver mutations (i.e., CALR, JAK2V617F, and MPL). CALR mutations were identified in 8.4% of cases with essential thrombocythemia (ET) and 5.3% of cases with primary myelofibrosis (PMF). Moreover, 25% of polycythemia vera, 29.5% of ET, and 48.1% of PMF were negative for all three mutations (JAK2V617F, MPL, and CALR). Compared with those patients with JAK2V617F mutation, CALR-mutated ET patients displayed unique hematological phenotypes, including higher platelet counts, and lower leukocyte counts and hemoglobin levels. Significant differences were not found between Chinese PMF patients with mutants CALR and JAK2V617F in terms of laboratory features. Interestingly, patients with CALR mutations showed markedly decreased levels of leukocyte alkaline phosphatase (LAP) expression, whereas those with JAK2V617F mutation presented with elevated levels. Overall, a lower mutant rate of CALR gene and a higher triple-negative rate were identified in the cohort of Chinese patients with MPNs. This result indicates that an undiscovered mutant gene may have a significant role in these patients. Moreover, these pathological features further imply that the disease biology varies considerably between mutants CALR and JAK2V617F. PMID:26375990

  13. Propagation of frequency-modulated pulses in active one-dimensional photonic crystals

    SciTech Connect

    Zolotovskii, I O; Korobko, D A; Ostatochnikov, V A

    2015-02-28

    The propagation of frequency-modulated pulses in onedimensional photonic crystals with gain is considered. A correct expression is derived for the delay time of the pulse maximum. This expression takes into account the input pulse characteristics: duration, frequency modulation and spectrum position in the photonic band gap. The analytical results are basically in agreement with the results of numerical simulation. The influence of gain in the photonic-crystal structure is considered. It is shown that the parameters of a transmitted pulse can be controlled by changing the inputpulse frequency modulation. (nonlinear optical phenomena)

  14. Naturally Occurring Changes in Time Spent Watching Television Are Inversely Related to Frequency of Physical Activity during Early Adolescence

    ERIC Educational Resources Information Center

    Motl, Robert W.; McAuley, Edward; Birnbaum, Amanda S.; Lytle, Leslie A.

    2006-01-01

    In this longitudinal study, we examined the relationship between changes in time spent watching television and playing video games with frequency of leisure-time physical activity across a 2-year period among adolescent boys and girls (N=4594). Latent growth modelling indicated that a decrease in time spent watching television was associated with…

  15. Dementia-Related Work Activities of Home Care Nurses and Aides: Frequency, Perceived Competence, and Continuing Education Priorities

    ERIC Educational Resources Information Center

    Morgan, Debra G.; Kosteniuk, Julie G.; O'Connell, Megan E.; Dal Bello-Haas, Vanina; Stewart, Norma J.; Karunanayake, Chandima

    2016-01-01

    An understanding of the specific dementia learning needs of home care staff is needed to plan relevant continuing education (CE) programs and supports. The study's objective was to examine frequency and perceived competence in performing 20 dementia-related work activities, and identify CE priorities among home care staff. A cross-sectional survey…

  16. Low Frequency Activity of Cortical Networks on Microelectrode Arrays is Differentially Altered by Bicuculline and Carbaryl

    EPA Science Inventory

    Thousands of chemicals need to be characterized for their neurotoxicity potential. Neurons grown on microelectrode arrays (MEAs) are an in vitro model used to screen chemicals for functional effects on neuronal networks. Typically, after removal of low frequency components, effec...

  17. A procedure for removing the effect of response bias errors from waterfowl hunter questionnaire responses

    USGS Publications Warehouse

    Atwood, E.L.

    1958-01-01

    Response bias errors are studied by comparing questionnaire responses from waterfowl hunters using four large public hunting areas with actual hunting data from these areas during two hunting seasons. To the extent that the data permit, the sources of the error in the responses were studied and the contribution of each type to the total error was measured. Response bias errors, including both prestige and memory bias, were found to be very large as compared to non-response and sampling errors. Good fits were obtained with the seasonal kill distribution of the actual hunting data and the negative binomial distribution and a good fit was obtained with the distribution of total season hunting activity and the semi-logarithmic curve. A comparison of the actual seasonal distributions with the questionnaire response distributions revealed that the prestige and memory bias errors are both positive. The comparisons also revealed the tendency for memory bias errors to occur at digit frequencies divisible by five and for prestige bias errors to occur at frequencies which are multiples of the legal daily bag limit. A graphical adjustment of the response distributions was carried out by developing a smooth curve from those frequency classes not included in the predictable biased frequency classes referred to above. Group averages were used in constructing the curve, as suggested by Ezekiel [1950]. The efficiency of the technique described for reducing response bias errors in hunter questionnaire responses on seasonal waterfowl kill is high in large samples. The graphical method is not as efficient in removing response bias errors in hunter questionnaire responses on seasonal hunting activity where an average of 60 percent was removed.

  18. Effects of in vivo-like activation frequency on the length-dependent force generation of skeletal muscle fibre bundles.

    PubMed

    Zuurbier, C J; Lee-de Groot, M B; Van der Laarse, W J; Huijing, P A

    1998-05-01

    It is known that a range of firing frequencies can be observed during in vivo muscle activity, yet information is lacking as to how different in vivo-like frequencies may affect force generation of skeletal muscle. This study examined the effects of constant (CSF, constant within one contraction) and decreasing stimulation frequencies (DSF) on mean sarcomere length-force characteristics of rat gastrocnemius medialis fibre bundles. The CSF resulted in an optimal mean sarcomere length (lso) of 2.30 (SEM 0.02), 2.46 (SEM 0.03), 2.76 (SEM 0.03) and more than 2.99 (SEM 0.07) lm, for 100, 50, 30 and 15 Hz, respectively. Compared to 100-Hz stimulation, both lso and the ascending limb of the relationship significantly shifted to higher lengths with lower frequencies. No shift was encountered for the initial part of the descending limb. The DSF reduced the frequency-induced shift to higher mean lengths [lso 2.33 (SEM 0.02), 2.52 (SEM 0.08) and more than 2.92 (SEM 0.10) microm, respectively, for 50, 30 and 15 Hz]. No effect of activation time on length-force characteristics was observed. It was concluded from these studies that the frequency and history of stimulation is a major determinant of the length-force characteristics of muscle fibre bundles, and should be taken into account when analysing animal and human locomotion. The previously observed frequency-induced shift in whole muscle length-force relationship resides mainly at the level of fibre bundles.

  19. GABAergic Activities Control Spike Timing- and Frequency-Dependent Long-Term Depression at Hippocampal Excitatory Synapses

    PubMed Central

    Nishiyama, Makoto; Togashi, Kazunobu; Aihara, Takeshi; Hong, Kyonsoo

    2010-01-01

    GABAergic interneuronal network activities in the hippocampus control a variety of neural functions, including learning and memory, by regulating θ and γ oscillations. How these GABAergic activities at pre- and postsynaptic sites of hippocampal CA1 pyramidal cells differentially contribute to synaptic function and plasticity during their repetitive pre- and postsynaptic spiking at θ and γ oscillations is largely unknown. We show here that activities mediated by postsynaptic GABAARs and presynaptic GABABRs determine, respectively, the spike timing- and frequency-dependence of activity-induced synaptic modifications at Schaffer collateral-CA1 excitatory synapses. We demonstrate that both feedforward and feedback GABAAR-mediated inhibition in the postsynaptic cell controls the spike timing-dependent long-term depression of excitatory inputs (“e-LTD”) at the θ frequency. We also show that feedback postsynaptic inhibition specifically causes e-LTD of inputs that induce small postsynaptic currents (<70 pA) with LTP-timing, thus enforcing the requirement of cooperativity for induction of long-term potentiation at excitatory inputs (“e-LTP”). Furthermore, under spike-timing protocols that induce e-LTP and e-LTD at excitatory synapses, we observed parallel induction of LTP and LTD at inhibitory inputs (“i-LTP” and “i-LTD”) to the same postsynaptic cells. Finally, we show that presynaptic GABABR-mediated inhibition plays a major role in the induction of frequency-dependent e-LTD at α and β frequencies. These observations demonstrate the critical influence of GABAergic interneuronal network activities in regulating the spike timing- and frequency-dependences of long-term synaptic modifications in the hippocampus. PMID:21423508

  20. High Frequency Migraine Is Associated with Lower Acute Pain Sensitivity and Abnormal Insula Activity Related to Migraine Pain Intensity, Attack Frequency, and Pain Catastrophizing

    PubMed Central

    Mathur, Vani A.; Moayedi, Massieh; Keaser, Michael L.; Khan, Shariq A.; Hubbard, Catherine S.; Goyal, Madhav; Seminowicz, David A.

