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Sample records for activity frequency questionnaire

  1. 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).

  2. Relationships between the Food Expectancy Questionnaire (FEQ) and the Food Frequency Questionnaire (FFQ).

    PubMed

    Reid, Marie; Bunting, Jane; Hammersley, Richard

    2005-10-01

    The outcome expectancies of 250 respondents were examined using the Food Expectancy Questionnaire (FEQ), comparing expectancies about four different foods: fruit, vegetables, chocolate and sweets and plain biscuits. These expectancies were related to diet as assessed by a Food Frequency Questionnaire. As with alcohol expectancies [Jones, B. T., Corbin, W. & Fromme, K. (2001). A review of expectancy theory and alcohol consumption. Addiction, 96, 57-72], on which this research was modelled, positive and negative outcomes were the main factors for all foods, accounting jointly for between 33 and 40% of expectancy variance in factor analysis and predicting as much as 16% of the variance in relevant food intake measures by linear regression. Expected positive and negative outcomes of eating were predominantly immediate psychological after-effects, rather than including orosensory experiences, or longer-term effects on health or well-being. Other expectancies varied from food to food. FEQ expectancies for different foods have similar factor structure and were related to self-reported diet, the FEQ therefore shows promise as a means of modelling cognitions about eating. PMID:15949872

  3. Test-Retest Reliability of the Parent Behavior Importance Questionnaire-Revised and the Parent Behavior Frequency Questionnaire-Revised

    ERIC Educational Resources Information Center

    Mowder, Barbara A.; Shamah, Renee

    2011-01-01

    This study evaluated the test-retest reliability of two parenting measures: the Parent Behavior Importance Questionnaire-Revised (PBIQ-R) and Parent Behavior Frequency Questionnaire-Revised (PBFQ-R). These self-report parenting behavior assessment measures may be utilized as pre- and post-parent education program measures, with parents as well as…

  4. Design and Development of a Dialysis Food Frequency Questionnaire

    PubMed Central

    Kalantar-Zadeh, Kamyar; Kovesdy, Csaba P; Bross, Rachelle; Benner, Debbie; Noori, Nazanin; Murali, Sameer B; Block, Torin; Norris, Jean; Kopple, Joel D; Block, Gladys

    2010-01-01

    OBJECTIVES Periodic assessment of dietary intake across a given dialysis population may help improve clinical outcomes related to such nutrients as dietary protein, phosphorus, or potassium. Whereas dietary recalls and food records are used to assess dietary intake at individual level and over shorter time periods, food frequency questionnaires (FFQ) are employed to rank subjects of a given population according to their nutrient intake over longer time periods. DESIGN To modify and refine the conventional Block’s FFQ in order to develop a dialysis patients specific FFQ. SETTING Eight DaVita outpatient dialysis clinics in Los Angeles area, which participated in the “Nutrition and Inflammation in Dialysis Patients” (NIED) Study. PATIENTS 154 maintenance hemodialysis (MHD) patients MAIN OUTCOME MEASURE Dietary intake of participating MHD patients using a 3-day food record, supplemented by a person-to-person dietary interview, to capture food intake over the last hemodialysis treatment day of the week and the 2 subsequent non-dialysis days. RESULTS Analyses of the food records identified the key contributors to the daily nutrient intake in the 154 participating MHD patients. A “Dialysis-FFQ” was developed to include approximately 100 food items representing 90% of the patients’ total food intake of the NIED Study population. Distinctions were made in several food items based on key nutritional issues in dialysis patients such as protein, phosphorus and potassium. CONCLUSIONS We have developed a “Dialysis FFQ” to compare and rank dialysis patients according to their diverse nutrient intake. Whereas, the Dialysis-FFQ may be a valuable tool to compare dialysis patients and to identify those who ingest higher or lower amounts of a given nutrient, studies are needed to examine the utility of the Dialysis-FFQ for nutritional assessment of dialysis patients. PMID:20833073

  5. A Physical Activity Questionnaire: Reproducibility and Validity

    PubMed Central

    Barbosa, Nicolas; Sanchez, Carlos E.; Vera, Jose A.; Perez, Wilson; Thalabard, Jean-Christophe; Rieu, Michel

    2007-01-01

    This study evaluates the Quantification de L’Activite Physique en Altitude chez les Enfants (QAPACE) supervised self-administered questionnaire reproducibility and validity on the estimation of the mean daily energy expenditure (DEE) on Bogotá’s schoolchildren. The comprehension was assessed on 324 students, whereas the reproducibility was studied on a different random sample of 162 who were exposed twice to it. Reproducibility was assessed using both the Bland-Altman plot and the intra-class correlation coefficient (ICC). The validity was studied in a sample of 18 girls and 18 boys randomly selected, which completed the test - re-test study. The DEE derived from the questionnaire was compared with the laboratory measurement results of the peak oxygen uptake (Peak VO2) from ergo-spirometry and Leger Test. The reproducibility ICC was 0.96 (95% C.I. 0.95-0.97); by age categories 8-10, 0.94 (0.89-0. 97); 11-13, 0.98 (0.96- 0.99); 14-16, 0.95 (0.91-0.98). The ICC between mean TEE as estimated by the questionnaire and the direct and indirect Peak VO2 was 0.76 (0.66) (p<0.01); by age categories, 8-10, 11-13, and 14-16 were 0.89 (0.87), 0.76 (0.78) and 0.88 (0.80) respectively. The QAPACE questionnaire is reproducible and valid for estimating PA and showed a high correlation with the Peak VO2 uptake. Key pointsThe presence of a supervisor, the limited size of the group with the possibility of answering to their questions could explain the high reproducibility for this questionnaire.No study in the literature had directly addressed the issue of estimating a yearly average PA including school and vacation period.A two step procedure, in the population of schoolchildren of Bogotá, gives confidence in the use of the QAPACE questionnaire in a large epidemiological survey in related populations. PMID:24149485

  6. Active frequency selective surfaces

    NASA Astrophysics Data System (ADS)

    Buchwald, Walter R.; Hendrickson, Joshua; Cleary, Justin W.; Guo, Junpeng

    2013-05-01

    Split ring resonator arrays are investigated for use as active elements for the realization of voltage controllable frequency selective surfaces. Finite difference time domain simulations suggest the absorptive and reflective properties of such surfaces can be externally controlled through modifications of the split ring resonator gap impedance. In this work, such voltage-controlled resonance tuning is obtained through the addition of an appropriately designed high electron mobility transistor positioned across the split ring resonator gap. It is shown that a 0.5μm gate length high electron mobility transistor allows voltage controllable switching between the two resonant conditions associated with a split ring resonator and that of a closed loop geometry when the surface is illuminated with THz radiation. Partial switching between these two resonant conditions is observed at larger gate lengths. Such active frequency selective surfaces are proposed, for example, for use as modulators in THz detection schemes and as RF filters in radar applications when scaled to operate at GHz frequencies.

  7. Counting calories: partitioning energy intake estimates from a food frequency questionnaire.

    PubMed

    Flegal, K M; Larkin, F A; Metzner, H L; Thompson, F E; Guire, K E

    1988-10-01

    Differences in energy estimates between a food frequency questionnaire and a multi-day dietary record can be partitioned into distinct components due to differences in reported frequency of consumption and in reported serving size, and to differences in nutrient composition between the questionnaire standards and the foods reported on the records. The effect of each component on the relative validity of the questionnaire can be assessed by examining its contribution to the differences between the two methods in estimated group intake and in the relative ranking of individual respondents. This methodology was used for the 1984-1985 University of Michigan Food Frequency Study, in which the estimated energy intake from a quantitative food frequency questionnaire was compared with that from 16 days of food records collected over the course of a year from 228 white and black men and women aged 24-51 years. For all race-sex subgroups, mean energy intake estimated from the questionnaire was significantly greater than mean intake estimated from the record. Within race-sex subgroups, the correlations between estimates from the two methods were low, and agreement in classification by tertiles was poor. The differences in group mean energy intake between the methods were due to the effects of discrepancies in both serving size and frequency of consumption. However, the low correlations and poor agreement in classification for individual respondents were due principally to the effect of discrepancies in frequency. These results suggest that improving the accuracy of frequency estimation is a key element in increasing the relative validity of food frequency questionnaires used for epidemiologic research. PMID:3421241

  8. 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

    2014-07-01

    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. 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

  10. The Learning Activities Questionnaire: A Tool to Enhance Teaching

    ERIC Educational Resources Information Center

    Ager, Richard

    2012-01-01

    This article describes the Learning Activities Questionnaire (LAQ) and how it can be employed to evaluate learning tasks not typically examined in course evaluation instruments such as readings and assignments. Drawing from behavioral theory in its focus on specific activities, this instrument is simple to interpret and provides clear direction…

  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. Diet Measurement in Vietnamese Youth: Concurrent Reliability of a Self-Administered Food Frequency Questionnaire.

    ERIC Educational Resources Information Center

    Wiecha, John M.; And Others

    1994-01-01

    Vietnamese high school students completed a food frequency questionnaire (FFQ) and completed daily diet reports for seven weeks. Data from the FFQ were compared to the food reports. The results indicated a few simple FFQ items, particularly for indicator foods such as rice, were reliable for dietary assessment for that population. (SM)

  13. 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...

  14. Validity and reliability of activities coaching context questionnaire

    PubMed Central

    Koohpayehzadeh, Jalil; Haji Ahmadi, Maryam; Dehnad, Afsaneh; Soltani Arabshahi, Seyed kamran; Bigdeli, Shoaleh; Yadollahi, Sohrab

    2014-01-01

    Background: Learning in a clinical environment is an inseparable part of a training program in medical education. To evaluate the quality of training in a clinical environment, a comprehensive questionnaire which is adjusted for local purposes is essential. This study was conducted to determine the validity and reliability of Activities Coaching Context (ACC)-questionnaire from the perspective of residents and students in a clinical learning environment. Methods: This was a cross-sectional study conducted with 65 residents and students of Semnan University of Medical Sciences. The Content Validity of the questionnaire was confirmed by the judgment of a panel of ten experts in medical education. The construct validity of the questionnaire was determined by factor analysis. Data were collected and analyzed by SPSS16. Results: The ratio and index of content validity calculated by experts’ view were quite acceptable (0.31 and 0.7, respectively). Construct validity was examined by factor analysis which confirmed seven first order factors. Cronbach’s Alfa coefficient revealed a high degree of internal consistency (0.932). The reliability of the questionnaire was measured by test - retest (0.9). Conclusions: The ACC questionnaire appeared to be a valid, reliable and also appropriate tool to evaluate the educational quality of a clinical learning environment. PMID:25405107

  15. 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 results…

  16. 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...

  17. 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...

  18. 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...

  19. 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. PMID:25883059

  20. Assessment of consumption of marine food in Greenland by a food frequency questionnaire and biomarkers

    PubMed Central

    Jeppesen, Charlotte; Jørgensen, Marit Eika; Bjerregaard, Peter

    2012-01-01

    Objectives We studied the association and agreement between questionnaire data and biomarkers of marine food among Greenland Inuit. Design Cross sectional study. Methods The study population comprised 2,224 Inuit, age 18+ (43% men); data collected 2005–2008 in Greenland. Using a food frequency questionnaire (FFQ), we calculated consumption of seal, whale, and fish (g/day) and as meals/month, intake of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), total N3, and mercury. We measured erythrocyte membrane fatty acids (FA) and whole blood mercury (Hg). Associations were assessed by Pearson correlation and agreement between the 2 methods was assessed by Bland–Altman plots depicting mean difference between the methods. Using multiple linear regressions, the associations were studied between whole blood mercury, erythrocyte FA and frequency or gram per day of seal, whale, and fish. Results Partial correlations ranged from r=0.16, p<0.0001 (DHA) to r=0.56, p<0.0001 (mercury). The best fitted lines were found for mercury and DHA. Mean difference was negative for mercury but positive for all the FA biomarkers. In a multiple logistic regression analysis, the best association was found between whole blood mercury and seal consumption, both as frequency in meals and actual intake gram per day: β=1.07 µg (95% CI: 1.06; 1.08) and β=1.04 µg (95% CI: 1.03; 1.04), respectively. Conclusion Mercury showed the best correlation and agreement between calculated and measured values. Calculated actual intake in gram per day and frequency of meals showed similar associations with whole blood mercury and erythrocyte membrane FAs. PMID:22663940

  1. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--TIME AND ACTIVITY DIARY QUESTIONNAIRE DATA

    EPA Science Inventory

    The Time and Activity Diary Questionnaire data set provides information about the daily activities of the respondents during the sampling week. The information is from 260 Time and Activity Diary Questionnaires for 91 households. Supplemental pages were provided. The informati...

  2. 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

  3. 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. PMID:25361349

  4. 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...

  5. Assessment of Pre-Pregnancy Dietary Intake with a Food Frequency Questionnaire in Alberta Women

    PubMed Central

    Ramage, Stephanie M.; McCargar, Linda J.; Berglund, Casey; Harber, Vicki; Bell, Rhonda C.

    2015-01-01

    Purpose: Pre-pregnancy is an under-examined and potentially important time to optimize dietary intake to support fetal growth and development as well as maternal health. The purpose of the study was to determine the extent to which dietary intake reported by non-pregnant women is similar to pre-pregnancy dietary intake reported by pregnant women using the same assessment tool. Methods: The self-administered, semi-quantitative food frequency questionnaire (FFQ) was adapted from the Canadian version of the Diet History Questionnaire, originally developed by the National Cancer Institute in the United States. Pregnant women (n = 98) completed the FFQ which assessed dietary intake for the year prior to pregnancy. Non-pregnant women (n = 103) completed the same FFQ which assessed dietary intake for the previous year. Energy, macronutrients, and key micronutrients: long-chain omega-3 fatty acids, folate, vitamin B6, vitamin B12, calcium, vitamin D and iron were examined. Results: Dietary intake between groups; reported with the FFQ; was similar except for saturated fat; trans fat; calcium; and alcohol. Pregnant women reported significantly higher intakes of saturated fat; trans fat; and calcium and lower intake of alcohol in the year prior to pregnancy compared to non-pregnant women who reported intake in the previous year. Conclusions: Despite limitations; a FFQ may be used to assist with retrospective assessment of pre-pregnancy dietary intake. PMID:26225996

  6. [Development of Japanese versions of the Daydream Frequency Scale and the Mind Wandering Questionnaire].

    PubMed

    Kajimura, Shogo; Nomura, Michio

    2016-04-01

    This study developed and examined the validity of Japanese versions of the Daydream Frequency Scale (DDFS) and the Mind Wandering Questionnaire (MWQ), which measures propensity for spontaneous thoughts and mind wandering, respectively. In Study 1, we translated the items of the DDFS and the MWQ into Japanese and verified their validity. In Study 2, we confirmed the correlation of both scales with mind wandering, as measured by thought sampling during an attention-demanding task. These two studies revealed a dissociation between the properties of the scales; while DDFS reflects propensity for spontaneous thoughts, MWQ specifically reflects propensity for mind,wandering. We discuss the usefulness of the DDFS and the MWQ for studying the psychological functions of spontaneous thoughts and mind wandering. PMID:27180516

  7. Development and validation of a quantitative food frequency questionnaire to assess nutritional status in Korean adults

    PubMed Central

    Na, Youn Ju

    2012-01-01

    This study was performed to evaluate the validity of the food frequency questionnaire (FFQ), which is being used at the Samsung Medical Center. In total, 305 (190 males and 115 females) participants consented and completed the 3-day diet records and FFQ. Age, gender and energy-adjusted and de-attenuated correlations ranged from 0.317 (polyunsaturated fatty acid) to 0.748 (carbohydrate) with a median value of 0.550. The weighted kappa value ranged from 0.18 (vitamin A) to 0.57 (carbohydrate) with a median value of 0.36. More than 75% of the subjects were classified into the same or adjacent quartiles. The FFQ had reasonably good validity compared with that of another study. Therefore, our FFQ is considered a proper method to assess nutrient intake in healthy Korean adults. PMID:23198024

  8. 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. PMID:24462267

  9. 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

  10. 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...

  11. 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...

  12. 75 FR 61248 - Proposed Information Collection (Pension Claim Questionnaire for Farm Income) Activity: Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-04

    ... 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...

  13. 78 FR 24469 - Proposed Information Collection (Marital Status Questionnaire) Activity; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-25

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

  14. 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...

  15. 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,...

  16. 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

  17. 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. PMID:20230157

  18. Validation of a food frequency questionnaire for use in Italian adults living in Sicily.

    PubMed

    Buscemi, Silvio; Rosafio, Giuseppe; Vasto, Sonya; Massenti, Fatima Maria; Grosso, Giuseppe; Galvano, Fabio; Rini, Nadia; Barile, Anna Maria; Maniaci, Vincenza; Cosentino, Loretta; Verga, Salvatore

    2015-01-01

    The objective of this study was to validate two interviewer-led food frequency questionnaires (FFQs) of very different lengths: a medium-length FFQ (medium-FFQ) of 36 items and a short-length FFQ (short-FFQ) of 18 items, intending to measure levels of intakes in a local population. Both FFQs were validated against intakes derived from a 3-day dietary record (3-day DR). Sixty-five non-diabetic adults with no known cardiovascular, renal or other systemic diseases were included. High correlation coefficients between the FFQ and the 3-day DR (0.45-0.73) were observed for energy intake, carbohydrates and lipid and protein intake. Bland-Altman plots showed good agreement between the methods. Low (0.26-0.37) correlation coefficients of the different nutrient intakes obtained with the short-FFQ and the 3-day DR were observed, with the exception of alcohol intake (rho = 0.49). This study showed promising evidence for the use of a medium-FFQ as a potentially useful tool for investigating the relationship between habitual diet and diseases in clinical and research settings. PMID:25830946

  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. PMID:27555870

  20. 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

    2016-01-01

    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

  1. 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. PMID:24068225

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

    PubMed Central

    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. PMID:27555870

  3. Relative validity of dietary patterns during pregnancy assessed with a food frequency questionnaire.

    PubMed

    Loy, See-Ling; Jan Mohamed, Hamid Jan B

    2013-09-01

    This study aimed to assess the relative validity of maternal dietary patterns derived from a semi-quantitative food frequency questionnaire (FFQ). A total of 162 pregnant women aged 19-40-years-old were enrolled from the Universiti Sains Malaysia (USM) Birth Cohort Study in year 2010 and 2011. The FFQ was compared with three 24-h dietary recalls (DRs). Two major dietary patterns were derived from the principle component analysis which are labeled as Healthy and Less-Healthy patterns. The Pearson correlation coefficients between FFQ and DRs for Healthy and Less-Healthy patterns were 0.59 and 0.63, respectively. At least 45% of the participants were correctly classified into the same third from the FFQ and DR for both dietary patterns. The weighted kappa showed moderate agreement for Healthy pattern while good agreement for Less-Healthy pattern between these two dietary assessment methods. Our results indicate reasonable validity of the dietary patterns identified from the FFQ in pregnant women. PMID:23594439

  4. 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

  5. Carotenoid Intakes, Assessed by food frequency questionnaires are associated with serum carotenoid concentrations in the Jackson Heart Study: Validation of the Jackson Heart Study Delta NIRI Adult Food Frequency Questionnaire

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objectives: Intake and status of carotenoids have been associated with chronic disease. The objectives of this study were to examine the association between carotenoid intakes as measured by two regional food-frequency questionnaires (FFQs) and their corresponding measures in serum, and to report ...

  6. 78 FR 36643 - Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ... 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...

  7. 78 FR 36307 - Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ... 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...

  8. 78 FR 35098 - Proposed Information Collection (Hand and Finger Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... AFFAIRS Proposed Information Collection (Hand and Finger Disability Benefits Questionnaire) Activity... . Please refer to ``OMB Control No. 2900-NEW (Hand or Finger Disability Benefits Questionnaire)'' in any.... Title: Hand and Finger Disability Benefits Questionnaire, VA Form 21-0960M-7. OMB Control Number:...

  9. NHEXAS PHASE I REGION 5 STUDY--TIME-ACTIVITY DIARY QUESTIONNAIRE DATA (MONITORING PERIOD 1)

    EPA Science Inventory

    This data set includes responses for 249 time-activity diary questionnaires. The Time Diary and Activity Questionnaire was used for collecting data on detailed (daily) time and location information and activity patterns (for relatively frequent activities when recalling events ov...

  10. Assessment of Physical Activity by Applying IPAQ Questionnaire

    ERIC Educational Resources Information Center

    Biernat, Elzbieta; Stupnicki, Romuald; Lebiedzinski, Bartlomiej; Janczewska, Lidia

    2008-01-01

    Study aim: To assess the suitability of the short 7-day IPAQ (self-completed) adapted to Polish population. Material and methods: Two surveys were conducted in 2005 on 296 random subjects (aged 20-60 years) from Warsaw and the Mazowiecki region. From these, 54 men and 79 women were requested to fill questionnaires, and 70 men and 93 women, were…

  11. Calibration of a food frequency questionnaire developed for the South Asian community in the United Kingdom.

    PubMed

    Norimah, A; Margetts, B

    1997-03-01

    An interview administered food frequency questionnaire (FFQ) consisting of 75 food items was developed and calibrated against a four day weighed record (WR). The FFQ was also calibrated against a proxy for biomarker, the energy intake/basal metabolic rate ratio (EI/BMR). A total of 58 subjects (35 women, 23 men) aged between 19 and 76 years of Pakistani and Indian origin in Southampton, United Kingdom (UK) participated in this calibration study. The results for men and women combined together suggested reasonable agreement between FFQ and WR estimates of intake with Spearman rank correlation coefficient ranging between 0.26 and 0.38 (energy unadjusted). Gender specific agreement was however, poor. The percent mean difference between nutrient estimates by FFQ and WR was in general within 10% for energy, fat and protein in women while in the range of 11% to 25% in men. The percent mean difference for other nutrients such as sugar and dietary fibre ranged between 18% and 99% in men and women; while was 9% and 6% for starch in men and women respectively. The ranking of subjects into the thirds of distribution was poor with gross misclassification in the range of 5% to 14% in men and 15% to 29% in women. Comparison of both FFQ and WR with EI/BMR ratio showed that there were more underreporters of energy intake when reporting intake using WR than FFQ in both men and women. Based on these results, it was concluded that further development of the FFQ was needed before the FFQ could be used to evaluate the usual dietary intake in the South Asian population. PMID:22692234

  12. Relative validity and reliability of a quantitative food frequency questionnaire for adults in Guam

    PubMed Central

    Guerrero, Rachael T. Leon; Chong, Marie; Novotny, Rachel; Wilkens, Lynne R.; Badowski, Grazyna; Blas-Laguana, Michelle; Murphy, Suzanne

    2015-01-01

    Background Guam is a US territory in the western Pacific with a diverse population that includes understudied ethnic groups such as Chamorros and Filipinos. A food frequency questionnaire (FFQ) to estimate dietary intake was needed to facilitate studies of diet and health among adults living in Guam. Objective To develop and validate an FFQ to assess dietary intake over a 1-year period among adult Guam residents. Design A three-part study was conducted: 1) an initial cross-sectional study using 24-h recalls to identify a food and beverage list for the FFQ and resulting in a final FFQ containing 142 food and drink items; 2) to test reliability, 56 different individuals completed the FFQ twice; and 3) to test relative validity, self-administered FFQs and up to 2 days of food record data from an additional 109 individuals were collected, and daily nutrient intake from the two methods was compared. Results The reliability of the FFQ was very good (ρ range=0.65–0.75), and the relative validity of the FFQ was good for women (median Spearman's correlation [ρ] between instruments of 0.45 across 20 nutrients and an interquartile range [IQR] of 0.42–0.58) and generally adequate for men (median ρ=0.31, IQR=0.23–0.55). Validity was also good for Chamorros (median ρ=0.47, IQR=0.38–0.53) and generally adequate for Filipinos (median ρ=0.42, IQR=0.20–0.62). Correlations after energy adjustment were lower (overall median ρ=0.20, IQR=0.14–0.26). Conclusions The FFQ can be used to rank nutrient intake for adults in Guam and may be helpful in the analysis of relationships between diet and chronic disease in Guam. PMID:25947296

  13. 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

  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. 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

  16. Validity and calibration of Food Frequency Questionnaires used with African American adults in the Jackson Heart Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This paper details the calibration process and validity of two Food Frequency Questionnaires (FFQs) developed for use in investigating diet disease relationships existing within the African American population. A calibration design was used which included comparison of mean nutrient intakes from fo...

  17. 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…

  18. Eating patterns of children in the Delta: Developing a child food frequency questionnaire for this rural impoverished population

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The epidemic of obesity and health risks for children currently present challenges in estimating food intakes and developing appropriate interventions. Obtaining eating patterns is important. No child food frequency questionnaires (FFQs) are specific to the Delta. Food intake data collected previous...

  19. Development and validation of a food-frequency questionnaire to assess short-term antioxidant intake in athletes.

    PubMed

    Braakhuis, Andrea J; Hopkins, Will G; Lowe, Timothy E; Rush, Elaine C

    2011-04-01

    A quantitative food-frequency questionnaire (FFQ) was developed to determine antioxidant intake in athletes. The questionnaire will be valuable for researchers wishing to standardize antioxidant intake or simply document habitual intake during an intervention trial. One hundred thirteen athletes participated in the validity study, of whom 96 completed the questionnaire and blood test, 81 completed the 7-d food diary and questionnaire, and 63 completed the 7-d food diary and blood test. Validity was investigated by comparing total and food-group antioxidant intakes from the questionnaire with those from a subsequent 7-d food diary. Measures of construct validity were determined by comparing a biomarker of antioxidant capacity (ferric-reducing ability of plasma) in a blood sample with antioxidant intakes from the questionnaire and diary. The correlation between the diary and questionnaire energy-adjusted estimates of total antioxidant intake was modest (.38; 90% confidence limits, ± .14); the correlation was highest for antioxidants from cereals (.55; ± .11), which contributed the greatest proportion (31%) of the total antioxidant intake. Correlations were also high for coffee and tea (.51; ± .15) and moderate for vegetables (.34; ± .16) and fruit (.31; ± .16). The correlation of the plasma biomarker with the questionnaire estimate was small (.28; ± .15), but the correlation with the diary estimate was inconsequential (-.03; ± .15). One-week test-retest reliability of the questionnaire's estimates of antioxidant intake in 20 participants was high (.83; ± .16). In conclusion, the FFQ is less labor intensive for participants and researchers than a 7-d diary and appears to be at least as trustworthy for estimating antioxidant intake. PMID:21558572

  20. Online Dietary Intake Estimation: The Food4Me Food Frequency Questionnaire

    PubMed Central

    Forster, Hannah; Fallaize, Rosalind; Gallagher, Caroline; O’Donovan, Clare B; Woolhead, Clara; Walsh, Marianne C; Macready, Anna L; Lovegrove, Julie A; Mathers, John C; Gibney, Michael J; Brennan, Lorraine

    2014-01-01

    Background Dietary assessment methods are important tools for nutrition research. Online dietary assessment tools have the potential to become invaluable methods of assessing dietary intake because, compared with traditional methods, they have many advantages including the automatic storage of input data and the immediate generation of nutritional outputs. Objective The aim of this study was to develop an online food frequency questionnaire (FFQ) for dietary data collection in the “Food4Me” study and to compare this with the validated European Prospective Investigation of Cancer (EPIC) Norfolk printed FFQ. Methods The Food4Me FFQ used in this analysis was developed to consist of 157 food items. Standardized color photographs were incorporated in the development of the Food4Me FFQ to facilitate accurate quantification of the portion size of each food item. Participants were recruited in two centers (Dublin, Ireland and Reading, United Kingdom) and each received the online Food4Me FFQ and the printed EPIC-Norfolk FFQ in random order. Participants completed the Food4Me FFQ online and, for most food items, participants were requested to choose their usual serving size among seven possibilities from a range of portion size pictures. The level of agreement between the two methods was evaluated for both nutrient and food group intakes using the Bland and Altman method and classification into quartiles of daily intake. Correlations were calculated for nutrient and food group intakes. Results A total of 113 participants were recruited with a mean age of 30 (SD 10) years (40.7% male, 46/113; 59.3%, 67/113 female). Cross-classification into exact plus adjacent quartiles ranged from 77% to 97% at the nutrient level and 77% to 99% at the food group level. Agreement at the nutrient level was highest for alcohol (97%) and lowest for percent energy from polyunsaturated fatty acids (77%). Crude unadjusted correlations for nutrients ranged between .43 and .86. Agreement at the

  1. Reproducibility and Relative Validity of a Food Frequency Questionnaire Developed for Adults in Taizhou, China

    PubMed Central

    Zhuang, Maoqiang; Yuan, Ziyu; Lin, Lanfang; Hu, Bin; Wang, Xiaofeng; Yang, Yajun; Chen, Xingdong; Jin, Li; Lu, Ming; Ye, Weimin

    2012-01-01

    Objective To evaluate the reproducibility and validity of a food frequency questionnaire (FFQ) developed to investigate the relationship between dietary factors and diseases in the adult Chinese population in East China. Methods A total of 78 males and 129 females aged 30–75 years completed four inconsecutive 24-hour dietary recalls (24-HRs, served as a reference method) and two FFQs (FFQ1 and FFQ2) over a nine-month interval. The reproducibility of the FFQ was estimated with correlation coefficients, cross-classification, and weighted kappa statistic. The validity was assessed by comparing the data obtained from FFQ and 24-HRs. Results The median nutrient intakes assessed with FFQs were higher than the average of four 24-HRs. For the food groups, Spearman, Pearson, and intraclass correlation coefficients between FFQ1 and FFQ2 ranged from 0.23 to 0.61, 0.27 to 0.64, and 0.26 to 0.65, respectively. For total energy and nutrient intakes, the corresponding coefficients ranged from 0.25 to 0.61, 0.28 to 0.64, and 0.28 to 0.62, respectively. The correlations between FFQ1 and FFQ2 for most nutrients decreased after adjustment with total energy intake. More than 70% of the subjects were classified into the same and adjacent categories by both FFQs. For food groups, the crude, energy-adjusted, and de-attenuated Spearman correlation coefficients between FFQ2 and the 24-HRs ranged from 0.17 to 0.59, 0.10 to 0.57, and 0.11 to 0.64, respectively. For total energy and nutrient intakes, the corresponding coefficients ranged from 0.20 to 0.58, 0.08 to 0.54, and 0.09 to 0.56, respectively. More than 67% of the subjects were classified into the same and adjacent categories by both instruments. Both weighted kappa statistic and Bland-Altman Plots showed reasonably acceptable agreement between the FFQ2 and 24-HRs. Conclusion The FFQ developed for adults in the Taizhou area is reasonably reliable and valid for assessment of most food and nutrient intakes. PMID:23139777

  2. Relative validity of a food frequency questionnaire with a meat-cooking and heterocyclic amine module.

    PubMed

    Cantwell, Marie; Mittl, Beth; Curtin, Jane; Carroll, Ray; Potischman, Nancy; Caporaso, Neil; Sinha, Rashmi

    2004-02-01

    The nutrient and heterocyclic amine (HCA) intake of 165 healthy participants was assessed using a self-administered food frequency questionnaire (FFQ), which included a meat-cooking practices module. A database containing the HCA [2-amino-3,8-dimethylimadazo [4,5-f] quinoxaline (MeIQx) and 2-amino-1-methyl-6-phenylimadazo [4,5-b] pyridine (PhIP)] composition of various types of meat, cooked by different methods and to varying degrees, was developed and validated in conjunction with this module. The relative validity of dietary and HCA intake estimated by the FFQ was investigated using multiple food diaries (3 sets of 4 nonconsecutive day diaries completed over a 3-month period) as the reference method. Crude correlation coefficients of HCA intake assessed by the FFQ and food diaries were 0.43 [95% confidence interval (CI) 0.30-0.55] for MeIQx and 0.22 (95% CI 0.07-0.36) for PhIP intake. Deattenuated correlations were 0.60 (95% CI 0.49-0.69) and 0.36 (95% CI 0.22-0.49), respectively. Absolute MeIQx and PhIP intake was, however, underestimated by the FFQ (21.9 and 78.1 ng/day) compared with the food diaries (34.9 and 263.8 ng/day). The FFQ underestimated total red meat intake, the percentage of consumers, and the median intake of roast/baked and microwaved red meat. PhIP intake was severely underestimated by the FFQ and was most likely because of an underestimation of the percentage of people who cooked chicken using PhIP-producing cooking methods such as broiling and pan-frying. Additionally, the FFQ overestimated the percentage of consumers of baked chicken, a cooking method that produces less PhIP. In conclusion, although the FFQ and meat module underestimated absolute MeIQx and PhIP intake, its ability to rank individuals according to intake was acceptable. PMID:14973110

  3. 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.

  4. Correlation between pedometer and the Global Physical Activity Questionnaire on physical activity measurement in office workers

    PubMed Central

    2014-01-01

    Background This study aimed to examine the correlation of physical activity levels assessed by pedometer and those by the Global Physical Activity Questionnaire (GPAQ) in a population of office workers. Methods A cross-sectional study was conducted on 320 office workers. A self-administered questionnaire was distributed to each office worker by hand. Physical activity level was objectively assessed by a pedometer for 7 consecutive days and subjectively assessed by the GPAQ. Based on the pedometer and GPAQ outcomes, participants were classified into 3 groups: inactive, moderately active, and highly active. Results No correlation in the physical activity level assessed by the pedometer and GPAQ was found (rs = .08, P = 0.15). When considering the pedometer as the criterion for comparison, 65.3% of participants had underestimated their physical activity level using the GPAQ, whereas 9.3% of participants overestimated their physical activity level. Conclusions Physical activity level in office workers assessed by a subjective measure was greatly different from assessed by an objective tool. Consequently, research on physical activity level, especially in those with sedentary lifestyle, should consider using an objective measure to ensure that it closely reflects a person’s physical activity level. PMID:24886593

  5. 75 FR 77957 - Agency Information Collection (Pension Claim Questionnaire for Farm Income) Activity Under OMB...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-14

    ... 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... INFORMATION: Title: Pension Claim Questionnaire for Farm Income, VA Form 21- 4165. OMB Control Number:...

  6. 76 FR 27386 - Proposed Information Collection (Employment Questionnaire) Activity; Comment Request

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  7. 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....

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    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...

  10. 75 FR 26346 - Agency Information Collection (Marital Status Questionnaire) Activity Under OMB Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-11

    ... 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...

  11. 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...

  12. 78 FR 9108 - Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-07

    ... AFFAIRS Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire) Activity... new research protocol in the VA. DATES: Written comments and recommendations on the proposed... refer to ``OMB Control No. 2900-NEW (Conduct the Point-of-Care Research Questionnaire)'' in...

  13. 78 FR 44624 - Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire); Activities...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... Research (POC-R). POC-R is an intermediary approach to bridge the gap between clinical trials and... AFFAIRS [OMB Control No. 2900-NEW (Conduct the Point-of-Care Research Questionnaire)] Proposed Information Collection (Conduct the Point-of-Care Research Questionnaire); Activities Under OMB Review AGENCY:...

  14. Active laser ranging with frequency transfer using frequency comb

    NASA Astrophysics Data System (ADS)

    Zhang, Hongyuan; Wei, Haoyun; Yang, Honglei; Li, Yan

    2016-05-01

    A comb-based active laser ranging scheme is proposed for enhanced distance resolution and a common time standard for the entire system. Three frequency combs with different repetition rates are used as light sources at the two ends where the distance is measured. Pulse positions are determined through asynchronous optical sampling and type II second harmonic generation. Results show that the system achieves a maximum residual of 379.6 nm and a standard deviation of 92.9 nm with 2000 averages over 23.6 m. Moreover, as for the frequency transfer, an atom clock and an adjustable signal generator, synchronized to the atom clock, are used as time standards for the two ends to appraise the frequency deviation introduced by the proposed system. The system achieves a residual fractional deviation of 1.3 × 10-16 for 1 s, allowing precise frequency transfer between the two clocks at the two ends.

  15. “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

  16. 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

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

    PubMed

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

    2015-12-01

    [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

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

    PubMed

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

    2015-10-01

    [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

  19. 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…

  20. 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

  1. Reliability of the modified child and adolescent physical activity and nutrition survey, physical activity (CAPANS-PA) questionnaire among chinese-australian youth

    PubMed Central

    2011-01-01

    Background Evidence suggests that differences exist in physical activity (PA) participation among Culturally and Linguistically Diverse (CALD) children and adolescents. It is possible that these differences could be influenced by variations in measurement technique and instrument reliability. However, culturally sensitive instruments for examining PA behaviour among CALD populations are lacking. This study tested the reliability of the Child and Adolescent Physical Activity and Nutrition Survey (CAPANS-PA) recall questionnaire among a sample of Chinese-Australian youth. Methods The psychometric property of the CAPANS-PA questionnaire was examined among a sample of 77 Chinese-Australian youth (aged 11 - 14 y) who completed the questionnaire twice within 7 days. Test-retest reliability of individual items and scales within the CAPANS-PA questionnaire was determined using Kappa statistics for categorical variables and intraclass correlation coefficients (ICC) for continuous variables. Results The CAPANS-PA questionnaire demonstrated acceptable test-retest reliability for frequency and duration of time spent in weekly Moderate to Vigorous Physical Activity (MVPA) (ICC ≥ 0.70) for all participants. Test-retest reliability for time spent in weekly sedentary activities was acceptable for females (ICC = 0.82) and males (ICC = 0.72). Conclusions The results suggest the CAPANS-PA questionnaire provides reliable estimates for type, frequency and duration of MVPA participation among Chinese-Australian youth. Further investigation into the reliability of the sedentary items within the CAPANS-PA is required before these items can be used with confidence. This study is novel in that the reliability of instruments among CALD groups nationally and internationally remains sparse and this study contributes to the wider body of available psychometrically tested instruments. In addition, this study is the first to our knowledge to successfully engage and investigate the basic health

  2. 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.

  3. 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…

  4. 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...

  5. NHEXAS PHASE I REGION 5 STUDY--TIME-ACTIVITY DIARY QUESTIONNAIRE DATA (ALL MONITORING PERIODS)

    EPA Science Inventory

    This data set includes responses for 249 participants with a total of 428 time-activity diaries. Some participants were studied for more than one monitoring period. The Time Diary and Activity Questionnaire was used for collecting data on detailed (daily) time and location inform...

  6. 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…

  7. 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

  8. Internet Use Frequency and Patient-Centered Care: Measuring Patient Preferences for Participation Using the Health Information Wants Questionnaire

    PubMed Central

    Wang, Mo; Feldman, Robert; Zhou, Le

    2013-01-01

    Background The Internet is bringing fundamental changes to medical practice through improved access to health information and participation in decision making. However, patient preferences for participation in health care vary greatly. Promoting patient-centered health care requires an understanding of the relationship between Internet use and a broader range of preferences for participation than previously measured. Objective To explore (1) whether there is a significant relationship between Internet use frequency and patients’ overall preferences for obtaining health information and decision-making autonomy, and (2) whether the relationships between Internet use frequency and information and decision-making preferences differ with respect to different aspects of health conditions. Methods The Health Information Wants Questionnaire (HIWQ) was administered to gather data about patients’ preferences for the (1) amount of information desired about different aspects of a health condition, and (2) level of decision-making autonomy desired across those same aspects. Results The study sample included 438 individuals: 226 undergraduates (mean age 20; SD 2.15) and 212 community-dwelling older adults (mean age 72; SD 9.00). A significant difference was found between the younger and older age groups’ Internet use frequencies, with the younger age group having significantly more frequent Internet use than the older age group (younger age group mean 5.98, SD 0.33; older age group mean 3.50, SD 2.00; t 436=17.42, P<.01). Internet use frequency was positively related to the overall preference rating (γ=.15, P<.05), suggesting that frequent Internet users preferred significantly more information and decision making than infrequent Internet users. The relationships between Internet use frequency and different types of preferences varied: compared with infrequent Internet users, frequent Internet users preferred more information but less decision making for diagnosis (γ=.57

  9. 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

    2015-08-01

    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

  10. 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

  11. 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…

  12. Pedometer-Determined Physical Activity and Its Comparison with the International Physical Activity Questionnaire in a Sample of Belgian Adults

    ERIC Educational Resources Information Center

    De Cocker, Katrien; Cardon, Greet; De Bourdeaudhuij, Ilse

    2007-01-01

    Pedometer-determined physical activity (PA) levels in Belgian adults were provided and compared to PA scores reported in the International Physical Activity Questionnaire (IPAQ). The representative sample (N = 1,239) of the Belgian population took on average 9,655 (4,526) steps/day. According to pedometer indices 58.4% were insufficiently active.…

  13. 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,…

  14. Validity and Reliability of the International Physical Activity Questionnaire in College Students

    ERIC Educational Resources Information Center

    Dinger, Mary K.; Behrens, Timothy K.; Han, Jennifer L.

    2006-01-01

    The purpose of this study was to examine the validity and reliability of the self-administered International Physical Activity Questionnaire (IPAQ) short form in college students. One hundred twenty-three undergraduate students (20.8 [plus or minus] 1.5 years of age, 76% Caucasian, 74% female) wore an accelerometer and pedometer at their waists…

  15. 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

  16. 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.