    2016-01-01

    Migraine is a pain disorder associated with abnormal brain structure and function, yet the effect of migraine on acute pain processing remains unclear. It also remains unclear whether altered pain-related brain responses and related structural changes are associated with clinical migraine characteristics. Using fMRI and three levels of thermal stimuli (non-painful, mildly painful, and moderately painful), we compared whole-brain activity between 14 migraine patients and 14 matched controls. Although, there were no significant differences in pain thresholds nor in pre-scan pain ratings to mildly painful thermal stimuli, patients did have aberrant suprathreshold nociceptive processing. Brain imaging showed that, compared to controls, patients had reduced activity in pain modulatory regions including left dorsolateral prefrontal, posterior parietal, and middle temporal cortices and, at a lower-threshold, greater activation in the right mid-insula to moderate pain vs. mild pain. We also found that pain-related activity in the insula was associated with clinical variables in patients, including associations between: bilateral anterior insula and pain catastrophizing (PCS); bilateral anterior insula and contralateral posterior insula and migraine pain intensity; and bilateral posterior insula and migraine frequency at a lower-threshold. PCS and migraine pain intensity were also negatively associated with activity in midline regions including posterior cingulate and medial prefrontal cortices. Diffusion tensor imaging revealed a negative correlation between fractional anisotropy (a measure of white matter integrity; FA) and migraine duration in the right mid-insula and a positive correlation between left mid-insula FA and PCS. In sum, while patients showed lower sensitivity to acute noxious stimuli, the neuroimaging findings suggest enhanced nociceptive processing and significantly disrupted modulatory networks, particularly involving the insula, associated with indices

  1. Decomposing delta, theta, and alpha time–frequency ERP activity from a visual oddball task using PCA

    PubMed Central

    Bernat, Edward M.; Malone, Stephen M.; Williams, William J.; Patrick, Christopher J.; Iacono, William G.

    2008-01-01

    Objective Time–frequency (TF) analysis has become an important tool for assessing electrical and magnetic brain activity from event-related paradigms. In electrical potential data, theta and delta activities have been shown to underlie P300 activity, and alpha has been shown to be inhibited during P300 activity. Measures of delta, theta, and alpha activity are commonly taken from TF surfaces. However, methods for extracting relevant activity do not commonly go beyond taking means of windows on the surface, analogous to measuring activity within a defined P300 window in time-only signal representations. The current objective was to use a data driven method to derive relevant TF components from event-related potential data from a large number of participants in an oddball paradigm. Methods A recently developed PCA approach was employed to extract TF components [Bernat, E. M., Williams, W. J., and Gehring, W. J. (2005). Decomposing ERP time-frequency energy using PCA. Clin Neurophysiol, 116(6), 1314–1334] from an ERP dataset of 2068 17 year olds (979 males). TF activity was taken from both individual trials and condition averages. Activity including frequencies ranging from 0 to 14 Hz and time ranging from stimulus onset to 1312.5 ms were decomposed. Results A coordinated set of time–frequency events was apparent across the decompositions. Similar TF components representing earlier theta followed by delta were extracted from both individual trials and averaged data. Alpha activity, as predicted, was apparent only when time–frequency surfaces were generated from trial level data, and was characterized by a reduction during the P300. Conclusions Theta, delta, and alpha activities were extracted with predictable time-courses. Notably, this approach was effective at characterizing data from a single-electrode. Finally, decomposition of TF data generated from individual trials and condition averages produced similar results, but with predictable differences

  2. The heat-shock factor is not activated in mammalian cells exposed to cellular phone frequency microwaves.

    PubMed

    Laszlo, Andrei; Moros, Eduardo G; Davidson, Teri; Bradbury, Matt; Straube, William; Roti Roti, Joseph

    2005-08-01

    There has been considerable interest in the biological effects of exposure to radiofrequency electromagnetic radiation, given the explosive growth of cellular telephone use, with the possible induction of malignancy being a significant concern. Thus the determination of whether nonthermal effects of radiofrequency electromagnetic radiation contribute to the process leading to malignancy is an important task. One proposed pathway to malignancy involves the induction of the stress response by exposures to cell phone frequency microwaves. The first step in the induction of the stress response is the activation of the DNA-binding activity of the specific transcription factor involved in this response, the heat-shock factor (HSF). The DNA-binding activity of HSF in hamster, mouse and human cells was determined after acute and continuous exposures to frequency domain multiple access (FDMA)- or code domain multiple access (CDMA)-modulated microwaves at low (0.6 W/kg) or high (approximately 5 W/kg) SARs at frequencies used for mobile communication. The DNA-binding activity of HSF was monitored using a gel shift assay; the calibration of this assay indicated that an increase of approximately 10% in the activation of the DNA-binding activity of HSF after a 1 degrees C increase in temperature could be detected. We failed to detect any increase in the DNA-binding ability of HSF in cultured mammalian cells as a consequence of any exposure tested, within the sensitivity of our assay. Our results do not support the notion that the stress response is activated as a consequence of exposure to microwaves of frequencies associated with mobile communication devices.

  3. Modulation of epileptic activity by deep brain stimulation: a model-based study of frequency-dependent effects

    PubMed Central

    Mina, Faten; Benquet, Pascal; Pasnicu, Anca; Biraben, Arnaud; Wendling, Fabrice

    2013-01-01

    A number of studies showed that deep brain stimulation (DBS) can modulate the activity in the epileptic brain and that a decrease of seizures can be achieved in “responding” patients. In most of these studies, the choice of stimulation parameters is critical to obtain desired clinical effects. In particular, the stimulation frequency is a key parameter that is difficult to tune. A reason is that our knowledge about the frequency-dependant mechanisms according to which DBS indirectly impacts the dynamics of pathological neuronal systems located in the neocortex is still limited. We address this issue using both computational modeling and intracerebral EEG (iEEG) data. We developed a macroscopic (neural mass) model of the thalamocortical network. In line with already-existing models, it includes interconnected neocortical pyramidal cells and interneurons, thalamocortical cells and reticular neurons. The novelty was to introduce, in the thalamic compartment, the biophysical effects of direct stimulation. Regarding clinical data, we used a quite unique data set recorded in a patient (drug-resistant epilepsy) with a focal cortical dysplasia (FCD). In this patient, DBS strongly reduced the sustained epileptic activity of the FCD for low-frequency (LFS, < 2 Hz) and high-frequency stimulation (HFS, > 70 Hz) while intermediate-frequency stimulation (IFS, around 50 Hz) had no effect. Signal processing, clustering, and optimization techniques allowed us to identify the necessary conditions for reproducing, in the model, the observed frequency-dependent stimulation effects. Key elements which explain the suppression of epileptic activity in the FCD include: (a) feed-forward inhibition and synaptic short-term depression of thalamocortical connections at LFS, and (b) inhibition of the thalamic output at HFS. Conversely, modeling results indicate that IFS favors thalamic oscillations and entrains epileptic dynamics. PMID:23882212

  4. α-Adrenergic effects on low-frequency oscillations in blood pressure and R-R intervals during sympathetic activation.

    PubMed

    Kiviniemi, Antti M; Frances, Maria F; Tiinanen, Suvi; Craen, Rosemary; Rachinsky, Maxim; Petrella, Robert J; Seppänen, Tapio; Huikuri, Heikki V; Tulppo, Mikko P; Shoemaker, J Kevin

    2011-08-01

    The present study was designed to address the contribution of α-adrenergic modulation to the genesis of low-frequency (LF; 0.04-0.15 Hz) oscillations in R-R interval (RRi), blood pressure (BP) and muscle sympathetic nerve activity (MSNA) during different sympathetic stimuli. Blood pressure and RRi were measured continuously in 12 healthy subjects during 5 min periods each of lower body negative pressure (LBNP; -40 mmHg), static handgrip exercise (HG; 20% of maximal force) and postexercise forearm circulatory occlusion (PECO) with and without α-adrenergic blockade by phentolamine. Muscle sympathetic nerve activity was recorded in five subjects during LBNP and in six subjects during HG and PECO. Low-frequency powers and median frequencies of BP, RRi and MSNA were calculated from power spectra. Low-frequency power during LBNP was lower with phentolamine versus without for both BP and RRi oscillations (1.6 ± 0.6 versus 1.2 ± 0.7 ln mmHg(2), P = 0.049; and 6.9 ± 0.8 versus 5.4 ± 0.9 ln ms(2), P = 0.001, respectively). In contrast, the LBNP with phentolamine increased the power of high-frequency oscillations (0.15-0.4 Hz) in BP and MSNA (P < 0.01 for both), which was not observed during saline infusion. Phentolamine also blunted the increases in the LBNP-induced increase in frequency of LF oscillations in BP and RRi. Phentolamine decreased the LF power of RRi during HG (P = 0.015) but induced no other changes in LF powers or frequencies during HG. Phentolamine resulted in decreased frequency of LF oscillations in RRi (P = 0.004) during PECO, and a similar tendency was observed in BP and MSNA. The power of LF oscillation in MSNA did not change during any intervention. We conclude that α-adrenergic modulation contributes to LF oscillations in BP and RRi during baroreceptor unloading (LBNP) but not during static exercise. Also, α-adrenergic modulation partly explains the shift to a higher frequency of LF oscillations during baroreceptor unloading and muscle

  5. The influence of vibration type, frequency, body position and additional load on the neuromuscular activity during whole body vibration.

    PubMed

    Ritzmann, Ramona; Gollhofer, Albert; Kramer, Andreas

    2013-01-01

    This study aimed to assess the influence of different whole body vibration (WBV) determinants on the electromyographic (EMG) activity during WBV in order to identify those training conditions that cause highest neuromuscular responses and therefore provide optimal training conditions. In a randomized cross-over study, the EMG activity of six leg muscles was analyzed in 18 subjects with respect to the following determinants: (1) vibration type (side-alternating vibration (SV) vs. synchronous vibration (SyV), (2) frequency (5-10-15-20-25-30 Hz), (3) knee flexion angle (10°-30°-60°), (4) stance condition (forefoot vs. normal stance) and (5) load variation (no extra load vs. additional load equal to one-third of the body weight). The results are: (1) neuromuscular activity during SV was enhanced compared to SyV (P < 0.05); (2) a progressive increase in frequency caused a progressive increase in EMG activity (P < 0.05); (3) the EMG activity was highest for the knee extensors when the knee joint was 60° flexed (P < 0.05); (4) for the plantar flexors in the forefoot stance condition (P < 0.05); and (5) additional load caused an increase in neuromuscular activation (P < 0.05). In conclusion, large variations of the EMG activation could be observed across conditions. However, with an appropriate adjustment of specific WBV determinants, high EMG activations and therefore high activation intensities could be achieved in the selected muscles. The combination of high vibration frequencies with additional load on an SV platform led to highest EMG activities. Regarding the body position, a knee flexion of 60° and forefoot stance appear to be beneficial for the knee extensors and the plantar flexors, respectively.

  6. Different pulse pattern generation by frequency detuning in pulse modulated actively mode-locked ytterbium doped fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, He; Chen, Sheng-Ping; Si, Lei; Zhang, Bin; Jiang, Zong-Fu

    2015-10-01

    We report the results of our recent experimental investigation of the modulation frequency detuning effect on the output pulse dynamics in a pulse modulated actively mode-locked ytterbium doped fiber laser. The experimental study shows the existence of five different mode-locking states that mainly depend on the modulation frequency detuning, which are: (a) amplitude-even harmonic/fundamental mode-locking, (b) Q-switched harmonic/fundamental mode-locking, (c) sinusoidal wave modulation mode, (d) pulses bundle state, and (e) noise-like state. A detailed experimental characterization of the output pulses dynamics in each operating mode is presented.

  7. Frequency of slow oscillations in arterial pressure and R-R intervals during muscle metaboreflex activation.

    PubMed

    Kiviniemi, Antti M; Tiinanen, Suvi; Hautala, Arto J; Seppänen, Tapio; Mäkikallio, Timo H; Huikuri, Heikki V; Tulppo, Mikko P

    2010-01-15

    Altered frequency of slow (0.04-0.15Hz) arterial pressure and R-R interval oscillations has been observed in various diseases but the mechanisms for this frequency shift are unclear. The median (Med) frequencies of slow R-R interval and blood pressure (BP) oscillations were recorded in 11 healthy subjects with paced breathing (0.25Hz) during muscle metaboreflex and baroreflex mediated sympathetic stimuli: 1) handgrip exercise (HG) followed by post-exercise circulatory occlusion (PECO), 2) handgrip exercise during ischemia by circulatory occlusion (IHG) and 3) passive head-up tilt (TILT). Med(BP) shifted to the higher frequency during HG, PECO and IHG (from 0.070+/-0.009Hz to 0.088+/-0.013, 0.085+/-0.015 and 0.099+/-0.013Hz, respectively, p<0.01 for all) but not during TILT (0.078+/-0.012Hz). Similarly, Med(R-R) shifted to the higher frequency during HG, PECO and IHG (from 0.072+/-0.009Hz to 0.085+/-0.014, 0.085+/-0.016 and 0.095+/-0.015Hz, respectively, p<0.01 for all) but not during TILT (0.075+/-0.012Hz). Med(BP) and Med(R-R) were higher during IHG compared to HG and lower during TILT compared to both HG and IHG (p<0.01 for all). We conclude that the sympathetic stimulus induced by muscle metaboreflex is an important mechanism increasing the frequency of slow oscillations in arterial pressure and R-R intervals. The present results give new insight to understand the physiology underlying the frequency of slow arterial pressure and R-R interval oscillations.

  8. EMG burst presence probability: a joint time-frequency representation of muscle activity and its application to onset detection.

    PubMed

    Liu, Jie; Ying, Dongwen; Rymer, William Zev

    2015-04-13

    The purpose of this study was to quantify muscle activity in the time-frequency domain, therefore providing an alternative tool to measure muscle activity. This paper presents a novel method to measure muscle activity by utilizing EMG burst presence probability (EBPP) in the time-frequency domain. The EMG signal is grouped into several Mel-scale subbands, and the logarithmic power sequence is extracted from each subband. Each log-power sequence can be regarded as a dynamic process that transits between the states of EMG burst and non-burst. The hidden Markov model (HMM) was employed to elaborate this dynamic process since HMM is intrinsically advantageous in modeling the temporal correlation of EMG burst/non-burst presence. The EBPP was eventually yielded by HMM based on the criterion of maximum likelihood. Our approach achieved comparable performance with the Bonato method.

  9. Characteristics of high-frequency precursors to edge-localized activity in the PBX-M tokamak

    SciTech Connect

    Kaye, S.M.; Manickam, J.; Bell, R.; LeBlanc, B.; Kessel, C.; Kugel, H.; Paul, S.; Sesnic, S.; Takahashi, H. . Plasma Physics Lab.); Asakura, N. ); Lau, Y.T. )

    1990-03-01

    High {beta}{sub pol} H-mode plasmas in the PBX-M tokamak often exhibit periods of Edge Localized Mode (ELM) activity, with each ELM preceded by a short duration ({le} 350 {mu}sec) burst of high frequency (200 to 250 kHz) magnetic activity. The burst grows on a time scale of 10 {mu}sec, and disappears just prior to the rapid increase in the D{sub {alpha}} emission that is characteristic of the ELM. The burst of activity is observed at all poloidal locations, with the largest amplitudes seen on the coils on the inner major radius side, indicating that the mode is not outward ballooning in character. Stability calculations indicate that a likely candidate for this high frequency ELM precursor is the pressure-driven ideal kink. 12 refs., 4 figs.