  17. 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

  18. 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

  19. Development of a semi-quantitative food frequency questionnaire for dietary studies--focus on vitamin C intake.

    PubMed

    Ngoan, Le Tran; Khan, Nguyen Cong; Mai, Le Bach; Huong, Nguyen Thi Thanh; Thu, Nguyen Thi; Lua, Nguyen Thi; Hang, Lai Thi Minh; Bich, Nguyen Ngoc; Hieu, Nguyen Van; Quyet, Ha Van; Tai, Le Thi; Van, Do Duc; Moore, Malcolm A; Tokudome, Shinkane; Yoshimura, Takesumi

    2008-01-01

    The present work aimed to provide a basis for examination of intake of selected food items determined with a semi-quantitative food frequency questionnaire (SQFFQ) and planned-food selection (PFS). From February to July of 2003, ninety one cancer patients and 90 matched (same sex and age within 5 years) non-cancer patients were directly interviewed by trained interviewers using the designed questionnaire at the inpatient-department of Viet Duc hospital, Ha Noi City, Viet Nam. Study subjects consumed more SQFFQ-food items than PFS-food items, so that the latter method might not accurately reflect dietary habits regarding estimation of nutrient intake, especially vitamins. Because these are beneficial factors acting against cancer development at many sites, the absence of food items selected by SQFFQ may result in a poor database regarding possible confounding factors. For futher clarification we then focused on vitamin C contributions of Vietnamese food and analyzed data of the National Nutritional Household Survey in 2000: 7,686 households throughout the country (vitamin C intake status) and 158 households with 741 persons of the population of Hanoi city (individual food items contributing to vitamin C). Direct interview using a validated questionnaire with an album of current Vietnamese food items-recipes and weighing checks was conducted to obtain information regarding all types of food intake over the last 24-hours. Contribution analysis using the Nutritive Composition Table of Vietnamese Foods, revision 2000, and stepwise regression analysis was applied. Average intake adjusted by ages of vitamin C per person per day was estimated. In total, the study subjects were found to currently consume 184 food items. Average intake of vitamin C was 72.5 mg per person per day at the national level: 57.9% from leafy vegetables, 33.4% from fresh fruits, and 6.4% from non-leafy vegetables. For vitamin C contribution, the highest 25 food items contributed to a cumulative 95

  20. Validity of two brief physical activity questionnaires with accelerometers among African-American women

    PubMed Central

    Joseph, Rodney P.; Keller, Colleen; Adams, Marc A.; Ainsworth, Barbara E.

    2015-01-01

    Aim To evaluate the validity of the Stanford Brief Activity Survey (SBAS) and Exercise Vital Sign (EVS) questionnaire against accelerometer-determined time in moderate-to-vigorous physical activity (MVPA) among African-American (AA) women. Background Limited research has evaluated the validity of brief physical activity (PA) questionnaires among AA women. Since the validity of PA questionnaires may differ among members of varying racial/ethnic groups, research is needed to explore the validity of self-report PA measures among AA women. Methods A total of 30 AA women [M age = 35.5 ± 5.3; M body mass index (BMI) = 31.1 ± 7.8] wore ActiGraph GT3X + accelerometers (ActiGraph, LLC, Pensacola FL, USA) for seven days and completed both the SBAS and EVS at two different assessment periods (T1 and T2). Criterion validity was calculated using Spearman's rank order correlations between each questionnaire score and accelerometer-measured MVPA. Sensitivity, specificity, and positive and negative predictive values were calculated using accelerometer-measured MVPA as the criterion to determine the ability of each questionnaire to predict whether or not a participant was meeting the 2008 US PA Guidelines Findings Spearman correlation coefficients between questionnaire scores and minutes of accelerometer-measured MVPA were low (EVS, r = 0.27 at T1 and r = 0.26 at T2; SBAS, r = 0.10 at T1 and r = 0.28 at T2) and not statistically significant (P's > 0.05). The EVS had sensitivity, specificity, and negative and positive predictive values of 27, 89, 59, and 68% at T1 and 33, 74, 38, and 70% at T2, respectively. The SBAS had sensitivity, specificity, and negative and positive predictive values were 18, 79, 33, and 62% at T1 and 67, 58, 43, and 79% at T2. While both questionnaires may be useful in identifying AA women who do not meet the 2008 PA Guidelines, using the questionnaires to identify AA women meeting the PA Guidelines should be done with caution. PMID:26178779

  1. 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…

  2. Assessing the Validity of a Physical Activity Questionnaire Developed for Parents of Preschool Children in Mexico

    PubMed Central

    Bacardi-Gascón, Montserrat; Reveles-Rojas, Claudia; Woodward-Lopez, Gail; Crawford, Patricia

    2012-01-01

    To assess the validity of a questionnaire developed for parents of preschool children to know their physical activity (PA) status, we compared the questionnaire results with the measures of accelerometer for children's activities. Thirty-five preschoolers who wore the accelerometer for at least 10 hours daily on 3 weekdays and one weekend day were included in the analyses. Time spent in activities of varied intensity was calculated by applying 15-second ActiGraph count cutoffs (ACC). Parents’ perceptions of their children's PA were associated with the percentage of vigorous and moderate physical activity recorded with ACC at r=0.62 (p=0.0001). An association was shown between the percentage of a child's time spent in vigorous physical activity, as reported by parents, with that measured by ACC at r=0.53 (p=0.001). Results of this study suggest that the designed questionnaire might be a useful tool for assessing children's activity while, additionally, it warrants further investigation on larger samples of children. PMID:23304910

  3. Use of a food frequency questionnaire to assess diets of Jamaican adults: validation and correlation with biomarkers

    PubMed Central

    2011-01-01

    Background Assessment of habitual diet is important in investigations of diet-disease relationships. Many epidemiological studies use the food frequency questionnaire (FFQ) to evaluate dietary intakes but few studies validate the instrument against biological markers. The aim of this study was to assess the validity and reproducibility of a previously validated 70-item food frequency questionnaire (FFQ) that was expanded to 120-items to assess diet - cancer relations. Methods Relative validity of the FFQ was assessed against twelve 24-hour recalls administered over 12 months in 70 subjects. The FFQ was repeated after one year (FFQ2) to assess reproducibility. The validity of the FFQ was evaluated by comparing nutrient and food group intakes from 24-hour recalls with the first and second FFQ. In addition, FFQ validity for cholesterol and folate were determined through correlation with biomarkers (serum cholesterol, serum folate and whole blood folate) in 159 control subjects participating in a case-control prostate cancer study. Results Compared to recalls the FFQ tended to overestimate energy and carbohydrate intakes but gave no differences in intake for protein and fat. Quartile agreement for energy-adjusted nutrient intakes between FFQ2 and recalls ranged from 31.8% - 77.3% for the lowest quartile and 20.8% - 81.0% in the highest quartile. Gross misclassification of nutrients was low with the exceptions of protein, vitamin E and retinol and weighted kappa values ranged from 0.33 to 0.64 for other nutrients. Validity correlations for energy-adjusted nutrients (excluding retinol) were moderate to high (0.38- 0.86). Correlation coefficients between multiple recalls and FFQ1 ranged from 0.27 (fruits) to 0.55 (red meat); the second FFQ gave somewhat higher coefficients (0.30 to 0.61). Reproducibility correlations for the nutrients ranged from 0.50 to 0.84. Calibration of the FFQ with biochemical markers showed modest correlations with serum cholesterol (0.24), serum

  4. Intakes of culinary herbs and spices from a food frequency questionnaire evaluated against 28-days estimated records

    PubMed Central

    2011-01-01

    Background Worldwide, herbs and spices are much used food flavourings. However, little data exist regarding actual dietary intake of culinary herbs and spices. We developed a food frequency questionnaire (FFQ) for the assessment of habitual diet the preceding year, with focus on phytochemical rich food, including herbs and spices. The aim of the present study was to evaluate the intakes of herbs and spices from the FFQ with estimates of intake from another dietary assessment method. Thus we compared the intake estimates from the FFQ with 28 days of estimated records of herb and spice consumption as a reference method. Methods The evaluation study was conducted among 146 free living adults, who filled in the FFQ and 2-4 weeks later carried out 28 days recording of herb and spice consumption. The FFQ included a section with questions about 27 individual culinary herbs and spices, while the records were open ended records for recording of herbs and spice consumption exclusively. Results Our study showed that the FFQ obtained slightly higher estimates of total intake of herbs and spices than the total intake assessed by the Herbs and Spice Records (HSR). The correlation between the two assessment methods with regard to total intake was good (r = 0.5), and the cross-classification suggests that the FFQ may be used to classify subjects according to total herb and spice intake. For the 8 most frequently consumed individual herbs and spices, the FFQ obtained good estimates of median frequency of intake for 2 herbs/spices, while good estimates of portion sizes were obtained for 4 out of 8 herbs/spices. Conclusions Our results suggested that the FFQ was able to give good estimates of frequency of intake and portion sizes on group level for several of the most frequently used herbs and spices. The FFQ was only able to fairly rank subjects according to frequency of intake of the 8 most frequently consumed herbs and spices. Other studies are warranted to further explore the

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

    PubMed

    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

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

    PubMed

    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

  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. Validity and reliability of a dish-based, semi-quantitative food frequency questionnaire for Korean diet and cancer research.

    PubMed

    Park, Min Kyung; Noh, Hwa Young; Song, Na Yeun; Paik, Hee Young; Park, Sohee; Joung, Hyojee; Song, Won O; Kim, Jeongseon

    2012-01-01

    This study evaluated the validity and reliability of applying a newly developed dish-based, semi-quantitative food frequency questionnaire (FFQ) for Korean diet and cancer research. The subjects in the present study were 288 Korean adults over 30 years of age who had completed two FFQs and four 3-day diet records (DRs) from May 2008 to February 2009. Student's t-tests, Chi-square tests, and Spearman's rank correlation coefficients were used to estimate and compare intakes from different dietary assessment tools. Agreement in quintiles was calculated to validate agreement between the results of the second FFQ (FFQ-2) conducted in February 2009 and the DRs. Median Spearman's correlation coefficients between the intake of nutrients and foods assessed by the FFQ-1 and FFQ-2 were 0.59 and 0.57, respectively, and the coefficients between the intake of nutrients and foods assessed by the FFQ-2 and the DRs were 0.31 and 0.29, respectively. The quintile classifications of same or adjacent quintile for intake of nutrients and foods were 64% and 65%, respectively. Misclassification into opposite quintiles occurred in less than 5% for all dietary factors. Thus this newly-developed, Korean dish-based FFQ demonstrated moderate correspondence with the four 3-day DRs. Its reliability and validity are comparable to those reported in other studies. PMID:22524822

  9. 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

  10. 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. PMID:26910251

  11. A Food Frequency Questionnaire for the Assessment of Calcium, Vitamin D and Vitamin K: A Pilot Validation Study

    PubMed Central

    Pritchard, Janet M.; Seechurn, Tinasha; Atkinson, Stephanie A.

    2010-01-01

    The study objective was to validate a food frequency questionnaire (FFQ) to assess calcium, vitamin D and vitamin K intakes in overweight and obese postmenopausal community-dwelling women. The FFQ was validated against intakes derived from a 5-day diet record (5DDR) that also included assessment of supplement intake. Strong correlations between methods were observed for all nutrients (r = 0.63, 0.89, 0.54 for calcium, vitamin D and vitamin K, respectively) and cross-classification analyses demonstrated no major misclassification of participants into intake quartiles. Bland-Altman analysis showed that the FFQ overestimated intakes for calcium, by 576 mg/day (95% CI, −668 to 1,821 mg/day), for vitamin D by 75 IU/day (95% CI, −359 to 510 IU/day), and forvitamin K by 167 mcg/day (95% CI, −233 to 568 mcg/day). This pilot study showed promising validation evidence for the use of this FFQ, which focuses on calcium, vitamin D and vitamin K intakes in postmenopausal women, as a screening tool in clinicaland research settings. PMID:22254057

  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. 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 ±…

  14. 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

  15. 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

  16. Validation of a Food Frequency Questionnaire for Calcium and Vitamin D Intake in Adolescent Girls with Anorexia Nervosa

    PubMed Central

    Taylor, Catherine; Lamparello, Brooke; Kruczek, Kimberly; Anderson, Ellen J.; Hubbard, Jane; Misra, Madhusmita

    2009-01-01

    Background Assessing calcium and vitamin D intake becomes important in conditions associated with low bone density such as anorexia nervosa (AN). Food records (FR) that assess intake over a representative time period are used in research and sometimes clinical settings. However, compliance in adolescents can be suboptimal. Objectives This study was undertaken to determine the validity of a food frequency questionnaire (FFQ) for assessing calcium and vitamin D intake in adolescent AN and healthy girls compared to a validated FR assessing intake over a four-day period, the hypothesis being that intake would be adequately predicted by the FFQ. Design Thirty-six girls with AN and 39 healthy girls 12–18 years old completed both the FR and the FFQ. An additional 31 subjects (20 AN, 11 controls) completed the FFQ, but not the FR, and one AN girl completed the FR, but not the FFQ. Results Subjects demonstrated greater compliance with the FFQ (99%) than the FR (71%). Daily calcium and vitamin D intake calculated using the FR and FFQ did not differ, although the FFQ tended to under-report vitamin D intake corrected for energy intake. Using quartile analysis, no gross misclassification was noted of calcium or vitamin D intake calculated using the FR or FFQ in AN. Strong correlations were observed of daily vitamin D intake derived from the FFQ versus the FR, particularly in AN (r=0.78, p<0.0001). Less robust correlations were observed for calcium intake (r=0.65, p<0.0001). Conclusion The FFQ used in this study can be effectively used to assess daily calcium and vitamin D intake in adolescent girls suffering from AN PMID:19248866

  17. Using exploratory factor analysis of food frequency questionnaires to identify dietary patterns among Yup’ik People

    PubMed Central

    Ryman, Tove K.; Austin, Melissa A.; Hopkins, Scarlett; Philip, Jacques; O’Brien, Diane; Thummel, Kenneth; Boyer, Bert B.

    2012-01-01

    Objective A food frequency questionnaire (FFQ) developed by the Center for Alaska Native Health Research for studies in Yup’ik people includes market foods and subsistence foods such as moose, seal, waterfowl and salmon that may be related to disease risk. Because the FFQ contains >100 food items, we sought to characterize dietary patterns more simply for use in ongoing pharmacogenomics studies. Design Exploratory factor analysis was used to derive a small number of “factors” that explain a substantial amount of the variation in the Yup’ik diet. We estimated factor scores and measured associations with demographic characteristics and biomarkers. Setting Southwest Alaska, US Subjects 358 Yup’ik people, ≥ 18 years Results We identified 3 factors that each accounted for ≥10% of the common variance: the first characterized by “processed foods” (e.g., salty snacks, sweetened cereals); the second by “fruits and vegetables” (e.g., fresh citrus, potato salad); and the third by “subsistence foods” (seal or walrus soup, non-oily fish). Participants from coastal communities had higher values for the “subsistence” factor, whereas participants from inland communities had higher values for the “fruits and vegetables” factor. A biomarker of marine intake, δ 15N, was correlated with the “subsistence” factor, whereas a biomarker of corn and sugar-cane based market food intake, δ 13C, was correlated with “processed foods”. Conclusions This exploratory factor analysis identified 3 factors that appear to reflect dietary patterns among Yup’ik based on associations with participant characteristics and biomarkers. These factors will be useful for chronic disease studies in this population. PMID:23290469

  18. 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

  19. 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

  20. Sources of macro- and micronutrients in Italian women: results from a food frequency questionnaire for cancer studies.

    PubMed

    Favero, A; Salvini, S; Russo, A; Parpinel, M; Negri, E; Decarli, A; La Vecchia, C; Giacosa, A; Franceschi, S

    1997-06-01

    The knowledge of major sources of macro- and micronutrients is essential in order to interpret differences in the diet-cancer link in various geographical areas and to provide better nutritional guidelines. For this purpose we took advantage of the control group of a case-control study on breast cancer carried out in six Italian areas. The dietary habits of 2,588 cancer-free women aged 20-74 years (median age 56) were elicited between 1991 and 1994 by means of an interviewer-administered food frequency questionnaire (FFQ) that included 78 foods or food groups, in addition to several questions on general dietary pattern (e.g., fat in seasoning). Bread was the first contributor for total energy (12%), protein (8%) and starch (32%) intake, whereas, for saturated fatty acid, the first sources were different types of cheese (28%); for monounsaturated fatty acids the dressing oils of salad and tomatoes (12%); and, for sugars, apples and pears (19%). Raw vegetables and fresh fruit represented the most important source of most vitamins. The first contributors of vitamin C and beta-carotene were citrus fruits (29%) and raw carrots (17%), respectively. Thus, between 40 and 80% of specific macronutrient intake and up to 90% intake of several micronutrients were derived from the first ten foods or food groups. Often, the major contributors to the intake of a specific component were foods with a relatively low content, but eaten in large quantities. This work further highlights the specificity of nutrient sources in southern European populations. PMID:9306075

  1. VALIDATION OF THREE FOOD FREQUENCY QUESTIONNAIRES AND 24-HOUR RECALLS WITH SERUM CAROTENOID LEVELS IN A SAMPLE OF AFRICAN-AMERICAN ADULTS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The validity of self-reported fruit and vegetable intake in minority populations has not been adequately established. In this study, the authors examined the association of three food frequency questionnaires (FFQs) and 24-hour dietary recalls with serum carotenoid levels. Approximately 1,000 Africa...

  2. A 7-ITEM VERSUS A 31-ITEM FOOD FREQUENCY QUESTIONNAIRE FOR MEASURING FRUIT, JUICE AND VEGETABLE INTAKE AMONG A PREDOMINANTLY AFRICAN AMERICAN POPULATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study sought to determine which of 2 fruit and vegetable food frequency questionnaires (FFQs) most closely approximated intake measured by the average of four 24-hour dietary recalls. Participants completed either a 31-item FFQ (n = 70) or 7-item FFQ (n = 76) on 2 occasions approximately 2 week...

  3. 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 ...

  4. 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

  5. 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...

  6. The Bahasa Melayu version of the Global Physical Activity Questionnaire: reliability and validity study in Malaysia.

    PubMed

    Soo, K L; Wan Abdul Manan, W M; Wan Suriati, W N

    2015-03-01

    This study aimed to assess the reliability and concurrent validity of the Bahasa Melayu version of the Global Physical Activity Questionnaire (GPAQ-M) by comparing it with the short form of the International Physical Activity Questionnaire (IPAQ-S) and objectively measuring physical activity using a Yamax DigiWalker (Yamax, Tokyo, Japan) pedometer. A total of 100 adults aged between 20 and 58 years from Kelantan in Malaysia voluntarily participated in this study. The Wilcoxon signed-rank analysis showed no significant differences in 2-week test-retest scores for total metabolic equivalent∙minutes∙per week and 4 domains of the GPAQ-M. There was a low but significant relationship between time spent on total physical activity measured by the GPAQ-M and average steps per day recorded using the pedometer (r s = .265, P = .013). Significant correlations were also found between GPAQ-M and the IPAQ-S for varying levels of intensity during physical activities (r s = .309-.466, P < .01). PMID:22234832

  7. A Validation Study of the Web-Based Physical Activity Questionnaire Active-Q Against the GENEA Accelerometer

    PubMed Central

    Bergman, Patrick; Trolle Lagerros, Ylva; Sjölander, Arvid; Bälter, Katarina

    2015-01-01

    Background Valid physical activity assessment in epidemiological studies is essential to study associations with various health outcomes. Objective To validate the Web-based physical activity questionnaire Active-Q by comparing results of time spent at different physical activity levels with results from the GENEA accelerometer and to assess the reproducibility of Active-Q by comparing two admissions of the questionnaire. Methods A total of 148 men (aged 33 to 86 years) responded to Active-Q twice and wore the accelerometer during seven consecutive days on two occasions. Time spent on six different physical activity levels including sedentary, light (LPA), moderate (MPA), and vigorous (VPA) as well as additional combined categories of sedentary-to-light and moderate-to-vigorous (MVPA) physical activity was assessed. Validity of Active-Q was determined using Spearman correlation coefficients with 95% confidence intervals (CI) and the Bland-Altman method. Reproducibility was assessed using intraclass correlation coefficients (ICCs) comparing two admissions of the questionnaire. Results The validity correlation coefficients were statistically significant for time spent at all activity levels; sedentary (r=0.19, 95% CI: 0.04-0.34), LPA (r=0.15, 95% CI: 0.00-0.31), sedentary-to-light (r=0.35, 95% CI: 0.19-0.51), MPA (r=0.27, 95% CI: 0.12-0.42), VPA (r=0.54, 95% CI: 0.42-0.67), and MVPA (r=0.35, 95% CI: 0.21-0.48). The Bland-Altman plots showed a negative mean difference for time in LPA and positive mean differences for time spent in MPA, VPA and MVPA. The ICCs of test-retest reliability ranged between r=0.51-0.80 for the different activity levels in Active-Q. Conclusions More moderate and vigorous activities and less light activities were reported in Active-Q compared to accelerometer measurements. Active-Q shows comparable validity and reproducibility to other physical activity questionnaires used today. PMID:26183896

  8. 76 FR 16478 - Proposed Information Collection (Disability Benefits Questionnaires-Group 2) Activity: Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-23

    ... following collection of information, VBA invites comments on: (1) Whether the proposed collection of... Questionnaire, VA Form 21- 0960E-1. f. Scar/Disfigurement Disability Benefits Questionnaire, VA Form 21-0960F-1... Benefits Questionnaire, VA Form 21-0960M- 1. i. Ankle Conditions Disability Benefits Questionnaire, VA...

  9. 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

  10. An audit questionnaire that examines specifically the management of technical activities clauses in ISO 15189.

    PubMed

    Hartley, T F

    2010-01-01

    The aim of this study was to design an audit questionnaire that focuses on the management of the technical activities in a Diagnostic Pathology Laboratory. The ISO 15189 Standard is written in such a way that it continually moves back and forth from topics where the auditor needs to question bench level staff, to topics where the auditor needs to question Technical Management Staff. This makes for a disjointed audit process - both Bench Staff and Technical Managers are repeatedly interrupted. The solution was to do a clause by clause analysis of the Standard and assign the major responsibility for the compliance to each clause to either Technical Managers or Bench Staff. The Clauses were then grouped under four topic headings regardless of whether they were a Section 4 or Section 5 Clause. Two questionnaires have emerged - the one described in this work and one directed primarily towards the activities of bench staff. There are 95 questions and it takes approximately two hours to complete. PMID:23105892

  11. Self-administered food frequency questionnaire used in the 5-year follow-up survey of the JPHC Study: questionnaire structure, computation algorithms, and area-based mean intake.

    PubMed

    Sasaki, Satoshi; Kobayashi, Minatsu; Ishihara, Junko; Tsugane, Shoichiro

    2003-01-01

    In this section we described the structure of the self-administered semiquantitative food frequency questionnaire used in the 5-year follow-up survey of the JPHC study, the computation algorithms, and the area-based mean intakes of nutrients and food groups in the subjects of the validation study. The FFQ consists of five sections: 1) semiquantitative frequency questions for rice and miso (fermented soybean paste)-soup, 2) those for alcoholic beverages, 3) those for vitamin supplements, 4) those for foods and beverages, and 5) questions on dietary and cooking behaviors. From the questions, intakes of nutrients and foods by food groups were computed. Although most of them were computed from the frequency and relative portion size indicated in the replies, together with the fixed portion size, a seasonal coefficient was added in the computation of vegetables and fruits. Only frequency of intake and fixed portion size were used for computation of beverages. Sugar and cream added in coffee and tea were computed from the frequency of coffee and tea intake. The intakes of cooking oil, cooking salt (sodium), and salt in noodle-soup were estimated from the questions of relative preference of oil, salt, and noodle-soup. PMID:12701629

  12. 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 ] Neuropathy), Disability Benefits Questionnaire, VA Form 21-0960C-4. e. Diabetes Mellitus Disability...

  13. 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

    ... Temporomandibular Joint Conditions) Disability Benefits Questionnaire, VA Form 21-0960D1. Endocrine Diseases (other... System) Disability Benefits Questionnaire, VA Form 21- 0960-J-4. Respiratory Conditions (other...

  14. The Diabetes Intention, Attitude, and Behavior Questionnaire: evaluation of a brief questionnaire to measure physical activity, dietary control, maintenance of a healthy weight, and psychological antecedents

    PubMed Central

    Traina, Shana B; Mathias, Susan D; Colwell, Hilary H; Crosby, Ross D; Abraham, Charles

    2016-01-01

    Background This study assessed measurement properties of the 17-item Diabetes Intention, Attitude, and Behavior Questionnaire (DIAB-Q), which measures intention to engage in self-care behaviors, including following a diabetes diet and engaging in appropriate physical activity. Methods The DIAB-Q includes questions based on the Theory of Planned Behavior. Items were developed using published literature, input from health care professionals, and qualitative research findings in patients with and without type 2 diabetes mellitus (T2DM). In Stage I of the study, 23 adults with T2DM were interviewed to evaluate the content and clarity of the DIAB-Q. In Stage II 1,015 individuals with T2DM completed the DIAB-Q and supplemental questionnaires, including the Short Form-36 acute (SF-36), section III of the Multidimensional Diabetes Questionnaire, the Summary of Diabetes Self-Care Activities questionnaire, and self-administered items relevant to the treatment and management of T2DM (eg, blood pressure and glycated hemoglobin [HbA1c]) at baseline and 3–7 days later. Once the DIAB-Q scale structure was determined, its test–retest reliability, construct validity, and known-groups validity were evaluated, and minimal clinically important change was estimated. Results In Stage I, the 23 respondents surveyed generally reported that the DIAB-Q was clear and comprehensive and endorsed questions as relevant to their intentions to engage in diabetes-related self-care activities. Most subjects in Stage II were male, Caucasian, and married. Mean age was 63 years. Factor analysis revealed six psychological constructs (Behavior, Planning, Intention, Perceived Behavioral Control, Attitude, and Subjective Norm). Test–retest reliability was acceptable (≥0.70) for all scales, except Perceived Behavioral Control. Construct validity was demonstrated based on correlations with diabetes-specific items/scales and the SF-36. Known-groups validity was confirmed for Behavior, Planning, and

  15. 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...

  16. Adapting and Validating the Global Physical Activity Questionnaire (GPAQ) for Trivandrum, India, 2013

    PubMed Central

    Salvo, Deborah; Sarma, Prabhakaran Sankara; Thankappan, Kavumpurathu Raman; Pratt, Michael

    2016-01-01

    Introduction A limitation of the Global Physical Activity Questionnaire (GPAQ) in assessing physical activity in India is that it does not capture the diversity of activities across cultures and by sex. The purpose of this study was to culturally adapt and validate the GPAQ by using an accelerometer in Thiruvananthapuram City, India. Methods We developed a modified version of the GPAQ by adding a physical activity chart specific to the locale. We identified local physical activities through in-depth interviews, group discussions, and observation, and used Actigraph GT3X accelerometers to validate the modified GPAQ for a subsample of 47 women. Participants were drawn from a cross-sectional survey of 1,303 women aged 18 to 64 years, selected by multistage cluster sampling. Spearman rank correlation coefficients and intraclass correlation coefficients (ICC) were calculated to determine the correlation and level of agreement in moderate-to-vigorous physical activity (MVPA) on the basis of accelerometer measurement and the modified GPAQ. Results The correlation for MVPA between the modified GPAQ (overall) and the accelerometer (non-bouted MVPA) was 0.69 (95% confidence interval [CI], 0.39–0.85) with a moderately high ICC of 0.78 (95% CI, 0.56–0.90). The correlation for MVPA between the modified GPAQ and the accelerometer-based MVPA within bouts of at least 10 minutes was 0.60 (95% CI, 0.26–0.80) with an ICC of 0.55 (95% CI, 0.20–0.77) indicating a moderate level of agreement. Conclusion The GPAQ can be used for assessing physical activity among women in India, and its adaptation and validation may be useful in other low-income or middle-income countries where activities are diverse in type and intensity. PMID:27103263

  17. 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

  18. Development and initial validation of the determinants of physical activity questionnaire

    PubMed Central

    2013-01-01

    Background Physical activity interventions are more likely to be effective if they target causal determinants of behaviour change. Targeting requires accurate identification of specific theoretical determinants of physical activity. Two studies were undertaken to develop and validate the Determinants of Physical Activity Questionnaire. Methods In Study 1, 832 male and female university staff and students were recruited from 49 universities across the UK and completed the 66-item measure, which is based on the Theoretical Domains Framework. Confirmatory factor analysis was undertaken on a calibration sample to generate the model, which resulted in a loss of 31 items. A validation sample was used to cross-validate the model. 20 new items were added and Study 2 tested the revised model in a sample of 466 male and female university students together with a physical activity measure. Results The final model consisted of 11 factors and 34 items, and CFA produced a reasonable fit χ2 (472) = 852.3, p < .001, CFI = .933, SRMR = .105, RMSEA = .042 (CI = .037-.046), as well as generally acceptable levels of discriminant validity, internal consistency, and test-retest reliability. Eight subscales significantly differentiated between high and low exercisers, indicating that those who exercise less report more barriers for physical activity. Conclusions A theoretically underpinned measure of determinants of physical activity has been developed with reasonable reliability and validity. Further work is required to test the measure amongst a more representative sample. This study provides an innovative approach to identifying potential barriers to physical activity. This approach illustrates a method for moving from diagnosing implementation difficulties to designing and evaluating interventions. PMID:23758912

  19. 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…

  20. Non-exercise estimation of VO2max using the International Physical Activity Questionnaire

    PubMed Central

    Schembre, Susan M.; Riebe, Deborah A.

    2011-01-01

    Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO2max) as well as submaximal exercise testing. The International Physical Activity Questionnaire (IPAQ) is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO2max estimation equation derived from the IPAQ-Short Form (IPAQ-S). College-aged males and females (n = 80) completed the IPAQ-S and performed a maximal exercise test. The estimation equation was created with multivariate regression in a gender-balanced subsample of participants, equally representing five levels of fitness (n = 50) and validated in the remaining participants (n = 30). The resulting equation explained 43% of the variance in measured VO2max (SEE = 5.45 ml·kg-1·min-1). Estimated VO2max for 87% of individuals fell within acceptable limits of error observed with submaximal exercise testing (20% error). The IPAQ-S can be used to successfully estimate VO2max as well as submaximal exercise tests. Development of other population-specific estimation equations is warranted. PMID:21927551

  1. 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. PMID:26265337

  2. Examining the spatial congruence between data obtained with a novel activity location questionnaire, continuous GPS tracking, and prompted recall surveys

    PubMed Central

    2013-01-01

    Background Place and health researchers are increasingly interested in integrating individuals’ mobility and the experience they have with multiple settings in their studies. In practice, however, few tools exist which allow for rapid and accurate gathering of detailed information on the geographic location of places where people regularly undertake activities. We describe the development and validation of a new activity location questionnaire which can be useful in accounting for multiple environmental influences in large population health investigations. Methods To develop the questionnaire, we relied on a literature review of similar data collection tools and on results of a pilot study wherein we explored content validity, test-retest reliability, and face validity. To estimate convergent validity, we used data from a study of users of a public bicycle share program conducted in Montreal, Canada in 2011. We examined the spatial congruence between questionnaire data and data from three other sources: 1) one-week GPS tracks; 2) activity locations extracted from the GPS tracks; and 3) a prompted recall survey of locations visited during the day. Proximity and convex hull measures were used to compare questionnaire-derived data and GPS and prompted recall survey data. Results In the sample, 75% of questionnaire-reported activity locations were located within 400 meters of an activity location recorded on the GPS track or through the prompted recall survey. Results from convex hull analyses suggested questionnaire activity locations were more concentrated in space than GPS or prompted-recall locations. Conclusions The new questionnaire has high convergent validity and can be used to accurately collect data on regular activity spaces in terms of locations regularly visited. The methods, measures, and findings presented provide new material to further study mobility in place and health research. PMID:24025119

  3. 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

  4. 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. PMID:23936636

  5. Development and validation of a Spanish translation of the Yale activity questionnaire

    PubMed Central

    2014-01-01

    Background Valid measures of physical activity are critical research tools. The objective of this study was to develop a Spanish translation of the Yale Physical Activity Survey, and to provide preliminary evidence of its validity in a population of Dominican patients with lower extremity arthritis. Methods A Dominican bilingual health care professional translated the Yale Physical Activity Survey (YPAS) from English to Spanish. Several Dominican adults reviewed the translation to ensure it was linguistically and culturally appropriate. The questionnaire was back-translated to English by a North American researcher who is fluent in Spanish. Discrepancies between the original and back-translated versions were resolved by the translator and back-translator. The Spanish translation was administered to 108 Dominican subjects with advanced hip or knee arthritis prior to (N = 44) or one to four years following (N = 64) total joint replacement. We assessed construct validity by examining the association of YPAS scores and measures of functional status and pain (WOMAC), quality of life (EQ-5D) and the number of painful lower extremity joints. Results A higher YPAS Part II Activity Dimensions Summary Index score had weak to modest correlations with worse function and quality of life as measured with the WOMAC function scale (r = 0.21, p = 0.03), SF-36 Physical Activity Scale (r = 0.29, p = 0.004) and EQ-5D (r = 0.34, p = 0.0007). Total minutes of vigorous activity and walking had weak to modest correlation with these measures (WOMAC Function Scale (r = 0.15, p = 0.15), SF-36 Physical Activity Scale (r = 0.21, p = 0.04) and EQ-5D utility (r = 0.24, p = 0.02)). Correlations between the YPAS Part I energy expenditure score and these measures were lower (WOMAC Function Scale (r = 0.07, p = 0.49), SF-36 Physical Activity Scale (r = 0.03, p = 0.74) and EQ-5D utility (r = 0.18, p = 0.07)). Conclusions We have developed a new Spanish translation of the Yale Physical Activity Survey

  6. 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...

  7. 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,...

  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. Validity of a short questionnaire to assess physical activity in 10 European countries.

    PubMed

    Peters, Tricia; Brage, Soren; Westgate, Kate; Franks, Paul W; Gradmark, Anna; Tormo Diaz, Maria Jose; Huerta, Jose Maria; Bendinelli, Benedetta; Vigl, Mattheaus; Boeing, Heiner; Wendel-Vos, Wanda; Spijkerman, Annemieke; Benjaminsen-Borch, Kristin; Valanou, Elisavet; de Lauzon Guillain, Blandine; Clavel-Chapelon, Françoise; Sharp, Stephen; Kerrison, Nicola; Langenberg, Claudia; Arriola, Larraitz; Barricarte, Aurelio; Gonzales, Carlos; Grioni, Sara; Kaaks, Rudolf; Key, Timothy; Khaw, Kay Tee; May, Anne; Nilsson, Peter; Norat, Teresa; Overvad, Kim; Palli, Domenico; Panico, Salvatore; Ramón Quirós, Jose; Ricceri, Fulvio; Sanchez, Maria-Jose; Slimani, Nadia; Tjonneland, Anne; Tumino, Rosario; Feskins, Edith; Riboli, Elio; Ekelund, Ulf; Wareham, Nick

    2012-01-01

    To accurately examine associations of physical activity (PA) with disease outcomes, a valid method of assessing free-living activity is required. We examined the validity of a brief PA questionnaire (PAQ) used in the European Prospective Investigation into Cancer and Nutrition (EPIC). PA energy expenditure (PAEE) and time spent in moderate and vigorous physical activity (MVPA) was measured in 1,941 healthy individuals from 10 European countries using individually-calibrated combined heart-rate and movement sensing. Participants also completed the short EPIC-PAQ, which refers to past year's activity. Pearson (r) and Spearman (σ) correlation coefficients were calculated for each country, and random effects meta-analysis was used to calculate the combined correlation across countries to estimate the validity of two previously- and one newly-derived ordered, categorical PA indices ("Cambridge index", "total PA index", and "recreational index") that categorized individuals as inactive, moderately inactive, moderately active, or active. The strongest associations with PAEE and MVPA were observed for the Cambridge index (r = 0.33 and r = 0.25, respectively). No significant heterogeneity by country was observed for this index (I(2) = 36.3%, P = 0.12; I(2) = 0.0%, P = 0.85), whereas heterogeneity was suggested for other indices (I(2) > 48%, P < 0.05, I(2) > 47%, P < 0.05). PAEE increased linearly across self-reported PA categories (P for trend <0.001), with an average difference of approximately 460 kJ/d for men and 365 kJ/d for women, between categories of the Cambridge index. The EPIC-PAQ is suitable for categorizing European men and women into four distinct categories of overall physical activity. The difference in PAEE between categories may be useful when estimating effect sizes from observational research. PMID:22089423

  10. 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.

  11. 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…

  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. PMID:25296962

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

    PubMed

    Helmerhorst, Hendrik J F; Brage, Søren; Warren, Janet; Besson, Herve; Ekelund, Ulf

    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

  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. 76 FR 21429 - Proposed Information Collection (Disability Benefits Questionnaires-Group 3) Activity: Comment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-15

    .... Titles a. Central Nervous System and Neuromusculo Diseases, Disability Benefits Questionnaire, VA Form 21... Management System (FDMS) at http://www.Regulations.gov or to Nancy J. Kessinger, Veterans...

  16. 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

  17. Walking at the preferred stride frequency minimizes muscle activity.

    PubMed

    Russell, Daniel M; Apatoczky, Dylan T

    2016-03-01

    This study determined whether walking at the preferred stride frequency minimizes muscle activity compared with other cadences at the same speed. Anthropometric measurements were recorded from 10 subjects and used to estimate their predicted resonant stride frequency. The preferred walking speed and stride frequency were determined from freely adopted walking on a treadmill. For the experimental trials the treadmill was set at each individual's preferred walking speed. Participants walked for 6 min at eight cadences prescribed by an auditory metronome: preferred stride frequency and -35, -25, -15, 0, +15, +25, +35% of predicted resonant stride frequency. Oxygen consumption was measured via gas analysis. Muscle activity of the right leg gastrocnemius (GA), tibialis anterior (TA), biceps femoris (BF) and rectus femoris (RF) muscles was recorded via electromyography (EMG). On average, participants preferred to walk with a stride frequency .07 Hz lower than their predicted resonant stride frequency, however a strong positive correlation was observed between these variables. Stride frequency had a significant and large quadratic effect on VO2 (RLR(2)=.76), and activity of the GA (RLR(2)=.66), TA (RLR(2)=.83), BF (RLR(2)=.70) and RF (RLR(2)=.78) muscles. VO2, GA and TA activity were all minimal at the preferred stride frequency and increased for faster or slower cadences. BF and RF activity were minimal across a broad range of slow frequencies including the preferred stride frequency and increased for faster frequencies. The preferred stride frequency that humans readily adopt during walking minimizes the activation of the GA, TA, BF and RF muscles, which in turn minimizes the overall metabolic cost. PMID:26979903

  18. Validity of Electronically Administered Recent Physical Activity Questionnaire (RPAQ) in Ten European Countries

    PubMed Central

    Golubic, Rajna; May, Anne M.; Benjaminsen Borch, Kristin; Overvad, Kim; Charles, Marie-Aline; Diaz, Maria Jose Tormo; Amiano, Pilar; Palli, Domenico; Valanou, Elisavet; Vigl, Matthaeus; Franks, Paul W.; Wareham, Nicholas; Ekelund, Ulf; Brage, Soren

    2014-01-01

    Objective To examine the validity of the Recent Physical Activity Questionnaire (RPAQ) which assesses physical activity (PA) in 4 domains (leisure, work, commuting, home) during past month. Methods 580 men and 1343 women from 10 European countries attended 2 visits at which PA energy expenditure (PAEE), time at moderate-to-vigorous PA (MVPA) and sedentary time were measured using individually-calibrated combined heart-rate and movement sensing. At the second visit, RPAQ was administered electronically. Validity was assessed using agreement analysis. Results RPAQ significantly underestimated PAEE in women [median(IQR) 34.1 (22.1, 52.2) vs. 40.6 (32.4, 50.9) kJ/kg/day, 95%LoA: −44.4, 63.4 kJ/kg/day) and in men (43.7 (29.0, 69.0) vs. 45.5 (34.1, 57.6) kJ/kg/day, 95%LoA: −47.2, 101.3 kJ/kg/day]. Using individualised definition of 1MET, RPAQ significantly underestimated MVPA in women [median(IQR): 62.1 (29.4, 124.3) vs. 73.6 (47.8, 107.2) min/day, 95%LoA: −130.5, 305.3 min/day] and men [82.7 (38.8, 185.6) vs. 83.3 (55.1, 125.0) min/day, 95%LoA: −136.4, 400.1 min/day]. Correlations (95%CI) between subjective and objective estimates were statistically significant [PAEE: women, rho = 0.20 (0.15–0.26); men, rho = 0.37 (0.30–0.44); MVPA: women, rho = 0.18 (0.13–0.23); men, rho = 0.31 (0.24–0.39)]. When using non-individualised definition of 1MET (3.5 mlO2/kg/min), MVPA was substantially overestimated (∼30 min/day). Revisiting occupational intensity assumptions in questionnaire estimation algorithms with occupational group-level empirical distributions reduced median PAEE-bias in manual (25.1 kJ/kg/day vs. −9.0 kJ/kg/day, p<0.001) and heavy manual workers (64.1 vs. −4.6 kJ/kg/day, p<0.001) in an independent hold-out sample. Conclusion Relative validity of RPAQ-derived PAEE and MVPA is comparable to previous studies but underestimation of PAEE is smaller. Electronic RPAQ may be used in large-scale epidemiological studies including surveys

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

    PubMed

    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

  1. 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…

  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. A study testing the usefulness of a dish-based food-frequency questionnaire developed for epidemiological studies in Korea.

    PubMed

    Kim, Young Ok; Kim, Mi Kyung; Lee, Sang-Ah; Yoon, Young Mi; Sasaki, Satoshi

    2009-04-01

    The purpose of the present study was to test the usefulness of dish items selected in developing a dish-based FFQ (DFFQ) to be used for epidemiological studies in Korea. The dietary data of 6817 subjects from the 2001 Korean National Health and Nutrition Examination Survey were used for the analysis. The 24 h recall method was employed for the dietary survey. Initially, ninety-five dish items were selected in developing the DFFQ based on consumption frequency, contribution of selected nutrients and coverage of between-person variations. The usefulness of the selected ninety-five dish items was tested based on their degree of contribution in supplying nutrients in the cumulative percentage contribution (cPC), as well as on their degree of explanation for between-person variation in the cumulative regression coefficient (cMRC). According to the results, the ninety-five selected dish items accounted for an average of 92.3 % of seventeen nutrients consumed by the study subjects based on cPC estimation. The top twenty items among the ninety-five dish items covered 70 to 91 % of the between-person variation for the seventeen nutrients based on cMRC estimation. Thus, the results suggest that the ninety-five items would be useful in developing a FFQ for use in epidemiological studies of Koreans, within less than 10 % underestimation. PMID:18786277

  4. [Measurement of activities of daily living in patients with dementia living at home: development of a questionnaire].