  10. A high frequency active voltage doubler in standard CMOS using offset-controlled comparators for inductive power transmission.

    PubMed

    Lee, Hyung-Min; Ghovanloo, Maysam

    2013-06-01

    In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μm 3M2P std . CMOS process, occupying 0.144 mm(2) of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE = 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages.

  11. A High Frequency Active Voltage Doubler in Standard CMOS Using Offset-Controlled Comparators for Inductive Power Transmission

    PubMed Central

    Lee, Hyung-Min; Ghovanloo, Maysam

    2014-01-01

    In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μm 3M2P std. CMOS process, occupying 0.144 mm2 of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE = 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages. PMID:23853321

  12. A multi-frequency study of an X ray selected sample of active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Grossan, Bruce Alan

    1992-01-01

    The LASS (Large Area Sky Survey) experiment, which flew aboard the HEAO-1 spacecraft, carried out a 2-20 keV survey of the sky during 1977-1978. The X-ray sources from this survey make up the LASS catalog (Wood et al. 1979). Optical counterparts have been identified for greater than 86 percent of the LASS sources above a flux of approx. 0.95 microns (mu)Jy Q 5 keV (Remillard 1992b). The LASS error boxes, along with the more precise positions from the Modulation Collimator (MC) X-ray experiment (also aboard HEAO-1), subsequent X-ray imaging, and optical search techniques were all used to identify the LASS sources. From these identifications, a high-latitude (absolute value of b greater than 20 deg.), flux limited (greater than or equal to 0.95 (mu)Jy) sample of 96 emission line Active Galactic Nuclei (AGN) have been selected for study. The sample is referred to as the LMA (for the LASS/MC identified sample of AGN). The objective of this work is to produce multi-frequency spectra of this sample of objects, in order to determine and interpret the statistical properties of the sample over nearly the full range of observable wavelengths. Data were obtained for as much of the radio through hard X-ray (less than 20 keV) spectrum as possible for each object in the LMA. Radio, near infrared, and other measurements were taken from the literature, far IR fluxes were extracted from co-added observations from IRAS, UV spectra were obtained from the IUE archives, and original observations were performed (with the help of collaborators) in the radio, near IR, optical, UV, and X-ray to fulfill this goal. Correlation studies of the continuum bands found poor correlations of X-ray and radio flux, good correlations for 12 and 26 micron flux with X-ray flux, excellent correlations for optical and near IR fluxes with X-rays, and poor correlations of UV and X-ray fluxes. Correlation studies of the line and X-ray continuum flux yield a good correlation between the flux of (OIII), the

  13. Ice Thickness Estimation of Thin Sea Ice Using Active Microwave Sensor Data Obtained at Different Frequencies

    NASA Astrophysics Data System (ADS)

    Brath, M.; Kern, S.; Stammer, D.

    2011-12-01

    We present a new approach to estimate thin sea ice thickness based on multi-frequency and multi-angle RADAR backscatter measurements. The method is based on the inversion of a first order backscattering model using Monte Carlo methods without any need for additional measured data than the measured radar cross section (RCS) except an optional guess of the surface temperature. The method is applied to RCS data obtained with the Multi3Scat during August and September 2007 over the Arctic Ocean. The Multi3Scat is a helicopter-borne scatterometer of the University of Hamburg, which simultaneously measures the like-polarization RCS at five different frequencies between 1 GHz and 15 GHz (in frequency bands L, S, C, X, and Ku) at incidence angles of 20° to 65°. A video and an infrared camera simultaneously sense the surface in the scatterometer's footprint for additional, independent information. The uncertainty of the thin sea ice thickness estimates obtained with our method is about 5 cm when combining two or more frequencies but only about 10 cm when using just one frequency. Thin sea ice thickness values obtained with our method are of the same order of independent in-situ observations.

  14. Resonant antidromic cortical circuit activation as a consequence of high-frequency subthalamic deep-brain stimulation.

    PubMed

    Li, S; Arbuthnott, G W; Jutras, M J; Goldberg, J A; Jaeger, D

    2007-12-01

    Deep brain stimulation (DBS) is an effective treatment of Parkinson's disease (PD) for many patients. The most effective stimulation consists of high-frequency biphasic stimulation pulses around 130 Hz delivered between two active sites of an implanted depth electrode to the subthalamic nucleus (STN-DBS). Multiple studies have shown that a key effect of STN-DBS that correlates well with clinical outcome is the reduction of synchronous and oscillatory activity in cortical and basal ganglia networks. We hypothesized that antidromic cortical activation may provide an underlying mechanism responsible for this effect, because stimulation is usually performed in proximity to cortical efferent pathways. We show with intracellular cortical recordings in rats that STN-DBS did in fact lead to antidromic spiking of deep layer cortical neurons. Furthermore, antidromic spikes triggered a dampened oscillation of local field potentials in cortex with a resonant frequency around 120 Hz. The amplitude of antidromic activation was significantly correlated with an observed suppression of slow wave and beta band activity during STN-DBS. These findings were seen in ketamine-xylazine or isoflurane anesthesia in both normal and 6-hydroxydopamine (6-OHDA)-lesioned rats. Thus antidromic resonant activation of cortical microcircuits may make an important contribution toward counteracting the overly synchronous and oscillatory activity characteristic of cortical activity in PD.

  15. Time-domain filtered-x-Newton narrowband algorithms for active isolation of frequency-fluctuating vibration

    NASA Astrophysics Data System (ADS)

    Li, Yan; He, Lin; Shuai, Chang-geng; Wang, Fei

    2016-04-01

    A time-domain filtered-x Newton narrowband algorithm (the Fx-Newton algorithm) is proposed to address three major problems in active isolation of machinery vibration: multiple narrowband components, MIMO coupling, and amplitude and frequency fluctuations. In this algorithm, narrowband components are extracted by narrowband-pass filters (NBPF) and independently controlled by multi-controllers, and fast convergence of the control algorithm is achieved by inverse secondary-path filtering of the extracted sinusoidal reference signal and its orthogonal component using L×L numbers of 2nd-order filters in the time domain. Controller adapting and control signal generation are also implemented in the time domain, to ensure good real-time performance. The phase shift caused by narrowband filter is compensated online to improve the robustness of control system to frequency fluctuations. A double-reference Fx-Newton algorithm is also proposed to control double sinusoids in the same frequency band, under the precondition of acquiring two independent reference signals. Experiments are conducted with an MIMO single-deck vibration isolation system on which a 200 kW ship diesel generator is mounted, and the algorithms are tested under the vibration alternately excited by the diesel generator and inertial shakers. The results of control over sinusoidal vibration excited by inertial shakers suggest that the Fx-Newton algorithm with NBPF have much faster convergence rate and better attenuation effect than the Fx-LMS algorithm. For swept, frequency-jumping, double, double frequency-swept and double frequency-jumping sinusoidal vibration, and multiple high-level harmonics in broadband vibration excited by the diesel generator, the proposed algorithms also demonstrate large vibration suppression at fast convergence rate, and good robustness to vibration with frequency fluctuations.

  16. High-resolution music with inaudible high-frequency components produces a lagged effect on human electroencephalographic activities.

    PubMed

    Kuribayashi, Ryuma; Yamamoto, Ryuta; Nittono, Hiroshi

    2014-06-18

    High-quality digital sound sources with inaudible high-frequency components (above 20 kHz) have become available because of recent advances in information technology. Listening to such sounds has been shown to increase the α-band power of an electroencephalogram (EEG). The present study scrutinized the time course of this effect by recording EEG along with autonomic measures (skin conductance level and heart rate) and facial electromyograms (corrugator supercilii and zygomaticus major). Twenty university students (19-24 years old) listened to two types of a 200-s musical excerpt (J. S. Bach's French Suite No. 5) with or without inaudible high-frequency components using a double-blind method. They were asked to rate the sound quality and to judge which excerpt contained high-frequency components. High-α EEG power (10.5-13 Hz) was larger for the excerpt with high-frequency components than for the excerpt without them. This effect was statistically significant only in the last quarter of the period (150-200 s). Participants were not able to distinguish between the excerpts, which did not produce any discernible differences in subjective, autonomic, and facial muscle measures. This study shows that inaudible high-frequency components have an impact on human brain activity without conscious awareness. Unlike a standard test for sound quality, at least 150 s of exposure is required to examine this effect in future research.