    PubMed

    Teunisse, S; Derix, M M

    1991-04-01

    In clinical practice and for scientific research a method is needed for the assessment of changes in functioning in daily life of dementia patients living at home. As existing methods have their limitations, a questionnaire was developed (the Interview for Deterioration in Daily life in Dementia: IDDD), to be answered by caregivers. The questionnaire concerns self-care and complex activities, that are usually performed by men as well as women. Attention is paid to the difference between lack of initiative and impaired performance itself. Caregivers are interviewed in a structured interview. A study among 30 caregivers of dementia patients living at home, showed the relevance and usefulness of the questions. The questionnaire shows high internal consistency, which may be the result of our structured interview technique. PMID:2042235

  5. The child play behavior and activity questionnaire: a parent-report measure of childhood gender-related behavior in China.

    PubMed

    Yu, Lu; Winter, Sam; Xie, Dong

    2010-06-01

    Boys and girls establish relatively stable gender stereotyped behavior patterns by middle childhood. Parent-report questionnaires measuring children's gender-related behavior enable researchers to conduct large-scale screenings of community samples of children. For school-aged children, two parent-report instruments, the Child Game Participation Questionnaire (CGPQ) and the Child Behavior and Attitude Questionnaire (CBAQ), have long been used for measuring children's sex-dimorphic behaviors in Western societies, but few studies have been conducted using these measures for Chinese populations. The current study aimed to empirically examine and modify the two instruments for their applications to Chinese society. Parents of 486 Chinese boys and 417 Chinese girls (6-12 years old) completed a questionnaire comprising items from the CGPQ and CBAQ, and an additional 14 items specifically related to Chinese gender-specific games. Items revealing gender differences in a Chinese sample were identified and used to construct a Child Play Behavior and Activity Questionnaire (CPBAQ). Four new scales were generated through factor analysis: a Gender Scale, a Girl Typicality Scale, a Boy Typicality Scale, and a Cross-Gender Scale (CGS). These scales had satisfactory internal reliabilities and large effect sizes for gender. The CPBAQ is believed to be a promising instrument for measuring children's gender-related behavior in China. PMID:18719986

  6. The Child Play Behavior and Activity Questionnaire: A Parent-Report Measure of Childhood Gender-Related Behavior in China

    PubMed Central

    Winter, Sam; Xie, Dong

    2008-01-01

    Boys and girls establish relatively stable gender stereotyped behavior patterns by middle childhood. Parent-report questionnaires measuring children’s gender-related behavior enable researchers to conduct large-scale screenings of community samples of children. For school-aged children, two parent-report instruments, the Child Game Participation Questionnaire (CGPQ) and the Child Behavior and Attitude Questionnaire (CBAQ), have long been used for measuring children’s sex-dimorphic behaviors in Western societies, but few studies have been conducted using these measures for Chinese populations. The current study aimed to empirically examine and modify the two instruments for their applications to Chinese society. Parents of 486 Chinese boys and 417 Chinese girls (6–12 years old) completed a questionnaire comprising items from the CGPQ and CBAQ, and an additional 14 items specifically related to Chinese gender-specific games. Items revealing gender differences in a Chinese sample were identified and used to construct a Child Play Behavior and Activity Questionnaire (CPBAQ). Four new scales were generated through factor analysis: a Gender Scale, a Girl Typicality Scale, a Boy Typicality Scale, and a Cross-Gender Scale (CGS). These scales had satisfactory internal reliabilities and large effect sizes for gender. The CPBAQ is believed to be a promising instrument for measuring children’s gender-related behavior in China. PMID:18719986

  7. Screening Physical Activity in Family Practice: Validity of the Spanish Version of a Brief Physical Activity Questionnaire

    PubMed Central

    Puig-Ribera, Anna; Martín-Cantera, Carlos; Puigdomenech, Elisa; Real, Jordi; Romaguera, Montserrat; Magdalena-Belio, José Félix; Recio-Rodríguez, Jose Ignacio; Rodriguez-Martin, Beatriz; Arietaleanizbeaskoa, Maria Soledad; Repiso–Gento, Irene; Garcia-Ortiz, Luis

    2015-01-01

    Objectives The use of brief screening tools to identify inactive patients is essential to improve the efficiency of primary care-based physical activity (PA) programs. However, the current employment of short PA questionnaires within the Spanish primary care pathway is unclear. This study evaluated the validity of the Spanish version of a Brief Physical Activity Assessment Tool (SBPAAT). Methods A validation study was carried out within the EVIDENT project. A convenience sample of patients (n = 1,184; age 58.9±13.7 years; 60.5% female) completed the SBPAAT and the 7-day Physical Activity Recall (7DPAR) and, in addition, wore an accelerometer (ActiGraph GT3X) for seven consecutive days. Validity was evaluated by measuring agreement, Kappa correlation coefficients, sensitivity and specificity in achieving current PA recommendations with the 7DPAR. Pearson correlation coefficients with the number of daily minutes engaged in moderate and vigorous intensity PA according to the accelerometer were also assessed. Comparison with accelerometer counts, daily minutes engaged in sedentary, light, moderate, and vigorous intensity PA, total daily kilocalories, and total PA and leisure time expenditure (METs-hour-week) between the sufficiently and insufficiently active groups identified by SBPAAT were reported. Results The SBPAAT identified 41.3% sufficiently active (n = 489) and 58.7% insufficiently active (n = 695) patients; it showed moderate validity (k = 0.454, 95% CI: 0.402–0.505) and a specificity and sensitivity of 74.3% and 74.6%, respectively. Validity was fair for identifying daily minutes engaged in moderate (r = 0.215, 95% CI:0.156 to 0.272) and vigorous PA (r = 0.282, 95% CI:0.165 to 0.391). Insufficiently active patients according to the SBPAAT significantly reported fewer counts/minute (-22%), fewer minutes/day of moderate (-11.38) and vigorous PA (-2.69), spent fewer total kilocalories/day (-753), and reported a lower energy cost (METs-hour-week) of physical

  8. 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...

  9. 78 FR 44625 - Proposed Information Collection (Wrist Conditions Disability Benefits Questionnaire) Activity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... 17, 2013 (78 FR 36307), inviting the public to comment on a proposed information collection titled ``Wrist Conditions Disability Benefits Questionnaire, VA Form 21-0960M-16.'' On June 18, 2013 (78 FR 36643... corrects that error by withdrawing the FR notice that published on June 18, 2013 (FR Doc 2013-14412)....

  10. Validation of a self-report questionnaire version of the Child Activity Limitations Interview (CALI): The CALI-21

    PubMed Central

    Palermo, Tonya M.; Lewandowski, Amy S.; Long, Anna C.; Burant, Christopher J.

    2011-01-01

    The Child Activity Limitations Interview (CALI) is a measure designed to assess functional impairment due to chronic pain in school-age children. In this study, we present a self-report questionnaire version of the CALI (the CALI-21) that extends the original interview measure. The purpose of the current study was to provide internal consistency, cross-informant reliability and construct validity of the CALI-21 on a clinical sample of children and adolescents with chronic pain conditions. One hundred fifty-five children and adolescents (65 males, 90 females; ages 8–18 years, M = 14.31, SD =2.45) with chronic pain completed questionnaires as part of their clinic intake procedures at their consultation visit in a pediatric pain management clinic. An exploratory factor analysis was conducted to measure latent constructs within the broader domain of functional impairment. Results of the exploratory factor analysis yielded two factors representing limitation in Active and Routine activities on both parent and child report. Parent and child total CALI scores correlated with measures of pain intensity, however, different patterns of correlations emerged between age, pain intensity, depressive symptoms, and the Active and Routine factors. The CALI-21 showed good internal consistency, high cross-informant reliability, and demonstrated construct validity. The CALI-21 provides increased flexibility via the questionnaire format in the assessment of pain-related activity limitations in children. Factor analysis extends information about specific types of activity limitations experienced by children. PMID:18692316

  11. Adaptation of Locally Available Portion Sizes for Food Frequency Questionnaires in Nutritional Epidemiological Studies: How Much Difference does it Make?

    PubMed Central

    Gupta, Neha; Verma, Sonika; Singh, Abhishek; Tandon, Nikhil; Puri, Seema; Arora, Narendra Kumar

    2016-01-01

    Introduction: There is need for employing strategies to minimize measurement errors while administering semi-quantitative FFQ. The current study was planned to adapt and standardize locally available portion sizes for semi-quantitative FFQ to improve its validity and document the process of standardization of portion sizes. Methodology: The study was conducted in 9 villages of the INCLEN-SOMAARTH DDESS (Demographic, Development and Environmental Surveillance Site), Palwal district, Haryana, India. The subjects in these nine villages are part of a cohort study to assess the interaction between societal and household factors with food intake and physical activity of children. Systematic utensil survey was undertaken in 3 randomly chosen households per village i.e. 27 households and the portion sizes were derived from a total of 74 serving utensils. The derived sizes were classified as small (240 ml), medium (320 ml) and large (600 ml). The semi-quantitative FFQ with locally derived portion sizes was then administered to 63 children in 6-12 year age group. Results: The volume of food measured by the reference portion sizes generally being employed in the national surveys, would have been underestimated the food consumed by the child by 55-60% as compared to what was being consumed by the children in the study area. The correlation between food intake assessed by 24-hr recall method and FFQ using derived (local) portion sizes was better as compared to that obtained with the semi-quantitative FFQ done with reference portions. Conclusion: In conclusion, local portion size adaptation of FFQ for semi-quantification is useful to mitigate measurement errors associated with this technique. PMID:27385878

  12. Development and evaluation of a food frequency questionnaire for Vietnamese female immigrants in Korea: the Korean Genome and Epidemiology Study (KoGES)

    PubMed Central

    Kim, Sun Hye; Choi, Ha Ney; Hwang, Ji-Yun; Chang, Namsoo; Kim, Wha Young; Chung, Hye Won

    2011-01-01

    The objectives of this study were to develop a food-frequency questionnaire (FFQ) for Vietnamese female immigrants in Korea and to evaluate the validity of the FFQ. A total of 80 food items were selected in developing the FFQ according to consumption frequency, the contribution of energy and other nutrients, and the cooking methods based on one-day 24 hour recall (24HR) from 918 Vietnamese female immigrants between November 2006 and November 2007. The FFQ was validated by comparison with 24HR of 425 Vietnamese female immigrants between November 2008 and August 2009. The absolute nutrient intake calculated from the FFQ was higher than that estimated by 24HR for most nutrients. The correlation coefficients between 24HR and FFQ ranged from 0.10 (vitamin C) - 0.36 (energy) for crude intake, 0.05 (vitamin E) - 0.32 (calcium) for per 1000 kcal, and 0.08 (zinc) - 0.34 (calcium) for energy-adjusted, respectively. More than 70% of subjects were classified into the same or adjacent agreement groups for nutrients other than fiber, sodium, vitamin A, vitamin C, and vitamin E, while less than 10% of subjects were classified into complete disagreement groups. We conclude that the FFQ appears to be an acceptable tool for estimating nutrient intake and dietary patterns of Vietnamese female immigrants in Korea. Future studies to validate the FFQ using various biomarkers or other dietary assessment methods are needed. PMID:21779531

  13. 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…

  14. 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

  15. Systematic review of the measurement properties of self-report physical activity questionnaires in healthy adult populations

    PubMed Central

    Silsbury, Zoë; Goldsmith, Robert; Rushton, Alison

    2015-01-01

    Objective This systematic review evaluated the measurement properties of current self-report physical activity questionnaires (SRPAQs) completed within healthy adult populations. Design Two reviewers independently searched seven electronic databases and hand searched for articles investigating measurement properties of a SRPAQ evaluating physical activity over the previous 6 months. Articles published from 1 May 2001 to 4 December 2014 were systematically screened and eligible studies were not limited to English language sources. Articles investigating specific race, gender or socioeconomic populations were excluded. Results 10 studies investigating 10 SRPAQs were included. The methodological quality of the included studies was evaluated using COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and ranged from ‘poor’ to ‘good’. The Recent Physical Activity Questionnaire, International Physical Activity Questionnaires and Physical Activity Assessment Tool demonstrated good/excellent test–retest reliability (intra-class coefficient (ICC)=0.76, p<0.0001; r=0.627–0.91; r=0.618, p<0.001, respectively), but variable criterion validity (r=0.67, p<0.0001; r=−0.02–0.43; r=0.392, p<0.01, respectively). The single-item measure showed significant criterion validity against an accelerometer (for moderate to vigorous physical activity (MVPA) k=0.23, 95% CI 0.05 to 0.41; and physical activity ≥10 min bouts 0.39 (95% CI 0.14 to 0.64). Construct validity of the six-point scale and Human Activity Profile varied significantly with age, marital status and presence of comorbidities (p<0.05, <0.01, <0.000 and p<0.05, <0.05, <0.000, respectively). The 1 week Godlin-Shephard recall demonstrated ‘moderate’ validity with the gold standard measure of accelerometry (r=0.43). Conclusions Inconclusive evidence exists. Further investigation of criterion validity of the short-form International Physical Activity Questionnaire is

  16. Concurrent Validity of a Self-Reported Physical Activity “Vital Sign” Questionnaire With Adult Primary Care Patients

    PubMed Central

    Joy, Elizabeth A.; Gren, Lisa H.; Shaw, Janet M.

    2016-01-01

    Introduction No tool currently used by primary health care providers to assess physical activity has been evaluated for its ability to determine whether or not patients achieve recommended levels of activity. The purpose of this study was to assess concurrent validity of physical activity self-reported to the brief (<30 sec) Physical Activity “Vital Sign” questionnaire (PAVS) compared with responses to the lengthier (3–5 min), validated Modifiable Activity Questionnaire (MAQ). Methods Agreement between activity reported to the PAVS and MAQ by primary care patients at 2 clinics in 2014 was assessed by using percentages and κ coefficients. Agreement consisted of meeting or not meeting the 2008 Aerobic Physical Activity Guidelines for Americans (PA Guidelines) of the US Department of Health and Human Services. We compared self-reported usual minutes per week of moderate-to-vigorous physical activity among patients at a primary care clinic in 2014 who reported to PAVS and to MAQ by using Pearson correlation and Bland–Altman plots of agreement. Results Among 269 consenting patients who reported physical activity, PAVS results agreed with those of MAQ 89.6% of the time and demonstrated good agreement in identifying patients who did not meet PA Guidelines recommendations (κ = 0.55, ρ = 0.57; P < .001). Usual minutes per week of moderate-to-vigorous physical activity reported to PAVS had a high positive correlation with the same reported to MAQ (r = 0.71; P < .001). Conclusion PAVS may be a valid tool for identifying primary care patients who need counseling about physical activity. PAVS should be assessed further for agreement with repeated objective measures of physical activity in the patient population. PMID:26851335

  17. 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

  18. Frequencies of inaudible high-frequency sounds differentially affect brain activity: positive and negative hypersonic effects.

    PubMed

    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

  19. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR CLEANING: TIME DIARY AND ACTIVITY QUESTIONNAIRE (UA-D-20.0)

    EPA Science Inventory

    The purpose of this SOP is to define the steps involved in cleaning the electronic data generated from data entry of the Time Diary and Activity Questionnaire. It applies to electronic data corresponding to the Time Diary and Activity Questionnaire that was scanned and verified ...

  20. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR CLEANING: TIME DIARY AND ACTIVITY QUESTIONNAIRE (UA-D-20.0)

    EPA Science Inventory

    The purpose of this SOP is to define the steps involved in cleaning the electronic data generated from data entry of the Time Diary and Activity Questionnaire. It applies to electronic data corresponding to the Time Diary and Activity Questionnaire that was scanned and verified ...

  1. The validity and reliability of a home environment preschool-age physical activity questionnaire (Pre-PAQ)

    PubMed Central

    2011-01-01

    Background There is a need for valid population level measures of physical activity in young children. The aim of this paper is to report the development, and the reliability and validity, of the Preschool-age Children's Physical Activity Questionnaire (Pre-PAQ) which was designed to measure activity of preschool-age children in the home environment in population studies. Methods Pre-PAQ was completed by 103 families, and validated against accelerometry for 67 children (mean age 3.8 years, SD 0.74; males 53%). Pre-PAQ categorizes activity into five progressive levels (stationary no movement, stationary with limb or trunk movement, slow, medium, or fast-paced activity). Pre-PAQ Levels 1-2 (stationary activities) were combined for analyses. Accelerometer data were categorized for stationary, sedentary (SED), non-sedentary (non-SED), light (LPA), moderate (MPA) and vigorous (VPA) physical activity using manufacturer's advice (stationary) or the cut-points described by Sirard et al and Reilly et al. Bland-Altman methods were used to assess agreement between the questionnaire and the accelerometer measures for corresponding activity levels. Reliability of the Pre-PAQ over one week was determined using intraclass correlations (ICC) or kappa (κ) values and percentage of agreement of responses between the two questionnaire administrations. Results Pre-PAQ had good agreement with LPA (mean difference 1.9 mins.day-1) and VPA (mean difference -4.8 mins.day-1), was adequate for stationary activity (mean difference 7.6 mins.day-1) and poor for sedentary activity, whether defined using the cut-points of Sirard et al (mean difference -235.4 mins.day-1) or Reilly et al (mean difference -208.6 mins.day-1) cut-points. Mean difference between the measures for total activity (i.e. Reilly's non-sedentary or Sirard's LMVPA) was 20.9 mins.day-1 and 45.2 mins.day-1. The limits of agreement were wide for all categories. The reliability of Pre-PAQ question responses ranged from 0

  2. NHEXAS PHASE I REGION 5 STUDY--BASELINE QUESTIONNAIRE DATA

    EPA Science Inventory

    This data set includes responses for 326 baseline questionnaires. The Baseline Questionnaire was used to provide more detailed information on the characteristics of the sample individual and housing, and on the usual frequency of activities over a longer time frame (i.e., last mo...

  3. An ultra-thin broadband active frequency selective surface absorber for ultrahigh-frequency applications

    NASA Astrophysics Data System (ADS)

    Xu, Wenhua; He, Yun; Kong, Peng; Li, Jialin; Xu, Haibing; Miao, Ling; Bie, Shaowei; Jiang, Jianjun

    2015-11-01

    At frequencies below 2 GHz, conventional microwave absorbers are limited in application by their thickness or narrow absorption bandwidth. In this paper, we propose and fabricate an ultra-thin broadband active frequency selective surface (AFSS) absorber with a stretching transformation (ST) pattern for use in the ultrahigh-frequency (UHF) band. This absorber is loaded with resistors and varactors to produce its tunability. To expand the tunable bandwidth, we applied the ST with various coefficients x and y to the unit cell pattern. With ST coefficients of x = y = 1, the tunability and strong absorption are concisely demonstrated, based on a discussion of impedance matching. On analyzing the patterns with various ST coefficients, we found that a small x/y effectively expands the tunable bandwidth. After this analysis, we fabricated an AFSS absorber with ST coefficients of x = 0.7 and y = 1. Its measured reflectivity covered a broad band of 0.7-1.9 GHz below -10 dB at bias voltages of 10-48 V. The total thickness of this absorber, 7.8 mm, was only ˜λ/54 of the lower limit frequency, ˜λ/29 of the center frequency, and ˜λ/20 of the higher limit frequency. Our measurements and simulated results indicate that this AFSS absorber can be thin and achieve a broad bandwidth simultaneously.

  4. Validity and Reproducibility of a Revised Semi-quantitative Food Frequency Questionnaire (SQFFQ) for Women of Age-group 12-44 Years in Chengdu

    PubMed Central

    Tang, Ying; Liu, Ying; Jia, Yujian; Shan, Dan; Li, Wenjuan; Pan, Xin; Kang, Deying; Huang, Chengyu; Li, Xiaosong; Zhang, Jing; Hu, Ying; Konglin, Lingli; Zhuang, Jing

    2015-01-01

    ABSTRACT To find a credible nutritional screening tool for evaluating relationship between nutritional status and diseases in Chengdu female residents, the reliability and validity of a revised semi-quantitative food frequency questionnaire (SQFFQ) were tested. The validity was assessed by comparing the SQFFQ with the ‘standard’ method of 3 days’ dietary recall, and the reliability was assessed by comparing the first SQFFQ with the second SQFFQ at 4 weeks interval. Correlation analysis showed that, for reliability, the average correlation coefficient (CC) of 22 kinds of nutrients was 0.66 and reduced to 0.60 after adjusting for energy; the average of intra-class correlation coefficients (ICC) was 0.65. For validity, the average CC was 0.35 and remained stable after adjusting for CC of energy or nutrients. Validity of 17 nutrients in SQFFQ survey had correlation with result of 3 days’ dietary recall. The results showed that the revised SQFFQ can be used for investigating the role of nutrients in development of disease in Chengdu female residents. PMID:25995721

  5. Development of an updated phytoestrogen database for use with the SWAN Food Frequency Questionnaire: intakes and food sources in a community-based, multiethnic cohort study

    PubMed Central

    Huang, Mei-Hua; Norris, Jean; Han, Weijuan; Block, Torin; Gold, Ellen; Crawford, Sybil; Greendale, Gail

    2013-01-01

    Phytoestrogens, heterocyclic phenols found in plants, may benefit several health outcomes. However, epidemiologic studies of the health effects of dietary phytoestrogens have yielded mixed results, in part due to challenges inherent in estimating dietary intakes. The goal of this study was to improve the estimates of dietary phytoestrogen consumption using a modified Block Food Frequency Questionnaire (FFQ), a 137-item FFQ created for the Study of Women’s Health Across the Nation (SWAN) in 1994. To expand the database of sources from which phytonutrient intakes were computed, we conducted a comprehensive PubMed/Medline search covering January, 1994 through September, 2008. The expanded database included 4 isoflavones, coumestrol and 4 lignans. The new database estimated isoflavone content of 105 food items (76.6%) versus 14 (10.2%) in the 1994 version and computed coumestrol content of 52 food items (38.0%), compared to 1 (0.7%) in the original version. Newly added were lignans; values for 104 FFQ food items (75.9%) were calculated. In addition, we report here the phytonutrient intakes for each racial and language group in the SWAN sample and present major food sources from which the phytonutrients came. This enhanced ascertainment of phytoestrogens will permit improved studies of their health effects. PMID:22211850

  6. 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

  7. Control of high frequency microactuators using active structures

    NASA Astrophysics Data System (ADS)

    Kreth, P. A.; Alvi, F. S.; Reese, B. M.; Oates, W. S.

    2015-02-01

    A fluidically driven microactuator that generates supersonic, pulsed microjets has been implemented with smart materials to actively and precisely control the frequency of the microjets in a closed-loop manner. Since this actuator relies on a number of microscale flow and acoustic phenomena to produce the pulsed microjets, its resonant frequency is determined by its geometry and other flow parameters. The design discussed in this paper integrates piezoelectric stacks by connecting them to movable sidewalls within the actuator such that the microactuator's internal geometry can be controlled by varying the voltage across the piezo-stacks. An open-loop control scheme demonstrates the frequency modulation capabilities that are enabled with this design: very large frequency deviations (up to +/- 500 Hz) around the actuator design frequency are attained at very high rates (up to 1 kHz). Closed-loop control of the microactuator's frequency was also demonstrated, and the results indicate that (combined with appropriate sensors) this actuator could be used effectively for active, feedback control in high-speed, resonance-dominated flowfields. This proof of concept study clearly illustrates the ability of this robust and compact actuator to produce perturbations that can be modulated and controlled based on the desired control objective.

  8. Use of food frequency questionnaire to assess relationships between dietary habits and cardiovascular risk factors in NESCAV study: validation with biomarkers

    PubMed Central

    2013-01-01

    Background Validation of Food frequency questionnaire (FFQ) is particularly important element, as incorrect information may lead to false associations between dietary factors and diseases. The aim of the study was to evaluate the validity of the FFQ used in NESCAV (Nutrition, Environment and Cardiovascular Health) study, by comparing the estimated intakes of fruits and vegetables and of several micro-nutrients with corresponding nutritional biomarkers. Methods Relative validity was assessed in a sample of 922 subjects (452 men and 470 women). Comparisons between FFQ-estimates and their corresponding biomarkers were performed through correlation and cross classification into quintiles by using both crude and energy-adjusted FFQ-estimates. Correlations adjusted for confounders were also computed. All analyses were performed separately for men and women. Results Concerning micro-nutrients, significant correlations were found for vitamin B9, D, E, B12 β-carotene and iodine in both men and women. Energy-adjustment led to an increase of all correlations cited previously. However, after excluding supplement users, correlations for vitamin D were not significant anymore. Concerning fruits and vegetables, all correlations were significant. Vegetables alone and fruits and vegetables correlated better in men (r around 0.2) than in women (r around 0.1). In men, correlation was also better for vegetables alone and fruits and vegetables than fruits alone. Conclusion These data demonstrate that this FFQ is a reasonable tool to assess intakes of fruits and vegetables and of several micro-nutrients. We conclude that our FFQ is suitable to be used in NESCAV study, although protein and vitamin D estimates should be interpreted with caution. PMID:24195492

  9. Comparison of energy intake in toddlers assessed by food frequency questionnaire and total energy expenditure measured by the doubly labeled water method.

    PubMed

    Collins, Clare E; Burrows, Tracy L; Truby, Helen; Morgan, Philip J; Wright, Ian M R; Davies, Peter S W; Callister, Robin

    2013-03-01

    The ability of parents to accurately report energy intake in toddlers has rarely been validated using the gold-standard doubly labeled water (DLW) method to assess total energy expenditure (TEE). The aim of the study was to evaluate the accuracy of toddler energy intake (EI), estimated using the Australian Child and Adolescent Eating Survey (ACAES) food frequency questionnaire (FFQ) by parent report compared with a weighed food record (WFR) and TEE measured by DLW. Twelve toddlers had TEE assessed over 10 days using DLW. Usual energy intake was estimated by the primary caregiver, using standard toddler portions in ACAES-FFQ and a 4-day WFR and daily EI (in kilocalories) derived using national nutrient databases. Accuracy of reporting was calculated from absolute (EI-TEE) and percentage (EI/TEE×100) differences between EI and TEE and Pearson correlations and limits of agreement from Bland-Altman plots. Toddlers (n=12, 7 boys) had a mean age of 3.2±0.5 years, body mass index 16.2±0.9 kg, body mass index z score 0.1±0.8, EI from ACAES-FFQ 1,183±281kcal/day, and WFR 1,179±278 kcal/day and DLW TEE 1,251±149 kcal/day. The mean difference and limits of agreement (±2 standard deviations) compared with DLW was -68 (-623, 488) kcal/day for the FFQ and for the WFR -72 (-499, 354) kcal/day. Although both a semiquantitative FFQ and WFR can adequately estimate toddler energy intake at the group level in this population, toddler-specific portion size estimates should be assigned to foods listed in the FFQ. Choice of method is likely to depend on practical issues, including cost and burden. PMID:23317500

  10. 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

  11. 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

  12. Comparison between omega-3 and omega-6 polyunsaturated fatty acid intakes as assessed by a food frequency questionnaire and erythrocyte membrane fatty acid composition in young children

    PubMed Central

    Orton, Heather D.; Szabo, Nancy J.; Clare-Salzler, Michael; Norris, Jill M.

    2010-01-01

    Objective We conducted a dietary validation study in youth aged 1 to 11 years by comparing dietary intake of omega-3 and omega-6 polyunsaturated fatty acids (PUFA) as assessed by a parent-completed semi-quantitative food frequency questionnaire (FFQ) over time to erythrocyte membrane composition of the same fatty acids. Design The study population included youth aged 1 to 11 years who were participants in the Diabetes Autoimmunity Study in the Young (DAISY), a longitudinal study in Denver, Colorado that is following a cohort of youth at risk for developing Type I diabetes. Four hundred four children who had erythrocyte membrane fatty acid data matched to an FFQ corresponding to the same time frame for a total of 917 visits (matches) were included. PUFA intake was expressed as both g/day (adjusted for total energy) and as percent of total fat intake. We used mixed models to test the association and calculate the correlation between the erythrocyte membrane estimates and PUFA intake using all records of data for each youth. Results Intakes of total omega-3 fatty acids (β=0.52, p<0.0001, ρ=0.23) and marine PUFAs (β=1.62, p<0.0001, ρ=0.42), as a percent of total fat in the diet, were associated with percent of omega-3 and marine PUFAs in the erythrocyte membrane. Intakes of omega-6 PUFAs (β=0.04, p=0.418, ρ=0.05) and arachidonic acid (β=0.31, p=0.774, ρ=0.01) were not associated. Conclusions In these young children, a FFQ using parental report provided estimates of average long-term intakes of marine PUFAs that correlated well with their erythrocyte cell membrane fatty acid status. PMID:17440518

  13. 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

  14. Validation of the IMMIDIET food frequency questionnaire in an adult Belgian population: a report from the Belgian case-control study on bladder cancer risk.

    PubMed

    Brinkman, M T; Kellen, E; Zeegers, M P; van Dongen, M C J M S; Dagnelie, P C; Muls, E; Buntinx, F

    2011-01-01

    We evaluated the performance of the IMMIDIET food frequency questionnaire (FFQ) used to collect dietary data for the Belgian case-control study on bladder cancer. Thirty-seven men and women aged 50 years and older were recruited from the University Hospital in Leuven, Belgium. Participants completed the IMMIDIET FFQ, a 7-day diet diary and a 24-hour diet recall. Median intakes and inter-quartile ranges were calculated for 27 foods and nutrients from each dietary assessment method. All dietary factors were log-transformed and adjusted for energy using the nutrient density method. Pearson correlation coefficients were used to compare the different dietary assessment methods. Bland-Altman plots were also used to assess levels of agreement between the dietary methods. Energy, fruit and vegetable intake estimates were higher from the IMMIDIET FFQ compared with the two reference methods.The highest deattenuated correlations between the FFQ and 7-day diary were meat (0.58), bread (0.44), fruit (0.38) and fish (0.38). The highest deattenuated correlations between the FFQ and 24-hour recall were for fruit (0.72), fat (0.48), alcohol (0.44), cholesterol (0.42), monounsaturated fatty acid (0.42) and polyunsaturated fatty acid (0.41). Generally, correlation was lower for the micro-nutrients except for phosphorus (0.42), vitamin C (0.41) and calcium (0.40). The IMMIDIET FFQ is an appropriate instrument to measure usual dietary intake for the Belgian case-control study on bladder cancer risk. Further investigation of nutritional assessment methods is necessary. PMID:21485759

  15. 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

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

    2009-05-15

    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 2 measures of acrylamide exposure: intake from a food frequency questionnaire (FFQ) and acrylamide adducts to hemoglobin. We also studied the correlation between these 2 exposure measures. We used data from the population-based case-control study Cancer of the Prostate in Sweden (CAPS). Dietary data was available for 1,499 cases and 1,118 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

  16. 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

  17. 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...

  18. 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…

  19. 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.

  20. Reliability and Validity of the Self- and Interviewer-Administered Versions of the Global Physical Activity Questionnaire (GPAQ)

    PubMed Central

    Chu, Anne H. Y.; Ng, Sheryl H. X.; Koh, David; Müller-Riemenschneider, Falk

    2015-01-01

    Objective The Global Physical Activity Questionnaire (GPAQ) was originally designed to be interviewer-administered by the World Health Organization in assessing physical activity. The main aim of this study was to compare the psychometric properties of a self-administered GPAQ with the original interviewer-administered approach. Additionally, this study explored whether using different accelerometry-based physical activity bout definitions might affect the questionnaire’s validity. Methods A total of 110 participants were recruited and randomly allocated to an interviewer- (n = 56) or a self-administered (n = 54) group for test-retest reliability, of which 108 participants who met the wear time criteria were included in the validity study. Reliability was assessed by administration of questionnaires twice with a one-week interval. Criterion validity was assessed by comparing against seven-day accelerometer measures. Two definitions for accelerometry-data scoring were employed: (1) total-min of activity, and (2) 10-min bout. Results Participants had similar baseline characteristics in both administration groups and no significant difference was found between the two formats in terms of validity (correlations between the GPAQ and accelerometer). For validity, the GPAQ demonstrated fair-to-moderate correlations for moderate-to-vigorous physical activity (MVPA) for self-administration (rs = 0.30) and interviewer-administration (rs = 0.46). Findings were similar when considering 10-min activity bouts in the accelerometer analysis for MVPA (rs = 0.29 vs. 0.42 for self vs. interviewer). Within each mode of administration, the strongest correlations were observed for vigorous-intensity activity. However, Bland-Altman plots illustrated bias toward overestimation for higher levels of MVPA, vigorous- and moderate-intensity activities, and underestimation for lower levels of these measures. Reliability for MVPA revealed moderate correlations (rs = 0.61 vs. 0.63 for self vs

  1. 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

  2. Construct Validity of the Work Productivity and Activity Impairment Questionnaire across Informal Caregivers of Chronically Ill Older Patients

    PubMed Central

    Giovannetti, Erin R.; Wolff, Jennifer L.; Frick, Kevin D.; Boult, Chad

    2011-01-01

    Objectives To assess the validity of the Work Productivity and Activity Impairment questionnaire as adapted for caregiving (WPAI:CG) to measure productivity loss (hours missed from work, impairment while at work, and impairment in regular activities) due to unpaid caregiving for medically complex older adults. Methods The WPAI:CG was administered along with the Caregiver Strain Index (CSI) and Center for Epidemiologic Studies Depression Scale (CESD) to a caregiving population (N = 308) enrolled with their older, medically complex care-recipient in a cluster-randomized controlled study. Correlation coefficients were calculated between each productivity variable derived from the WPAI:CG and CSI/CESD scores. Nonparametric tests for trend across ordered groups were carried out to examine the relationship between each productivity variable and the intensity of the caregiving. Results Significant positive correlations were found between work productivity loss and caregiving-related strain (r = 0.45) and depression (r = 0.30). Measures of productivity loss were also highly associated with caregiving intensity (P < 0.05) and care-recipient medical care use (P < 0.05). The average employed caregiver reported 1.5 hours absence from work in the previous week and 18.5% reduced productivity while at work due to caregiving. Employed and nonemployed caregivers reported 27.2% reduced productivity in regular activities in the previous week. Conclusion The results indicate high convergent validity of the WPAI:CG questionnaire. This measure could facilitate research on the cost-effectiveness of caregiver-workplace interventions and provide employers and policy experts with a more accurate and comprehensive estimate of caregiving-related costs incurred by employers and society. PMID:19402853

  3. 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

  4. 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

  5. Radar activities of the DFVLR Institute for Radio Frequency Technology

    NASA Technical Reports Server (NTRS)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  6. 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.

  7. Powerful Low-Frequency Vibrators for Active Seismology

    SciTech Connect

    Alekseev, A.S.; Chichinin, I.S.; Korneev, V.A.

    2003-12-01

    In the past two decades, active seismology studies in Russia have made use of powerful (40- and 100-ton) low-frequency vibrators. These sources create a force amplitude of up to 100 tons and function in the 1.5 3, 3 6, and 5 10 Hz frequency bands. The mobile versions of the vibrator have a force amplitude of 40 tons and a 6 12 Hz frequency band. Recording distances for the 100-ton vibrator are as large as 350 km, enabling the refracted waves to penetrate down to 50 km depths. Vibrator operation sessions are highly repeatable, having distinct summer or winter spectral patterns. A long profile of seismic records allows estimation of fault zone depths using changes in recorded spectra. Other applications include deep seismic profiling, seismic hazard mapping, structural testing, stress-induced anisotropy studies, seismic station calibration, and large-structure integrity testing. The theoretical description of the low-frequency vibrator is given in the appendices, which contain numerical examples.

  8. Inaudible high-frequency sounds affect brain activity: hypersonic effect.

    PubMed

    Oohashi, T; Nishina, E; Honda, M; Yonekura, Y; Fuwamoto, Y; Kawai, N; Maekawa, T; Nakamura, S; Fukuyama, H; Shibasaki, H

    2000-06-01

    Although it is generally accepted that humans cannot perceive sounds in the frequency range above 20 kHz, the question of whether the existence of such "inaudible" high-frequency components may affect the acoustic perception of audible sounds remains unanswered. In this study, we used noninvasive physiological measurements of brain responses to provide evidence that sounds containing high-frequency components (HFCs) above the audible range significantly affect the brain activity of listeners. We used the gamelan music of Bali, which is extremely rich in HFCs with a nonstationary structure, as a natural sound source, dividing it into two components: an audible low-frequency component (LFC) below 22 kHz and an HFC above 22 kHz. Brain electrical activity and regional cerebral blood flow (rCBF) were measured as markers of neuronal activity while subjects were exposed to sounds with various combinations of LFCs and HFCs. None of the subjects recognized the HFC as sound when it was presented alone. Nevertheless, the power spectra of the alpha frequency range of the spontaneous electroencephalogram (alpha-EEG) recorded from the occipital region increased with statistical significance when the subjects were exposed to sound containing both an HFC and an LFC, compared with an otherwise identical sound from which the HFC was removed (i.e., LFC alone). In contrast, compared with the baseline, no enhancement of alpha-EEG was evident when either an HFC or an LFC was presented separately. Positron emission tomography measurements revealed that, when an HFC and an LFC were presented together, the rCBF in the brain stem and the left thalamus increased significantly compared with a sound lacking the HFC above 22 kHz but that was otherwise identical. Simultaneous EEG measurements showed that the power of occipital alpha-EEGs correlated significantly with the rCBF in the left thalamus. Psychological evaluation indicated that the subjects felt the sound containing an HFC to be more

  9. The short international physical activity questionnaire: cross-cultural adaptation, validation and reliability of the Hausa language version in Nigeria

    PubMed Central

    2011-01-01

    Background Accurate assessment of physical activity is important in determining the risk for chronic diseases such as cardiovascular disease, stroke, type 2 diabetes, cancer and obesity. The absence of culturally relevant measures in indigenous languages could pose challenges to epidemiological studies on physical activity in developing countries. The purpose of this study was to translate and cross-culturally adapt the Short International Physical Activity Questionnaire (IPAQ-SF) to the Hausa language, and to evaluate the validity and reliability of the Hausa version of IPAQ-SF in Nigeria. Methods The English IPAQ-SF was translated into the Hausa language, synthesized, back translated, and subsequently subjected to expert committee review and pre-testing. The final product (Hausa IPAQ-SF) was tested in a cross-sectional study for concurrent (correlation with the English version) and construct validity, and test-retest reliability in a sample of 102 apparently healthy adults. Results The Hausa IPAQ-SF has good concurrent validity with Spearman correlation coefficients (ρ) ranging from 0.78 for vigorous activity (Min Week-1) to 0.92 for total physical activity (Metabolic Equivalent of Task [MET]-Min Week-1), but poor construct validity, with cardiorespiratory fitness (ρ = 0.21, p = 0.01) and body mass index (ρ = 0.22, p = 0.04) significantly correlated with only moderate activity and sitting time (Min Week-1), respectively. Reliability was good for vigorous (ICC = 0.73, 95% C.I = 0.55-0.84) and total physical activity (ICC = 0.61, 95% C.I = 0.47-0.72), but fair for moderate activity (ICC = 0.33, 95% C.I = 0.12-0.51), and few meaningful differences were found in the gender and socioeconomic status specific analyses. Conclusions The Hausa IPAQ-SF has acceptable concurrent validity and test-retest reliability for vigorous-intensity activity, walking, sitting and total physical activity, but demonstrated only fair construct validity for moderate and sitting

  10. Low frequency sawtooth precursor activity in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Papp, G.; Pokol, G. I.; Por, G.; Magyarkuti, A.; Lazányi, N.; Horváth, L.; Igochine, V.; Maraschek, M.; ASDEX Upgrade Team

    2011-06-01

    This paper describes the precursor activity observed in the ASDEX Upgrade tokamak before sawtooth crashes in various neutral beam heated plasmas, utilizing the soft x-ray diagnostic. In addition to the well-known (m, n) = (1,1) internal kink mode and its harmonics, a lower frequency mode is studied in detail. Power modulation of this mode is found to correlate with the power modulation of the (1, 1) kink mode in the quasistationary intervals indicating possible nonlinear interaction. Throughout the studied sawtooth crashes, the power of the lower frequency mode rose by several orders of magnitude just before the crash. In addition to its temporal behaviour, its spatial structure was estimated and the most likely value was found to be (1, 1). A possible role of this mode in the mechanism of the sawtooth crash is discussed.

  11. 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

  12. A General Questionnaire Analysis Program

    ERIC Educational Resources Information Center

    Aiken, Lewis R.

    1978-01-01

    A general FORTRAN computer program for analyzing categorical or frequency data obtained from questionnaires is described. A variety of descriptive statistics, chi square, Kendall's tau and Cramer's statistic are provided. (Author/JKS)

  13. 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

  14. 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

  15. Comparison of a Full Food-Frequency Questionnaire with the Three-Day Unweighted Food Records in Young Polish Adult Women: Implications for Dietary Assessment

    PubMed Central

    Kowalkowska, Joanna; Slowinska, Malgorzata A.; Slowinski, Dariusz; Dlugosz, Anna; Niedzwiedzka, Ewa; Wadolowska, Lidia

    2013-01-01

    The food frequency questionnaire (FFQ) and the food record (FR) are among the most common methods used in dietary research. It is important to know that is it possible to use both methods simultaneously in dietary assessment and prepare a single, comprehensive interpretation. The aim of this study was to compare the energy and nutritional value of diets, determined by the FFQ and by the three-day food records of young women. The study involved 84 female students aged 21–26 years (mean of 22.2 ± 0.8 years). Completing the FFQ was preceded by obtaining unweighted food records covering three consecutive days. Energy and nutritional value of diets was assessed for both methods (FFQ-crude, FR-crude). Data obtained for FFQ-crude were adjusted with beta-coefficient equaling 0.5915 (FFQ-adjusted) and regression analysis (FFQ-regressive). The FFQ-adjusted was calculated as FR-crude/FFQ-crude ratio of mean daily energy intake. FFQ-regressive was calculated for energy and each nutrient separately using regression equation, including FFQ-crude and FR-crude as covariates. For FR-crude and FFQ-crude the energy value of diets was standardized to 2000 kcal (FR-standardized, FFQ-standardized). Methods of statistical comparison included a dependent samples t-test, a chi-square test, and the Bland-Altman method. The mean energy intake in FFQ-crude was significantly higher than FR-crude (2740.5 kcal vs. 1621.0 kcal, respectively). For FR-standardized and FFQ-standardized, significance differences were found in the mean intake of 18 out of 31 nutrients, for FR-crude and FFQ-adjusted in 13 out of 31 nutrients and FR-crude and FFQ-regressive in 11 out of 31 nutrients. The Bland-Altman method showed an overestimation of energy and nutrient intake by FFQ-crude in comparison to FR-crude, e.g., total protein was overestimated by 34.7 g/day (95% Confidence Interval, CI: −29.6, 99.0 g/day) and fat by 48.6 g/day (95% CI: −36.4, 133.6 g/day). After regressive transformation of FFQ, the

  16. High-frequency TRNS reduces BOLD activity during visuomotor learning.

    PubMed

    Saiote, Catarina; Polanía, Rafael; Rosenberger, Konstantin; Paulus, Walter; Antal, Andrea

    2013-01-01

    Transcranial direct current stimulation (tDCS) and transcranial random noise stimulation (tRNS) consist in the application of electrical current of small intensity through the scalp, able to modulate perceptual and motor learning, probably by changing brain excitability. We investigated the effects of these transcranial electrical stimulation techniques in the early and later stages of visuomotor learning, as well as associated brain activity changes using functional magnetic resonance imaging (fMRI). We applied anodal and cathodal tDCS, low-frequency and high-frequency tRNS (lf-tRNS, 0.1-100 Hz; hf-tRNS 101-640 Hz, respectively) and sham stimulation over the primary motor cortex (M1) during the first 10 minutes of a visuomotor learning paradigm and measured performance changes for 20 minutes after stimulation ceased. Functional imaging scans were acquired throughout the whole experiment. Cathodal tDCS and hf-tRNS showed a tendency to improve and lf-tRNS to hinder early learning during stimulation, an effect that remained for 20 minutes after cessation of stimulation in the late learning phase. Motor learning-related activity decreased in several regions as reported previously, however, there was no significant modulation of brain activity by tDCS. In opposition to this, hf-tRNS was associated with reduced motor task-related-activity bilaterally in the frontal cortex and precuneous, probably due to interaction with ongoing neuronal oscillations. This result highlights the potential of lf-tRNS and hf-tRNS to differentially modulate visuomotor learning and advances our knowledge on neuroplasticity induction approaches combined with functional imaging methods. PMID:23527247

  17. Treatment of Hypophosphatemic Rickets with Phosphate and Active Vitamin D in Japan: A Questionnaire-based Survey

    PubMed Central

    Fujiwara, Makoto; Namba, Noriyuki; Ozono, Keiichi; Arisaka, Osamu; Yokoya, Susumu

    2013-01-01

    Hereditary hypophosphatemic rickets represented by X-linked hypophosphatemic rickets (XLH) is a rare disorder characterized by hypophosphatemia, elevated alkaline phosphatase (ALP) and undermineralization of bone. Active vitamin D and phosphate are administered to correct hypophosphatemia and elevation of ALP. Overtreatment with phosphate leads to secondary hyperparathyroidism, and a large dose of active vitamin D has a risk of hypercalciuria. To understand the situation concerning treatment of patients with hereditary hypophosphatemic rickets in Japan, we conducted a questionnaire survey of pediatric endocrinologists. Answers were obtained from 53 out of 68 hospitals where the pediatric endocrinologists worked. One hundred and thirty-five patients were treated in 28 hospitals during November 2009 and May 2010; 126 patients suffered from hereditary hypophosphatemic rickets, and 9 had hypophosphatemia caused by other miscellaneous reasons. The distribution of patient age was as follows: 27 (21%) were between 6 mo and 6 yr of age, 39 (31%) were between 6 and 12 yr of age, and 60 (48%) were more than 12 yr of age. Active vitamin D was given to 123 patients, and phosphate was given to 106 patients. As for the dose of phosphorus, 37.2–58.1 mg/kg/d was given divided into 2 to 6 aliquots. There were various control targets of treatment, including serum phosphate, serum ALP, rachitic change, urinary Ca/Cr, parathyroid hormone and growth. It is very important to avoid side effects of these treatments. No evidence is available about the optimal dose of phosphate or number of administrations in the treatment of patients with hypophosphatemic rickets. Although there is a recommendation for clinical management of patients with hypophosphatemic rickets, we should set a clinical guideline for it in Japan. PMID:23966755

  18. 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

    2016-05-01

    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. PMID:27553398

  19. High Frequency Monitoring of the Aigion Fault Activity

    NASA Astrophysics Data System (ADS)

    Cornet, Francois; Bourouis, Seid

    2013-04-01

    In 2007, a high frequency monitoring system was deployed in the 1000 m deep AIG10 well that intersects the Aigion fault at a depth of 760 m. This active 15 km long fault is located on the south shore of the Corinth rift, some 40 km east from Patras, in western central Greece. The borehole intersects quaternary sediments down to 495 m, then cretaceous and tertiary heavily tectonized deposits from the Pindos nappe. Below the fault encountered at 760 m, the borehole remains within karstic limestone of the Gavrovo Tripolitza nappe. The monitoring system involved two geophones located some 15 m above the fault, and two hydrophones located respectively at depths equal to 500 m and 250 m. The frequency domain for the data acquisition system ranged from a few Hz to 2500 Hz. The seismic velocity structure close to the borehole was determined through both sonic logs and vertical seismic profiles. This monitoring system has been active during slightly over six months and has recorded signals from microseismic events that occurred in the rift, the location of which was determined thanks to the local 11 stations, three components, short period (2 Hz), monitoring system. In addition, the borehole monitoring system has recorded more than 1000 events not identified with the regional network. Events were precisely correlated with pressure variations associated with two human interventions. These extremely low magnitude events occurred at distances that reached at least up to 1500 m from the well. They were associated, some ten days later, with some local rift activity. A tentative model is proposed that associates local short slip instabilities in the upper part of the fault close to the well, with a longer duration pore pressure diffusion process. Results demonstrate that the Aigion fault is continuously creeping down to a depth at least equal to 5 km but probably deeper.

  20. Reliability of the ALPHA environmental questionnaire and its association with physical activity in female fibromyalgia patients: the al-Ándalus project.

    PubMed

    Herrador-Colmenero, Manuel; Ruiz, Jonatan R; Ortega, Francisco B; Segura-Jiménez, Víctor; Álvarez-Gallardo, Inmaculada C; Camiletti-Moirón, Daniel; Estévez-López, Fernando; Delgado-Fernández, Manuel; Chillón, Palma

    2015-01-01

    Physical activity attenuates the symptoms of fibromyalgia, and its level is oftentimes associated with the perceived environment of fibromyalgia patients. Within this context, we aimed to study the reliability of the Spanish version of the Assessing Levels of Physical Activity (ALPHA) environmental questionnaire and the mode of commuting questionnaire. We also studied the association between the perceived environment and mode of commuting with physical activity levels among female fibromyalgia patients in Spain. Test-retest reliability was judged by the intra-class correlation coefficient (ICC), weighted kappa statistic, Spearman correlations and the proportion of agreement. We calculated bivariate Pearson's correlations between environmental sum scores and physical activity measured by both International Physical Activity Questionnaire (IPAQ) and accelerometry. More than 70% of the scales and items showed a good reliability regarding the ICC, the weighted kappa, the Spearman correlation and the percentage of inter-agreement (higher than 50%). The perceived environment assessed with the ALPHA showed a low correlation with both IPAQ and accelerometry. The Spanish version of the ALPHA environmental questionnaire proved to be reliable and showed a weak degree of association with physical activity in female fibromyalgia patients. PMID:25357996

  1. 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.

  2. The Depression Coping Questionnaire.

    ERIC Educational Resources Information Center

    Kleinke, Chris L.

    College students (N=396), chronic pain patients (N=319), and schizophrenic veterans (N=43) completed the Depression Coping Questionnaire (DCQ) and the Beck Depression Inventory (BDI). Factor analysis of the DCQ identified eleven coping responses: social support, problem solving, self-blame/escape, aggression, indulgence, activities, medication,…

  3. Daily Physical Activities and Sports in Adult Survivors of Childhood Cancer and Healthy Controls: A Population-Based Questionnaire Survey

    PubMed Central

    Rueegg, Corina S.; von der Weid, Nicolas X.; Rebholz, Cornelia E.; Michel, Gisela; Zwahlen, Marcel; Grotzer, Michael; Kuehni, Claudia E.

    2012-01-01

    Background Healthy lifestyle including sufficient physical activity may mitigate or prevent adverse long-term effects of childhood cancer. We described daily physical activities and sports in childhood cancer survivors and controls, and assessed determinants of both activity patterns. Methodology/Principal Findings The Swiss Childhood Cancer Survivor Study is a questionnaire survey including all children diagnosed with cancer 1976–2003 at age 0–15 years, registered in the Swiss Childhood Cancer Registry, who survived ≥5years and reached adulthood (≥20years). Controls came from the population-based Swiss Health Survey. We compared the two populations and determined risk factors for both outcomes in separate multivariable logistic regression models. The sample included 1058 survivors and 5593 controls (response rates 78% and 66%). Sufficient daily physical activities were reported by 52% (n = 521) of survivors and 37% (n = 2069) of controls (p<0.001). In contrast, 62% (n = 640) of survivors and 65% (n = 3635) of controls reported engaging in sports (p = 0.067). Risk factors for insufficient daily activities in both populations were: older age (OR for ≥35years: 1.5, 95CI 1.2–2.0), female gender (OR 1.6, 95CI 1.3–1.9), French/Italian Speaking (OR 1.4, 95CI 1.1–1.7), and higher education (OR for university education: 2.0, 95CI 1.5–2.6). Risk factors for no sports were: being a survivor (OR 1.3, 95CI 1.1–1.6), older age (OR for ≥35years: 1.4, 95CI 1.1–1.8), migration background (OR 1.5, 95CI 1.3–1.8), French/Italian speaking (OR 1.4, 95CI 1.2–1.7), lower education (OR for compulsory schooling only: 1.6, 95CI 1.2–2.2), being married (OR 1.7, 95CI 1.5–2.0), having children (OR 1.3, 95CI 1.4–1.9), obesity (OR 2.4, 95CI 1.7–3.3), and smoking (OR 1.7, 95CI 1.5–2.1). Type of diagnosis was only associated with sports. Conclusions/Significance Physical activity levels in survivors were lower than recommended, but

  4. Carotenoid intakes, assessed by food-frequency questionnaires (FFQs), are associated with serum carotenoid concentrations in the Jackson Heart Study: validation of the Jackson Heart Study Delta NIRI Adult FFQs

    PubMed Central

    Talegawkar, Sameera A; Johnson, Elizabeth J; Carithers, Teresa C; Taylor, Herman A; Bogle, Margaret L; Tucker, Katherine L

    2009-01-01

    Objectives Intake and status of carotenoids have been associated with chronic disease. The objectives of this study were to examine the association between carotenoid intakes as measured by two regional food-frequency questionnaires (FFQs) and their corresponding measures in serum, and to report on dietary food sources of carotenoids in Jackson Heart Study (JHS) participants. Design Cross-sectional analysis of data for 402 African American men and women participating in the Diet and Physical Activity Sub-Study (DPASS) of the JHS. Results Mean serum carotenoid concentrations and intakes in this population were comparable to those reported for the general US population. After adjustment for covariates, correlations between serum and dietary measures of each carotenoid, for the average of the recalls (deattenuated), the short FFQ and the long FFQ, respectively, were: 0.37, 0.35 and 0.21 for α-carotene; 0.35, 0.26 and 0.28 for total (diet plus supplements) β-carotene; 0.25, 0.17 and 0.20 for dietary β-carotene; 0.42, 0.34 and 0.26 for β-cryptoxanthin; 0.33, 0.15 and 0.17 for lutein plus zeaxanthin; and 0.37, 0.19 and 0.14 for lycopene. Major dietary sources of α-carotene were orange vegetables; of β-carotene and lutein plus zeaxanthin, mustard, turnip and collard greens; of β-cryptoxanthin, orange juice; and of lycopene, tomato juice. Conclusions On average, carotenoid intakes and serum concentrations are not lower in this southern African American population than the general US population. The two regional FFQs developed for a southern US population and used as dietary assessment tools in the JHS appear to provide reasonably valid information for most of these carotenoids. PMID:18053294

  5. Low diversity and low frequency of participation in leisure activities compromise working memory efficiency in young adults.

    PubMed

    Ruiz-Contreras, Alejandra E; Soria-Rodríguez, Gerardo; Almeida-Rosas, Georgina A; García-Vaca, Paola A; Delgado-Herrera, Maribel; Méndez-Díaz, Mónica; Prospéro-García, Oscar

    2012-01-01

    People perform leisure activities (LA) every day; pursuits that entail applying cognitive, physical and social abilities. As in old age, doing LA during early and middle adulthood is related to a reduced risk of dementias, probably by generating a cognitive reserve. As it is possible that a relation between doing LA and working memory (WM) efficiency exists in young adults, we assessed whether the diversity and frequency of LA are related to WM efficiency in this population. Ninety-three healthy young subjects solved the n-back task at two levels of difficulty (2, 3), and answered an LA questionnaire on the activities in which they had participated in the month prior to the experiment. Subjects were classified separately on their scores for (1) diversity (high/low) and (2) frequency (high/low) in order to test the relation between each variable and WM efficiency. Though no differences were found, a subsequent analysis of the average of diversity and frequency ratios of LA performance taken together-the diversity/frequency index-showed that low diversity plus low frequency was significantly associated with reduced WM efficiency at this age; results that suggest that frequent participation in diverse LA during youth is related to WM efficiency. PMID:22093383

  6. 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. PMID:25324099

  7. Multi-frequency periodic vibration suppressing in active magnetic bearing-rotor systems via response matching in frequency domain

    NASA Astrophysics Data System (ADS)

    Jiang, Kejian; Zhu, Changsheng

    2011-05-01

    A method for multi-frequency periodic vibration suppressing in active magnetic bearing (AMB)-rotor systems is proposed, which is based on an adaptive finite-duration impulse response (FIR) filter in time domain. Firstly, the theoretic feasibility of the method is proved. However, two problems would be unavoidable, if the conventional adaptive FIR filter is adopted in practical application. One is that the convergence rate of the different frequency components may be highly disparate in multi-frequency vibration control. The other is that the computational complexity is significantly increased because the long memory FIR filter is required to match the transient response time of the AMB-rotor system. To overcome the problems above, the Fast Block Least Mean Square (FBLMS) algorithm is adopted to efficiently implement the computation in frequency domain at a computational cost far less than that of the conventional FIR filter. By the FBLMS algorithm, regardless of the number of the considered frequency components in vibration disturbance, the computational complexity would be invariable. Moreover, filter's weights in the FBLMS algorithm have the intuitional relation with signal's frequency. As a result, the convergence rate of each frequency component can be adjusted by assigning the individual step size parameter for each weight. Experiments with the reciprocating simulating disturbance test and the rotating harmonic vibration test were carried out on an AMB-rigid rotor test rig with a vertical shaft. The experiment results indicate that the proposed method with the FBLMS algorithm can achieve the good effectiveness for suppressing the multi-frequency vibration. The convergence property of each frequency component can be adjusted conveniently. Each harmonic component of the vibration can be addressed, respectively, by reconfiguring the frequency components of the reference input signal.

  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. Enhancement and quenching of high-intensity focused ultrasound cavitation activity via short frequency sweep gaps.

    PubMed

    Hallez, Loïc; Lee, Judy; Touyeras, Francis; Nevers, Aymeric; Ashokkumar, Muthupandian; Hihn, Jean-Yves

    2016-03-01

    This letter reports on the use of frequency sweeps to probe acoustic cavitation activity generated by high-intensity focused ultrasound (HIFU). Unprecedented enhancement and quenching of HIFU cavitation activity were observed when short frequency sweep gaps were applied in negative and positive directions, respectively. It was revealed that irrespective of the frequency gap, it is the direction and frequency sweep rate that govern the cavitation activity. These effects are related to the response of bubbles generated by the starting frequency to the direction of the frequency sweep, and the influence of the sweep rate on growth and coalescence of bubbles, which in turn affects the active bubble population. These findings are relevant for the use of HIFU in chemical and therapeutic applications, where greater control of cavitation bubble population is critical. PMID:26584998

  10. Comparison of major dish item and food group consumption between normal and obese Korean children: application to development of a brief food frequency questionnaire for obesity-related eating behaviors

    PubMed Central

    Lee, Seungmin

    2007-01-01

    This study sought to compare intake levels of major dish items and food groups between normal and obese Korean children in order to understand obesity-related eating behaviors. The study was also conducted to apply the information on the differences in major dish items and food groups found in this study to development of a brief food frequency questionnaire (FFQ) for children's obesity-related eating behaviors. Finally, the developed FFQ was evaluated for reliability. A total of 290, 24-hour dietary recall data from 9-11 year-old normal or obese participants in the 2001 Korean National Health and Nutrition Examination Survey (KNHANES) were reviewed to identify dish items and food groups showing outstanding differences between the normal and obese groups. Based on the level of intake amount between the two groups, a total of 7 items, including ddeokbokggi, spaghetti, ham roast, pork cutlet, dairy products & ices, kimchi, and fruits, were selected to be included in the FFQ. The former 5 items were seen to be consumed more in the obese group, while the latter 2 items were so in the normal group. The questionnaire was formatted into a frequency response section of a seven-category option and reference period of the last 7 days. Test-retest reliability of the developed FFQ was examined by administering it to 153, 9-11 year-old children at a public elementary school in Seoul twice at a month interval. The level of reliability was found to be reasonably high. In conclusion, this study suggests that high consumption of several high-calorie dish items and low consumption of kimchi and fruits may be important eating behaviors in relation to obesity risk among 9-11 year-old children who need nutrition educators' attention. The current study also implies that a simple FFQ can be utilized to reliably assess 9-11 year-old children's diets. PMID:20368956

  11. 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. PMID:25655955

  12. Feasibility of simultaneous operation of passive remote microwave sensors and active services occupying adjacent frequency bands

    NASA Technical Reports Server (NTRS)

    Sue, M. K.

    1982-01-01

    To ensure proper sensor operations, it is necessary to understand the situation of potential interference to sensors due to active equipment sharing common frequency bands as well as equipment occupying adjacent bands. The feasibility of sharing common frequency bands between passive sensors and other active services was analyzed. Potential interference to sensors due to equipment in bands adjacent to sensor frequency bands is examined and criteria to avoid interference is developed.

  13. 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...

  14. 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.

  15. 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…

  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

    ... technology would be used in support of USCG missions to locate, image, and classify submerged/underwater... ability to locate, image, and classify underwater threats and other TOIs. HF and UHF SONAR technology... activities. The USCG needs to broaden its capability to locate, image, and classify submerged/underwater...

  17. 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

    ... in the January 17, 2008, issue of the Federal Register (73 FR 3316). Background and Purpose Purpose.... Active SONAR technology would be used in support of USCG missions to locate, image, and classify... the ability to locate, image, and classify underwater threats and other TOIs. HF and UHF...

  18. 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.

  19. 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. PMID:26635347

  20. Radio Frequency-Activated Nanoliposomes for Controlled Combination Drug Delivery.

    PubMed

    Malekar, Swapnil A; Sarode, Ashish L; Bach, Alvin C; Bose, Arijit; Bothun, Geoffrey; Worthen, David R

    2015-12-01

    This work was conducted in order to design, characterize, and evaluate stable liposomes containing the hydrophobic drug raloxifene HCl (RAL) and hydrophilic doxycycline HCl (DOX), two potentially synergistic agents for treating osteoporosis and other bone lesions, in conjunction with a radio frequency-induced, hydrophobic magnetic nanoparticle-dependent triggering mechanism for drug release. Both drugs were successfully incorporated into liposomes by lipid film hydration, although combination drug loading compromised liposome stability. Liposome stability was improved by reducing the drug load and by including Pluronics® (PL) in the formulations. DOX did not appear to interact with the phospholipid membranes comprising the liposomes, and its release was maximized in the presence of radio frequency (RF) heating. In contrast, differential scanning calorimetry (DSC) and phosphorus-31 nuclear magnetic resonance ((31)P-NMR) analysis revealed that RAL developed strong interactions with the phospholipid membranes, most notably with lipid phosphate head groups, resulting in significant changes in membrane thermodynamics. Likewise, RAL release from liposomes was minimal, even in the presence of RF heating. These studies may offer useful insights into the design and optimization of multidrug containing liposomes. The effects of RAL on liposome characteristics and drug release performance underscore the importance of appropriate physical-chemical analysis in order to identify and characterize drug-lipid interactions that may profoundly affect liposome properties and performance early in the formulation development process. PMID:25899799

  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. 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…

  3. Development and psychometric properties of the Y-PASS questionnaire to assess correlates of lunchtime and after-school physical activity in children

    PubMed Central

    2014-01-01

    Background To frame interventions, it is useful to understand context- and time-specific correlates of children’s physical activity. To do this, we need accurate assessment of these correlates. There are currently no measures that assess correlates at all levels of the social ecological model, contain items that are specifically worded for the lunchtime and/or after-school time periods, and assess correlates that have been conceptualised and defined by children. The aim of this study was to develop and evaluate the psychometric properties of the lunchtime and after-school Youth Physical Activity Survey for Specific Settings (Y-PASS) questionnaires. Methods The Y-PASS questionnaire was administered to 264 South Australian children (146 boys, 118 girls; mean age = 11.7 ± 0.93 years). Factorial structure and internal consistency of the intrapersonal, sociocultural and physical environmental/policy lunchtime and after-school subscales were examined through an exploratory factor analysis. The test-retest reliability of the Y-PASS subscales was assessed over a one-week period on a subsample of children (lunchtime Y-PASS: n = 12 boys, 12 girls, mean age of 11.6 ± 0.8 years; after-school Y-PASS: n = 9 boys, 13 girls; mean age = 11.4 ± 0.9 years). Results For the lunchtime Y-PASS, three factors were identified under each of the intrapersonal, sociocultural and physical environmental/policy subscales. For the after-school Y-PASS, six factors were identified in the intrapersonal subscale, four factors in the sociocultural subscale and seven factors in the physical environmental/policy subscale. Following item reduction, all subscales demonstrated acceptable internal consistency (Cronbach alpha = 0.78 – 0.85), except for the lunchtime sociocultural subscale (Cronbach alpha = 0.55). The factors and items demonstrated fair to very high test-retest reliability (ICC = 0.26 – 0.93). Conclusion The preliminary reliability and

  4. Development and validation of a questionnaire assessing volitional competencies to enhance the performance of physical activities in chronic low back pain patients

    PubMed Central

    2011-01-01

    Background Motivation has long been emphasized as the most important determinant of action. However, there is a substantial gap between people's goals and their attainment. Patients may be motivated and yet unable to take action if their volitional competencies are insufficient. One of the important tasks of volition is goal-maintenance. Research has stressed the importance of a volitional tool, the implementation intentions. Implementation intentions indicate where, when, and how the action leading to the goal will be performed. Forming implementation intentions favours the execution of goal-directed efforts, and reinforces the relationship between intentions and behaviours. Results from various studies clearly suggest that volitional competencies and implementation intentions could play a role in low back pain (LBP) patients. However, there is at present no questionnaire allowing assessing the capacity of implementation intentions of physical activities in LBP patients. Methods/Design This study will develop such a questionnaire, using a 3-step approach. A first qualitative step to build categories and generate items; 30 patients suffering chronic LBP will be invited to participate in semi-structured interviews; verbatim and derived items will then be submitted to a panel of experts, using a Delphi method; a second quantitative step to examine the properties of items, and determine the factorial structure of the questionnaire; 100 patients suffering chronic LBP will be recruited to respond to this phase; and third, preliminary psychometric analyses (item-scale correlations, construct validity, reliability); 180 chronic LBP patients will be recruited for this phase of the study. The relationships between implementation intentions and variables affecting physical activity on chronic LBP patients, i.e. pain, physical capacities, fear-avoidance beliefs, kinesiophobia, work status, and level of physical activity will be considered. Discussion Developing a

  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. Stay tuned: active amplification tunes tree cricket ears to track temperature-dependent song frequency.

    PubMed

    Mhatre, Natasha; Pollack, Gerald; Mason, Andrew

    2016-04-01

    Tree cricket males produce tonal songs, used for mate attraction and male-male interactions. Active mechanics tunes hearing to conspecific song frequency. However, tree cricket song frequency increases with temperature, presenting a problem for tuned listeners. We show that the actively amplified frequency increases with temperature, thus shifting mechanical and neuronal auditory tuning to maintain a match with conspecific song frequency. Active auditory processes are known from several taxa, but their adaptive function has rarely been demonstrated. We show that tree crickets harness active processes to ensure that auditory tuning remains matched to conspecific song frequency, despite changing environmental conditions and signal characteristics. Adaptive tuning allows tree crickets to selectively detect potential mates or rivals over large distances and is likely to bestow a strong selective advantage by reducing mate-finding effort and facilitating intermale interactions. PMID:27122007

  7. Age- and Sex-Specific Criterion Validity of the Health Survey for England Physical Activity and Sedentary Behavior Assessment Questionnaire as Compared With Accelerometry

    PubMed Central

    Scholes, Shaun; Coombs, Ngaire; Pedisic, Zeljko; Mindell, Jennifer S.; Bauman, Adrian; Rowlands, Alex V.; Stamatakis, Emmanuel

    2014-01-01

    The criterion validity of the 2008 Physical Activity and Sedentary Behavior Assessment Questionnaire (PASBAQ) was examined in a nationally representative sample of 2,175 persons aged ≥16 years in England using accelerometry. Using accelerometer minutes/day greater than or equal to 200 counts as a criterion, Spearman's correlation coefficient (ρ) for PASBAQ-assessed total activity was 0.30 (95% confidence interval (CI): 0.25, 0.35) in women and 0.20 (95% CI: 0.15, 0.26) in men. Correlations between accelerometer counts/minute of wear time and questionnaire-assessed relative energy expenditure (metabolic equivalent-minutes/day) were higher in women (ρ = 0.41, 95% CI: 0.36, 0.46) than in men (ρ = 0.32, 95% CI: 0.26, 0.38). Similar correlations were observed for minutes/day spent in vigorous activity (women: ρ = 0.39, 95% CI: 0.33, 0.46; men: ρ = 0.31, 95% CI: 0.26, 0.36) and moderate-to-vigorous activity (women: ρ = 0.42, 95% CI: 0.36, 0.48; men: ρ = 0.38, 95% CI: 0.32, 0.45). Correlations for time spent being sedentary (<100 counts/minute) were 0.30 (95% CI: 0.24, 0.35) and 0.25 (95% CI: 0.19, 0.30) in women and men, respectively. Sedentary behavior correlations showed no sex difference. The validity of sedentary behavior and total physical activity was higher in older age groups, but validity was higher in younger persons for vigorous-intensity activity. The PASBAQ is a useful and valid instrument for ranking individuals according to levels of physical activity and sedentary behavior. PMID:24863551

  8. 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

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

    PubMed Central

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

    2012-01-01

    SUMMARY 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. PMID:23044219

  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. 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.

  12. 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

  13. 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.

  14. 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 ...

  15. 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…

  16. 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…

  17. Patient Acceptable Symptom State in Self-Report Questionnaires and Composite Clinical Disease Index for Assessing Rheumatoid Arthritis Activity: Identification of Cut-Off Points for Routine Care

    PubMed Central

    Salaffi, Fausto; Carotti, Marina; Gutierrez, Marwin; Di Carlo, Marco; De Angelis, Rossella

    2015-01-01

    Objective. To provide information on the value of Patient Acceptable Symptom State (PASS) in rheumatoid arthritis (RA) by the identification of PASS thresholds for patient-reported outcomes (PROs) composite scores. Methods. The characteristics of RA patients with affirmative and negative assignment to PASS were compared. Contributors to physician response were estimated by logistic regression models and PASS thresholds by the 75th percentile and receiver-operating characteristic (ROC) curve methods. Results. 303 RA patients completed the study. All PROs were different between the PASS (+) and PASS (−) groups (p < 0.0001). The thresholds with the 75th percentile approach were 2.0 for the RA Impact of Disease (RAID) score, 2.5 for the PRO-CLinical ARthritis Activity (PRO-CLARA) index, and 1.0 for the Recent-Onset Arthritis Disability (ROAD) questionnaire. The cut-off values for Clinical Disease Activity Index (CDAI) were in the moderate range of disease activity. Assessing the size of the logistic regression coefficients, the strongest predictors of PASS were the disease activity (p = 0.0007) and functional state level (0.006). Conclusion. PASS thresholds were relatively high and many patients in PASS had moderate disease activity states according to CDAI. Factors such as disease activity and physical function may influence a negative PASS. PMID:26167506

  18. 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.

  19. Comparison of validity of food group intake by food frequency questionnaire between pre- and post- adjustment estimates derived from 2-day 24-hour recalls in combination with the probability of consumption.

    PubMed

    Kim, Dong Woo; Oh, Se-Young; Kwon, Sung-Ok; Kim, Jeongseon

    2012-01-01

    Validation of a food frequency questionnaire (FFQ) utilising a short-term measurement method is challenging when the reference method does not accurately reflect the usual food intake. In addition, food group intake that is not consumed on daily basis is more critical when episodically consumed foods are related and compared. To overcome these challenges, several statistical approaches have been developed to determine usual food intake distributions. The Multiple Source Method (MSM) can calculate the usual food intake by combining the frequency questions of an FFQ with the short-term food intake amount data. In this study, we applied the MSM to estimate the usual food group intake and evaluate the validity of an FFQ with a group of 333 Korean children (aged 3-6 y) who completed two 24-hour recalls (24HR) and one FFQ in 2010. After adjusting the data using the MSM procedure, the true rate of non-consumption for all food groups was less than 1% except for the beans group. The median Spearman correlation coefficients against FFQ of the mean of 2-d 24HRs data and the MSM-adjusted data were 0.20 (range: 0.11 to 0.40) and 0.35 (range: 0.14 to 0.60), respectively. The weighted kappa values against FFQ ranged from 0.08 to 0.25 for the mean of 2-d 24HRs data and from 0.10 to 0.41 for the MSM-adjusted data. For most food groups, the MSM-adjusted data showed relatively stronger correlations against FFQ than raw 2-d 24HRs data, from 0.03 (beverages) to 0.34 (mushrooms). The results of this study indicated that the application of the MSM, which was a better estimate of the usual intake, could be worth considering in FFQ validation studies among Korean children. PMID:22938437

  20. 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.

  1. 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

  2. Cross-cultural, age and gender validation of a computerised questionnaire measuring personal, social and environmental associations with children's physical activity: the European Youth Heart Study

    PubMed Central

    Ommundsen, Yngvar; Page, Angie; Ku, Po-Wen; Cooper, Ashley R

    2008-01-01

    Objective This study investigated the construct validity of a computerised self-assessment tool to measure psychological, social and environmental influences of young peoples' physical activity. First, analyses of the measure's factorial validity, invariance across, age, gender culture were conducted. Second, the ability of the derived subscales to discriminate between children representing different levels of self-reported and objectively measured physical activity behaviour was examined. Methods Participants were 1875 boys and 2078 girls (total = 3958) aged 9–10 years (n = 1955, mean age = 9.65 ± 0.42) and 15–16 years (n = 2003, mean age = 15.49 ± 0.50) from four European countries in Northern, Southern and Eastern Europe who took part in the European Youth Heart Study (EYHS). Children completed the computerised self-assessment tool with support from the researcher if requested. Self-reported exercise and an objective measure of physical activity (Actigraph model 7164) were used for additional construct validation purposes. Results Overall evidence of good fit indicating satisfactory factorial validity and cross-cultural, age and gender invariance for 3 of the 4 measurement models were obtained. The majority of measures were also significantly different for those with high versus low levels of physical activity. Conclusion Overall, the computerised questionnaire holds promise for use cross-culturally with male and female children and adolescents to measure perceived personal, social and environmental influences on physical activity. Further development of the measures pertaining to perceived environmental influences seems warranted. PMID:18489736

  3. Objective assessment of intensity categorization of the previous day physical activity recall questionnaire in 11-13 year old children.

    PubMed

    McBrearty, Donough; McCrorie, Paul; Granat, Malcolm; Duncan, Elaine; Stansfield, Ben

    2014-11-01

    The Previous Day Physical Activity Recall (PDPAR) self-report questionnaire asks children to categories their time in 30 min blocks under activity codes and activity intensity (ActInt). Text and visual descriptors of ActInt are used which include posture and stepping intensity. This study aimed to objectively examine postures and stepping activity associated with PDPAR ActInt. Forty-three (19M/24F) 11-13 year children completed the PDPAR and wore a physical activity monitor (8 d). Within 30 min blocks the % sitting/lying, standing and stepping, steps, cadence and sit-to-stand transitions (STS) were examined by PDPAR ActInt across and within all activity codes. Data (14 083 30 min blocks) showed from light to moderate ActInt lower sedentary time, higher standing and stepping time, steps, sit-to-stand transitions and cadence (all P < 0.001). Between moderate and hard ActInt, time sedentary was lower and time stepping, steps and STS higher (all P < 0.005). No significant differences between hard and very hard. There was a wide variation of activity levels between activity codes within ActInt. ActInt within the PDPAR was not used consistently between activity codes. However, over all codes children demonstrated that they could distinguish between light and moderate and in some objective measures between moderate and hard, but not between hard and very hard ActInt. PMID:25340303

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

    PubMed Central

    Liang, Yan; Lau, Patrick W.C.; Huang, Wendy Y.J.; Maddison, Ralph; Baranowski, Tom

    2014-01-01

    Background Physical activity (PA) correlates have not been extensively studied in Hong Kong children. Objective 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. Methods Sample 1 (n = 273, aged 8–12 years) was recruited (May–June, 2013) from two primary schools. Confirmatory factor analyses (CFA) were conducted to assess factorial validity. Criterion validity was assessed by correlating measured constructs with self-reported PA. Cronbach's alpha was computed to assess scale internal consistency. The intraclass correlation coefficient (ICC) was performed to assess scale test–retest reliability. Criterion validity was further examined in Sample 2 (n = 84, aged 8–12 years) from a third school by correlating measured constructs with objectively measured PA collected in September 2013 and February 2014. Results The CFA results supported the one-factor structure of the scales. All PA correlates were significantly (p < 0.01) associated with self-reported PA in Sample 1. Self-efficacy and enjoyment were significantly (p < 0.05) correlated with objectively measured PA in Sample 2. All the scales demonstrated acceptable internal consistency. All ICC values of the scales suggested acceptable test–retest reliability. Conclusion The results provide psychometric support for using the scales to measure PA correlates among Hong Kong Chinese children. PMID:26844039

  5. 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.

  6. Effect of Word and Syllable Frequency on Activation During Lexical Decision and Reading Aloud

    PubMed Central

    Carreiras, Manuel; Mechelli, Andrea; Price, Cathy J

    2006-01-01

    This functional MRI (fMRI) study investigated the effect of lexical and syllable frequency on visual word processing during lexical decision and reading aloud. Previous research has shown a dissociation of syllable and word frequency effects in Spanish using behavioral and electrophysiological measures, suggesting that sublexical (syllabic) representations are computed and mediate the firing of lexical candidates. Here, we characterize the neuroanatomical basis of these lexical and sublexical manipulations and their dependence on task. During lexical decision, words with low vs. high lexical frequency increased activation in left frontal, anterior cingulate, supplemental motor area (SMA), and pre-SMA regions; while words with high vs. low syllable frequency increased activation in a left anterior inferior temporal region. In contrast, when the words were read aloud those with low vs. high syllable frequency increased activation in the left anterior insula, with no other significant effects. On the basis of the neuroanatomy, we propose that the contrasting effects of syllable frequency during lexical decision and reading aloud reflect two different cognitive processes in visual word processing. Specifically, words with high-frequency syllables may increase lexical competition in the inferior temporal lobe while facilitating articulatory planning in the left anterior insula. Hum Brain Mapp, 2006. © 2006 Wiley-Liss, Inc. PMID:16628608

  7. 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

  8. 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.

  9. 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

  10. 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…

  11. Active phase drift cancellation for optic-fiber frequency transfer using a photonic radio-frequency phase shifter.

    PubMed

    Shen, Jianguo; Wu, Guiling; Hu, Liang; Zou, Weiwen; Chen, Jianping

    2014-04-15

    We propose an active photonic phase drift cancellation scheme for frequency transfer over optical fiber based on a linear photonic RF phase shifter. The photonic RF phase shifter consists of a dual parallel Mach-Zehnder modulator and optical filter with the assistance of the local microwave signal. The phase drift induced by fiber transmission can be compensated by simply tuning the bias voltage of the modulator. The principle of the phase cancellation scheme based on the photonic phase shifter is demonstrated and validated experimentally by transferring a 0.5 GHz reference signal over a 20 km single-mode fiber with a root mean square jitter of less than 0.5 ps. PMID:24978989

  12. 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. PMID:26498697

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

    PubMed

    Peng, Jiegang

    2015-12-01

    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. PMID:26531142

  14. 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

  15. Reproducibility and Validity of Dietary Patterns Assessed by a Food Frequency Questionnaire Used in the 5-Year Follow-Up Survey of the Japan Public Health Center-Based Prospective Study

    PubMed Central

    Nanri, Akiko; Shimazu, Taichi; Ishihara, Junko; Takachi, Ribeka; Mizoue, Tetsuya; Inoue, Manami; Tsugane, Shoichiro

    2012-01-01

    Background Analysis of dietary pattern is increasingly popular in nutritional epidemiology. However, few studies have examined the validity and reproducibility of dietary patterns. We assessed the reproducibility and validity of dietary patterns identified by a food frequency questionnaire (FFQ) used in the 5-year follow-up survey of the Japan Public Health Center-Based Prospective Study (JPHC Study). Methods The participants were a subsample (244 men and 254 women) from the JPHC Study. Principal component analysis was used to identify dietary patterns from 28- or 14-day dietary records and 2 FFQs. To assess reproducibility and validity, we calculated Spearman correlation coefficients between dietary pattern scores derived from FFQs separated by a 1-year interval, and between dietary pattern scores derived from dietary records and those derived from a FFQ completed after the dietary records, respectively. Results We identified 3 Japanese dietary patterns from the dietary records and 2 FFQs: prudent, westernized, and traditional. Regarding reproducibility, Spearman correlation coefficients between the 2 FFQs ranged from 0.55 for the westernized Japanese pattern in men and the prudent Japanese pattern in women to 0.77 for the traditional Japanese pattern in men. Regarding validity, the corresponding values between dietary records and the FFQ ranged from 0.32 for the westernized Japanese pattern in men to 0.63 for the traditional Japanese pattern in women. Conclusions Acceptable reproducibility and validity was shown by the 3 dietary patterns identified by principal component analysis based on the FFQ used in the 5-year follow-up survey of the JPHC Study. PMID:22343330

  16. 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

  17. 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)

  18. 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…

  19. Henry County School Questionnaire.

    ERIC Educational Resources Information Center

    Goolsby, Thomas M., Jr.; Frary, Robert B.

    This 14-item questionnaire was designed to measure parent opinion regarding the effect of integration on third grade pupils in Henry County Schools. The questionnaire is not standardized, and field testing has been on a small scale. (See also TM 000 940 for a description of the study, and 942, 943 for the desegregation and school integration…

  20. 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…

  1. Questionnaire for Parents.

    ERIC Educational Resources Information Center

    Purdue Univ., Lafayette, IN. Educational Research Center.

    The 116-item parent questionnaire is designed for parents of elementary school children. It is intended to be used with the child's mother, or the person acting as the child's mother. The questionnaire consists of a section devoted to demographic variables and scales measuring 14 parent variables: (1) parent's achievement aspirations for the…

  2. 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.

  3. Does the Five Facet Mindfulness Questionnaire measure what we think it does? Construct validity evidence from an active controlled randomized clinical trial.

    PubMed

    Goldberg, Simon B; Wielgosz, Joseph; Dahl, Cortland; Schuyler, Brianna; MacCoon, Donal S; Rosenkranz, Melissa; Lutz, Antoine; Sebranek, Chad A; Davidson, Richard J

    2016-08-01

    The current study attempted a rigorous test of the construct validity of a widely used self-report measure of dispositional mindfulness, the Five Facet Mindfulness Questionnaire (FFMQ), within the context of an active controlled randomized trial (n = 130). The trial included three arms: mindfulness-based stress reduction (MBSR), an active control condition that did not include instruction in mindfulness meditation (Health Enhancement Program [HEP]), and a waitlist control condition. Partial evidence for the convergent validity of the FFMQ was shown in correlations at baseline between FFMQ facets and measures of psychological symptoms and psychological well-being. In addition, facets of the FFMQ were shown to increase over the course of an MBSR intervention relative to a waitlist control condition. However, the FFMQ failed to show discriminant validity. Specifically, facets of the FFMQ were shown to increase over the course of the HEP intervention relative to the waitlist control condition. MBSR and HEP, in contrast, did not differ in changes in FFMQ score over time. Implications of these findings for the measurement and theory of mindfulness and MBSR are discussed. (PsycINFO Database Record PMID:26460893

  4. Intralaminar stimulation of the inferior colliculus facilitates frequency-specific activation in the auditory cortex

    NASA Astrophysics Data System (ADS)

    Allitt, B. J.; Benjaminsen, C.; Morgan, S. J.; Paolini, A. G.