  17. Impact of atmospheric changes on the low-frequency variations of convective afternoon rainfall activity over Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, Wan-Ru; Hsu, Huang-Hsiung; Wang, Shih-Yu; Chen, Jian-Pu

    2015-09-01

    This study examines the characteristics of low-frequency variations (defined as decadal-scale changes) in summer (June-August) convective afternoon rainfall (CAR) activity over Taiwan during 1961-2012. Using 3-hourly rain gauge data, it was found that (1) the CAR frequency exhibits a secular trend and the 10-20 decadal oscillation, (2) the trend in CAR frequency is positive in northern Taiwan but negative in central and southern Taiwan, and (3) the CAR rate increased over most of the lower plains but decreased over the mountain range of Taiwan. Diagnoses using the Japanese ReAnalysis (JRA-55) data and surface observations indicate that the low-frequency variations in CAR frequency are closely associated with the variations in monsoon southwesterly winds over the South China Sea and island-wide sea breeze convergence. The regional low-level circulation changes are linked to sea surface temperature anomalies over the Niño-4 region and its 10-20 year (quasi-decadal) oscillation. Regarding the processes that change the CAR rate in the trending patterns, it was found that increases in the moisture flux convergence and the moist (conditional) instability over the lower plains together explain the stronger CAR events in the long run.

  18. The MPC&A Questionnaire

    SciTech Connect

    Powell, Danny H; Elwood Jr, Robert H

    2011-01-01

    The questionnaire is the instrument used for recording performance data on the nuclear material protection, control, and accountability (MPC&A) system at a nuclear facility. The performance information provides a basis for evaluating the effectiveness of the MPC&A system. The goal for the questionnaire is to provide an accurate representation of the performance of the MPC&A system as it currently exists in the facility. Performance grades for all basic MPC&A functions should realistically reflect the actual level of performance at the time the survey is conducted. The questionnaire was developed after testing and benchmarking the material control and accountability (MC&A) system effectiveness tool (MSET) in the United States. The benchmarking exercise at the Idaho National Laboratory (INL) proved extremely valuable for improving the content and quality of the early versions of the questionnaire. Members of the INL benchmark team identified many areas of the questionnaire where questions should be clarified and areas where additional questions should be incorporated. The questionnaire addresses all elements of the MC&A system. Specific parts pertain to the foundation for the facility's overall MPC&A system, and other parts pertain to the specific functions of the operational MPC&A system. The questionnaire includes performance metrics for each of the basic functions or tasks performed in the operational MPC&A system. All of those basic functions or tasks are represented as basic events in the MPC&A fault tree. Performance metrics are to be used during completion of the questionnaire to report what is actually being done in relation to what should be done in the performance of MPC&A functions.

  19. The Michigan data needs questionnaire

    NASA Technical Reports Server (NTRS)

    Hill-Rowley, R.

    1981-01-01

    The data needs questionnaire is an element in the project design study for the Michigan Resource Inventory Act and is aimed at gathering information on what inventory information is required by land use planners throughout the state. Analysis of questionnaire responses is discussed. Some information on current use categories was tabulated. The respondents selected a broad range of categories at all levels of detail. Those most frequently indicated were urban categories.

  20. Dynamic response of cardiac autonomic nervous system activity to habitual exercise during gradual variation of breathing frequency.

    PubMed

    Nakamura, H

    2015-01-01

    The purpose of this study is to measure cardiac autonomic nervous system activity during breathing control with gradual alteration of the frequency between habitual exercise and sedentary young male subjects. In this study, to evaluate CANS activity, Tone-Entropy analysis, which is based on statistical property of acceleration between consecutive R-R intervals, was used. Sixteen healthy young male subjects (21.6+/-1.4yrs) were participated in these experiments and their R-R interval sequences were recorded. The controlled breathing trials let the subjects synchronize their breathing frequency ranging 3 to 30 breathing per minute. After that, breathing frequency was gradually and reversely decreased from 30 to 3 breathing per minute. Before and after the breathing controlled trials, 5 minute voluntary breathing trials were performed. Our results showed that total CANS activities of HE group were activated more than those of SE group in the entire sections and also that, as compared with HE group, maximum of average HR in SE group was appeared at 30 breathing per minute and it is recognized that the statistically significant difference between HE and SE group was shown. In conclusion, our results suggest that efficiency of cardiac function on habitual exercise in breathing control may be quantitatively and graphically evaluated with HR and Tone-Entropy analysis without any physical stimulation.

  1. The OnyCOE-t™ questionnaire: responsiveness and clinical meaningfulness of a patient-reported outcomes questionnaire for toenail onychomycosis

    PubMed Central

    Potter, Lori P; Mathias, Susan D; Raut, Monika; Kianifard, Farid; Tavakkol, Amir

    2006-01-01

    Background This research was conducted to confirm the validity and reliability and to assess the responsiveness and clinical meaningfulness of the OnyCOE-t™, a questionnaire specifically designed to measure patient-reported outcomes (PRO) associated with toenail onychomycosis. Methods 504 patients with toenail onychomycosis randomized to receive 12 weeks of terbinafine 250 mg/day with or without target toenail debridement in the IRON-CLAD® trial completed the OnyCOE-t™ at baseline, weeks 6, 12, 24, and 48. The OnyCOE-t™ is composed of 6 multi-item scales and 1 single-item scale. These include a 7-item Toenail Symptom assessment, which comprises both Symptom Frequency and Symptom Bothersomeness scales; an 8-item Appearance Problems scale; a 7-item Physical Activities Problems scale; a 1-item Overall Problem scale; a 7-item Stigma scale; and a 3-item Treatment Satisfaction scale. In total, 33 toenail onychomycosis-specific items are included in the OnyCOE-t™. Clinical data, in particular the percent clearing of mycotic involvement in the target toenail, and OnyCOE-t™ responses were used to evaluate the questionnaire's reliability, validity, responsiveness, and the minimally clinical important difference (MCID). Results The OnyCOE-t™ was shown to be reliable and valid. Construct validity and known groups validity were acceptable. Internal consistency reliability of multi-item scales was demonstrated by Cronbach's alpha > .84. Responsiveness was good, with the Treatment Satisfaction, Symptom Frequency, Overall Problem, and Appearance Problem scales demonstrating the most responsiveness (Guyatt's statistic of 1.72, 1.31, 1.13, and 1.11, respectively). MCID was evaluated for three different clinical measures, and indicated that approximately an 8.5-point change (on a 0 to 100 scale) was clinically meaningful based on a 25% improvement in target nail clearing. Conclusion The OnyCOE-t™ questionnaire is a unique, toenail-specific PRO questionnaire that can be

  2. High frequency drive mechanism for an active controls systems aircraft control surface

    NASA Technical Reports Server (NTRS)

    Smith, H. E.

    1981-01-01

    The mechanism was successfully utilized on a wind tunnel model tested in the transonic blow down tunnel. The mechanism is also applicable to a flying aircraft. Several interrelated mechanical subsystems were utilized, including a low inertia antibacklash drive mechanism for high frequency oscillation and a compact antibacklash drive mechanism for conversion of rotary motion to linear motion.

  3. Detection of epileptiform activity in EEG signals based on time-frequency and non-linear analysis.

    PubMed

    Gajic, Dragoljub; Djurovic, Zeljko; Gligorijevic, Jovan; Di Gennaro, Stefano; Savic-Gajic, Ivana

    2015-01-01

    We present a new technique for detection of epileptiform activity in EEG signals. After preprocessing of EEG signals we extract representative features in time, frequency and time-frequency domain as well as using non-linear analysis. The features are extracted in a few frequency sub-bands of clinical interest since these sub-bands showed much better discriminatory characteristics compared with the whole frequency band. Then we optimally reduce the dimension of feature space to two using scatter matrices. A decision about the presence of epileptiform activity in EEG signals is made by quadratic classifiers designed in the reduced two-dimensional feature space. The accuracy of the technique was tested on three sets of electroencephalographic (EEG) signals recorded at the University Hospital Bonn: surface EEG signals from healthy volunteers, intracranial EEG signals from the epilepsy patients during the seizure free interval from within the seizure focus and intracranial EEG signals of epileptic seizures also from within the seizure focus. An overall detection accuracy of 98.7% was achieved.