    2013-08-01

    Objective. Auditory midbrain implants (AMI) provide inadequate frequency discrimination for open set speech perception. AMIs that can take advantage of the tonotopic laminar of the midbrain may be able to better deliver frequency specific perception and lead to enhanced performance. Stimulation strategies that best elicit frequency specific activity need to be identified. This research examined the characteristic frequency (CF) relationship between regions of the auditory cortex (AC), in response to stimulated regions of the inferior colliculus (IC), comparing monopolar, and intralaminar bipolar electrical stimulation. Approach. Electrical stimulation using multi-channel micro-electrode arrays in the IC was used to elicit AC responses in anaesthetized male hooded Wistar rats. The rate of activity in AC regions with CFs within 3 kHz (CF-aligned) and unaligned CFs was used to assess the frequency specificity of responses. Main results. Both monopolar and bipolar IC stimulation led to CF-aligned neural activity in the AC. Altering the distance between the stimulation and reference electrodes in the IC led to changes in both threshold and dynamic range, with bipolar stimulation with 400 µm spacing evoking the lowest AC threshold and widest dynamic range. At saturation, bipolar stimulation elicited a significantly higher mean spike count in the AC at CF-aligned areas than at CF-unaligned areas when electrode spacing was 400 µm or less. Bipolar stimulation using electrode spacing of 400 µm or less also elicited a higher rate of elicited activity in the AC in both CF-aligned and CF-unaligned regions than monopolar stimulation. When electrodes were spaced 600 µm apart no benefit over monopolar stimulation was observed. Furthermore, monopolar stimulation of the external cortex of the IC resulted in more localized frequency responses than bipolar stimulation when stimulation and reference sites were 200 µm apart. Significance. These findings have implications for the

  5. Translating the Dutch Walking Stairs, Walking Ability and Rising and Sitting Questionnaires into German and assessing their concurrent validity with VAS measures of pain and activities in daily living

    PubMed Central

    2010-01-01

    Background The Dutch Walking Stairs, Walking Ability and Rising and Sitting Questionnaires are three validated instruments to measure physical activity and limitations in daily living in patients with lower extremity disorders living at home of which no German equivalents are available. Our scope was to translate the Walking Stairs, Walking Ability and Rising and Sitting Questionnaires into German and to verify its concurrent validity in the two domains pain and activities in daily living by comparing them with the corresponding measures on the Visual Analogue Scale. Methods We translated the Walking Stairs, Walking Ability and Rising and Sitting Questionnaires according to published guidelines. Demographic data and validity were assessed in 52 consecutive patients with Complex Regional Pain Syndrome 1 of the lower extremity. Information on age, duration of symptoms, type of Complex Regional Pain Syndrome 1 and type of initiating event were obtained. We assessed the concurrent validity in the two domains pain and activities in daily living by comparing them with the corresponding measures on the Visual Analogue Scale. Results We found that variability in the German Walking Stairs, Walking Ability and Rising and Sitting Questionnaires was largely explained by measures of pain and activities in daily living on the Visual Analogue Scale. Conclusion Our study shows that the domains pain and activities in daily living are properly represented in the German versions of the Walking Stairs, Walking Ability and Raising and Sitting Questionnaires. We would like to propagate their use in clinical practice and research alike. PMID:20515456

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. Electrical stimulation of the frontal cortex enhances slow-frequency EEG activity and sleepiness.

    PubMed

    D'Atri, A; De Simoni, E; Gorgoni, M; Ferrara, M; Ferlazzo, F; Rossini, P M; De Gennaro, L

    2016-06-01

    Our aim was to enhance the spontaneous slow-frequency EEG activity during the resting state using oscillating transcranial direct currents (tDCS) with a stimulation frequency that resembles the spontaneous oscillations of sleep onset. Accordingly, in this preliminary study, we assessed EEG after-effects of a frontal oscillatory tDCS with different frequency (0.8 vs. 5Hz) and polarity (anodal, cathodal, and sham). Two single-blind experiments compared the after effects on the resting EEG of oscillatory tDCS [Exp. 1=0.8Hz, 10 subjects (26.2±2.5years); Exp. 2=5Hz, 10 subjects (27.4±2.4years)] by manipulating its polarity. EEG signals recorded (28 scalp derivations) before and after stimulation [slow oscillations (0.5-1Hz), delta (1-4Hz), theta (5-7Hz), alpha (8-12Hz), beta 1 (13-15Hz) and beta 2 (16-24Hz)] were compared between conditions as a function of polarity (anodal vs. cathodal vs. sham) and frequency of stimulation (0.8 vs. 5Hz). We found a significant relative enhancement of the delta activity after the anodal tDCS at 5Hz compared to that at 0.8Hz. This increase, even though not reaching the statistical significance compared to sham, is concomitant to a significant increase of subjective sleepiness, as assessed by a visual analog scale. These two phenomena are linearly related with a regional specificity, correlations being restricted to cortical areas perifocal to the stimulation site. We have shown that a frontal oscillating anodal tDCS at 5Hz results in an effective change of both subjective sleepiness and spontaneous slow-frequency EEG activity. These changes are critically associated to both stimulation polarity (anodal) and frequency (5Hz). However, evidence of frequency-dependence seems more unequivocal than evidence of polarity-dependence. PMID:26964682

  11. 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

  12. 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.

  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. The contribution of frequency-specific activity to hierarchical information processing in the human auditory cortex

    PubMed Central

    Fontolan, L.; Morillon, B.; Liegeois-Chauvel, C.; Giraud, Anne-Lise

    2014-01-01

    The fact that feed-forward and top-down propagation of sensory information use distinct frequency bands is an appealing assumption for which evidence remains scarce. Here we obtain human depth recordings from two auditory cortical regions in both hemispheres, while subjects listen to sentences, and show that information travels in each direction using separate frequency channels. Bottom-up and top-down propagation dominates in γ- and δ–β (<40 Hz) bands, respectively. The predominance of low frequencies for top-down information transfer is confirmed by cross-regional frequency coupling, which indicates that the power of γ-activity in A1 is modulated by the phase of δ–β activity sampled from association auditory cortex (AAC). This cross-regional coupling effect is absent in the opposite direction. Finally, we show that information transfer does not proceed continuously but by time windows where bottom-up or top-down processing alternatively dominates. These findings suggest that the brain uses both frequency- and time-division multiplexing to optimize directional information transfer. PMID:25178489

  15. Simultaneous Measurement of Noise-Activated Middle-Ear Muscle Reflex and Stimulus Frequency Otoacoustic Emissions

    PubMed Central

    Keefe, Douglas H.

    2006-01-01

    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. PMID:16568366

  16. 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

  17. 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

  18. 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…

  19. 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

  20. The contribution of high frequencies to human brain activity underlying horizontal localization of natural spatial sounds

    PubMed Central

    Leino, Sakari; May, Patrick JC; Alku, Paavo; Liikkanen, Lassi A; Tiitinen, Hannu

    2007-01-01

    Background In the field of auditory neuroscience, much research has focused on the neural processes underlying human sound localization. A recent magnetoencephalography (MEG) study investigated localization-related brain activity by measuring the N1m event-related response originating in the auditory cortex. It was found that the dynamic range of the right-hemispheric N1m response, defined as the mean difference in response magnitude between contralateral and ipsilateral stimulation, reflects cortical activity related to the discrimination of horizontal sound direction. Interestingly, the results also suggested that the presence of realistic spectral information within horizontally located spatial sounds resulted in a larger right-hemispheric N1m dynamic range. Spectral cues being predominant at high frequencies, the present study further investigated the issue by removing frequencies from the spatial stimuli with low-pass filtering. This resulted in a stepwise elimination of direction-specific spectral information. Interaural time and level differences were kept constant. The original, unfiltered stimuli were broadband noise signals presented from five frontal horizontal directions and binaurally recorded for eight human subjects with miniature microphones placed in each subject's ear canals. Stimuli were presented to the subjects during MEG registration and in a behavioral listening experiment. Results The dynamic range of the right-hemispheric N1m amplitude was not significantly affected even when all frequencies above 600 Hz were removed. The dynamic range of the left-hemispheric N1m response was significantly diminished by the removal of frequencies over 7.5 kHz. The subjects' behavioral sound direction discrimination was only affected by the removal of frequencies over 600 Hz. Conclusion In accord with previous psychophysical findings, the current results indicate that frontal horizontal sound localization and related right-hemispheric cortical processes are

  1. 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

  2. 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. PMID:26064536

  3. Computationally efficient algorithm for high sampling-frequency operation of active noise control

    NASA Astrophysics Data System (ADS)

    Rout, Nirmal Kumar; Das, Debi Prasad; Panda, Ganapati

    2015-05-01

    In high sampling-frequency operation of active noise control (ANC) system the length of the secondary path estimate and the ANC filter are very long. This increases the computational complexity of the conventional filtered-x least mean square (FXLMS) algorithm. To reduce the computational complexity of long order ANC system using FXLMS algorithm, frequency domain block ANC algorithms have been proposed in past. These full block frequency domain ANC algorithms are associated with some disadvantages such as large block delay, quantization error due to computation of large size transforms and implementation difficulties in existing low-end DSP hardware. To overcome these shortcomings, the partitioned block ANC algorithm is newly proposed where the long length filters in ANC are divided into a number of equal partitions and suitably assembled to perform the FXLMS algorithm in the frequency domain. The complexity of this proposed frequency domain partitioned block FXLMS (FPBFXLMS) algorithm is quite reduced compared to the conventional FXLMS algorithm. It is further reduced by merging one fast Fourier transform (FFT)-inverse fast Fourier transform (IFFT) combination to derive the reduced structure FPBFXLMS (RFPBFXLMS) algorithm. Computational complexity analysis for different orders of filter and partition size are presented. Systematic computer simulations are carried out for both the proposed partitioned block ANC algorithms to show its accuracy compared to the time domain FXLMS algorithm.

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

    PubMed Central

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

    2014-01-01

    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. PMID:26064536

  5. Active low-frequency vertical vibration isolation system for precision measurements

    NASA Astrophysics Data System (ADS)

    Wu, Kang; Li, Gang; Hu, Hua; Wang, Lijun

    2016-06-01

    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.

  6. 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

  7. A self-reported questionnaire for quantifying illness symptoms in elite athletes

    PubMed Central

    Matthews, Alexander; Pyne, David; Saunders, Philo; Fallon, Kieran; Fricker, Peter

    2010-01-01

    Purpose To develop and evaluate a questionnaire that quantifies the self-reported frequency, duration and severity of illness symptoms in highly-trained athletes. We examined whether runners had more symptoms than recreationally-active individuals, and whether runners more prone to illness were undertaking more strenuous training programs. Methods A daily illness questionnaire was administered for three months during the summer to quantify the type, frequency, duration, and severity of illness symptoms as well as the functional impact on the ability to undertake exercise performance. A total of 35 participants (12 highly-trained runners living in a community setting and 23 recreationally-active medical students) completed the questionnaire. Results Runners had a similar frequency of illness (2.1 ± 1.2 vs. 1.8 ± 2.3 episodes, mean ± SD, P = 0.58), but substantially longer duration (5.5 ± 9.9 vs 2.8 ± 3.1 days, P < 0.01) and illness load (7.7 ± 16.2 vs 4.5 ± 4.8 units, P = 0.001) than age- and sex-matched recreationally-active individuals respectively. Runners more prone to illness symptoms had marginally higher training loads. Conclusions The athlete illness questionnaire is useful for quantifying the pattern of self-reported symptoms of illness in field settings. Highly-trained runners experience longer episodes of illness with a greater impact on daily activity than recreationally-active individuals. PMID:24198538

  8. Active phase-nulling of the self-mixing phase in a terahertz frequency quantum cascade laser.

    PubMed

    Dean, P; Keeley, J; Valavanis, A; Bertling, K; Lim, Y L; Taimre, T; Alhathlool, R; Li, L H; Indjin, D; Rakić, A D; Linfield, E H; Davies, A G

    2015-03-15

    We demonstrate an active phase-nulling scheme for terahertz (THz) frequency quantum cascade lasers (QCLs) under optical feedback, by active electronic feedback control of the emission frequency. Using this scheme, the frequency tuning rate of a THz QCL is characterized, with significantly reduced experimental complexity compared to alternative approaches. Furthermore, we demonstrate real-time displacement sensing of targets, overcoming the resolution limits imposed by quantization in previously implemented fringe-counting methods. Our approach is readily applicable to high-frequency vibrometry and surface profiling of targets, as well as frequency-stabilization schemes for THz QCLs. PMID:25768154

  9. Effects of ultrasound frequency and acoustic amplitude on the size of sonochemically active bubbles - Theoretical study.

    PubMed

    Merouani, Slimane; Hamdaoui, Oualid; Rezgui, Yacine; Guemini, Miloud

    2013-05-01

    Numerical simulation of chemical reactions inside an isolated spherical bubble of oxygen has been performed for various ambient bubble radii at different frequencies and acoustic amplitudes to study the effects of these two parameters on the range of ambient radius for an active bubble in sonochemical reactions. The employed model combines the dynamic of bubble collapse with the chemical kinetics of single cavitation bubble. Results from this model were compared with some experimental results presented in the literature and good apparent trends between them were observed. The numerical calculations of this study showed that there always exists an optimal ambient bubble radius at which the production of oxidizing species at the end of the bubble collapse attained their upper limit. It was shown that the range of ambient radius for an active bubble increased with increasing acoustic amplitude and decreased with increasing ultrasound frequency. The optimal ambient radius decreased with increasing frequency. Analysis of curves showing optimal ambient radius versus acoustic amplitude for different ultrasonic frequencies indicated that for 200 and 300kHz, the optimal ambient radius increased linearly with increasing acoustic amplitude up to 3atm. However, slight minima of optimal radius were observed for the curves obtained at 500 and 1000kHz. PMID:23187064

  10. 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.

  11. 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

  12. 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.

  13. The vital activity of organisms in infralow frequency magnetic fields. 5. Isolated blood cells

    SciTech Connect

    Khizhenkov, P.K.; Zinkovich, I.I.; Bilobrov, V.M.

    1995-07-01

    Results are presented of experimental investigations of the effect of alternating magnetic fields H of various amplitudes, shapes, and frequencies on the osmotic resistance of erythrocytes (ORE), the phagocytic activity of leukocytes (PAL), the malonic dialdehyde accumulation (MDA), and the albumen escape to the incubative medium. The specificity and intraspecific variability of the ORE and PAL characteristics are also shown. Under the effect of H the albumen escape was noted to decrease while the MDA concentration became larger.

  14. [High-frequency active oscillation of the head in testing vestibuloocular reflex in healthy subjects].

    PubMed

    Pal'chun, V T; Derevianko, S N

    2000-01-01

    An original device has been designed in the ENT clinic of the Russian Medical University in cooperation with GUTA-clinic laboratory. The device registers high-frequency active oscillation of the head. This oscillation test was tried in 20 healthy individuals aged 20 to 60 years and was found easy to perform and highly informative. This technique can be used as an additional vestibular test in assessing function of the vestibular analyser. PMID:10771602

  15. Satisfaction With Teaching Questionnaire.

    ERIC Educational Resources Information Center

    Merwin, J. C.; DiVesta , F. J.

    As part of the instrumentation to assess the effectiveness of the Schools Without Failure (SEF) program in 10 elementary schools in the New Castle, Pa. School District, the Satisfaction with Teaching Questionnaire was used. In a study by its developers this scale discriminated between students choosing to be teachers and those choosing other…

  16. 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

  17. 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.

  18. A relationship between solar activity and frequency of natural disasters in China

    NASA Astrophysics Data System (ADS)

    Wang, Zhongrui; Song, Feng; Tang, Maocang

    2003-11-01

    The relationship between the length of the solar cycle, a good indicator of long-term change in solar activity, and natural disasters (drought, flood, and strong earthquakes) in China during the last 108 years is analyzed. The results suggest that the length of solar cycle may be a useful indicator for drought/flood and strong earthquakes. When the solar activity strengthens, we see the length of the solar cycle shorten and more floods occur in South China and frequent strong earthquakes happen in the Tibetan Plateau, but the droughts in East China as well as the strong earthquakes in Taiwan and at the western boundary of China are very few. The opposite frequencies occur when the solar activity weakens. The current study indicates that the solar activity may play an important role in the climate extremes and behavior in the lithosphere.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. EEG frequency tagging to explore the cortical activity related to the tactile exploration of natural textures.

    PubMed

    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

  5. A low-power integrated bioamplifier with active low-frequency suppression.

    PubMed

    Gosselin, B; Sawan, M; Chapman, C A

    2007-09-01

    We present in this paper a low-power bioamplifier suitable for massive integration in dense multichannel recording devices. This bioamplifier achieves reduced-size compared to previous designs by means of active low-frequency suppression. An active integrator located in the feedback path of a low-noise amplifier is employed for placing a highpass cutoff frequency within the transfer function. A very long integrating time constant is achieved using a small integrated capacitor and a MOS-bipolar equivalent resistor. This configuration rejects unwanted low-frequency contents without the need for input RC networks or large feedback capacitors. Therefore, the bioamplifier high-input impedance and small size are preserved. The bioamplifier, implemented in a 0.18-mum CMOS process, has been designed for neural recording of action potentials, and optimised through a transconductance-ef-ficiency design methodology for micropower operation. Measured performance and results obtained from in vivo recordings are presented. The integrated bioamplifier provides a midband gain of 50 dB, and achieves an input-referred noise of 5.6 muVrms. It occupies less than 0.050 mm(2) of chip area and dissipates 8.6 muW. PMID:23852412

  6. 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

  7. Robust fault-tolerant H∞ control of active suspension systems with finite-frequency constraint

    NASA Astrophysics Data System (ADS)

    Wang, Rongrong; Jing, Hui; Karimi, Hamid Reza; Chen, Nan

    2015-10-01

    In this paper, the robust fault-tolerant (FT) H∞ control problem of active suspension systems with finite-frequency constraint is investigated. A full-car model is employed in the controller design such that the heave, pitch and roll motions can be simultaneously controlled. Both the actuator faults and external disturbances are considered in the controller synthesis. As the human body is more sensitive to the vertical vibration in 4-8 Hz, robust H∞ control with this finite-frequency constraint is designed. Other performances such as suspension deflection and actuator saturation are also considered. As some of the states such as the sprung mass pitch and roll angles are hard to measure, a robust H∞ dynamic output-feedback controller with fault tolerant ability is proposed. Simulation results show the performance of the proposed controller.

  8. 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. PMID:25532936

  9. 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

  10. Recurrence and Frequency of Disturbance have Cumulative Effect on Methanotrophic Activity, Abundance, and Community Structure.

    PubMed

    Ho, Adrian; van den Brink, Erik; Reim, Andreas; Krause, Sascha M B; Bodelier, Paul L E

    2015-01-01

    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

  11. Mild Airflow Limitation during N2 Sleep Increases K-complex Frequency and Slows Electroencephalographic Activity

    PubMed Central

    Nguyen, Chinh D.; Wellman, Andrew; Jordan, Amy S.; Eckert, Danny J.

    2016-01-01

    Study Objectives: To determine the effects of mild airflow limitation on K-complex frequency and morphology and electroencephalogram (EEG) spectral power. Methods: Transient reductions in continuous positive airway pressure (CPAP) during stable N2 sleep were performed to induce mild airflow limitation in 20 patients with obstructive sleep apnea (OSA) and 10 healthy controls aged 44 ± 13 y. EEG at C3 and airflow were measured in 1-min windows to quantify K-complex properties and EEG spectral power immediately before and during transient reductions in CPAP. The frequency and morphology (amplitude and latency of P200, N550 and N900 components) of K-complexes and EEG spectral power were compared between conditions. Results: During mild airflow limitation (18% reduction in peak inspiratory airflow from baseline, 0.38 ± 0.11 versus 0.31 ± 0.1 L/sec) insufficient to cause American Academy of Sleep Medicine-defined cortical arousal, K-complex frequency (9.5 ± 4.5 versus 13.7 ± 6.4 per min, P < 0.01), N550 amplitude (25 ± 3 versus 27 ± 3 μV, P < 0.01) and EEG spectral power (delta: 147 ± 48 versus 230 ± 99 μV2, P < 0.01 and theta bands: 31 ± 14 versus 34 ± 13 μV2, P < 0.01) significantly increased whereas beta band power decreased (14 ± 5 versus 11 ± 4 μV2, P < 0.01) compared to the preceding non flow-limited period on CPAP. K-complex frequency, morphology, and timing did not differ between patients and controls. Conclusion: Mild airflow limitation increases K-complex frequency, N550 amplitude, and spectral power of delta and theta bands. In addition to providing mechanistic insight into the role of mild airflow limitation on K-complex characteristics and EEG activity, these findings may have important implications for respiratory conditions in which airflow limitation during sleep is common (e.g., snoring and OSA). Citation: Nguyen CD, Wellman A, Jordan AS, Eckert DJ. Mild airflow limitation during N2 sleep increases k-complex frequency and slows

  12. Lysogen stability is determined by the frequency of activity bursts from the fate-determining gene

    PubMed Central

    Zong, Chenghang; So, Lok-hang; Sepúlveda, Leonardo A; Skinner, Samuel O; Golding, Ido

    2010-01-01

    The ability of living cells to maintain an inheritable memory of their gene-expression state is key to cellular differentiation. Bacterial lysogeny serves as a simple paradigm for long-term cellular memory. In this study, we address the following question: in the absence of external perturbation, how long will a cell stay in the lysogenic state before spontaneously switching away from that state? We show by direct measurement that lysogen stability exhibits a simple exponential dependence on the frequency of activity bursts from the fate-determining gene, cI. We quantify these gene-activity bursts using single-molecule-resolution mRNA measurements in individual cells, analyzed using a stochastic mathematical model of the gene-network kinetics. The quantitative relation between stability and gene activity is independent of the fine details of gene regulation, suggesting that a quantitative prediction of cell-state stability may also be possible in more complex systems. PMID:21119634

  13. Looking for activity cycles in late-type Kepler stars using time-frequency analysis

    NASA Astrophysics Data System (ADS)

    Vida, K.; Oláh, K.; Szabó, R.

    2014-07-01

    We analyse light curves covering four years of 39 fast-rotating (Prot ≲ 1 d) late-type active stars from the Kepler data base. Using time-frequency analysis (short-term Fourier transform), we find hints for activity cycles of 300-900 d at nine targets from the changing typical latitude of the starspots, which with the differential rotation of the stellar surface change the observed rotation period over the activity cycle. We also give a lowest estimation for the shear parameter of the differential rotation, which is ≈0.001 for the cycling targets. These results populate the less studied, short-period end of the rotation-cycle length relation.

  14. Lysogen stability is determined by the frequency of activity bursts from the fate-determining gene.

    PubMed

    Zong, Chenghang; So, Lok-hang; Sepúlveda, Leonardo A; Skinner, Samuel O; Golding, Ido

    2010-11-30

    The ability of living cells to maintain an inheritable memory of their gene-expression state is key to cellular differentiation. Bacterial lysogeny serves as a simple paradigm for long-term cellular memory. In this study, we address the following question: in the absence of external perturbation, how long will a cell stay in the lysogenic state before spontaneously switching away from that state? We show by direct measurement that lysogen stability exhibits a simple exponential dependence on the frequency of activity bursts from the fate-determining gene, cI. We quantify these gene-activity bursts using single-molecule-resolution mRNA measurements in individual cells, analyzed using a stochastic mathematical model of the gene-network kinetics. The quantitative relation between stability and gene activity is independent of the fine details of gene regulation, suggesting that a quantitative prediction of cell-state stability may also be possible in more complex systems. PMID:21119634

  15. 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

  16. [The dynamics of the high-frequency components of the brain electrical activity in dogs during cognitive activities].

    PubMed

    Dumenko, V N

    1995-01-01

    Dynamics of parameters of low-voltage high-frequency components (HFC; 40 Hz and higher) of electrical activity (EA) of the brain in a broad frequency range (1-256 Hz) was studied in dogs in the process of conditioning using correlation and spectral analysis. Motor skill of pressing the pedal of the food dispenser in response to presentation of sound stimuli was elaborated. Spectra of power, coherence and phase of EA were studied in interstimulus intervals (2-3 minutes) and intervals (1 sec) of EEG reaction to conditioned stimuli preceding the motor response. It follows from the distinctions between the parameters of EA at these states that underlying them mechanisms are different. It is assumed that the dynamics of HFC (40-170 Hz) in interstimulus intervals (intensification of HFC and dominance of small phase shifts) is an expression of cognitive activity (forming of the internal integral image of forthcoming activity). Characteristics of EEG reactions to the conditioned stimuli (increase of phase shifts between potentials) are regarded as a "motor program" which ensure direct realization of multicomponent motor reaction. PMID:8560929

  17. 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

  18. After-brush rinsing protocols, frequency of toothpaste use: fluoride and other active ingredients.

    PubMed

    Parnell, C; O'Mullane, D

    2013-01-01

    The intra-oral retention or substantivity of active ingredients in toothpastes is important for their effectiveness, and this is influenced by product-related and user-related factors. Product-related factors include the formulation and the compatibility of active and other agents in the toothpaste and the concentration of the active ingredient. User-related factors include biological aspects such as salivary flow and salivary clearance, and behavioural aspects, such as frequency and duration of brushing, amount of toothpaste used and post-brushing rinsing behaviour. To date, product-related factors have dominated the research agenda for toothpastes, but user-related factors have the potential to significantly enhance or reduce the effectiveness of toothpaste. In this chapter, we will focus on two of the user-related factors that have been most widely studied: (1) frequency of toothbrushing and (2) post-brushing rinsing behaviour. We will then provide an overview of how evidence on these two behaviours has been used to produce guidance both for the profession and for the public, and make suggestions for the future direction of research in this area. PMID:23817066

  19. Low-frequency summation of synaptically activated TRP channel-mediated depolarizations

    PubMed Central

    Petersson, Marcus E.; Yoshida, Motoharu; Fransén, Erik A.

    2011-01-01

    Neurons sum their input by spatial and temporal integration. Temporally, presynaptic firing rates are converted to dendritic membrane depolarizations by postsynaptic receptors and ion channels. In several regions of the brain, including higher association areas, a majority of firing rates are low. For rates below 20 Hz the ionotropic receptors AMPA and NMDA will not produce effective temporal summation. We hypothesized that depolarization mediated by transient receptor potential (TRP) channels activated by metabotropic glutamate receptors would be more effective due to their slow kinetics. Based on voltage-clamp and current-clamp recordings from a rat slice preparation, we constructed a computational model of the TRP channel and its intracellular activation pathway, including the metabotropic glutamate receptor. We show that synaptic input frequencies down to 3-4 Hz and inputs consisting of as few as 3-5 pulses can be effectively summed. We further show that the time constant of integration increases with increasing stimulation frequency and duration. We suggest that the temporal summation characteristics of TRP channels may be important at distal dendritic arbors where spatial summation is limited by the number of concurrently active synapses. It may be particularly important in regions characterized by low and irregular rates. PMID:21777305

  20. Multi-frequency auditory stimulation disrupts spindling activity in anesthetized animals.

    PubMed

    Britvina, T; Eggermont, J J

    2008-02-01

    It is often implied that during the occurrence of spindle oscillations, thalamocortical neurons do not respond to signals from the outside world. Since recording of sound-evoked activity from cat auditory cortex is common during spindling this implies that sound stimulation changes the spindle-related brain state. Local field potentials and multi-unit activity recorded from cat primary auditory cortex under ketamine anesthesia during successive silence-stimulus-silence conditions were used to investigate the effect of sound on cortical spindle oscillations. Multi-frequency stimulation suppresses spindle waves, as shown by the decrease of spectral power within the spindle frequency range during stimulation as compared with the previous silent period. We show that the percentage suppression is independent of the power of the spindle waves during silence, and that the suppression of spindle power occurs very fast after stimulus onset. The global inter-spindle rhythm was not disturbed during stimulation. Spectrotemporal and correlation analysis revealed that beta waves (15-26 Hz), and to a lesser extent delta waves, were modulated by the same inter-spindle rhythm as spindle oscillations. The suppression of spindle power during stimulation had no effect on the spatial correlation of spindle waves. Firing rates increased under stimulation and spectro-temporal receptive fields could reliably be obtained. The possible mechanism of suppression of spindle waves is discussed and it is suggested that suppression likely occurs through activity of the specific auditory pathway. PMID:18164553

  1. A programmable broadband low frequency active vibration isolation system for atom interferometry.

    PubMed

    Tang, Biao; Zhou, Lin; Xiong, Zongyuan; Wang, Jin; Zhan, Mingsheng

    2014-09-01

    Vibration isolation at low frequency is important for some precision measurement experiments that use atom interferometry. To decrease the vibrational noise caused by the reflecting mirror of Raman beams in atom interferometry, we designed and demonstrated a compact stable active low frequency vibration isolation system. In this system, a digital control subsystem is used to process and feedback the vibration measured by a seismometer. A voice coil actuator is used to control and cancel the motion of a commercial passive vibration isolation platform. With the help of field programmable gate array-based control subsystem, the vibration isolation system performed flexibly and accurately. When the feedback is on, the intrinsic resonance frequency of the system will change from 0.8 Hz to about 0.015 Hz. The vertical vibration (0.01-10 Hz) measured by the in-loop seismometer is reduced by an additional factor of up to 500 on the basis of a passive vibration isolation platform, and we have proved the performance by adding an additional seismometer as well as applying it in the atom interferometry experiment. PMID:25273709

  2. 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.

  3. Minimizing high spatial frequency residual error in active space telescope mirrors

    NASA Astrophysics Data System (ADS)

    Gray, Thomas L.; Smith, Matthew W.; Cohan, Lucy E.; Miller, David W.

    2009-08-01

    The trend in future space telescopes is towards larger apertures, which provide increased sensitivity and improved angular resolution. Lightweight, segmented, rib-stiffened, actively controlled primary mirrors are an enabling technology, permitting large aperture telescopes to meet the mass and volume restrictions imposed by launch vehicles. Such mirrors, however, are limited in the extent to which their discrete surface-parallel electrostrictive actuators can command global prescription changes. Inevitably some amount of high spatial frequency residual error is added to the wavefront due to the discrete nature of the actuators. A parameterized finite element mirror model is used to simulate this phenomenon and determine designs that mitigate high spatial frequency residual errors in the mirror surface figure. Two predominant residual components are considered: dimpling induced by embedded actuators and print-through induced by facesheet polishing. A gradient descent algorithm is combined with the parameterized mirror model to allow rapid trade space navigation and optimization of the mirror design, yielding advanced design heuristics formulated in terms of minimum machinable rib thickness. These relationships produce mirrors that satisfy manufacturing constraints and minimize uncorrectable high spatial frequency error.

  4. 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.

  5. Escape conditioning and low-frequency whole-body vibration - The effects of frequency, amplitude, and controls for noise and activation.

    NASA Technical Reports Server (NTRS)

    Wike, E. L.; Wike, S. S.

    1972-01-01

    Seven experiments are reported on low-frequency whole-body vibration and rats' escape conditioning in a modified Skinner box. In the first three studies, conditioning was observed but was independent of frequency. In experiment four, the number of escape responses was directly related to vibration amplitude. Experiment five was a control for vibration noise and noise termination; experiments six and seven studied vibration-induced activation. Noise termination did not produce conditioning. In experiment six, subjects made more responses when responding led to termination than when it did not. In experiment seven, subjects preferred a bar which terminated vibration to one which did not.

  6. Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus

    PubMed Central

    Lv, Han; Zhao, Pengfei; Liu, Zhaohui; Wang, Guopeng; Zeng, Rong; Yan, Fei; Dong, Cheng; Zhang, Ling; Li, Rui; Wang, Peng; Li, Ting

    2016-01-01

    Previous resting-state functional magnetic resonance imaging (rs-fMRI) studies have shown that neurological changes are important findings in vascular pulsatile tinnitus (PT) patients. Here, we utilized rs-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) in forty patients with unilateral PT and forty age-, gender-, and education-matched normal control subjects. Two different frequency bands (slow-4, 0.027–0.073 Hz, and slow-5, 0.010–0.027 Hz, which are more sensitive to subcortical and cortical neurological signal changes, resp.) were analyzed to examine the intrinsic brain activity in detail. Compared to controls, PT patients had increased ALFF values mainly in the PCu, bilateral IPL (inferior parietal lobule), left IFG (inferior frontal gyrus), and right IFG/anterior insula and decreased ALFF values in the multiple occipital areas including bilateral middle-inferior occipital lobe. For the differences of the two frequency bands, widespread ALFF differences were observed. The ALFF abnormalities in aMPFC/ACC, PCu, right IPL, and some regions of occipital and parietal cortices were greater in the slow-5 band compared to the slow-4 band. Additionally, the THI score of PT patients was positively correlated with changes in slow-5 and slow-4 band in PCu. Pulsatile tinnitus is a disease affecting the neurological activities of multiple brain regions. Slow-5 band is more sensitive in detecting the alternations. Our results also indicated the importance of pathophysiological investigations in patients with pulsatile tinnitus in the future. PMID:27413554

  7. Frequency-Dependent Neural Activity in Patients with Unilateral Vascular Pulsatile Tinnitus.

    PubMed

    Lv, Han; Zhao, Pengfei; Liu, Zhaohui; Wang, Guopeng; Zeng, Rong; Yan, Fei; Dong, Cheng; Zhang, Ling; Li, Rui; Wang, Peng; Li, Ting; Gong, Shusheng; Wang, Zhenchang

    2016-01-01

    Previous resting-state functional magnetic resonance imaging (rs-fMRI) studies have shown that neurological changes are important findings in vascular pulsatile tinnitus (PT) patients. Here, we utilized rs-fMRI to measure the amplitude of low-frequency fluctuations (ALFF) in forty patients with unilateral PT and forty age-, gender-, and education-matched normal control subjects. Two different frequency bands (slow-4, 0.027-0.073 Hz, and slow-5, 0.010-0.027 Hz, which are more sensitive to subcortical and cortical neurological signal changes, resp.) were analyzed to examine the intrinsic brain activity in detail. Compared to controls, PT patients had increased ALFF values mainly in the PCu, bilateral IPL (inferior parietal lobule), left IFG (inferior frontal gyrus), and right IFG/anterior insula and decreased ALFF values in the multiple occipital areas including bilateral middle-inferior occipital lobe. For the differences of the two frequency bands, widespread ALFF differences were observed. The ALFF abnormalities in aMPFC/ACC, PCu, right IPL, and some regions of occipital and parietal cortices were greater in the slow-5 band compared to the slow-4 band. Additionally, the THI score of PT patients was positively correlated with changes in slow-5 and slow-4 band in PCu. Pulsatile tinnitus is a disease affecting the neurological activities of multiple brain regions. Slow-5 band is more sensitive in detecting the alternations. Our results also indicated the importance of pathophysiological investigations in patients with pulsatile tinnitus in the future. PMID:27413554

  8. Multi-frequency activation of neuronal networks by coordinated reset stimulation

    PubMed Central

    Lysyansky, Borys; Popovych, Oleksandr V.; Tass, Peter A.

    2011-01-01

    We computationally study whether it is possible to stimulate a neuronal population in such a way that its mean firing rate increases without an increase of the population's net synchronization. For this, we use coordinated reset (CR) stimulation, which has previously been developed to desynchronize populations of oscillatory neurons. Intriguingly, delivered to a population of predominantly silent FitzHugh–Nagumo or Hindmarsh–Rose neurons at sufficient stimulation amplitudes, CR robustly causes a multi-frequency activation: different Arnold tongues such as 1 : 1 or n : m entrained neuronal clusters emerge, which consist of phase-shifted sub clusters. Owing to the clustering pattern the neurons' timing is well balanced, so that in total there is no synchronization. Our findings may contribute to the development of novel and safe stimulation treatments that specifically counteract cerebral hypo-activity without promoting pathological synchronization or inducing epileptic seizures. PMID:22419975

  9. Effect of whole body vibration frequency on neuromuscular activity in ACL-deficient and healthy males.

    PubMed

    Giombini, A; Menotti, F; Laudani, L; Piccinini, A; Fagnani, F; Di Cagno, A; Macaluso, A; Pigozzi, F

    2015-09-01

    Whole-body vibration (WBV) has been shown to enhance muscle activity via reflex pathways, thus having the potential to contrast muscle weakness in individuals with rupture of the anterior cruciate ligament (ACL). The present study aimed to compare the magnitude of neuromuscular activation during WBV over a frequency spectrum from 20 to 45 Hz between ACL-deficient and healthy individuals. Fifteen males aged 28±4 with ACL rupture and 15 age-matched healthy males were recruited. Root mean square (RMS) of the surface electromyogram from the vastus lateralis in both limbs was computed during WBV in a static half-squat position at 20, 25, 30, 35, 40 and 45 Hz, and normalized to the RMS while maintaining the half-squat position without vibration. The RMS of the vastus lateralis in the ACL-deficient limb was significantly greater than in the contralateral limb at 25, 30, 35 and 40 Hz (P<0.05) and in both limbs of the healthy participants (dominant limb at 25, 30, 35, 40 and 45 Hz, P<0.05; non dominant limb at 20, 25, 30, 35, 40 and 45 Hz, P<0.05). The greater neuromuscular activity in the injured limb compared to the uninjured limb of the ACL-deficient patients and to both limbs of the healthy participants during WBV might be due to either augmented excitatory or reduced inhibitory neural inflow to motoneurons of the vastus lateralis through the reflex pathways activated by vibratory stimuli. The study provides optimal WBV frequencies which might be used as reference values for ACL-deficient patients. PMID:26424928

  10. Effect of whole body vibration frequency on neuromuscular activity in ACL-deficient and healthy males

    PubMed Central

    Giombini, A; Menotti, F; Piccinini, A; Fagnani, F; Di Cagno, A; Macaluso, A; Pigozzi, F

    2015-01-01

    Whole-body vibration (WBV) has been shown to enhance muscle activity via reflex pathways, thus having the potential to contrast muscle weakness in individuals with rupture of the anterior cruciate ligament (ACL). The present study aimed to compare the magnitude of neuromuscular activation during WBV over a frequency spectrum from 20 to 45 Hz between ACL-deficient and healthy individuals. Fifteen males aged 28±4 with ACL rupture and 15 age-matched healthy males were recruited. Root mean square (RMS) of the surface electromyogram from the vastus lateralis in both limbs was computed during WBV in a static half-squat position at 20, 25, 30, 35, 40 and 45 Hz, and normalized to the RMS while maintaining the half-squat position without vibration. The RMS of the vastus lateralis in the ACL-deficient limb was significantly greater than in the contralateral limb at 25, 30, 35 and 40 Hz (P<0.05) and in both limbs of the healthy participants (dominant limb at 25, 30, 35, 40 and 45 Hz, P<0.05; non dominant limb at 20, 25, 30, 35, 40 and 45 Hz, P<0.05). The greater neuromuscular activity in the injured limb compared to the uninjured limb of the ACL-deficient patients and to both limbs of the healthy participants during WBV might be due to either augmented excitatory or reduced inhibitory neural inflow to motoneurons of the vastus lateralis through the reflex pathways activated by vibratory stimuli. The study provides optimal WBV frequencies which might be used as reference values for ACL-deficient patients. PMID:26424928

  11. Measurement Properties of a Park Use Questionnaire

    PubMed Central

    Evenson, Kelly R.; Wen, Fang; Golinelli, Daniela; Rodríguez, Daniel A.; Cohen, Deborah A.

    2012-01-01

    We determined the criterion validity and test-retest reliability of a brief park use questionnaire. From five US locations, 232 adults completed a brief survey four times and wore a global positioning system (GPS) monitor for three weeks. We assessed validity for park visits during the past week and during a usual week by examining agreement between frequency and duration of park visits reported in the questionnaire to the GPS monitor results. Spearman correlation coefficients (SCC) were used to measure agreement. For past week park visit frequency and duration, the SCC were 0.62–0.65 and 0.62–0.67, respectively. For usual week park visit frequency and duration, the SCC were 0.40–0.50 and 0.50–0.53, respectively. Usual park visit frequency reliability was 0.78–0.88 (percent agreement 69%–82%) and usual park visit duration was 0.75–0.84 (percent agreement 64%–73%). These results suggest that the questionnaire to assess usual and past week park use had acceptable validity and reliability. PMID:23853386

  12. 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…

  13. NHEXAS PHASE I MARYLAND STUDY--FOLLOW-UP QUESTIONNAIRE DATA

    EPA Science Inventory

    The Follow-up questionnaire data set contains information concerning the activities within the household during the sampling week. The information is from 402 follow-up questionnaires for 80 households across 6 cycles. The Follow-up Questionnaire specifically addressed the time ...

  14. 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.

  15. 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.

  16. 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.

  17. Naftopidil improves locomotor activity and urinary frequency in rats with pelvic venous congestion.

    PubMed

    Sugaya, Kimio; Nishijima, Saori; Kadekawa, Katsumi; Ashitomi, Katsuhiro; Ueda, Tomoyuki; Yamamoto, Hideyuki

    2016-01-01

    The α1D/A receptor antagonist, naftopidil, inhibits micturition reflex by acting on various different sites. We examined the effects of naftopidil on bladder activity and changes in the induced urinary frequency using female rats with pelvic venous congestion (PC). Twenty-four female rats were divided into sham, PC, and PC/naftopidil groups. After anesthetizing rats in the PC and PC/naftopidil groups, the bilateral common iliac veins and uterine veins were ligated. Rats in the sham and PC groups were fed a standard diet, while rats in the PC/naftopidil group were fed diets containing 0.04% naftopidil. After 4 weeks of treatment, locomotor activity, urinary nitric oxide metabolites (NOx), continuous cystometry, and plasma monoamine measurements were performed. PC rats exhibited a decrease of locomotor activity, a shorter interval between bladder contractions on continuous cystometry, and decreased urinary NOx and plasma serotonin levels than the sham rats. The PC/naftopidil rats exhibited an increase of locomotor activity, a longer interval between bladder contractions, and increased urinary NOx and plasma serotonin levels. Therefore, naftopidil might improve bladder dysfunction induced by pelvic venous congestion due to several actions in the central nervous system and bladder tissue, as well as acting as an α1 blocker to cause pelvic venous dilation. PMID:27544997

  18. Frequency of Maternal Touch Predicts Resting Activity and Connectivity of the Developing Social Brain.

    PubMed

    Brauer, Jens; Xiao, Yaqiong; Poulain, Tanja; Friederici, Angela D; Schirmer, Annett

    2016-08-01

    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

  19. 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.

  20. Generation of High Frequency Electric Field Activity by Turbulence in the Earth's Magnetotail

    NASA Astrophysics Data System (ADS)

    Stawarz, J. E.; Ergun, R.