  4. Coincident frequencies and relative phases among brain activity and hormonal signals

    PubMed Central

    Solís-Ortíz, Silvia; Campos, Rafael G; Félix, Julián; Obregón, Octavio

    2009-01-01

    Background Fourier transform is a basic tool for analyzing biological signals and is computed for a finite sequence of data sample. The electroencephalographic (EEG) signals analyzed with this method provide only information based on the frequency range, for short periods. In some cases, for long periods it can be useful to know whether EEG signals coincide or have a relative phase between them or with other biological signals. Some studies have evidenced that sex hormones and EEG signals show oscillations in their frequencies across a period of 28 days; so it seems of relevance to seek after possible patterns relating EEG signals and endogenous sex hormones, assumed as long time-periodic functions to determine their typical periods, frequencies and relative phases. Methods In this work we propose a method that can be used to analyze brain signals and hormonal levels and obtain frequencies and relative phases among them. This method involves the application of a discrete Fourier Transform on previously reported datasets of absolute power of brain signals delta, theta, alpha1, alpha2, beta1 and beta2 and the endogenous estrogen and progesterone levels along 28 days. Results Applying the proposed method to exemplary datasets and comparing each brain signal with both sex hormones signals, we found a characteristic profile of coincident periods and typical relative phases. For the corresponding coincident periods the progesterone seems to be essentially in phase with theta, alpha1, alpha2 and beta1, while delta and beta2 go oppositely. For the relevant coincident periods, the estrogen goes in phase with delta and theta and goes oppositely with alpha2. Conclusion Findings suggest that the procedure applied here provides a method to analyze typical frequencies, or periods and phases between signals with the same period. It generates specific patterns for brain signals and hormones and relations among them. PMID:19284671

  5. Modulation of activity and conduction in single dorsal column axons by kilohertz-frequency spinal cord stimulation.

    PubMed

    Crosby, Nathan D; Janik, John J; Grill, Warren M

    2017-01-01

    Kilohertz-frequency spinal cord stimulation (KHF-SCS) is a potential paresthesia-free treatment for chronic pain. However, the effects of KHF-SCS on spinal dorsal column (DC) axons and its mechanisms of action remain unknown. The objectives of this study were to quantify activation and conduction block of DC axons by KHF-SCS across a range of frequencies (1, 5, 10, or 20 kHz) and waveforms (biphasic pulses or sinusoids). Custom platinum electrodes delivered SCS to the T10/T11 dorsal columns of anesthetized male Sprague-Dawley rats. Single DC axons and compound action potentials were recorded during KHF-SCS to evaluate SCS-evoked activity. Responses to KHF-SCS in DC axons included brief onset firing, slowly accommodating asynchronous firing, and conduction block. The effects of KHF-SCS mostly occurred well above motor thresholds, but isolated units were activated at amplitudes shown to reduce behavioral sensitivity in rats. Activity evoked by SCS was similar across a range of frequencies (5-20 kHz) and waveforms (biphasic and sinusoidal). Stimulation at 1-kHz SCS evoked more axonal firing that was also more phase-synchronized to the SCS waveform, but only at amplitudes above motor threshold. These data quantitatively characterize the central nervous system activity that may modulate pain perception and paresthesia, and thereby provide a foundation for continued investigation of the mechanisms of KHF-SCS and its optimization as a therapy for chronic pain. Given the asynchronous and transient nature of DC activity, it is unlikely that the same mechanisms underlying conventional SCS (i.e., persistent, periodic DC activation) apply to KHF-SCS.

  6. Brain activity in adults who stutter: similarities across speaking tasks and correlations with stuttering frequency and speaking rate.

    PubMed

    Ingham, Roger J; Grafton, Scott T; Bothe, Anne K; Ingham, Janis C

    2012-07-01

    Many differences in brain activity have been reported between persons who stutter (PWS) and typically fluent controls during oral reading tasks. An earlier meta-analysis of imaging studies identified stutter-related regions, but recent studies report less agreement with those regions. A PET study on adult dextral PWS (n=18) and matched fluent controls (CONT, n=12) is reported that used both oral reading and monologue tasks. After correcting for speech rate differences between the groups the task-activation differences were surprisingly small. For both analyses only some regions previously considered stutter-related were more activated in the PWS group than in the CONT group, and these were also activated during eyes-closed rest (ECR). In the PWS group, stuttering frequency was correlated with cortico-striatal-thalamic circuit activity in both speaking tasks. The neuroimaging findings for the PWS group, relative to the CONT group, appear consistent with neuroanatomic abnormalities being increasingly reported among PWS.

  7. Characterization of the cerebral activity by time-frequency representation of evoked EEG potentials.

    PubMed

    Clariá, Francesc; Vallverdú, Montserrat; Riba, Jordi; Romero, Sergio; Barbanoj, Manuel J; Caminal, Pere

    2011-08-01

    Event-related brain potentials (ERPs) are the electrical response of the brain while performing a particular task. Methods traditionally used to study ERPs measure the amplitude and duration of the waveform in order to quantify the changes, being signal morphology dependent. However, the frequency characteristics of those events remain uncovered. The aim of this work was the study of new measures to characterize, by means of time-frequency representation (TFR) techniques, the ERPs recorded while subjects conducted a choice reaction time task (Ericksen flanker task) following the administration of different alprazolam doses. Several measures defined from energy, instantaneous frequency and group delay functions were obtained by means of TFR techniques applied to the Choi-Williams distribution (CWD) of EEG signals. These measures, which are signal morphology independent, were studied in four frequency bands, δ (0-4 Hz), θ (4-8 Hz), α (8-15 Hz), β (15-30 Hz), and for certain time periods. Based on these measures, differences between ERPs were analyzed by comparing the different response types (successes or successfully corrected failures) of the subject performing the task, and comparing the applied drug doses. For each subject, the CWD of EEG signals was applied in two different ways: (a) all ERPs were averaged per channel, and then the CWD was applied; (b) the CWD was applied to each one of the ERPs. When the CWD was applied to each ERP, the energy measures in the δ, θ and β bands, the instantaneous frequency measures in the α and β bands, and the group delay measures in the δ, θ and α bands showed a statistically significant level p < 0.0005 in the analysis of the response type. Also, the energy measures in the θ and β bands and the instantaneous frequency measures in the α band showed statistically significant differences (p < 0.0005) between placebo and low and high drug doses. In contrast, poor results were obtained when all epochs of each subject

  8. Report on the Time and Frequency Activities of the Time Service Department of the U.S. Naval Observatory

    DTIC Science & Technology

    2001-11-01

    33’’ Annual Precise Time and Time Interval (PTTI) Meeting Administrators Secretary Engineers and Technicians REPORT ON THE TIME AND FREQUENCY OF...THE U.S. NAVAL OBSERVATORY ACTIVITIES OF THE TIME SERVICE DEPARTMENT 2 1 4 Demetrios Matsakis and the staff of the Time Service Department U.S...requirements of many real- time users, the best known among them being GPS. 1 THE BASICS The most important part of the USNO Time Service Department is its

  9. Time and Frequency Activities at the U.S. Naval Observatory

    DTIC Science & Technology

    2012-01-01

    and 4 rubidium fountain frequency standards in several buildings at two sites. USNO disseminates time via voice, telephone modem, Network Time...November 2012, 41 of those standards were weighted in the operational timescale computations; this includes four rubidium atomic fountains [1], which...of an upgrade. The data from the four USNO rubidium fountains have been contributed to the BIPM since December 1, 2011 and the clocks have now

  10. Beta-frequency EEG activity increased during transcranial direct current stimulation.

    PubMed

    Song, Myeongseop; Shin, Yungjae; Yun, Kyongsik

    2014-12-17

    Transcranial direct current stimulation (tDCS) is a technique for noninvasively stimulating specific cortical regions of the brain with small (<2 mA) and constant direct current on the scalp. tDCS has been widely applied, not only for medical treatment, but also for cognitive and somatosensory function enhancement, motor learning improvement, and social behavioral change. However, the mechanism that underlies the effect of tDCS is unclear. In this study, we performed simultaneous electroencephalogram (EEG) monitoring during tDCS to understand the dynamic electrophysiological changes throughout the stimulation. A total of 10 healthy individuals participated in this experiment. We recorded EEGs with direct current stimulation, as well as during a 5-min resting state before and after the stimulation. All participants kept their eyes closed during the experiment. Anode and cathode patches of tDCS were placed on the left and the right dorsolateral prefrontal cortex, respectively. In addition, an EEG electrode was placed on the medial prefrontal cortex. The beta-frequency power increased promptly after starting the stimulation. The significant beta-power increase was maintained during the stimulation. Other frequency bands did not show any significant changes. The results indicate that tDCS of the left dorsolateral prefrontal cortex changed the brain to a ready state for efficient cognitive functioning by increasing the beta-frequency power. This is the first attempt to simultaneously stimulate the cortex and record the EEG and then systematically analyze the prestimulation, during-stimulation, and poststimulation EEG data.

  11. [Biological effects of electromagnetic radiation of extremely high frequencies combined with physiologically active compounds].

    PubMed

    Rogacheva, S M; Denisova, S A; Shul'gin, S V; Somov, A Iu; Kuznetsov, P E

    2008-01-01

    The study of the action of the electromagnetic radiation (EMR) of low intensity (10 microW/cm2) in the range of frequencies 120-170 GHz at the test-reaction of Infusoria Paramecium caudatum was carried out. The resonant character of the effects was established. The EMR action at 156.6 and 161.3 GHz caused the increase of infusorians mobility, the action at frequencies 151.8, 155.7, 167.1 GHz caused the mobility reduction. Isolated and combined with EMR effects of nicotine (10(-4)-10(-15) mol/l) and antimicrobial drug metronidazole (10(-5), 10(-8), 10(-9) mol/l) were investigated. The radiation at the frequency 167.1 GHz was shown to reduce the effect of nicotine (10(-9) mol/l) and to enhance the effect of metronidazole (10(-9) mol/l). This phenomenon may be explained by different effects of the substances in low concentration at the water hydrogen bonds net structure.

  12. Active cancellation of residual amplitude modulation in a frequency-modulation based Fabry-Perot interferometer

    NASA Astrophysics Data System (ADS)

    Yu, Yinan; Wang, Yicheng; Pratt, Jon R.

    2016-03-01

    Residual amplitude modulation (RAM) is one of the most common noise sources known to degrade the sensitivity of frequency modulation spectroscopy. RAM can arise as a result of the temperature dependent birefringence of the modulator crystal, which causes the orientation of the crystal's optical axis to shift with respect to the polarization of the incident light with temperature. In the fiber-based optical interferometer used on the National Institute of Standards and Technology calculable capacitor, RAM degrades the measured laser frequency stability and correlates with the environmental temperature fluctuations. We have demonstrated a simple approach that cancels out excessive RAM due to polarization mismatch between the light and the optical axis of the crystal. The approach allows us to measure the frequency noise of a heterodyne beat between two lasers individually locked to different resonant modes of a cavity with an accuracy better than 0.5 ppm, which meets the requirement to further determine the longitudinal mode number of the cavity length. Also, this approach has substantially mitigated the temperature dependency of the measurements of the cavity length and consequently the capacitance.

  13. Psychometric properties of the Violent Experiences Questionnaire.

    PubMed

    King, Alan R; Russell, Tiffany D

    2017-02-24

    The Violent Experiences Questionnaire-Revised (VEQ-R) is a brief retrospective self-report inventory which provides estimates of annual frequencies of childhood physical abuse, sibling physical abuse, exposure to parental violence, peer bullying, and corporal punishment as they were experienced from ages 5 to 16. The VEQ-R indices rely on a frequency metric that estimates the number of days on average per year a specified class of behavior occurred over a 12year retrospective period. All scores range from a frequency of 0 to a high of 104. Scale normative data was generated from both a college (N=1266) and national (N=1290) sample to expand the research applicability of this relatively new inventory. Subscales were added to estimate the frequency of victimization during childhood, the pre-teen years, and adolescence. Four "hostility" component indices were derived from perpetrator source (parent, sibling, peer, or domestic). Thresholds were established to for High, Moderate, Low, and No Risk classifications. Subscales dimensions were found to have both adequate internal and temporal consistency. Evidence of concurrent and discriminant validity was generated using the Parent-Child Conflict Tactics Scale-Short-Form(©), LONGSCAN Physical Abuse Self-Report scale, and Physical Punishment scale of the Assessing Environments III inventory.

  14. Unmyelinated axons in the rat hippocampus hyperpolarize and activate an H current when spike frequency exceeds 1 Hz

    PubMed Central

    Soleng, A F; Chiu, K; Raastad, M

    2003-01-01

    The mammalian cortex is densely populated by extensively branching, thin, unmyelinated axons that form en passant synapses. Some thin axons in the peripheral nervous system hyperpolarize if action potential frequency exceeds 1-5 Hz. To test the hypothesis that cortical axons also show activity-induced hyperpolarization, we recorded extracellularly from individual CA3 pyramidal neurons while activating their axon with trains consisting of 30 electrical stimuli. Synaptic excitation was blocked by kynurenic acid. We observed a positive correlation between stimulation strength and the number of consecutive axonal stimuli that resulted in soma spikes, suggesting that the threshold increased as a function of the number of spikes. During trains without response failures there was always a cumulative increase in the soma response latency. Intermittent failures, however, decreased the latency of the subsequent response. At frequencies of > 1 Hz, the threshold and latency increases were enhanced by blocking the hyperpolarization-activated H current (Ih)by applying the specific Ih blocker ZD7288 (25 μM) or 2 mM Cs+. Under these conditions, response failures occurred after 15–25 stimuli, independent of the stimulation strength. Adding GABA receptor blockers (saclofen and bicuculline) and a blocker of metabotropic glutamate receptors did not change the activity-induced latency increase in recordings of the compound action potential. We interpret these results as an activity-induced hyperpolarization that is partly counteracted by Ih. Such a hyperpolarization may influence transmitter release and the conduction reliability of these axons. PMID:14561829

  15. Frequency of private spiritual activity and cardiovascular risk in postmenopausal women: the Women’s Health Initiative

    PubMed Central

    Salmoirago-Blotcher, Elena; Fitchett, George; Hovey, Kathleen M.; Schnall, Eliezer; Thomson, Cynthia; Andrews, Christopher A.; Crawford, Sybil; O’Sullivan, Mary Jo; Post, Stephen; Chlebowski, Rowan T.; Ockene, Judith

    2013-01-01

    Purpose Spirituality has been associated with better cardiac autonomic balance, but its association with cardiovascular risk is not well studied. We examined whether more frequent private spiritual activity was associated with reduced cardiovascular risk in postmenopausal women enrolled in the Women’s Health Initiative Observational Study. Methods Frequency of private spiritual activity (prayer, Bible reading, and meditation) was self-reported at year 5 of follow-up. Cardiovascular outcomes were centrally adjudicated, and cardiovascular risk was estimated from proportional hazards models. Results Final models included 43,708 women (mean age, 68.9 ± 7.3 years; median follow-up, 7.0 years) free of cardiac disease through year 5 of follow-up. In age-adjusted models, private spiritual activity was associated with increased cardiovascular risk (hazard ratio [HR], 1.16; 95% confidence interval [CI], 1.02–1.31 for weekly vs. never; HR, 1.25; 95% CI, 1.11–1.40 for daily vs. never). In multivariate models adjusted for demographics, lifestyle, risk factors, and psychosocial factors, such association remained significant only in the group with daily activity (HR, 1.16; 95% CI, 1.03–1.30). Subgroup analyses indicate this association may be driven by the presence of severe chronic diseases. Conclusions Among aging women, higher frequency of private spiritual activity was associated with increased cardiovascular risk, likely reflecting a mobilization of spiritual resources to cope with aging and illness. PMID:23621989

  16. Geomagnetic activity that corresponds to the median of the F2-layer critical frequency at various latitudes

    NASA Astrophysics Data System (ADS)

    Deminov, M. G.; Deminova, G. F.