    2013-12-01

    Bursty Bulk Flow (BBF) events, frequently observed in the magnetotail, carry significant energy and mass from the tail region at ~20 RE into the near-earth plasma sheet at ~10 RE, which is often referred to as the BBF 'braking region'. A number of possible channels are available for the transfer or dissipation of energy in BBF events including adiabatic heating of ions and electrons, the propagation of Alfvén waves out of the BBF braking region and into the auroral region, and energy dissipation within the braking region itself. This study investigates the generation of strong high frequency electric field activity observed within the braking region. A theory by which the large and small scales are coupled through a turbulent cascade of Alfvén waves, generated by the BBF braking event, is considered. At small kinetic spatial scales magnetic field aligned currents can be generated. These currents can be unstable to high frequency electrostatic waves, as well as, non-linear electrostatic structures such as double layers and electron phase space holes that are observed in the breaking region. The theoretical work is supported by observations from the THEMIS satellites. This work provides a possible mechanism for the dissipation of energy in turbulent plasma environments.

  1. Limits on information transduction through amplitude and frequency regulation of transcription factor activity

    PubMed Central

    Hansen, Anders S; O'Shea, Erin K

    2015-01-01

    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. DOI: http://dx.doi.org/10.7554/eLife.06559.001 PMID:25985085

  2. 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

  3. 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.

  4. The Potential Use of Radio Frequency Identification Devices for Active Monitoring of Blood Glucose Levels

    PubMed Central

    Moore, Bert

    2009-01-01

    Imagine a diabetes patient receiving a text message on his mobile phone warning him that his blood glucose level is too low or a patient's mobile phone calling an emergency number when the patient goes into diabetic shock. Both scenarios depend on automatic, continuous monitoring of blood glucose levels and transmission of that information to a phone. The development of advanced biological sensors and integration with passive radio frequency identification technologies are the key to this. These hold the promise of being able to free patients from finger stick sampling or externally worn devices while providing continuous blood glucose monitoring that allows patients to manage their health more actively. To achieve this promise, however, a number of technical issues need to be addressed. PMID:20046663

  5. 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.

  6. 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.

  7. Some insights about the activity of the Ceboruco Volcano (Nayarit, Mexico) from recent seismic low-frequency activity

    NASA Astrophysics Data System (ADS)

    Rodríguez Uribe, María Carolina; Núñez-Cornú, Francisco Javier; Nava Pichardo, Fidencio Alejandro; Suárez-Plascencia, Carlos

    2013-10-01

    The Ceboruco stratovolcano (2,280 m.a.s.l.) is located in Nayarit, Mexico, at the western end of the Mexican volcanic belt, near several population centers and by the side of a strategic highway. During the last 1,000 years it has had, on the average, one eruption every 125 years. It last eruptive activity began in 1870, and during the following 5 years it presented superficial activity including vapor emissions, ash falls, and rhyodacitic lava flows along the southeast side. A data set consisting of 139 low-frequency volcanic-type earthquakes, recorded from March 2003 to July 2008 at the CEBN triaxial short period digital station on the southwestern side of the volcano, was classified according to waveform and spectral characteristics into four families: short duration, extended coda, bobbin, and modulated amplitude. Approximate hypocentral locations indicate that there is no particular location for events of any family, but rather that all events occur at different points within the volcano. The presence of ongoing volcanic-earthquake activity together with the ongoing vapor emissions indicate that the Ceboruco volcano continues to be active, and the higher occurrence rates of short-duration events, as compared with those for the other families, could indicate an increase in the stress in the volcanic edifice. This apparent stress increase, together with the fact that the last eruption occurred 143 years ago, tell us that the Ceboruco may be approaching a critical state, and may represent a hazard to the surrounding communities and economic activities.

  8. Dose dependence of acetylcholinesterase activity in neuroblastoma cells exposed to modulated radio-frequency electromagnetic radiation.

    PubMed

    Dutta, S K; Das, K; Ghosh, B; Blackman, C F

    1992-01-01

    Radio-frequency electromagnetic radiation (RFR) at 915 and 147 MHz, when sinusoidally amplitude modulated (AM) at 16 Hz, has been shown to enhance release of calcium ions from neuroblastoma cells in culture. The dose-response relation is unusual, consisting of two power-density "windows" in which enhanced efflux occurs, separated by power-density regions in which no effect is observed. To explore the physiological importance of these findings, we have examined the impact of RFR exposure on a membrane-bound enzyme, acetylcholinesterase (AChE), which is intimately involved with the acetylcholine (ACh) neurotransmitter system. Neuroblastoma cells (NG108), exposed for 30 min to 147-MHz radiation, AM at 16 Hz, demonstrated enhanced AChE activity, as assayed by a procedure using 14C-labeled ACh. Enhanced activity was observed within a time window between 7.0 and 7.5 h after the cells were plated and only when the exposure occurred at power densities identified in a previous report as being effective for altering the release of calcium ions. Thus RFR affects both calcium-ion release and AChE activity in nervous system-derived cells in culture in a common dose-dependent manner. PMID:1510740

  9. Increased frequency of activated T-cells in the Helicobacter pylori-infected antrum and duodenum.

    PubMed

    Strömberg, E; Lundgren, A; Edebo, A; Lundin, S; Svennerholm, A-M; Lindholm, C

    2003-05-25

    Helicobacter pylori colonize the human stomach and duodenum. The infection has been shown to induce a strong T-cell response in the stomach, whereas the response within the duodenum has been poorly characterized. Furthermore, it remains to be elucidated whether the T-cell response may contribute to ulcer formation in the host. In this study, the frequency of different T-cell subsets, their degree of activation and expression of co-stimulatory receptors in biopsies from the duodenum as well as the antrum were studied by immunohistochemistry and flow cytometry. It was also evaluated whether there are differences in the T-cell responses between duodenal ulcer patients and asymptomatic carriers that might explain why only 10-15% of the infected subjects develop duodenal ulcers. The frequencies of CD4+, CD8+ and CD45RO+, i.e. memory T-cells, were significantly increased in the antrum, and the number of CD25+ cells was considerably higher in both the antrum and duodenum of duodenal ulcer patients and asymptomatic carriers as compared to uninfected individuals. Interestingly, the levels of immunosuppressive CTLA-4+ cells were significantly higher in the duodenum of duodenal ulcer patients, as compared to the asymptomatic carriers. H. pylori cause activation of T-cells in the duodenum as well as in the stomach. Our observation of higher levels of CTLA-4+ cells in the duodenum of duodenal ulcer patients than in the asymptomatic carriers suggests that a suppressive T-cell response may be related to the development of duodenal ulcers. PMID:12738386

  10. 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. PMID:26222207

  11. Prefrontal activity during working memory is modulated by the interaction of variation in CB1 and COX2 coding genes and correlates with frequency of cannabis use.

    PubMed

    Taurisano, Paolo; Antonucci, Linda A; Fazio, Leonardo; Rampino, Antonio; Romano, Raffaella; Porcelli, Annamaria; Masellis, Rita; Colizzi, Marco; Quarto, Tiziana; Torretta, Silvia; Di Giorgio, Annabella; Pergola, Giulio; Bertolino, Alessandro; Blasi, Giuseppe

    2016-08-01

    The CB1 cannabinoid receptor is targeted in the brain by endocannabinoids under physiological conditions as well as by delta9-tetrahydrocannabinol under cannabis use. Furthermore, its signaling appears to affect brain cognitive processing. Recent findings highlight a crucial role of cyclooxygenase-2 (COX-2) in the mechanism of intraneuronal CB1 signaling transduction, while others indicate that two single nucleotide polymorphisms (SNPs) (rs1406977 and rs20417) modulate expression of CB1 (CNR1) and COX-2 (PTGS2) coding genes, respectively. Here, our aim was to use fMRI to investigate in healthy humans whether these SNPs interact in modulating prefrontal activity during working memory processing and if this modulation is linked with cannabis use. We recruited 242 healthy subjects genotyped for CNR1 rs1406977 and PTGS2 rs20417 that performed the N-back working memory task during fMRI and were interviewed using the Cannabis Experience Questionnaire (CEQ). We found that the interaction between CNR1 rs1406977 and PTGS2 rs20417 is associated with dorsolateral prefrontal cortex (DLPFC) activity such that specific genotype configurations (CNR1 C carriers/PTGS2 C carriers and CNR1 TT/PTGS2 GG) predict lower cortical response versus others in spite of similar behavioral accuracy. Furthermore, DLPFC activity in the cluster associated with the CNR1 by PTGS2 interaction was negatively correlated with behavioral efficiency and positively correlated with frequency of cannabis use in cannabis users. These results suggest that a genetically modulated balancing of signaling within the CB1-COX-2 pathway may reflect on more or less efficient patterns of prefrontal activity during working memory. Frequency of cannabis use may be a factor for further modulation of CNR1/PTGS2-mediated cortical processing associated with this cognitive process. PMID:27261878

  12. The Perceived Deficits Questionnaire

    PubMed Central

    Binder, Allison; Nikelshpur, Olga M.; Chiaravalloti, Nancy; DeLuca, John

    2016-01-01

    Background: Cognitive dysfunction affects approximately 43% to 70% of individuals with multiple sclerosis (MS) and is an important determinant of several functional outcomes in MS and quality of life. Brief neuropsychological test batteries have been developed specifically for use in MS and are widely used to aid clinicians in assessing levels of cognitive impairment in MS. Neuropsychologists and neurologists also frequently use briefer screening measures, such as the Perceived Deficits Questionnaire (PDQ), to assist in determining whether a more extensive neuropsychological evaluation is warranted. However, despite the ease of such measures, the relationship between self-report and objective cognitive impairment has been inconsistent, at best. Moreover, factors such as depression, fatigue, anxiety, and personality have been found to be more related to reports of cognitive difficulties. The purpose of the present study was to clarify the relationship between subjective cognitive concerns and objective cognitive impairment while accounting for related symptoms. Methods: We examined the association of self-reported cognitive concerns on the PDQ with objective cognitive measures, as well as depression, anxiety, fatigue, and self-efficacy. Results: There was no relationship between self-reported cognitive concerns and objective performance. Rather, reports on the PDQ were more correlated with reports of depression, anxiety, fatigue, and self-efficacy. Conclusions: Depression and poor self-efficacy can contribute to reports of cognitive difficulties. Effective treatment to improve these factors seems warranted given the impact of perceived cognitive impairment on outcomes in MS and the potential for more accurate self-reports. PMID:27551243

  13. The quest for better questionnaires.

    PubMed

    Wilcox, A J

    1999-12-15

    The development of questionnaires is a neglected enterprise in epidemiology. It has recently been proposed that a prestigious health authority such as the World Health Organization establish a committee to tackle issues of questionnaire quality, moving eventually toward standardized instruments. However, standardization may not be the best way to invigorate this enterprise. As an alternative, the author suggests that the first step in improving questionnaires would be to make them more accessible. Ideally, questionnaires should be as easily scrutinized as a study's methods or results. To this end, the author suggests that when a research paper is published, the entire questionnaire be made available on the worldwide web. Electronic access to questionnaires could stimulate a new era of awareness about the importance of questionnaire design. PMID:10604766

  14. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--BORDER SUPPLEMENT QUESTIONNAIRE DATA

    EPA Science Inventory

    The Border Supplement Questionnaire data set provides information on the local environmental conditions. The information is from 203 Questionnaires for 91 households. In addition, the frequency of border crossing into Mexico and the characteristics of consumer purchases while t...

  15. Naturally occurring changes in time spent watching television are inversely related to frequency of physical activity during early adolescence.

    PubMed

    Motl, Robert W; McAuley, Edward; Birnbaum, Amanda S; Lytle, Leslie A

    2006-02-01

    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 an increase in frequency of leisure-time physical activity. That relationship was strong in magnitude and independent of sex, socioeconomic status, smoking, and the value participants placed on health, appearance, and achievement. Our results encourage the design of interventions that reduce television watching as a possible means of increasing adolescent physical activity. PMID:16338428

  16. 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.

  17. 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. PMID:26020354

  18. 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. PMID:26775970

  19. Does greater low frequency EEG activity in normal immaturity and in children with epilepsy arise in the same neuronal network?

    PubMed

    Michels, L; Bucher, K; Brem, S; Halder, P; Lüchinger, R; Liechti, M; Martin, E; Jeanmonod, D; Kröll, J; Brandeis, D

    2011-03-01

    Greater low frequency power (<8 Hz) in the electroencephalogram (EEG) at rest is normal in the immature developing brain of children when compared to adults. Children with epilepsy also have greater low frequency interictal resting EEG activity. Whether these power elevations reflect brain immaturity due to a developmental lag or the underlying epileptic pathophysiology is unclear. The present study addresses this question by analyzing spectral EEG topographies and sources for normally developing children and children with epilepsy. We first compared the resting EEG of healthy children to that of healthy adults to isolate effects related to normal brain immaturity. Next, we compared the EEG from 10 children with generalized cryptogenic epilepsy to the EEG of 24 healthy children to isolate effects related to epilepsy. Spectral analysis revealed that global low (delta: 1-3 Hz, theta: 4-7 Hz), medium (alpha: 8-12 Hz) and high (beta: 13-25 Hz) frequency EEG activity was greater in children without epilepsy compared to adults, and even further elevated for children with epilepsy. Topographical and tomographic EEG analyses showed that normal immaturity corresponded to greater delta and theta activity at fronto-central scalp and brain regions, respectively. In contrast, the epilepsy-related activity elevations were predominantly in the alpha band at parieto-occipital electrodes and brain regions, respectively. We conclude that lower frequency activity can be a sign of normal brain immaturity or brain pathology depending on the specific topography and frequency of the oscillating neuronal network. PMID:20820898

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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. PMID:23825085

  5. First direct measurements of behavioural responses by Cuvier's beaked whales to mid-frequency active sonar

    PubMed Central

    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.

    2013-01-01

    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. PMID:23825085

  6. 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.

  7. 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. PMID:25343340

  8. Myelinating satellite oligodendrocytes are integrated in a glial syncytium constraining neuronal high-frequency activity.

    PubMed

    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 Ba(2+)-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

  9. 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).

  10. EEG frequency analysis of cortical brain activities induced by effect of light touch.

    PubMed

    Ishigaki, Tomoya; Ueta, Kozo; Imai, Ryota; Morioka, Shu

    2016-06-01

    In human postural control, touching a fingertip to a stable object with a slight force (<1 N) reduces postural sway independent of mechanical support, which is referred to as the effect of light touch (LT effect). The LT effect is achieved by the spatial orientation according to haptic feedback acquired from an external spatial reference. However, the neural mechanism of the LT effect is incompletely understood. Therefore, the purpose of this study was to employ EEG frequency analysis to investigate the cortical brain activity associated with the LT effect when attentional focus was strictly controlled with the eyes closed during standing (i.e., control, fixed-point touch, sway-referenced touch, and only fingertip attention). We used EEG to measure low-alpha (about 8-10 Hz) and high-alpha rhythm (about 10-12 Hz) task-related power decrease/increase (TRPD/TRPI). The LT effect was apparent only when the subject acquired the stable external spatial reference (i.e., fixed-point touch). Furthermore, the LT-specific effect increased the high-alpha TRPD of two electrodes (C3, P3), which were mainly projected from cortical brain activities of the left primary sensorimotor cortex area and left posterior parietal cortex area. Furthermore, there was a negative correlation between the LT effect and increased TRPD of C3. In contrast, the LT effect correlated positively with increased TRPD of P3. These results suggest that central and parietal high-alpha TRPD of the contralateral hemisphere reflects the sensorimotor information processing and sensory integration for the LT effect. These novel findings reveal a partial contribution of a cortical neural mechanism for the LT effect. PMID:26758719

  11. Measurement Services Association Questionnaire Results.

    ERIC Educational Resources Information Center

    Wood, Lewis J.; Gillis, Rod

    This paper presents the results of a questionnaire sent to 211 Measurement Services Association members. Sixty-four centers responded. The main purpose of the questionnaire was to find out what hardware and software are used by testing centers throughout the country. Results indicate that 52 institutions use mainframe computers, 50 use…

  12. 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.

  13. 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…

  14. 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.

  15. Active laser frequency stabilization and resolution enhancement of interferometers for the measurement of gravitational waves in space

    NASA Astrophysics Data System (ADS)

    Herz, Markus

    2005-09-01

    Laser frequency stabilization is notably one of the major challenges on the way to a space-borne gravitational wave observatory. The proposed Laser Interferometer Space Antenna (LISA) is presently under development in an ESA, NASA collaboration. We present a novel method for active laser stabilization and phase noise suppression in such a gravitational wave detector. The proposed approach is a further evolution of the "arm-locking" method, which in essence consists of using an interferometer arm as an optical cavity, exploiting the extreme long-run stability of the cavity size in the frequency band of interest. We extend this method by using the natural interferometer arm length differences and existing interferometer signals as additional information sources for the reconstruction and active suppression of the quasi-periodic laser frequency noise, enhancing the resolution power of space-borne gravitational wave detectors.

  16. 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

  17. 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

    2011-01-01

    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. PMID:22832400

  18. 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

  19. 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…

  20. 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…

  1. Low-Frequency Sound Field Control in a Reverberant Room with a Single Active Controller Source.

    NASA Astrophysics Data System (ADS)

    Bullock, John Drayton, Jr.

    The operation of a single active controller source in a reverberant room has been investigated. The system consists of a controlled transducer source and a near-source microphone, with electronics arranged as a closed feedback loop. The controller system responds to a single source placed arbitrarily in the room. A theoretical analysis is presented based on the two port model of the controller transducer interfaced to an equivalent description of the reverberant room. The room acoustic transfer impedances between the active controller, room exciter source, near controller pressure sensor, and an arbitrary point in the reverberant sound field are described by a Green's function model. To minimize resonant effects of the controller piston diaphragm, a second control feedback loop using a diaphragm mounted accelerometer was added to the pressure control loop. Examples of the controller system operation were drawn from a computer model. Experimental data were gathered in a test reverberation room at the Applied Research Laboratory of The Pennsylvania State University. This investigation has brought forth three factors which define the limits on wide band control loop gain. They are (i) the position of an accelerometer on the controller diaphragm, (ii) the spacing between the controller and pressure sensor microphone, and (iii) the first mode frequency and the Q of the controller diaphragm. These system and transducer constraints can introduce instability in the control system. The controller system operation in the room has been modeled as a lumped element ideal piston using a flow graph representation. Additional loops on the graph are used to represent non-ideal transducer aberrations, and to define the pressure at various points in the room. Four cases for controller operation have been defined based on the proximity of the room source, the pressure sensor, and the controller. Two of these are important for practical applications: (i) the sensor microphone and

  2. 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...

  3. Decreased Frequencies of Circulating CD4+ T Follicular Helper Cells Associated with Diminished Plasma IL-21 in Active Pulmonary Tuberculosis

    PubMed Central

    Kumar, Nathella Pavan; Sridhar, Rathinam; Hanna, Luke E.; Banurekha, Vaithilingam V.; Nutman, Thomas B.; Babu, Subash

    2014-01-01

    Background Circulating T follicular helper (Tfh) cells represent a distinct subset of CD4+ T cells and are important in immunity to infections. Although they have been shown to play a role in experimental models of tuberculosis infection, their role in human tuberculosis remains unexplored. Aims/Methodology To determine the distribution of circulating Tfh cells in human TB, we measured the frequencies of Tfh cells ex vivo and following TB - antigen or polyclonal stimulation in pulmonary TB (PTB; n = 30) and latent TB (LTB; n = 20) individuals, using the markers CXCR5, PD-1 and ICOS. Results We found that both ex vivo and TB - antigen induced frequencies of Tfh cell subsets was significantly lower in PTB compared to LTB individuals. Similarly, antigen induced frequencies of Tfh cells expressing IL-21 was also significantly lower in PTB individuals and this was reflected in diminished circulating levels of IL-21 and IFNγ. This was not accompanied by diminished frequencies of activated or memory B cell subsets. Finally, the diminution in frequency of Tfh cells in PTB individuals was dependent on IL-10, CTLA-4 and PD-L1 in vitro. Conclusions Thus, PTB is characterized by adiminution in the frequency of Tfh cell subsets. PMID:25343703

  4. Radio Frequency Interference: Projects and Activities Developed for the High School Earth Science, Astronomy, and Physics Classroom

    NASA Astrophysics Data System (ADS)

    Dunn, S. K.; Brown, J.

    2003-12-01

    Radio Frequency Interference: Projects and Activities Developed for the High School Earth Science, Astronomy, and Physics Classroom Susan Dunn Tewksbury Memorial High School Jason Brown Tyngsboro High School Preethi Pratap MIT Haystack Observatory The Research Experiences for Teachers (RET) program, funded by the NSF, brings teachers into research environments to interact with scientists and translate the experience into the classroom. We will describe a RET experience at the MIT Haystack Observatory which involved using an AR3000A communications receiver and a discone antenna as the basis for an Earth Science, Astronomy, and Physics classroom unit. The projects and activities in this unit were developed to help foster student learning and understanding of radio astronomy, the electromagnetic spectrum, wave dynamics, signal propagation, meteor detection, and radio frequency interference. Additionally, this RET project utilizes the SEARFE (Students Examining Australia???s Radio Frequency Environment) software developed for use with the AR3000A communications receiver to scan and monitor frequencies across the radio bandwidth to determine areas of low and high usage in the radio spectrum. Classroom activities include Scanning Protected Radio Astronomy Bandwidths, Investigating the Radio Environment, Time Variation of Signal Strength, Signal Strength vs. Location Studies, Detecting Meteors using the AR300A Receiver, Mapping the RFI Environment of Your School, AM Radio Interference, and Signal Propagation Effects. The primary focus of the unit???s activities is to address the Massachusetts State Science Frameworks for electromagnetic radiation, waves, cosmology, and matter and energy in the Earth system and foster an understanding of how everyday communications devices may cause radio frequency interference with sensitive radio astronomy equipment. The projects and activities in the unit will be used in the classroom, amended, and the results of the classroom

  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. PMID:22538279

  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. Differences in the impact of the frequency and enjoyment of joint family activities on adolescent substance use and violence.

    PubMed

    Windlin, Béat; Kuntsche, Emmanuel

    2012-05-01

    Previous research has concentrated exclusively on the association between the frequency of joint family activities (JFA) and adolescent problem behaviours. In this study, multiple linear regressions based on a national sample of 3467 13- to 16-year-olds in Switzerland revealed that JFA enjoyment rather than JFA frequency is consistently related to low adolescent substance use and violence. By choosing JFA that their children enjoy, parents might provide opportunities for disclosure, strengthen family bonds and reduce the likelihood of adolescent problem behaviours. In terms of prevention, a shift in focus towards the quality rather than the quantity of JFA could prove more effective. PMID:21963683

  8. 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.

  9. 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.

  10. 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

  11. 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. PMID:23853321

  12. 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

  13. Effects of time-variant extremely low-frequency (ELF) electromagnetic fields (EMF) on cholinesterase activity in Dictyostelium discoideum (Protista).

    PubMed

    Amaroli, Andrea; Trielli, Francesca; Bianco, Bruno; Giordano, Stefano; Moggia, Elsa; Corrado, Maria U Delmonte

    2005-12-15

    Recently, we detected propionylcholinesterase (PrChE) activity in single-cell amoebae of Dictyostelium discoideum using cytochemical, electrophoretic, and spectrophotometric methods. The involvement of this enzyme activity in cell-cell and cell-environment interactions was suggested. In this work, we found that exposure of single-cell amoebae to an extremely low-frequency electromagnetic fields (ELF-EMF) of 300 microT, 50 Hz, from 1 h up to 48 h at 21 +/- 1 degrees C affected PrChE activity. PMID:16425446

  14. Effects of different resistance training frequencies on the muscle strength and functional performance of active women older than 60 years.

    PubMed

    Farinatti, Paulo T V; Geraldes, Amandio A R; Bottaro, Martim F; Lima, Maria Verônica I C; Albuquerque, Rodrigo B; Fleck, Steve J

    2013-08-01

    Training frequency is an important resistance training variable, but its relative contribution to strength and functional performance (FP) gains in senior populations is not yet well defined. The present study investigated the effect of different resistance training frequencies on the strength and FP in active women aged 60 years and older. A total of 48 women (60-78 years) underwent a 16-week training program for 1 set of 10 repetition maximums (10RMs) of each exercise, being assigned in groups that performed training frequencies of 1, 2, or 3 days per week (EG1, EG2, and EG3) and a control group. Strength and FP tests were applied before and after the training protocol. All EGs, but not the control group, exhibited 10RM increases (bench press, seated dumbbell curl, knee extension, standing calf raise, p < 0.01). The 10RM increase for seated dumbbell curl and knee extension was always greater in the higher frequencies (p < 0.05). Timed up and go test improved equally in all EGs (p < 0.01). Chair sit-and-stand improvements in EG3 (-15.7%) and EG2 (-9.8%) were greater than in EG1 (-4.6%) (p < 0.01). Gait-speed improvement in EG3 (-11.6%) was greater than in EG2 (-5.1%) and EG1 (-3.9%) (p < 0.01). In conclusion, a higher weekly training frequency increased FP and strength to a greater extent than lower frequencies in active senior women. PMID:23168371

  15. Cycle Slips Detection in Quad-Frequency Mode: Galileo's Contribution to an Efficient Approach under High Ionospheric Activity

    NASA Astrophysics Data System (ADS)

    Van de Vyvere, Laura; Warnant, René

    2016-04-01

    Cycle slips detection has always been a key issue in phase measurements accuracy, thus impacting positioning precision. Since Galileo is the first constellation to offer four carrier frequencies available in Open Service, we were able to develop an innovative detection algorithm, especially promising in harsh environment like high ionospheric activity. This improves previous dual and triple-frequency methods, whose efficiency was somehow limited in tricky situations, like ionospheric events or particular configurations. In our algorithm, two types of testing quantities were used: triple-frequency Simsky combination and dual-frequency Geometry-Free combination, each one being associated to a suitable detection algorithm. Simsky combination allows to detect almost every configuration, except for cycle slips of the same magnitude, appearing simultaneously on all carriers. Geometry-Free combination is only used to detect this particular case, since it suffers from quick variation of ionospheric delay. Together - through the choice of the most efficient combination alternatives - they enable the detection of any cycle slips configuration. This is now made possible thanks to the availability of data from Galileo's four carriers. The quad-frequency algorithm has been tested on Galileo observations from both GMSD (Japan) and NKLG (Gabon) stations. On the first ones, cycle slips were artificially inserted in order to simulate particular cases and test algorithm robustness. NKLG raw data were used to assess algorithm behaviour for cases met in the equatorial area. Enhanced with a suitable cycle slip correction method and a real-time feature, our algorithm could directly be integrated into the software receiver, enabling the supply of continuous and corrected data to the user. In conclusion, this first quad-frequency cycle slips detection algorithm is obviously a step forward and every Galileo user will indeed be able to benefit from a highly better-quality positioning. With

  16. 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.

  17. 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. PMID:24722228

  18. 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.

  19. Analysis of frequency noise in ultra-stable optical oscillators with active control of residual amplitude modulation

    NASA Astrophysics Data System (ADS)

    Li, Liufeng; Shen, Hui; Bi, Jin; Wang, Chun; Lv, Shasha; Chen, Lisheng

    2014-12-01

    Two 1,064-nm Nd:YAG lasers frequency stabilized by high-finesse optical cavities are developed to investigate various noise mechanisms in ultra-stable optical oscillators. Active control of residual amplitude modulation using a separate sensing path is implemented and its effectiveness in the presence of a resonant optical cavity is theoretically analyzed and experimentally verified by measuring the rejection ratios in optical heterodyne beat between a perturbed laser and a stable reference. Laser frequency noises originated from vibration, residual amplitude modulation, quantum-limited shot noise, and electronic noise are experimentally analyzed. With active control, residual amplitude modulation is suppressed to below 1 × 10-6 at 0.02-1,000 s, reaching a minimum of 2 × 10-7 at ~2 s. A frequency stability of 2 × 10-15 is obtained from 0.1 to 10 s, and the optical heterodyne beat of the two Nd:YAG lasers shows 1-Hz linewidth with a measurement time of 4.096 s. In addition, the experimentally determined linewidths agree well with the calculation according to a simplified relationship between the linewidth and the underlying flicker noise that modulates the laser frequency.

  20. Analysis of frequency noise in ultra-stable optical oscillators with active control of residual amplitude modulation

    NASA Astrophysics Data System (ADS)

    Li, Liufeng; Shen, Hui; Bi, Jin; Wang, Chun; Lv, Shasha; Chen, Lisheng

    2014-09-01

    Two 1,064-nm Nd:YAG lasers frequency stabilized by high-finesse optical cavities are developed to investigate various noise mechanisms in ultra-stable optical oscillators. Active control of residual amplitude modulation using a separate sensing path is implemented and its effectiveness in the presence of a resonant optical cavity is theoretically analyzed and experimentally verified by measuring the rejection ratios in optical heterodyne beat between a perturbed laser and a stable reference. Laser frequency noises originated from vibration, residual amplitude modulation, quantum-limited shot noise, and electronic noise are experimentally analyzed. With active control, residual amplitude modulation is suppressed to below 1 × 10-6 at 0.02-1,000 s, reaching a minimum of 2 × 10-7 at ~2 s. A frequency stability of 2 × 10-15 is obtained from 0.1 to 10 s, and the optical heterodyne beat of the two Nd:YAG lasers shows 1-Hz linewidth with a measurement time of 4.096 s. In addition, the experimentally determined linewidths agree well with the calculation according to a simplified relationship between the linewidth and the underlying flicker noise that modulates the laser frequency.

  1. Detection of epileptiform activity in EEG signals based on time-frequency and non-linear analysis

    PubMed Central

    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. PMID:25852534

  2. Validity of Short and Long Self-Administered Food Frequency Questionnaires in Ranking Dietary Intake in Middle-Aged and Elderly Japanese in the Japan Public Health Center-Based Prospective Study for the Next Generation (JPHC-NEXT) Protocol Area

    PubMed Central

    Yokoyama, Yuta; Takachi, Ribeka; Ishihara, Junko; Ishii, Yuri; Sasazuki, Shizuka; Sawada, Norie; Shinozawa, Yurie; Tanaka, Junta; Kato, Erika; Kitamura, Kaori; Nakamura, Kazutoshi; Tsugane, Shoichiro

    2016-01-01

    Background Longitudinal epidemiological studies require both the periodic update of intake information via repeated dietary survey and the minimization of subject burden in responding to questionnaires. We developed a 66-item Food Frequency Questionnaire (short-FFQ) for the Japan Public Health Center-based prospective Study for the Next Generation (JPHC-NEXT) follow-up survey using major foods from the FFQ developed for the original JPHC Study. For the JPHC-NEXT baseline survey, we used a larger 172-item FFQ (long-FFQ), which was also derived from the JPHC-FFQ. We compared the validity of ranking individuals by levels of dietary consumption by these FFQs among residents of selected JPHC-NEXT study areas. Methods From 2012 to 2013, 240 men and women aged 40–74 years from five areas in the JPHC-NEXT protocol were asked to respond to the long-FFQ and provide 12-day weighed food records (WFR) as reference; 228 also completed the short-FFQ. Spearman’s correlation coefficients (CCs) between estimates from the FFQs and WFR were calculated and corrected for intra-individual variation of the WFR. Results Median CC values for energy and 53 nutrients for the short-FFQ for men and women were 0.46 and 0.44, respectively. Respective values for the long-FFQ were 0.50 and 0.43. Compared with the long-FFQ, cross-classification into exact plus adjacent quintiles with the short-FFQ ranged from 68% to 91% in men and 58% to 85% in women. Conclusions Similar to the long-FFQ, the short-FFQ provided reasonably valid measures for ranking middle-aged and elderly Japanese for many nutrients and food groups. The short-FFQ can be used in follow-up surveys in prospective cohort studies aimed at updating diet rank information. PMID:27064130

  3. Orbital changes, variation in solar activity and increased anthropogenic activities: controls on the Holocene flood frequency in the Lake Ledro area, Northern Italy

    NASA Astrophysics Data System (ADS)

    Vannière, B.; Magny, M.; Joannin, S.; Simonneau, A.; Wirth, S. B.; Hamann, Y.; Chapron, E.; Gilli, A.; Desmet, M.; Anselmetti, F. S.

    2012-09-01

    Two lacustrine sediment cores from Lake Ledro in Northern Italy were studied to produce chronologies of flood events for the past 10 000 yr. For this purpose, we have developed an automatic method that objectively identifies the sedimentary imprint of river floods in the downstream lake basin. The automatic counting of flood deposits was based on colour data extracted from processed core photographs, and the count data were processed to capture the flood signal. Automatic quantification was compared with naked-eye counting. Counts were performed twice on the proximal and distal cores to provide an objective and reproducible record of flood frequency. Geophysical and geochemical analyses made it possible to distinguish event deposits from background sedimentation. Flood frequency and reconstructed sedimentary dynamics were compared with lake-level changes and pollen dynamics inferred from vegetation data. The data suggest a record marked by low flood frequency during the early and middle Holocene (10 000-4500 cal BP). Only modest increases during short intervals are recorded at ca. 8000, 7500, and 7100 cal BP. The last third of the Holocene is characterised by a shift toward increased flood frequency at ca. 4500-4000 cal BP. With the exception of two short intervals around 2900-2500 and 1800-1400 cal BP, which show a slightly reduced number of floods, the trend of increasing flood frequency prevailed until the 20th century, reaching a maximum between the 16th and the 19th centuries. Brief-flood frequency increases recorded during the early and middle Holocene can be attributed to cold climatic oscillations. On a centennial time scale, major changes in flood frequency, such as those observed at ca. 4500 and 500 cal BP, can be attributed to large-scale climatic changes such as the Neo-glacial and Little Ice Age, which are under orbital and possibly solar control. The role of climate as the main forcing factor in flood activity is supported by the lake-level records

  4. High frequencies of activated B cells and T follicular helper cells are correlated with disease activity in patients with new-onset rheumatoid arthritis

    PubMed Central

    Wang, J; Shan, Y; Jiang, Z; Feng, J; Li, C; Ma, L; Jiang, Y

    2013-01-01

    This study aimed to examine the frequency of different subsets of circulating B and T follicular helper (Tfh) cells in patients with new-onset rheumatoid arthritis (RA) and following standard therapies. Twenty-five RA patients and 15 healthy controls (HC) were recruited for characterizing the frequency of CD27+, immunoglobulin (Ig)D+, CD86+, CD95+, Toll-like receptor (TLR)-9+ B cells and inducible T cell co-stimulator (ICOS) and programmed death 1 (PD-1)-positive Tfh cells and the level of serum interleukin (IL)-21. The potential correlation between the frequency of different subsets of B and Tfh cells and the values of clinical measures in RA patients was analysed. In comparison with HC, significantly higher percentages of circulating IgD+CD27−CD19+ naive B, CD86+CD19+ and CD95+CD19+ activated B, CD3+CD4+CXCR5+, CD3+CD4+CXCR5+ICOS+, CD3+CD4+CXCR5+PD-1+ and CD3+CD4+CXCR5+ICOS+PD-1+ Tfh cells but lower IgD+CD27+CD19+ preswitch memory B cells were detected, accompanied by significantly higher levels of serum IL-21 in the RA patients. Furthermore, the percentages of CD95+ B cells were correlated positively with the frequency of PD-1+ Tfh cells, but negatively with ICOS+ Tfh cells. The percentages of CD86+ B cells and ICOS+ Tfh cells were correlated positively with the values of disease activity score 28 (DAS28). Following the drug therapies for 1 month, the percentages of CD86+ B and PD-1+ Tfh cells were reduced significantly in the drug-responding patients. Our data suggest that activated B and Tfh cells may contribute to the pathogenesis of RA and the frequency of activated B and Tfh cells may be used as biomarkers for evaluating the therapeutic responses of individual patients with RA. PMID:23786438

  5. Level-dependent auditory tuning: Transducer-based active processes in hearing and best-frequency shifts.

    PubMed

    Nadrowski, Björn; Göpfert, Martin C

    2009-01-01

    Ears boost their sensitivity by means of active, force-generating processes that augment the minute vibrations induced by soft sounds. These processes can alter auditory frequency-tuning in a level-dependent way. In the antennal hearing organ of Drosophila, for example, the active process shifts the best frequency (BF) of the antennal sound receiver when the sound intensity is varied, tuning the receiver to conspecific songs. Here we show that this level-dependent tuning can be reproduced by an active transduction model as proposed for vertebrate hair cells and the Drosophila ear. We further show that the direction of the frequency shift depends on the system to which the molecular modules for auditory transduction connect: If this system is mass-less such as the sensory hair bundles of bullfrog saccular hair cells, the BF of the displacement response will increase as the sound intensity declines. Conversely, BF will decrease with declining intensity if the transduction modules couple to inertial systems such as the fly's antennal sound receiver or cupulae in the fish lateral line. PMID:19704854

  6. Altered immunoglobulin hypermutation pattern and frequency in complementary mouse models of DNA polymerase ζ activity

    PubMed Central

    Daly, Janssen; Bebenek, Katarzyna; Watt, Danielle L.; Richter, Kathleen; Jiang, Chuancang; Zhao, Ming-Lang; Ray, Madhumita; McGregor, W. Glenn; Kunkel, Thomas A.; Diaz, Marilyn

    2012-01-01

    To test the hypothesis that DNA polymerase ζ participates in immunoglobulin hypermutation, we generated two mouse models of Pol ζ function: a B-cell specific conditional knock-out and a knock-in strain with a Pol ζ mutagenesis-enhancing mutation. Pol ζ-deficient B-cells had a reduction in mutation frequency at immunoglobulin loci in the spleen and in Peyer’s Patches, while knock-in mice with a mutagenic Pol ζ, displayed a marked increase in mutation frequency in Peyer’s Patches revealing a pattern that was similar to mutations in yeast strains with a homologous mutation in the gene encoding the catalytic subunit of Pol ζ. Combined, these data are best explained by a direct role for DNA polymerase ζ in immunoglobulin hypermutation. PMID:22547703

  7. Active cancellation of residual amplitude modulation in a frequency-modulation based Fabry-Perot interferometer.

    PubMed

    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. PMID:27036752

  8. 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.

  9. Distribution of electrical activation to the external intercostal muscles during high frequency spinal cord stimulation in dogs

    PubMed Central

    DiMarco, Anthony F; Kowalski, Krzysztof E

    2011-01-01

    Abstract In contrast to previous methods of electrical stimulation of the inspiratory muscles, high frequency spinal cord stimulation (HF-SCS) results in more physiological activation of these muscles. The spatial distribution of activation to the external intercostal muscles by this method is unknown. In anaesthetized dogs, multiunit and single motor unit (SMU) EMG activity was monitored in the dorsal portion of the 3rd, 5th and 7th interspaces and ventral portion of the 3rd interspace during spontaneous breathing and HF-SCS following C2 spinal section. Stimulus amplitude during HF-SCS was adjusted such that inspired volumes matched spontaneous breathing (Protocol 1). During HF-SCS, mean peak SMU firing frequency was highest in the 3rd interspace (dorsal) (18.8 ± 0.3 Hz) and significantly lower in the 3rd interspace (ventral) (12.2 ± 0.2 Hz) and 5th interspace (dorsal) (15.3 ± 0.3 Hz) (P < 0.05 for each comparison). Similar rostrocaudal and dorsoventral gradients of activity were observed during spontaneous breathing prior to C2 section. No significant activity was observed in the 7th interspace during either spontaneous breathing or HF-SCS. Since peak discharge frequencies of the SMUs were higher and rib cage movement greater during HF-SCS compared to spontaneous breathing, stimulus amplitude during HF-SCS was adjusted such that rib cage movement matched (Protocol 2). Under these conditions, mean peak SMU frequencies and rostrocaudal and dorsoventral gradients of activity during HF-SCS were not significantly different compared to spontaneous breathing. These results indicate that (a) the topographic pattern of electrical activation of the external intercostal muscles during HF-SCS is similar to that occurring during spontaneous breathing and (b) differential descending synaptic input from supraspinal centres is not a required component of the differential spatial distribution of external intercostal muscle activation. HF-SCS may provide a more physiological

  10. 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

  11. College Student Services Accreditation Questionnaire.

    ERIC Educational Resources Information Center

    Cassel, Russell N.

    1979-01-01

    This questionnaire is intended for use as one aspect in accrediting the "Student Personnel Services" which an institution of higher learning provides for students. Areas in question include personal development, health fostering, vocational preparation, effective personalized learning, economic viability, transpersonal offerings, and satisfactory…

  12. Diet History Questionnaire: Canadian Version

    Cancer.gov

    The Diet History Questionnaire (DHQ) and the DHQ nutrient database were modified for use in Canada through the collaborative efforts of Dr. Amy Subar and staff at the Risk Factor Monitoring and Methods Branch, and Dr. Ilona Csizmadi and colleagues in the Division of Population Health and Information at the Alberta Cancer Board in Canada.

  13. 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. PMID:25383460

  14. Active modulation of refractive index by stress in the terahertz frequency range: erratum.

    PubMed

    Song, Wei; Wang, Zhiyong

    2016-03-20

    A previous paper [Appl. Opt.52, 6364 (2013)APOPAI0003-693510.1364/AO.52.006364] presented experimental work on the stress-optical effect in the terahertz frequency range. Although the theoretical model of experimental measurement is correct, there are two errors in the original version. As a result, the presented experimentally measured value of the refractive index-stress coefficient A of polytetrafluoroethylene (PTFE) is erroneous. This erratum points out the errors in the original paper and reports the correct values. PMID:27140555

  15. 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

  16. Using high frequency GPS to determine spatial-temporal activity of ungualtes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Range and wildlife managers are interested in the spatial-temporal context of behavioral activities such as foraging, resting, and sheltering as well as herding dynamics of ungulates on landscapes. They are particularly interested in these activities because of their importance for animal energeti...

  17. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging.