    2016-09-01

    On the basis of the F2-layer critical frequency foF2 for the noon at some European stations for 1958-2005, it is found that the geomagnetic activity corresponding to the foF2 median is systematically lower than that averaged over the month; the difference increases with an increase in latitude. Moreover, the dispersion of geomagnetic activity for the foF2 median at relatively high latitudes is lower than at middle latitudes. These regularities are related to the fact that high geomagnetic activity usually leads to a distinct deviation of foF2 from the typical average value, i.e., from the foF2 median, and such deviation is more substantial at relatively high latitudes. That is why the geomagnetic activity for the foF2 median is lower at relatively high latitudes than at middle latitudes.

  17. Frequency of sexual activity and cardiovascular risk in subjects with erectile dysfunction: cross-sectional and longitudinal analyses.

    PubMed

    Corona, G; Rastrelli, G; Monami, M; Maseroli, E; Jannini, E A; Balercia, G; Sforza, A; Forti, G; Mannucci, E; Maggi, M

    2013-11-01

    Erectile dysfunction (ED) is risk factor for cardiovascular (CV) events. The relationship between sexual activity and incident major adverse cardiovascular events (MACE) in subjects at high CV risk is conflicting and never investigated in ED subjects. The aim of this study was to investigate relationships between frequency of sexual attempts and incident MACE and to retrospectively explore its main determinants in subjects with sexual dysfunction. A consecutive series of 2187 subjects (mean age 49.9 ± 11.6 years old) attending the Outpatient Clinic for sexual dysfunction was retrospectively studied. A subset of the previous sample (N = 1687) was enrolled in a longitudinal study. Frequency of sexual intercourse (coital and non-coital) was assessed using a standard question ('During the last 3 months how many sexual attempts per month did you have?'). In the whole sample, sexual attempts were an age- and testosterone-dependent phenomenon, while no association between frequency of sexual intercourse and ED or premature and delayed ejaculation, was observed. However, when the same analysis was performed according to age tertiles (I = 17-46, II = 47-59, III = 60-88 years old), ED was significantly associated with a higher risk of reduced sexual intercourse in younger (hazard ratio = 1.857 [1.066-3.234]; p = 0.029), but not in middle-aged or older individuals. The marital component, as assessed by SIEDY Scale 2, played a major role in regulating sexual frequency in all age bands. Depressive symptoms represent another independent risk factor for reduced sexual activity (adj r = -0.139; p < 0.0001), in an age-dependent manner. When longitudinal data were analysed, a higher frequency of sexual intercourse significantly reduced the risk of MACE even after adjusting for known CV risk factors for this cohort. Identifying among mild-to-moderate ED subjects those with lower frequency of sexual activity might provide an opportunity to modify their behaviour

  18. Modelling a response as a function of high-frequency count data: The association between physical activity and fat mass.

    PubMed

    Augustin, Nicole H; Mattocks, Calum; Faraway, Julian J; Greven, Sonja; Ness, Andy R

    2015-07-17

    Accelerometers are widely used in health sciences, ecology and other application areas. They quantify the intensity of physical activity as counts per epoch over a given period of time. Currently, health scientists use very lossy summaries of the accelerometer time series, some of which are based on coarse discretisation of activity levels, and make certain implicit assumptions, including linear or constant effects of physical activity. We propose the histogram as a functional summary for achieving a near lossless dimension reduction, comparability between individual time series and easy interpretability. Using the histogram as a functional summary avoids registration of accelerometer counts in time. In our novel method, a scalar response is regressed on additive multi-dimensional functional predictors, including the histogram of the high-frequency counts, and additive non-linear predictors for other continuous covariates. The method improves on the current state-of-the art, as it can deal with high-frequency time series of different lengths and missing values and yields a flexible way to model the physical activity effect with fewer assumptions. It also allows the commonly made modelling assumptions to be tested. We investigate the relationship between the response fat mass and physical activity measured by accelerometer, in data from the Avon Longitudinal Study of Parents and Children. Our method allows testing of whether the effect of physical activity varies over its intensity by gender, by time of day or by day of the week. We show that meaningful interpretation requires careful treatment of identifiability constraints in the light of the sum-to-one property of a histogram. We find that the (not necessarily causal) effect of physical activity on kg fat mass is not linear and not constant over the activity intensity.

  19. Functional cerebral activation detected by frequency-domain near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Toronov, Vladislav Y.; Webb, Andrew G.; Choi, Jee H.; Wolf, Martin; Safonova, Larisa P.; Wolf, Ursula; Gratton, Enrico

    2002-07-01

    The aim of our study was to explore the possibility of detecting haemodynamic changes in the brain using frequency- domain near-IR spectroscopy by exploiting the phase of the intensity modulated optical signal. To obtain optical signals with eh highest possible signal-to-noise ratio, we performed simultaneous NIRS-fMRI measurements, with subsequent correlation of the time courses of both measurements. The cognitive paradigm used arithmetic calculations, with optical signals acquired with sensors placed on the forehead. In three subjects we demonstrated correlation between the haemodynamic signals obtained using NIRS and BOLD fMRI.

  20. Is the Gambling Motives Questionnaire really three-dimensional? A proposition of a four-dimensional Gambling Motives Questionnaire - Revised.

    PubMed

    Myrseth, Helga; Notelaers, Guy

    2017-02-01

    The aim of the present study was to improve the weaknesses of the three-dimensional Gambling Motives Questionnaire and to examine the psychometric properties and factor structure of the Gambling Motives Questionnaire-Revised. The Gambling Motives Questionnaire was administered to a sample of 418 gamblers (92% men, mean age 19.5years). Participants completed the Gambling Motives Questionnaire and an additional item tapping boredom, as well as a variety of measures of gambling behavior and gambling problems as criterion measures. Results showed that the Gambling Motives Questionnaire-Revised is better represented as a four-factor structure tapping the following four gambling motives factors; enhancement, coping, social, and self-gratification, Δχ(2) Δ(df)=24.76 (3), p<0.001. Removing two problematic items from the Gambling Motives Questionnaire and adding an extra item tapping boredom also improved the fit of the Gambling Motives Questionnaire-Revised. The subscales enhancement, social, and coping were all significant predictors of variety of gambling behaviors (p<0.05), whereas enhancement, coping, and self-gratification predicted frequency of gambling behaviors (p<0.01). Coping and self-gratification predicted loss of control (p<0.01), whereas self-gratification predicted gambling problems (p<0.001). The Gambling Motives Questionnaire - Revised, consisting of the four dimensions enhancement motives, social motives, coping motives and self-gratification motives, is a reliable and valid instrument to measuring gambling motives.

  1. Time-Frequency Mixed-Norm Estimates: Sparse M/EEG imaging with non-stationary source activations

    PubMed Central

    Gramfort, A.; Strohmeier, D.; Haueisen, J.; Hämäläinen, M.; Kowalski, M.

    2013-01-01

    Magnetoencephalography (MEG) and electroencephalography (EEG) allow functional brain imaging with high temporal resolution. While solving the inverse problem independently at every time point can give an image of the active brain at every millisecond, such a procedure does not capitalize on the temporal dynamics of the signal. Linear inverse methods (Minimum-norm, dSPM, sLORETA, beamformers) typically assume that the signal is stationary: regularization parameter and data covariance are independent of time and the time varying signal-to-noise ratio (SNR). Other recently proposed non-linear inverse solvers promoting focal activations estimate the sources in both space and time while also assuming stationary sources during a time interval. However such an hypothesis only holds for short time intervals. To overcome this limitation, we propose time-frequency mixed-norm estimates (TF-MxNE), which use time-frequency analysis to regularize the ill-posed inverse problem. This method makes use of structured sparse priors defined in the time-frequency domain, offering more accurate estimates by capturing the non-stationary and transient nature of brain signals. State-of-the-art convex optimization procedures based on proximal operators are employed, allowing the derivation of a fast estimation algorithm. The accuracy of the TF-MxNE is compared to recently proposed inverse solvers with help of simulations and by analyzing publicly available MEG datasets. PMID:23291276

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