    PubMed

    Nozaradan, Sylvie

    2014-12-19

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain. PMID:25385771

  18. Analysis of EEG activity in response to binaural beats with different frequencies.

    PubMed

    Gao, Xiang; Cao, Hongbao; Ming, Dong; Qi, Hongzhi; Wang, Xuemin; Wang, Xiaolu; Chen, Runge; Zhou, Peng

    2014-12-01

    When two coherent sounds with nearly similar frequencies are presented to each ear respectively with stereo headphones, the brain integrates the two signals and produces a sensation of a third sound called binaural beat (BB). Although earlier studies showed that BB could influence behavior and cognition, common agreement on the mechanism of BB has not been reached yet. In this work, we employed Relative Power (RP), Phase Locking Value (PLV) and Cross-Mutual Information (CMI) to track EEG changes during BB stimulations. EEG signals were acquired from 13 healthy subjects. Five-minute BBs with four different frequencies were tested: delta band (1 Hz), theta band (5 Hz), alpha band (10 Hz) and beta band (20 Hz). We observed RP increase in theta and alpha bands and decrease in beta band during delta and alpha BB stimulations. RP decreased in beta band during theta BB, while RP decreased in theta band during beta BB. However, no clear brainwave entrainment effect was identified. Connectivity changes were detected following the variation of RP during BB stimulations. Our observation supports the hypothesis that BBs could affect functional brain connectivity, suggesting that the mechanism of BB-brain interaction is worth further study. PMID:25448376

  19. Exploring how musical rhythm entrains brain activity with electroencephalogram frequency-tagging

    PubMed Central

    Nozaradan, Sylvie

    2014-01-01

    The ability to perceive a regular beat in music and synchronize to this beat is a widespread human skill. Fundamental to musical behaviour, beat and meter refer to the perception of periodicities while listening to musical rhythms and often involve spontaneous entrainment to move on these periodicities. Here, we present a novel experimental approach inspired by the frequency-tagging approach to understand the perception and production of rhythmic inputs. This approach is illustrated here by recording the human electroencephalogram responses at beat and meter frequencies elicited in various contexts: mental imagery of meter, spontaneous induction of a beat from rhythmic patterns, multisensory integration and sensorimotor synchronization. Collectively, our observations support the view that entrainment and resonance phenomena subtend the processing of musical rhythms in the human brain. More generally, they highlight the potential of this approach to help us understand the link between the phenomenology of musical beat and meter and the bias towards periodicities arising under certain circumstances in the nervous system. Entrainment to music provides a highly valuable framework to explore general entrainment mechanisms as embodied in the human brain. PMID:25385771

  20. Frequency specific interactions of MEG resting state activity within and across brain networks as revealed by the multivariate interaction measure.

    PubMed

    Marzetti, L; Della Penna, S; Snyder, A Z; Pizzella, V; Nolte, G; de Pasquale, F; Romani, G L; Corbetta, M

    2013-10-01

    Resting state networks (RSNs) are sets of brain regions exhibiting temporally coherent activity fluctuations in the absence of imposed task structure. RSNs have been extensively studied with fMRI in the infra-slow frequency range (nominally <10(-1)Hz). The topography of fMRI RSNs reflects stationary temporal correlation over minutes. However, neuronal communication occurs on a much faster time scale, at frequencies nominally in the range of 10(0)-10(2)Hz. We examined phase-shifted interactions in the delta (2-3.5 Hz), theta (4-7 Hz), alpha (8-12 Hz) and beta (13-30 Hz) frequency bands of resting-state source space MEG signals. These analyses were conducted between nodes of the dorsal attention network (DAN), one of the most robust RSNs, and between the DAN and other networks. Phase shifted interactions were mapped by the multivariate interaction measure (MIM), a measure of true interaction constructed from the maximization of imaginary coherency in the virtual channels comprised of voxel signals in source space. Non-zero-phase interactions occurred between homologous left and right hemisphere regions of the DAN in the delta and alpha frequency bands. Even stronger non-zero-phase interactions were detected between networks. Visual regions bilaterally showed phase-shifted interactions in the alpha band with regions of the DAN. Bilateral somatomotor regions interacted with DAN nodes in the beta band. These results demonstrate the existence of consistent, frequency specific phase-shifted interactions on a millisecond time scale between cortical regions within RSN as well as across RSNs. PMID:23631996

  1. Use of 130Te 2 for frequency referencing and active stabilisation of a violet extended cavity diode laser

    NASA Astrophysics Data System (ADS)

    Burns, I. S.; Hult, J.; Kaminski, C. F.

    2006-04-01

    This paper reports on the use of 130Te 2 absorption lines in active laser-locking, and in frequency referencing, of the emission of a violet extended cavity diode laser with a wavelength of around 410 nm. We note the existence of closely spaced tellurium absorption lines, suitable for referencing purposes in gas sensing applications, at wavelengths below the lower limit (417 nm) of the spectral region covered by the tellurium atlas [J. Cariou, P. Luc, Atlas du spectre d'Absorption de la Molecule de Tellure, CNRS, Paris, 1980]. The absolute positions of the lines in the acquired spectra were estimated by comparison to a simultaneously acquired fluorescence spectrum of atomic indium, and were identified using calculations based on fundamental spectroscopic data. The laser frequency was stabilised within a range of 40 MHz, which is negligible compared to typical transition widths at atmospheric pressure.

  2. Use of (130)Te(2) for frequency referencing and active stabilisation of a violet extended cavity diode laser.

    PubMed

    Burns, I S; Hult, J; Kaminski, C F

    2006-04-01

    This paper reports on the use of (130)Te(2) absorption lines in active laser-locking, and in frequency referencing, of the emission of a violet extended cavity diode laser with a wavelength of around 410 nm. We note the existence of closely spaced tellurium absorption lines, suitable for referencing purposes in gas sensing applications, at wavelengths below the lower limit (417 nm) of the spectral region covered by the tellurium atlas [J. Cariou, P. Luc, Atlas du spectre d'Absorption de la Molecule de Tellure, CNRS, Paris, 1980]. The absolute positions of the lines in the acquired spectra were estimated by comparison to a simultaneously acquired fluorescence spectrum of atomic indium, and were identified using calculations based on fundamental spectroscopic data. The laser frequency was stabilised within a range of 40 MHz, which is negligible compared to typical transition widths at atmospheric pressure. PMID:16503188

  3. Orbital changes, variation in solar activity and increased anthropogenic activities: controls on the Holocene flood frequency in the Lake Ledro area, Northern Italy

    NASA Astrophysics Data System (ADS)

    Vannière, B.; Magny, M.; Joannin, S.; Simonneau, A.; Wirth, S. B.; Hamann, Y.; Chapron, E.; Gilli, A.; Desmet, M.; Anselmetti, F. S.

    2013-05-01

    Two lacustrine sediment cores from Lake Ledro in northern Italy were studied to produce chronologies of flood events for the past 10 000 yr. For this purpose, we have developed an automatic method that objectively identifies the sedimentary imprint of river floods in the downstream lake basin. The method was based on colour data extracted from processed core photographs, and the count data were analysed to capture the flood signal. Flood frequency and reconstructed sedimentary dynamics were compared with lake-level changes and pollen inferred vegetation dynamics. The results suggest a record marked by low flood frequency during the early and middle Holocene (10 000-4500 cal BP). Only modest increases during short intervals are recorded at ca. 8000, 7500, and 7100 cal BP. After 4500-4000 cal BP, the record shows a shift toward increased flood frequency. With the exception of two short intervals around 2900-2500 and 1800-1400 cal BP, which show a slightly reduced number of floods, the trend of increasing flood frequency prevailed until the 20th century, reaching a maximum between the 16th and the 19th centuries. Brief-flood frequency increases recorded during the early and middle Holocene can be attributed to cold climatic oscillations. On a centennial time scale, major changes in flood frequency, such as those observed after ca. 4500/4000 and 500 cal BP, can be attributed to large-scale climatic changes such as the Neo-glacial and Little Ice Age, which are under orbital and possibly solar control. However, in the Bronze Age and during the Middle Ages and modern times, forest clearing and land use probably partially control the flood activity.

  4. Frequency dependence of sensitivities in second-order RC active filters

    NASA Astrophysics Data System (ADS)

    Kunieda, T.; Hiramatsu, Y.; Fukui, A.

    1980-02-01

    This paper presents that gain and phase sensitivities to some element in biquadratic filters approximately constitute a circle on the complex sensitivity plane, provided that the quality factor Q of the circuit is appreciably larger than unity. Moreover, the group delay sensitivity is represented by the imaginary part of a cardioid. Using these results, bounds of maximum values of gain, phase, and group delay sensitivities are obtained. Further, it is proved that the maximum values of these sensitivities can be simultaneously minimized by minimizing the absolute value of the transfer function sensitivity at the center frequency provided that w(0)-sensitivities are constant and do not contain design parameters. Next, a statistical variability measure for the optimal-filter design is proposed. Finally, the relation between some variability measures proposed to the present time is made clear.

  5. An overview of DREV's activities on pulsed CO2 laser transmitters: Frequency stability and lifetime aspects

    NASA Technical Reports Server (NTRS)

    Cruickshank, James; Pace, Paul; Mathieu, Pierre

    1987-01-01

    After introducing the desired features in a transmitter for laser radar applications, the output characteristics of several configurations of frequency-stable TEA-CO2 lasers are reviewed. Based on work carried out at the Defence Research Establishment Valcartier (DREV), output pulses are examined from short cavity lasers, CW-TEA hybrid lasers, and amplifiers for low power pulses. It is concluded that the technique of injecting a low-power laser beam into a TEA laser resonator with Gaussian reflectivity mirrors should be investigated because it appears well adapted to producing high energy, single mode, low chirp pulses. Finally, a brief report on tests carried out on catalysts composed of stannic oxide and noble metals demonstrates the potential of these catalysts, operating at close to room temperature, to provide complete closed-cycle laser operation.

  6. Frequency of effective wave activity and the recession of coastal bluffs: Calvert Cliffs, Maryland

    USGS Publications Warehouse

    Wilcock, P.R.; Miller, D.S.; Shea, R.H.; Kerkin, R.T.

    1998-01-01

    The Calvert Cliffs, Chesapeake Bay, Maryland, USA, erode by direct wave undercutting or by freeze/thaw erosion accompanied by wave removal of slope debris. Directly undercut slopes recede more rapidly, with long-term rates exceeding 1.0 m/yr; freeze/thaw slopes recede at rates approaching 0.5 m/yr. The frequency of wave height and water level at the shoreline is estimated for eleven sites based on a 37-year wind record, estimates of storm surge, offshore wave geometry, nearshore wave transformation, and breaking wave type. Locations experiencing the largest slope recession are not uniformly those with the largest cumulative wave energy; the resistance to erosion of the slope toe must also be accounted for. An index of relative wave strength is defined as the ratio of wave pressure T and the cohesive strength S of the slope material. For the Calvert Cliffs, a minimum relative wave strength for initiating erosion of intact material is 0.05 < T/S < 0.1. A cumulative duration of ???50 hours per year for T/S ??? 0.1 distinguishes undercut and nonundercut slopes and recession rates greater or lesser than 0.5 m/yr. The relative wave strength index may be used to identify sites at risk of increased erosion. At one site with a small historical erosion rate, the loss of a protective beach and associated decrease in toe elevation caused a positive shift in the frequency of large T/S. Direct wave undercutting and increased slope recession may be anticipated at this site, as indicated by the development of an undercut notch during the course of the study.

  7. Ionospheric VLF waves and optical phenomena over active thunderstorms. [VLF (very low frequency)

    SciTech Connect

    Li, Y.Q.

    1993-01-01

    In 1987 and 1988, two campaigns, the Wave Induced Particle Precipitation campaign and the Thunderstorm II campaign, were conducted to investigate lightning-generated effects in the upper atmosphere and ionosphere. Two rockets and 6 balloons were launched near thunderstorms in these campaigns. Optical and electrical signals from hundreds of lightning strokes were recorded. The author has been able to study some problems about lightning-generated VLF waves in the ionosphere which have not been well investigated previously. This dissertation reports the following: (1) The downward-looking optical detector on the rocket recorded some anomalous characteristic optical phenomena. (2) The author studied the relation between the amplitude of lightning-generated VLF waves in the ionosphere and the lightning current recorded by the SUNYA lightning network. This study shows that the amplitude of waves at frequencies below 5 kHz has linear response to the lightning current. (3) The author has been able to determine the propagation path of the lightning-generated VLF waves from the source to the rocket. The path is consistent with the leaky waveguide hypothesis. (4) The amplitude of lightning-generated VLF waves has been found to have maxima and minima at different altitudes, instead of being attenuated monotonically with altitude as expected. A theoretical model has been proposed which shows that the wave amplitude profiles are the result of interference between waves from an aperture area below the rocket. (5) The author numerically calculated the absorption of VLF waves at the bottom of the ionosphere. The electron density gradient of the ionosphere was taken into account. The characteristics of the absorption, such as the frequency dependence, were investigated. The author deduced that significant heating of the ionosphere is caused by lightning-generated VLF waves.

  8. Active sources in the cutoff of centrifugal fans to reduce the blade tones at higher-order duct mode frequencies

    NASA Astrophysics Data System (ADS)

    Neise, W.; Koopmann, G. H.

    1991-01-01

    A previously developed (e.g., Neise and Koopmann, 1984; Koopmann et al., 1988) active noise control technique in which the unwanted acoustic signals from centrifugal fans are suppressed by placing two externally driven sources near the cutoff of the casing was applied to the frequency region where not only plane sound waves are propagational in the fan ducts but also higher-order acoustic modes. Using a specially designed fan noise testing facility, the performance of two fans (280-mm impeller diam and 508 mm diam) was monitored with static pressure taps mounted peripherally around the inlet nozzle. Experimental results show that the aerodynamically generated source pressure field around the cutoff is too complex to be successfully counterimaged by only two active sources introduced in this region. It is suggested that, for an efficient application of this noise control technique in the higher-order mode frequency regime, it is neccessary to use an active source involving larger number of individually driven loudspeakers.

  9. [Effect of Low-Intensity 900 MHz Frequency Electromagnetic Radiation on Rat Brain Enzyme Activities Linked to Energy Metabolism].

    PubMed

    Petrosyan, M S; Nersesova, L S; Gazaryants, M G; Meliksetyan, G O; Malakyan, M G; Bajinyan, S A; Akopian, J I

    2015-01-01

    The research deals with the effect of low-intensity 900 MHz frequency electromagnetic radiation (EMR), power density 25 μW/cm2, on the following rat brain and blood serum enzyme activities: creatine kinase (CK), playing a central role in the process of storing and distributing the cell energy, as well as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) that play a key role in providing the conjunction of carbohydrate and amino acid metabolism. The comparative analysis of the changes in the enzyme activity studied at different times following the two-hour single, as well as fractional, radiation equivalent of the total time showed that the most radiosensitive enzyme is the brain creatine kinase, which may then be recommended as a marker of the radio frequency radiation impact. According to the analysis of the changing dynamics of the CK, ALT and AST activity level, with time these changes acquire the adaptive character and are directed to compensate the damaged cell energy metabolism. PMID:26964348

  10. Improving mechanical properties of polyethylene orthopaedic implants by high frequency cold plasma surface activation

    NASA Astrophysics Data System (ADS)

    Tudoran, Cristian D.; Vlad, Iulia E.; Dadarlat, Dorin N.; Anghel, Sorin D.

    2013-11-01

    Although a tremendous progress has been made in developing new methods and materials for manufacturing orthopaedic implants, the new technology still faces various problems. Polyethylene implants are relatively easy to manufacture and at lower cost compared to metallic or ceramic implants, but they present a fundamental problem: during usage and in time, due to their manufacturing technology, the material suffers from pitting and delamination which leads to crack propagation and finally to sudden fracture. Our studies and tests performed on polyethylene showed that, using cold plasma surface activation during the manufacturing process of the orthopaedic implants made from polyethylene can significantly increase their mechanical properties. The breaking tests revealed an increase of the tensile strength in the laminated polyethylene samples by a factor of 4 after plasma activation. "Aging" tests have been also performed to investigate how the cold plasma treated samples maintain their properties in time, after the surface activation process.

  11. Spatial pattern of spontaneous retinal waves instructs retinotopic map refinement more than activity frequency.

    PubMed

    Xu, Hong-Ping; Burbridge, Timothy J; Chen, Ming-Gang; Ge, Xinxin; Zhang, Yueyi; Zhou, Zhimin Jimmy; Crair, Michael C

    2015-06-01

    Spontaneous activity during early development is necessary for the formation of precise neural connections, but it remains uncertain whether activity plays an instructive or permissive role in brain wiring. In the visual system, retinal ganglion cell (RGC) projections to the brain form two prominent sensory maps, one reflecting eye of origin and the other retinotopic location. Recent studies provide compelling evidence supporting an instructive role for spontaneous retinal activity in the development of eye-specific projections, but evidence for a similarly instructive role in the development of retinotopy is more equivocal. Here, we report on experiments in which we knocked down the expression of β2-containing nicotinic acetylcholine receptors (β2-nAChRs) specifically in the retina through a Cre-loxP recombination strategy. Overall levels of spontaneous retinal activity in retina-specific β2-nAChR mutant mice (Rx-β2cKO), examined in vitro and in vivo, were reduced to a degree comparable to that observed in whole animal β2-nAChR mouse mutants (β2KO). However, many residual spontaneous waves in Rx-β2cKO mice displayed local propagating features with strong correlations between nearby but not distant RGCs typical of waves observed in wild-type (WT) but not β2KO mice. We further observed that eye-specific segregation was disrupted in Rx-β2cKO mice, but retinotopy was spared in a competition-dependent manner. These results suggest that propagating patterns of spontaneous retinal waves are essential for normal development of the retinotopic map, even while overall activity levels are significantly reduced, and support an instructive role for spontaneous retinal activity in both eye-specific segregation and retinotopic refinement. PMID:25787992

  12. Spatial pattern of spontaneous retinal waves instructs retinotopic map refinement more than activity frequency

    PubMed Central

    Xu, Hong-Ping; Burbridge, Timothy J.; Chen, Ming-Gang; Ge, Xinxin; Zhang, Yueyi; Zhou, Z. Jimmy; Crair, Michael C.

    2015-01-01

    Spontaneous activity during early development is necessary for the formation of precise neural connections, but it remains uncertain whether activity plays an instructive or permissive role in brain wiring. In the visual system, retinal ganglion cell (RGC) projections to the brain form two prominent sensory maps, one reflecting eye of origin and the other retinotopic location. Recent studies provide compelling evidence supporting an instructive role for spontaneous retinal activity in the development of eye-specific projections, but evidence for a similarly instructive role in the development of retinotopy is more equivocal. Here, we report on experiments in which we knocked down the expression of β2-containing nicotinic acetylcholine receptors (β2-nAChRs) specifically in the retina through a Cre-loxP recombination strategy. Overall levels of spontaneous retinal activity in retina-specific β2-nAChR mutant mice (Rx-β2cKO), examined in vitro and in vivo, were reduced to a degree comparable to that observed in whole animal β2-nAChR mouse mutants (β2KO). However, many residual spontaneous waves in Rx-β2cKO mice displayed local propagating features with strong correlations between nearby but not distant RGCs typical of waves observed in WT, but not β2KO mice. We further observed that eye-specific segregation was disrupted in Rx-β2cKO mice, but retinotopy was spared in a competition-dependent manner. These results suggest that propagating patterns of spontaneous retinal waves are essential for normal development of the retinotopic map, even while overall activity levels are significantly reduced, and support an instructive role for spontaneous retinal activity in both eye-specific segregation and retinotopic refinement. PMID:25787992

  13. The vital activity of organisms in infralow frequency magnetic field. 4. Mycobacteria tuberculosis

    SciTech Connect

    Khizhenkov, P.K.; Noreiko, B.V.; Lepshina, S.M.

    1995-07-01

    It is shown that a periodic (0.5 or 7 h/day) application of an alternating magnetic field H (f = 8 Hz, amplitude 60-80 Oe) enhances the vital activity of tuberculosis mycobacteria (TMB), which leads to a doubling of the biocycles and a 48-h reduction in the lag-phase. The increase in the functional activity of the TMB is accompanied by a lowering of the their resistance to medication. In the experiment, the TMB exposed to the magnetic field effect completely lost their resistance to three of the four tested medicines.

  14. Temporal evolution of pump beam self-focusing at the High-Frequency Active Auroral Research Program

    NASA Astrophysics Data System (ADS)

    Kosch, M. J.; Pedersen, T.; Mishin, E.; Starks, M.; Gerken-Kendall, E.; Sentman, D.; Oyama, S.; Watkins, B.

    2007-08-01

    On 4 February 2005 the High-Frequency Active Auroral Research Program (HAARP) facility was operated at 2.85 MHz to produce artificial optical emissions in the ionosphere while passing through the second electron gyroharmonic. All-sky optical recordings were performed with 15 s integration, alternating between 557.7 and 630 nm. We report the first optical observations showing the temporal evolution of large-scale pump wave self-focusing in the magnetic zenith, observed in the 557.7 nm images. These clearly show that the maximum intensity was not reached after 15 s of pumping, which is unexpected since the emission delay time is <1 s, and that the optical signature had intensified in a much smaller region within the beam after 45 s of pumping. In addition, adjacent regions within the beam lost intensity. Radar measurements indicate a plasma depletion of ~1% near the HF reflection altitude. Ray tracing of the pump wave through the plasma depletion region, which forms a concave reflecting radio wave mirror, reproduces the optical spatial morphology. A radio wave flux density gain of up to ~30 dB may occur. In addition, the ray trace is consistent with the observed artificial optical emissions for critical plasma frequencies down to ~0.5 MHz below the pump frequency.

  15. Soil Moisture Active Passive (SMAP) Microwave Radiometer Radio-Frequency Interference (RFI) Mitigation: Initial On-Orbit Results

    NASA Technical Reports Server (NTRS)

    Mohammed, Priscilla N.; Piepmeier, Jeffrey R.; Johnson, Joel T.; Aksoy, Mustafa; Bringer, Alexandra

    2015-01-01

    The Soil Moisture Active Passive (SMAP) mission, launched in January 2015, provides global measurements of soil moisture using a microwave radiometer. SMAPs radiometer passband lies within the passive frequency allocation. However, both unauthorized in-band transmitters as well as out-of-band emissions from transmitters operating at frequencies adjacent to this allocated spectrum have been documented as sources of radio frequency interference (RFI) to the L-band radiometers on SMOS and Aquarius. The spectral environment consists of high RFI levels as well as significant occurrences of low level RFI equivalent to 0.1 to 10 K. The SMAP ground processor reports the antenna temperature both before and after RFI mitigation is applied. The difference between these quantities represents the detected RFI level. The presentation will review the SMAP RFI detection and mitigation procedure and discuss early on-orbit RFI measurements from the SMAP radiometer. Assessments of global RFI properties and source types will be provided, as well as the implications of these results for SMAP soil moisture measurements.

  16. Magnetic activity cycles in solar-like stars: The cross-correlation technique of p-mode frequency shifts

    NASA Astrophysics Data System (ADS)

    Régulo, C.; García, R. A.; Ballot, J.

    2016-04-01

    Aims: We set out to study the use of cross-correlation techniques to infer the frequency shifts that are induced by changing magnetic fields in p-mode frequencies and to provide a precise estimation of error bars. Methods: This technique and the calculation of the associated errors is first tested and validated on the Sun where p-mode magnetic behaviour is very well known. These validation tests are performed on 6000-day time series of Sun-as-a-star observations delivered by the SoHO spacecraft. Errors of the frequency shifts are quantified through Monte Carlo simulations. The same methodology is then applied to three solar-like oscillating stars: HD 49933, observed by CoRoT, as well as KIC 3733735 and KIC 7940546, observed by Kepler. Results: We first demonstrate the reliability of the error bars computed with the Monte Carlo simulations using the Sun. From the three stars analyzed, we confirm the presence of a magnetic activity cycle in HD 49933 with this methodology and we unveil the seismic signature of ongoing magnetic variations in KIC 3733735. Finally, the third star, KIC 7940546, seems to be in a quiet regime.

  17. Active Control of Multi-Tonal Noise with Reference Generator Based on On-Line Frequency Estimation

    NASA Astrophysics Data System (ADS)

    KIM, S.; PARK, Y.

    1999-10-01

    In this paper, a novel active noise control (ANC) structure with a frequency estimator is proposed for systems with multi-tonal noise. The conventional feedforward ANC algorithms need a measured reference signal to calculate the gradient of the squared error and filter coefficients. For ANC systems applied to aircraft or passenger ships, which reference signals are usually measured are so far from seats where engines from the main part of controllers is placed that the scheme might be difficult to implement or very costly. Feedback ANC algorithms which do not require a measure of reference signals, use error signals alone to update the filter and are usually sensitive to measurement noise and unexpected transient noise such as a sneeze, clapping of hands and so on.The proposed algorithm, which estimates frequencies of the multi-tonal noise in real time using adaptive notch filter (ANF), improves convergence rate, threshold SNR and computational efficiency compared with the conventional ones. The reference signal needed for the feedforward control is not measured directly, but is generated with the estimated frequencies. It has a strong similarity to the conventional IMC-based feedback control because the reference is generated from the error signal in both cases. The proposed ANC algorithm is compared with the conventional IMC-based feedback control algorithm.Cascade ANF, which has a low computational burden, is used to implement the ANC system in real time. Experiments for verifying efficacy of the proposed algorithm are carried out in the laboratory.

  18. Attentional selection of location and modality in vision and touch modulates low-frequency activity in associated sensory cortices

    PubMed Central

    Kennett, Steffan; Driver, Jon

    2012-01-01

    Selective attention allows us to focus on particular sensory modalities and locations. Relatively little is known about how attention to a sensory modality may relate to selection of other features, such as spatial location, in terms of brain oscillations, although it has been proposed that low-frequency modulation (α- and β-bands) may be key. Here, we investigated how attention to space (left or right) and attention to modality (vision or touch) affect ongoing low-frequency oscillatory brain activity over human sensory cortex. Magnetoencephalography was recorded while participants performed a visual or tactile task. In different blocks, touch or vision was task-relevant, whereas spatial attention was cued to the left or right on each trial. Attending to one or other modality suppressed α-oscillations over the corresponding sensory cortex. Spatial attention led to reduced α-oscillations over both sensorimotor and occipital cortex contralateral to the attended location in the cue-target interval, when either modality was task-relevant. Even modality-selective sensors also showed spatial-attention effects for both modalities. The visual and sensorimotor results were generally highly convergent, yet, although attention effects in occipital cortex were dominant in the α-band, in sensorimotor cortex, these were also clearly present in the β-band. These results extend previous findings that spatial attention can operate in a multimodal fashion and indicate that attention to space and modality both rely on similar mechanisms that modulate low-frequency oscillations. PMID:22323628

  19. High frequency ultrasound as a selective advanced oxidation process to remove penicillinic antibiotics and eliminate its antimicrobial activity from water.

    PubMed

    Serna-Galvis, Efraim A; Silva-Agredo, Javier; Giraldo-Aguirre, Ana L; Flórez-Acosta, Oscar A; Torres-Palma, Ricardo A

    2016-07-01

    This work studies the sonochemical degradation of a penicillinic antibiotic (oxacillin) in simulated pharmaceutical wastewater. High frequency ultrasound was applied to water containing the antibiotic combined with mannitol or calcium carbonate. In the presence of additives, oxacillin was efficiently removed through sonochemical action. For comparative purposes, the photo-Fenton, TiO2 photocatalysis and electrochemical oxidation processes were also tested. Therefore, the evolution of the antibiotic and its associated antimicrobial activity (AA) were monitored. A high inhibition was found for the other three oxidation processes in the elimination of the antimicrobial activity caused by the additives; while for the ultrasonic treatment, a negligible effect was observed. The sonochemical process was able to completely degrade the antibiotic, generating solutions without AA. In fact, the elimination of antimicrobial activity showed an excellent performance adjusted to exponential kinetic-type decay. The main sonogenerated organic by-products were determined by means of HPLC-MS. Four intermediaries were identified and they have modified the penicillinic structure, which is the moiety responsible for the antimicrobial activity. Additionally, the possible oxacillin sonodegradation mechanism was proposed based on the evolution of the by-products and their chemical structure. Furthermore, the high-frequency ultrasound action over 120 min readily removed oxacillin and eliminated its antimicrobial activity. However, the pollutant was not mineralized even after a long period of ultrasonic irradiation (360 min). Interestingly, the previously sonicated water containing oxacillin and both additives was completely mineralized using non-adapted microorganisms from a municipal wastewater treatment plant. These results show that the sonochemical treatment transformed the initial pollutant into substances that are biotreatable with a typical aerobic biological system. PMID:26964950

  20. Emotion Recognition with Eigen Features of Frequency Band Activities Embedded in Induced Brain Oscillations Mediated by Affective Pictures.

    PubMed

    Aydin, Serap; Demirtaş, Serdar; Ateş, Kahraman; Tunga, M Alper

    2016-05-01

    In this study, singular spectrum analysis (SSA) has been used for the first time in order to extract emotional features from well-defined electroencephalography (EEG) frequency band activities (BAs) so-called delta (0.5-4 Hz), theta (4-8 Hz), alpha (8-16 Hz), beta (16-32 Hz), gamma (32-64 Hz). These five BAs were estimated by applying sixth-level multi-resolution wavelet decomposition (MRWD) with Daubechies wavelets (db-8) to single channel nonaveraged emotional EEG oscillations of 6 s for each scalp location over 16 recording sites (Fp1, Fp2, F3, F4, F7, F8, C3, C4, P3, P4, T3, T4, T5, T6, O1, O2). Every trial was mediated by different emotional stimuli which were selected from international affective picture system (IAPS) to induce emotional states such as pleasant (P), neutral (N), and unpleasant (UP). Largest principal components (PCs) of BAs were considered as emotional features and data mining approaches were used for the first time in order to classify both three different (P, N, UP) and two contrasting (P and UP) emotional states for 30 healthy controls. Emotional features extracted from gamma BAs (GBAs) for 16 recording sites provided the high classification accuracies of 87.1% and 100% for classification of three emotional states and two contrasting emotional states, respectively. In conclusion, we found the followings: (1) Eigenspectra of high frequency BAs in EEG are highly sensitive to emotional hemispheric activations, (2) emotional states are mostly mediated by GBA, (3) pleasant pictures induce the higher cortical activation in contrast to unpleasant pictures, (4) contrasting emotions induce opposite cortical activations, (5) cognitive activities are necessary for an emotion to occur. PMID:26971786

  1. A modified inflammatory bowel disease questionnaire and the Vaizey Incontinence questionnaire are more sensitive measures of acute gastrointestinal toxicity during pelvic radiotherapy than RTOG grading

    SciTech Connect

    Khalid, Usman; McGough, Camilla; Hackett, Claire; Blake, Peter; Harrington, Kevin J.; Khoo, Vincent S.; Tait, Diana; Norman, Andrew R.; Andreyev, H. Jervoise N. . E-mail: j@andreyev.demon.co.uk

    2006-04-01

    Purpose: Simple scales with greater sensitivity than Radiation Therapy Oncology Group (RTOG) grading to detect acute gastrointestinal toxicity during pelvic radiotherapy, could be clinically useful. Methods and Materials: Do questionnaires used in benign gastrointestinal diseases detect toxicity in patients undergoing radiotherapy? The patient-completed Inflammatory Bowel Disease (IBDQ) and Vaizey Incontinence questionnaires were compared prospectively at baseline and at Week 5 to physician-completed RTOG grading. Results: A total of 107 patients, median age 63 years, were recruited. After 5 weeks of treatment, patients with gynecologic and gastrointestinal cancer were more symptomatic than urologic patients (p 0.012; p = 0.014). Overall, 94% had altered bowel habits, 80% loose stool, 74% frequency, 65% difficult gas, 60% pain, >48% distress, 44% tenesmus, >40% restrictions in daily activity, 39% urgency, 37% fecal incontinence, and 40% required antidiarrheal medication. The median RTOG score was 1 (range, 0-2), median IBDQ score 204.5 (range, 74-224), and median Vaizey score 5 (range, 0-20). Chemotherapy preceding radiotherapy increased fecal incontinence (p 0.002). RTOG scores stabilized after 3 weeks, IBDQ scores peaked at Week 4, and Vaizey scores worsened throughout treatment. IBDQ and Vaizey scores distinguished between groups with different RTOG scores. Conclusion: The IBDQ and Vaizey questionnaires are reliable and sensitive, offering greater insight into the severity and range of symptoms compared with RTOG grading.

  2. A Neuroanatomical Basis for the Frequency of Discrete Spontaneous Activities in Schizophrenia

    PubMed Central

    Farrow, Tom F.D; Hunter, Michael D; Wilkinson, Iain D; Spence, Sean A

    2009-01-01

    Limited behavioural repertoire impacts quality of life in chronic schizophrenia. We have previously shown that the amount of movement exhibited by patients with schizophrenia is positively correlated with the volume of left anterior cingulate cortex and that this quantity of movement can be increased by modafinil. However, increased movement in itself may be of limited clinical significance. Hence, we sought to analyse the ‘structure’ of spontaneous movement in patients with schizophrenia and to examine whether the chunking of spontaneous activity has a neuroanatomical basis. ‘Actiwatches’ were used to record spontaneous motor activity over a 20 hour period in sixteen male patients with schizophrenia. Time-series data were analysed for the number of discrete spontaneous activities, which might indicate a degree of structure to ongoing activity. Subjects underwent a whole-brain structural MRI scan. The ‘number of discrete movement epochs’ correlated with volumes of regions within bilateral rostro-ventral putamen and temporal poles. These data suggest that in people with schizophrenia the volume of bilateral putamen may influence the complexity of their behaviours, as distinct from the overall amount of behaviour. The results are presented in the context of a large body of previous research examining the role of the basal ganglia in motor and cognitive pattern generation. PMID:19572020

  3. CHANDRA OBSERVATIONS OF GALAXY ZOO MERGERS: FREQUENCY OF BINARY ACTIVE NUCLEI IN MASSIVE MERGERS

    SciTech Connect

    Teng, Stacy H.; Darg, Dan W.; Kaviraj, Sugata; Lintott, Chris J.; Oh, Kyuseok; Cardamone, Carolin N.; Keel, William C.; Simmons, Brooke D.; Treister, Ezequiel

    2012-07-10

    We present the results from a Chandra pilot study of 12 massive galaxy mergers selected from Galaxy Zoo. The sample includes major mergers down to a host galaxy mass of 10{sup 11} M{sub Sun} that already have optical active galactic nucleus (AGN) signatures in at least one of the progenitors. We find that the coincidences of optically selected active nuclei with mildly obscured (N{sub H} {approx}< 1.1 Multiplication-Sign 10{sup 22} cm{sup -2}) X-ray nuclei are relatively common (8/12), but the detections are too faint (<40 counts per nucleus; f{sub 2-10keV} {approx}< 1.2 Multiplication-Sign 10{sup -13} erg s{sup -1} cm{sup -2}) to reliably separate starburst and nuclear activity as the origin of the X-ray emission. Only one merger is found to have confirmed binary X-ray nuclei, though the X-ray emission from its southern nucleus could be due solely to star formation. Thus, the occurrences of binary AGNs in these mergers are rare (0%-8%), unless most merger-induced active nuclei are very heavily obscured or Compton thick.

  4. Radio-Frequency Interference (RFI) Mitigation for the Soil, Moisture Active/Passive (SMAP) Radiometer

    NASA Technical Reports Server (NTRS)

    Bradley, Damon; Brambora, Cliff; Wong, Mark Englin; Miles, Lynn; Durachka, David; Farmer, Brian; Mohammed, Priscilla; Piepmier, Jeff; Medeiros, Jim; Martin Neil; Garcia, Rafael

    2010-01-01

    The presence of anthropogenic RFI is expected to adversely impact soil moisture measurement by NASA s Soil Moisture Active Passive mission. The digital signal processing approach and preliminary design for detecting and mitigating this RFI is presented in this paper. This approach is largely based upon the work of Johnson and Ruf.

  5. Differential frequency modulation of neural activity in the lateral cerebellar nucleus in failed and successful grasps.

    PubMed

    Cooperrider, Jessica; Gale, John T; Gopalakrishnan, Raghavan; Chan, Hugh H; Wathen, Connor; Park, Hyun-Joo; Baker, Kenneth B; Shaikh, Aasef G; Machado, Andre G

    2016-03-01

    The olivo-cerebellar system has an essential role in the detection and adaptive correction of movement errors. While there is evidence of an error signal in the cerebellar cortex and inferior olivary nucleus, the deep cerebellar nuclei have been less thoroughly investigated. Here, we recorded local field potential activity in the rodent lateral cerebellar nucleus during a skilled reaching task and compared event-related changes in neural activity between unsuccessful and successful attempts. Increased low gamma (40-50 Hz) band power was present throughout the reach and grasp behavior, with no difference between successful and unsuccessful trials. Beta band (12-30 Hz) power, however, was significantly increased in unsuccessful reaches, compared to successful, throughout the trial, including during the epoch preceding knowledge of the trial's outcome. This beta band activity was greater in unsuccessful trials of high-performing days, compared to unsuccessful trials of low-performing days, indicating that this activity may reflect an error prediction signal, developed over the course of motor learning. These findings suggest an error-related discriminatory oscillatory hallmark of movement in the deep cerebellar nuclei. PMID:26698925

  6. Connection of Very High Energy Gamma-ray Flares in Blazars to Activity at Lower Frequencies

    NASA Astrophysics Data System (ADS)

    Marscher, Alan P.; Jorstad, Svetlana G.

    2016-04-01

    The author will briefly review the results of multi-wavelength observations of blazars that emit very high-energy (VHE) gamma rays. The VHE gamma-ray emission is generally episodic, including flares that are often very short-lived. While many of these flares have counterparts only at X-ray energies, or no counterparts at all, some events are seen also at optical wavelengths, and a number are associated with the passage of new superluminal knots passing through the core in mm-wave VLBA images. Two explanations for the short-term VHE flares in the relativistic jets are supersonic turbulence and ultra-fast plasma jets resulting from magnetic reconnections. Observations of frequency-dependent linear polarization during flares can potentially decide between these models. VLBA images can help to locate VHE events that are seen at millimeter wavelengths. In some cases, the flares take place near the parsec-scale core, while in others they occur closer to the black hole.This research is supported in part by NASA through Swift Guest Investigator grants NNX15AR45G and NNX15AR34G.

  7. Gold nanoparticle-based sensors activated by external radio frequency fields.

    PubMed

    Vedova, Paolo Della; Ilieva, Mirolyuba; Zhurbenko, Vitaliy; Mateiu, Ramona; Faralli, Adele; Dufva, Martin; Hansen, Ole

    2015-01-14

    A novel molecular beacon (a nanomachine) is constructed that can be actuated by a radio frequency (RF) field. The nanomachine consists of the following elements arranged in molecular beacon configuration: a gold nanoparticle that acts both as quencher for fluorescence and a localized heat source; one reporter fluorochrome, and; a piece of DNA as a hinge and recognition sequence. When the nanomachines are irradiated with a 3 GHz RF field the fluorescence signal increases due to melting of the stem of the molecular beacon. A control experiment, performed using molecular beacons synthesized by substituting the gold nanoparticle by an organic quencher, shows no increase in fluorescence signal when exposed to the RF field. It may therefore be concluded that the increased fluorescence for the gold nanoparticle-conjugated nanomachines is not due to bulk heating of the solution, but is caused by the presence of the gold nanoparticles and their interaction with the RF field; however, existing models for heating of gold nanoparticles in a RF field are unable to explain the experimental results. Due to the biocompatibility of the construct and RF treatment, the nanomachines may possibly be used inside living cells. In a separate experiment a substantial increase in the dielectric losses can be detected in a RF waveguide setup coupled to a microfluidic channel when gold nanoparticles are added to a low RF loss liquid. This work sheds some light on RF heating of gold nanoparticles, which is a subject of significant controversy in the literature. PMID:25180655

  8. FREQUENCY OF MAUNDER MINIMUM EVENTS IN SOLAR-TYPE STARS INFERRED FROM ACTIVITY AND METALLICITY OBSERVATIONS

    SciTech Connect

    Lubin, Dan; Tytler, David; Kirkman, David

    2012-03-10

    We consider the common proposition that the fraction of chromospherically very inactive stars in a solar-type sample is analogous to the fraction of the Sun's main-sequence lifetime spent in a grand minimum state. In a new approach to this proposition, we examine chromospheric activity log R'{sub HK} in a stellar sample having Hipparcos parallax measurements, and having spectroscopically determined metallicity close to solar (-0.1 {<=} [Fe/H] {<=} 0.1). We evaluate height above the Hipparcos main sequence, and estimate age using isochrones, to identify the most Sun-like stars in this sample. As a threshold below which a star is labeled very inactive, we use the peak of the HK activity distribution mapped over the quiet Sun during the 1968 epoch. We estimate the fraction of Maunder Minimum (MM) analog candidates in our sample at 11.1%. Given the 70 yr duration of the historical MM, this suggests that in any given year there is a 1/630 chance of entering a similar grand minimum. There are three important cautions with this type of estimate. First, recent investigation using actual activity and photometric time series has suggested that very low activity may not be a necessary criterion for identifying a non-cycling MM analog candidate. Second, this type of estimate depends very strongly on the choice of very low activity threshold. Third, in instantaneous measurements of log R'{sub HK}, it is not always clear whether a star is a viable MM analog candidate or merely an older star nearing the end of its main-sequence lifetime.

  9. Globus pallidus neurons dynamically regulate the activity pattern of subthalamic nucleus neurons through the frequency-dependent activation of postsynaptic GABAA and GABAB receptors.

    PubMed

    Hallworth, Nicholas E; Bevan, Mark D

    2005-07-01

    Reciprocally connected GABAergic neurons of the globus pallidus (GP) and glutamatergic neurons of the subthalamic nucleus (STN) are a putative generator of pathological rhythmic burst firing in Parkinson's disease (PD). Burst firing of STN neurons may be driven by rebound depolarization after barrages of GABA(A) receptor (GABA(A)R)-mediated IPSPs arising from pallidal fibers. To determine the conditions under which pallidosubthalamic transmission activates these and other postsynaptic GABARs, a parasagittal mouse brain slice preparation was developed in which pallidosubthalamic connections were preserved. Intact connectivity was first confirmed through the injection of a neuronal tracer into the GP. Voltage-clamp and gramicidin-based perforated-patch current-clamp recordings were then used to study the relative influences of GABA(A)R- and GABA(B)R-mediated pallidosubthalamic transmission on STN neurons. Spontaneous phasic, but not tonic, activation of postsynaptic GABA(A)Rs reduced the frequency and disrupted the rhythmicity of autonomous firing in STN neurons. However, postsynaptic GABA(B)Rs were only sufficiently activated to impact STN firing when pallidosubthalamic transmission was elevated or pallidal fibers were synchronously activated by electrical stimulation. In a subset of neurons, rebound burst depolarizations followed high-frequency, synchronous stimulation of pallidosubthalamic fibers. Although GABA(B)R-mediated hyperpolarization was itself sufficient to generate rebound bursts, coincident activation of postsynaptic GABA(A)Rs produced longer and more intense burst firing. These findings elucidate a novel route through which burst activity can be generated in the STN, and suggest that GABARs on STN neurons could act in a synergistic manner to generate abnormal burst activity in PD. PMID:16000620

  10. Identification of human activities in a thermal system with noise varied in temporal frequency

    NASA Astrophysics Data System (ADS)

    Brooks, Jason; Jacobs, Eddie; Smith, Forrest

    2011-05-01

    The ability of observers to identify human activities in noise is expected to differ from performance with static targets in noise due to the unmasking that is provided by target motion. At a minimum, the probability of identification should increase when the temporal bandwidth of the noise is less than that of the system. Results from a human activities identification experiment are presented in this paper, along with results from a moving character experiment that is intended to provide better understanding of basic motion in noise with varied temporal bandwidth. These results along with further experiments and analysis will eventually be used to improve performance predictions derived from the Targeting Task Performance (TTP) metric.

  11. Sound quality of low-frequency and car engine noises after active noise control

    NASA Astrophysics Data System (ADS)

    Gonzalez, A.; Ferrer, M.; de Diego, M.; Piñero, G.; Garcia-Bonito, J. J.

    2003-08-01

    The ability of active noise control (ANC) systems to achieve a more pleasant sound has been evaluated by means of sound quality analysis of a real multi-channel active noise controller. Recordings of real car engine noises had been carried out using a Head acoustics TM binaural head simulator seated in a typical car seat, and these signals together with synthesized noise have been actively controlled in an enclosed room. The sound quality study has focused on the estimation of noise quality changes through the evaluation of the sense of comfort. Two methods have been developed: firstly, a predictive method based on psychoacoustic parameters (loudness, roughness, tonality and sharpness); and secondly, a subjective method using a jury test. Both results have been related to the spectral characteristics of the sounds before and after active control. It can be concluded from both analyses that ANC positively affects acoustic comfort. The engine noise mathematical comfort predictor is based on loudness and roughness (two psychoacoustic parameters directly influenced by ANC), and has satisfactorily predicted the improvements in the pleasantness of the sounds. As far as the subjective evaluation method is concerned, the jury test has showed that acoustic comfort is, in most cases, directly related to the sense of quietness. However, ANC has also been assessed negatively by the jury in the cases that it was unable to reduce the loudness, perhaps because of the low amplitudes of the original sounds. Finally, from what has been shown, it can be said that the subjective improvements strongly depends on the attenuation level achieved by the ANC system operation, as well as the spectral characteristics of the sounds before and after control.

  12. High power single-frequency and frequency-doubled laser with active compensation for the thermal lens effect of terbium gallium garnet crystal.

    PubMed

    Yin, Qiwei; Lu, Huadong; Su, Jing; Peng, Kunchi

    2016-05-01

    The thermal lens effect of terbium gallium garnet (TGG) crystal in a high power single-frequency laser severely limits the output power and the beam quality of the laser. By inserting a potassium dideuterium phosphate (DKDP) slice with negative thermo-optical coefficient into the laser resonator, the harmful influence of the thermal lens effect of the TGG crystal can be effectively mitigated. Using this method, the stable range of the laser is broadened, the bistability phenomenon of the laser during the process of changing the pump power is completely eliminated, the highest output power of an all-solid-state continuous-wave intracavity-frequency-doubling single-frequency laser at 532 nm is enhanced to 30.2 W, and the beam quality of the laser is significantly improved. PMID:27128067

  13. Chandra Observations of Galaxy Zoo Mergers: Frequency of Binary Active Nuclei in Massive Mergers

    NASA Technical Reports Server (NTRS)

    Teng, Stacy H.; Schawinski, Kevin; Urry, C. Megan; Darg, Dan W.; Kaviraj, Sugata; Oh, Kyuseok; Bonning, Erin W.; Cardamone, Carolin N.; Keel, William C.; Lintott, Chris J.; Simmons, Brooke D.; Treister, Ezequiel

    2012-01-01

    We present the results from a Chandra pilot study of 12 massive galaxy mergers selected from Galaxy Zoo. The sample includes major mergers down to a host galaxy mass of 1011 M that already have optical AGN signatures in at least one of the progenitors. We find that the coincidences of optically selected active nuclei with mildly obscured (N(sub H) approx < 1.1 10(exp 22)/sq cm) X-ray nuclei are relatively common (8/12), but the detections are too faint (< 40 counts per nucleus; (sub -10) keV approx < 1.2 10(exp -13) erg/s/sq cm) to reliably separate starburst and nuclear activity as the origin of the X-ray emission. Only one merger is found to have confirmed binary X-ray nuclei, though the X-ray emission from its southern nucleus could be due solely to star formation. Thus, the occurrences of binary AGN in these mergers are rare (0-8%), unless most merger-induced active nuclei are very heavily obscured or Compton thick.

  14. Chandra Observations of Galaxy Zoo Mergers: Frequency of Binary Active Nuclei in Massive Mergers

    NASA Technical Reports Server (NTRS)

    Teng, Stacy H.; Schwainski, Kevin; Urry, C. Megan; Darg, Dan W.; Kaviraj, Sugata; Oh, Kyuseok; Bonning, Erin W.; Cardamone, Carolin N.; Keel, William C.; Lintott, Chris J.; Simmons, Brooke D.; Treister, Ezequiel

    2012-01-01

    We present the results from a Chandra pilot study of 12 massive mergers selected from Galaxy Zoo. The sample includes major mergers down to a host galaxy mass of 10(sup 11) solar mass that already have optical AGN signatures in at least one of the progenitors. We find that the coincidences of optically selected active nuclei with mildly obscured (N(sub H) less than or approximately 1.1 x 10(exp 22) per square centimeter) X-ray nuclei are relatively common (8/12), but the detections are too faint (less than 40 counts per nucleus; f(sub 2-10 keV) less than or approximately 1.2 x 10(exp -13) ergs per second per square centimeter) to separate starburst and nuclear activity as the origin of the X-ray emission. Only one merger is found to have confirmed binary X-ray nuclei, though the X-ray emission from its southern nucleus could be due solely to star formation. Thus, the occurrences of binary AGN in these mergers are rare (0-8%), unless most merger-induced active nuclei are very heavily obscured or Compton thick.

  15. Assessment of functional gastrointestinal disorders using the Gastro-Questionnaire.

    PubMed

    Leibbrand, Rolf; Cuntz, Ulrich; Hiller, Wolfgang

    2002-01-01

    The purpose was to investigate the reliability and factorial structure of the Gastro-Questionnaire for the screening and psychometric measurement of functional gastrointestinal disorders (FGDs). The questionnaire contains 27 gastrointestinal symptom items drawn from the Rome-II criteria, which are rated by frequency and severity, as well as some items to exclude organic diseases. The questionnaire was administered to 259 normal participants and to 69 participants of the annual German meeting of patients with irritable bowel syndrome. Reliability was good (Cronbach's alpha for frequency and severity items: alpha = .86 and alpha = .87). Factor analysis yielded a six-factor solution explaining 60.7% of the variance. Diagnostic frequencies ranged from 32.8% to 100% for FGDs in general, from 1.3% to 76.8% for irritable bowel syndrome, and from 7.0% to 100% for functional dyspepsia, depending on samples and symptom definitions. The Gastro-Questionnaire is a very economic, reliable, and content-valid instrument for the assessment of FGDs. PMID:12174533

  16. A mechanism for weak double layers and coherent low-frequency electrostatic wave activity in the solar wind

    NASA Astrophysics Data System (ADS)

    Singh Lakhina, Gurbax; Singh, Satyavir

    2016-07-01

    A mechanism for the weak double layers and coherent low-frequency electrostatic wave activity observed by Wind spacecraft in the solar wind at 1 AU is proposed in terms of ion-acoustic solitons and double layers. The solar wind plasma is modelled by a three component plasma consisting of fluid hot protons, hot alpha particles streaming with respect to protons, and suprathermal electrons having κ- distribution. This system supports two types of, slow and fast, ion-acoustic solitary waves. The fast ion-acoustic mode is similar to the ion-acoustic mode of proton-electron plasma, and can support only positive potential solitons. The slow ion-acoustic mode is a new mode that occurs due to the presence of alpha particles. This mode can support both positive and negative solitons and double layers. An increase of the κ- index leads to an increase in the critical Mach number, maximum Mach number and the maximum amplitude of both slow and fast ion-acoustic solitons. The slow ion-acoustic double layer can explain the amplitudes and widths, but not shapes, of the weak double layers (WDLs) observed in the solar wind at 1 AU by Wind spacecraft. The Fourier transform of the slow ion-acoustic solitons/double layers would produce broadband low-frequency electrostatic waves having main peaks between 0.35 kHz to 1.6 kHz, with electric field in the range of E = (0.01 - 0.7 ) mV/m, in excellent agreement with the observed low-frequency electrostatic wave activity in the solar wind at 1 AU.

  17. Application of frequency ratio and logistic regression to active rock glacier occurrence in the Andes of San Juan, Argentina

    NASA Astrophysics Data System (ADS)

    Angillieri, María Yanina Esper

    2010-01-01

    This study employs statistical modeling techniques and geomorphological mapping to analyze the distribution of active rock glaciers in relation to altitude, aspect, slope, lithology and solar radiation using optical remote sensing techniques with GIS. The study area includes a portion of the Dry Andes of the Cordillera Frontal of San Juan around 30°S latitude, where few geomorphological studies have been conducted. Over 155 rock glaciers have been identified, and 85 are considered active. The relationship between the variables and the rock glaciers distribution was analyzed using the frequency ratio method and logistic regression models. The analytical results show that elevations > 3824 m a.s.l., a south-facing or east-facing aspect, areas with relatively low solar radiation, and slope between 2° and 20° favor the existence of the rock glaciers, and demonstrate that lithology and slope exert major influences.

  18. The brain's resting-state activity is shaped by synchronized cross-frequency coupling of neural oscillations

    PubMed Central

    Florin, Esther; Baillet, Sylvain

    2015-01-01

    Functional imaging of the resting brain consistently reveals broad motifs of correlated blood oxygen level dependent (BOLD) activity that engage cerebral regions from distinct functional systems. Yet, the neurophysiological processes underlying these organized, large-scale fluctuations remain to be uncovered. Using magnetoencephalography (MEG) imaging during rest in 12 healthy subjects we analyse the resting state networks and their underlying neurophysiology. We first demonstrate non-invasively that cortical occurrences of high-frequency oscillatory activity are conditioned to the phase of slower spontaneous fluctuations in neural ensembles. We further show that resting-state networks emerge from synchronized phase-amplitude coupling across the brain. Overall, these findings suggest a unified principle of local-to-global neural signaling for long-range brain communication. PMID:25680519

  19. Beta-coupled high-frequency activity and beta-locked neuronal spiking in the subthalamic nucleus of Parkinson's disease.

    PubMed

    Yang, Andrew I; Vanegas, Nora; Lungu, Codrin; Zaghloul, Kareem A

    2014-09-17

    Beta frequency (13-30 Hz) oscillatory activity in the subthalamic nucleus (STN) of Parkinson's disease (PD) has been shown to influence the temporal dynamics of high-frequency oscillations (HFOs; 200-500 Hz) and single neurons, potentially compromising the functional flexibility of the motor circuit. We examined these interactions by simultaneously recording both local field potential and single-unit activity from the basal ganglia of 15 patients with PD during deep brain stimulation (DBS) surgery of the bilateral STN. Phase-amplitude coupling (PAC) in the STN was specific to beta phase and HFO amplitude, and this coupling was strongest at the dorsal STN border. We found higher beta-HFO PAC near DBS lead contacts that were clinically effective compared with the remaining non-effective contacts, indicating that PAC may be predictive of response to STN DBS. Neuronal spiking was locked to the phase of 8-30 Hz oscillations, and the spatial topography of spike-phase locking (SPL) was similar to that of PAC. Comparisons of PAC and SPL showed a lack of spatiotemporal correlations. Beta-coupled HFOs and field-locked neurons had different preferred phase angles and did not co-occur within the same cycle of the modulating oscillation. Our findings provide additional support that beta-HFO PAC may be central to the pathophysiology of PD and suggest that field-locked neurons alone are not sufficient for the emergence of beta-coupled HFOs. PMID:25232117

  20. Functional Connectivity in Frequency-Tagged Cortical Networks During Active Harm Avoidance

    PubMed Central

    Miskovic, Vladimir; Príncipe, José C.; Keil, Andreas

    2015-01-01

    Abstract Many behavioral and cognitive processes are grounded in widespread and dynamic communication between brain regions. Thus, the quantification of functional connectivity with high temporal resolution is highly desirable for capturing in vivo brain function. However, many of the commonly used measures of functional connectivity capture only linear signal dependence and are based entirely on relatively simple quantitative measures such as mean and variance. In this study, the authors used a recently developed algorithm, the generalized measure of association (GMA), to quantify dynamic changes in cortical connectivity using steady-state visual evoked potentials (ssVEPs) measured in the context of a conditioned behavioral avoidance task. GMA uses a nonparametric estimator of statistical dependence based on ranks that are efficient and capable of providing temporal precision roughly corresponding to the timing of cognitive acts (∼100–200 msec). Participants viewed simple gratings predicting the presence/absence of an aversive loud noise, co-occurring with peripheral cues indicating whether the loud noise could be avoided by means of a key press (active) or not (passive). For active compared with passive trials, heightened connectivity between visual and central areas was observed in time segments preceding and surrounding the avoidance cue. Viewing of the threat stimuli also led to greater initial connectivity between occipital and central regions, followed by heightened local coupling among visual regions surrounding the motor response. Local neural coupling within extended visual regions was sustained throughout major parts of the viewing epoch. These findings are discussed in a framework of flexible synchronization between cortical networks as a function of experience and active sensorimotor coupling. PMID:25557925

  1. Scattering efficiency and near field enhancement of active semiconductor plasmonic antennas at terahertz frequencies.

    PubMed

    Giannini, Vincenzo; Berrier, Audrey; Maier, Stefan A; Sánchez-Gil, José Antonio; Rivas, Jaime Gómez

    2010-02-01

    Terahertz plasmonic resonances in semiconductor (indium antimonide, InSb) dimer antennas are investigated theoretically. The antennas are formed by two rods separated by a small gap. We demonstrate that, with an appropriate choice of the shape and dimension of the semiconductor antennas, it is possible to obtain large electromagnetic field enhancement inside the gap. Unlike metallic antennas, the enhancement around the semiconductor plasmonics antenna can be easily adjusted by varying the concentration of free carriers, which can be achieved by optical or thermal excitation of carriers or electrical carrier injection. Such active plasmonic antennas are interesting structures for THz applications such as modulators and sensors. PMID:20174108

  2. Real-time, time-frequency mapping of event-related cortical activation

    NASA Astrophysics Data System (ADS)

    Cheung, Connie; Chang, Edward F.

    2012-08-01

    Functional mapping of eloquent cortex is a common and necessary component of neurosurgical operative planning. Current electrical stimulation-based techniques are inefficient, can evoke seizures and are prone to false-negative results. Here, we present a novel cortical mapping system that extracts event-related neural activity from passive electrocorticographic recordings to quickly and accurately localize sensory and motor cortices using the precise temporal properties of spectral alteration. This procedure generates a robust functional motor and sensory cortical map in seconds, and usually with less than five to ten trial events. Our algorithm demonstrates high concordance with results derived using independent electrical cortical stimulation mapping.

  3. Modulation of muscle sympathetic nerve activity by low-frequency physiological activation of the vestibular utricle in awake humans.

    PubMed

    Hammam, Elie; Kwok, Kenny; Macefield, Vaughan G

    2013-09-01

    We recently showed that selective stimulation of one set of otolithic organs-those located in the utricle, sensitive to displacement in the horizontal axis-causes a marked entrainment of skin sympathetic nerve activity (SSNA). Here, we assessed whether muscle sympathetic nerve activity (MSNA) is similarly modulated. MSNA was recorded via tungsten microelectrodes inserted into cutaneous fascicles of the common peroneal nerve in 12 awake subjects, seated (head vertical, eyes closed) on a motorised platform. Slow sinusoidal accelerations-decelerations (±4 mG) were applied in the X (antero-posterior) or Y (medio-lateral) direction at 0.08 Hz. Cross-correlation analysis revealed partial entrainment of MSNA: vestibular modulation was 32 ± 3 % for displacements in the X-axis and 29 ± 3 % in the Y-axis; these were significantly smaller than those evoked in SSNA (97 ± 3 and 91 ± 5 %, respectively). For each sinusoidal cycle, there were two peaks of modulation-one associated with acceleration as the platform moved forward or to the side and one associated with acceleration in the opposite direction. We believe the two peaks reflect inertial displacement of the stereocilia within the utricle during sinusoidal acceleration, which evokes vestibulosympathetic reflexes that are expressed as vestibular modulation of MSNA as well as of SSNA. The smaller vestibular modulation of MSNA can be explained by the dominant modulation of MSNA by the arterial baroreceptors. PMID:23852323

  4. High Frequency and Diversity of Antimicrobial Activities Produced by Nasal Staphylococcus Strains against Bacterial Competitors

    PubMed Central

    Janek, Daniela; Zipperer, Alexander; Kulik, Andreas; Krismer, Bernhard; Peschel, Andreas

    2016-01-01

    The human nasal microbiota is highly variable and dynamic often enclosing major pathogens such as Staphylococcus aureus. The potential roles of bacteriocins or other mechanisms allowing certain bacterial clones to prevail in this nutrient-poor habitat have hardly been studied. Of 89 nasal Staphylococcus isolates, unexpectedly, the vast majority (84%) was found to produce antimicrobial substances in particular under habitat-specific stress conditions, such as iron limitation or exposure to hydrogen peroxide. Activity spectra were generally narrow but highly variable with activities against certain nasal members of the Actinobacteria, Proteobacteria, Firmicutes, or several groups of bacteria. Staphylococcus species and many other Firmicutes were insusceptible to most of the compounds. A representative bacteriocin was identified as a nukacin-related peptide whose inactivation reduced the capacity of the producer Staphylococcus epidermidis IVK45 to limit growth of other nasal bacteria. Of note, the bacteriocin genes were found on mobile genetic elements exhibiting signs of extensive horizontal gene transfer and rearrangements. Thus, continuously evolving bacteriocins appear to govern bacterial competition in the human nose and specific bacteriocins may become important agents for eradication of notorious opportunistic pathogens from human microbiota. PMID:27490492

  5. Final report on passive and active low-frequency electromagnetic spectroscopy for airborne detection of underground facilities

    SciTech Connect

    SanFilipo, Bill

    2000-04-01

    The objective of this program is to perform research to advance the science in the application of both passive and active electromagnetic measurement techniques for the detection and spatial delineation of underground facilities. Passive techniques exploit the electromagnetic fields generated by electrical apparatus within the structure, including generators, motors, power distribution circuitry, as well as communications hardware and similar electronics equipment. Frequencies monitored are generally in the audio range (60-20,000 Hz), anticipating strong sources associated with normal AC power (i.e., 50 or 60 Hz and associated harmonics), and low frequency power from broad-band sources such as switching circuits. Measurements are made using receiver induction coils wired to electronics that digitize and record the voltage induced by the time varying magnetic fields. Active techniques employ electromagnetic field transmitters in the form of AC current carrying loops also in the audio frequency range, and receiving coils that measure the resultant time varying magnetic fields. These fields are perturbed from those expected in free space by any conductive material in the vicinity of the coils, including the ground, so that the total measured field is comprised of the primary free-space component and the secondary scattered component. The latter can be further delineated into an average background field (uniform conductive half-space earth) and anomalous field associated with heterogeneous zones in the earth, including both highly conductive objects such as metallic structures as well as highly resistive structures such as empty voids corresponding to rooms or tunnels. Work performed during Phase I included the development of the prototype GEM-2H instrumentation, collection of data at several test sites in the passive mode and a single site in the active mode, development of processing and interpretation software. The technical objectives of Phase II were to: (1

  6. Pattern segmentation with activity dependent natural frequency shift and sub-threshold resonance

    NASA Astrophysics Data System (ADS)

    Shtrahman, E.; Zochowski, M.

    2015-03-01

    Understanding the mechanisms underlying distributed pattern formation in brain networks and its content driven dynamical segmentation is an area of intense study. We investigate a theoretical mechanism for selective activation of diverse neural populations that is based on dynamically shifting cellular resonances in functionally or structurally coupled networks. We specifically show that sub-threshold neuronal depolarization from synaptic coupling or external input can shift neurons into and out of resonance with specific bands of existing extracellular oscillations, and this can act as a dynamic readout mechanism during information storage and retrieval. We find that this mechanism is robust and suggest it as a general coding strategy that can be applied to any network with oscillatory nodes.

  7. Frequency translating phase conjugation circuit for active retrodirective antenna array. [microwave transmission

    NASA Technical Reports Server (NTRS)

    Chernoff, R. (Inventor)

    1980-01-01

    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.

  8. The Splicing Efficiency of Activating HRAS Mutations Can Determine Costello Syndrome Phenotype and Frequency in Cancer.

    PubMed

    Hartung, Anne-Mette; Swensen, Jeff; Uriz, Inaki E; Lapin, Morten; Kristjansdottir, Karen; Petersen, Ulrika S S; Bang, Jeanne Mari V; Guerra, Barbara; Andersen, Henriette Skovgaard; Dobrowolski, Steven F; Carey, John C; Yu, Ping; Vaughn, Cecily; Calhoun, Amy; Larsen, Martin R; Dyrskjøt, Lars; Stevenson, David A; Andresen, Brage S

    2016-05-01

    Costello syndrome (CS) may be caused by activating mutations in codon 12/13 of the HRAS proto-oncogene. HRAS p.Gly12Val mutations have the highest transforming activity, are very frequent in cancers, but very rare in CS, where they are reported to cause a severe, early lethal, phenotype. We identified an unusual, new germline p.Gly12Val mutation, c.35_36GC>TG, in a 12-year-old boy with attenuated CS. Analysis of his HRAS cDNA showed high levels of exon 2 skipping. Using wild type and mutant HRAS minigenes, we confirmed that c.35_36GC>TG results in exon 2 skipping by simultaneously disrupting the function of a critical Exonic Splicing Enhancer (ESE) and creation of an Exonic Splicing Silencer (ESS). We show that this vulnerability of HRAS exon 2 is caused by a weak 3' splice site, which makes exon 2 inclusion dependent on binding of splicing stimulatory proteins, like SRSF2, to the critical ESE. Because the majority of cancer- and CS- causing mutations are located here, they affect splicing differently. Therefore, our results also demonstrate that the phenotype in CS and somatic cancers is not only determined by the different transforming potentials of mutant HRAS proteins, but also by the efficiency of exon 2 inclusion resulting from the different HRAS mutations. Finally, we show that a splice switching oligonucleotide (SSO) that blocks access to the critical ESE causes exon 2 skipping and halts proliferation of cancer cells. This unravels a potential for development of new anti-cancer therapies based on SSO-mediated HRAS exon 2 skipping. PMID:27195699

  9. The Splicing Efficiency of Activating HRAS Mutations Can Determine Costello Syndrome Phenotype and Frequency in Cancer

    PubMed Central

    Kristjansdottir, Karen; Petersen, Ulrika S. S.; Bang, Jeanne Mari V.; Guerra, Barbara; Andersen, Henriette Skovgaard; Dobrowolski, Steven F.; Carey, John C.; Yu, Ping; Calhoun, Amy; Larsen, Martin R.; Dyrskjøt, Lars; Stevenson, David A.; Andresen, Brage S.

    2016-01-01

    Costello syndrome (CS) may be caused by activating mutations in codon 12/13 of the HRAS proto-oncogene. HRAS p.Gly12Val mutations have the highest transforming activity, are very frequent in cancers, but very rare in CS, where they are reported to cause a severe, early lethal, phenotype. We identified an unusual, new germline p.Gly12Val mutation, c.35_36GC>TG, in a 12-year-old boy with attenuated CS. Analysis of his HRAS cDNA showed high levels of exon 2 skipping. Using wild type and mutant HRAS minigenes, we confirmed that c.35_36GC>TG results in exon 2 skipping by simultaneously disrupting the function of a critical Exonic Splicing Enhancer (ESE) and creation of an Exonic Splicing Silencer (ESS). We show that this vulnerability of HRAS exon 2 is caused by a weak 3’ splice site, which makes exon 2 inclusion dependent on binding of splicing stimulatory proteins, like SRSF2, to the critical ESE. Because the majority of cancer- and CS- causing mutations are located here, they affect splicing differently. Therefore, our results also demonstrate that the phenotype in CS and somatic cancers is not only determined by the different transforming potentials of mutant HRAS proteins, but also by the efficiency of exon 2 inclusion resulting from the different HRAS mutations. Finally, we show that a splice switching oligonucleotide (SSO) that blocks access to the critical ESE causes exon 2 skipping and halts proliferation of cancer cells. This unravels a potential for development of new anti-cancer therapies based on SSO-mediated HRAS exon 2 skipping. PMID:27195699

  10. Self-regulation of circumscribed brain activity modulates spatially selective and frequency specific connectivity of distributed resting state networks

    PubMed Central

    Vukelić, Mathias; Gharabaghi, Alireza

    2015-01-01

    The mechanisms of learning involved in brain self-regulation have still to be unveiled to exploit the full potential of this methodology for therapeutic interventions. This skill of volitionally changing brain activity presumably resembles motor skill learning which in turn is accompanied by plastic changes modulating resting state networks. Along these lines, we hypothesized that brain regulation and neurofeedback would similarly modify intrinsic networks at rest while presenting a distinct spatio-temporal pattern. High-resolution electroencephalography preceded and followed a single neurofeedback training intervention of modulating circumscribed sensorimotor low β-activity by kinesthetic motor imagery in eleven healthy participants. The participants were kept in the deliberative phase of skill acquisition with high demands for learning self-regulation through stepwise increases of task difficulty. By applying the corrected imaginary part of the coherency function, we observed increased functional connectivity of both the primary motor and the primary somatosensory cortex with their respective contralateral homologous cortices in the low β-frequency band which was self-regulated during feedback. At the same time, the primary motor cortex—but none of the surrounding cortical areas—showed connectivity to contralateral supplementary motor and dorsal premotor areas in the high β-band. Simultaneously, the neurofeedback target displayed a specific increase of functional connectivity with an ipsilateral fronto-parietal network in the α-band while presenting a de-coupling with contralateral primary and secondary sensorimotor areas in the very same frequency band. Brain self-regulation modifies resting state connections spatially selective to the neurofeedback target of the dominant hemisphere. These are anatomically distinct with regard to the cortico-cortical connectivity pattern and are functionally specific with regard to the time domain of coherent activity

  11. Self-regulation of circumscribed brain activity modulates spatially selective and frequency specific connectivity of distributed resting state networks.

    PubMed

    Vukelić, Mathias; Gharabaghi, Alireza

    2015-01-01

    The mechanisms of learning involved in brain self-regulation have still to be unveiled to exploit the full potential of this methodology for therapeutic interventions. This skill of volitionally changing brain activity presumably resembles motor skill learning which in turn is accompanied by plastic changes modulating resting state networks. Along these lines, we hypothesized that brain regulation and neurofeedback would similarly modify intrinsic networks at rest while presenting a distinct spatio-temporal pattern. High-resolution electroencephalography preceded and followed a single neurofeedback training intervention of modulating circumscribed sensorimotor low β-activity by kinesthetic motor imagery in eleven healthy participants. The participants were kept in the deliberative phase of skill acquisition with high demands for learning self-regulation through stepwise increases of task difficulty. By applying the corrected imaginary part of the coherency function, we observed increased functional connectivity of both the primary motor and the primary somatosensory cortex with their respective contralateral homologous cortices in the low β-frequency band which was self-regulated during feedback. At the same time, the primary motor cortex-but none of the surrounding cortical areas-showed connectivity to contralateral supplementary motor and dorsal premotor areas in the high β-band. Simultaneously, the neurofeedback target displayed a specific increase of functional connectivity with an ipsilateral fronto-parietal network in the α-band while presenting a de-coupling with contralateral primary and secondary sensorimotor areas in the very same frequency band. Brain self-regulation modifies resting state connections spatially selective to the neurofeedback target of the dominant hemisphere. These are anatomically distinct with regard to the cortico-cortical connectivity pattern and are functionally specific with regard to the time domain of coherent activity

  12. A hyperpolarization-activated inward current alters swim frequency of the pteropod mollusk Clione limacina.

    PubMed

    Pirtle, Thomas J; Willingham, Kyle; Satterlie, Richard A

    2010-12-01

    The pteropod mollusk, Clione limacina, exhibits behaviorally relevant swim speed changes that occur within the context of the animal's ecology. Modulation of C. limacina swimming speed involves changes that occur at the network and cellular levels. Intracellular recordings from interneurons of the swim central pattern generator show the presence of a sag potential that is indicative of the hyperpolarization-activated inward current (I(h)). Here we provide evidence that I(h) in primary swim interneurons plays a role in C. limacina swimming speed control and may be a modulatory target. Recordings from central pattern generator swim interneurons show that hyperpolarizing current injection produces a sag potential that lasts for the duration of the hyperpolarization, a characteristic of cells possessing I(h). Following the hyperpolarizing current injection, swim interneurons also exhibit postinhibitory rebound (PIR). Serotonin enhances the sag potential of C. limacina swim interneurons while the I(h) blocker, ZD7288, reduces the sag potential. Furthermore, a negative correlation was found between the amplitude of the sag potential and latency to PIR. Because latency to PIR was previously shown to influence swimming speed, we hypothesize that I(h) has an effect on swimming speed. The I(h) blocker, ZD7288, suppresses swimming in C. limacina and inhibits serotonin-induced acceleration, evidence that supports our hypothesis. PMID:20696266

  13. Neural activation during response inhibition is associated with adolescents’ frequency of risky sex and substance use

    PubMed Central

    Feldstein Ewing, Sarah W.; Houck, Jon M.; Bryan, Angela D.

    2015-01-01

    While many have identified the important role of the developing brain in youth risk behavior, few have examined the relationship between salient cognitive factors (response inhibition) and different types of real-world adolescent health risk behaviors (substance use and risky sex) within the same sample of youth. We therefore sought to examine these relationships with 95 high-risk youth (ages 14-18; M age = 16.29 years). We examined the relationship between blood oxygen level dependent (BOLD) response to an fMRI-based cognitive task designed to assess response inhibition (Go/NoGo) and past month risk behavior (number of substance use days; number of unprotected sex days). For this sample of youth, we found significant negative correlations between past month substance use and response inhibition within the left inferior frontal gyrus (IFG) and right insula (uncorrected p < .001; extent threshold ≥ 10 voxels). In addition, in the same contrast, we found significant positive correlations between past month risky sex and activation within the right IFG and left middle occipital gyrus (uncorrected p < .001; extent threshold ≥ 10 voxels). These results suggest the particular relevance of these regions in this compelling, albeit slightly different pattern of response for adolescent substance use and risky sex. PMID:25532443

  14. Coherent combining of fiber-laser-pumped frequency converters using all fiber electro-optic modulator for active phase control

    NASA Astrophysics Data System (ADS)

    Bourdon, P.; Durécu, A.; Canat, G.; Le Gouët, J.; Goular, D.; Lombard, L.

    2015-03-01

    Coherent beam combining (CBC) by active phase control could be useful for power scaling fiber-laser-pumped optical frequency converters like OPOs. However, a phase modulator operating at the frequency-converted wavelength is needed, which is non standard component. Fortunately, nonlinear conversion processes rely on a phase-matching condition correlating, not only the wave vectors of the coupled waves, but also their phases. This paper demonstrates that, using this phase correlation for indirect control of the phase, coherent combining of optical frequency converters is feasible using standard all-fibered electro-optic modulators. For the sake of demonstration, this new technique is experimentally applied twice for continuous wave second-harmonic-generator (SHG) combination: i) combining 2 SHG of 1.55-μm erbium-doped fiber amplifiers in PPLN crystals generating 775-nm beams; ii) combining 2 SHG of 1.064-μm ytterbium-doped fiber amplifiers in LBO crystals generating 532-nm beams. Excellent CBC efficiency is achieved on the harmonic waves in both these experiments, with λ/20 and λ/30 residual phase error respectively. In the second experiment, I/Q phase detection is added on fundamental and harmonic waves to measure their phase variations simultaneously. These measurements confirm the theoretical expectations and formulae of correlation between the phases of the fundamental and harmonic waves. Unexpectedly, in both experiments, when harmonic waves are phase-locked, a residual phase difference remains between the fundamen tal waves. Measurements of the spectrum of these residual phase differences locate them above 50 Hz, revealing that they most probably originate in fast-varying optical path differences induced by turbulence and acoustic-waves on the experimental breadboard.

  15. The effects of high-frequency oscillations in hippocampal electrical activities on the classification of epileptiform events using artificial neural networks

    NASA Astrophysics Data System (ADS)

    Chiu, Alan W. L.; Jahromi, Shokrollah S.; Khosravani, Houman; Carlen, Peter L.; Bardakjian, Berj L.

    2006-03-01

    The existence of hippocampal high-frequency electrical activities (greater than 100 Hz) during the progression of seizure episodes in both human and animal experimental models of epilepsy has been well documented (Bragin A, Engel J, Wilson C L, Fried I and Buzsáki G 1999 Hippocampus 9 137-42 Khosravani H, Pinnegar C R, Mitchell J R, Bardakjian B L, Federico P and Carlen P L 2005 Epilepsia 46 1-10). However, this information has not been studied between successive seizure episodes or utilized in the application of seizure classification. In this study, we examine the dynamical changes of an in vitro low Mg2+ rat hippocampal slice model of epilepsy at different frequency bands using wavelet transforms and artificial neural networks. By dividing the time-frequency spectrum of each seizure-like event (SLE) into frequency bins, we can analyze their burst-to-burst variations within individual SLEs as well as between successive SLE episodes. Wavelet energy and wavelet entropy are estimated for intracellular and extracellular electrical recordings using sufficiently high sampling rates (10 kHz). We demonstrate that the activities of high-frequency oscillations in the 100-400 Hz range increase as the slice approaches SLE onsets and in later episodes of SLEs. Utilizing the time-dependent relationship between different frequency bands, we can achieve frequency-dependent state classification. We demonstrate that activities in the frequency range 100-400 Hz are critical for the accurate classification of the different states of electrographic seizure-like episodes (containing interictal, preictal and ictal states) in brain slices undergoing recurrent spontaneous SLEs. While preictal activities can be classified with an average accuracy of 77.4 ± 6.7% utilizing the frequency spectrum in the range 0-400 Hz, we can also achieve a similar level of accuracy by using a nonlinear relationship between 100-400 Hz and <4 Hz frequency bands only.

  16. Theta frequency activity during rapid eye movement (REM) sleep is greater in people with resilience versus PTSD

    PubMed Central

    Cowdin, Nancy; Kobayashi, Ihori

    2015-01-01

    Emotional memory consolidation has been associated with rapid eye movement (REM) sleep, and recent evidence suggests that increased electroencephalogram spectral power in the theta (4–8 Hz) frequency range indexes this activity. REM sleep has been implicated in posttraumatic stress disorder (PTSD) as well as in emotional adaption. In this cross-sectional study, thirty young healthy African American adults with trauma exposure were assessed for PTSD status using the Clinician Administered PTSD Scale. Two consecutive night polysomnographic (PSG) recordings were performed and data scored for sleep stages. Quantitative electroencephalographic spectral analysis was used to measure theta frequency components sampled from REM sleep periods of the second-night PSG recordings. Our objective was to compare relative theta power between trauma-exposed participants who were either resilient or had developed PTSD. Results indicated higher right prefrontal theta power during the first and last REM periods in resilient participants compared with participants with PTSD. Right hemisphere prefrontal theta power during REM sleep may serve as a biomarker of the capacity for adaptive emotional memory processing among trauma-exposed individuals. PMID:24531640

  17. 75 FR 16737 - Proposed Information Collection; Comment Request; Generic Clearance for Questionnaire Pretesting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-02

    ... Questionnaire Pretesting Research AGENCY: U.S. Census Bureau. ACTION: Notice. SUMMARY: The Department of...-scale questionnaire pretesting activities under this generic clearance. A block of hours will be... will be used by the Census Bureau and survey sponsors to improve questionnaires and procedures,...

  18. Major histocompatibility complex-unrestricted cytolytic activity of human T cells: analysis of precursor frequency and effector phenotype

    SciTech Connect

    Patel, S.S.; Thiele, D.L.; Lipsky, P.E.

    1987-12-01

    The frequency and phenotype of human T cells that mediate major histocompatibility complex (MHC)-unrestricted cytolysis were analyzed. T cell clones were generated by culturing adherent cell-depleted peripheral blood mononuclear cells at a density of 0.3 cell/well with phytohemagglutinin, recombinant interleukin 2 (rIL-2), and irradiated autologous peripheral blood mononuclear cells and/or Epstein-Barr virus-transformed lymphoblastoid cell lines. All of the 198 clones generated by this method were T cells (CD2/sup +/, CD3/sup +/, CD4/sup +/ or CD2/sup +/, CD3/sup +/, CD8/sup +/) that possessed potent lytic activity against K562, an erythroleukemia line sensitive to lysis by human natural killer cells, and Cur, a renal carcinoma cell line resistant to human natural killer activity. Cytolysis, measured by /sup 51/Cr release, was MHC-unrestricted, since the clones were able to lyse MHC class I or class II negative targets, as well as MHC class I and class II negative targets. Although the clones produced tissue necrosis factor/lymphotoxin-like molecules, lysis of Cur of K562 was not mediated by a soluble factor secreted by the clones. These data indicate that the capacity for MHC-unrestricted tumoricidal activity and expression of NKH1 and CD11b, but not CD 16, are properties common to all or nearly all human peripheral blood-derived T cell clones regardless of CD4 or CD8 phenotype.

  19. Methods to estimate aspects of physical activity and sedentary behavior from high-frequency wrist accelerometer measurements.

    PubMed

    Staudenmayer, John; He, Shai; Hickey, Amanda; Sasaki, Jeffer; Freedson, Patty

    2015-08-15

    This investigation developed models to estimate aspects of physical activity and sedentary behavior from three-axis high-frequency wrist-worn accelerometer data. The models were developed and tested on 20 participants (n = 10 males, n = 10 females, mean age = 24.1, mean body mass index = 23.9), who wore an ActiGraph GT3X+ accelerometer on their dominant wrist and an ActiGraph GT3X on the hip while performing a variety of scripted activities. Energy expenditure was concurrently measured by a portable indirect calorimetry system. Those calibration data were then used to develop and assess both machine-learning and simpler models with fewer unknown parameters (linear regression and decision trees) to estimate metabolic equivalent scores (METs) and to classify activity intensity, sedentary time, and locomotion time. The wrist models, applied to 15-s windows, estimated METs [random forest: root mean squared error (rSME) = 1.21 METs, hip: rMSE = 1.67 METs] and activity intensity (random forest: 75% correct, hip: 60% correct) better than a previously developed model that used counts per minute measured at the hip. In a separate set of comparisons, the simpler decision trees classified activity intensity (random forest: 75% correct, tree: 74% correct), sedentary time (random forest: 96% correct, decision tree: 97% correct), and locomotion time (random forest: 99% correct, decision tree: 96% correct) nearly as well or better than the machine-learning approaches. Preliminary investigation of the models' performance on two free-living people suggests that they may work well outside of controlled conditions. PMID:26112238

  20. U.S. Jet Contrail Frequency Changes: Influences of Jet Aircraft Flight Activity, Atmospheric Conditions, and Resultant Policy Implications

    NASA Astrophysics Data System (ADS)

    Travis, D. J.; Carleton, A. M.

    2005-12-01

    In regions where jet air traffic is most abundant, condensation trails (contrails) may substantially increase the high cloud coverage, potentially affecting climate. This is particularly so when atmospheric conditions support prolonged persistence of contrails, which results in their occurrence in clusters, or ``outbreaks'', thus, allowing them to represent a substantial percentage of the overall high cloud amount. In the U.S., jet kilometers flown have increased dramatically during the past three decades leading to speculation that contrail coverage also has increased. However, contrail occurrence depends heavily upon the meteorological conditions near aircraft cruising altitudes (i.e., near the tropopause, 10-12 km altitude). Moreover, the tropopause figures prominently in projecting future climate changes. This study reports a contrail mid-season climatology for the coterminous U.S. (2000-02), and compares the frequencies with those previously reported for an earlier (1977-79) period, to determine the contrail frequency increase (CFI). For the 2000-02 period, we also report the seasonal frequency and areal coverage of contrail outbreaks as a means to assess the typical size of contrail susceptible regions on a seasonal and daily basis. Contrail frequency for both periods, and occurrence of outbreaks for 2000-02, is derived from analysis of high-resolution satellite imagery. Data on jet aircraft flight activity (JFA) over the U.S. were obtained to assess their relationship to CFI, as were NCEP-NCAR reanalysis data to determine changes in tropopause-level conditions. For 2000-02, contrails comprise distinct high (low) frequencies in the East (West) U.S. Seasonally, there is a contrail association with the latitudinal migration of the jet stream. The inter-monthly variations in contrail frequency are statistically significant but show no association with JFA, indicating a greater role for meteorological conditions. Contrail outbreaks occur most frequently during